[PATCH ipsec-next v4 00/18] Add IP-TFS mode to xfrm

[PATCH ipsec-next v4 00/18] Add IP-TFS mode to xfrm

[Christian Hopps]

* Summary of Changes:

This patchset adds a new xfrm mode implementing on-demand IP-TFS. IP-TFS
(AggFrag encapsulation) has been standardized in RFC9347.

  Link: https://www.rfc-editor.org/rfc/rfc9347.txt

This feature supports demand driven (i.e., non-constant send rate)
IP-TFS to take advantage of the AGGFRAG ESP payload encapsulation. This
payload type supports aggregation and fragmentation of the inner IP
packet stream which in turn yields higher small-packet bandwidth as well
as reducing MTU/PMTU issues. Congestion control is unimplementated as
the send rate is demand driven rather than constant.

In order to allow loading this fucntionality as a module a set of
callbacks xfrm_mode_cbs has been added to xfrm as well.

Patchset Changes:
-----------------

  23 files changed, 3300 insertions(+), 19 deletions(-)
  Documentation/networking/xfrm_sysctl.rst |   30 +
  include/net/netns/xfrm.h                 |    6 +
  include/net/xfrm.h                       |   40 +
  include/uapi/linux/in.h                  |    2 +
  include/uapi/linux/ip.h                  |   16 +
  include/uapi/linux/ipsec.h               |    3 +-
  include/uapi/linux/snmp.h                |    3 +
  include/uapi/linux/xfrm.h                |    9 +-
  net/ipv4/esp4.c                          |    3 +-
  net/ipv6/esp6.c                          |    3 +-
  net/netfilter/nft_xfrm.c                 |    3 +-
  net/xfrm/Makefile                        |    1 +
  net/xfrm/trace_iptfs.h                   |  218 +++
  net/xfrm/xfrm_compat.c                   |   10 +-
  net/xfrm/xfrm_device.c                   |    4 +-
  net/xfrm/xfrm_input.c                    |   14 +-
  net/xfrm/xfrm_iptfs.c                    | 2746 ++++++++++++++++++++++++++++++
  net/xfrm/xfrm_output.c                   |    6 +
  net/xfrm/xfrm_policy.c                   |   26 +-
  net/xfrm/xfrm_proc.c                     |    3 +
  net/xfrm/xfrm_state.c                    |   60 +
  net/xfrm/xfrm_sysctl.c                   |   38 +
  net/xfrm/xfrm_user.c                     |   75 +

Patchset Structure:
-------------------

The first 7 commits are changes to the xfrm infrastructure to support
the callbacks as well as more generic IP-TFS additions that may be used
outside the actual IP-TFS implementation.

  - xfrm: config: add CONFIG_XFRM_IPTFS
  - include: uapi: add ip_tfs_*_hdr packet formats
  - include: uapi: add IPPROTO_AGGFRAG for AGGFRAG in ESP
  - xfrm: sysctl: allow configuration of global default values
  - xfrm: netlink: add config (netlink) options
  - xfrm: add mode_cbs module functionality
  - xfrm: add generic iptfs defines and functionality

The last 11 commits constitute the IP-TFS implementation constructed in
layers to make review easier. The first 10 commits all apply to a single
file `net/xfrm/xfrm_iptfs.c`, the last commit adds a new tracepoint
header file along with the use of these new tracepoint calls.

  - xfrm: iptfs: add new iptfs xfrm mode impl
  - xfrm: iptfs: add user packet (tunnel ingress) handling
  - xfrm: iptfs: share page fragments of inner packets
  - xfrm: iptfs: add fragmenting of larger than MTU user packets
  - xfrm: iptfs: add basic receive packet (tunnel egress) handling
  - xfrm: iptfs: handle received fragmented inner packets
  - xfrm: iptfs: add reusing received skb for the tunnel egress packet
  - xfrm: iptfs: add skb-fragment sharing code
  - xfrm: iptfs: handle reordering of received packets
  - xfrm: iptfs: only send the NL attrs that corr. to the SA dir
  - xfrm: iptfs: add tracepoint functionality

Patchset History:
-----------------

RFCv1 (11/10/2023)

RFCv1 -> RFCv2 (11/12/2023)

  Updates based on feedback from Simon Horman, Antony,
  Michael Richardson, and kernel test robot.

RFCv2 -> v1 (2/19/2024)

  Updates based on feedback from Sabrina Dubroca, kernel test robot

v1 -> v2 (5/19/2024)

  Updates based on feedback from Sabrina Dubroca, Simon Horman, Antony.

  o Add handling of new netlink SA direction attribute (Antony).
  o Split single patch/commit of xfrm_iptfs.c (the actual IP-TFS impl)
    into 9+1 distinct layered functionality commits for aiding review.
  - xfrm: fix return check on clone() callback
  - xfrm: add sa_len() callback in xfrm_mode_cbs for copy to user
  - iptfs: remove unneeded skb free count variable
  - iptfs: remove unused variable and "breadcrumb" for future code.
  - iptfs: use do_div() to avoid "__udivd13 missing" link failure.
  - iptfs: remove some BUG_ON() assertions questioned in review.

v2->v3
  - Git User Glitch

v2->v4 (6/17/2024)

  - iptfs: copy only the netlink attributes to user based on the
    direction of the SA.

  - xfrm: stats: in the output path check for skb->dev == NULL prior to
    setting xfrm statistics on dev_net(skb->dev) as skb->dev may be NULL
    for locally generated packets.

  - xfrm: stats: fix an input use case where dev_net(skb->dev) is used
    to inc stats after skb is possibly NULL'd earlier. Switch to using
    existing saved `net` pointer.

[PATCH ipsec-next v4 01/18] xfrm: config: add CONFIG_XFRM_IPTFS

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Add new Kconfig option to enable IP-TFS (RFC9347) functionality.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 net/xfrm/Kconfig | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/net/xfrm/Kconfig b/net/xfrm/Kconfig
index d7b16f2c23e9..f0157702718f 100644
--- a/net/xfrm/Kconfig
+++ b/net/xfrm/Kconfig
@@ -135,6 +135,22 @@ config NET_KEY_MIGRATE
 
 	  If unsure, say N.
 
+config XFRM_IPTFS
+	tristate "IPsec IP-TFS/AGGFRAG (RFC 9347) encapsulation support"
+	depends on XFRM
+	help
+	  Information on the IP-TFS/AGGFRAG encapsulation can be found
+	  in RFC 9347. This feature supports demand driven (i.e.,
+	  non-constant send rate) IP-TFS to take advantage of the
+	  AGGFRAG ESP payload encapsulation. This payload type
+	  supports aggregation and fragmentation of the inner IP
+	  packet stream which in turn yields higher small-packet
+	  bandwidth as well as reducing MTU/PMTU issues. Congestion
+	  control is unimplementated as the send rate is demand driven
+	  rather than constant.
+
+	  If unsure, say N.
+
 config XFRM_ESPINTCP
 	bool
 
-- 
2.45.2

[PATCH ipsec-next v4 02/18] include: uapi: add ip_tfs_*_hdr packet formats

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Add the on-wire basic and congestion-control IP-TFS packet headers.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 include/uapi/linux/ip.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/include/uapi/linux/ip.h b/include/uapi/linux/ip.h
index 283dec7e3645..5bd7ce934d74 100644
--- a/include/uapi/linux/ip.h
+++ b/include/uapi/linux/ip.h
@@ -137,6 +137,22 @@ struct ip_beet_phdr {
 	__u8 reserved;
 };
 
+struct ip_iptfs_hdr {
+	__u8 subtype;		/* 0*: basic, 1: CC */
+	__u8 flags;
+	__be16 block_offset;
+};
+
+struct ip_iptfs_cc_hdr {
+	__u8 subtype;		/* 0: basic, 1*: CC */
+	__u8 flags;
+	__be16 block_offset;
+	__be32 loss_rate;
+	__be64 rtt_adelay_xdelay;
+	__be32 tval;
+	__be32 techo;
+};
+
 /* index values for the variables in ipv4_devconf */
 enum
 {
-- 
2.45.2

[PATCH ipsec-next v4 03/18] include: uapi: add IPPROTO_AGGFRAG for AGGFRAG in ESP

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Add the RFC assigned IP protocol number for AGGFRAG.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 include/uapi/linux/in.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h
index e682ab628dfa..e6a1f3e4c58c 100644
--- a/include/uapi/linux/in.h
+++ b/include/uapi/linux/in.h
@@ -79,6 +79,8 @@ enum {
 #define IPPROTO_MPLS		IPPROTO_MPLS
   IPPROTO_ETHERNET = 143,	/* Ethernet-within-IPv6 Encapsulation	*/
 #define IPPROTO_ETHERNET	IPPROTO_ETHERNET
+  IPPROTO_AGGFRAG = 144,	/* AGGFRAG in ESP (RFC 9347)		*/
+#define IPPROTO_AGGFRAG		IPPROTO_AGGFRAG
   IPPROTO_RAW = 255,		/* Raw IP packets			*/
 #define IPPROTO_RAW		IPPROTO_RAW
   IPPROTO_MPTCP = 262,		/* Multipath TCP connection		*/
-- 
2.45.2

[PATCH ipsec-next v4 04/18] xfrm: sysctl: allow configuration of global default values

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Add sysctls for the changing the IPTFS default SA values.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 Documentation/networking/xfrm_sysctl.rst | 30 +++++++++++++++++++
 include/net/netns/xfrm.h                 |  6 ++++
 net/xfrm/xfrm_sysctl.c                   | 38 ++++++++++++++++++++++++
 3 files changed, 74 insertions(+)

diff --git a/Documentation/networking/xfrm_sysctl.rst b/Documentation/networking/xfrm_sysctl.rst
index 47b9bbdd0179..4d900c74b405 100644
--- a/Documentation/networking/xfrm_sysctl.rst
+++ b/Documentation/networking/xfrm_sysctl.rst
@@ -9,3 +9,33 @@ XFRM Syscall
 
 xfrm_acq_expires - INTEGER
 	default 30 - hard timeout in seconds for acquire requests
+
+xfrm_iptfs_max_qsize - UNSIGNED INTEGER
+        The default IPTFS max output queue size in octets. The output queue is
+        where received packets destined for output over an IPTFS tunnel are
+        stored prior to being output in aggregated/fragmented form over the
+        IPTFS tunnel.
+
+        Default 1M.
+
+xfrm_iptfs_drop_time - UNSIGNED INTEGER
+        The default IPTFS drop time in microseconds. The drop time is the amount
+        of time before a missing out-of-order IPTFS tunnel packet is considered
+        lost. See also the reorder window.
+
+        Default 1s (1000000).
+
+xfrm_iptfs_init_delay - UNSIGNED INTEGER
+        The default IPTFS initial output delay in microseconds. The initial
+        output delay is the amount of time prior to servicing the output queue
+        after queueing the first packet on said queue. This applies anytime
+        the output queue was previously empty.
+
+        Default 0.
+
+xfrm_iptfs_reorder_window - UNSIGNED INTEGER
+        The default IPTFS reorder window size. The reorder window size dictates
+        the maximum number of IPTFS tunnel packets in a sequence that may arrive
+        out of order.
+
+        Default 3.
diff --git a/include/net/netns/xfrm.h b/include/net/netns/xfrm.h
index 423b52eca908..e11e71c8ceef 100644
--- a/include/net/netns/xfrm.h
+++ b/include/net/netns/xfrm.h
@@ -66,6 +66,12 @@ struct netns_xfrm {
 	u32			sysctl_aevent_rseqth;
 	int			sysctl_larval_drop;
 	u32			sysctl_acq_expires;
+#if IS_ENABLED(CONFIG_XFRM_IPTFS)
+	u32			sysctl_iptfs_drop_time;
+	u32			sysctl_iptfs_init_delay;
+	u32			sysctl_iptfs_max_qsize;
+	u32			sysctl_iptfs_reorder_window;
+#endif
 
 	u8			policy_default[XFRM_POLICY_MAX];
 
diff --git a/net/xfrm/xfrm_sysctl.c b/net/xfrm/xfrm_sysctl.c
index 7fdeafc838a7..dddb1025b7de 100644
--- a/net/xfrm/xfrm_sysctl.c
+++ b/net/xfrm/xfrm_sysctl.c
@@ -10,6 +10,12 @@ static void __net_init __xfrm_sysctl_init(struct net *net)
 	net->xfrm.sysctl_aevent_rseqth = XFRM_AE_SEQT_SIZE;
 	net->xfrm.sysctl_larval_drop = 1;
 	net->xfrm.sysctl_acq_expires = 30;
+#if IS_ENABLED(CONFIG_XFRM_IPTFS)
+	net->xfrm.sysctl_iptfs_max_qsize = 1024 * 1024; /* 1M */
+	net->xfrm.sysctl_iptfs_drop_time = 1000000;	/* 1s */
+	net->xfrm.sysctl_iptfs_init_delay = 0;		/* no initial delay */
+	net->xfrm.sysctl_iptfs_reorder_window = 3;	/* tcp folks suggested */
+#endif
 }
 
 #ifdef CONFIG_SYSCTL
@@ -38,6 +44,32 @@ static struct ctl_table xfrm_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
+#if IS_ENABLED(CONFIG_XFRM_IPTFS)
+	{
+		.procname	= "xfrm_iptfs_drop_time",
+		.maxlen		= sizeof(uint),
+		.mode		= 0644,
+		.proc_handler	= proc_douintvec
+	},
+	{
+		.procname	= "xfrm_iptfs_init_delay",
+		.maxlen		= sizeof(uint),
+		.mode		= 0644,
+		.proc_handler	= proc_douintvec
+	},
+	{
+		.procname	= "xfrm_iptfs_max_qsize",
+		.maxlen		= sizeof(uint),
+		.mode		= 0644,
+		.proc_handler	= proc_douintvec
+	},
+	{
+		.procname	= "xfrm_iptfs_reorder_window",
+		.maxlen		= sizeof(uint),
+		.mode		= 0644,
+		.proc_handler	= proc_douintvec
+	},
+#endif
 	{}
 };
 
@@ -55,6 +87,12 @@ int __net_init xfrm_sysctl_init(struct net *net)
 	table[1].data = &net->xfrm.sysctl_aevent_rseqth;
 	table[2].data = &net->xfrm.sysctl_larval_drop;
 	table[3].data = &net->xfrm.sysctl_acq_expires;
+#if IS_ENABLED(CONFIG_XFRM_IPTFS)
+	table[4].data = &net->xfrm.sysctl_iptfs_drop_time;
+	table[5].data = &net->xfrm.sysctl_iptfs_init_delay;
+	table[6].data = &net->xfrm.sysctl_iptfs_max_qsize;
+	table[7].data = &net->xfrm.sysctl_iptfs_reorder_window;
+#endif
 
 	/* Don't export sysctls to unprivileged users */
 	if (net->user_ns != &init_user_ns) {
-- 
2.45.2

[PATCH ipsec-next v4 05/18] xfrm: netlink: add config (netlink) options

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Add netlink options for configuring IP-TFS SAs.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 include/uapi/linux/xfrm.h |  9 ++++++-
 net/xfrm/xfrm_compat.c    | 10 ++++++--
 net/xfrm/xfrm_user.c      | 52 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 68 insertions(+), 3 deletions(-)

diff --git a/include/uapi/linux/xfrm.h b/include/uapi/linux/xfrm.h
index 18ceaba8486e..3bd1f810e079 100644
--- a/include/uapi/linux/xfrm.h
+++ b/include/uapi/linux/xfrm.h
@@ -158,7 +158,8 @@ enum {
 #define XFRM_MODE_ROUTEOPTIMIZATION 2
 #define XFRM_MODE_IN_TRIGGER 3
 #define XFRM_MODE_BEET 4
-#define XFRM_MODE_MAX 5
+#define XFRM_MODE_IPTFS 5
+#define XFRM_MODE_MAX 6
 
 /* Netlink configuration messages.  */
 enum {
@@ -321,6 +322,12 @@ enum xfrm_attr_type_t {
 	XFRMA_IF_ID,		/* __u32 */
 	XFRMA_MTIMER_THRESH,	/* __u32 in seconds for input SA */
 	XFRMA_SA_DIR,		/* __u8 */
+	XFRMA_IPTFS_DROP_TIME,	/* __u32 in: usec to wait for next seq */
+	XFRMA_IPTFS_REORDER_WINDOW, /* __u16 in: reorder window size */
+	XFRMA_IPTFS_DONT_FRAG,	/* out: don't use fragmentation */
+	XFRMA_IPTFS_INIT_DELAY,	/* __u32 out: initial packet wait delay (usec) */
+	XFRMA_IPTFS_MAX_QSIZE,	/* __u32 out: max ingress queue size */
+	XFRMA_IPTFS_PKT_SIZE,	/* __u32 out: size of outer packet, 0 for PMTU */
 	__XFRMA_MAX
 
 #define XFRMA_OUTPUT_MARK XFRMA_SET_MARK	/* Compatibility */
diff --git a/net/xfrm/xfrm_compat.c b/net/xfrm/xfrm_compat.c
index 703d4172c7d7..fa570b3ff69b 100644
--- a/net/xfrm/xfrm_compat.c
+++ b/net/xfrm/xfrm_compat.c
@@ -280,9 +280,15 @@ static int xfrm_xlate64_attr(struct sk_buff *dst, const struct nlattr *src)
 	case XFRMA_IF_ID:
 	case XFRMA_MTIMER_THRESH:
 	case XFRMA_SA_DIR:
+	case XFRMA_IPTFS_DROP_TIME:
+	case XFRMA_IPTFS_REORDER_WINDOW:
+	case XFRMA_IPTFS_DONT_FRAG:
+	case XFRMA_IPTFS_INIT_DELAY:
+	case XFRMA_IPTFS_MAX_QSIZE:
+	case XFRMA_IPTFS_PKT_SIZE:
 		return xfrm_nla_cpy(dst, src, nla_len(src));
 	default:
-		BUILD_BUG_ON(XFRMA_MAX != XFRMA_SA_DIR);
+		BUILD_BUG_ON(XFRMA_MAX != XFRMA_IPTFS_PKT_SIZE);
 		pr_warn_once("unsupported nla_type %d\n", src->nla_type);
 		return -EOPNOTSUPP;
 	}
@@ -437,7 +443,7 @@ static int xfrm_xlate32_attr(void *dst, const struct nlattr *nla,
 	int err;
 
 	if (type > XFRMA_MAX) {
-		BUILD_BUG_ON(XFRMA_MAX != XFRMA_SA_DIR);
+		BUILD_BUG_ON(XFRMA_MAX != XFRMA_IPTFS_PKT_SIZE);
 		NL_SET_ERR_MSG(extack, "Bad attribute");
 		return -EOPNOTSUPP;
 	}
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index e83c687bd64e..6537bd520363 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -297,6 +297,16 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
 			NL_SET_ERR_MSG(extack, "TFC padding can only be used in tunnel mode");
 			goto out;
 		}
+		if ((attrs[XFRMA_IPTFS_DROP_TIME] ||
+		     attrs[XFRMA_IPTFS_REORDER_WINDOW] ||
+		     attrs[XFRMA_IPTFS_DONT_FRAG] ||
+		     attrs[XFRMA_IPTFS_INIT_DELAY] ||
+		     attrs[XFRMA_IPTFS_MAX_QSIZE] ||
+		     attrs[XFRMA_IPTFS_PKT_SIZE]) &&
+		    p->mode != XFRM_MODE_IPTFS) {
+			NL_SET_ERR_MSG(extack, "IP-TFS options can only be used in IP-TFS mode");
+			goto out;
+		}
 		break;
 
 	case IPPROTO_COMP:
@@ -417,6 +427,18 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
 			goto out;
 		}
 
+		if (attrs[XFRMA_IPTFS_DROP_TIME]) {
+			NL_SET_ERR_MSG(extack, "Drop time should not be set for output SA");
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (attrs[XFRMA_IPTFS_REORDER_WINDOW]) {
+			NL_SET_ERR_MSG(extack, "Reorder window should not be set for output SA");
+			err = -EINVAL;
+			goto out;
+		}
+
 		if (attrs[XFRMA_REPLAY_VAL]) {
 			struct xfrm_replay_state *replay;
 
@@ -454,6 +476,30 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
 			}
 
 		}
+
+		if (attrs[XFRMA_IPTFS_DONT_FRAG]) {
+			NL_SET_ERR_MSG(extack, "Don't fragment should not be set for input SA");
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (attrs[XFRMA_IPTFS_INIT_DELAY]) {
+			NL_SET_ERR_MSG(extack, "Initial delay should not be set for input SA");
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (attrs[XFRMA_IPTFS_MAX_QSIZE]) {
+			NL_SET_ERR_MSG(extack, "Max queue size should not be set for input SA");
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (attrs[XFRMA_IPTFS_PKT_SIZE]) {
+			NL_SET_ERR_MSG(extack, "Packet size should not be set for input SA");
+			err = -EINVAL;
+			goto out;
+		}
 	}
 
 out:
@@ -3165,6 +3211,12 @@ const struct nla_policy xfrma_policy[XFRMA_MAX+1] = {
 	[XFRMA_IF_ID]		= { .type = NLA_U32 },
 	[XFRMA_MTIMER_THRESH]   = { .type = NLA_U32 },
 	[XFRMA_SA_DIR]          = NLA_POLICY_RANGE(NLA_U8, XFRM_SA_DIR_IN, XFRM_SA_DIR_OUT),
+	[XFRMA_IPTFS_DROP_TIME]		= { .type = NLA_U32 },
+	[XFRMA_IPTFS_REORDER_WINDOW]	= { .type = NLA_U16 },
+	[XFRMA_IPTFS_DONT_FRAG]		= { .type = NLA_FLAG },
+	[XFRMA_IPTFS_INIT_DELAY]	= { .type = NLA_U32 },
+	[XFRMA_IPTFS_MAX_QSIZE]		= { .type = NLA_U32 },
+	[XFRMA_IPTFS_PKT_SIZE]	= { .type = NLA_U32 },
 };
 EXPORT_SYMBOL_GPL(xfrma_policy);
 
-- 
2.45.2

[PATCH ipsec-next v4 06/18] xfrm: add mode_cbs module functionality

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Add a set of callbacks xfrm_mode_cbs to xfrm_state. These callbacks
enable the addition of new xfrm modes, such as IP-TFS to be defined
in modules.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 include/net/xfrm.h     | 39 ++++++++++++++++++++++++++++++++++
 net/xfrm/xfrm_device.c |  3 ++-
 net/xfrm/xfrm_input.c  | 14 ++++++++++--
 net/xfrm/xfrm_output.c |  2 ++
 net/xfrm/xfrm_policy.c | 18 ++++++++++------
 net/xfrm/xfrm_state.c  | 48 ++++++++++++++++++++++++++++++++++++++++++
 net/xfrm/xfrm_user.c   | 13 ++++++++++++
 7 files changed, 127 insertions(+), 10 deletions(-)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 7c9be06f8302..cb75ec2993bf 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -206,6 +206,7 @@ struct xfrm_state {
 		u16		family;
 		xfrm_address_t	saddr;
 		int		header_len;
+		int		enc_hdr_len;
 		int		trailer_len;
 		u32		extra_flags;
 		struct xfrm_mark	smark;
@@ -292,6 +293,9 @@ struct xfrm_state {
 	 * interpreted by xfrm_type methods. */
 	void			*data;
 	u8			dir;
+
+	const struct xfrm_mode_cbs	*mode_cbs;
+	void				*mode_data;
 };
 
 static inline struct net *xs_net(struct xfrm_state *x)
@@ -444,6 +448,41 @@ struct xfrm_type_offload {
 int xfrm_register_type_offload(const struct xfrm_type_offload *type, unsigned short family);
 void xfrm_unregister_type_offload(const struct xfrm_type_offload *type, unsigned short family);
 
+struct xfrm_mode_cbs {
+	struct module	*owner;
+	/* Add/delete state in the new xfrm_state in `x`. */
+	int	(*create_state)(struct xfrm_state *x);
+	void	(*delete_state)(struct xfrm_state *x);
+
+	/* Called while handling the user netlink options. */
+	int	(*user_init)(struct net *net, struct xfrm_state *x,
+			     struct nlattr **attrs,
+			     struct netlink_ext_ack *extack);
+	int	(*copy_to_user)(struct xfrm_state *x, struct sk_buff *skb);
+	int     (*clone)(struct xfrm_state *x, struct xfrm_state *orig);
+	unsigned int (*sa_len)(const struct xfrm_state *x);
+
+	u32	(*get_inner_mtu)(struct xfrm_state *x, int outer_mtu);
+
+	/* Called to handle received xfrm (egress) packets. */
+	int	(*input)(struct xfrm_state *x, struct sk_buff *skb);
+
+	/* Placed in dst_output of the dst when an xfrm_state is bound. */
+	int	(*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
+
+	/**
+	 * Prepare the skb for output for the given mode. Returns:
+	 *    Error value, if 0 then skb values should be as follows:
+	 *    transport_header should point at ESP header
+	 *    network_header should point at Outer IP header
+	 *    mac_header should point at protocol/nexthdr of the outer IP
+	 */
+	int	(*prepare_output)(struct xfrm_state *x, struct sk_buff *skb);
+};
+
+int xfrm_register_mode_cbs(u8 mode, const struct xfrm_mode_cbs *mode_cbs);
+void xfrm_unregister_mode_cbs(u8 mode);
+
 static inline int xfrm_af2proto(unsigned int family)
 {
 	switch(family) {
diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
index 2455a76a1cff..f91b2bee8190 100644
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c
@@ -42,7 +42,8 @@ static void __xfrm_mode_tunnel_prep(struct xfrm_state *x, struct sk_buff *skb,
 		skb->transport_header = skb->network_header + hsize;
 
 	skb_reset_mac_len(skb);
-	pskb_pull(skb, skb->mac_len + x->props.header_len);
+	pskb_pull(skb,
+		  skb->mac_len + x->props.header_len - x->props.enc_hdr_len);
 }
 
 static void __xfrm_mode_beet_prep(struct xfrm_state *x, struct sk_buff *skb,
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 71b42de6e3c9..8ef1af2d39bf 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -438,6 +438,9 @@ static int xfrm_inner_mode_input(struct xfrm_state *x,
 		WARN_ON_ONCE(1);
 		break;
 	default:
+		if (x->mode_cbs && x->mode_cbs->input)
+			return x->mode_cbs->input(x, skb);
+
 		WARN_ON_ONCE(1);
 		break;
 	}
@@ -485,6 +488,10 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 
 		family = x->props.family;
 
+		/* An encap_type of -3 indicates reconstructed inner packet */
+		if (encap_type == -3)
+			goto resume_decapped;
+
 		/* An encap_type of -1 indicates async resumption. */
 		if (encap_type == -1) {
 			async = 1;
@@ -672,11 +679,14 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 
 		XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
 
-		if (xfrm_inner_mode_input(x, skb)) {
+		err = xfrm_inner_mode_input(x, skb);
+		if (err == -EINPROGRESS)
+			return 0;
+		else if (err) {
 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
 			goto drop;
 		}
-
+resume_decapped:
 		if (x->outer_mode.flags & XFRM_MODE_FLAG_TUNNEL) {
 			decaps = 1;
 			break;
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index e5722c95b8bb..ef81359e4038 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -472,6 +472,8 @@ static int xfrm_outer_mode_output(struct xfrm_state *x, struct sk_buff *skb)
 		WARN_ON_ONCE(1);
 		break;
 	default:
+		if (x->mode_cbs && x->mode_cbs->prepare_output)
+			return x->mode_cbs->prepare_output(x, skb);
 		WARN_ON_ONCE(1);
 		break;
 	}
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 298b3a9eb48d..a3b50e8bc85a 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2721,13 +2721,17 @@ static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
 
 		dst1->input = dst_discard;
 
-		rcu_read_lock();
-		afinfo = xfrm_state_afinfo_get_rcu(inner_mode->family);
-		if (likely(afinfo))
-			dst1->output = afinfo->output;
-		else
-			dst1->output = dst_discard_out;
-		rcu_read_unlock();
+		if (xfrm[i]->mode_cbs && xfrm[i]->mode_cbs->output) {
+			dst1->output = xfrm[i]->mode_cbs->output;
+		} else {
+			rcu_read_lock();
+			afinfo = xfrm_state_afinfo_get_rcu(inner_mode->family);
+			if (likely(afinfo))
+				dst1->output = afinfo->output;
+			else
+				dst1->output = dst_discard_out;
+			rcu_read_unlock();
+		}
 
 		xdst_prev = xdst;
 
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 649bb739df0d..e9ea5c5dd183 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -513,6 +513,36 @@ static const struct xfrm_mode *xfrm_get_mode(unsigned int encap, int family)
 	return NULL;
 }
 
+static struct xfrm_mode_cbs xfrm_mode_cbs_map[XFRM_MODE_MAX];
+
+int xfrm_register_mode_cbs(u8 mode, const struct xfrm_mode_cbs *mode_cbs)
+{
+	if (mode >= XFRM_MODE_MAX)
+		return -EINVAL;
+
+	xfrm_mode_cbs_map[mode] = *mode_cbs;
+	return 0;
+}
+EXPORT_SYMBOL(xfrm_register_mode_cbs);
+
+void xfrm_unregister_mode_cbs(u8 mode)
+{
+	if (mode >= XFRM_MODE_MAX)
+		return;
+
+	memset(&xfrm_mode_cbs_map[mode], 0, sizeof(xfrm_mode_cbs_map[mode]));
+}
+EXPORT_SYMBOL(xfrm_unregister_mode_cbs);
+
+static const struct xfrm_mode_cbs *xfrm_get_mode_cbs(u8 mode)
+{
+	if (mode >= XFRM_MODE_MAX)
+		return NULL;
+	if (mode == XFRM_MODE_IPTFS && !xfrm_mode_cbs_map[mode].create_state)
+		request_module("xfrm-iptfs");
+	return &xfrm_mode_cbs_map[mode];
+}
+
 void xfrm_state_free(struct xfrm_state *x)
 {
 	kmem_cache_free(xfrm_state_cache, x);
@@ -521,6 +551,8 @@ EXPORT_SYMBOL(xfrm_state_free);
 
 static void ___xfrm_state_destroy(struct xfrm_state *x)
 {
+	if (x->mode_cbs && x->mode_cbs->delete_state)
+		x->mode_cbs->delete_state(x);
 	hrtimer_cancel(&x->mtimer);
 	del_timer_sync(&x->rtimer);
 	kfree(x->aead);
@@ -678,6 +710,7 @@ struct xfrm_state *xfrm_state_alloc(struct net *net)
 		x->replay_maxage = 0;
 		x->replay_maxdiff = 0;
 		spin_lock_init(&x->lock);
+		x->mode_data = NULL;
 	}
 	return x;
 }
@@ -1747,6 +1780,12 @@ static struct xfrm_state *xfrm_state_clone(struct xfrm_state *orig,
 	x->new_mapping_sport = 0;
 	x->dir = orig->dir;
 
+	x->mode_cbs = orig->mode_cbs;
+	if (x->mode_cbs && x->mode_cbs->clone) {
+		if (x->mode_cbs->clone(x, orig))
+			goto error;
+	}
+
 	return x;
 
  error:
@@ -2786,6 +2825,9 @@ u32 xfrm_state_mtu(struct xfrm_state *x, int mtu)
 	case XFRM_MODE_TUNNEL:
 		break;
 	default:
+		if (x->mode_cbs && x->mode_cbs->get_inner_mtu)
+			return x->mode_cbs->get_inner_mtu(x, mtu);
+
 		WARN_ON_ONCE(1);
 		break;
 	}
@@ -2871,6 +2913,12 @@ int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload,
 			goto error;
 	}
 
+	x->mode_cbs = xfrm_get_mode_cbs(x->props.mode);
+	if (x->mode_cbs && x->mode_cbs->create_state) {
+		err = x->mode_cbs->create_state(x);
+		if (err)
+			goto error;
+	}
 error:
 	return err;
 }
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 6537bd520363..dfd52637abed 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -914,6 +914,12 @@ static struct xfrm_state *xfrm_state_construct(struct net *net,
 			goto error;
 	}
 
+	if (x->mode_cbs && x->mode_cbs->user_init) {
+		err = x->mode_cbs->user_init(net, x, attrs, extack);
+		if (err)
+			goto error;
+	}
+
 	return x;
 
 error:
@@ -1327,6 +1333,10 @@ static int copy_to_user_state_extra(struct xfrm_state *x,
 		if (ret)
 			goto out;
 	}
+	if (x->mode_cbs && x->mode_cbs->copy_to_user)
+		ret = x->mode_cbs->copy_to_user(x, skb);
+	if (ret)
+		goto out;
 	if (x->mapping_maxage) {
 		ret = nla_put_u32(skb, XFRMA_MTIMER_THRESH, x->mapping_maxage);
 		if (ret)
@@ -3526,6 +3536,9 @@ static inline unsigned int xfrm_sa_len(struct xfrm_state *x)
 	if (x->dir)
 		l += nla_total_size(sizeof(x->dir));
 
+	if (x->mode_cbs && x->mode_cbs->sa_len)
+		l += x->mode_cbs->sa_len(x);
+
 	return l;
 }
 
-- 
2.45.2

[PATCH ipsec-next v4 07/18] xfrm: add generic iptfs defines and functionality

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Define `XFRM_MODE_IPTFS` and `IPSEC_MODE_IPTFS` constants, and add these to
switch case and conditionals adjacent with the existing TUNNEL modes.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 include/net/xfrm.h         |  1 +
 include/uapi/linux/ipsec.h |  3 ++-
 include/uapi/linux/snmp.h  |  3 +++
 net/ipv4/esp4.c            |  3 ++-
 net/ipv6/esp6.c            |  3 ++-
 net/netfilter/nft_xfrm.c   |  3 ++-
 net/xfrm/xfrm_device.c     |  1 +
 net/xfrm/xfrm_output.c     |  4 ++++
 net/xfrm/xfrm_policy.c     |  8 ++++++--
 net/xfrm/xfrm_proc.c       |  3 +++
 net/xfrm/xfrm_state.c      | 12 ++++++++++++
 net/xfrm/xfrm_user.c       | 10 ++++++++++
 12 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index cb75ec2993bf..0d8abf7bd32e 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -37,6 +37,7 @@
 #define XFRM_PROTO_COMP		108
 #define XFRM_PROTO_IPIP		4
 #define XFRM_PROTO_IPV6		41
+#define XFRM_PROTO_IPTFS	IPPROTO_AGGFRAG
 #define XFRM_PROTO_ROUTING	IPPROTO_ROUTING
 #define XFRM_PROTO_DSTOPTS	IPPROTO_DSTOPTS
 
diff --git a/include/uapi/linux/ipsec.h b/include/uapi/linux/ipsec.h
index 50d8ee1791e2..696b790f4346 100644
--- a/include/uapi/linux/ipsec.h
+++ b/include/uapi/linux/ipsec.h
@@ -14,7 +14,8 @@ enum {
 	IPSEC_MODE_ANY		= 0,	/* We do not support this for SA */
 	IPSEC_MODE_TRANSPORT	= 1,
 	IPSEC_MODE_TUNNEL	= 2,
-	IPSEC_MODE_BEET         = 3
+	IPSEC_MODE_BEET         = 3,
+	IPSEC_MODE_IPTFS        = 4
 };
 
 enum {
diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
index adf5fd78dd50..77eb078f06a6 100644
--- a/include/uapi/linux/snmp.h
+++ b/include/uapi/linux/snmp.h
@@ -339,6 +339,9 @@ enum
 	LINUX_MIB_XFRMACQUIREERROR,		/* XfrmAcquireError */
 	LINUX_MIB_XFRMOUTSTATEDIRERROR,		/* XfrmOutStateDirError */
 	LINUX_MIB_XFRMINSTATEDIRERROR,		/* XfrmInStateDirError */
+	LINUX_MIB_XFRMNOSKBERROR,		/* XfrmNoSkbError */
+	LINUX_MIB_XFRMINIPTFSERROR,		/* XfrmInIptfsError */
+	LINUX_MIB_XFRMOUTNOQSPACE,		/* XfrmOutNoQueueSpace */
 	__LINUX_MIB_XFRMMAX
 };
 
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 7d38ddd64115..2da9fd4efb70 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -809,7 +809,8 @@ int esp_input_done2(struct sk_buff *skb, int err)
 	}
 
 	skb_pull_rcsum(skb, hlen);
-	if (x->props.mode == XFRM_MODE_TUNNEL)
+	if (x->props.mode == XFRM_MODE_TUNNEL ||
+	    x->props.mode == XFRM_MODE_IPTFS)
 		skb_reset_transport_header(skb);
 	else
 		skb_set_transport_header(skb, -ihl);
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 27df148530a6..0e50ff3eccdb 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -858,7 +858,8 @@ int esp6_input_done2(struct sk_buff *skb, int err)
 	skb_postpull_rcsum(skb, skb_network_header(skb),
 			   skb_network_header_len(skb));
 	skb_pull_rcsum(skb, hlen);
-	if (x->props.mode == XFRM_MODE_TUNNEL)
+	if (x->props.mode == XFRM_MODE_TUNNEL ||
+	    x->props.mode == XFRM_MODE_IPTFS)
 		skb_reset_transport_header(skb);
 	else
 		skb_set_transport_header(skb, -hdr_len);
diff --git a/net/netfilter/nft_xfrm.c b/net/netfilter/nft_xfrm.c
index 1c866757db55..620238c6ef4c 100644
--- a/net/netfilter/nft_xfrm.c
+++ b/net/netfilter/nft_xfrm.c
@@ -112,7 +112,8 @@ static bool xfrm_state_addr_ok(enum nft_xfrm_keys k, u8 family, u8 mode)
 		return true;
 	}
 
-	return mode == XFRM_MODE_BEET || mode == XFRM_MODE_TUNNEL;
+	return mode == XFRM_MODE_BEET || mode == XFRM_MODE_TUNNEL ||
+	       mode == XFRM_MODE_IPTFS;
 }
 
 static void nft_xfrm_state_get_key(const struct nft_xfrm *priv,
diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
index f91b2bee8190..b73af6918028 100644
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c
@@ -69,6 +69,7 @@ static void __xfrm_mode_beet_prep(struct xfrm_state *x, struct sk_buff *skb,
 static void xfrm_outer_mode_prep(struct xfrm_state *x, struct sk_buff *skb)
 {
 	switch (x->outer_mode.encap) {
+	case XFRM_MODE_IPTFS:
 	case XFRM_MODE_TUNNEL:
 		if (x->outer_mode.family == AF_INET)
 			return __xfrm_mode_tunnel_prep(x, skb,
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index ef81359e4038..b5025cf6136e 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -677,6 +677,10 @@ static void xfrm_get_inner_ipproto(struct sk_buff *skb, struct xfrm_state *x)
 
 		return;
 	}
+	if (x->outer_mode.encap == XFRM_MODE_IPTFS) {
+		xo->inner_ipproto = IPPROTO_AGGFRAG;
+		return;
+	}
 
 	/* non-Tunnel Mode */
 	if (!skb->encapsulation)
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index a3b50e8bc85a..dd58f84b4c13 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2474,6 +2474,7 @@ xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
 		struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
 
 		if (tmpl->mode == XFRM_MODE_TUNNEL ||
+		    tmpl->mode == XFRM_MODE_IPTFS ||
 		    tmpl->mode == XFRM_MODE_BEET) {
 			remote = &tmpl->id.daddr;
 			local = &tmpl->saddr;
@@ -3266,7 +3267,8 @@ struct dst_entry *xfrm_lookup_with_ifid(struct net *net,
 ok:
 	xfrm_pols_put(pols, drop_pols);
 	if (dst && dst->xfrm &&
-	    dst->xfrm->props.mode == XFRM_MODE_TUNNEL)
+	    (dst->xfrm->props.mode == XFRM_MODE_TUNNEL ||
+	     dst->xfrm->props.mode == XFRM_MODE_IPTFS))
 		dst->flags |= DST_XFRM_TUNNEL;
 	return dst;
 
@@ -4503,6 +4505,7 @@ static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tm
 		switch (t->mode) {
 		case XFRM_MODE_TUNNEL:
 		case XFRM_MODE_BEET:
+		case XFRM_MODE_IPTFS:
 			if (xfrm_addr_equal(&t->id.daddr, &m->old_daddr,
 					    m->old_family) &&
 			    xfrm_addr_equal(&t->saddr, &m->old_saddr,
@@ -4545,7 +4548,8 @@ static int xfrm_policy_migrate(struct xfrm_policy *pol,
 				continue;
 			n++;
 			if (pol->xfrm_vec[i].mode != XFRM_MODE_TUNNEL &&
-			    pol->xfrm_vec[i].mode != XFRM_MODE_BEET)
+			    pol->xfrm_vec[i].mode != XFRM_MODE_BEET &&
+			    pol->xfrm_vec[i].mode != XFRM_MODE_IPTFS)
 				continue;
 			/* update endpoints */
 			memcpy(&pol->xfrm_vec[i].id.daddr, &mp->new_daddr,
diff --git a/net/xfrm/xfrm_proc.c b/net/xfrm/xfrm_proc.c
index eeb984be03a7..e851b388995a 100644
--- a/net/xfrm/xfrm_proc.c
+++ b/net/xfrm/xfrm_proc.c
@@ -43,6 +43,9 @@ static const struct snmp_mib xfrm_mib_list[] = {
 	SNMP_MIB_ITEM("XfrmAcquireError", LINUX_MIB_XFRMACQUIREERROR),
 	SNMP_MIB_ITEM("XfrmOutStateDirError", LINUX_MIB_XFRMOUTSTATEDIRERROR),
 	SNMP_MIB_ITEM("XfrmInStateDirError", LINUX_MIB_XFRMINSTATEDIRERROR),
+	SNMP_MIB_ITEM("XfrmNoSkbError", LINUX_MIB_XFRMNOSKBERROR),
+	SNMP_MIB_ITEM("XfrmInIptfsError", LINUX_MIB_XFRMINIPTFSERROR),
+	SNMP_MIB_ITEM("XfrmOutNoQueueSpace", LINUX_MIB_XFRMOUTNOQSPACE),
 	SNMP_MIB_SENTINEL
 };
 
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index e9ea5c5dd183..dad36ff30510 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -465,6 +465,11 @@ static const struct xfrm_mode xfrm4_mode_map[XFRM_MODE_MAX] = {
 		.flags = XFRM_MODE_FLAG_TUNNEL,
 		.family = AF_INET,
 	},
+	[XFRM_MODE_IPTFS] = {
+		.encap = XFRM_MODE_IPTFS,
+		.flags = XFRM_MODE_FLAG_TUNNEL,
+		.family = AF_INET,
+	},
 };
 
 static const struct xfrm_mode xfrm6_mode_map[XFRM_MODE_MAX] = {
@@ -486,6 +491,11 @@ static const struct xfrm_mode xfrm6_mode_map[XFRM_MODE_MAX] = {
 		.flags = XFRM_MODE_FLAG_TUNNEL,
 		.family = AF_INET6,
 	},
+	[XFRM_MODE_IPTFS] = {
+		.encap = XFRM_MODE_IPTFS,
+		.flags = XFRM_MODE_FLAG_TUNNEL,
+		.family = AF_INET6,
+	},
 };
 
 static const struct xfrm_mode *xfrm_get_mode(unsigned int encap, int family)
@@ -2111,6 +2121,7 @@ static int __xfrm6_state_sort_cmp(const void *p)
 #endif
 	case XFRM_MODE_TUNNEL:
 	case XFRM_MODE_BEET:
+	case XFRM_MODE_IPTFS:
 		return 4;
 	}
 	return 5;
@@ -2137,6 +2148,7 @@ static int __xfrm6_tmpl_sort_cmp(const void *p)
 #endif
 	case XFRM_MODE_TUNNEL:
 	case XFRM_MODE_BEET:
+	case XFRM_MODE_IPTFS:
 		return 3;
 	}
 	return 4;
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index dfd52637abed..177dc0b23002 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -379,6 +379,14 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
 	case XFRM_MODE_ROUTEOPTIMIZATION:
 	case XFRM_MODE_BEET:
 		break;
+	case XFRM_MODE_IPTFS:
+		if (sa_dir == 0) {
+			NL_SET_ERR_MSG(
+				extack,
+				"IP-TFS mode requires in or out direction attribute");
+			goto out;
+		}
+		break;
 
 	default:
 		NL_SET_ERR_MSG(extack, "Unsupported mode");
@@ -1973,6 +1981,8 @@ static int validate_tmpl(int nr, struct xfrm_user_tmpl *ut, u16 family,
 				return -EINVAL;
 			}
 			break;
+		case XFRM_MODE_IPTFS:
+			break;
 		default:
 			if (ut[i].family != prev_family) {
 				NL_SET_ERR_MSG(extack, "Mode in template doesn't support a family change");
-- 
2.45.2

[PATCH ipsec-next v4 08/18] xfrm: iptfs: add new iptfs xfrm mode impl

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Add a new xfrm mode implementing AggFrag/IP-TFS from RFC9347.

This utilizes the new xfrm_mode_cbs to implement demand-driven IP-TFS
functionality. This functionality can be used to increase bandwidth
utilization through small packet aggregation, as well as help solve PMTU
issues through it's efficient use of fragmentation.

  Link: https://www.rfc-editor.org/rfc/rfc9347.txt

Multiple commits follow to build the functionality into xfrm_iptfs.c

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 net/xfrm/Makefile     |   1 +
 net/xfrm/xfrm_iptfs.c | 225 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 226 insertions(+)
 create mode 100644 net/xfrm/xfrm_iptfs.c

diff --git a/net/xfrm/Makefile b/net/xfrm/Makefile
index 547cec77ba03..cd6520d4d777 100644
--- a/net/xfrm/Makefile
+++ b/net/xfrm/Makefile
@@ -20,5 +20,6 @@ obj-$(CONFIG_XFRM_USER) += xfrm_user.o
 obj-$(CONFIG_XFRM_USER_COMPAT) += xfrm_compat.o
 obj-$(CONFIG_XFRM_IPCOMP) += xfrm_ipcomp.o
 obj-$(CONFIG_XFRM_INTERFACE) += xfrm_interface.o
+obj-$(CONFIG_XFRM_IPTFS) += xfrm_iptfs.o
 obj-$(CONFIG_XFRM_ESPINTCP) += espintcp.o
 obj-$(CONFIG_DEBUG_INFO_BTF) += xfrm_state_bpf.o
diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
new file mode 100644
index 000000000000..e7b5546e1f6a
--- /dev/null
+++ b/net/xfrm/xfrm_iptfs.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0
+/* xfrm_iptfs: IPTFS encapsulation support
+ *
+ * April 21 2022, Christian Hopps <chopps@labn.net>
+ *
+ * Copyright (c) 2022, LabN Consulting, L.L.C.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/icmpv6.h>
+#include <net/gro.h>
+#include <net/icmp.h>
+#include <net/ip6_route.h>
+#include <net/inet_ecn.h>
+#include <net/xfrm.h>
+
+#include <crypto/aead.h>
+
+#include "xfrm_inout.h"
+
+struct xfrm_iptfs_config {
+	u32 pkt_size;	    /* outer_packet_size or 0 */
+};
+
+struct xfrm_iptfs_data {
+	struct xfrm_iptfs_config cfg;
+
+	/* Ingress User Input */
+	struct xfrm_state *x;	    /* owning state */
+	u32 payload_mtu;	    /* max payload size */
+};
+
+/* ========================== */
+/* State Management Functions */
+/* ========================== */
+
+/**
+ * iptfs_get_inner_mtu() - return inner MTU with no fragmentation.
+ * @x: xfrm state.
+ * @outer_mtu: the outer mtu
+ */
+static u32 iptfs_get_inner_mtu(struct xfrm_state *x, int outer_mtu)
+{
+	struct crypto_aead *aead;
+	u32 blksize;
+
+	aead = x->data;
+	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
+	return ((outer_mtu - x->props.header_len - crypto_aead_authsize(aead)) &
+		~(blksize - 1)) - 2;
+}
+
+/**
+ * iptfs_user_init() - initialize the SA with IPTFS options from netlink.
+ * @net: the net data
+ * @x: xfrm state
+ * @attrs: netlink attributes
+ * @extack: extack return data
+ */
+static int iptfs_user_init(struct net *net, struct xfrm_state *x,
+			   struct nlattr **attrs,
+			   struct netlink_ext_ack *extack)
+{
+	struct xfrm_iptfs_data *xtfs = x->mode_data;
+	struct xfrm_iptfs_config *xc;
+
+	xc = &xtfs->cfg;
+
+	if (attrs[XFRMA_IPTFS_PKT_SIZE]) {
+		xc->pkt_size = nla_get_u32(attrs[XFRMA_IPTFS_PKT_SIZE]);
+		if (!xc->pkt_size) {
+			xtfs->payload_mtu = 0;
+		} else if (xc->pkt_size > x->props.header_len) {
+			xtfs->payload_mtu = xc->pkt_size - x->props.header_len;
+		} else {
+			NL_SET_ERR_MSG(extack,
+				       "Packet size must be 0 or greater than IPTFS/ESP header length");
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+static unsigned int iptfs_sa_len(const struct xfrm_state *x)
+{
+	struct xfrm_iptfs_data *xtfs = x->mode_data;
+	struct xfrm_iptfs_config *xc = &xtfs->cfg;
+	unsigned int l = 0;
+
+	l += nla_total_size(0);
+	l += nla_total_size(sizeof(u16));
+	l += nla_total_size(sizeof(xc->pkt_size));
+	l += nla_total_size(sizeof(u32));
+	l += nla_total_size(sizeof(u32)); /* drop time usec */
+	l += nla_total_size(sizeof(u32)); /* init delay usec */
+
+	return l;
+}
+
+static int iptfs_copy_to_user(struct xfrm_state *x, struct sk_buff *skb)
+{
+	struct xfrm_iptfs_data *xtfs = x->mode_data;
+	struct xfrm_iptfs_config *xc = &xtfs->cfg;
+	int ret;
+
+	ret = nla_put_flag(skb, XFRMA_IPTFS_DONT_FRAG);
+	if (ret)
+		return ret;
+	ret = nla_put_u16(skb, XFRMA_IPTFS_REORDER_WINDOW, 0);
+	if (ret)
+		return ret;
+	ret = nla_put_u32(skb, XFRMA_IPTFS_PKT_SIZE, xc->pkt_size);
+	if (ret)
+		return ret;
+	ret = nla_put_u32(skb, XFRMA_IPTFS_MAX_QSIZE, 0);
+	if (ret)
+		return ret;
+
+	ret = nla_put_u32(skb, XFRMA_IPTFS_DROP_TIME, 0);
+	if (ret)
+		return ret;
+
+	ret = nla_put_u32(skb, XFRMA_IPTFS_INIT_DELAY, 0);
+
+	return ret;
+}
+
+static int __iptfs_init_state(struct xfrm_state *x,
+			      struct xfrm_iptfs_data *xtfs)
+{
+	/* Modify type (esp) adjustment values */
+
+	if (x->props.family == AF_INET)
+		x->props.header_len += sizeof(struct iphdr) + sizeof(struct ip_iptfs_hdr);
+	else if (x->props.family == AF_INET6)
+		x->props.header_len += sizeof(struct ipv6hdr) + sizeof(struct ip_iptfs_hdr);
+	x->props.enc_hdr_len = sizeof(struct ip_iptfs_hdr);
+
+	/* Always have a module reference if x->mode_data is set */
+	if (!try_module_get(x->mode_cbs->owner))
+		return -EINVAL;
+
+	x->mode_data = xtfs;
+	xtfs->x = x;
+
+	return 0;
+}
+
+static int iptfs_clone(struct xfrm_state *x, struct xfrm_state *orig)
+{
+	struct xfrm_iptfs_data *xtfs;
+	int err;
+
+	xtfs = kmemdup(orig->mode_data, sizeof(*xtfs), GFP_KERNEL);
+	if (!xtfs)
+		return -ENOMEM;
+
+	err = __iptfs_init_state(x, xtfs);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int iptfs_create_state(struct xfrm_state *x)
+{
+	struct xfrm_iptfs_data *xtfs;
+	int err;
+
+	xtfs = kzalloc(sizeof(*xtfs), GFP_KERNEL);
+	if (!xtfs)
+		return -ENOMEM;
+
+	err = __iptfs_init_state(x, xtfs);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static void iptfs_delete_state(struct xfrm_state *x)
+{
+	struct xfrm_iptfs_data *xtfs = x->mode_data;
+
+	if (!xtfs)
+		return;
+
+	kfree_sensitive(xtfs);
+
+	module_put(x->mode_cbs->owner);
+}
+
+static const struct xfrm_mode_cbs iptfs_mode_cbs = {
+	.owner = THIS_MODULE,
+	.create_state = iptfs_create_state,
+	.delete_state = iptfs_delete_state,
+	.user_init = iptfs_user_init,
+	.copy_to_user = iptfs_copy_to_user,
+	.sa_len = iptfs_sa_len,
+	.clone = iptfs_clone,
+	.get_inner_mtu = iptfs_get_inner_mtu,
+};
+
+static int __init xfrm_iptfs_init(void)
+{
+	int err;
+
+	pr_info("xfrm_iptfs: IPsec IP-TFS tunnel mode module\n");
+
+	err = xfrm_register_mode_cbs(XFRM_MODE_IPTFS, &iptfs_mode_cbs);
+	if (err < 0)
+		pr_info("%s: can't register IP-TFS\n", __func__);
+
+	return err;
+}
+
+static void __exit xfrm_iptfs_fini(void)
+{
+	xfrm_unregister_mode_cbs(XFRM_MODE_IPTFS);
+}
+
+module_init(xfrm_iptfs_init);
+module_exit(xfrm_iptfs_fini);
+MODULE_LICENSE("GPL");
-- 
2.45.2

[PATCH ipsec-next v4 09/18] xfrm: iptfs: add user packet (tunnel ingress) handling

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Add tunnel packet output functionality. This is code handles
the ingress to the tunnel.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 net/xfrm/xfrm_iptfs.c | 522 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 519 insertions(+), 3 deletions(-)

diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
index e7b5546e1f6a..de836c4f361f 100644
--- a/net/xfrm/xfrm_iptfs.c
+++ b/net/xfrm/xfrm_iptfs.c
@@ -19,8 +19,13 @@
 
 #include "xfrm_inout.h"
 
+#define NSECS_IN_USEC 1000
+
+#define IPTFS_HRTIMER_MODE HRTIMER_MODE_REL_SOFT
+
 struct xfrm_iptfs_config {
 	u32 pkt_size;	    /* outer_packet_size or 0 */
+	u32 max_queue_size; /* octets */
 };
 
 struct xfrm_iptfs_data {
@@ -28,9 +33,498 @@ struct xfrm_iptfs_data {
 
 	/* Ingress User Input */
 	struct xfrm_state *x;	    /* owning state */
+	struct sk_buff_head queue;  /* output queue */
+	u32 queue_size;		    /* octets */
+	u32 ecn_queue_size;	    /* octets above which ECN mark */
+	u64 init_delay_ns;	    /* nanoseconds */
+	struct hrtimer iptfs_timer; /* output timer */
+	time64_t iptfs_settime;	    /* time timer was set */
 	u32 payload_mtu;	    /* max payload size */
 };
 
+static u32 iptfs_get_inner_mtu(struct xfrm_state *x, int outer_mtu);
+static enum hrtimer_restart iptfs_delay_timer(struct hrtimer *me);
+
+/* ================================= */
+/* IPTFS Sending (ingress) Functions */
+/* ================================= */
+
+/* ------------------------- */
+/* Enqueue to send functions */
+/* ------------------------- */
+
+/**
+ * iptfs_enqueue() - enqueue packet if ok to send.
+ * @xtfs: xtfs state
+ * @skb: the packet
+ *
+ * Return: true if packet enqueued.
+ */
+static bool iptfs_enqueue(struct xfrm_iptfs_data *xtfs, struct sk_buff *skb)
+{
+	u64 newsz = xtfs->queue_size + skb->len;
+	struct iphdr *iph;
+
+	assert_spin_locked(&xtfs->x->lock);
+
+	if (newsz > xtfs->cfg.max_queue_size)
+		return false;
+
+	/* Set ECN CE if we are above our ECN queue threshold */
+	if (newsz > xtfs->ecn_queue_size) {
+		iph = ip_hdr(skb);
+		if (iph->version == 4)
+			IP_ECN_set_ce(iph);
+		else if (iph->version == 6)
+			IP6_ECN_set_ce(skb, ipv6_hdr(skb));
+	}
+
+	__skb_queue_tail(&xtfs->queue, skb);
+	xtfs->queue_size += skb->len;
+	return true;
+}
+
+static int iptfs_get_cur_pmtu(struct xfrm_state *x,
+			      struct xfrm_iptfs_data *xtfs, struct sk_buff *skb)
+{
+	struct xfrm_dst *xdst = (struct xfrm_dst *)skb_dst(skb);
+	u32 payload_mtu = xtfs->payload_mtu;
+	u32 pmtu = iptfs_get_inner_mtu(x, xdst->child_mtu_cached);
+
+	if (payload_mtu && payload_mtu < pmtu)
+		pmtu = payload_mtu;
+
+	return pmtu;
+}
+
+static int iptfs_is_too_big(struct sock *sk, struct sk_buff *skb, u32 pmtu)
+{
+	if (skb->len <= pmtu)
+		return 0;
+
+	/* We only send ICMP too big if the user has configured us as
+	 * dont-fragment.
+	 */
+	if (skb->dev)
+		XFRM_INC_STATS(dev_net(skb->dev), LINUX_MIB_XFRMOUTERROR);
+
+	if (sk) {
+		xfrm_local_error(skb, pmtu);
+	} else if (ip_hdr(skb)->version == 4) {
+		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
+			  htonl(pmtu));
+	} else {
+		WARN_ON_ONCE(ip_hdr(skb)->version != 6);
+		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, pmtu);
+	}
+	return 1;
+}
+
+/* IPv4/IPv6 packet ingress to IPTFS tunnel, arrange to send in IPTFS payload
+ * (i.e., aggregating or fragmenting as appropriate).
+ * This is set in dst->output for an SA.
+ */
+static int iptfs_output_collect(struct net *net, struct sock *sk,
+				struct sk_buff *skb)
+{
+	struct dst_entry *dst = skb_dst(skb);
+	struct xfrm_state *x = dst->xfrm;
+	struct xfrm_iptfs_data *xtfs = x->mode_data;
+	struct sk_buff *segs, *nskb;
+	u32 pmtu = 0;
+	bool ok = true;
+	bool was_gso;
+
+	/* We have hooked into dst_entry->output which means we have skipped the
+	 * protocol specific netfilter (see xfrm4_output, xfrm6_output).
+	 * when our timer runs we will end up calling xfrm_output directly on
+	 * the encapsulated traffic.
+	 *
+	 * For both cases this is the NF_INET_POST_ROUTING hook which allows
+	 * changing the skb->dst entry which then may not be xfrm based anymore
+	 * in which case a REROUTED flag is set. and dst_output is called.
+	 *
+	 * For IPv6 we are also skipping fragmentation handling for local
+	 * sockets, which may or may not be good depending on our tunnel DF
+	 * setting. Normally with fragmentation supported we want to skip this
+	 * fragmentation.
+	 */
+
+	BUG_ON(!xtfs);
+
+	pmtu = iptfs_get_cur_pmtu(x, xtfs, skb);
+
+	/* Break apart GSO skbs. If the queue is nearing full then we want the
+	 * accounting and queuing to be based on the individual packets not on the
+	 * aggregate GSO buffer.
+	 */
+	was_gso = skb_is_gso(skb);
+	if (!was_gso) {
+		segs = skb;
+	} else {
+		segs = skb_gso_segment(skb, 0);
+		if (IS_ERR_OR_NULL(segs)) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
+			kfree_skb(skb);
+			return PTR_ERR(segs);
+		}
+		consume_skb(skb);
+		skb = NULL;
+	}
+
+	/* We can be running on multiple cores and from the network softirq or
+	 * from user context depending on where the packet is coming from.
+	 */
+	spin_lock_bh(&x->lock);
+
+	skb_list_walk_safe(segs, skb, nskb)
+	{
+		skb_mark_not_on_list(skb);
+
+		/* Once we drop due to no queue space we continue to drop the
+		 * rest of the packets from that GRO.
+		 */
+		if (!ok) {
+nospace:
+			if (skb->dev)
+				XFRM_INC_STATS(dev_net(skb->dev),
+				       LINUX_MIB_XFRMOUTNOQSPACE);
+			kfree_skb_reason(skb, SKB_DROP_REASON_FULL_RING);
+			continue;
+		}
+
+		/* Fragmenting handled in following commits. */
+		if (iptfs_is_too_big(sk, skb, pmtu)) {
+			kfree_skb_reason(skb, SKB_DROP_REASON_PKT_TOO_BIG);
+			continue;
+		}
+
+		/* Enqueue to send in tunnel */
+		ok = iptfs_enqueue(xtfs, skb);
+		if (!ok)
+			goto nospace;
+	}
+
+	/* Start a delay timer if we don't have one yet */
+	if (!hrtimer_is_queued(&xtfs->iptfs_timer)) {
+		hrtimer_start(&xtfs->iptfs_timer, xtfs->init_delay_ns,
+			      IPTFS_HRTIMER_MODE);
+		xtfs->iptfs_settime = ktime_get_raw_fast_ns();
+	}
+
+	spin_unlock_bh(&x->lock);
+	return 0;
+}
+
+/* -------------------------- */
+/* Dequeue and send functions */
+/* -------------------------- */
+
+static void iptfs_output_prepare_skb(struct sk_buff *skb, u32 blkoff)
+{
+	struct ip_iptfs_hdr *h;
+	size_t hsz = sizeof(*h);
+
+	/* now reset values to be pointing at the rest of the packets */
+	h = skb_push(skb, hsz);
+	memset(h, 0, hsz);
+	if (blkoff)
+		h->block_offset = htons(blkoff);
+
+	/* network_header current points at the inner IP packet
+	 * move it to the iptfs header
+	 */
+	skb->transport_header = skb->network_header;
+	skb->network_header -= hsz;
+
+	IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
+}
+
+static struct sk_buff **iptfs_rehome_fraglist(struct sk_buff **nextp,
+					      struct sk_buff *child)
+{
+	u32 fllen = 0;
+
+	/* It might be possible to account for a frag list in addition to page
+	 * fragment if it's a valid state to be in. The page fragments size
+	 * should be kept as data_len so only the frag_list size is removed,
+	 * this must be done above as well.
+	 */
+	BUG_ON(skb_shinfo(child)->nr_frags);
+	*nextp = skb_shinfo(child)->frag_list;
+	while (*nextp) {
+		fllen += (*nextp)->len;
+		nextp = &(*nextp)->next;
+	}
+	skb_frag_list_init(child);
+	BUG_ON(fllen > child->data_len);
+	child->len -= fllen;
+	child->data_len -= fllen;
+
+	return nextp;
+}
+
+static void iptfs_output_queued(struct xfrm_state *x, struct sk_buff_head *list)
+{
+	struct xfrm_iptfs_data *xtfs = x->mode_data;
+	struct sk_buff *skb, *skb2, **nextp;
+	struct skb_shared_info *shi;
+
+	while ((skb = __skb_dequeue(list))) {
+		u32 mtu = iptfs_get_cur_pmtu(x, xtfs, skb);
+		int remaining;
+
+		/* protocol comes to us cleared sometimes */
+		skb->protocol = x->outer_mode.family == AF_INET ?
+					      htons(ETH_P_IP) :
+					      htons(ETH_P_IPV6);
+
+		if (skb->len > mtu) {
+			/* We handle this case before enqueueing so we are only
+			 * here b/c MTU changed after we enqueued before we
+			 * dequeued, just drop these.
+			 */
+			if (skb->dev)
+				XFRM_INC_STATS(dev_net(skb->dev),
+				       LINUX_MIB_XFRMOUTERROR);
+
+			kfree_skb_reason(skb, SKB_DROP_REASON_PKT_TOO_BIG);
+			continue;
+		}
+
+		/* If we don't have a cksum in the packet we need to add one
+		 * before encapsulation.
+		 */
+		if (skb->ip_summed == CHECKSUM_PARTIAL) {
+			if (skb_checksum_help(skb)) {
+				XFRM_INC_STATS(dev_net(skb_dst(skb)->dev),
+					       LINUX_MIB_XFRMOUTERROR);
+				kfree_skb(skb);
+				continue;
+			}
+		}
+
+		/* Convert first inner packet into an outer IPTFS packet */
+		iptfs_output_prepare_skb(skb, 0);
+
+		/* The space remaining to send more inner packet data is `mtu` -
+		 * (skb->len - sizeof iptfs header). This is b/c the `mtu` value
+		 * has the basic IPTFS header len accounted for, and we added
+		 * that header to the skb so it is a part of skb->len, thus we
+		 * subtract it from the skb length.
+		 */
+		remaining = mtu - (skb->len - sizeof(struct ip_iptfs_hdr));
+
+		/* Re-home (un-nest) nested fragment lists. We need to do this
+		 * b/c we will simply be appending any following aggregated
+		 * inner packets to the frag list.
+		 */
+		shi = skb_shinfo(skb);
+		nextp = &shi->frag_list;
+		while (*nextp) {
+			if (skb_has_frag_list(*nextp))
+				nextp = iptfs_rehome_fraglist(&(*nextp)->next,
+							      *nextp);
+			else
+				nextp = &(*nextp)->next;
+		}
+
+		/* See if we have enough space to simply append.
+		 *
+		 * NOTE: Maybe do not append if we will be mis-aligned,
+		 * SW-based endpoints will probably have to copy in this
+		 * case.
+		 */
+		while ((skb2 = skb_peek(list))) {
+			if (skb2->len > remaining)
+				break;
+
+			__skb_unlink(skb2, list);
+
+			/* If we don't have a cksum in the packet we need to add
+			 * one before encapsulation.
+			 */
+			if (skb2->ip_summed == CHECKSUM_PARTIAL) {
+				if (skb_checksum_help(skb2)) {
+					XFRM_INC_STATS(
+						dev_net(skb_dst(skb2)->dev),
+						LINUX_MIB_XFRMOUTERROR);
+					kfree_skb(skb2);
+					continue;
+				}
+			}
+
+			/* Do accounting */
+			skb->data_len += skb2->len;
+			skb->len += skb2->len;
+			remaining -= skb2->len;
+
+			/* Append to the frag_list */
+			*nextp = skb2;
+			nextp = &skb2->next;
+			BUG_ON(*nextp);
+			if (skb_has_frag_list(skb2))
+				nextp = iptfs_rehome_fraglist(nextp, skb2);
+			skb->truesize += skb2->truesize;
+		}
+
+		xfrm_output(NULL, skb);
+	}
+}
+
+static enum hrtimer_restart iptfs_delay_timer(struct hrtimer *me)
+{
+	struct sk_buff_head list;
+	struct xfrm_iptfs_data *xtfs;
+	struct xfrm_state *x;
+	time64_t settime;
+
+	xtfs = container_of(me, typeof(*xtfs), iptfs_timer);
+	x = xtfs->x;
+
+	/* Process all the queued packets
+	 *
+	 * softirq execution order: timer > tasklet > hrtimer
+	 *
+	 * Network rx will have run before us giving one last chance to queue
+	 * ingress packets for us to process and transmit.
+	 */
+
+	spin_lock(&x->lock);
+	__skb_queue_head_init(&list);
+	skb_queue_splice_init(&xtfs->queue, &list);
+	xtfs->queue_size = 0;
+	settime = xtfs->iptfs_settime;
+	spin_unlock(&x->lock);
+
+	/* After the above unlock, packets can begin queuing again, and the
+	 * timer can be set again, from another CPU either in softirq or user
+	 * context (not from this one since we are running at softirq level
+	 * already).
+	 */
+
+	iptfs_output_queued(x, &list);
+
+	return HRTIMER_NORESTART;
+}
+
+/**
+ * iptfs_encap_add_ipv4() - add outer encaps
+ * @x: xfrm state
+ * @skb: the packet
+ *
+ * This was originally taken from xfrm4_tunnel_encap_add. The reason for the
+ * copy is that IP-TFS/AGGFRAG can have different functionality for how to set
+ * the TOS/DSCP bits. Sets the protocol to a different value and doesn't do
+ * anything with inner headers as they aren't pointing into a normal IP
+ * singleton inner packet.
+ */
+static int iptfs_encap_add_ipv4(struct xfrm_state *x, struct sk_buff *skb)
+{
+	struct dst_entry *dst = skb_dst(skb);
+	struct iphdr *top_iph;
+
+	skb_reset_inner_network_header(skb);
+	skb_reset_inner_transport_header(skb);
+
+	skb_set_network_header(skb,
+			       -(x->props.header_len - x->props.enc_hdr_len));
+	skb->mac_header =
+		skb->network_header + offsetof(struct iphdr, protocol);
+	skb->transport_header = skb->network_header + sizeof(*top_iph);
+
+	top_iph = ip_hdr(skb);
+	top_iph->ihl = 5;
+	top_iph->version = 4;
+	top_iph->protocol = IPPROTO_AGGFRAG;
+
+	/* As we have 0, fractional, 1 or N inner packets there's no obviously
+	 * correct DSCP mapping to inherit. ECN should be cleared per RFC9347
+	 * 3.1.
+	 */
+	top_iph->tos = 0;
+
+	top_iph->frag_off = htons(IP_DF);
+	top_iph->ttl = ip4_dst_hoplimit(xfrm_dst_child(dst));
+	top_iph->saddr = x->props.saddr.a4;
+	top_iph->daddr = x->id.daddr.a4;
+	ip_select_ident(dev_net(dst->dev), skb, NULL);
+
+	return 0;
+}
+
+/**
+ * iptfs_encap_add_ipv6() - add outer encaps
+ * @x: xfrm state
+ * @skb: the packet
+ *
+ * This was originally taken from xfrm6_tunnel_encap_add. The reason for the
+ * copy is that IP-TFS/AGGFRAG can have different functionality for how to set
+ * the flow label and TOS/DSCP bits. It also sets the protocol to a different
+ * value and doesn't do anything with inner headers as they aren't pointing into
+ * a normal IP singleton inner packet.
+ */
+static int iptfs_encap_add_ipv6(struct xfrm_state *x, struct sk_buff *skb)
+{
+	struct dst_entry *dst = skb_dst(skb);
+	struct ipv6hdr *top_iph;
+	int dsfield;
+
+	skb_reset_inner_network_header(skb);
+	skb_reset_inner_transport_header(skb);
+
+	skb_set_network_header(skb,
+			       -x->props.header_len + x->props.enc_hdr_len);
+	skb->mac_header =
+		skb->network_header + offsetof(struct ipv6hdr, nexthdr);
+	skb->transport_header = skb->network_header + sizeof(*top_iph);
+
+	top_iph = ipv6_hdr(skb);
+	top_iph->version = 6;
+	top_iph->priority = 0;
+	memset(top_iph->flow_lbl, 0, sizeof(top_iph->flow_lbl));
+	top_iph->nexthdr = IPPROTO_AGGFRAG;
+
+	/* As we have 0, fractional, 1 or N inner packets there's no obviously
+	 * correct DSCP mapping to inherit. ECN should be cleared per RFC9347
+	 * 3.1.
+	 */
+	dsfield = 0;
+	ipv6_change_dsfield(top_iph, 0, dsfield);
+
+	top_iph->hop_limit = ip6_dst_hoplimit(xfrm_dst_child(dst));
+	top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
+	top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
+
+	return 0;
+}
+
+/**
+ * iptfs_prepare_output() -  prepare the skb for output
+ * @x: xfrm state
+ * @skb: the packet
+ *
+ * Return: Error value, if 0 then skb values should be as follows:
+ *    - transport_header should point at ESP header
+ *    - network_header should point at Outer IP header
+ *    - mac_header should point at protocol/nexthdr of the outer IP
+ */
+static int iptfs_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+	if (x->outer_mode.family == AF_INET)
+		return iptfs_encap_add_ipv4(x, skb);
+	if (x->outer_mode.family == AF_INET6) {
+#if IS_ENABLED(CONFIG_IPV6)
+		return iptfs_encap_add_ipv6(x, skb);
+#else
+		WARN_ON_ONCE(1);
+		return -EAFNOSUPPORT;
+#endif
+	}
+	WARN_ON_ONCE(1);
+	return -EOPNOTSUPP;
+}
+
 /* ========================== */
 /* State Management Functions */
 /* ========================== */
@@ -66,6 +560,9 @@ static int iptfs_user_init(struct net *net, struct xfrm_state *x,
 	struct xfrm_iptfs_config *xc;
 
 	xc = &xtfs->cfg;
+	xc->max_queue_size = net->xfrm.sysctl_iptfs_max_qsize;
+	xtfs->init_delay_ns =
+		(u64)net->xfrm.sysctl_iptfs_init_delay * NSECS_IN_USEC;
 
 	if (attrs[XFRMA_IPTFS_PKT_SIZE]) {
 		xc->pkt_size = nla_get_u32(attrs[XFRMA_IPTFS_PKT_SIZE]);
@@ -79,6 +576,15 @@ static int iptfs_user_init(struct net *net, struct xfrm_state *x,
 			return -EINVAL;
 		}
 	}
+	if (attrs[XFRMA_IPTFS_MAX_QSIZE])
+		xc->max_queue_size = nla_get_u32(attrs[XFRMA_IPTFS_MAX_QSIZE]);
+	if (attrs[XFRMA_IPTFS_INIT_DELAY])
+		xtfs->init_delay_ns =
+			(u64)nla_get_u32(attrs[XFRMA_IPTFS_INIT_DELAY]) *
+			NSECS_IN_USEC;
+
+	xtfs->ecn_queue_size = (u64)xc->max_queue_size * 95 / 100;
+
 	return 0;
 }
 
@@ -91,7 +597,7 @@ static unsigned int iptfs_sa_len(const struct xfrm_state *x)
 	l += nla_total_size(0);
 	l += nla_total_size(sizeof(u16));
 	l += nla_total_size(sizeof(xc->pkt_size));
-	l += nla_total_size(sizeof(u32));
+	l += nla_total_size(sizeof(xc->max_queue_size));
 	l += nla_total_size(sizeof(u32)); /* drop time usec */
 	l += nla_total_size(sizeof(u32)); /* init delay usec */
 
@@ -103,6 +609,7 @@ static int iptfs_copy_to_user(struct xfrm_state *x, struct sk_buff *skb)
 	struct xfrm_iptfs_data *xtfs = x->mode_data;
 	struct xfrm_iptfs_config *xc = &xtfs->cfg;
 	int ret;
+	u64 q;
 
 	ret = nla_put_flag(skb, XFRMA_IPTFS_DONT_FRAG);
 	if (ret)
@@ -113,7 +620,7 @@ static int iptfs_copy_to_user(struct xfrm_state *x, struct sk_buff *skb)
 	ret = nla_put_u32(skb, XFRMA_IPTFS_PKT_SIZE, xc->pkt_size);
 	if (ret)
 		return ret;
-	ret = nla_put_u32(skb, XFRMA_IPTFS_MAX_QSIZE, 0);
+	ret = nla_put_u32(skb, XFRMA_IPTFS_MAX_QSIZE, xc->max_queue_size);
 	if (ret)
 		return ret;
 
@@ -121,7 +628,9 @@ static int iptfs_copy_to_user(struct xfrm_state *x, struct sk_buff *skb)
 	if (ret)
 		return ret;
 
-	ret = nla_put_u32(skb, XFRMA_IPTFS_INIT_DELAY, 0);
+	q = xtfs->init_delay_ns;
+	(void)do_div(q, NSECS_IN_USEC);
+	ret = nla_put_u32(skb, XFRMA_IPTFS_INIT_DELAY, q);
 
 	return ret;
 }
@@ -129,6 +638,10 @@ static int iptfs_copy_to_user(struct xfrm_state *x, struct sk_buff *skb)
 static int __iptfs_init_state(struct xfrm_state *x,
 			      struct xfrm_iptfs_data *xtfs)
 {
+	__skb_queue_head_init(&xtfs->queue);
+	hrtimer_init(&xtfs->iptfs_timer, CLOCK_MONOTONIC, IPTFS_HRTIMER_MODE);
+	xtfs->iptfs_timer.function = iptfs_delay_timer;
+
 	/* Modify type (esp) adjustment values */
 
 	if (x->props.family == AF_INET)
@@ -186,6 +699,7 @@ static void iptfs_delete_state(struct xfrm_state *x)
 	if (!xtfs)
 		return;
 
+	hrtimer_cancel(&xtfs->iptfs_timer);
 	kfree_sensitive(xtfs);
 
 	module_put(x->mode_cbs->owner);
@@ -200,6 +714,8 @@ static const struct xfrm_mode_cbs iptfs_mode_cbs = {
 	.sa_len = iptfs_sa_len,
 	.clone = iptfs_clone,
 	.get_inner_mtu = iptfs_get_inner_mtu,
+	.output = iptfs_output_collect,
+	.prepare_output = iptfs_prepare_output,
 };
 
 static int __init xfrm_iptfs_init(void)
-- 
2.45.2

[PATCH ipsec-next v4 10/18] xfrm: iptfs: share page fragments of inner packets

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

When possible rather than appending secondary (aggregated) inner packets
to the fragment list, share their page fragments with the outer IPTFS
packet. This allows for more efficient packet transmission.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 net/xfrm/xfrm_iptfs.c | 88 ++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 79 insertions(+), 9 deletions(-)

diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
index de836c4f361f..f9224b1d4cd3 100644
--- a/net/xfrm/xfrm_iptfs.c
+++ b/net/xfrm/xfrm_iptfs.c
@@ -45,6 +45,24 @@ struct xfrm_iptfs_data {
 static u32 iptfs_get_inner_mtu(struct xfrm_state *x, int outer_mtu);
 static enum hrtimer_restart iptfs_delay_timer(struct hrtimer *me);
 
+/* ================= */
+/* SK_BUFF Functions */
+/* ================= */
+
+/**
+ * skb_head_to_frag() - initialize a skb_frag_t based on skb head data
+ * @skb: skb with the head data
+ * @frag: frag to initialize
+ */
+static void skb_head_to_frag(const struct sk_buff *skb, skb_frag_t *frag)
+{
+	struct page *page = virt_to_head_page(skb->data);
+	unsigned char *addr = (unsigned char *)page_address(page);
+
+	BUG_ON(!skb->head_frag);
+	skb_frag_fill_page_desc(frag, page, skb->data - addr, skb_headlen(skb));
+}
+
 /* ================================= */
 /* IPTFS Sending (ingress) Functions */
 /* ================================= */
@@ -264,14 +282,44 @@ static struct sk_buff **iptfs_rehome_fraglist(struct sk_buff **nextp,
 	return nextp;
 }
 
+static void iptfs_consume_frags(struct sk_buff *to, struct sk_buff *from)
+{
+	struct skb_shared_info *fromi = skb_shinfo(from);
+	struct skb_shared_info *toi = skb_shinfo(to);
+	unsigned int new_truesize;
+
+	/* If we have data in a head page, grab it */
+	if (!skb_headlen(from)) {
+		new_truesize = SKB_TRUESIZE(skb_end_offset(from));
+	} else {
+		skb_head_to_frag(from, &toi->frags[toi->nr_frags]);
+		skb_frag_ref(to, toi->nr_frags++);
+		new_truesize = SKB_DATA_ALIGN(sizeof(struct sk_buff));
+	}
+
+	/* Move any other page fragments rather than copy */
+	memcpy(&toi->frags[toi->nr_frags], fromi->frags,
+	       sizeof(fromi->frags[0]) * fromi->nr_frags);
+	toi->nr_frags += fromi->nr_frags;
+	fromi->nr_frags = 0;
+	from->data_len = 0;
+	from->len = 0;
+	to->truesize += from->truesize - new_truesize;
+	from->truesize = new_truesize;
+
+	/* We are done with this SKB */
+	consume_skb(from);
+}
+
 static void iptfs_output_queued(struct xfrm_state *x, struct sk_buff_head *list)
 {
 	struct xfrm_iptfs_data *xtfs = x->mode_data;
 	struct sk_buff *skb, *skb2, **nextp;
-	struct skb_shared_info *shi;
+	struct skb_shared_info *shi, *shi2;
 
 	while ((skb = __skb_dequeue(list))) {
 		u32 mtu = iptfs_get_cur_pmtu(x, xtfs, skb);
+		bool share_ok = true;
 		int remaining;
 
 		/* protocol comes to us cleared sometimes */
@@ -317,7 +365,7 @@ static void iptfs_output_queued(struct xfrm_state *x, struct sk_buff_head *list)
 
 		/* Re-home (un-nest) nested fragment lists. We need to do this
 		 * b/c we will simply be appending any following aggregated
-		 * inner packets to the frag list.
+		 * inner packets using the frag list.
 		 */
 		shi = skb_shinfo(skb);
 		nextp = &shi->frag_list;
@@ -329,6 +377,9 @@ static void iptfs_output_queued(struct xfrm_state *x, struct sk_buff_head *list)
 				nextp = &(*nextp)->next;
 		}
 
+		if (shi->frag_list || skb_cloned(skb) || skb_shared(skb))
+			share_ok = false;
+
 		/* See if we have enough space to simply append.
 		 *
 		 * NOTE: Maybe do not append if we will be mis-aligned,
@@ -354,18 +405,37 @@ static void iptfs_output_queued(struct xfrm_state *x, struct sk_buff_head *list)
 				}
 			}
 
+			/* skb->pp_recycle is passed to __skb_flag_unref for all
+			 * frag pages so we can only share pages with skb's who
+			 * match ourselves.
+			 */
+			shi2 = skb_shinfo(skb2);
+			if (share_ok &&
+			    (shi2->frag_list ||
+			     (!skb2->head_frag && skb_headlen(skb)) ||
+			     skb->pp_recycle != skb2->pp_recycle ||
+			     skb_zcopy(skb2) ||
+			     (shi->nr_frags + shi2->nr_frags + 1 >
+			      MAX_SKB_FRAGS)))
+				share_ok = false;
+
 			/* Do accounting */
 			skb->data_len += skb2->len;
 			skb->len += skb2->len;
 			remaining -= skb2->len;
 
-			/* Append to the frag_list */
-			*nextp = skb2;
-			nextp = &skb2->next;
-			BUG_ON(*nextp);
-			if (skb_has_frag_list(skb2))
-				nextp = iptfs_rehome_fraglist(nextp, skb2);
-			skb->truesize += skb2->truesize;
+			if (share_ok) {
+				iptfs_consume_frags(skb, skb2);
+			} else {
+				/* Append to the frag_list */
+				*nextp = skb2;
+				nextp = &skb2->next;
+				BUG_ON(*nextp);
+				if (skb_has_frag_list(skb2))
+					nextp = iptfs_rehome_fraglist(nextp,
+								      skb2);
+				skb->truesize += skb2->truesize;
+			}
 		}
 
 		xfrm_output(NULL, skb);
-- 
2.45.2

[PATCH ipsec-next v4 11/18] xfrm: iptfs: add fragmenting of larger than MTU user packets

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Add support for tunneling user (inner) packets that are larger than the
tunnel's path MTU (outer) using IP-TFS fragmentation.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 net/xfrm/xfrm_iptfs.c | 404 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 374 insertions(+), 30 deletions(-)

diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
index f9224b1d4cd3..1a1d86de1a6c 100644
--- a/net/xfrm/xfrm_iptfs.c
+++ b/net/xfrm/xfrm_iptfs.c
@@ -19,11 +19,22 @@
 
 #include "xfrm_inout.h"
 
+/* 1) skb->head should be cache aligned.
+ * 2) when resv is for L2 headers (i.e., ethernet) we want the cacheline to
+ * start -16 from data.
+ * 3) when resv is for L3+L2 headers IOW skb->data points at the IPTFS payload
+ * we want data to be cache line aligned so all the pushed headers will be in
+ * another cacheline.
+ */
+#define XFRM_IPTFS_MIN_L3HEADROOM 128
+#define XFRM_IPTFS_MIN_L2HEADROOM (64 + 16)
+#define IPTFS_FRAG_COPY_MAX 256 /* max for copying to create iptfs frags */
 #define NSECS_IN_USEC 1000
 
 #define IPTFS_HRTIMER_MODE HRTIMER_MODE_REL_SOFT
 
 struct xfrm_iptfs_config {
+	bool dont_frag : 1;
 	u32 pkt_size;	    /* outer_packet_size or 0 */
 	u32 max_queue_size; /* octets */
 };
@@ -42,13 +53,71 @@ struct xfrm_iptfs_data {
 	u32 payload_mtu;	    /* max payload size */
 };
 
-static u32 iptfs_get_inner_mtu(struct xfrm_state *x, int outer_mtu);
+static u32 __iptfs_get_inner_mtu(struct xfrm_state *x, int outer_mtu);
 static enum hrtimer_restart iptfs_delay_timer(struct hrtimer *me);
 
 /* ================= */
 /* SK_BUFF Functions */
 /* ================= */
 
+/**
+ * iptfs_alloc_skb() - Allocate a new `skb` using a meta-data template.
+ * @tpl: the template to copy the new `skb`s meta-data from.
+ * @len: the linear length of the head data, zero is fine.
+ * @l3resv: true if reserve needs to support pushing L3 headers
+ *
+ * A new `skb` is allocated and it's meta-data is initialized from `tpl`, the
+ * head data is sized to `len` + reserved space set according to the @l3resv
+ * boolean. When @l3resv is false, resv is XFRM_IPTFS_MIN_L2HEADROOM which
+ * arranges for `skb->data - 16` (etherhdr space) to be the start of a cacheline.
+ * Otherwise, @l3resv is true and resv is either the size of headroom from `tpl` or
+ * XFRM_IPTFS_MIN_L3HEADROOM whichever is greater, which tries to align
+ * skb->data to a cacheline as all headers will be pushed on the previous
+ * cacheline bytes.
+ *
+ * When copying meta-data from the @tpl, the sk_buff->headers are not copied.
+ *
+ * Zero length skbs are allocated when we only need a head skb to hold new
+ * packet headers (basically the mac header) that sit on top of existing shared
+ * packet data.
+ *
+ * Return: the new skb or NULL.
+ */
+static struct sk_buff *iptfs_alloc_skb(struct sk_buff *tpl, u32 len,
+				       bool l3resv)
+{
+	struct sk_buff *skb;
+	u32 resv;
+
+	if (!l3resv) {
+		resv = XFRM_IPTFS_MIN_L2HEADROOM;
+	} else {
+		resv = skb_headroom(tpl);
+		if (resv < XFRM_IPTFS_MIN_L3HEADROOM)
+			resv = XFRM_IPTFS_MIN_L3HEADROOM;
+	}
+
+	skb = alloc_skb(len + resv, GFP_ATOMIC);
+	if (!skb) {
+		XFRM_INC_STATS(dev_net(tpl->dev), LINUX_MIB_XFRMINERROR);
+		return NULL;
+	}
+
+	skb_reserve(skb, resv);
+
+	/* Code from __copy_skb_header() -- we do not want any of the
+	 * tpl->headers copied over, so we aren't using `skb_copy_header()`.
+	 */
+	skb->tstamp = tpl->tstamp;
+	skb->dev = tpl->dev;
+	memcpy(skb->cb, tpl->cb, sizeof(skb->cb));
+	skb_dst_copy(skb, tpl);
+	__skb_ext_copy(skb, tpl);
+	__nf_copy(skb, tpl, false);
+
+	return skb;
+}
+
 /**
  * skb_head_to_frag() - initialize a skb_frag_t based on skb head data
  * @skb: skb with the head data
@@ -63,6 +132,39 @@ static void skb_head_to_frag(const struct sk_buff *skb, skb_frag_t *frag)
 	skb_frag_fill_page_desc(frag, page, skb->data - addr, skb_headlen(skb));
 }
 
+/**
+ * skb_copy_bits_seq - copy bits from a skb_seq_state to kernel buffer
+ * @st: source skb_seq_state
+ * @offset: offset in source
+ * @to: destination buffer
+ * @len: number of bytes to copy
+ *
+ * Copy @len bytes from @offset bytes into the source @st to the destination
+ * buffer @to. `offset` should increase (or be unchanged) with each subsequent
+ * call to this function. If offset needs to decrease from the previous use `st`
+ * should be reset first.
+ */
+static int skb_copy_bits_seq(struct skb_seq_state *st, int offset, void *to,
+			     int len)
+{
+	const u8 *data;
+	u32 sqlen;
+
+	for (;;) {
+		sqlen = skb_seq_read(offset, &data, st);
+		if (sqlen == 0)
+			return -ENOMEM;
+		if (sqlen >= len) {
+			memcpy(to, data, len);
+			return 0;
+		}
+		memcpy(to, data, sqlen);
+		to += sqlen;
+		offset += sqlen;
+		len -= sqlen;
+	}
+}
+
 /* ================================= */
 /* IPTFS Sending (ingress) Functions */
 /* ================================= */
@@ -107,7 +209,7 @@ static int iptfs_get_cur_pmtu(struct xfrm_state *x,
 {
 	struct xfrm_dst *xdst = (struct xfrm_dst *)skb_dst(skb);
 	u32 payload_mtu = xtfs->payload_mtu;
-	u32 pmtu = iptfs_get_inner_mtu(x, xdst->child_mtu_cached);
+	u32 pmtu = __iptfs_get_inner_mtu(x, xdst->child_mtu_cached);
 
 	if (payload_mtu && payload_mtu < pmtu)
 		pmtu = payload_mtu;
@@ -170,7 +272,8 @@ static int iptfs_output_collect(struct net *net, struct sock *sk,
 
 	BUG_ON(!xtfs);
 
-	pmtu = iptfs_get_cur_pmtu(x, xtfs, skb);
+	if (xtfs->cfg.dont_frag)
+		pmtu = iptfs_get_cur_pmtu(x, xtfs, skb);
 
 	/* Break apart GSO skbs. If the queue is nearing full then we want the
 	 * accounting and queuing to be based on the individual packets not on the
@@ -211,8 +314,10 @@ static int iptfs_output_collect(struct net *net, struct sock *sk,
 			continue;
 		}
 
-		/* Fragmenting handled in following commits. */
-		if (iptfs_is_too_big(sk, skb, pmtu)) {
+		/* If the user indicated no iptfs fragmenting check before
+		 * enqueue.
+		 */
+		if (xtfs->cfg.dont_frag && iptfs_is_too_big(sk, skb, pmtu)) {
 			kfree_skb_reason(skb, SKB_DROP_REASON_PKT_TOO_BIG);
 			continue;
 		}
@@ -258,6 +363,217 @@ static void iptfs_output_prepare_skb(struct sk_buff *skb, u32 blkoff)
 	IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
 }
 
+/**
+ * iptfs_copy_create_frag() - create an inner fragment skb.
+ * @st: The source packet data.
+ * @offset: offset in @st of the new fragment data.
+ * @copy_len: the amount of data to copy from @st.
+ *
+ * Create a new skb holding a single IPTFS inner packet fragment. @copy_len must
+ * not be greater than the max fragment size.
+ *
+ * Return: the new fragment skb or an ERR_PTR().
+ */
+static struct sk_buff *iptfs_copy_create_frag(struct skb_seq_state *st,
+					      u32 offset, u32 copy_len)
+{
+	struct sk_buff *src = st->root_skb;
+	struct sk_buff *skb;
+	int err;
+
+	skb = iptfs_alloc_skb(src, copy_len, true);
+	if (!skb)
+		return ERR_PTR(-ENOMEM);
+
+	/* Now copy `copy_len` data from src */
+	err = skb_copy_bits_seq(st, offset, skb_put(skb, copy_len), copy_len);
+	if (err) {
+		XFRM_INC_STATS(dev_net(src->dev), LINUX_MIB_XFRMOUTERROR);
+		kfree_skb(skb);
+		return ERR_PTR(err);
+	}
+
+	return skb;
+}
+
+/**
+ * iptfs_copy_create_frags() - create and send N-1 fragments of a larger skb.
+ * @skbp: the source packet skb (IN), skb holding the last fragment in
+ *        the fragment stream (OUT).
+ * @xtfs: IPTFS SA state.
+ * @mtu: the max IPTFS fragment size.
+ *
+ * This function is responsible for fragmenting a larger inner packet into a
+ * sequence of IPTFS payload packets. The last fragment is returned rather than
+ * being sent so that the caller can append more inner packets (aggregation) if
+ * there is room.
+ */
+static int iptfs_copy_create_frags(struct sk_buff **skbp,
+				   struct xfrm_iptfs_data *xtfs, u32 mtu)
+{
+	struct skb_seq_state skbseq;
+	struct list_head sublist;
+	struct sk_buff *skb = *skbp;
+	struct sk_buff *nskb = *skbp;
+	u32 copy_len, offset;
+	u32 to_copy = skb->len - mtu;
+	u32 blkoff = 0;
+	int err = 0;
+
+	INIT_LIST_HEAD(&sublist);
+
+	BUG_ON(skb->len <= mtu);
+	skb_prepare_seq_read(skb, 0, skb->len, &skbseq);
+
+	/* A trimmed `skb` will be sent as the first fragment, later. */
+	offset = mtu;
+	to_copy = skb->len - offset;
+	while (to_copy) {
+		/* Send all but last fragment to allow agg. append */
+		list_add_tail(&nskb->list, &sublist);
+
+		/* FUTURE: if the packet has an odd/non-aligning length we could
+		 * send less data in the penultimate fragment so that the last
+		 * fragment then ends on an aligned boundary.
+		 */
+		copy_len = to_copy <= mtu ? to_copy : mtu;
+		nskb = iptfs_copy_create_frag(&skbseq, offset, copy_len);
+		if (IS_ERR(nskb)) {
+			XFRM_INC_STATS(dev_net(skb->dev),
+				       LINUX_MIB_XFRMOUTERROR);
+			skb_abort_seq_read(&skbseq);
+			err = PTR_ERR(nskb);
+			nskb = NULL;
+			break;
+		}
+		iptfs_output_prepare_skb(nskb, to_copy);
+		offset += copy_len;
+		to_copy -= copy_len;
+		blkoff = to_copy;
+	}
+	skb_abort_seq_read(&skbseq);
+
+	/* return last fragment that will be unsent (or NULL) */
+	*skbp = nskb;
+
+	/* trim the original skb to MTU */
+	if (!err)
+		err = pskb_trim(skb, mtu);
+
+	if (err) {
+		/* Free all frags. Don't bother sending a partial packet we will
+		 * never complete.
+		 */
+		kfree_skb(nskb);
+		list_for_each_entry_safe(skb, nskb, &sublist, list) {
+			skb_list_del_init(skb);
+			kfree_skb(skb);
+		}
+		return err;
+	}
+
+	/* prepare the initial fragment with an iptfs header */
+	iptfs_output_prepare_skb(skb, 0);
+
+	/* Send all but last fragment, if we fail to send a fragment then free
+	 * the rest -- no point in sending a packet that can't be reassembled.
+	 */
+	list_for_each_entry_safe(skb, nskb, &sublist, list) {
+		skb_list_del_init(skb);
+		if (!err)
+			err = xfrm_output(NULL, skb);
+		else
+			kfree_skb(skb);
+	}
+	if (err)
+		kfree_skb(*skbp);
+	return err;
+}
+
+/**
+ * iptfs_first_should_copy() - determine if we should copy packet data.
+ * @first_skb: the first skb in the packet
+ * @mtu: the MTU.
+ *
+ * Determine if we should create subsequent skbs to hold the remaining data from
+ * a large inner packet by copying the packet data, or cloning the original skb
+ * and adjusting the offsets.
+ */
+static bool iptfs_first_should_copy(struct sk_buff *first_skb, u32 mtu)
+{
+	u32 frag_copy_max;
+
+	/* If we have less than frag_copy_max for remaining packet we copy
+	 * those tail bytes as it is more efficient.
+	 */
+	frag_copy_max = mtu <= IPTFS_FRAG_COPY_MAX ? mtu : IPTFS_FRAG_COPY_MAX;
+	if ((int)first_skb->len - (int)mtu < (int)frag_copy_max)
+		return true;
+
+	/* If we have non-linear skb just use copy */
+	if (skb_is_nonlinear(first_skb))
+		return true;
+
+	/* So we have a simple linear skb, easy to clone and share */
+	return false;
+}
+
+/**
+ * iptfs_first_skb() - handle the first dequeued inner packet for output
+ * @skbp: the source packet skb (IN), skb holding the last fragment in
+ *        the fragment stream (OUT).
+ * @xtfs: IPTFS SA state.
+ * @mtu: the max IPTFS fragment size.
+ *
+ * This function is responsible for fragmenting a larger inner packet into a
+ * sequence of IPTFS payload packets. If it needs to fragment into subsequent
+ * skb's, it will either do so by copying or cloning.
+ *
+ * The last fragment is returned rather than being sent so that the caller can
+ * append more inner packets (aggregation) if there is room.
+ *
+ */
+static int iptfs_first_skb(struct sk_buff **skbp, struct xfrm_iptfs_data *xtfs,
+			   u32 mtu)
+{
+	struct sk_buff *skb = *skbp;
+	int err;
+
+	/* Classic ESP skips the don't fragment ICMP error if DF is clear on
+	 * the inner packet or ignore_df is set. Otherwise it will send an ICMP
+	 * or local error if the inner packet won't fit it's MTU.
+	 *
+	 * With IPTFS we do not care about the inner packet DF bit. If the
+	 * tunnel is configured to "don't fragment" we error back if things
+	 * don't fit in our max packet size. Otherwise we iptfs-fragment as
+	 * normal.
+	 */
+
+	/* The opportunity for HW offload has ended */
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		err = skb_checksum_help(skb);
+		if (err)
+			return err;
+	}
+
+	/* We've split these up before queuing */
+	BUG_ON(skb_is_gso(skb));
+
+	/* Simple case -- it fits. `mtu` accounted for all the overhead
+	 * including the basic IPTFS header.
+	 */
+	if (skb->len <= mtu) {
+		iptfs_output_prepare_skb(skb, 0);
+		return 0;
+	}
+
+	if (iptfs_first_should_copy(skb, mtu))
+		return iptfs_copy_create_frags(skbp, xtfs, mtu);
+
+	/* For now we always copy */
+	return iptfs_copy_create_frags(skbp, xtfs, mtu);
+}
+
 static struct sk_buff **iptfs_rehome_fraglist(struct sk_buff **nextp,
 					      struct sk_buff *child)
 {
@@ -317,6 +633,15 @@ static void iptfs_output_queued(struct xfrm_state *x, struct sk_buff_head *list)
 	struct sk_buff *skb, *skb2, **nextp;
 	struct skb_shared_info *shi, *shi2;
 
+	/* If we are fragmenting due to a large inner packet we will output all
+	 * the outer IPTFS packets required to contain the fragments of the
+	 * single large inner packet. These outer packets need to be sent
+	 * consecutively (ESP seq-wise). Since this output function is always
+	 * running from a timer we do not need a lock to provide this guarantee.
+	 * We will output our packets consecutively before the timer is allowed
+	 * to run again on some other CPU.
+	 */
+
 	while ((skb = __skb_dequeue(list))) {
 		u32 mtu = iptfs_get_cur_pmtu(x, xtfs, skb);
 		bool share_ok = true;
@@ -327,7 +652,7 @@ static void iptfs_output_queued(struct xfrm_state *x, struct sk_buff_head *list)
 					      htons(ETH_P_IP) :
 					      htons(ETH_P_IPV6);
 
-		if (skb->len > mtu) {
+		if (skb->len > mtu && xtfs->cfg.dont_frag) {
 			/* We handle this case before enqueueing so we are only
 			 * here b/c MTU changed after we enqueued before we
 			 * dequeued, just drop these.
@@ -340,26 +665,22 @@ static void iptfs_output_queued(struct xfrm_state *x, struct sk_buff_head *list)
 			continue;
 		}
 
-		/* If we don't have a cksum in the packet we need to add one
-		 * before encapsulation.
+		/* Convert first inner packet into an outer IPTFS packet,
+		 * dealing with any fragmentation into multiple outer packets
+		 * if necessary.
 		 */
-		if (skb->ip_summed == CHECKSUM_PARTIAL) {
-			if (skb_checksum_help(skb)) {
-				XFRM_INC_STATS(dev_net(skb_dst(skb)->dev),
-					       LINUX_MIB_XFRMOUTERROR);
-				kfree_skb(skb);
-				continue;
-			}
-		}
-
-		/* Convert first inner packet into an outer IPTFS packet */
-		iptfs_output_prepare_skb(skb, 0);
+		if (iptfs_first_skb(&skb, xtfs, mtu))
+			continue;
 
-		/* The space remaining to send more inner packet data is `mtu` -
-		 * (skb->len - sizeof iptfs header). This is b/c the `mtu` value
-		 * has the basic IPTFS header len accounted for, and we added
-		 * that header to the skb so it is a part of skb->len, thus we
-		 * subtract it from the skb length.
+		/* If fragmentation was required the returned skb is the last
+		 * IPTFS fragment in the chain, and it's IPTFS header blkoff has
+		 * been set just past the end of the fragment data.
+		 *
+		 * In either case the space remaining to send more inner packet
+		 * data is `mtu` - (skb->len - sizeof iptfs header). This is b/c
+		 * the `mtu` value has the basic IPTFS header len accounted for,
+		 * and we added that header to the skb so it is a part of
+		 * skb->len, thus we subtract it from the skb length.
 		 */
 		remaining = mtu - (skb->len - sizeof(struct ip_iptfs_hdr));
 
@@ -600,11 +921,11 @@ static int iptfs_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
 /* ========================== */
 
 /**
- * iptfs_get_inner_mtu() - return inner MTU with no fragmentation.
+ * __iptfs_get_inner_mtu() - return inner MTU with no fragmentation.
  * @x: xfrm state.
  * @outer_mtu: the outer mtu
  */
-static u32 iptfs_get_inner_mtu(struct xfrm_state *x, int outer_mtu)
+static u32 __iptfs_get_inner_mtu(struct xfrm_state *x, int outer_mtu)
 {
 	struct crypto_aead *aead;
 	u32 blksize;
@@ -615,6 +936,24 @@ static u32 iptfs_get_inner_mtu(struct xfrm_state *x, int outer_mtu)
 		~(blksize - 1)) - 2;
 }
 
+/**
+ * iptfs_get_inner_mtu() - return the inner MTU for an IPTFS xfrm.
+ * @x: xfrm state.
+ * @outer_mtu: Outer MTU for the encapsulated packet.
+ *
+ * Return: Correct MTU taking in to account the encap overhead.
+ */
+static u32 iptfs_get_inner_mtu(struct xfrm_state *x, int outer_mtu)
+{
+	struct xfrm_iptfs_data *xtfs = x->mode_data;
+
+	/* If not dont-frag we have no MTU */
+	if (!xtfs->cfg.dont_frag)
+		return x->outer_mode.family == AF_INET ? IP_MAX_MTU :
+							       IP6_MAX_MTU;
+	return __iptfs_get_inner_mtu(x, outer_mtu);
+}
+
 /**
  * iptfs_user_init() - initialize the SA with IPTFS options from netlink.
  * @net: the net data
@@ -634,6 +973,8 @@ static int iptfs_user_init(struct net *net, struct xfrm_state *x,
 	xtfs->init_delay_ns =
 		(u64)net->xfrm.sysctl_iptfs_init_delay * NSECS_IN_USEC;
 
+	if (attrs[XFRMA_IPTFS_DONT_FRAG])
+		xc->dont_frag = true;
 	if (attrs[XFRMA_IPTFS_PKT_SIZE]) {
 		xc->pkt_size = nla_get_u32(attrs[XFRMA_IPTFS_PKT_SIZE]);
 		if (!xc->pkt_size) {
@@ -664,7 +1005,8 @@ static unsigned int iptfs_sa_len(const struct xfrm_state *x)
 	struct xfrm_iptfs_config *xc = &xtfs->cfg;
 	unsigned int l = 0;
 
-	l += nla_total_size(0);
+	if (xc->dont_frag)
+		l += nla_total_size(0);
 	l += nla_total_size(sizeof(u16));
 	l += nla_total_size(sizeof(xc->pkt_size));
 	l += nla_total_size(sizeof(xc->max_queue_size));
@@ -681,9 +1023,11 @@ static int iptfs_copy_to_user(struct xfrm_state *x, struct sk_buff *skb)
 	int ret;
 	u64 q;
 
-	ret = nla_put_flag(skb, XFRMA_IPTFS_DONT_FRAG);
-	if (ret)
-		return ret;
+	if (xc->dont_frag) {
+		ret = nla_put_flag(skb, XFRMA_IPTFS_DONT_FRAG);
+		if (ret)
+			return ret;
+	}
 	ret = nla_put_u16(skb, XFRMA_IPTFS_REORDER_WINDOW, 0);
 	if (ret)
 		return ret;
-- 
2.45.2

[PATCH ipsec-next v4 12/18] xfrm: iptfs: add basic receive packet (tunnel egress) handling

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Add handling of packets received from the tunnel. This implements
tunnel egress functionality.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 net/xfrm/xfrm_iptfs.c | 283 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 283 insertions(+)

diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
index 1a1d86de1a6c..ee75be187539 100644
--- a/net/xfrm/xfrm_iptfs.c
+++ b/net/xfrm/xfrm_iptfs.c
@@ -19,6 +19,10 @@
 
 #include "xfrm_inout.h"
 
+/* IPTFS encap (header) values. */
+#define IPTFS_SUBTYPE_BASIC 0
+#define IPTFS_SUBTYPE_CC 1
+
 /* 1) skb->head should be cache aligned.
  * 2) when resv is for L2 headers (i.e., ethernet) we want the cacheline to
  * start -16 from data.
@@ -56,6 +60,17 @@ struct xfrm_iptfs_data {
 static u32 __iptfs_get_inner_mtu(struct xfrm_state *x, int outer_mtu);
 static enum hrtimer_restart iptfs_delay_timer(struct hrtimer *me);
 
+/* ================= */
+/* Utility Functions */
+/* ================= */
+
+static u64 __esp_seq(struct sk_buff *skb)
+{
+	u64 seq = ntohl(XFRM_SKB_CB(skb)->seq.input.low);
+
+	return seq | (u64)ntohl(XFRM_SKB_CB(skb)->seq.input.hi) << 32;
+}
+
 /* ================= */
 /* SK_BUFF Functions */
 /* ================= */
@@ -165,6 +180,273 @@ static int skb_copy_bits_seq(struct skb_seq_state *st, int offset, void *to,
 	}
 }
 
+/* ================================== */
+/* IPTFS Receiving (egress) Functions */
+/* ================================== */
+
+/**
+ * iptfs_pskb_extract_seq() - Create and load data into a new sk_buff.
+ * @skblen: the total data size for `skb`.
+ * @st: The source for the rest of the data to copy into `skb`.
+ * @off: The offset into @st to copy data from.
+ * @len: The length of data to copy from @st into `skb`. This must be <=
+ *       @skblen.
+ *
+ * Create a new sk_buff `skb` with @skblen of packet data space. If non-zero,
+ * copy @rlen bytes of @runt into `skb`. Then using seq functions copy @len
+ * bytes from @st into `skb` starting from @off.
+ *
+ * It is an error for @len to be greater than the amount of data left in @st.
+ *
+ * Return: The newly allocated sk_buff `skb` or NULL if an error occurs.
+ */
+static struct sk_buff *
+iptfs_pskb_extract_seq(u32 skblen, struct skb_seq_state *st, u32 off, int len)
+{
+	struct sk_buff *skb = iptfs_alloc_skb(st->root_skb, skblen, false);
+
+	if (!skb)
+		return NULL;
+	if (skb_copy_bits_seq(st, off, skb_put(skb, len), len)) {
+		XFRM_INC_STATS(dev_net(st->root_skb->dev),
+			       LINUX_MIB_XFRMINERROR);
+		kfree_skb(skb);
+		return NULL;
+	}
+	return skb;
+}
+
+/**
+ * iptfs_complete_inner_skb() - finish preparing the inner packet for gro recv.
+ * @x: xfrm state
+ * @skb: the inner packet
+ *
+ * Finish the standard xfrm processing on the inner packet prior to sending back
+ * through gro_cells_receive. We do this separately b/c we are building a list
+ * of packets in the hopes that one day a list will be taken by
+ * xfrm_input.
+ */
+static void iptfs_complete_inner_skb(struct xfrm_state *x, struct sk_buff *skb)
+{
+	skb_reset_network_header(skb);
+
+	/* The packet is going back through gro_cells_receive no need to
+	 * set this.
+	 */
+	skb_reset_transport_header(skb);
+
+	/* Packet already has checksum value set. */
+	skb->ip_summed = CHECKSUM_NONE;
+
+	/* Our skb will contain the header data copied when this outer packet
+	 * which contained the start of this inner packet. This is true
+	 * when we allocate a new skb as well as when we reuse the existing skb.
+	 */
+	if (ip_hdr(skb)->version == 0x4) {
+		struct iphdr *iph = ip_hdr(skb);
+
+		if (x->props.flags & XFRM_STATE_DECAP_DSCP)
+			ipv4_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, iph);
+		if (!(x->props.flags & XFRM_STATE_NOECN))
+			if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
+				IP_ECN_set_ce(iph);
+
+		skb->protocol = htons(ETH_P_IP);
+	} else {
+		struct ipv6hdr *iph = ipv6_hdr(skb);
+
+		if (x->props.flags & XFRM_STATE_DECAP_DSCP)
+			ipv6_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, iph);
+		if (!(x->props.flags & XFRM_STATE_NOECN))
+			if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
+				IP6_ECN_set_ce(skb, iph);
+
+		skb->protocol = htons(ETH_P_IPV6);
+	}
+}
+
+/**
+ * iptfs_input() - handle receipt of iptfs payload
+ * @x: xfrm state
+ * @skb: the packet
+ *
+ * Process the IPTFS payload in `skb` and consume it afterwards.
+ */
+static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+	u8 hbytes[sizeof(struct ipv6hdr)];
+	struct ip_iptfs_cc_hdr iptcch;
+	struct skb_seq_state skbseq;
+	struct list_head sublist; /* rename this it's just a list */
+	struct sk_buff *first_skb, *next;
+	const unsigned char *old_mac;
+	struct xfrm_iptfs_data *xtfs;
+	struct ip_iptfs_hdr *ipth;
+	struct iphdr *iph;
+	struct net *net;
+	u32 remaining, iplen, iphlen, data, tail;
+	u32 blkoff;
+	u64 seq;
+
+	xtfs = x->mode_data;
+	net = dev_net(skb->dev);
+	first_skb = NULL;
+
+	seq = __esp_seq(skb);
+
+	/* Large enough to hold both types of header */
+	ipth = (struct ip_iptfs_hdr *)&iptcch;
+
+	/* Save the old mac header if set */
+	old_mac = skb_mac_header_was_set(skb) ? skb_mac_header(skb) : NULL;
+
+	skb_prepare_seq_read(skb, 0, skb->len, &skbseq);
+
+	/* Get the IPTFS header and validate it */
+
+	if (skb_copy_bits_seq(&skbseq, 0, ipth, sizeof(*ipth))) {
+		XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
+		goto done;
+	}
+	data = sizeof(*ipth);
+
+	/* Set data past the basic header */
+	if (ipth->subtype == IPTFS_SUBTYPE_CC) {
+		/* Copy the rest of the CC header */
+		remaining = sizeof(iptcch) - sizeof(*ipth);
+		if (skb_copy_bits_seq(&skbseq, data, ipth + 1, remaining)) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
+			goto done;
+		}
+		data += remaining;
+	} else if (ipth->subtype != IPTFS_SUBTYPE_BASIC) {
+		XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
+		goto done;
+	}
+
+	if (ipth->flags != 0) {
+		XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
+		goto done;
+	}
+
+	INIT_LIST_HEAD(&sublist);
+
+	/* Fragment handling in following commits */
+	blkoff = ntohs(ipth->block_offset);
+	data += blkoff;
+
+	/* New packets */
+	tail = skb->len;
+	while (data < tail) {
+		__be16 protocol = 0;
+
+		/* Gather information on the next data block.
+		 * `data` points to the start of the data block.
+		 */
+		remaining = tail - data;
+
+		/* try and copy enough bytes to read length from ipv4/ipv6 */
+		iphlen = min_t(u32, remaining, 6);
+		if (skb_copy_bits_seq(&skbseq, data, hbytes, iphlen)) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
+			goto done;
+		}
+
+		iph = (struct iphdr *)hbytes;
+		if (iph->version == 0x4) {
+			/* must have at least tot_len field present */
+			if (remaining < 4)
+				break;
+
+			iplen = be16_to_cpu(iph->tot_len);
+			iphlen = iph->ihl << 2;
+			protocol = cpu_to_be16(ETH_P_IP);
+			XFRM_MODE_SKB_CB(skbseq.root_skb)->tos = iph->tos;
+		} else if (iph->version == 0x6) {
+			/* must have at least payload_len field present */
+			if (remaining < 6)
+				break;
+
+			iplen = be16_to_cpu(
+				((struct ipv6hdr *)hbytes)->payload_len);
+			iplen += sizeof(struct ipv6hdr);
+			iphlen = sizeof(struct ipv6hdr);
+			protocol = cpu_to_be16(ETH_P_IPV6);
+			XFRM_MODE_SKB_CB(skbseq.root_skb)->tos =
+				ipv6_get_dsfield((struct ipv6hdr *)iph);
+		} else if (iph->version == 0x0) {
+			/* pad */
+			break;
+		} else {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
+			goto done;
+		}
+
+		if (unlikely(skbseq.stepped_offset)) {
+			/* We need to reset our seq read, it can't backup at
+			 * this point.
+			 */
+			struct sk_buff *save = skbseq.root_skb;
+
+			skb_abort_seq_read(&skbseq);
+			skb_prepare_seq_read(save, data, tail, &skbseq);
+		}
+
+		if (!first_skb)
+			first_skb = skb;
+
+		/* Fragment handling in following commits */
+		if (iplen > remaining)
+			break;
+
+		skb = iptfs_pskb_extract_seq(iplen, &skbseq, data, iplen);
+		if (!skb) {
+			/* skip to next packet or done */
+			data += iplen;
+			continue;
+		}
+
+		skb->protocol = protocol;
+		if (old_mac) {
+			/* rebuild the mac header */
+			skb_set_mac_header(skb, -first_skb->mac_len);
+			memcpy(skb_mac_header(skb), old_mac,
+			       first_skb->mac_len);
+			eth_hdr(skb)->h_proto = skb->protocol;
+		}
+
+		data += iplen;
+		iptfs_complete_inner_skb(x, skb);
+		list_add_tail(&skb->list, &sublist);
+	}
+
+	/* Send the packets! */
+	list_for_each_entry_safe(skb, next, &sublist, list) {
+		skb_list_del_init(skb);
+		if (xfrm_input(skb, 0, 0, -3))
+			kfree_skb(skb);
+	}
+
+done:
+	skb = skbseq.root_skb;
+	skb_abort_seq_read(&skbseq);
+
+	if (first_skb) {
+		consume_skb(first_skb);
+	} else {
+		/* skb is the original passed in skb, but we didn't get far
+		 * enough to process it as the first_skb.
+		 */
+		kfree_skb(skb);
+	}
+
+	/* We always have dealt with the input SKB, either we are re-using it,
+	 * or we have freed it. Return EINPROGRESS so that xfrm_input stops
+	 * processing it.
+	 */
+	return -EINPROGRESS;
+}
+
 /* ================================= */
 /* IPTFS Sending (ingress) Functions */
 /* ================================= */
@@ -1128,6 +1410,7 @@ static const struct xfrm_mode_cbs iptfs_mode_cbs = {
 	.sa_len = iptfs_sa_len,
 	.clone = iptfs_clone,
 	.get_inner_mtu = iptfs_get_inner_mtu,
+	.input = iptfs_input,
 	.output = iptfs_output_collect,
 	.prepare_output = iptfs_prepare_output,
 };
-- 
2.45.2

[PATCH ipsec-next v4 13/18] xfrm: iptfs: handle received fragmented inner packets

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Add support for handling receipt of partial inner packets that have
been fragmented across multiple outer IP-TFS tunnel packets.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 net/xfrm/xfrm_iptfs.c | 438 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 425 insertions(+), 13 deletions(-)

diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
index ee75be187539..a8ef3eb7427c 100644
--- a/net/xfrm/xfrm_iptfs.c
+++ b/net/xfrm/xfrm_iptfs.c
@@ -55,10 +55,22 @@ struct xfrm_iptfs_data {
 	struct hrtimer iptfs_timer; /* output timer */
 	time64_t iptfs_settime;	    /* time timer was set */
 	u32 payload_mtu;	    /* max payload size */
+
+	/* Tunnel egress */
+	spinlock_t drop_lock;
+	struct hrtimer drop_timer;
+	u64 drop_time_ns;
+
+	/* Tunnel egress reassembly */
+	struct sk_buff *ra_newskb; /* new pkt being reassembled */
+	u64 ra_wantseq;		   /* expected next sequence */
+	u8 ra_runt[6];		   /* last pkt bytes from last skb */
+	u8 ra_runtlen;		   /* count of ra_runt */
 };
 
 static u32 __iptfs_get_inner_mtu(struct xfrm_state *x, int outer_mtu);
 static enum hrtimer_restart iptfs_delay_timer(struct hrtimer *me);
+static enum hrtimer_restart iptfs_drop_timer(struct hrtimer *me);
 
 /* ================= */
 /* Utility Functions */
@@ -216,6 +228,63 @@ iptfs_pskb_extract_seq(u32 skblen, struct skb_seq_state *st, u32 off, int len)
 	return skb;
 }
 
+/**
+ * iptfs_input_save_runt() - save data in xtfs runt space.
+ * @xtfs: xtfs state
+ * @seq: the current sequence
+ * @buf: packet data
+ * @len: length of packet data
+ *
+ * Save the small (`len`) start of a fragmented packet in `buf` in the xtfs data
+ * runt space.
+ */
+static void iptfs_input_save_runt(struct xfrm_iptfs_data *xtfs, u64 seq,
+				  u8 *buf, int len)
+{
+	BUG_ON(xtfs->ra_newskb); /* we won't have a new SKB yet */
+
+	memcpy(xtfs->ra_runt, buf, len);
+
+	xtfs->ra_runtlen = len;
+	xtfs->ra_wantseq = seq + 1;
+}
+
+/**
+ * __iptfs_iphlen() - return the v4/v6 header length using packet data.
+ * @data: pointer at octet with version nibble
+ *
+ * The version data is expected to be valid (i.e., either 4 or 6).
+ */
+static u32 __iptfs_iphlen(u8 *data)
+{
+	struct iphdr *iph = (struct iphdr *)data;
+
+	if (iph->version == 0x4)
+		return sizeof(*iph);
+	BUG_ON(iph->version != 0x6);
+	return sizeof(struct ipv6hdr);
+}
+
+/**
+ * __iptfs_iplen() - return the v4/v6 length using packet data.
+ * @data: pointer to ip (v4/v6) packet header
+ *
+ * Grab the IPv4 or IPv6 length value in the start of the inner packet header
+ * pointed to by `data`. Assumes data len is enough for the length field only.
+ *
+ * The version data is expected to be valid (i.e., either 4 or 6).
+ */
+static u32 __iptfs_iplen(u8 *data)
+{
+	struct iphdr *iph = (struct iphdr *)data;
+
+	if (iph->version == 0x4)
+		return ntohs(iph->tot_len);
+	BUG_ON(iph->version != 0x6);
+	return ntohs(((struct ipv6hdr *)iph)->payload_len) +
+	       sizeof(struct ipv6hdr);
+}
+
 /**
  * iptfs_complete_inner_skb() - finish preparing the inner packet for gro recv.
  * @x: xfrm state
@@ -265,6 +334,238 @@ static void iptfs_complete_inner_skb(struct xfrm_state *x, struct sk_buff *skb)
 	}
 }
 
+static void __iptfs_reassem_done(struct xfrm_iptfs_data *xtfs, bool free)
+{
+	assert_spin_locked(&xtfs->drop_lock);
+
+	/* We don't care if it works locking takes care of things */
+	hrtimer_try_to_cancel(&xtfs->drop_timer);
+	if (free)
+		kfree_skb(xtfs->ra_newskb);
+	xtfs->ra_newskb = NULL;
+}
+
+/**
+ * iptfs_reassem_abort() - In-progress packet is aborted free the state.
+ * @xtfs: xtfs state
+ */
+static void iptfs_reassem_abort(struct xfrm_iptfs_data *xtfs)
+{
+	__iptfs_reassem_done(xtfs, true);
+}
+
+/**
+ * iptfs_reassem_done() - In-progress packet is complete, clear the state.
+ * @xtfs: xtfs state
+ */
+static void iptfs_reassem_done(struct xfrm_iptfs_data *xtfs)
+{
+	__iptfs_reassem_done(xtfs, false);
+}
+
+/**
+ * iptfs_reassem_cont() - Continue the reassembly of an inner packets.
+ * @xtfs: xtfs state
+ * @seq: sequence of current packet
+ * @st: seq read stat for current packet
+ * @skb: current packet
+ * @data: offset into sequential packet data
+ * @blkoff: packet blkoff value
+ * @list: list of skbs to enqueue completed packet on
+ *
+ * Process an IPTFS payload that has a non-zero `blkoff` or when we are
+ * expecting the continuation b/c we have a runt or in-progress packet.
+ */
+static u32 iptfs_reassem_cont(struct xfrm_iptfs_data *xtfs, u64 seq,
+			      struct skb_seq_state *st, struct sk_buff *skb,
+			      u32 data, u32 blkoff, struct list_head *list)
+{
+	struct sk_buff *newskb = xtfs->ra_newskb;
+	u32 remaining = skb->len - data;
+	u32 runtlen = xtfs->ra_runtlen;
+	u32 copylen, fraglen, ipremain, iphlen, iphremain, rrem;
+
+	/* Handle packet fragment we aren't expecting */
+	if (!runtlen && !xtfs->ra_newskb)
+		return data + min(blkoff, remaining);
+
+	/* Important to remember that input to this function is an ordered
+	 * packet stream (unless the user disabled the reorder window). Thus if
+	 * we are waiting for, and expecting the next packet so we can continue
+	 * assembly, a newer sequence number indicates older ones are not coming
+	 * (or if they do should be ignored). Technically we can receive older
+	 * ones when the reorder window is disabled; however, the user should
+	 * have disabled fragmentation in this case, and regardless we don't
+	 * deal with it.
+	 *
+	 * blkoff could be zero if the stream is messed up (or it's an all pad
+	 * insertion) be careful to handle that case in each of the below
+	 */
+
+	/* Too old case: This can happen when the reorder window is disabled so
+	 * ordering isn't actually guaranteed.
+	 */
+	if (seq < xtfs->ra_wantseq)
+		return data + remaining;
+
+	/* Too new case: We missed what we wanted cleanup. */
+	if (seq > xtfs->ra_wantseq) {
+		XFRM_INC_STATS(dev_net(skb->dev),
+			       LINUX_MIB_XFRMINIPTFSERROR);
+		goto abandon;
+	}
+
+	if (blkoff == 0) {
+		if ((*skb->data & 0xF0) != 0) {
+			XFRM_INC_STATS(dev_net(skb->dev),
+				       LINUX_MIB_XFRMINIPTFSERROR);
+			goto abandon;
+		}
+		/* Handle all pad case, advance expected sequence number.
+		 * (RFC 9347 S2.2.3)
+		 */
+		xtfs->ra_wantseq++;
+		/* will end parsing */
+		return data + remaining;
+	}
+
+	if (runtlen) {
+		BUG_ON(xtfs->ra_newskb);
+
+		/* Regardless of what happens we're done with the runt */
+		xtfs->ra_runtlen = 0;
+
+		/* The start of this inner packet was at the very end of the last
+		 * iptfs payload which didn't include enough for the ip header
+		 * length field. We must have *at least* that now.
+		 */
+		rrem = sizeof(xtfs->ra_runt) - runtlen;
+		if (remaining < rrem || blkoff < rrem) {
+			XFRM_INC_STATS(dev_net(skb->dev),
+				       LINUX_MIB_XFRMINIPTFSERROR);
+			goto abandon;
+		}
+
+		/* fill in the runt data */
+		if (skb_copy_bits_seq(st, data, &xtfs->ra_runt[runtlen],
+				      rrem)) {
+			XFRM_INC_STATS(dev_net(skb->dev),
+				       LINUX_MIB_XFRMINBUFFERERROR);
+			goto abandon;
+		}
+
+		/* We have enough data to get the ip length value now,
+		 * allocate an in progress skb
+		 */
+		ipremain = __iptfs_iplen(xtfs->ra_runt);
+		if (ipremain < sizeof(xtfs->ra_runt)) {
+			/* length has to be at least runtsize large */
+			XFRM_INC_STATS(dev_net(skb->dev),
+				       LINUX_MIB_XFRMINIPTFSERROR);
+			goto abandon;
+		}
+
+		/* For the runt case we don't attempt sharing currently. NOTE:
+		 * Currently, this IPTFS implementation will not create runts.
+		 */
+
+		newskb = iptfs_alloc_skb(skb, ipremain, false);
+		if (!newskb) {
+			XFRM_INC_STATS(dev_net(skb->dev),
+				       LINUX_MIB_XFRMINERROR);
+			goto abandon;
+		}
+		xtfs->ra_newskb = newskb;
+
+		/* Copy the runt data into the buffer, but leave data
+		 * pointers the same as normal non-runt case. The extra `rrem`
+		 * recopied bytes are basically cacheline free. Allows using
+		 * same logic below to complete.
+		 */
+		memcpy(skb_put(newskb, runtlen), xtfs->ra_runt,
+		       sizeof(xtfs->ra_runt));
+	}
+
+	/* Continue reassembling the packet */
+	ipremain = __iptfs_iplen(newskb->data);
+	iphlen = __iptfs_iphlen(newskb->data);
+
+	/* Sanity check, we created the newskb knowing the IP length so the IP
+	 * length can't now be shorter.
+	 */
+	BUG_ON(newskb->len > ipremain);
+
+	ipremain -= newskb->len;
+	if (blkoff < ipremain) {
+		/* Corrupt data, we don't have enough to complete the packet */
+		XFRM_INC_STATS(dev_net(skb->dev), LINUX_MIB_XFRMINIPTFSERROR);
+		goto abandon;
+	}
+
+	/* We want the IP header in linear space */
+	if (newskb->len < iphlen)  {
+		iphremain = iphlen - newskb->len;
+		if (blkoff < iphremain) {
+			XFRM_INC_STATS(dev_net(skb->dev),
+				       LINUX_MIB_XFRMINIPTFSERROR);
+			goto abandon;
+		}
+		fraglen = min(blkoff, remaining);
+		copylen = min(fraglen, iphremain);
+		BUG_ON(skb_tailroom(newskb) < copylen);
+		if (skb_copy_bits_seq(st, data, skb_put(newskb, copylen), copylen)) {
+			XFRM_INC_STATS(dev_net(skb->dev),
+				       LINUX_MIB_XFRMINBUFFERERROR);
+			goto abandon;
+		}
+		/* this is a silly condition that might occur anyway */
+		if (copylen < iphremain) {
+			xtfs->ra_wantseq++;
+			return data + fraglen;
+		}
+		/* update data and things derived from it */
+		data += copylen;
+		blkoff -= copylen;
+		remaining -= copylen;
+		ipremain -= copylen;
+	}
+
+	fraglen = min(blkoff, remaining);
+	copylen = min(fraglen, ipremain);
+
+	/* We verified this was true in the main receive routine */
+	BUG_ON(skb_tailroom(newskb) < copylen);
+
+	/* copy fragment data into newskb */
+	if (skb_copy_bits_seq(st, data, skb_put(newskb, copylen), copylen)) {
+		XFRM_INC_STATS(dev_net(skb->dev), LINUX_MIB_XFRMINBUFFERERROR);
+		goto abandon;
+	}
+
+	if (copylen < ipremain) {
+		xtfs->ra_wantseq++;
+	} else {
+		/* We are done with packet reassembly! */
+		BUG_ON(copylen != ipremain);
+		iptfs_reassem_done(xtfs);
+		iptfs_complete_inner_skb(xtfs->x, newskb);
+		list_add_tail(&newskb->list, list);
+	}
+
+	/* will continue on to new data block or end */
+	return data + fraglen;
+
+abandon:
+	if (xtfs->ra_newskb) {
+		iptfs_reassem_abort(xtfs);
+	} else {
+		xtfs->ra_runtlen = 0;
+		xtfs->ra_wantseq = 0;
+	}
+	/* skip past fragment, maybe to end */
+	return data + min(blkoff, remaining);
+}
+
 /**
  * iptfs_input() - handle receipt of iptfs payload
  * @x: xfrm state
@@ -285,7 +586,7 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 	struct iphdr *iph;
 	struct net *net;
 	u32 remaining, iplen, iphlen, data, tail;
-	u32 blkoff;
+	u32 blkoff, capturelen;
 	u64 seq;
 
 	xtfs = x->mode_data;
@@ -331,12 +632,27 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 
 	INIT_LIST_HEAD(&sublist);
 
-	/* Fragment handling in following commits */
+	/* Handle fragment at start of payload, and/or waiting reassembly. */
+
 	blkoff = ntohs(ipth->block_offset);
-	data += blkoff;
+	/* check before locking i.e., maybe */
+	if (blkoff || xtfs->ra_runtlen || xtfs->ra_newskb) {
+		spin_lock(&xtfs->drop_lock);
+
+		/* check again after lock */
+		if (blkoff || xtfs->ra_runtlen || xtfs->ra_newskb) {
+			data = iptfs_reassem_cont(xtfs, seq, &skbseq, skb, data,
+						  blkoff, &sublist);
+		}
+
+		spin_unlock(&xtfs->drop_lock);
+	}
 
 	/* New packets */
+
 	tail = skb->len;
+	BUG_ON(xtfs->ra_newskb && data < tail);
+
 	while (data < tail) {
 		__be16 protocol = 0;
 
@@ -355,8 +671,13 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 		iph = (struct iphdr *)hbytes;
 		if (iph->version == 0x4) {
 			/* must have at least tot_len field present */
-			if (remaining < 4)
+			if (remaining < 4) {
+				/* save the bytes we have, advance data and exit */
+				iptfs_input_save_runt(xtfs, seq, hbytes,
+						      remaining);
+				data += remaining;
 				break;
+			}
 
 			iplen = be16_to_cpu(iph->tot_len);
 			iphlen = iph->ihl << 2;
@@ -364,8 +685,13 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 			XFRM_MODE_SKB_CB(skbseq.root_skb)->tos = iph->tos;
 		} else if (iph->version == 0x6) {
 			/* must have at least payload_len field present */
-			if (remaining < 6)
+			if (remaining < 6) {
+				/* save the bytes we have, advance data and exit */
+				iptfs_input_save_runt(xtfs, seq, hbytes,
+						      remaining);
+				data += remaining;
 				break;
+			}
 
 			iplen = be16_to_cpu(
 				((struct ipv6hdr *)hbytes)->payload_len);
@@ -376,6 +702,7 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 				ipv6_get_dsfield((struct ipv6hdr *)iph);
 		} else if (iph->version == 0x0) {
 			/* pad */
+			data = tail;
 			break;
 		} else {
 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
@@ -395,16 +722,14 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 		if (!first_skb)
 			first_skb = skb;
 
-		/* Fragment handling in following commits */
-		if (iplen > remaining)
-			break;
-
-		skb = iptfs_pskb_extract_seq(iplen, &skbseq, data, iplen);
+		capturelen = min(iplen, remaining);
+		skb = iptfs_pskb_extract_seq(iplen, &skbseq, data, capturelen);
 		if (!skb) {
 			/* skip to next packet or done */
-			data += iplen;
+			data += capturelen;
 			continue;
 		}
+		BUG_ON(skb->len != capturelen);
 
 		skb->protocol = protocol;
 		if (old_mac) {
@@ -415,11 +740,38 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 			eth_hdr(skb)->h_proto = skb->protocol;
 		}
 
-		data += iplen;
+		data += capturelen;
+
+		if (skb->len < iplen) {
+			BUG_ON(data != tail);
+			BUG_ON(xtfs->ra_newskb);
+
+			/* Start reassembly */
+			spin_lock(&xtfs->drop_lock);
+
+			xtfs->ra_newskb = skb;
+			xtfs->ra_wantseq = seq + 1;
+			if (!hrtimer_is_queued(&xtfs->drop_timer)) {
+				/* softirq blocked lest the timer fire and interrupt us */
+				BUG_ON(!in_interrupt());
+				hrtimer_start(&xtfs->drop_timer,
+					      xtfs->drop_time_ns,
+					      IPTFS_HRTIMER_MODE);
+			}
+
+			spin_unlock(&xtfs->drop_lock);
+
+			break;
+		}
+
 		iptfs_complete_inner_skb(x, skb);
 		list_add_tail(&skb->list, &sublist);
 	}
 
+	if (data != tail)
+		/* this should not happen from the above code */
+		XFRM_INC_STATS(net, LINUX_MIB_XFRMINIPTFSERROR);
+
 	/* Send the packets! */
 	list_for_each_entry_safe(skb, next, &sublist, list) {
 		skb_list_del_init(skb);
@@ -447,6 +799,45 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 	return -EINPROGRESS;
 }
 
+/**
+ * iptfs_drop_timer() - Handle drop timer expiry.
+ * @me: the timer
+ *
+ * This is similar to our input function.
+ *
+ * The drop timer is set when we start an in progress reassembly, and also when
+ * we save a future packet in the window saved array.
+ *
+ * NOTE packets in the save window are always newer WRT drop times as
+ * they get further in the future. i.e. for:
+ *
+ *    if slots (S0, S1, ... Sn) and `Dn` is the drop time for slot `Sn`,
+ *    then D(n-1) <= D(n).
+ *
+ * So, regardless of why the timer is firing we can always discard any inprogress
+ * fragment; either it's the reassembly timer, or slot 0 is going to be
+ * dropped as S0 must have the most recent drop time, and slot 0 holds the
+ * continuation fragment of the in progress packet.
+ */
+static enum hrtimer_restart iptfs_drop_timer(struct hrtimer *me)
+{
+	struct xfrm_iptfs_data *xtfs;
+	struct xfrm_state *x;
+
+	xtfs = container_of(me, typeof(*xtfs), drop_timer);
+	x = xtfs->x;
+
+	/* Drop any in progress packet */
+	spin_lock(&xtfs->drop_lock);
+	if (xtfs->ra_newskb) {
+		kfree_skb(xtfs->ra_newskb);
+		xtfs->ra_newskb = NULL;
+	}
+	spin_unlock(&xtfs->drop_lock);
+
+	return HRTIMER_NORESTART;
+}
+
 /* ================================= */
 /* IPTFS Sending (ingress) Functions */
 /* ================================= */
@@ -1254,6 +1645,8 @@ static int iptfs_user_init(struct net *net, struct xfrm_state *x,
 	xc->max_queue_size = net->xfrm.sysctl_iptfs_max_qsize;
 	xtfs->init_delay_ns =
 		(u64)net->xfrm.sysctl_iptfs_init_delay * NSECS_IN_USEC;
+	xtfs->drop_time_ns =
+		(u64)net->xfrm.sysctl_iptfs_drop_time * NSECS_IN_USEC;
 
 	if (attrs[XFRMA_IPTFS_DONT_FRAG])
 		xc->dont_frag = true;
@@ -1271,6 +1664,10 @@ static int iptfs_user_init(struct net *net, struct xfrm_state *x,
 	}
 	if (attrs[XFRMA_IPTFS_MAX_QSIZE])
 		xc->max_queue_size = nla_get_u32(attrs[XFRMA_IPTFS_MAX_QSIZE]);
+	if (attrs[XFRMA_IPTFS_DROP_TIME])
+		xtfs->drop_time_ns =
+			(u64)nla_get_u32(attrs[XFRMA_IPTFS_DROP_TIME]) *
+			NSECS_IN_USEC;
 	if (attrs[XFRMA_IPTFS_INIT_DELAY])
 		xtfs->init_delay_ns =
 			(u64)nla_get_u32(attrs[XFRMA_IPTFS_INIT_DELAY]) *
@@ -1320,7 +1717,9 @@ static int iptfs_copy_to_user(struct xfrm_state *x, struct sk_buff *skb)
 	if (ret)
 		return ret;
 
-	ret = nla_put_u32(skb, XFRMA_IPTFS_DROP_TIME, 0);
+	q = xtfs->drop_time_ns;
+	(void)do_div(q, NSECS_IN_USEC);
+	ret = nla_put_u32(skb, XFRMA_IPTFS_DROP_TIME, q);
 	if (ret)
 		return ret;
 
@@ -1338,6 +1737,10 @@ static int __iptfs_init_state(struct xfrm_state *x,
 	hrtimer_init(&xtfs->iptfs_timer, CLOCK_MONOTONIC, IPTFS_HRTIMER_MODE);
 	xtfs->iptfs_timer.function = iptfs_delay_timer;
 
+	spin_lock_init(&xtfs->drop_lock);
+	hrtimer_init(&xtfs->drop_timer, CLOCK_MONOTONIC, IPTFS_HRTIMER_MODE);
+	xtfs->drop_timer.function = iptfs_drop_timer;
+
 	/* Modify type (esp) adjustment values */
 
 	if (x->props.family == AF_INET)
@@ -1365,6 +1768,8 @@ static int iptfs_clone(struct xfrm_state *x, struct xfrm_state *orig)
 	if (!xtfs)
 		return -ENOMEM;
 
+	xtfs->ra_newskb = NULL;
+
 	err = __iptfs_init_state(x, xtfs);
 	if (err)
 		return err;
@@ -1395,7 +1800,14 @@ static void iptfs_delete_state(struct xfrm_state *x)
 	if (!xtfs)
 		return;
 
+	spin_lock_bh(&xtfs->drop_lock);
 	hrtimer_cancel(&xtfs->iptfs_timer);
+	hrtimer_cancel(&xtfs->drop_timer);
+	spin_unlock_bh(&xtfs->drop_lock);
+
+	if (xtfs->ra_newskb)
+		kfree_skb(xtfs->ra_newskb);
+
 	kfree_sensitive(xtfs);
 
 	module_put(x->mode_cbs->owner);
-- 
2.45.2

[PATCH ipsec-next v4 14/18] xfrm: iptfs: add reusing received skb for the tunnel egress packet

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Add an optimization of re-using the tunnel outer skb re-transmission
of the inner packet to avoid skb allocation and copy.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 net/xfrm/xfrm_iptfs.c | 126 +++++++++++++++++++++++++++++++++++-------
 1 file changed, 105 insertions(+), 21 deletions(-)

diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
index a8ef3eb7427c..2a8781dbcc85 100644
--- a/net/xfrm/xfrm_iptfs.c
+++ b/net/xfrm/xfrm_iptfs.c
@@ -579,19 +579,20 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 	struct ip_iptfs_cc_hdr iptcch;
 	struct skb_seq_state skbseq;
 	struct list_head sublist; /* rename this it's just a list */
-	struct sk_buff *first_skb, *next;
+	struct sk_buff *first_skb, *defer, *next;
 	const unsigned char *old_mac;
 	struct xfrm_iptfs_data *xtfs;
 	struct ip_iptfs_hdr *ipth;
 	struct iphdr *iph;
 	struct net *net;
-	u32 remaining, iplen, iphlen, data, tail;
+	u32 remaining, first_iplen, iplen, iphlen, data, tail;
 	u32 blkoff, capturelen;
 	u64 seq;
 
 	xtfs = x->mode_data;
 	net = dev_net(skb->dev);
 	first_skb = NULL;
+	defer = NULL;
 
 	seq = __esp_seq(skb);
 
@@ -719,25 +720,94 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 			skb_prepare_seq_read(save, data, tail, &skbseq);
 		}
 
-		if (!first_skb)
+		if (first_skb) {
+			skb = NULL;
+		} else {
 			first_skb = skb;
+			first_iplen = iplen;
+
+			/* We are going to skip over `data` bytes to reach the
+			 * start of the IP header of `iphlen` len for `iplen`
+			 * inner packet.
+			 */
+
+			if (skb_has_frag_list(skb)) {
+				defer = skb;
+				skb = NULL;
+			} else if (data + iphlen <= skb_headlen(skb) &&
+				   /* make sure our header is 32-bit aligned? */
+				   /* ((uintptr_t)(skb->data + data) & 0x3) == 0 && */
+				   skb_tailroom(skb) + tail - data >= iplen) {
+				/* Reuse the received skb.
+				 *
+				 * We have enough headlen to pull past any
+				 * initial fragment data, leaving at least the
+				 * IP header in the linear buffer space.
+				 *
+				 * For linear buffer space we only require that
+				 * linear buffer space is large enough to
+				 * eventually hold the entire reassembled
+				 * packet (by including tailroom in the check).
+				 *
+				 * For non-linear tailroom is 0 and so we only
+				 * re-use if the entire packet is present
+				 * already.
+				 *
+				 * NOTE: there are many more options for
+				 * sharing, KISS for now. Also, this can produce
+				 * skb's with the IP header unaligned to 32
+				 * bits. If that ends up being a problem then a
+				 * check should be added to the conditional
+				 * above that the header lies on a 32-bit
+				 * boundary as well.
+				 */
+				skb_pull(skb, data);
+
+				/* our range just changed */
+				data = 0;
+				tail = skb->len;
+				remaining = skb->len;
+
+				skb->protocol = protocol;
+				skb_mac_header_rebuild(skb);
+				if (skb->mac_len)
+					eth_hdr(skb)->h_proto = skb->protocol;
+
+				/* all pointers could be changed now reset walk */
+				skb_abort_seq_read(&skbseq);
+				skb_prepare_seq_read(skb, data, tail, &skbseq);
+			} else {
+				/* We couldn't reuse the input skb so allocate a
+				 * new one.
+				 */
+				defer = skb;
+				skb = NULL;
+			}
+
+			/* Don't trim `first_skb` until the end as we are
+			 * walking that data now.
+			 */
+		}
 
 		capturelen = min(iplen, remaining);
-		skb = iptfs_pskb_extract_seq(iplen, &skbseq, data, capturelen);
 		if (!skb) {
-			/* skip to next packet or done */
-			data += capturelen;
-			continue;
-		}
-		BUG_ON(skb->len != capturelen);
-
-		skb->protocol = protocol;
-		if (old_mac) {
-			/* rebuild the mac header */
-			skb_set_mac_header(skb, -first_skb->mac_len);
-			memcpy(skb_mac_header(skb), old_mac,
-			       first_skb->mac_len);
-			eth_hdr(skb)->h_proto = skb->protocol;
+			skb = iptfs_pskb_extract_seq(iplen, &skbseq, data,
+						     capturelen);
+			if (!skb) {
+				/* skip to next packet or done */
+				data += capturelen;
+				continue;
+			}
+			BUG_ON(skb->len != capturelen);
+
+			skb->protocol = protocol;
+			if (old_mac) {
+				/* rebuild the mac header */
+				skb_set_mac_header(skb, -first_skb->mac_len);
+				memcpy(skb_mac_header(skb), old_mac,
+				       first_skb->mac_len);
+				eth_hdr(skb)->h_proto = skb->protocol;
+			}
 		}
 
 		data += capturelen;
@@ -772,8 +842,19 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 		/* this should not happen from the above code */
 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINIPTFSERROR);
 
+	if (first_skb && first_iplen && !defer && first_skb != xtfs->ra_newskb) {
+		/* first_skb is queued b/c !defer and not partial */
+		if (pskb_trim(first_skb, first_iplen)) {
+			/* error trimming */
+			list_del(&first_skb->list);
+			defer = first_skb;
+		}
+		first_skb->ip_summed = CHECKSUM_NONE;
+	}
+
 	/* Send the packets! */
 	list_for_each_entry_safe(skb, next, &sublist, list) {
+		BUG_ON(skb == defer);
 		skb_list_del_init(skb);
 		if (xfrm_input(skb, 0, 0, -3))
 			kfree_skb(skb);
@@ -783,12 +864,15 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 	skb = skbseq.root_skb;
 	skb_abort_seq_read(&skbseq);
 
-	if (first_skb) {
-		consume_skb(first_skb);
-	} else {
+	if (defer) {
+		consume_skb(defer);
+	} else if (!first_skb) {
 		/* skb is the original passed in skb, but we didn't get far
-		 * enough to process it as the first_skb.
+		 * enough to process it as the first_skb, if we had it would
+		 * either be save in ra_newskb, trimmed and sent on as an skb or
+		 * placed in defer to be freed.
 		 */
+		BUG_ON(!skb);
 		kfree_skb(skb);
 	}
 
-- 
2.45.2

[PATCH ipsec-next v4 15/18] xfrm: iptfs: add skb-fragment sharing code

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Avoid copying the inner packet data by sharing the skb data fragments
from the output packet skb into new inner packet skb.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 net/xfrm/xfrm_iptfs.c | 303 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 295 insertions(+), 8 deletions(-)

diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
index 2a8781dbcc85..d54ac197199f 100644
--- a/net/xfrm/xfrm_iptfs.c
+++ b/net/xfrm/xfrm_iptfs.c
@@ -33,6 +33,7 @@
 #define XFRM_IPTFS_MIN_L3HEADROOM 128
 #define XFRM_IPTFS_MIN_L2HEADROOM (64 + 16)
 #define IPTFS_FRAG_COPY_MAX 256 /* max for copying to create iptfs frags */
+#define IPTFS_PKT_SHARE_MIN 129 /* min to try to share vs copy pkt data */
 #define NSECS_IN_USEC 1000
 
 #define IPTFS_HRTIMER_MODE HRTIMER_MODE_REL_SOFT
@@ -159,6 +160,205 @@ static void skb_head_to_frag(const struct sk_buff *skb, skb_frag_t *frag)
 	skb_frag_fill_page_desc(frag, page, skb->data - addr, skb_headlen(skb));
 }
 
+/**
+ * struct skb_frag_walk - use to track a walk through fragments
+ * @fragi: current fragment index
+ * @past: length of data in fragments before @fragi
+ * @total: length of data in all fragments
+ * @nr_frags: number of fragments present in array
+ * @initial_offset: the value passed in to skb_prepare_frag_walk()
+ * @pp_recycle: copy of skb->pp_recycle
+ * @frags: the page fragments inc. room for head page
+ */
+struct skb_frag_walk {
+	u32 fragi;
+	u32 past;
+	u32 total;
+	u32 nr_frags;
+	u32 initial_offset;
+	bool pp_recycle;
+	skb_frag_t frags[MAX_SKB_FRAGS + 1];
+};
+
+/**
+ * skb_prepare_frag_walk() - initialize a frag walk over an skb.
+ * @skb: the skb to walk.
+ * @initial_offset: start the walk @initial_offset into the skb.
+ * @walk: the walk to initialize
+ *
+ * Future calls to skb_add_frags() will expect the @offset value to be at
+ * least @initial_offset large.
+ */
+static void skb_prepare_frag_walk(struct sk_buff *skb, u32 initial_offset,
+				  struct skb_frag_walk *walk)
+{
+	struct skb_shared_info *shinfo = skb_shinfo(skb);
+	skb_frag_t *frag, *from;
+	u32 i;
+
+	walk->initial_offset = initial_offset;
+	walk->fragi = 0;
+	walk->past = 0;
+	walk->total = 0;
+	walk->nr_frags = 0;
+	walk->pp_recycle = skb->pp_recycle;
+
+	if (skb->head_frag) {
+		if (initial_offset >= skb_headlen(skb)) {
+			initial_offset -= skb_headlen(skb);
+		} else {
+			frag = &walk->frags[walk->nr_frags++];
+			skb_head_to_frag(skb, frag);
+			frag->offset += initial_offset;
+			frag->len -= initial_offset;
+			walk->total += frag->len;
+			initial_offset = 0;
+		}
+	} else {
+		BUG_ON(skb_headlen(skb) > initial_offset);
+		initial_offset -= skb_headlen(skb);
+	}
+
+	for (i = 0; i < shinfo->nr_frags; i++) {
+		from = &shinfo->frags[i];
+		if (initial_offset >= from->len) {
+			initial_offset -= from->len;
+			continue;
+		}
+		frag = &walk->frags[walk->nr_frags++];
+		*frag = *from;
+		if (initial_offset) {
+			frag->offset += initial_offset;
+			frag->len -= initial_offset;
+			initial_offset = 0;
+		}
+		walk->total += frag->len;
+	}
+	BUG_ON(initial_offset != 0);
+}
+
+static u32 __skb_reset_frag_walk(struct skb_frag_walk *walk, u32 offset)
+{
+	/* Adjust offset to refer to internal walk values */
+	BUG_ON(offset < walk->initial_offset);
+	offset -= walk->initial_offset;
+
+	/* Get to the correct fragment for offset */
+	while (offset < walk->past) {
+		walk->past -= walk->frags[--walk->fragi].len;
+		if (offset >= walk->past)
+			break;
+		BUG_ON(walk->fragi == 0);
+	}
+	while (offset >= walk->past + walk->frags[walk->fragi].len)
+		walk->past += walk->frags[walk->fragi++].len;
+
+	/* offset now relative to this current frag */
+	offset -= walk->past;
+	return offset;
+}
+
+/**
+ * skb_can_add_frags() - check if ok to add frags from walk to skb
+ * @skb: skb to check for adding frags to
+ * @walk: the walk that will be used as source for frags.
+ * @offset: offset from beginning of original skb to start from.
+ * @len: amount of data to add frag references to in @skb.
+ */
+static bool skb_can_add_frags(const struct sk_buff *skb,
+			      struct skb_frag_walk *walk, u32 offset, u32 len)
+{
+	struct skb_shared_info *shinfo = skb_shinfo(skb);
+	u32 fragi, nr_frags, fraglen;
+
+	if (skb_has_frag_list(skb) || skb->pp_recycle != walk->pp_recycle)
+		return false;
+
+	/* Make offset relative to current frag after setting that */
+	offset = __skb_reset_frag_walk(walk, offset);
+
+	/* Verify we have array space for the fragments we need to add */
+	fragi = walk->fragi;
+	nr_frags = shinfo->nr_frags;
+	while (len && fragi < walk->nr_frags) {
+		skb_frag_t *frag = &walk->frags[fragi];
+
+		fraglen = frag->len;
+		if (offset) {
+			fraglen -= offset;
+			offset = 0;
+		}
+		if (++nr_frags > MAX_SKB_FRAGS)
+			return false;
+		if (len <= fraglen)
+			return true;
+		len -= fraglen;
+		fragi++;
+	}
+	/* We may not copy all @len but what we have will fit. */
+	return true;
+}
+
+/**
+ * skb_add_frags() - add a range of fragment references into an skb
+ * @skb: skb to add references into
+ * @walk: the walk to add referenced fragments from.
+ * @offset: offset from beginning of original skb to start from.
+ * @len: amount of data to add frag references to in @skb.
+ *
+ * skb_can_add_frags() should be called before this function to verify that the
+ * destination @skb is compatible with the walk and has space in the array for
+ * the to be added frag references.
+ *
+ * Return: The number of bytes not added to @skb b/c we reached the end of the
+ * walk before adding all of @len.
+ */
+static int skb_add_frags(struct sk_buff *skb, struct skb_frag_walk *walk,
+			 u32 offset, u32 len)
+{
+	struct skb_shared_info *shinfo = skb_shinfo(skb);
+	u32 fraglen;
+
+	BUG_ON(skb->pp_recycle != walk->pp_recycle);
+	if (!walk->nr_frags || offset >= walk->total + walk->initial_offset)
+		return len;
+
+	/* make offset relative to current frag after setting that */
+	offset = __skb_reset_frag_walk(walk, offset);
+	BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
+
+	while (len && walk->fragi < walk->nr_frags) {
+		skb_frag_t *frag = &walk->frags[walk->fragi];
+		skb_frag_t *tofrag = &shinfo->frags[shinfo->nr_frags];
+
+		*tofrag = *frag;
+		if (offset) {
+			tofrag->offset += offset;
+			tofrag->len -= offset;
+			offset = 0;
+		}
+		__skb_frag_ref(tofrag);
+		shinfo->nr_frags++;
+		BUG_ON(shinfo->nr_frags > MAX_SKB_FRAGS);
+
+		/* see if we are done */
+		fraglen = tofrag->len;
+		if (len < fraglen) {
+			tofrag->len = len;
+			skb->len += len;
+			skb->data_len += len;
+			return 0;
+		}
+		/* advance to next source fragment */
+		len -= fraglen;			/* careful, use dst bv_len */
+		skb->len += fraglen;		/* careful, "   "    "     */
+		skb->data_len += fraglen;	/* careful, "   "    "     */
+		walk->past += frag->len;	/* careful, use src bv_len */
+		walk->fragi++;
+	}
+	return len;
+}
+
 /**
  * skb_copy_bits_seq - copy bits from a skb_seq_state to kernel buffer
  * @st: source skb_seq_state
@@ -196,6 +396,53 @@ static int skb_copy_bits_seq(struct skb_seq_state *st, int offset, void *to,
 /* IPTFS Receiving (egress) Functions */
 /* ================================== */
 
+/**
+ * iptfs_pskb_add_frags() - Create and add frags into a new sk_buff.
+ * @tpl: template to create new skb from.
+ * @walk: The source for fragments to add.
+ * @off: The offset into @walk to add frags from, also used with @st and
+ *       @copy_len.
+ * @len: The length of data to add covering frags from @walk into @skb.
+ *       This must be <= @skblen.
+ * @st: The sequence state to copy from into the new head skb.
+ * @copy_len: Copy @copy_len bytes from @st at offset @off into the new skb
+ *            linear space.
+ *
+ * Create a new sk_buff `skb` using the template @tpl. Copy @copy_len bytes from
+ * @st into the new skb linear space, and then add shared fragments from the
+ * frag walk for the remaining @len of data (i.e., @len - @copy_len bytes).
+ *
+ * Return: The newly allocated sk_buff `skb` or NULL if an error occurs.
+ */
+static struct sk_buff *iptfs_pskb_add_frags(struct sk_buff *tpl,
+					    struct skb_frag_walk *walk, u32 off,
+					    u32 len, struct skb_seq_state *st,
+					    u32 copy_len)
+{
+	struct sk_buff *skb;
+
+	skb = iptfs_alloc_skb(tpl, copy_len, false);
+	if (!skb)
+		return NULL;
+
+	/* this should not normally be happening */
+	if (!skb_can_add_frags(skb, walk, off + copy_len, len - copy_len)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (copy_len &&
+	    skb_copy_bits_seq(st, off, skb_put(skb, copy_len), copy_len)) {
+		XFRM_INC_STATS(dev_net(st->root_skb->dev),
+			       LINUX_MIB_XFRMINERROR);
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	skb_add_frags(skb, walk, off + copy_len, len - copy_len);
+	return skb;
+}
+
 /**
  * iptfs_pskb_extract_seq() - Create and load data into a new sk_buff.
  * @skblen: the total data size for `skb`.
@@ -380,6 +627,8 @@ static u32 iptfs_reassem_cont(struct xfrm_iptfs_data *xtfs, u64 seq,
 			      struct skb_seq_state *st, struct sk_buff *skb,
 			      u32 data, u32 blkoff, struct list_head *list)
 {
+	struct skb_frag_walk _fragwalk;
+	struct skb_frag_walk *fragwalk = NULL;
 	struct sk_buff *newskb = xtfs->ra_newskb;
 	u32 remaining = skb->len - data;
 	u32 runtlen = xtfs->ra_runtlen;
@@ -533,13 +782,31 @@ static u32 iptfs_reassem_cont(struct xfrm_iptfs_data *xtfs, u64 seq,
 	fraglen = min(blkoff, remaining);
 	copylen = min(fraglen, ipremain);
 
-	/* We verified this was true in the main receive routine */
-	BUG_ON(skb_tailroom(newskb) < copylen);
+	/* If we may have the opportunity to share prepare a fragwalk. */
+	if (!skb_has_frag_list(skb) && !skb_has_frag_list(newskb) &&
+	    (skb->head_frag || skb->len == skb->data_len) &&
+	    skb->pp_recycle == newskb->pp_recycle) {
+		fragwalk = &_fragwalk;
+		skb_prepare_frag_walk(skb, data, fragwalk);
+	}
 
-	/* copy fragment data into newskb */
-	if (skb_copy_bits_seq(st, data, skb_put(newskb, copylen), copylen)) {
-		XFRM_INC_STATS(dev_net(skb->dev), LINUX_MIB_XFRMINBUFFERERROR);
-		goto abandon;
+	/* Try share then copy. */
+	if (fragwalk && skb_can_add_frags(newskb, fragwalk, data, copylen)) {
+		u32 leftover;
+
+		leftover = skb_add_frags(newskb, fragwalk, data, copylen);
+		BUG_ON(leftover != 0);
+	} else {
+		/* We verified this was true in the main receive routine */
+		BUG_ON(skb_tailroom(newskb) < copylen);
+
+		/* copy fragment data into newskb */
+		if (skb_copy_bits_seq(st, data, skb_put(newskb, copylen),
+				      copylen)) {
+			XFRM_INC_STATS(dev_net(skb->dev),
+				       LINUX_MIB_XFRMINBUFFERERROR);
+			goto abandon;
+		}
 	}
 
 	if (copylen < ipremain) {
@@ -578,6 +845,8 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 	u8 hbytes[sizeof(struct ipv6hdr)];
 	struct ip_iptfs_cc_hdr iptcch;
 	struct skb_seq_state skbseq;
+	struct skb_frag_walk _fragwalk;
+	struct skb_frag_walk *fragwalk = NULL;
 	struct list_head sublist; /* rename this it's just a list */
 	struct sk_buff *first_skb, *defer, *next;
 	const unsigned char *old_mac;
@@ -725,6 +994,7 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 		} else {
 			first_skb = skb;
 			first_iplen = iplen;
+			fragwalk = NULL;
 
 			/* We are going to skip over `data` bytes to reach the
 			 * start of the IP header of `iphlen` len for `iplen`
@@ -776,6 +1046,13 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 				/* all pointers could be changed now reset walk */
 				skb_abort_seq_read(&skbseq);
 				skb_prepare_seq_read(skb, data, tail, &skbseq);
+			} else if (skb->head_frag &&
+				   /* We have the IP header right now */
+				   remaining >= iphlen) {
+				fragwalk = &_fragwalk;
+				skb_prepare_frag_walk(skb, data, fragwalk);
+				defer = skb;
+				skb = NULL;
 			} else {
 				/* We couldn't reuse the input skb so allocate a
 				 * new one.
@@ -791,8 +1068,18 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 
 		capturelen = min(iplen, remaining);
 		if (!skb) {
-			skb = iptfs_pskb_extract_seq(iplen, &skbseq, data,
-						     capturelen);
+			if (!fragwalk ||
+			    /* Large enough to be worth sharing */
+			    iplen < IPTFS_PKT_SHARE_MIN ||
+			    /* Have IP header + some data to share. */
+			    capturelen <= iphlen ||
+			    /* Try creating skb and adding frags */
+			    !(skb = iptfs_pskb_add_frags(first_skb, fragwalk,
+							 data, capturelen,
+							 &skbseq, iphlen))) {
+				skb = iptfs_pskb_extract_seq(iplen, &skbseq,
+							     data, capturelen);
+			}
 			if (!skb) {
 				/* skip to next packet or done */
 				data += capturelen;
-- 
2.45.2

[PATCH ipsec-next v4 16/18] xfrm: iptfs: handle reordering of received packets

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Handle the receipt of the outer tunnel packets out-of-order. Pointers to
the out-of-order packets are saved in a window (array) awaiting needed
prior packets. When the required prior packets are received the now
in-order packets are then passed on to the regular packet receive code.
A timer is used to consider missing earlier packet as lost so the
algorithm will advance.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 net/xfrm/xfrm_iptfs.c | 481 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 469 insertions(+), 12 deletions(-)

diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
index d54ac197199f..59fd8ee49cd4 100644
--- a/net/xfrm/xfrm_iptfs.c
+++ b/net/xfrm/xfrm_iptfs.c
@@ -38,8 +38,14 @@
 
 #define IPTFS_HRTIMER_MODE HRTIMER_MODE_REL_SOFT
 
+struct skb_wseq {
+	struct sk_buff *skb;
+	u64 drop_time;
+};
+
 struct xfrm_iptfs_config {
 	bool dont_frag : 1;
+	u16 reorder_win_size;
 	u32 pkt_size;	    /* outer_packet_size or 0 */
 	u32 max_queue_size; /* octets */
 };
@@ -57,12 +63,16 @@ struct xfrm_iptfs_data {
 	time64_t iptfs_settime;	    /* time timer was set */
 	u32 payload_mtu;	    /* max payload size */
 
-	/* Tunnel egress */
+	/* Tunnel input reordering */
+	bool w_seq_set;		  /* true after first seq received */
+	u64 w_wantseq;		  /* expected next sequence */
+	struct skb_wseq *w_saved; /* the saved buf array */
+	u32 w_savedlen;		  /* the saved len (not size) */
 	spinlock_t drop_lock;
 	struct hrtimer drop_timer;
 	u64 drop_time_ns;
 
-	/* Tunnel egress reassembly */
+	/* Tunnel input reassembly */
 	struct sk_buff *ra_newskb; /* new pkt being reassembled */
 	u64 ra_wantseq;		   /* expected next sequence */
 	u8 ra_runt[6];		   /* last pkt bytes from last skb */
@@ -834,13 +844,13 @@ static u32 iptfs_reassem_cont(struct xfrm_iptfs_data *xtfs, u64 seq,
 }
 
 /**
- * iptfs_input() - handle receipt of iptfs payload
+ * iptfs_input_ordered() - handle next in order IPTFS payload.
  * @x: xfrm state
- * @skb: the packet
+ * @skb: current packet
  *
  * Process the IPTFS payload in `skb` and consume it afterwards.
  */
-static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
+static int iptfs_input_ordered(struct xfrm_state *x, struct sk_buff *skb)
 {
 	u8 hbytes[sizeof(struct ipv6hdr)];
 	struct ip_iptfs_cc_hdr iptcch;
@@ -1163,11 +1173,369 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
 		kfree_skb(skb);
 	}
 
-	/* We always have dealt with the input SKB, either we are re-using it,
-	 * or we have freed it. Return EINPROGRESS so that xfrm_input stops
-	 * processing it.
+	return 0;
+}
+
+/* ------------------------------- */
+/* Input (Egress) Re-ordering Code */
+/* ------------------------------- */
+
+static void __vec_shift(struct xfrm_iptfs_data *xtfs, u32 shift)
+{
+	u32 savedlen = xtfs->w_savedlen;
+
+	if (shift > savedlen)
+		shift = savedlen;
+	if (shift != savedlen)
+		memcpy(xtfs->w_saved, xtfs->w_saved + shift,
+		       (savedlen - shift) * sizeof(*xtfs->w_saved));
+	memset(xtfs->w_saved + savedlen - shift, 0,
+	       shift * sizeof(*xtfs->w_saved));
+	xtfs->w_savedlen -= shift;
+}
+
+static void __reorder_past(struct xfrm_iptfs_data *xtfs, struct sk_buff *inskb,
+			   struct list_head *freelist)
+{
+	list_add_tail(&inskb->list, freelist);
+}
+
+static u32 __reorder_drop(struct xfrm_iptfs_data *xtfs, struct list_head *list)
+
+{
+	struct skb_wseq *s, *se;
+	const u32 savedlen = xtfs->w_savedlen;
+	time64_t now = ktime_get_raw_fast_ns();
+	u32 count = 0;
+	u32 scount = 0;
+
+	BUG_ON(!savedlen);
+	if (xtfs->w_saved[0].drop_time > now)
+		goto set_timer;
+
+	++xtfs->w_wantseq;
+
+	/* Keep flushing packets until we reach a drop time greater than now. */
+	s = xtfs->w_saved;
+	se = s + savedlen;
+	do {
+		/* Walking past empty slots until we reach a packet */
+		for (; s < se && !s->skb; s++)
+			if (s->drop_time > now)
+				goto outerdone;
+		/* Sending packets until we hit another empty slot. */
+		for (; s < se && s->skb; scount++, s++)
+			list_add_tail(&s->skb->list, list);
+	} while (s < se);
+outerdone:
+
+	count = s - xtfs->w_saved;
+	if (count) {
+		xtfs->w_wantseq += count;
+
+		/* Shift handled slots plus final empty slot into slot 0. */
+		__vec_shift(xtfs, count);
+	}
+
+	if (xtfs->w_savedlen) {
+set_timer:
+		/* Drifting is OK */
+		hrtimer_start(&xtfs->drop_timer,
+			      xtfs->w_saved[0].drop_time - now,
+			      IPTFS_HRTIMER_MODE);
+	}
+	return scount;
+}
+
+static void __reorder_this(struct xfrm_iptfs_data *xtfs, struct sk_buff *inskb,
+			   struct list_head *list)
+{
+	struct skb_wseq *s, *se;
+	const u32 savedlen = xtfs->w_savedlen;
+	u32 count = 0;
+
+	/* Got what we wanted. */
+	list_add_tail(&inskb->list, list);
+	++xtfs->w_wantseq;
+	if (!savedlen)
+		return;
+
+	/* Flush remaining consecutive packets. */
+
+	/* Keep sending until we hit another missed pkt. */
+	for (s = xtfs->w_saved, se = s + savedlen; s < se && s->skb; s++)
+		list_add_tail(&s->skb->list, list);
+	count = s - xtfs->w_saved;
+	if (count)
+		xtfs->w_wantseq += count;
+
+	/* Shift handled slots plus final empty slot into slot 0. */
+	__vec_shift(xtfs, count + 1);
+}
+
+/* Set the slot's drop time and all the empty slots below it until reaching a
+ * filled slot which will already be set.
+ */
+static void iptfs_set_window_drop_times(struct xfrm_iptfs_data *xtfs, int index)
+{
+	const u32 savedlen = xtfs->w_savedlen;
+	struct skb_wseq *s = xtfs->w_saved;
+	time64_t drop_time;
+
+	assert_spin_locked(&xtfs->drop_lock);
+
+	if (savedlen > index + 1) {
+		/* we are below another, our drop time and the timer are already set */
+		BUG_ON(xtfs->w_saved[index + 1].drop_time !=
+		       xtfs->w_saved[index].drop_time);
+		return;
+	}
+	/* we are the most future so get a new drop time. */
+	drop_time = ktime_get_raw_fast_ns();
+	drop_time += xtfs->drop_time_ns;
+
+	/* Walk back through the array setting drop times as we go */
+	s[index].drop_time = drop_time;
+	while (index-- > 0 && !s[index].skb)
+		s[index].drop_time = drop_time;
+
+	/* If we walked all the way back, schedule the drop timer if needed */
+	if (index == -1 && !hrtimer_is_queued(&xtfs->drop_timer))
+		hrtimer_start(&xtfs->drop_timer, xtfs->drop_time_ns,
+			      IPTFS_HRTIMER_MODE);
+}
+
+static void __reorder_future_fits(struct xfrm_iptfs_data *xtfs,
+				  struct sk_buff *inskb,
+				  struct list_head *freelist)
+{
+	const u32 nslots = xtfs->cfg.reorder_win_size + 1;
+	const u64 inseq = __esp_seq(inskb);
+	const u64 wantseq = xtfs->w_wantseq;
+	const u64 distance = inseq - wantseq;
+	const u32 savedlen = xtfs->w_savedlen;
+	const u32 index = distance - 1;
+
+	BUG_ON(distance >= nslots);
+
+	/* Handle future sequence number received which fits in the window.
+	 *
+	 * We know we don't have the seq we want so we won't be able to flush
+	 * anything.
 	 */
-	return -EINPROGRESS;
+
+	/* slot count is 4, saved size is 3 savedlen is 2
+	 *
+	 * "window boundary" is based on the fixed window size
+	 * distance is also slot number
+	 * index is an array index (i.e., - 1 of slot)
+	 * : : - implicit NULL after array len
+	 *
+	 *          +--------- used length (savedlen == 2)
+	 *          |   +----- array size (nslots - 1 == 3)
+	 *          |   |   + window boundary (nslots == 4)
+	 *          V   V | V
+	 *                |
+	 *  0   1   2   3 |   slot number
+	 * ---  0   1   2 |   array index
+	 *     [-] [b] : :|   array
+	 *
+	 * "2" "3" "4" *5*|   seq numbers
+	 *
+	 * We receive seq number 5
+	 * distance == 3 [inseq(5) - w_wantseq(2)]
+	 * index == 2 [distance(6) - 1]
+	 */
+
+	if (xtfs->w_saved[index].skb) {
+		/* a dup of a future */
+		list_add_tail(&inskb->list, freelist);
+		return;
+	}
+
+	xtfs->w_saved[index].skb = inskb;
+	xtfs->w_savedlen = max(savedlen, index + 1);
+	iptfs_set_window_drop_times(xtfs, index);
+}
+
+static void __reorder_future_shifts(struct xfrm_iptfs_data *xtfs,
+				    struct sk_buff *inskb,
+				    struct list_head *list,
+				    struct list_head *freelist)
+{
+	const u32 nslots = xtfs->cfg.reorder_win_size + 1;
+	const u64 inseq = __esp_seq(inskb);
+	u32 savedlen = xtfs->w_savedlen;
+	u64 wantseq = xtfs->w_wantseq;
+	struct sk_buff *slot0 = NULL;
+	struct skb_wseq *wnext;
+	u32 beyond, shifting, slot;
+	u64 distance;
+
+	BUG_ON(inseq <= wantseq);
+	distance = inseq - wantseq;
+	BUG_ON(distance <= nslots - 1);
+	beyond = distance - (nslots - 1);
+
+	/* Handle future sequence number received.
+	 *
+	 * IMPORTANT: we are at least advancing w_wantseq (i.e., wantseq) by 1
+	 * b/c we are beyond the window boundary.
+	 *
+	 * We know we don't have the wantseq so that counts as a drop.
+	 */
+
+	/* ex: slot count is 4, array size is 3 savedlen is 2, slot 0 is the
+	 * missing sequence number.
+	 *
+	 * the final slot at savedlen (index savedlen - 1) is always occupied.
+	 *
+	 * beyond is "beyond array size" not savedlen.
+	 *
+	 *          +--------- array length (savedlen == 2)
+	 *          |   +----- array size (nslots - 1 == 3)
+	 *          |   |   +- window boundary (nslots == 4)
+	 *          V   V | V
+	 *                |
+	 *  0   1   2   3 |   slot number
+	 * ---  0   1   2 |   array index
+	 *     [b] [c] : :|   array
+	 *                |
+	 * "2" "3" "4" "5"|*6*  seq numbers
+	 *
+	 * We receive seq number 6
+	 * distance == 4 [inseq(6) - w_wantseq(2)]
+	 * newslot == distance
+	 * index == 3 [distance(4) - 1]
+	 * beyond == 1 [newslot(4) - lastslot((nslots(4) - 1))]
+	 * shifting == 1 [min(savedlen(2), beyond(1)]
+	 * slot0_skb == [b], and should match w_wantseq
+	 *
+	 *                +--- window boundary (nslots == 4)
+	 *  0   1   2   3 | 4   slot number
+	 * ---  0   1   2 | 3   array index
+	 *     [b] : : : :|     array
+	 * "2" "3" "4" "5" *6*  seq numbers
+	 *
+	 * We receive seq number 6
+	 * distance == 4 [inseq(6) - w_wantseq(2)]
+	 * newslot == distance
+	 * index == 3 [distance(4) - 1]
+	 * beyond == 1 [newslot(4) - lastslot((nslots(4) - 1))]
+	 * shifting == 1 [min(savedlen(1), beyond(1)]
+	 * slot0_skb == [b] and should match w_wantseq
+	 *
+	 *                +-- window boundary (nslots == 4)
+	 *  0   1   2   3 | 4   5   6   slot number
+	 * ---  0   1   2 | 3   4   5   array index
+	 *     [-] [c] : :|             array
+	 * "2" "3" "4" "5" "6" "7" *8*  seq numbers
+	 *
+	 * savedlen = 2, beyond = 3
+	 * iter 1: slot0 == NULL, missed++, lastdrop = 2 (2+1-1), slot0 = [-]
+	 * iter 2: slot0 == NULL, missed++, lastdrop = 3 (2+2-1), slot0 = [c]
+	 * 2 < 3, extra = 1 (3-2), missed += extra, lastdrop = 4 (2+2+1-1)
+	 *
+	 * We receive seq number 8
+	 * distance == 6 [inseq(8) - w_wantseq(2)]
+	 * newslot == distance
+	 * index == 5 [distance(6) - 1]
+	 * beyond == 3 [newslot(6) - lastslot((nslots(4) - 1))]
+	 * shifting == 2 [min(savedlen(2), beyond(3)]
+	 *
+	 * slot0_skb == NULL changed from [b] when "savedlen < beyond" is true.
+	 */
+
+	/* Now send any packets that are being shifted out of saved, and account
+	 * for missing packets that are exiting the window as we shift it.
+	 */
+
+	/* If savedlen > beyond we are shifting some, else all. */
+	shifting = min(savedlen, beyond);
+
+	/* slot0 is the buf that just shifted out and into slot0 */
+	slot0 = NULL;
+	wnext = xtfs->w_saved;
+	for (slot = 1; slot <= shifting; slot++, wnext++) {
+		/* handle what was in slot0 before we occupy it */
+		if (slot0)
+			list_add_tail(&slot0->list, list);
+		slot0 = wnext->skb;
+		wnext->skb = NULL;
+	}
+
+	/* slot0 is now either NULL (in which case it's what we now are waiting
+	 * for, or a buf in which case we need to handle it like we received it;
+	 * however, we may be advancing past that buffer as well..
+	 */
+
+	/* Handle case where we need to shift more than we had saved, slot0 will
+	 * be NULL iff savedlen is 0, otherwise slot0 will always be
+	 * non-NULL b/c we shifted the final element, which is always set if
+	 * there is any saved, into slot0.
+	 */
+	if (savedlen < beyond) {
+		if (savedlen == 0) {
+			BUG_ON(slot0);
+		} else {
+			BUG_ON(!slot0);
+			list_add_tail(&slot0->list, list);
+		}
+		slot0 = NULL;
+		/* slot0 has had an empty slot pushed into it */
+	}
+
+	/* Remove the entries */
+	__vec_shift(xtfs, beyond);
+
+	/* Advance want seq */
+	xtfs->w_wantseq += beyond;
+
+	/* Process drops here when implementing congestion control */
+
+	/* We've shifted. plug the packet in at the end. */
+	xtfs->w_savedlen = nslots - 1;
+	xtfs->w_saved[xtfs->w_savedlen - 1].skb = inskb;
+	iptfs_set_window_drop_times(xtfs, xtfs->w_savedlen - 1);
+
+	/* if we don't have a slot0 then we must wait for it */
+	if (!slot0)
+		return;
+
+	/* If slot0, seq must match new want seq */
+	BUG_ON(xtfs->w_wantseq != __esp_seq(slot0));
+
+	/* slot0 is valid, treat like we received expected. */
+	__reorder_this(xtfs, slot0, list);
+}
+
+/* Receive a new packet into the reorder window. Return a list of ordered
+ * packets from the window.
+ */
+static void iptfs_input_reorder(struct xfrm_iptfs_data *xtfs,
+				struct sk_buff *inskb, struct list_head *list,
+				struct list_head *freelist)
+{
+	const u32 nslots = xtfs->cfg.reorder_win_size + 1;
+	u64 inseq = __esp_seq(inskb);
+	u64 wantseq;
+
+	assert_spin_locked(&xtfs->drop_lock);
+
+	if (unlikely(!xtfs->w_seq_set)) {
+		xtfs->w_seq_set = true;
+		xtfs->w_wantseq = inseq;
+	}
+	wantseq = xtfs->w_wantseq;
+
+	if (likely(inseq == wantseq))
+		__reorder_this(xtfs, inskb, list);
+	else if (inseq < wantseq)
+		__reorder_past(xtfs, inskb, freelist);
+	else if ((inseq - wantseq) < nslots)
+		__reorder_future_fits(xtfs, inskb, freelist);
+	else
+		__reorder_future_shifts(xtfs, inskb, list, freelist);
 }
 
 /**
@@ -1192,23 +1560,90 @@ static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
  */
 static enum hrtimer_restart iptfs_drop_timer(struct hrtimer *me)
 {
+	struct sk_buff *skb, *next;
+	struct list_head freelist, list;
 	struct xfrm_iptfs_data *xtfs;
 	struct xfrm_state *x;
+	u32 count;
 
 	xtfs = container_of(me, typeof(*xtfs), drop_timer);
 	x = xtfs->x;
 
-	/* Drop any in progress packet */
 	spin_lock(&xtfs->drop_lock);
+
+	INIT_LIST_HEAD(&list);
+	INIT_LIST_HEAD(&freelist);
+
+	/* Drop any in progress packet */
+
 	if (xtfs->ra_newskb) {
 		kfree_skb(xtfs->ra_newskb);
 		xtfs->ra_newskb = NULL;
 	}
+
+	/* Now drop as many packets as we should from the reordering window
+	 * saved array
+	 */
+	count = xtfs->w_savedlen ? __reorder_drop(xtfs, &list) : 0;
+
 	spin_unlock(&xtfs->drop_lock);
 
+	if (count) {
+		list_for_each_entry_safe(skb, next, &list, list) {
+			skb_list_del_init(skb);
+			(void)iptfs_input_ordered(x, skb);
+		}
+	}
 	return HRTIMER_NORESTART;
 }
 
+/**
+ * iptfs_input() - handle receipt of iptfs payload
+ * @x: xfrm state
+ * @skb: the packet
+ *
+ * We have an IPTFS payload order it if needed, then process newly in order
+ * packets.
+ */
+static int iptfs_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+	struct list_head freelist, list;
+	struct xfrm_iptfs_data *xtfs = x->mode_data;
+	struct sk_buff *next;
+
+	/* Fast path for no reorder window. */
+	if (xtfs->cfg.reorder_win_size == 0) {
+		iptfs_input_ordered(x, skb);
+		goto done;
+	}
+
+	/* Fetch list of in-order packets from the reordering window as well as
+	 * a list of buffers we need to now free.
+	 */
+	INIT_LIST_HEAD(&list);
+	INIT_LIST_HEAD(&freelist);
+
+	spin_lock(&xtfs->drop_lock);
+	iptfs_input_reorder(xtfs, skb, &list, &freelist);
+	spin_unlock(&xtfs->drop_lock);
+
+	list_for_each_entry_safe(skb, next, &list, list) {
+		skb_list_del_init(skb);
+		(void)iptfs_input_ordered(x, skb);
+	}
+
+	list_for_each_entry_safe(skb, next, &freelist, list) {
+		skb_list_del_init(skb);
+		kfree_skb(skb);
+	}
+done:
+	/* We always have dealt with the input SKB, either we are re-using it,
+	 * or we have freed it. Return EINPROGRESS so that xfrm_input stops
+	 * processing it.
+	 */
+	return -EINPROGRESS;
+}
+
 /* ================================= */
 /* IPTFS Sending (ingress) Functions */
 /* ================================= */
@@ -2013,6 +2448,7 @@ static int iptfs_user_init(struct net *net, struct xfrm_state *x,
 	struct xfrm_iptfs_config *xc;
 
 	xc = &xtfs->cfg;
+	xc->reorder_win_size = net->xfrm.sysctl_iptfs_reorder_window;
 	xc->max_queue_size = net->xfrm.sysctl_iptfs_max_qsize;
 	xtfs->init_delay_ns =
 		(u64)net->xfrm.sysctl_iptfs_init_delay * NSECS_IN_USEC;
@@ -2021,6 +2457,13 @@ static int iptfs_user_init(struct net *net, struct xfrm_state *x,
 
 	if (attrs[XFRMA_IPTFS_DONT_FRAG])
 		xc->dont_frag = true;
+	if (attrs[XFRMA_IPTFS_REORDER_WINDOW])
+		xc->reorder_win_size =
+			nla_get_u16(attrs[XFRMA_IPTFS_REORDER_WINDOW]);
+	/* saved array is for saving 1..N seq nums from wantseq */
+	if (xc->reorder_win_size)
+		xtfs->w_saved = kcalloc(xc->reorder_win_size,
+					sizeof(*xtfs->w_saved), GFP_KERNEL);
 	if (attrs[XFRMA_IPTFS_PKT_SIZE]) {
 		xc->pkt_size = nla_get_u32(attrs[XFRMA_IPTFS_PKT_SIZE]);
 		if (!xc->pkt_size) {
@@ -2057,7 +2500,7 @@ static unsigned int iptfs_sa_len(const struct xfrm_state *x)
 
 	if (xc->dont_frag)
 		l += nla_total_size(0);
-	l += nla_total_size(sizeof(u16));
+	l += nla_total_size(sizeof(xc->reorder_win_size));
 	l += nla_total_size(sizeof(xc->pkt_size));
 	l += nla_total_size(sizeof(xc->max_queue_size));
 	l += nla_total_size(sizeof(u32)); /* drop time usec */
@@ -2078,7 +2521,7 @@ static int iptfs_copy_to_user(struct xfrm_state *x, struct sk_buff *skb)
 		if (ret)
 			return ret;
 	}
-	ret = nla_put_u16(skb, XFRMA_IPTFS_REORDER_WINDOW, 0);
+	ret = nla_put_u16(skb, XFRMA_IPTFS_REORDER_WINDOW, xc->reorder_win_size);
 	if (ret)
 		return ret;
 	ret = nla_put_u32(skb, XFRMA_IPTFS_PKT_SIZE, xc->pkt_size);
@@ -2140,6 +2583,14 @@ static int iptfs_clone(struct xfrm_state *x, struct xfrm_state *orig)
 		return -ENOMEM;
 
 	xtfs->ra_newskb = NULL;
+	if (xtfs->cfg.reorder_win_size) {
+		xtfs->w_saved = kcalloc(xtfs->cfg.reorder_win_size,
+					sizeof(*xtfs->w_saved), GFP_KERNEL);
+		if (!xtfs->w_saved) {
+			kfree_sensitive(xtfs);
+			return -ENOMEM;
+		}
+	}
 
 	err = __iptfs_init_state(x, xtfs);
 	if (err)
@@ -2167,6 +2618,7 @@ static int iptfs_create_state(struct xfrm_state *x)
 static void iptfs_delete_state(struct xfrm_state *x)
 {
 	struct xfrm_iptfs_data *xtfs = x->mode_data;
+	struct skb_wseq *s, *se;
 
 	if (!xtfs)
 		return;
@@ -2179,6 +2631,11 @@ static void iptfs_delete_state(struct xfrm_state *x)
 	if (xtfs->ra_newskb)
 		kfree_skb(xtfs->ra_newskb);
 
+	for (s = xtfs->w_saved, se = s + xtfs->w_savedlen; s < se; s++)
+		if (s->skb)
+			kfree_skb(s->skb);
+
+	kfree_sensitive(xtfs->w_saved);
 	kfree_sensitive(xtfs);
 
 	module_put(x->mode_cbs->owner);
-- 
2.45.2

[PATCH ipsec-next v4 17/18] xfrm: iptfs: only send the NL attrs that corr. to the SA dir

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

When sending the netlink attributes to the user for a given SA, only
send those NL attributes which correspond to the SA's direction.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 net/xfrm/xfrm_iptfs.c | 64 ++++++++++++++++++++++++-------------------
 1 file changed, 36 insertions(+), 28 deletions(-)

diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
index 59fd8ee49cd4..049a94a5531b 100644
--- a/net/xfrm/xfrm_iptfs.c
+++ b/net/xfrm/xfrm_iptfs.c
@@ -2498,13 +2498,16 @@ static unsigned int iptfs_sa_len(const struct xfrm_state *x)
 	struct xfrm_iptfs_config *xc = &xtfs->cfg;
 	unsigned int l = 0;
 
-	if (xc->dont_frag)
-		l += nla_total_size(0);
-	l += nla_total_size(sizeof(xc->reorder_win_size));
-	l += nla_total_size(sizeof(xc->pkt_size));
-	l += nla_total_size(sizeof(xc->max_queue_size));
-	l += nla_total_size(sizeof(u32)); /* drop time usec */
-	l += nla_total_size(sizeof(u32)); /* init delay usec */
+	if (x->dir == XFRM_SA_DIR_IN) {
+		l += nla_total_size(sizeof(u32)); /* drop time usec */
+		l += nla_total_size(sizeof(xc->reorder_win_size));
+	} else {
+		if (xc->dont_frag)
+			l += nla_total_size(0);	  /* dont-frag flag */
+		l += nla_total_size(sizeof(u32)); /* init delay usec */
+		l += nla_total_size(sizeof(xc->max_queue_size));
+		l += nla_total_size(sizeof(xc->pkt_size));
+	}
 
 	return l;
 }
@@ -2516,30 +2519,35 @@ static int iptfs_copy_to_user(struct xfrm_state *x, struct sk_buff *skb)
 	int ret;
 	u64 q;
 
-	if (xc->dont_frag) {
-		ret = nla_put_flag(skb, XFRMA_IPTFS_DONT_FRAG);
+	if (x->dir == XFRM_SA_DIR_IN) {
+		q = xtfs->drop_time_ns;
+		(void)do_div(q, NSECS_IN_USEC);
+		ret = nla_put_u32(skb, XFRMA_IPTFS_DROP_TIME, q);
+		if (ret)
+			return ret;
+
+		ret = nla_put_u16(skb, XFRMA_IPTFS_REORDER_WINDOW,
+				  xc->reorder_win_size);
+	} else {
+		if (xc->dont_frag) {
+			ret = nla_put_flag(skb, XFRMA_IPTFS_DONT_FRAG);
+			if (ret)
+				return ret;
+		}
+
+		q = xtfs->init_delay_ns;
+		(void)do_div(q, NSECS_IN_USEC);
+		ret = nla_put_u32(skb, XFRMA_IPTFS_INIT_DELAY, q);
+		if (ret)
+			return ret;
+
+		ret = nla_put_u32(skb, XFRMA_IPTFS_MAX_QSIZE,
+				  xc->max_queue_size);
 		if (ret)
 			return ret;
+
+		ret = nla_put_u32(skb, XFRMA_IPTFS_PKT_SIZE, xc->pkt_size);
 	}
-	ret = nla_put_u16(skb, XFRMA_IPTFS_REORDER_WINDOW, xc->reorder_win_size);
-	if (ret)
-		return ret;
-	ret = nla_put_u32(skb, XFRMA_IPTFS_PKT_SIZE, xc->pkt_size);
-	if (ret)
-		return ret;
-	ret = nla_put_u32(skb, XFRMA_IPTFS_MAX_QSIZE, xc->max_queue_size);
-	if (ret)
-		return ret;
-
-	q = xtfs->drop_time_ns;
-	(void)do_div(q, NSECS_IN_USEC);
-	ret = nla_put_u32(skb, XFRMA_IPTFS_DROP_TIME, q);
-	if (ret)
-		return ret;
-
-	q = xtfs->init_delay_ns;
-	(void)do_div(q, NSECS_IN_USEC);
-	ret = nla_put_u32(skb, XFRMA_IPTFS_INIT_DELAY, q);
 
 	return ret;
 }
-- 
2.45.2

[PATCH ipsec-next v4 18/18] xfrm: iptfs: add tracepoint functionality

[Christian Hopps]

From: Christian Hopps <chopps@labn.net>

Add tracepoints to the IP-TFS code.

Signed-off-by: Christian Hopps <chopps@labn.net>
---
 net/xfrm/trace_iptfs.h | 218 +++++++++++++++++++++++++++++++++++++++++
 net/xfrm/xfrm_iptfs.c  |  62 +++++++++++-
 2 files changed, 279 insertions(+), 1 deletion(-)
 create mode 100644 net/xfrm/trace_iptfs.h

diff --git a/net/xfrm/trace_iptfs.h b/net/xfrm/trace_iptfs.h
new file mode 100644
index 000000000000..0425f051572f
--- /dev/null
+++ b/net/xfrm/trace_iptfs.h
@@ -0,0 +1,218 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* xfrm_trace_iptfs.h
+ *
+ * August 12 2023, Christian Hopps <chopps@labn.net>
+ *
+ * Copyright (c) 2023, LabN Consulting, L.L.C.
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM iptfs
+
+#if !defined(_TRACE_IPTFS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_IPTFS_H
+
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/tracepoint.h>
+#include <net/ip.h>
+
+struct xfrm_iptfs_data;
+
+TRACE_EVENT(iptfs_egress_recv,
+	    TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs, u16 blkoff),
+	    TP_ARGS(skb, xtfs, blkoff),
+	    TP_STRUCT__entry(__field(struct sk_buff *, skb)
+			     __field(void *, head)
+			     __field(void *, head_pg_addr)
+			     __field(void *, pg0addr)
+			     __field(u32, skb_len)
+			     __field(u32, data_len)
+			     __field(u32, headroom)
+			     __field(u32, tailroom)
+			     __field(u32, tail)
+			     __field(u32, end)
+			     __field(u32, pg0off)
+			     __field(u8, head_frag)
+			     __field(u8, frag_list)
+			     __field(u8, nr_frags)
+			     __field(u16, blkoff)),
+	    TP_fast_assign(__entry->skb = skb;
+			   __entry->head = skb->head;
+			   __entry->skb_len = skb->len;
+			   __entry->data_len = skb->data_len;
+			   __entry->headroom = skb_headroom(skb);
+			   __entry->tailroom = skb_tailroom(skb);
+			   __entry->tail = skb->tail;
+			   __entry->end = skb->end;
+			   __entry->head_frag = skb->head_frag;
+			   __entry->frag_list = (bool)skb_shinfo(skb)->frag_list;
+			   __entry->nr_frags = skb_shinfo(skb)->nr_frags;
+			   __entry->blkoff = blkoff;
+			   __entry->head_pg_addr = page_address(virt_to_head_page(skb->head));
+			   __entry->pg0addr = (__entry->nr_frags
+					       ? page_address(netmem_to_page(skb_shinfo(skb)->frags[0].netmem))
+					       : NULL);
+			   __entry->pg0off = (__entry->nr_frags
+					      ? skb_shinfo(skb)->frags[0].offset
+					      : 0);
+		    ),
+	    TP_printk("EGRESS: skb=%p len=%u data_len=%u headroom=%u head_frag=%u frag_list=%u nr_frags=%u blkoff=%u\n\t\ttailroom=%u tail=%u end=%u head=%p hdpgaddr=%p pg0->addr=%p pg0->data=%p pg0->off=%u",
+		      __entry->skb, __entry->skb_len, __entry->data_len, __entry->headroom,
+		      __entry->head_frag, __entry->frag_list, __entry->nr_frags, __entry->blkoff,
+		      __entry->tailroom, __entry->tail, __entry->end, __entry->head,
+		      __entry->head_pg_addr, __entry->pg0addr, __entry->pg0addr + __entry->pg0off,
+		      __entry->pg0off)
+	)
+
+DECLARE_EVENT_CLASS(iptfs_ingress_preq_event,
+		    TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs,
+			     u32 pmtu, u8 was_gso),
+		    TP_ARGS(skb, xtfs, pmtu, was_gso),
+		    TP_STRUCT__entry(__field(struct sk_buff *, skb)
+				     __field(u32, skb_len)
+				     __field(u32, data_len)
+				     __field(u32, pmtu)
+				     __field(u32, queue_size)
+				     __field(u32, proto_seq)
+				     __field(u8, proto)
+				     __field(u8, was_gso)
+			    ),
+		    TP_fast_assign(__entry->skb = skb;
+				   __entry->skb_len = skb->len;
+				   __entry->data_len = skb->data_len;
+				   __entry->queue_size =
+					xtfs->cfg.max_queue_size - xtfs->queue_size;
+				   __entry->proto = __trace_ip_proto(ip_hdr(skb));
+				   __entry->proto_seq = __trace_ip_proto_seq(ip_hdr(skb));
+				   __entry->pmtu = pmtu;
+				   __entry->was_gso = was_gso;
+			    ),
+		    TP_printk("INGRPREQ: skb=%p len=%u data_len=%u qsize=%u proto=%u proto_seq=%u pmtu=%u was_gso=%u",
+			      __entry->skb, __entry->skb_len, __entry->data_len,
+			      __entry->queue_size, __entry->proto, __entry->proto_seq,
+			      __entry->pmtu, __entry->was_gso));
+
+DEFINE_EVENT(iptfs_ingress_preq_event, iptfs_enqueue,
+	     TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs, u32 pmtu, u8 was_gso),
+	     TP_ARGS(skb, xtfs, pmtu, was_gso));
+
+DEFINE_EVENT(iptfs_ingress_preq_event, iptfs_no_queue_space,
+	     TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs, u32 pmtu, u8 was_gso),
+	     TP_ARGS(skb, xtfs, pmtu, was_gso));
+
+DEFINE_EVENT(iptfs_ingress_preq_event, iptfs_too_big,
+	     TP_PROTO(struct sk_buff *skb, struct xfrm_iptfs_data *xtfs, u32 pmtu, u8 was_gso),
+	     TP_ARGS(skb, xtfs, pmtu, was_gso));
+
+DECLARE_EVENT_CLASS(iptfs_ingress_postq_event,
+		    TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff, struct iphdr *iph),
+		    TP_ARGS(skb, mtu, blkoff, iph),
+		    TP_STRUCT__entry(__field(struct sk_buff *, skb)
+				     __field(u32, skb_len)
+				     __field(u32, data_len)
+				     __field(u32, mtu)
+				     __field(u32, proto_seq)
+				     __field(u16, blkoff)
+				     __field(u8, proto)),
+		    TP_fast_assign(__entry->skb = skb;
+				   __entry->skb_len = skb->len;
+				   __entry->data_len = skb->data_len;
+				   __entry->mtu = mtu;
+				   __entry->blkoff = blkoff;
+				   __entry->proto = iph ? __trace_ip_proto(iph) : 0;
+				   __entry->proto_seq = iph ? __trace_ip_proto_seq(iph) : 0;
+			    ),
+		    TP_printk("INGRPSTQ: skb=%p len=%u data_len=%u mtu=%u blkoff=%u proto=%u proto_seq=%u",
+			      __entry->skb, __entry->skb_len, __entry->data_len, __entry->mtu,
+			      __entry->blkoff, __entry->proto, __entry->proto_seq));
+
+DEFINE_EVENT(iptfs_ingress_postq_event, iptfs_first_dequeue,
+	     TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff,
+		      struct iphdr *iph),
+	     TP_ARGS(skb, mtu, blkoff, iph));
+
+DEFINE_EVENT(iptfs_ingress_postq_event, iptfs_first_fragmenting,
+	     TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff,
+		      struct iphdr *iph),
+	     TP_ARGS(skb, mtu, blkoff, iph));
+
+DEFINE_EVENT(iptfs_ingress_postq_event, iptfs_first_final_fragment,
+	     TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff,
+		      struct iphdr *iph),
+	     TP_ARGS(skb, mtu, blkoff, iph));
+
+DEFINE_EVENT(iptfs_ingress_postq_event, iptfs_first_toobig,
+	     TP_PROTO(struct sk_buff *skb, u32 mtu, u16 blkoff,
+		      struct iphdr *iph),
+	     TP_ARGS(skb, mtu, blkoff, iph));
+
+TRACE_EVENT(iptfs_ingress_nth_peek,
+	    TP_PROTO(struct sk_buff *skb, u32 remaining),
+	    TP_ARGS(skb, remaining),
+	    TP_STRUCT__entry(__field(struct sk_buff *, skb)
+			     __field(u32, skb_len)
+			     __field(u32, remaining)),
+	    TP_fast_assign(__entry->skb = skb;
+			   __entry->skb_len = skb->len;
+			   __entry->remaining = remaining;
+		    ),
+	    TP_printk("INGRPSTQ: NTHPEEK: skb=%p len=%u remaining=%u",
+		      __entry->skb, __entry->skb_len, __entry->remaining));
+
+TRACE_EVENT(iptfs_ingress_nth_add, TP_PROTO(struct sk_buff *skb, u8 share_ok),
+	    TP_ARGS(skb, share_ok),
+	    TP_STRUCT__entry(__field(struct sk_buff *, skb)
+			     __field(u32, skb_len)
+			     __field(u32, data_len)
+			     __field(u8, share_ok)
+			     __field(u8, head_frag)
+			     __field(u8, pp_recycle)
+			     __field(u8, cloned)
+			     __field(u8, shared)
+			     __field(u8, nr_frags)
+			     __field(u8, frag_list)
+		    ),
+	    TP_fast_assign(__entry->skb = skb;
+			   __entry->skb_len = skb->len;
+			   __entry->data_len = skb->data_len;
+			   __entry->share_ok = share_ok;
+			   __entry->head_frag = skb->head_frag;
+			   __entry->pp_recycle = skb->pp_recycle;
+			   __entry->cloned = skb_cloned(skb);
+			   __entry->shared = skb_shared(skb);
+			   __entry->nr_frags = skb_shinfo(skb)->nr_frags;
+			   __entry->frag_list = (bool)skb_shinfo(skb)->frag_list;
+		    ),
+	    TP_printk("INGRPSTQ: NTHADD: skb=%p len=%u data_len=%u share_ok=%u head_frag=%u pp_recycle=%u cloned=%u shared=%u nr_frags=%u frag_list=%u",
+		      __entry->skb, __entry->skb_len, __entry->data_len, __entry->share_ok,
+		      __entry->head_frag, __entry->pp_recycle, __entry->cloned, __entry->shared,
+		      __entry->nr_frags, __entry->frag_list));
+
+DECLARE_EVENT_CLASS(iptfs_timer_event,
+		    TP_PROTO(struct xfrm_iptfs_data *xtfs, u64 time_val),
+		    TP_ARGS(xtfs, time_val),
+		    TP_STRUCT__entry(__field(u64, time_val)
+				     __field(u64, set_time)),
+		    TP_fast_assign(__entry->time_val = time_val;
+				   __entry->set_time = xtfs->iptfs_settime;
+			    ),
+		    TP_printk("TIMER: set_time=%llu time_val=%llu",
+			      __entry->set_time, __entry->time_val));
+
+DEFINE_EVENT(iptfs_timer_event, iptfs_timer_start,
+	     TP_PROTO(struct xfrm_iptfs_data *xtfs, u64 time_val),
+	     TP_ARGS(xtfs, time_val));
+
+DEFINE_EVENT(iptfs_timer_event, iptfs_timer_expire,
+	     TP_PROTO(struct xfrm_iptfs_data *xtfs, u64 time_val),
+	     TP_ARGS(xtfs, time_val));
+
+#endif /* _TRACE_IPTFS_H */
+
+/* This part must be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH ../../net/xfrm
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace_iptfs
+#include <trace/define_trace.h>
diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
index 049a94a5531b..1cebe0f56d60 100644
--- a/net/xfrm/xfrm_iptfs.c
+++ b/net/xfrm/xfrm_iptfs.c
@@ -18,6 +18,7 @@
 #include <crypto/aead.h>
 
 #include "xfrm_inout.h"
+#include "trace_iptfs.h"
 
 /* IPTFS encap (header) values. */
 #define IPTFS_SUBTYPE_BASIC 0
@@ -87,6 +88,39 @@ static enum hrtimer_restart iptfs_drop_timer(struct hrtimer *me);
 /* Utility Functions */
 /* ================= */
 
+static u32 __trace_ip_proto(struct iphdr *iph)
+{
+	if (iph->version == 4)
+		return iph->protocol;
+	return ((struct ipv6hdr *)iph)->nexthdr;
+}
+
+static u32 __trace_ip_proto_seq(struct iphdr *iph)
+{
+	void *nexthdr;
+	u32 protocol = 0;
+
+	if (iph->version == 4) {
+		nexthdr = (void *)(iph + 1);
+		protocol = iph->protocol;
+	} else if (iph->version == 6) {
+		nexthdr = (void *)(((struct ipv6hdr *)(iph)) + 1);
+		protocol = ((struct ipv6hdr *)(iph))->nexthdr;
+	}
+	switch (protocol) {
+	case IPPROTO_ICMP:
+		return ntohs(((struct icmphdr *)nexthdr)->un.echo.sequence);
+	case IPPROTO_ICMPV6:
+		return ntohs(((struct icmp6hdr *)nexthdr)->icmp6_sequence);
+	case IPPROTO_TCP:
+		return ntohl(((struct tcphdr *)nexthdr)->seq);
+	case IPPROTO_UDP:
+		return ntohs(((struct udphdr *)nexthdr)->source);
+	default:
+		return 0;
+	}
+}
+
 static u64 __esp_seq(struct sk_buff *skb)
 {
 	u64 seq = ntohl(XFRM_SKB_CB(skb)->seq.input.low);
@@ -402,6 +436,13 @@ static int skb_copy_bits_seq(struct skb_seq_state *st, int offset, void *to,
 	}
 }
 
+/* ================================== */
+/* IPTFS Trace Event Definitions      */
+/* ================================== */
+
+#define CREATE_TRACE_POINTS
+#include "trace_iptfs.h"
+
 /* ================================== */
 /* IPTFS Receiving (egress) Functions */
 /* ================================== */
@@ -891,6 +932,8 @@ static int iptfs_input_ordered(struct xfrm_state *x, struct sk_buff *skb)
 	}
 	data = sizeof(*ipth);
 
+	trace_iptfs_egress_recv(skb, xtfs, be16_to_cpu(ipth->block_offset));
+
 	/* Set data past the basic header */
 	if (ipth->subtype == IPTFS_SUBTYPE_CC) {
 		/* Copy the rest of the CC header */
@@ -1786,9 +1829,10 @@ static int iptfs_output_collect(struct net *net, struct sock *sk,
 		 */
 		if (!ok) {
 nospace:
+			trace_iptfs_no_queue_space(skb, xtfs, pmtu, was_gso);
 			if (skb->dev)
 				XFRM_INC_STATS(dev_net(skb->dev),
-				       LINUX_MIB_XFRMOUTNOQSPACE);
+					       LINUX_MIB_XFRMOUTNOQSPACE);
 			kfree_skb_reason(skb, SKB_DROP_REASON_FULL_RING);
 			continue;
 		}
@@ -1797,6 +1841,7 @@ static int iptfs_output_collect(struct net *net, struct sock *sk,
 		 * enqueue.
 		 */
 		if (xtfs->cfg.dont_frag && iptfs_is_too_big(sk, skb, pmtu)) {
+			trace_iptfs_too_big(skb, xtfs, pmtu, was_gso);
 			kfree_skb_reason(skb, SKB_DROP_REASON_PKT_TOO_BIG);
 			continue;
 		}
@@ -1805,6 +1850,8 @@ static int iptfs_output_collect(struct net *net, struct sock *sk,
 		ok = iptfs_enqueue(xtfs, skb);
 		if (!ok)
 			goto nospace;
+
+		trace_iptfs_enqueue(skb, xtfs, pmtu, was_gso);
 	}
 
 	/* Start a delay timer if we don't have one yet */
@@ -1812,6 +1859,7 @@ static int iptfs_output_collect(struct net *net, struct sock *sk,
 		hrtimer_start(&xtfs->iptfs_timer, xtfs->init_delay_ns,
 			      IPTFS_HRTIMER_MODE);
 		xtfs->iptfs_settime = ktime_get_raw_fast_ns();
+		trace_iptfs_timer_start(xtfs, xtfs->init_delay_ns);
 	}
 
 	spin_unlock_bh(&x->lock);
@@ -1909,6 +1957,7 @@ static int iptfs_copy_create_frags(struct sk_buff **skbp,
 	to_copy = skb->len - offset;
 	while (to_copy) {
 		/* Send all but last fragment to allow agg. append */
+		trace_iptfs_first_fragmenting(nskb, mtu, to_copy, NULL);
 		list_add_tail(&nskb->list, &sublist);
 
 		/* FUTURE: if the packet has an odd/non-aligning length we could
@@ -1934,6 +1983,8 @@ static int iptfs_copy_create_frags(struct sk_buff **skbp,
 
 	/* return last fragment that will be unsent (or NULL) */
 	*skbp = nskb;
+	if (nskb)
+		trace_iptfs_first_final_fragment(nskb, mtu, blkoff, NULL);
 
 	/* trim the original skb to MTU */
 	if (!err)
@@ -2038,6 +2089,8 @@ static int iptfs_first_skb(struct sk_buff **skbp, struct xfrm_iptfs_data *xtfs,
 	/* We've split these up before queuing */
 	BUG_ON(skb_is_gso(skb));
 
+	trace_iptfs_first_dequeue(skb, mtu, 0, ip_hdr(skb));
+
 	/* Simple case -- it fits. `mtu` accounted for all the overhead
 	 * including the basic IPTFS header.
 	 */
@@ -2140,6 +2193,7 @@ static void iptfs_output_queued(struct xfrm_state *x, struct sk_buff_head *list)
 				XFRM_INC_STATS(dev_net(skb->dev),
 				       LINUX_MIB_XFRMOUTERROR);
 
+			trace_iptfs_first_toobig(skb, mtu, 0, ip_hdr(skb));
 			kfree_skb_reason(skb, SKB_DROP_REASON_PKT_TOO_BIG);
 			continue;
 		}
@@ -2187,6 +2241,7 @@ static void iptfs_output_queued(struct xfrm_state *x, struct sk_buff_head *list)
 		 * case.
 		 */
 		while ((skb2 = skb_peek(list))) {
+			trace_iptfs_ingress_nth_peek(skb2, remaining);
 			if (skb2->len > remaining)
 				break;
 
@@ -2224,6 +2279,8 @@ static void iptfs_output_queued(struct xfrm_state *x, struct sk_buff_head *list)
 			skb->len += skb2->len;
 			remaining -= skb2->len;
 
+			trace_iptfs_ingress_nth_add(skb2, share_ok);
+
 			if (share_ok) {
 				iptfs_consume_frags(skb, skb2);
 			} else {
@@ -2273,6 +2330,9 @@ static enum hrtimer_restart iptfs_delay_timer(struct hrtimer *me)
 	 * already).
 	 */
 
+	trace_iptfs_timer_expire(
+		xtfs, (unsigned long long)(ktime_get_raw_fast_ns() - settime));
+
 	iptfs_output_queued(x, &list);
 
 	return HRTIMER_NORESTART;
-- 
2.45.2

Re: [PATCH ipsec-next v4 00/18] Add IP-TFS mode to xfrm

[Simon Horman]

On Mon, Jun 17, 2024 at 04:52:58PM -0400, Christian Hopps wrote:
> * Summary of Changes:
> 
> This patchset adds a new xfrm mode implementing on-demand IP-TFS. IP-TFS
> (AggFrag encapsulation) has been standardized in RFC9347.
> 
>   Link: https://www.rfc-editor.org/rfc/rfc9347.txt
> 
> This feature supports demand driven (i.e., non-constant send rate)
> IP-TFS to take advantage of the AGGFRAG ESP payload encapsulation. This
> payload type supports aggregation and fragmentation of the inner IP
> packet stream which in turn yields higher small-packet bandwidth as well
> as reducing MTU/PMTU issues. Congestion control is unimplementated as
> the send rate is demand driven rather than constant.
> 
> In order to allow loading this fucntionality as a module a set of
> callbacks xfrm_mode_cbs has been added to xfrm as well.

Hi Christian,

This does not appear to apply to ipsec-next.
Would it be possible for you to rebase?

Re: [PATCH ipsec-next v4 08/18] xfrm: iptfs: add new iptfs xfrm mode impl

[Jeff Johnson]

On 6/17/24 13:53, Christian Hopps wrote:
> From: Christian Hopps <chopps@labn.net>
> 
> Add a new xfrm mode implementing AggFrag/IP-TFS from RFC9347.
> 
> This utilizes the new xfrm_mode_cbs to implement demand-driven IP-TFS
> functionality. This functionality can be used to increase bandwidth
> utilization through small packet aggregation, as well as help solve PMTU
> issues through it's efficient use of fragmentation.
> 
>    Link: https://www.rfc-editor.org/rfc/rfc9347.txt
> 
> Multiple commits follow to build the functionality into xfrm_iptfs.c
> 
> Signed-off-by: Christian Hopps <chopps@labn.net>
> ---
>   net/xfrm/Makefile     |   1 +
>   net/xfrm/xfrm_iptfs.c | 225 ++++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 226 insertions(+)
>   create mode 100644 net/xfrm/xfrm_iptfs.c
> 
> diff --git a/net/xfrm/Makefile b/net/xfrm/Makefile
> index 547cec77ba03..cd6520d4d777 100644
> --- a/net/xfrm/Makefile
> +++ b/net/xfrm/Makefile
> @@ -20,5 +20,6 @@ obj-$(CONFIG_XFRM_USER) += xfrm_user.o
>   obj-$(CONFIG_XFRM_USER_COMPAT) += xfrm_compat.o
>   obj-$(CONFIG_XFRM_IPCOMP) += xfrm_ipcomp.o
>   obj-$(CONFIG_XFRM_INTERFACE) += xfrm_interface.o
> +obj-$(CONFIG_XFRM_IPTFS) += xfrm_iptfs.o
>   obj-$(CONFIG_XFRM_ESPINTCP) += espintcp.o
>   obj-$(CONFIG_DEBUG_INFO_BTF) += xfrm_state_bpf.o
> diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
> new file mode 100644
> index 000000000000..e7b5546e1f6a
> --- /dev/null
> +++ b/net/xfrm/xfrm_iptfs.c
> @@ -0,0 +1,225 @@
> +// SPDX-License-Identifier: GPL-2.0
...

> +module_init(xfrm_iptfs_init);
> +module_exit(xfrm_iptfs_fini);
> +MODULE_LICENSE("GPL");

missing MODULE_DESCRIPTION() which will cause a warning with make W=1

Re: [devel-ipsec] [PATCH ipsec-next v4 17/18] xfrm: iptfs: only send the NL attrs that corr. to the SA dir

[Antony Antony]

On Mon, Jun 17, 2024 at 04:53:15PM -0400, Christian Hopps via Devel wrote:
> From: Christian Hopps <chopps@labn.net>
> 
> When sending the netlink attributes to the user for a given SA, only
> send those NL attributes which correspond to the SA's direction.
> 
> Signed-off-by: Christian Hopps <chopps@labn.net>
> ---
>  net/xfrm/xfrm_iptfs.c | 64 ++++++++++++++++++++++++-------------------
>  1 file changed, 36 insertions(+), 28 deletions(-)
> 
> diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
> index 59fd8ee49cd4..049a94a5531b 100644
> --- a/net/xfrm/xfrm_iptfs.c
> +++ b/net/xfrm/xfrm_iptfs.c
> @@ -2498,13 +2498,16 @@ static unsigned int iptfs_sa_len(const struct xfrm_state *x)
>  	struct xfrm_iptfs_config *xc = &xtfs->cfg;
>  	unsigned int l = 0;
>  
> -	if (xc->dont_frag)
> -		l += nla_total_size(0);
> -	l += nla_total_size(sizeof(xc->reorder_win_size));
> -	l += nla_total_size(sizeof(xc->pkt_size));
> -	l += nla_total_size(sizeof(xc->max_queue_size));
> -	l += nla_total_size(sizeof(u32)); /* drop time usec */
> -	l += nla_total_size(sizeof(u32)); /* init delay usec */
> +	if (x->dir == XFRM_SA_DIR_IN) {
> +		l += nla_total_size(sizeof(u32)); /* drop time usec */
> +		l += nla_total_size(sizeof(xc->reorder_win_size));
> +	} else {
> +		if (xc->dont_frag)
> +			l += nla_total_size(0);	  /* dont-frag flag */
> +		l += nla_total_size(sizeof(u32)); /* init delay usec */
> +		l += nla_total_size(sizeof(xc->max_queue_size));
> +		l += nla_total_size(sizeof(xc->pkt_size));
> +	}
>  
>  	return l;
>  }
> @@ -2516,30 +2519,35 @@ static int iptfs_copy_to_user(struct xfrm_state *x, struct sk_buff *skb)
>  	int ret;
>  	u64 q;
>  
> -	if (xc->dont_frag) {
> -		ret = nla_put_flag(skb, XFRMA_IPTFS_DONT_FRAG);
> +	if (x->dir == XFRM_SA_DIR_IN) {
> +		q = xtfs->drop_time_ns;
> +		(void)do_div(q, NSECS_IN_USEC);
> +		ret = nla_put_u32(skb, XFRMA_IPTFS_DROP_TIME, q);
> +		if (ret)
> +			return ret;
> +
> +		ret = nla_put_u16(skb, XFRMA_IPTFS_REORDER_WINDOW,
> +				  xc->reorder_win_size);
> +	} else {
> +		if (xc->dont_frag) {
> +			ret = nla_put_flag(skb, XFRMA_IPTFS_DONT_FRAG);
> +			if (ret)
> +				return ret;
> +		}
> +
> +		q = xtfs->init_delay_ns;
> +		(void)do_div(q, NSECS_IN_USEC);
> +		ret = nla_put_u32(skb, XFRMA_IPTFS_INIT_DELAY, q);
> +		if (ret)
> +			return ret;
> +
> +		ret = nla_put_u32(skb, XFRMA_IPTFS_MAX_QSIZE,
> +				  xc->max_queue_size);
>  		if (ret)
>  			return ret;
> +
> +		ret = nla_put_u32(skb, XFRMA_IPTFS_PKT_SIZE, xc->pkt_size);
>  	}
> -	ret = nla_put_u16(skb, XFRMA_IPTFS_REORDER_WINDOW, xc->reorder_win_size);
> -	if (ret)
> -		return ret;
> -	ret = nla_put_u32(skb, XFRMA_IPTFS_PKT_SIZE, xc->pkt_size);
> -	if (ret)
> -		return ret;
> -	ret = nla_put_u32(skb, XFRMA_IPTFS_MAX_QSIZE, xc->max_queue_size);
> -	if (ret)
> -		return ret;
> -
> -	q = xtfs->drop_time_ns;
> -	(void)do_div(q, NSECS_IN_USEC);
> -	ret = nla_put_u32(skb, XFRMA_IPTFS_DROP_TIME, q);
> -	if (ret)
> -		return ret;
> -
> -	q = xtfs->init_delay_ns;
> -	(void)do_div(q, NSECS_IN_USEC);
> -	ret = nla_put_u32(skb, XFRMA_IPTFS_INIT_DELAY, q);
>  
>  	return ret;
>  }

looking at this patch, why this should be seperate patch? why not squash 
into [PATCH ipsec-next v4 08/18] xfrm: iptfs: add new iptfs xfrm mode impl

I also think in the v3 it was squashed into some other patch.

-antony

Re: [PATCH ipsec-next v4 05/18] xfrm: netlink: add config (netlink) options

[Antony Antony]

On Mon, Jun 17, 2024 at 04:53:03PM -0400, Christian Hopps via Devel wrote:
> From: Christian Hopps <chopps@labn.net>
> 
> Add netlink options for configuring IP-TFS SAs.
> 
> Signed-off-by: Christian Hopps <chopps@labn.net>
> ---
>  include/uapi/linux/xfrm.h |  9 ++++++-
>  net/xfrm/xfrm_compat.c    | 10 ++++++--
>  net/xfrm/xfrm_user.c      | 52 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 68 insertions(+), 3 deletions(-)
> 
> diff --git a/include/uapi/linux/xfrm.h b/include/uapi/linux/xfrm.h
> index 18ceaba8486e..3bd1f810e079 100644
> --- a/include/uapi/linux/xfrm.h
> +++ b/include/uapi/linux/xfrm.h
> @@ -158,7 +158,8 @@ enum {
>  #define XFRM_MODE_ROUTEOPTIMIZATION 2
>  #define XFRM_MODE_IN_TRIGGER 3
>  #define XFRM_MODE_BEET 4
> -#define XFRM_MODE_MAX 5
> +#define XFRM_MODE_IPTFS 5
> +#define XFRM_MODE_MAX 6
>  
>  /* Netlink configuration messages.  */
>  enum {
> @@ -321,6 +322,12 @@ enum xfrm_attr_type_t {
>  	XFRMA_IF_ID,		/* __u32 */
>  	XFRMA_MTIMER_THRESH,	/* __u32 in seconds for input SA */
>  	XFRMA_SA_DIR,		/* __u8 */
> +	XFRMA_IPTFS_DROP_TIME,	/* __u32 in: usec to wait for next seq */
> +	XFRMA_IPTFS_REORDER_WINDOW, /* __u16 in: reorder window size */
> +	XFRMA_IPTFS_DONT_FRAG,	/* out: don't use fragmentation */
> +	XFRMA_IPTFS_INIT_DELAY,	/* __u32 out: initial packet wait delay (usec) */
> +	XFRMA_IPTFS_MAX_QSIZE,	/* __u32 out: max ingress queue size */

+	XFRMA_IPTFS_MAX_QSIZE,	/* __u32 out: max ingress queue size octets */

Add the units in comments? This would help the users.  The "struct 
xfrm_iptfs_config {" mentions it is octets. Adding it to uapi would help the 
users more. The defaults are not so obvious to find. 

Re: [devel-ipsec] [PATCH ipsec-next v4 17/18] xfrm: iptfs: only send the NL attrs that corr. to the SA dir

[Christian Hopps]

> On Jun 24, 2024, at 11:27, Antony Antony <antony@phenome.org> wrote:
> 
> On Mon, Jun 17, 2024 at 04:53:15PM -0400, Christian Hopps via Devel wrote:
>> From: Christian Hopps <chopps@labn.net>
>> 
>> When sending the netlink attributes to the user for a given SA, only
>> send those NL attributes which correspond to the SA's direction.
>> 
>> Signed-off-by: Christian Hopps <chopps@labn.net>
>> ---
>> net/xfrm/xfrm_iptfs.c | 64 ++++++++++++++++++++++++-------------------
>> 1 file changed, 36 insertions(+), 28 deletions(-)
>> 
>> diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
>> index 59fd8ee49cd4..049a94a5531b 100644
>> --- a/net/xfrm/xfrm_iptfs.c
>> +++ b/net/xfrm/xfrm_iptfs.c
>> @@ -2498,13 +2498,16 @@ static unsigned int iptfs_sa_len(const struct xfrm_state *x)
>> struct xfrm_iptfs_config *xc = &xtfs->cfg;
>> unsigned int l = 0;
>> 
>> - if (xc->dont_frag)
>> - l += nla_total_size(0);
>> - l += nla_total_size(sizeof(xc->reorder_win_size));
>> - l += nla_total_size(sizeof(xc->pkt_size));
>> - l += nla_total_size(sizeof(xc->max_queue_size));
>> - l += nla_total_size(sizeof(u32)); /* drop time usec */
>> - l += nla_total_size(sizeof(u32)); /* init delay usec */
>> + if (x->dir == XFRM_SA_DIR_IN) {
>> + l += nla_total_size(sizeof(u32)); /* drop time usec */
>> + l += nla_total_size(sizeof(xc->reorder_win_size));
>> + } else {
>> + if (xc->dont_frag)
>> + l += nla_total_size(0);   /* dont-frag flag */
>> + l += nla_total_size(sizeof(u32)); /* init delay usec */
>> + l += nla_total_size(sizeof(xc->max_queue_size));
>> + l += nla_total_size(sizeof(xc->pkt_size));
>> + }
>> 
>> return l;
>> }
>> @@ -2516,30 +2519,35 @@ static int iptfs_copy_to_user(struct xfrm_state *x, struct sk_buff *skb)
>> int ret;
>> u64 q;
>> 
>> - if (xc->dont_frag) {
>> - ret = nla_put_flag(skb, XFRMA_IPTFS_DONT_FRAG);
>> + if (x->dir == XFRM_SA_DIR_IN) {
>> + q = xtfs->drop_time_ns;
>> + (void)do_div(q, NSECS_IN_USEC);
>> + ret = nla_put_u32(skb, XFRMA_IPTFS_DROP_TIME, q);
>> + if (ret)
>> + return ret;
>> +
>> + ret = nla_put_u16(skb, XFRMA_IPTFS_REORDER_WINDOW,
>> +   xc->reorder_win_size);
>> + } else {
>> + if (xc->dont_frag) {
>> + ret = nla_put_flag(skb, XFRMA_IPTFS_DONT_FRAG);
>> + if (ret)
>> + return ret;
>> + }
>> +
>> + q = xtfs->init_delay_ns;
>> + (void)do_div(q, NSECS_IN_USEC);
>> + ret = nla_put_u32(skb, XFRMA_IPTFS_INIT_DELAY, q);
>> + if (ret)
>> + return ret;
>> +
>> + ret = nla_put_u32(skb, XFRMA_IPTFS_MAX_QSIZE,
>> +   xc->max_queue_size);
>> if (ret)
>> return ret;
>> +
>> + ret = nla_put_u32(skb, XFRMA_IPTFS_PKT_SIZE, xc->pkt_size);
>> }
>> - ret = nla_put_u16(skb, XFRMA_IPTFS_REORDER_WINDOW, xc->reorder_win_size);
>> - if (ret)
>> - return ret;
>> - ret = nla_put_u32(skb, XFRMA_IPTFS_PKT_SIZE, xc->pkt_size);
>> - if (ret)
>> - return ret;
>> - ret = nla_put_u32(skb, XFRMA_IPTFS_MAX_QSIZE, xc->max_queue_size);
>> - if (ret)
>> - return ret;
>> -
>> - q = xtfs->drop_time_ns;
>> - (void)do_div(q, NSECS_IN_USEC);
>> - ret = nla_put_u32(skb, XFRMA_IPTFS_DROP_TIME, q);
>> - if (ret)
>> - return ret;
>> -
>> - q = xtfs->init_delay_ns;
>> - (void)do_div(q, NSECS_IN_USEC);
>> - ret = nla_put_u32(skb, XFRMA_IPTFS_INIT_DELAY, q);
>> 
>> return ret;
>> }
> 
> looking at this patch, why this should be seperate patch? why not squash 
> into [PATCH ipsec-next v4 08/18] xfrm: iptfs: add new iptfs xfrm mode impl

The various attributes get modified by the layered functionality commits, so it ends up needing to be worked into a bunch of commits. So given it was a simple patch addressing a review comment I thought it would be OK to just leave it a single simple patch. If it's important I will do the work to incorporate the change into the N different commits :)

Thanks,
Chris.

> 
> I also think in the v3 it was squashed into some other patch.
> 
> -antony

Re: [devel-ipsec] [PATCH ipsec-next v4 05/18] xfrm: netlink: add config (netlink) options

[Christian Hopps]

[-- Attachment #1: Type: text/plain, Size: 1863 bytes --]


Antony Antony via Devel <devel@linux-ipsec.org> writes:

> On Mon, Jun 17, 2024 at 04:53:03PM -0400, Christian Hopps via Devel wrote:
>> From: Christian Hopps <chopps@labn.net>
>>
>> Add netlink options for configuring IP-TFS SAs.
>>
>> Signed-off-by: Christian Hopps <chopps@labn.net>
>> ---
>>  include/uapi/linux/xfrm.h |  9 ++++++-
>>  net/xfrm/xfrm_compat.c    | 10 ++++++--
>>  net/xfrm/xfrm_user.c      | 52 +++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 68 insertions(+), 3 deletions(-)
>>
>> diff --git a/include/uapi/linux/xfrm.h b/include/uapi/linux/xfrm.h
>> index 18ceaba8486e..3bd1f810e079 100644
>> --- a/include/uapi/linux/xfrm.h
>> +++ b/include/uapi/linux/xfrm.h
>> @@ -158,7 +158,8 @@ enum {
>>  #define XFRM_MODE_ROUTEOPTIMIZATION 2
>>  #define XFRM_MODE_IN_TRIGGER 3
>>  #define XFRM_MODE_BEET 4
>> -#define XFRM_MODE_MAX 5
>> +#define XFRM_MODE_IPTFS 5
>> +#define XFRM_MODE_MAX 6
>>
>>  /* Netlink configuration messages.  */
>>  enum {
>> @@ -321,6 +322,12 @@ enum xfrm_attr_type_t {
>>  	XFRMA_IF_ID,		/* __u32 */
>>  	XFRMA_MTIMER_THRESH,	/* __u32 in seconds for input SA */
>>  	XFRMA_SA_DIR,		/* __u8 */
>> +	XFRMA_IPTFS_DROP_TIME,	/* __u32 in: usec to wait for next seq */
>> +	XFRMA_IPTFS_REORDER_WINDOW, /* __u16 in: reorder window size */
>> +	XFRMA_IPTFS_DONT_FRAG,	/* out: don't use fragmentation */
>> +	XFRMA_IPTFS_INIT_DELAY,	/* __u32 out: initial packet wait delay (usec) */
>> +	XFRMA_IPTFS_MAX_QSIZE,	/* __u32 out: max ingress queue size */
>
> +	XFRMA_IPTFS_MAX_QSIZE,	/* __u32 out: max ingress queue size octets */
>
> Add the units in comments? This would help the users.  The "struct
> xfrm_iptfs_config {" mentions it is octets. Adding it to uapi would help the
> users more. The defaults are not so obvious to find.

Will add "octets" to comment (and "pkts" to reorder window comment).

Thanks,
Chris.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 857 bytes --]

Re: [PATCH ipsec-next v4 08/18] xfrm: iptfs: add new iptfs xfrm mode impl

[Christian Hopps]

[-- Attachment #1: Type: text/plain, Size: 1804 bytes --]


Jeff Johnson <quic_jjohnson@quicinc.com> writes:

> On 6/17/24 13:53, Christian Hopps wrote:
>> From: Christian Hopps <chopps@labn.net>
>> Add a new xfrm mode implementing AggFrag/IP-TFS from RFC9347.
>> This utilizes the new xfrm_mode_cbs to implement demand-driven IP-TFS
>> functionality. This functionality can be used to increase bandwidth
>> utilization through small packet aggregation, as well as help solve PMTU
>> issues through it's efficient use of fragmentation.
>>    Link: https://www.rfc-editor.org/rfc/rfc9347.txt
>> Multiple commits follow to build the functionality into xfrm_iptfs.c
>> Signed-off-by: Christian Hopps <chopps@labn.net>
>> ---
>>   net/xfrm/Makefile     |   1 +
>>   net/xfrm/xfrm_iptfs.c | 225 ++++++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 226 insertions(+)
>>   create mode 100644 net/xfrm/xfrm_iptfs.c
>> diff --git a/net/xfrm/Makefile b/net/xfrm/Makefile
>> index 547cec77ba03..cd6520d4d777 100644
>> --- a/net/xfrm/Makefile
>> +++ b/net/xfrm/Makefile
>> @@ -20,5 +20,6 @@ obj-$(CONFIG_XFRM_USER) += xfrm_user.o
>>   obj-$(CONFIG_XFRM_USER_COMPAT) += xfrm_compat.o
>>   obj-$(CONFIG_XFRM_IPCOMP) += xfrm_ipcomp.o
>>   obj-$(CONFIG_XFRM_INTERFACE) += xfrm_interface.o
>> +obj-$(CONFIG_XFRM_IPTFS) += xfrm_iptfs.o
>>   obj-$(CONFIG_XFRM_ESPINTCP) += espintcp.o
>>   obj-$(CONFIG_DEBUG_INFO_BTF) += xfrm_state_bpf.o
>> diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
>> new file mode 100644
>> index 000000000000..e7b5546e1f6a
>> --- /dev/null
>> +++ b/net/xfrm/xfrm_iptfs.c
>> @@ -0,0 +1,225 @@
>> +// SPDX-License-Identifier: GPL-2.0
> ...
>
>> +module_init(xfrm_iptfs_init);
>> +module_exit(xfrm_iptfs_fini);
>> +MODULE_LICENSE("GPL");
>
> missing MODULE_DESCRIPTION() which will cause a warning with make W=1

Added.

Thanks,
Chris.

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