* [PATCH bpf-next v7 1/6] bpf: add plumbing for BPF_LWT_ENCAP_IP in bpf_lwt_push_encap
2019-02-07 0:37 [PATCH bpf-next v7 0/6] bpf: add BPF_LWT_ENCAP_IP option to bpf_lwt_push_encap Peter Oskolkov
@ 2019-02-07 0:37 ` Peter Oskolkov
2019-02-07 14:20 ` Jesper Dangaard Brouer
2019-02-07 0:37 ` [PATCH bpf-next v7 2/6] bpf: implement BPF_LWT_ENCAP_IP mode " Peter Oskolkov
` (4 subsequent siblings)
5 siblings, 1 reply; 12+ messages in thread
From: Peter Oskolkov @ 2019-02-07 0:37 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, netdev
Cc: Peter Oskolkov, David Ahern, Willem de Bruijn, Peter Oskolkov
This patch adds all needed plumbing in preparation to allowing
bpf programs to do IP encapping via bpf_lwt_push_encap. Actual
implementation is added in the next patch in the patchset.
Of note:
- bpf_lwt_push_encap can now be called from BPF_PROG_TYPE_LWT_XMIT
prog types in addition to BPF_PROG_TYPE_LWT_IN;
- if the skb being encapped has GSO set, encapsulation is limited
to IPIP/IP+GRE/IP+GUE (both IPv4 and IPv6);
- as route lookups are different for ingress vs egress, the single
external bpf_lwt_push_encap BPF helper is routed internally to
either bpf_lwt_in_push_encap or bpf_lwt_xmit_push_encap BPF_CALLs,
depending on prog type.
Signed-off-by: Peter Oskolkov <posk@google.com>
---
include/uapi/linux/bpf.h | 26 +++++++++++++++++++++--
net/core/filter.c | 46 +++++++++++++++++++++++++++++++++++-----
2 files changed, 65 insertions(+), 7 deletions(-)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 1777fa0c61e4..138089ff24cf 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2016,6 +2016,19 @@ union bpf_attr {
* Only works if *skb* contains an IPv6 packet. Insert a
* Segment Routing Header (**struct ipv6_sr_hdr**) inside
* the IPv6 header.
+ * **BPF_LWT_ENCAP_IP**
+ * IP encapsulation (GRE/GUE/IPIP/etc). The outer header
+ * must be IPv4 or IPv6, followed by zero or more
+ * additional headers, up to LWT_BPF_MAX_HEADROOM total
+ * bytes in all prepended headers. PLease note that
+ * if skb_is_gso(skb) is true, no more than two headers
+ * can be prepended, and the inner header, if present,
+ * should be either GRE or UDP/GUE.
+ *
+ * BPF_LWT_ENCAP_SEG6*** types can be called by bpf programs of
+ * type BPF_PROG_TYPE_LWT_IN; BPF_LWT_ENCAP_IP type can be called
+ * by bpf programs of types BPF_PROG_TYPE_LWT_IN and
+ * BPF_PROG_TYPE_LWT_XMIT.
*
* A call to this helper is susceptible to change the underlaying
* packet buffer. Therefore, at load time, all checks on pointers
@@ -2498,7 +2511,8 @@ enum bpf_hdr_start_off {
/* Encapsulation type for BPF_FUNC_lwt_push_encap helper. */
enum bpf_lwt_encap_mode {
BPF_LWT_ENCAP_SEG6,
- BPF_LWT_ENCAP_SEG6_INLINE
+ BPF_LWT_ENCAP_SEG6_INLINE,
+ BPF_LWT_ENCAP_IP,
};
#define __bpf_md_ptr(type, name) \
@@ -2586,7 +2600,15 @@ enum bpf_ret_code {
BPF_DROP = 2,
/* 3-6 reserved */
BPF_REDIRECT = 7,
- /* >127 are reserved for prog type specific return codes */
+ /* >127 are reserved for prog type specific return codes.
+ *
+ * BPF_LWT_REROUTE: used by BPF_PROG_TYPE_LWT_IN and
+ * BPF_PROG_TYPE_LWT_XMIT to indicate that skb had been
+ * changed and should be routed based on its new L3 header.
+ * (This is an L3 redirect, as opposed to L2 redirect
+ * represented by BPF_REDIRECT above).
+ */
+ BPF_LWT_REROUTE = 128,
};
struct bpf_sock {
diff --git a/net/core/filter.c b/net/core/filter.c
index 3a49f68eda10..8884120fe458 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4801,7 +4801,13 @@ static int bpf_push_seg6_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len
}
#endif /* CONFIG_IPV6_SEG6_BPF */
-BPF_CALL_4(bpf_lwt_push_encap, struct sk_buff *, skb, u32, type, void *, hdr,
+static int bpf_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len,
+ bool ingress)
+{
+ return -EINVAL; /* Implemented in the next patch. */
+}
+
+BPF_CALL_4(bpf_lwt_in_push_encap, struct sk_buff *, skb, u32, type, void *, hdr,
u32, len)
{
switch (type) {
@@ -4809,14 +4815,41 @@ BPF_CALL_4(bpf_lwt_push_encap, struct sk_buff *, skb, u32, type, void *, hdr,
case BPF_LWT_ENCAP_SEG6:
case BPF_LWT_ENCAP_SEG6_INLINE:
return bpf_push_seg6_encap(skb, type, hdr, len);
+#endif
+#if IS_ENABLED(CONFIG_LWTUNNEL_BPF)
+ case BPF_LWT_ENCAP_IP:
+ return bpf_push_ip_encap(skb, hdr, len, true /* ingress */);
#endif
default:
return -EINVAL;
}
}
-static const struct bpf_func_proto bpf_lwt_push_encap_proto = {
- .func = bpf_lwt_push_encap,
+BPF_CALL_4(bpf_lwt_xmit_push_encap, struct sk_buff *, skb, u32, type,
+ void *, hdr, u32, len)
+{
+ switch (type) {
+#if IS_ENABLED(CONFIG_LWTUNNEL_BPF)
+ case BPF_LWT_ENCAP_IP:
+ return bpf_push_ip_encap(skb, hdr, len, false /* egress */);
+#endif
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct bpf_func_proto bpf_lwt_in_push_encap_proto = {
+ .func = bpf_lwt_in_push_encap,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_ANYTHING,
+ .arg3_type = ARG_PTR_TO_MEM,
+ .arg4_type = ARG_CONST_SIZE
+};
+
+static const struct bpf_func_proto bpf_lwt_xmit_push_encap_proto = {
+ .func = bpf_lwt_xmit_push_encap,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
@@ -5282,7 +5315,8 @@ bool bpf_helper_changes_pkt_data(void *func)
func == bpf_lwt_seg6_adjust_srh ||
func == bpf_lwt_seg6_action ||
#endif
- func == bpf_lwt_push_encap)
+ func == bpf_lwt_in_push_encap ||
+ func == bpf_lwt_xmit_push_encap)
return true;
return false;
@@ -5670,7 +5704,7 @@ lwt_in_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
switch (func_id) {
case BPF_FUNC_lwt_push_encap:
- return &bpf_lwt_push_encap_proto;
+ return &bpf_lwt_in_push_encap_proto;
default:
return lwt_out_func_proto(func_id, prog);
}
@@ -5706,6 +5740,8 @@ lwt_xmit_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_l4_csum_replace_proto;
case BPF_FUNC_set_hash_invalid:
return &bpf_set_hash_invalid_proto;
+ case BPF_FUNC_lwt_push_encap:
+ return &bpf_lwt_xmit_push_encap_proto;
default:
return lwt_out_func_proto(func_id, prog);
}
--
2.20.1.611.gfbb209baf1-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [PATCH bpf-next v7 1/6] bpf: add plumbing for BPF_LWT_ENCAP_IP in bpf_lwt_push_encap
2019-02-07 0:37 ` [PATCH bpf-next v7 1/6] bpf: add plumbing for BPF_LWT_ENCAP_IP in bpf_lwt_push_encap Peter Oskolkov
@ 2019-02-07 14:20 ` Jesper Dangaard Brouer
0 siblings, 0 replies; 12+ messages in thread
From: Jesper Dangaard Brouer @ 2019-02-07 14:20 UTC (permalink / raw)
To: Peter Oskolkov
Cc: brouer, Alexei Starovoitov, Daniel Borkmann, netdev,
Peter Oskolkov, David Ahern, Willem de Bruijn
On Wed, 6 Feb 2019 16:37:15 -0800
Peter Oskolkov <posk@google.com> wrote:
> This patch adds all needed plumbing in preparation to allowing
> bpf programs to do IP encapping via bpf_lwt_push_encap. Actual
> implementation is added in the next patch in the patchset.
>
> Of note:
> - bpf_lwt_push_encap can now be called from BPF_PROG_TYPE_LWT_XMIT
> prog types in addition to BPF_PROG_TYPE_LWT_IN;
> - if the skb being encapped has GSO set, encapsulation is limited
> to IPIP/IP+GRE/IP+GUE (both IPv4 and IPv6);
> - as route lookups are different for ingress vs egress, the single
> external bpf_lwt_push_encap BPF helper is routed internally to
> either bpf_lwt_in_push_encap or bpf_lwt_xmit_push_encap BPF_CALLs,
> depending on prog type.
>
> Signed-off-by: Peter Oskolkov <posk@google.com>
> ---
> include/uapi/linux/bpf.h | 26 +++++++++++++++++++++--
> net/core/filter.c | 46 +++++++++++++++++++++++++++++++++++-----
> 2 files changed, 65 insertions(+), 7 deletions(-)
>
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 1777fa0c61e4..138089ff24cf 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -2016,6 +2016,19 @@ union bpf_attr {
> * Only works if *skb* contains an IPv6 packet. Insert a
> * Segment Routing Header (**struct ipv6_sr_hdr**) inside
> * the IPv6 header.
> + * **BPF_LWT_ENCAP_IP**
> + * IP encapsulation (GRE/GUE/IPIP/etc). The outer header
> + * must be IPv4 or IPv6, followed by zero or more
> + * additional headers, up to LWT_BPF_MAX_HEADROOM total
> + * bytes in all prepended headers. PLease note that
^^
Trivial typo PLease
> + * if skb_is_gso(skb) is true, no more than two headers
> + * can be prepended, and the inner header, if present,
> + * should be either GRE or UDP/GUE.
> +
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH bpf-next v7 2/6] bpf: implement BPF_LWT_ENCAP_IP mode in bpf_lwt_push_encap
2019-02-07 0:37 [PATCH bpf-next v7 0/6] bpf: add BPF_LWT_ENCAP_IP option to bpf_lwt_push_encap Peter Oskolkov
2019-02-07 0:37 ` [PATCH bpf-next v7 1/6] bpf: add plumbing for BPF_LWT_ENCAP_IP in bpf_lwt_push_encap Peter Oskolkov
@ 2019-02-07 0:37 ` Peter Oskolkov
2019-02-07 13:43 ` kbuild test robot
2019-02-07 14:04 ` kbuild test robot
2019-02-07 0:37 ` [PATCH bpf-next v7 3/6] bpf: handle GSO " Peter Oskolkov
` (3 subsequent siblings)
5 siblings, 2 replies; 12+ messages in thread
From: Peter Oskolkov @ 2019-02-07 0:37 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, netdev
Cc: Peter Oskolkov, David Ahern, Willem de Bruijn, Peter Oskolkov
This patch implements BPF_LWT_ENCAP_IP mode in bpf_lwt_push_encap
BPF helper. It enables BPF programs (specifically, BPF_PROG_TYPE_LWT_IN
and BPF_PROG_TYPE_LWT_XMIT prog types) to add IP encapsulation headers
to packets (e.g. IP/GRE, GUE, IPIP).
This is useful when thousands of different short-lived flows should be
encapped, each with different and dynamically determined destination.
Although lwtunnels can be used in some of these scenarios, the ability
to dynamically generate encap headers adds more flexibility, e.g.
when routing depends on the state of the host (reflected in global bpf
maps).
v7 changes:
- added a call skb_clear_hash();
- removed calls to skb_set_transport_header();
- refuse to encap GSO-enabled packets.
Note: the next patch in the patchset with deal with GSO-enabled packets,
which are currently rejected at encapping attempt.
Signed-off-by: Peter Oskolkov <posk@google.com>
---
include/net/lwtunnel.h | 3 ++
net/core/filter.c | 3 +-
net/core/lwt_bpf.c | 65 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 70 insertions(+), 1 deletion(-)
diff --git a/include/net/lwtunnel.h b/include/net/lwtunnel.h
index 33fd9ba7e0e5..f0973eca8036 100644
--- a/include/net/lwtunnel.h
+++ b/include/net/lwtunnel.h
@@ -126,6 +126,8 @@ int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b);
int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb);
int lwtunnel_input(struct sk_buff *skb);
int lwtunnel_xmit(struct sk_buff *skb);
+int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len,
+ bool ingress);
static inline void lwtunnel_set_redirect(struct dst_entry *dst)
{
@@ -138,6 +140,7 @@ static inline void lwtunnel_set_redirect(struct dst_entry *dst)
dst->input = lwtunnel_input;
}
}
+
#else
static inline void lwtstate_free(struct lwtunnel_state *lws)
diff --git a/net/core/filter.c b/net/core/filter.c
index 8884120fe458..7b7e7c9125e2 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -73,6 +73,7 @@
#include <linux/seg6_local.h>
#include <net/seg6.h>
#include <net/seg6_local.h>
+#include <net/lwtunnel.h>
/**
* sk_filter_trim_cap - run a packet through a socket filter
@@ -4804,7 +4805,7 @@ static int bpf_push_seg6_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len
static int bpf_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len,
bool ingress)
{
- return -EINVAL; /* Implemented in the next patch. */
+ return bpf_lwt_push_ip_encap(skb, hdr, len, ingress);
}
BPF_CALL_4(bpf_lwt_in_push_encap, struct sk_buff *, skb, u32, type, void *, hdr,
diff --git a/net/core/lwt_bpf.c b/net/core/lwt_bpf.c
index a648568c5e8f..786b96148937 100644
--- a/net/core/lwt_bpf.c
+++ b/net/core/lwt_bpf.c
@@ -390,6 +390,71 @@ static const struct lwtunnel_encap_ops bpf_encap_ops = {
.owner = THIS_MODULE,
};
+static int handle_gso_encap(struct sk_buff *skb, bool ipv4, int encap_len)
+{
+ /* Handling of GSO-enabled packets is added in the next patch. */
+ if (unlikely(skb_is_gso(skb)))
+ return -EINVAL;
+
+ return 0;
+}
+
+int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, bool ingress)
+{
+ struct iphdr *iph;
+ bool ipv4;
+ int err;
+
+ if (unlikely(len < sizeof(struct iphdr) || len > LWT_BPF_MAX_HEADROOM))
+ return -EINVAL;
+
+ /* validate protocol and length */
+ iph = (struct iphdr *)hdr;
+ if (iph->version == 4) {
+ ipv4 = true;
+ if (unlikely(len < iph->ihl * 4))
+ return -EINVAL;
+ } else if (iph->version == 6) {
+ ipv4 = false;
+ if (unlikely(len < sizeof(struct ipv6hdr)))
+ return -EINVAL;
+ } else {
+ return -EINVAL;
+ }
+
+ if (ingress)
+ err = skb_cow_head(skb, len + skb->mac_len);
+ else
+ err = skb_cow_head(skb,
+ len + LL_RESERVED_SPACE(skb_dst(skb)->dev));
+ if (unlikely(err))
+ return err;
+
+ /* push the encap headers and fix pointers */
+ skb_reset_inner_headers(skb);
+ skb->encapsulation = 1;
+ skb_push(skb, len);
+ if (ingress)
+ skb_postpush_rcsum(skb, iph, len);
+ skb_reset_network_header(skb);
+ memcpy(skb_network_header(skb), hdr, len);
+ bpf_compute_data_pointers(skb);
+ skb_clear_hash(skb);
+
+ if (ipv4) {
+ skb->protocol = htons(ETH_P_IP);
+ iph = ip_hdr(skb);
+
+ if (!iph->check)
+ iph->check = ip_fast_csum((unsigned char *)iph,
+ iph->ihl);
+ } else {
+ skb->protocol = htons(ETH_P_IPV6);
+ }
+
+ return handle_gso_encap(skb, ipv4, len);
+}
+
static int __init bpf_lwt_init(void)
{
return lwtunnel_encap_add_ops(&bpf_encap_ops, LWTUNNEL_ENCAP_BPF);
--
2.20.1.611.gfbb209baf1-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [PATCH bpf-next v7 2/6] bpf: implement BPF_LWT_ENCAP_IP mode in bpf_lwt_push_encap
2019-02-07 0:37 ` [PATCH bpf-next v7 2/6] bpf: implement BPF_LWT_ENCAP_IP mode " Peter Oskolkov
@ 2019-02-07 13:43 ` kbuild test robot
2019-02-07 14:04 ` kbuild test robot
1 sibling, 0 replies; 12+ messages in thread
From: kbuild test robot @ 2019-02-07 13:43 UTC (permalink / raw)
To: Peter Oskolkov
Cc: kbuild-all, Alexei Starovoitov, Daniel Borkmann, netdev,
Peter Oskolkov, David Ahern, Willem de Bruijn, Peter Oskolkov
[-- Attachment #1: Type: text/plain, Size: 1514 bytes --]
Hi Peter,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on bpf-next/master]
url: https://github.com/0day-ci/linux/commits/Peter-Oskolkov/bpf-add-BPF_LWT_ENCAP_IP-option-to-bpf_lwt_push_encap/20190207-205725
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: i386-randconfig-l1-02071408 (attached as .config)
compiler: gcc-5 (Debian 5.5.0-3) 5.4.1 20171010
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All errors (new ones prefixed by >>):
net//core/filter.c: In function 'bpf_push_ip_encap':
>> net//core/filter.c:4808:9: error: implicit declaration of function 'bpf_lwt_push_ip_encap' [-Werror=implicit-function-declaration]
return bpf_lwt_push_ip_encap(skb, hdr, len, ingress);
^
net//core/filter.c: At top level:
net//core/filter.c:4805:12: warning: 'bpf_push_ip_encap' defined but not used [-Wunused-function]
static int bpf_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len,
^
cc1: some warnings being treated as errors
vim +/bpf_lwt_push_ip_encap +4808 net//core/filter.c
4804
4805 static int bpf_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len,
4806 bool ingress)
4807 {
> 4808 return bpf_lwt_push_ip_encap(skb, hdr, len, ingress);
4809 }
4810
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 28818 bytes --]
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH bpf-next v7 2/6] bpf: implement BPF_LWT_ENCAP_IP mode in bpf_lwt_push_encap
2019-02-07 0:37 ` [PATCH bpf-next v7 2/6] bpf: implement BPF_LWT_ENCAP_IP mode " Peter Oskolkov
2019-02-07 13:43 ` kbuild test robot
@ 2019-02-07 14:04 ` kbuild test robot
1 sibling, 0 replies; 12+ messages in thread
From: kbuild test robot @ 2019-02-07 14:04 UTC (permalink / raw)
To: Peter Oskolkov
Cc: kbuild-all, Alexei Starovoitov, Daniel Borkmann, netdev,
Peter Oskolkov, David Ahern, Willem de Bruijn, Peter Oskolkov
[-- Attachment #1: Type: text/plain, Size: 1550 bytes --]
Hi Peter,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on bpf-next/master]
url: https://github.com/0day-ci/linux/commits/Peter-Oskolkov/bpf-add-BPF_LWT_ENCAP_IP-option-to-bpf_lwt_push_encap/20190207-205725
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: i386-defconfig (attached as .config)
compiler: gcc-8 (Debian 8.2.0-14) 8.2.0
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All errors (new ones prefixed by >>):
net//core/filter.c: In function 'bpf_push_ip_encap':
>> net//core/filter.c:4808:9: error: implicit declaration of function 'bpf_lwt_push_ip_encap'; did you mean 'bpf_push_ip_encap'? [-Werror=implicit-function-declaration]
return bpf_lwt_push_ip_encap(skb, hdr, len, ingress);
^~~~~~~~~~~~~~~~~~~~~
bpf_push_ip_encap
At top level:
net//core/filter.c:4805:12: warning: 'bpf_push_ip_encap' defined but not used [-Wunused-function]
static int bpf_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len,
^~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
vim +4808 net//core/filter.c
4804
4805 static int bpf_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len,
4806 bool ingress)
4807 {
> 4808 return bpf_lwt_push_ip_encap(skb, hdr, len, ingress);
4809 }
4810
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 26942 bytes --]
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH bpf-next v7 3/6] bpf: handle GSO in bpf_lwt_push_encap
2019-02-07 0:37 [PATCH bpf-next v7 0/6] bpf: add BPF_LWT_ENCAP_IP option to bpf_lwt_push_encap Peter Oskolkov
2019-02-07 0:37 ` [PATCH bpf-next v7 1/6] bpf: add plumbing for BPF_LWT_ENCAP_IP in bpf_lwt_push_encap Peter Oskolkov
2019-02-07 0:37 ` [PATCH bpf-next v7 2/6] bpf: implement BPF_LWT_ENCAP_IP mode " Peter Oskolkov
@ 2019-02-07 0:37 ` Peter Oskolkov
2019-02-07 17:57 ` Willem de Bruijn
2019-02-07 0:37 ` [PATCH bpf-next v7 4/6] bpf: add handling of BPF_LWT_REROUTE to lwt_bpf.c Peter Oskolkov
` (2 subsequent siblings)
5 siblings, 1 reply; 12+ messages in thread
From: Peter Oskolkov @ 2019-02-07 0:37 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, netdev
Cc: Peter Oskolkov, David Ahern, Willem de Bruijn, Peter Oskolkov
This patch adds handling of GSO packets in bpf_lwt_push_ip_encap()
(called from bpf_lwt_push_encap):
* IPIP, GRE, and UDP encapsulation types are deduced by looking
into iphdr->protocol or ipv6hdr->next_header;
* an error is returned if the same GSO encap type is set on the skb;
* SCTP GSO packets are not supported (as bpf_skb_proto_4_to_6
and similar do);
* UDP_L4 GSO packets are also not supported (although they are
not blocked in bpf_skb_proto_4_to_6 and similar), as
skb_decrease_gso_size() will break it;
* SKB_GSO_DODGY bit is set.
Note: it may be possible to support SCTP and UDP_L4 gso packets;
but as these cases seem to be not well handled by other
tunneling/encapping code paths, the solution should
be generic enough to apply to all tunneling/encapping code.
Signed-off-by: Peter Oskolkov <posk@google.com>
---
net/core/lwt_bpf.c | 62 +++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 59 insertions(+), 3 deletions(-)
diff --git a/net/core/lwt_bpf.c b/net/core/lwt_bpf.c
index 786b96148937..4ff60757bf23 100644
--- a/net/core/lwt_bpf.c
+++ b/net/core/lwt_bpf.c
@@ -16,6 +16,7 @@
#include <linux/types.h>
#include <linux/bpf.h>
#include <net/lwtunnel.h>
+#include <net/gre.h>
struct bpf_lwt_prog {
struct bpf_prog *prog;
@@ -390,15 +391,70 @@ static const struct lwtunnel_encap_ops bpf_encap_ops = {
.owner = THIS_MODULE,
};
-static int handle_gso_encap(struct sk_buff *skb, bool ipv4, int encap_len)
+static int handle_gso_type(struct sk_buff *skb, unsigned int gso_type,
+ int encap_len)
{
- /* Handling of GSO-enabled packets is added in the next patch. */
- if (unlikely(skb_is_gso(skb)))
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+
+ /* Refuse to double-encap with the same type. */
+ if (shinfo->gso_type & gso_type)
return -EINVAL;
+ gso_type |= SKB_GSO_DODGY;
+ shinfo->gso_type |= gso_type;
+ skb_decrease_gso_size(shinfo, encap_len);
+ shinfo->gso_segs = 0;
return 0;
}
+static int handle_gso_encap(struct sk_buff *skb, bool ipv4, int encap_len)
+{
+ void *next_hdr;
+ __u8 protocol;
+
+ if (!skb_is_gso(skb))
+ return 0;
+
+ /* SCTP and UDP_L4 gso need more nuanced handling than what
+ * handle_gso_type() does above: skb_decrease_gso_size() is not enough.
+ */
+ if (unlikely(skb_shinfo(skb)->gso_type &
+ (SKB_GSO_SCTP | SKB_GSO_UDP_L4)))
+ return -ENOTSUPP;
+
+ if (ipv4) {
+ protocol = ip_hdr(skb)->protocol;
+ next_hdr = skb_network_header(skb) + sizeof(struct iphdr);
+ } else {
+ protocol = ipv6_hdr(skb)->nexthdr;
+ next_hdr = skb_network_header(skb) + sizeof(struct ipv6hdr);
+ }
+
+ switch (protocol) {
+ case IPPROTO_GRE:
+ if (((struct gre_base_hdr *)next_hdr)->flags & GRE_CSUM)
+ return handle_gso_type(skb, SKB_GSO_GRE_CSUM,
+ encap_len);
+ return handle_gso_type(skb, SKB_GSO_GRE, encap_len);
+
+ case IPPROTO_UDP:
+ if (((struct udphdr *)next_hdr)->check)
+ return handle_gso_type(skb, SKB_GSO_UDP_TUNNEL_CSUM,
+ encap_len);
+ return handle_gso_type(skb, SKB_GSO_UDP_TUNNEL, encap_len);
+
+ case IPPROTO_IP:
+ case IPPROTO_IPV6:
+ if (ipv4)
+ return handle_gso_type(skb, SKB_GSO_IPXIP4, encap_len);
+ else
+ return handle_gso_type(skb, SKB_GSO_IPXIP6, encap_len);
+
+ default:
+ return -EPROTONOSUPPORT;
+ }
+}
+
int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, bool ingress)
{
struct iphdr *iph;
--
2.20.1.611.gfbb209baf1-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [PATCH bpf-next v7 3/6] bpf: handle GSO in bpf_lwt_push_encap
2019-02-07 0:37 ` [PATCH bpf-next v7 3/6] bpf: handle GSO " Peter Oskolkov
@ 2019-02-07 17:57 ` Willem de Bruijn
0 siblings, 0 replies; 12+ messages in thread
From: Willem de Bruijn @ 2019-02-07 17:57 UTC (permalink / raw)
To: Peter Oskolkov
Cc: Alexei Starovoitov, Daniel Borkmann, Network Development,
Peter Oskolkov, David Ahern, Willem de Bruijn
On Wed, Feb 6, 2019 at 7:39 PM Peter Oskolkov <posk@google.com> wrote:
>
> This patch adds handling of GSO packets in bpf_lwt_push_ip_encap()
> (called from bpf_lwt_push_encap):
>
> * IPIP, GRE, and UDP encapsulation types are deduced by looking
> into iphdr->protocol or ipv6hdr->next_header;
> * an error is returned if the same GSO encap type is set on the skb;
> * SCTP GSO packets are not supported (as bpf_skb_proto_4_to_6
> and similar do);
> * UDP_L4 GSO packets are also not supported (although they are
> not blocked in bpf_skb_proto_4_to_6 and similar), as
> skb_decrease_gso_size() will break it;
Yes, I was not aware of this gso_size resizing when adding udp gso.
Good catch. Will send a separate patch. That's unrelated to this
patchset.
> * SKB_GSO_DODGY bit is set.
>
> Note: it may be possible to support SCTP and UDP_L4 gso packets;
> but as these cases seem to be not well handled by other
> tunneling/encapping code paths, the solution should
> be generic enough to apply to all tunneling/encapping code.
>
> Signed-off-by: Peter Oskolkov <posk@google.com>
> ---
> net/core/lwt_bpf.c | 62 +++++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 59 insertions(+), 3 deletions(-)
>
> diff --git a/net/core/lwt_bpf.c b/net/core/lwt_bpf.c
> index 786b96148937..4ff60757bf23 100644
> --- a/net/core/lwt_bpf.c
> +++ b/net/core/lwt_bpf.c
> @@ -16,6 +16,7 @@
> #include <linux/types.h>
> #include <linux/bpf.h>
> #include <net/lwtunnel.h>
> +#include <net/gre.h>
>
> struct bpf_lwt_prog {
> struct bpf_prog *prog;
> @@ -390,15 +391,70 @@ static const struct lwtunnel_encap_ops bpf_encap_ops = {
> .owner = THIS_MODULE,
> };
>
> -static int handle_gso_encap(struct sk_buff *skb, bool ipv4, int encap_len)
> +static int handle_gso_type(struct sk_buff *skb, unsigned int gso_type,
> + int encap_len)
> {
> - /* Handling of GSO-enabled packets is added in the next patch. */
> - if (unlikely(skb_is_gso(skb)))
Passing all packets to a function called with gso in the name and then
filtering out non-gso in there is a bit confusing. It is customary to
only have gso packets traverse functions names gso. Please move this
test (in patch 2) into the main encap function and only call this
function for gso packets.
> + struct skb_shared_info *shinfo = skb_shinfo(skb);
> +
> + /* Refuse to double-encap with the same type. */
> + if (shinfo->gso_type & gso_type)
> return -EINVAL;
Why is double encap allowed with different protocols, but not the
same? That seems arbitrary.
The current interface does not set an upper bound on the encap, so a
single program could also double encap directly.
As of commit 121d57af308d ("gso: validate gso_type in GSO handlers")
at least the GSO stack is robust against packets with mismatching
gso_types, so it is safe to accept types given by untrusted sources
like PF_PACKET or a BPF program, even if they prove wrong or (with
double encap) incomplete. The packet will just get dropped.
>
> + gso_type |= SKB_GSO_DODGY;
> + shinfo->gso_type |= gso_type;
> + skb_decrease_gso_size(shinfo, encap_len);
> + shinfo->gso_segs = 0;
> return 0;
> }
>
> +static int handle_gso_encap(struct sk_buff *skb, bool ipv4, int encap_len)
> +{
> + void *next_hdr;
> + __u8 protocol;
> +
> + if (!skb_is_gso(skb))
> + return 0;
> +
> + /* SCTP and UDP_L4 gso need more nuanced handling than what
> + * handle_gso_type() does above: skb_decrease_gso_size() is not enough.
> + */
> + if (unlikely(skb_shinfo(skb)->gso_type &
> + (SKB_GSO_SCTP | SKB_GSO_UDP_L4)))
> + return -ENOTSUPP;
> +
> + if (ipv4) {
> + protocol = ip_hdr(skb)->protocol;
> + next_hdr = skb_network_header(skb) + sizeof(struct iphdr);
> + } else {
> + protocol = ipv6_hdr(skb)->nexthdr;
> + next_hdr = skb_network_header(skb) + sizeof(struct ipv6hdr);
> + }
> +
> + switch (protocol) {
> + case IPPROTO_GRE:
> + if (((struct gre_base_hdr *)next_hdr)->flags & GRE_CSUM)
> + return handle_gso_type(skb, SKB_GSO_GRE_CSUM,
> + encap_len);
> + return handle_gso_type(skb, SKB_GSO_GRE, encap_len);
> +
> + case IPPROTO_UDP:
> + if (((struct udphdr *)next_hdr)->check)
These tests may read beyond the end of the packet. The only guarantee
is that encap_len >= sizeof(struct iphdr). Not that there is an actual
fully formed follow on header.
If this is called from LWT_XMIT, there is the assurance that the inner
packet is at least sizeof(struct iphdr) as well. But that is still not
sufficient to unconditionally peek inside the packet.
We probably need the usual precaution wrt pskb_may_pull.
> + return handle_gso_type(skb, SKB_GSO_UDP_TUNNEL_CSUM,
> + encap_len);
> + return handle_gso_type(skb, SKB_GSO_UDP_TUNNEL, encap_len);
> +
> + case IPPROTO_IP:
> + case IPPROTO_IPV6:
> + if (ipv4)
> + return handle_gso_type(skb, SKB_GSO_IPXIP4, encap_len);
> + else
> + return handle_gso_type(skb, SKB_GSO_IPXIP6, encap_len);
> +
> + default:
> + return -EPROTONOSUPPORT;
> + }
> +}
> +
> int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, bool ingress)
> {
> struct iphdr *iph;
> --
> 2.20.1.611.gfbb209baf1-goog
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH bpf-next v7 4/6] bpf: add handling of BPF_LWT_REROUTE to lwt_bpf.c
2019-02-07 0:37 [PATCH bpf-next v7 0/6] bpf: add BPF_LWT_ENCAP_IP option to bpf_lwt_push_encap Peter Oskolkov
` (2 preceding siblings ...)
2019-02-07 0:37 ` [PATCH bpf-next v7 3/6] bpf: handle GSO " Peter Oskolkov
@ 2019-02-07 0:37 ` Peter Oskolkov
2019-02-07 14:40 ` kbuild test robot
2019-02-07 0:37 ` [PATCH bpf-next v7 5/6] bpf: sync <kdir>/include/.../bpf.h with tools/include/.../bpf.h Peter Oskolkov
2019-02-07 0:37 ` [PATCH bpf-next v7 6/6] selftests: bpf: add test_lwt_ip_encap selftest Peter Oskolkov
5 siblings, 1 reply; 12+ messages in thread
From: Peter Oskolkov @ 2019-02-07 0:37 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, netdev
Cc: Peter Oskolkov, David Ahern, Willem de Bruijn, Peter Oskolkov
This patch builds on top of the previous patch in the patchset,
which added BPF_LWT_ENCAP_IP mode to bpf_lwt_push_encap. As the
encapping can result in the skb needing to go via a different
interface/route/dst, bpf programs can indicate this by returning
BPF_LWT_REROUTE, which triggers a new route lookup for the skb.
Signed-off-by: Peter Oskolkov <posk@google.com>
---
net/core/lwt_bpf.c | 125 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 125 insertions(+)
diff --git a/net/core/lwt_bpf.c b/net/core/lwt_bpf.c
index 4ff60757bf23..faeeb2ed3f1f 100644
--- a/net/core/lwt_bpf.c
+++ b/net/core/lwt_bpf.c
@@ -17,6 +17,7 @@
#include <linux/bpf.h>
#include <net/lwtunnel.h>
#include <net/gre.h>
+#include <net/ip6_route.h>
struct bpf_lwt_prog {
struct bpf_prog *prog;
@@ -56,6 +57,7 @@ static int run_lwt_bpf(struct sk_buff *skb, struct bpf_lwt_prog *lwt,
switch (ret) {
case BPF_OK:
+ case BPF_LWT_REROUTE:
break;
case BPF_REDIRECT:
@@ -88,6 +90,32 @@ static int run_lwt_bpf(struct sk_buff *skb, struct bpf_lwt_prog *lwt,
return ret;
}
+static int bpf_lwt_input_reroute(struct sk_buff *skb)
+{
+ int err = -EINVAL;
+
+ if (skb->protocol == htons(ETH_P_IP)) {
+ struct iphdr *iph = ip_hdr(skb);
+
+ err = ip_route_input_noref(skb, iph->daddr, iph->saddr,
+ iph->tos, skb_dst(skb)->dev);
+ } else if (skb->protocol == htons(ETH_P_IPV6)) {
+ ip6_route_input(skb);
+ err = skb_dst(skb)->error;
+ } else {
+ pr_warn_once("BPF_LWT_REROUTE input: unsupported proto %d\n",
+ skb->protocol);
+ }
+
+ if (err)
+ goto err;
+ return dst_input(skb);
+
+err:
+ kfree_skb(skb);
+ return err;
+}
+
static int bpf_input(struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
@@ -99,6 +127,8 @@ static int bpf_input(struct sk_buff *skb)
ret = run_lwt_bpf(skb, &bpf->in, dst, NO_REDIRECT);
if (ret < 0)
return ret;
+ if (ret == BPF_LWT_REROUTE)
+ return bpf_lwt_input_reroute(skb);
}
if (unlikely(!dst->lwtstate->orig_input)) {
@@ -148,6 +178,90 @@ static int xmit_check_hhlen(struct sk_buff *skb)
return 0;
}
+static int bpf_lwt_xmit_reroute(struct sk_buff *skb)
+{
+ struct net_device *l3mdev = l3mdev_master_dev_rcu(skb_dst(skb)->dev);
+ int oif = l3mdev ? l3mdev->ifindex : 0;
+ struct dst_entry *dst = NULL;
+ struct sock *sk;
+ struct net *net;
+ bool ipv4;
+ int err;
+
+ if (skb->protocol == htons(ETH_P_IP)) {
+ ipv4 = true;
+ } else if (skb->protocol == htons(ETH_P_IPV6)) {
+ ipv4 = false;
+ } else {
+ pr_warn_once("BPF_LWT_REROUTE xmit: unsupported proto %d\n",
+ skb->protocol);
+ return -EINVAL;
+ }
+
+ sk = sk_to_full_sk(skb->sk);
+ if (sk) {
+ if (sk->sk_bound_dev_if)
+ oif = sk->sk_bound_dev_if;
+ net = sock_net(sk);
+ } else {
+ net = dev_net(skb_dst(skb)->dev);
+ }
+
+ if (ipv4) {
+ struct iphdr *iph = ip_hdr(skb);
+ struct flowi4 fl4 = {0};
+ struct rtable *rt;
+
+ fl4.flowi4_oif = oif;
+ fl4.flowi4_mark = skb->mark;
+ fl4.flowi4_uid = sock_net_uid(net, sk);
+ fl4.flowi4_tos = RT_TOS(iph->tos);
+ fl4.flowi4_flags = FLOWI_FLAG_ANYSRC;
+ fl4.flowi4_proto = iph->protocol;
+ fl4.daddr = iph->daddr;
+ fl4.saddr = iph->saddr;
+
+ rt = ip_route_output_key(net, &fl4);
+ if (IS_ERR(rt) || rt->dst.error)
+ return -EINVAL;
+ dst = &rt->dst;
+ } else {
+ struct ipv6hdr *iph6 = ipv6_hdr(skb);
+ struct flowi6 fl6 = {0};
+
+ fl6.flowi6_oif = oif;
+ fl6.flowi6_mark = skb->mark;
+ fl6.flowi6_uid = sock_net_uid(net, sk);
+ fl6.flowlabel = ip6_flowinfo(iph6);
+ fl6.flowi6_proto = iph6->nexthdr;
+ fl6.daddr = iph6->daddr;
+ fl6.saddr = iph6->saddr;
+
+ dst = ip6_route_output(net, skb->sk, &fl6);
+ if (IS_ERR(dst) || dst->error)
+ return -EINVAL;
+ }
+
+ /* Although skb header was reserved in bpf_lwt_push_ip_encap(), it
+ * was done for the previous dst, so we are doing it here again, in
+ * case the new dst needs much more space. The call below is a noop
+ * if there is enough header space in skb.
+ */
+ err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev));
+ if (unlikely(err))
+ return err;
+
+ skb_dst_drop(skb);
+ skb_dst_set(skb, dst);
+
+ err = dst_output(dev_net(skb_dst(skb)->dev), skb->sk, skb);
+ if (unlikely(err))
+ return err;
+
+ /* ip[6]_finish_output2 understand LWTUNNEL_XMIT_DONE */
+ return LWTUNNEL_XMIT_DONE;
+}
+
static int bpf_xmit(struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
@@ -155,11 +269,20 @@ static int bpf_xmit(struct sk_buff *skb)
bpf = bpf_lwt_lwtunnel(dst->lwtstate);
if (bpf->xmit.prog) {
+ __be16 proto = skb->protocol;
int ret;
ret = run_lwt_bpf(skb, &bpf->xmit, dst, CAN_REDIRECT);
switch (ret) {
case BPF_OK:
+ /* If the header changed, e.g. via bpf_lwt_push_encap,
+ * BPF_LWT_REROUTE below should have been used if the
+ * protocol was also changed.
+ */
+ if (skb->protocol != proto) {
+ kfree_skb(skb);
+ return -EINVAL;
+ }
/* If the header was expanded, headroom might be too
* small for L2 header to come, expand as needed.
*/
@@ -170,6 +293,8 @@ static int bpf_xmit(struct sk_buff *skb)
return LWTUNNEL_XMIT_CONTINUE;
case BPF_REDIRECT:
return LWTUNNEL_XMIT_DONE;
+ case BPF_LWT_REROUTE:
+ return bpf_lwt_xmit_reroute(skb);
default:
return ret;
}
--
2.20.1.611.gfbb209baf1-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [PATCH bpf-next v7 4/6] bpf: add handling of BPF_LWT_REROUTE to lwt_bpf.c
2019-02-07 0:37 ` [PATCH bpf-next v7 4/6] bpf: add handling of BPF_LWT_REROUTE to lwt_bpf.c Peter Oskolkov
@ 2019-02-07 14:40 ` kbuild test robot
0 siblings, 0 replies; 12+ messages in thread
From: kbuild test robot @ 2019-02-07 14:40 UTC (permalink / raw)
To: Peter Oskolkov
Cc: kbuild-all, Alexei Starovoitov, Daniel Borkmann, netdev,
Peter Oskolkov, David Ahern, Willem de Bruijn, Peter Oskolkov
[-- Attachment #1: Type: text/plain, Size: 1306 bytes --]
Hi Peter,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on bpf-next/master]
url: https://github.com/0day-ci/linux/commits/Peter-Oskolkov/bpf-add-BPF_LWT_ENCAP_IP-option-to-bpf_lwt_push_encap/20190207-205725
base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: m68k-sun3_defconfig (attached as .config)
compiler: m68k-linux-gnu-gcc (Debian 8.2.0-11) 8.2.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
GCC_VERSION=8.2.0 make.cross ARCH=m68k
All errors (new ones prefixed by >>):
m68k-linux-gnu-ld: drivers/rtc/proc.o: in function `is_rtc_hctosys.isra.0':
proc.c:(.text+0x178): undefined reference to `strcmp'
m68k-linux-gnu-ld: net/core/lwt_bpf.o: in function `bpf_lwt_xmit_reroute':
>> lwt_bpf.c:(.text+0x256): undefined reference to `ip6_route_output_flags'
m68k-linux-gnu-ld: net/core/lwt_bpf.o: in function `bpf_input':
>> lwt_bpf.c:(.text+0x836): undefined reference to `ip6_route_input'
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 12133 bytes --]
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH bpf-next v7 5/6] bpf: sync <kdir>/include/.../bpf.h with tools/include/.../bpf.h
2019-02-07 0:37 [PATCH bpf-next v7 0/6] bpf: add BPF_LWT_ENCAP_IP option to bpf_lwt_push_encap Peter Oskolkov
` (3 preceding siblings ...)
2019-02-07 0:37 ` [PATCH bpf-next v7 4/6] bpf: add handling of BPF_LWT_REROUTE to lwt_bpf.c Peter Oskolkov
@ 2019-02-07 0:37 ` Peter Oskolkov
2019-02-07 0:37 ` [PATCH bpf-next v7 6/6] selftests: bpf: add test_lwt_ip_encap selftest Peter Oskolkov
5 siblings, 0 replies; 12+ messages in thread
From: Peter Oskolkov @ 2019-02-07 0:37 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, netdev
Cc: Peter Oskolkov, David Ahern, Willem de Bruijn, Peter Oskolkov
This patch copies changes in bpf.h done by a previous patch
in this patchset from the kernel uapi include dir into tools
uapi include dir.
Signed-off-by: Peter Oskolkov <posk@google.com>
---
tools/include/uapi/linux/bpf.h | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 1777fa0c61e4..138089ff24cf 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -2016,6 +2016,19 @@ union bpf_attr {
* Only works if *skb* contains an IPv6 packet. Insert a
* Segment Routing Header (**struct ipv6_sr_hdr**) inside
* the IPv6 header.
+ * **BPF_LWT_ENCAP_IP**
+ * IP encapsulation (GRE/GUE/IPIP/etc). The outer header
+ * must be IPv4 or IPv6, followed by zero or more
+ * additional headers, up to LWT_BPF_MAX_HEADROOM total
+ * bytes in all prepended headers. PLease note that
+ * if skb_is_gso(skb) is true, no more than two headers
+ * can be prepended, and the inner header, if present,
+ * should be either GRE or UDP/GUE.
+ *
+ * BPF_LWT_ENCAP_SEG6*** types can be called by bpf programs of
+ * type BPF_PROG_TYPE_LWT_IN; BPF_LWT_ENCAP_IP type can be called
+ * by bpf programs of types BPF_PROG_TYPE_LWT_IN and
+ * BPF_PROG_TYPE_LWT_XMIT.
*
* A call to this helper is susceptible to change the underlaying
* packet buffer. Therefore, at load time, all checks on pointers
@@ -2498,7 +2511,8 @@ enum bpf_hdr_start_off {
/* Encapsulation type for BPF_FUNC_lwt_push_encap helper. */
enum bpf_lwt_encap_mode {
BPF_LWT_ENCAP_SEG6,
- BPF_LWT_ENCAP_SEG6_INLINE
+ BPF_LWT_ENCAP_SEG6_INLINE,
+ BPF_LWT_ENCAP_IP,
};
#define __bpf_md_ptr(type, name) \
@@ -2586,7 +2600,15 @@ enum bpf_ret_code {
BPF_DROP = 2,
/* 3-6 reserved */
BPF_REDIRECT = 7,
- /* >127 are reserved for prog type specific return codes */
+ /* >127 are reserved for prog type specific return codes.
+ *
+ * BPF_LWT_REROUTE: used by BPF_PROG_TYPE_LWT_IN and
+ * BPF_PROG_TYPE_LWT_XMIT to indicate that skb had been
+ * changed and should be routed based on its new L3 header.
+ * (This is an L3 redirect, as opposed to L2 redirect
+ * represented by BPF_REDIRECT above).
+ */
+ BPF_LWT_REROUTE = 128,
};
struct bpf_sock {
--
2.20.1.611.gfbb209baf1-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH bpf-next v7 6/6] selftests: bpf: add test_lwt_ip_encap selftest
2019-02-07 0:37 [PATCH bpf-next v7 0/6] bpf: add BPF_LWT_ENCAP_IP option to bpf_lwt_push_encap Peter Oskolkov
` (4 preceding siblings ...)
2019-02-07 0:37 ` [PATCH bpf-next v7 5/6] bpf: sync <kdir>/include/.../bpf.h with tools/include/.../bpf.h Peter Oskolkov
@ 2019-02-07 0:37 ` Peter Oskolkov
5 siblings, 0 replies; 12+ messages in thread
From: Peter Oskolkov @ 2019-02-07 0:37 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, netdev
Cc: Peter Oskolkov, David Ahern, Willem de Bruijn, Peter Oskolkov
This patch adds a bpf self-test to cover BPF_LWT_ENCAP_IP mode
in bpf_lwt_push_encap.
Covered:
- encapping in LWT_IN and LWT_XMIT
- IPv4 and IPv6
A follow-up patch will add VRF-enabled tests.
Signed-off-by: Peter Oskolkov <posk@google.com>
---
tools/testing/selftests/bpf/Makefile | 6 +-
.../testing/selftests/bpf/test_lwt_ip_encap.c | 85 +++++
.../selftests/bpf/test_lwt_ip_encap.sh | 311 ++++++++++++++++++
3 files changed, 400 insertions(+), 2 deletions(-)
create mode 100644 tools/testing/selftests/bpf/test_lwt_ip_encap.c
create mode 100755 tools/testing/selftests/bpf/test_lwt_ip_encap.sh
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 383d2ff13fc7..d56c74727b6c 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -35,7 +35,8 @@ BPF_OBJ_FILES = \
sendmsg4_prog.o sendmsg6_prog.o test_lirc_mode2_kern.o \
get_cgroup_id_kern.o socket_cookie_prog.o test_select_reuseport_kern.o \
test_skb_cgroup_id_kern.o bpf_flow.o netcnt_prog.o test_xdp_vlan.o \
- xdp_dummy.o test_map_in_map.o test_spin_lock.o test_map_lock.o
+ xdp_dummy.o test_map_in_map.o test_spin_lock.o test_map_lock.o \
+ test_lwt_ip_encap.o
# Objects are built with default compilation flags and with sub-register
# code-gen enabled.
@@ -73,7 +74,8 @@ TEST_PROGS := test_kmod.sh \
test_lirc_mode2.sh \
test_skb_cgroup_id.sh \
test_flow_dissector.sh \
- test_xdp_vlan.sh
+ test_xdp_vlan.sh \
+ test_lwt_ip_encap.sh
TEST_PROGS_EXTENDED := with_addr.sh \
with_tunnels.sh \
diff --git a/tools/testing/selftests/bpf/test_lwt_ip_encap.c b/tools/testing/selftests/bpf/test_lwt_ip_encap.c
new file mode 100644
index 000000000000..c957d6dfe6d7
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_lwt_ip_encap.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stddef.h>
+#include <string.h>
+#include <linux/bpf.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include "bpf_helpers.h"
+#include "bpf_endian.h"
+
+struct grehdr {
+ __be16 flags;
+ __be16 protocol;
+};
+
+SEC("encap_gre")
+int bpf_lwt_encap_gre(struct __sk_buff *skb)
+{
+ struct encap_hdr {
+ struct iphdr iph;
+ struct grehdr greh;
+ } hdr;
+ int err;
+
+ memset(&hdr, 0, sizeof(struct encap_hdr));
+
+ hdr.iph.ihl = 5;
+ hdr.iph.version = 4;
+ hdr.iph.ttl = 0x40;
+ hdr.iph.protocol = 47; /* IPPROTO_GRE */
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+ hdr.iph.saddr = 0x640110ac; /* 172.16.1.100 */
+ hdr.iph.daddr = 0x641010ac; /* 172.16.16.100 */
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+ hdr.iph.saddr = 0xac100164; /* 172.16.1.100 */
+ hdr.iph.daddr = 0xac101064; /* 172.16.16.100 */
+#else
+#error "Fix your compiler's __BYTE_ORDER__?!"
+#endif
+ hdr.iph.tot_len = bpf_htons(skb->len + sizeof(struct encap_hdr));
+
+ hdr.greh.protocol = skb->protocol;
+
+ err = bpf_lwt_push_encap(skb, BPF_LWT_ENCAP_IP, &hdr,
+ sizeof(struct encap_hdr));
+ if (err)
+ return BPF_DROP;
+
+ return BPF_LWT_REROUTE;
+}
+
+SEC("encap_gre6")
+int bpf_lwt_encap_gre6(struct __sk_buff *skb)
+{
+ struct encap_hdr {
+ struct ipv6hdr ip6hdr;
+ struct grehdr greh;
+ } hdr;
+ int err;
+
+ memset(&hdr, 0, sizeof(struct encap_hdr));
+
+ hdr.ip6hdr.version = 6;
+ hdr.ip6hdr.payload_len = bpf_htons(skb->len + sizeof(struct grehdr));
+ hdr.ip6hdr.nexthdr = 47; /* IPPROTO_GRE */
+ hdr.ip6hdr.hop_limit = 0x40;
+ /* fb01::1 */
+ hdr.ip6hdr.saddr.s6_addr[0] = 0xfb;
+ hdr.ip6hdr.saddr.s6_addr[1] = 1;
+ hdr.ip6hdr.saddr.s6_addr[15] = 1;
+ /* fb10::1 */
+ hdr.ip6hdr.daddr.s6_addr[0] = 0xfb;
+ hdr.ip6hdr.daddr.s6_addr[1] = 0x10;
+ hdr.ip6hdr.daddr.s6_addr[15] = 1;
+
+ hdr.greh.protocol = skb->protocol;
+
+ err = bpf_lwt_push_encap(skb, BPF_LWT_ENCAP_IP, &hdr,
+ sizeof(struct encap_hdr));
+ if (err)
+ return BPF_DROP;
+
+ return BPF_LWT_REROUTE;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/test_lwt_ip_encap.sh b/tools/testing/selftests/bpf/test_lwt_ip_encap.sh
new file mode 100755
index 000000000000..4ca714e23ab0
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_lwt_ip_encap.sh
@@ -0,0 +1,311 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Setup/topology:
+#
+# NS1 NS2 NS3
+# veth1 <---> veth2 veth3 <---> veth4 (the top route)
+# veth5 <---> veth6 veth7 <---> veth8 (the bottom route)
+#
+# each vethN gets IPv[4|6]_N address
+#
+# IPv*_SRC = IPv*_1
+# IPv*_DST = IPv*_4
+#
+# all tests test pings from IPv*_SRC to IPv*_DST
+#
+# by default, routes are configured to allow packets to go
+# IP*_1 <=> IP*_2 <=> IP*_3 <=> IP*_4 (the top route)
+#
+# a GRE device is installed in NS3 with IPv*_GRE, and
+# NS1/NS2 are configured to route packets to IPv*_GRE via IP*_8
+# (the bottom route)
+#
+# Tests:
+#
+# 1. routes NS2->IPv*_DST are brought down, so the only way a ping
+# from IP*_SRC to IP*_DST can work is via IPv*_GRE
+#
+# 2a. in an egress test, a bpf LWT_XMIT program is installed on veth1
+# that encaps the packets with an IP/GRE header to route to IPv*_GRE
+#
+# ping: SRC->[encap at veth1:egress]->GRE:decap->DST
+# ping replies go DST->SRC directly
+#
+# 2b. in an ingress test, a bpf LWT_IN program is installed on veth2
+# that encaps the packets with an IP/GRE header to route to IPv*_GRE
+#
+# ping: SRC->[encap at veth2:ingress]->GRE:decap->DST
+# ping replies go DST->SRC directly
+
+set -e # exit on error
+
+if [[ $EUID -ne 0 ]]; then
+ echo "This script must be run as root"
+ echo "FAIL"
+ exit 1
+fi
+
+readonly NS1="ns1-$(mktemp -u XXXXXX)"
+readonly NS2="ns2-$(mktemp -u XXXXXX)"
+readonly NS3="ns3-$(mktemp -u XXXXXX)"
+
+readonly IPv4_1="172.16.1.100"
+readonly IPv4_2="172.16.2.100"
+readonly IPv4_3="172.16.3.100"
+readonly IPv4_4="172.16.4.100"
+readonly IPv4_5="172.16.5.100"
+readonly IPv4_6="172.16.6.100"
+readonly IPv4_7="172.16.7.100"
+readonly IPv4_8="172.16.8.100"
+readonly IPv4_GRE="172.16.16.100"
+
+readonly IPv4_SRC=$IPv4_1
+readonly IPv4_DST=$IPv4_4
+
+readonly IPv6_1="fb01::1"
+readonly IPv6_2="fb02::1"
+readonly IPv6_3="fb03::1"
+readonly IPv6_4="fb04::1"
+readonly IPv6_5="fb05::1"
+readonly IPv6_6="fb06::1"
+readonly IPv6_7="fb07::1"
+readonly IPv6_8="fb08::1"
+readonly IPv6_GRE="fb10::1"
+
+readonly IPv6_SRC=$IPv6_1
+readonly IPv6_DST=$IPv6_4
+
+setup() {
+set -e # exit on error
+ # create devices and namespaces
+ ip netns add "${NS1}"
+ ip netns add "${NS2}"
+ ip netns add "${NS3}"
+
+ ip link add veth1 type veth peer name veth2
+ ip link add veth3 type veth peer name veth4
+ ip link add veth5 type veth peer name veth6
+ ip link add veth7 type veth peer name veth8
+
+ ip netns exec ${NS2} sysctl -wq net.ipv4.ip_forward=1
+ ip netns exec ${NS2} sysctl -wq net.ipv6.conf.all.forwarding=1
+
+ ip link set veth1 netns ${NS1}
+ ip link set veth2 netns ${NS2}
+ ip link set veth3 netns ${NS2}
+ ip link set veth4 netns ${NS3}
+ ip link set veth5 netns ${NS1}
+ ip link set veth6 netns ${NS2}
+ ip link set veth7 netns ${NS2}
+ ip link set veth8 netns ${NS3}
+
+ # configure addesses: the top route (1-2-3-4)
+ ip -netns ${NS1} addr add ${IPv4_1}/24 dev veth1
+ ip -netns ${NS2} addr add ${IPv4_2}/24 dev veth2
+ ip -netns ${NS2} addr add ${IPv4_3}/24 dev veth3
+ ip -netns ${NS3} addr add ${IPv4_4}/24 dev veth4
+ ip -netns ${NS1} -6 addr add ${IPv6_1}/128 nodad dev veth1
+ ip -netns ${NS2} -6 addr add ${IPv6_2}/128 nodad dev veth2
+ ip -netns ${NS2} -6 addr add ${IPv6_3}/128 nodad dev veth3
+ ip -netns ${NS3} -6 addr add ${IPv6_4}/128 nodad dev veth4
+
+ # configure addresses: the bottom route (5-6-7-8)
+ ip -netns ${NS1} addr add ${IPv4_5}/24 dev veth5
+ ip -netns ${NS2} addr add ${IPv4_6}/24 dev veth6
+ ip -netns ${NS2} addr add ${IPv4_7}/24 dev veth7
+ ip -netns ${NS3} addr add ${IPv4_8}/24 dev veth8
+ ip -netns ${NS1} -6 addr add ${IPv6_5}/128 nodad dev veth5
+ ip -netns ${NS2} -6 addr add ${IPv6_6}/128 nodad dev veth6
+ ip -netns ${NS2} -6 addr add ${IPv6_7}/128 nodad dev veth7
+ ip -netns ${NS3} -6 addr add ${IPv6_8}/128 nodad dev veth8
+
+
+ ip -netns ${NS1} link set dev veth1 up
+ ip -netns ${NS2} link set dev veth2 up
+ ip -netns ${NS2} link set dev veth3 up
+ ip -netns ${NS3} link set dev veth4 up
+ ip -netns ${NS1} link set dev veth5 up
+ ip -netns ${NS2} link set dev veth6 up
+ ip -netns ${NS2} link set dev veth7 up
+ ip -netns ${NS3} link set dev veth8 up
+
+ # configure routes: IP*_SRC -> veth1/IP*_2 (= top route) default;
+ # the bottom route to specific bottom addresses
+
+ # NS1
+ # top route
+ ip -netns ${NS1} route add ${IPv4_2}/32 dev veth1
+ ip -netns ${NS1} route add default dev veth1 via ${IPv4_2} # go top by default
+ ip -netns ${NS1} -6 route add ${IPv6_2}/128 dev veth1
+ ip -netns ${NS1} -6 route add default dev veth1 via ${IPv6_2} # go top by default
+ # bottom route
+ ip -netns ${NS1} route add ${IPv4_6}/32 dev veth5
+ ip -netns ${NS1} route add ${IPv4_7}/32 dev veth5 via ${IPv4_6}
+ ip -netns ${NS1} route add ${IPv4_8}/32 dev veth5 via ${IPv4_6}
+ ip -netns ${NS1} -6 route add ${IPv6_6}/128 dev veth5
+ ip -netns ${NS1} -6 route add ${IPv6_7}/128 dev veth5 via ${IPv6_6}
+ ip -netns ${NS1} -6 route add ${IPv6_8}/128 dev veth5 via ${IPv6_6}
+
+ # NS2
+ # top route
+ ip -netns ${NS2} route add ${IPv4_1}/32 dev veth2
+ ip -netns ${NS2} route add ${IPv4_4}/32 dev veth3
+ ip -netns ${NS2} -6 route add ${IPv6_1}/128 dev veth2
+ ip -netns ${NS2} -6 route add ${IPv6_4}/128 dev veth3
+ # bottom route
+ ip -netns ${NS2} route add ${IPv4_5}/32 dev veth6
+ ip -netns ${NS2} route add ${IPv4_8}/32 dev veth7
+ ip -netns ${NS2} -6 route add ${IPv6_5}/128 dev veth6
+ ip -netns ${NS2} -6 route add ${IPv6_8}/128 dev veth7
+
+ # NS3
+ # top route
+ ip -netns ${NS3} route add ${IPv4_3}/32 dev veth4
+ ip -netns ${NS3} route add ${IPv4_1}/32 dev veth4 via ${IPv4_3}
+ ip -netns ${NS3} route add ${IPv4_2}/32 dev veth4 via ${IPv4_3}
+ ip -netns ${NS3} -6 route add ${IPv6_3}/128 dev veth4
+ ip -netns ${NS3} -6 route add ${IPv6_1}/128 dev veth4 via ${IPv6_3}
+ ip -netns ${NS3} -6 route add ${IPv6_2}/128 dev veth4 via ${IPv6_3}
+ # bottom route
+ ip -netns ${NS3} route add ${IPv4_7}/32 dev veth8
+ ip -netns ${NS3} route add ${IPv4_5}/32 dev veth8 via ${IPv4_7}
+ ip -netns ${NS3} route add ${IPv4_6}/32 dev veth8 via ${IPv4_7}
+ ip -netns ${NS3} -6 route add ${IPv6_7}/128 dev veth8
+ ip -netns ${NS3} -6 route add ${IPv6_5}/128 dev veth8 via ${IPv6_7}
+ ip -netns ${NS3} -6 route add ${IPv6_6}/128 dev veth8 via ${IPv6_7}
+
+ # configure IPv4 GRE device in NS3, and a route to it via the "bottom" route
+ ip -netns ${NS3} tunnel add gre_dev mode gre remote ${IPv4_1} local ${IPv4_GRE} ttl 255
+ ip -netns ${NS3} link set gre_dev up
+ ip -netns ${NS3} addr add ${IPv4_GRE} dev gre_dev
+ ip -netns ${NS1} route add ${IPv4_GRE}/32 dev veth5 via ${IPv4_6}
+ ip -netns ${NS2} route add ${IPv4_GRE}/32 dev veth7 via ${IPv4_8}
+
+
+ # configure IPv6 GRE device in NS3, and a route to it via the "bottom" route
+ ip -netns ${NS3} -6 tunnel add name gre6_dev mode ip6gre remote ${IPv6_1} local ${IPv6_GRE} ttl 255
+ ip -netns ${NS3} link set gre6_dev up
+ ip -netns ${NS3} -6 addr add ${IPv6_GRE} nodad dev gre6_dev
+ ip -netns ${NS1} -6 route add ${IPv6_GRE}/128 dev veth5 via ${IPv6_6}
+ ip -netns ${NS2} -6 route add ${IPv6_GRE}/128 dev veth7 via ${IPv6_8}
+
+ # rp_filter gets confused by what these tests are doing, so disable it
+ ip netns exec ${NS1} sysctl -wq net.ipv4.conf.all.rp_filter=0
+ ip netns exec ${NS2} sysctl -wq net.ipv4.conf.all.rp_filter=0
+ ip netns exec ${NS3} sysctl -wq net.ipv4.conf.all.rp_filter=0
+}
+
+cleanup() {
+ ip netns del ${NS1} 2> /dev/null
+ ip netns del ${NS2} 2> /dev/null
+ ip netns del ${NS3} 2> /dev/null
+}
+
+trap cleanup EXIT
+
+test_ping() {
+ local readonly PROTO=$1
+ local readonly EXPECTED=$2
+ local RET=0
+
+ set +e
+ if [ "${PROTO}" == "IPv4" ] ; then
+ ip netns exec ${NS1} ping -c 1 -W 1 -I ${IPv4_SRC} ${IPv4_DST} 2>&1 > /dev/null
+ RET=$?
+ elif [ "${PROTO}" == "IPv6" ] ; then
+ ip netns exec ${NS1} ping6 -c 1 -W 6 -I ${IPv6_SRC} ${IPv6_DST} 2>&1 > /dev/null
+ RET=$?
+ else
+ echo "test_ping: unknown PROTO: ${PROTO}"
+ exit 1
+ fi
+ set -e
+
+ if [ "0" != "${RET}" ]; then
+ RET=1
+ fi
+
+ if [ "${EXPECTED}" != "${RET}" ] ; then
+ echo "FAIL: test_ping: ${RET}"
+ exit 1
+ fi
+}
+
+test_egress() {
+ local readonly ENCAP=$1
+ echo "starting egress ${ENCAP} encap test"
+ setup
+
+ # need to wait a bit for IPv6 to autoconf, otherwise
+ # ping6 sometimes fails with "unable to bind to address"
+
+ # by default, pings work
+ test_ping IPv4 0
+ test_ping IPv6 0
+
+ # remove NS2->DST routes, ping fails
+ ip -netns ${NS2} route del ${IPv4_DST}/32 dev veth3
+ ip -netns ${NS2} -6 route del ${IPv6_DST}/128 dev veth3
+ test_ping IPv4 1
+ test_ping IPv6 1
+
+ # install replacement routes (LWT/eBPF), pings succeed
+ if [ "${ENCAP}" == "IPv4" ] ; then
+ ip -netns ${NS1} route add ${IPv4_DST} encap bpf xmit obj test_lwt_ip_encap.o sec encap_gre dev veth1
+ ip -netns ${NS1} -6 route add ${IPv6_DST} encap bpf xmit obj test_lwt_ip_encap.o sec encap_gre dev veth1
+ elif [ "${ENCAP}" == "IPv6" ] ; then
+ ip -netns ${NS1} route add ${IPv4_DST} encap bpf xmit obj test_lwt_ip_encap.o sec encap_gre6 dev veth1
+ ip -netns ${NS1} -6 route add ${IPv6_DST} encap bpf xmit obj test_lwt_ip_encap.o sec encap_gre6 dev veth1
+ else
+ echo "FAIL: unknown encap ${ENCAP}"
+ fi
+ test_ping IPv4 0
+ test_ping IPv6 0
+
+ cleanup
+ echo "PASS"
+}
+
+test_ingress() {
+ local readonly ENCAP=$1
+ echo "starting ingress ${ENCAP} encap test"
+ setup
+
+ # need to wait a bit for IPv6 to autoconf, otherwise
+ # ping6 sometimes fails with "unable to bind to address"
+
+ # by default, pings work
+ test_ping IPv4 0
+ test_ping IPv6 0
+
+ # remove NS2->DST routes, pings fail
+ ip -netns ${NS2} route del ${IPv4_DST}/32 dev veth3
+ ip -netns ${NS2} -6 route del ${IPv6_DST}/128 dev veth3
+ test_ping IPv4 1
+ test_ping IPv6 1
+
+ # install replacement routes (LWT/eBPF), pings succeed
+ if [ "${ENCAP}" == "IPv4" ] ; then
+ ip -netns ${NS2} route add ${IPv4_DST} encap bpf in obj test_lwt_ip_encap.o sec encap_gre dev veth2
+ ip -netns ${NS2} -6 route add ${IPv6_DST} encap bpf in obj test_lwt_ip_encap.o sec encap_gre dev veth2
+ elif [ "${ENCAP}" == "IPv6" ] ; then
+ ip -netns ${NS2} route add ${IPv4_DST} encap bpf in obj test_lwt_ip_encap.o sec encap_gre6 dev veth2
+ ip -netns ${NS2} -6 route add ${IPv6_DST} encap bpf in obj test_lwt_ip_encap.o sec encap_gre6 dev veth2
+ else
+ echo "FAIL: unknown encap ${ENCAP}"
+ fi
+ test_ping IPv4 0
+ test_ping IPv6 0
+
+ cleanup
+ echo "PASS"
+}
+
+test_egress IPv4
+test_egress IPv6
+
+test_ingress IPv4
+test_ingress IPv6
+
+echo "all tests passed"
--
2.20.1.611.gfbb209baf1-goog
^ permalink raw reply related [flat|nested] 12+ messages in thread