[PATCH 0/11] pull request (net-next): ipsec-next 2024-09-09

[PATCH 0/11] pull request (net-next): ipsec-next 2024-09-09

[Steffen Klassert]

1) Remove an unneeded WARN_ON on packet offload.
   From Patrisious Haddad.

2) Add a copy from skb_seq_state to buffer function.
   This is needed for the upcomming IPTFS patchset.
   From Christian Hopps.

3) Spelling fix in xfrm.h.
   From Simon Horman.

4) Speed up xfrm policy insertions.
   From Florian Westphal.

5) Add and revert a patch to support xfrm interfaces
   for packet offload. This patch was just half coocked.

6) Extend usage of the new xfrm_policy_is_dead_or_sk helper.
   From Florian Westphal.

7) Update comments on sdb and xfrm_policy.
   From Florian Westphal.

Please pull or let me know if there are problems.

Thanks!

The following changes since commit 8e0c0ec9b7dc2aec84f141c26c501e24906ff765:

  Merge branch 'ethernet-convert-from-tasklet-to-bh-workqueue' (2024-07-31 19:05:20 -0700)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next.git tags/ipsec-next-2024-09-09

for you to fetch changes up to 69716a3babe1165a9ab1b3770b55d303d5bb5fa3:

  Revert "xfrm: add SA information to the offloaded packet" (2024-09-09 11:43:39 +0200)

----------------------------------------------------------------
ipsec-next-2024-09-09

----------------------------------------------------------------
Christian Hopps (1):
      net: add copy from skb_seq_state to buffer function

Florian Westphal (6):
      selftests: add xfrm policy insertion speed test script
      xfrm: policy: don't iterate inexact policies twice at insert time
      xfrm: switch migrate to xfrm_policy_lookup_bytype
      xfrm: policy: remove remaining use of inexact list
      xfrm: policy: use recently added helper in more places
      xfrm: minor update to sdb and xfrm_policy comments

Patrisious Haddad (1):
      xfrm: Remove documentation WARN_ON to limit return values for offloaded SA

Simon Horman (1):
      xfrm: Correct spelling in xfrm.h

Steffen Klassert (2):
      Merge branch 'xfrm: speed up policy insertions'
      Revert "xfrm: add SA information to the offloaded packet"

wangfe (1):
      xfrm: add SA information to the offloaded packet

 include/linux/skbuff.h                             |   1 +
 include/net/xfrm.h                                 |  45 ++++-
 net/core/skbuff.c                                  |  35 ++++
 net/xfrm/xfrm_device.c                             |   6 +-
 net/xfrm/xfrm_policy.c                             | 220 +++++++++------------
 tools/testing/selftests/net/Makefile               |   2 +-
 .../testing/selftests/net/xfrm_policy_add_speed.sh |  83 ++++++++
 7 files changed, 256 insertions(+), 136 deletions(-)
 create mode 100755 tools/testing/selftests/net/xfrm_policy_add_speed.sh

[PATCH 01/11] xfrm: Remove documentation WARN_ON to limit return values for offloaded SA

[Steffen Klassert]

From: Patrisious Haddad <phaddad@nvidia.com>

The original idea to put WARN_ON() on return value from driver code was
to make sure that packet offload doesn't have silent fallback to
SW implementation, like crypto offload has.

In reality, this is not needed as all *swan implementations followed
this request and used explicit configuration style to make sure that
"users will get what they ask".
So instead of forcing drivers to make sure that even their internal flows
don't return -EOPNOTSUPP, let's remove this WARN_ON.

Signed-off-by: Patrisious Haddad <phaddad@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_device.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
index 9a44d363ba62..f123b7c9ec82 100644
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c
@@ -328,12 +328,8 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
 		/* User explicitly requested packet offload mode and configured
 		 * policy in addition to the XFRM state. So be civil to users,
 		 * and return an error instead of taking fallback path.
-		 *
-		 * This WARN_ON() can be seen as a documentation for driver
-		 * authors to do not return -EOPNOTSUPP in packet offload mode.
 		 */
-		WARN_ON(err == -EOPNOTSUPP && is_packet_offload);
-		if (err != -EOPNOTSUPP || is_packet_offload) {
+		if ((err != -EOPNOTSUPP && !is_packet_offload) || is_packet_offload) {
 			NL_SET_ERR_MSG_WEAK(extack, "Device failed to offload this state");
 			return err;
 		}
-- 
2.34.1

[PATCH 02/11] net: add copy from skb_seq_state to buffer function

[Steffen Klassert]

From: Christian Hopps <chopps@labn.net>

Add an skb helper function to copy a range of bytes from within
an existing skb_seq_state.

Signed-off-by: Christian Hopps <chopps@labn.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 include/linux/skbuff.h |  1 +
 net/core/skbuff.c      | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 29c3ea5b6e93..a871533b8568 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1433,6 +1433,7 @@ void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
 unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
 			  struct skb_seq_state *st);
 void skb_abort_seq_read(struct skb_seq_state *st);
+int skb_copy_seq_read(struct skb_seq_state *st, int offset, void *to, int len);
 
 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
 			   unsigned int to, struct ts_config *config);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 83f8cd8aa2d1..fe4b2dc5c19b 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4409,6 +4409,41 @@ void skb_abort_seq_read(struct skb_seq_state *st)
 }
 EXPORT_SYMBOL(skb_abort_seq_read);
 
+/**
+ * skb_copy_seq_read() - copy from a skb_seq_state to a 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.
+ *
+ * Return: 0 on success or -EINVAL if the copy ended early
+ */
+int skb_copy_seq_read(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 -EINVAL;
+		if (sqlen >= len) {
+			memcpy(to, data, len);
+			return 0;
+		}
+		memcpy(to, data, sqlen);
+		to += sqlen;
+		offset += sqlen;
+		len -= sqlen;
+	}
+}
+EXPORT_SYMBOL(skb_copy_seq_read);
+
 #define TS_SKB_CB(state)	((struct skb_seq_state *) &((state)->cb))
 
 static unsigned int skb_ts_get_next_block(unsigned int offset, const u8 **text,
-- 
2.34.1

[PATCH 03/11] xfrm: Correct spelling in xfrm.h

[Steffen Klassert]

From: Simon Horman <horms@kernel.org>

Correct spelling in xfrm.h.
As reported by codespell.

Signed-off-by: Simon Horman <horms@kernel.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 include/net/xfrm.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 54cef89f6c1e..f7244ac4fa08 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -79,7 +79,7 @@
    policy entry has list of up to XFRM_MAX_DEPTH transformations,
    described by templates xfrm_tmpl. Each template is resolved
    to a complete xfrm_state (see below) and we pack bundle of transformations
-   to a dst_entry returned to requestor.
+   to a dst_entry returned to requester.
 
    dst -. xfrm  .-> xfrm_state #1
     |---. child .-> dst -. xfrm .-> xfrm_state #2
@@ -1016,7 +1016,7 @@ void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev);
 
 struct xfrm_if_parms {
 	int link;		/* ifindex of underlying L2 interface */
-	u32 if_id;		/* interface identifyer */
+	u32 if_id;		/* interface identifier */
 	bool collect_md;
 };
 
-- 
2.34.1

[PATCH 04/11] selftests: add xfrm policy insertion speed test script

[Steffen Klassert]

From: Florian Westphal <fw@strlen.de>

Nothing special, just test how long insertion of x policies takes.
This should ideally show linear insertion speeds.

Do not run this by default, it has little value, but it can be useful to
check for insertion speed chahnges when altering the xfrm policy db
implementation.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 tools/testing/selftests/net/Makefile          |  2 +-
 .../selftests/net/xfrm_policy_add_speed.sh    | 83 +++++++++++++++++++
 2 files changed, 84 insertions(+), 1 deletion(-)
 create mode 100755 tools/testing/selftests/net/xfrm_policy_add_speed.sh

diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index 8eaffd7a641c..e127a80ff713 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -56,7 +56,7 @@ TEST_PROGS += ip_local_port_range.sh
 TEST_PROGS += rps_default_mask.sh
 TEST_PROGS += big_tcp.sh
 TEST_PROGS += netns-sysctl.sh
-TEST_PROGS_EXTENDED := toeplitz_client.sh toeplitz.sh
+TEST_PROGS_EXTENDED := toeplitz_client.sh toeplitz.sh xfrm_policy_add_speed.sh
 TEST_GEN_FILES =  socket nettest
 TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy reuseport_addr_any
 TEST_GEN_FILES += tcp_mmap tcp_inq psock_snd txring_overwrite
diff --git a/tools/testing/selftests/net/xfrm_policy_add_speed.sh b/tools/testing/selftests/net/xfrm_policy_add_speed.sh
new file mode 100755
index 000000000000..2fab29d3cb91
--- /dev/null
+++ b/tools/testing/selftests/net/xfrm_policy_add_speed.sh
@@ -0,0 +1,83 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+source lib.sh
+
+timeout=4m
+ret=0
+tmp=$(mktemp)
+cleanup() {
+	cleanup_all_ns
+	rm -f "$tmp"
+}
+
+trap cleanup EXIT
+
+maxpolicies=100000
+[ "$KSFT_MACHINE_SLOW" = "yes" ] && maxpolicies=10000
+
+do_dummies4() {
+	local dir="$1"
+	local max="$2"
+
+	local policies
+	local pfx
+	pfx=30
+	policies=0
+
+	ip netns exec "$ns" ip xfrm policy flush
+
+	for i in $(seq 1 100);do
+		local s
+		local d
+		for j in $(seq 1 255);do
+			s=$((i+0))
+			d=$((i+100))
+
+			for a in $(seq 1 8 255); do
+				policies=$((policies+1))
+				[ "$policies" -gt "$max" ] && return
+				echo xfrm policy add src 10.$s.$j.0/30 dst 10.$d.$j.$a/$pfx dir $dir action block
+			done
+			for a in $(seq 1 8 255); do
+				policies=$((policies+1))
+				[ "$policies" -gt "$max" ] && return
+				echo xfrm policy add src 10.$s.$j.$a/30 dst 10.$d.$j.0/$pfx dir $dir action block
+			done
+		done
+	done
+}
+
+setup_ns ns
+
+do_bench()
+{
+	local max="$1"
+
+	start=$(date +%s%3N)
+	do_dummies4 "out" "$max" > "$tmp"
+	if ! timeout "$timeout" ip netns exec "$ns" ip -batch "$tmp";then
+		echo "WARNING: policy insertion cancelled after $timeout"
+		ret=1
+	fi
+	stop=$(date +%s%3N)
+
+	result=$((stop-start))
+
+	policies=$(wc -l < "$tmp")
+	printf "Inserted %-06s policies in $result ms\n" $policies
+
+	have=$(ip netns exec "$ns" ip xfrm policy show | grep "action block" | wc -l)
+	if [ "$have" -ne "$policies" ]; then
+		echo "WARNING: mismatch, have $have policies, expected $policies"
+		ret=1
+	fi
+}
+
+p=100
+while [ $p -le "$maxpolicies" ]; do
+	do_bench "$p"
+	p="${p}0"
+done
+
+exit $ret
-- 
2.34.1

[PATCH 05/11] xfrm: policy: don't iterate inexact policies twice at insert time

[Steffen Klassert]

From: Florian Westphal <fw@strlen.de>

Since commit
6be3b0db6db8 ("xfrm: policy: add inexact policy search tree infrastructure")
policy lookup no longer walks a list but has a set of candidate lists.

This set has to be searched for the best match.
In case there are several matches, the priority wins.

If the priority is also the same, then the historic behaviour with
a single list was to return the first match (first-in-list).

With introduction of serval lists, this doesn't work and a new
'pos' member was added that reflects the xfrm_policy structs position
in the list.

This value is not exported to userspace and it does not need to be
the 'position in the list', it just needs to make sure that
a->pos < b->pos means that a was added to the lists more recently
than b.

This re-walk is expensive when many inexact policies are in use.

Speed this up: when appending the policy to the end of the walker list,
then just take the ->pos value of the last entry made and add 1.

Add a slowpath version to prevent overflow, if we'd assign UINT_MAX
then iterate the entire list and fix the ordering.

While this speeds up insertion considerably finding the insertion spot
in the inexact list still requires a partial list walk.

This is addressed in followup patches.

Before:
./xfrm_policy_add_speed.sh
Inserted 1000   policies in 72 ms
Inserted 10000  policies in 1540 ms
Inserted 100000 policies in 334780 ms

After:
Inserted 1000   policies in 68 ms
Inserted 10000  policies in 1137 ms
Inserted 100000 policies in 157307 ms

Reported-by: Noel Kuntze <noel@familie-kuntze.de>
Cc: Tobias Brunner <tobias@strongswan.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_policy.c | 59 +++++++++++++++++++++++++++++++++++++-----
 1 file changed, 53 insertions(+), 6 deletions(-)

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index c56c61b0c12e..423d1eb24f31 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1237,6 +1237,17 @@ xfrm_policy_inexact_insert(struct xfrm_policy *policy, u8 dir, int excl)
 	return delpol;
 }
 
+static bool xfrm_policy_is_dead_or_sk(const struct xfrm_policy *policy)
+{
+	int dir;
+
+	if (policy->walk.dead)
+		return true;
+
+	dir = xfrm_policy_id2dir(policy->index);
+	return dir >= XFRM_POLICY_MAX;
+}
+
 static void xfrm_hash_rebuild(struct work_struct *work)
 {
 	struct net *net = container_of(work, struct net,
@@ -1524,7 +1535,6 @@ static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
 {
 	struct xfrm_policy *pol, *delpol = NULL;
 	struct hlist_node *newpos = NULL;
-	int i = 0;
 
 	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
 		if (pol->type == policy->type &&
@@ -1548,11 +1558,6 @@ static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
 		hlist_add_behind_rcu(&policy->bydst_inexact_list, newpos);
 	else
 		hlist_add_head_rcu(&policy->bydst_inexact_list, chain);
-
-	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
-		pol->pos = i;
-		i++;
-	}
 }
 
 static struct xfrm_policy *xfrm_policy_insert_list(struct hlist_head *chain,
@@ -2294,10 +2299,52 @@ static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
 	return pol;
 }
 
+static u32 xfrm_gen_pos_slow(struct net *net)
+{
+	struct xfrm_policy *policy;
+	u32 i = 0;
+
+	/* oldest entry is last in list */
+	list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
+		if (!xfrm_policy_is_dead_or_sk(policy))
+			policy->pos = ++i;
+	}
+
+	return i;
+}
+
+static u32 xfrm_gen_pos(struct net *net)
+{
+	const struct xfrm_policy *policy;
+	u32 i = 0;
+
+	/* most recently added policy is at the head of the list */
+	list_for_each_entry(policy, &net->xfrm.policy_all, walk.all) {
+		if (xfrm_policy_is_dead_or_sk(policy))
+			continue;
+
+		if (policy->pos == UINT_MAX)
+			return xfrm_gen_pos_slow(net);
+
+		i = policy->pos + 1;
+		break;
+	}
+
+	return i;
+}
+
 static void __xfrm_policy_link(struct xfrm_policy *pol, int dir)
 {
 	struct net *net = xp_net(pol);
 
+	switch (dir) {
+	case XFRM_POLICY_IN:
+	case XFRM_POLICY_FWD:
+	case XFRM_POLICY_OUT:
+		pol->pos = xfrm_gen_pos(net);
+		break;
+	}
+
 	list_add(&pol->walk.all, &net->xfrm.policy_all);
 	net->xfrm.policy_count[dir]++;
 	xfrm_pol_hold(pol);
-- 
2.34.1

[PATCH 06/11] xfrm: switch migrate to xfrm_policy_lookup_bytype

[Steffen Klassert]

From: Florian Westphal <fw@strlen.de>

XFRM_MIGRATE still uses the old lookup method:
first check the bydst hash table, then search the list of all the other
policies.

Switch MIGRATE to use the same lookup function as the packetpath.

This is done to remove the last remaining users of the pernet
xfrm.policy_inexact lists with the intent of removing this list.

After this patch, policies are still added to the list on insertion
and they are rehashed as-needed but no single API makes use of these
anymore.

This change is compile tested only.

Cc: Tobias Brunner <tobias@strongswan.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_policy.c | 106 +++++++++++++++--------------------------
 1 file changed, 39 insertions(+), 67 deletions(-)

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 423d1eb24f31..d2feee60bb62 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1252,13 +1252,10 @@ static void xfrm_hash_rebuild(struct work_struct *work)
 {
 	struct net *net = container_of(work, struct net,
 				       xfrm.policy_hthresh.work);
-	unsigned int hmask;
 	struct xfrm_policy *pol;
 	struct xfrm_policy *policy;
 	struct hlist_head *chain;
-	struct hlist_head *odst;
 	struct hlist_node *newpos;
-	int i;
 	int dir;
 	unsigned seq;
 	u8 lbits4, rbits4, lbits6, rbits6;
@@ -1322,23 +1319,7 @@ static void xfrm_hash_rebuild(struct work_struct *work)
 			goto out_unlock;
 	}
 
-	/* reset the bydst and inexact table in all directions */
 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
-		struct hlist_node *n;
-
-		hlist_for_each_entry_safe(policy, n,
-					  &net->xfrm.policy_inexact[dir],
-					  bydst_inexact_list) {
-			hlist_del_rcu(&policy->bydst);
-			hlist_del_init(&policy->bydst_inexact_list);
-		}
-
-		hmask = net->xfrm.policy_bydst[dir].hmask;
-		odst = net->xfrm.policy_bydst[dir].table;
-		for (i = hmask; i >= 0; i--) {
-			hlist_for_each_entry_safe(policy, n, odst + i, bydst)
-				hlist_del_rcu(&policy->bydst);
-		}
 		if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
 			/* dir out => dst = remote, src = local */
 			net->xfrm.policy_bydst[dir].dbits4 = rbits4;
@@ -1363,6 +1344,10 @@ static void xfrm_hash_rebuild(struct work_struct *work)
 			/* skip socket policies */
 			continue;
 		}
+
+		hlist_del_rcu(&policy->bydst);
+		hlist_del_init(&policy->bydst_inexact_list);
+
 		newpos = NULL;
 		chain = policy_hash_bysel(net, &policy->selector,
 					  policy->family, dir);
@@ -4484,63 +4469,50 @@ EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
 #endif
 
 #ifdef CONFIG_XFRM_MIGRATE
-static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp,
-					const struct xfrm_selector *sel_tgt)
-{
-	if (sel_cmp->proto == IPSEC_ULPROTO_ANY) {
-		if (sel_tgt->family == sel_cmp->family &&
-		    xfrm_addr_equal(&sel_tgt->daddr, &sel_cmp->daddr,
-				    sel_cmp->family) &&
-		    xfrm_addr_equal(&sel_tgt->saddr, &sel_cmp->saddr,
-				    sel_cmp->family) &&
-		    sel_tgt->prefixlen_d == sel_cmp->prefixlen_d &&
-		    sel_tgt->prefixlen_s == sel_cmp->prefixlen_s) {
-			return true;
-		}
-	} else {
-		if (memcmp(sel_tgt, sel_cmp, sizeof(*sel_tgt)) == 0) {
-			return true;
-		}
-	}
-	return false;
-}
-
 static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel,
 						    u8 dir, u8 type, struct net *net, u32 if_id)
 {
 	struct xfrm_policy *pol, *ret = NULL;
-	struct hlist_head *chain;
-	u32 priority = ~0U;
+	struct flowi fl;
 
-	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
-	chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);
-	hlist_for_each_entry(pol, chain, bydst) {
-		if ((if_id == 0 || pol->if_id == if_id) &&
-		    xfrm_migrate_selector_match(sel, &pol->selector) &&
-		    pol->type == type) {
-			ret = pol;
-			priority = ret->priority;
-			break;
-		}
-	}
-	chain = &net->xfrm.policy_inexact[dir];
-	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
-		if ((pol->priority >= priority) && ret)
-			break;
+	memset(&fl, 0, sizeof(fl));
 
-		if ((if_id == 0 || pol->if_id == if_id) &&
-		    xfrm_migrate_selector_match(sel, &pol->selector) &&
-		    pol->type == type) {
-			ret = pol;
+	fl.flowi_proto = sel->proto;
+
+	switch (sel->family) {
+	case AF_INET:
+		fl.u.ip4.saddr = sel->saddr.a4;
+		fl.u.ip4.daddr = sel->daddr.a4;
+		if (sel->proto == IPSEC_ULPROTO_ANY)
 			break;
-		}
+		fl.u.flowi4_oif = sel->ifindex;
+		fl.u.ip4.fl4_sport = sel->sport;
+		fl.u.ip4.fl4_dport = sel->dport;
+		break;
+	case AF_INET6:
+		fl.u.ip6.saddr = sel->saddr.in6;
+		fl.u.ip6.daddr = sel->daddr.in6;
+		if (sel->proto == IPSEC_ULPROTO_ANY)
+			break;
+		fl.u.flowi6_oif = sel->ifindex;
+		fl.u.ip6.fl4_sport = sel->sport;
+		fl.u.ip6.fl4_dport = sel->dport;
+		break;
+	default:
+		return ERR_PTR(-EAFNOSUPPORT);
 	}
 
-	xfrm_pol_hold(ret);
+	rcu_read_lock();
 
-	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	pol = xfrm_policy_lookup_bytype(net, type, &fl, sel->family, dir, if_id);
+	if (IS_ERR_OR_NULL(pol))
+		goto out_unlock;
 
-	return ret;
+	if (!xfrm_pol_hold_rcu(ret))
+		pol = NULL;
+out_unlock:
+	rcu_read_unlock();
+	return pol;
 }
 
 static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tmpl *t)
@@ -4677,9 +4649,9 @@ int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
 
 	/* Stage 1 - find policy */
 	pol = xfrm_migrate_policy_find(sel, dir, type, net, if_id);
-	if (!pol) {
+	if (IS_ERR_OR_NULL(pol)) {
 		NL_SET_ERR_MSG(extack, "Target policy not found");
-		err = -ENOENT;
+		err = IS_ERR(pol) ? PTR_ERR(pol) : -ENOENT;
 		goto out;
 	}
 
-- 
2.34.1

Re: [PATCH 06/11] xfrm: switch migrate to xfrm_policy_lookup_bytype

[Florian Westphal]

Steffen Klassert <steffen.klassert@secunet.com> wrote:
> From: Florian Westphal <fw@strlen.de>
> 
> XFRM_MIGRATE still uses the old lookup method:
> first check the bydst hash table, then search the list of all the other
> policies.
> 
> Switch MIGRATE to use the same lookup function as the packetpath.
> 
> This is done to remove the last remaining users of the pernet
> xfrm.policy_inexact lists with the intent of removing this list.
> 
> After this patch, policies are still added to the list on insertion
> and they are rehashed as-needed but no single API makes use of these
> anymore.
> 
> This change is compile tested only.

This needs following fixup:

https://patchwork.kernel.org/project/netdevbpf/patch/20240830143920.9478-1-fw@strlen.de/

Re: [PATCH 06/11] xfrm: switch migrate to xfrm_policy_lookup_bytype

[Steffen Klassert]

On Mon, Sep 09, 2024 at 01:01:11PM +0200, Florian Westphal wrote:
> Steffen Klassert <steffen.klassert@secunet.com> wrote:
> > From: Florian Westphal <fw@strlen.de>
> > 
> > XFRM_MIGRATE still uses the old lookup method:
> > first check the bydst hash table, then search the list of all the other
> > policies.
> > 
> > Switch MIGRATE to use the same lookup function as the packetpath.
> > 
> > This is done to remove the last remaining users of the pernet
> > xfrm.policy_inexact lists with the intent of removing this list.
> > 
> > After this patch, policies are still added to the list on insertion
> > and they are rehashed as-needed but no single API makes use of these
> > anymore.
> > 
> > This change is compile tested only.
> 
> This needs following fixup:
> 
> https://patchwork.kernel.org/project/netdevbpf/patch/20240830143920.9478-1-fw@strlen.de/

Hm, looks like I've overlooked this and the other patch.

[PATCH 07/11] xfrm: policy: remove remaining use of inexact list

[Steffen Klassert]

From: Florian Westphal <fw@strlen.de>

No consumers anymore, remove it.  After this, insertion of policies
no longer require list walk of all inexact policies but only those
that are reachable via the candidate sets.

This gives almost linear insertion speeds provided the inserted
policies are for non-overlapping networks.

Before:
Inserted 1000   policies in 70 ms
Inserted 10000  policies in 1155 ms
Inserted 100000 policies in 216848 ms

After:
Inserted 1000   policies in 56 ms
Inserted 10000  policies in 478 ms
Inserted 100000 policies in 4580 ms

Insertion of 1m entries takes about ~40s after this change
on my test vm.

Cc: Noel Kuntze <noel@familie-kuntze.de>
Cc: Tobias Brunner <tobias@strongswan.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 include/net/xfrm.h     |  1 -
 net/xfrm/xfrm_policy.c | 38 --------------------------------------
 2 files changed, 39 deletions(-)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index f7244ac4fa08..1fa2da22a49e 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -555,7 +555,6 @@ struct xfrm_policy {
 	u16			family;
 	struct xfrm_sec_ctx	*security;
 	struct xfrm_tmpl       	xfrm_vec[XFRM_MAX_DEPTH];
-	struct hlist_node	bydst_inexact_list;
 	struct rcu_head		rcu;
 
 	struct xfrm_dev_offload xdo;
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index d2feee60bb62..b79ac453ea37 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -196,8 +196,6 @@ xfrm_policy_inexact_lookup_rcu(struct net *net,
 static struct xfrm_policy *
 xfrm_policy_insert_list(struct hlist_head *chain, struct xfrm_policy *policy,
 			bool excl);
-static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
-					    struct xfrm_policy *policy);
 
 static bool
 xfrm_policy_find_inexact_candidates(struct xfrm_pol_inexact_candidates *cand,
@@ -410,7 +408,6 @@ struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp)
 	if (policy) {
 		write_pnet(&policy->xp_net, net);
 		INIT_LIST_HEAD(&policy->walk.all);
-		INIT_HLIST_NODE(&policy->bydst_inexact_list);
 		INIT_HLIST_NODE(&policy->bydst);
 		INIT_HLIST_NODE(&policy->byidx);
 		rwlock_init(&policy->lock);
@@ -1228,9 +1225,6 @@ xfrm_policy_inexact_insert(struct xfrm_policy *policy, u8 dir, int excl)
 		return ERR_PTR(-EEXIST);
 	}
 
-	chain = &net->xfrm.policy_inexact[dir];
-	xfrm_policy_insert_inexact_list(chain, policy);
-
 	if (delpol)
 		__xfrm_policy_inexact_prune_bin(bin, false);
 
@@ -1346,7 +1340,6 @@ static void xfrm_hash_rebuild(struct work_struct *work)
 		}
 
 		hlist_del_rcu(&policy->bydst);
-		hlist_del_init(&policy->bydst_inexact_list);
 
 		newpos = NULL;
 		chain = policy_hash_bysel(net, &policy->selector,
@@ -1515,36 +1508,6 @@ static const struct rhashtable_params xfrm_pol_inexact_params = {
 	.automatic_shrinking	= true,
 };
 
-static void xfrm_policy_insert_inexact_list(struct hlist_head *chain,
-					    struct xfrm_policy *policy)
-{
-	struct xfrm_policy *pol, *delpol = NULL;
-	struct hlist_node *newpos = NULL;
-
-	hlist_for_each_entry(pol, chain, bydst_inexact_list) {
-		if (pol->type == policy->type &&
-		    pol->if_id == policy->if_id &&
-		    !selector_cmp(&pol->selector, &policy->selector) &&
-		    xfrm_policy_mark_match(&policy->mark, pol) &&
-		    xfrm_sec_ctx_match(pol->security, policy->security) &&
-		    !WARN_ON(delpol)) {
-			delpol = pol;
-			if (policy->priority > pol->priority)
-				continue;
-		} else if (policy->priority >= pol->priority) {
-			newpos = &pol->bydst_inexact_list;
-			continue;
-		}
-		if (delpol)
-			break;
-	}
-
-	if (newpos && policy->xdo.type != XFRM_DEV_OFFLOAD_PACKET)
-		hlist_add_behind_rcu(&policy->bydst_inexact_list, newpos);
-	else
-		hlist_add_head_rcu(&policy->bydst_inexact_list, chain);
-}
-
 static struct xfrm_policy *xfrm_policy_insert_list(struct hlist_head *chain,
 						   struct xfrm_policy *policy,
 						   bool excl)
@@ -2346,7 +2309,6 @@ static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
 	/* Socket policies are not hashed. */
 	if (!hlist_unhashed(&pol->bydst)) {
 		hlist_del_rcu(&pol->bydst);
-		hlist_del_init(&pol->bydst_inexact_list);
 		hlist_del(&pol->byidx);
 	}
 
-- 
2.34.1

[PATCH 08/11] xfrm: add SA information to the offloaded packet

[Steffen Klassert]

From: wangfe <wangfe@google.com>

In packet offload mode, append Security Association (SA) information
to each packet, replicating the crypto offload implementation.
The XFRM_XMIT flag is set to enable packet to be returned immediately
from the validate_xmit_xfrm function, thus aligning with the existing
code path for packet offload mode.

This SA info helps HW offload match packets to their correct security
policies. The XFRM interface ID is included, which is crucial in setups
with multiple XFRM interfaces where source/destination addresses alone
can't pinpoint the right policy.

Signed-off-by: wangfe <wangfe@google.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_output.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index e5722c95b8bb..a12588e7b060 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -706,6 +706,8 @@ int xfrm_output(struct sock *sk, struct sk_buff *skb)
 	struct xfrm_state *x = skb_dst(skb)->xfrm;
 	int family;
 	int err;
+	struct xfrm_offload *xo;
+	struct sec_path *sp;
 
 	family = (x->xso.type != XFRM_DEV_OFFLOAD_PACKET) ? x->outer_mode.family
 		: skb_dst(skb)->ops->family;
@@ -728,6 +730,25 @@ int xfrm_output(struct sock *sk, struct sk_buff *skb)
 			kfree_skb(skb);
 			return -EHOSTUNREACH;
 		}
+		sp = secpath_set(skb);
+		if (!sp) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
+			kfree_skb(skb);
+			return -ENOMEM;
+		}
+
+		sp->olen++;
+		sp->xvec[sp->len++] = x;
+		xfrm_state_hold(x);
+
+		xo = xfrm_offload(skb);
+		if (!xo) {
+			secpath_reset(skb);
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
+			kfree_skb(skb);
+			return -EINVAL;
+		}
+		xo->flags |= XFRM_XMIT;
 
 		return xfrm_output_resume(sk, skb, 0);
 	}
-- 
2.34.1

[PATCH 09/11] xfrm: policy: use recently added helper in more places

[Steffen Klassert]

From: Florian Westphal <fw@strlen.de>

No logical change intended.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_policy.c | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index b79ac453ea37..94859b2182ec 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1276,11 +1276,7 @@ static void xfrm_hash_rebuild(struct work_struct *work)
 		struct xfrm_pol_inexact_bin *bin;
 		u8 dbits, sbits;
 
-		if (policy->walk.dead)
-			continue;
-
-		dir = xfrm_policy_id2dir(policy->index);
-		if (dir >= XFRM_POLICY_MAX)
+		if (xfrm_policy_is_dead_or_sk(policy))
 			continue;
 
 		if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
@@ -1331,13 +1327,8 @@ static void xfrm_hash_rebuild(struct work_struct *work)
 
 	/* re-insert all policies by order of creation */
 	list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
-		if (policy->walk.dead)
-			continue;
-		dir = xfrm_policy_id2dir(policy->index);
-		if (dir >= XFRM_POLICY_MAX) {
-			/* skip socket policies */
+		if (xfrm_policy_is_dead_or_sk(policy))
 			continue;
-		}
 
 		hlist_del_rcu(&policy->bydst);
 
-- 
2.34.1

Re: [PATCH 09/11] xfrm: policy: use recently added helper in more places

[Florian Westphal]

Steffen Klassert <steffen.klassert@secunet.com> wrote:
> From: Florian Westphal <fw@strlen.de>
> 
> No logical change intended.

This patch is bogus and needs to be dropped/reverted or following
patch:

https://patchwork.kernel.org/project/netdevbpf/patch/20240829-xfrm-restore-dir-assign-xfrm_hash_rebuild-v2-1-1cf8958f6e8e@kernel.org/

Re: [PATCH 09/11] xfrm: policy: use recently added helper in more places

[Steffen Klassert]

On Mon, Sep 09, 2024 at 12:59:54PM +0200, Florian Westphal wrote:
> Steffen Klassert <steffen.klassert@secunet.com> wrote:
> > From: Florian Westphal <fw@strlen.de>
> > 
> > No logical change intended.
> 
> This patch is bogus and needs to be dropped/reverted or following
> patch:
> 
> https://patchwork.kernel.org/project/netdevbpf/patch/20240829-xfrm-restore-dir-assign-xfrm_hash_rebuild-v2-1-1cf8958f6e8e@kernel.org/

I'll take both patches and resend the pull request.

Thanks for the heads up!

[PATCH 10/11] xfrm: minor update to sdb and xfrm_policy comments

[Steffen Klassert]

From: Florian Westphal <fw@strlen.de>

The spd is no longer maintained as a linear list.
We also haven't been caching bundles in the xfrm_policy
struct since 2010.

While at it, add kdoc style comments for the xfrm_policy structure
and extend the description of the current rbtree based search to
mention why it needs to search the candidate set.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 include/net/xfrm.h     | 40 +++++++++++++++++++++++++++++++++++-----
 net/xfrm/xfrm_policy.c |  6 +++++-
 2 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 1fa2da22a49e..b6bfdc6416c7 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -67,13 +67,15 @@
    - instance of a transformer, struct xfrm_state (=SA)
    - template to clone xfrm_state, struct xfrm_tmpl
 
-   SPD is plain linear list of xfrm_policy rules, ordered by priority.
+   SPD is organized as hash table (for policies that meet minimum address prefix
+   length setting, net->xfrm.policy_hthresh).  Other policies are stored in
+   lists, sorted into rbtree ordered by destination and source address networks.
+   See net/xfrm/xfrm_policy.c for details.
+
    (To be compatible with existing pfkeyv2 implementations,
    many rules with priority of 0x7fffffff are allowed to exist and
    such rules are ordered in an unpredictable way, thanks to bsd folks.)
 
-   Lookup is plain linear search until the first match with selector.
-
    If "action" is "block", then we prohibit the flow, otherwise:
    if "xfrms_nr" is zero, the flow passes untransformed. Otherwise,
    policy entry has list of up to XFRM_MAX_DEPTH transformations,
@@ -86,8 +88,6 @@
                      |---. child .-> dst -. xfrm .-> xfrm_state #3
                                       |---. child .-> NULL
 
-   Bundles are cached at xrfm_policy struct (field ->bundles).
-
 
    Resolution of xrfm_tmpl
    -----------------------
@@ -526,6 +526,36 @@ struct xfrm_policy_queue {
 	unsigned long		timeout;
 };
 
+/**
+ *	struct xfrm_policy - xfrm policy
+ *	@xp_net: network namespace the policy lives in
+ *	@bydst: hlist node for SPD hash table or rbtree list
+ *	@byidx: hlist node for index hash table
+ *	@lock: serialize changes to policy structure members
+ *	@refcnt: reference count, freed once it reaches 0
+ *	@pos: kernel internal tie-breaker to determine age of policy
+ *	@timer: timer
+ *	@genid: generation, used to invalidate old policies
+ *	@priority: priority, set by userspace
+ *	@index:  policy index (autogenerated)
+ *	@if_id: virtual xfrm interface id
+ *	@mark: packet mark
+ *	@selector: selector
+ *	@lft: liftime configuration data
+ *	@curlft: liftime state
+ *	@walk: list head on pernet policy list
+ *	@polq: queue to hold packets while aqcuire operaion in progress
+ *	@bydst_reinsert: policy tree node needs to be merged
+ *	@type: XFRM_POLICY_TYPE_MAIN or _SUB
+ *	@action: XFRM_POLICY_ALLOW or _BLOCK
+ *	@flags: XFRM_POLICY_LOCALOK, XFRM_POLICY_ICMP
+ *	@xfrm_nr: number of used templates in @xfrm_vec
+ *	@family: protocol family
+ *	@security: SELinux security label
+ *	@xfrm_vec: array of templates to resolve state
+ *	@rcu: rcu head, used to defer memory release
+ *	@xdo: hardware offload state
+ */
 struct xfrm_policy {
 	possible_net_t		xp_net;
 	struct hlist_node	bydst;
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 94859b2182ec..6336baa8a93c 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -109,7 +109,11 @@ struct xfrm_pol_inexact_node {
  * 4. saddr:any list from saddr tree
  *
  * This result set then needs to be searched for the policy with
- * the lowest priority.  If two results have same prio, youngest one wins.
+ * the lowest priority.  If two candidates have the same priority, the
+ * struct xfrm_policy pos member with the lower number is used.
+ *
+ * This replicates previous single-list-search algorithm which would
+ * return first matching policy in the (ordered-by-priority) list.
  */
 
 struct xfrm_pol_inexact_key {
-- 
2.34.1

[PATCH 11/11] Revert "xfrm: add SA information to the offloaded packet"

[Steffen Klassert]

This reverts commit e7cd191f83fd899c233dfbe7dc6d96ef703dcbbd.

While supporting xfrm interfaces in the packet offload API
is needed, this patch does not do the right thing. There are
more things to do to really support xfrm interfaces, so revert
it for now.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_output.c | 21 ---------------------
 1 file changed, 21 deletions(-)

diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index a12588e7b060..e5722c95b8bb 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -706,8 +706,6 @@ int xfrm_output(struct sock *sk, struct sk_buff *skb)
 	struct xfrm_state *x = skb_dst(skb)->xfrm;
 	int family;
 	int err;
-	struct xfrm_offload *xo;
-	struct sec_path *sp;
 
 	family = (x->xso.type != XFRM_DEV_OFFLOAD_PACKET) ? x->outer_mode.family
 		: skb_dst(skb)->ops->family;
@@ -730,25 +728,6 @@ int xfrm_output(struct sock *sk, struct sk_buff *skb)
 			kfree_skb(skb);
 			return -EHOSTUNREACH;
 		}
-		sp = secpath_set(skb);
-		if (!sp) {
-			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
-			kfree_skb(skb);
-			return -ENOMEM;
-		}
-
-		sp->olen++;
-		sp->xvec[sp->len++] = x;
-		xfrm_state_hold(x);
-
-		xo = xfrm_offload(skb);
-		if (!xo) {
-			secpath_reset(skb);
-			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
-			kfree_skb(skb);
-			return -EINVAL;
-		}
-		xo->flags |= XFRM_XMIT;
 
 		return xfrm_output_resume(sk, skb, 0);
 	}
-- 
2.34.1

Re: [PATCH 0/11] pull request (net-next): ipsec-next 2024-09-09

[Steffen Klassert]

On Mon, Sep 09, 2024 at 12:03:17PM +0200, Steffen Klassert wrote:
> 1) Remove an unneeded WARN_ON on packet offload.
>    From Patrisious Haddad.
> 
> 2) Add a copy from skb_seq_state to buffer function.
>    This is needed for the upcomming IPTFS patchset.
>    From Christian Hopps.
> 
> 3) Spelling fix in xfrm.h.
>    From Simon Horman.
> 
> 4) Speed up xfrm policy insertions.
>    From Florian Westphal.
> 
> 5) Add and revert a patch to support xfrm interfaces
>    for packet offload. This patch was just half coocked.
> 
> 6) Extend usage of the new xfrm_policy_is_dead_or_sk helper.
>    From Florian Westphal.
> 
> 7) Update comments on sdb and xfrm_policy.
>    From Florian Westphal.
> 
> Please pull or let me know if there are problems.

Please wait with pulling, I forgot to apply two fixes
for the policy changes. Will send another pull request
tomorrow.