Merge tag 'ipsec-next-2024-09-10' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next

Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2024-09-10

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 cooked.

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.

8) Fix a null pointer dereference in the new policy insertion
   code From Florian Westphal.

9) Fix an uninitialized variable in the new policy insertion
   code. From Nathan Chancellor.

* tag 'ipsec-next-2024-09-10' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next:
  xfrm: policy: Restore dir assignments in xfrm_hash_rebuild()
  xfrm: policy: fix null dereference
  Revert "xfrm: add SA information to the offloaded packet"
  xfrm: minor update to sdb and xfrm_policy comments
  xfrm: policy: use recently added helper in more places
  xfrm: add SA information to the offloaded packet
  xfrm: policy: remove remaining use of inexact list
  xfrm: switch migrate to xfrm_policy_lookup_bytype
  xfrm: policy: don't iterate inexact policies twice at insert time
  selftests: add xfrm policy insertion speed test script
  xfrm: Correct spelling in xfrm.h
  net: add copy from skb_seq_state to buffer function
  xfrm: Remove documentation WARN_ON to limit return values for offloaded SA
====================

Link: https://patch.msgid.link/20240910065507.2436394-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 35 insertions, 0 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index a52638363ea5..038a059b5924 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4411,6 +4411,41 @@ 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,