Run raw IP input in parallel.

Running raw IPv4 input with shared net lock in parallel is less
complex than UDP.  Especially there is no socket splicing.

New ip_deliver() may run with shared or exclusive net lock.  The
last parameter indicates the mode.  If is is running with shared
netlock and encounters a protocol that needs exclusive lock, the
packet is queued.  Old ip_ours() always queued the packet.  Now it
calls ip_deliver() with shared net lock, and if that cannot handle
the packet completely, the packet is queued and later processed
with exclusive net lock.

In case of an IPv6 header chain, that switches from shared to
exclusive processing, the next protocol and mbuf offset are stored
in a mbuf tag.

OK mvs@

1 files changed, 10 insertions, 11 deletions

diff --git a/sys/netinet6/ip6_input.c b/sys/netinet6/ip6_input.c
index 112fe60376d..5f4e991e0f8 100644
--- a/sys/netinet6/ip6_input.c
+++ b/sys/netinet6/ip6_input.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip6_input.c,v 1.259 2024/02/28 10:57:20 bluhm Exp $	*/
+/*	$OpenBSD: ip6_input.c,v 1.260 2024/04/14 20:46:27 bluhm Exp $	*/
 /*	$KAME: ip6_input.c,v 1.188 2001/03/29 05:34:31 itojun Exp $	*/
 
 /*
@@ -166,11 +166,6 @@ ip6_init(void)
 #endif
 }
 
-struct ip6_offnxt {
-	int	ion_off;
-	int	ion_nxt;
-};
-
 /*
  * Enqueue packet for local delivery.  Queuing is used as a boundary
  * between the network layer (input/forward path) running with
@@ -190,10 +185,14 @@ ip6_ours(struct mbuf **mp, int *offp, int nxt, int af)
 	if (af != AF_UNSPEC)
 		return nxt;
 
+	nxt = ip_deliver(mp, offp, nxt, AF_INET6, 1);
+	if (nxt == IPPROTO_DONE)
+		return IPPROTO_DONE;
+
 	/* save values for later, use after dequeue */
 	if (*offp != sizeof(struct ip6_hdr)) {
 		struct m_tag *mtag;
-		struct ip6_offnxt *ion;
+		struct ipoffnxt *ion;
 
 		/* mbuf tags are expensive, but only used for header options */
 		mtag = m_tag_get(PACKET_TAG_IP6_OFFNXT, sizeof(*ion),
@@ -203,7 +202,7 @@ ip6_ours(struct mbuf **mp, int *offp, int nxt, int af)
 			m_freemp(mp);
 			return IPPROTO_DONE;
 		}
-		ion = (struct ip6_offnxt *)(mtag + 1);
+		ion = (struct ipoffnxt *)(mtag + 1);
 		ion->ion_off = *offp;
 		ion->ion_nxt = nxt;
 
@@ -234,9 +233,9 @@ ip6intr(void)
 #endif
 		mtag = m_tag_find(m, PACKET_TAG_IP6_OFFNXT, NULL);
 		if (mtag != NULL) {
-			struct ip6_offnxt *ion;
+			struct ipoffnxt *ion;
 
-			ion = (struct ip6_offnxt *)(mtag + 1);
+			ion = (struct ipoffnxt *)(mtag + 1);
 			off = ion->ion_off;
 			nxt = ion->ion_nxt;
 
@@ -248,7 +247,7 @@ ip6intr(void)
 			off = sizeof(struct ip6_hdr);
 			nxt = ip6->ip6_nxt;
 		}
-		nxt = ip_deliver(&m, &off, nxt, AF_INET6);
+		nxt = ip_deliver(&m, &off, nxt, AF_INET6, 0);
 		KASSERT(nxt == IPPROTO_DONE);
 	}
 }