From f3c8d50914a0d7408be632f4a866925bf1fe4db8 Mon Sep 17 00:00:00 2001
From: mpi <mpi@openbsd.org>
Date: Mon, 29 May 2017 14:36:22 +0000
Subject: [PATCH] Per-interface list of addresses, both multicast and unicast,
 are currently protected by the NET_LOCK().

They are not accessed in the hot path, so protecting them with a
mutex could be an option.  However since we're now going to run
with a NET_LOCK() for some time, assert that it is held.

IPsec is not yet ready to run without KERNEL_LOCK(), so assert it
is held, even in the forwarding path.

Tested by sthen@, ok visa@, claudio@, bluhm@
---
 sys/netinet/in.c         |  6 +-----
 sys/netinet/in_var.h     |  4 +++-
 sys/netinet/ip_input.c   |  9 ++++-----
 sys/netinet/ip_output.c  | 12 +++---------
 sys/netinet6/ip6_input.c |  5 ++---
 5 files changed, 13 insertions(+), 23 deletions(-)

diff --git a/sys/netinet/in.c b/sys/netinet/in.c
index e2f0ed59b7b..4aa12f06985 100644
--- a/sys/netinet/in.c
+++ b/sys/netinet/in.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: in.c,v 1.138 2017/05/16 12:24:01 mpi Exp $	*/
+/*	$OpenBSD: in.c,v 1.139 2017/05/29 14:36:22 mpi Exp $	*/
 /*	$NetBSD: in.c,v 1.26 1996/02/13 23:41:39 christos Exp $	*/
 
 /*
@@ -798,8 +798,6 @@ in_addmulti(struct in_addr *ap, struct ifnet *ifp)
 	struct in_multi *inm;
 	struct ifreq ifr;
 
-	NET_ASSERT_LOCKED();
-
 	/*
 	 * See if address already in list.
 	 */
@@ -901,10 +899,8 @@ in_hasmulti(struct in_addr *ap, struct ifnet *ifp)
 	struct in_multi *inm;
 	int joined;
 
-	KERNEL_LOCK();
 	IN_LOOKUP_MULTI(*ap, ifp, inm);
 	joined = (inm != NULL);
-	KERNEL_UNLOCK();
 
 	return (joined);
 }
diff --git a/sys/netinet/in_var.h b/sys/netinet/in_var.h
index a265580cd43..d1f7d1fcd21 100644
--- a/sys/netinet/in_var.h
+++ b/sys/netinet/in_var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: in_var.h,v 1.39 2016/06/15 19:39:34 gerhard Exp $	*/
+/*	$OpenBSD: in_var.h,v 1.40 2017/05/29 14:36:22 mpi Exp $	*/
 /*	$NetBSD: in_var.h,v 1.16 1996/02/13 23:42:15 christos Exp $	*/
 
 /*
@@ -86,6 +86,7 @@ struct	in_aliasreq {
 	/* struct in_ifaddr *ia; */					\
 do {									\
 	struct ifaddr *ifa;						\
+	NET_ASSERT_LOCKED();						\
 	TAILQ_FOREACH(ifa, &(ifp)->if_addrlist, ifa_list) {		\
 		if (ifa->ifa_addr->sa_family == AF_INET)		\
 			break;						\
@@ -142,6 +143,7 @@ do {									\
 	struct ifmaddr *ifma;						\
 									\
 	(inm) = NULL;							\
+	NET_ASSERT_LOCKED();						\
 	TAILQ_FOREACH(ifma, &(ifp)->if_maddrlist, ifma_list)		\
 		if (ifma->ifma_addr->sa_family == AF_INET &&		\
 		    ifmatoinm(ifma)->inm_addr.s_addr == (addr).s_addr) {\
diff --git a/sys/netinet/ip_input.c b/sys/netinet/ip_input.c
index 7e79db49813..7eeb83b07c9 100644
--- a/sys/netinet/ip_input.c
+++ b/sys/netinet/ip_input.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip_input.c,v 1.306 2017/05/28 12:22:54 jsg Exp $	*/
+/*	$OpenBSD: ip_input.c,v 1.307 2017/05/29 14:36:22 mpi Exp $	*/
 /*	$NetBSD: ip_input.c,v 1.30 1996/03/16 23:53:58 christos Exp $	*/
 
 /*
@@ -441,9 +441,9 @@ ipv4_input(struct mbuf *m)
 	if (ipsec_in_use) {
 		int rv;
 
-		KERNEL_LOCK();
+		KERNEL_ASSERT_LOCKED();
+
 		rv = ipsec_forward_check(m, hlen, AF_INET);
-		KERNEL_UNLOCK();
 		if (rv != 0) {
 			ipstat_inc(ips_cantforward);
 			goto bad;
@@ -667,7 +667,7 @@ in_ouraddr(struct mbuf *m, struct ifnet *ifp, struct rtentry **prt)
 		 * interface, and that M_BCAST will only be set on a BROADCAST
 		 * interface.
 		 */
-		KERNEL_LOCK();
+		NET_ASSERT_LOCKED();
 		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
 			if (ifa->ifa_addr->sa_family != AF_INET)
 				continue;
@@ -678,7 +678,6 @@ in_ouraddr(struct mbuf *m, struct ifnet *ifp, struct rtentry **prt)
 				break;
 			}
 		}
-		KERNEL_UNLOCK();
 	}
 
 	return (match);
diff --git a/sys/netinet/ip_output.c b/sys/netinet/ip_output.c
index aa2d3dd2380..3536c450e67 100644
--- a/sys/netinet/ip_output.c
+++ b/sys/netinet/ip_output.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip_output.c,v 1.339 2017/04/19 15:21:54 bluhm Exp $	*/
+/*	$OpenBSD: ip_output.c,v 1.340 2017/05/29 14:36:22 mpi Exp $	*/
 /*	$NetBSD: ip_output.c,v 1.28 1996/02/13 23:43:07 christos Exp $	*/
 
 /*
@@ -192,11 +192,9 @@ reroute:
 		if (ip->ip_src.s_addr == INADDR_ANY) {
 			struct in_ifaddr *ia;
 
-			KERNEL_LOCK();
 			IFP_TO_IA(ifp, ia);
 			if (ia != NULL)
 				ip->ip_src = ia->ia_addr.sin_addr;
-			KERNEL_UNLOCK();
 		}
 	} else {
 		struct in_ifaddr *ia;
@@ -233,11 +231,10 @@ reroute:
 
 #ifdef IPSEC
 	if (ipsec_in_use || inp != NULL) {
-		KERNEL_LOCK();
+		KERNEL_ASSERT_LOCKED();
 		/* Do we have any pending SAs to apply ? */
 		tdb = ip_output_ipsec_lookup(m, hlen, &error, inp,
 		    ipsecflowinfo);
-		KERNEL_UNLOCK();
 		if (error != 0) {
 			/* Should silently drop packet */
 			if (error == -EINVAL)
@@ -307,11 +304,9 @@ reroute:
 		if (ip->ip_src.s_addr == INADDR_ANY) {
 			struct in_ifaddr *ia;
 
-			KERNEL_LOCK();
 			IFP_TO_IA(ifp, ia);
 			if (ia != NULL)
 				ip->ip_src = ia->ia_addr.sin_addr;
-			KERNEL_UNLOCK();
 		}
 
 		if ((imo == NULL || imo->imo_loop) &&
@@ -407,10 +402,9 @@ sendit:
 	 * Check if the packet needs encapsulation.
 	 */
 	if (tdb != NULL) {
-		KERNEL_LOCK();
+		KERNEL_ASSERT_LOCKED();
 		/* Callee frees mbuf */
 		error = ip_output_ipsec_send(tdb, m, ifp, ro);
-		KERNEL_UNLOCK();
 		goto done;
 	}
 #endif /* IPSEC */
diff --git a/sys/netinet6/ip6_input.c b/sys/netinet6/ip6_input.c
index 00b30139913..183d7807e81 100644
--- a/sys/netinet6/ip6_input.c
+++ b/sys/netinet6/ip6_input.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip6_input.c,v 1.190 2017/05/28 09:25:51 bluhm Exp $	*/
+/*	$OpenBSD: ip6_input.c,v 1.191 2017/05/29 14:36:22 mpi Exp $	*/
 /*	$KAME: ip6_input.c,v 1.188 2001/03/29 05:34:31 itojun Exp $	*/
 
 /*
@@ -474,9 +474,8 @@ ip6_input(struct mbuf *m)
 	if (ipsec_in_use) {
 		int rv;
 
-		KERNEL_LOCK();
+		KERNEL_ASSERT_LOCKED();
 		rv = ipsec_forward_check(m, off, AF_INET6);
-		KERNEL_UNLOCK();
 		if (rv != 0) {
 			ip6stat_inc(ip6s_cantforward);
 			goto bad;
-- 
2.20.1