From: bluhm <bluhm@openbsd.org>
Date: Mon, 5 Sep 2022 15:47:39 +0000 (+0000)
Subject: Move mld6 address variables from data to stack memory to make them
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=56bdcea2438f0672fb665051b5f930370b0f032e;p=openbsd

Move mld6 address variables from data to stack memory to make them
MP safe.  Due to the KAME scope address hack, the link-local all
nodes and all routers IPv6 addresses cannot be const.
OK benno@
---

diff --git a/sys/netinet6/mld6.c b/sys/netinet6/mld6.c
index 205d7cc297f..15502939c30 100644
--- a/sys/netinet6/mld6.c
+++ b/sys/netinet6/mld6.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mld6.c,v 1.59 2022/09/04 06:49:11 jsg Exp $	*/
+/*	$OpenBSD: mld6.c,v 1.60 2022/09/05 15:47:39 bluhm Exp $	*/
 /*	$KAME: mld6.c,v 1.26 2001/02/16 14:50:35 itojun Exp $	*/
 
 /*
@@ -85,9 +85,6 @@
 
 static struct ip6_pktopts ip6_opts;
 int	mld6_timers_are_running;	/* [N] shortcut for fast timer */
-/* XXX: These are necessary for KAME's link-local hack */
-static struct in6_addr mld_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
-static struct in6_addr mld_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
 
 void mld6_checktimer(struct ifnet *);
 static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *);
@@ -118,6 +115,9 @@ mld6_init(void)
 void
 mld6_start_listening(struct in6_multi *in6m)
 {
+	/* XXX: These are necessary for KAME's link-local hack */
+	struct in6_addr all_nodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
+
 	/*
 	 * RFC2710 page 10:
 	 * The node never sends a Report or Done for the link-scope all-nodes
@@ -125,9 +125,10 @@ mld6_start_listening(struct in6_multi *in6m)
 	 * MLD messages are never sent for multicast addresses whose scope is 0
 	 * (reserved) or 1 (node-local).
 	 */
-	mld_all_nodes_linklocal.s6_addr16[1] = htons(in6m->in6m_ifidx);/* XXX */
-	if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld_all_nodes_linklocal) ||
-	    __IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < __IPV6_ADDR_SCOPE_LINKLOCAL) {
+	all_nodes.s6_addr16[1] = htons(in6m->in6m_ifidx);
+	if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_nodes) ||
+	    __IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
+	    __IPV6_ADDR_SCOPE_LINKLOCAL) {
 		in6m->in6m_timer = 0;
 		in6m->in6m_state = MLD_OTHERLISTENER;
 	} else {
@@ -143,15 +144,19 @@ mld6_start_listening(struct in6_multi *in6m)
 void
 mld6_stop_listening(struct in6_multi *in6m)
 {
-	mld_all_nodes_linklocal.s6_addr16[1] = htons(in6m->in6m_ifidx);/* XXX */
-	mld_all_routers_linklocal.s6_addr16[1] =
-	    htons(in6m->in6m_ifidx); /* XXX: necessary when mrouting */
+	/* XXX: These are necessary for KAME's link-local hack */
+	struct in6_addr all_nodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
+	struct in6_addr all_routers = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
+
+	all_nodes.s6_addr16[1] = htons(in6m->in6m_ifidx);
+	/* XXX: necessary when mrouting */
+	all_routers.s6_addr16[1] = htons(in6m->in6m_ifidx);
 
 	if (in6m->in6m_state == MLD_IREPORTEDLAST &&
-	    (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld_all_nodes_linklocal)) &&
-	    __IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > __IPV6_ADDR_SCOPE_INTFACELOCAL)
-		mld6_sendpkt(in6m, MLD_LISTENER_DONE,
-		    &mld_all_routers_linklocal);
+	    (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_nodes)) &&
+	    __IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) >
+	    __IPV6_ADDR_SCOPE_INTFACELOCAL)
+		mld6_sendpkt(in6m, MLD_LISTENER_DONE, &all_routers);
 }
 
 void
@@ -163,6 +168,8 @@ mld6_input(struct mbuf *m, int off)
 	struct in6_multi *in6m;
 	struct ifmaddr *ifma;
 	int timer;		/* timer value in the MLD query header */
+	/* XXX: These are necessary for KAME's link-local hack */
+	struct in6_addr all_nodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
 
 	IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh));
 	if (mldh == NULL) {
@@ -239,15 +246,13 @@ mld6_input(struct mbuf *m, int off)
 		timer = ntohs(mldh->mld_maxdelay)*PR_FASTHZ/MLD_TIMER_SCALE;
 		if (timer == 0 && mldh->mld_maxdelay)
 			timer = 1;
-		mld_all_nodes_linklocal.s6_addr16[1] =
-			htons(ifp->if_index); /* XXX */
+		all_nodes.s6_addr16[1] = htons(ifp->if_index);
 
 		TAILQ_FOREACH(ifma, &ifp->if_maddrlist, ifma_list) {
 			if (ifma->ifma_addr->sa_family != AF_INET6)
 				continue;
 			in6m = ifmatoin6m(ifma);
-			if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
-						&mld_all_nodes_linklocal) ||
+			if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_nodes) ||
 			    __IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
 			    __IPV6_ADDR_SCOPE_LINKLOCAL)
 				continue;