1 files changed, 107 insertions, 78 deletions

diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 185fe05..0bb0d7c 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -80,6 +80,13 @@
 
 #include <asm/uaccess.h>
 
+static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
+					 union sctp_addr *s2);
+static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
+			      __be16 port);
+static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
+			    const union sctp_addr *addr2);
+
 /* Event handler for inet6 address addition/deletion events.
  * The sctp_local_addr_list needs to be protocted by a spin lock since
  * multiple notifiers (say IPv4 and IPv6) may be running at the same
@@ -240,37 +247,107 @@ static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 /* Returns the dst cache entry for the given source and destination ip
  * addresses.
  */
-static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
-					 union sctp_addr *daddr,
-					 union sctp_addr *saddr)
+static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
+			    struct flowi *fl, struct sock *sk)
 {
-	struct dst_entry *dst;
-	struct flowi6 fl6;
+	struct sctp_association *asoc = t->asoc;
+	struct dst_entry *dst = NULL;
+	struct flowi6 *fl6 = &fl->u.ip6;
+	struct sctp_bind_addr *bp;
+	struct sctp_sockaddr_entry *laddr;
+	union sctp_addr *baddr = NULL;
+	union sctp_addr *daddr = &t->ipaddr;
+	union sctp_addr dst_saddr;
+	__u8 matchlen = 0;
+	__u8 bmatchlen;
+	sctp_scope_t scope;
 
-	memset(&fl6, 0, sizeof(fl6));
-	ipv6_addr_copy(&fl6.daddr, &daddr->v6.sin6_addr);
+	memset(fl6, 0, sizeof(struct flowi6));
+	ipv6_addr_copy(&fl6->daddr, &daddr->v6.sin6_addr);
+	fl6->fl6_dport = daddr->v6.sin6_port;
+	fl6->flowi6_proto = IPPROTO_SCTP;
 	if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
-		fl6.flowi6_oif = daddr->v6.sin6_scope_id;
+		fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 
+	SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl6->daddr);
 
-	SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl6.daddr);
+	if (asoc)
+		fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 
 	if (saddr) {
-		ipv6_addr_copy(&fl6.saddr, &saddr->v6.sin6_addr);
-		SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl6.saddr);
+		ipv6_addr_copy(&fl6->saddr, &saddr->v6.sin6_addr);
+		fl6->fl6_sport = saddr->v6.sin6_port;
+		SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl6->saddr);
+	}
+
+	dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
+	if (!asoc || saddr)
+		goto out;
+
+	bp = &asoc->base.bind_addr;
+	scope = sctp_scope(daddr);
+	/* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
+	 * to see if we can use it.
+	 */
+	if (!IS_ERR(dst)) {
+		/* Walk through the bind address list and look for a bind
+		 * address that matches the source address of the returned dst.
+		 */
+		sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
+		rcu_read_lock();
+		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
+			if (!laddr->valid || (laddr->state != SCTP_ADDR_SRC))
+				continue;
+
+			/* Do not compare against v4 addrs */
+			if ((laddr->a.sa.sa_family == AF_INET6) &&
+			    (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
+				rcu_read_unlock();
+				goto out;
+			}
+		}
+		rcu_read_unlock();
+		/* None of the bound addresses match the source address of the
+		 * dst. So release it.
+		 */
+		dst_release(dst);
+		dst = NULL;
 	}
 
-	dst = ip6_route_output(&init_net, NULL, &fl6);
-	if (!dst->error) {
+	/* Walk through the bind address list and try to get the
+	 * best source address for a given destination.
+	 */
+	rcu_read_lock();
+	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
+		if (!laddr->valid && laddr->state != SCTP_ADDR_SRC)
+			continue;
+		if ((laddr->a.sa.sa_family == AF_INET6) &&
+		    (scope <= sctp_scope(&laddr->a))) {
+			bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
+			if (!baddr || (matchlen < bmatchlen)) {
+				baddr = &laddr->a;
+				matchlen = bmatchlen;
+			}
+		}
+	}
+	rcu_read_unlock();
+	if (baddr) {
+		ipv6_addr_copy(&fl6->saddr, &baddr->v6.sin6_addr);
+		fl6->fl6_sport = baddr->v6.sin6_port;
+		dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
+	}
+
+out:
+	if (!IS_ERR(dst)) {
 		struct rt6_info *rt;
 		rt = (struct rt6_info *)dst;
+		t->dst = dst;
 		SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
-			&rt->rt6i_dst.addr, &rt->rt6i_src.addr);
-		return dst;
+			&rt->rt6i_dst.addr, &fl6->saddr);
+	} else {
+		t->dst = NULL;
+		SCTP_DEBUG_PRINTK("NO ROUTE\n");
 	}
-	SCTP_DEBUG_PRINTK("NO ROUTE\n");
-	dst_release(dst);
-	return NULL;
 }
 
 /* Returns the number of consecutive initial bits that match in the 2 ipv6
@@ -286,64 +363,18 @@ static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
  * and asoc's bind address list.
  */
 static void sctp_v6_get_saddr(struct sctp_sock *sk,
-			      struct sctp_association *asoc,
-			      struct dst_entry *dst,
-			      union sctp_addr *daddr,
-			      union sctp_addr *saddr)
+			      struct sctp_transport *t,
+			      struct flowi *fl)
 {
-	struct sctp_bind_addr *bp;
-	struct sctp_sockaddr_entry *laddr;
-	sctp_scope_t scope;
-	union sctp_addr *baddr = NULL;
-	__u8 matchlen = 0;
-	__u8 bmatchlen;
+	struct flowi6 *fl6 = &fl->u.ip6;
+	union sctp_addr *saddr = &t->saddr;
 
-	SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p daddr:%pI6 ",
-			  __func__, asoc, dst, &daddr->v6.sin6_addr);
-
-	if (!asoc) {
-		ipv6_dev_get_saddr(sock_net(sctp_opt2sk(sk)),
-				   dst ? ip6_dst_idev(dst)->dev : NULL,
-				   &daddr->v6.sin6_addr,
-				   inet6_sk(&sk->inet.sk)->srcprefs,
-				   &saddr->v6.sin6_addr);
-		SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: %pI6\n",
-				  &saddr->v6.sin6_addr);
-		return;
-	}
-
-	scope = sctp_scope(daddr);
-
-	bp = &asoc->base.bind_addr;
+	SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 
-	/* Go through the bind address list and find the best source address
-	 * that matches the scope of the destination address.
-	 */
-	rcu_read_lock();
-	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
-		if (!laddr->valid)
-			continue;
-		if ((laddr->state == SCTP_ADDR_SRC) &&
-		    (laddr->a.sa.sa_family == AF_INET6) &&
-		    (scope <= sctp_scope(&laddr->a))) {
-			bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
-			if (!baddr || (matchlen < bmatchlen)) {
-				baddr = &laddr->a;
-				matchlen = bmatchlen;
-			}
-		}
-	}
-
-	if (baddr) {
-		memcpy(saddr, baddr, sizeof(union sctp_addr));
-		SCTP_DEBUG_PRINTK("saddr: %pI6\n", &saddr->v6.sin6_addr);
-	} else {
-		pr_err("%s: asoc:%p Could not find a valid source "
-		       "address for the dest:%pI6\n",
-		       __func__, asoc, &daddr->v6.sin6_addr);
+	if (t->dst) {
+		saddr->v6.sin6_family = AF_INET6;
+		ipv6_addr_copy(&saddr->v6.sin6_addr, &fl6->saddr);
 	}
-
-	rcu_read_unlock();
 }
 
 /* Make a copy of all potential local addresses. */
@@ -465,14 +496,13 @@ static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 	return length;
 }
 
-/* Initialize a sctp_addr from a dst_entry. */
-static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
+/* Initialize a sctp_addr from struct in6_addr. */
+static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 			      __be16 port)
 {
-	struct rt6_info *rt = (struct rt6_info *)dst;
 	addr->sa.sa_family = AF_INET6;
 	addr->v6.sin6_port = port;
-	ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
+	ipv6_addr_copy(&addr->v6.sin6_addr, saddr);
 }
 
 /* Compare addresses exactly.
@@ -531,7 +561,7 @@ static int sctp_v6_is_any(const union sctp_addr *addr)
 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 {
 	int type;
-	struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
+	const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 
 	type = ipv6_addr_type(in6);
 	if (IPV6_ADDR_ANY == type)
@@ -959,7 +989,6 @@ static struct sctp_af sctp_af_inet6 = {
 	.to_sk_daddr	   = sctp_v6_to_sk_daddr,
 	.from_addr_param   = sctp_v6_from_addr_param,
 	.to_addr_param	   = sctp_v6_to_addr_param,
-	.dst_saddr	   = sctp_v6_dst_saddr,
 	.cmp_addr	   = sctp_v6_cmp_addr,
 	.scope		   = sctp_v6_scope,
 	.addr_valid	   = sctp_v6_addr_valid,