sctp: clean up route lookup calls

Change the call to take the transport parameter and set the
cached 'dst' appropriately inside the get_dst() function calls.

This will allow us in the future  to clean up source address
storage as well.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 24 insertions, 31 deletions

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index bb2f43b7e9a8..ff3e8cce7d66 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -564,8 +564,7 @@ struct sctp_af {
                                          int optname,
                                          char __user *optval,
                                          int __user *optlen);
-        struct dst_entry *(*get_dst)    (struct sctp_association *asoc,
-                                         union sctp_addr *daddr,
+        void            (*get_dst)      (struct sctp_transport *t,
                                          union sctp_addr *saddr,
                                          struct flowi *fl,
                                          struct sock *sk);
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index a1913a4b6f3a..500875f4dc41 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -247,17 +247,16 @@ 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,
-                                         struct flowi *fl,
-                                         struct sock *sk)
+static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
+                            struct flowi *fl, struct sock *sk)
 {
+        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;
@@ -270,7 +269,6 @@ static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 
-
         SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl6->daddr);
 
         if (asoc)
@@ -343,12 +341,13 @@ 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, &fl6->saddr);
-                return dst;
+        } else {
+                t->dst = NULL;
+                SCTP_DEBUG_PRINTK("NO ROUTE\n");
         }
-        SCTP_DEBUG_PRINTK("NO ROUTE\n");
-        return NULL;
 }
 
 /* Returns the number of consecutive initial bits that match in the 2 ipv6
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 68b4c4317d61..9d3f15957d12 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -463,17 +463,16 @@ static sctp_scope_t sctp_v4_scope(union sctp_addr *addr)
  * addresses. If an association is passed, trys to get a dst entry with a
  * source address that matches an address in the bind address list.
  */
-static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
-                                         union sctp_addr *daddr,
-                                         union sctp_addr *saddr,
-                                         struct flowi *fl,
-                                         struct sock *sk)
+static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
+                                struct flowi *fl, struct sock *sk)
 {
+        struct sctp_association *asoc = t->asoc;
         struct rtable *rt;
         struct flowi4 *fl4 = &fl->u.ip4;
         struct sctp_bind_addr *bp;
         struct sctp_sockaddr_entry *laddr;
         struct dst_entry *dst = NULL;
+        union sctp_addr *daddr = &t->ipaddr;
         union sctp_addr dst_saddr;
 
         memset(fl4, 0x0, sizeof(struct flowi4));
@@ -548,13 +547,12 @@ static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
 out_unlock:
         rcu_read_unlock();
 out:
+        t->dst = dst;
         if (dst)
                 SCTP_DEBUG_PRINTK("rt_dst:%pI4, rt_src:%pI4\n",
                                   &rt->rt_dst, &rt->rt_src);
         else
                 SCTP_DEBUG_PRINTK("NO ROUTE\n");
-
-        return dst;
 }
 
 /* For v4, the source address is cached in the route entry(dst). So no need
diff --git a/net/sctp/transport.c b/net/sctp/transport.c
index 1fbb920f8dfb..d8595dd1a8a7 100644
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c
@@ -213,17 +213,17 @@ void sctp_transport_set_owner(struct sctp_transport *transport,
 /* Initialize the pmtu of a transport. */
 void sctp_transport_pmtu(struct sctp_transport *transport, struct sock *sk)
 {
-        struct dst_entry *dst;
         struct flowi fl;
 
-        dst = transport->af_specific->get_dst(transport->asoc,
-                                              &transport->ipaddr,
-                                              &transport->saddr,
+        /* If we don't have a fresh route, look one up */
+        if (!transport->dst || transport->dst->obsolete > 1) {
+                dst_release(transport->dst);
+                transport->af_specific->get_dst(transport, &transport->saddr,
                                               &fl, sk);
+        }
 
-        if (dst) {
-                transport->pathmtu = dst_mtu(dst);
-                dst_release(dst);
+        if (transport->dst) {
+                transport->pathmtu = dst_mtu(transport->dst);
         } else
                 transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
 }
@@ -274,12 +274,9 @@ void sctp_transport_route(struct sctp_transport *transport,
 {
         struct sctp_association *asoc = transport->asoc;
         struct sctp_af *af = transport->af_specific;
-        union sctp_addr *daddr = &transport->ipaddr;
-        struct dst_entry *dst;
         struct flowi fl;
 
-        dst = af->get_dst(asoc, daddr, saddr, &fl, sctp_opt2sk(opt));
-        transport->dst = dst;
+        af->get_dst(transport, saddr, &fl, sctp_opt2sk(opt));
 
         if (saddr)
                 memcpy(&transport->saddr, saddr, sizeof(union sctp_addr));
@@ -289,8 +286,8 @@ void sctp_transport_route(struct sctp_transport *transport,
         if ((transport->param_flags & SPP_PMTUD_DISABLE) && transport->pathmtu) {
                 return;
         }
-        if (dst) {
-                transport->pathmtu = dst_mtu(dst);
+        if (transport->dst) {
+                transport->pathmtu = dst_mtu(transport->dst);
 
                 /* Initialize sk->sk_rcv_saddr, if the transport is the
                  * association's active path for getsockname().