[SCTP]: ADDIP: Don't use an address as source until it is ASCONF-ACKed

This implements Rules D1 and D4 of Sec 4.3 in the ADDIP draft.

Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 58 insertions, 14 deletions

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 518c55ab610b..54722e622e6d 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -369,7 +369,7 @@ SCTP_STATIC int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len)
 
         /* Use GFP_ATOMIC since BHs are disabled.  */
         addr->v4.sin_port = ntohs(addr->v4.sin_port);
-        ret = sctp_add_bind_addr(bp, addr, GFP_ATOMIC);
+        ret = sctp_add_bind_addr(bp, addr, 1, GFP_ATOMIC);
         addr->v4.sin_port = htons(addr->v4.sin_port);
         sctp_write_unlock(&ep->base.addr_lock);
         sctp_local_bh_enable();
@@ -491,6 +491,7 @@ static int sctp_send_asconf_add_ip(struct sock		*sk,
         struct sctp_chunk               *chunk;
         struct sctp_sockaddr_entry      *laddr;
         union sctp_addr                 *addr;
+        union sctp_addr                 saveaddr;
         void                            *addr_buf;
         struct sctp_af                  *af;
         struct list_head                *pos;
@@ -558,14 +559,26 @@ static int sctp_send_asconf_add_ip(struct sock		*sk,
                 }
 
                 retval = sctp_send_asconf(asoc, chunk);
+                if (retval)
+                        goto out;
 
-                /* FIXME: After sending the add address ASCONF chunk, we
-                 * cannot append the address to the association's binding
-                 * address list, because the new address may be used as the
-                 * source of a message sent to the peer before the ASCONF
-                 * chunk is received by the peer.  So we should wait until
-                 * ASCONF_ACK is received.
+                /* Add the new addresses to the bind address list with
+                 * use_as_src set to 0.
                  */
+                sctp_local_bh_disable();
+                sctp_write_lock(&asoc->base.addr_lock);
+                addr_buf = addrs;
+                for (i = 0; i < addrcnt; i++) {
+                        addr = (union sctp_addr *)addr_buf;
+                        af = sctp_get_af_specific(addr->v4.sin_family);
+                        memcpy(&saveaddr, addr, af->sockaddr_len);
+                        saveaddr.v4.sin_port = ntohs(saveaddr.v4.sin_port);
+                        retval = sctp_add_bind_addr(bp, &saveaddr, 0,
+                                                    GFP_ATOMIC);
+                        addr_buf += af->sockaddr_len;
+                }
+                sctp_write_unlock(&asoc->base.addr_lock);
+                sctp_local_bh_enable();
         }
 
 out:
@@ -676,12 +689,15 @@ static int sctp_send_asconf_del_ip(struct sock		*sk,
         struct sctp_sock        *sp;
         struct sctp_endpoint    *ep;
         struct sctp_association *asoc;
+        struct sctp_transport   *transport;
         struct sctp_bind_addr   *bp;
         struct sctp_chunk       *chunk;
         union sctp_addr         *laddr;
+        union sctp_addr         saveaddr;
         void                    *addr_buf;
         struct sctp_af          *af;
-        struct list_head        *pos;
+        struct list_head        *pos, *pos1;
+        struct sctp_sockaddr_entry *saddr;
         int                     i;
         int                     retval = 0;
 
@@ -748,14 +764,42 @@ static int sctp_send_asconf_del_ip(struct sock		*sk,
                         goto out;
                 }
 
-                retval = sctp_send_asconf(asoc, chunk);
+                /* Reset use_as_src flag for the addresses in the bind address
+                 * list that are to be deleted.
+                 */
+                sctp_local_bh_disable();
+                sctp_write_lock(&asoc->base.addr_lock);
+                addr_buf = addrs;
+                for (i = 0; i < addrcnt; i++) {
+                        laddr = (union sctp_addr *)addr_buf;
+                        af = sctp_get_af_specific(laddr->v4.sin_family);
+                        memcpy(&saveaddr, laddr, af->sockaddr_len);
+                        saveaddr.v4.sin_port = ntohs(saveaddr.v4.sin_port);
+                        list_for_each(pos1, &bp->address_list) {
+                                saddr = list_entry(pos1,
+                                                   struct sctp_sockaddr_entry,
+                                                   list);
+                                if (sctp_cmp_addr_exact(&saddr->a, &saveaddr))
+                                        saddr->use_as_src = 0;
+                        }
+                        addr_buf += af->sockaddr_len;
+                }
+                sctp_write_unlock(&asoc->base.addr_lock);
+                sctp_local_bh_enable();
 
-                /* FIXME: After sending the delete address ASCONF chunk, we
-                 * cannot remove the addresses from the association's bind
-                 * address list, because there maybe some packet send to
-                 * the delete addresses, so we should wait until ASCONF_ACK
-                 * packet is received.
+                /* Update the route and saddr entries for all the transports
+                 * as some of the addresses in the bind address list are
+                 * about to be deleted and cannot be used as source addresses.
                  */
+                list_for_each(pos1, &asoc->peer.transport_addr_list) {
+                        transport = list_entry(pos1, struct sctp_transport,
+                                               transports);
+                        dst_release(transport->dst);
+                        sctp_transport_route(transport, NULL,
+                                             sctp_sk(asoc->base.sk));
+                }
+
+                retval = sctp_send_asconf(asoc, chunk);
         }
 out:
         return retval;