[SCTP]: ADDIP: Don't use an address as source until it is ASCONF-ACKed
Sridhar Samudrala [Fri, 21 Jul 2006 21:49:25 +0000 (14:49 -0700)]
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>

include/net/sctp/structs.h
net/sctp/bind_addr.c
net/sctp/ipv6.c
net/sctp/protocol.c
net/sctp/sm_make_chunk.c
net/sctp/socket.c

index 268f2e1..e5aa7ff 100644 (file)
@@ -731,13 +731,10 @@ void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
 
 /* This is a structure for holding either an IPv6 or an IPv4 address.  */
-/* sin_family -- AF_INET or AF_INET6
- * sin_port -- ordinary port number
- * sin_addr -- cast to either (struct in_addr) or (struct in6_addr)
- */
 struct sctp_sockaddr_entry {
        struct list_head list;
        union sctp_addr a;
+       __u8 use_as_src;
 };
 
 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
@@ -1142,7 +1139,7 @@ int sctp_bind_addr_copy(struct sctp_bind_addr *dest,
                        sctp_scope_t scope, gfp_t gfp,
                        int flags);
 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
-                      gfp_t gfp);
+                      __u8 use_as_src, gfp_t gfp);
 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
                         struct sctp_sock *);
index 2b96262..2b9c12a 100644 (file)
@@ -146,7 +146,7 @@ void sctp_bind_addr_free(struct sctp_bind_addr *bp)
 
 /* Add an address to the bind address list in the SCTP_bind_addr structure. */
 int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
-                      gfp_t gfp)
+                      __u8 use_as_src, gfp_t gfp)
 {
        struct sctp_sockaddr_entry *addr;
 
@@ -163,6 +163,8 @@ int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
        if (!addr->a.v4.sin_port)
                addr->a.v4.sin_port = bp->port;
 
+       addr->use_as_src = use_as_src;
+
        INIT_LIST_HEAD(&addr->list);
        list_add_tail(&addr->list, &bp->address_list);
        SCTP_DBG_OBJCNT_INC(addr);
@@ -274,7 +276,7 @@ int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list,
                }
 
                af->from_addr_param(&addr, rawaddr, port, 0);
-               retval = sctp_add_bind_addr(bp, &addr, gfp);
+               retval = sctp_add_bind_addr(bp, &addr, 1, gfp);
                if (retval) {
                        /* Can't finish building the list, clean up. */
                        sctp_bind_addr_clean(bp);
@@ -367,7 +369,7 @@ static int sctp_copy_one_addr(struct sctp_bind_addr *dest,
                    (((AF_INET6 == addr->sa.sa_family) &&
                      (flags & SCTP_ADDR6_ALLOWED) &&
                      (flags & SCTP_ADDR6_PEERSUPP))))
-                       error = sctp_add_bind_addr(dest, addr, gfp);
+                       error = sctp_add_bind_addr(dest, addr, 1, gfp);
        }
 
        return error;
index 8ef0807..99c0cef 100644 (file)
@@ -290,7 +290,8 @@ static void sctp_v6_get_saddr(struct sctp_association *asoc,
        sctp_read_lock(addr_lock);
        list_for_each(pos, &bp->address_list) {
                laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
-               if ((laddr->a.sa.sa_family == AF_INET6) &&
+               if ((laddr->use_as_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)) {
index 816c033..1ab03a2 100644 (file)
@@ -240,7 +240,7 @@ int sctp_copy_local_addr_list(struct sctp_bind_addr *bp, sctp_scope_t scope,
                            (((AF_INET6 == addr->a.sa.sa_family) &&
                              (copy_flags & SCTP_ADDR6_ALLOWED) &&
                              (copy_flags & SCTP_ADDR6_PEERSUPP)))) {
-                               error = sctp_add_bind_addr(bp, &addr->a, 
+                               error = sctp_add_bind_addr(bp, &addr->a, 1,
                                                           GFP_ATOMIC);
                                if (error)
                                        goto end_copy;
@@ -486,6 +486,8 @@ static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
                list_for_each(pos, &bp->address_list) {
                        laddr = list_entry(pos, struct sctp_sockaddr_entry,
                                           list);
+                       if (!laddr->use_as_src)
+                               continue;
                        sctp_v4_dst_saddr(&dst_saddr, dst, bp->port);
                        if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
                                goto out_unlock;
@@ -506,7 +508,8 @@ static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
        list_for_each(pos, &bp->address_list) {
                laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
 
-               if (AF_INET == laddr->a.sa.sa_family) {
+               if ((laddr->use_as_src) &&
+                   (AF_INET == laddr->a.sa.sa_family)) {
                        fl.fl4_src = laddr->a.v4.sin_addr.s_addr;
                        if (!ip_route_output_key(&rt, &fl)) {
                                dst = &rt->u.dst;
index 8134e8b..4f11f58 100644 (file)
@@ -1493,7 +1493,7 @@ no_hmac:
 
        /* Also, add the destination address. */
        if (list_empty(&retval->base.bind_addr.address_list)) {
-               sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
+               sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1,
                                   GFP_ATOMIC);
        }
 
@@ -2565,6 +2565,7 @@ static int sctp_asconf_param_success(struct sctp_association *asoc,
        union sctp_addr_param *addr_param;
        struct list_head *pos;
        struct sctp_transport *transport;
+       struct sctp_sockaddr_entry *saddr;
        int retval = 0;
 
        addr_param = (union sctp_addr_param *)
@@ -2578,7 +2579,11 @@ static int sctp_asconf_param_success(struct sctp_association *asoc,
        case SCTP_PARAM_ADD_IP:
                sctp_local_bh_disable();
                sctp_write_lock(&asoc->base.addr_lock);
-               retval = sctp_add_bind_addr(bp, &addr, GFP_ATOMIC);
+               list_for_each(pos, &bp->address_list) {
+                       saddr = list_entry(pos, struct sctp_sockaddr_entry, list);
+                       if (sctp_cmp_addr_exact(&saddr->a, &addr))
+                               saddr->use_as_src = 1;
+               }
                sctp_write_unlock(&asoc->base.addr_lock);
                sctp_local_bh_enable();
                break;
@@ -2591,6 +2596,7 @@ static int sctp_asconf_param_success(struct sctp_association *asoc,
                list_for_each(pos, &asoc->peer.transport_addr_list) {
                        transport = list_entry(pos, struct sctp_transport,
                                                 transports);
+                       dst_release(transport->dst);
                        sctp_transport_route(transport, NULL,
                                             sctp_sk(asoc->base.sk));
                }
index 518c55a..54722e6 100644 (file)
@@ -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;