sctp: Support ipv6only AF_INET6 sockets.

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

5 files changed, 91 insertions, 10 deletions

diff --git a/net/sctp/bind_addr.c b/net/sctp/bind_addr.c
index 80e6df06967a..f62bc2468935 100644
--- a/net/sctp/bind_addr.c
+++ b/net/sctp/bind_addr.c
@@ -348,6 +348,43 @@ int sctp_bind_addr_match(struct sctp_bind_addr *bp,
         return match;
 }
 
+/* Does the address 'addr' conflict with any addresses in
+ * the bp.
+ */
+int sctp_bind_addr_conflict(struct sctp_bind_addr *bp,
+                            const union sctp_addr *addr,
+                            struct sctp_sock *bp_sp,
+                            struct sctp_sock *addr_sp)
+{
+        struct sctp_sockaddr_entry *laddr;
+        int conflict = 0;
+        struct sctp_sock *sp;
+
+        /* Pick the IPv6 socket as the basis of comparison
+         * since it's usually a superset of the IPv4.
+         * If there is no IPv6 socket, then default to bind_addr.
+         */
+        if (sctp_opt2sk(bp_sp)->sk_family == AF_INET6)
+                sp = bp_sp;
+        else if (sctp_opt2sk(addr_sp)->sk_family == AF_INET6)
+                sp = addr_sp;
+        else
+                sp = bp_sp;
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(laddr, &bp->address_list, list) {
+                if (!laddr->valid)
+                        continue;
+
+                conflict = sp->pf->cmp_addr(&laddr->a, addr, sp);
+                if (conflict)
+                        break;
+        }
+        rcu_read_unlock();
+
+        return conflict;
+}
+
 /* Get the state of the entry in the bind_addr_list */
 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
                          const union sctp_addr *addr)
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index a2f4d4d51593..a238d6834b33 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -818,7 +818,7 @@ static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
                 return 1;
         /* v4-mapped-v6 addresses */
         case AF_INET:
-                if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
+                if (!__ipv6_only_sock(sctp_opt2sk(sp)))
                         return 1;
         default:
                 return 0;
@@ -840,6 +840,11 @@ static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 
         if (!af1 || !af2)
                 return 0;
+
+        /* If the socket is IPv6 only, v4 addrs will not match */
+        if (__ipv6_only_sock(sctp_opt2sk(opt)) && af1 != af2)
+                return 0;
+
         /* Today, wildcard AF_INET/AF_INET6. */
         if (sctp_is_any(addr1) || sctp_is_any(addr2))
                 return 1;
@@ -876,7 +881,11 @@ static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
                                 return 0;
                         }
                         dev_put(dev);
+                } else if (type == IPV6_ADDR_MAPPED) {
+                        if (!opt->v4mapped)
+                                return 0;
                 }
+
                 af = opt->pf->af;
         }
         return af->available(addr, opt);
@@ -919,9 +928,12 @@ static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
                                       __be16 *types)
 {
-        types[0] = SCTP_PARAM_IPV4_ADDRESS;
-        types[1] = SCTP_PARAM_IPV6_ADDRESS;
-        return 2;
+        types[0] = SCTP_PARAM_IPV6_ADDRESS;
+        if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
+                types[1] = SCTP_PARAM_IPV4_ADDRESS;
+                return 2;
+        }
+        return 1;
 }
 
 static const struct proto_ops inet6_seqpacket_ops = {
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index dd811a8456a8..cdd881142f2c 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -381,6 +381,10 @@ static int sctp_v4_addr_valid(union sctp_addr *addr,
                               struct sctp_sock *sp,
                               const struct sk_buff *skb)
 {
+        /* IPv4 addresses not allowed */
+        if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
+                return 0;
+
         /* Is this a non-unicast address or a unusable SCTP address? */
         if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr))
                 return 0;
@@ -404,6 +408,9 @@ static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
            !sysctl_ip_nonlocal_bind)
                 return 0;
 
+        if (ipv6_only_sock(sctp_opt2sk(sp)))
+                return 0;
+
         return 1;
 }
 
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index bbc7107c86cf..e8ca4e54981f 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -2364,8 +2364,13 @@ static int sctp_process_param(struct sctp_association *asoc,
         case SCTP_PARAM_IPV6_ADDRESS:
                 if (PF_INET6 != asoc->base.sk->sk_family)
                         break;
-                /* Fall through. */
+                goto do_addr_param;
+
         case SCTP_PARAM_IPV4_ADDRESS:
+                /* v4 addresses are not allowed on v6-only socket */
+                if (ipv6_only_sock(asoc->base.sk))
+                        break;
+do_addr_param:
                 af = sctp_get_af_specific(param_type2af(param.p->type));
                 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
                 scope = sctp_scope(peer_addr);
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 6aba01b0ce4e..a0e879bb202d 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -308,9 +308,16 @@ static struct sctp_af *sctp_sockaddr_af(struct sctp_sock *opt,
         if (len < sizeof (struct sockaddr))
                 return NULL;
 
-        /* Does this PF support this AF? */
-        if (!opt->pf->af_supported(addr->sa.sa_family, opt))
-                return NULL;
+        /* V4 mapped address are really of AF_INET family */
+        if (addr->sa.sa_family == AF_INET6 &&
+            ipv6_addr_v4mapped(&addr->v6.sin6_addr)) {
+                if (!opt->pf->af_supported(AF_INET, opt))
+                        return NULL;
+        } else {
+                /* Does this PF support this AF? */
+                if (!opt->pf->af_supported(addr->sa.sa_family, opt))
+                        return NULL;
+        }
 
         /* If we get this far, af is valid. */
         af = sctp_get_af_specific(addr->sa.sa_family);
@@ -4395,6 +4402,11 @@ static int sctp_getsockopt_local_addrs_num_old(struct sock *sk, int len,
                                     (AF_INET6 == addr->a.sa.sa_family))
                                         continue;
 
+                                if ((PF_INET6 == sk->sk_family) &&
+                                    inet_v6_ipv6only(sk) &&
+                                    (AF_INET == addr->a.sa.sa_family))
+                                        continue;
+
                                 cnt++;
                         }
                         rcu_read_unlock();
@@ -4435,6 +4447,10 @@ static int sctp_copy_laddrs_old(struct sock *sk, __u16 port,
                 if ((PF_INET == sk->sk_family) &&
                     (AF_INET6 == addr->a.sa.sa_family))
                         continue;
+                if ((PF_INET6 == sk->sk_family) &&
+                    inet_v6_ipv6only(sk) &&
+                    (AF_INET == addr->a.sa.sa_family))
+                        continue;
                 memcpy(&temp, &addr->a, sizeof(temp));
                 if (!temp.v4.sin_port)
                         temp.v4.sin_port = htons(port);
@@ -4470,6 +4486,10 @@ static int sctp_copy_laddrs(struct sock *sk, __u16 port, void *to,
                 if ((PF_INET == sk->sk_family) &&
                     (AF_INET6 == addr->a.sa.sa_family))
                         continue;
+                if ((PF_INET6 == sk->sk_family) &&
+                    inet_v6_ipv6only(sk) &&
+                    (AF_INET == addr->a.sa.sa_family))
+                        continue;
                 memcpy(&temp, &addr->a, sizeof(temp));
                 if (!temp.v4.sin_port)
                         temp.v4.sin_port = htons(port);
@@ -5568,8 +5588,8 @@ pp_found:
                             sk2->sk_state != SCTP_SS_LISTENING)
                                 continue;
 
-                        if (sctp_bind_addr_match(&ep2->base.bind_addr, addr,
-                                                 sctp_sk(sk))) {
+                        if (sctp_bind_addr_conflict(&ep2->base.bind_addr, addr,
+                                                 sctp_sk(sk2), sctp_sk(sk))) {
                                 ret = (long)sk2;
                                 goto fail_unlock;
                         }