[SCTP]: Fix the bind_addr info during migration.

During accept/migrate the code attempts to copy the addresses from
the parent endpoint to the new endpoint.   However, if the parent
was bound to a wildcard address, then we end up pointlessly copying
all of the current addresses on the system.

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

3 files changed, 31 insertions, 10 deletions

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index eb3113c38a94..002a00a4e6be 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -1184,6 +1184,9 @@ int sctp_bind_addr_copy(struct sctp_bind_addr *dest,
                         const struct sctp_bind_addr *src,
                         sctp_scope_t scope, gfp_t gfp,
                         int flags);
+int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
+                        const struct sctp_bind_addr *src,
+                        gfp_t gfp);
 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
                        __u8 use_as_src, gfp_t gfp);
 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
diff --git a/net/sctp/bind_addr.c b/net/sctp/bind_addr.c
index cae95af9a8cc..6a7d01091f0c 100644
--- a/net/sctp/bind_addr.c
+++ b/net/sctp/bind_addr.c
@@ -105,6 +105,32 @@ out:
         return error;
 }
 
+/* Exactly duplicate the address lists.  This is necessary when doing
+ * peer-offs and accepts.  We don't want to put all the current system
+ * addresses into the endpoint.  That's useless.  But we do want duplicat
+ * the list of bound addresses that the older endpoint used.
+ */
+int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
+                        const struct sctp_bind_addr *src,
+                        gfp_t gfp)
+{
+        struct sctp_sockaddr_entry *addr;
+        struct list_head *pos;
+        int error = 0;
+
+        /* All addresses share the same port.  */
+        dest->port = src->port;
+
+        list_for_each(pos, &src->address_list) {
+                addr = list_entry(pos, struct sctp_sockaddr_entry, list);
+                error = sctp_add_bind_addr(dest, &addr->a, 1, gfp);
+                if (error < 0)
+                        break;
+        }
+
+        return error;
+}
+
 /* Initialize the SCTP_bind_addr structure for either an endpoint or
  * an association.
  */
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 9f5d7930f54d..ea9649ca0b2a 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -6326,7 +6326,6 @@ static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
         struct sk_buff *skb, *tmp;
         struct sctp_ulpevent *event;
         struct sctp_bind_hashbucket *head;
-        int flags = 0;
 
         /* Migrate socket buffer sizes and all the socket level options to the
          * new socket.
@@ -6356,15 +6355,8 @@ static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
         /* Copy the bind_addr list from the original endpoint to the new
          * endpoint so that we can handle restarts properly
          */
-        if (PF_INET6 == assoc->base.sk->sk_family)
-                flags = SCTP_ADDR6_ALLOWED;
-        if (assoc->peer.ipv4_address)
-                flags |= SCTP_ADDR4_PEERSUPP;
-        if (assoc->peer.ipv6_address)
-                flags |= SCTP_ADDR6_PEERSUPP;
-        sctp_bind_addr_copy(&newsp->ep->base.bind_addr,
-                             &oldsp->ep->base.bind_addr,
-                             SCTP_SCOPE_GLOBAL, GFP_KERNEL, flags);
+        sctp_bind_addr_dup(&newsp->ep->base.bind_addr,
+                                &oldsp->ep->base.bind_addr, GFP_KERNEL);
 
         /* Move any messages in the old socket's receive queue that are for the
          * peeled off association to the new socket's receive queue.