1 files changed, 37 insertions, 0 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)