ipv6: Fix conflict resolutions during ipv6 binding

The ipv6 version of bind_conflict code calls ipv6_rcv_saddr_equal()
which at times wrongly identified intersections between addresses.
It particularly broke down under a few instances and caused erroneous
bind conflicts.

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

2 files changed, 28 insertions, 34 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 8499da9e76a2..a8218bc1806a 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1370,40 +1370,6 @@ struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, const struct in6_addr *add
         return ifp;
 }
 
-int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
-{
-        const struct in6_addr *sk_rcv_saddr6 = &inet6_sk(sk)->rcv_saddr;
-        const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
-        __be32 sk_rcv_saddr = inet_sk(sk)->rcv_saddr;
-        __be32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
-        int sk_ipv6only = ipv6_only_sock(sk);
-        int sk2_ipv6only = inet_v6_ipv6only(sk2);
-        int addr_type = ipv6_addr_type(sk_rcv_saddr6);
-        int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
-
-        if (!sk2_rcv_saddr && !sk_ipv6only)
-                return 1;
-
-        if (addr_type2 == IPV6_ADDR_ANY &&
-            !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
-                return 1;
-
-        if (addr_type == IPV6_ADDR_ANY &&
-            !(sk_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
-                return 1;
-
-        if (sk2_rcv_saddr6 &&
-            ipv6_addr_equal(sk_rcv_saddr6, sk2_rcv_saddr6))
-                return 1;
-
-        if (addr_type == IPV6_ADDR_MAPPED &&
-            !sk2_ipv6only &&
-            (!sk2_rcv_saddr || !sk_rcv_saddr || sk_rcv_saddr == sk2_rcv_saddr))
-                return 1;
-
-        return 0;
-}
-
 /* Gets referenced address, destroys ifaddr */
 
 static void addrconf_dad_stop(struct inet6_ifaddr *ifp)
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 84b1a296eecb..6842dd2edd5b 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -49,6 +49,34 @@
 #include <linux/seq_file.h>
 #include "udp_impl.h"
 
+int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
+{
+        const struct in6_addr *sk_rcv_saddr6 = &inet6_sk(sk)->rcv_saddr;
+        const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
+        int sk_ipv6only = ipv6_only_sock(sk);
+        int sk2_ipv6only = inet_v6_ipv6only(sk2);
+        int addr_type = ipv6_addr_type(sk_rcv_saddr6);
+        int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
+
+        /* if both are mapped, treat as IPv4 */
+        if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED)
+                return ipv4_rcv_saddr_equal(sk, sk2);
+
+        if (addr_type2 == IPV6_ADDR_ANY &&
+            !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
+                return 1;
+
+        if (addr_type == IPV6_ADDR_ANY &&
+            !(sk_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
+                return 1;
+
+        if (sk2_rcv_saddr6 &&
+            ipv6_addr_equal(sk_rcv_saddr6, sk2_rcv_saddr6))
+                return 1;
+
+        return 0;
+}
+
 int udp_v6_get_port(struct sock *sk, unsigned short snum)
 {
         return udp_lib_get_port(sk, snum, ipv6_rcv_saddr_equal);