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>

1 files changed, 28 insertions, 0 deletions

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);