ipv6: Make v4-mapped bindings consistent with IPv4

Binding to a v4-mapped address on an AF_INET6 socket should
produce the same result as binding to an IPv4 address on
AF_INET socket.  The two are interchangable as v4-mapped
address is really a portability aid.

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

1 files changed, 11 insertions, 3 deletions

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 9b6a37d16fb0..61f55386a236 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -276,6 +276,8 @@ int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 
         /* Check if the address belongs to the host. */
         if (addr_type == IPV6_ADDR_MAPPED) {
+                int chk_addr_ret;
+
                 /* Binding to v4-mapped address on a v6-only socket
                  * makes no sense
                  */
@@ -283,11 +285,17 @@ int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
                         err = -EINVAL;
                         goto out;
                 }
+
+                /* Reproduce AF_INET checks to make the bindings consitant */
                 v4addr = addr->sin6_addr.s6_addr32[3];
-                if (inet_addr_type(net, v4addr) != RTN_LOCAL) {
-                        err = -EADDRNOTAVAIL;
+                chk_addr_ret = inet_addr_type(net, v4addr);
+                if (!sysctl_ip_nonlocal_bind &&
+                    !(inet->freebind || inet->transparent) &&
+                    v4addr != htonl(INADDR_ANY) &&
+                    chk_addr_ret != RTN_LOCAL &&
+                    chk_addr_ret != RTN_MULTICAST &&
+                    chk_addr_ret != RTN_BROADCAST)
                         goto out;
-                }
         } else {
                 if (addr_type != IPV6_ADDR_ANY) {
                         struct net_device *dev = NULL;