ipv4: Allow sending multicast packets on specific i/f using VRF socket

It is useful to be able to use the same socket for listening in a
specific VRF, as for sending multicast packets out of a specific
interface. However, the bound device on the socket currently takes
precedence and results in the packets not being sent.

Relax the condition on overriding the output interface to use for
sending packets out of UDP, raw and ping sockets to allow multicast
packets to be sent using the specified multicast interface.

Signed-off-by: Robert Shearman <rshearma@vyatta.att-mail.com>
Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
index f915abff1350a86af8d5bb89725b751c061b0fb5..300921417f89f387e70c4ed0acb2e8bca01591bb 100644 (file)
--- a/net/ipv4/datagram.c
+++ b/net/ipv4/datagram.c
@@ -42,7 +42,7 @@ int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len
        oif = sk->sk_bound_dev_if;
        saddr = inet->inet_saddr;
        if (ipv4_is_multicast(usin->sin_addr.s_addr)) {
-               if (!oif)
+               if (!oif || netif_index_is_l3_master(sock_net(sk), oif))
                        oif = inet->mc_index;
                if (!saddr)
                        saddr = inet->mc_addr;

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 8d7aaf118a30106030d26780dd1c6e3ae5b90ba9..7ccb5f87f70b90ebb33e514dd75f158b1c4f55f7 100644 (file)
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -779,7 +779,7 @@ static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
        }
 
        if (ipv4_is_multicast(daddr)) {
-               if (!ipc.oif)
+               if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
                        ipc.oif = inet->mc_index;
                if (!saddr)
                        saddr = inet->mc_addr;

diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 33df4d76db2d948d620ffc809574b364ae24ad4b..8ca3eb06ba04246ce9f53045488f1da57dc8e689 100644 (file)
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -608,7 +608,7 @@ static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
                tos |= RTO_ONLINK;
 
        if (ipv4_is_multicast(daddr)) {
-               if (!ipc.oif)
+               if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
                        ipc.oif = inet->mc_index;
                if (!saddr)
                        saddr = inet->mc_addr;

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 7d69dd6fa7e8c63929a27edad74fb0d6f9f3ee31..5fc4beb1c3361497f8fac0b124edc98d8a566b3b 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1042,7 +1042,7 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
        }
 
        if (ipv4_is_multicast(daddr)) {
-               if (!ipc.oif)
+               if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
                        ipc.oif = inet->mc_index;
                if (!saddr)
                        saddr = inet->mc_addr;