From 854da991733d1b4f60042423875e32be7f8f0421 Mon Sep 17 00:00:00 2001 From: Robert Shearman Date: Mon, 1 Oct 2018 09:40:23 +0100 Subject: [PATCH] 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 Signed-off-by: Mike Manning Reviewed-by: David Ahern Signed-off-by: David S. Miller --- net/ipv4/datagram.c | 2 +- net/ipv4/ping.c | 2 +- net/ipv4/raw.c | 2 +- net/ipv4/udp.c | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c index f915abf..3009214 100644 --- 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 8d7aaf1..7ccb5f8 100644 --- 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 33df4d7..8ca3eb06 100644 --- 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 7d69dd6..5fc4beb 100644 --- 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; -- 2.7.4