From 3777ed688fba82d0bd43f9fc1ebbc6abe788576d Mon Sep 17 00:00:00 2001 From: Quentin Armitage Date: Thu, 16 Jun 2016 08:00:14 +0100 Subject: [PATCH] ipvs: fix bind to link-local mcast IPv6 address in backup When using HEAD from https://git.kernel.org/cgit/utils/kernel/ipvsadm/ipvsadm.git/, the command: ipvsadm --start-daemon backup --mcast-interface eth0.60 \ --mcast-group ff02::1:81 fails with the error message: Argument list too long whereas both: ipvsadm --start-daemon master --mcast-interface eth0.60 \ --mcast-group ff02::1:81 and: ipvsadm --start-daemon backup --mcast-interface eth0.60 \ --mcast-group 224.0.0.81 are successful. The error message "Argument list too long" isn't helpful. The error occurs because an IPv6 address is given in backup mode. The error is in make_receive_sock() in net/netfilter/ipvs/ip_vs_sync.c, since it fails to set the interface on the address or the socket before calling inet6_bind() (via sock->ops->bind), where the test 'if (!sk->sk_bound_dev_if)' failed. Setting sock->sk->sk_bound_dev_if on the socket before calling inet6_bind() resolves the issue. Fixes: d33288172e72 ("ipvs: add more mcast parameters for the sync daemon") Signed-off-by: Quentin Armitage Acked-by: Julian Anastasov Signed-off-by: Simon Horman --- net/netfilter/ipvs/ip_vs_sync.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c index 803001a45aa1..1b07578bedf3 100644 --- a/net/netfilter/ipvs/ip_vs_sync.c +++ b/net/netfilter/ipvs/ip_vs_sync.c @@ -1545,7 +1545,8 @@ error: /* * Set up receiving multicast socket over UDP */ -static struct socket *make_receive_sock(struct netns_ipvs *ipvs, int id) +static struct socket *make_receive_sock(struct netns_ipvs *ipvs, int id, + int ifindex) { /* multicast addr */ union ipvs_sockaddr mcast_addr; @@ -1566,6 +1567,7 @@ static struct socket *make_receive_sock(struct netns_ipvs *ipvs, int id) set_sock_size(sock->sk, 0, result); get_mcast_sockaddr(&mcast_addr, &salen, &ipvs->bcfg, id); + sock->sk->sk_bound_dev_if = ifindex; result = sock->ops->bind(sock, (struct sockaddr *)&mcast_addr, salen); if (result < 0) { pr_err("Error binding to the multicast addr\n"); @@ -1868,7 +1870,7 @@ int start_sync_thread(struct netns_ipvs *ipvs, struct ipvs_sync_daemon_cfg *c, if (state == IP_VS_STATE_MASTER) sock = make_send_sock(ipvs, id); else - sock = make_receive_sock(ipvs, id); + sock = make_receive_sock(ipvs, id, dev->ifindex); if (IS_ERR(sock)) { result = PTR_ERR(sock); goto outtinfo; -- 2.20.1