From aa9667e7f626232cde5310435dc96bfbe796f05c Mon Sep 17 00:00:00 2001 From: Simon Horman Date: Sun, 10 Jul 2016 10:20:11 +0900 Subject: [PATCH] tunnels: correct conditional build of MPLS and IPv6 Using a combination if #if conditionals and goto labels to unwind tunnel4_init seems unwieldy. This patch takes a simpler approach of directly unregistering previously registered protocols when an error occurs. This fixes a number of problems with the current implementation including the potential presence of labels when they are unused and the potential absence of unregister code when it is needed. Fixes: 8afe97e5d416 ("tunnels: support MPLS over IPv4 tunnels") Signed-off-by: Simon Horman Signed-off-by: David S. Miller --- net/ipv4/tunnel4.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/net/ipv4/tunnel4.c b/net/ipv4/tunnel4.c index 45cd4253583a..ec35eaa5c029 100644 --- a/net/ipv4/tunnel4.c +++ b/net/ipv4/tunnel4.c @@ -208,24 +208,25 @@ static const struct net_protocol tunnelmpls4_protocol = { static int __init tunnel4_init(void) { if (inet_add_protocol(&tunnel4_protocol, IPPROTO_IPIP)) - goto err_ipip; + goto err; #if IS_ENABLED(CONFIG_IPV6) - if (inet_add_protocol(&tunnel64_protocol, IPPROTO_IPV6)) - goto err_ipv6; + if (inet_add_protocol(&tunnel64_protocol, IPPROTO_IPV6)) { + inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP); + goto err; + } #endif #if IS_ENABLED(CONFIG_MPLS) - if (inet_add_protocol(&tunnelmpls4_protocol, IPPROTO_MPLS)) - goto err_mpls; + if (inet_add_protocol(&tunnelmpls4_protocol, IPPROTO_MPLS)) { + inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP); +#if IS_ENABLED(CONFIG_IPV6) + inet_del_protocol(&tunnel64_protocol, IPPROTO_IPV6); +#endif + goto err; + } #endif return 0; -#if IS_ENABLED(CONFIG_IPV6) -err_mpls: - inet_del_protocol(&tunnel4_protocol, IPPROTO_IPV6); -#endif -err_ipv6: - inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP); -err_ipip: +err: pr_err("%s: can't add protocol\n", __func__); return -EAGAIN; } -- 2.20.1