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: 8afe97e5d4 ("tunnels: support MPLS over IPv4 tunnels")
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Simon Horman 2016-07-10 10:20:11 +09:00 committed by David S. Miller
parent 4154cb40e7
commit aa9667e7f6
1 changed files with 13 additions and 12 deletions

View File

@ -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;
}