tunnels: correct conditional build of MPLS and IPv6 (aa9667e7) · Commits · 戴 / test

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: ("tunnels: support MPLS over IPv4 tunnels") Signed-off-by:

Simon Horman <simon.horman@netronome.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ipv4/tunnel4.c

+13 −12

Original line number	Diff line number	Diff line
		@@ -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;
		}

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