From a0ecb85a2c3af73c63b6d44ce82aea52347ccf55 Mon Sep 17 00:00:00 2001 From: Jozsef Kadlecsik Date: Fri, 30 Nov 2012 12:37:26 +0000 Subject: netfilter: nf_nat: Handle routing changes in MASQUERADE target When the route changes (backup default route, VPNs) which affect a masqueraded target, the packets were sent out with the outdated source address. The patch addresses the issue by comparing the outgoing interface directly with the masqueraded interface in the nat table. Events are inefficient in this case, because it'd require adding route events to the network core and then scanning the whole conntrack table and re-checking the route for all entry. Signed-off-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_nat.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'include/net') diff --git a/include/net/netfilter/nf_nat.h b/include/net/netfilter/nf_nat.h index bd8eea7..ad14a79 100644 --- a/include/net/netfilter/nf_nat.h +++ b/include/net/netfilter/nf_nat.h @@ -68,4 +68,19 @@ static inline struct nf_conn_nat *nfct_nat(const struct nf_conn *ct) #endif } +static inline bool nf_nat_oif_changed(unsigned int hooknum, + enum ip_conntrack_info ctinfo, + struct nf_conn_nat *nat, + const struct net_device *out) +{ +#if IS_ENABLED(CONFIG_IP_NF_TARGET_MASQUERADE) || \ + IS_ENABLED(CONFIG_IP6_NF_TARGET_MASQUERADE) + return nat->masq_index && hooknum == NF_INET_POST_ROUTING && + CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL && + nat->masq_index != out->ifindex; +#else + return false; +#endif +} + #endif -- cgit v1.1