diff options
| author | Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> | 2012-11-30 12:37:26 +0000 |
|---|---|---|
| committer | firebird11 <hbgassel@gmail.com> | 2018-11-29 19:26:54 +0100 |
| commit | 39cc01b63c02e3b4873c9ee2b58755d0efba66eb (patch) | |
| tree | 64ad0b61978a22b95537523d68f7d024d0ea11b6 | |
| parent | 5a870651843873e830dbe690a0e5ce2b7baf72e5 (diff) | |
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masqueraded target, the packets were sent out with the outdated source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 <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| -rw-r--r-- | include/net/netfilter/nf_nat.h | 15 | ||||
| -rw-r--r-- | net/ipv4/netfilter/iptable_nat.c | 4 | ||||
| -rw-r--r-- | net/ipv6/netfilter/ip6table_nat.c | 4 |
3 files changed, 23 insertions, 0 deletions
diff --git a/include/net/netfilter/nf_nat.h b/include/net/netfilter/nf_nat.h index bd8eea720f2..ad14a799fd2 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 diff --git a/net/ipv4/netfilter/iptable_nat.c b/net/ipv4/netfilter/iptable_nat.c index 9e0ffaf1d94..2fefe54f93e 100644 --- a/net/ipv4/netfilter/iptable_nat.c +++ b/net/ipv4/netfilter/iptable_nat.c @@ -134,6 +134,10 @@ nf_nat_ipv4_fn(unsigned int hooknum, /* ESTABLISHED */ NF_CT_ASSERT(ctinfo == IP_CT_ESTABLISHED || ctinfo == IP_CT_ESTABLISHED_REPLY); + if (nf_nat_oif_changed(hooknum, ctinfo, nat, out)) { + nf_ct_kill_acct(ct, ctinfo, skb); + return NF_DROP; + } } return nf_nat_packet(ct, ctinfo, hooknum, skb); diff --git a/net/ipv6/netfilter/ip6table_nat.c b/net/ipv6/netfilter/ip6table_nat.c index e418bd6350a..667e39567e9 100644 --- a/net/ipv6/netfilter/ip6table_nat.c +++ b/net/ipv6/netfilter/ip6table_nat.c @@ -137,6 +137,10 @@ nf_nat_ipv6_fn(unsigned int hooknum, /* ESTABLISHED */ NF_CT_ASSERT(ctinfo == IP_CT_ESTABLISHED || ctinfo == IP_CT_ESTABLISHED_REPLY); + if (nf_nat_oif_changed(hooknum, ctinfo, nat, out)) { + nf_ct_kill_acct(ct, ctinfo, skb); + return NF_DROP; + } } return nf_nat_packet(ct, ctinfo, hooknum, skb); |