From 4a75ed32132d8e2292dd276f3ea7f4edec4f3d06 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 15 Sep 2016 17:28:00 +0200 Subject: src: add fib expression This adds the 'fib' expression which can be used to obtain the output interface from the route table based on either source or destination address of a packet. This can be used to e.g. add reverse path filtering: # drop if not coming from the same interface packet # arrived on # nft add rule x prerouting fib saddr . iif oif eq 0 drop # accept only if from eth0 # nft add rule x prerouting fib saddr . iif oif eq "eth0" accept # accept if from any valid interface # nft add rule x prerouting fib saddr oif accept Querying of address type is also supported. This can be used to e.g. only accept packets to addresses configured in the same interface: # fib daddr . iif type local Its also possible to use mark and verdict map, e.g.: # nft add rule x prerouting meta mark set 0xdead fib daddr . mark type vmap { blackhole : drop, prohibit : drop, unicast : accept } Signed-off-by: Florian Westphal --- include/expression.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/expression.h') diff --git a/include/expression.h b/include/expression.h index 3ae4e804..3a52a45c 100644 --- a/include/expression.h +++ b/include/expression.h @@ -61,6 +61,7 @@ enum expr_types { EXPR_NUMGEN, EXPR_HASH, EXPR_RT, + EXPR_FIB, }; enum ops { @@ -180,6 +181,7 @@ enum expr_flags { #include #include +#include #include #include #include @@ -306,6 +308,11 @@ struct expr { uint32_t mod; uint32_t seed; } hash; + struct { + /* EXPR_FIB */ + uint32_t flags; + uint32_t result; + } fib; }; }; -- cgit v1.2.3