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/fib.h | 7 +++++++ 1 file changed, 7 insertions(+) create mode 100644 include/fib.h (limited to 'include/fib.h') diff --git a/include/fib.h b/include/fib.h new file mode 100644 index 00000000..3a019e65 --- /dev/null +++ b/include/fib.h @@ -0,0 +1,7 @@ +#ifndef NFTABLES_FIB_H +#define NFTABLES_FIB_H + +extern struct expr *fib_expr_alloc(const struct location *loc, + unsigned int flags, + unsigned int result); +#endif /* NFTABLES_FIB_H */ -- cgit v1.2.3