From 521a8d7df423a0b5aaf259d49ca9230705bc25ee Mon Sep 17 00:00:00 2001 From: Neale Ranns Date: Thu, 6 Dec 2018 13:46:49 +0000 Subject: FIB recusrion loop checks traverse midchain adjacencies if a tunnel's destination address is reachable through the tunnel (see example config belwo) then search for and detect a recursion loop and don't stack the adjacency. Otherwise this results in a nasty surprise. DBGvpp# loop cre DBGvpp# set int state loop0 up DBGvpp# set int ip addr loop0 10.0.0.1/24 DBGvpp# create gre tunnel src 10.0.0.1 dst 1.1.1.1 DBGvpp# set int state gre0 up DBGvpp# set int unnum gre0 use loop0 DBGvpp# ip route 1.1.1.1/32 via gre0 DBGvpp# sh ip fib 1.1.1.1 ipv4-VRF:0, fib_index:0, flow hash:[src dst sport dport proto ] locks:[src:plugin-hi:2, src:default-route:1, ] 1.1.1.1/32 fib:0 index:11 locks:4 <<< this is entry #11 src:CLI refs:1 entry-flags:attached, src-flags:added,contributing,active, path-list:[14] locks:2 flags:shared,looped, uPRF-list:12 len:1 itfs:[2, ] path:[14] pl-index:14 ip4 weight=1 pref=0 attached-nexthop: oper-flags:recursive-loop,resolved, cfg-flags:attached, 1.1.1.1 gre0 (p2p) [@0]: ipv4 via 0.0.0.0 gre0: mtu:9000 4500000000000000fe2fb0cc0a0000010101010100000800 stacked-on entry:11: <<<< and the midchain forwards via entry #11 [@2]: dpo-drop ip4 src:recursive-resolution refs:1 src-flags:added, cover:-1 forwarding: unicast-ip4-chain [@0]: dpo-load-balance: [proto:ip4 index:13 buckets:1 uRPF:12 to:[0:0]] [0] [@6]: ipv4 via 0.0.0.0 gre0: mtu:9000 4500000000000000fe2fb0cc0a0000010101010100000800 stacked-on entry:11: [@2]: dpo-drop ip4 DBGvpp# sh adj 1 [@1] ipv4 via 0.0.0.0 gre0: mtu:9000 4500000000000000fe2fb0cc0a0000010101010100000800 stacked-on entry:11: [@2]: dpo-drop ip4 flags:midchain-ip-stack midchain-looped <<<<< this is a loop counts:[0:0] locks:4 delegates: children: {path:14} Change-Id: I39b82bd1ea439be4611c88b130d40289fa0c1b59 Signed-off-by: Neale Ranns --- src/vnet/ipip/sixrd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'src/vnet/ipip/sixrd.c') diff --git a/src/vnet/ipip/sixrd.c b/src/vnet/ipip/sixrd.c index cc5bfa33d91..30c37c80fe8 100644 --- a/src/vnet/ipip/sixrd.c +++ b/src/vnet/ipip/sixrd.c @@ -152,9 +152,9 @@ ip6ip_tunnel_stack (adj_index_t ai, u32 fib_entry_index) if (vnet_hw_interface_get_flags (vnet_get_main (), t->hw_if_index) & VNET_HW_INTERFACE_FLAG_LINK_UP) { - adj_nbr_midchain_stack (ai, - fib_entry_contribute_ip_forwarding - (fib_entry_index)); + adj_nbr_midchain_stack_on_fib_entry (ai, + fib_entry_index, + FIB_FORW_CHAIN_TYPE_UNICAST_IP4); } else { -- cgit 1.2.3-korg