From 49378f206b8e780a898e632f7dd8db912b9b118e Mon Sep 17 00:00:00 2001 From: Neale Ranns Date: Mon, 10 Jan 2022 10:38:43 +0000 Subject: ipsec: IPSec interface correct drop w/ no protection Type: improvement When an IPSec interface is first constructed, the end node of the feature arc is not changed, which means it is interface-output. This means that traffic directed into adjacencies on the link, that do not have protection (w/ an SA), drop like this: ... 00:00:01:111710: ip4-midchain tx_sw_if_index 4 dpo-idx 24 : ipv4 via 0.0.0.0 ipsec0: mtu:9000 next:6 flags:[] stacked-on: [@1]: dpo-drop ip4 flow hash: 0x00000000 00000000: 4500005c000100003f01cb8cac100202010101010800ecf40000000058585858 00000020: 58585858585858585858585858585858585858585858585858585858 00:00:01:111829: local0-output ipsec0 00000000: 4500005c000100003f01cb8cac100202010101010800ecf40000000058585858 00000020: 5858585858585858585858585858585858585858585858585858585858585858 00000040: 58585858585858585858585858585858585858585858585858585858c2cf08c0 00000060: 2a2c103cd0126bd8b03c4ec20ce2bd02dd77b3e3a4f49664 00:00:01:112017: error-drop rx:pg1 00:00:01:112034: drop local0-output: interface is down although that's a drop, no packets should go to local0, and we want all IPvX packets to go through ipX-drop. This change sets the interface's end-arc node to the appropriate drop node when the interface is created, and when the last protection is removed. The resulting drop is: ... 00:00:01:111504: ip4-midchain tx_sw_if_index 4 dpo-idx 24 : ipv4 via 0.0.0.0 ipsec0: mtu:9000 next:0 flags:[] stacked-on: [@1]: dpo-drop ip4 flow hash: 0x00000000 00000000: 4500005c000100003f01cb8cac100202010101010800ecf40000000058585858 00000020: 58585858585858585858585858585858585858585858585858585858 00:00:01:111533: ip4-drop ICMP: 172.16.2.2 -> 1.1.1.1 tos 0x00, ttl 63, length 92, checksum 0xcb8c dscp CS0 ecn NON_ECN fragment id 0x0001 ICMP echo_request checksum 0xecf4 id 0 00:00:01:111620: error-drop rx:pg1 00:00:01:111640: drop null-node: blackholed packets Signed-off-by: Neale Ranns Change-Id: I7e7de23c541d9f1210a05e6984a688f1f821a155 --- src/vnet/ipsec/ipsec_itf.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'src/vnet/ipsec/ipsec_itf.c') diff --git a/src/vnet/ipsec/ipsec_itf.c b/src/vnet/ipsec/ipsec_itf.c index fc0bf85a517..f9c1d77a37d 100644 --- a/src/vnet/ipsec/ipsec_itf.c +++ b/src/vnet/ipsec/ipsec_itf.c @@ -21,6 +21,7 @@ #include #include #include +#include /* bitmap of Allocated IPSEC_ITF instances */ static uword *ipsec_itf_instances; @@ -274,6 +275,20 @@ ipsec_itf_instance_free (u32 instance) return 0; } +void +ipsec_itf_reset_tx_nodes (u32 sw_if_index) +{ + vnet_feature_modify_end_node ( + ip4_main.lookup_main.output_feature_arc_index, sw_if_index, + vlib_get_node_by_name (vlib_get_main (), (u8 *) "ip4-drop")->index); + vnet_feature_modify_end_node ( + ip6_main.lookup_main.output_feature_arc_index, sw_if_index, + vlib_get_node_by_name (vlib_get_main (), (u8 *) "ip6-drop")->index); + vnet_feature_modify_end_node ( + mpls_main.output_feature_arc_index, sw_if_index, + vlib_get_node_by_name (vlib_get_main (), (u8 *) "mpls-drop")->index); +} + int ipsec_itf_create (u32 user_instance, tunnel_mode_t mode, u32 * sw_if_indexp) { @@ -318,6 +333,7 @@ ipsec_itf_create (u32 user_instance, tunnel_mode_t mode, u32 * sw_if_indexp) ipsec_itf_index_by_sw_if_index[hi->sw_if_index] = t_idx; ipsec_itf->ii_sw_if_index = *sw_if_indexp = hi->sw_if_index; + ipsec_itf_reset_tx_nodes (hi->sw_if_index); return 0; } -- cgit 1.2.3-korg