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 <neale@graphiant.com>
Change-Id: I7e7de23c541d9f1210a05e6984a688f1f821a155
49378f206b