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authorMatus Fabian <matfabia@cisco.com>2017-06-05 05:55:48 -0700
committerDamjan Marion <dmarion.lists@gmail.com>2017-06-05 19:58:35 +0000
commit6fa74c60ea5930864750d64005b213647f12fe08 (patch)
tree6eb181c96f04540e96f96aaa37f4008080f14d12 /src
parent47366b19fb7f65dba1a7c731ee765b1216f47e33 (diff)
SNAT: fix ICMP hairpinning
Change-Id: I9d63133bd1db72917571ade868040c4597c896a1 Signed-off-by: Matus Fabian <matfabia@cisco.com>
Diffstat (limited to 'src')
-rw-r--r--src/plugins/snat/in2out.c68
1 files changed, 67 insertions, 1 deletions
diff --git a/src/plugins/snat/in2out.c b/src/plugins/snat/in2out.c
index bc86a7a4d23..ddde702a50c 100644
--- a/src/plugins/snat/in2out.c
+++ b/src/plugins/snat/in2out.c
@@ -515,7 +515,7 @@ u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
goto out;
}
- if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request))
+ if (PREDICT_FALSE(icmp_is_error_message (icmp0)))
{
b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
next0 = SNAT_IN2OUT_NEXT_DROP;
@@ -869,11 +869,77 @@ static inline u32 icmp_in2out_slow_path (snat_main_t *sm,
u32 thread_index,
snat_session_t ** p_s0)
{
+ snat_session_key_t key0, sm0;
+ clib_bihash_kv_8_8_t kv0, value0;
+ snat_worker_key_t k0;
+ u32 new_dst_addr0 = 0, old_dst_addr0, si, ti = 0;
+ ip_csum_t sum0;
+
next0 = icmp_in2out(sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
next0, thread_index, p_s0, 0);
snat_session_t * s0 = *p_s0;
if (PREDICT_TRUE(next0 != SNAT_IN2OUT_NEXT_DROP && s0))
{
+ /* Hairpinning */
+ if (!icmp_is_error_message (icmp0))
+ {
+ icmp_echo_header_t *echo0 = (icmp_echo_header_t *)(icmp0+1);
+ u16 icmp_id0 = echo0->identifier;
+ key0.addr = ip0->dst_address;
+ key0.port = icmp_id0;
+ key0.protocol = SNAT_PROTOCOL_ICMP;
+ key0.fib_index = sm->outside_fib_index;
+ kv0.key = key0.as_u64;
+
+ /* Check if destination is in active sessions */
+ if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
+ {
+ /* or static mappings */
+ if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0))
+ {
+ new_dst_addr0 = sm0.addr.as_u32;
+ vnet_buffer(b0)->sw_if_index[VLIB_TX] = sm0.fib_index;
+ }
+ }
+ else
+ {
+ si = value0.value;
+ if (sm->num_workers > 1)
+ {
+ k0.addr = ip0->dst_address;
+ k0.port = icmp_id0;
+ k0.fib_index = sm->outside_fib_index;
+ kv0.key = k0.as_u64;
+ if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv0, &value0))
+ ASSERT(0);
+ else
+ ti = value0.value;
+ }
+ else
+ ti = sm->num_workers;
+
+ s0 = pool_elt_at_index (sm->per_thread_data[ti].sessions, si);
+ new_dst_addr0 = s0->in2out.addr.as_u32;
+ vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
+ echo0->identifier = s0->in2out.port;
+ sum0 = icmp0->checksum;
+ sum0 = ip_csum_update (sum0, icmp_id0, s0->in2out.port,
+ icmp_echo_header_t, identifier);
+ icmp0->checksum = ip_csum_fold (sum0);
+ }
+
+ /* Destination is behind the same NAT, use internal address and port */
+ if (new_dst_addr0)
+ {
+ old_dst_addr0 = ip0->dst_address.as_u32;
+ ip0->dst_address.as_u32 = new_dst_addr0;
+ sum0 = ip0->checksum;
+ sum0 = ip_csum_update (sum0, old_dst_addr0, new_dst_addr0,
+ ip4_header_t, dst_address);
+ ip0->checksum = ip_csum_fold (sum0);
+ }
+ }
+
/* Accounting */
s0->last_heard = now;
s0->total_pkts++;