From 87233b51bc4d088ff566cef09a7c96f1f0dac078 Mon Sep 17 00:00:00 2001 From: Matus Fabian Date: Fri, 26 Jan 2018 03:17:01 -0800 Subject: [PATCH] NAT44: fix ICMP error translation for endpoint dependent sessions (VPP-1150) Change-Id: I85c799f28c4246884107e569a36482af10d9be9d Signed-off-by: Matus Fabian --- src/plugins/nat/in2out.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++-- src/plugins/nat/out2in.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++-- test/test_nat.py | 36 ++++++++++++++++++++++ 3 files changed, 186 insertions(+), 4 deletions(-) diff --git a/src/plugins/nat/in2out.c b/src/plugins/nat/in2out.c index 0b87ba47812..a453328c38f 100755 --- a/src/plugins/nat/in2out.c +++ b/src/plugins/nat/in2out.c @@ -402,6 +402,53 @@ snat_in2out_error_t icmp_get_key(ip4_header_t *ip0, return -1; /* success */ } +static_always_inline int +icmp_get_ed_key(ip4_header_t *ip0, nat_ed_ses_key_t *p_key0) +{ + icmp46_header_t *icmp0; + nat_ed_ses_key_t key0; + icmp_echo_header_t *echo0, *inner_echo0 = 0; + ip4_header_t *inner_ip0 = 0; + void *l4_header = 0; + icmp46_header_t *inner_icmp0; + + icmp0 = (icmp46_header_t *) ip4_next_header (ip0); + echo0 = (icmp_echo_header_t *)(icmp0+1); + + if (!icmp_is_error_message (icmp0)) + { + key0.proto = IP_PROTOCOL_ICMP; + key0.l_addr = ip0->src_address; + key0.r_addr = ip0->dst_address; + key0.l_port = key0.r_port = echo0->identifier; + } + else + { + inner_ip0 = (ip4_header_t *)(echo0+1); + l4_header = ip4_next_header (inner_ip0); + key0.proto = inner_ip0->protocol; + key0.r_addr = inner_ip0->src_address; + key0.l_addr = inner_ip0->dst_address; + switch (ip_proto_to_snat_proto (inner_ip0->protocol)) + { + case SNAT_PROTOCOL_ICMP: + inner_icmp0 = (icmp46_header_t*)l4_header; + inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1); + key0.r_port = key0.l_port = inner_echo0->identifier; + break; + case SNAT_PROTOCOL_UDP: + case SNAT_PROTOCOL_TCP: + key0.l_port = ((tcp_udp_header_t*)l4_header)->dst_port; + key0.r_port = ((tcp_udp_header_t*)l4_header)->src_port; + break; + default: + return SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL; + } + } + *p_key0 = key0; + return 0; +} + /** * Get address and port values to be used for ICMP packet translation * and create session if needed @@ -482,8 +529,34 @@ u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node, goto out; } - s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions, - value0.value); + if (PREDICT_FALSE (value0.value == ~0ULL)) + { + nat_ed_ses_key_t key; + clib_bihash_kv_16_8_t s_kv, s_value; + + key.as_u64[0] = 0; + key.as_u64[1] = 0; + if (icmp_get_ed_key (ip0, &key)) + { + b0->error = node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL]; + next0 = SNAT_IN2OUT_NEXT_DROP; + goto out; + } + key.fib_index = rx_fib_index0; + s_kv.key[0] = key.as_u64[0]; + s_kv.key[1] = key.as_u64[1]; + if (!clib_bihash_search_16_8 (&sm->in2out_ed, &s_kv, &s_value)) + s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions, + s_value.value); + else + { + next0 = SNAT_IN2OUT_NEXT_DROP; + goto out; + } + } + else + s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions, + value0.value); } out: diff --git a/src/plugins/nat/out2in.c b/src/plugins/nat/out2in.c index d548ab31fc5..7f500a916f0 100755 --- a/src/plugins/nat/out2in.c +++ b/src/plugins/nat/out2in.c @@ -264,6 +264,53 @@ snat_out2in_error_t icmp_get_key(ip4_header_t *ip0, return -1; /* success */ } +static_always_inline int +icmp_get_ed_key(ip4_header_t *ip0, nat_ed_ses_key_t *p_key0) +{ + icmp46_header_t *icmp0; + nat_ed_ses_key_t key0; + icmp_echo_header_t *echo0, *inner_echo0 = 0; + ip4_header_t *inner_ip0; + void *l4_header = 0; + icmp46_header_t *inner_icmp0; + + icmp0 = (icmp46_header_t *) ip4_next_header (ip0); + echo0 = (icmp_echo_header_t *)(icmp0+1); + + if (!icmp_is_error_message (icmp0)) + { + key0.proto = IP_PROTOCOL_ICMP; + key0.l_addr = ip0->dst_address; + key0.r_addr = ip0->src_address; + key0.l_port = key0.r_port = echo0->identifier; + } + else + { + inner_ip0 = (ip4_header_t *)(echo0+1); + l4_header = ip4_next_header (inner_ip0); + key0.proto = inner_ip0->protocol; + key0.l_addr = inner_ip0->src_address; + key0.r_addr = inner_ip0->dst_address; + switch (ip_proto_to_snat_proto (inner_ip0->protocol)) + { + case SNAT_PROTOCOL_ICMP: + inner_icmp0 = (icmp46_header_t*)l4_header; + inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1); + key0.l_port = key0.r_port = inner_echo0->identifier; + break; + case SNAT_PROTOCOL_UDP: + case SNAT_PROTOCOL_TCP: + key0.l_port = ((tcp_udp_header_t*)l4_header)->src_port; + key0.r_port = ((tcp_udp_header_t*)l4_header)->dst_port; + break; + default: + return -1; + } + } + *p_key0 = key0; + return 0; +} + /** * Get address and port values to be used for ICMP packet translation * and create session if needed @@ -369,8 +416,34 @@ u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node, goto out; } - s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions, - value0.value); + if (PREDICT_FALSE (value0.value == ~0ULL)) + { + nat_ed_ses_key_t key; + clib_bihash_kv_16_8_t s_kv, s_value; + + key.as_u64[0] = 0; + key.as_u64[1] = 0; + if (icmp_get_ed_key (ip0, &key)) + { + b0->error = node->errors[SNAT_OUT2IN_ERROR_UNSUPPORTED_PROTOCOL]; + next0 = SNAT_OUT2IN_NEXT_DROP; + goto out; + } + key.fib_index = rx_fib_index0; + s_kv.key[0] = key.as_u64[0]; + s_kv.key[1] = key.as_u64[1]; + if (!clib_bihash_search_16_8 (&sm->out2in_ed, &s_kv, &s_value)) + s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions, + s_value.value); + else + { + next0 = SNAT_OUT2IN_NEXT_DROP; + goto out; + } + } + else + s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions, + value0.value); } out: diff --git a/test/test_nat.py b/test/test_nat.py index f0614da2f3c..b9785f01c7a 100644 --- a/test/test_nat.py +++ b/test/test_nat.py @@ -1542,6 +1542,24 @@ class TestNAT44(MethodHolder): self.logger.error(ppp("Unexpected or invalid packet:", p)) raise + # ICMP error + p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) / + IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) / + ICMP(type=11) / capture[0][IP]) + self.pg0.add_stream(p) + self.pg_enable_capture(self.pg_interfaces) + self.pg_start() + capture = self.pg1.get_capture(1) + p = capture[0] + try: + self.assertEqual(p[IP].src, self.nat_addr) + inner = p[IPerror] + self.assertEqual(inner.dst, self.nat_addr) + self.assertEqual(inner[TCPerror].dport, external_port) + except: + self.logger.error(ppp("Unexpected or invalid packet:", p)) + raise + # from service back to client p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) / @@ -1562,6 +1580,24 @@ class TestNAT44(MethodHolder): self.logger.error(ppp("Unexpected or invalid packet:", p)) raise + # ICMP error + p = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) / + IP(src=self.pg1.remote_ip4, dst=self.nat_addr) / + ICMP(type=11) / capture[0][IP]) + self.pg1.add_stream(p) + self.pg_enable_capture(self.pg_interfaces) + self.pg_start() + capture = self.pg0.get_capture(1) + p = capture[0] + try: + self.assertEqual(p[IP].dst, self.pg0.remote_ip4) + inner = p[IPerror] + self.assertEqual(inner.src, self.pg0.remote_ip4) + self.assertEqual(inner[TCPerror].sport, local_port) + except: + self.logger.error(ppp("Unexpected or invalid packet:", p)) + raise + # from client to server (no translation) p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) / IP(src=self.pg1.remote_ip4, dst=self.pg0.remote_ip4) / -- 2.16.6