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authorJuraj Sloboda <jsloboda@cisco.com>2017-02-08 23:54:21 -0800
committerOle Trøan <otroan@employees.org>2017-02-16 10:48:53 +0000
commitb33f413af46ec8dff7f222dbd5bc3bcec1502d3d (patch)
tree6c3118bfce76a0fe65f757b32d3d1d2f4b8d5789
parent205e934ee7530dac475be14d9054183625171ccc (diff)
Add handling of ICMP error packets in SNAT (VPP-629)
Change-Id: I8d2022b7cb3ef3da736c085bccbb5b9c057a8d76 Signed-off-by: Juraj Sloboda <jsloboda@cisco.com>
-rw-r--r--src/plugins/snat/in2out.c197
-rw-r--r--src/plugins/snat/out2in.c199
-rw-r--r--test/test_snat.py195
3 files changed, 534 insertions, 57 deletions
diff --git a/src/plugins/snat/in2out.c b/src/plugins/snat/in2out.c
index b0047737..e30c913c 100644
--- a/src/plugins/snat/in2out.c
+++ b/src/plugins/snat/in2out.c
@@ -112,6 +112,7 @@ typedef enum {
SNAT_IN2OUT_NEXT_LOOKUP,
SNAT_IN2OUT_NEXT_DROP,
SNAT_IN2OUT_NEXT_SLOW_PATH,
+ SNAT_IN2OUT_NEXT_ICMP_ERROR,
SNAT_IN2OUT_N_NEXT,
} snat_in2out_next_t;
@@ -410,6 +411,10 @@ static u32 slow_path (snat_main_t *sm, vlib_buffer_t *b0,
return next0;
}
+typedef struct {
+ u16 src_port, dst_port;
+} tcp_udp_header_t;
+
static inline u32 icmp_in2out_slow_path (snat_main_t *sm,
vlib_buffer_t * b0,
ip4_header_t * ip0,
@@ -419,67 +424,171 @@ static inline u32 icmp_in2out_slow_path (snat_main_t *sm,
vlib_node_runtime_t * node,
u32 next0,
f64 now,
- u32 cpu_index)
+ u32 cpu_index,
+ snat_session_t ** p_s0)
{
snat_session_key_t key0;
- icmp_echo_header_t *echo0;
+ icmp_echo_header_t *echo0, *inner_echo0 = 0;
+ ip4_header_t *inner_ip0;
+ void *l4_header = 0;
+ icmp46_header_t *inner_icmp0;
clib_bihash_kv_8_8_t kv0, value0;
- snat_session_t * s0;
+ snat_session_t * s0 = 0;
u32 new_addr0, old_addr0;
u16 old_id0, new_id0;
ip_csum_t sum0;
+ u16 checksum0;
snat_runtime_t * rt = (snat_runtime_t *)node->runtime_data;
+ u8 is_error_message = 0;
- if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request))
- {
- b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
- return SNAT_IN2OUT_NEXT_DROP;
- }
-
echo0 = (icmp_echo_header_t *)(icmp0+1);
key0.addr = ip0->src_address;
- key0.port = echo0->identifier;
- key0.protocol = SNAT_PROTOCOL_ICMP;
key0.fib_index = rx_fib_index0;
+ switch(icmp0->type)
+ {
+ case ICMP4_destination_unreachable:
+ case ICMP4_time_exceeded:
+ case ICMP4_parameter_problem:
+ case ICMP4_source_quench:
+ case ICMP4_redirect:
+ case ICMP4_alternate_host_address:
+ is_error_message = 1;
+ }
+
+ if (!is_error_message)
+ {
+ if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request))
+ {
+ b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
+ next0 = SNAT_IN2OUT_NEXT_DROP;
+ goto out;
+ }
+ key0.protocol = SNAT_PROTOCOL_ICMP;
+ key0.port = echo0->identifier;
+ }
+ else
+ {
+ inner_ip0 = (ip4_header_t *)(echo0+1);
+ l4_header = ip4_next_header (inner_ip0);
+ key0.protocol = ip_proto_to_snat_proto (inner_ip0->protocol);
+ switch (key0.protocol)
+ {
+ case SNAT_PROTOCOL_ICMP:
+ inner_icmp0 = (icmp46_header_t*)l4_header;
+ inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
+ key0.port = inner_echo0->identifier;
+ break;
+ case SNAT_PROTOCOL_UDP:
+ case SNAT_PROTOCOL_TCP:
+ key0.port = ((tcp_udp_header_t*)l4_header)->dst_port;
+ break;
+ default:
+ b0->error = node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
+ next0 = SNAT_IN2OUT_NEXT_DROP;
+ goto out;
+ }
+ }
+
kv0.key = key0.as_u64;
if (clib_bihash_search_8_8 (&sm->in2out, &kv0, &value0))
{
if (PREDICT_FALSE(snat_not_translate(sm, rt, sw_if_index0, ip0,
IP_PROTOCOL_ICMP, rx_fib_index0)))
- return next0;
+ goto out;
+
+ if (is_error_message)
+ {
+ next0 = SNAT_IN2OUT_NEXT_DROP;
+ goto out;
+ }
next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
&s0, node, next0, cpu_index);
if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
- return next0;
+ goto out;
}
else
s0 = pool_elt_at_index (sm->per_thread_data[cpu_index].sessions,
value0.value);
+ sum0 = ip_incremental_checksum (0, icmp0,
+ ntohs(ip0->length) - ip4_header_bytes (ip0));
+ checksum0 = ~ip_csum_fold (sum0);
+ if (PREDICT_FALSE(checksum0 != 0 && checksum0 != 0xffff))
+ {
+ next0 = SNAT_IN2OUT_NEXT_DROP;
+ goto out;
+ }
+
old_addr0 = ip0->src_address.as_u32;
ip0->src_address = s0->out2in.addr;
new_addr0 = ip0->src_address.as_u32;
vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->out2in.fib_index;
-
+
sum0 = ip0->checksum;
- sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
- ip4_header_t,
+ sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
src_address /* changed member */);
ip0->checksum = ip_csum_fold (sum0);
- old_id0 = echo0->identifier;
- new_id0 = s0->out2in.port;
- echo0->identifier = new_id0;
+ if (!is_error_message)
+ {
+ old_id0 = echo0->identifier;
+ new_id0 = s0->out2in.port;
+ echo0->identifier = new_id0;
- sum0 = icmp0->checksum;
- sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
- identifier);
- icmp0->checksum = ip_csum_fold (sum0);
+ sum0 = icmp0->checksum;
+ sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
+ identifier);
+ icmp0->checksum = ip_csum_fold (sum0);
+ }
+ else
+ {
+ if (!ip4_header_checksum_is_valid (inner_ip0))
+ {
+ next0 = SNAT_IN2OUT_NEXT_DROP;
+ goto out;
+ }
+
+ old_addr0 = inner_ip0->dst_address.as_u32;
+ inner_ip0->dst_address = s0->out2in.addr;
+ new_addr0 = inner_ip0->src_address.as_u32;
+
+ sum0 = icmp0->checksum;
+ sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
+ dst_address /* changed member */);
+ icmp0->checksum = ip_csum_fold (sum0);
+
+ switch (key0.protocol)
+ {
+ case SNAT_PROTOCOL_ICMP:
+ old_id0 = inner_echo0->identifier;
+ new_id0 = s0->out2in.port;
+ inner_echo0->identifier = new_id0;
+
+ sum0 = icmp0->checksum;
+ sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
+ identifier);
+ icmp0->checksum = ip_csum_fold (sum0);
+ break;
+ case SNAT_PROTOCOL_UDP:
+ case SNAT_PROTOCOL_TCP:
+ old_id0 = ((tcp_udp_header_t*)l4_header)->dst_port;
+ new_id0 = s0->out2in.port;
+ ((tcp_udp_header_t*)l4_header)->dst_port = new_id0;
+
+ sum0 = icmp0->checksum;
+ sum0 = ip_csum_update (sum0, old_id0, new_id0, tcp_udp_header_t,
+ dst_port);
+ icmp0->checksum = ip_csum_fold (sum0);
+ break;
+ default:
+ ASSERT(0);
+ }
+ }
/* Accounting */
s0->last_heard = now;
@@ -495,6 +604,8 @@ static inline u32 icmp_in2out_slow_path (snat_main_t *sm,
s0->per_user_index);
}
+out:
+ *p_s0 = s0;
return next0;
}
@@ -685,6 +796,16 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
proto0 = ip_proto_to_snat_proto (ip0->protocol);
+ if (PREDICT_FALSE(ip0->ttl == 1))
+ {
+ vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+ icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
+ ICMP4_time_exceeded_ttl_exceeded_in_transit,
+ 0);
+ next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
+ goto trace00;
+ }
+
/* Next configured feature, probably ip4-lookup */
if (is_slow_path)
{
@@ -695,7 +816,7 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
{
next0 = icmp_in2out_slow_path
(sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0,
- node, next0, now, cpu_index);
+ node, next0, now, cpu_index, &s0);
goto trace00;
}
}
@@ -815,6 +936,16 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
proto1 = ip_proto_to_snat_proto (ip1->protocol);
+ if (PREDICT_FALSE(ip0->ttl == 1))
+ {
+ vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+ icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
+ ICMP4_time_exceeded_ttl_exceeded_in_transit,
+ 0);
+ next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
+ goto trace01;
+ }
+
/* Next configured feature, probably ip4-lookup */
if (is_slow_path)
{
@@ -825,7 +956,7 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
{
next1 = icmp_in2out_slow_path
(sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
- next1, now, cpu_index);
+ next1, now, cpu_index, &s1);
goto trace01;
}
}
@@ -980,6 +1111,16 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
proto0 = ip_proto_to_snat_proto (ip0->protocol);
+ if (PREDICT_FALSE(ip0->ttl == 1))
+ {
+ vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+ icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
+ ICMP4_time_exceeded_ttl_exceeded_in_transit,
+ 0);
+ next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
+ goto trace0;
+ }
+
/* Next configured feature, probably ip4-lookup */
if (is_slow_path)
{
@@ -990,7 +1131,7 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
{
next0 = icmp_in2out_slow_path
(sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
- next0, now, cpu_index);
+ next0, now, cpu_index, &s0);
goto trace0;
}
}
@@ -1020,6 +1161,7 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
next0 = slow_path (sm, b0, ip0, rx_fib_index0, &key0,
&s0, node, next0, cpu_index);
+
if (PREDICT_FALSE (next0 == SNAT_IN2OUT_NEXT_DROP))
goto trace0;
}
@@ -1141,6 +1283,7 @@ VLIB_REGISTER_NODE (snat_in2out_node) = {
[SNAT_IN2OUT_NEXT_DROP] = "error-drop",
[SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
[SNAT_IN2OUT_NEXT_SLOW_PATH] = "snat-in2out-slowpath",
+ [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
},
};
@@ -1173,6 +1316,7 @@ VLIB_REGISTER_NODE (snat_in2out_slowpath_node) = {
[SNAT_IN2OUT_NEXT_DROP] = "error-drop",
[SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
[SNAT_IN2OUT_NEXT_SLOW_PATH] = "snat-in2out-slowpath",
+ [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
},
};
@@ -1604,6 +1748,7 @@ VLIB_REGISTER_NODE (snat_in2out_fast_node) = {
[SNAT_IN2OUT_NEXT_DROP] = "error-drop",
[SNAT_IN2OUT_NEXT_LOOKUP] = "ip4-lookup",
[SNAT_IN2OUT_NEXT_SLOW_PATH] = "snat-in2out-slowpath",
+ [SNAT_IN2OUT_NEXT_ICMP_ERROR] = "ip4-icmp-error",
},
};
diff --git a/src/plugins/snat/out2in.c b/src/plugins/snat/out2in.c
index 4f3322a3..3c1bb885 100644
--- a/src/plugins/snat/out2in.c
+++ b/src/plugins/snat/out2in.c
@@ -103,6 +103,7 @@ static char * snat_out2in_error_strings[] = {
typedef enum {
SNAT_OUT2IN_NEXT_DROP,
SNAT_OUT2IN_NEXT_LOOKUP,
+ SNAT_OUT2IN_NEXT_ICMP_ERROR,
SNAT_OUT2IN_N_NEXT,
} snat_out2in_next_t;
@@ -222,6 +223,10 @@ create_session_for_static_mapping (snat_main_t *sm,
return s;
}
+typedef struct {
+ u16 src_port, dst_port;
+} tcp_udp_header_t;
+
static inline u32 icmp_out2in_slow_path (snat_main_t *sm,
vlib_buffer_t * b0,
ip4_header_t * ip0,
@@ -230,24 +235,73 @@ static inline u32 icmp_out2in_slow_path (snat_main_t *sm,
u32 rx_fib_index0,
vlib_node_runtime_t * node,
u32 next0, f64 now,
- u32 cpu_index)
+ u32 cpu_index,
+ snat_session_t ** p_s0)
{
snat_session_key_t key0, sm0;
- icmp_echo_header_t *echo0;
+ icmp_echo_header_t *echo0, *inner_echo0 = 0;
+ ip4_header_t *inner_ip0 = 0;
+ void *l4_header = 0;
+ icmp46_header_t *inner_icmp0;
clib_bihash_kv_8_8_t kv0, value0;
- snat_session_t * s0;
+ snat_session_t * s0 = 0;
u32 new_addr0, old_addr0;
u16 old_id0, new_id0;
ip_csum_t sum0;
+ u16 checksum0;
snat_runtime_t * rt = (snat_runtime_t *)node->runtime_data;
+ u8 is_error_message = 0;
echo0 = (icmp_echo_header_t *)(icmp0+1);
key0.addr = ip0->dst_address;
- key0.port = echo0->identifier;
- key0.protocol = SNAT_PROTOCOL_ICMP;
key0.fib_index = rx_fib_index0;
-
+
+ switch(icmp0->type)
+ {
+ case ICMP4_destination_unreachable:
+ case ICMP4_time_exceeded:
+ case ICMP4_parameter_problem:
+ case ICMP4_source_quench:
+ case ICMP4_redirect:
+ case ICMP4_alternate_host_address:
+ is_error_message = 1;
+ }
+
+ if (!is_error_message)
+ {
+ if (PREDICT_FALSE(icmp0->type != ICMP4_echo_reply))
+ {
+ b0->error = node->errors[SNAT_OUT2IN_ERROR_BAD_ICMP_TYPE];
+ next0 = SNAT_OUT2IN_NEXT_DROP;
+ goto out;
+ }
+ key0.protocol = SNAT_PROTOCOL_ICMP;
+ key0.port = echo0->identifier;
+ }
+ else
+ {
+ inner_ip0 = (ip4_header_t *)(echo0+1);
+ l4_header = ip4_next_header (inner_ip0);
+ key0.protocol = ip_proto_to_snat_proto (inner_ip0->protocol);
+ switch (key0.protocol)
+ {
+ case SNAT_PROTOCOL_ICMP:
+ inner_icmp0 = (icmp46_header_t*)l4_header;
+ inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
+ key0.port = inner_echo0->identifier;
+ break;
+ case SNAT_PROTOCOL_UDP:
+ case SNAT_PROTOCOL_TCP:
+ key0.port = ((tcp_udp_header_t*)l4_header)->src_port;
+ break;
+ default:
+ b0->error = node->errors[SNAT_OUT2IN_ERROR_UNSUPPORTED_PROTOCOL];
+ next0 = SNAT_OUT2IN_NEXT_DROP;
+ goto out;
+ }
+ }
+
kv0.key = key0.as_u64;
if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
@@ -271,43 +325,108 @@ static inline u32 icmp_out2in_slow_path (snat_main_t *sm,
}
/* Don't NAT packet aimed at the intfc address */
- if (PREDICT_FALSE(ip0->dst_address.as_u32 ==
- rt->cached_ip4_address))
- return next0;
+ if (PREDICT_FALSE(ip0->dst_address.as_u32 == rt->cached_ip4_address))
+ goto out;
b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
- return SNAT_OUT2IN_NEXT_DROP;
+ next0 = SNAT_OUT2IN_NEXT_DROP;
+ goto out;
+ }
+
+ if (is_error_message)
+ {
+ next0 = SNAT_OUT2IN_NEXT_DROP;
+ goto out;
}
/* Create session initiated by host from external network */
s0 = create_session_for_static_mapping(sm, b0, sm0, key0,
node, cpu_index);
+
if (!s0)
- return SNAT_OUT2IN_NEXT_DROP;
+ {
+ next0 = SNAT_OUT2IN_NEXT_DROP;
+ goto out;
+ }
}
else
s0 = pool_elt_at_index (sm->per_thread_data[cpu_index].sessions,
value0.value);
+ sum0 = ip_incremental_checksum (0, icmp0,
+ ntohs(ip0->length) - ip4_header_bytes (ip0));
+ checksum0 = ~ip_csum_fold (sum0);
+ if (checksum0 != 0 && checksum0 != 0xffff)
+ {
+ next0 = SNAT_OUT2IN_NEXT_DROP;
+ goto out;
+ }
+
old_addr0 = ip0->dst_address.as_u32;
ip0->dst_address = s0->in2out.addr;
new_addr0 = ip0->dst_address.as_u32;
vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
sum0 = ip0->checksum;
- sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
- ip4_header_t,
+ sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
dst_address /* changed member */);
ip0->checksum = ip_csum_fold (sum0);
- old_id0 = echo0->identifier;
- new_id0 = s0->in2out.port;
- echo0->identifier = new_id0;
+ if (!is_error_message)
+ {
+ old_id0 = echo0->identifier;
+ new_id0 = s0->in2out.port;
+ echo0->identifier = new_id0;
+
+ sum0 = icmp0->checksum;
+ sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
+ identifier /* changed member */);
+ icmp0->checksum = ip_csum_fold (sum0);
+ }
+ else
+ {
+ if (!ip4_header_checksum_is_valid (inner_ip0))
+ {
+ next0 = SNAT_OUT2IN_NEXT_DROP;
+ goto out;
+ }
+
+ old_addr0 = inner_ip0->src_address.as_u32;
+ inner_ip0->src_address = s0->in2out.addr;
+ new_addr0 = inner_ip0->src_address.as_u32;
+
+ sum0 = icmp0->checksum;
+ sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
+ src_address /* changed member */);
+ icmp0->checksum = ip_csum_fold (sum0);
- sum0 = icmp0->checksum;
- sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
- identifier);
- icmp0->checksum = ip_csum_fold (sum0);
+ switch (key0.protocol)
+ {
+ case SNAT_PROTOCOL_ICMP:
+ old_id0 = inner_echo0->identifier;
+ new_id0 = s0->in2out.port;
+ inner_echo0->identifier = new_id0;
+
+ sum0 = icmp0->checksum;
+ sum0 = ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
+ identifier);
+ icmp0->checksum = ip_csum_fold (sum0);
+ break;
+ case SNAT_PROTOCOL_UDP:
+ case SNAT_PROTOCOL_TCP:
+ old_id0 = ((tcp_udp_header_t*)l4_header)->src_port;
+ new_id0 = s0->in2out.port;
+ ((tcp_udp_header_t*)l4_header)->src_port = new_id0;
+
+ sum0 = icmp0->checksum;
+ sum0 = ip_csum_update (sum0, old_id0, new_id0, tcp_udp_header_t,
+ src_port);
+ icmp0->checksum = ip_csum_fold (sum0);
+ break;
+ default:
+ ASSERT(0);
+ }
+ }
/* Accounting */
s0->last_heard = now;
@@ -323,6 +442,8 @@ static inline u32 icmp_out2in_slow_path (snat_main_t *sm,
s0->per_user_index);
}
+out:
+ *p_s0 = s0;
return next0;
}
@@ -410,11 +531,21 @@ snat_out2in_node_fn (vlib_main_t * vm,
if (PREDICT_FALSE (proto0 == ~0))
goto trace0;
+ if (PREDICT_FALSE(ip0->ttl == 1))
+ {
+ vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+ icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
+ ICMP4_time_exceeded_ttl_exceeded_in_transit,
+ 0);
+ next0 = SNAT_OUT2IN_NEXT_ICMP_ERROR;
+ goto trace0;
+ }
+
if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
{
next0 = icmp_out2in_slow_path
(sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
- next0, now, cpu_index);
+ next0, now, cpu_index, &s0);
goto trace0;
}
@@ -535,11 +666,21 @@ snat_out2in_node_fn (vlib_main_t * vm,
if (PREDICT_FALSE (proto1 == ~0))
goto trace1;
+ if (PREDICT_FALSE(ip0->ttl == 1))
+ {
+ vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+ icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
+ ICMP4_time_exceeded_ttl_exceeded_in_transit,
+ 0);
+ next0 = SNAT_OUT2IN_NEXT_ICMP_ERROR;
+ goto trace1;
+ }
+
if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
{
next1 = icmp_out2in_slow_path
(sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
- next1, now, cpu_index);
+ next1, now, cpu_index, &s1);
goto trace1;
}
@@ -694,11 +835,21 @@ snat_out2in_node_fn (vlib_main_t * vm,
if (PREDICT_FALSE (proto0 == ~0))
goto trace00;
+ if (PREDICT_FALSE(ip0->ttl == 1))
+ {
+ vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+ icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
+ ICMP4_time_exceeded_ttl_exceeded_in_transit,
+ 0);
+ next0 = SNAT_OUT2IN_NEXT_ICMP_ERROR;
+ goto trace00;
+ }
+
if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
{
next0 = icmp_out2in_slow_path
(sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
- next0, now, cpu_index);
+ next0, now, cpu_index, &s0);
goto trace00;
}
@@ -838,6 +989,7 @@ VLIB_REGISTER_NODE (snat_out2in_node) = {
.next_nodes = {
[SNAT_OUT2IN_NEXT_DROP] = "error-drop",
[SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
+ [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
},
};
VLIB_NODE_FUNCTION_MULTIARCH (snat_out2in_node, snat_out2in_node_fn);
@@ -1295,6 +1447,7 @@ VLIB_REGISTER_NODE (snat_out2in_fast_node) = {
.next_nodes = {
[SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
[SNAT_OUT2IN_NEXT_DROP] = "error-drop",
+ [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
},
};
VLIB_NODE_FUNCTION_MULTIARCH (snat_out2in_fast_node, snat_out2in_fast_node_fn);
diff --git a/test/test_snat.py b/test/test_snat.py
index 9d2070a0..500d629d 100644
--- a/test/test_snat.py
+++ b/test/test_snat.py
@@ -6,6 +6,7 @@ import struct
from framework import VppTestCase, VppTestRunner
from scapy.layers.inet import IP, TCP, UDP, ICMP
+from scapy.layers.inet import IPerror, TCPerror, UDPerror, ICMPerror
from scapy.layers.l2 import Ether, ARP
from scapy.data import IP_PROTOS
from util import ppp
@@ -64,59 +65,61 @@ class TestSNAT(VppTestCase):
super(TestSNAT, cls).tearDownClass()
raise
- def create_stream_in(self, in_if, out_if):
+ def create_stream_in(self, in_if, out_if, ttl=64):
"""
Create packet stream for inside network
:param in_if: Inside interface
:param out_if: Outside interface
+ :param ttl: TTL of generated packets
"""
pkts = []
# TCP
p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
- IP(src=in_if.remote_ip4, dst=out_if.remote_ip4) /
+ IP(src=in_if.remote_ip4, dst=out_if.remote_ip4, ttl=ttl) /
TCP(sport=self.tcp_port_in))
pkts.append(p)
# UDP
p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
- IP(src=in_if.remote_ip4, dst=out_if.remote_ip4) /
+ IP(src=in_if.remote_ip4, dst=out_if.remote_ip4, ttl=ttl) /
UDP(sport=self.udp_port_in))
pkts.append(p)
# ICMP
p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
- IP(src=in_if.remote_ip4, dst=out_if.remote_ip4) /
+ IP(src=in_if.remote_ip4, dst=out_if.remote_ip4, ttl=ttl) /
ICMP(id=self.icmp_id_in, type='echo-request'))
pkts.append(p)
return pkts
- def create_stream_out(self, out_if, dst_ip=None):
+ def create_stream_out(self, out_if, dst_ip=None, ttl=64):
"""
Create packet stream for outside network
:param out_if: Outside interface
:param dst_ip: Destination IP address (Default use global SNAT address)
+ :param ttl: TTL of generated packets
"""
if dst_ip is None:
dst_ip = self.snat_addr
pkts = []
# TCP
p = (Ether(dst=out_if.local_mac, src=out_if.remote_mac) /
- IP(src=out_if.remote_ip4, dst=dst_ip) /
+ IP(src=out_if.remote_ip4, dst=dst_ip, ttl=ttl) /
TCP(dport=self.tcp_port_out))
pkts.append(p)
# UDP
p = (Ether(dst=out_if.local_mac, src=out_if.remote_mac) /
- IP(src=out_if.remote_ip4, dst=dst_ip) /
+ IP(src=out_if.remote_ip4, dst=dst_ip, ttl=ttl) /
UDP(dport=self.udp_port_out))
pkts.append(p)
# ICMP
p = (Ether(dst=out_if.local_mac, src=out_if.remote_mac) /
- IP(src=out_if.remote_ip4, dst=dst_ip) /
+ IP(src=out_if.remote_ip4, dst=dst_ip, ttl=ttl) /
ICMP(id=self.icmp_id_out, type='echo-reply'))
pkts.append(p)
@@ -209,6 +212,75 @@ class TestSNAT(VppTestCase):
"(inside network):", packet))
raise
+ def verify_capture_out_with_icmp_errors(self, capture, src_ip=None,
+ packet_num=3, icmp_type=11):
+ """
+ Verify captured packets with ICMP errors on outside network
+
+ :param capture: Captured packets
+ :param src_ip: Translated IP address or IP address of VPP
+ (Default use global SNAT address)
+ :param packet_num: Expected number of packets (Default 3)
+ :param icmp_type: Type of error ICMP packet
+ we are expecting (Default 11)
+ """
+ if src_ip is None:
+ src_ip = self.snat_addr
+ self.assertEqual(packet_num, len(capture))
+ for packet in capture:
+ try:
+ self.assertEqual(packet[IP].src, src_ip)
+ self.assertTrue(packet.haslayer(ICMP))
+ icmp = packet[ICMP]
+ self.assertEqual(icmp.type, icmp_type)
+ self.assertTrue(icmp.haslayer(IPerror))
+ inner_ip = icmp[IPerror]
+ if inner_ip.haslayer(TCPerror):
+ self.assertEqual(inner_ip[TCPerror].dport,
+ self.tcp_port_out)
+ elif inner_ip.haslayer(UDPerror):
+ self.assertEqual(inner_ip[UDPerror].dport,
+ self.udp_port_out)
+ else:
+ self.assertEqual(inner_ip[ICMPerror].id, self.icmp_id_out)
+ except:
+ self.logger.error(ppp("Unexpected or invalid packet "
+ "(outside network):", packet))
+ raise
+
+ def verify_capture_in_with_icmp_errors(self, capture, in_if, packet_num=3,
+ icmp_type=11):
+ """
+ Verify captured packets with ICMP errors on inside network
+
+ :param capture: Captured packets
+ :param in_if: Inside interface
+ :param packet_num: Expected number of packets (Default 3)
+ :param icmp_type: Type of error ICMP packet
+ we are expecting (Default 11)
+ """
+ self.assertEqual(packet_num, len(capture))
+ for packet in capture:
+ try:
+ self.assertEqual(packet[IP].dst, in_if.remote_ip4)
+ self.assertTrue(packet.haslayer(ICMP))
+ icmp = packet[ICMP]
+ self.assertEqual(icmp.type, icmp_type)
+ self.assertTrue(icmp.haslayer(IPerror))
+ inner_ip = icmp[IPerror]
+ if inner_ip.haslayer(TCPerror):
+ self.assertEqual(inner_ip[TCPerror].sport,
+ self.tcp_port_in)
+ elif inner_ip.haslayer(UDPerror):
+ self.assertEqual(inner_ip[UDPerror].sport,
+ self.udp_port_in)
+ else:
+ self.assertEqual(inner_ip[ICMPerror].id, self.icmp_id_in)
+ except:
+ self.logger.error(ppp("Unexpected or invalid packet "
+ "(inside network):", packet))
+ raise
+
def verify_ipfix_nat44_ses(self, data):
"""
Verify IPFIX NAT44 session create/delete event
@@ -367,6 +439,113 @@ class TestSNAT(VppTestCase):
capture = self.pg0.get_capture(len(pkts))
self.verify_capture_in(capture, self.pg0)
+ def test_dynamic_icmp_errors_in2out_ttl_1(self):
+ """ SNAT handling of client packets with TTL=1 """
+
+ self.snat_add_address(self.snat_addr)
+ self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
+ self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
+ is_inside=0)
+
+ # Client side - generate traffic
+ pkts = self.create_stream_in(self.pg0, self.pg1, ttl=1)
+ self.pg0.add_stream(pkts)
+ self.pg_enable_capture(self.pg_interfaces)
+ self.pg_start()
+
+ # Client side - verify ICMP type 11 packets
+ capture = self.pg0.get_capture(len(pkts))
+ self.verify_capture_in_with_icmp_errors(capture, self.pg0)
+
+ def test_dynamic_icmp_errors_out2in_ttl_1(self):
+ """ SNAT handling of server packets with TTL=1 """
+
+ self.snat_add_address(self.snat_addr)
+ self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
+ self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
+ is_inside=0)
+
+ # Client side - create sessions
+ pkts = self.create_stream_in(self.pg0, self.pg1)
+ self.pg0.add_stream(pkts)
+ self.pg_enable_capture(self.pg_interfaces)
+ self.pg_start()
+
+ # Server side - generate traffic
+ capture = self.pg1.get_capture(len(pkts))
+ self.verify_capture_out(capture)
+ pkts = self.create_stream_out(self.pg1, ttl=1)
+ self.pg1.add_stream(pkts)
+ self.pg_enable_capture(self.pg_interfaces)
+ self.pg_start()
+
+ # Server side - verify ICMP type 11 packets
+ capture = self.pg1.get_capture(len(pkts))
+ self.verify_capture_out_with_icmp_errors(capture,
+ src_ip=self.pg1.local_ip4)
+
+ def test_dynamic_icmp_errors_in2out_ttl_2(self):
+ """ SNAT handling of error respones to client packets with TTL=2 """
+
+ self.snat_add_address(self.snat_addr)
+ self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
+ self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
+ is_inside=0)
+
+ # Client side - generate traffic
+ pkts = self.create_stream_in(self.pg0, self.pg1, ttl=2)
+ self.pg0.add_stream(pkts)
+ self.pg_enable_capture(self.pg_interfaces)
+ self.pg_start()
+
+ # Server side - simulate ICMP type 11 response
+ capture = self.pg1.get_capture(len(pkts))
+ pkts = [Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
+ IP(src=self.pg1.remote_ip4, dst=self.snat_addr) /
+ ICMP(type=11) / packet[IP] for packet in capture]
+ self.pg1.add_stream(pkts)
+ self.pg_enable_capture(self.pg_interfaces)
+ self.pg_start()
+
+ # Client side - verify ICMP type 11 packets
+ capture = self.pg0.get_capture(len(pkts))
+ self.verify_capture_in_with_icmp_errors(capture, self.pg0)
+
+ def test_dynamic_icmp_errors_out2in_ttl_2(self):
+ """ SNAT handling of error respones to server packets with TTL=2 """
+
+ self.snat_add_address(self.snat_addr)
+ self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
+ self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
+ is_inside=0)
+
+ # Client side - create sessions
+ pkts = self.create_stream_in(self.pg0, self.pg1)
+ self.pg0.add_stream(pkts)
+ self.pg_enable_capture(self.pg_interfaces)
+ self.pg_start()
+
+ # Server side - generate traffic
+ capture = self.pg1.get_capture(len(pkts))
+ self.verify_capture_out(capture)
+ pkts = self.create_stream_out(self.pg1, ttl=2)
+ self.pg1.add_stream(pkts)
+ self.pg_enable_capture(self.pg_interfaces)
+ self.pg_start()
+
+ # Client side - simulate ICMP type 11 response
+ capture = self.pg0.get_capture(len(pkts))
+ pkts = [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) / packet[IP] for packet in capture]
+ self.pg0.add_stream(pkts)
+ self.pg_enable_capture(self.pg_interfaces)
+ self.pg_start()
+
+ # Server side - verify ICMP type 11 packets
+ capture = self.pg1.get_capture(len(pkts))
+ self.verify_capture_out_with_icmp_errors(capture)
+
def test_static_in(self):
""" SNAT 1:1 NAT initialized from inside network """