CGN: Send ICMP error packet if user is out of sessions available

[vpp.git] / src / plugins / snat / in2out.c

diff --git a/src/plugins/snat/in2out.c b/src/plugins/snat/in2out.c
index 1e8e144..f7d29c6 100644 (file)
--- a/src/plugins/snat/in2out.c
+++ b/src/plugins/snat/in2out.c
@@ -94,7 +94,7 @@ _(UNSUPPORTED_PROTOCOL, "Unsupported protocol")         \
 _(IN2OUT_PACKETS, "Good in2out packets processed")      \
 _(OUT_OF_PORTS, "Out of ports")                         \
 _(BAD_OUTSIDE_FIB, "Outside VRF ID not found")          \
-_(BAD_ICMP_TYPE, "icmp type not echo-request")          \
+_(BAD_ICMP_TYPE, "unsupported ICMP type")               \
 _(NO_TRANSLATION, "No translation")
   
 typedef enum {
@@ -194,7 +194,7 @@ snat_not_translate (snat_main_t * sm, vlib_node_runtime_t *node,
   if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
     {
       /* or is static mappings */
-      if (!snat_static_mapping_match(sm, key0, &sm0, 1))
+      if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0))
         return 0;
     }
   else
@@ -332,7 +332,7 @@ static u32 slow_path (snat_main_t *sm, vlib_buffer_t *b0,
       u8 static_mapping = 1;
 
       /* First try to match static mapping by local address and port */
-      if (snat_static_mapping_match (sm, *key0, &key1, 0))
+      if (snat_static_mapping_match (sm, *key0, &key1, 0, 0))
         {
           static_mapping = 0;
           /* Try to create dynamic translation */
@@ -515,8 +515,9 @@ u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
           goto out;
         }
 
-      if (icmp_is_error_message (icmp0))
+      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;
         }
@@ -528,15 +529,18 @@ u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
         goto out;
     }
   else
-    s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
-                            value0.value);
-
-  if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request &&
-                    !icmp_is_error_message (icmp0)))
     {
-      b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
-      next0 = SNAT_IN2OUT_NEXT_DROP;
-      goto out;
+      if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request &&
+                        icmp0->type != ICMP4_echo_reply &&
+                        !icmp_is_error_message (icmp0)))
+        {
+          b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
+          next0 = SNAT_IN2OUT_NEXT_DROP;
+          goto out;
+        }
+
+      s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
+                              value0.value);
     }
 
 out:
@@ -574,6 +578,7 @@ u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
   snat_session_key_t key0;
   snat_session_key_t sm0;
   u8 dont_translate = 0;
+  u8 is_addr_only;
   u32 next0 = ~0;
   int err;
 
@@ -591,7 +596,7 @@ u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
     }
   key0.fib_index = rx_fib_index0;
 
-  if (snat_static_mapping_match(sm, key0, &sm0, 0))
+  if (snat_static_mapping_match(sm, key0, &sm0, 0, &is_addr_only))
     {
       if (PREDICT_FALSE(snat_not_translate_fast(sm, node, sw_if_index0, ip0,
           IP_PROTOCOL_ICMP, rx_fib_index0)))
@@ -612,14 +617,12 @@ u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
     }
 
   if (PREDICT_FALSE(icmp0->type != ICMP4_echo_request &&
+                    (icmp0->type != ICMP4_echo_reply || !is_addr_only) &&
                     !icmp_is_error_message (icmp0)))
     {
-      if (icmp0->type != ICMP4_echo_reply || key0.port != sm0.port)
-        {
-          b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
-          next0 = SNAT_IN2OUT_NEXT_DROP;
-          goto out;
-        }
+      b0->error = node->errors[SNAT_IN2OUT_ERROR_BAD_ICMP_TYPE];
+      next0 = SNAT_IN2OUT_NEXT_DROP;
+      goto out;
     }
 
 out:
@@ -792,7 +795,7 @@ snat_hairpinning (snat_main_t *sm,
   if (clib_bihash_search_8_8 (&sm->out2in, &kv0, &value0))
     {
       /* or static mappings */
-      if (!snat_static_mapping_match(sm, key0, &sm0, 1))
+      if (!snat_static_mapping_match(sm, key0, &sm0, 1, 0))
         {
           new_dst_addr0 = sm0.addr.as_u32;
           new_dst_port0 = sm0.port;
@@ -1613,11 +1616,12 @@ snat_det_in2out_node_fn (vlib_main_t * vm,
 
           snat_det_forward(dm0, &ip0->src_address, &new_addr0, &lo_port0);
 
-          ses0 = snat_det_find_ses_by_in(dm0, &ip0->src_address, tcp0->src);
+          key0.ext_host_addr = ip0->dst_address;
+          key0.ext_host_port = tcp0->dst;
+
+          ses0 = snat_det_find_ses_by_in(dm0, &ip0->src_address, tcp0->src, key0);
           if (PREDICT_FALSE(!ses0))
             {
-              key0.ext_host_addr = ip0->dst_address;
-              key0.ext_host_port = tcp0->dst;
               for (i0 = 0; i0 < dm0->ports_per_host; i0++)
                 {
                   key0.out_port = clib_host_to_net_u16 (lo_port0 +
@@ -1631,8 +1635,13 @@ snat_det_in2out_node_fn (vlib_main_t * vm,
                 }
               if (PREDICT_FALSE(!ses0))
                 {
-                  next0 = SNAT_IN2OUT_NEXT_DROP;
-                  b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
+                  /* too many sessions for user, send ICMP error packet */
+
+                  vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+                  icmp4_error_set_vnet_buffer (b0, ICMP4_destination_unreachable,
+                                               ICMP4_destination_unreachable_destination_unreachable_host,
+                                               0);
+                  next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
                   goto trace0;
                 }
             }
@@ -1757,11 +1766,12 @@ snat_det_in2out_node_fn (vlib_main_t * vm,
 
           snat_det_forward(dm1, &ip1->src_address, &new_addr1, &lo_port1);
 
-          ses1 = snat_det_find_ses_by_in(dm1, &ip1->src_address, tcp1->src);
+          key1.ext_host_addr = ip1->dst_address;
+          key1.ext_host_port = tcp1->dst;
+
+          ses1 = snat_det_find_ses_by_in(dm1, &ip1->src_address, tcp1->src, key1);
           if (PREDICT_FALSE(!ses1))
             {
-              key1.ext_host_addr = ip1->dst_address;
-              key1.ext_host_port = tcp1->dst;
               for (i1 = 0; i1 < dm1->ports_per_host; i1++)
                 {
                   key1.out_port = clib_host_to_net_u16 (lo_port1 +
@@ -1775,8 +1785,13 @@ snat_det_in2out_node_fn (vlib_main_t * vm,
                 }
               if (PREDICT_FALSE(!ses1))
                 {
-                  next1 = SNAT_IN2OUT_NEXT_DROP;
-                  b1->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
+                  /* too many sessions for user, send ICMP error packet */
+
+                  vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+                  icmp4_error_set_vnet_buffer (b1, ICMP4_destination_unreachable,
+                                               ICMP4_destination_unreachable_destination_unreachable_host,
+                                               0);
+                  next1 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
                   goto trace1;
                 }
             }
@@ -1937,11 +1952,12 @@ snat_det_in2out_node_fn (vlib_main_t * vm,
 
           snat_det_forward(dm0, &ip0->src_address, &new_addr0, &lo_port0);
 
-          ses0 = snat_det_find_ses_by_in(dm0, &ip0->src_address, tcp0->src);
+          key0.ext_host_addr = ip0->dst_address;
+          key0.ext_host_port = tcp0->dst;
+
+          ses0 = snat_det_find_ses_by_in(dm0, &ip0->src_address, tcp0->src, key0);
           if (PREDICT_FALSE(!ses0))
             {
-              key0.ext_host_addr = ip0->dst_address;
-              key0.ext_host_port = tcp0->dst;
               for (i0 = 0; i0 < dm0->ports_per_host; i0++)
                 {
                   key0.out_port = clib_host_to_net_u16 (lo_port0 +
@@ -1955,8 +1971,13 @@ snat_det_in2out_node_fn (vlib_main_t * vm,
                 }
               if (PREDICT_FALSE(!ses0))
                 {
-                  next0 = SNAT_IN2OUT_NEXT_DROP;
-                  b0->error = node->errors[SNAT_IN2OUT_ERROR_OUT_OF_PORTS];
+                  /* too many sessions for user, send ICMP error packet */
+
+                  vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+                  icmp4_error_set_vnet_buffer (b0, ICMP4_destination_unreachable,
+                                               ICMP4_destination_unreachable_destination_unreachable_host,
+                                               0);
+                  next0 = SNAT_IN2OUT_NEXT_ICMP_ERROR;
                   goto trace00;
                 }
             }
@@ -2171,7 +2192,10 @@ u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node,
 
   snat_det_forward(dm0, &in_addr, &new_addr0, &lo_port0);
 
-  ses0 = snat_det_find_ses_by_in(dm0, &in_addr, in_port);
+  key0.ext_host_addr = ip0->dst_address;
+  key0.ext_host_port = 0;
+
+  ses0 = snat_det_find_ses_by_in(dm0, &in_addr, in_port, key0);
   if (PREDICT_FALSE(!ses0))
     {
       if (PREDICT_FALSE(snat_not_translate_fast(sm, node, sw_if_index0, ip0,
@@ -2186,8 +2210,6 @@ u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node,
           next0 = SNAT_IN2OUT_NEXT_DROP;
           goto out;
         }
-      key0.ext_host_addr = ip0->dst_address;
-      key0.ext_host_port = 0;
       for (i0 = 0; i0 < dm0->ports_per_host; i0++)
         {
           key0.out_port = clib_host_to_net_u16 (lo_port0 +
@@ -2485,7 +2507,7 @@ snat_in2out_fast_static_map_fn (vlib_main_t * vm,
           key0.port = udp0->src_port;
           key0.fib_index = rx_fib_index0;
 
-          if (snat_static_mapping_match(sm, key0, &sm0, 0))
+          if (snat_static_mapping_match(sm, key0, &sm0, 0, 0))
             {
               b0->error = node->errors[SNAT_IN2OUT_ERROR_NO_TRANSLATION];
               next0= SNAT_IN2OUT_NEXT_DROP;