VPP-598: tcp stack initial commit
[vpp.git] / src / plugins / snat / out2in.c
index 0c9c9cd..3bfc0aa 100644 (file)
 #include <vnet/handoff.h>
 
 #include <vnet/ip/ip.h>
+#include <vnet/udp/udp.h>
 #include <vnet/ethernet/ethernet.h>
 #include <vnet/fib/ip4_fib.h>
 #include <snat/snat.h>
+#include <snat/snat_ipfix_logging.h>
 
 #include <vppinfra/hash.h>
 #include <vppinfra/error.h>
@@ -101,6 +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;
 
@@ -210,9 +213,20 @@ create_session_for_static_mapping (snat_main_t *sm,
   if (clib_bihash_add_del_8_8 (&sm->out2in, &kv0, 1 /* is_add */))
       clib_warning ("out2in key add failed");
 
-  return s;
+  /* log NAT event */
+  snat_ipfix_logging_nat44_ses_create(s->in2out.addr.as_u32,
+                                      s->out2in.addr.as_u32,
+                                      s->in2out.protocol,
+                                      s->in2out.port,
+                                      s->out2in.port,
+                                      s->in2out.fib_index);
+   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,
@@ -221,24 +235,67 @@ 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)
+    {
+      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))
@@ -262,43 +319,115 @@ 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);
 
+  if (PREDICT_FALSE(icmp0->type != ICMP4_echo_reply && !is_error_message))
+    {
+      b0->error = node->errors[SNAT_OUT2IN_ERROR_BAD_ICMP_TYPE];
+      next0 = SNAT_OUT2IN_NEXT_DROP;
+      goto out;
+    }
+
+  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);
-  icmp0->checksum = ip_csum_fold (sum0);
+      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);
+
+      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;
@@ -314,6 +443,8 @@ static inline u32 icmp_out2in_slow_path (snat_main_t *sm,
                           s0->per_user_index);
     }
 
+out:
+  *p_s0 = s0;
   return next0;
 }
 
@@ -396,22 +527,26 @@ snat_out2in_node_fn (vlib_main_t * vm,
          rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index, 
                                    sw_if_index0);
 
-          proto0 = ~0;
-          proto0 = (ip0->protocol == IP_PROTOCOL_UDP) 
-            ? SNAT_PROTOCOL_UDP : proto0;
-          proto0 = (ip0->protocol == IP_PROTOCOL_TCP) 
-            ? SNAT_PROTOCOL_TCP : proto0;
-          proto0 = (ip0->protocol == IP_PROTOCOL_ICMP) 
-            ? SNAT_PROTOCOL_ICMP : proto0;
+          proto0 = ip_proto_to_snat_proto (ip0->protocol);
 
           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;
             }
 
@@ -429,6 +564,14 @@ snat_out2in_node_fn (vlib_main_t * vm,
               if (snat_static_mapping_match(sm, key0, &sm0, 1))
                 {
                   b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+                  /* 
+                   * Send DHCP packets to the ipv4 stack, or we won't
+                   * be able to use dhcp client on the outside interface
+                   */
+                  if (proto0 != SNAT_PROTOCOL_UDP 
+                      || (udp0->dst_port 
+                          != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client)))
+                    next0 = SNAT_OUT2IN_NEXT_DROP;
                   goto trace0;
                 }
 
@@ -436,7 +579,11 @@ snat_out2in_node_fn (vlib_main_t * vm,
               s0 = create_session_for_static_mapping(sm, b0, sm0, key0, node,
                                                      cpu_index);
               if (!s0)
-                goto trace0;
+                {
+                  b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+                  next0 = SNAT_OUT2IN_NEXT_DROP;
+                  goto trace0;
+                }
             }
           else
             s0 = pool_elt_at_index (sm->per_thread_data[cpu_index].sessions,
@@ -455,9 +602,9 @@ snat_out2in_node_fn (vlib_main_t * vm,
 
           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
             {
-              old_port0 = tcp0->ports.dst;
-              tcp0->ports.dst = s0->in2out.port;
-              new_port0 = tcp0->ports.dst;
+              old_port0 = tcp0->dst_port;
+              tcp0->dst_port = s0->in2out.port;
+              new_port0 = tcp0->dst_port;
 
               sum0 = tcp0->checksum;
               sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
@@ -515,22 +662,26 @@ snat_out2in_node_fn (vlib_main_t * vm,
          rx_fib_index1 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index, 
                                    sw_if_index1);
 
-          proto1 = ~0;
-          proto1 = (ip1->protocol == IP_PROTOCOL_UDP) 
-            ? SNAT_PROTOCOL_UDP : proto1;
-          proto1 = (ip1->protocol == IP_PROTOCOL_TCP) 
-            ? SNAT_PROTOCOL_TCP : proto1;
-          proto1 = (ip1->protocol == IP_PROTOCOL_ICMP) 
-            ? SNAT_PROTOCOL_ICMP : proto1;
+          proto1 = ip_proto_to_snat_proto (ip1->protocol);
 
           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;
             }
 
@@ -548,6 +699,14 @@ snat_out2in_node_fn (vlib_main_t * vm,
               if (snat_static_mapping_match(sm, key1, &sm1, 1))
                 {
                   b1->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+                  /* 
+                   * Send DHCP packets to the ipv4 stack, or we won't
+                   * be able to use dhcp client on the outside interface
+                   */
+                  if (proto1 != SNAT_PROTOCOL_UDP 
+                      || (udp1->dst_port 
+                          != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client)))
+                    next1 = SNAT_OUT2IN_NEXT_DROP;
                   goto trace1;
                 }
 
@@ -555,7 +714,11 @@ snat_out2in_node_fn (vlib_main_t * vm,
               s1 = create_session_for_static_mapping(sm, b1, sm1, key1, node,
                                                      cpu_index);
               if (!s1)
-                goto trace1;
+                {
+                  b1->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+                  next1 = SNAT_OUT2IN_NEXT_DROP;
+                  goto trace1;
+                }
             }
           else
             s1 = pool_elt_at_index (sm->per_thread_data[cpu_index].sessions,
@@ -574,9 +737,9 @@ snat_out2in_node_fn (vlib_main_t * vm,
 
           if (PREDICT_TRUE(proto1 == SNAT_PROTOCOL_TCP))
             {
-              old_port1 = tcp1->ports.dst;
-              tcp1->ports.dst = s1->in2out.port;
-              new_port1 = tcp1->ports.dst;
+              old_port1 = tcp1->dst_port;
+              tcp1->dst_port = s1->in2out.port;
+              new_port1 = tcp1->dst_port;
 
               sum1 = tcp1->checksum;
               sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
@@ -668,22 +831,26 @@ snat_out2in_node_fn (vlib_main_t * vm,
          rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index, 
                                    sw_if_index0);
 
-          proto0 = ~0;
-          proto0 = (ip0->protocol == IP_PROTOCOL_UDP) 
-            ? SNAT_PROTOCOL_UDP : proto0;
-          proto0 = (ip0->protocol == IP_PROTOCOL_TCP) 
-            ? SNAT_PROTOCOL_TCP : proto0;
-          proto0 = (ip0->protocol == IP_PROTOCOL_ICMP) 
-            ? SNAT_PROTOCOL_ICMP : proto0;
+          proto0 = ip_proto_to_snat_proto (ip0->protocol);
 
           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;
             }
 
@@ -701,6 +868,15 @@ snat_out2in_node_fn (vlib_main_t * vm,
               if (snat_static_mapping_match(sm, key0, &sm0, 1))
                 {
                   b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+                  /* 
+                   * Send DHCP packets to the ipv4 stack, or we won't
+                   * be able to use dhcp client on the outside interface
+                   */
+                  if (proto0 != SNAT_PROTOCOL_UDP 
+                      || (udp0->dst_port 
+                          != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client)))
+
+                    next0 = SNAT_OUT2IN_NEXT_DROP;
                   goto trace00;
                 }
 
@@ -708,7 +884,11 @@ snat_out2in_node_fn (vlib_main_t * vm,
               s0 = create_session_for_static_mapping(sm, b0, sm0, key0, node,
                                                      cpu_index);
               if (!s0)
-                goto trace00;
+                {
+                  b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
+                    next0 = SNAT_OUT2IN_NEXT_DROP;
+                  goto trace00;
+                }
             }
           else
             s0 = pool_elt_at_index (sm->per_thread_data[cpu_index].sessions,
@@ -727,9 +907,9 @@ snat_out2in_node_fn (vlib_main_t * vm,
 
           if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
             {
-              old_port0 = tcp0->ports.dst;
-              tcp0->ports.dst = s0->in2out.port;
-              new_port0 = tcp0->ports.dst;
+              old_port0 = tcp0->dst_port;
+              tcp0->dst_port = s0->in2out.port;
+              new_port0 = tcp0->dst_port;
 
               sum0 = tcp0->checksum;
               sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
@@ -810,6 +990,7 @@ 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);
@@ -855,7 +1036,7 @@ snat_out2in_worker_handoff_fn (vlib_main_t * vm,
       u32 rx_fib_index0;
       ip4_header_t * ip0;
       udp_header_t * udp0;
-      snat_static_mapping_key_t key0;
+      snat_worker_key_t key0;
       clib_bihash_kv_8_8_t kv0, value0;
       u8 do_handoff;
 
@@ -893,8 +1074,12 @@ snat_out2in_worker_handoff_fn (vlib_main_t * vm,
           if (clib_bihash_search_8_8 (&sm->worker_by_out, &kv0, &value0))
             {
               /* No, assign next available worker (RR) */
-              next_worker_index = sm->first_worker_index +
-                sm->workers[sm->next_worker++ % vec_len (sm->workers)];
+              next_worker_index = sm->first_worker_index;
+              if (vec_len (sm->workers))
+                {
+                  next_worker_index += 
+                    sm->workers[sm->next_worker++ % _vec_len (sm->workers)];
+                }
             }
           else
             {
@@ -1146,13 +1331,7 @@ snat_out2in_fast_node_fn (vlib_main_t * vm,
 
          vnet_feature_next (sw_if_index0, &next0, b0);
 
-          proto0 = ~0;
-          proto0 = (ip0->protocol == IP_PROTOCOL_UDP)
-            ? SNAT_PROTOCOL_UDP : proto0;
-          proto0 = (ip0->protocol == IP_PROTOCOL_TCP)
-            ? SNAT_PROTOCOL_TCP : proto0;
-          proto0 = (ip0->protocol == IP_PROTOCOL_ICMP)
-            ? SNAT_PROTOCOL_ICMP : proto0;
+          proto0 = ip_proto_to_snat_proto (ip0->protocol);
 
           if (PREDICT_FALSE (proto0 == ~0))
               goto trace00;
@@ -1190,8 +1369,8 @@ snat_out2in_fast_node_fn (vlib_main_t * vm,
             {
                if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP))
                 {
-                  old_port0 = tcp0->ports.dst;
-                  tcp0->ports.dst = new_port0;
+                  old_port0 = tcp0->dst_port;
+                  tcp0->dst_port = new_port0;
 
                   sum0 = tcp0->checksum;
                   sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
@@ -1269,6 +1448,7 @@ 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);