NAT44: fix ICMP checksum update crash (VPP-1205)
[vpp.git] / src / plugins / nat / out2in.c
index d548ab3..ebd0dc4 100755 (executable)
@@ -133,6 +133,7 @@ typedef enum {
   SNAT_OUT2IN_NEXT_LOOKUP,
   SNAT_OUT2IN_NEXT_ICMP_ERROR,
   SNAT_OUT2IN_NEXT_REASS,
+  SNAT_OUT2IN_NEXT_IN2OUT,
   SNAT_OUT2IN_N_NEXT,
 } snat_out2in_next_t;
 
@@ -264,6 +265,110 @@ 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;
+}
+
+static int
+next_src_nat (snat_main_t * sm, ip4_header_t * ip, u32 proto, u16 src_port,
+              u32 thread_index)
+{
+  snat_session_key_t key;
+  clib_bihash_kv_8_8_t kv, value;
+
+  key.addr = ip->src_address;
+  key.port = src_port;
+  key.protocol = proto;
+  key.fib_index = sm->inside_fib_index;
+  kv.key = key.as_u64;
+
+  if (!clib_bihash_search_8_8 (&sm->per_thread_data[thread_index].in2out, &kv,
+                               &value))
+    return 1;
+
+  return 0;
+}
+
+static void
+create_bypass_for_fwd(snat_main_t * sm, ip4_header_t * ip)
+{
+  nat_ed_ses_key_t key;
+  clib_bihash_kv_16_8_t kv;
+  udp_header_t *udp;
+
+  if (ip->protocol == IP_PROTOCOL_ICMP)
+    {
+      if (icmp_get_ed_key (ip, &key))
+        return;
+    }
+  else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
+    {
+      udp = ip4_next_header(ip);
+      key.r_addr = ip->src_address;
+      key.l_addr = ip->dst_address;
+      key.proto = ip->protocol;
+      key.l_port = udp->dst_port;
+      key.r_port = udp->src_port;
+    }
+  else
+    {
+      key.r_addr = ip->src_address;
+      key.l_addr = ip->dst_address;
+      key.proto = ip->protocol;
+      key.l_port = key.r_port = 0;
+    }
+  key.fib_index = 0;
+  kv.key[0] = key.as_u64[0];
+  kv.key[1] = key.as_u64[1];
+  kv.value = ~0ULL;
+
+  if (clib_bihash_add_del_16_8 (&sm->in2out_ed, &kv, 1))
+    clib_warning ("in2out_ed key add failed");
+}
+
 /**
  * Get address and port values to be used for ICMP packet translation
  * and create session if needed
@@ -336,6 +441,12 @@ u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node,
           else
             {
               dont_translate = 1;
+              if (next_src_nat(sm, ip0, key0.protocol, key0.port, thread_index))
+                {
+                  next0 = SNAT_OUT2IN_NEXT_IN2OUT;
+                  goto out;
+                }
+              create_bypass_for_fwd(sm, ip0);
               goto out;
             }
         }
@@ -369,8 +480,34 @@ 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:
@@ -507,6 +644,9 @@ static inline u32 icmp_out2in (snat_main_t *sm,
                          dst_address /* changed member */);
   ip0->checksum = ip_csum_fold (sum0);
 
+  if (icmp0->checksum == 0)
+    icmp0->checksum = 0xffff;
+
   if (!icmp_is_error_message (icmp0))
     {
       new_id0 = sm0.port;
@@ -992,8 +1132,9 @@ snat_out2in_node_fn (vlib_main_t * vm,
             {
               s0 = snat_out2in_unknown_proto(sm, b0, ip0, rx_fib_index0,
                                              thread_index, now, vm, node);
-              if (!s0)
-                next0 = SNAT_OUT2IN_NEXT_DROP;
+             if (!sm->forwarding_enabled)
+               if (!s0)
+                 next0 = SNAT_OUT2IN_NEXT_DROP;
               goto trace0;
             }
 
@@ -1032,14 +1173,26 @@ snat_out2in_node_fn (vlib_main_t * vm,
                        * 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
+                      if (PREDICT_TRUE (proto0 != SNAT_PROTOCOL_UDP
                           || (udp0->dst_port
-                              != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client)))
+                              != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client))))
                         next0 = SNAT_OUT2IN_NEXT_DROP;
+                      else
+                        vnet_feature_next
+                          (vnet_buffer (b0)->sw_if_index[VLIB_RX],
+                           &next0, b0);
                       goto trace0;
                     }
                   else
-                    goto trace0;
+                    {
+                      if (next_src_nat(sm, ip0, proto0, udp0->src_port, thread_index))
+                        {
+                          next0 = SNAT_OUT2IN_NEXT_IN2OUT;
+                          goto trace0;
+                        }
+                      create_bypass_for_fwd(sm, ip0);
+                      goto trace0;
+                    }
                 }
 
               /* Create session initiated by host from external network */
@@ -1155,8 +1308,9 @@ snat_out2in_node_fn (vlib_main_t * vm,
             {
               s1 = snat_out2in_unknown_proto(sm, b1, ip1, rx_fib_index1,
                                              thread_index, now, vm, node);
-              if (!s1)
-                next1 = SNAT_OUT2IN_NEXT_DROP;
+             if (!sm->forwarding_enabled)
+               if (!s1)
+                 next1 = SNAT_OUT2IN_NEXT_DROP;
               goto trace1;
             }
 
@@ -1195,14 +1349,26 @@ snat_out2in_node_fn (vlib_main_t * vm,
                        * 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
+                      if (PREDICT_TRUE (proto1 != SNAT_PROTOCOL_UDP
                           || (udp1->dst_port
-                              != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client)))
+                              != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client))))
                         next1 = SNAT_OUT2IN_NEXT_DROP;
+                      else
+                        vnet_feature_next
+                          (vnet_buffer (b1)->sw_if_index[VLIB_RX],
+                           &next1, b1);
                       goto trace1;
                     }
                   else
-                    goto trace1;
+                    {
+                      if (next_src_nat(sm, ip1, proto1, udp1->src_port, thread_index))
+                        {
+                          next1 = SNAT_OUT2IN_NEXT_IN2OUT;
+                          goto trace1;
+                        }
+                      create_bypass_for_fwd(sm, ip1);
+                      goto trace1;
+                    }
                 }
 
               /* Create session initiated by host from external network */
@@ -1344,8 +1510,9 @@ snat_out2in_node_fn (vlib_main_t * vm,
             {
               s0 = snat_out2in_unknown_proto(sm, b0, ip0, rx_fib_index0,
                                              thread_index, now, vm, node);
-              if (!s0)
-                next0 = SNAT_OUT2IN_NEXT_DROP;
+             if (!sm->forwarding_enabled)
+               if (!s0)
+                 next0 = SNAT_OUT2IN_NEXT_DROP;
               goto trace00;
             }
 
@@ -1394,14 +1561,26 @@ snat_out2in_node_fn (vlib_main_t * vm,
                        * 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
+                      if (PREDICT_TRUE (proto0 != SNAT_PROTOCOL_UDP
                           || (udp0->dst_port
-                              != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client)))
+                              != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client))))
                         next0 = SNAT_OUT2IN_NEXT_DROP;
+                      else
+                        vnet_feature_next
+                          (vnet_buffer (b0)->sw_if_index[VLIB_RX],
+                           &next0, b0);
                       goto trace00;
                     }
                   else
-                    goto trace00;
+                    {
+                      if (next_src_nat(sm, ip0, proto0, udp0->src_port, thread_index))
+                        {
+                          next0 = SNAT_OUT2IN_NEXT_IN2OUT;
+                          goto trace00;
+                        }
+                      create_bypass_for_fwd(sm, ip0);
+                      goto trace00;
+                    }
                 }
 
               /* Create session initiated by host from external network */
@@ -1526,6 +1705,7 @@ VLIB_REGISTER_NODE (snat_out2in_node) = {
     [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
     [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
     [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass",
+    [SNAT_OUT2IN_NEXT_IN2OUT] = "nat44-in2out",
   },
 };
 VLIB_NODE_FUNCTION_MULTIARCH (snat_out2in_node, snat_out2in_node_fn);
@@ -1634,14 +1814,26 @@ nat44_out2in_reass_node_fn (vlib_main_t * vm,
                            * 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
+                          if (PREDICT_TRUE (proto0 != SNAT_PROTOCOL_UDP
                               || (udp0->dst_port
-                                  != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client)))
+                                  != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client))))
                             next0 = SNAT_OUT2IN_NEXT_DROP;
+                          else
+                            vnet_feature_next
+                              (vnet_buffer (b0)->sw_if_index[VLIB_RX],
+                               &next0, b0);
                           goto trace0;
                         }
                       else
-                        goto trace0;
+                        {
+                          if (next_src_nat(sm, ip0, proto0, udp0->src_port, thread_index))
+                            {
+                              next0 = SNAT_OUT2IN_NEXT_IN2OUT;
+                              goto trace0;
+                            }
+                          create_bypass_for_fwd(sm, ip0);
+                          goto trace0;
+                        }
                     }
 
                   /* Create session initiated by host from external network */
@@ -1810,6 +2002,7 @@ VLIB_REGISTER_NODE (nat44_out2in_reass_node) = {
     [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
     [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
     [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass",
+    [SNAT_OUT2IN_NEXT_IN2OUT] = "nat44-in2out",
   },
 };
 VLIB_NODE_FUNCTION_MULTIARCH (nat44_out2in_reass_node,
@@ -2299,6 +2492,7 @@ VLIB_REGISTER_NODE (snat_det_out2in_node) = {
     [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
     [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
     [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass",
+    [SNAT_OUT2IN_NEXT_IN2OUT] = "nat44-in2out",
   },
 };
 VLIB_NODE_FUNCTION_MULTIARCH (snat_det_out2in_node, snat_det_out2in_node_fn);
@@ -2792,6 +2986,7 @@ VLIB_REGISTER_NODE (snat_out2in_fast_node) = {
     [SNAT_OUT2IN_NEXT_DROP] = "error-drop",
     [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
     [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass",
+    [SNAT_OUT2IN_NEXT_IN2OUT] = "nat44-in2out",
   },
 };
 VLIB_NODE_FUNCTION_MULTIARCH (snat_out2in_fast_node, snat_out2in_fast_node_fn);