tcp: validate connections in output

Type: feature

This shouldn't happen unless connections are removed after buffers were
enqueued to tcp-output and before tcp-output runs. For instance, packet
is enqueued to tcp output and cleanup is called for connection.

Change-Id: Ib7dd82ffa6cfb21ff5068aba010e0a3497eeea13
Signed-off-by: Florin Coras <fcoras@cisco.com>
(cherry picked from commit 78dae00881d26b205ee6721ce8c2bcae76996e79)

1 files changed, 46 insertions, 9 deletions

diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c
index 239f6035d5f..d15d710eafe 100644
--- a/src/vnet/tcp/tcp_output.c
+++ b/src/vnet/tcp/tcp_output.c
@@ -2138,6 +2138,10 @@ tcp_output_handle_packet (tcp_connection_t * tc0, vlib_buffer_t * b0,
       *next0 = tc0->next_node_index;
       vnet_buffer (b0)->tcp.next_node_opaque = tc0->next_node_opaque;
     }
+  else
+    {
+      *next0 = TCP_OUTPUT_NEXT_IP_LOOKUP;
+    }
 
   vnet_buffer (b0)->sw_if_index[VLIB_TX] = tc0->c_fib_index;
   vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
@@ -2196,18 +2200,44 @@ tcp46_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	CLIB_PREFETCH (b[3]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
       }
 
-      next[0] = next[1] = TCP_OUTPUT_NEXT_IP_LOOKUP;
-
       tc0 = tcp_connection_get (vnet_buffer (b[0])->tcp.connection_index,
 				thread_index);
       tc1 = tcp_connection_get (vnet_buffer (b[1])->tcp.connection_index,
 				thread_index);
 
-      tcp_output_push_ip (vm, b[0], tc0, is_ip4);
-      tcp_output_push_ip (vm, b[1], tc1, is_ip4);
+      if (PREDICT_TRUE (!tc0 + !tc1 == 0))
+	{
+	  tcp_output_push_ip (vm, b[0], tc0, is_ip4);
+	  tcp_output_push_ip (vm, b[1], tc1, is_ip4);
 
-      tcp_output_handle_packet (tc0, b[0], error_node, &next[0], is_ip4);
-      tcp_output_handle_packet (tc1, b[1], error_node, &next[1], is_ip4);
+	  tcp_output_handle_packet (tc0, b[0], error_node, &next[0], is_ip4);
+	  tcp_output_handle_packet (tc1, b[1], error_node, &next[1], is_ip4);
+	}
+      else
+	{
+	  if (tc0 != 0)
+	    {
+	      tcp_output_push_ip (vm, b[0], tc0, is_ip4);
+	      tcp_output_handle_packet (tc0, b[0], error_node, &next[0],
+					is_ip4);
+	    }
+	  else
+	    {
+	      b[0]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION];
+	      next[0] = TCP_OUTPUT_NEXT_DROP;
+	    }
+	  if (tc1 != 0)
+	    {
+	      tcp_output_push_ip (vm, b[1], tc1, is_ip4);
+	      tcp_output_handle_packet (tc1, b[1], error_node, &next[1],
+					is_ip4);
+	    }
+	  else
+	    {
+	      b[1]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION];
+	      next[1] = TCP_OUTPUT_NEXT_DROP;
+	    }
+	}
 
       b += 2;
       next += 2;
@@ -2223,12 +2253,19 @@ tcp46_output_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	  CLIB_PREFETCH (b[1]->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
 	}
 
-      next[0] = TCP_OUTPUT_NEXT_IP_LOOKUP;
       tc0 = tcp_connection_get (vnet_buffer (b[0])->tcp.connection_index,
 				thread_index);
 
-      tcp_output_push_ip (vm, b[0], tc0, is_ip4);
-      tcp_output_handle_packet (tc0, b[0], error_node, &next[0], is_ip4);
+      if (PREDICT_TRUE (tc0 != 0))
+	{
+	  tcp_output_push_ip (vm, b[0], tc0, is_ip4);
+	  tcp_output_handle_packet (tc0, b[0], error_node, &next[0], is_ip4);
+	}
+      else
+	{
+	  b[0]->error = error_node->errors[TCP_ERROR_INVALID_CONNECTION];
+	  next[0] = TCP_OUTPUT_NEXT_DROP;
+	}
 
       b += 1;
       next += 1;