add mactime plugin unit / code coverage tests

The unit and code coverage tests are boring. The rest of the patch
involves test and packet-generator infra cleanups.

Teach the "make test-xxx" family of targets to set the api test plugin
path correctly, to make "binary-api <api-message-name> <args>" debug
CLI commands work correctly in the "make test"
environment. Unfortunately involves both the top-level and test
Makefiles.

Add a minor pg cli feature, a CLI to manually set
s->sw_if_index[VLIB_TX].

Consider the case where one configures an interface with both a
device-input and an output feature. To test the output feature using
the pg, it's necessary to inject packets into the interface output
node with both b->sw_if_index[VLIB_TX] and b->sw_if_index[VLIB_RX] set
correctly. For example:

packet-generator new {
 name tx
 limit 15
 size 128-128
 interface local0  # rx: device input feature not configured on local0
 tx-interface loop0 # tx: output node requires b->sw_if_index[VLIB_TX]
 node loop0-output
 data {
   hex 0x01005e7ffffa000dead0000008000102030405060708090a0b0c0d0e0f0102030405
   }
}

Fix a longstanding bug in the packet generator stream setup.  Remove
kludges which set b->sw_if_index[VLIB_TX] to ~0 [in multiple places]
instead of using the stream value s->sw_if_index[VLIB_TX], and setting
THAT datum correctly.

Change-Id: I1097a18e8db73661ded6b822c1d718f7e5cf36ed
Signed-off-by: Dave Barach <dave@barachs.net>

3 files changed, 30 insertions, 20 deletions

diff --git a/src/vnet/pg/cli.c b/src/vnet/pg/cli.c
index 4526986d1ff..9c42d70a383 100644
--- a/src/vnet/pg/cli.c
+++ b/src/vnet/pg/cli.c
@@ -109,19 +109,26 @@ static clib_error_t *
 enable_disable_stream (vlib_main_t * vm,
 		       unformat_input_t * input, vlib_cli_command_t * cmd)
 {
+  unformat_input_t _line_input, *line_input = &_line_input;
   pg_main_t *pg = &pg_main;
   int is_enable = cmd->function_arg != 0;
   u32 stream_index = ~0;
 
-  if (unformat (input, "%U", unformat_eof))
-    ;
-  else if (unformat (input, "%U", unformat_hash_vec_string,
-		     pg->stream_index_by_name, &stream_index))
-    ;
-  else
-    return clib_error_create ("unknown input `%U'",
-			      format_unformat_error, input);
+  if (!unformat_user (input, unformat_line_input, line_input))
+    goto doit;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "%U", unformat_hash_vec_string,
+		    pg->stream_index_by_name, &stream_index))
+	;
+      else
+	return clib_error_create ("unknown input `%U'",
+				  format_unformat_error, line_input);
+    }
+  unformat_free (line_input);
 
+doit:
   pg_enable_disable (stream_index, is_enable);
 
   return 0;
@@ -374,6 +381,10 @@ new_stream (vlib_main_t * vm,
 			 unformat_vnet_sw_interface, vnm,
 			 &s.sw_if_index[VLIB_RX]))
 	;
+      else if (unformat (input, "tx-interface %U",
+			 unformat_vnet_sw_interface, vnm,
+			 &s.sw_if_index[VLIB_TX]))
+	;
 
       else if (unformat (input, "pcap %s", &pcap_file_name))
 	;
diff --git a/src/vnet/pg/input.c b/src/vnet/pg/input.c
index 39f06923072..7171bbdda65 100644
--- a/src/vnet/pg/input.c
+++ b/src/vnet/pg/input.c
@@ -1108,7 +1108,7 @@ init_buffers_inline (vlib_main_t * vm,
 	vnet_buffer (b1)->sw_if_index[VLIB_RX] = s->sw_if_index[VLIB_RX];
 
       vnet_buffer (b0)->sw_if_index[VLIB_TX] =
-	vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+	vnet_buffer (b1)->sw_if_index[VLIB_TX] = s->sw_if_index[VLIB_TX];
 
       if (set_data)
 	{
@@ -1133,8 +1133,7 @@ init_buffers_inline (vlib_main_t * vm,
 
       b0 = vlib_get_buffer (vm, bi0);
       vnet_buffer (b0)->sw_if_index[VLIB_RX] = s->sw_if_index[VLIB_RX];
-      /* s->sw_if_index[VLIB_TX]; */
-      vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+      vnet_buffer (b0)->sw_if_index[VLIB_TX] = s->sw_if_index[VLIB_TX];
 
       if (set_data)
 	clib_memcpy_fast (b0->data, data, n_data);
@@ -1266,7 +1265,7 @@ pg_stream_fill_replay (pg_main_t * pg, pg_stream_t * s, u32 n_alloc)
 	  b = vlib_get_buffer (vm, buffers[current_buffer_index]);
 	  clib_memcpy_fast (b->data, d0 + data_offset, bytes_this_chunk);
 	  vnet_buffer (b)->sw_if_index[VLIB_RX] = s->sw_if_index[VLIB_RX];
-	  vnet_buffer (b)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+	  vnet_buffer (b)->sw_if_index[VLIB_TX] = s->sw_if_index[VLIB_TX];
 	  b->flags = 0;
 	  b->next_buffer = 0;
 	  b->current_data = 0;
diff --git a/src/vnet/pg/stream.c b/src/vnet/pg/stream.c
index c60c5845af6..64fe7c859ae 100644
--- a/src/vnet/pg/stream.c
+++ b/src/vnet/pg/stream.c
@@ -447,16 +447,16 @@ pg_stream_add (pg_main_t * pg, pg_stream_t * s_init)
   /* Find an interface to use. */
   s->pg_if_index = pg_interface_add_or_get (pg, s->if_id);
 
-  {
-    pg_interface_t *pi = pool_elt_at_index (pg->interfaces, s->pg_if_index);
-    vlib_rx_or_tx_t rx_or_tx;
-
-    vlib_foreach_rx_tx (rx_or_tx)
+  if (s->sw_if_index[VLIB_RX] == ~0)
     {
-      if (s->sw_if_index[rx_or_tx] == ~0)
-	s->sw_if_index[rx_or_tx] = pi->sw_if_index;
+      pg_interface_t *pi = pool_elt_at_index (pg->interfaces, s->pg_if_index);
+      /*
+       * Default the RX interface if unset. It's a bad mistake to
+       * set [VLIB_TX] prior to ip lookup, since the ip lookup code
+       * interprets [VLIB_TX] as a fib index...
+       */
+      s->sw_if_index[VLIB_RX] = pi->sw_if_index;
     }
-  }
 
   /* Connect the graph. */
   s->next_index = vlib_node_add_next (vm, device_input_node.index,