VPP-635: CLI Memory leak with invalid parameter

In the CLI parsing, below is a common pattern:
  /* Get a line of input. */
  if (!unformat_user (input, unformat_line_input, line_input))
    return 0;

  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (line_input, "x"))
	x = 1;
      :
      else
	return clib_error_return (0, "unknown input `%U'",
				  format_unformat_error, line_input);
    }
  unformat_free (line_input);

The 'else' returns if an unknown string is encountered. There a memory
leak because the 'unformat_free(line_input)' is not called. There is a
large number of instances of this pattern.

Replaced the previous pattern with:
  /* Get a line of input. */
  if (!unformat_user (input, unformat_line_input, line_input))
    return 0;

  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (line_input, "x"))
	x = 1;
      :
      else
        {
	  error = clib_error_return (0, "unknown input `%U'",
				     format_unformat_error, line_input);
	  goto done:
        }
    }

  /* ...Remaining code... */

done:
  unformat_free (line_input);
  return error;
}

In multiple files, 'unformat_free (line_input);' was never called, so
there was a memory leak whether an invalid string was entered or not.

Also, there were multiple instance where:
	  error = clib_error_return (0, "unknown input `%U'",
				     format_unformat_error, line_input);
used 'input' as the last parameter instead of 'line_input'. The result
is that output did not contain the substring in error, instead just an
empty string. Fixed all of those as well.

There are a lot of file, and very mind numbing work, so tried to keep
it to a pattern to avoid mistakes.

Change-Id: I8902f0c32a47dd7fb3bb3471a89818571702f1d2
Signed-off-by: Billy McFall <bmcfall@redhat.com>
Signed-off-by: Dave Barach <dave@barachs.net>

1 files changed, 28 insertions, 11 deletions

diff --git a/src/vnet/l2tp/l2tp.c b/src/vnet/l2tp/l2tp.c
index a4531dab85c..2d3233972a8 100644
--- a/src/vnet/l2tp/l2tp.c
+++ b/src/vnet/l2tp/l2tp.c
@@ -427,6 +427,7 @@ create_l2tpv3_tunnel_command_fn (vlib_main_t * vm,
   u32 sw_if_index;
   u32 encap_fib_id = ~0;
   u32 encap_fib_index = ~0;
+  clib_error_t *error = NULL;
 
   /* Get a line of input. */
   if (!unformat_user (input, unformat_line_input, line_input))
@@ -455,18 +456,22 @@ create_l2tpv3_tunnel_command_fn (vlib_main_t * vm,
       else if (unformat (line_input, "l2-sublayer-present"))
 	l2_sublayer_present = 1;
       else
-	return clib_error_return (0, "parse error: '%U'",
-				  format_unformat_error, line_input);
+	{
+	  error = clib_error_return (0, "parse error: '%U'",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
     }
 
-  unformat_free (line_input);
-
   if (encap_fib_id != ~0)
     {
       uword *p;
       ip6_main_t *im = &ip6_main;
       if (!(p = hash_get (im->fib_index_by_table_id, encap_fib_id)))
-	return clib_error_return (0, "No fib with id %d", encap_fib_id);
+	{
+	  error = clib_error_return (0, "No fib with id %d", encap_fib_id);
+	  goto done;
+	}
       encap_fib_index = p[0];
     }
   else
@@ -475,9 +480,15 @@ create_l2tpv3_tunnel_command_fn (vlib_main_t * vm,
     }
 
   if (our_address_set == 0)
-    return clib_error_return (0, "our address not specified");
+    {
+      error = clib_error_return (0, "our address not specified");
+      goto done;
+    }
   if (client_address_set == 0)
-    return clib_error_return (0, "client address not specified");
+    {
+      error = clib_error_return (0, "client address not specified");
+      goto done;
+    }
 
   rv = create_l2tpv3_ipv6_tunnel (lm, &client_address, &our_address,
 				  local_session_id, remote_session_id,
@@ -491,16 +502,22 @@ create_l2tpv3_tunnel_command_fn (vlib_main_t * vm,
 		       vnet_get_main (), sw_if_index);
       break;
     case VNET_API_ERROR_INVALID_VALUE:
-      return clib_error_return (0, "session already exists...");
+      error = clib_error_return (0, "session already exists...");
+      goto done;
 
     case VNET_API_ERROR_NO_SUCH_ENTRY:
-      return clib_error_return (0, "session does not exist...");
+      error = clib_error_return (0, "session does not exist...");
+      goto done;
 
     default:
-      return clib_error_return (0, "l2tp_session_add_del returned %d", rv);
+      error = clib_error_return (0, "l2tp_session_add_del returned %d", rv);
+      goto done;
     }
 
-  return 0;
+done:
+  unformat_free (line_input);
+
+  return error;
 }
 
 /* *INDENT-OFF* */