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>
diff --git a/src/vnet/devices/netmap/cli.c b/src/vnet/devices/netmap/cli.c
index 6157f27..7136329 100644
--- a/src/vnet/devices/netmap/cli.c
+++ b/src/vnet/devices/netmap/cli.c
@@ -37,6 +37,7 @@
   u8 is_pipe = 0;
   u8 is_master = 0;
   u32 sw_if_index = ~0;
+  clib_error_t *error = NULL;
 
   /* Get a line of input. */
   if (!unformat_user (input, unformat_line_input, line_input))
@@ -57,30 +58,48 @@
       else if (unformat (line_input, "slave"))
 	is_master = 0;
       else
-	return clib_error_return (0, "unknown input `%U'",
-				  format_unformat_error, input);
+	{
+	  error = clib_error_return (0, "unknown input `%U'",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
     }
-  unformat_free (line_input);
 
   if (host_if_name == NULL)
-    return clib_error_return (0, "missing host interface name");
+    {
+      error = clib_error_return (0, "missing host interface name");
+      goto done;
+    }
 
   r =
     netmap_create_if (vm, host_if_name, hw_addr_ptr, is_pipe, is_master,
 		      &sw_if_index);
 
   if (r == VNET_API_ERROR_SYSCALL_ERROR_1)
-    return clib_error_return (0, "%s (errno %d)", strerror (errno), errno);
+    {
+      error = clib_error_return (0, "%s (errno %d)", strerror (errno), errno);
+      goto done;
+    }
 
   if (r == VNET_API_ERROR_INVALID_INTERFACE)
-    return clib_error_return (0, "Invalid interface name");
+    {
+      error = clib_error_return (0, "Invalid interface name");
+      goto done;
+    }
 
   if (r == VNET_API_ERROR_SUBIF_ALREADY_EXISTS)
-    return clib_error_return (0, "Interface already exists");
+    {
+      error = clib_error_return (0, "Interface already exists");
+      goto done;
+    }
 
   vlib_cli_output (vm, "%U\n", format_vnet_sw_if_index_name, vnet_get_main (),
 		   sw_if_index);
-  return 0;
+
+done:
+  unformat_free (line_input);
+
+  return error;
 }
 
 /*?
@@ -144,6 +163,7 @@
 {
   unformat_input_t _line_input, *line_input = &_line_input;
   u8 *host_if_name = NULL;
+  clib_error_t *error = NULL;
 
   /* Get a line of input. */
   if (!unformat_user (input, unformat_line_input, line_input))
@@ -154,17 +174,25 @@
       if (unformat (line_input, "name %s", &host_if_name))
 	;
       else
-	return clib_error_return (0, "unknown input `%U'",
-				  format_unformat_error, input);
+	{
+	  error = clib_error_return (0, "unknown input `%U'",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
     }
-  unformat_free (line_input);
 
   if (host_if_name == NULL)
-    return clib_error_return (0, "missing host interface name");
+    {
+      error = clib_error_return (0, "missing host interface name");
+      goto done;
+    }
 
   netmap_delete_if (vm, host_if_name);
 
-  return 0;
+done:
+  unformat_free (line_input);
+
+  return error;
 }
 
 /*?