Fix Segfault When Syntax Of A Line Under [applicationmap] Is Invalid

When processing the lines under the [applicationmap] context in features.conf, a
segfault occurs from attempting to process a line with an invalid syntax
(basically missing most of the arguments).

Example:
[applicationmap]
automon=*6

* This patch moves the checking for empty arguments to before they are accessed.

* Also, checked the "todo" comment and removed it.  Some applications do not
  require arguments.

(closes issue ASTERISK-22416)
Reported by: CGI.NET
Tested by: CGI.NET
Patches:
    asterisk-22416-check-syntax-first_v2.diff by Michael L. Young (license 5026)

Review: https://reviewboard.asterisk.org/r/2803
........

Merged revisions 399304 from http://svn.asterisk.org/svn/asterisk/branches/1.8

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@399305 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/main/features.c b/main/features.c
index 0a3a24bd64fcd902d2f206c8801223534dc7f75b..8789e4295207ac1ccbcf93353624b566fc194621 100644 (file)
--- a/main/features.c
+++ b/main/features.c
@@ -6136,19 +6136,9 @@ static void process_applicationmap_line(struct ast_variable *var)
        );
 
        AST_STANDARD_APP_ARGS(args, tmp_val);
-       if ((new_syn = strchr(args.app, '('))) {
-               /* New syntax */
-               args.moh_class = args.app_args;
-               args.app_args = new_syn;
-               *args.app_args++ = '\0';
-               if (args.app_args[strlen(args.app_args) - 1] == ')') {
-                       args.app_args[strlen(args.app_args) - 1] = '\0';
-               }
-       }
 
        activateon = strsep(&args.activatedby, "/");
 
-       /*! \todo XXX var_name or app_args ? */
        if (ast_strlen_zero(args.app)
                || ast_strlen_zero(args.exten)
                || ast_strlen_zero(activateon)
@@ -6159,6 +6149,16 @@ static void process_applicationmap_line(struct ast_variable *var)
                return;
        }
 
+       if ((new_syn = strchr(args.app, '('))) {
+               /* New syntax */
+               args.moh_class = args.app_args;
+               args.app_args = new_syn;
+               *args.app_args++ = '\0';
+               if (args.app_args[strlen(args.app_args) - 1] == ')') {
+                       args.app_args[strlen(args.app_args) - 1] = '\0';
+               }
+       }
+       
        AST_RWLIST_RDLOCK(&feature_list);
        if (find_dynamic_feature(var->name)) {
                AST_RWLIST_UNLOCK(&feature_list);