Changeset 1591

Timestamp:

03/10/10 23:34:43 (6 months ago)

Author:

marek

Message:

batctl: fix crash in bat-hosts parser on embedded systems

The bat-hosts parser uses the realpath() function to recognize already
parsed files. On most systems realpath() allocates a buffer containing
the file's location. Some embedded libc implementations seem to expect
an allocated buffer as second argument otherwise they simply crash.
batctl now always allocates a buffer to handle this case.

Reported-by: Linus Luessing <linus.luessing@…>
Signed-off-by: Marek Lindner <lindner_marek@…>

Files:

• branches/batctl-0.2.x/bat-hosts.c (modified) (4 diffs)

branches/batctl-0.2.x/bat-hosts.c

@@ -151 +151 @@
         char *homedir;
         size_t locations = sizeof(bat_hosts_path) / sizeof(char *);
-        char *normalized[locations];
-
+        char *normalized;
+
+        /***
+         * realpath could allocate the memory for us but some embedded libc
+         * implementations seem to expect a buffer as second argument
+         */
+        normalized = malloc(locations * PATH_MAX);
+        if (!normalized) {
+                printf("Warning - couldn't not get memory for bat-hosts file parsing\n");
+                return;
+        }
+
+        memset(normalized, 0, locations * PATH_MAX);
         host_hash = hash_new(64, compare_mac, choose_mac);
 
@@ -175 +186 @@
                 }
 
-                normalized[i] = realpath(confdir, NULL);
-                if (normalized[i] == NULL)
+                if (!realpath(confdir, normalized + (i * PATH_MAX)))
                         continue;
 
@@ -182 +192 @@
                 parse = 1;
                 for (j = 0; j < i; j++) {
-                        if (normalized[j] == NULL)
-                                continue;
-
-                        if (strncmp(normalized[i], normalized[j], CONF_DIR_LEN) == 0) {
+                        if (strncmp(normalized + (i * PATH_MAX), normalized + (j * PATH_MAX), CONF_DIR_LEN) == 0) {
                                 parse = 0;
                                 break;
@@ -191 +198 @@
                 }
 
-                if (parse && (normalized[i] != NULL))
-                        parse_hosts_file(&host_hash, normalized[i]);
-        }
-
-        for (i = 0; i < locations; i++) {
-                if (normalized[i])
-                        free(normalized[i]);
-        }
+                if (parse)
+                        parse_hosts_file(&host_hash, normalized + (i * PATH_MAX));
+        }
+
+        free(normalized);
 }