Fix some refcounting in app_queue.c and change the

hashing used by app_queue.c to be case-insensitive.
This is accomplished by adding a new case-insensitive
hashing function.

This was necessary to prevent bad refcount errors
(and potential crashes) which would occur due to the
fact that queues were initially read from the config
file in a case-sensitive manner. Then, when a user
issued a CLI command or manager action, we allowed
for case-insensitive input and used that input to 
directly try to find the queue in the hash table. The result
was either that we could not find a queue that was input or
worse, we would end up hashing to a completely bogus value
based on the input.

This commit resolves the problem presented in
issue #13703. However, that issue was reported against
1.6.0. Since this fix introduces a behavior change, I am
electing to not place this same fix in to the 1.6.0 or 1.6.1
branches, and instead will opt for a change which does not
change behavior.



git-svn-id: http://svn.digium.com/svn/asterisk/trunk@156883 f38db490-d61c-443f-a65b-d21fe96a405b

UPGRADE.txt

@@ -291,6 +291,13 @@ Queues:
   new value has been added to the TRANSFER event that indicates the caller's
   original position in the queue they are being transfered from.
 
+* Prior to Asterisk 1.6.2, queue names were treated in a case-sensitive
+  manner, meaning that queues with names like "sales" and "sALeS" would
+  be seen as unique queues. The parsing logic has changed to use case-
+  insensitive comparisons now when originally hashing based on queue
+  names, meaning that now the two queues mentioned as examples earlier
+  will be seen as having the same name.
+
 iLBC Codec:
 
 * Previously, the Asterisk source code distribution included the iLBC

apps/app_queue.c

@@ -67,6 +67,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include <sys/time.h>
 #include <sys/signal.h>
 #include <netinet/in.h>
+#include <ctype.h>
 
 #include "asterisk/lock.h"
 #include "asterisk/file.h"
@@ -850,7 +851,8 @@ static int strat2int(const char *strategy)
 static int queue_hash_cb(const void *obj, const int flags)
 {
 	const struct call_queue *q = obj;
-	return ast_str_hash(q->name);
+
+	return ast_str_case_hash(q->name);
 }
 
 static int queue_cmp_cb(void *obj, void *arg, void *data, int flags)
@@ -1671,7 +1673,6 @@ static struct call_queue *find_queue_by_name_rt(const char *queuename, struct as
 			/* Delete if unused (else will be deleted when last caller leaves). */
 			ao2_unlink(queues, q);
 			ao2_unlock(q);
-			queue_unref(q);
 		}
 		return NULL;
 	}
@@ -2192,8 +2193,6 @@ static void leave_queue(struct queue_ent *qe)
 	if (q->dead) {	
 		/* It's dead and nobody is in it, so kill it */
 		ao2_unlink(queues, q);
-		/* unref the container's reference to the queue */
-		queue_unref(q);
 	}
 	/* unref the explicit ref earlier in the function */
 	queue_unref(q);
@@ -2248,11 +2247,10 @@ static int compare_weight(struct call_queue *rq, struct member *member)
 			}
 		}
 		ao2_unlock(q);
+		queue_unref(q);
 		if (found) {
-			queue_unref(q);
 			break;
 		}
-		queue_unref(q);
 	}
 	return found;
 }
@@ -4186,6 +4184,8 @@ static int remove_from_queue(const char *queuename, const char *interface)
 			if (!mem->dynamic) {
 				ao2_ref(mem, -1);
 				ao2_unlock(q);
+				queue_unref(q);
+				ao2_unlock(queues);
 				return RES_NOT_DYNAMIC;
 			}
 			q->membercount--;
@@ -5691,13 +5691,15 @@ static char *__queues_show(struct mansession *s, int fd, int argc, char **argv)
 		}
 	}
 
-	queue_iter = ao2_iterator_init(queues, 0);
+	queue_iter = ao2_iterator_init(queues, F_AO2I_DONTLOCK);
+	ao2_lock(queues);
 	while ((q = ao2_iterator_next(&queue_iter))) {
 		float sl;
 
 		ao2_lock(q);
 		if (argc == 3 && strcasecmp(q->name, argv[2])) {
 			ao2_unlock(q);
+			queue_unref(q);
 			continue;
 		}
 		found = 1;
@@ -5768,6 +5770,7 @@ static char *__queues_show(struct mansession *s, int fd, int argc, char **argv)
 		}
 		queue_unref(q); /* Unref the iterator's reference */
 	}
+	ao2_unlock(queues);
 	if (!found) {
 		if (argc == 3)
 			ast_str_set(&out, 0, "No such queue: %s.", argv[2]);

include/asterisk/strings.h

@@ -23,6 +23,8 @@
 #ifndef _ASTERISK_STRINGS_H
 #define _ASTERISK_STRINGS_H
 
+#include <ctype.h>
+
 #include "asterisk/inline_api.h"
 #include "asterisk/utils.h"
 #include "asterisk/threadstorage.h"
@@ -738,4 +740,21 @@ static force_inline int ast_str_hash(const char *str)
 	return abs(hash);
 }
 
+/*!
+ * \brief Compute a hash value on a case-insensitive string
+ *
+ * Uses the same hash algorithm as ast_str_hash, but converts
+ * all characters to lowercase prior to computing a hash. This
+ * allows for easy case-insensitive lookups in a hash table.
+ */
+static force_inline int ast_str_case_hash(const char *str)
+{
+	int hash = 5381;
+
+	while (*str) {
+		hash = hash * 33 ^ tolower(*str++);
+	}
+
+	return abs(hash);
+}
 #endif /* _ASTERISK_STRINGS_H */