Add missing pbx_loopback file...

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@4071 65c4cc65-6c06-0410-ace0-fbb531ad65f3

pbx/pbx_loopback.c

+/*
+ * Loopback PBX Module
+ *
+ * Copyright (C) 2004, Digium Inc.
+ *
+ * Written by Mark Spencer <markster@digium.com>
+ *
+ * This program is Free Software distributed under the terms of
+ * of the GNU General Public License.
+ */
+
+#include <asterisk/file.h>
+#include <asterisk/logger.h>
+#include <asterisk/channel.h>
+#include <asterisk/config.h>
+#include <asterisk/options.h>
+#include <asterisk/pbx.h>
+#include <asterisk/module.h>
+#include <asterisk/frame.h>
+#include <asterisk/file.h>
+#include <asterisk/cli.h>
+#include <asterisk/lock.h>
+#include <asterisk/md5.h>
+#include <asterisk/linkedlists.h>
+#include <asterisk/chanvars.h>
+#include <asterisk/sched.h>
+#include <asterisk/io.h>
+#include <asterisk/utils.h>
+#include <asterisk/crypto.h>
+#include <asterisk/astdb.h>
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+static char *tdesc = "Loopback Switch";
+
+/* Loopback switch substitutes ${EXTEN}, ${CONTEXT}, and ${PRIORITY} into
+   the data passed to it to try to get a string of the form:
+
+	[exten]@context[:priority][/extramatch]
+   
+   Where exten, context, and priority are another extension, context, and priority
+   to lookup and "extramatch" is an extra match restriction the *original* number 
+   must fit if  specified.  The "extramatch" begins with _ like an exten pattern
+   if it is specified.  Note that the search context MUST be a different context
+   from the current context or the search will not succeed in an effort to reduce
+   the likelihood of loops (they're still possible if you try hard, so be careful!)
+
+*/
+
+
+#define LOOPBACK_COMMON \
+	char buf[1024]; \
+	int res; \
+	char *newexten=(char *)exten, *newcontext=(char *)context; \
+	int newpriority=priority; \
+	char *newpattern=NULL; \
+	loopback_helper(buf, sizeof(buf), exten, context, priority, data); \
+	loopback_subst(&newexten, &newcontext, &newpriority, &newpattern, buf); \
+	ast_log(LOG_DEBUG, "Parsed into %s @ %s priority %d\n", newexten, newcontext, newpriority); \
+	if (!strcasecmp(newcontext, context)) return -1
+
+
+static char *loopback_helper(char *buf, int buflen, const char *exten, const char *context, int priority, const char *data)
+{
+	struct ast_var_t *newvariable;
+	struct varshead headp;
+	char tmp[80];
+
+	snprintf(tmp, sizeof(tmp), "%d", priority);
+	memset(buf, 0, buflen);
+	AST_LIST_HEAD_INIT(&headp);
+	newvariable = ast_var_assign("EXTEN", exten);
+	AST_LIST_INSERT_HEAD(&headp, newvariable, entries);
+	newvariable = ast_var_assign("CONTEXT", context);
+	AST_LIST_INSERT_HEAD(&headp, newvariable, entries);
+	newvariable = ast_var_assign("PRIORITY", tmp);
+	AST_LIST_INSERT_HEAD(&headp, newvariable, entries);
+	pbx_substitute_variables_varshead(&headp, data, buf, buflen);
+	/* Substitute variables */
+	while (!AST_LIST_EMPTY(&headp)) {           /* List Deletion. */
+		newvariable = AST_LIST_FIRST(&headp);
+		AST_LIST_REMOVE_HEAD(&headp, entries);
+		ast_var_delete(newvariable);
+	}
+	return buf;
+}
+
+static void loopback_subst(char **newexten, char **newcontext, int *priority, char **newpattern, char *buf)
+{
+	char *con;
+	char *pri;
+	*newpattern = strchr(buf, '/');
+	if (*newpattern) {
+		*(*newpattern) = '\0';
+		(*newpattern)++;
+	}
+	con = strchr(buf, '@');
+	if (con) {
+		*con = '\0';
+		con++;
+		pri = strchr(con, ':');
+	} else
+		pri = strchr(buf, ':');
+	if (!ast_strlen_zero(buf))
+		*newexten = buf;
+	if (con && !ast_strlen_zero(con))
+		*newcontext = con;
+	if (pri && !ast_strlen_zero(pri))
+		sscanf(pri, "%i", priority);
+}
+
+static int loopback_exists(struct ast_channel *chan, const char *context, const char *exten, int priority, const char *callerid, const char *data)
+{
+	LOOPBACK_COMMON;
+	res = ast_exists_extension(chan, newcontext, newexten, newpriority, callerid);
+	if (newpattern && !ast_extension_match(newpattern, exten))
+		res = 0;
+	return res;
+}
+
+static int loopback_canmatch(struct ast_channel *chan, const char *context, const char *exten, int priority, const char *callerid, const char *data)
+{
+	LOOPBACK_COMMON;
+	res = ast_canmatch_extension(chan, newcontext, newexten, newpriority, callerid);
+	if (newpattern && !ast_extension_match(newpattern, exten))
+		res = 0;
+	return res;
+}
+
+static int loopback_exec(struct ast_channel *chan, const char *context, const char *exten, int priority, const char *callerid, int newstack, const char *data)
+{
+	LOOPBACK_COMMON;
+	if (newstack)
+		res = ast_spawn_extension(chan, newcontext, newexten, newpriority, callerid);
+	else
+		res = ast_exec_extension(chan, newcontext, newexten, newpriority, callerid);
+	if (newpattern && !ast_extension_match(newpattern, exten))
+		res = -1;
+	return res;
+}
+
+static int loopback_matchmore(struct ast_channel *chan, const char *context, const char *exten, int priority, const char *callerid, const char *data)
+{
+	LOOPBACK_COMMON;
+	res = ast_matchmore_extension(chan, newcontext, newexten, newpriority, callerid);
+	if (newpattern && !ast_extension_match(newpattern, exten))
+		res = 0;
+	return res;
+}
+
+static struct ast_switch loopback_switch =
+{
+        name:                   "Loopback",
+        description:    		"Loopback Dialplan Switch",
+        exists:                 loopback_exists,
+        canmatch:               loopback_canmatch,
+        exec:                   loopback_exec,
+        matchmore:              loopback_matchmore,
+};
+
+char *description(void)
+{
+	return tdesc;
+}
+
+int usecount(void)
+{
+	return 1;
+}
+
+char *key()
+{
+	return ASTERISK_GPL_KEY;
+}
+
+int unload_module(void)
+{
+	ast_unregister_switch(&loopback_switch);
+	return 0;
+}
+
+int load_module(void)
+{
+	ast_register_switch(&loopback_switch);
+	return 0;
+}
+