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-rw-r--r--trunk/apps/app_stack.c416
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diff --git a/trunk/apps/app_stack.c b/trunk/apps/app_stack.c
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+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (c) 2004-2006 Tilghman Lesher <app_stack_v003@the-tilghman.com>.
+ *
+ * This code is released by the author with no restrictions on usage.
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file
+ *
+ * \brief Stack applications Gosub, Return, etc.
+ *
+ * \author Tilghman Lesher <app_stack_v003@the-tilghman.com>
+ *
+ * \ingroup applications
+ */
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include "asterisk/pbx.h"
+#include "asterisk/module.h"
+#include "asterisk/app.h"
+#include "asterisk/manager.h"
+#include "asterisk/channel.h"
+
+static const char *app_gosub = "Gosub";
+static const char *app_gosubif = "GosubIf";
+static const char *app_return = "Return";
+static const char *app_pop = "StackPop";
+
+static const char *gosub_synopsis = "Jump to label, saving return address";
+static const char *gosubif_synopsis = "Conditionally jump to label, saving return address";
+static const char *return_synopsis = "Return from gosub routine";
+static const char *pop_synopsis = "Remove one address from gosub stack";
+
+static const char *gosub_descrip =
+" Gosub([[context,]exten,]priority[(arg1[,...][,argN])]):\n"
+"Jumps to the label specified, saving the return address.\n";
+static const char *gosubif_descrip =
+" GosubIf(condition?labeliftrue[(arg1[,...])][:labeliffalse[(arg1[,...])]]):\n"
+"If the condition is true, then jump to labeliftrue. If false, jumps to\n"
+"labeliffalse, if specified. In either case, a jump saves the return point\n"
+"in the dialplan, to be returned to with a Return.\n";
+static const char *return_descrip =
+" Return([return-value]):\n"
+"Jumps to the last label on the stack, removing it. The return value, if\n"
+"any, is saved in the channel variable GOSUB_RETVAL.\n";
+static const char *pop_descrip =
+" StackPop():\n"
+"Removes last label on the stack, discarding it.\n";
+
+
+static void gosub_free(void *data);
+
+static struct ast_datastore_info stack_info = {
+ .type = "GOSUB",
+ .destroy = gosub_free,
+};
+
+struct gosub_stack_frame {
+ AST_LIST_ENTRY(gosub_stack_frame) entries;
+ /* 100 arguments is all that we support anyway, but this will handle up to 255 */
+ unsigned char arguments;
+ struct varshead varshead;
+ int priority;
+ char *context;
+ char extension[0];
+};
+
+static int frame_set_var(struct ast_channel *chan, struct gosub_stack_frame *frame, const char *var, const char *value)
+{
+ struct ast_var_t *variables;
+ int found = 0;
+
+ /* Does this variable already exist? */
+ AST_LIST_TRAVERSE(&frame->varshead, variables, entries) {
+ if (!strcmp(var, ast_var_name(variables))) {
+ found = 1;
+ break;
+ }
+ }
+
+ if (!ast_strlen_zero(value)) {
+ if (!found) {
+ variables = ast_var_assign(var, "");
+ AST_LIST_INSERT_HEAD(&frame->varshead, variables, entries);
+ pbx_builtin_pushvar_helper(chan, var, value);
+ } else
+ pbx_builtin_setvar_helper(chan, var, value);
+
+ manager_event(EVENT_FLAG_DIALPLAN, "VarSet",
+ "Channel: %s\r\n"
+ "Variable: LOCAL(%s)\r\n"
+ "Value: %s\r\n"
+ "Uniqueid: %s\r\n",
+ chan->name, var, value, chan->uniqueid);
+ }
+ return 0;
+}
+
+static void gosub_release_frame(struct ast_channel *chan, struct gosub_stack_frame *frame)
+{
+ unsigned char i;
+ char argname[15];
+ struct ast_var_t *vardata;
+
+ /* If chan is not defined, then we're calling it as part of gosub_free,
+ * and the channel variables will be deallocated anyway. Otherwise, we're
+ * just releasing a single frame, so we need to clean up the arguments for
+ * that frame, so that we re-expose the variables from the previous frame
+ * that were hidden by this one.
+ */
+ if (chan) {
+ for (i = 1; i <= frame->arguments && i != 0; i++) {
+ snprintf(argname, sizeof(argname), "ARG%hhd", i);
+ pbx_builtin_setvar_helper(chan, argname, NULL);
+ }
+ }
+
+ /* Delete local variables */
+ while ((vardata = AST_LIST_REMOVE_HEAD(&frame->varshead, entries))) {
+ if (chan)
+ pbx_builtin_setvar_helper(chan, ast_var_name(vardata), NULL);
+ ast_var_delete(vardata);
+ }
+
+ ast_free(frame);
+}
+
+static struct gosub_stack_frame *gosub_allocate_frame(const char *context, const char *extension, int priority, unsigned char arguments)
+{
+ struct gosub_stack_frame *new = NULL;
+ int len_extension = strlen(extension), len_context = strlen(context);
+
+ if ((new = ast_calloc(1, sizeof(*new) + 2 + len_extension + len_context))) {
+ AST_LIST_HEAD_INIT_NOLOCK(&new->varshead);
+ strcpy(new->extension, extension);
+ new->context = new->extension + len_extension + 1;
+ strcpy(new->context, context);
+ new->priority = priority;
+ new->arguments = arguments;
+ }
+ return new;
+}
+
+static void gosub_free(void *data)
+{
+ AST_LIST_HEAD(, gosub_stack_frame) *oldlist = data;
+ struct gosub_stack_frame *oldframe;
+ AST_LIST_LOCK(oldlist);
+ while ((oldframe = AST_LIST_REMOVE_HEAD(oldlist, entries))) {
+ gosub_release_frame(NULL, oldframe);
+ }
+ AST_LIST_UNLOCK(oldlist);
+ AST_LIST_HEAD_DESTROY(oldlist);
+ ast_free(oldlist);
+}
+
+static int pop_exec(struct ast_channel *chan, void *data)
+{
+ struct ast_datastore *stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
+ struct gosub_stack_frame *oldframe;
+ AST_LIST_HEAD(, gosub_stack_frame) *oldlist;
+
+ if (!stack_store) {
+ ast_log(LOG_WARNING, "%s called with no gosub stack allocated.\n", app_pop);
+ return 0;
+ }
+
+ oldlist = stack_store->data;
+ AST_LIST_LOCK(oldlist);
+ oldframe = AST_LIST_REMOVE_HEAD(oldlist, entries);
+ AST_LIST_UNLOCK(oldlist);
+
+ if (oldframe) {
+ gosub_release_frame(chan, oldframe);
+ } else {
+ ast_debug(1, "%s called with an empty gosub stack\n", app_pop);
+ }
+ return 0;
+}
+
+static int return_exec(struct ast_channel *chan, void *data)
+{
+ struct ast_datastore *stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
+ struct gosub_stack_frame *oldframe;
+ AST_LIST_HEAD(, gosub_stack_frame) *oldlist;
+ char *retval = data;
+
+ if (!stack_store) {
+ ast_log(LOG_ERROR, "Return without Gosub: stack is unallocated\n");
+ return -1;
+ }
+
+ oldlist = stack_store->data;
+ AST_LIST_LOCK(oldlist);
+ oldframe = AST_LIST_REMOVE_HEAD(oldlist, entries);
+ AST_LIST_UNLOCK(oldlist);
+
+ if (!oldframe) {
+ ast_log(LOG_ERROR, "Return without Gosub: stack is empty\n");
+ return -1;
+ }
+
+ ast_explicit_goto(chan, oldframe->context, oldframe->extension, oldframe->priority);
+ gosub_release_frame(chan, oldframe);
+
+ /* Set a return value, if any */
+ pbx_builtin_setvar_helper(chan, "GOSUB_RETVAL", S_OR(retval, ""));
+ return 0;
+}
+
+static int gosub_exec(struct ast_channel *chan, void *data)
+{
+ struct ast_datastore *stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
+ AST_LIST_HEAD(, gosub_stack_frame) *oldlist;
+ struct gosub_stack_frame *newframe;
+ char argname[15], *tmp = ast_strdupa(data), *label, *endparen;
+ int i;
+ AST_DECLARE_APP_ARGS(args2,
+ AST_APP_ARG(argval)[100];
+ );
+
+ if (ast_strlen_zero(data)) {
+ ast_log(LOG_ERROR, "%s requires an argument: %s([[context|]exten|]priority[(arg1[|...][|argN])])\n", app_gosub, app_gosub);
+ return -1;
+ }
+
+ if (!stack_store) {
+ ast_debug(1, "Channel %s has no datastore, so we're allocating one.\n", chan->name);
+ stack_store = ast_channel_datastore_alloc(&stack_info, NULL);
+ if (!stack_store) {
+ ast_log(LOG_ERROR, "Unable to allocate new datastore. Gosub will fail.\n");
+ return -1;
+ }
+
+ oldlist = ast_calloc(1, sizeof(*oldlist));
+ if (!oldlist) {
+ ast_log(LOG_ERROR, "Unable to allocate datastore list head. Gosub will fail.\n");
+ ast_channel_datastore_free(stack_store);
+ return -1;
+ }
+
+ stack_store->data = oldlist;
+ AST_LIST_HEAD_INIT(oldlist);
+ ast_channel_datastore_add(chan, stack_store);
+ }
+
+ /* Separate the arguments from the label */
+ /* NOTE: you cannot use ast_app_separate_args for this, because '(' cannot be used as a delimiter. */
+ label = strsep(&tmp, "(");
+ if (tmp) {
+ endparen = strrchr(tmp, ')');
+ if (endparen)
+ *endparen = '\0';
+ else
+ ast_log(LOG_WARNING, "Ouch. No closing paren: '%s'?\n", (char *)data);
+ AST_STANDARD_APP_ARGS(args2, tmp);
+ } else
+ args2.argc = 0;
+
+ /* Create the return address, but don't save it until we know that the Gosub destination exists */
+ newframe = gosub_allocate_frame(chan->context, chan->exten, chan->priority + 1, args2.argc);
+
+ if (!newframe)
+ return -1;
+
+ if (ast_parseable_goto(chan, label)) {
+ ast_log(LOG_ERROR, "Gosub address is invalid: '%s'\n", (char *)data);
+ ast_free(newframe);
+ return -1;
+ }
+
+ /* Now that we know for certain that we're going to a new location, set our arguments */
+ for (i = 0; i < args2.argc; i++) {
+ snprintf(argname, sizeof(argname), "ARG%d", i + 1);
+ frame_set_var(chan, newframe, argname, args2.argval[i]);
+ ast_debug(1, "Setting '%s' to '%s'\n", argname, args2.argval[i]);
+ }
+
+ /* And finally, save our return address */
+ oldlist = stack_store->data;
+ AST_LIST_LOCK(oldlist);
+ AST_LIST_INSERT_HEAD(oldlist, newframe, entries);
+ AST_LIST_UNLOCK(oldlist);
+
+ return 0;
+}
+
+static int gosubif_exec(struct ast_channel *chan, void *data)
+{
+ char *args;
+ int res=0;
+ AST_DECLARE_APP_ARGS(cond,
+ AST_APP_ARG(ition);
+ AST_APP_ARG(labels);
+ );
+ AST_DECLARE_APP_ARGS(label,
+ AST_APP_ARG(iftrue);
+ AST_APP_ARG(iffalse);
+ );
+
+ if (ast_strlen_zero(data)) {
+ ast_log(LOG_WARNING, "GosubIf requires an argument: GosubIf(cond?label1(args):label2(args)\n");
+ return 0;
+ }
+
+ args = ast_strdupa(data);
+ AST_NONSTANDARD_APP_ARGS(cond, args, '?');
+ if (cond.argc != 2) {
+ ast_log(LOG_WARNING, "GosubIf requires an argument: GosubIf(cond?label1(args):label2(args)\n");
+ return 0;
+ }
+
+ AST_NONSTANDARD_APP_ARGS(label, cond.labels, ':');
+
+ if (pbx_checkcondition(cond.ition)) {
+ if (!ast_strlen_zero(label.iftrue))
+ res = gosub_exec(chan, label.iftrue);
+ } else if (!ast_strlen_zero(label.iffalse)) {
+ res = gosub_exec(chan, label.iffalse);
+ }
+
+ return res;
+}
+
+static int local_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
+{
+ struct ast_datastore *stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
+ AST_LIST_HEAD(, gosub_stack_frame) *oldlist;
+ struct gosub_stack_frame *frame;
+ struct ast_var_t *variables;
+
+ if (!stack_store)
+ return -1;
+
+ oldlist = stack_store->data;
+ AST_LIST_LOCK(oldlist);
+ frame = AST_LIST_FIRST(oldlist);
+ AST_LIST_TRAVERSE(&frame->varshead, variables, entries) {
+ if (!strcmp(data, ast_var_name(variables))) {
+ const char *tmp = pbx_builtin_getvar_helper(chan, data);
+ ast_copy_string(buf, S_OR(tmp, ""), len);
+ break;
+ }
+ }
+ AST_LIST_UNLOCK(oldlist);
+ return 0;
+}
+
+static int local_write(struct ast_channel *chan, const char *cmd, char *var, const char *value)
+{
+ struct ast_datastore *stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
+ AST_LIST_HEAD(, gosub_stack_frame) *oldlist;
+ struct gosub_stack_frame *frame;
+
+ if (!stack_store) {
+ ast_log(LOG_ERROR, "Tried to set LOCAL(%s), but we aren't within a Gosub routine\n", var);
+ return -1;
+ }
+
+ oldlist = stack_store->data;
+ AST_LIST_LOCK(oldlist);
+ frame = AST_LIST_FIRST(oldlist);
+
+ if (frame)
+ frame_set_var(chan, frame, var, value);
+
+ AST_LIST_UNLOCK(oldlist);
+
+ return 0;
+}
+
+static struct ast_custom_function local_function = {
+ .name = "LOCAL",
+ .synopsis = "Variables local to the gosub stack frame",
+ .syntax = "LOCAL(<varname>)",
+ .write = local_write,
+ .read = local_read,
+};
+
+static int unload_module(void)
+{
+ ast_unregister_application(app_return);
+ ast_unregister_application(app_pop);
+ ast_unregister_application(app_gosubif);
+ ast_unregister_application(app_gosub);
+ ast_custom_function_unregister(&local_function);
+
+ return 0;
+}
+
+static int load_module(void)
+{
+ ast_register_application(app_pop, pop_exec, pop_synopsis, pop_descrip);
+ ast_register_application(app_return, return_exec, return_synopsis, return_descrip);
+ ast_register_application(app_gosubif, gosubif_exec, gosubif_synopsis, gosubif_descrip);
+ ast_register_application(app_gosub, gosub_exec, gosub_synopsis, gosub_descrip);
+ ast_custom_function_register(&local_function);
+
+ return 0;
+}
+
+AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Dialplan subroutines (Gosub, Return, etc)");