diff --git a/apps/app_stack.c b/apps/app_stack.c index d34d13d725..93597cc3a0 100644 --- a/apps/app_stack.c +++ b/apps/app_stack.c @@ -45,7 +45,6 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$") #define STACKVAR "~GOSUB~STACK~" - static const char *app_gosub = "Gosub"; static const char *app_gosubif = "GosubIf"; static const char *app_return = "Return"; @@ -73,55 +72,118 @@ static const char *pop_descrip = " Removes last label on the stack, discarding it.\n"; -static int pop_exec(struct ast_channel *chan, void *data) +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; + int priority; + char *context; + char extension[0]; +}; + +static void gosub_release_frame(struct ast_channel *chan, struct gosub_stack_frame *frame) { - const char *frame = pbx_builtin_getvar_helper(chan, STACKVAR); - int numargs = 0, i; + unsigned char i; char argname[15]; - /* Pop any arguments for this stack frame off the variable stack */ - if (frame) { - numargs = atoi(frame); - for (i = 1; i <= numargs; i++) { - snprintf(argname, sizeof(argname), "ARG%d", i); + /* 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); } } + ast_free(frame); +} - /* Remove the last frame from the Gosub stack */ - pbx_builtin_setvar_helper(chan, STACKVAR, NULL); +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))) { + 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_log(LOG_DEBUG, "%s called with an empty gosub stack\n", app_pop); return 0; } static int return_exec(struct ast_channel *chan, void *data) { - const char *label = pbx_builtin_getvar_helper(chan, STACKVAR); - char argname[15], *retval = data; - int numargs, i; + 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 (ast_strlen_zero(label)) { + 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; } - /* Pop any arguments for this stack frame off the variable stack */ - numargs = atoi(label); - for (i = 1; i <= numargs; i++) { - snprintf(argname, sizeof(argname), "ARG%d", i); - pbx_builtin_setvar_helper(chan, argname, NULL); - } - - /* If the label exists, it will always have a ':' */ - label = strchr(label, ':') + 1; - - if (ast_parseable_goto(chan, label)) { - ast_log(LOG_WARNING, "No next statement after Gosub?\n"); - return -1; - } - - /* Remove the current frame from the Gosub stack */ - pbx_builtin_setvar_helper(chan, STACKVAR, NULL); + 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, "")); @@ -130,7 +192,9 @@ static int return_exec(struct ast_channel *chan, void *data) static int gosub_exec(struct ast_channel *chan, void *data) { - char newlabel[AST_MAX_EXTENSION + AST_MAX_CONTEXT + 11 + 11 + 4]; + 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; struct ast_module_user *u; @@ -145,6 +209,28 @@ static int gosub_exec(struct ast_channel *chan, void *data) u = ast_module_user_add(chan); + if (!stack_store) { + ast_log(LOG_DEBUG, "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"); + ast_module_user_remove(u); + 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); + ast_module_user_remove(u); + 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, "("); @@ -159,10 +245,11 @@ static int gosub_exec(struct ast_channel *chan, void *data) args2.argc = 0; /* Create the return address, but don't save it until we know that the Gosub destination exists */ - snprintf(newlabel, sizeof(newlabel), "%d:%s|%s|%d", args2.argc, chan->context, chan->exten, chan->priority + 1); + newframe = gosub_allocate_frame(chan->context, chan->exten, chan->priority + 1, args2.argc); if (ast_parseable_goto(chan, label)) { ast_log(LOG_ERROR, "Gosub address is invalid: '%s'\n", (char *)data); + ast_free(newframe); ast_module_user_remove(u); return -1; } @@ -175,8 +262,11 @@ static int gosub_exec(struct ast_channel *chan, void *data) } /* And finally, save our return address */ - pbx_builtin_pushvar_helper(chan, STACKVAR, newlabel); - ast_log(LOG_DEBUG, "Setting gosub return address to '%s'\n", newlabel); + oldlist = stack_store->data; + AST_LIST_LOCK(oldlist); + AST_LIST_INSERT_HEAD(oldlist, newframe, entries); + AST_LIST_UNLOCK(oldlist); + ast_module_user_remove(u); return 0;