asterisk/apps/app_stack.c

1324 lines
38 KiB
C

/*
* 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
*/
/*** MODULEINFO
<use type="module">res_agi</use>
<support_level>core</support_level>
***/
#include "asterisk.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/app.h"
#include "asterisk/manager.h"
#include "asterisk/channel.h"
#include "asterisk/agi.h"
#include "asterisk/stasis_channels.h"
/*** DOCUMENTATION
<application name="Gosub" language="en_US">
<synopsis>
Jump to label, saving return address.
</synopsis>
<syntax>
<parameter name="context" />
<parameter name="exten" />
<parameter name="priority" required="true" hasparams="optional">
<argument name="arg1" multiple="true" required="true" />
<argument name="argN" />
</parameter>
</syntax>
<description>
<para>Jumps to the label specified, saving the return address.</para>
</description>
<see-also>
<ref type="application">GosubIf</ref>
<ref type="application">Macro</ref>
<ref type="application">Goto</ref>
<ref type="application">Return</ref>
<ref type="application">StackPop</ref>
</see-also>
</application>
<application name="GosubIf" language="en_US">
<synopsis>
Conditionally jump to label, saving return address.
</synopsis>
<syntax argsep="?">
<parameter name="condition" required="true" />
<parameter name="destination" required="true" argsep=":">
<argument name="labeliftrue" hasparams="optional">
<para>Continue at <replaceable>labeliftrue</replaceable> if the condition is true.
Takes the form similar to Goto() of [[context,]extension,]priority.</para>
<argument name="arg1" required="true" multiple="true" />
<argument name="argN" />
</argument>
<argument name="labeliffalse" hasparams="optional">
<para>Continue at <replaceable>labeliffalse</replaceable> if the condition is false.
Takes the form similar to Goto() of [[context,]extension,]priority.</para>
<argument name="arg1" required="true" multiple="true" />
<argument name="argN" />
</argument>
</parameter>
</syntax>
<description>
<para>If the condition is true, then jump to labeliftrue. If false, jumps to
labeliffalse, if specified. In either case, a jump saves the return point
in the dialplan, to be returned to with a Return.</para>
</description>
<see-also>
<ref type="application">Gosub</ref>
<ref type="application">Return</ref>
<ref type="application">MacroIf</ref>
<ref type="function">IF</ref>
<ref type="application">GotoIf</ref>
<ref type="application">Goto</ref>
</see-also>
</application>
<application name="Return" language="en_US">
<synopsis>
Return from gosub routine.
</synopsis>
<syntax>
<parameter name="value">
<para>Return value.</para>
</parameter>
</syntax>
<description>
<para>Jumps to the last label on the stack, removing it. The return <replaceable>value</replaceable>, if
any, is saved in the channel variable <variable>GOSUB_RETVAL</variable>.</para>
</description>
<see-also>
<ref type="application">Gosub</ref>
<ref type="application">StackPop</ref>
</see-also>
</application>
<application name="StackPop" language="en_US">
<synopsis>
Remove one address from gosub stack.
</synopsis>
<syntax />
<description>
<para>Removes last label on the stack, discarding it.</para>
</description>
<see-also>
<ref type="application">Return</ref>
<ref type="application">Gosub</ref>
</see-also>
</application>
<function name="LOCAL" language="en_US">
<synopsis>
Manage variables local to the gosub stack frame.
</synopsis>
<syntax>
<parameter name="varname" required="true" />
</syntax>
<description>
<para>Read and write a variable local to the gosub stack frame, once we Return() it will be lost
(or it will go back to whatever value it had before the Gosub()).</para>
</description>
<see-also>
<ref type="application">Gosub</ref>
<ref type="application">GosubIf</ref>
<ref type="application">Return</ref>
</see-also>
</function>
<function name="LOCAL_PEEK" language="en_US">
<synopsis>
Retrieve variables hidden by the local gosub stack frame.
</synopsis>
<syntax>
<parameter name="n" required="true" />
<parameter name="varname" required="true" />
</syntax>
<description>
<para>Read a variable <replaceable>varname</replaceable> hidden by
<replaceable>n</replaceable> levels of gosub stack frames. Note that ${LOCAL_PEEK(0,foo)}
is the same as <variable>foo</variable>, since the value of <replaceable>n</replaceable>
peeks under 0 levels of stack frames; in other words, 0 is the current level. If
<replaceable>n</replaceable> exceeds the available number of stack frames, then an empty
string is returned.</para>
</description>
<see-also>
<ref type="application">Gosub</ref>
<ref type="application">GosubIf</ref>
<ref type="application">Return</ref>
</see-also>
</function>
<function name="STACK_PEEK" language="en_US">
<synopsis>
View info about the location which called Gosub
</synopsis>
<syntax>
<parameter name="n" required="true" />
<parameter name="which" required="true" />
<parameter name="suppress" required="false" />
</syntax>
<description>
<para>Read the calling <literal>c</literal>ontext, <literal>e</literal>xtension,
<literal>p</literal>riority, or <literal>l</literal>abel, as specified by
<replaceable>which</replaceable>, by going up <replaceable>n</replaceable> frames
in the Gosub stack. If <replaceable>suppress</replaceable> is true, then if the
number of available stack frames is exceeded, then no error message will be
printed.</para>
</description>
</function>
<agi name="gosub" language="en_US">
<synopsis>
Cause the channel to execute the specified dialplan subroutine.
</synopsis>
<syntax>
<parameter name="context" required="true" />
<parameter name="extension" required="true" />
<parameter name="priority" required="true" />
<parameter name="optional-argument" />
</syntax>
<description>
<para>Cause the channel to execute the specified dialplan subroutine,
returning to the dialplan with execution of a Return().</para>
</description>
<see-also>
<ref type="application">GoSub</ref>
</see-also>
</agi>
<managerEvent language="en_US" name="VarSet">
<managerEventInstance class="EVENT_FLAG_DIALPLAN">
<synopsis>Raised when a variable local to the gosub stack frame is set due to a subroutine call.</synopsis>
<syntax>
<channel_snapshot/>
<parameter name="Variable">
<para>The LOCAL variable being set.</para>
<note><para>The variable name will always be enclosed with
<literal>LOCAL()</literal></para></note>
</parameter>
<parameter name="Value">
<para>The new value of the variable.</para>
</parameter>
</syntax>
<see-also>
<ref type="application">GoSub</ref>
<ref type="agi">gosub</ref>
<ref type="function">LOCAL</ref>
<ref type="function">LOCAL_PEEK</ref>
</see-also>
</managerEventInstance>
</managerEvent>
***/
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 void gosub_free(void *data);
static const 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;
/*! TRUE if the return location marks the end of a special routine. */
unsigned int is_special:1;
/*! Whether or not we were in a subroutine when this one was created */
unsigned int in_subroutine:1;
char *context;
char extension[0];
};
AST_LIST_HEAD(gosub_stack_list, gosub_stack_frame);
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;
int len;
RAII_VAR(char *, local_buffer, NULL, ast_free);
/* Does this variable already exist? */
AST_LIST_TRAVERSE(&frame->varshead, variables, entries) {
if (!strcmp(var, ast_var_name(variables))) {
found = 1;
break;
}
}
if (!found) {
if ((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);
}
len = 8 + strlen(var); /* LOCAL() + var */
local_buffer = ast_malloc(len);
if (!local_buffer) {
return 0;
}
sprintf(local_buffer, "LOCAL(%s)", var);
ast_channel_publish_varset(chan, local_buffer, value);
return 0;
}
static void gosub_release_frame(struct ast_channel *chan, struct gosub_stack_frame *frame)
{
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.
*/
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, int in_subroutine, unsigned char arguments)
{
struct gosub_stack_frame *new = NULL;
int len_extension = strlen(extension) + 1;
int len_context = strlen(context) + 1;
if ((new = ast_calloc(1, sizeof(*new) + len_extension + len_context))) {
AST_LIST_HEAD_INIT_NOLOCK(&new->varshead);
ast_copy_string(new->extension, extension, len_extension);
new->context = new->extension + len_extension;
ast_copy_string(new->context, context, len_context);
new->priority = priority;
new->in_subroutine = in_subroutine ? 1 : 0;
new->arguments = arguments;
}
return new;
}
static void gosub_free(void *data)
{
struct gosub_stack_list *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, const char *data)
{
struct ast_datastore *stack_store;
struct gosub_stack_frame *oldframe;
struct gosub_stack_list *oldlist;
int res = 0;
ast_channel_lock(chan);
if (!(stack_store = ast_channel_datastore_find(chan, &stack_info, NULL))) {
ast_log(LOG_WARNING, "%s called with no gosub stack allocated.\n", app_pop);
ast_channel_unlock(chan);
return 0;
}
oldlist = stack_store->data;
AST_LIST_LOCK(oldlist);
oldframe = AST_LIST_FIRST(oldlist);
if (oldframe) {
if (oldframe->is_special) {
ast_debug(1, "%s attempted to pop special return location.\n", app_pop);
/* Abort the special routine dialplan execution. Dialplan programming error. */
res = -1;
} else {
AST_LIST_REMOVE_HEAD(oldlist, entries);
gosub_release_frame(chan, oldframe);
}
} else {
ast_debug(1, "%s called with an empty gosub stack\n", app_pop);
}
AST_LIST_UNLOCK(oldlist);
ast_channel_unlock(chan);
return res;
}
static int return_exec(struct ast_channel *chan, const char *data)
{
struct ast_datastore *stack_store;
struct gosub_stack_frame *oldframe;
struct gosub_stack_list *oldlist;
const char *retval = data;
int res = 0;
ast_channel_lock(chan);
if (!(stack_store = ast_channel_datastore_find(chan, &stack_info, NULL))) {
ast_log(LOG_ERROR, "Return without Gosub: stack is unallocated\n");
ast_channel_unlock(chan);
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");
ast_channel_unlock(chan);
return -1;
}
if (oldframe->is_special) {
/* Exit from special routine. */
res = -1;
}
/*
* We cannot use ast_explicit_goto() because we MUST restore
* what was there before. Channels that do not have a PBX may
* not have the context or exten set.
*/
ast_channel_context_set(chan, oldframe->context);
ast_channel_exten_set(chan, oldframe->extension);
if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_IN_AUTOLOOP)) {
--oldframe->priority;
}
ast_channel_priority_set(chan, oldframe->priority);
ast_set2_flag(ast_channel_flags(chan), oldframe->in_subroutine, AST_FLAG_SUBROUTINE_EXEC);
gosub_release_frame(chan, oldframe);
/* Set a return value, if any */
pbx_builtin_setvar_helper(chan, "GOSUB_RETVAL", S_OR(retval, ""));
ast_channel_unlock(chan);
return res;
}
/*!
* \internal
* \brief Add missing context and/or exten to Gosub application argument string.
* \since 11.0
*
* \param chan Channel to obtain context/exten.
* \param args Gosub application argument string.
*
* \details
* Fills in the optional context and exten from the given channel.
* Convert: [[context,]exten,]priority[(arg1[,...][,argN])]
* To: context,exten,priority[(arg1[,...][,argN])]
*
* \retval expanded Gosub argument string on success. Must be freed.
* \retval NULL on error.
*
* \note The parsing needs to be kept in sync with the
* gosub_exec() argument format.
*/
static const char *expand_gosub_args(struct ast_channel *chan, const char *args)
{
int len;
char *parse;
char *label;
char *new_args;
const char *context;
const char *exten;
const char *pri;
/* Separate the context,exten,pri from the optional routine arguments. */
parse = ast_strdupa(args);
label = strsep(&parse, "(");
if (parse) {
char *endparen;
endparen = strrchr(parse, ')');
if (endparen) {
*endparen = '\0';
} else {
ast_log(LOG_WARNING, "Ouch. No closing paren: '%s'?\n", args);
}
}
/* Split context,exten,pri */
context = strsep(&label, ",");
exten = strsep(&label, ",");
pri = strsep(&label, ",");
if (!exten) {
/* Only a priority in this one */
pri = context;
exten = NULL;
context = NULL;
} else if (!pri) {
/* Only an extension and priority in this one */
pri = exten;
exten = context;
context = NULL;
}
ast_channel_lock(chan);
if (ast_strlen_zero(exten)) {
exten = ast_channel_exten(chan);
}
if (ast_strlen_zero(context)) {
context = ast_channel_context(chan);
}
len = strlen(context) + strlen(exten) + strlen(pri) + 3;
if (!ast_strlen_zero(parse)) {
len += 2 + strlen(parse);
}
new_args = ast_malloc(len);
if (new_args) {
if (ast_strlen_zero(parse)) {
snprintf(new_args, len, "%s,%s,%s", context, exten, pri);
} else {
snprintf(new_args, len, "%s,%s,%s(%s)", context, exten, pri, parse);
}
}
ast_channel_unlock(chan);
ast_debug(4, "Gosub args:%s new_args:%s\n", args, new_args ? new_args : "");
return new_args;
}
static int gosub_exec(struct ast_channel *chan, const char *data)
{
struct ast_datastore *stack_store;
struct gosub_stack_list *oldlist;
struct gosub_stack_frame *newframe;
struct gosub_stack_frame *lastframe;
char argname[15];
char *parse;
char *label;
char *caller_id;
char *orig_context;
char *orig_exten;
char *dest_context;
char *dest_exten;
int orig_in_subroutine;
int orig_priority;
int dest_priority;
int i;
int max_argc = 0;
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;
}
/*
* Separate the arguments from the label
*
* NOTE: You cannot use ast_app_separate_args for this, because
* '(' cannot be used as a delimiter.
*/
parse = ast_strdupa(data);
label = strsep(&parse, "(");
if (parse) {
char *endparen;
endparen = strrchr(parse, ')');
if (endparen) {
*endparen = '\0';
} else {
ast_log(LOG_WARNING, "Ouch. No closing paren: '%s'?\n", data);
}
AST_STANDARD_RAW_ARGS(args2, parse);
} else {
args2.argc = 0;
}
ast_channel_lock(chan);
orig_context = ast_strdupa(ast_channel_context(chan));
orig_exten = ast_strdupa(ast_channel_exten(chan));
orig_priority = ast_channel_priority(chan);
orig_in_subroutine = ast_test_flag(ast_channel_flags(chan), AST_FLAG_SUBROUTINE_EXEC);
ast_channel_unlock(chan);
if (ast_parseable_goto(chan, label)) {
ast_log(LOG_ERROR, "%s address is invalid: '%s'\n", app_gosub, data);
goto error_exit;
}
ast_channel_lock(chan);
dest_context = ast_strdupa(ast_channel_context(chan));
dest_exten = ast_strdupa(ast_channel_exten(chan));
dest_priority = ast_channel_priority(chan);
if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_IN_AUTOLOOP)) {
++dest_priority;
}
caller_id = S_COR(ast_channel_caller(chan)->id.number.valid,
ast_channel_caller(chan)->id.number.str, NULL);
if (caller_id) {
caller_id = ast_strdupa(caller_id);
}
ast_channel_unlock(chan);
if (!ast_exists_extension(chan, dest_context, dest_exten, dest_priority, caller_id)) {
ast_log(LOG_ERROR, "%s attempted to reach non-existent destination '%s,%s,%d' from '%s,%s,%d'",
app_gosub, dest_context, dest_exten, dest_priority, orig_context, orig_exten, orig_priority);
goto error_exit;
}
/* Now we know that we're going to a new location */
ast_channel_lock(chan);
/* Find stack datastore return list. */
if (!(stack_store = ast_channel_datastore_find(chan, &stack_info, NULL))) {
ast_debug(1, "Channel %s has no datastore, so we're allocating one.\n",
ast_channel_name(chan));
stack_store = ast_datastore_alloc(&stack_info, NULL);
if (!stack_store) {
ast_log(LOG_ERROR, "Unable to allocate new datastore. %s failed.\n",
app_gosub);
goto error_exit_locked;
}
oldlist = ast_calloc(1, sizeof(*oldlist));
if (!oldlist) {
ast_log(LOG_ERROR, "Unable to allocate datastore list head. %s failed.\n",
app_gosub);
ast_datastore_free(stack_store);
goto error_exit_locked;
}
AST_LIST_HEAD_INIT(oldlist);
stack_store->data = oldlist;
ast_channel_datastore_add(chan, stack_store);
} else {
oldlist = stack_store->data;
}
if ((lastframe = AST_LIST_FIRST(oldlist))) {
max_argc = lastframe->arguments;
}
/* Mask out previous Gosub arguments in this invocation */
if (args2.argc > max_argc) {
max_argc = args2.argc;
}
/* Create the return address */
newframe = gosub_allocate_frame(orig_context, orig_exten, orig_priority + 1, orig_in_subroutine, max_argc);
if (!newframe) {
goto error_exit_locked;
}
/* Set our arguments */
for (i = 0; i < max_argc; i++) {
snprintf(argname, sizeof(argname), "ARG%d", i + 1);
frame_set_var(chan, newframe, argname, i < args2.argc ? args2.argval[i] : "");
ast_debug(1, "Setting '%s' to '%s'\n", argname, i < args2.argc ? args2.argval[i] : "");
}
snprintf(argname, sizeof(argname), "%u", args2.argc);
frame_set_var(chan, newframe, "ARGC", argname);
ast_set_flag(ast_channel_flags(chan), AST_FLAG_SUBROUTINE_EXEC);
/* And finally, save our return address */
AST_LIST_LOCK(oldlist);
AST_LIST_INSERT_HEAD(oldlist, newframe, entries);
AST_LIST_UNLOCK(oldlist);
ast_channel_unlock(chan);
return 0;
error_exit:
ast_channel_lock(chan);
error_exit_locked:
/* Restore the original dialplan location. */
ast_channel_context_set(chan, orig_context);
ast_channel_exten_set(chan, orig_exten);
ast_channel_priority_set(chan, orig_priority);
ast_channel_unlock(chan);
return -1;
}
static int gosubif_exec(struct ast_channel *chan, const char *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_RAW_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_RAW_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;
struct gosub_stack_list *oldlist;
struct gosub_stack_frame *frame;
struct ast_var_t *variables;
if (!chan) {
ast_log(LOG_WARNING, "No channel was provided to %s function.\n", cmd);
return -1;
}
ast_channel_lock(chan);
if (!(stack_store = ast_channel_datastore_find(chan, &stack_info, NULL))) {
ast_channel_unlock(chan);
return -1;
}
oldlist = stack_store->data;
AST_LIST_LOCK(oldlist);
if (!(frame = AST_LIST_FIRST(oldlist))) {
/* Not within a Gosub routine */
AST_LIST_UNLOCK(oldlist);
ast_channel_unlock(chan);
return -1;
}
AST_LIST_TRAVERSE(&frame->varshead, variables, entries) {
if (!strcmp(data, ast_var_name(variables))) {
const char *tmp;
tmp = pbx_builtin_getvar_helper(chan, data);
ast_copy_string(buf, S_OR(tmp, ""), len);
break;
}
}
AST_LIST_UNLOCK(oldlist);
ast_channel_unlock(chan);
return 0;
}
static int local_write(struct ast_channel *chan, const char *cmd, char *var, const char *value)
{
struct ast_datastore *stack_store;
struct gosub_stack_list *oldlist;
struct gosub_stack_frame *frame;
if (!chan) {
ast_log(LOG_WARNING, "No channel was provided to %s function.\n", cmd);
return -1;
}
ast_channel_lock(chan);
if (!(stack_store = ast_channel_datastore_find(chan, &stack_info, NULL))) {
ast_log(LOG_ERROR, "Tried to set LOCAL(%s), but we aren't within a Gosub routine\n", var);
ast_channel_unlock(chan);
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);
ast_channel_unlock(chan);
return 0;
}
static struct ast_custom_function local_function = {
.name = "LOCAL",
.write = local_write,
.read = local_read,
};
static int peek_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
{
int found = 0, n;
struct ast_var_t *variables;
AST_DECLARE_APP_ARGS(args,
AST_APP_ARG(n);
AST_APP_ARG(name);
);
if (!chan) {
ast_log(LOG_ERROR, "LOCAL_PEEK must be called on an active channel\n");
return -1;
}
AST_STANDARD_RAW_ARGS(args, data);
if (ast_strlen_zero(args.n) || ast_strlen_zero(args.name)) {
ast_log(LOG_ERROR, "LOCAL_PEEK requires parameters n and varname\n");
return -1;
}
n = atoi(args.n);
*buf = '\0';
ast_channel_lock(chan);
AST_LIST_TRAVERSE(ast_channel_varshead(chan), variables, entries) {
if (!strcmp(args.name, ast_var_name(variables)) && ++found > n) {
ast_copy_string(buf, ast_var_value(variables), len);
break;
}
}
ast_channel_unlock(chan);
return 0;
}
static struct ast_custom_function peek_function = {
.name = "LOCAL_PEEK",
.read = peek_read,
};
static int stackpeek_read(struct ast_channel *chan, const char *cmd, char *data, struct ast_str **str, ssize_t len)
{
struct ast_datastore *stack_store;
struct gosub_stack_list *oldlist;
struct gosub_stack_frame *frame;
int n;
AST_DECLARE_APP_ARGS(args,
AST_APP_ARG(n);
AST_APP_ARG(which);
AST_APP_ARG(suppress);
);
if (!chan) {
ast_log(LOG_ERROR, "STACK_PEEK must be called on an active channel\n");
return -1;
}
data = ast_strdupa(data);
AST_STANDARD_APP_ARGS(args, data);
if (ast_strlen_zero(args.n) || ast_strlen_zero(args.which)) {
ast_log(LOG_ERROR, "STACK_PEEK requires parameters n and which\n");
return -1;
}
n = atoi(args.n);
if (n <= 0) {
ast_log(LOG_ERROR, "STACK_PEEK must be called with a positive peek value\n");
return -1;
}
ast_channel_lock(chan);
if (!(stack_store = ast_channel_datastore_find(chan, &stack_info, NULL))) {
if (!ast_true(args.suppress)) {
ast_log(LOG_ERROR, "STACK_PEEK called on a channel without a gosub stack\n");
}
ast_channel_unlock(chan);
return -1;
}
oldlist = stack_store->data;
AST_LIST_LOCK(oldlist);
AST_LIST_TRAVERSE(oldlist, frame, entries) {
if (--n == 0) {
break;
}
}
if (!frame) {
/* Too deep */
if (!ast_true(args.suppress)) {
ast_log(LOG_ERROR, "Stack peek of '%s' is more stack frames than I have\n", args.n);
}
AST_LIST_UNLOCK(oldlist);
ast_channel_unlock(chan);
return -1;
}
args.which = ast_skip_blanks(args.which);
switch (args.which[0]) {
case 'l': /* label */
ast_str_set(str, len, "%s,%s,%d", frame->context, frame->extension, frame->priority - 1);
break;
case 'c': /* context */
ast_str_set(str, len, "%s", frame->context);
break;
case 'e': /* extension */
ast_str_set(str, len, "%s", frame->extension);
break;
case 'p': /* priority */
ast_str_set(str, len, "%d", frame->priority - 1);
break;
default:
ast_log(LOG_ERROR, "Unknown argument '%s' to STACK_PEEK\n", args.which);
break;
}
AST_LIST_UNLOCK(oldlist);
ast_channel_unlock(chan);
return 0;
}
static struct ast_custom_function stackpeek_function = {
.name = "STACK_PEEK",
.read2 = stackpeek_read,
};
/*!
* \internal
* \brief Pop stack frames until remove a special return location.
* \since 11.0
*
* \param chan Channel to balance stack on.
*
* \note The channel is already locked when called.
*/
static void balance_stack(struct ast_channel *chan)
{
struct ast_datastore *stack_store;
struct gosub_stack_list *oldlist;
struct gosub_stack_frame *oldframe;
int found;
stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
if (!stack_store) {
ast_log(LOG_WARNING, "No %s stack allocated.\n", app_gosub);
return;
}
oldlist = stack_store->data;
AST_LIST_LOCK(oldlist);
do {
oldframe = AST_LIST_REMOVE_HEAD(oldlist, entries);
if (!oldframe) {
break;
}
found = oldframe->is_special;
gosub_release_frame(chan, oldframe);
} while (!found);
AST_LIST_UNLOCK(oldlist);
}
/*!
* \internal
* \brief Run a subroutine on a channel.
* \since 11.0
*
* \note Absolutely _NO_ channel locks should be held before calling this function.
*
* \param chan Channel to execute subroutine on.
* \param sub_args Gosub application argument string.
* \param ignore_hangup TRUE if a hangup does not stop execution of the routine.
*
* \retval 0 success
* \retval -1 on error
*/
static int gosub_run(struct ast_channel *chan, const char *sub_args, int ignore_hangup)
{
const char *saved_context;
const char *saved_exten;
int saved_priority;
int saved_hangup_flags;
int saved_autoloopflag;
int saved_in_subroutine;
int res;
ast_channel_lock(chan);
ast_verb(3, "%s Internal %s(%s) start\n",
ast_channel_name(chan), app_gosub, sub_args);
/* Save non-hangup softhangup flags. */
saved_hangup_flags = ast_channel_softhangup_internal_flag(chan)
& AST_SOFTHANGUP_ASYNCGOTO;
if (saved_hangup_flags) {
ast_channel_clear_softhangup(chan, AST_SOFTHANGUP_ASYNCGOTO);
}
/* Save autoloop flag */
saved_autoloopflag = ast_test_flag(ast_channel_flags(chan), AST_FLAG_IN_AUTOLOOP);
ast_set_flag(ast_channel_flags(chan), AST_FLAG_IN_AUTOLOOP);
/* Save current dialplan location */
saved_context = ast_strdupa(ast_channel_context(chan));
saved_exten = ast_strdupa(ast_channel_exten(chan));
saved_priority = ast_channel_priority(chan);
/* Save whether or not we are in a subroutine */
saved_in_subroutine = ast_test_flag(ast_channel_flags(chan), AST_FLAG_SUBROUTINE_EXEC);
ast_debug(4, "%s Original location: %s,%s,%d\n", ast_channel_name(chan),
saved_context, saved_exten, saved_priority);
ast_channel_unlock(chan);
res = gosub_exec(chan, sub_args);
ast_debug(4, "%s exited with status %d\n", app_gosub, res);
ast_channel_lock(chan);
if (!res) {
struct ast_datastore *stack_store;
/* Mark the return location as special. */
stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
if (!stack_store) {
/* Should never happen! */
ast_log(LOG_ERROR, "No %s stack!\n", app_gosub);
res = -1;
} else {
struct gosub_stack_list *oldlist;
struct gosub_stack_frame *cur;
oldlist = stack_store->data;
cur = AST_LIST_FIRST(oldlist);
cur->is_special = 1;
}
}
if (!res) {
int found = 0; /* set if we find at least one match */
/*
* Run gosub body autoloop.
*
* Note that this loop is inverted from the normal execution
* loop because we just executed the Gosub application as the
* first extension of the autoloop.
*/
do {
/* Check for hangup. */
if (ast_check_hangup(chan)) {
if (ast_channel_softhangup_internal_flag(chan) & AST_SOFTHANGUP_ASYNCGOTO) {
ast_log(LOG_ERROR, "%s An async goto just messed up our execution location.\n",
ast_channel_name(chan));
break;
}
if (!ignore_hangup) {
break;
}
}
/* Next dialplan priority. */
ast_channel_priority_set(chan, ast_channel_priority(chan) + 1);
ast_channel_unlock(chan);
res = ast_spawn_extension(chan, ast_channel_context(chan),
ast_channel_exten(chan), ast_channel_priority(chan),
S_COR(ast_channel_caller(chan)->id.number.valid,
ast_channel_caller(chan)->id.number.str, NULL),
&found, 1);
ast_channel_lock(chan);
} while (!res);
if (found && res) {
/* Something bad happened, or a hangup has been requested. */
ast_debug(1, "Spawn extension (%s,%s,%d) exited with %d on '%s'\n",
ast_channel_context(chan), ast_channel_exten(chan),
ast_channel_priority(chan), res, ast_channel_name(chan));
ast_verb(2, "Spawn extension (%s, %s, %d) exited non-zero on '%s'\n",
ast_channel_context(chan), ast_channel_exten(chan),
ast_channel_priority(chan), ast_channel_name(chan));
}
/* Did the routine return? */
if (ast_channel_priority(chan) == saved_priority
&& !strcmp(ast_channel_context(chan), saved_context)
&& !strcmp(ast_channel_exten(chan), saved_exten)) {
ast_verb(3, "%s Internal %s(%s) complete GOSUB_RETVAL=%s\n",
ast_channel_name(chan), app_gosub, sub_args,
S_OR(pbx_builtin_getvar_helper(chan, "GOSUB_RETVAL"), ""));
} else {
ast_log(LOG_WARNING, "%s Abnormal '%s(%s)' exit. Popping routine return locations.\n",
ast_channel_name(chan), app_gosub, sub_args);
balance_stack(chan);
pbx_builtin_setvar_helper(chan, "GOSUB_RETVAL", "");
}
/* We executed the requested subroutine to the best of our ability. */
res = 0;
}
ast_debug(4, "%s Ending location: %s,%s,%d\n", ast_channel_name(chan),
ast_channel_context(chan), ast_channel_exten(chan),
ast_channel_priority(chan));
/* Restore dialplan location */
if (!(ast_channel_softhangup_internal_flag(chan) & AST_SOFTHANGUP_ASYNCGOTO)) {
ast_channel_context_set(chan, saved_context);
ast_channel_exten_set(chan, saved_exten);
ast_channel_priority_set(chan, saved_priority);
}
/* Restore autoloop flag */
ast_set2_flag(ast_channel_flags(chan), saved_autoloopflag, AST_FLAG_IN_AUTOLOOP);
/* Restore subroutine flag */
ast_set2_flag(ast_channel_flags(chan), saved_in_subroutine, AST_FLAG_SUBROUTINE_EXEC);
/* Restore non-hangup softhangup flags. */
if (saved_hangup_flags) {
ast_softhangup_nolock(chan, saved_hangup_flags);
}
ast_channel_unlock(chan);
return res;
}
static int handle_gosub(struct ast_channel *chan, AGI *agi, int argc, const char * const *argv)
{
int res;
int priority;
int old_autoloopflag;
int old_in_subroutine;
int old_priority;
const char *old_context;
const char *old_extension;
char *gosub_args;
if (argc < 4 || argc > 5) {
return RESULT_SHOWUSAGE;
}
ast_debug(1, "Gosub called with %d arguments: 0:%s 1:%s 2:%s 3:%s 4:%s\n", argc, argv[0], argv[1], argv[2], argv[3], argc == 5 ? argv[4] : "");
if (sscanf(argv[3], "%30d", &priority) != 1 || priority < 1) {
/* Lookup the priority label */
priority = ast_findlabel_extension(chan, argv[1], argv[2], argv[3],
S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL));
if (priority < 0) {
ast_log(LOG_ERROR, "Priority '%s' not found in '%s@%s'\n", argv[3], argv[2], argv[1]);
ast_agi_send(agi->fd, chan, "200 result=-1 Gosub label not found\n");
return RESULT_FAILURE;
}
} else if (!ast_exists_extension(chan, argv[1], argv[2], priority,
S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL))) {
ast_agi_send(agi->fd, chan, "200 result=-1 Gosub label not found\n");
return RESULT_FAILURE;
}
if (argc == 5) {
if (ast_asprintf(&gosub_args, "%s,%s,%d(%s)", argv[1], argv[2], priority, argv[4]) < 0) {
gosub_args = NULL;
}
} else {
if (ast_asprintf(&gosub_args, "%s,%s,%d", argv[1], argv[2], priority) < 0) {
gosub_args = NULL;
}
}
if (!gosub_args) {
ast_agi_send(agi->fd, chan, "503 result=-2 Memory allocation failure\n");
return RESULT_FAILURE;
}
ast_channel_lock(chan);
ast_verb(3, "%s AGI %s(%s) start\n", ast_channel_name(chan), app_gosub, gosub_args);
/* Save autoloop flag */
old_autoloopflag = ast_test_flag(ast_channel_flags(chan), AST_FLAG_IN_AUTOLOOP);
ast_set_flag(ast_channel_flags(chan), AST_FLAG_IN_AUTOLOOP);
/* Save subroutine flag */
old_in_subroutine = ast_test_flag(ast_channel_flags(chan), AST_FLAG_SUBROUTINE_EXEC);
/* Save previous location, since we're going to change it */
old_context = ast_strdupa(ast_channel_context(chan));
old_extension = ast_strdupa(ast_channel_exten(chan));
old_priority = ast_channel_priority(chan);
ast_debug(4, "%s Original location: %s,%s,%d\n", ast_channel_name(chan),
old_context, old_extension, old_priority);
ast_channel_unlock(chan);
res = gosub_exec(chan, gosub_args);
if (!res) {
struct ast_datastore *stack_store;
/* Mark the return location as special. */
ast_channel_lock(chan);
stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
if (!stack_store) {
/* Should never happen! */
ast_log(LOG_ERROR, "No %s stack!\n", app_gosub);
res = -1;
} else {
struct gosub_stack_list *oldlist;
struct gosub_stack_frame *cur;
oldlist = stack_store->data;
cur = AST_LIST_FIRST(oldlist);
cur->is_special = 1;
}
ast_channel_unlock(chan);
}
if (!res) {
struct ast_pbx *pbx;
struct ast_pbx_args args;
int abnormal_exit;
memset(&args, 0, sizeof(args));
args.no_hangup_chan = 1;
ast_channel_lock(chan);
/* Next dialplan priority. */
ast_channel_priority_set(chan, ast_channel_priority(chan) + 1);
/* Suppress warning about PBX already existing */
pbx = ast_channel_pbx(chan);
ast_channel_pbx_set(chan, NULL);
ast_channel_unlock(chan);
ast_agi_send(agi->fd, chan, "100 result=0 Trying...\n");
ast_pbx_run_args(chan, &args);
ast_channel_lock(chan);
ast_free(ast_channel_pbx(chan));
ast_channel_pbx_set(chan, pbx);
/* Did the routine return? */
if (ast_channel_priority(chan) == old_priority
&& !strcmp(ast_channel_context(chan), old_context)
&& !strcmp(ast_channel_exten(chan), old_extension)) {
ast_verb(3, "%s AGI %s(%s) complete GOSUB_RETVAL=%s\n",
ast_channel_name(chan), app_gosub, gosub_args,
S_OR(pbx_builtin_getvar_helper(chan, "GOSUB_RETVAL"), ""));
abnormal_exit = 0;
} else {
ast_log(LOG_NOTICE, "%s Abnormal AGI %s(%s) exit. Popping routine return locations.\n",
ast_channel_name(chan), app_gosub, gosub_args);
balance_stack(chan);
pbx_builtin_setvar_helper(chan, "GOSUB_RETVAL", "");
abnormal_exit = 1;
}
ast_channel_unlock(chan);
ast_agi_send(agi->fd, chan, "200 result=0 Gosub complete%s\n",
abnormal_exit ? " (abnormal exit)" : "");
} else {
ast_agi_send(agi->fd, chan, "200 result=%d Gosub failed\n", res);
}
ast_free(gosub_args);
ast_channel_lock(chan);
ast_debug(4, "%s Ending location: %s,%s,%d\n", ast_channel_name(chan),
ast_channel_context(chan), ast_channel_exten(chan),
ast_channel_priority(chan));
/* Restore previous location */
ast_channel_context_set(chan, old_context);
ast_channel_exten_set(chan, old_extension);
ast_channel_priority_set(chan, old_priority);
/* Restore autoloop flag */
ast_set2_flag(ast_channel_flags(chan), old_autoloopflag, AST_FLAG_IN_AUTOLOOP);
/* Restore subroutine flag */
ast_set2_flag(ast_channel_flags(chan), old_in_subroutine, AST_FLAG_SUBROUTINE_EXEC);
ast_channel_unlock(chan);
return RESULT_SUCCESS;
}
static struct agi_command gosub_agi_command =
{ { "gosub", NULL }, handle_gosub, NULL, NULL, 0 };
static int unload_module(void)
{
ast_install_stack_functions(NULL);
ast_agi_unregister(&gosub_agi_command);
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);
ast_custom_function_unregister(&peek_function);
ast_custom_function_unregister(&stackpeek_function);
return 0;
}
static int load_module(void)
{
/* Setup the stack application callback functions. */
static struct ast_app_stack_funcs funcs = {
.run_sub = gosub_run,
.expand_sub_args = expand_gosub_args,
};
ast_agi_register(ast_module_info->self, &gosub_agi_command);
ast_register_application_xml(app_pop, pop_exec);
ast_register_application_xml(app_return, return_exec);
ast_register_application_xml(app_gosubif, gosubif_exec);
ast_register_application_xml(app_gosub, gosub_exec);
ast_custom_function_register(&local_function);
ast_custom_function_register(&peek_function);
ast_custom_function_register(&stackpeek_function);
funcs.module = ast_module_info->self,
ast_install_stack_functions(&funcs);
return 0;
}
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT | AST_MODFLAG_LOAD_ORDER, "Dialplan subroutines (Gosub, Return, etc)",
.support_level = AST_MODULE_SUPPORT_CORE,
.load = load_module,
.unload = unload_module,
.load_pri = AST_MODPRI_APP_DEPEND,
.optional_modules = "res_agi",
);