Skip to content

Commit e3ea1b8

Browse files
InterLinked1Friendly Automation
InterLinked1
authored and
Friendly Automation
committed
app_if: Adds conditional branch applications
Adds the If, ElseIf, Else, ExitIf, and EndIf applications for conditional execution of a block of dialplan, similar to the While, EndWhile, and ExitWhile applications. The appropriate branch is executed at most once if available and may be broken out of while inside. ASTERISK-29497 Change-Id: I3aa3bd35a5add82465c6ee9bd86b64601f0e1f49
1 parent 99cef84 commit e3ea1b8

File tree

2 files changed

+386
-0
lines changed

2 files changed

+386
-0
lines changed

‎apps/app_if.c

+382
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,382 @@
1+
/*
2+
* Asterisk -- An open source telephony toolkit.
3+
*
4+
* Copyright 2022, Naveen Albert <asterisk@phreaknet.org>
5+
*
6+
* Naveen Albert <asterisk@phreaknet.org>
7+
*
8+
* See http://www.asterisk.org for more information about
9+
* the Asterisk project. Please do not directly contact
10+
* any of the maintainers of this project for assistance;
11+
* the project provides a web site, mailing lists and IRC
12+
* channels for your use.
13+
*
14+
* This program is free software, distributed under the terms of
15+
* the GNU General Public License Version 2. See the LICENSE file
16+
* at the top of the source tree.
17+
*/
18+
19+
/*! \file
20+
*
21+
* \brief If Branch Implementation
22+
*
23+
* \author Naveen Albert <asterisk@phreaknet.org>
24+
*
25+
* \ingroup applications
26+
*/
27+
28+
/*** MODULEINFO
29+
<support_level>extended</support_level>
30+
***/
31+
32+
#include "asterisk.h"
33+
34+
#include "asterisk/pbx.h"
35+
#include "asterisk/module.h"
36+
#include "asterisk/channel.h"
37+
38+
/*** DOCUMENTATION
39+
<application name="If" language="en_US">
40+
<synopsis>
41+
Start an if branch.
42+
</synopsis>
43+
<syntax>
44+
<parameter name="expr" required="true" />
45+
</syntax>
46+
<description>
47+
<para>Start an If branch. Execution will continue inside the branch
48+
if expr is true.</para>
49+
<note><para>This application (and related applications) set variables
50+
internally during execution.</para></note>
51+
</description>
52+
<see-also>
53+
<ref type="application">ElseIf</ref>
54+
<ref type="application">Else</ref>
55+
<ref type="application">EndIf</ref>
56+
<ref type="application">ExitIf</ref>
57+
</see-also>
58+
</application>
59+
<application name="ElseIf" language="en_US">
60+
<synopsis>
61+
Start an else if branch.
62+
</synopsis>
63+
<syntax>
64+
<parameter name="expr" required="true" />
65+
</syntax>
66+
<description>
67+
<para>Start an optional ElseIf branch. Execution will continue inside the branch
68+
if expr is true and if previous If and ElseIf branches evaluated to false.</para>
69+
<para>Please note that execution inside a true If branch will fallthrough into
70+
ElseIf unless the If segment is terminated with an ExitIf call. This is only
71+
necessary with ElseIf but not with Else.</para>
72+
</description>
73+
<see-also>
74+
<ref type="application">If</ref>
75+
<ref type="application">Else</ref>
76+
<ref type="application">EndIf</ref>
77+
<ref type="application">ExitIf</ref>
78+
</see-also>
79+
</application>
80+
<application name="Else" language="en_US">
81+
<synopsis>
82+
Define an optional else branch.
83+
</synopsis>
84+
<syntax>
85+
<parameter name="expr" required="true" />
86+
</syntax>
87+
<description>
88+
<para>Start an Else branch. Execution will jump here if all previous
89+
If and ElseIf branches evaluated to false.</para>
90+
</description>
91+
<see-also>
92+
<ref type="application">If</ref>
93+
<ref type="application">ElseIf</ref>
94+
<ref type="application">EndIf</ref>
95+
<ref type="application">ExitIf</ref>
96+
</see-also>
97+
</application>
98+
<application name="EndIf" language="en_US">
99+
<synopsis>
100+
End an if branch.
101+
</synopsis>
102+
<syntax />
103+
<description>
104+
<para>Ends the branch begun by the preceding <literal>If()</literal> application.</para>
105+
</description>
106+
<see-also>
107+
<ref type="application">If</ref>
108+
<ref type="application">ElseIf</ref>
109+
<ref type="application">Else</ref>
110+
<ref type="application">ExitIf</ref>
111+
</see-also>
112+
</application>
113+
<application name="ExitIf" language="en_US">
114+
<synopsis>
115+
End an If branch.
116+
</synopsis>
117+
<syntax />
118+
<description>
119+
<para>Exits an <literal>If()</literal> branch, whether or not it has completed.</para>
120+
</description>
121+
<see-also>
122+
<ref type="application">If</ref>
123+
<ref type="application">ElseIf</ref>
124+
<ref type="application">Else</ref>
125+
<ref type="application">EndIf</ref>
126+
</see-also>
127+
</application>
128+
***/
129+
130+
static char *if_app = "If";
131+
static char *elseif_app = "ElseIf";
132+
static char *else_app = "Else";
133+
static char *stop_app = "EndIf";
134+
static char *exit_app = "ExitIf";
135+
136+
#define VAR_SIZE 64
137+
138+
static const char *get_index(struct ast_channel *chan, const char *prefix, int idx)
139+
{
140+
char varname[VAR_SIZE];
141+
142+
snprintf(varname, VAR_SIZE, "%s_%d", prefix, idx);
143+
return pbx_builtin_getvar_helper(chan, varname);
144+
}
145+
146+
static struct ast_exten *find_matching_priority(struct ast_context *c, const char *exten, int priority, const char *callerid)
147+
{
148+
struct ast_exten *e;
149+
struct ast_context *c2;
150+
int idx;
151+
152+
for (e = ast_walk_context_extensions(c, NULL); e; e = ast_walk_context_extensions(c, e)) {
153+
if (ast_extension_match(ast_get_extension_name(e), exten)) {
154+
int needmatch = ast_get_extension_matchcid(e);
155+
if ((needmatch && ast_extension_match(ast_get_extension_cidmatch(e), callerid)) ||
156+
(!needmatch)) {
157+
/* This is the matching extension we want */
158+
struct ast_exten *p;
159+
for (p = ast_walk_extension_priorities(e, NULL); p; p = ast_walk_extension_priorities(e, p)) {
160+
if (priority != ast_get_extension_priority(p))
161+
continue;
162+
return p;
163+
}
164+
}
165+
}
166+
}
167+
168+
/* No match; run through includes */
169+
for (idx = 0; idx < ast_context_includes_count(c); idx++) {
170+
const struct ast_include *i = ast_context_includes_get(c, idx);
171+
172+
for (c2 = ast_walk_contexts(NULL); c2; c2 = ast_walk_contexts(c2)) {
173+
if (!strcmp(ast_get_context_name(c2), ast_get_include_name(i))) {
174+
e = find_matching_priority(c2, exten, priority, callerid);
175+
if (e)
176+
return e;
177+
}
178+
}
179+
}
180+
return NULL;
181+
}
182+
183+
static int find_matching_endif(struct ast_channel *chan, const char *otherapp)
184+
{
185+
struct ast_context *c;
186+
int res = -1;
187+
188+
if (ast_rdlock_contexts()) {
189+
ast_log(LOG_ERROR, "Failed to lock contexts list\n");
190+
return -1;
191+
}
192+
193+
for (c = ast_walk_contexts(NULL); c; c = ast_walk_contexts(c)) {
194+
struct ast_exten *e;
195+
196+
if (!ast_rdlock_context(c)) {
197+
if (!strcmp(ast_get_context_name(c), ast_channel_context(chan))) {
198+
/* This is the matching context we want */
199+
int cur_priority = ast_channel_priority(chan) + 1, level = 1;
200+
201+
for (e = find_matching_priority(c, ast_channel_exten(chan), cur_priority,
202+
S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL));
203+
e;
204+
e = find_matching_priority(c, ast_channel_exten(chan), ++cur_priority,
205+
S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL))) {
206+
if (!strcasecmp(ast_get_extension_app(e), "IF")) {
207+
level++;
208+
} else if (!strcasecmp(ast_get_extension_app(e), "ENDIF")) {
209+
level--;
210+
}
211+
212+
if (!otherapp && level == 0) {
213+
res = cur_priority;
214+
break;
215+
} else if (otherapp && level == 1 && !strcasecmp(ast_get_extension_app(e), otherapp)) {
216+
res = cur_priority;
217+
break;
218+
}
219+
}
220+
}
221+
ast_unlock_context(c);
222+
if (res > 0) {
223+
break;
224+
}
225+
}
226+
}
227+
ast_unlock_contexts();
228+
return res;
229+
}
230+
231+
static int if_helper(struct ast_channel *chan, const char *data, int end)
232+
{
233+
int res = 0;
234+
const char *if_pri = NULL;
235+
char *my_name = NULL;
236+
const char *label = NULL;
237+
char varname[VAR_SIZE], end_varname[VAR_SIZE + 4];
238+
const char *prefix = "IF";
239+
size_t size = 0;
240+
int used_index_i = -1, x = 0;
241+
char used_index[VAR_SIZE] = "0", new_index[VAR_SIZE] = "0";
242+
243+
if (!chan) {
244+
return -1;
245+
}
246+
247+
for (x = 0 ;; x++) {
248+
if (get_index(chan, prefix, x)) {
249+
used_index_i = x;
250+
} else {
251+
break;
252+
}
253+
}
254+
255+
snprintf(used_index, VAR_SIZE, "%d", used_index_i);
256+
snprintf(new_index, VAR_SIZE, "%d", used_index_i + 1);
257+
258+
size = strlen(ast_channel_context(chan)) + strlen(ast_channel_exten(chan)) + 32;
259+
my_name = ast_alloca(size);
260+
memset(my_name, 0, size);
261+
snprintf(my_name, size, "%s_%s_%d", ast_channel_context(chan), ast_channel_exten(chan), ast_channel_priority(chan));
262+
263+
ast_channel_lock(chan);
264+
if (end > 1) {
265+
label = used_index;
266+
} else if (!(label = pbx_builtin_getvar_helper(chan, my_name))) {
267+
label = new_index;
268+
pbx_builtin_setvar_helper(chan, my_name, label);
269+
}
270+
snprintf(varname, sizeof(varname), "%s_%s", prefix, label);
271+
if ((if_pri = pbx_builtin_getvar_helper(chan, varname)) && !end) {
272+
if_pri = ast_strdupa(if_pri);
273+
snprintf(end_varname,sizeof(end_varname),"END_%s",varname);
274+
}
275+
ast_channel_unlock(chan);
276+
277+
if ((end <= 1 && !pbx_checkcondition(ast_strdupa(data))) || (end > 1)) {
278+
/* Condition Met (clean up helper vars) */
279+
const char *goto_str;
280+
int pri, endifpri;
281+
pbx_builtin_setvar_helper(chan, varname, NULL);
282+
pbx_builtin_setvar_helper(chan, my_name, NULL);
283+
snprintf(end_varname,sizeof(end_varname),"END_%s",varname);
284+
ast_channel_lock(chan);
285+
endifpri = find_matching_endif(chan, NULL);
286+
if ((goto_str = pbx_builtin_getvar_helper(chan, end_varname))) {
287+
ast_parseable_goto(chan, goto_str);
288+
pbx_builtin_setvar_helper(chan, end_varname, NULL);
289+
} else if (end <= 1 && (pri = find_matching_endif(chan, "ElseIf")) > 0 && pri < endifpri) {
290+
pri--; /* back up a priority, since it returned the priority after the ElseIf */
291+
/* If is false, and ElseIf exists, so jump to ElseIf */
292+
ast_verb(3, "Taking conditional false branch, jumping to priority %d\n", pri);
293+
ast_channel_priority_set(chan, pri);
294+
} else if (end <= 1 && (pri = find_matching_endif(chan, "Else")) > 0 && pri < endifpri) {
295+
/* don't need to back up a priority, because we don't actually need to execute Else, just jump to the priority after. Directly executing Else will exit the conditional. */
296+
/* If is false, and Else exists, so jump to Else */
297+
ast_verb(3, "Taking absolute false branch, jumping to priority %d\n", pri);
298+
ast_channel_priority_set(chan, pri);
299+
} else {
300+
pri = endifpri;
301+
if (pri > 0) {
302+
ast_verb(3, "Exiting conditional, jumping to priority %d\n", pri);
303+
ast_channel_priority_set(chan, pri);
304+
} else if (end == 4) { /* Condition added because of end > 0 instead of end == 4 */
305+
ast_log(LOG_WARNING, "Couldn't find matching EndIf? (If at %s@%s priority %d)\n", ast_channel_context(chan), ast_channel_exten(chan), ast_channel_priority(chan));
306+
}
307+
}
308+
ast_channel_unlock(chan);
309+
return res;
310+
}
311+
312+
if (end <= 1 && !if_pri) {
313+
char *goto_str;
314+
size = strlen(ast_channel_context(chan)) + strlen(ast_channel_exten(chan)) + 32;
315+
goto_str = ast_alloca(size);
316+
memset(goto_str, 0, size);
317+
snprintf(goto_str, size, "%s,%s,%d", ast_channel_context(chan), ast_channel_exten(chan), ast_channel_priority(chan));
318+
pbx_builtin_setvar_helper(chan, varname, goto_str);
319+
} else if (end > 1 && if_pri) {
320+
/* END of branch */
321+
snprintf(end_varname, sizeof(end_varname), "END_%s", varname);
322+
if (!pbx_builtin_getvar_helper(chan, end_varname)) {
323+
char *goto_str;
324+
size = strlen(ast_channel_context(chan)) + strlen(ast_channel_exten(chan)) + 32;
325+
goto_str = ast_alloca(size);
326+
memset(goto_str, 0, size);
327+
snprintf(goto_str, size, "%s,%s,%d", ast_channel_context(chan), ast_channel_exten(chan), ast_channel_priority(chan)+1);
328+
pbx_builtin_setvar_helper(chan, end_varname, goto_str);
329+
}
330+
ast_parseable_goto(chan, if_pri);
331+
}
332+
333+
return res;
334+
}
335+
336+
static int if_exec(struct ast_channel *chan, const char *data) {
337+
return if_helper(chan, data, 0);
338+
}
339+
340+
static int elseif_exec(struct ast_channel *chan, const char *data) {
341+
return if_helper(chan, data, 1);
342+
}
343+
344+
static int end_exec(struct ast_channel *chan, const char *data) {
345+
return if_helper(chan, data, 2);
346+
}
347+
348+
static int else_exec(struct ast_channel *chan, const char *data) {
349+
return if_helper(chan, data, 3);
350+
}
351+
352+
static int exit_exec(struct ast_channel *chan, const char *data) {
353+
return if_helper(chan, data, 4);
354+
}
355+
356+
static int unload_module(void)
357+
{
358+
int res;
359+
360+
res = ast_unregister_application(if_app);
361+
res |= ast_unregister_application(elseif_app);
362+
res |= ast_unregister_application(stop_app);
363+
res |= ast_unregister_application(else_app);
364+
res |= ast_unregister_application(exit_app);
365+
366+
return res;
367+
}
368+
369+
static int load_module(void)
370+
{
371+
int res;
372+
373+
res = ast_register_application_xml(if_app, if_exec);
374+
res |= ast_register_application_xml(elseif_app, elseif_exec);
375+
res |= ast_register_application_xml(stop_app, end_exec);
376+
res |= ast_register_application_xml(else_app, else_exec);
377+
res |= ast_register_application_xml(exit_app, exit_exec);
378+
379+
return res;
380+
}
381+
382+
AST_MODULE_INFO_STANDARD_EXTENDED(ASTERISK_GPL_KEY, "If Branch and Conditional Execution");

‎doc/CHANGES-staging/app_if.txt

+4
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,4 @@
1+
Subject: app_if
2+
3+
Adds the If, ElseIf, Else, EndIf, and ExitIf applications
4+
for conditional execution of a block of code.

0 commit comments

Comments
 (0)