Asterisk - The Open Source Telephony Project GIT-master-3dae2cf
app_if.c
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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
130static char *if_app = "If";
131static char *elseif_app = "ElseIf";
132static char *else_app = "Else";
133static char *stop_app = "EndIf";
134static char *exit_app = "ExitIf";
135
136#define VAR_SIZE 64
137
138static 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
146static 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
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;
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
183static 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
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
200 int cur_priority = ast_channel_priority(chan) + 1, level = 1;
201
202 for (e = find_matching_priority(c, ast_channel_exten(chan), cur_priority,
203 S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL));
204 e;
205 e = find_matching_priority(c, ast_channel_exten(chan), ++cur_priority,
206 S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL))) {
207
208 if (!strcasecmp(ast_get_extension_app(e), "IF")) {
209 level++;
210 } else if (!strcasecmp(ast_get_extension_app(e), "ENDIF")) {
211 level--;
212 }
213
214 if (!otherapp && level == 0) {
215 res = cur_priority;
216 break;
217 } else if (otherapp && level == 1 && !strcasecmp(ast_get_extension_app(e), otherapp)) {
218 res = cur_priority;
219 break;
220 }
221 }
222 }
224 if (res > 0) {
225 break;
226 }
227 }
228 }
230 return res;
231}
232
233static int if_helper(struct ast_channel *chan, const char *data, int end)
234{
235 int res = 0;
236 const char *if_pri = NULL;
237 char *my_name = NULL;
238 const char *label = NULL;
239 char varname[VAR_SIZE + 3]; /* + IF_ */
240 char end_varname[sizeof(varname) + 4]; /* + END_ + sizeof(varname) */
241 const char *prefix = "IF";
242 size_t size = 0;
243 int used_index_i = -1, x = 0;
244 char used_index[VAR_SIZE] = "0", new_index[VAR_SIZE] = "0";
245
246 if (!chan) {
247 return -1;
248 }
249
250 for (x = 0 ;; x++) {
251 if (get_index(chan, prefix, x)) {
252 used_index_i = x;
253 } else {
254 break;
255 }
256 }
257
258 snprintf(used_index, sizeof(used_index), "%d", used_index_i);
259 snprintf(new_index, sizeof(new_index), "%d", used_index_i + 1);
260
261 size = strlen(ast_channel_context(chan)) + strlen(ast_channel_exten(chan)) + 32;
262 my_name = ast_alloca(size);
263 memset(my_name, 0, size);
264 snprintf(my_name, size, "%s_%s_%d", ast_channel_context(chan), ast_channel_exten(chan), ast_channel_priority(chan));
265
266 ast_channel_lock(chan);
267 if (end > 1) {
268 label = used_index;
269 } else if (!(label = pbx_builtin_getvar_helper(chan, my_name))) {
270 label = new_index;
271 pbx_builtin_setvar_helper(chan, my_name, label);
272 }
273 snprintf(varname, sizeof(varname), "%s_%s", prefix, label);
274 if ((if_pri = pbx_builtin_getvar_helper(chan, varname)) && !end) {
275 if_pri = ast_strdupa(if_pri);
276 snprintf(end_varname,sizeof(end_varname),"END_%s",varname);
277 }
278 ast_channel_unlock(chan);
279
280 if ((end <= 1 && !pbx_checkcondition(ast_strdupa(data))) || (end > 1)) {
281 /* Condition Met (clean up helper vars) */
282 const char *goto_str;
283 int pri, endifpri;
284 pbx_builtin_setvar_helper(chan, varname, NULL);
285 pbx_builtin_setvar_helper(chan, my_name, NULL);
286 snprintf(end_varname,sizeof(end_varname),"END_%s",varname);
287 ast_channel_lock(chan);
288 /* For EndIf, simply go to the next priority.
289 * We do not add 1 to ast_channel_priority because the dialplan will
290 * auto-increment the priority when we return, so just keep the priority as is.
291 * For ExitIf or false If() condition, we need to find the end of the current
292 * If branch (at same indentation) and branch there. */
293 endifpri = end == 2 ? ast_channel_priority(chan) : find_matching_endif(chan, NULL);
294 if ((goto_str = pbx_builtin_getvar_helper(chan, end_varname))) {
295 ast_parseable_goto(chan, goto_str);
296 pbx_builtin_setvar_helper(chan, end_varname, NULL);
297 } else if (end <= 1 && (pri = find_matching_endif(chan, "ElseIf")) > 0 && pri < endifpri) {
298 pri--; /* back up a priority, since it returned the priority after the ElseIf */
299 /* If is false, and ElseIf exists, so jump to ElseIf */
300 ast_verb(3, "Taking conditional false branch, jumping to priority %d\n", pri);
301 ast_channel_priority_set(chan, pri);
302 } else if (end <= 1 && (pri = find_matching_endif(chan, "Else")) > 0 && pri < endifpri) {
303 /* 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. */
304 /* If is false, and Else exists, so jump to Else */
305 ast_verb(3, "Taking absolute false branch, jumping to priority %d\n", pri);
306 ast_channel_priority_set(chan, pri);
307 } else {
308 pri = endifpri;
309 if (pri > 0) {
310 ast_verb(3, "Exiting conditional, jumping to priority %d\n", pri);
311 ast_channel_priority_set(chan, pri);
312 } else if (end == 4) { /* Condition added because of end > 0 instead of end == 4 */
313 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));
314 }
315 }
316 ast_channel_unlock(chan);
317 return res;
318 }
319
320 if (end <= 1 && !if_pri) {
321 char *goto_str;
322 size = strlen(ast_channel_context(chan)) + strlen(ast_channel_exten(chan)) + 32;
323 goto_str = ast_alloca(size);
324 memset(goto_str, 0, size);
325 snprintf(goto_str, size, "%s,%s,%d", ast_channel_context(chan), ast_channel_exten(chan), ast_channel_priority(chan));
326 pbx_builtin_setvar_helper(chan, varname, goto_str);
327 } else if (end > 1 && if_pri) {
328 /* END of branch */
329 snprintf(end_varname, sizeof(end_varname), "END_%s", varname);
330 if (!pbx_builtin_getvar_helper(chan, end_varname)) {
331 char *goto_str;
332 size = strlen(ast_channel_context(chan)) + strlen(ast_channel_exten(chan)) + 32;
333 goto_str = ast_alloca(size);
334 memset(goto_str, 0, size);
335 snprintf(goto_str, size, "%s,%s,%d", ast_channel_context(chan), ast_channel_exten(chan), ast_channel_priority(chan)+1);
336 pbx_builtin_setvar_helper(chan, end_varname, goto_str);
337 }
338 ast_parseable_goto(chan, if_pri);
339 }
340
341 return res;
342}
343
344static int if_exec(struct ast_channel *chan, const char *data) {
345 return if_helper(chan, data, 0);
346}
347
348static int elseif_exec(struct ast_channel *chan, const char *data) {
349 return if_helper(chan, data, 1);
350}
351
352static int end_exec(struct ast_channel *chan, const char *data) {
353 return if_helper(chan, data, 2);
354}
355
356static int else_exec(struct ast_channel *chan, const char *data) {
357 return if_helper(chan, data, 3);
358}
359
360static int exit_exec(struct ast_channel *chan, const char *data) {
361 return if_helper(chan, data, 4);
362}
363
364static int unload_module(void)
365{
366 int res;
367
373
374 return res;
375}
376
377static int load_module(void)
378{
379 int res;
380
386
387 return res;
388}
389
390AST_MODULE_INFO_STANDARD_EXTENDED(ASTERISK_GPL_KEY, "If Branch and Conditional Execution");
static char * else_app
Definition: app_if.c:132
static const char * get_index(struct ast_channel *chan, const char *prefix, int idx)
Definition: app_if.c:138
static struct ast_exten * find_matching_priority(struct ast_context *c, const char *exten, int priority, const char *callerid)
Definition: app_if.c:146
static int if_exec(struct ast_channel *chan, const char *data)
Definition: app_if.c:344
static char * stop_app
Definition: app_if.c:133
static char * if_app
Definition: app_if.c:130
static int if_helper(struct ast_channel *chan, const char *data, int end)
Definition: app_if.c:233
AST_MODULE_INFO_STANDARD_EXTENDED(ASTERISK_GPL_KEY, "If Branch and Conditional Execution")
static char * exit_app
Definition: app_if.c:134
static int find_matching_endif(struct ast_channel *chan, const char *otherapp)
Definition: app_if.c:183
#define VAR_SIZE
Definition: app_if.c:136
static int elseif_exec(struct ast_channel *chan, const char *data)
Definition: app_if.c:348
static int load_module(void)
Definition: app_if.c:377
static char * elseif_app
Definition: app_if.c:131
static int end_exec(struct ast_channel *chan, const char *data)
Definition: app_if.c:352
static int unload_module(void)
Definition: app_if.c:364
static int else_exec(struct ast_channel *chan, const char *data)
Definition: app_if.c:356
static int exit_exec(struct ast_channel *chan, const char *data)
Definition: app_if.c:360
Asterisk main include file. File version handling, generic pbx functions.
#define ast_alloca(size)
call __builtin_alloca to ensure we get gcc builtin semantics
Definition: astmm.h:288
#define ast_strdupa(s)
duplicate a string in memory from the stack
Definition: astmm.h:298
#define ast_log
Definition: astobj2.c:42
static int priority
General Asterisk PBX channel definitions.
#define ast_channel_lock(chan)
Definition: channel.h:2968
int ast_channel_priority(const struct ast_channel *chan)
const char * ast_channel_context(const struct ast_channel *chan)
struct ast_party_caller * ast_channel_caller(struct ast_channel *chan)
void ast_channel_priority_set(struct ast_channel *chan, int value)
const char * ast_channel_exten(const struct ast_channel *chan)
#define ast_channel_unlock(chan)
Definition: channel.h:2969
char * end
Definition: eagi_proxy.c:73
static char prefix[MAX_PREFIX]
Definition: http.c:144
#define LOG_ERROR
#define ast_verb(level,...)
#define LOG_WARNING
Asterisk module definitions.
#define ASTERISK_GPL_KEY
The text the key() function should return.
Definition: module.h:46
int ast_unregister_application(const char *app)
Unregister an application.
Definition: pbx_app.c:392
#define ast_register_application_xml(app, execute)
Register an application using XML documentation.
Definition: module.h:640
Core PBX routines and definitions.
struct ast_context * ast_walk_contexts(struct ast_context *con)
Definition: extconf.c:4024
int ast_get_extension_priority(struct ast_exten *exten)
Definition: pbx.c:8519
int ast_get_extension_matchcid(struct ast_exten *e)
Definition: pbx.c:8547
const char * ast_get_extension_app(struct ast_exten *e)
Definition: pbx.c:8557
const char * ast_get_extension_cidmatch(struct ast_exten *e)
Definition: pbx.c:8552
const char * pbx_builtin_getvar_helper(struct ast_channel *chan, const char *name)
Return a pointer to the value of the corresponding channel variable.
int pbx_builtin_setvar_helper(struct ast_channel *chan, const char *name, const char *value)
Add a variable to the channel variable stack, removing the most recently set value for the same name.
const char * ast_get_include_name(const struct ast_include *include)
Definition: pbx_include.c:50
int ast_unlock_context(struct ast_context *con)
Definition: pbx.c:8491
struct ast_exten * ast_walk_extension_priorities(struct ast_exten *exten, struct ast_exten *priority)
Definition: extconf.c:4061
const char * ast_get_context_name(struct ast_context *con)
Definition: ael_main.c:421
int ast_extension_match(const char *pattern, const char *extension)
Determine if a given extension matches a given pattern (in NXX format)
Definition: extconf.c:4295
int ast_rdlock_contexts(void)
Read locks the context list.
Definition: pbx.c:8468
const struct ast_include * ast_context_includes_get(const struct ast_context *con, int idx)
Definition: pbx.c:8684
struct ast_exten * ast_walk_context_extensions(struct ast_context *con, struct ast_exten *priority)
Definition: ael_main.c:427
int pbx_checkcondition(const char *condition)
Evaluate a condition.
Definition: pbx.c:8282
int ast_unlock_contexts(void)
Unlocks contexts.
Definition: pbx.c:8473
int ast_parseable_goto(struct ast_channel *chan, const char *goto_string)
Definition: pbx.c:8866
int ast_context_includes_count(const struct ast_context *con)
Definition: pbx.c:8679
const char * ast_get_extension_name(struct ast_exten *exten)
Definition: pbx.c:8509
int ast_rdlock_context(struct ast_context *con)
Read locks a given context.
Definition: pbx.c:8486
#define NULL
Definition: resample.c:96
#define S_COR(a, b, c)
returns the equivalent of logic or for strings, with an additional boolean check: second one if not e...
Definition: strings.h:87
Main Channel structure associated with a channel.
ast_context: An extension context
Definition: pbx.c:284
ast_exten: An extension The dialplan is saved as a linked list with each context having it's own link...
Definition: pbx.c:237
char * exten
Definition: pbx.c:238
void * data
Definition: pbx.c:248
const char * label
Definition: pbx.c:244
ast_include: include= support in extensions.conf
Definition: pbx_include.c:37
Number structure.
Definition: app_followme.c:154
static struct test_val c