Asterisk - The Open Source Telephony Project  GIT-master-a24979a
Data Structures | Macros | Enumerations | Functions | Variables
app_directed_pickup.c File Reference

Directed Call Pickup Support. More...

#include "asterisk.h"
#include "asterisk/file.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/lock.h"
#include "asterisk/app.h"
#include "asterisk/pickup.h"
#include "asterisk/manager.h"
#include "asterisk/callerid.h"
Include dependency graph for app_directed_pickup.c:

Go to the source code of this file.

Data Structures

struct  pickup_by_name_args
 

Macros

#define PICKUPMARK   "PICKUPMARK"
 

Enumerations

enum  OPT_PICKUPCHAN_FLAGS { OPT_PICKUPCHAN_PARTIAL = (1 << 0) }
 

Functions

static void __reg_module (void)
 
static void __unreg_module (void)
 
struct ast_moduleAST_MODULE_SELF_SYM (void)
 
static struct ast_channelfind_by_channel (struct ast_channel *chan, const char *channame)
 Helper Function to walk through ALL channels checking NAME and STATE. More...
 
static int find_by_mark (void *obj, void *arg, void *data, int flags)
 
static int find_by_name (void *obj, void *arg, void *data, int flags)
 
static struct ast_channelfind_by_part (struct ast_channel *chan, const char *part)
 
static int find_by_uniqueid (void *obj, void *arg, void *data, int flags)
 
static int load_module (void)
 
static int pickup_by_channel (struct ast_channel *chan, const char *name)
 Attempt to pick up named channel. More...
 
static int pickup_by_exten (struct ast_channel *chan, const char *exten, const char *context)
 
static int pickup_by_group (struct ast_channel *chan)
 
static int pickup_by_mark (struct ast_channel *chan, const char *mark)
 
static int pickup_by_part (struct ast_channel *chan, const char *part)
 
static int pickup_exec (struct ast_channel *chan, const char *data)
 
static int pickupchan_exec (struct ast_channel *chan, const char *data)
 
static int unload_module (void)
 

Variables

static struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "Directed Call Pickup Application" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_DEFAULT, .support_level = AST_MODULE_SUPPORT_CORE, }
 
static const char app [] = "Pickup"
 
static const char app2 [] = "PickupChan"
 
static const struct ast_module_infoast_module_info = &__mod_info
 
static const struct ast_app_option pickupchan_opts [128] = { [ 'p' ] = { .flag = OPT_PICKUPCHAN_PARTIAL }, }
 

Detailed Description

Directed Call Pickup Support.

Author
Joshua Colp jcolp.nosp@m.@dig.nosp@m.ium.c.nosp@m.om
Gary Cook

Definition in file app_directed_pickup.c.

Macro Definition Documentation

◆ PICKUPMARK

#define PICKUPMARK   "PICKUPMARK"

Definition at line 48 of file app_directed_pickup.c.

Enumeration Type Documentation

◆ OPT_PICKUPCHAN_FLAGS

Enumerator
OPT_PICKUPCHAN_PARTIAL 

Definition at line 411 of file app_directed_pickup.c.

411  {
412  OPT_PICKUPCHAN_PARTIAL = (1 << 0), /* Channel name is a partial name. */
413 };
@ OPT_PICKUPCHAN_PARTIAL

Function Documentation

◆ __reg_module()

static void __reg_module ( void  )
static

Definition at line 492 of file app_directed_pickup.c.

◆ __unreg_module()

static void __unreg_module ( void  )
static

Definition at line 492 of file app_directed_pickup.c.

◆ AST_MODULE_SELF_SYM()

struct ast_module* AST_MODULE_SELF_SYM ( void  )

Definition at line 492 of file app_directed_pickup.c.

◆ find_by_channel()

static struct ast_channel* find_by_channel ( struct ast_channel chan,
const char *  channame 
)
static

Helper Function to walk through ALL channels checking NAME and STATE.

Definition at line 180 of file app_directed_pickup.c.

181 {
182  struct ast_channel *target;
183  char *chkchan;
184  struct pickup_by_name_args pickup_args;
185 
186  pickup_args.chan = chan;
187 
188  if (strchr(channame, '-')) {
189  /*
190  * Use the given channel name string as-is. This allows a full channel
191  * name with a typical sequence number to be used as well as still
192  * allowing the odd partial channel name that has a '-' in it to still
193  * work, i.e. Local/bob@en-phone.
194  */
195  pickup_args.len = strlen(channame);
196  pickup_args.name = channame;
197  } else {
198  /*
199  * Append a '-' for the comparison so we check the channel name less
200  * a sequence number, i.e Find SIP/bob- and not SIP/bobby.
201  */
202  pickup_args.len = strlen(channame) + 1;
203  chkchan = ast_alloca(pickup_args.len + 1);
204  strcpy(chkchan, channame);/* Safe */
205  strcat(chkchan, "-");
206  pickup_args.name = chkchan;
207  }
208  target = ast_channel_callback(find_by_name, NULL, &pickup_args, 0);
209  if (target) {
210  return target;
211  }
212 
213  /* Now try a search for uniqueid. */
214  pickup_args.name = channame;
215  pickup_args.len = 0;
216  return ast_channel_callback(find_by_uniqueid, NULL, &pickup_args, 0);
217 }
static int find_by_name(void *obj, void *arg, void *data, int flags)
static int find_by_uniqueid(void *obj, void *arg, void *data, int flags)
#define ast_alloca(size)
call __builtin_alloca to ensure we get gcc builtin semantics
Definition: astmm.h:288
struct ast_channel * ast_channel_callback(ao2_callback_data_fn *cb_fn, void *arg, void *data, int ao2_flags)
Call a function with every active channel.
Definition: channel.c:1272
#define NULL
Definition: resample.c:96
Main Channel structure associated with a channel.
const ast_string_field name
struct ast_channel * chan

References ast_alloca, ast_channel_callback(), pickup_by_name_args::chan, find_by_name(), find_by_uniqueid(), pickup_by_name_args::len, pickup_by_name_args::name, and NULL.

Referenced by pickup_by_channel().

◆ find_by_mark()

static int find_by_mark ( void *  obj,
void *  arg,
void *  data,
int  flags 
)
static

< Potential pickup target

Definition at line 268 of file app_directed_pickup.c.

269 {
270  struct ast_channel *target = obj;/*!< Potential pickup target */
271  struct ast_channel *chan = arg;
272  const char *mark = data;
273  const char *tmp;
274 
275  if (chan == target) {
276  /* The channel attempting to pickup a call cannot pickup itself. */
277  return 0;
278  }
279 
280  ast_channel_lock(target);
282  if (tmp && !strcasecmp(tmp, mark) && ast_can_pickup(target)) {
283  /* Return with the channel still locked on purpose */
284  return CMP_MATCH | CMP_STOP;
285  }
286  ast_channel_unlock(target);
287 
288  return 0;
289 }
#define PICKUPMARK
@ CMP_MATCH
Definition: astobj2.h:1027
@ CMP_STOP
Definition: astobj2.h:1028
static int tmp()
Definition: bt_open.c:389
#define ast_channel_lock(chan)
Definition: channel.h:2922
#define ast_channel_unlock(chan)
Definition: channel.h:2923
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 ast_can_pickup(struct ast_channel *chan)
Test if a channel can be picked up.
Definition: pickup.c:77
const char * data

References ast_can_pickup(), ast_channel_lock, ast_channel_unlock, CMP_MATCH, CMP_STOP, ast_channel::data, pbx_builtin_getvar_helper(), PICKUPMARK, and tmp().

Referenced by pickup_by_mark().

◆ find_by_name()

static int find_by_name ( void *  obj,
void *  arg,
void *  data,
int  flags 
)
static

< Potential pickup target

Definition at line 137 of file app_directed_pickup.c.

138 {
139  struct ast_channel *target = obj;/*!< Potential pickup target */
140  struct pickup_by_name_args *args = data;
141 
142  if (args->chan == target) {
143  /* The channel attempting to pickup a call cannot pickup itself. */
144  return 0;
145  }
146 
147  ast_channel_lock(target);
148  if (!strncasecmp(ast_channel_name(target), args->name, args->len)
149  && ast_can_pickup(target)) {
150  /* Return with the channel still locked on purpose */
151  return CMP_MATCH | CMP_STOP;
152  }
153  ast_channel_unlock(target);
154 
155  return 0;
156 }
const char * ast_channel_name(const struct ast_channel *chan)
const char * args

References args, ast_can_pickup(), ast_channel_lock, ast_channel_name(), ast_channel_unlock, CMP_MATCH, and CMP_STOP.

Referenced by find_by_channel(), and find_by_part().

◆ find_by_part()

static struct ast_channel* find_by_part ( struct ast_channel chan,
const char *  part 
)
static

Definition at line 373 of file app_directed_pickup.c.

374 {
375  struct ast_channel *target;
376  struct pickup_by_name_args pickup_args;
377 
378  pickup_args.chan = chan;
379 
380  /* Try a partial channel name search. */
381  pickup_args.name = part;
382  pickup_args.len = strlen(part);
383  target = ast_channel_callback(find_by_name, NULL, &pickup_args, 0);
384  if (target) {
385  return target;
386  }
387 
388  /* Now try a search for uniqueid. */
389  pickup_args.name = part;
390  pickup_args.len = 0;
391  return ast_channel_callback(find_by_uniqueid, NULL, &pickup_args, 0);
392 }

References ast_channel_callback(), pickup_by_name_args::chan, find_by_name(), find_by_uniqueid(), pickup_by_name_args::len, pickup_by_name_args::name, and NULL.

Referenced by pickup_by_part().

◆ find_by_uniqueid()

static int find_by_uniqueid ( void *  obj,
void *  arg,
void *  data,
int  flags 
)
static

< Potential pickup target

Definition at line 158 of file app_directed_pickup.c.

159 {
160  struct ast_channel *target = obj;/*!< Potential pickup target */
161  struct pickup_by_name_args *args = data;
162 
163  if (args->chan == target) {
164  /* The channel attempting to pickup a call cannot pickup itself. */
165  return 0;
166  }
167 
168  ast_channel_lock(target);
169  if (!strcasecmp(ast_channel_uniqueid(target), args->name)
170  && ast_can_pickup(target)) {
171  /* Return with the channel still locked on purpose */
172  return CMP_MATCH | CMP_STOP;
173  }
174  ast_channel_unlock(target);
175 
176  return 0;
177 }
const char * ast_channel_uniqueid(const struct ast_channel *chan)

References args, ast_can_pickup(), ast_channel_lock, ast_channel_uniqueid(), ast_channel_unlock, CMP_MATCH, and CMP_STOP.

Referenced by find_by_channel(), and find_by_part().

◆ load_module()

static int load_module ( void  )
static

Definition at line 482 of file app_directed_pickup.c.

483 {
484  int res;
485 
488 
489  return res;
490 }
static const char app[]
static int pickupchan_exec(struct ast_channel *chan, const char *data)
static int pickup_exec(struct ast_channel *chan, const char *data)
static const char app2[]
#define ast_register_application_xml(app, execute)
Register an application using XML documentation.
Definition: module.h:626

◆ pickup_by_channel()

static int pickup_by_channel ( struct ast_channel chan,
const char *  name 
)
static

Attempt to pick up named channel.

< Potential pickup target

Definition at line 220 of file app_directed_pickup.c.

221 {
222  int res = -1;
223  struct ast_channel *target;/*!< Potential pickup target */
224 
225  /* The found channel is already locked. */
226  target = find_by_channel(chan, name);
227  if (target) {
228  res = ast_do_pickup(chan, target);
229  ast_channel_unlock(target);
230  target = ast_channel_unref(target);
231  }
232 
233  return res;
234 }
static struct ast_channel * find_by_channel(struct ast_channel *chan, const char *channame)
Helper Function to walk through ALL channels checking NAME and STATE.
#define ast_channel_unref(c)
Decrease channel reference count.
Definition: channel.h:2958
static const char name[]
Definition: format_mp3.c:68
int ast_do_pickup(struct ast_channel *chan, struct ast_channel *target)
Pickup a call target.
Definition: pickup.c:301

References ast_channel_unlock, ast_channel_unref, ast_do_pickup(), find_by_channel(), and name.

Referenced by pickupchan_exec().

◆ pickup_by_exten()

static int pickup_by_exten ( struct ast_channel chan,
const char *  exten,
const char *  context 
)
static

< Potential pickup target

Definition at line 237 of file app_directed_pickup.c.

238 {
239  struct ast_channel *target = NULL;/*!< Potential pickup target */
240  struct ast_channel_iterator *iter;
241  int res = -1;
242 
244  return -1;
245  }
246 
247  while ((target = ast_channel_iterator_next(iter))) {
248  ast_channel_lock(target);
249  if ((chan != target) && ast_can_pickup(target)) {
250  ast_log(LOG_NOTICE, "%s pickup by %s\n", ast_channel_name(target), ast_channel_name(chan));
251  break;
252  }
253  ast_channel_unlock(target);
254  target = ast_channel_unref(target);
255  }
256 
258 
259  if (target) {
260  res = ast_do_pickup(chan, target);
261  ast_channel_unlock(target);
262  target = ast_channel_unref(target);
263  }
264 
265  return res;
266 }
#define ast_log
Definition: astobj2.c:42
static char exten[AST_MAX_EXTENSION]
Definition: chan_alsa.c:122
static char context[AST_MAX_CONTEXT]
Definition: chan_alsa.c:120
struct ast_channel_iterator * ast_channel_iterator_destroy(struct ast_channel_iterator *i)
Destroy a channel iterator.
Definition: channel.c:1354
struct ast_channel * ast_channel_iterator_next(struct ast_channel_iterator *i)
Get the next channel for a channel iterator.
Definition: channel.c:1416
struct ast_channel_iterator * ast_channel_iterator_by_exten_new(const char *exten, const char *context)
Create a new channel iterator based on extension.
Definition: channel.c:1362
#define LOG_NOTICE

References ast_can_pickup(), ast_channel_iterator_by_exten_new(), ast_channel_iterator_destroy(), ast_channel_iterator_next(), ast_channel_lock, ast_channel_name(), ast_channel_unlock, ast_channel_unref, ast_do_pickup(), ast_log, context, exten, LOG_NOTICE, and NULL.

Referenced by pickup_exec().

◆ pickup_by_group()

static int pickup_by_group ( struct ast_channel chan)
static

< Potential pickup target

Definition at line 308 of file app_directed_pickup.c.

309 {
310  struct ast_channel *target;/*!< Potential pickup target */
311  int res = -1;
312 
313  /* The found channel is already locked. */
314  target = ast_pickup_find_by_group(chan);
315  if (target) {
316  ast_log(LOG_NOTICE, "pickup %s attempt by %s\n", ast_channel_name(target), ast_channel_name(chan));
317  res = ast_do_pickup(chan, target);
318  ast_channel_unlock(target);
319  target = ast_channel_unref(target);
320  }
321 
322  return res;
323 }
struct ast_channel * ast_pickup_find_by_group(struct ast_channel *chan)
Find a pickup channel target by group.
Definition: pickup.c:133

References ast_channel_name(), ast_channel_unlock, ast_channel_unref, ast_do_pickup(), ast_log, ast_pickup_find_by_group(), and LOG_NOTICE.

Referenced by pickup_exec().

◆ pickup_by_mark()

static int pickup_by_mark ( struct ast_channel chan,
const char *  mark 
)
static

< Potential pickup target

Definition at line 292 of file app_directed_pickup.c.

293 {
294  struct ast_channel *target;/*!< Potential pickup target */
295  int res = -1;
296 
297  /* The found channel is already locked. */
298  target = ast_channel_callback(find_by_mark, chan, (char *) mark, 0);
299  if (target) {
300  res = ast_do_pickup(chan, target);
301  ast_channel_unlock(target);
302  target = ast_channel_unref(target);
303  }
304 
305  return res;
306 }
static int find_by_mark(void *obj, void *arg, void *data, int flags)

References ast_channel_callback(), ast_channel_unlock, ast_channel_unref, ast_do_pickup(), and find_by_mark().

Referenced by pickup_exec().

◆ pickup_by_part()

static int pickup_by_part ( struct ast_channel chan,
const char *  part 
)
static

< Potential pickup target

Definition at line 395 of file app_directed_pickup.c.

396 {
397  struct ast_channel *target;/*!< Potential pickup target */
398  int res = -1;
399 
400  /* The found channel is already locked. */
401  target = find_by_part(chan, part);
402  if (target) {
403  res = ast_do_pickup(chan, target);
404  ast_channel_unlock(target);
405  target = ast_channel_unref(target);
406  }
407 
408  return res;
409 }
static struct ast_channel * find_by_part(struct ast_channel *chan, const char *part)

References ast_channel_unlock, ast_channel_unref, ast_do_pickup(), and find_by_part().

Referenced by pickupchan_exec().

◆ pickup_exec()

static int pickup_exec ( struct ast_channel chan,
const char *  data 
)
static

Definition at line 326 of file app_directed_pickup.c.

327 {
328  char *parse;
329  char *exten;
330  char *context;
331 
332  if (ast_strlen_zero(data)) {
333  return pickup_by_group(chan) ? 0 : -1;
334  }
335 
336  /* Parse extension (and context if there) */
337  parse = ast_strdupa(data);
338  for (;;) {
339  if (ast_strlen_zero(parse)) {
340  break;
341  }
342  exten = strsep(&parse, "&");
343  if (ast_strlen_zero(exten)) {
344  continue;
345  }
346 
347  context = strchr(exten, '@');
348  if (context) {
349  *context++ = '\0';
350  }
351  if (!ast_strlen_zero(context) && !strcasecmp(context, PICKUPMARK)) {
352  if (!pickup_by_mark(chan, exten)) {
353  /* Pickup successful. Stop the dialplan this channel is a zombie. */
354  return -1;
355  }
356  } else {
357  if (ast_strlen_zero(context)) {
358  context = (char *) ast_channel_context(chan);
359  }
360  if (!pickup_by_exten(chan, exten, context)) {
361  /* Pickup successful. Stop the dialplan this channel is a zombie. */
362  return -1;
363  }
364  }
365  ast_log(LOG_NOTICE, "No target channel found for %s@%s.\n", exten, context);
366  }
367 
368  /* Pickup failed. Keep going in the dialplan. */
369  return 0;
370 }
static int pickup_by_exten(struct ast_channel *chan, const char *exten, const char *context)
static int pickup_by_mark(struct ast_channel *chan, const char *mark)
static int pickup_by_group(struct ast_channel *chan)
#define ast_strdupa(s)
duplicate a string in memory from the stack
Definition: astmm.h:298
static void parse(struct mgcp_request *req)
Definition: chan_mgcp.c:1844
const char * ast_channel_context(const struct ast_channel *chan)
char * strsep(char **str, const char *delims)
static force_inline int attribute_pure ast_strlen_zero(const char *s)
Definition: strings.h:65

References ast_channel_context(), ast_log, ast_strdupa, ast_strlen_zero(), context, ast_channel::data, exten, LOG_NOTICE, parse(), pickup_by_exten(), pickup_by_group(), pickup_by_mark(), PICKUPMARK, and strsep().

◆ pickupchan_exec()

static int pickupchan_exec ( struct ast_channel chan,
const char *  data 
)
static

Definition at line 420 of file app_directed_pickup.c.

421 {
422  char *pickup = NULL;
423  char *parse = ast_strdupa(data);
425  AST_APP_ARG(channel);
427  AST_APP_ARG(other); /* Any remining unused arguments */
428  );
429  struct ast_flags opts;
430 
432 
433  if (ast_strlen_zero(args.channel)) {
434  ast_log(LOG_WARNING, "PickupChan requires an argument (channel)!\n");
435  /* Pickup failed. Keep going in the dialplan. */
436  return 0;
437  }
438  if (ast_app_parse_options(pickupchan_opts, &opts, NULL, args.options)) {
439  /*
440  * General invalid option syntax.
441  * Pickup failed. Keep going in the dialplan.
442  */
443  return 0;
444  }
445 
446  /* Parse channel */
447  for (;;) {
448  if (ast_strlen_zero(args.channel)) {
449  break;
450  }
451  pickup = strsep(&args.channel, "&");
452  if (ast_strlen_zero(pickup)) {
453  continue;
454  }
455 
457  if (!pickup_by_part(chan, pickup)) {
458  /* Pickup successful. Stop the dialplan this channel is a zombie. */
459  return -1;
460  }
461  } else if (!pickup_by_channel(chan, pickup)) {
462  /* Pickup successful. Stop the dialplan this channel is a zombie. */
463  return -1;
464  }
465  ast_log(LOG_NOTICE, "No target channel found for %s.\n", pickup);
466  }
467 
468  /* Pickup failed. Keep going in the dialplan. */
469  return 0;
470 }
static int pickup_by_part(struct ast_channel *chan, const char *part)
static const struct ast_app_option pickupchan_opts[128]
static int pickup_by_channel(struct ast_channel *chan, const char *name)
Attempt to pick up named channel.
#define AST_APP_ARG(name)
Define an application argument.
#define AST_DECLARE_APP_ARGS(name, arglist)
Declare a structure to hold an application's arguments.
#define AST_STANDARD_APP_ARGS(args, parse)
Performs the 'standard' argument separation process for an application.
int ast_app_parse_options(const struct ast_app_option *options, struct ast_flags *flags, char **args, char *optstr)
Parses a string containing application options and sets flags/arguments.
Definition: main/app.c:3126
#define LOG_WARNING
Structure used to handle boolean flags.
Definition: utils.h:199
static struct test_options options
#define ast_test_flag(p, flag)
Definition: utils.h:63

References args, AST_APP_ARG, ast_app_parse_options(), AST_DECLARE_APP_ARGS, ast_log, AST_STANDARD_APP_ARGS, ast_strdupa, ast_strlen_zero(), ast_test_flag, ast_channel::data, LOG_NOTICE, LOG_WARNING, NULL, OPT_PICKUPCHAN_PARTIAL, options, parse(), pickup_by_channel(), pickup_by_part(), pickupchan_opts, and strsep().

◆ unload_module()

static int unload_module ( void  )
static

Definition at line 472 of file app_directed_pickup.c.

473 {
474  int res;
475 
478 
479  return res;
480 }
int ast_unregister_application(const char *app)
Unregister an application.
Definition: pbx_app.c:392

References app, app2, and ast_unregister_application().

Variable Documentation

◆ __mod_info

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "Directed Call Pickup Application" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_DEFAULT, .support_level = AST_MODULE_SUPPORT_CORE, }
static

Definition at line 482 of file app_directed_pickup.c.

◆ app

const char app[] = "Pickup"
static

Definition at line 125 of file app_directed_pickup.c.

Referenced by unload_module().

◆ app2

const char app2[] = "PickupChan"
static

Definition at line 126 of file app_directed_pickup.c.

Referenced by unload_module().

◆ ast_module_info

const struct ast_module_info* ast_module_info = &__mod_info
static

Definition at line 492 of file app_directed_pickup.c.

◆ pickupchan_opts

const struct ast_app_option pickupchan_opts[128] = { [ 'p' ] = { .flag = OPT_PICKUPCHAN_PARTIAL }, }
static

Definition at line 395 of file app_directed_pickup.c.

Referenced by pickupchan_exec().