main/autoservice.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2006, Digium, Inc.
   5  *
   6  * Mark Spencer <markster@digium.com>
   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 Automatic channel service routines
  22  *
  23  * \author Mark Spencer <markster@digium.com>
  24  */
  25
  26 #include "asterisk.h"
  27
  28 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  29
  30 #include <sys/time.h>
  31 #include <signal.h>
  32
  33 #include "asterisk/pbx.h"
  34 #include "asterisk/frame.h"
  35 #include "asterisk/sched.h"
  36 #include "asterisk/channel.h"
  37 #include "asterisk/file.h"
  38 #include "asterisk/translate.h"
  39 #include "asterisk/manager.h"
  40 #include "asterisk/chanvars.h"
  41 #include "asterisk/linkedlists.h"
  42 #include "asterisk/indications.h"
  43 #include "asterisk/lock.h"
  44 #include "asterisk/utils.h"
  45
  46 #define MAX_AUTOMONS 256
  47
  48 struct asent {
  49         struct ast_channel *chan;
  50         /*! This gets incremented each time autoservice gets started on the same
  51          *  channel.  It will ensure that it doesn't actually get stopped until
  52          *  it gets stopped for the last time. */
  53         unsigned int use_count;
  54         unsigned int orig_end_dtmf_flag:1;
  55         AST_LIST_HEAD_NOLOCK(, ast_frame) dtmf_frames;
  56         AST_LIST_ENTRY(asent) list;
  57 };
  58
  59 static AST_RWLIST_HEAD_STATIC(aslist, asent);
  60
  61 static pthread_t asthread = AST_PTHREADT_NULL;
  62
  63 static void defer_frame(struct ast_channel *chan, struct ast_frame *f)
  64 {
  65         struct ast_frame *dup_f;
  66         struct asent *as;
  67
  68         AST_RWLIST_WRLOCK(&aslist);
  69         AST_RWLIST_TRAVERSE(&aslist, as, list) {
  70                 if (as->chan != chan)
  71                         continue;
  72                 if ((dup_f = ast_frdup(f)))
  73                         AST_LIST_INSERT_TAIL(&as->dtmf_frames, dup_f, frame_list);
  74         }
  75         AST_RWLIST_UNLOCK(&aslist);
  76 }
  77
  78 static void *autoservice_run(void *ign)
  79 {
  80         for (;;) {
  81                 struct ast_channel *mons[MAX_AUTOMONS], *chan;
  82                 struct asent *as;
  83                 int x = 0, ms = 500;
  84
  85                 AST_RWLIST_RDLOCK(&aslist);
  86                 AST_RWLIST_TRAVERSE(&aslist, as, list) {
  87                         if (!ast_check_hangup(as->chan)) {
  88                                 if (x < MAX_AUTOMONS)
  89                                         mons[x++] = as->chan;
  90                                 else
  91                                         ast_log(LOG_WARNING, "Exceeded maximum number of automatic monitoring events.  Fix autoservice.c\n");
  92                         }
  93                 }
  94                 AST_RWLIST_UNLOCK(&aslist);
  95
  96                 if ((chan = ast_waitfor_n(mons, x, &ms))) {
  97                         struct ast_frame *f = ast_read(chan);
  98
  99                         if (!f) {
 100                                 struct ast_frame hangup_frame = { 0, };
 101                                 /* No frame means the channel has been hung up.
 102                                  * A hangup frame needs to be queued here as ast_waitfor() may
 103                                  * never return again for the condition to be detected outside
 104                                  * of autoservice.  So, we'll leave a HANGUP queued up so the
 105                                  * thread in charge of this channel will know. */
 106
 107                                 hangup_frame.frametype = AST_FRAME_CONTROL;
 108                                 hangup_frame.subclass = AST_CONTROL_HANGUP;
 109
 110                                 defer_frame(chan, &hangup_frame);
 111
 112                                 continue;
 113                         }
 114
 115                         /* Do not add a default entry in this switch statement.  Each new
 116                          * frame type should be addressed directly as to whether it should
 117                          * be queued up or not. */
 118                         switch (f->frametype) {
 119                         /* Save these frames */
 120                         case AST_FRAME_DTMF_END:
 121                         case AST_FRAME_CONTROL:
 122                         case AST_FRAME_TEXT:
 123                         case AST_FRAME_IMAGE:
 124                         case AST_FRAME_HTML:
 125                                 defer_frame(chan, f);
 126                                 break;
 127
 128                         /* Throw these frames away */
 129                         case AST_FRAME_DTMF_BEGIN:
 130                         case AST_FRAME_VOICE:
 131                         case AST_FRAME_VIDEO:
 132                         case AST_FRAME_NULL:
 133                         case AST_FRAME_IAX:
 134                         case AST_FRAME_CNG:
 135                         case AST_FRAME_MODEM:
 136                                 break;
 137                         }
 138
 139                         if (f)
 140                                 ast_frfree(f);
 141                 }
 142         }
 143
 144         asthread = AST_PTHREADT_NULL;
 145
 146         return NULL;
 147 }
 148
 149 int ast_autoservice_start(struct ast_channel *chan)
 150 {
 151         int res = 0;
 152         struct asent *as;
 153
 154         AST_RWLIST_WRLOCK(&aslist);
 155         AST_RWLIST_TRAVERSE(&aslist, as, list) {
 156                 if (as->chan == chan) {
 157                         as->use_count++;
 158                         break;
 159                 }
 160         }
 161         AST_RWLIST_UNLOCK(&aslist);
 162
 163         if (as) {
 164                 /* Entry exists, autoservice is already handling this channel */
 165                 return 0;
 166         }
 167
 168         if (!(as = ast_calloc(1, sizeof(*as))))
 169                 return -1;
 170
 171         /* New entry created */
 172         as->chan = chan;
 173         as->use_count = 1;
 174
 175         ast_channel_lock(chan);
 176         as->orig_end_dtmf_flag = ast_test_flag(chan, AST_FLAG_END_DTMF_ONLY) ? 1 : 0;
 177         if (!as->orig_end_dtmf_flag)
 178                 ast_set_flag(chan, AST_FLAG_END_DTMF_ONLY);
 179         ast_channel_unlock(chan);
 180
 181         AST_RWLIST_WRLOCK(&aslist);
 182         AST_RWLIST_INSERT_HEAD(&aslist, as, list);
 183         AST_RWLIST_UNLOCK(&aslist);
 184
 185         if (asthread == AST_PTHREADT_NULL) { /* need start the thread */
 186                 if (ast_pthread_create_background(&asthread, NULL, autoservice_run, NULL)) {
 187                         ast_log(LOG_WARNING, "Unable to create autoservice thread :(\n");
 188                         /* There will only be a single member in the list at this point,
 189                            the one we just added. */
 190                         AST_RWLIST_WRLOCK(&aslist);
 191                         AST_RWLIST_REMOVE(&aslist, as, list);
 192                         AST_RWLIST_UNLOCK(&aslist);
 193                         free(as);
 194                         res = -1;
 195                 } else
 196                         pthread_kill(asthread, SIGURG);
 197         }
 198
 199         return res;
 200 }
 201
 202 int ast_autoservice_stop(struct ast_channel *chan)
 203 {
 204         int res = -1;
 205         struct asent *as;
 206         AST_LIST_HEAD_NOLOCK(, ast_frame) dtmf_frames;
 207         struct ast_frame *f;
 208         int removed = 0;
 209         int orig_end_dtmf_flag = 0;
 210
 211         AST_LIST_HEAD_INIT_NOLOCK(&dtmf_frames);
 212
 213         AST_RWLIST_WRLOCK(&aslist);
 214         AST_RWLIST_TRAVERSE_SAFE_BEGIN(&aslist, as, list) {
 215                 if (as->chan == chan) {
 216                         AST_RWLIST_REMOVE_CURRENT(list);
 217                         as->use_count--;
 218                         if (as->use_count)
 219                                 break;
 220                         AST_LIST_APPEND_LIST(&dtmf_frames, &as->dtmf_frames, frame_list);
 221                         orig_end_dtmf_flag = as->orig_end_dtmf_flag;
 222                         ast_free(as);
 223                         removed = 1;
 224                         if (!ast_check_hangup(chan))
 225                                 res = 0;
 226                         break;
 227                 }
 228         }
 229         AST_RWLIST_TRAVERSE_SAFE_END;
 230
 231         if (removed && asthread != AST_PTHREADT_NULL)
 232                 pthread_kill(asthread, SIGURG);
 233
 234         AST_RWLIST_UNLOCK(&aslist);
 235
 236         if (!removed)
 237                 return 0;
 238
 239         if (!orig_end_dtmf_flag)
 240                 ast_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
 241
 242         /* Wait for it to un-block */
 243         while (ast_test_flag(chan, AST_FLAG_BLOCKING))
 244                 usleep(1000);
 245
 246         while ((f = AST_LIST_REMOVE_HEAD(&dtmf_frames, frame_list))) {
 247                 ast_queue_frame(chan, f);
 248                 ast_frfree(f);
 249         }
 250
 251         return res;
 252 }