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         AST_LIST_HEAD_NOLOCK(, ast_frame) dtmf_frames;
  55         AST_LIST_ENTRY(asent) list;
  56 };
  57
  58 static AST_RWLIST_HEAD_STATIC(aslist, asent);
  59
  60 static pthread_t asthread = AST_PTHREADT_NULL;
  61
  62 static void defer_frame(struct ast_channel *chan, struct ast_frame *f)
  63 {
  64         struct ast_frame *dup_f;
  65         struct asent *as;
  66
  67         AST_RWLIST_WRLOCK(&aslist);
  68         AST_RWLIST_TRAVERSE(&aslist, as, list) {
  69                 if (as->chan != chan)
  70                         continue;
  71                 if ((dup_f = ast_frdup(f)))
  72                         AST_LIST_INSERT_TAIL(&as->dtmf_frames, dup_f, frame_list);
  73         }
  74         AST_RWLIST_UNLOCK(&aslist);
  75 }
  76
  77 static void *autoservice_run(void *ign)
  78 {
  79         for (;;) {
  80                 struct ast_channel *mons[MAX_AUTOMONS], *chan;
  81                 struct asent *as;
  82                 int x = 0, ms = 500;
  83
  84                 AST_RWLIST_RDLOCK(&aslist);
  85                 AST_RWLIST_TRAVERSE(&aslist, as, list) {
  86                         if (!ast_check_hangup(as->chan)) {
  87                                 if (x < MAX_AUTOMONS)
  88                                         mons[x++] = as->chan;
  89                                 else
  90                                         ast_log(LOG_WARNING, "Exceeded maximum number of automatic monitoring events.  Fix autoservice.c\n");
  91                         }
  92                 }
  93                 AST_RWLIST_UNLOCK(&aslist);
  94
  95                 if ((chan = ast_waitfor_n(mons, x, &ms))) {
  96                         struct ast_frame *f = ast_read(chan);
  97
  98                         if (!f) {
  99                                 struct ast_frame hangup_frame = { 0, };
 100                                 /* No frame means the channel has been hung up.
 101                                  * A hangup frame needs to be queued here as ast_waitfor() may
 102                                  * never return again for the condition to be detected outside
 103                                  * of autoservice.  So, we'll leave a HANGUP queued up so the
 104                                  * thread in charge of this channel will know. */
 105
 106                                 hangup_frame.frametype = AST_FRAME_CONTROL;
 107                                 hangup_frame.subclass = AST_CONTROL_HANGUP;
 108
 109                                 defer_frame(chan, &hangup_frame);
 110
 111                                 continue;
 112                         }
 113
 114                         /* Do not add a default entry in this switch statement.  Each new
 115                          * frame type should be addressed directly as to whether it should
 116                          * be queued up or not. */
 117                         switch (f->frametype) {
 118                         /* Save these frames */
 119                         case AST_FRAME_DTMF_BEGIN:
 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_VOICE:
 130                         case AST_FRAME_VIDEO:
 131                         case AST_FRAME_NULL:
 132                         case AST_FRAME_IAX:
 133                         case AST_FRAME_CNG:
 134                         case AST_FRAME_MODEM:
 135                                 break;
 136                         }
 137
 138                         if (f)
 139                                 ast_frfree(f);
 140                 }
 141         }
 142
 143         asthread = AST_PTHREADT_NULL;
 144
 145         return NULL;
 146 }
 147
 148 int ast_autoservice_start(struct ast_channel *chan)
 149 {
 150         int res = 0;
 151         struct asent *as;
 152
 153         AST_RWLIST_WRLOCK(&aslist);
 154
 155         /* Check if the channel already has autoservice */
 156         AST_RWLIST_TRAVERSE(&aslist, as, list) {
 157                 if (as->chan == chan) {
 158                         as->use_count++;
 159                         break;
 160                 }
 161         }
 162
 163         /* If not, start autoservice on channel */
 164         if (as) {
 165                 /* Entry extist, autoservice is already handling this channel */
 166         } else if ((as = ast_calloc(1, sizeof(*as))) == NULL) {
 167                 /* Memory allocation failed */
 168                 res = -1;
 169         } else {
 170                 /* New entry created */
 171                 as->chan = chan;
 172                 as->use_count = 1;
 173                 AST_RWLIST_INSERT_HEAD(&aslist, as, list);
 174                 if (asthread == AST_PTHREADT_NULL) { /* need start the thread */
 175                         if (ast_pthread_create_background(&asthread, NULL, autoservice_run, NULL)) {
 176                                 ast_log(LOG_WARNING, "Unable to create autoservice thread :(\n");
 177                                 /* There will only be a single member in the list at this point,
 178                                    the one we just added. */
 179                                 AST_RWLIST_REMOVE(&aslist, as, list);
 180                                 ast_free(as);
 181                                 res = -1;
 182                         } else
 183                                 pthread_kill(asthread, SIGURG);
 184                 }
 185         }
 186
 187         AST_RWLIST_UNLOCK(&aslist);
 188
 189         return res;
 190 }
 191
 192 int ast_autoservice_stop(struct ast_channel *chan)
 193 {
 194         int res = -1;
 195         struct asent *as;
 196         AST_LIST_HEAD_NOLOCK(, ast_frame) dtmf_frames;
 197         struct ast_frame *f;
 198         int removed = 0;
 199
 200         AST_LIST_HEAD_INIT_NOLOCK(&dtmf_frames);
 201
 202         AST_RWLIST_WRLOCK(&aslist);
 203         AST_RWLIST_TRAVERSE_SAFE_BEGIN(&aslist, as, list) {
 204                 if (as->chan == chan) {
 205                         AST_RWLIST_REMOVE_CURRENT(list);
 206                         as->use_count--;
 207                         if (as->use_count)
 208                                 break;
 209                         AST_LIST_APPEND_LIST(&dtmf_frames, &as->dtmf_frames, frame_list);
 210                         ast_free(as);
 211                         removed = 1;
 212                         if (!ast_check_hangup(chan))
 213                                 res = 0;
 214                         break;
 215                 }
 216         }
 217         AST_RWLIST_TRAVERSE_SAFE_END;
 218
 219         if (removed && asthread != AST_PTHREADT_NULL)
 220                 pthread_kill(asthread, SIGURG);
 221
 222         AST_RWLIST_UNLOCK(&aslist);
 223
 224         if (!removed)
 225                 return 0;
 226
 227         /* Wait for it to un-block */
 228         while (ast_test_flag(chan, AST_FLAG_BLOCKING))
 229                 usleep(1000);
 230
 231         while ((f = AST_LIST_REMOVE_HEAD(&dtmf_frames, frame_list))) {
 232                 ast_queue_frame(chan, f);
 233                 ast_frfree(f);
 234         }
 235
 236         return res;
 237 }