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 *autoservice_run(void *ign)
  63 {
  64
  65         for (;;) {
  66                 struct ast_channel *mons[MAX_AUTOMONS], *chan;
  67                 struct asent *as;
  68                 int x = 0, ms = 500;
  69
  70                 AST_RWLIST_RDLOCK(&aslist);
  71                 AST_RWLIST_TRAVERSE(&aslist, as, list) {
  72                         if (!ast_check_hangup(as->chan)) {
  73                                 if (x < MAX_AUTOMONS)
  74                                         mons[x++] = as->chan;
  75                                 else
  76                                         ast_log(LOG_WARNING, "Exceeded maximum number of automatic monitoring events.  Fix autoservice.c\n");
  77                         }
  78                 }
  79                 AST_RWLIST_UNLOCK(&aslist);
  80
  81                 if ((chan = ast_waitfor_n(mons, x, &ms))) {
  82                         struct ast_frame *f = ast_read(chan);
  83
  84                         if (!f)
  85                                 continue;
  86
  87                         /* Do not add a default entry in this switch statement.  Each new
  88                          * frame type should be addressed directly as to whether it should
  89                          * be queued up or not. */
  90                         switch (f->frametype) {
  91                         /* Save these frames */
  92                         case AST_FRAME_DTMF_BEGIN:
  93                         case AST_FRAME_DTMF_END:
  94                         case AST_FRAME_CONTROL:
  95                         case AST_FRAME_TEXT:
  96                         case AST_FRAME_IMAGE:
  97                         case AST_FRAME_HTML:
  98                         {
  99                                 struct ast_frame *dup_f;
 100
 101                                 AST_RWLIST_WRLOCK(&aslist);
 102                                 AST_RWLIST_TRAVERSE(&aslist, as, list) {
 103                                         if (as->chan != chan)
 104                                                 continue;
 105                                         if ((dup_f = ast_frdup(f)))
 106                                                 AST_LIST_INSERT_TAIL(&as->dtmf_frames, dup_f, frame_list);
 107                                 }
 108                                 AST_RWLIST_UNLOCK(&aslist);
 109                         }
 110
 111                         /* Throw these frames away */
 112                         case AST_FRAME_VOICE:
 113                         case AST_FRAME_VIDEO:
 114                         case AST_FRAME_NULL:
 115                         case AST_FRAME_IAX:
 116                         case AST_FRAME_CNG:
 117                         case AST_FRAME_MODEM:
 118                                 break;
 119                         }
 120
 121                         if (f)
 122                                 ast_frfree(f);
 123                 }
 124         }
 125
 126         asthread = AST_PTHREADT_NULL;
 127
 128         return NULL;
 129 }
 130
 131 int ast_autoservice_start(struct ast_channel *chan)
 132 {
 133         int res = 0;
 134         struct asent *as;
 135
 136         AST_RWLIST_WRLOCK(&aslist);
 137
 138         /* Check if the channel already has autoservice */
 139         AST_RWLIST_TRAVERSE(&aslist, as, list) {
 140                 if (as->chan == chan) {
 141                         as->use_count++;
 142                         break;
 143                 }
 144         }
 145
 146         /* If not, start autoservice on channel */
 147         if (as) {
 148                 /* Entry extist, autoservice is already handling this channel */
 149         } else if ((as = ast_calloc(1, sizeof(*as))) == NULL) {
 150                 /* Memory allocation failed */
 151                 res = -1;
 152         } else {
 153                 /* New entry created */
 154                 as->chan = chan;
 155                 as->use_count = 1;
 156                 AST_RWLIST_INSERT_HEAD(&aslist, as, list);
 157                 if (asthread == AST_PTHREADT_NULL) { /* need start the thread */
 158                         if (ast_pthread_create_background(&asthread, NULL, autoservice_run, NULL)) {
 159                                 ast_log(LOG_WARNING, "Unable to create autoservice thread :(\n");
 160                                 /* There will only be a single member in the list at this point,
 161                                    the one we just added. */
 162                                 AST_RWLIST_REMOVE(&aslist, as, list);
 163                                 ast_free(as);
 164                                 res = -1;
 165                         } else
 166                                 pthread_kill(asthread, SIGURG);
 167                 }
 168         }
 169
 170         AST_RWLIST_UNLOCK(&aslist);
 171
 172         return res;
 173 }
 174
 175 int ast_autoservice_stop(struct ast_channel *chan)
 176 {
 177         int res = -1;
 178         struct asent *as;
 179         AST_LIST_HEAD_NOLOCK(, ast_frame) dtmf_frames;
 180         struct ast_frame *f;
 181         int removed = 0;
 182
 183         AST_LIST_HEAD_INIT_NOLOCK(&dtmf_frames);
 184
 185         AST_RWLIST_WRLOCK(&aslist);
 186         AST_RWLIST_TRAVERSE_SAFE_BEGIN(&aslist, as, list) {
 187                 if (as->chan == chan) {
 188                         AST_RWLIST_REMOVE_CURRENT(list);
 189                         as->use_count--;
 190                         if (as->use_count)
 191                                 break;
 192                         AST_LIST_APPEND_LIST(&dtmf_frames, &as->dtmf_frames, frame_list);
 193                         ast_free(as);
 194                         removed = 1;
 195                         if (!ast_check_hangup(chan))
 196                                 res = 0;
 197                         break;
 198                 }
 199         }
 200         AST_RWLIST_TRAVERSE_SAFE_END;
 201
 202         if (removed && asthread != AST_PTHREADT_NULL)
 203                 pthread_kill(asthread, SIGURG);
 204
 205         AST_RWLIST_UNLOCK(&aslist);
 206
 207         if (!removed)
 208                 return 0;
 209
 210         /* Wait for it to un-block */
 211         while (ast_test_flag(chan, AST_FLAG_BLOCKING))
 212                 usleep(1000);
 213
 214         while ((f = AST_LIST_REMOVE_HEAD(&dtmf_frames, frame_list))) {
 215                 ast_queue_frame(chan, f);
 216                 ast_frfree(f);
 217         }
 218
 219         return res;
 220 }