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                                 /* NULL means we got a hangup*/
  86                                 ast_queue_hangup(chan);
  87                                 continue;
  88                         }
  89
  90                         /* Do not add a default entry in this switch statement.  Each new
  91                          * frame type should be addressed directly as to whether it should
  92                          * be queued up or not. */
  93                         switch (f->frametype) {
  94                         /* Save these frames */
  95                         case AST_FRAME_DTMF_BEGIN:
  96                         case AST_FRAME_DTMF_END:
  97                         case AST_FRAME_CONTROL:
  98                         case AST_FRAME_TEXT:
  99                         case AST_FRAME_IMAGE:
 100                         case AST_FRAME_HTML:
 101                         {
 102                                 struct ast_frame *dup_f;
 103
 104                                 AST_RWLIST_WRLOCK(&aslist);
 105                                 AST_RWLIST_TRAVERSE(&aslist, as, list) {
 106                                         if (as->chan != chan)
 107                                                 continue;
 108                                         if ((dup_f = ast_frdup(f)))
 109                                                 AST_LIST_INSERT_TAIL(&as->dtmf_frames, dup_f, frame_list);
 110                                 }
 111                                 AST_RWLIST_UNLOCK(&aslist);
 112                         }
 113
 114                         /* Throw these frames away */
 115                         case AST_FRAME_VOICE:
 116                         case AST_FRAME_VIDEO:
 117                         case AST_FRAME_NULL:
 118                         case AST_FRAME_IAX:
 119                         case AST_FRAME_CNG:
 120                         case AST_FRAME_MODEM:
 121                                 break;
 122                         }
 123
 124                         if (f)
 125                                 ast_frfree(f);
 126                 }
 127         }
 128
 129         asthread = AST_PTHREADT_NULL;
 130
 131         return NULL;
 132 }
 133
 134 int ast_autoservice_start(struct ast_channel *chan)
 135 {
 136         int res = 0;
 137         struct asent *as;
 138
 139         AST_RWLIST_WRLOCK(&aslist);
 140
 141         /* Check if the channel already has autoservice */
 142         AST_RWLIST_TRAVERSE(&aslist, as, list) {
 143                 if (as->chan == chan) {
 144                         as->use_count++;
 145                         break;
 146                 }
 147         }
 148
 149         /* If not, start autoservice on channel */
 150         if (as) {
 151                 /* Entry extist, autoservice is already handling this channel */
 152         } else if ((as = ast_calloc(1, sizeof(*as))) == NULL) {
 153                 /* Memory allocation failed */
 154                 res = -1;
 155         } else {
 156                 /* New entry created */
 157                 as->chan = chan;
 158                 as->use_count = 1;
 159                 AST_RWLIST_INSERT_HEAD(&aslist, as, list);
 160                 if (asthread == AST_PTHREADT_NULL) { /* need start the thread */
 161                         if (ast_pthread_create_background(&asthread, NULL, autoservice_run, NULL)) {
 162                                 ast_log(LOG_WARNING, "Unable to create autoservice thread :(\n");
 163                                 /* There will only be a single member in the list at this point,
 164                                    the one we just added. */
 165                                 AST_RWLIST_REMOVE(&aslist, as, list);
 166                                 ast_free(as);
 167                                 res = -1;
 168                         } else
 169                                 pthread_kill(asthread, SIGURG);
 170                 }
 171         }
 172
 173         AST_RWLIST_UNLOCK(&aslist);
 174
 175         return res;
 176 }
 177
 178 int ast_autoservice_stop(struct ast_channel *chan)
 179 {
 180         int res = -1;
 181         struct asent *as;
 182         AST_LIST_HEAD_NOLOCK(, ast_frame) dtmf_frames;
 183         struct ast_frame *f;
 184         int removed = 0;
 185
 186         AST_LIST_HEAD_INIT_NOLOCK(&dtmf_frames);
 187
 188         AST_RWLIST_WRLOCK(&aslist);
 189         AST_RWLIST_TRAVERSE_SAFE_BEGIN(&aslist, as, list) {
 190                 if (as->chan == chan) {
 191                         AST_RWLIST_REMOVE_CURRENT(list);
 192                         as->use_count--;
 193                         if (as->use_count)
 194                                 break;
 195                         AST_LIST_APPEND_LIST(&dtmf_frames, &as->dtmf_frames, frame_list);
 196                         ast_free(as);
 197                         removed = 1;
 198                         if (!ast_check_hangup(chan))
 199                                 res = 0;
 200                         break;
 201                 }
 202         }
 203         AST_RWLIST_TRAVERSE_SAFE_END;
 204
 205         if (removed && asthread != AST_PTHREADT_NULL)
 206                 pthread_kill(asthread, SIGURG);
 207
 208         AST_RWLIST_UNLOCK(&aslist);
 209
 210         if (!removed)
 211                 return 0;
 212
 213         /* Wait for it to un-block */
 214         while (ast_test_flag(chan, AST_FLAG_BLOCKING))
 215                 usleep(1000);
 216
 217         while ((f = AST_LIST_REMOVE_HEAD(&dtmf_frames, frame_list))) {
 218                 ast_queue_frame(chan, f);
 219                 ast_frfree(f);
 220         }
 221
 222         return res;
 223 }