res_fax: Add T.38 negotiation timeout option

This change makes the T.38 negotiation timeout configurable via
't38timeout' in res_fax.conf or FAXOPT(t38timeout). It was previously
hard coded to be 5000 milliseconds.

This change also handles T.38 switch failures by aborting the fax since
in the case where this can happen, both sides have agreed to switch to
T.38 and Asterisk is unable to do so.

Review: https://reviewboard.asterisk.org/r/4320/

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@430415 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/CHANGES b/CHANGES
index 6fd5cee1610705e96730d5a89209274bb94b86fe..449c2e75bbe321df77bc3b1245448fe7880fa0b8 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -8,6 +8,17 @@
 ===
 ==============================================================================
 
+------------------------------------------------------------------------------
+--- Functionality changes since Asterisk 11.15 --------------------------------
+------------------------------------------------------------------------------
+
+res_fax
+-----------
+ * The T.38 negotiation timeout was previously hard coded at 5000 milliseconds
+   and is now configurable via the 't38timeout' configuration option in
+   res_fax.conf and via the fax options dialplan function 'FAXOPT(t38timeout)'.
+   The default remains at 5000 milliseconds.
+
 ------------------------------------------------------------------------------
 --- Functionality changes since Asterisk 11.8 --------------------------------
 ------------------------------------------------------------------------------

diff --git a/configs/res_fax.conf.sample b/configs/res_fax.conf.sample
index dfaa4ce93bddbfb405e8133e176debc0776fe645..022a23aad1e0584a69ef73e6bf1884392645dc4b 100644 (file)
--- a/configs/res_fax.conf.sample
+++ b/configs/res_fax.conf.sample
@@ -26,3 +26,7 @@ statusevents=yes
 ; Enable/disable T.30 ECM (error correction mode) by default.
 ; Default: Enabled
 ;ecm=yes
+
+; T.38 Negotiation Timeout in milliseconds
+; Default: 5000
+t38timeout=5000

diff --git a/include/asterisk/res_fax.h b/include/asterisk/res_fax.h
index b397bd44586f92c8c8e8677de344c2d0fb7644f5..5bff3ffa0b62e778dbfaa395b02eac7cd8b92963 100644 (file)
--- a/include/asterisk/res_fax.h
+++ b/include/asterisk/res_fax.h
@@ -174,6 +174,8 @@ struct ast_fax_session_details {
        struct ast_fax_t38_parameters our_t38_parameters;
        /*! the other endpoint's T.38 session parameters, if any */
        struct ast_fax_t38_parameters their_t38_parameters;
+       /*! T.38 negotiation in ms */
+       unsigned int t38timeout;
        /*! the id of the t.38 gateway framehook for this channel */
        int gateway_id;
        /*! the timeout for this gateway in seconds */

diff --git a/res/res_fax.c b/res/res_fax.c
index df7e1374294b87632e86b72861a49dcccb457ad2..55be79fd1229c91cf5f99bc9ff4abbb01bbee953 100644 (file)
--- a/res/res_fax.c
+++ b/res/res_fax.c
@@ -213,6 +213,9 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
                                        <enum name="statusstr">
                                                <para>R/O Verbose Result Status of the FAX transmission.</para>
                                        </enum>
+                                       <enum name="t38timeout">
+                                               <para>R/W The timeout used for T.38 negotiation.</para>
+                                       </enum>
                                </enumlist>
                        </parameter>
                </syntax>
@@ -327,6 +330,7 @@ static AST_RWLIST_HEAD_STATIC(faxmodules, fax_module);
 #define RES_FAX_MAXRATE 14400
 #define RES_FAX_STATUSEVENTS 0
 #define RES_FAX_MODEM (AST_FAX_MODEM_V17 | AST_FAX_MODEM_V27 | AST_FAX_MODEM_V29)
+#define RES_FAX_T38TIMEOUT 5000
 
 struct fax_options {
        enum ast_fax_modems modems;
@@ -334,6 +338,7 @@ struct fax_options {
        uint32_t ecm:1;
        unsigned int minrate;
        unsigned int maxrate;
+       unsigned int t38timeout;
 };
 
 static struct fax_options general_options;
@@ -344,6 +349,7 @@ static const struct fax_options default_options = {
        .statusevents = RES_FAX_STATUSEVENTS,
        .modems = RES_FAX_MODEM,
        .ecm = AST_FAX_OPTFLAG_TRUE,
+       .t38timeout = RES_FAX_T38TIMEOUT,
 };
 
 AST_RWLOCK_DEFINE_STATIC(options_lock);
@@ -489,6 +495,7 @@ static struct ast_fax_session_details *session_details_new(void)
        d->modems = options.modems;
        d->minrate = options.minrate;
        d->maxrate = options.maxrate;
+       d->t38timeout = options.t38timeout;
        d->gateway_id = -1;
        d->faxdetect_id = -1;
        d->gateway_timeout = 0;
@@ -1469,7 +1476,10 @@ static int generic_fax_exec(struct ast_channel *chan, struct ast_fax_session_det
                                        break;
                                }
                                if (t38negotiated && !was_t38) {
-                                       fax->tech->switch_to_t38(fax);
+                                       if (fax->tech->switch_to_t38(fax)) {
+                                               GENERIC_FAX_EXEC_ERROR(fax, chan, "UNKNOWN", "T.38 switch failed");
+                                               break;
+                                       }
                                        details->caps &= ~AST_FAX_TECH_AUDIO;
                                        expected_frametype = AST_FRAME_MODEM;
                                        expected_framesubclass.integer = AST_MODEM_T38;
@@ -1655,8 +1665,8 @@ static int receivefax_t38_init(struct ast_channel *chan, struct ast_fax_session_
        /* request T.38 */
        ast_debug(1, "Negotiating T.38 for receive on %s\n", ast_channel_name(chan));
 
-       /* wait up to five seconds for negotiation to complete */
-       timeout_ms = 5000;
+       /* wait for negotiation to complete */
+       timeout_ms = details->t38timeout;
 
        /* set parameters based on the session's parameters */
        t38_parameters_fax_to_ast(&t38_parameters, &details->our_t38_parameters);
@@ -3631,6 +3641,7 @@ static char *cli_fax_show_settings(struct ast_cli_entry *e, int cmd, struct ast_
        ast_cli(a->fd, "\tMaximum Bit Rate: %u\n", options.maxrate);
        ast_fax_modem_to_str(options.modems, modems, sizeof(modems));
        ast_cli(a->fd, "\tModem Modulations Allowed: %s\n", modems);
+       ast_cli(a->fd, "\tT.38 Negotiation Timeout: %u\n", options.t38timeout);
        ast_cli(a->fd, "\n\nFAX Technology Modules:\n\n");
        AST_RWLIST_RDLOCK(&faxmodules);
        AST_RWLIST_TRAVERSE(&faxmodules, fax, list) {
@@ -3810,6 +3821,23 @@ static void get_general_options(struct fax_options *options)
        ast_rwlock_unlock(&options_lock);
 }
 
+static int set_t38timeout(const char *value, unsigned int *t38timeout)
+{
+       unsigned int timeout;
+
+       if (sscanf(value, "%u", &timeout) != 1) {
+               ast_log(LOG_ERROR, "Unable to get timeout from '%s'\n", value);
+               return -1;
+       } else if (timeout) {
+               *t38timeout = timeout;
+       } else {
+               ast_log(LOG_ERROR, "T.38 negotiation timeout must be non-zero\n");
+               return -1;
+       }
+
+       return 0;
+}
+
 /*! \brief configure res_fax */
 static int set_config(int reload)
 {
@@ -3879,6 +3907,11 @@ static int set_config(int reload)
                } else if ((!strcasecmp(v->name, "modem")) || (!strcasecmp(v->name, "modems"))) {
                        options.modems = 0;
                        update_modem_bits(&options.modems, v->value);
+               } else if (!strcasecmp(v->name, "t38timeout")) {
+                       if (set_t38timeout(v->value, &options.t38timeout)) {
+                               res = -1;
+                               goto end;
+                       }
                }
        }
 
@@ -3978,6 +4011,8 @@ static int acf_faxopt_read(struct ast_channel *chan, const char *cmd, char *data
                ast_copy_string(buf, details->resultstr, len);
        } else if ((!strcasecmp(data, "modem")) || (!strcasecmp(data, "modems"))) {
                ast_fax_modem_to_str(details->modems, buf, len);
+       } else if (!strcasecmp(data, "t38timeout")) {
+               snprintf(buf, len, "%u", details->t38timeout);
        } else {
                ast_log(LOG_WARNING, "channel '%s' can't read FAXOPT(%s) because it is unhandled!\n", ast_channel_name(chan), data);
                res = -1;
@@ -4104,6 +4139,10 @@ static int acf_faxopt_write(struct ast_channel *chan, const char *cmd, char *dat
                if (!details->minrate) {
                        details->minrate = ast_fax_minrate();
                }
+       } else if (!strcasecmp(data, "t38timeout")) {
+               if (set_t38timeout(value, &details->t38timeout)) {
+                       res = -1;
+               }
        } else if ((!strcasecmp(data, "modem")) || (!strcasecmp(data, "modems"))) {
                update_modem_bits(&details->modems, value);
        } else {