]> git.ipfire.org Git - thirdparty/asterisk.git/commitdiff
res_tonedetect: Add call progress tone detection
authorNaveen Albert <asterisk@phreaknet.org>
Sat, 6 Nov 2021 23:35:16 +0000 (23:35 +0000)
committerFriendly Automation <jenkins2@gerrit.asterisk.org>
Fri, 19 Nov 2021 14:09:50 +0000 (08:09 -0600)
Makes basic call progress tone detection available
in a tech-agnostic manner with the addition of the
ToneScan application. This can determine if the channel
has encountered a busy signal, SIT tones, dial tone,
modem, fax machine, etc. A few basic async progress
tone detect options are also added to the TONE_DETECT
function.

ASTERISK-29720 #close

Change-Id: Ia02437e0450473031e294798b8cb421fb8f24e90

doc/CHANGES-staging/tonescan.txt [new file with mode: 0644]
res/res_tonedetect.c

diff --git a/doc/CHANGES-staging/tonescan.txt b/doc/CHANGES-staging/tonescan.txt
new file mode 100644 (file)
index 0000000..cbed34f
--- /dev/null
@@ -0,0 +1,6 @@
+Subject: ToneScan application
+
+A new application, ToneScan, allows for
+synchronous detection of call progress
+signals such as dial tone, busy tone,
+Special Information Tones, and modems.
index 1d5db8334470a27596ab5ae287aef79f2013b978..b65a69b9774c03a812cd5e55e7028989efe2ac1e 100644 (file)
                        <ref type="application">PlayTones</ref>
                </see-also>
        </application>
+       <application name="ToneScan" language="en_US">
+               <synopsis>
+                       Wait for period of time while scanning for call progress tones
+               </synopsis>
+               <syntax>
+                       <parameter name="zone" required="false">
+                               <para>Call progress zone. Default is the system default.</para>
+                       </parameter>
+                       <parameter name="timeout" required="false">
+                               <para>Maximum amount of time, in seconds, to wait for call progress
+                               or signal tones. Default is forever.</para>
+                       </parameter>
+                       <parameter name="threshold" required="false">
+                               <para>DSP threshold required for a match. A higher number will
+                               require a longer match and may reduce false positives, at the
+                               expense of false negatives. Default is 1.</para>
+                       </parameter>
+                       <parameter name="options" required="false">
+                               <optionlist>
+                                       <option name="f">
+                                               <para>Enable fax machine detection. By default, this is disabled.</para>
+                                       </option>
+                                       <option name="v">
+                                               <para>Enable voice detection. By default, this is disabled.</para>
+                                       </option>
+                               </optionlist>
+                       </parameter>
+               </syntax>
+               <description>
+                       <para>Waits for a a distinguishable call progress tone and then exits.
+                       Unlike a conventional scanner, this is not currently capable of
+                       scanning for modem carriers.</para>
+                       <variablelist>
+                       <variable name="TONESCANSTATUS">
+                               This indicates the result of the scan.
+                               <value name="RINGING">
+                                       Audible ringback tone
+                               </value>
+                               <value name="BUSY">
+                                       Busy tone
+                               </value>
+                               <value name="SIT">
+                                       Special Information Tones
+                               </value>
+                               <value name="VOICE">
+                                       Human voice detected
+                               </value>
+                               <value name="DTMF">
+                                       DTMF digit
+                               </value>
+                               <value name="FAX">
+                                       Fax (answering)
+                               </value>
+                               <value name="MODEM">
+                                       Modem (answering)
+                               </value>
+                               <value name="DIALTONE">
+                                       Dial tone
+                               </value>
+                               <value name="NUT">
+                                       UK Number Unobtainable tone
+                               </value>
+                               <value name="TIMEOUT">
+                                       Timeout reached before any positive detection
+                               </value>
+                               <value name="HANGUP">
+                                       Caller hung up before any positive detection
+                               </value>
+                       </variable>
+               </variablelist>
+               </description>
+               <see-also>
+                       <ref type="application">WaitForTone</ref>
+               </see-also>
+       </application>
        <function name="TONE_DETECT" language="en_US">
                <synopsis>
                        Asynchronously detects a tone
                </synopsis>
                <syntax>
                        <parameter name="freq" required="true">
-                               <para>Frequency of the tone to detect.</para>
+                               <para>Frequency of the tone to detect. To disable frequency
+                               detection completely (e.g. for signal detection only),
+                               specify 0 for the frequency.</para>
                        </parameter>
                        <parameter name="duration_ms" required="false">
                                <para>Minimum duration of tone, in ms. Default is 500ms.
                        </parameter>
                        <parameter name="options">
                                <optionlist>
+                                       <option name="a">
+                                               <para>Match immediately on Special Information Tones, instead of or in addition
+                                               to a particular frequency.</para>
+                                       </option>
+                                       <option name="b">
+                                               <para>Match immediately on a busy signal, instead of or in addition to
+                                               a particular frequency.</para>
+                                       </option>
+                                       <option name="c">
+                                               <para>Match immediately on a dial tone, instead of or in addition to
+                                               a particular frequency.</para>
+                                       </option>
                                        <option name="d">
                                                <para>Custom decibel threshold to use. Default is 16.</para>
                                        </option>
                        <literal>rx</literal> to get the number of times a tone has been detected in the
                        RX direction.</para>
                        <example title="intercept2600">
-                       same => n,Set(TONE_DETECT(2600,1000,g(got-2600,s,1))=)
+                       same => n,Set(TONE_DETECT(2600,1000,g(got-2600,s,1))=) ; detect 2600 Hz
                        same => n,Wait(15)
                        same => n,NoOp(${TONE_DETECT(rx)})
                        </example>
+                       <example title="dropondialtone">
+                       same => n,Set(TONE_DETECT(0,,bg(my-hangup,s,1))=) ; disconnect a call if we hear a busy signal
+                       same => n,Goto(somewhere-else)
+                       same => n(myhangup),Hangup()
+                       </example>
+                       <example title="removedetector">
+                       same => n,Set(TONE_DETECT(0,,x)=) ; remove the detector from the channel
+                       </example>
                </description>
        </function>
  ***/
@@ -170,6 +267,7 @@ struct detect_information {
        int txcount;
        int rxcount;
        int hitsrequired;
+       int signalfeatures;
 };
 
 enum td_opts {
@@ -181,6 +279,9 @@ enum td_opts {
        OPT_DECIBEL = (1 << 6),
        OPT_SQUELCH = (1 << 7),
        OPT_HITS_REQ = (1 << 8),
+       OPT_SIT = (1 << 9),
+       OPT_BUSY = (1 << 10),
+       OPT_DIALTONE = (1 << 11),
 };
 
 enum {
@@ -193,6 +294,9 @@ enum {
 };
 
 AST_APP_OPTIONS(td_opts, {
+       AST_APP_OPTION('a', OPT_SIT),
+       AST_APP_OPTION('b', OPT_BUSY),
+       AST_APP_OPTION('c', OPT_DIALTONE),
        AST_APP_OPTION_ARG('d', OPT_DECIBEL, OPT_ARG_DECIBEL),
        AST_APP_OPTION_ARG('g', OPT_GOTO_RX, OPT_ARG_GOTO_RX),
        AST_APP_OPTION_ARG('h', OPT_GOTO_TX, OPT_ARG_GOTO_TX),
@@ -230,6 +334,7 @@ static int detect_callback(struct ast_audiohook *audiohook, struct ast_channel *
 {
        struct ast_datastore *datastore = NULL;
        struct detect_information *di = NULL;
+       int match = 0;
 
        /* If the audiohook is stopping it means the channel is shutting down.... but we let the datastore destroy take care of it */
        if (audiohook->status == AST_AUDIOHOOK_STATUS_DONE) {
@@ -258,6 +363,7 @@ static int detect_callback(struct ast_audiohook *audiohook, struct ast_channel *
                char result = frame->subclass.integer;
                if (result == 'q') {
                        int now;
+                       match = 1;
                        if (direction == AST_AUDIOHOOK_DIRECTION_READ) {
                                di->rxcount = di->rxcount + 1;
                                now = di->rxcount;
@@ -275,6 +381,42 @@ static int detect_callback(struct ast_audiohook *audiohook, struct ast_channel *
                        }
                }
        }
+       if (di->signalfeatures && !match) { /* skip unless there are call progress/signal options */
+               int tstate, tcount;
+               tcount = ast_dsp_get_tcount(di->dsp);
+               tstate = ast_dsp_get_tstate(di->dsp);
+               if (tstate > 0) {
+                       ast_debug(3, "tcount: %d, tstate: %d\n", tcount, tstate);
+                       switch (tstate) {
+                       case DSP_TONE_STATE_DIALTONE:
+                               if (di->signalfeatures & DSP_FEATURE_WAITDIALTONE) {
+                                       match = 1;
+                               }
+                               break;
+                       case DSP_TONE_STATE_BUSY:
+                               if (di->signalfeatures & DSP_PROGRESS_BUSY) {
+                                       match = 1;
+                               }
+                               break;
+                       case DSP_TONE_STATE_SPECIAL3:
+                               if (di->signalfeatures & DSP_PROGRESS_CONGESTION) {
+                                       match = 1;
+                               }
+                               break;
+                       default: /* ignore */
+                               break;
+                       }
+                       if (match) {
+                               if (direction == AST_AUDIOHOOK_DIRECTION_READ && di->gotorx) {
+                                       ast_async_parseable_goto(chan, di->gotorx);
+                               } else if (di->gototx) {
+                                       ast_async_parseable_goto(chan, di->gototx);
+                               } else {
+                                       ast_debug(3, "Detected call progress signal, but don't know where to go\n");
+                               }
+                       }
+               }
+       }
        /* this could be the duplicated frame or a new one, doesn't matter */
        ast_frfree(frame);
        return 0;
@@ -326,8 +468,8 @@ static int freq_parser(char *freqs, int *freq1, int *freq2) {
                ast_log(LOG_WARNING, "Frequency must be an integer: %s\n", f1);
                return -1;
        }
-       if (*freq1 < 1) {
-               ast_log(LOG_WARNING, "Sorry, positive frequencies only: %d\n", *freq1);
+       if (*freq1 < 0) {
+               ast_log(LOG_WARNING, "Sorry, no negative frequencies: %d\n", *freq1);
                return -1;
        }
        if (!ast_strlen_zero(f2)) {
@@ -413,6 +555,23 @@ static int detect_read(struct ast_channel *chan, const char *cmd, char *data, ch
        return 0;
 }
 
+static int parse_signal_features(struct ast_flags *flags)
+{
+       int features = 0;
+
+       if (ast_test_flag(flags, OPT_SIT)) {
+               features |= DSP_PROGRESS_CONGESTION;
+       }
+       if (ast_test_flag(flags, OPT_BUSY)) {
+               features |= DSP_PROGRESS_BUSY;
+       }
+       if (ast_test_flag(flags, OPT_DIALTONE)) {
+               features |= DSP_FEATURE_WAITDIALTONE;
+       }
+
+       return features;
+}
+
 static int detect_write(struct ast_channel *chan, const char *cmd, char *data, const char *value)
 {
        char *parse;
@@ -422,6 +581,7 @@ static int detect_write(struct ast_channel *chan, const char *cmd, char *data, c
        char *opt_args[OPT_ARG_ARRAY_SIZE];
        struct ast_dsp *dsp;
        int freq1 = 0, freq2 = 0, duration = 500, db = 16, squelch = 0, hitsrequired = 1;
+       int signalfeatures = 0;
 
        AST_DECLARE_APP_ARGS(args,
                AST_APP_ARG(freqs);
@@ -461,6 +621,7 @@ static int detect_write(struct ast_channel *chan, const char *cmd, char *data, c
                        return -1;
                }
        }
+       signalfeatures = parse_signal_features(&flags);
 
        ast_channel_lock(chan);
        if (!(datastore = ast_channel_datastore_find(chan, &detect_datastore, NULL))) {
@@ -481,8 +642,12 @@ static int detect_write(struct ast_channel *chan, const char *cmd, char *data, c
                        ast_log(LOG_WARNING, "Unable to allocate DSP!\n");
                        return -1;
                }
-               ast_dsp_set_features(dsp, DSP_FEATURE_FREQ_DETECT);
-               ast_dsp_set_freqmode(dsp, freq1, duration, db, squelch);
+               di->signalfeatures = signalfeatures; /* we're not including freq detect */
+               if (freq1 > 0) {
+                       signalfeatures |= DSP_FEATURE_FREQ_DETECT;
+                       ast_dsp_set_freqmode(dsp, freq1, duration, db, squelch);
+               }
+               ast_dsp_set_features(dsp, signalfeatures);
                di->dsp = dsp;
                di->txcount = 0;
                di->rxcount = 0;
@@ -493,7 +658,12 @@ static int detect_write(struct ast_channel *chan, const char *cmd, char *data, c
        } else {
                di = datastore->data;
                dsp = di->dsp;
-               ast_dsp_set_freqmode(dsp, freq1, duration, db, squelch);
+               di->signalfeatures = signalfeatures; /* we're not including freq detect */
+               if (freq1 > 0) {
+                       signalfeatures |= DSP_FEATURE_FREQ_DETECT;
+                       ast_dsp_set_freqmode(dsp, freq1, duration, db, squelch);
+               }
+               ast_dsp_set_features(dsp, signalfeatures);
        }
        di->duration = duration;
        di->gotorx = NULL;
@@ -641,6 +811,185 @@ static int wait_exec(struct ast_channel *chan, const char *data)
 }
 
 static char *waitapp = "WaitForTone";
+static char *scanapp = "ToneScan";
+
+static int scan_exec(struct ast_channel *chan, const char *data)
+{
+       char *appdata;
+       double timeoutf = 0;
+       int timeout = 0;
+       struct ast_frame *frame = NULL, *frame2 = NULL;
+       struct ast_dsp *dsp = NULL, *dsp2 = NULL;
+       struct timeval start;
+       int remaining_time = 0;
+       int features, match = 0, fax = 0, voice = 0, threshold = 1;
+       AST_DECLARE_APP_ARGS(args,
+               AST_APP_ARG(zone);
+               AST_APP_ARG(timeout);
+               AST_APP_ARG(threshold);
+               AST_APP_ARG(options);
+       );
+
+       appdata = ast_strdupa(data);
+       AST_STANDARD_APP_ARGS(args, appdata);
+
+       if (!ast_strlen_zero(args.timeout) && (sscanf(args.timeout, "%30lf", &timeoutf) != 1 || timeout < 0)) {
+               ast_log(LOG_WARNING, "Invalid timeout: %s\n", args.timeout);
+               pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "ERROR");
+               return -1;
+       }
+       if (!ast_strlen_zero(args.threshold) && (ast_str_to_int(args.threshold, &threshold) || threshold < 1)) {
+               ast_log(LOG_WARNING, "Invalid threshold: %s\n", args.threshold);
+               pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "ERROR");
+               return -1;
+       }
+       timeout = 1000 * timeoutf;
+
+       if (!ast_strlen_zero(args.options) && strchr(args.options, 'f')) {
+               fax = 1;
+       }
+       if (!ast_strlen_zero(args.options) && strchr(args.options, 'v')) {
+               voice = 1;
+       }
+
+       if (!(dsp = ast_dsp_new())) {
+               ast_log(LOG_WARNING, "Unable to allocate DSP!\n");
+               pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "ERROR");
+               return -1;
+       }
+
+       if (!ast_strlen_zero(args.zone)) {
+               if (ast_dsp_set_call_progress_zone(dsp, args.zone)) {
+                       ast_log(LOG_WARNING, "Invalid call progress zone: %s\n", args.zone);
+                       pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "ERROR");
+                       ast_dsp_free(dsp);
+                       return -1;
+               }
+       }
+
+       if (fax) {
+               if (!(dsp2 = ast_dsp_new())) {
+                       ast_dsp_free(dsp);
+                       ast_log(LOG_WARNING, "Unable to allocate DSP!\n");
+                       pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "ERROR");
+                       return -1;
+               }
+       }
+
+       features = DSP_PROGRESS_RINGING; /* audible ringback tone */
+       features |= DSP_PROGRESS_BUSY; /* busy signal */
+       features |= DSP_PROGRESS_CONGESTION; /* SIT tones (not reorder!) */
+       features |= DSP_PROGRESS_TALK; /* voice. */
+       features |= DSP_FEATURE_WAITDIALTONE; /* dial tone */
+       features |= DSP_FEATURE_FREQ_DETECT; /* modem answer */
+       if (voice) {
+               features |= DSP_TONE_STATE_TALKING; /* voice */
+       }
+       ast_dsp_set_features(dsp, features);
+       /* all modems begin negotiating with Bell 103. An answering modem just sends mark tone, or 2225 Hz */
+       ast_dsp_set_freqmode(dsp, 2225, 400, 16, 0); /* this needs to be pretty short, or the progress tones code will thing this is voice */
+
+       if (fax) { /* fax detect uses same tone detect internals as modem and causes things to not work as intended, so use a separate DSP if needed. */
+               ast_dsp_set_features(dsp2, DSP_FEATURE_FAX_DETECT); /* fax tone */
+               ast_dsp_set_faxmode(dsp2, DSP_FAXMODE_DETECT_CED); /* we only care about the answering side (CED), not originating (CNG) */
+       }
+
+       ast_debug(1, "Starting tone scan, timeout: %d ms, threshold: %d\n", timeout, threshold);
+       start = ast_tvnow();
+       do {
+               if (timeout > 0) {
+                       remaining_time = ast_remaining_ms(start, timeout);
+                       if (remaining_time <= 0) {
+                               pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "TIMEOUT");
+                               break;
+                       }
+               }
+               if (ast_waitfor(chan, 1000) > 0) {
+                       if (!(frame = ast_read(chan))) {
+                               ast_debug(1, "Channel '%s' did not return a frame; probably hung up.\n", ast_channel_name(chan));
+                               pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "HANGUP");
+                               break;
+                       } else if (frame->frametype == AST_FRAME_VOICE) {
+                               if (fax) {
+                                       frame2 = ast_frdup(frame);
+                               }
+                               frame = ast_dsp_process(chan, dsp, frame);
+                               if (frame->frametype == AST_FRAME_DTMF) {
+                                       char result = frame->subclass.integer;
+                                       match = 1;
+                                       if (result == 'q') {
+                                               pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "MODEM");
+                                       } else {
+                                               pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "DTMF");
+                                       }
+                               } else if (fax) {
+                                       char result;
+                                       frame2 = ast_dsp_process(chan, dsp2, frame2);
+                                       result = frame->subclass.integer;
+                                       if (result == AST_FRAME_DTMF) {
+                                               if (result == 'e') {
+                                                       pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "FAX");
+                                                       match = 1;
+                                               } else {
+                                                       ast_debug(1, "Ignoring inactionable event\n"); /* shouldn't happen */
+                                               }
+                                       }
+                                       ast_frfree(frame2);
+                               }
+                               if (!match) {
+                                       int tstate, tcount;
+                                       tcount = ast_dsp_get_tcount(dsp);
+                                       tstate = ast_dsp_get_tstate(dsp);
+                                       if (tstate > 0) {
+                                               ast_debug(3, "tcount: %d, tstate: %d\n", tcount, tstate);
+                                               if (tcount >= threshold) {
+                                                       match = 1;
+                                                       switch (tstate) {
+                                                       case DSP_TONE_STATE_RINGING:
+                                                               pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "RINGING");
+                                                               break;
+                                                       case DSP_TONE_STATE_DIALTONE:
+                                                               pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "DIALTONE");
+                                                               break;
+                                                       case DSP_TONE_STATE_TALKING:
+                                                               /* even if we don't specify this feature, it's still checked, so we always need to handle it.
+                                                                       Even if we are looking for it, we need to wait a while or tones will be interpreted
+                                                                       as voice, because this will match first (and this should match last). */
+                                                               if (voice && tcount > 15 && tcount >= threshold) {
+                                                                       pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "VOICE");
+                                                               } else {
+                                                                       match = 0;
+                                                               }
+                                                               break;
+                                                       case DSP_TONE_STATE_BUSY:
+                                                               pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "BUSY");
+                                                               break;
+                                                       case DSP_TONE_STATE_SPECIAL3:
+                                                               pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "SIT");
+                                                               break;
+                                                       case DSP_TONE_STATE_HUNGUP: /* UK only */
+                                                               pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "NUT");
+                                                               break;
+                                                       default:
+                                                               match = 0;
+                                                               ast_debug(1, "Something else we weren't expecting? tstate: %d, #%d\n", tstate, tcount);
+                                                       }
+                                               }
+                                       }
+                               }
+                       }
+                       ast_frfree(frame);
+               } else {
+                       pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "HANGUP");
+               }
+       } while (!match && (timeout == 0 || remaining_time > 0));
+       ast_dsp_free(dsp);
+       if (dsp2) {
+               ast_dsp_free(dsp2);
+        }
+
+       return 0;
+}
 
 static struct ast_custom_function detect_function = {
        .name = "TONE_DETECT",
@@ -653,6 +1002,7 @@ static int unload_module(void)
        int res;
 
        res = ast_unregister_application(waitapp);
+       res |= ast_unregister_application(scanapp);
        res |= ast_custom_function_unregister(&detect_function);
 
        return res;
@@ -663,6 +1013,7 @@ static int load_module(void)
        int res;
 
        res = ast_register_application_xml(waitapp, wait_exec);
+       res |= ast_register_application_xml(scanapp, scan_exec);
        res |= ast_custom_function_register(&detect_function);
 
        return res;