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Diffstat (limited to 'res')
-rw-r--r--res/res_fax.c101
1 files changed, 63 insertions, 38 deletions
diff --git a/res/res_fax.c b/res/res_fax.c
index 55e30b0c2..0b04b1b31 100644
--- a/res/res_fax.c
+++ b/res/res_fax.c
@@ -654,6 +654,7 @@ static int generic_fax_exec(struct ast_channel *chan, struct ast_fax_session_det
struct ast_channel *c = chan;
unsigned int orig_write_format = 0, orig_read_format = 0;
unsigned int request_t38 = 0;
+ unsigned int send_audio = 1;
details->our_t38_parameters.version = 0;
details->our_t38_parameters.max_ifp = 400;
@@ -662,8 +663,57 @@ static int generic_fax_exec(struct ast_channel *chan, struct ast_fax_session_det
chancount = 1;
- /* generate 3 seconds of CED if we are in receive mode */
- if (details->caps & AST_FAX_TECH_RECEIVE) {
+ switch ((t38_state = ast_channel_get_t38_state(chan))) {
+ case T38_STATE_UNKNOWN:
+ if (details->caps & AST_FAX_TECH_SEND) {
+ if (details->option.allow_audio) {
+ details->caps |= AST_FAX_TECH_AUDIO;
+ } else {
+ /* we are going to send CNG to attempt to stimulate the receiver
+ * into switching to T.38, since audio mode is not allowed
+ */
+ send_cng = 0;
+ }
+ } else {
+ /* we *always* request a switch to T.38 if allowed; if audio is also
+ * allowed, then we will allow the switch to happen later if needed
+ */
+ if (details->option.allow_audio) {
+ details->caps |= AST_FAX_TECH_AUDIO;
+ }
+ request_t38 = 1;
+ }
+ details->caps |= AST_FAX_TECH_T38;
+ break;
+ case T38_STATE_UNAVAILABLE:
+ details->caps |= AST_FAX_TECH_AUDIO;
+ break;
+ case T38_STATE_NEGOTIATING: {
+ /* the other end already sent us a T.38 reinvite, so we need to prod the channel
+ * driver into resending their parameters to us if it supports doing so... if
+ * not, we can't proceed, because we can't create a proper reply without them.
+ * if it does work, the channel driver will send an AST_CONTROL_T38_PARAMETERS
+ * with a request of AST_T38_REQUEST_NEGOTIATE, which will be read by the function
+ * that gets called after this one completes
+ */
+ struct ast_control_t38_parameters parameters = { .request_response = AST_T38_REQUEST_PARMS, };
+ ast_log(LOG_NOTICE, "Channel is already in T.38 negotiation state; retrieving remote parameters.\n");
+ if (ast_indicate_data(chan, AST_CONTROL_T38_PARAMETERS, &parameters, sizeof(parameters)) != AST_T38_REQUEST_PARMS) {
+ ast_log(LOG_ERROR, "channel '%s' is in an unsupported T.38 negotiation state, cannot continue.\n", chan->name);
+ return -1;
+ }
+ details->caps |= AST_FAX_TECH_T38;
+ details->option.allow_audio = 0;
+ send_audio = 0;
+ break;
+ }
+ default:
+ ast_log(LOG_ERROR, "channel '%s' is in an unsupported T.38 negotiation state, cannot continue.\n", chan->name);
+ return -1;
+ }
+
+ /* generate 3 seconds of CED if we are in receive mode and not already negotiating T.38 */
+ if (send_audio && (details->caps & AST_FAX_TECH_RECEIVE)) {
ms = 3000;
if (ast_tonepair_start(chan, 2100, 0, ms, 0)) {
ast_log(LOG_ERROR, "error generating CED tone on %s\n", chan->name);
@@ -719,36 +769,6 @@ static int generic_fax_exec(struct ast_channel *chan, struct ast_fax_session_det
ast_tonepair_stop(chan);
}
- switch ((t38_state = ast_channel_get_t38_state(chan))) {
- case T38_STATE_UNKNOWN:
- if (details->caps & AST_FAX_TECH_SEND) {
- if (details->option.allow_audio) {
- details->caps |= AST_FAX_TECH_AUDIO;
- } else {
- /* we are going to send CNG to attempt to stimulate the receiver
- * into switching to T.38, since audio mode is not allowed
- */
- send_cng = 0;
- }
- } else {
- /* we *always* request a switch to T.38 if allowed; if audio is also
- * allowed, then we will allow the switch to happen later if needed
- */
- if (details->option.allow_audio) {
- details->caps |= AST_FAX_TECH_AUDIO;
- }
- request_t38 = 1;
- }
- details->caps |= AST_FAX_TECH_T38;
- break;
- case T38_STATE_UNAVAILABLE:
- details->caps |= AST_FAX_TECH_AUDIO;
- break;
- default:
- ast_log(LOG_ERROR, "channel '%s' is in an unsupported T.38 negotiation state, cannot continue.\n", chan->name);
- return -1;
- }
-
if (request_t38) {
/* wait up to five seconds for negotiation to complete */
timeout = 5000;
@@ -772,19 +792,23 @@ static int generic_fax_exec(struct ast_channel *chan, struct ast_fax_session_det
if (request_t38 || !details->option.allow_audio) {
struct ast_silence_generator *silence_gen = NULL;
- if (send_cng != -1) {
+ if (send_audio && (send_cng != -1)) {
silence_gen = ast_channel_start_silence_generator(chan);
}
while (timeout > 0) {
if (send_cng > 3000) {
- ast_channel_stop_silence_generator(chan, silence_gen);
- silence_gen = NULL;
- ast_tonepair_start(chan, 1100, 0, 500, 0);
+ if (send_audio) {
+ ast_channel_stop_silence_generator(chan, silence_gen);
+ silence_gen = NULL;
+ ast_tonepair_start(chan, 1100, 0, 500, 0);
+ }
send_cng = 0;
} else if (!chan->generator && (send_cng != -1)) {
- /* The CNG tone is done so restart silence generation. */
- silence_gen = ast_channel_start_silence_generator(chan);
+ if (send_audio) {
+ /* The CNG tone is done so restart silence generation. */
+ silence_gen = ast_channel_start_silence_generator(chan);
+ }
}
/* this timeout *MUST* be 500ms, in order to keep the spacing
* of CNG tones correct when this loop is sending them
@@ -828,6 +852,7 @@ static int generic_fax_exec(struct ast_channel *chan, struct ast_fax_session_det
t38_parameters.request_response = AST_T38_NEGOTIATED;
ast_indicate_data(chan, AST_CONTROL_T38_PARAMETERS, &t38_parameters, sizeof(t38_parameters));
stop = 0;
+ send_audio = 0;
break;
case AST_T38_NEGOTIATED:
ast_log(LOG_NOTICE, "Negotiated T.38 for %s on %s\n", (details->caps & AST_FAX_TECH_SEND) ? "send" : "receive", chan->name);
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-20 00:33:40 +0000