Delay sending an CED tone generated T.38 reinvite to give the CED tone

generating party time to send its own T.38 reinvite.

Also don't forward frames through the gateway if we are negotiating T.38.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@327511 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/res/res_fax.c b/res/res_fax.c
index 06b39e05c88ce2f2ec731741a766ac7bf2846a3e..5202e6323cfcfcc9e8019425ebaf0af4ccce878e 100644 (file)
--- a/res/res_fax.c
+++ b/res/res_fax.c
@@ -246,6 +246,8 @@ struct fax_gateway {
        struct ast_fax_tech_token *token;
        /*! \brief the start of our timeout counter */
        struct timeval timeout_start;
+       /*! \brief the start of our ced timeout */
+       struct timeval ced_timeout_start;
        /*! \brief DSP Processor */
        struct ast_dsp *chan_dsp;
        struct ast_dsp *peer_dsp;
@@ -253,6 +255,8 @@ struct fax_gateway {
        int framehook;
        /*! \brief bridged */
        int bridged:1;
+       /*! \brief 1 if the ced tone came from chan, 0 if it came from peer */
+       int ced_chan:1;
        /*! \brief a flag to track the state of our negotiation */
        enum ast_t38_state t38_state;
        /*! \brief original audio formats */
@@ -269,6 +273,7 @@ static int fax_logger_level = -1;
 
 #define RES_FAX_TIMEOUT 10000
 #define FAX_GATEWAY_TIMEOUT RES_FAX_TIMEOUT
+#define FAX_GATEWAY_CED_TIMEOUT 3000
 
 /*! \brief The faxregistry is used to manage information and statistics for all FAX sessions. */
 static struct {
@@ -2465,6 +2470,46 @@ static int fax_gateway_start(struct fax_gateway *gateway, struct ast_fax_session
        return 0;
 }
 
+static struct ast_frame *fax_gateway_send_ced(struct fax_gateway *gateway, struct ast_channel *chan, struct ast_frame *f)
+{
+       struct ast_frame *fp;
+       struct ast_control_t38_parameters t38_parameters = {
+               .request_response = AST_T38_REQUEST_NEGOTIATE,
+       };
+       struct ast_frame control_frame = {
+               .src = "res_fax",
+               .frametype = AST_FRAME_CONTROL,
+               .datalen = sizeof(t38_parameters),
+               .subclass.integer = AST_CONTROL_T38_PARAMETERS,
+               .data.ptr = &t38_parameters,
+       };
+
+       struct ast_fax_session_details *details = find_details(chan);
+
+       if (!details) {
+               ast_log(LOG_ERROR, "no FAX session details found on chan %s for T.38 gateway session, odd\n", chan->name);
+               ast_framehook_detach(chan, gateway->framehook);
+               return f;
+       }
+
+       t38_parameters_fax_to_ast(&t38_parameters, &details->our_t38_parameters);
+       ao2_ref(details, -1);
+
+       if (!(fp = ast_frisolate(&control_frame))) {
+               ast_log(LOG_ERROR, "error generating T.38 request control frame on chan %s for T.38 gateway session\n", chan->name);
+               return f;
+       }
+
+       gateway->t38_state = T38_STATE_NEGOTIATING;
+       gateway->timeout_start = ast_tvnow();
+
+       gateway->ced_timeout_start.tv_sec = 0;
+       gateway->ced_timeout_start.tv_usec = 0;
+
+       ast_debug(1, "detected CED tone; requesting T.38 for gateway session for %s\n", chan->name);
+       return fp;
+}
+
 static struct ast_frame *fax_gateway_detect_ced(struct fax_gateway *gateway, struct ast_channel *chan, struct ast_channel *peer, struct ast_channel *active, struct ast_frame *f)
 {
        struct ast_frame *dfr = ast_frdup(f);
@@ -2480,40 +2525,13 @@ static struct ast_frame *fax_gateway_detect_ced(struct fax_gateway *gateway, str
        }
 
        if (dfr->frametype == AST_FRAME_DTMF && dfr->subclass.integer == 'e') {
-               if (ast_channel_get_t38_state(other) == T38_STATE_UNKNOWN) {
-                       struct ast_control_t38_parameters t38_parameters = {
-                               .request_response = AST_T38_REQUEST_NEGOTIATE,
-                       };
-                       struct ast_frame control_frame = {
-                               .src = "res_fax",
-                               .frametype = AST_FRAME_CONTROL,
-                               .datalen = sizeof(t38_parameters),
-                               .subclass.integer = AST_CONTROL_T38_PARAMETERS,
-                               .data.ptr = &t38_parameters,
-                       };
-
-                       struct ast_fax_session_details *details = find_details(chan);
-                       ast_frfree(dfr);
-
-                       if (!details) {
-                               ast_log(LOG_ERROR, "no FAX session details found on chan %s for T.38 gateway session, odd\n", chan->name);
-                               ast_framehook_detach(chan, gateway->framehook);
-                               return f;
-                       }
-
-                       t38_parameters_fax_to_ast(&t38_parameters, &details->our_t38_parameters);
-                       ao2_ref(details, -1);
-
-                       if (!(dfr = ast_frisolate(&control_frame))) {
-                               ast_log(LOG_ERROR, "error generating T.38 request control frame on chan %s for T.38 gateway session\n", chan->name);
-                               return f;
+               if (ast_channel_get_t38_state(other) == T38_STATE_UNKNOWN && ast_tvzero(gateway->ced_timeout_start)) {
+                       if (ast_channel_get_t38_state(active) == T38_STATE_UNKNOWN) {
+                               gateway->ced_timeout_start = ast_tvnow();
+                               gateway->ced_chan = (active == chan);
+                       } else {
+                               return fax_gateway_send_ced(gateway, chan, f);
                        }
-
-                       gateway->t38_state = T38_STATE_NEGOTIATING;
-                       gateway->timeout_start = ast_tvnow();
-
-                       ast_debug(1, "detected CED tone on %s, requesting T.38 on %s for T.38 gateway session\n", active->name, other->name);
-                       return dfr;
                } else {
                        ast_debug(1, "detected CED tone on %s, but %s does not support T.38 for T.38 gateway session\n", active->name, other->name);
                }
@@ -2568,6 +2586,10 @@ static struct ast_frame *fax_gateway_detect_t38(struct fax_gateway *gateway, str
 
        if (control_params->request_response == AST_T38_REQUEST_NEGOTIATE) {
                enum ast_t38_state state = ast_channel_get_t38_state(other);
+
+               gateway->ced_timeout_start.tv_sec = 0;
+               gateway->ced_timeout_start.tv_usec = 0;
+
                if (state == T38_STATE_UNKNOWN) {
                        /* we detected a request to negotiate T.38 and the
                         * other channel appears to support T.38, we'll pass
@@ -2922,6 +2944,17 @@ static struct ast_frame *fax_gateway_framehook(struct ast_channel *chan, struct
                return fax_gateway_detect_ced(gateway, chan, peer, active, f);
        }
 
+       /* handle the ced timeout delay */
+       if (!ast_tvzero(gateway->ced_timeout_start)) {
+               if (ast_tvdiff_ms(ast_tvnow(), gateway->ced_timeout_start) > FAX_GATEWAY_CED_TIMEOUT) {
+                       if (gateway->ced_chan && chan == active) {
+                               return fax_gateway_send_ced(gateway, chan, f);
+                       } else if (!gateway->ced_chan && peer == active) {
+                               return fax_gateway_send_ced(gateway, chan, f);
+                       }
+               }
+       }
+
        /* in gateway mode, gateway some packets */
        if (gateway->t38_state == T38_STATE_NEGOTIATED) {
                /* framehooks are called in __ast_read() before frame format
@@ -2942,6 +2975,12 @@ static struct ast_frame *fax_gateway_framehook(struct ast_channel *chan, struct
                return f;
        }
 
+       /* force silence on the line if T.38 negotiation might be taking place */
+       if (!ast_tvzero(gateway->ced_timeout_start) || (gateway->t38_state != T38_STATE_UNAVAILABLE && gateway->t38_state != T38_STATE_REJECTED)) {
+               /* XXX may need to return a silence frame here */
+               return &ast_null_frame;
+       }
+
        return f;
 }