Add a non-invasive API for application level manipulation of T38 on a channel. This...

(closes issue #11873)
Reported by: dimas
Patches:
      v4-t38-api.patch uploaded by dimas (license 88)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@103799 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 43ed864..54e233a 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -1689,6 +1689,7 @@ static int sip_transfer(struct ast_channel *ast, const char *dest);
 static int sip_fixup(struct ast_channel *oldchan, struct ast_channel *newchan);
 static int sip_senddigit_begin(struct ast_channel *ast, char digit);
 static int sip_senddigit_end(struct ast_channel *ast, char digit, unsigned int duration);
+static int sip_queryoption(struct ast_channel *chan, int option, void *data, int *datalen);
 static const char *sip_get_callid(struct ast_channel *chan);
 
 static int handle_request_do(struct sip_request *req, struct sockaddr_in *sin);
@@ -2009,6 +2010,7 @@ static int sip_handle_t38_reinvite(struct ast_channel *chan, struct sip_pvt *pvt
 static int transmit_response_with_t38_sdp(struct sip_pvt *p, char *msg, struct sip_request *req, int retrans);
 static struct ast_udptl *sip_get_udptl_peer(struct ast_channel *chan);
 static int sip_set_udptl_peer(struct ast_channel *chan, struct ast_udptl *udptl);
+static void change_t38_state(struct sip_pvt *p, int state);
 
 /*------ Session-Timers functions --------- */
 static void proc_422_rsp(struct sip_pvt *p, struct sip_request *rsp);
@@ -2050,6 +2052,7 @@ static const struct ast_channel_tech sip_tech = {
        .early_bridge = ast_rtp_early_bridge,
        .send_text = sip_sendtext,              /* called with chan locked */
        .func_channel_read = acf_channel_read,
+       .queryoption = sip_queryoption,
        .get_pvt_uniqueid = sip_get_callid,
 };
 
@@ -3083,6 +3086,53 @@ static int send_request(struct sip_pvt *p, struct sip_request *req, enum xmittyp
        return res;
 }
 
+/*! \brief Query an option on a SIP dialog */
+static int sip_queryoption(struct ast_channel *chan, int option, void *data, int *datalen)
+{
+       int res = -1;
+       enum ast_t38_state state = T38_STATE_UNAVAILABLE;
+       struct sip_pvt *p = (struct sip_pvt *) chan->tech_pvt;
+
+       switch (option) {
+       case AST_OPTION_T38_STATE:
+               /* Make sure we got an ast_t38_state enum passed in */
+               if (*datalen != sizeof(enum ast_t38_state)) {
+                       ast_log(LOG_ERROR, "Invalid datalen for AST_OPTION_T38_STATE option. Expected %d, got %d\n", (int)sizeof(enum ast_t38_state), *datalen);
+                       return -1;
+               }
+
+               sip_pvt_lock(p);
+
+               /* Now if T38 support is enabled we need to look and see what the current state is to get what we want to report back */
+               if (ast_test_flag(&p->t38.t38support, SIP_PAGE2_T38SUPPORT)) {
+                       switch (p->t38.state) {
+                       case T38_LOCAL_DIRECT:
+                       case T38_LOCAL_REINVITE:
+                       case T38_PEER_DIRECT:
+                       case T38_PEER_REINVITE:
+                               state = T38_STATE_NEGOTIATING;
+                               break;
+                       case T38_ENABLED:
+                               state = T38_STATE_NEGOTIATED;
+                               break;
+                       default:
+                               state = T38_STATE_UNKNOWN;
+                       }
+               }
+
+               sip_pvt_unlock(p);
+
+               *((enum ast_t38_state *) data) = state;
+               res = 0;
+
+               break;
+       default:
+               break;
+       }
+
+       return res;
+}
+
 /*! \brief Locate closing quote in a string, skipping escaped quotes.
  * optionally with a limit on the search.
  * start must be past the first quote.
@@ -3773,6 +3823,37 @@ static void do_setnat(struct sip_pvt *p, int natflags)
        }
 }
 
+/*! \brief Change the T38 state on a SIP dialog */
+static void change_t38_state(struct sip_pvt *p, int state)
+{
+       int old = p->t38.state;
+       struct ast_channel *chan = p->owner;
+       enum ast_control_t38 message = 0;
+
+       /* Don't bother changing if we are already in the state wanted */
+       if (old == state)
+               return;
+
+       p->t38.state = state;
+       ast_debug(2, "T38 state changed to %d on channel %s\n", p->t38.state, chan ? chan->name : "<none>");
+
+       /* If no channel was provided we can't send off a control frame */
+       if (!chan)
+               return;
+
+       /* Given the state requested and old state determine what control frame we want to queue up */
+       if (state == T38_ENABLED)
+               message = AST_T38_NEGOTIATED;
+       else if (state == T38_DISABLED && old == T38_ENABLED)
+               message = AST_T38_TERMINATED;
+       else if (state == T38_DISABLED && old == T38_LOCAL_REINVITE)
+               message = AST_T38_REFUSED;
+
+       /* Woot we got a message, create a control frame and send it on! */
+       if (message)
+               ast_queue_control_data(chan, AST_CONTROL_T38, &message, sizeof(message));
+}
+
 /*! \brief Set the global T38 capabilities on a SIP dialog structure */
 static void set_t38_capabilities(struct sip_pvt *p)
 {
@@ -4741,8 +4822,7 @@ static int sip_answer(struct ast_channel *ast)
                ast_setstate(ast, AST_STATE_UP);
                ast_debug(1, "SIP answering channel: %s\n", ast->name);
                if (p->t38.state == T38_PEER_DIRECT) {
-                       p->t38.state = T38_ENABLED;
-                       ast_debug(2,"T38State change to %d on channel %s\n", p->t38.state, ast->name);
+                       change_t38_state(p, T38_ENABLED);
                        res = transmit_response_with_t38_sdp(p, "200 OK", &p->initreq, XMIT_CRITICAL);
                } else 
                        res = transmit_response_with_sdp(p, "200 OK", &p->initreq, XMIT_CRITICAL, FALSE);
@@ -5027,6 +5107,26 @@ static int sip_indicate(struct ast_channel *ast, int condition, const void *data
                } else
                        res = -1;
                break;
+       case AST_CONTROL_T38:   /* T38 control frame */
+               if (datalen != sizeof(enum ast_control_t38)) {
+                       ast_log(LOG_ERROR, "Invalid datalen for AST_CONTROL_T38. Expected %d, got %d\n", (int)sizeof(enum ast_control_t38), (int)datalen);
+               } else {
+                       switch (*((enum ast_control_t38 *) data)) {
+                       case AST_T38_REQUEST_NEGOTIATE:         /* Request T38 */
+                               if (p->t38.state != T38_ENABLED) {
+                                       change_t38_state(p, T38_LOCAL_REINVITE);
+                                       transmit_reinvite_with_sdp(p, TRUE, FALSE);
+                               }
+                               break;
+                       case AST_T38_REQUEST_TERMINATE:         /* Shutdown T38 */
+                               if (p->t38.state == T38_ENABLED)
+                                       transmit_reinvite_with_sdp(p, FALSE, FALSE);
+                               break;
+                       default:
+                               break;
+                       }
+               }
+               break;
        case -1:
                res = -1;
                break;
@@ -5459,9 +5559,8 @@ static struct ast_frame *sip_read(struct ast_channel *ast)
                if (!ast_test_flag(&p->flags[0], SIP_GOTREFER)) {
                        if (!p->pendinginvite) {
                                ast_debug(3, "Sending reinvite on SIP (%s) for T.38 negotiation.\n",ast->name);
-                               p->t38.state = T38_LOCAL_REINVITE;
+                               change_t38_state(p, T38_LOCAL_REINVITE);
                                transmit_reinvite_with_sdp(p, TRUE, FALSE);
-                               ast_debug(2, "T38 state changed to %d on channel %s\n", p->t38.state, ast->name);
                        }
                } else if (!ast_test_flag(&p->flags[0], SIP_PENDINGBYE)) {
                        ast_debug(3, "Deferring reinvite on SIP (%s) - it will be re-negotiated for T.38\n", ast->name);
@@ -6627,24 +6726,21 @@ static int process_sdp(struct sip_pvt *p, struct sip_request *req, int t38action
                                p->t38.peercapability,
                                p->t38.jointcapability);
 
-
                /* Remote party offers T38, we need to update state */
                if (t38action == SDP_T38_ACCEPT) {
                        if (p->t38.state == T38_LOCAL_DIRECT || p->t38.state == T38_LOCAL_REINVITE)
-                               p->t38.state = T38_ENABLED;
+                               change_t38_state(p, T38_ENABLED);
                } else if (t38action == SDP_T38_INITIATE) {
                        if (p->owner && p->lastinvite) {
-                               p->t38.state = T38_PEER_REINVITE; /* T38 Offered in re-invite from remote party */
+                               change_t38_state(p, T38_PEER_REINVITE); /* T38 Offered in re-invite from remote party */
                        } else {
-                               p->t38.state = T38_PEER_DIRECT; /* T38 Offered directly from peer in first invite */
+                               change_t38_state(p, T38_PEER_DIRECT); /* T38 Offered directly from peer in first invite */
                        }
                }
        } else {
-               p->t38.state = T38_DISABLED;
+               change_t38_state(p, T38_DISABLED);
        }
 
-       ast_debug(3, "T38 state changed to %d on channel %s\n", p->t38.state, p->owner ? p->owner->name : "<none>");
-
        /* Now gather all of the codecs that we are asked for: */
        ast_rtp_get_current_formats(newaudiortp, &peercapability, &peernoncodeccapability);
        ast_rtp_get_current_formats(newvideortp, &vpeercapability, &vpeernoncodeccapability);
@@ -14438,23 +14534,19 @@ static void handle_response_invite(struct sip_pvt *p, int resp, char *rest, stru
                                } else {
                                        ast_debug(2, "Strange... The other side of the bridge does not have a udptl struct\n");
                                        sip_pvt_lock(bridgepvt);
-                                       bridgepvt->t38.state = T38_DISABLED;
+                                       change_t38_state(bridgepvt, T38_DISABLED);
                                        sip_pvt_unlock(bridgepvt);
-                                       ast_debug(1,"T38 state changed to %d on channel %s\n", bridgepvt->t38.state, bridgepeer->tech->type);
-                                       p->t38.state = T38_DISABLED;
-                                       ast_debug(2,"T38 state changed to %d on channel %s\n", p->t38.state, p->owner ? p->owner->name : "<none>");
+                                       change_t38_state(p, T38_DISABLED);
                                }
                        } else {
                                /* Other side is not a SIP channel */
                                ast_debug(2, "Strange... The other side of the bridge is not a SIP channel\n");
-                               p->t38.state = T38_DISABLED;
-                               ast_debug(2,"T38 state changed to %d on channel %s\n", p->t38.state, p->owner ? p->owner->name : "<none>");
+                               change_t38_state(p, T38_DISABLED);
                        }
                }
                if ((p->t38.state == T38_LOCAL_REINVITE) || (p->t38.state == T38_LOCAL_DIRECT)) {
                        /* If there was T38 reinvite and we are supposed to answer with 200 OK than this should set us to T38 negotiated mode */
-                       p->t38.state = T38_ENABLED;
-                       ast_debug(1, "T38 changed state to %d on channel %s\n", p->t38.state, p->owner ? p->owner->name : "<none>");
+                       change_t38_state(p, T38_ENABLED);
                }
 
                if (!req->ignore && p->owner) {
@@ -14591,7 +14683,7 @@ static void handle_response_invite(struct sip_pvt *p, int resp, char *rest, stru
                           terribly wrong since we don't renegotiate codecs,
                           only IP/port .
                        */
-                       p->t38.state = T38_DISABLED;
+                       change_t38_state(p, T38_DISABLED);
                        /* Try to reset RTP timers */
                        ast_rtp_set_rtptimers_onhold(p->rtp);
                        ast_log(LOG_ERROR, "Got error on T.38 re-invite. Bad configuration. Peer needs to have T.38 disabled.\n");
@@ -14607,11 +14699,11 @@ static void handle_response_invite(struct sip_pvt *p, int resp, char *rest, stru
                        /* We tried to send T.38 out in an initial INVITE and the remote side rejected it,
                           right now we can't fall back to audio so totally abort.
                        */
-                       p->t38.state = T38_DISABLED;
                        /* Try to reset RTP timers */
                        ast_rtp_set_rtptimers_onhold(p->rtp);
                        ast_log(LOG_ERROR, "Got error on T.38 initial invite. Bailing out.\n");
 
+                       change_t38_state(p, T38_DISABLED);
                        /* The dialog is now terminated */
                        if (p->owner && !req->ignore)
                                ast_queue_control(p->owner, AST_CONTROL_CONGESTION);
@@ -16497,9 +16589,8 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
                                                        } else { /* Something is wrong with peers udptl struct */
                                                                ast_log(LOG_WARNING, "Strange... The other side of the bridge don't have udptl struct\n");
                                                                sip_pvt_lock(bridgepvt);
-                                                               bridgepvt->t38.state = T38_DISABLED;
+                                                               change_t38_state(bridgepvt, T38_DISABLED);
                                                                sip_pvt_unlock(bridgepvt);
-                                                               ast_debug(2,"T38 state changed to %d on channel %s\n", bridgepvt->t38.state, bridgepeer->name);
                                                                if (req->ignore)
                                                                        transmit_response(p, "488 Not acceptable here", req);
                                                                else
@@ -16509,8 +16600,7 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
                                                } else {
                                                        /* The other side is already setup for T.38 most likely so we need to acknowledge this too */
                                                        transmit_response_with_t38_sdp(p, "200 OK", req, XMIT_CRITICAL);
-                                                       p->t38.state = T38_ENABLED;
-                                                       ast_debug(1, "T38 state changed to %d on channel %s\n", p->t38.state, p->owner ? p->owner->name : "<none>");
+                                                       change_t38_state(p, T38_ENABLED);
                                                }
                                        } else {
                                                /* Other side is not a SIP channel */
@@ -16518,8 +16608,7 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
                                                        transmit_response(p, "488 Not acceptable here", req);
                                                else
                                                        transmit_response_reliable(p, "488 Not acceptable here", req);
-                                               p->t38.state = T38_DISABLED;
-                                               ast_debug(2,"T38 state changed to %d on channel %s\n", p->t38.state, p->owner ? p->owner->name : "<none>");
+                                               change_t38_state(p, T38_DISABLED);
 
                                                if (!p->lastinvite) /* Only destroy if this is *not* a re-invite */
                                                        sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
@@ -16527,8 +16616,7 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
                                } else {
                                        /* we are not bridged in a call */
                                        transmit_response_with_t38_sdp(p, "200 OK", req, XMIT_CRITICAL);
-                                       p->t38.state = T38_ENABLED;
-                                       ast_debug(1,"T38 state changed to %d on channel %s\n", p->t38.state, p->owner ? p->owner->name : "<none>");
+                                       change_t38_state(p, T38_ENABLED);
                                }
                        } else if (p->t38.state == T38_DISABLED) { /* Channel doesn't have T38 offered or enabled */
                                int sendok = TRUE;
@@ -20711,10 +20799,8 @@ static int sip_handle_t38_reinvite(struct ast_channel *chan, struct sip_pvt *pvt
                        ast_debug(3, "Responding 200 OK on SIP '%s' - It's UDPTL soon redirected to IP %s:%d\n", p->callid, ast_inet_ntoa(p->udptlredirip.sin_addr), ntohs(p->udptlredirip.sin_port));
                else
                        ast_debug(3, "Responding 200 OK on SIP '%s' - It's UDPTL soon redirected to us (IP %s)\n", p->callid, ast_inet_ntoa(p->ourip.sin_addr));
-               pvt->t38.state = T38_ENABLED;
-               p->t38.state = T38_ENABLED;
-               ast_debug(2, "T38 changed state to %d on channel %s\n", pvt->t38.state, pvt->owner ? pvt->owner->name : "<none>");
-               ast_debug(2, "T38 changed state to %d on channel %s\n", p->t38.state, chan ? chan->name : "<none>");
+               change_t38_state(pvt, T38_ENABLED);
+               change_t38_state(p, T38_ENABLED);
                transmit_response_with_t38_sdp(p, "200 OK", &p->initreq, XMIT_CRITICAL);
                p->lastrtprx = p->lastrtptx = time(NULL);
                sip_pvt_unlock(p);

diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index 0faddb8..e5fd5ba 100644 (file)
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -389,6 +389,17 @@ enum ast_channel_state {
        AST_STATE_MUTE = (1 << 16),     /*!< Do not transmit voice data */
 };
 
+/*!
+ * \brief Possible T38 states on channels
+ */
+enum ast_t38_state {
+       T38_STATE_UNAVAILABLE,  /*!< T38 is unavailable on this channel or disabled by configuration */
+       T38_STATE_UNKNOWN,      /*!< The channel supports T38 but the current status is unknown */
+       T38_STATE_NEGOTIATING,  /*!< T38 is being negotiated */
+       T38_STATE_REJECTED,     /*!< Remote side has rejected our offer */
+       T38_STATE_NEGOTIATED,   /*!< T38 established */
+};
+
 /*! \brief Main Channel structure associated with a channel. 
  * This is the side of it mostly used by the pbx and call management.
  *
@@ -1300,10 +1311,10 @@ int ast_best_codec(int fmts);
 
 /*! Checks the value of an option */
 /*! 
- * Query the value of an option, optionally blocking until a reply is received
+ * Query the value of an option
  * Works similarly to setoption except only reads the options.
  */
-struct ast_frame *ast_channel_queryoption(struct ast_channel *channel, int option, void *data, int *datalen, int block);
+int ast_channel_queryoption(struct ast_channel *channel, int option, void *data, int *datalen, int block);
 
 /*! Checks for HTML support on a channel */
 /*! Returns 0 if channel does not support HTML or non-zero if it does */
@@ -1557,6 +1568,18 @@ static inline int ast_select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds,
 #endif
 }
 
+/*! \brief Retrieves the current T38 state of a channel */
+static inline enum ast_t38_state ast_channel_get_t38_state(struct ast_channel *chan)
+{
+       enum ast_t38_state state = T38_STATE_UNAVAILABLE;
+       int datalen = sizeof(state);
+
+       ast_channel_queryoption(chan, AST_OPTION_T38_STATE, &state, &datalen, 0);
+
+       return state;
+}
+
+
 #ifdef DO_CRASH
 #define CRASH do { fprintf(stderr, "!! Forcing immediate crash a-la abort !!\n"); *((int *)0) = 0; } while(0)
 #else

diff --git a/include/asterisk/frame.h b/include/asterisk/frame.h
index 3983c84..012f7a9 100644 (file)
--- a/include/asterisk/frame.h
+++ b/include/asterisk/frame.h
@@ -292,6 +292,15 @@ enum ast_control_frame_type {
        AST_CONTROL_HOLD = 16,          /*!< Indicate call is placed on hold */
        AST_CONTROL_UNHOLD = 17,        /*!< Indicate call is left from hold */
        AST_CONTROL_VIDUPDATE = 18,     /*!< Indicate video frame update */
+       AST_CONTROL_T38 = 19            /*!< T38 state change request/notification */
+};
+
+enum ast_control_t38 {
+       AST_T38_REQUEST_NEGOTIATE = 1,  /*!< Request T38 on a channel (voice to fax) */
+       AST_T38_REQUEST_TERMINATE,      /*!< Terminate T38 on a channel (fax to voice) */
+       AST_T38_NEGOTIATED,             /*!< T38 negotiated (fax mode) */
+       AST_T38_TERMINATED,             /*!< T38 terminated (back to voice) */
+       AST_T38_REFUSED                 /*!< T38 refused for some reason (usually rejected by remote end) */
 };
 
 #define AST_SMOOTHER_FLAG_G729         (1 << 0)
@@ -340,6 +349,12 @@ enum ast_control_frame_type {
 /*! Explicitly enable or disable echo cancelation for the given channel */
 #define        AST_OPTION_ECHOCAN              8
 
+/* !
+ * Read-only. Allows query current status of T38 on the channel.
+ * data: ast_t38state
+ */
+#define AST_OPTION_T38_STATE           10
+
 struct oprmode {
        struct ast_channel *peer;
        int mode;

diff --git a/main/channel.c b/main/channel.c
index bbfcfdd..197cf1e 100644 (file)
--- a/main/channel.c
+++ b/main/channel.c
@@ -4481,23 +4481,28 @@ enum ast_bridge_result ast_channel_bridge(struct ast_channel *c0, struct ast_cha
 /*! \brief Sets an option on a channel */
 int ast_channel_setoption(struct ast_channel *chan, int option, void *data, int datalen, int block)
 {
-       int res;
-
-       if (chan->tech->setoption) {
-               res = chan->tech->setoption(chan, option, data, datalen);
-               if (res < 0)
-                       return res;
-       } else {
+       if (!chan->tech->setoption) {
                errno = ENOSYS;
                return -1;
        }
-       if (block) {
-               /* XXX Implement blocking -- just wait for our option frame reply, discarding
-                  intermediate packets. XXX */
+
+       if (block)
                ast_log(LOG_ERROR, "XXX Blocking not implemented yet XXX\n");
+
+       return chan->tech->setoption(chan, option, data, datalen);
+}
+
+int ast_channel_queryoption(struct ast_channel *chan, int option, void *data, int *datalen, int block)
+{
+       if (!chan->tech->queryoption) {
+               errno = ENOSYS;
                return -1;
        }
-       return 0;
+
+       if (block)
+               ast_log(LOG_ERROR, "XXX Blocking not implemented yet XXX\n");
+
+       return chan->tech->queryoption(chan, option, data, datalen);
 }
 
 struct tonepair_def {

diff --git a/main/frame.c b/main/frame.c
index ff182cc..304bd27 100644 (file)
--- a/main/frame.c
+++ b/main/frame.c
@@ -710,6 +710,7 @@ void ast_frame_dump(const char *name, struct ast_frame *f, char *prefix)
        char cn[60];
        char cp[40];
        char cmn[40];
+       const char *message = "Unknown";
 
        if (!name)
                name = noname;
@@ -786,6 +787,24 @@ void ast_frame_dump(const char *name, struct ast_frame *f, char *prefix)
                case AST_CONTROL_UNHOLD:
                        strcpy(subclass, "Unhold");
                        break;
+               case AST_CONTROL_T38:
+                       if (f->datalen != sizeof(enum ast_control_t38)) {
+                               message = "Invalid";
+                       } else {
+                               enum ast_control_t38 state = *((enum ast_control_t38 *) f->data);
+                               if (state == AST_T38_REQUEST_NEGOTIATE)
+                                       message = "Negotiation Requested";
+                               else if (state == AST_T38_REQUEST_TERMINATE)
+                                       message = "Negotiation Request Terminated";
+                               else if (state == AST_T38_NEGOTIATED)
+                                       message = "Negotiated";
+                               else if (state == AST_T38_TERMINATED)
+                                       message = "Terminated";
+                               else if (state == AST_T38_REFUSED)
+                                       message = "Refused";
+                       }
+                       snprintf(subclass, sizeof(subclass), "T38/%s", message);
+                       break;
                case -1:
                        strcpy(subclass, "Stop generators");
                        break;