Add support for reserving a fax session before answering the channel.

Note: this change breaks ABI compatibility.

FAX-217

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@297486 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/include/asterisk/res_fax.h b/include/asterisk/res_fax.h
index a6b3a21c1b4959dae20b1e2a6ee0f3c06c1499d9..70715d58c37fdd3c6c89ddb092357e14605e6611 100644 (file)
--- a/include/asterisk/res_fax.h
+++ b/include/asterisk/res_fax.h
@@ -58,8 +58,10 @@ enum ast_fax_modems {
 
 /*! \brief current state of a fax session */
 enum ast_fax_state {
+       /*! reserved state */
+       AST_FAX_STATE_RESERVED = 0,
        /*! uninitialized state */
-       AST_FAX_STATE_UNINITIALIZED = 0,
+       AST_FAX_STATE_UNINITIALIZED,
        /*! initialized state */
        AST_FAX_STATE_INITIALIZED,
        /*! fax resources open state */
@@ -168,7 +170,8 @@ struct ast_fax_session_details {
 
 struct ast_fax_tech;
 struct ast_fax_debug_info;
-       
+struct ast_fax_tech_token;
+
 /*! \brief The data required to handle a fax session */
 struct ast_fax_session {
        /*! session id */
@@ -183,6 +186,8 @@ struct ast_fax_session {
        unsigned long frames_sent;
        /*! the fax technology callbacks */
        const struct ast_fax_tech *tech;
+       /*! the token used to reserve this session */
+       struct ast_fax_tech_token *token;
        /*! private implementation pointer */
        void *tech_pvt;
        /*! fax state */
@@ -197,9 +202,11 @@ struct ast_fax_session {
        struct ast_fax_debug_info *debug_info;
        /*! used to take variable-sized frames in and output frames of an expected size to the fax stack */
        struct ast_smoother *smoother;
-};
 
-struct ast_fax_tech_token;
+       /*! some flags to track the stat counters for this session */
+       unsigned int reserved:1;
+       unsigned int active:1;
+};
 
 /*! \brief used to register a FAX technology module with res_fax */
 struct ast_fax_tech {
@@ -242,7 +249,15 @@ struct ast_fax_tech {
        /*! displays settings from the fax technology module */
        char * (* const cli_show_settings)(int);
 };
-  
+
+/*! \brief used by res_fax to reserve a FAX session */
+struct ast_fax_tech_token {
+       /*! the fax technology callbacks */
+       const struct ast_fax_tech *tech;
+       /*! private implementation pointer */
+       void *tech_pvt;
+};
+
 /*! \brief register a fax technology */
 int ast_fax_tech_register(struct ast_fax_tech *tech);
 

diff --git a/res/res_fax.c b/res/res_fax.c
index 6867ed8c161890fbed3e060a5843a9b310281e3c..3e878d577f720b714a7b3cfecbb553c50d0484df 100644 (file)
--- a/res/res_fax.c
+++ b/res/res_fax.c
@@ -220,6 +220,8 @@ static int fax_logger_level = -1;
 static struct {
        /*! The number of active FAX sessions */
        int active_sessions;
+       /*! The number of reserved FAX sessions */
+       int reserved_sessions;
        /*! active sessions are astobj2 objects */
        struct ao2_container *container;
        /*! Total number of Tx FAX attempts */
@@ -631,12 +633,26 @@ static unsigned int fax_rate_str_to_int(const char *ratestr)
        }
 }
 
+static void fax_session_release(struct ast_fax_session *s)
+{
+       if (s->token) {
+               s->tech->release_token(s->token);
+               s->token = NULL;
+       }
+
+       if (s->reserved) {
+               ast_atomic_fetchadd_int(&faxregistry.reserved_sessions, -1);
+               s->reserved = 0;
+       }
+}
+
 /*! \brief destroy a FAX session structure */
 static void destroy_session(void *session)
 {
        struct ast_fax_session *s = session;
 
        if (s->tech) {
+               fax_session_release(s);
                if (s->tech_pvt) {
                        s->tech->destroy_session(s);
                }
@@ -656,14 +672,16 @@ static void destroy_session(void *session)
                ast_smoother_free(s->smoother);
        }
 
-       ast_atomic_fetchadd_int(&faxregistry.active_sessions, -1);
+       if (s->active) {
+               ast_atomic_fetchadd_int(&faxregistry.active_sessions, -1);
+               s->active = 0;
+       }
 
        ast_free(s->channame);
        ast_free(s->chan_uniqueid);
 }
 
-/*! \brief create a FAX session */
-static struct ast_fax_session *fax_session_new(struct ast_fax_session_details *details, struct ast_channel *chan)
+static struct ast_fax_session *fax_session_reserve(struct ast_fax_session_details *details)
 {
        struct ast_fax_session *s;
        struct fax_module *faxmod;
@@ -672,7 +690,68 @@ static struct ast_fax_session *fax_session_new(struct ast_fax_session_details *d
                return NULL;
        }
 
+       s->state = AST_FAX_STATE_RESERVED;
+
+       /* locate a FAX technology module that can handle said requirements
+        * Note: the requirements have not yet been finalized as T.38
+        * negotiation has not yet occured. */
+       AST_RWLIST_RDLOCK(&faxmodules);
+       AST_RWLIST_TRAVERSE(&faxmodules, faxmod, list) {
+               if ((faxmod->tech->caps & details->caps) != details->caps) {
+                       continue;
+               }
+               ast_debug(4, "Reserving a FAX session from '%s'.\n", faxmod->tech->description);
+               ast_module_ref(faxmod->tech->module);
+               s->tech = faxmod->tech;
+               break;
+       }
+       AST_RWLIST_UNLOCK(&faxmodules);
+
+       if (!faxmod) {
+               ast_log(LOG_ERROR, "Could not locate a FAX technology module with capabilities (0x%X)\n", details->caps);
+               ao2_ref(s, -1);
+               return NULL;
+       }
+
+       if (!s->tech->reserve_session) {
+               ast_log(LOG_WARNING, "Selected FAX technology module (%s) does not support reserving sessions.\n", s->tech->description);
+               return s;
+       }
+
+       if (!(s->token = s->tech->reserve_session(s))) {
+               ao2_ref(s, -1);
+               return NULL;
+       }
+
+       s->reserved = 1;
+       ast_atomic_fetchadd_int(&faxregistry.reserved_sessions, 1);
+
+       return s;
+}
+
+/*! \brief create a FAX session */
+static struct ast_fax_session *fax_session_new(struct ast_fax_session_details *details, struct ast_channel *chan, struct ast_fax_session *reserved)
+{
+       struct ast_fax_session *s = NULL;
+       struct fax_module *faxmod;
+
+       if (reserved) {
+               s = reserved;
+               ao2_ref(reserved, +1);
+
+               if (s->reserved) {
+                       ast_atomic_fetchadd_int(&faxregistry.reserved_sessions, -1);
+                       s->reserved = 0;
+               }
+       }
+
+       if (!s && !(s = ao2_alloc(sizeof(*s), destroy_session))) {
+               return NULL;
+       }
+
+       s->active = 1;
        ast_atomic_fetchadd_int(&faxregistry.active_sessions, 1);
+       s->state = AST_FAX_STATE_UNINITIALIZED;
 
        if (details->option.debug && (details->caps & AST_FAX_TECH_AUDIO)) {
                if (!(s->debug_info = ast_calloc(1, sizeof(*(s->debug_info))))) {
@@ -701,39 +780,39 @@ static struct ast_fax_session *fax_session_new(struct ast_fax_session_details *d
        s->chan = chan;
        s->details = details;
        ao2_ref(s->details, 1);
-       s->state = AST_FAX_STATE_UNINITIALIZED;
 
        details->id = s->id = ast_atomic_fetchadd_int(&faxregistry.nextsessionname, 1);
 
-       /* locate a FAX technology module that can handle said requirements */
-       AST_RWLIST_RDLOCK(&faxmodules);
-       AST_RWLIST_TRAVERSE(&faxmodules, faxmod, list) {
-               if ((faxmod->tech->caps & details->caps) != details->caps) {
-                       continue;
+       if (!s->tech) {
+               /* locate a FAX technology module that can handle said requirements */
+               AST_RWLIST_RDLOCK(&faxmodules);
+               AST_RWLIST_TRAVERSE(&faxmodules, faxmod, list) {
+                       if ((faxmod->tech->caps & details->caps) != details->caps) {
+                               continue;
+                       }
+                       ast_debug(4, "Requesting a new FAX session from '%s'.\n", faxmod->tech->description);
+                       ast_module_ref(faxmod->tech->module);
+                       s->tech = faxmod->tech;
+                       break;
                }
-               ast_debug(4, "Requesting a new FAX session from '%s'.\n", faxmod->tech->description);
-               ast_module_ref(faxmod->tech->module);
-               s->tech = faxmod->tech;
-               break;
-       }
-       AST_RWLIST_UNLOCK(&faxmodules);
+               AST_RWLIST_UNLOCK(&faxmodules);
 
-       if (!faxmod) {
-               ast_log(LOG_ERROR, "Could not locate a FAX technology module with capabilities (0x%X)\n", details->caps);
-               ao2_ref(s, -1);
-               return NULL;
+               if (!faxmod) {
+                       ast_log(LOG_ERROR, "Could not locate a FAX technology module with capabilities (0x%X)\n", details->caps);
+                       ao2_ref(s, -1);
+                       return NULL;
+               }
        }
-       if (!(s->tech_pvt = s->tech->new_session(s, NULL))) {
+
+       if (!(s->tech_pvt = s->tech->new_session(s, s->token))) {
                ast_log(LOG_ERROR, "FAX session failed to initialize.\n");
                ao2_ref(s, -1);
-               ast_module_unref(faxmod->tech->module);
                return NULL;
        }
        /* link the session to the session container */
        if (!(ao2_link(faxregistry.container, s))) {
                ast_log(LOG_ERROR, "failed to add FAX session '%d' to container.\n", s->id);
                ao2_ref(s, -1);
-               ast_module_unref(faxmod->tech->module);
                return NULL;
        }
        ast_debug(4, "channel '%s' using FAX session '%d'\n", s->channame, s->id);
@@ -987,7 +1066,7 @@ static struct ast_control_t38_parameters our_t38_parameters = {
 };
 
 /*! \brief this is the generic FAX session handling function */
-static int generic_fax_exec(struct ast_channel *chan, struct ast_fax_session_details *details)
+static int generic_fax_exec(struct ast_channel *chan, struct ast_fax_session_details *details, struct ast_fax_session *reserved)
 {
        int ms;
        int timeout = RES_FAX_TIMEOUT;
@@ -1005,7 +1084,7 @@ static int generic_fax_exec(struct ast_channel *chan, struct ast_fax_session_det
        chancount = 1;
 
        /* create the FAX session */
-       if (!(fax = fax_session_new(details, chan))) {
+       if (!(fax = fax_session_new(details, chan, reserved))) {
                ast_log(LOG_ERROR, "Can't create a FAX session, FAX attempt failed.\n");
                report_fax_status(chan, details, "No Available Resource");
                return -1;
@@ -1402,6 +1481,7 @@ static int receivefax_exec(struct ast_channel *chan, const char *data)
        char *parse, modems[128] = "";
        int channel_alive;
        struct ast_fax_session_details *details;
+       struct ast_fax_session *s;
        struct ast_fax_document *doc;
        AST_DECLARE_APP_ARGS(args,
                AST_APP_ARG(filename);
@@ -1498,15 +1578,6 @@ static int receivefax_exec(struct ast_channel *chan, const char *data)
                return -1;
        }
        
-       /* make sure the channel is up */
-       if (chan->_state != AST_STATE_UP) {
-               if (ast_answer(chan)) {
-                       ast_log(LOG_WARNING, "Channel '%s' failed answer attempt.\n", chan->name);
-                       ao2_ref(details, -1);
-                       return -1;
-               }
-       }
-
        ast_atomic_fetchadd_int(&faxregistry.fax_rx_attempts, 1);
 
        pbx_builtin_setvar_helper(chan, "FAXERROR", "Channel Problems");
@@ -1551,11 +1622,32 @@ static int receivefax_exec(struct ast_channel *chan, const char *data)
                return -1;
        }
 
+       if (!(s = fax_session_reserve(details))) {
+               ast_string_field_set(details, resultstr, "error reserving fax session");
+               set_channel_variables(chan, details);
+               ast_log(LOG_ERROR, "Unable to reserve FAX session.\n");
+               ao2_ref(details, -1);
+               return -1;
+       }
+
+       /* make sure the channel is up */
+       if (chan->_state != AST_STATE_UP) {
+               if (ast_answer(chan)) {
+                       ast_string_field_set(details, resultstr, "error answering channel");
+                       set_channel_variables(chan, details);
+                       ast_log(LOG_WARNING, "Channel '%s' failed answer attempt.\n", chan->name);
+                       ao2_ref(s, -1);
+                       ao2_ref(details, -1);
+                       return -1;
+               }
+       }
+
        if (details->caps & AST_FAX_TECH_T38) {
                if (receivefax_t38_init(chan, details)) {
                        ast_string_field_set(details, error, "T38_NEG_ERROR");
                        ast_string_field_set(details, resultstr, "error negotiating T.38");
                        set_channel_variables(chan, details);
+                       ao2_ref(s, -1);
                        ao2_ref(details, -1);
                        ast_log(LOG_ERROR, "error initializing channel '%s' in T.38 mode\n", chan->name);
                        return -1;
@@ -1564,7 +1656,7 @@ static int receivefax_exec(struct ast_channel *chan, const char *data)
                details->option.send_ced = 1;
        }
 
-       if ((channel_alive = generic_fax_exec(chan, details)) < 0) {
+       if ((channel_alive = generic_fax_exec(chan, details, s)) < 0) {
                ast_atomic_fetchadd_int(&faxregistry.fax_failures, 1);
        }
 
@@ -1602,6 +1694,7 @@ static int receivefax_exec(struct ast_channel *chan, const char *data)
                      args.filename);
        ast_channel_unlock(chan);
 
+       ao2_ref(s, -1);
        ao2_ref(details, -1);
 
        /* If the channel hungup return -1; otherwise, return 0 to continue in the dialplan */
@@ -1839,6 +1932,7 @@ static int sendfax_exec(struct ast_channel *chan, const char *data)
        char *parse, *filenames, *c, modems[128] = "";
        int channel_alive, file_count;
        struct ast_fax_session_details *details;
+       struct ast_fax_session *s;
        struct ast_fax_document *doc;
        AST_DECLARE_APP_ARGS(args,
                AST_APP_ARG(filenames);
@@ -1936,15 +2030,6 @@ static int sendfax_exec(struct ast_channel *chan, const char *data)
                return -1;
        }
 
-       /* make sure the channel is up */
-       if (chan->_state != AST_STATE_UP) {
-               if (ast_answer(chan)) {
-                       ast_log(LOG_WARNING, "Channel '%s' failed answer attempt.\n", chan->name);
-                       ao2_ref(details, -1);
-                       return -1;
-               }
-       }
-
        ast_atomic_fetchadd_int(&faxregistry.fax_tx_attempts, 1);
 
        file_count = 0;
@@ -2011,11 +2096,32 @@ static int sendfax_exec(struct ast_channel *chan, const char *data)
                return -1;
        }
 
+       if (!(s = fax_session_reserve(details))) {
+               ast_string_field_set(details, resultstr, "error reserving fax session");
+               set_channel_variables(chan, details);
+               ast_log(LOG_ERROR, "Unable to reserve FAX session.\n");
+               ao2_ref(details, -1);
+               return -1;
+       }
+
+       /* make sure the channel is up */
+       if (chan->_state != AST_STATE_UP) {
+               if (ast_answer(chan)) {
+                       ast_string_field_set(details, resultstr, "error answering channel");
+                       set_channel_variables(chan, details);
+                       ast_log(LOG_WARNING, "Channel '%s' failed answer attempt.\n", chan->name);
+                       ao2_ref(s, -1);
+                       ao2_ref(details, -1);
+                       return -1;
+               }
+       }
+
        if (details->caps & AST_FAX_TECH_T38) {
                if (sendfax_t38_init(chan, details)) {
                        ast_string_field_set(details, error, "T38_NEG_ERROR");
                        ast_string_field_set(details, resultstr, "error negotiating T.38");
                        set_channel_variables(chan, details);
+                       ao2_ref(s, -1);
                        ao2_ref(details, -1);
                        ast_log(LOG_ERROR, "error initializing channel '%s' in T.38 mode\n", chan->name);
                        return -1;
@@ -2024,7 +2130,7 @@ static int sendfax_exec(struct ast_channel *chan, const char *data)
                details->option.send_cng = 1;
        }
 
-       if ((channel_alive = generic_fax_exec(chan, details)) < 0) {
+       if ((channel_alive = generic_fax_exec(chan, details, s)) < 0) {
                ast_atomic_fetchadd_int(&faxregistry.fax_failures, 1);
        }
 
@@ -2036,6 +2142,7 @@ static int sendfax_exec(struct ast_channel *chan, const char *data)
 
        if (!(filenames = generate_filenames_string(details, "FileName: ", "\r\n"))) {
                ast_log(LOG_ERROR, "Error generating SendFAX manager event\n");
+               ao2_ref(s, -1);
                ao2_ref(details, -1);
                return (!channel_alive) ? -1 : 0;
        }
@@ -2069,6 +2176,7 @@ static int sendfax_exec(struct ast_channel *chan, const char *data)
 
        ast_free(filenames);
 
+       ao2_ref(s, -1);
        ao2_ref(details, -1);
 
        /* If the channel hungup return -1; otherwise, return 0 to continue in the dialplan */
@@ -2307,6 +2415,7 @@ static char *cli_fax_show_stats(struct ast_cli_entry *e, int cmd, struct ast_cli
 
        ast_cli(a->fd, "\nFAX Statistics:\n---------------\n\n");
        ast_cli(a->fd, "%-20.20s : %d\n", "Current Sessions", faxregistry.active_sessions);
+       ast_cli(a->fd, "%-20.20s : %d\n", "Reserved Sessions", faxregistry.reserved_sessions);
        ast_cli(a->fd, "%-20.20s : %d\n", "Transmit Attempts", faxregistry.fax_tx_attempts);
        ast_cli(a->fd, "%-20.20s : %d\n", "Receive Attempts", faxregistry.fax_rx_attempts);
        ast_cli(a->fd, "%-20.20s : %d\n", "Completed FAXes", faxregistry.fax_complete);
@@ -2616,6 +2725,7 @@ static int load_module(void)
 
        /* initialize the registry */
        faxregistry.active_sessions = 0;
+       faxregistry.reserved_sessions = 0;
        if (!(faxregistry.container = ao2_container_alloc(FAX_MAXBUCKETS, session_hash_cb, session_cmp_cb))) {
                return AST_MODULE_LOAD_DECLINE;
        }