/* * Asterisk -- An open source telephony toolkit. * * Copyright (C) 2013 Digium, Inc. * * Richard Mudgett * * See http://www.asterisk.org for more information about * the Asterisk project. Please do not directly contact * any of the maintainers of this project for assistance; * the project provides a web site, mailing lists and IRC * channels for your use. * * This program is free software, distributed under the terms of * the GNU General Public License Version 2. See the LICENSE file * at the top of the source tree. */ /*! * \file * \brief Local proxy channel driver. * * \author Richard Mudgett * * See Also: * \arg \ref AstCREDITS */ /*** MODULEINFO core ***/ #include "asterisk.h" ASTERISK_FILE_VERSION(__FILE__, "$Revision$") /* ------------------------------------------------------------------- */ #include "asterisk/channel.h" #include "asterisk/pbx.h" #include "asterisk/cli.h" #include "asterisk/manager.h" #include "asterisk/devicestate.h" #include "asterisk/astobj2.h" #include "asterisk/bridging.h" #include "asterisk/core_unreal.h" #include "asterisk/core_local.h" #include "asterisk/_private.h" /*** DOCUMENTATION Optimize away a local channel when possible. The channel name to optimize away. A local channel created with "/n" will not automatically optimize away. Calling this command on the local channel will clear that flag and allow it to optimize away if it's bridged or when it becomes bridged. ***/ static const char tdesc[] = "Local Proxy Channel Driver"; static struct ao2_container *locals; static struct ast_channel *local_request(const char *type, struct ast_format_cap *cap, const struct ast_channel *requestor, const char *data, int *cause); static int local_call(struct ast_channel *ast, const char *dest, int timeout); static int local_hangup(struct ast_channel *ast); static int local_devicestate(const char *data); /* PBX interface structure for channel registration */ static struct ast_channel_tech local_tech = { .type = "Local", .description = tdesc, .requester = local_request, .send_digit_begin = ast_unreal_digit_begin, .send_digit_end = ast_unreal_digit_end, .call = local_call, .hangup = local_hangup, .answer = ast_unreal_answer, .read = ast_unreal_read, .write = ast_unreal_write, .write_video = ast_unreal_write, .exception = ast_unreal_read, .indicate = ast_unreal_indicate, .fixup = ast_unreal_fixup, .send_html = ast_unreal_sendhtml, .send_text = ast_unreal_sendtext, .devicestate = local_devicestate, .queryoption = ast_unreal_queryoption, .setoption = ast_unreal_setoption, }; /*! What to do with the ;2 channel when ast_call() happens. */ enum local_call_action { /* The ast_call() will run dialplan on the ;2 channel. */ LOCAL_CALL_ACTION_DIALPLAN, /* The ast_call() will impart the ;2 channel into a bridge. */ LOCAL_CALL_ACTION_BRIDGE, /* The ast_call() will masquerade the ;2 channel into a channel. */ LOCAL_CALL_ACTION_MASQUERADE, }; /*! Join a bridge on ast_call() parameters. */ struct local_bridge { /*! Bridge to join. */ struct ast_bridge *join; /*! Channel to swap with when joining bridge. */ struct ast_channel *swap; /*! Features that are specific to this channel when pushed into the bridge. */ struct ast_bridge_features *features; }; /*! * \brief the local pvt structure for all channels * * The local channel pvt has two ast_chan objects - the "owner" and the "next channel", the outbound channel * * ast_chan owner -> local_pvt -> ast_chan chan */ struct local_pvt { /*! Unreal channel driver base class values. */ struct ast_unreal_pvt base; /*! Additional action arguments */ union { /*! Make ;2 join a bridge on ast_call(). */ struct local_bridge bridge; /*! Make ;2 masquerade into this channel on ast_call(). */ struct ast_channel *masq; } action; /*! What to do with the ;2 channel on ast_call(). */ enum local_call_action type; /*! Context to call */ char context[AST_MAX_CONTEXT]; /*! Extension to call */ char exten[AST_MAX_EXTENSION]; }; struct ast_channel *ast_local_get_peer(struct ast_channel *ast) { struct local_pvt *p = ast_channel_tech_pvt(ast); struct local_pvt *found; struct ast_channel *peer; if (!p) { return NULL; } found = p ? ao2_find(locals, p, 0) : NULL; if (!found) { /* ast is either not a local channel or it has alredy been hungup */ return NULL; } ao2_lock(found); if (ast == p->base.owner) { peer = p->base.chan; } else if (ast == p->base.chan) { peer = p->base.owner; } else { peer = NULL; } if (peer) { ast_channel_ref(peer); } ao2_unlock(found); ao2_ref(found, -1); return peer; } /*! \brief Adds devicestate to local channels */ static int local_devicestate(const char *data) { int is_inuse = 0; int res = AST_DEVICE_INVALID; char *exten = ast_strdupa(data); char *context; char *opts; struct local_pvt *lp; struct ao2_iterator it; /* Strip options if they exist */ opts = strchr(exten, '/'); if (opts) { *opts = '\0'; } context = strchr(exten, '@'); if (!context) { ast_log(LOG_WARNING, "Someone used Local/%s somewhere without a @context. This is bad.\n", data); return AST_DEVICE_INVALID; } *context++ = '\0'; it = ao2_iterator_init(locals, 0); for (; (lp = ao2_iterator_next(&it)); ao2_ref(lp, -1)) { ao2_lock(lp); if (!strcmp(exten, lp->exten) && !strcmp(context, lp->context)) { res = AST_DEVICE_NOT_INUSE; if (lp->base.owner && ast_test_flag(&lp->base, AST_UNREAL_CARETAKER_THREAD)) { is_inuse = 1; } } ao2_unlock(lp); if (is_inuse) { res = AST_DEVICE_INUSE; ao2_ref(lp, -1); break; } } ao2_iterator_destroy(&it); if (res == AST_DEVICE_INVALID) { ast_debug(3, "Checking if extension %s@%s exists (devicestate)\n", exten, context); if (ast_exists_extension(NULL, context, exten, 1, NULL)) { res = AST_DEVICE_NOT_INUSE; } } return res; } /*! * \internal * \brief Post the LocalBridge AMI event. * \since 12.0.0 * * \param p local_pvt to raise the bridge event. * * \return Nothing */ static void local_bridge_event(struct local_pvt *p) { ao2_lock(p); /*** DOCUMENTATION Raised when two halves of a Local Channel form a bridge. The name of the Local Channel half that bridges to another channel. The name of the Local Channel half that executes the dialplan. The context in the dialplan that Channel2 starts in. The extension in the dialplan that Channel2 starts in. ***/ manager_event(EVENT_FLAG_CALL, "LocalBridge", "Channel1: %s\r\n" "Channel2: %s\r\n" "Uniqueid1: %s\r\n" "Uniqueid2: %s\r\n" "Context: %s\r\n" "Exten: %s\r\n" "LocalOptimization: %s\r\n", ast_channel_name(p->base.owner), ast_channel_name(p->base.chan), ast_channel_uniqueid(p->base.owner), ast_channel_uniqueid(p->base.chan), p->context, p->exten, ast_test_flag(&p->base, AST_UNREAL_NO_OPTIMIZATION) ? "Yes" : "No"); ao2_unlock(p); } int ast_local_setup_bridge(struct ast_channel *ast, struct ast_bridge *bridge, struct ast_channel *swap, struct ast_bridge_features *features) { struct local_pvt *p; struct local_pvt *found; int res = -1; /* Sanity checks. */ if (!ast || !bridge) { ast_bridge_features_destroy(features); return -1; } ast_channel_lock(ast); p = ast_channel_tech_pvt(ast); ast_channel_unlock(ast); found = p ? ao2_find(locals, p, 0) : NULL; if (found) { ao2_lock(found); if (found->type == LOCAL_CALL_ACTION_DIALPLAN && found->base.owner && found->base.chan && !ast_test_flag(&found->base, AST_UNREAL_CARETAKER_THREAD)) { ao2_ref(bridge, +1); if (swap) { ast_channel_ref(swap); } found->type = LOCAL_CALL_ACTION_BRIDGE; found->action.bridge.join = bridge; found->action.bridge.swap = swap; found->action.bridge.features = features; res = 0; } else { ast_bridge_features_destroy(features); } ao2_unlock(found); ao2_ref(found, -1); } return res; } int ast_local_setup_masquerade(struct ast_channel *ast, struct ast_channel *masq) { struct local_pvt *p; struct local_pvt *found; int res = -1; /* Sanity checks. */ if (!ast || !masq) { return -1; } ast_channel_lock(ast); p = ast_channel_tech_pvt(ast); ast_channel_unlock(ast); found = p ? ao2_find(locals, p, 0) : NULL; if (found) { ao2_lock(found); if (found->type == LOCAL_CALL_ACTION_DIALPLAN && found->base.owner && found->base.chan && !ast_test_flag(&found->base, AST_UNREAL_CARETAKER_THREAD)) { ast_channel_ref(masq); found->type = LOCAL_CALL_ACTION_MASQUERADE; found->action.masq = masq; res = 0; } ao2_unlock(found); ao2_ref(found, -1); } return res; } /*! \brief Initiate new call, part of PBX interface * dest is the dial string */ static int local_call(struct ast_channel *ast, const char *dest, int timeout) { struct local_pvt *p = ast_channel_tech_pvt(ast); int pvt_locked = 0; struct ast_channel *owner = NULL; struct ast_channel *chan = NULL; int res; char *reduced_dest = ast_strdupa(dest); char *slash; const char *chan_cid; if (!p) { return -1; } /* since we are letting go of channel locks that were locked coming into * this function, then we need to give the tech pvt a ref */ ao2_ref(p, 1); ast_channel_unlock(ast); ast_unreal_lock_all(&p->base, &chan, &owner); pvt_locked = 1; if (owner != ast) { res = -1; goto return_cleanup; } if (!owner || !chan) { res = -1; goto return_cleanup; } ast_unreal_call_setup(owner, chan); /* * If the local channel has /n on the end of it, we need to lop * that off for our argument to setting up the CC_INTERFACES * variable. */ if ((slash = strrchr(reduced_dest, '/'))) { *slash = '\0'; } ast_set_cc_interfaces_chanvar(chan, reduced_dest); ao2_unlock(p); pvt_locked = 0; ast_channel_unlock(owner); chan_cid = S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL); if (chan_cid) { chan_cid = ast_strdupa(chan_cid); } ast_channel_unlock(chan); res = -1; switch (p->type) { case LOCAL_CALL_ACTION_DIALPLAN: if (!ast_exists_extension(NULL, p->context, p->exten, 1, chan_cid)) { ast_log(LOG_NOTICE, "No such extension/context %s@%s while calling Local channel\n", p->exten, p->context); } else { local_bridge_event(p); /* Start switch on sub channel */ res = ast_pbx_start(chan); } break; case LOCAL_CALL_ACTION_BRIDGE: local_bridge_event(p); ast_answer(chan); res = ast_bridge_impart(p->action.bridge.join, chan, p->action.bridge.swap, p->action.bridge.features, 1); ao2_ref(p->action.bridge.join, -1); p->action.bridge.join = NULL; ao2_cleanup(p->action.bridge.swap); p->action.bridge.swap = NULL; p->action.bridge.features = NULL; break; case LOCAL_CALL_ACTION_MASQUERADE: local_bridge_event(p); ast_answer(chan); res = ast_channel_masquerade(p->action.masq, chan); if (!res) { ast_do_masquerade(p->action.masq); /* Chan is now an orphaned zombie. Destroy it. */ ast_hangup(chan); } p->action.masq = ast_channel_unref(p->action.masq); break; } if (!res) { ao2_lock(p); ast_set_flag(&p->base, AST_UNREAL_CARETAKER_THREAD); ao2_unlock(p); } /* we already unlocked them, clear them here so the cleanup label won't touch them. */ owner = ast_channel_unref(owner); chan = ast_channel_unref(chan); return_cleanup: if (p) { if (pvt_locked) { ao2_unlock(p); } ao2_ref(p, -1); } if (chan) { ast_channel_unlock(chan); ast_channel_unref(chan); } /* * owner is supposed to be == to ast, if it is, don't unlock it * because ast must exit locked */ if (owner) { if (owner != ast) { ast_channel_unlock(owner); ast_channel_lock(ast); } ast_channel_unref(owner); } else { /* we have to exit with ast locked */ ast_channel_lock(ast); } return res; } /*! \brief Hangup a call through the local proxy channel */ static int local_hangup(struct ast_channel *ast) { struct local_pvt *p = ast_channel_tech_pvt(ast); int res; if (!p) { return -1; } /* give the pvt a ref to fulfill calling requirements. */ ao2_ref(p, +1); res = ast_unreal_hangup(&p->base, ast); if (!res) { int unlink; ao2_lock(p); unlink = !p->base.owner && !p->base.chan; ao2_unlock(p); if (unlink) { ao2_unlink(locals, p); } } ao2_ref(p, -1); return res; } /*! * \internal * \brief struct local_pvt destructor. * * \param vdoomed Object to destroy. * * \return Nothing */ static void local_pvt_destructor(void *vdoomed) { struct local_pvt *doomed = vdoomed; switch (doomed->type) { case LOCAL_CALL_ACTION_DIALPLAN: break; case LOCAL_CALL_ACTION_BRIDGE: ao2_cleanup(doomed->action.bridge.join); ao2_cleanup(doomed->action.bridge.swap); ast_bridge_features_destroy(doomed->action.bridge.features); break; case LOCAL_CALL_ACTION_MASQUERADE: ao2_cleanup(doomed->action.masq); break; } ast_unreal_destructor(&doomed->base); } /*! \brief Create a call structure */ static struct local_pvt *local_alloc(const char *data, struct ast_format_cap *cap) { struct local_pvt *pvt; char *parse; char *context; char *opts; pvt = (struct local_pvt *) ast_unreal_alloc(sizeof(*pvt), local_pvt_destructor, cap); if (!pvt) { return NULL; } parse = ast_strdupa(data); /* * Local channels intercept MOH by default. * * This is a silly default because it represents state held by * the local channels. Unless local channel optimization is * disabled, the state will dissapear when the local channels * optimize out. */ ast_set_flag(&pvt->base, AST_UNREAL_MOH_INTERCEPT); /* Look for options */ if ((opts = strchr(parse, '/'))) { *opts++ = '\0'; if (strchr(opts, 'n')) { ast_set_flag(&pvt->base, AST_UNREAL_NO_OPTIMIZATION); } if (strchr(opts, 'j')) { if (ast_test_flag(&pvt->base, AST_UNREAL_NO_OPTIMIZATION)) { ast_set_flag(&pvt->base.jb_conf, AST_JB_ENABLED); } else { ast_log(LOG_ERROR, "You must use the 'n' option with the 'j' option to enable the jitter buffer\n"); } } if (strchr(opts, 'm')) { ast_clear_flag(&pvt->base, AST_UNREAL_MOH_INTERCEPT); } } /* Look for a context */ if ((context = strchr(parse, '@'))) { *context++ = '\0'; } ast_copy_string(pvt->context, S_OR(context, "default"), sizeof(pvt->context)); ast_copy_string(pvt->exten, parse, sizeof(pvt->exten)); snprintf(pvt->base.name, sizeof(pvt->base.name), "%s@%s", pvt->exten, pvt->context); return pvt; /* this is returned with a ref */ } /*! \brief Part of PBX interface */ static struct ast_channel *local_request(const char *type, struct ast_format_cap *cap, const struct ast_channel *requestor, const char *data, int *cause) { struct local_pvt *p; struct ast_channel *chan; struct ast_callid *callid; /* Allocate a new private structure and then Asterisk channels */ p = local_alloc(data, cap); if (!p) { return NULL; } callid = ast_read_threadstorage_callid(); chan = ast_unreal_new_channels(&p->base, &local_tech, AST_STATE_DOWN, AST_STATE_RING, p->exten, p->context, requestor, callid); if (chan) { ao2_link(locals, p); } if (callid) { ast_callid_unref(callid); } ao2_ref(p, -1); /* kill the ref from the alloc */ return chan; } /*! \brief CLI command "local show channels" */ static char *locals_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a) { struct local_pvt *p; struct ao2_iterator it; switch (cmd) { case CLI_INIT: e->command = "local show channels"; e->usage = "Usage: local show channels\n" " Provides summary information on active local proxy channels.\n"; return NULL; case CLI_GENERATE: return NULL; } if (a->argc != 3) { return CLI_SHOWUSAGE; } if (ao2_container_count(locals) == 0) { ast_cli(a->fd, "No local channels in use\n"); return RESULT_SUCCESS; } it = ao2_iterator_init(locals, 0); while ((p = ao2_iterator_next(&it))) { ao2_lock(p); ast_cli(a->fd, "%s -- %s\n", p->base.owner ? ast_channel_name(p->base.owner) : "", p->base.name); ao2_unlock(p); ao2_ref(p, -1); } ao2_iterator_destroy(&it); return CLI_SUCCESS; } static struct ast_cli_entry cli_local[] = { AST_CLI_DEFINE(locals_show, "List status of local channels"), }; static int manager_optimize_away(struct mansession *s, const struct message *m) { const char *channel; struct local_pvt *p; struct local_pvt *found; struct ast_channel *chan; channel = astman_get_header(m, "Channel"); if (ast_strlen_zero(channel)) { astman_send_error(s, m, "'Channel' not specified."); return 0; } chan = ast_channel_get_by_name(channel); if (!chan) { astman_send_error(s, m, "Channel does not exist."); return 0; } p = ast_channel_tech_pvt(chan); ast_channel_unref(chan); found = p ? ao2_find(locals, p, 0) : NULL; if (found) { ao2_lock(found); ast_clear_flag(&found->base, AST_UNREAL_NO_OPTIMIZATION); ao2_unlock(found); ao2_ref(found, -1); astman_send_ack(s, m, "Queued channel to be optimized away"); } else { astman_send_error(s, m, "Unable to find channel"); } return 0; } static int locals_cmp_cb(void *obj, void *arg, int flags) { return (obj == arg) ? CMP_MATCH : 0; } /*! * \internal * \brief Shutdown the local proxy channel. * \since 12.0.0 * * \return Nothing */ static void local_shutdown(void) { struct local_pvt *p; struct ao2_iterator it; /* First, take us out of the channel loop */ ast_cli_unregister_multiple(cli_local, ARRAY_LEN(cli_local)); ast_manager_unregister("LocalOptimizeAway"); ast_channel_unregister(&local_tech); it = ao2_iterator_init(locals, 0); while ((p = ao2_iterator_next(&it))) { if (p->base.owner) { ast_softhangup(p->base.owner, AST_SOFTHANGUP_APPUNLOAD); } ao2_ref(p, -1); } ao2_iterator_destroy(&it); ao2_ref(locals, -1); locals = NULL; ast_format_cap_destroy(local_tech.capabilities); } int ast_local_init(void) { if (!(local_tech.capabilities = ast_format_cap_alloc())) { return -1; } ast_format_cap_add_all(local_tech.capabilities); locals = ao2_container_alloc_list(AO2_ALLOC_OPT_LOCK_MUTEX, 0, NULL, locals_cmp_cb); if (!locals) { ast_format_cap_destroy(local_tech.capabilities); return -1; } /* Make sure we can register our channel type */ if (ast_channel_register(&local_tech)) { ast_log(LOG_ERROR, "Unable to register channel class 'Local'\n"); ao2_ref(locals, -1); ast_format_cap_destroy(local_tech.capabilities); return -1; } ast_cli_register_multiple(cli_local, ARRAY_LEN(cli_local)); ast_manager_register_xml_core("LocalOptimizeAway", EVENT_FLAG_SYSTEM|EVENT_FLAG_CALL, manager_optimize_away); ast_register_atexit(local_shutdown); return 0; }