chan_iax2.c

Asterisk中信道部分的源码 。。。。

			iax2_frame_free(frame.data);
		}

		jb_destroy(pvt->jb);
		ast_string_field_free_memory(pvt);
	}
}

static struct chan_iax2_pvt *new_iax(struct sockaddr_in *sin, const char *host)
{
	struct chan_iax2_pvt *tmp;
	jb_conf jbconf;

	if (!(tmp = ao2_alloc(sizeof(*tmp), pvt_destructor))) {
		return NULL;
	}

	if (ast_string_field_init(tmp, 32)) {
		ao2_ref(tmp, -1);
		tmp = NULL;
		return NULL;
	}
		
	tmp->prefs = prefs;
	tmp->callno = 0;
	tmp->peercallno = 0;
	tmp->transfercallno = 0;
	tmp->bridgecallno = 0;
	tmp->pingid = -1;
	tmp->lagid = -1;
	tmp->autoid = -1;
	tmp->authid = -1;
	tmp->initid = -1;

	ast_string_field_set(tmp,exten, "s");
	ast_string_field_set(tmp,host, host);

	tmp->jb = jb_new();
	tmp->jbid = -1;
	jbconf.max_jitterbuf = maxjitterbuffer;
	jbconf.resync_threshold = resyncthreshold;
	jbconf.max_contig_interp = maxjitterinterps;
	jb_setconf(tmp->jb,&jbconf);

	return tmp;
}

static struct iax_frame *iaxfrdup2(struct iax_frame *fr)
{
	struct iax_frame *new = iax_frame_new(DIRECTION_INGRESS, fr->af.datalen, fr->cacheable);
	if (new) {
		size_t afdatalen = new->afdatalen;
		memcpy(new, fr, sizeof(*new));
		iax_frame_wrap(new, &fr->af);
		new->afdatalen = afdatalen;
		new->data = NULL;
		new->datalen = 0;
		new->direction = DIRECTION_INGRESS;
		new->retrans = -1;
	}
	return new;
}

#define NEW_PREVENT 	0
#define NEW_ALLOW 	1
#define NEW_FORCE 	2

static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, struct chan_iax2_pvt *cur, int check_dcallno)
{
	if ((cur->addr.sin_addr.s_addr == sin->sin_addr.s_addr) &&
		(cur->addr.sin_port == sin->sin_port)) {
		/* This is the main host */
		if ( (cur->peercallno == 0 || cur->peercallno == callno) &&
			 (check_dcallno ? dcallno == cur->callno : 1) ) {
			/* That's us.  Be sure we keep track of the peer call number */
			return 1;
		}
	}
	if ((cur->transfer.sin_addr.s_addr == sin->sin_addr.s_addr) &&
	    (cur->transfer.sin_port == sin->sin_port) && (cur->transferring)) {
		/* We're transferring */
		if ((dcallno == cur->callno) || (cur->transferring == TRANSFER_MEDIAPASS && cur->transfercallno == callno))
			return 1;
	}
	return 0;
}

static void update_max_nontrunk(void)
{
	int max = 1;
	int x;
	/* XXX Prolly don't need locks here XXX */
	for (x=1;x<TRUNK_CALL_START - 1; x++) {
		if (iaxs[x])
			max = x + 1;
	}
	maxnontrunkcall = max;
	if (option_debug && iaxdebug)
		ast_log(LOG_DEBUG, "New max nontrunk callno is %d\n", max);
}

static int make_trunk(unsigned short callno, int locked)
{
	int x;
	int res= 0;
	struct timeval now;
	if (iaxs[callno]->oseqno) {
		ast_log(LOG_WARNING, "Can't make trunk once a call has started!\n");
		return -1;
	}
	if (callno & TRUNK_CALL_START) {
		ast_log(LOG_WARNING, "Call %d is already a trunk\n", callno);
		return -1;
	}
	gettimeofday(&now, NULL);
	for (x = TRUNK_CALL_START; x < ARRAY_LEN(iaxs) - 1; x++) {
		ast_mutex_lock(&iaxsl[x]);
		if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) {
			/* Update the two timers that should have been started */
			/*!
			 * \note We delete these before switching the slot, because if
			 * they fire in the meantime, they will generate a warning.
			 */
			AST_SCHED_DEL(sched, iaxs[callno]->pingid);
			AST_SCHED_DEL(sched, iaxs[callno]->lagid);
			iaxs[x] = iaxs[callno];
			iaxs[x]->callno = x;
			iaxs[callno] = NULL;
			iaxs[x]->pingid = iax2_sched_add(sched, ping_time * 1000, send_ping, (void *)(long)x);
			iaxs[x]->lagid = iax2_sched_add(sched, lagrq_time * 1000, send_lagrq, (void *)(long)x);
			if (locked)
				ast_mutex_unlock(&iaxsl[callno]);
			res = x;
			if (!locked)
				ast_mutex_unlock(&iaxsl[x]);
			break;
		}
		ast_mutex_unlock(&iaxsl[x]);
	}
	if (x >= ARRAY_LEN(iaxs) - 1) {
		ast_log(LOG_WARNING, "Unable to trunk call: Insufficient space\n");
		return -1;
	}
	if (option_debug)
		ast_log(LOG_DEBUG, "Made call %d into trunk call %d\n", callno, x);
	/* We move this call from a non-trunked to a trunked call */
	update_max_trunk();
	update_max_nontrunk();
	return res;
}

/*!
 * \note Calling this function while holding another pvt lock can cause a deadlock.
 */
static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked, int check_dcallno)
{
	int res = 0;
	int x;
	struct timeval now;
	char host[80];

	if (new <= NEW_ALLOW) {
 		if (callno) {
 			struct chan_iax2_pvt *pvt;
 			struct chan_iax2_pvt tmp_pvt = {
 				.callno = dcallno,
 				.peercallno = callno,
 				/* hack!! */
 				.frames_received = check_dcallno,
 			};
 
 			memcpy(&tmp_pvt.addr, sin, sizeof(tmp_pvt.addr));
 
 			if ((pvt = ao2_find(iax_peercallno_pvts, &tmp_pvt, OBJ_POINTER))) {
 				if (return_locked) {
 					ast_mutex_lock(&iaxsl[pvt->callno]);
 				}
 				res = pvt->callno;
 				ao2_ref(pvt, -1);
 				pvt = NULL;
 				return res;
 			}
 		}

		/* This will occur on the first response to a message that we initiated,
		 * such as a PING. */
		if (callno && dcallno && iaxs[dcallno] && !iaxs[dcallno]->peercallno && match(sin, callno, dcallno, iaxs[dcallno], check_dcallno)) {
			iaxs[dcallno]->peercallno = callno;
			res = dcallno;
			store_by_peercallno(iaxs[dcallno]);
			return res;
		}

#ifdef IAX_OLD_FIND
		/* If we get here, we SHOULD NOT find a call structure for this
		   callno; if we do, it means that there is a call structure that
		   has a peer callno but did NOT get entered into the hash table,
		   which is bad.

		   If we find a call structure using this old, slow method, output a log
		   message so we'll know about it. After a few months of leaving this in
		   place, if we don't hear about people seeing these messages, we can
		   remove this code for good.
		*/

		for (x = 1; !res && x < maxnontrunkcall; x++) {
			ast_mutex_lock(&iaxsl[x]);
			if (iaxs[x]) {
				/* Look for an exact match */
				if (match(sin, callno, dcallno, iaxs[x], check_dcallno)) {
					res = x;
				}
			}
			if (!res || !return_locked)
				ast_mutex_unlock(&iaxsl[x]);
		}

		for (x = TRUNK_CALL_START; !res && x < maxtrunkcall; x++) {
			ast_mutex_lock(&iaxsl[x]);
			if (iaxs[x]) {
				/* Look for an exact match */
				if (match(sin, callno, dcallno, iaxs[x], check_dcallno)) {
					res = x;
				}
			}
			if (!res || !return_locked)
				ast_mutex_unlock(&iaxsl[x]);
		}

		if (res) {
			ast_log(LOG_WARNING, "Old call search code found call number %d that was not in hash table!\n", res);
		}
#endif
	}
	if (!res && (new >= NEW_ALLOW)) {
		int start, found = 0;

		/* It may seem odd that we look through the peer list for a name for
		 * this *incoming* call.  Well, it is weird.  However, users don't
		 * have an IP address/port number that we can match against.  So,
		 * this is just checking for a peer that has that IP/port and
		 * assuming that we have a user of the same name.  This isn't always
		 * correct, but it will be changed if needed after authentication. */
		if (!iax2_getpeername(*sin, host, sizeof(host)))
			snprintf(host, sizeof(host), "%s:%d", ast_inet_ntoa(sin->sin_addr), ntohs(sin->sin_port));

		now = ast_tvnow();
		start = 2 + (ast_random() % (TRUNK_CALL_START - 1));
		for (x = start; 1; x++) {
			if (x == TRUNK_CALL_START) {
				x = 1;
				continue;
			}

			/* Find first unused call number that hasn't been used in a while */
			ast_mutex_lock(&iaxsl[x]);
			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) {
				found = 1;
				break;
			}
			ast_mutex_unlock(&iaxsl[x]);
			
			if (x == start - 1) {
				break;
			}
		}
		/* We've still got lock held if we found a spot */
		if (x == start - 1 && !found) {
			ast_log(LOG_WARNING, "No more space\n");
			return 0;
		}
		iaxs[x] = new_iax(sin, host);
		update_max_nontrunk();
		if (iaxs[x]) {
			if (option_debug && iaxdebug)
				ast_log(LOG_DEBUG, "Creating new call structure %d\n", x);
			iaxs[x]->sockfd = sockfd;
			iaxs[x]->addr.sin_port = sin->sin_port;
			iaxs[x]->addr.sin_family = sin->sin_family;
			iaxs[x]->addr.sin_addr.s_addr = sin->sin_addr.s_addr;
			iaxs[x]->peercallno = callno;
			iaxs[x]->callno = x;
			iaxs[x]->pingtime = DEFAULT_RETRY_TIME;
			iaxs[x]->expiry = min_reg_expire;
			iaxs[x]->pingid = iax2_sched_add(sched, ping_time * 1000, send_ping, (void *)(long)x);
			iaxs[x]->lagid = iax2_sched_add(sched, lagrq_time * 1000, send_lagrq, (void *)(long)x);
			iaxs[x]->amaflags = amaflags;
			ast_copy_flags(iaxs[x], (&globalflags), IAX_NOTRANSFER | IAX_TRANSFERMEDIA | IAX_USEJITTERBUF | IAX_FORCEJITTERBUF);
			
			ast_string_field_set(iaxs[x], accountcode, accountcode);
			ast_string_field_set(iaxs[x], mohinterpret, mohinterpret);
			ast_string_field_set(iaxs[x], mohsuggest, mohsuggest);

			if (iaxs[x]->peercallno) {
				store_by_peercallno(iaxs[x]);
			}
		} else {
			ast_log(LOG_WARNING, "Out of resources\n");
			ast_mutex_unlock(&iaxsl[x]);
			return 0;
		}
		if (!return_locked)
			ast_mutex_unlock(&iaxsl[x]);
		res = x;
	}
	return res;
}

static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {

	return __find_callno(callno, dcallno, sin, new, sockfd, 0, full_frame);
}

static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {

	return __find_callno(callno, dcallno, sin, new, sockfd, 1, full_frame);
}

/*!
 * \brief Queue a frame to a call's owning asterisk channel
 *
 * \pre This function assumes that iaxsl[callno] is locked when called.
 *
 * \note IMPORTANT NOTE!!! Any time this function is used, even if iaxs[callno]
 * was valid before calling it, it may no longer be valid after calling it.
 * This function may unlock and lock the mutex associated with this callno,
 * meaning that another thread may grab it and destroy the call.
 */
static int iax2_queue_frame(int callno, struct ast_frame *f)
{
	for (;;) {
		if (iaxs[callno] && iaxs[callno]->owner) {
			if (ast_mutex_trylock(&iaxs[callno]->owner->lock)) {
				/* Avoid deadlock by pausing and trying again */
				DEADLOCK_AVOIDANCE(&iaxsl[callno]);
			} else {
				ast_queue_frame(iaxs[callno]->owner, f);
				ast_mutex_unlock(&iaxs[callno]->owner->lock);
				break;
			}
		} else
			break;
	}
	return 0;
}

/*!
 * \brief Queue a hangup frame on the ast_channel owner
 *
 * This function queues a hangup frame on the owner of the IAX2 pvt struct that
 * is active for the given call number.
 *
 * \pre Assumes lock for callno is already held.
 *
 * \note IMPORTANT NOTE!!! Any time this function is used, even if iaxs[callno]
 * was valid before calling it, it may no longer be valid after calling it.
 * This function may unlock and lock the mutex associated with this callno,
 * meaning that another thread may grab it and destroy the call.
 */
static int iax2_queue_hangup(int callno)
{
	for (;;) {
		if (iaxs[callno] && iaxs[callno]->owner) {
			if (ast_mutex_trylock(&iaxs[callno]->owner->lock)) {
				/* Avoid deadlock by pausing and trying again */
				DEADLOCK_AVOIDANCE(&iaxsl[callno]);
			} else {
				ast_queue_hangup(iaxs[callno]->owner);
				ast_mutex_unlock(&iaxs[callno]->owner->lock);
				break;
			}
		} else
			break;
	}
	return 0;
}

/*!
 * \brief Queue a control frame on the ast_channel owner
 *
 * This function queues a control frame on the owner of the IAX2 pvt struct that
 * is active for the given call number.
 *
 * \pre Assumes lock for callno is already held.
 *
 * \note IMPORTANT NOTE!!! Any time this function is used, even if iaxs[callno]
 * was valid before calling it, it may no longer be valid after calling it.
 * This function may unlock and lock the mutex associated with this callno,
 * meaning that another thread may grab it and destroy the call.
 */
static int iax2_queue_control_data(int callno, 
	enum ast_control_frame_type control, const void *data, size_t datalen)
{
	for (;;) {
		if (iaxs[callno] && iaxs[callno]->owner) {
			if (ast_mutex_trylock(&iaxs[callno]->owner->lock)) {
				/* Avoid deadlock by pausing and trying again */
				DEADLOCK_AVOIDANCE(&iaxsl[callno]);
			} else {
				ast_queue_control_data(iaxs[callno]->owner, control, data, datalen);
				ast_mutex_unlock(&iaxs[callno]->owner->lock);
				break;
			}
		} else
			break;
	}
	return 0;
}
static void destroy_firmware(struct iax_firmware *cur)
{
	/* Close firmware */
	if (cur->fwh) {
		munmap((void*)cur->fwh, ntohl(cur->fwh->datalen) + sizeof(*(cur->fwh)));
	}
	close(cur->fd);
	free(cur);
}

static int try_firmware(char *s)
{
	struct stat stbuf;
	struct iax_firmware *cur;
	int ifd;
	int fd;
	int res;
	
	struct ast_iax2_firmware_header *fwh, fwh2;
	struct MD5Context md5;
	unsigned char sum[16];
	unsigned char buf[1024];
	int len, chunk;
	char *s2;
	char *last;
	s2 = alloca(strlen(s) + 100);
	if (!s2) {
		ast_log(LOG_WARNING, "Alloca failed!\n");
		return -1;
	}
	last = strrchr(s, '/');
	if (last)
		last++;
	else
		last = s;
	snprintf(s2, strlen(s) + 100, "/var/tmp/%s-%ld", last, (unsigned long)ast_random());
	res = stat(s, &stbuf);
	if (res < 0) {
		ast_log(LOG_WARNING, "Failed to stat '%s': %s\n", s, strerror(errno));
		return -1;
	}
	/* Make sure it's not a directory */
	if (S_ISDIR(stbuf.st_mode))
		return -1;
	ifd = open(s, O_RDONLY);
	if (ifd < 0) {
		ast_log(LOG_WARNING, "Cannot open '%s': %s\n", s, strerror(errno));
		return -1;
	}
	fd = open(s2, O_RDWR | O_CREAT | O_EXCL, 0600);