chan_iax2.c

Asterisk中信道部分的源码 。。。。

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2006, Digium, Inc.
 *
 * Mark Spencer <[e-mail]>
 *
 * 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 Implementation of Inter-Asterisk eXchange Version 2
 *
 * \author Mark Spencer <[e-mail]>
 *
 * \par See also
 * \arg \ref Config_iax
 *
 * \ingroup channel_drivers
 */

/*** MODULEINFO
	<use>dahdi</use>
        <depend>res_features</depend>
 ***/

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 140605 $")

#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <dirent.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <sys/time.h>
#include <sys/signal.h>
#include <signal.h>
#include <string.h>
#include <strings.h>
#include <errno.h>
#include <unistd.h>
#include <netdb.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <regex.h>

#if defined(HAVE_ZAPTEL) || defined (HAVE_DAHDI)
#include <sys/ioctl.h>
#include "asterisk/dahdi_compat.h"
#endif

#include "asterisk/lock.h"
#include "asterisk/frame.h" 
#include "asterisk/channel.h"
#include "asterisk/logger.h"
#include "asterisk/module.h"
#include "asterisk/pbx.h"
#include "asterisk/sched.h"
#include "asterisk/io.h"
#include "asterisk/config.h"
#include "asterisk/options.h"
#include "asterisk/cli.h"
#include "asterisk/translate.h"
#include "asterisk/md5.h"
#include "asterisk/cdr.h"
#include "asterisk/crypto.h"
#include "asterisk/acl.h"
#include "asterisk/manager.h"
#include "asterisk/callerid.h"
#include "asterisk/app.h"
#include "asterisk/astdb.h"
#include "asterisk/musiconhold.h"
#include "asterisk/features.h"
#include "asterisk/utils.h"
#include "asterisk/causes.h"
#include "asterisk/localtime.h"
#include "asterisk/aes.h"
#include "asterisk/dnsmgr.h"
#include "asterisk/devicestate.h"
#include "asterisk/netsock.h"
#include "asterisk/stringfields.h"
#include "asterisk/linkedlists.h"
#include "asterisk/astobj2.h"

#include "iax2.h"
#include "iax2-parser.h"
#include "iax2-provision.h"
#include "jitterbuf.h"

/* Define SCHED_MULTITHREADED to run the scheduler in a special
   multithreaded mode. */
#define SCHED_MULTITHREADED

/* Define DEBUG_SCHED_MULTITHREADED to keep track of where each
   thread is actually doing. */
#define DEBUG_SCHED_MULTITHREAD

#ifndef IPTOS_MINCOST
#define IPTOS_MINCOST 0x02
#endif

#ifdef SO_NO_CHECK
static int nochecksums = 0;
#endif


#define PTR_TO_CALLNO(a) ((unsigned short)(unsigned long)(a))
#define CALLNO_TO_PTR(a) ((void *)(unsigned long)(a))

#define DEFAULT_THREAD_COUNT 10
#define DEFAULT_MAX_THREAD_COUNT 100
#define DEFAULT_RETRY_TIME 1000
#define MEMORY_SIZE 100
#define DEFAULT_DROP 3

#define DEBUG_SUPPORT

#define MIN_REUSE_TIME		60	/* Don't reuse a call number within 60 seconds */

/* Sample over last 100 units to determine historic jitter */
#define GAMMA (0.01)

static struct ast_codec_pref prefs;

static const char tdesc[] = "Inter Asterisk eXchange Driver (Ver 2)";

static char context[80] = "default";

static char language[MAX_LANGUAGE] = "";
static char regcontext[AST_MAX_CONTEXT] = "";

static int maxauthreq = 3;
static int max_retries = 4;
static int ping_time = 21;
static int lagrq_time = 10;
static int maxjitterbuffer=1000;
static int resyncthreshold=1000;
static int maxjitterinterps=10;
static int trunkfreq = 20;
static int authdebug = 1;
static int autokill = 0;
static int iaxcompat = 0;

static int iaxdefaultdpcache=10 * 60;	/* Cache dialplan entries for 10 minutes by default */

static int iaxdefaulttimeout = 5;		/* Default to wait no more than 5 seconds for a reply to come back */

static unsigned int tos = 0;

static int min_reg_expire;
static int max_reg_expire;

static int timingfd = -1;				/* Timing file descriptor */

static struct ast_netsock_list *netsock;
static struct ast_netsock_list *outsock;		/*!< used if sourceaddress specified and bindaddr == INADDR_ANY */
static int defaultsockfd = -1;

int (*iax2_regfunk)(const char *username, int onoff) = NULL;

/* Ethernet, etc */
#define IAX_CAPABILITY_FULLBANDWIDTH 	0xFFFF
/* T1, maybe ISDN */
#define IAX_CAPABILITY_MEDBANDWIDTH 	(IAX_CAPABILITY_FULLBANDWIDTH & 	\
					 ~AST_FORMAT_SLINEAR &			\
					 ~AST_FORMAT_ULAW &			\
					 ~AST_FORMAT_ALAW &			\
					 ~AST_FORMAT_G722) 
/* A modem */
#define IAX_CAPABILITY_LOWBANDWIDTH	(IAX_CAPABILITY_MEDBANDWIDTH & 		\
					 ~AST_FORMAT_G726 &			\
					 ~AST_FORMAT_G726_AAL2 &		\
					 ~AST_FORMAT_ADPCM)

#define IAX_CAPABILITY_LOWFREE		(IAX_CAPABILITY_LOWBANDWIDTH & 		\
					 ~AST_FORMAT_G723_1)


#define DEFAULT_MAXMS		2000		/* Must be faster than 2 seconds by default */
#define DEFAULT_FREQ_OK		60 * 1000	/* How often to check for the host to be up */
#define DEFAULT_FREQ_NOTOK	10 * 1000	/* How often to check, if the host is down... */

static	struct io_context *io;
static	struct sched_context *sched;

static int iax2_capability = IAX_CAPABILITY_FULLBANDWIDTH;

static int iaxdebug = 0;

static int iaxtrunkdebug = 0;

static int test_losspct = 0;
#ifdef IAXTESTS
static int test_late = 0;
static int test_resync = 0;
static int test_jit = 0;
static int test_jitpct = 0;
#endif /* IAXTESTS */

static char accountcode[AST_MAX_ACCOUNT_CODE];
static char mohinterpret[MAX_MUSICCLASS];
static char mohsuggest[MAX_MUSICCLASS];
static int amaflags = 0;
static int adsi = 0;
static int delayreject = 0;
static int iax2_encryption = 0;

static struct ast_flags globalflags = { 0 };

static pthread_t netthreadid = AST_PTHREADT_NULL;
static pthread_t schedthreadid = AST_PTHREADT_NULL;
AST_MUTEX_DEFINE_STATIC(sched_lock);
static ast_cond_t sched_cond;

enum {
	IAX_STATE_STARTED = 		(1 << 0),
	IAX_STATE_AUTHENTICATED = 	(1 << 1),
	IAX_STATE_TBD = 		(1 << 2),
	IAX_STATE_UNCHANGED = 		(1 << 3),
} iax2_state;

struct iax2_context {
	char context[AST_MAX_CONTEXT];
	struct iax2_context *next;
};

enum {
	IAX_HASCALLERID = 	(1 << 0),	/*!< CallerID has been specified */
	IAX_DELME =		(1 << 1),	/*!< Needs to be deleted */
	IAX_TEMPONLY =		(1 << 2),	/*!< Temporary (realtime) */
	IAX_TRUNK =		(1 << 3),	/*!< Treat as a trunk */
	IAX_NOTRANSFER =	(1 << 4),	/*!< Don't native bridge */
	IAX_USEJITTERBUF =	(1 << 5),	/*!< Use jitter buffer */
	IAX_DYNAMIC =		(1 << 6),	/*!< dynamic peer */
	IAX_SENDANI = 		(1 << 7),	/*!< Send ANI along with CallerID */
        /* (1 << 8) is currently unused due to the deprecation of an old option. Go ahead, take it! */
	IAX_ALREADYGONE =	(1 << 9),	/*!< Already disconnected */
	IAX_PROVISION =		(1 << 10),	/*!< This is a provisioning request */
	IAX_QUELCH = 		(1 << 11),	/*!< Whether or not we quelch audio */
	IAX_ENCRYPTED =		(1 << 12),	/*!< Whether we should assume encrypted tx/rx */
	IAX_KEYPOPULATED = 	(1 << 13),	/*!< Whether we have a key populated */
	IAX_CODEC_USER_FIRST = 	(1 << 14),	/*!< are we willing to let the other guy choose the codec? */
	IAX_CODEC_NOPREFS =  	(1 << 15), 	/*!< Force old behaviour by turning off prefs */
	IAX_CODEC_NOCAP = 	(1 << 16),	/*!< only consider requested format and ignore capabilities*/
	IAX_RTCACHEFRIENDS = 	(1 << 17), 	/*!< let realtime stay till your reload */
	IAX_RTUPDATE = 		(1 << 18), 	/*!< Send a realtime update */
	IAX_RTAUTOCLEAR = 	(1 << 19), 	/*!< erase me on expire */ 
	IAX_FORCEJITTERBUF =	(1 << 20),	/*!< Force jitterbuffer, even when bridged to a channel that can take jitter */ 
	IAX_RTIGNOREREGEXPIRE =	(1 << 21),	/*!< When using realtime, ignore registration expiration */
	IAX_TRUNKTIMESTAMPS =	(1 << 22),	/*!< Send trunk timestamps */
	IAX_TRANSFERMEDIA = 	(1 << 23),      /*!< When doing IAX2 transfers, transfer media only */
	IAX_MAXAUTHREQ =        (1 << 24),      /*!< Maximum outstanding AUTHREQ restriction is in place */
	IAX_DELAYPBXSTART =	(1 << 25),	/*!< Don't start a PBX on the channel until the peer sends us a
						     response, so that we've achieved a three-way handshake with
						     them before sending voice or anything else*/
	IAX_ALLOWFWDOWNLOAD = (1 << 26),	/*!< Allow the FWDOWNL command? */
} iax2_flags;

static int global_rtautoclear = 120;

static int reload_config(void);
static int iax2_reload(int fd, int argc, char *argv[]);


struct iax2_user {
	AST_DECLARE_STRING_FIELDS(
		AST_STRING_FIELD(name);
		AST_STRING_FIELD(secret);
		AST_STRING_FIELD(dbsecret);
		AST_STRING_FIELD(accountcode);
		AST_STRING_FIELD(mohinterpret);
		AST_STRING_FIELD(mohsuggest);
		AST_STRING_FIELD(inkeys);               /*!< Key(s) this user can use to authenticate to us */
		AST_STRING_FIELD(language);
		AST_STRING_FIELD(cid_num);
		AST_STRING_FIELD(cid_name);
	);
	
	int authmethods;
	int encmethods;
	int amaflags;
	int adsi;
	unsigned int flags;
	int capability;
	int maxauthreq; /*!< Maximum allowed outstanding AUTHREQs */
	int curauthreq; /*!< Current number of outstanding AUTHREQs */
	struct ast_codec_pref prefs;
	struct ast_ha *ha;
	struct iax2_context *contexts;
	struct ast_variable *vars;
};

struct iax2_peer {
	AST_DECLARE_STRING_FIELDS(
		AST_STRING_FIELD(name);
		AST_STRING_FIELD(username);
		AST_STRING_FIELD(secret);
		AST_STRING_FIELD(dbsecret);
		AST_STRING_FIELD(outkey);	    /*!< What key we use to talk to this peer */

		AST_STRING_FIELD(regexten);     /*!< Extension to register (if regcontext is used) */
		AST_STRING_FIELD(context);      /*!< For transfers only */
		AST_STRING_FIELD(peercontext);  /*!< Context to pass to peer */
		AST_STRING_FIELD(mailbox);	    /*!< Mailbox */
		AST_STRING_FIELD(mohinterpret);
		AST_STRING_FIELD(mohsuggest);
		AST_STRING_FIELD(inkeys);		/*!< Key(s) this peer can use to authenticate to us */
		/* Suggested caller id if registering */
		AST_STRING_FIELD(cid_num);		/*!< Default context (for transfer really) */
		AST_STRING_FIELD(cid_name);		/*!< Default context (for transfer really) */
		AST_STRING_FIELD(zonetag);		/*!< Time Zone */
	);
	struct ast_codec_pref prefs;
	struct ast_dnsmgr_entry *dnsmgr;		/*!< DNS refresh manager */
	struct sockaddr_in addr;
	int formats;
	int sockfd;					/*!< Socket to use for transmission */
	struct in_addr mask;
	int adsi;
	unsigned int flags;

	/* Dynamic Registration fields */
	struct sockaddr_in defaddr;			/*!< Default address if there is one */
	int authmethods;				/*!< Authentication methods (IAX_AUTH_*) */
	int encmethods;					/*!< Encryption methods (IAX_ENCRYPT_*) */

	int expire;					/*!< Schedule entry for expiry */
	int expiry;					/*!< How soon to expire */
	int capability;					/*!< Capability */

	/* Qualification */
	int callno;					/*!< Call number of POKE request */
	int pokeexpire;					/*!< Scheduled qualification-related task (ie iax2_poke_peer_s or iax2_poke_noanswer) */
	int lastms;					/*!< How long last response took (in ms), or -1 for no response */
	int maxms;					/*!< Max ms we will accept for the host to be up, 0 to not monitor */

	int pokefreqok;					/*!< How often to check if the host is up */
	int pokefreqnotok;				/*!< How often to check when the host has been determined to be down */
	int historicms;					/*!< How long recent average responses took */
	int smoothing;					/*!< Sample over how many units to determine historic ms */
	
	struct ast_ha *ha;
};

#define IAX2_TRUNK_PREFACE (sizeof(struct iax_frame) + sizeof(struct ast_iax2_meta_hdr) + sizeof(struct ast_iax2_meta_trunk_hdr))

static struct iax2_trunk_peer {
	ast_mutex_t lock;
	int sockfd;
	struct sockaddr_in addr;
	struct timeval txtrunktime;		/*!< Transmit trunktime */
	struct timeval rxtrunktime;		/*!< Receive trunktime */
	struct timeval lasttxtime;		/*!< Last transmitted trunktime */
	struct timeval trunkact;		/*!< Last trunk activity */
	unsigned int lastsent;			/*!< Last sent time */
	/* Trunk data and length */
	unsigned char *trunkdata;
	unsigned int trunkdatalen;
	unsigned int trunkdataalloc;
	struct iax2_trunk_peer *next;
	int trunkerror;
	int calls;
} *tpeers = NULL;

AST_MUTEX_DEFINE_STATIC(tpeerlock);

struct iax_firmware {
	struct iax_firmware *next;
	int fd;
	int mmaplen;
	int dead;
	struct ast_iax2_firmware_header *fwh;
	unsigned char *buf;
};

enum iax_reg_state {
	REG_STATE_UNREGISTERED = 0,
	REG_STATE_REGSENT,
	REG_STATE_AUTHSENT,
	REG_STATE_REGISTERED,
	REG_STATE_REJECTED,
	REG_STATE_TIMEOUT,
	REG_STATE_NOAUTH
};

enum iax_transfer_state {
	TRANSFER_NONE = 0,
	TRANSFER_BEGIN,
	TRANSFER_READY,
	TRANSFER_RELEASED,
	TRANSFER_PASSTHROUGH,
	TRANSFER_MBEGIN,
	TRANSFER_MREADY,
	TRANSFER_MRELEASED,
	TRANSFER_MPASSTHROUGH,
	TRANSFER_MEDIA,
	TRANSFER_MEDIAPASS
};

struct iax2_registry {
	struct sockaddr_in addr;		/*!< Who we connect to for registration purposes */
	char username[80];
	char secret[80];			/*!< Password or key name in []'s */
	char random[80];
	int expire;				/*!< Sched ID of expiration */
	int refresh;				/*!< How often to refresh */
	enum iax_reg_state regstate;
	int messages;				/*!< Message count, low 8 bits = new, high 8 bits = old */
	int callno;				/*!< Associated call number if applicable */
	struct sockaddr_in us;			/*!< Who the server thinks we are */
	struct ast_dnsmgr_entry *dnsmgr;	/*!< DNS refresh manager */
	AST_LIST_ENTRY(iax2_registry) entry;
};

static AST_LIST_HEAD_STATIC(registrations, iax2_registry);

/* Don't retry more frequently than every 10 ms, or less frequently than every 5 seconds */
#define MIN_RETRY_TIME		100
#define MAX_RETRY_TIME  	10000

#define MAX_JITTER_BUFFER 	50
#define MIN_JITTER_BUFFER 	10

#define DEFAULT_TRUNKDATA	640 * 10	/*!< 40ms, uncompressed linear * 10 channels */
#define MAX_TRUNKDATA		640 * 200	/*!< 40ms, uncompressed linear * 200 channels */

#define MAX_TIMESTAMP_SKEW	160		/*!< maximum difference between actual and predicted ts for sending */

/* If consecutive voice frame timestamps jump by more than this many milliseconds, then jitter buffer will resync */
#define TS_GAP_FOR_JB_RESYNC	5000

static int iaxthreadcount = DEFAULT_THREAD_COUNT;
static int iaxmaxthreadcount = DEFAULT_MAX_THREAD_COUNT;
static int iaxdynamicthreadcount = 0;
static int iaxdynamicthreadnum = 0;
static int iaxactivethreadcount = 0;

struct iax_rr {
	int jitter;
	int losspct;
	int losscnt;
	int packets;
	int delay;