iax.c

来自网络的iaxclient的协议栈源码

 /*
 * libiax: An implementation of Inter-Asterisk eXchange
 *
 * Copyright (C) 2001, Linux Support Services, Inc.
 *
 * Mark Spencer <[e-mail]>
 * Frik Strecker <[e-mail]>
 *
 * This program is free software, distributed under the terms of
 * the GNU Lesser (Library) General Public License
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#if defined(WIN32)  ||  defined(_WIN32_WCE)
#undef __STRICT_ANSI__ //for strdup with ms

#if defined(_WIN32_WCE)
#define strdup _strdup
#else
#include <process.h>
#include <fcntl.h>
#include <io.h>
#include <errno.h>
#endif
#include <string.h>
#include <windows.h>
#include <winsock.h>
#include <time.h>
#include <stdlib.h>
#include <malloc.h>
#include <stdarg.h>
#include <stdio.h>
#include <limits.h>


#define	snprintf _snprintf

#if defined(_MSC_VER)
#define	close		closesocket
#if !defined(_WIN32_WCE)
#define inline      __inline
#endif
#endif

#ifdef __cplusplus
extern "C" {
#endif
void gettimeofday(struct timeval *tv, void /*struct timezone*/ *tz);
#ifdef __cplusplus
}
#endif

#else

#include <netdb.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/time.h>
#include <stdlib.h>
#ifdef __GNUC__
#ifndef __USE_SVID
#define __USE_SVID
#endif
#endif
#include <string.h>
#include <stdarg.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/select.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <time.h>

#ifndef MACOSX
#include <malloc.h>
#ifndef SOLARIS
#include <error.h>
#endif
#endif

#endif

#include "jitterbuf.h"
#include "iax-client.h"
#include "md5.h"

/* Define socket options for IAX2 sockets, based on platform
 * availability of flags */
#if defined(WIN32)  ||  defined(_WIN32_WCE)
#define IAX_SOCKOPTS 0
#else
#ifdef MACOSX
#define IAX_SOCKOPTS MSG_DONTWAIT
#else
#ifdef SOLARIS
#define IAX_SOCKOPTS MSG_DONTWAIT
#else  /* Linux and others */
#define IAX_SOCKOPTS MSG_DONTWAIT | MSG_NOSIGNAL
#endif
#endif
#endif


#ifdef SNOM_HACK
/* The snom phone seems to improperly execute memset in some cases */
#include "../../snom_phonecore2/include/snom_memset.h"
#endif

/* Voice TS Prediction causes libiax2 to clean up the timestamps on
 * outgoing frames.  It works best with either continuous voice, or
 * callers who call iax_send_cng to indicate DTX for silence */
#define USE_VOICE_TS_PREDICTION

#define MIN_RETRY_TIME 10
#define MAX_RETRY_TIME 4000
#define MEMORY_SIZE 1000

#define TRANSFER_NONE  0
#define TRANSFER_BEGIN 1
#define TRANSFER_READY 2
#define TRANSFER_REL   3

/* Video frames bypass jitterbuffer */
static int video_bypass_jitterbuffer = 0;

/* UDP Socket (file descriptor) */
static int netfd = -1;

/* Max timeouts */
static const int maxretries = 10;

/* configurable jitterbuffer options */
static long jb_target_extra = -1;

/* external global networking replacements */
static iax_sendto_t   iax_sendto = (iax_sendto_t) sendto;
static iax_recvfrom_t iax_recvfrom = (iax_recvfrom_t) recvfrom;

/* ping interval (seconds) */
static int ping_time = 10;
static void send_ping(void *session);

struct iax_session {
	/* Private data */
	void *pvt;
	/* session-local Sendto function */
	iax_sendto_t sendto;
	/* Is voice quelched (e.g. hold) */
	int quelch;
	/* Codec Pref Order */
	char codec_order[32];
	/* Codec Pref Order Index*/
	int codec_order_len;
	/* Last received voice format */
	int voiceformat;
	/* Last transmitted voice format */
	int svoiceformat;
	/* Last received video format */
	int videoformat;
	/* Last transmitted video format */
	int svideoformat;
	/* Per session capability */
	int capability;
	/* Last received timestamp */
	unsigned int last_ts;
	/* Last transmitted timestamp */
	unsigned int lastsent;
#ifdef USE_VOICE_TS_PREDICTION
	/* Next predicted voice ts */
	unsigned int nextpred;
	/* True if the last voice we transmitted was not silence/CNG */
	int notsilenttx;
#endif
	/* Our last measured ping time */
	unsigned int pingtime;
	/* Address of peer */
	struct sockaddr_in peeraddr;
	/* Our call number */
	int callno;
	/* Peer's call number */
	int peercallno;
	/* Our next outgoing sequence number */
	unsigned char oseqno;
	/* Next sequence number they have not yet acknowledged */
	unsigned char rseqno;
	/* Our last received incoming sequence number */
	unsigned char iseqno;
	/* Last acknowledged sequence number */
	unsigned char aseqno;
	/* Last sequence number we VNAKd */
	unsigned char lastvnak;
	/* Time value that we base our transmission on */
	struct timeval offset;
	/* Time value we base our delivery on */
	struct timeval rxcore;
	/* Current link state */
	int state;
	/* Expected Username */
	char username[MAXSTRLEN];
	/* Expected Secret */
	char secret[MAXSTRLEN];
	/* Refresh if applicable */
	int refresh;

	/* ping scheduler id */
	int pingid;

	/* Transfer stuff */
	struct sockaddr_in transfer;
	int transferring;
	int transfercallno;
	int transferid;
	int transferpeer;	/* for attended transfer */
	int transfer_moh;	/* for music on hold while performing attended transfer */

	jitterbuf *jb;

	struct iax_netstat remote_netstats;

	/* For linking if there are multiple connections */
	struct iax_session *next;
};

char iax_errstr[256];


#define IAXERROR snprintf(iax_errstr, sizeof(iax_errstr),

#ifdef DEBUG_SUPPORT

#ifdef DEBUG_DEFAULT
static int debug = 1;
#else
static int debug = 0;
#endif

void iax_enable_debug(void)
{
	debug = 1;
}

void iax_disable_debug(void)
{
	debug = 0;
}

void iax_set_private(struct iax_session *s, void *ptr)
{
	s->pvt = ptr;
}

void *iax_get_private(struct iax_session *s)
{
	return s->pvt;
}

void iax_set_sendto(struct iax_session *s, iax_sendto_t ptr)
{
	s->sendto = ptr;
}


/* This is a little strange, but to debug you call DEBU(G "Hello World!\n"); */
#if defined(WIN32)  ||  defined(_WIN32_WCE)
#define G __FILE__, __LINE__,
#else
#define G __FILE__, __LINE__, __PRETTY_FUNCTION__,
#endif

#define DEBU __debug
#if defined(WIN32)  ||  defined(_WIN32_WCE)
static int __debug(char *file, int lineno, char *fmt, ...)
{
	va_list args;
	va_start(args, fmt);
	if (debug) {
		fprintf(stderr, "%s line %d: ", file, lineno);
		vfprintf(stderr, fmt, args);
	}
	va_end(args);
	return 0;
}
#else
static int __debug(char *file, int lineno, char *func, char *fmt, ...)
{
	va_list args;
	va_start(args, fmt);
	if (debug) {
		fprintf(stderr, "%s line %d in %s: ", file, lineno, func);
		vfprintf(stderr, fmt, args);
	}
	va_end(args);
	return 0;
}
#endif
#else /* No debug support */

#if defined(WIN32)  ||  defined(_WIN32_WCE)
#define	DEBU
#else
#define DEBU(fmt...) \
    do {} while(0)
#endif
#define G
#endif

typedef void (*sched_func)(void *);

struct iax_sched {
	/* These are scheduled things to be delivered */
	struct timeval when;
	/* If event is non-NULL then we're delivering an event */
	struct iax_event *event;
	/* If frame is non-NULL then we're transmitting a frame */
	struct iax_frame *frame;
	/* If func is non-NULL then we should call it */
	sched_func func;
	/* and pass it this argument */
	void *arg;
	/* Easy linking */
	struct iax_sched *next;
};

static struct iax_sched *schedq = NULL;
static struct iax_session *sessions = NULL;
static int callnums = 1;
static int transfer_id = 1;		/* for attended transfer */


void iax_set_private(struct iax_session *s, void *ptr)
{
	s->pvt = ptr;
}

void *iax_get_private(struct iax_session *s)
{
	return s->pvt;
}

void iax_set_sendto(struct iax_session *s, iax_sendto_t ptr)
{
	s->sendto = ptr;
}


unsigned int iax_session_get_capability(struct iax_session *s)
{
	return s->capability;
}


static int inaddrcmp(struct sockaddr_in *sin1, struct sockaddr_in *sin2)
{
	return (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr) || (sin1->sin_port != sin2->sin_port);
}

static int iax_sched_add(struct iax_event *event, struct iax_frame *frame, sched_func func, void *arg, int ms)
{

	/* Schedule event to be delivered to the client
	   in ms milliseconds from now, or a reliable frame to be retransmitted */
	struct iax_sched *sched, *cur, *prev = NULL;

	if (!event && !frame && !func) {
		DEBU(G "No event, no frame, no func?  what are we scheduling?\n");
		return -1;
	}

	//fprintf(stderr, "scheduling event %d ms from now\n", ms);
	sched = (struct iax_sched*)malloc(sizeof(struct iax_sched));
	if (sched) {
		memset(sched, 0, sizeof(struct iax_sched));
		gettimeofday(&sched->when, NULL);
		sched->when.tv_sec += (ms / 1000);
		ms = ms % 1000;
		sched->when.tv_usec += (ms * 1000);
		if (sched->when.tv_usec > 1000000) {
			sched->when.tv_usec -= 1000000;
			sched->when.tv_sec++;
		}
		sched->event = event;
		sched->frame = frame;
		sched->func = func;
		sched->arg = arg;
		/* Put it in the list, in order */
		cur = schedq;
		while(cur && ((cur->when.tv_sec < sched->when.tv_sec) ||
					 ((cur->when.tv_usec <= sched->when.tv_usec) &&
					  (cur->when.tv_sec == sched->when.tv_sec)))) {
				prev = cur;
				cur = cur->next;
		}
		sched->next = cur;
		if (prev) {
			prev->next = sched;
		} else {
			schedq = sched;
		}
		return 0;
	} else {
		DEBU(G "Out of memory!\n");
		return -1;
	}
}

static int iax_sched_del(struct iax_event *event, struct iax_frame *frame, sched_func func, void *arg, int all)
{
	struct iax_sched *cur, *tmp, *prev = NULL;

	cur = schedq;
	while (cur) {
		if (cur->event == event && cur->frame == frame && cur->func == func && cur->arg == arg) {
			if (prev)
				prev->next = cur->next;
			else
				schedq = cur->next;
			tmp = cur;
			cur = cur->next;
			free(tmp);
			if (!all)
				return -1;
		} else {
			prev = cur;
			cur = cur->next;
		}
	}
	return 0;
}


int iax_time_to_next_event(void)
{
	struct timeval tv;
	struct iax_sched *cur = schedq;
	int ms, min = 999999999;

	/* If there are no pending events, we don't need to timeout */
	if (!cur)
		return -1;
	gettimeofday(&tv, NULL);
	while(cur) {
		ms = (cur->when.tv_sec - tv.tv_sec) * 1000 +
		     (cur->when.tv_usec - tv.tv_usec) / 1000;
		if (ms < min)
			min = ms;
		cur = cur->next;
	}
	if (min < 0)
		min = 0;
	return min;
}

struct iax_session *iax_session_new(void)
{
	struct iax_session *s;
	s = (struct iax_session *)malloc(sizeof(struct iax_session));
	if (s) {
		jb_conf jbconf;

		memset(s, 0, sizeof(struct iax_session));
		/* Initialize important fields */
		s->voiceformat = -1;
		s->svoiceformat = -1;
		s->videoformat = -1;
		/* Default pingtime to 100 ms -- should cover most decent net connections */
		s->pingtime = 100;
		/* XXX Not quite right -- make sure it's not in use, but that won't matter
		   unless you've had at least 65k calls.  XXX */
		s->callno = callnums++;
		if (callnums > 32767)
			callnums = 1;
		s->peercallno = 0;
		s->lastvnak = -1;
		s->transferpeer = 0; /* for attended transfer */
		s->next = sessions;
		s->sendto = iax_sendto;
		s->pingid = -1;

		s->jb = jb_new();
		if ( !s->jb )
		{
			free(s);
			return 0;
		}
		jbconf.max_jitterbuf = 0;
		jbconf.resync_threshold = 1000;
		jbconf.max_contig_interp = 0;
		jbconf.target_extra = jb_target_extra;
		jb_setconf(s->jb, &jbconf);

		sessions = s;
	}
	return s;
}

static int iax_session_valid(struct iax_session *session)
{
	/* Return -1 on a valid iax session pointer, 0 on a failure */
	struct iax_session *cur = sessions;
	while(cur) {
		if (session == cur)