sockd.c

Linux下的socks的程序源程序,用于socks的代理服务

#else /* SUPPORT_RCMD is not defined */
	if ((out = socket(AF_INET, SOCK_STREAM, 0)) < 0)
		socks_fail("socket()", in, &ndst);
#endif /* #if defined(SUPPORT_RCMD) */

	sin.sin_family = AF_INET;
	sin.sin_port = dst->port;
	sin.sin_addr.s_addr = dst->host;

	ndst.version = Version;
	ndst.cmd = SOCKS_RESULT;

	if (connect(out, (struct sockaddr *)&sin, sizeof(struct sockaddr_in)) < 0)
		socks_fail("connect()", in, &ndst);

	syslog(LOG_LOW, "connected -- %s", log_msg);
#if defined(SO_OOBINLINE)
	setsockopt(out, SOL_SOCKET, SO_OOBINLINE, &turnon, sizeof(turnon));
#endif
	socks_SendDst(in, &ndst);
	Pump(in, out);
	syslog(LOG_LOW, "terminated -- %s.", log_msg);
	syslog(LOG_LOW, "%lu bytes from %s, %lu bytes from %s", from_in, socks_src_name, from_out, socks_dst_name);
}

/*
**  Set up a socket to be connected to from the outside world.
**   diffrence between this an the Version1 protocal is that
**   the socket has to be bound from a specific host that
**   is passed.
*/
DoNewBind(in, dst)
int	in;
Socks_t	*dst;
{
	struct in_addr sockd_route();
	int			new, out, len = sizeof(struct sockaddr_in);
	struct sockaddr_in	sin;
	Socks_t			ndst;
	char	dsthost[16];
	char	socks_dst_name[NAMELEN], socks_dst_serv[NAMELEN];
	int	outport = IPPORT_RESERVED - 1;
	int	turnon = 1;

	bzero((char *)&sin, sizeof(sin));
#if defined(SO_OOBINLINE)
	setsockopt(in, SOL_SOCKET, SO_OOBINLINE, &turnon, sizeof(turnon));
#endif

	sin.sin_family = AF_INET;
	ndst.version = Version;
	ndst.cmd  = SOCKS_RESULT;
	sin.sin_port = htons(0);
#ifdef MULTIHOMED_SERVER
	sin.sin_addr = sockd_route(dst->host);
#else
	sin.sin_addr.s_addr = htonl(INADDR_ANY);
#endif

#if defined(SUPPORT_RCMD)
#ifdef DEBUG
	syslog(LOG_LOW, "DoNewBind(): client port=%u", socks_client_port);
#endif /* #ifdef DEBUG */
	if ((socks_client_port < IPPORT_RESERVED) && (socks_client_port >= IPPORT_RESERVED/2)){
		if((out = rresvport(&outport)) < 0)
			socks_fail("rresrvport()", in, &ndst);
#ifdef DEBUG
		syslog(LOG_LOW, "DoNewBind(): outport=%d", outport);
#endif /* #ifdef DEBUG */
#if !defined(SCO) && !defined(ISC)
#if defined(hpux)
		ioctl(out, FIOSSAIOOWN, getpid());
#else /* hpux not defined */
		fcntl(out, F_SETOWN, getpid());
#endif /* #if defined(hpux) */
#endif /* #if !defined(SCO) && !defined(ISC) */
		sin.sin_port = htons((short)outport);
#ifdef DEBUG
		syslog(LOG_LOW, "DoNewBind(): sin.sin_addr=%s, sin.sin_port=%u",
		    inet_ntoa(sin.sin_addr), ntohs(sin.sin_port));
#endif /* #ifdef DEBUG */
	} else {
#endif /* #if defined(SUPPORT_RCMD) */
	if ((out = socket(AF_INET, SOCK_STREAM, 0)) < 0)
		socks_fail("socket()", in, &ndst);

	if (bind(out, (struct sockaddr *)&sin, sizeof(sin)) < 0)
		socks_fail("bind()", in, &ndst);
	if (getsockname(out, (struct sockaddr *)&sin, &len) < 0)
		socks_fail("getsockname()", in, &ndst);
#if defined(SUPPORT_RCMD)
	}
#endif /* if defined(SUPPORT_RCMD) */

	ndst.port = sin.sin_port;
	ndst.host = sin.sin_addr.s_addr;

	if (listen(out, 1) < 0)
		socks_fail("listen()", in, &ndst);

#if defined(SO_OOBINLINE)
	setsockopt(new, SOL_SOCKET, SO_OOBINLINE, &turnon, sizeof(turnon));
#endif
	socks_SendDst(in, &ndst);

	len = sizeof(struct sockaddr_in);
	if ((new = accept(out, (struct sockaddr *)&sin, &len)) < 0)
		socks_fail("accept()", in, &ndst);
	close(out);

	if (sin.sin_addr.s_addr == 0)
		strcpy(socks_dst_name, "Unspecified.Host");
	else
		socks_saddrtoname(&sin.sin_addr, socks_dst_name, sizeof(socks_dst_name));
	socks_porttoserv(sin.sin_port, socks_dst_serv, sizeof(socks_dst_serv));

#ifdef SHORTENED_RBIND
	if ((dst->host != 0L) && (sin.sin_addr.s_addr != dst->host)) {
#else
	if (sin.sin_addr.s_addr != dst->host) {
#endif
	{
		struct	in_addr	inaddr;

		inaddr.s_addr = dst->host;
		strncpy(dsthost, inet_ntoa(inaddr), sizeof(dsthost));
	}
		syslog(LOG_LOW, "failed -- %s. Error: connected to wrong host %s (%s)",
			log_msg, socks_dst_name, socks_dst_serv);
		ndst.cmd = SOCKS_FAIL;
		socks_SendDst(in, &ndst);
		exit(1);
	}

	syslog(LOG_LOW, "connected -- %s (%s)", log_msg, socks_dst_serv);
	ndst.port = sin.sin_port;
	ndst.host = sin.sin_addr.s_addr;
	socks_SendDst(in, &ndst);
	Pump(in, new);
	syslog(LOG_LOW, "terminated -- %s (%s).", log_msg, socks_dst_serv);
	syslog(LOG_LOW, "%lu bytes from %s, %lu bytes from %s", from_in, socks_src_name, from_out,  socks_dst_name);
}

/*
**  Now just pump the packets/character through..
*/
Pump(in, out)
int	in, out;
{
	static char		buf[4096];
	fd_set			fds;
	int			s, n, fdsbits;
	static struct timeval	tout = { SOCKS_TIMEOUT, 0 };
/* >>> Andy McFadden [e-mail] */
 	struct linger ling;	/* for linger */
 	int length;		/* for linger */

	alarm(0);

 	/*
 	 * ATM: use SO_LINGER so it won't hang up on client
 	 */
 	ling.l_onoff = 1;   /* turn it on */
 	ling.l_linger = /*3*/  10;
 	length = sizeof(ling);
 	if (setsockopt(in,  SOL_SOCKET, SO_LINGER, &ling, length) < 0)
 		syslog(LOG_LOW, "setsockopt (SO_LINGER): %m");
 	if (setsockopt(out, SOL_SOCKET, SO_LINGER, &ling, length) < 0)
 		syslog(LOG_LOW, "setsockopt (SO_LINGER): %m");
/* <<< Andy McFadden [e-mail] */

	FD_ZERO(&fds);
	if (in > out)
		fdsbits = in + 1;
	else
		fdsbits = out +1;

	while (1) {
		tout.tv_sec = SOCKS_TIMEOUT;
		tout.tv_usec = 0;
		FD_SET(in, &fds);
		FD_SET(out, &fds);
		if ((s = select(fdsbits, &fds, NULL,NULL, &tout)) > 0) {
			if (FD_ISSET(in, &fds)) {
				if ((n = read(in, buf, sizeof buf)) > 0) {
					from_in += n;
					if (write(out, buf, n) < 0) {
						goto bad;
					}
				} else {
					goto bad;
				}
			}
			if (FD_ISSET(out, &fds)) {
				if ((n = read(out, buf, sizeof buf)) > 0) {
					from_out += n;
					if (write(in, buf, n) < 0) {
						goto bad;
					}
				} else {
					goto bad;
				}
			}
		} else if ((s == 0) || ((s < 0) && (errno == EINTR))) {
				continue;
		} else {
			syslog(LOG_LOW, "select %m\n");
			goto bad;
		}
	}

bad:
	;	/* Make the goto happy */
}


#ifdef FOR_PS

/*
**  SETPROCTITLE -- set process title for ps
**
**    Parameters:
**	    fmt -- a printf style format string.
**	    a, b, c -- possible parameters to fmt.
**
**    Returns:
**	    none.
**
**      Side Effects:
**	      Clobbers argv of our main procedure so ps(1) will
**	      display the title.
**
**    Stolen from IDA Sendmail - I don't think it's UCB code.
*/

/*VARARGS1*/
setproctitle(buf, Argv, LastArgv)
char *buf;
char **Argv, *LastArgv;
{
#if defined(FOR_PS) && !defined(SYSV)
	register char *p;
	register int i;

	/* make ps print "(sockd)" */
	p = Argv[0];
	*p++ = '-';

	i = strlen(buf);
	if (i > LastArgv - p - 2)
	{
		i = LastArgv - p - 2;
		buf[i] = '\0';
	}
	(void) strcpy(p, buf);
	p += i;
	while (p < LastArgv)
		*p++ = ' ';
#endif /* FOR_PS && !SYSV */
}
#endif /* #ifdef FOR_PS */

#ifdef MULTIHOMED_SERVER

static char *sockd_route_file = SOCKD_ROUTE_FILE;

#ifndef NOT_THROUGH_INETD

struct in_addr sockd_route(dsthost)
u_int32 dsthost;
{
	struct in_addr interface, destip, destmask;

#else /* NOT_THROUGH_INETD defined */

int readRoute()
{
#endif /* #infdef NOT_THROUGH_INETD */
	FILE	*fd;
	static char buf[1024];
	char	*bp;
	int	linenum = 0;
	char	*argv[3];	
	int	argc;
	int	badline = 0;
	int	error = 0;
	
	if ((fd = fopen(sockd_route_file, "r")) == NULL) {
		syslog(LOG_HIGH, "Unable to open routing file (%s): %m", sockd_route_file);
		exit(1);
	}

#ifdef NOT_THROUGH_INETD
	rtEntries = (struct config **) malloc(CONF_INCR *sizeof(struct config **));
	rtPtr = *rtEntries;
#endif /* #ifdef NOT_THROUGH_INETD */
	
	while (fgets(buf, sizeof(buf) - 1, fd) != NULL) {
		linenum++;
		/* Comment starts with # anywhere in the line */
		if ((bp = index(buf, '\n')) != NULL)
			*bp ='\0';
		for (bp = buf; *bp; bp++ ) {
			if (*bp == '#') {
				*bp = '\0';
				break;
			} else if (*bp == '\t')
				*bp = ' ';
		}
		socks_mkargs(buf, &argc, argv, 3);
		if (argc == 0)
			continue;
		if (argc != 3) {
			syslog(LOG_LOW, "Invalid entry at line %d in file %s", linenum, sockd_route_file);
			exit(1);
		}
		
#ifndef NOT_THROUGH_INETD
		if (socks_GetQuad(argv[0], &interface) == -1) {
			syslog(LOG_HIGH, "Illegal interface field at line %d in file %s", linenum, sockd_route_file);
			exit(1);
		}
		if (socks_GetAddr(argv[1], &destip) == -1) {
			syslog(LOG_HIGH, "Illegal destination IP at line %d in file %s", linenum, sockd_route_file);
			exit(1);
		}
		if (socks_GetQuad(argv[2], &destmask) == -1) {
			syslog(LOG_HIGH, "Illegal destination mask at line %d in file %s", linenum, sockd_route_file);
			exit(1);
		}
		if ((destip.s_addr & destmask.s_addr) == (dsthost & destmask.s_addr)) {
			fclose(fd);
			return(interface);
		}
	}
	fclose(fd);
    {
	struct in_addr inaddr;

	inaddr.s_addr = dsthost;
	syslog(LOG_LOW, "Cannot find appropriate interface to communicate with %s\n", inet_ntoa(inaddr));
    }
	exit(1);
}

#else /* NOT_THROUGH_INETD defined */
		/* cache parsed entries */
		if (rtPtr - *rtEntries >= rtNtries) 
		    rtEntries = (struct config **) realloc(rtEntries, (rtNtries +CONF_INCR) *sizeof(struct config **));
		*(rtEntries +rtNtries) = (struct config *) malloc(sizeof (struct config));
		rtPtr = *(rtEntries +rtNtries);
		rtNtries++;

		if (socks_GetQuad(argv[0], &rtPtr->interface) == -1) {
			syslog(LOG_HIGH, "Illegal interface field at line %d in file %s", linenum, sockd_route_file);
			exit(1);
		}
		if (socks_GetAddr(argv[1], &rtPtr->daddr) == -1) {
			syslog(LOG_HIGH, "Illegal destination IP at line %d in file %s", linenum, sockd_route_file);
			exit(1);
		}
		if (socks_GetQuad(argv[2], &rtPtr->dmask) == -1) {
			syslog(LOG_HIGH, "Illegal destination mask at line %d in file %s", linenum, sockd_route_file);
			exit(1);
		}
	}
	syslog(LOG_LOW, "Parsed %d lines in route file", rtNtries);
	fclose(fd);
	if (!rtNtries) {
		syslog(LOG_LOW, "No valid lines found in file %s", sockd_route_file);
		exit(1);
	}
	return 1;
}

struct in_addr sockd_route(dsthost)
u_int32 dsthost;
{
struct in_addr dummy;
int i;

for (i = 0; i < rtNtries; i++) {
	rtPtr = *(rtEntries +i);

	if ((rtPtr->daddr.s_addr & rtPtr->dmask.s_addr) == (dsthost & rtPtr->dmask.s_addr)) {
	return(rtPtr->interface);
	}
}
    {
	struct in_addr inaddr;

	inaddr.s_addr = dsthost;
	syslog(LOG_LOW, "Cannot find appropriate interface to communicate with %s\n", inet_ntoa(inaddr));
    }
	exit(1);
}
#endif /* #ifndef NOT_THROUGH_INETD */

#endif /* #ifdef MULTIHOMED_SERVER */


#ifndef NOT_THROUGH_INETD

check_sp_conf(fd, s, src, dst)
FILE	*fd;
char	*s;
struct sockaddr_in	*src, *dst;
{
	char	buf[1024], *p;
	while (fgets(buf, sizeof(buf) - 1, fd) != NULL) {
		if ((p = index(buf, '\n')) != NULL)
			*p = '\0';
		if (strncmp(s, buf, strlen(s)) == 0) {
			socks_shell_cmd(buf+strlen(s), src, dst);
			break;
		}
	}
	return;
}

Validate(src, dst, in)
struct sockaddr_in      *src, *dst;
int     in;
{
        unsigned short  dst_sin_port = ntohs(dst->sin_port); /* dst->sin_port in host byte order */
	IDENT   *ident_lookup(), *idp;

#else /* NOT_THROUGH_INETD defined */


/* read the config file once after startup and cache all parsed configuration.
* also re-read after receiving a HUP signal.
*/
readConfig()
{
#endif /* #ifndef NOT_THROUGH_INETD */
	FILE		*fd;
	static char	buf[1024];
	char		*bp;
	int		linenum = 0, permit;
	char		*argv[10];
	int		argc;
	struct in_addr	saddr, smask, daddr, dmask;
	unsigned short	dport;
	long	p;
	char		*userlist;
	int		next_arg;
	int		useIdentd;
	char	*cmdp;
	Portcmp tst;

	if ((fd = fopen(sockd_conf, "r")) == NULL) {
		syslog(LOG_HIGH, "Unable to open config file (%s): %m", sockd_conf);
		exit(1);
	}
#ifdef NOT_THROUGH_INETD
	cfEntries = (struct config **) malloc(CONF_INCR *sizeof(struct config **));
	cfPtr = *cfEntries;
	*bad_id_cmd = '\0';
	*no_identd_cmd ='\0';
#endif /* #ifdef NOT_THROUGH_INETD */

	while (fgets(buf, sizeof(buf) - 1, fd) != NULL) {
		linenum++;
		useIdentd = use_identd;
		/*
		**  Comments start with a '#' anywhere on the line
		*/
		cmdp = (char *)0;