tsbridge.c

来自「ftam等标准协议服务器和客户端的源代码。」· C语言 代码 · 共 824 行 · 第 1/2 页

		nta -> ta_naddr = 1;
		return nta;
	}
	isnew = 0;
	/* try old form... */
	bcopy (ta -> ta_selector, buffer, ta -> ta_selectlen);
	buffer[ta -> ta_selectlen] = NULL;

	if ((nta = str2taddr (buffer)) == NULLTA) {
		ts_close (sd, "unable to translate address");
		adios (NULLCP, "unable to translate \"%s\"", buffer);
	}
	newta = *nta;

	return &newta;
}

/*  */

static struct TSAPaddr *maketa (ta, type, ctp)
struct TSAPaddr *ta;
long	type;
ContTbl *ctp;
{
    static struct TSAPaddr newta;
    register struct TSAPaddr *nta = &newta;
    char	*p;
    int	i;
    struct PSAPaddr pas;
    struct PSAPaddr *pa = &pas;

    if (ctp -> flags & CONN_NOMUNGE) {
	*nta = *ta;	/* struct copy */
    }
    if (!(ctp -> flags & CONN_NOMUNGE) || (ctp -> flags & CONN_FORCEMUNGE)) {
	if (isnew == 0) {
	    bzero ((char *)pa, sizeof *pa);
	    pa -> pa_addr.sa_addr = *ta;
	    if ((p = _paddr2str (pa, NULLNA, -1)) == NULL ||
		(nta -> ta_selectlen = strlen (p)) >= TSSIZE) {
		if (ctp -> flags & CONN_STRICT)
		    adios (NULLCP, "new selector not encodable");

		advise (LLOG_NOTICE, NULLCP,
			"new selector not encodable");
		nta -> ta_selectlen = 0;
	    }
	    else
		bcopy (p, nta -> ta_selector, TSSIZE);
	}
	else {
	    struct NSAPaddr *nna = na2norm (&ta -> ta_addrs[0]);

	    if ((nta -> ta_selectlen = 2 + nna -> na_addrlen +
		 ta -> ta_selectlen) >= TSSIZE)
		nta -> ta_selectlen = 0;
	    else {
		bcopy (nna -> na_address, &nta -> ta_selector[2],
		       nna -> na_addrlen);
		bcopy (ta -> ta_selector,
		       &nta -> ta_selector[2 + nna -> na_addrlen],
		       ta -> ta_selectlen);
		nta -> ta_selector[0] = nta -> ta_selector[1] =
		    nna -> na_addrlen;
	    }
	}
    }
    for (i = 0; i < ctp -> src.ta_naddr; i++) {
	if (ctp -> src.ta_addrs[i].na_stack == type) {
	    /* our address */
	    nta -> ta_addrs[0] = ctp->src.ta_addrs[i]; 
	    nta -> ta_naddr = 1;
	    return nta;
	}
    }
    /*
     * This requires an explanation:
     * If NOMUNGE && FORCEMUNGE  we have a semi-transparent bridge
     * and since [at least on my machine] the recipient of a "transparent"
     * call sees it as coming from the bridge host, ie the effect is that
     * of a strict call, the structure that is now in nta, viz:
     * "calling address"/calling address
     * is going to get clobbered and appear at the final host as originating
     * "calling address"/bridge host
     * anyway.  This is what I want.
     * => return nta
     */
    if ((ctp -> flags & CONN_NOMUNGE) 
	&& (ctp -> flags & CONN_FORCEMUNGE)
	&& !(ctp -> flags & CONN_STRICT)) {
	return nta;
    }
    if (ctp -> flags & CONN_STRICT)
	adios (NULLCP, "not listening on this network (%d)", type);

    advise (LLOG_NOTICE, NULLCP,
	    "not listening on this network (%d)", type);

    return ta;
}

/*  */

static ContTbl *find_connection (ta)
struct TSAPaddr *ta;
{
    ContTbl *ctp;
    struct NSAPaddr *na1, *na2;

    na2 = &ta -> ta_addrs[0];

    for (ctp = con_tbl; ctp < &con_tbl[con_tbl_cnt]; ctp ++) {
	if (na2 -> na_type == NA_NSAP && ctp->src.ta_naddr == 0 &&
	    ta -> ta_selectlen == ctp -> src.ta_selectlen &&
	    bcmp (ta -> ta_selector, ctp -> src.ta_selector,
		  ta -> ta_selectlen) == 0)
	    return ctp;

	for (na1 = &ctp -> src.ta_addrs[0];
	     na1 < &ctp -> src.ta_addrs[ctp->src.ta_naddr]; na1++)
	{
	    if (na1 -> na_type != na2 -> na_type)
		    continue;

		switch (na1 -> na_stack) {
		case NA_NSAP:
		if ((na1 -> na_addrlen == 0 ||
		     (na1 -> na_addrlen == na2 -> na_addrlen &&
			bcmp (na1 -> na_address, na2 -> na_address,
			  na1 -> na_addrlen) == 0))
		    &&
			ta -> ta_selectlen == ctp -> src.ta_selectlen &&
			bcmp (ta -> ta_selector, ctp -> src.ta_selector,
			      ta -> ta_selectlen) == 0)
			return ctp;
		    break;

		case NA_TCP:
		    if (na1 -> na_port == na2 -> na_port &&
		       strcmp (na1 -> na_domain, na2 -> na_domain) == 0)
			return ctp;
		    break;

		case NA_X25:
		    if (na1 -> na_dtelen == na2 -> na_dtelen &&
			bcmp (na1 -> na_dte, na2 -> na_dte,
			      na1 -> na_dtelen) == 0 &&
			na1 -> na_pidlen == na2 -> na_pidlen &&
			bcmp (na1 -> na_pid, na2 -> na_pid,
			      na1 -> na_pidlen) == 0)
			return ctp;
		    break;
		}
	    }
	}
    return NULL;
}

/*  */

static void	arginit (vec)
char	**vec;
{
	register char   *ap;
	register struct TSAPaddr *ta;

	if (myname = rindex (*vec, '/'))
		myname++;
	if (myname == NULL || *myname == NULL)
		myname = *vec;

	for (vec++; ap = *vec; vec++) {
	    if (*ap == '-' && ap[1])
		switch (*++ap) {
		    case 'T':
		    	if ((ap = *++vec) == NULL || *ap == '-')
			    adios (NULLCP, "usage: %s -T tailorfile", myname);
		    	(void) isodesetailor (ap);
			isodetailor (myname, 0);
			ll_hdinit (pgm_log, myname);
			continue;

		    case 'a':
			isodetailor (myname, 0);
			ll_hdinit (pgm_log, myname);
		        if ((ap = *++vec) == NULL || *ap == '-')
			    adios (NULLCP, "usage: %s -a address", myname);
			if ((ta = str2taddr (ap)) == NULLTA)
			    adios (NULLCP, "bad address \"%s\"", ap);
			con_tbl[0].src = *ta; /* struct copy */
			con_tbl[0].flags =  0;
			con_tbl_cnt = 1;
		        continue;

		    case 's':
			con_tbl[0].flags |= CONN_STRICT;
			continue;

		    default:
			adios (NULLCP, "unknown switch -%s", ap);
		}
	    else
		break;
	    
	}
	isodetailor (myname, 0);
	ll_hdinit (pgm_log, myname);

	for (; ap = *vec; vec++)
	    read_file (ap);

	if (con_tbl_cnt <= 0) {
	    if ((ta = str2taddr (tsb_default_address)) == NULLTA)
		adios (NULLCP, "bad default address \"%s\"",
		       tsb_default_address);
	    con_tbl[0].src = *ta; /* struct copy */
	    con_tbl_cnt = 1;
	}
}

/*  */

static void read_file (file)
char	*file;
{
    FILE	*fp;
    char	buf[BUFSIZ];
    char	*vec[50];
    char	*ap;
    int		vecp, i;
    ContTbl	*ctp;
    struct TSAPaddr *ta;

    if (strcmp (file, "-") == 0)
	fp = stdin;
    else if ((fp = fopen (file, "r")) == NULL)
	adios (file, "Can't open ");

    while (fgets (buf, sizeof buf, fp) != NULLCP) {
	if (buf[0] == '#' || buf[0] == '\n')
	    continue;

	vecp = sstr2arg (buf, 50, vec, " \t,\n");
	if (vecp <= 0)
	    continue;

	if ((ta = str2taddr (vec[0])) == NULLTA)
	    adios (NULLCP, "Bad address \"%s\" in file %s", vec[0], file);

	ctp = &con_tbl[con_tbl_cnt];
	ctp -> src = *ta; /* struct copy */
	con_tbl_cnt ++;

	for (i = 1; i < vecp; i++) {
	    ap = vec[i];
	    if (*ap == '\0')
		continue;
	    if (*ap == '-') {
		switch (*++ap) {
		case 's':
		    ctp -> flags |= CONN_STRICT;
		    break;
		case 't':
		    ctp -> flags |= CONN_TRANS;
		    break;
		case 'n':
		    ctp -> flags |= CONN_NOMUNGE;
		    break;
		case 'f':
		    ctp -> flags |= CONN_FORCEMUNGE;
		    break;

		default:
		    adios (NULLCP, "Unknown option -%c", *ap);
		}
	    }
	    else {
		if ((ta = str2taddr (ap)) == NULLTA)
		    adios (NULLCP, "Bad address \"%s\" in file %s",
			   ap, file);
		ctp -> dest = *ta; /* struct copy */
		ctp -> flags |= (CONN_TRANS|CONN_NOMUNGE);
	    }
	}

    }

    if (strcmp (file, "-") != 0)
	(void) fclose (fp);
}

/*  */

static	void envinit () {
	int     i,
		sd;

	nbits = getdtablesize ();

	if (!(debug = isatty (2))) {
		for (i = 0; i < 5; i++) {
			switch (fork ()) {
			    case NOTOK: 
				sleep (5);
				continue;

			    case OK: 
				break;

			    default: 
				_exit (0);
			}
			break;
		}

		(void) chdir ("/");

		if ((sd = open ("/dev/null", O_RDWR)) == NOTOK)
			adios ("/dev/null", "unable to read");
		if (sd != 0)
			(void) dup2 (sd, 0), (void) close (sd);
		(void) dup2 (0, 1);
		(void) dup2 (0, 2);

#ifdef	SETSID
		if (setsid () == NOTOK)
		    advise (LLOG_EXCEPTIONS, "failed", "setsid");
#endif
#ifdef  TIOCNOTTY
		if ((sd = open ("/dev/tty", O_RDWR)) != NOTOK) {
			(void) ioctl (sd, TIOCNOTTY, NULLCP);
			(void) close (sd);
		}
#else
#ifdef  SYS5
		(void) setpgrp ();
		(void) signal (SIGINT, SIG_IGN);
		(void) signal (SIGQUIT, SIG_IGN);
#endif
#endif
	}
	else
		ll_dbinit (pgm_log, myname);

#ifndef sun			/* damn YP... */
	for (sd = 3; sd < nbits; sd++)
	    if (pgm_log -> ll_fd != sd)
		(void) close (sd);
#endif

	(void) signal (SIGPIPE, SIG_IGN);

	ll_hdinit (pgm_log, myname);
	advise (LLOG_NOTICE, NULLCP, "starting");
}

/*    ERRORS */

#ifndef lint
static void    adios (va_alist)
va_dcl
{
    va_list ap;

    va_start (ap);

    _ll_log (pgm_log, LLOG_FATAL, ap);

    va_end (ap);

    _exit (1);
}
#else
/* VARARGS */

static void    adios (what, fmt)
char   *what,
       *fmt;
{
    adios (what, fmt);
}
#endif


#ifndef lint
static void    advise (va_alist)
va_dcl
{
    int     code;
    va_list ap;

    va_start (ap);

    code = va_arg (ap, int);

    _ll_log (pgm_log, code, ap);

    va_end (ap);
}
#else
/* VARARGS */

static void    advise (code, what, fmt)
char   *what,
       *fmt;
int     code;
{
    advise (code, what, fmt);
}
#endif