rlogin.c

早期freebsd实现

 * ~^Z				suspend rlogin process.
 * ~<delayed-suspend char>	suspend rlogin process, but leave reader alone.
 */
void
writer()
{
	register int bol, local, n;
	char c;

	bol = 1;			/* beginning of line */
	local = 0;
	for (;;) {
		n = read(STDIN_FILENO, &c, 1);
		if (n <= 0) {
			if (n < 0 && errno == EINTR)
				continue;
			break;
		}
		/*
		 * If we're at the beginning of the line and recognize a
		 * command character, then we echo locally.  Otherwise,
		 * characters are echo'd remotely.  If the command character
		 * is doubled, this acts as a force and local echo is
		 * suppressed.
		 */
		if (bol) {
			bol = 0;
			if (!noescape && c == escapechar) {
				local = 1;
				continue;
			}
		} else if (local) {
			local = 0;
			if (c == '.' || c == deftc.t_eofc) {
				echo(c);
				break;
			}
			if (c == defltc.t_suspc || c == defltc.t_dsuspc) {
				bol = 1;
				echo(c);
				stop(c);
				continue;
			}
			if (c != escapechar)
#ifdef CRYPT
#ifdef KERBEROS
				if (doencrypt)
					(void)des_write(rem,
					    (char *)&escapechar, 1);
				else
#endif
#endif
					(void)write(rem, &escapechar, 1);
		}

#ifdef CRYPT
#ifdef KERBEROS
		if (doencrypt) {
			if (des_write(rem, &c, 1) == 0) {
				msg("line gone");
				break;
			}
		} else
#endif
#endif
			if (write(rem, &c, 1) == 0) {
				msg("line gone");
				break;
			}
		bol = c == defkill || c == deftc.t_eofc ||
		    c == deftc.t_intrc || c == defltc.t_suspc ||
		    c == '\r' || c == '\n';
	}
}

void
#if __STDC__
echo(register char c)
#else
echo(c)
	register char c;
#endif
{
	register char *p;
	char buf[8];

	p = buf;
	c &= 0177;
	*p++ = escapechar;
	if (c < ' ') {
		*p++ = '^';
		*p++ = c + '@';
	} else if (c == 0177) {
		*p++ = '^';
		*p++ = '?';
	} else
		*p++ = c;
	*p++ = '\r';
	*p++ = '\n';
	(void)write(STDOUT_FILENO, buf, p - buf);
}

void
#if __STDC__
stop(char cmdc)
#else
stop(cmdc)
	char cmdc;
#endif
{
	mode(0);
	(void)signal(SIGCHLD, SIG_IGN);
	(void)kill(cmdc == defltc.t_suspc ? 0 : getpid(), SIGTSTP);
	(void)signal(SIGCHLD, catch_child);
	mode(1);
	sigwinch(0);			/* check for size changes */
}

void
sigwinch(signo)
	int signo;
{
	struct winsize ws;

	if (dosigwinch && get_window_size(0, &ws) == 0 &&
	    bcmp(&ws, &winsize, sizeof(ws))) {
		winsize = ws;
		sendwindow();
	}
}

/*
 * Send the window size to the server via the magic escape
 */
void
sendwindow()
{
	struct winsize *wp;
	char obuf[4 + sizeof (struct winsize)];

	wp = (struct winsize *)(obuf+4);
	obuf[0] = 0377;
	obuf[1] = 0377;
	obuf[2] = 's';
	obuf[3] = 's';
	wp->ws_row = htons(winsize.ws_row);
	wp->ws_col = htons(winsize.ws_col);
	wp->ws_xpixel = htons(winsize.ws_xpixel);
	wp->ws_ypixel = htons(winsize.ws_ypixel);

#ifdef CRYPT
#ifdef KERBEROS
	if(doencrypt)
		(void)des_write(rem, obuf, sizeof(obuf));
	else
#endif
#endif
		(void)write(rem, obuf, sizeof(obuf));
}

/*
 * reader: read from remote: line -> 1
 */
#define	READING	1
#define	WRITING	2

jmp_buf rcvtop;
int ppid, rcvcnt, rcvstate;
char rcvbuf[8 * 1024];

void
oob(signo)
	int signo;
{
	struct sgttyb sb;
	int atmark, n, out, rcvd;
	char waste[BUFSIZ], mark;

	out = O_RDWR;
	rcvd = 0;
	while (recv(rem, &mark, 1, MSG_OOB) < 0) {
		switch (errno) {
		case EWOULDBLOCK:
			/*
			 * Urgent data not here yet.  It may not be possible
			 * to send it yet if we are blocked for output and
			 * our input buffer is full.
			 */
			if (rcvcnt < sizeof(rcvbuf)) {
				n = read(rem, rcvbuf + rcvcnt,
				    sizeof(rcvbuf) - rcvcnt);
				if (n <= 0)
					return;
				rcvd += n;
			} else {
				n = read(rem, waste, sizeof(waste));
				if (n <= 0)
					return;
			}
			continue;
		default:
			return;
		}
	}
	if (mark & TIOCPKT_WINDOW) {
		/* Let server know about window size changes */
		(void)kill(ppid, SIGUSR1);
	}
	if (!eight && (mark & TIOCPKT_NOSTOP)) {
		(void)ioctl(0, TIOCGETP, (char *)&sb);
		sb.sg_flags &= ~CBREAK;
		sb.sg_flags |= RAW;
		(void)ioctl(0, TIOCSETN, (char *)&sb);
		notc.t_stopc = -1;
		notc.t_startc = -1;
		(void)ioctl(0, TIOCSETC, (char *)&notc);
	}
	if (!eight && (mark & TIOCPKT_DOSTOP)) {
		(void)ioctl(0, TIOCGETP, (char *)&sb);
		sb.sg_flags &= ~RAW;
		sb.sg_flags |= CBREAK;
		(void)ioctl(0, TIOCSETN, (char *)&sb);
		notc.t_stopc = deftc.t_stopc;
		notc.t_startc = deftc.t_startc;
		(void)ioctl(0, TIOCSETC, (char *)&notc);
	}
	if (mark & TIOCPKT_FLUSHWRITE) {
		(void)ioctl(1, TIOCFLUSH, (char *)&out);
		for (;;) {
			if (ioctl(rem, SIOCATMARK, &atmark) < 0) {
				(void)fprintf(stderr, "rlogin: ioctl: %s.\n",
				    strerror(errno));
				break;
			}
			if (atmark)
				break;
			n = read(rem, waste, sizeof (waste));
			if (n <= 0)
				break;
		}
		/*
		 * Don't want any pending data to be output, so clear the recv
		 * buffer.  If we were hanging on a write when interrupted,
		 * don't want it to restart.  If we were reading, restart
		 * anyway.
		 */
		rcvcnt = 0;
		longjmp(rcvtop, 1);
	}

	/* oob does not do FLUSHREAD (alas!) */

	/*
	 * If we filled the receive buffer while a read was pending, longjmp
	 * to the top to restart appropriately.  Don't abort a pending write,
	 * however, or we won't know how much was written.
	 */
	if (rcvd && rcvstate == READING)
		longjmp(rcvtop, 1);
}

/* reader: read from remote: line -> 1 */
int
reader(omask)
	int omask;
{
	int pid, n, remaining;
	char *bufp;

#if BSD >= 43 || defined(SUNOS4)
	pid = getpid();		/* modern systems use positives for pid */
#else
	pid = -getpid();	/* old broken systems use negatives */
#endif
	(void)signal(SIGTTOU, SIG_IGN);
	(void)signal(SIGURG, oob);
	ppid = getppid();
	(void)fcntl(rem, F_SETOWN, pid);
	(void)setjmp(rcvtop);
	(void)sigsetmask(omask);
	bufp = rcvbuf;
	for (;;) {
		while ((remaining = rcvcnt - (bufp - rcvbuf)) > 0) {
			rcvstate = WRITING;
			n = write(STDOUT_FILENO, bufp, remaining);
			if (n < 0) {
				if (errno != EINTR)
					return (-1);
				continue;
			}
			bufp += n;
		}
		bufp = rcvbuf;
		rcvcnt = 0;
		rcvstate = READING;

#ifdef CRYPT
#ifdef KERBEROS
		if (doencrypt)
			rcvcnt = des_read(rem, rcvbuf, sizeof(rcvbuf));
		else
#endif
#endif
			rcvcnt = read(rem, rcvbuf, sizeof (rcvbuf));
		if (rcvcnt == 0)
			return (0);
		if (rcvcnt < 0) {
			if (errno == EINTR)
				continue;
			(void)fprintf(stderr, "rlogin: read: %s.\n",
			    strerror(errno));
			return (-1);
		}
	}
}

void
mode(f)
	int f;
{
	struct ltchars *ltc;
	struct sgttyb sb;
	struct tchars *tc;
	int lflags;

	(void)ioctl(0, TIOCGETP, (char *)&sb);
	(void)ioctl(0, TIOCLGET, (char *)&lflags);
	switch(f) {
	case 0:
		sb.sg_flags &= ~(CBREAK|RAW|TBDELAY);
		sb.sg_flags |= defflags|tabflag;
		tc = &deftc;
		ltc = &defltc;
		sb.sg_kill = defkill;
		sb.sg_erase = deferase;
		lflags = deflflags;
		break;
	case 1:
		sb.sg_flags |= (eight ? RAW : CBREAK);
		sb.sg_flags &= ~defflags;
		/* preserve tab delays, but turn off XTABS */
		if ((sb.sg_flags & TBDELAY) == XTABS)
			sb.sg_flags &= ~TBDELAY;
		tc = &notc;
		ltc = &noltc;
		sb.sg_kill = sb.sg_erase = -1;
		if (litout)
			lflags |= LLITOUT;
		break;
	default:
		return;
	}
	(void)ioctl(0, TIOCSLTC, (char *)ltc);
	(void)ioctl(0, TIOCSETC, (char *)tc);
	(void)ioctl(0, TIOCSETN, (char *)&sb);
	(void)ioctl(0, TIOCLSET, (char *)&lflags);
}

void
lostpeer(signo)
	int signo;
{
	(void)signal(SIGPIPE, SIG_IGN);
	msg("\007connection closed.");
	done(1);
}

/* copy SIGURGs to the child process. */
void
copytochild(signo)
	int signo;
{
	(void)kill(child, SIGURG);
}

void
msg(str)
	char *str;
{
	(void)fprintf(stderr, "rlogin: %s\r\n", str);
}

#ifdef KERBEROS
/* VARARGS */
void
#if __STDC__
warning(const char *fmt, ...)
#else
warning(fmt, va_alist)
	char *fmt;
	va_dcl
#endif
{
	va_list ap;

	(void)fprintf(stderr, "rlogin: warning, using standard rlogin: ");
#ifdef __STDC__
	va_start(ap, fmt);
#else
	va_start(ap);
#endif
	vfprintf(stderr, fmt, ap);
	va_end(ap);
	(void)fprintf(stderr, ".\n");
}
#endif

__dead void
usage()
{
	(void)fprintf(stderr,
	    "usage: rlogin [ -%s]%s[-e char] [ -l username ] host\n",
#ifdef KERBEROS
#ifdef CRYPT
	    "8EKLx", " [-k realm] ");
#else
	    "8EKL", " [-k realm] ");
#endif
#else
	    "8EL", " ");
#endif
	exit(1);
}

/*
 * The following routine provides compatibility (such as it is) between older
 * Suns and others.  Suns have only a `ttysize', so we convert it to a winsize.
 */
#ifdef OLDSUN
int
get_window_size(fd, wp)
	int fd;
	struct winsize *wp;
{
	struct ttysize ts;
	int error;

	if ((error = ioctl(0, TIOCGSIZE, &ts)) != 0)
		return (error);
	wp->ws_row = ts.ts_lines;
	wp->ws_col = ts.ts_cols;
	wp->ws_xpixel = 0;
	wp->ws_ypixel = 0;
	return (0);
}
#endif

u_int
getescape(p)
	register char *p;
{
	long val;
	int len;

	if ((len = strlen(p)) == 1)	/* use any single char, including '\' */
		return ((u_int)*p);
					/* otherwise, \nnn */
	if (*p == '\\' && len >= 2 && len <= 4) {
		val = strtol(++p, NULL, 8);
		for (;;) {
			if (!*++p)
				return ((u_int)val);
			if (*p < '0' || *p > '8')
				break;
		}
	}
	msg("illegal option value -- e");
	usage();
	/* NOTREACHED */
}