4.4BSD/usr/src/usr.bin/rlogin/rlogin.c
/*
* Copyright (c) 1983, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1983, 1990, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)rlogin.c 8.1 (Berkeley) 6/6/93";
#endif /* not lint */
/*
* rlogin - remote login
*/
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <pwd.h>
#include <setjmp.h>
#include <sgtty.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif
#ifdef KERBEROS
#include <kerberosIV/des.h>
#include <kerberosIV/krb.h>
#include "krb.h"
CREDENTIALS cred;
Key_schedule schedule;
int use_kerberos = 1, doencrypt;
char dst_realm_buf[REALM_SZ], *dest_realm = NULL;
#endif
#ifndef TIOCPKT_WINDOW
#define TIOCPKT_WINDOW 0x80
#endif
/* concession to Sun */
#ifndef SIGUSR1
#define SIGUSR1 30
#endif
int eight, litout, rem;
int noescape;
u_char escapechar = '~';
char *speeds[] = {
"0", "50", "75", "110", "134", "150", "200", "300", "600", "1200",
"1800", "2400", "4800", "9600", "19200", "38400"
};
#ifdef OLDSUN
struct winsize {
unsigned short ws_row, ws_col;
unsigned short ws_xpixel, ws_ypixel;
};
#else
#define get_window_size(fd, wp) ioctl(fd, TIOCGWINSZ, wp)
#endif
struct winsize winsize;
void catch_child __P((int));
void copytochild __P((int));
__dead void doit __P((long));
__dead void done __P((int));
void echo __P((char));
u_int getescape __P((char *));
void lostpeer __P((int));
void mode __P((int));
void msg __P((char *));
void oob __P((int));
int reader __P((int));
void sendwindow __P((void));
void setsignal __P((int));
void sigwinch __P((int));
void stop __P((char));
__dead void usage __P((void));
void writer __P((void));
void writeroob __P((int));
#ifdef KERBEROS
void warning __P((const char *, ...));
#endif
#ifdef OLDSUN
int get_window_size __P((int, struct winsize *));
#endif
int
main(argc, argv)
int argc;
char *argv[];
{
extern char *optarg;
extern int optind;
struct passwd *pw;
struct servent *sp;
struct sgttyb ttyb;
long omask;
int argoff, ch, dflag, one, uid;
char *host, *p, *user, term[1024];
argoff = dflag = 0;
one = 1;
host = user = NULL;
if (p = rindex(argv[0], '/'))
++p;
else
p = argv[0];
if (strcmp(p, "rlogin"))
host = p;
/* handle "rlogin host flags" */
if (!host && argc > 2 && argv[1][0] != '-') {
host = argv[1];
argoff = 1;
}
#ifdef KERBEROS
#define OPTIONS "8EKLde:k:l:x"
#else
#define OPTIONS "8EKLde:l:"
#endif
while ((ch = getopt(argc - argoff, argv + argoff, OPTIONS)) != EOF)
switch(ch) {
case '8':
eight = 1;
break;
case 'E':
noescape = 1;
break;
case 'K':
#ifdef KERBEROS
use_kerberos = 0;
#endif
break;
case 'L':
litout = 1;
break;
case 'd':
dflag = 1;
break;
case 'e':
noescape = 0;
escapechar = getescape(optarg);
break;
#ifdef KERBEROS
case 'k':
dest_realm = dst_realm_buf;
(void)strncpy(dest_realm, optarg, REALM_SZ);
break;
#endif
case 'l':
user = optarg;
break;
#ifdef CRYPT
#ifdef KERBEROS
case 'x':
doencrypt = 1;
des_set_key(cred.session, schedule);
break;
#endif
#endif
case '?':
default:
usage();
}
optind += argoff;
argc -= optind;
argv += optind;
/* if haven't gotten a host yet, do so */
if (!host && !(host = *argv++))
usage();
if (*argv)
usage();
if (!(pw = getpwuid(uid = getuid()))) {
(void)fprintf(stderr, "rlogin: unknown user id.\n");
exit(1);
}
if (!user)
user = pw->pw_name;
sp = NULL;
#ifdef KERBEROS
if (use_kerberos) {
sp = getservbyname((doencrypt ? "eklogin" : "klogin"), "tcp");
if (sp == NULL) {
use_kerberos = 0;
warning("can't get entry for %s/tcp service",
doencrypt ? "eklogin" : "klogin");
}
}
#endif
if (sp == NULL)
sp = getservbyname("login", "tcp");
if (sp == NULL) {
(void)fprintf(stderr, "rlogin: login/tcp: unknown service.\n");
exit(1);
}
(void)strcpy(term, (p = getenv("TERM")) ? p : "network");
if (ioctl(0, TIOCGETP, &ttyb) == 0) {
(void)strcat(term, "/");
(void)strcat(term, speeds[(int)ttyb.sg_ospeed]);
}
(void)get_window_size(0, &winsize);
(void)signal(SIGPIPE, lostpeer);
/* will use SIGUSR1 for window size hack, so hold it off */
omask = sigblock(sigmask(SIGURG) | sigmask(SIGUSR1));
/*
* We set SIGURG and SIGUSR1 below so that an
* incoming signal will be held pending rather than being
* discarded. Note that these routines will be ready to get
* a signal by the time that they are unblocked below.
*/
(void)signal(SIGURG, copytochild);
(void)signal(SIGUSR1, writeroob);
#ifdef KERBEROS
try_connect:
if (use_kerberos) {
struct hostent *hp;
/* Fully qualify hostname (needed for krb_realmofhost). */
hp = gethostbyname(host);
if (hp != NULL && !(host = strdup(hp->h_name))) {
(void)fprintf(stderr, "rlogin: %s\n",
strerror(ENOMEM));
exit(1);
}
rem = KSUCCESS;
errno = 0;
if (dest_realm == NULL)
dest_realm = krb_realmofhost(host);
#ifdef CRYPT
if (doencrypt)
rem = krcmd_mutual(&host, sp->s_port, user, term, 0,
dest_realm, &cred, schedule);
else
#endif /* CRYPT */
rem = krcmd(&host, sp->s_port, user, term, 0,
dest_realm);
if (rem < 0) {
use_kerberos = 0;
sp = getservbyname("login", "tcp");
if (sp == NULL) {
(void)fprintf(stderr,
"rlogin: unknown service login/tcp.\n");
exit(1);
}
if (errno == ECONNREFUSED)
warning("remote host doesn't support Kerberos");
if (errno == ENOENT)
warning("can't provide Kerberos auth data");
goto try_connect;
}
} else {
#ifdef CRYPT
if (doencrypt) {
(void)fprintf(stderr,
"rlogin: the -x flag requires Kerberos authentication.\n");
exit(1);
}
#endif /* CRYPT */
rem = rcmd(&host, sp->s_port, pw->pw_name, user, term, 0);
}
#else
rem = rcmd(&host, sp->s_port, pw->pw_name, user, term, 0);
#endif /* KERBEROS */
if (rem < 0)
exit(1);
if (dflag &&
setsockopt(rem, SOL_SOCKET, SO_DEBUG, &one, sizeof(one)) < 0)
(void)fprintf(stderr, "rlogin: setsockopt: %s.\n",
strerror(errno));
one = IPTOS_LOWDELAY;
if (setsockopt(rem, IPPROTO_IP, IP_TOS, (char *)&one, sizeof(int)) < 0)
perror("rlogin: setsockopt TOS (ignored)");
(void)setuid(uid);
doit(omask);
/*NOTREACHED*/
}
int child, defflags, deflflags, tabflag;
char deferase, defkill;
struct tchars deftc;
struct ltchars defltc;
struct tchars notc = { -1, -1, -1, -1, -1, -1 };
struct ltchars noltc = { -1, -1, -1, -1, -1, -1 };
void
doit(omask)
long omask;
{
struct sgttyb sb;
(void)ioctl(0, TIOCGETP, (char *)&sb);
defflags = sb.sg_flags;
tabflag = defflags & TBDELAY;
defflags &= ECHO | CRMOD;
deferase = sb.sg_erase;
defkill = sb.sg_kill;
(void)ioctl(0, TIOCLGET, &deflflags);
(void)ioctl(0, TIOCGETC, &deftc);
notc.t_startc = deftc.t_startc;
notc.t_stopc = deftc.t_stopc;
(void)ioctl(0, TIOCGLTC, &defltc);
(void)signal(SIGINT, SIG_IGN);
setsignal(SIGHUP);
setsignal(SIGQUIT);
child = fork();
if (child == -1) {
(void)fprintf(stderr, "rlogin: fork: %s.\n", strerror(errno));
done(1);
}
if (child == 0) {
mode(1);
if (reader(omask) == 0) {
msg("connection closed.");
exit(0);
}
sleep(1);
msg("\007connection closed.");
exit(1);
}
/*
* We may still own the socket, and may have a pending SIGURG (or might
* receive one soon) that we really want to send to the reader. When
* one of these comes in, the trap copytochild simply copies such
* signals to the child. We can now unblock SIGURG and SIGUSR1
* that were set above.
*/
(void)sigsetmask(omask);
(void)signal(SIGCHLD, catch_child);
writer();
msg("closed connection.");
done(0);
}
/* trap a signal, unless it is being ignored. */
void
setsignal(sig)
int sig;
{
int omask = sigblock(sigmask(sig));
if (signal(sig, exit) == SIG_IGN)
(void)signal(sig, SIG_IGN);
(void)sigsetmask(omask);
}
__dead void
done(status)
int status;
{
int w, wstatus;
mode(0);
if (child > 0) {
/* make sure catch_child does not snap it up */
(void)signal(SIGCHLD, SIG_DFL);
if (kill(child, SIGKILL) >= 0)
while ((w = wait(&wstatus)) > 0 && w != child);
}
exit(status);
}
int dosigwinch;
/*
* This is called when the reader process gets the out-of-band (urgent)
* request to turn on the window-changing protocol.
*/
void
writeroob(signo)
int signo;
{
if (dosigwinch == 0) {
sendwindow();
(void)signal(SIGWINCH, sigwinch);
}
dosigwinch = 1;
}
void
catch_child(signo)
int signo;
{
union wait status;
int pid;
for (;;) {
pid = wait3((int *)&status, WNOHANG|WUNTRACED, NULL);
if (pid == 0)
return;
/* if the child (reader) dies, just quit */
if (pid < 0 || (pid == child && !WIFSTOPPED(status)))
done((int)(status.w_termsig | status.w_retcode));
}
/* NOTREACHED */
}
/*
* writer: write to remote: 0 -> line.
* ~. terminate
* ~^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 *)¬c);
}
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 *)¬c);
}
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 = ¬c;
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 */
}