freebsd-dev/crypto/kerberosIV/appl/bsd/rlogin.c
2000-12-29 21:00:22 +00:00

712 lines
15 KiB
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.
*/
/*
* rlogin - remote login
*/
#include "bsd_locl.h"
RCSID("$Id: rlogin.c,v 1.67.2.2 2000/10/10 12:54:26 assar Exp $");
CREDENTIALS cred;
Key_schedule schedule;
int use_kerberos = 1, doencrypt;
char dst_realm_buf[REALM_SZ], *dest_realm = NULL;
#ifndef CCEQ
#define c2uc(x) ((unsigned char) x)
#define CCEQ__(val, c) (c == val ? val != c2uc(_POSIX_VDISABLE) : 0)
#define CCEQ(val, c) CCEQ__(c2uc(val), c2uc(c))
#endif
int eight, rem;
struct termios deftty;
int noescape;
char escapechar = '~';
struct winsize winsize;
int parent, rcvcnt;
char rcvbuf[8 * 1024];
int child;
static void
echo(char c)
{
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';
write(STDOUT_FILENO, buf, p - buf);
}
static void
mode(int f)
{
struct termios tty;
switch (f) {
case 0:
tcsetattr(0, TCSANOW, &deftty);
break;
case 1:
tcgetattr(0, &deftty);
tty = deftty;
/* This is loosely derived from sys/compat/tty_compat.c. */
tty.c_lflag &= ~(ECHO|ICANON|ISIG|IEXTEN);
tty.c_iflag &= ~ICRNL;
tty.c_oflag &= ~OPOST;
tty.c_cc[VMIN] = 1;
tty.c_cc[VTIME] = 0;
if (eight) {
tty.c_iflag &= IXOFF;
tty.c_cflag &= ~(CSIZE|PARENB);
tty.c_cflag |= CS8;
}
tcsetattr(0, TCSANOW, &tty);
break;
default:
return;
}
}
static void
done(int status)
{
int w, wstatus;
mode(0);
if (child > 0) {
/* make sure catch_child does not snap it up */
signal(SIGCHLD, SIG_DFL);
if (kill(child, SIGKILL) >= 0)
while ((w = wait(&wstatus)) > 0 && w != child);
}
exit(status);
}
static
RETSIGTYPE
catch_child(int foo)
{
int status;
int pid;
for (;;) {
pid = waitpid(-1, &status, WNOHANG|WUNTRACED);
if (pid == 0)
return;
/* if the child (reader) dies, just quit */
if (pid < 0 || (pid == child && !WIFSTOPPED(status)))
done(WTERMSIG(status) | WEXITSTATUS(status));
}
/* NOTREACHED */
}
/*
* There is a race in the SunOS5 rlogind. If the slave end has not yet
* been opened by the child when setting tty size the size is reset to
* zero when the child opens it. Therefore we send the window update
* twice.
*/
static int tty_kludge = 1;
/* Return the number of OOB bytes processed. */
static int
oob_real(void)
{
struct termios tty;
int atmark, n, out, rcvd;
char waste[BUFSIZ], mark;
out = O_RDWR;
rcvd = 0;
if (recv(rem, &mark, 1, MSG_OOB) < 0) {
return -1;
}
if (mark & TIOCPKT_WINDOW) {
/* Let server know about window size changes */
kill(parent, SIGUSR1);
} else if (tty_kludge) {
/* Let server know about window size changes */
kill(parent, SIGUSR1);
tty_kludge = 0;
}
if (!eight && (mark & TIOCPKT_NOSTOP)) {
tcgetattr(0, &tty);
tty.c_iflag &= ~IXON;
tcsetattr(0, TCSANOW, &tty);
}
if (!eight && (mark & TIOCPKT_DOSTOP)) {
tcgetattr(0, &tty);
tty.c_iflag |= (deftty.c_iflag & IXON);
tcsetattr(0, TCSANOW, &tty);
}
if (mark & TIOCPKT_FLUSHWRITE) {
#ifdef TCOFLUSH
tcflush(1, TCOFLUSH);
#else
ioctl(1, TIOCFLUSH, (char *)&out);
#endif
for (;;) {
if (ioctl(rem, SIOCATMARK, &atmark) < 0) {
warn("ioctl");
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;
}
/* oob does not do FLUSHREAD (alas!) */
return 1;
}
/* reader: read from remote: line -> 1 */
static int
reader(void)
{
int n, remaining;
char *bufp;
int kludgep = 1;
bufp = rcvbuf;
for (;;) {
fd_set readfds, exceptfds;
while ((remaining = rcvcnt - (bufp - rcvbuf)) > 0) {
n = write(STDOUT_FILENO, bufp, remaining);
if (n < 0) {
if (errno != EINTR)
return (-1);
continue;
}
bufp += n;
}
bufp = rcvbuf;
rcvcnt = 0;
FD_ZERO (&readfds);
if (rem >= FD_SETSIZE)
errx (1, "fd too large");
FD_SET (rem, &readfds);
FD_ZERO (&exceptfds);
if (kludgep)
FD_SET (rem, &exceptfds);
if (select(rem+1, &readfds, 0, &exceptfds, 0) == -1) {
if (errno == EINTR)
continue; /* Got signal */
else
errx(1, "select failed mysteriously");
}
if (!FD_ISSET(rem, &exceptfds) && !FD_ISSET(rem, &readfds)) {
warnx("select: nothing to read?");
continue;
}
if (FD_ISSET(rem, &exceptfds)) {
int foo = oob_real ();
if (foo >= 1)
continue; /* First check if there is more OOB data. */
else if (foo < 0)
kludgep = 0;
}
if (!FD_ISSET(rem, &readfds))
continue; /* Nothing to read. */
kludgep = 1;
#ifndef NOENCRYPTION
if (doencrypt)
rcvcnt = des_enc_read(rem, rcvbuf,
sizeof(rcvbuf),
schedule, &cred.session);
else
#endif
rcvcnt = read(rem, rcvbuf, sizeof (rcvbuf));
if (rcvcnt == 0)
return (0);
if (rcvcnt < 0) {
if (errno == EINTR)
continue;
warn("read");
return (-1);
}
}
}
/*
* Send the window size to the server via the magic escape
*/
static void
sendwindow(void)
{
char obuf[4 + 4 * sizeof (u_int16_t)];
unsigned short *p;
p = (u_int16_t *)(obuf + 4);
obuf[0] = 0377;
obuf[1] = 0377;
obuf[2] = 's';
obuf[3] = 's';
*p++ = htons(winsize.ws_row);
*p++ = htons(winsize.ws_col);
#ifdef HAVE_WS_XPIXEL
*p++ = htons(winsize.ws_xpixel);
#else
*p++ = htons(0);
#endif
#ifdef HAVE_WS_YPIXEL
*p++ = htons(winsize.ws_ypixel);
#else
*p++ = htons(0);
#endif
#ifndef NOENCRYPTION
if(doencrypt)
des_enc_write(rem, obuf, sizeof(obuf), schedule,
&cred.session);
else
#endif
write(rem, obuf, sizeof(obuf));
}
static
RETSIGTYPE
sigwinch(int foo)
{
struct winsize ws;
if (get_window_size(0, &ws) == 0 &&
memcmp(&ws, &winsize, sizeof(ws))) {
winsize = ws;
sendwindow();
}
}
static void
stop(int all)
{
mode(0);
signal(SIGCHLD, SIG_IGN);
kill(all ? 0 : getpid(), SIGTSTP);
signal(SIGCHLD, catch_child);
mode(1);
#ifdef SIGWINCH
kill(SIGWINCH, getpid()); /* check for size changes, if caught */
#endif
}
/*
* writer: write to remote: 0 -> line.
* ~. terminate
* ~^Z suspend rlogin process.
* ~<delayed-suspend char> suspend rlogin process, but leave reader alone.
*/
static void
writer(void)
{
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 == '.' || CCEQ(deftty.c_cc[VEOF], c)) {
echo(c);
break;
}
if (CCEQ(deftty.c_cc[VSUSP], c)) {
bol = 1;
echo(c);
stop(1);
continue;
}
#ifdef VDSUSP
/* Is VDSUSP called something else on Linux?
* Perhaps VDELAY is a better thing? */
if (CCEQ(deftty.c_cc[VDSUSP], c)) {
bol = 1;
echo(c);
stop(0);
continue;
}
#endif /* VDSUSP */
if (c != escapechar) {
#ifndef NOENCRYPTION
if (doencrypt)
des_enc_write(rem, &escapechar,1, schedule, &cred.session);
else
#endif
write(rem, &escapechar, 1);
}
}
if (doencrypt) {
#ifdef NOENCRYPTION
if (write(rem, &c, 1) == 0) {
#else
if (des_enc_write(rem, &c, 1, schedule, &cred.session) == 0) {
#endif
warnx("line gone");
break;
}
} else
if (write(rem, &c, 1) == 0) {
warnx("line gone");
break;
}
bol = CCEQ(deftty.c_cc[VKILL], c) ||
CCEQ(deftty.c_cc[VEOF], c) ||
CCEQ(deftty.c_cc[VINTR], c) ||
CCEQ(deftty.c_cc[VSUSP], c) ||
c == '\r' || c == '\n';
}
}
static
RETSIGTYPE
lostpeer(int foo)
{
signal(SIGPIPE, SIG_IGN);
warnx("\aconnection closed.\r");
done(1);
}
/*
* This is called in the parent when the reader process gets the
* out-of-band (urgent) request to turn on the window-changing
* protocol. It is signalled from the child(reader).
*/
static
RETSIGTYPE
sigusr1(int foo)
{
/*
* Now we now daemon supports winsize hack,
*/
sendwindow();
#ifdef SIGWINCH
signal(SIGWINCH, sigwinch); /* so we start to support it */
#endif
SIGRETURN(0);
}
static void
doit(void)
{
signal(SIGINT, SIG_IGN);
signal(SIGHUP, SIG_IGN);
signal(SIGQUIT, SIG_IGN);
signal(SIGCHLD, catch_child);
/*
* Child sends parent this signal for window size hack.
*/
signal(SIGUSR1, sigusr1);
signal(SIGPIPE, lostpeer);
mode(1);
parent = getpid();
child = fork();
if (child == -1) {
warn("fork");
done(1);
}
if (child == 0) {
signal(SIGCHLD, SIG_IGN);
signal(SIGTTOU, SIG_IGN);
if (reader() == 0)
errx(1, "connection closed.\r");
sleep(1);
errx(1, "\aconnection closed.\r");
}
writer();
warnx("closed connection.\r");
done(0);
}
static void
usage(void)
{
fprintf(stderr,
"usage: rlogin [ -%s]%s[-e char] [ -l username ] host\n",
"8DEKLdx", " [-k realm] ");
exit(1);
}
static u_int
getescape(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;
}
}
warnx("illegal option value -- e");
usage();
return 0;
}
int
main(int argc, char **argv)
{
struct passwd *pw;
int sv_port, user_port = 0;
int argoff, ch, dflag, Dflag, one, uid;
char *host, *user, term[1024];
argoff = dflag = Dflag = 0;
one = 1;
host = user = NULL;
set_progname(argv[0]);
/* handle "rlogin host flags" */
if (argc > 2 && argv[1][0] != '-') {
host = argv[1];
argoff = 1;
}
#define OPTIONS "8DEKLde:k:l:xp:"
while ((ch = getopt(argc - argoff, argv + argoff, OPTIONS)) != -1)
switch(ch) {
case '8':
eight = 1;
break;
case 'D':
Dflag = 1;
break;
case 'E':
noescape = 1;
break;
case 'K':
use_kerberos = 0;
break;
case 'd':
dflag = 1;
break;
case 'e':
noescape = 0;
escapechar = getescape(optarg);
break;
case 'k':
dest_realm = dst_realm_buf;
strlcpy(dest_realm, optarg, REALM_SZ);
break;
case 'l':
user = optarg;
break;
case 'x':
doencrypt = 1;
break;
case 'p': {
char *endptr;
user_port = strtol (optarg, &endptr, 0);
if (user_port == 0 && optarg == endptr)
errx (1, "Bad port `%s'", optarg);
user_port = htons(user_port);
break;
}
case '?':
default:
usage();
}
optind += argoff;
/* if haven't gotten a host yet, do so */
if (!host && !(host = argv[optind++]))
usage();
if (argv[optind])
usage();
if (!(pw = k_getpwuid(uid = getuid())))
errx(1, "unknown user id.");
if (!user)
user = pw->pw_name;
if (user_port)
sv_port = user_port;
else
sv_port = get_login_port(use_kerberos, doencrypt);
{
char *p = getenv("TERM");
struct termios tty;
int i;
if (p == NULL)
p = "network";
if (tcgetattr(0, &tty) == 0
&& (i = speed_t2int (cfgetospeed(&tty))) > 0)
snprintf (term, sizeof(term),
"%s/%d",
p, i);
else
snprintf (term, sizeof(term),
"%s",
p);
}
get_window_size(0, &winsize);
if (use_kerberos) {
paranoid_setuid(getuid());
rem = KSUCCESS;
errno = 0;
if (dest_realm == NULL)
dest_realm = krb_realmofhost(host);
if (doencrypt)
rem = krcmd_mutual(&host, sv_port, user, term, 0,
dest_realm, &cred, schedule);
else
rem = krcmd(&host, sv_port, user, term, 0,
dest_realm);
if (rem < 0) {
int i;
char **newargv;
if (errno == ECONNREFUSED)
warning("remote host doesn't support Kerberos");
if (errno == ENOENT)
warning("can't provide Kerberos auth data");
newargv = malloc((argc + 2) * sizeof(*newargv));
if (newargv == NULL)
err(1, "malloc");
newargv[0] = argv[0];
newargv[1] = "-K";
for(i = 1; i < argc; ++i)
newargv[i + 1] = argv[i];
newargv[argc + 1] = NULL;
execv(_PATH_RLOGIN, newargv);
}
} else {
if (doencrypt)
errx(1, "the -x flag requires Kerberos authentication.");
if (geteuid() != 0)
errx(1, "not installed setuid root, "
"only root may use non kerberized rlogin");
rem = rcmd(&host, sv_port, pw->pw_name, user, term, 0);
}
if (rem < 0)
exit(1);
#ifdef HAVE_SETSOCKOPT
#ifdef SO_DEBUG
if (dflag &&
setsockopt(rem, SOL_SOCKET, SO_DEBUG, (void *)&one,
sizeof(one)) < 0)
warn("setsockopt");
#endif
#ifdef TCP_NODELAY
if (Dflag &&
setsockopt(rem, IPPROTO_TCP, TCP_NODELAY, (void *)&one,
sizeof(one)) < 0)
warn("setsockopt(TCP_NODELAY)");
#endif
#ifdef IP_TOS
one = IPTOS_LOWDELAY;
if (setsockopt(rem, IPPROTO_IP, IP_TOS, (void *)&one, sizeof(int)) < 0)
warn("setsockopt(IP_TOS)");
#endif /* IP_TOS */
#endif /* HAVE_SETSOCKOPT */
paranoid_setuid(uid);
doit();
return 0;
}