2.11BSD/src/libexec/rlogind/rlogind.c
/*
* Copyright (c) 1983, 1988 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#if !defined(lint) && defined(DOSCCS)
char copyright[] =
"@(#) Copyright (c) 1983, 1988 The Regents of the University of California.\n\
All rights reserved.\n";
static char sccsid[] = "@(#)rlogind.c 5.22.1.8 (2.11BSD) 1996/3/22";
#endif
/*
* remote login server:
* \0
* remuser\0
* locuser\0
* terminal_type/speed\0
* data
*
* Automatic login protocol is done here, using login -f upon success,
* unless OLD_LOGIN is defined (then done in login, ala 4.2/4.3BSD).
*/
#include <stdio.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#ifdef FOURdotFOUR
#include <sys/termios.h>
#endif
#include <netinet/in.h>
#include <errno.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <netdb.h>
#include <syslog.h>
#include <strings.h>
#include <arpa/nameser.h>
#include <resolv.h>
#ifndef TIOCPKT_WINDOW
#define TIOCPKT_WINDOW 0x80
#endif
char *env[2];
#define NMAX 30
char lusername[NMAX+1], rusername[NMAX+1];
static char term[64] = "TERM=";
#define ENVSIZE (sizeof("TERM=")-1) /* skip null for concatenation */
int keepalive = 1;
int check_all = 0;
#define SUPERUSER(pwd) ((pwd)->pw_uid == 0)
int reapchild();
struct passwd *getpwnam(), *pwd;
main(argc, argv)
int argc;
char **argv;
{
extern int opterr, optind, _check_rhosts_file;
int ch;
int on = 1, fromlen;
struct sockaddr_in from;
openlog("rlogind", LOG_PID | LOG_CONS, LOG_AUTH);
opterr = 0;
while ((ch = getopt(argc, argv, "aln")) != EOF)
switch (ch) {
case 'a':
check_all = 1;
break;
case 'l':
_check_rhosts_file = 0;
break;
case 'n':
keepalive = 0;
break;
case '?':
default:
syslog(LOG_ERR, "usage: rlogind [-a] [-l] [-n]");
break;
}
argc -= optind;
argv += optind;
fromlen = sizeof (from);
if (getpeername(0, &from, &fromlen) < 0) {
syslog(LOG_ERR, "Couldn't get peer name of remote host: %m");
fatalperror("Can't get peer name of remote host");
}
if (keepalive &&
setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof (on)) < 0)
syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
doit(0, &from);
}
int child;
int cleanup();
int netf;
char *line;
extern char *inet_ntoa();
struct winsize win = { 0, 0, 0, 0 };
doit(f, fromp)
int f;
struct sockaddr_in *fromp;
{
int i, p, t, pid, on = 1;
#ifndef OLD_LOGIN
int authenticated = 0, hostok = 0;
char remotehost[2 * MAXHOSTNAMELEN + 1];
#endif
register struct hostent *hp;
struct hostent hostent;
char c;
alarm(60);
read(f, &c, 1);
if (c != 0)
exit(1);
alarm(0);
fromp->sin_port = ntohs((u_short)fromp->sin_port);
hp = gethostbyaddr(&fromp->sin_addr, sizeof (struct in_addr),
fromp->sin_family);
if (hp == 0) {
/*
* Only the name is used below.
*/
hp = &hostent;
hp->h_name = inet_ntoa(fromp->sin_addr);
#ifndef OLD_LOGIN
hostok++;
#endif
}
#ifndef OLD_LOGIN
else if (check_all || local_domain(hp->h_name)) {
/*
* If name returned by gethostbyaddr is in our domain,
* attempt to verify that we haven't been fooled by someone
* in a remote net; look up the name and check that this
* address corresponds to the name.
*/
strncpy(remotehost, hp->h_name, sizeof(remotehost) - 1);
remotehost[sizeof(remotehost) - 1] = 0;
#ifdef RES_DNSRCH
/*
* gethostbyaddr returns a FQDN, so now the domain search
* action must be turned off to avoid unwanted queries to
* the nameservor.
*/
_res.options &= ~RES_DNSRCH;
#endif RES_DNSRCH
hp = gethostbyname(remotehost);
if (hp)
#ifdef h_addr /* 4.2 hack */
for (; hp->h_addr_list[0]; hp->h_addr_list++)
if (!bcmp(hp->h_addr_list[0], (caddr_t)&fromp->sin_addr,
sizeof(fromp->sin_addr))) {
hostok++;
break;
}
#else
if (!bcmp(hp->h_addr, (caddr_t)&fromp->sin_addr,
sizeof(fromp->sin_addr)))
hostok++;
#endif
} else
hostok++;
#endif /* OLD_LOGIN */
if (fromp->sin_family != AF_INET ||
fromp->sin_port >= IPPORT_RESERVED ||
fromp->sin_port < IPPORT_RESERVED/2) {
syslog(LOG_NOTICE, "Connection from %s on illegal port",
inet_ntoa(fromp->sin_addr));
fatal(f, "Permission denied");
}
#ifdef IP_OPTIONS
{
u_char optbuf[BUFSIZ/3], *cp;
char lbuf[BUFSIZ], *lp;
int optsize = sizeof(optbuf), ipproto;
struct protoent *ip;
if ((ip = getprotobyname("ip")) != NULL)
ipproto = ip->p_proto;
else
ipproto = IPPROTO_IP;
if (getsockopt(0, ipproto, IP_OPTIONS, (char *)optbuf, &optsize) == 0 &&
optsize != 0) {
lp = lbuf;
for (cp = optbuf; optsize > 0; cp++, optsize--, lp += 3)
sprintf(lp, " %2.2x", *cp);
syslog(LOG_NOTICE,
"Connection received using IP options (ignored):%s", lbuf);
if (setsockopt(0, ipproto, IP_OPTIONS,
(char *)NULL, &optsize) != 0) {
syslog(LOG_ERR, "setsockopt IP_OPTIONS NULL: %m");
exit(1);
}
}
}
#endif
write(f, "", 1);
#ifndef OLD_LOGIN
if (do_rlogin(hp->h_name) == 0) {
if (hostok)
authenticated++;
else
write(f, "rlogind: Host address mismatch.\r\n",
sizeof("rlogind: Host address mismatch.\r\n") - 1);
}
#endif
for (c = 'p'; c <= 's'; c++) {
struct stat stb;
line = "/dev/ptyXX";
line[strlen("/dev/pty")] = c;
line[strlen("/dev/ptyp")] = '0';
if (stat(line, &stb) < 0)
break;
for (i = 0; i < 16; i++) {
line[sizeof("/dev/ptyp") - 1] = "0123456789abcdef"[i];
p = open(line, O_RDWR);
if (p > 0)
goto gotpty;
}
}
fatal(f, "Out of ptys");
/*NOTREACHED*/
gotpty:
(void) ioctl(p, TIOCSWINSZ, &win);
netf = f;
line[strlen("/dev/")] = 't';
t = open(line, O_RDWR);
if (t < 0)
fatalperror(f, line);
if (fchmod(t, 0))
fatalperror(f, line);
(void)signal(SIGHUP, SIG_IGN);
vhangup();
(void)signal(SIGHUP, SIG_DFL);
t = open(line, O_RDWR);
if (t < 0)
fatalperror(f, line);
setup_term(t);
pid = fork();
if (pid < 0)
fatalperror(f, "");
if (pid == 0) {
#ifdef FOURdotFOUR
if (setsid() < 0)
fatalperror(f, "setsid");
if (ioctl(t, TIOCSCTTY, 0) < 0)
fatalperror(f, "ioctl(sctty)");
#endif
close(f), close(p);
dup2(t, 0), dup2(t, 1), dup2(t, 2);
close(t);
#ifdef OLD_LOGIN
execl("/bin/login", "login", "-r", hp->h_name, 0);
#else /* OLD_LOGIN */
if (authenticated)
execl("/bin/login", "login", "-p", "-h", hp->h_name,
"-f", lusername, 0);
else
execl("/bin/login", "login", "-p", "-h", hp->h_name,
lusername, 0);
#endif /* OLD_LOGIN */
fatalperror(2, "/bin/login");
/*NOTREACHED*/
}
#ifndef DEBUG
{
int tt = open("/dev/tty", O_RDWR);
if (tt > 0) {
(void)ioctl(tt, TIOCNOTTY, 0);
(void)close(tt);
}
}
#endif
close(t);
ioctl(f, FIONBIO, &on);
ioctl(p, FIONBIO, &on);
ioctl(p, TIOCPKT, &on);
signal(SIGTSTP, SIG_IGN);
signal(SIGCHLD, cleanup);
setpgrp(0, 0);
protocol(f, p);
signal(SIGCHLD, SIG_IGN);
cleanup();
}
char magic[2] = { 0377, 0377 };
char oobdata[] = {TIOCPKT_WINDOW};
/*
* Handle a "control" request (signaled by magic being present)
* in the data stream. For now, we are only willing to handle
* window size changes.
*/
control(pty, cp, n)
int pty;
char *cp;
int n;
{
struct winsize w;
if (n < 4+sizeof (w) || cp[2] != 's' || cp[3] != 's')
return (0);
oobdata[0] &= ~TIOCPKT_WINDOW; /* we know he heard */
bcopy(cp+4, (char *)&w, sizeof(w));
w.ws_row = ntohs(w.ws_row);
w.ws_col = ntohs(w.ws_col);
w.ws_xpixel = ntohs(w.ws_xpixel);
w.ws_ypixel = ntohs(w.ws_ypixel);
(void)ioctl(pty, TIOCSWINSZ, &w);
return (4+sizeof (w));
}
/*
* rlogin "protocol" machine.
*/
protocol(f, p)
register int f, p;
{
char pibuf[1024], fibuf[1024], *pbp, *fbp;
register pcc = 0, fcc = 0;
int cc, nfd, n;
char cntl;
/*
* Must ignore SIGTTOU, otherwise we'll stop
* when we try and set slave pty's window shape
* (our controlling tty is the master pty).
*/
(void) signal(SIGTTOU, SIG_IGN);
send(f, oobdata, 1, MSG_OOB); /* indicate new rlogin */
if (f > p)
nfd = f + 1;
else
nfd = p + 1;
for (;;) {
fd_set ibits, obits, ebits;
FD_ZERO(&ibits);
FD_ZERO(&obits);
if (fcc)
FD_SET(p, &obits);
else
FD_SET(f, &ibits);
if (pcc >= 0)
if (pcc)
FD_SET(f, &obits);
else
FD_SET(p, &ibits);
FD_SET(p, &ebits);
if ((n = select(nfd, &ibits, &obits, &ebits, 0)) < 0) {
if (errno == EINTR)
continue;
fatalperror(f, "select");
}
if (n == 0) {
/* shouldn't happen... */
sleep(5);
continue;
}
#define pkcontrol(c) ((c)&(TIOCPKT_FLUSHWRITE|TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))
if (FD_ISSET(p, &ebits)) {
cc = read(p, &cntl, 1);
if (cc == 1 && pkcontrol(cntl)) {
cntl |= oobdata[0];
send(f, &cntl, 1, MSG_OOB);
if (cntl & TIOCPKT_FLUSHWRITE) {
pcc = 0;
FD_CLR(p, &ibits);
}
}
}
if (FD_ISSET(f, &ibits)) {
fcc = read(f, fibuf, sizeof(fibuf));
if (fcc < 0 && errno == EWOULDBLOCK)
fcc = 0;
else {
register char *cp;
int left, n;
if (fcc <= 0)
break;
fbp = fibuf;
top:
for (cp = fibuf; cp < fibuf+fcc-1; cp++)
if (cp[0] == magic[0] &&
cp[1] == magic[1]) {
left = fcc - (cp-fibuf);
n = control(p, cp, left);
if (n) {
left -= n;
if (left > 0)
bcopy(cp+n, cp, left);
fcc -= n;
goto top; /* n^2 */
}
}
FD_SET(p, &obits); /* try write */
}
}
if (FD_ISSET(p, &obits) && fcc > 0) {
cc = write(p, fbp, fcc);
if (cc > 0) {
fcc -= cc;
fbp += cc;
}
}
if (FD_ISSET(p, &ibits)) {
pcc = read(p, pibuf, sizeof (pibuf));
pbp = pibuf;
if (pcc < 0 && errno == EWOULDBLOCK)
pcc = 0;
else if (pcc <= 0)
break;
else if (pibuf[0] == 0) {
pbp++, pcc--;
FD_SET(f, &obits); /* try a write */
} else {
if (pkcontrol(pibuf[0])) {
pibuf[0] |= oobdata[0];
send(f, &pibuf[0], 1, MSG_OOB);
}
pcc = 0;
}
}
if ((FD_ISSET(f, &obits)) && pcc > 0) {
cc = write(f, pbp, pcc);
if (cc < 0 && errno == EWOULDBLOCK) {
/* also shouldn't happen */
sleep(5);
continue;
}
if (cc > 0) {
pcc -= cc;
pbp += cc;
}
}
}
}
cleanup()
{
char *p;
p = line + sizeof("/dev/") - 1;
if (logout(p))
logwtmp(p, "", "");
(void)chmod(line, 0666);
(void)chown(line, 0, 0);
*p = 'p';
(void)chmod(line, 0666);
(void)chown(line, 0, 0);
shutdown(netf, 2);
exit(1);
}
fatal(f, msg)
int f;
char *msg;
{
char buf[BUFSIZ];
buf[0] = '\01'; /* error indicator */
(void) sprintf(buf + 1, "rlogind: %s.\r\n", msg);
(void) write(f, buf, strlen(buf));
exit(1);
}
fatalperror(f, msg)
int f;
char *msg;
{
char buf[BUFSIZ];
(void) sprintf(buf, "%s: %s", msg, strerror(errno));
fatal(f, buf);
}
#ifndef OLD_LOGIN
do_rlogin(host)
char *host;
{
getstr(rusername, sizeof(rusername), "remuser too long");
getstr(lusername, sizeof(lusername), "locuser too long");
getstr(term+ENVSIZE, sizeof(term)-ENVSIZE, "Terminal type too long");
if (getuid())
return(-1);
pwd = getpwnam(lusername);
if (pwd == NULL)
return(-1);
return(ruserok(host, SUPERUSER(pwd), rusername, lusername));
}
getstr(buf, cnt, errmsg)
char *buf;
int cnt;
char *errmsg;
{
char c;
do {
if (read(0, &c, 1) != 1)
exit(1);
if (--cnt < 0)
fatal(1, errmsg);
*buf++ = c;
} while (c != 0);
}
extern char **environ;
char *speeds[] = {
"0", "50", "75", "110", "134", "150", "200", "300", "600",
"1200", "1800", "2400", "4800", "9600", "19200", "38400",
};
#define NSPEEDS (sizeof(speeds) / sizeof(speeds[0]))
setup_term(fd)
int fd;
{
register char *cp = index(term, '/'), **cpp;
char *speed;
#ifdef FOURdotFOUR
struct termios tt;
tcgetattr(fd, &tt);
if (cp) {
*cp++ = '\0';
speed = cp;
cp = index(speed, '/');
if (cp)
*cp++ = '\0';
cfsetspeed(&tt, atoi(speed));
}
tt.c_iflag = TTYDEF_IFLAG;
tt.c_oflag = TTYDEF_OFLAG;
tt.c_lflag = TTYDEF_LFLAG;
tcsetattr(fd, TCSADFLUSH, &tt);
#else
struct sgttyb sgttyb;
(void)ioctl(fd, TIOCGETP, &sgttyb);
if (cp) {
*cp++ = '\0';
speed = cp;
cp = index(speed, '/');
if (cp)
*cp++ = '\0';
for (cpp = speeds; cpp < &speeds[NSPEEDS]; cpp++)
if (strcmp(*cpp, speed) == 0) {
sgttyb.sg_ispeed = sgttyb.sg_ospeed = cpp - speeds;
break;
}
}
sgttyb.sg_flags = ECHO|CRMOD|ANYP|XTABS;
(void)ioctl(fd, TIOCSETP, &sgttyb);
#endif
env[0] = term;
env[1] = 0;
environ = env;
}
/*
* Check whether host h is in our local domain,
* defined as sharing the last two components of the domain part,
* or the entire domain part if the local domain has only one component.
* If either name is unqualified (contains no '.'),
* assume that the host is local, as it will be
* interpreted as such.
*/
local_domain(h)
char *h;
{
char localhost[MAXHOSTNAMELEN];
char *p1, *p2, *topdomain();
localhost[0] = 0;
(void) gethostname(localhost, sizeof(localhost));
p1 = topdomain(localhost);
p2 = topdomain(h);
if (p1 == NULL || p2 == NULL || !strcasecmp(p1, p2))
return(1);
return(0);
}
char *
topdomain(h)
char *h;
{
register char *p;
char *maybe = NULL;
int dots = 0;
for (p = h + strlen(h); p >= h; p--) {
if (*p == '.') {
if (++dots == 2)
return (p);
maybe = p;
}
}
return (maybe);
}
#endif /* OLD_LOGIN */