4.3BSD/usr/src/etc/rlogind.c
/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1983 Regents of the University of California.\n\
All rights reserved.\n";
#endif not lint
#ifndef lint
static char sccsid[] = "@(#)rlogind.c 5.11 (Berkeley) 5/23/86";
#endif not lint
/*
* remote login server:
* remuser\0
* locuser\0
* terminal info\0
* data
*/
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <sys/file.h>
#include <netinet/in.h>
#include <errno.h>
#include <pwd.h>
#include <signal.h>
#include <sgtty.h>
#include <stdio.h>
#include <netdb.h>
#include <syslog.h>
#include <strings.h>
# ifndef TIOCPKT_WINDOW
# define TIOCPKT_WINDOW 0x80
# endif TIOCPKT_WINDOW
extern errno;
int reapchild();
struct passwd *getpwnam();
char *malloc();
main(argc, argv)
int argc;
char **argv;
{
int on = 1, options = 0, fromlen;
struct sockaddr_in from;
openlog("rlogind", LOG_PID | LOG_AUTH, LOG_AUTH);
fromlen = sizeof (from);
if (getpeername(0, &from, &fromlen) < 0) {
fprintf(stderr, "%s: ", argv[0]);
perror("getpeername");
_exit(1);
}
if (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;
extern errno;
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;
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);
}
if (fromp->sin_family != AF_INET ||
fromp->sin_port >= IPPORT_RESERVED)
fatal(f, "Permission denied");
write(f, "", 1);
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[strlen("/dev/ptyp")] = "0123456789abcdef"[i];
p = open(line, 2);
if (p > 0)
goto gotpty;
}
}
fatal(f, "Out of ptys");
/*NOTREACHED*/
gotpty:
(void) ioctl(p, TIOCSWINSZ, &win);
netf = f;
line[strlen("/dev/")] = 't';
#ifdef DEBUG
{ int tt = open("/dev/tty", 2);
if (tt > 0) {
ioctl(tt, TIOCNOTTY, 0);
close(tt);
}
}
#endif
t = open(line, 2);
if (t < 0)
fatalperror(f, line, errno);
{ struct sgttyb b;
gtty(t, &b); b.sg_flags = RAW|ANYP; stty(t, &b);
}
pid = fork();
if (pid < 0)
fatalperror(f, "", errno);
if (pid == 0) {
close(f), close(p);
dup2(t, 0), dup2(t, 1), dup2(t, 2);
close(t);
execl("/bin/login", "login", "-r", hp->h_name, 0);
fatalperror(2, "/bin/login", errno);
/*NOTREACHED*/
}
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);
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)
int f, p;
{
char pibuf[1024], fibuf[1024], *pbp, *fbp;
register pcc = 0, fcc = 0;
int cc;
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 */
for (;;) {
int ibits, obits, ebits;
ibits = 0;
obits = 0;
if (fcc)
obits |= (1<<p);
else
ibits |= (1<<f);
if (pcc >= 0)
if (pcc)
obits |= (1<<f);
else
ibits |= (1<<p);
ebits = (1<<p);
if (select(16, &ibits, &obits, &ebits, 0) < 0) {
if (errno == EINTR)
continue;
fatalperror(f, "select", errno);
}
if (ibits == 0 && obits == 0 && ebits == 0) {
/* shouldn't happen... */
sleep(5);
continue;
}
#define pkcontrol(c) ((c)&(TIOCPKT_FLUSHWRITE|TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))
if (ebits & (1<<p)) {
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;
ibits &= ~(1<<p);
}
}
}
if (ibits & (1<<f)) {
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 */
}
}
}
}
if ((obits & (1<<p)) && fcc > 0) {
cc = write(p, fbp, fcc);
if (cc > 0) {
fcc -= cc;
fbp += cc;
}
}
if (ibits & (1<<p)) {
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--;
else {
if (pkcontrol(pibuf[0])) {
pibuf[0] |= oobdata[0];
send(f, &pibuf[0], 1, MSG_OOB);
}
pcc = 0;
}
}
if ((obits & (1<<f)) && 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()
{
rmut();
vhangup(); /* XXX */
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, errno)
int f;
char *msg;
int errno;
{
char buf[BUFSIZ];
extern int sys_nerr;
extern char *sys_errlist[];
if ((unsigned)errno < sys_nerr)
(void) sprintf(buf, "%s: %s", msg, sys_errlist[errno]);
else
(void) sprintf(buf, "%s: Error %d", msg, errno);
fatal(f, buf);
}
#include <utmp.h>
struct utmp wtmp;
char wtmpf[] = "/usr/adm/wtmp";
char utmpf[] = "/etc/utmp";
#define SCPYN(a, b) strncpy(a, b, sizeof(a))
#define SCMPN(a, b) strncmp(a, b, sizeof(a))
rmut()
{
register f;
int found = 0;
struct utmp *u, *utmp;
int nutmp;
struct stat statbf;
f = open(utmpf, O_RDWR);
if (f >= 0) {
fstat(f, &statbf);
utmp = (struct utmp *)malloc(statbf.st_size);
if (!utmp)
syslog(LOG_ERR, "utmp malloc failed");
if (statbf.st_size && utmp) {
nutmp = read(f, utmp, statbf.st_size);
nutmp /= sizeof(struct utmp);
for (u = utmp ; u < &utmp[nutmp] ; u++) {
if (SCMPN(u->ut_line, line+5) ||
u->ut_name[0]==0)
continue;
lseek(f, ((long)u)-((long)utmp), L_SET);
SCPYN(u->ut_name, "");
SCPYN(u->ut_host, "");
time(&u->ut_time);
write(f, (char *)u, sizeof(wtmp));
found++;
}
}
close(f);
}
if (found) {
f = open(wtmpf, O_WRONLY|O_APPEND);
if (f >= 0) {
SCPYN(wtmp.ut_line, line+5);
SCPYN(wtmp.ut_name, "");
SCPYN(wtmp.ut_host, "");
time(&wtmp.ut_time);
write(f, (char *)&wtmp, sizeof(wtmp));
close(f);
}
}
chmod(line, 0666);
chown(line, 0, 0);
line[strlen("/dev/")] = 'p';
chmod(line, 0666);
chown(line, 0, 0);
}