NetBSD-5.0.2/libexec/rlogind/rlogind.c
/* $NetBSD: rlogind.c,v 1.38 2008/07/20 01:09:07 lukem Exp $ */
/*
* Copyright (C) 1998 WIDE Project.
* 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 WIDE Project and
* its contributors.
* 4. Neither the name of the project 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 PROJECT 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 PROJECT 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.
*/
/*-
* Copyright (c) 1983, 1988, 1989, 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. 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.
*/
#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1983, 1988, 1989, 1993\
The Regents of the University of California. All rights reserved.");
#if 0
static char sccsid[] = "@(#)rlogind.c 8.2 (Berkeley) 4/28/95";
#else
__RCSID("$NetBSD: rlogind.c,v 1.38 2008/07/20 01:09:07 lukem Exp $");
#endif
#endif /* not lint */
/*
* remote login server:
* \0
* remuser\0
* locuser\0
* terminal_type/speed\0
* data
*/
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <signal.h>
#include <termios.h>
#include <poll.h>
#include <vis.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <pwd.h>
#include <syslog.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <util.h>
#include "pathnames.h"
#ifndef TIOCPKT_WINDOW
#define TIOCPKT_WINDOW 0x80
#endif
#define OPTIONS "alnL"
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;
int log_success = 0;
struct passwd *pwd;
void doit __P((int, struct sockaddr_storage *));
int control __P((int, char *, int));
void protocol __P((int, int));
void cleanup __P((int));
void fatal __P((int, const char *, int));
int do_rlogin __P((struct sockaddr *, char *));
void getstr __P((char *, int, const char *));
void setup_term __P((int));
#if 0
int do_krb_login __P((union sockunion *));
#endif
void usage __P((void));
int local_domain __P((char *));
char *topdomain __P((char *));
int main __P((int, char *[]));
extern int __check_rhosts_file;
extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c */
extern char **environ;
int
main(argc, argv)
int argc;
char *argv[];
{
struct sockaddr_storage from;
int ch, on;
socklen_t fromlen = sizeof(from);
openlog("rlogind", LOG_PID, LOG_AUTH);
opterr = 0;
while ((ch = getopt(argc, argv, OPTIONS)) != -1)
switch (ch) {
case 'a':
check_all = 1;
break;
case 'l':
__check_rhosts_file = 0;
break;
case 'n':
keepalive = 0;
break;
case 'L':
log_success = 1;
break;
case '?':
default:
usage();
break;
}
argc -= optind;
argv += optind;
if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) {
syslog(LOG_ERR,"Can't get peer name of remote host: %m");
fatal(STDERR_FILENO, "Can't get peer name of remote host", 1);
}
#ifdef INET6
if (from.ss_family == AF_INET6 &&
IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&from)->sin6_addr) &&
sizeof(struct sockaddr_in) <= sizeof(from)) {
struct sockaddr_in sin4;
struct sockaddr_in6 *sin6;
const int off = sizeof(struct sockaddr_in6) -
sizeof(struct sockaddr_in);
sin6 = (struct sockaddr_in6 *)&from;
memset(&sin4, 0, sizeof(sin4));
sin4.sin_family = AF_INET;
sin4.sin_len = sizeof(struct sockaddr_in);
memcpy(&sin4.sin_addr, &sin6->sin6_addr.s6_addr[off],
sizeof(sin4.sin_addr));
memcpy(&from, &sin4, sizeof(sin4));
}
#else
if (from.ss_family == AF_INET6 &&
IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&from)->sin6_addr)) {
char hbuf[NI_MAXHOST];
if (getnameinfo((struct sockaddr *)&from, fromlen, hbuf,
sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0) {
strlcpy(hbuf, "invalid", sizeof(hbuf));
}
syslog(LOG_ERR, "malformed \"from\" address (v4 mapped, %s)\n",
hbuf);
exit(1);
}
#endif
on = 1;
if (keepalive &&
setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof (on)) < 0)
syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
#if defined(IP_TOS)
if (from.ss_family == AF_INET) {
on = IPTOS_LOWDELAY;
if (setsockopt(0, IPPROTO_IP, IP_TOS, (char *)&on, sizeof(int)) < 0)
syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
}
#endif
doit(0, &from);
/* NOTREACHED */
#ifdef __GNUC__
exit(0);
#endif
}
int child;
int netf;
char line[MAXPATHLEN];
int confirmed;
struct winsize win = { 0, 0, 0, 0 };
void
doit(f, fromp)
int f;
struct sockaddr_storage *fromp;
{
int master, pid, on = 1;
int authenticated = 0;
char *hostname;
char hostnamebuf[2 * MAXHOSTNAMELEN + 1];
char hostaddrbuf[sizeof(*fromp) * 4 + 1];
char c;
char naddr[NI_MAXHOST];
char saddr[NI_MAXHOST];
char raddr[NI_MAXHOST];
int af = fromp->ss_family;
u_int16_t *portp;
struct addrinfo hints, *res, *res0;
int gaierror;
socklen_t fromlen = fromp->ss_len > sizeof(*fromp)
? sizeof(*fromp) : fromp->ss_len;
const int niflags = NI_NUMERICHOST | NI_NUMERICSERV;
alarm(60);
read(f, &c, 1);
if (c != 0)
exit(1);
alarm(0);
switch (af) {
case AF_INET:
portp = &((struct sockaddr_in *)fromp)->sin_port;
break;
#ifdef INET6
case AF_INET6:
portp = &((struct sockaddr_in6 *)fromp)->sin6_port;
break;
#endif
default:
syslog(LOG_ERR, "malformed \"from\" address (af %d)\n", af);
exit(1);
}
if (getnameinfo((struct sockaddr *)fromp, fromlen,
naddr, sizeof(naddr), NULL, 0, niflags) != 0) {
syslog(LOG_ERR, "malformed \"from\" address (af %d)\n", af);
exit(1);
}
if (getnameinfo((struct sockaddr *)fromp, fromlen,
saddr, sizeof(saddr), NULL, 0, NI_NAMEREQD) == 0) {
/*
* If name returned by getnameinfo 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.
*/
hostname = saddr;
res0 = NULL;
if (check_all || local_domain(saddr)) {
strlcpy(hostnamebuf, saddr, sizeof(hostnamebuf));
memset(&hints, 0, sizeof(hints));
hints.ai_family = fromp->ss_family;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_CANONNAME;
gaierror = getaddrinfo(hostnamebuf, "0", &hints, &res0);
if (gaierror) {
syslog(LOG_NOTICE,
"Couldn't look up address for %s: %s",
hostnamebuf, gai_strerror(gaierror));
hostname = naddr;
} else {
for (res = res0; res; res = res->ai_next) {
if (res->ai_family != fromp->ss_family)
continue;
if (res->ai_addrlen != fromp->ss_len)
continue;
if (getnameinfo(res->ai_addr,
res->ai_addrlen,
raddr, sizeof(raddr), NULL, 0,
niflags) == 0
&& strcmp(naddr, raddr) == 0) {
hostname = res->ai_canonname
? res->ai_canonname
: saddr;
break;
}
}
if (res == NULL) {
syslog(LOG_NOTICE,
"Host addr %s not listed for host %s",
naddr, res0->ai_canonname
? res0->ai_canonname
: saddr);
hostname = naddr;
}
}
}
strlcpy(hostnamebuf, hostname, sizeof(hostnamebuf));
hostname = hostnamebuf;
if (res0)
freeaddrinfo(res0);
} else {
strlcpy(hostnamebuf, naddr, sizeof(hostnamebuf));
hostname = hostnamebuf;
}
if (ntohs(*portp) >= IPPORT_RESERVED ||
ntohs(*portp) < IPPORT_RESERVED/2) {
syslog(LOG_NOTICE, "Connection from %s on illegal port",
naddr);
fatal(f, "Permission denied", 0);
}
#ifdef IP_OPTIONS
if (fromp->ss_family == AF_INET) {
u_char optbuf[BUFSIZ/3], *cp;
char lbuf[BUFSIZ], *lp, *ep;
socklen_t optsize = sizeof(optbuf);
int 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;
ep = lbuf + sizeof(lbuf);
for (cp = optbuf; optsize > 0; cp++, optsize--, lp += 3)
snprintf(lp, ep - 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
if (do_rlogin((struct sockaddr *)fromp, hostname) == 0)
authenticated++;
if (confirmed == 0) {
write(f, "", 1);
confirmed = 1; /* we sent the null! */
}
netf = f;
pid = forkpty(&master, line, NULL, &win);
if (pid < 0) {
if (errno == ENOENT)
fatal(f, "Out of ptys", 0);
else
fatal(f, "Forkpty", 1);
}
if (pid == 0) {
if (f > 2) /* f should always be 0, but... */
(void) close(f);
setup_term(0);
(void)strvisx(hostaddrbuf, (const char *)(const void *)fromp,
sizeof(*fromp), VIS_WHITE);
if (authenticated)
execl(_PATH_LOGIN, "login", "-p",
"-h", hostname, "-a", hostaddrbuf,
"-f", "--", lusername, (char *)0);
else
execl(_PATH_LOGIN, "login", "-p",
"-h", hostname, "-a", hostaddrbuf,
"--", lusername, (char *)0);
fatal(STDERR_FILENO, _PATH_LOGIN, 1);
/*NOTREACHED*/
}
ioctl(f, FIONBIO, &on);
ioctl(master, FIONBIO, &on);
ioctl(master, TIOCPKT, &on);
signal(SIGCHLD, cleanup);
protocol(f, master);
signal(SIGCHLD, SIG_IGN);
cleanup(0);
}
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.
*/
int
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 */
memmove(&w, cp+4, 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.
*/
void
protocol(f, p)
int f, p;
{
char pibuf[1024+1], fibuf[1024], *pbp = NULL, *fbp = NULL;
/* XXX gcc above */
int pcc = 0, fcc = 0;
int cc, nfd;
char cntl;
struct pollfd set[2];
/*
* 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 */
set[0].fd = p;
set[1].fd = f;
for (;;) {
set[0].events = POLLPRI;
set[1].events = 0;
if (fcc)
set[0].events |= POLLOUT;
else
set[1].events |= POLLIN;
if (pcc >= 0) {
if (pcc)
set[1].events |= POLLOUT;
else
set[0].events |= POLLIN;
}
if ((nfd = poll(set, 2, INFTIM)) < 0) {
if (errno == EINTR)
continue;
fatal(f, "poll", 1);
}
if (nfd == 0) {
/* shouldn't happen... */
sleep(5);
continue;
}
#define pkcontrol(c) ((c)&(TIOCPKT_FLUSHWRITE|TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))
if (set[0].revents & POLLPRI) {
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;
}
}
if (set[1].revents & POLLIN) {
fcc = read(f, fibuf, sizeof(fibuf));
if (fcc < 0 && errno == EWOULDBLOCK)
fcc = 0;
else {
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)
memmove(cp,
cp+n,
left);
fcc -= n;
goto top; /* n^2 */
}
}
}
}
if (set[0].revents & POLLOUT && fcc > 0) {
cc = write(p, fbp, fcc);
if (cc > 0) {
fcc -= cc;
fbp += cc;
}
}
if (set[0].revents & POLLIN) {
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 (set[1].revents & POLLOUT && pcc > 0) {
cc = write(f, pbp, pcc);
if (cc > 0) {
pcc -= cc;
pbp += cc;
}
}
}
}
void
cleanup(signo)
int signo;
{
char *p, c;
p = line + sizeof(_PATH_DEV) - 1;
#ifdef SUPPORT_UTMP
if (logout(p))
logwtmp(p, "", "");
#endif
#ifdef SUPPORT_UTMPX
if (logoutx(p, 0, DEAD_PROCESS))
logwtmpx(p, "", "", 0, DEAD_PROCESS);
#endif
(void)chmod(line, 0666);
(void)chown(line, 0, 0);
c = *p; *p = 'p';
(void)chmod(line, 0666);
(void)chown(line, 0, 0);
*p = c;
if (ttyaction(line, "rlogind", "root"))
syslog(LOG_ERR, "%s: ttyaction failed", line);
shutdown(netf, 2);
exit(1);
}
void
fatal(f, msg, syserr)
int f;
const char *msg;
int syserr;
{
int len;
char buf[BUFSIZ], *bp, *ep;
bp = buf;
ep = buf + sizeof(buf);
/*
* Prepend binary one to message if we haven't sent
* the magic null as confirmation.
*/
if (!confirmed)
*bp++ = '\001'; /* error indicator */
if (syserr)
len = snprintf(bp, ep - bp, "rlogind: %s: %s.\r\n",
msg, strerror(errno));
else
len = snprintf(bp, ep - bp, "rlogind: %s.\r\n", msg);
(void) write(f, buf, bp + len - buf);
exit(1);
}
int
do_rlogin(dest, host)
struct sockaddr *dest;
char *host;
{
int retval;
getstr(rusername, sizeof(rusername), "remuser too long");
getstr(lusername, sizeof(lusername), "locuser too long");
getstr(term+ENVSIZE, sizeof(term)-ENVSIZE, "Terminal type too long");
pwd = getpwnam(lusername);
if (pwd == NULL) {
syslog(LOG_INFO,
"%s@%s as %s: unknown login.", rusername, host, lusername);
return (-1);
}
retval = iruserok_sa(dest, dest->sa_len, pwd->pw_uid == 0, rusername,
lusername);
/* XXX put inet_ntoa(dest->sin_addr.s_addr) into all messages below */
if (retval == 0) {
if (log_success)
syslog(LOG_INFO, "%s@%s as %s: iruserok succeeded",
rusername, host, lusername);
} else {
if (__rcmd_errstr)
syslog(LOG_INFO, "%s@%s as %s: iruserok failed (%s)",
rusername, host, lusername, __rcmd_errstr);
else
syslog(LOG_INFO, "%s@%s as %s: iruserok failed",
rusername, host, lusername);
}
return(retval);
}
void
getstr(buf, cnt, errmsg)
char *buf;
int cnt;
const char *errmsg;
{
char c;
do {
if (read(0, &c, 1) != 1)
exit(1);
if (--cnt < 0)
fatal(STDOUT_FILENO, errmsg, 0);
*buf++ = c;
} while (c != 0);
}
void
setup_term(fd)
int fd;
{
char *cp = index(term+ENVSIZE, '/');
char *speed;
struct termios tt;
#ifndef notyet
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, TCSAFLUSH, &tt);
#else
if (cp) {
*cp++ = '\0';
speed = cp;
cp = index(speed, '/');
if (cp)
*cp++ = '\0';
tcgetattr(fd, &tt);
cfsetspeed(&tt, atoi(speed));
tcsetattr(fd, TCSAFLUSH, &tt);
}
#endif
env[0] = term;
env[1] = 0;
environ = env;
}
void
usage()
{
syslog(LOG_ERR, "usage: rlogind [-alnL]");
}
/*
* 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.
*/
int
local_domain(h)
char *h;
{
char localhost[MAXHOSTNAMELEN + 1];
char *p1, *p2;
localhost[0] = 0;
(void) gethostname(localhost, sizeof(localhost));
localhost[sizeof(localhost) - 1] = '\0';
p1 = topdomain(localhost);
p2 = topdomain(h);
if (p1 == NULL || p2 == NULL || !strcasecmp(p1, p2))
return (1);
return (0);
}
char *
topdomain(h)
char *h;
{
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);
}