2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * @(#) Copyright (c) 1990, 1993 The Regents of the University of California. All rights reserved.
30 * @(#)sliplogin.c 8.2 (Berkeley) 2/1/94
31 * $FreeBSD: src/usr.sbin/sliplogin/sliplogin.c,v 1.9.6.2 2001/07/19 05:21:28 kris Exp $
36 * [MUST BE RUN SUID, SLOPEN DOES A SUSER()!]
38 * This program initializes its own tty port to be an async TCP/IP interface.
39 * It sets the line discipline to slip, invokes a shell script to initialize
40 * the network interface, then pauses forever waiting for hangup.
42 * It is a remote descendant of several similar programs with incestuous ties:
43 * - Kirk Smith's slipconf, modified by Richard Johnsson @ DEC WRL.
44 * - slattach, probably by Rick Adams but touched by countless hordes.
45 * - the original sliplogin for 4.2bsd, Doug Kingston the mover behind it.
47 * There are two forms of usage:
50 * Invoked simply as "sliplogin", the program looks up the username
51 * in the file /etc/slip.hosts.
52 * If an entry is found, the line on fd0 is configured for SLIP operation
53 * as specified in the file.
55 * "sliplogin IPhostlogin </dev/ttyb"
56 * Invoked by root with a username, the name is looked up in the
57 * /etc/slip.hosts file and if found fd0 is configured as in case 1.
60 #include <sys/param.h>
61 #include <sys/socket.h>
68 #include <sys/ioctl.h>
80 #include "pathnames.h"
82 extern char **environ
;
84 static char *restricted_environ
[] = {
85 "PATH=" _PATH_STDPATH
,
96 static char loginargs
[BUFSIZ
];
97 static char loginfile
[MAXPATHLEN
];
98 static char loginname
[BUFSIZ
];
99 static char raddr
[32]; /* remote address */
100 static char ifname
[IFNAMSIZ
]; /* interface name */
101 static char pidfilename
[MAXPATHLEN
]; /* name of pid file */
102 static char iffilename
[MAXPATHLEN
]; /* name of if file */
103 static pid_t pid
; /* our pid */
108 static char address
[20] ="";
110 unsigned long ipaddr
;
113 if ((he
= gethostbyname(raddr
)) != NULL
) {
114 ipaddr
= ntohl(*(long *)he
->h_addr_list
[0]);
115 sprintf(address
, "%hu.%hu.%hu.%hu",
116 (ushort
)(ipaddr
>> 24),
117 (ushort
)((ipaddr
& 0x00ff0000) >> 16),
118 (ushort
)((ipaddr
& 0x0000ff00) >> 8),
119 (ushort
)((ipaddr
& 0x000000ff)));
125 static struct slip_modes
{
131 { "compress", IFF_LINK0
, IFF_LINK2
},
132 { "noicmp", IFF_LINK1
, 0 },
133 { "autocomp", IFF_LINK2
, IFF_LINK0
}
140 static char slopt
[5][16];
141 static char laddr
[16];
142 static char mask
[16];
143 char slparmsfile
[MAXPATHLEN
];
148 environ
= restricted_environ
; /* minimal protection for system() */
150 strncpy(loginname
, name
, sizeof(loginname
)-1);
151 loginname
[sizeof(loginname
)-1] = '\0';
153 if ((fp
= fopen(_PATH_ACCESS
, "r")) == NULL
) {
155 syslog(LOG_ERR
, "%s: %m\n", _PATH_ACCESS
);
158 while (fgets(loginargs
, sizeof(loginargs
) - 1, fp
)) {
161 if (loginargs
[0] == '#' || isspace(loginargs
[0]))
163 n
= sscanf(loginargs
, "%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s\n",
164 user
, laddr
, raddr
, mask
, slopt
[0], slopt
[1],
165 slopt
[2], slopt
[3], slopt
[4]);
167 syslog(LOG_ERR
, "%s: wrong format\n", _PATH_ACCESS
);
170 if (strcmp(user
, name
) != 0)
176 for (i
= 0; i
< n
- 4; i
++) {
177 for (j
= 0; j
< (int)NELEM(modes
); j
++) {
178 if (strcmp(modes
[j
].sm_name
, slopt
[i
]) == 0) {
179 slip_mode
|= (modes
[j
].sm_or_flag
);
180 slip_mode
&= ~(modes
[j
].sm_and_flag
);
187 * we've found the guy we're looking for -- see if
188 * there's a login file we can use. First check for
189 * one specific to this host. If none found, try for
192 snprintf(loginfile
, sizeof(loginfile
), "%s.%s", _PATH_SLOGIN
, name
);
193 if (access(loginfile
, R_OK
|X_OK
) != 0) {
194 strncpy(loginfile
, _PATH_SLOGIN
, sizeof(loginfile
)-1);
195 loginfile
[sizeof(loginfile
)-1] = '\0';
196 if (access(loginfile
, R_OK
|X_OK
)) {
198 "access denied for %s - no %s\n",
203 snprintf(slparmsfile
, sizeof(slparmsfile
), "%s.%s", _PATH_SLPARMS
, name
);
204 if (access(slparmsfile
, R_OK
|X_OK
) != 0) {
205 strncpy(slparmsfile
, _PATH_SLPARMS
, sizeof(slparmsfile
)-1);
206 slparmsfile
[sizeof(slparmsfile
)-1] = '\0';
207 if (access(slparmsfile
, R_OK
|X_OK
))
210 keepal
= outfill
= 0;
213 if ((fp
= fopen(slparmsfile
, "r")) == NULL
) {
215 syslog(LOG_ERR
, "%s: %m\n", slparmsfile
);
219 while (fgets(buf
, sizeof(buf
) - 1, fp
) != NULL
) {
222 if (buf
[0] == '#' || isspace(buf
[0]))
224 n
= sscanf(buf
, "%d %d %d", &keepal
, &outfill
, &slunit
);
227 syslog(LOG_ERR
, "%s: wrong format\n", slparmsfile
);
239 syslog(LOG_ERR
, "SLIP access denied for %s\n", name
);
250 case SIGHUP
: return("HUP");
251 case SIGINT
: return("INT");
252 case SIGQUIT
: return("QUIT");
253 case SIGILL
: return("ILL");
254 case SIGTRAP
: return("TRAP");
255 case SIGIOT
: return("IOT");
256 case SIGEMT
: return("EMT");
257 case SIGFPE
: return("FPE");
258 case SIGKILL
: return("KILL");
259 case SIGBUS
: return("BUS");
260 case SIGSEGV
: return("SEGV");
261 case SIGSYS
: return("SYS");
262 case SIGPIPE
: return("PIPE");
263 case SIGALRM
: return("ALRM");
264 case SIGTERM
: return("TERM");
265 case SIGURG
: return("URG");
266 case SIGSTOP
: return("STOP");
267 case SIGTSTP
: return("TSTP");
268 case SIGCONT
: return("CONT");
269 case SIGCHLD
: return("CHLD");
270 case SIGTTIN
: return("TTIN");
271 case SIGTTOU
: return("TTOU");
272 case SIGIO
: return("IO");
273 case SIGXCPU
: return("XCPU");
274 case SIGXFSZ
: return("XFSZ");
275 case SIGVTALRM
: return("VTALRM");
276 case SIGPROF
: return("PROF");
277 case SIGWINCH
: return("WINCH");
279 case SIGLOST
: return("LOST");
281 case SIGUSR1
: return("USR1");
282 case SIGUSR2
: return("USR2");
284 snprintf(buf
, sizeof(buf
), "sig %d", s
);
291 char logoutfile
[MAXPATHLEN
];
295 snprintf(logoutfile
, sizeof(logoutfile
), "%s.%.990s", _PATH_SLOGOUT
, loginname
);
296 if (access(logoutfile
, R_OK
|X_OK
) != 0) {
297 strncpy(logoutfile
, _PATH_SLOGOUT
, sizeof(logoutfile
)-1);
298 logoutfile
[sizeof(logoutfile
)-1] = '\0';
300 if (access(logoutfile
, R_OK
|X_OK
) == 0) {
301 char logincmd
[2*MAXPATHLEN
+32];
303 snprintf(logincmd
, sizeof(logincmd
), "%s %d %u %s", logoutfile
, unit
, speed
, loginargs
);
306 syslog(LOG_INFO
, "closed %s slip unit %d (%s)\n", loginname
, unit
,
308 if (unlink(pidfilename
) < 0 && errno
!= ENOENT
)
309 syslog(LOG_WARNING
, "unable to delete pid file: %m");
310 if (unlink(iffilename
) < 0 && errno
!= ENOENT
)
311 syslog(LOG_WARNING
, "unable to delete if file: %m");
317 /* Modify the slip line mode and add any compression or no-icmp flags. */
319 line_flags(int _unit
)
324 /* open a socket as the handle to the interface */
325 s
= socket(AF_INET
, SOCK_DGRAM
, 0);
327 syslog(LOG_ERR
, "socket: %m");
330 sprintf(ifr
.ifr_name
, "sl%d", _unit
);
332 /* get the flags for the interface */
333 if (ioctl(s
, SIOCGIFFLAGS
, (caddr_t
)&ifr
) < 0) {
334 syslog(LOG_ERR
, "ioctl (SIOCGIFFLAGS): %m");
338 /* Assert any compression or no-icmp flags. */
339 #define SLMASK (~(IFF_LINK0 | IFF_LINK1 | IFF_LINK2))
340 ifr
.ifr_flags
&= SLMASK
;
341 ifr
.ifr_flags
|= slip_mode
;
342 if (ioctl(s
, SIOCSIFFLAGS
, (caddr_t
)&ifr
) < 0) {
343 syslog(LOG_ERR
, "ioctl (SIOCSIFFLAGS): %m");
350 main(int argc
, char *argv
[])
355 char logincmd
[2*BUFSIZ
+32];
357 FILE *pidfile
; /* pid file */
358 FILE *iffile
; /* interfaces file */
361 char devnam
[MAXPATHLEN
] = _PATH_TTY
; /* Device name */
363 if ((name
= strrchr(argv
[0], '/')) == NULL
)
366 for (fd
= 3 ; fd
< s
; fd
++)
368 openlog(name
, LOG_PID
|LOG_PERROR
, LOG_DAEMON
);
374 * Disassociate from current controlling terminal, if any,
375 * and ensure that the slip line is our controlling terminal.
378 syslog(LOG_ERR
, "daemon(1, 1): %m");
382 if ((fd
= open(argv
[2], O_RDWR
)) == -1) {
383 syslog(LOG_ERR
, "open %s: %m", argv
[2]);
390 if (ioctl(0, TIOCSCTTY
, 0) == -1) {
391 syslog(LOG_ERR
, "ioctl (TIOCSCTTY): %m");
394 if (tcsetpgrp(0, getpid()) < 0) {
395 syslog(LOG_ERR
, "tcsetpgrp failed: %m");
399 if ((name
= getlogin()) == NULL
) {
400 syslog(LOG_ERR
, "access denied - login name not found\n");
406 fprintf(stderr
, "starting slip login for %s\n", loginname
);
407 fprintf(stderr
, "your address is %s\n\n", make_ipaddr());
412 /* set up the line parameters */
413 if (tcgetattr(0, &tios
) < 0) {
414 syslog(LOG_ERR
, "tcgetattr: %m");
418 if (tcsetattr(0, TCSAFLUSH
, &tios
) < 0) {
419 syslog(LOG_ERR
, "tcsetattr: %m");
422 speed
= cfgetispeed(&tios
);
425 if (ioctl(0, TIOCSETD
, &ldisc
) < 0) {
426 syslog(LOG_ERR
, "ioctl(TIOCSETD): %m");
429 if (slunit
>= 0 && ioctl(0, SLIOCSUNIT
, &slunit
) < 0) {
430 syslog(LOG_ERR
, "ioctl (SLIOCSUNIT): %m");
433 /* find out what unit number we were assigned */
434 if (ioctl(0, SLIOCGUNIT
, &unit
) < 0) {
435 syslog(LOG_ERR
, "ioctl (SLIOCGUNIT): %m");
438 signal(SIGHUP
, hup_handler
);
439 signal(SIGTERM
, hup_handler
);
442 signal(SIGURG
, hup_handler
);
443 if (ioctl(0, SLIOCSKEEPAL
, &keepal
) < 0) {
444 syslog(LOG_ERR
, "ioctl(SLIOCSKEEPAL): %m");
448 if (outfill
> 0 && ioctl(0, SLIOCSOUTFILL
, &outfill
) < 0) {
449 syslog(LOG_ERR
, "ioctl(SLIOCSOUTFILL): %m");
453 /* write pid to file */
455 sprintf(ifname
, "sl%d", unit
);
456 sprintf(pidfilename
, "%s%s.pid", _PATH_VARRUN
, ifname
);
457 if ((pidfile
= fopen(pidfilename
, "w")) != NULL
) {
458 fprintf(pidfile
, "%d\n", pid
);
461 syslog(LOG_ERR
, "Failed to create pid file %s: %m",
466 /* write interface unit number to file */
470 for (n
= strlen(devnam
); n
> 0; n
--)
471 if (devnam
[n
] == '/') {
475 sprintf(iffilename
, "%s%s.if", _PATH_VARRUN
, &devnam
[n
]);
476 if ((iffile
= fopen(iffilename
, "w")) != NULL
) {
477 fprintf(iffile
, "sl%d\n", unit
);
480 syslog(LOG_ERR
, "Failed to create if file %s: %m", iffilename
);
485 syslog(LOG_INFO
, "attaching slip unit %d for %s\n", unit
, loginname
);
486 snprintf(logincmd
, sizeof(logincmd
), "%s %d %u %s", loginfile
, unit
, speed
,
489 * aim stdout and errout at /dev/null so logincmd output won't
490 * babble into the slip tty line.
493 if ((fd
= open(_PATH_DEVNULL
, O_WRONLY
)) != 1) {
495 syslog(LOG_ERR
, "open %s: %m", _PATH_DEVNULL
);
504 * Run login and logout scripts as root (real and effective);
505 * current route(8) is setuid root, and checks the real uid
506 * to see whether changes are allowed (or just "route get").
509 if ((s
= system(logincmd
)) == -1) {
510 syslog(LOG_ERR
, "%s login failed: exit status %d from %s",
511 loginname
, s
, loginfile
);
515 /* Handle any compression or no-icmp flags. */
518 /* reset uid to users' to allow the user to give a signal. */
520 /* twiddle thumbs until we get a signal */