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>
67 #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 */