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. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 static char copyright[] =
36 "@(#) Copyright (c) 1990, 1993\n\
37 The Regents of the University of California. All rights reserved.\n";
41 static char sccsid[] = "@(#)sliplogin.c 8.2 (Berkeley) 2/1/94";
42 static char rscid[] = "@(#)$FreeBSD$";
47 * [MUST BE RUN SUID, SLOPEN DOES A SUSER()!]
49 * This program initializes its own tty port to be an async TCP/IP interface.
50 * It sets the line discipline to slip, invokes a shell script to initialize
51 * the network interface, then pauses forever waiting for hangup.
53 * It is a remote descendant of several similar programs with incestuous ties:
54 * - Kirk Smith's slipconf, modified by Richard Johnsson @ DEC WRL.
55 * - slattach, probably by Rick Adams but touched by countless hordes.
56 * - the original sliplogin for 4.2bsd, Doug Kingston the mover behind it.
58 * There are two forms of usage:
61 * Invoked simply as "sliplogin", the program looks up the username
62 * in the file /etc/slip.hosts.
63 * If an entry is found, the line on fd0 is configured for SLIP operation
64 * as specified in the file.
66 * "sliplogin IPhostlogin </dev/ttyb"
67 * Invoked by root with a username, the name is looked up in the
68 * /etc/slip.hosts file and if found fd0 is configured as in case 1.
71 #include <sys/param.h>
72 #include <sys/socket.h>
79 #include <sys/ioctl.h>
91 #include "pathnames.h"
93 extern char **environ;
95 static char *restricted_environ[] = {
96 "PATH=" _PATH_STDPATH,
107 char loginargs[BUFSIZ];
108 char loginfile[MAXPATHLEN];
109 char loginname[BUFSIZ];
110 static char raddr[32]; /* remote address */
111 char ifname[IFNAMSIZ]; /* interface name */
112 static char pidfilename[MAXPATHLEN]; /* name of pid file */
113 static char iffilename[MAXPATHLEN]; /* name of if file */
114 static pid_t pid; /* our pid */
119 static char address[20] ="";
121 unsigned long ipaddr;
124 if ((he = gethostbyname(raddr)) != NULL) {
125 ipaddr = ntohl(*(long *)he->h_addr_list[0]);
126 sprintf(address, "%lu.%lu.%lu.%lu",
128 (ipaddr & 0x00ff0000) >> 16,
129 (ipaddr & 0x0000ff00) >> 8,
130 (ipaddr & 0x000000ff));
142 "compress", IFF_LINK0, IFF_LINK2,
143 "noicmp", IFF_LINK1, 0 ,
144 "autocomp", IFF_LINK2, IFF_LINK0,
152 static char slopt[5][16];
153 static char laddr[16];
154 static char mask[16];
155 char slparmsfile[MAXPATHLEN];
160 environ = restricted_environ; /* minimal protection for system() */
162 (void)strncpy(loginname, name, sizeof(loginname)-1);
163 loginname[sizeof(loginname)-1] = '\0';
165 if ((fp = fopen(_PATH_ACCESS, "r")) == NULL) {
167 syslog(LOG_ERR, "%s: %m\n", _PATH_ACCESS);
170 while (fgets(loginargs, sizeof(loginargs) - 1, fp)) {
173 if (loginargs[0] == '#' || isspace(loginargs[0]))
175 n = sscanf(loginargs, "%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s\n",
176 user, laddr, raddr, mask, slopt[0], slopt[1],
177 slopt[2], slopt[3], slopt[4]);
179 syslog(LOG_ERR, "%s: wrong format\n", _PATH_ACCESS);
182 if (strcmp(user, name) != 0)
188 for (i = 0; i < n - 4; i++) {
189 for (j = 0; j < sizeof(modes)/sizeof(struct slip_modes);
191 if (strcmp(modes[j].sm_name, slopt[i]) == 0) {
192 slip_mode |= (modes[j].sm_or_flag);
193 slip_mode &= ~(modes[j].sm_and_flag);
200 * we've found the guy we're looking for -- see if
201 * there's a login file we can use. First check for
202 * one specific to this host. If none found, try for
205 (void)snprintf(loginfile, sizeof(loginfile), "%s.%s",
206 _PATH_SLIP_LOGIN, name);
207 if (access(loginfile, R_OK|X_OK) != 0) {
208 (void)strncpy(loginfile, _PATH_SLIP_LOGIN,
209 sizeof(loginfile) - 1);
210 loginfile[sizeof(loginfile) - 1] = '\0';
211 if (access(loginfile, R_OK|X_OK)) {
213 "access denied for %s - no %s\n",
214 name, _PATH_SLIP_LOGIN);
218 (void)snprintf(slparmsfile, sizeof(slparmsfile), "%s.%s", _PATH_SLPARMS, name);
219 if (access(slparmsfile, R_OK|X_OK) != 0) {
220 (void)strncpy(slparmsfile, _PATH_SLPARMS, sizeof(slparmsfile)-1);
221 slparmsfile[sizeof(slparmsfile)-1] = '\0';
222 if (access(slparmsfile, R_OK|X_OK))
225 keepal = outfill = 0;
228 if ((fp = fopen(slparmsfile, "r")) == NULL) {
230 syslog(LOG_ERR, "%s: %m\n", slparmsfile);
234 while (fgets(buf, sizeof(buf) - 1, fp) != NULL) {
237 if (buf[0] == '#' || isspace(buf[0]))
239 n = sscanf(buf, "%d %d %d", &keepal, &outfill, &slunit);
242 syslog(LOG_ERR, "%s: wrong format\n", slparmsfile);
254 syslog(LOG_ERR, "SLIP access denied for %s\n", name);
266 case SIGHUP: return("HUP");
267 case SIGINT: return("INT");
268 case SIGQUIT: return("QUIT");
269 case SIGILL: return("ILL");
270 case SIGTRAP: return("TRAP");
271 case SIGIOT: return("IOT");
272 case SIGEMT: return("EMT");
273 case SIGFPE: return("FPE");
274 case SIGKILL: return("KILL");
275 case SIGBUS: return("BUS");
276 case SIGSEGV: return("SEGV");
277 case SIGSYS: return("SYS");
278 case SIGPIPE: return("PIPE");
279 case SIGALRM: return("ALRM");
280 case SIGTERM: return("TERM");
281 case SIGURG: return("URG");
282 case SIGSTOP: return("STOP");
283 case SIGTSTP: return("TSTP");
284 case SIGCONT: return("CONT");
285 case SIGCHLD: return("CHLD");
286 case SIGTTIN: return("TTIN");
287 case SIGTTOU: return("TTOU");
288 case SIGIO: return("IO");
289 case SIGXCPU: return("XCPU");
290 case SIGXFSZ: return("XFSZ");
291 case SIGVTALRM: return("VTALRM");
292 case SIGPROF: return("PROF");
293 case SIGWINCH: return("WINCH");
295 case SIGLOST: return("LOST");
297 case SIGUSR1: return("USR1");
298 case SIGUSR2: return("USR2");
300 (void)snprintf(buf, sizeof(buf), "sig %d", s);
308 char logoutfile[MAXPATHLEN];
312 (void)snprintf(logoutfile, sizeof(logoutfile), "%s.%s",
313 _PATH_SLIP_LOGOUT, loginname);
314 if (access(logoutfile, R_OK|X_OK) != 0) {
315 (void)strncpy(logoutfile, _PATH_SLIP_LOGOUT,
316 sizeof(logoutfile) - 1);
317 logoutfile[sizeof(logoutfile) - 1] = '\0';
319 if (access(logoutfile, R_OK|X_OK) == 0) {
320 char logincmd[2*MAXPATHLEN+32];
322 (void) snprintf(logincmd, sizeof(logincmd), "%s %d %ld %s", logoutfile, unit, speed, loginargs);
323 (void) system(logincmd);
325 syslog(LOG_INFO, "closed %s slip unit %d (%s)\n", loginname, unit,
327 if (unlink(pidfilename) < 0 && errno != ENOENT)
328 syslog(LOG_WARNING, "unable to delete pid file: %m");
329 if (unlink(iffilename) < 0 && errno != ENOENT)
330 syslog(LOG_WARNING, "unable to delete if file: %m");
336 /* Modify the slip line mode and add any compression or no-icmp flags. */
337 void line_flags(unit)
343 /* open a socket as the handle to the interface */
344 s = socket(AF_INET, SOCK_DGRAM, 0);
346 syslog(LOG_ERR, "socket: %m");
349 sprintf(ifr.ifr_name, "sl%d", unit);
351 /* get the flags for the interface */
352 if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) {
353 syslog(LOG_ERR, "ioctl (SIOCGIFFLAGS): %m");
357 /* Assert any compression or no-icmp flags. */
358 #define SLMASK (~(IFF_LINK0 | IFF_LINK1 | IFF_LINK2))
359 ifr.ifr_flags &= SLMASK;
360 ifr.ifr_flags |= slip_mode;
361 if (ioctl(s, SIOCSIFFLAGS, (caddr_t)&ifr) < 0) {
362 syslog(LOG_ERR, "ioctl (SIOCSIFFLAGS): %m");
375 struct termios tios, otios;
376 char logincmd[2*BUFSIZ+32];
377 extern uid_t getuid();
379 FILE *pidfile; /* pid file */
380 FILE *iffile; /* interfaces file */
383 char devnam[MAXPATHLEN] = _PATH_TTY; /* Device name */
385 if ((name = strrchr(argv[0], '/')) == NULL)
388 for (fd = 3 ; fd < s ; fd++)
390 openlog(name, LOG_PID|LOG_PERROR, LOG_DAEMON);
396 * Disassociate from current controlling terminal, if any,
397 * and ensure that the slip line is our controlling terminal.
400 syslog(LOG_ERR, "daemon(1, 1): %m");
404 if ((fd = open(argv[2], O_RDWR)) == -1) {
405 syslog(LOG_ERR, "open %s: %m", argv[2]);
412 if (ioctl(0, TIOCSCTTY, 0) == -1) {
413 syslog(LOG_ERR, "ioctl (TIOCSCTTY): %m");
416 if (tcsetpgrp(0, getpid()) < 0) {
417 syslog(LOG_ERR, "tcsetpgrp failed: %m");
421 if ((name = getlogin()) == NULL) {
422 syslog(LOG_ERR, "access denied - login name not found\n");
427 (void) fchmod(0, 0600);
428 (void) fprintf(stderr, "starting slip login for %s\n", loginname);
429 (void) fprintf(stderr, "your address is %s\n\n", make_ipaddr());
431 (void) fflush(stderr);
434 /* set up the line parameters */
435 if (tcgetattr(0, &tios) < 0) {
436 syslog(LOG_ERR, "tcgetattr: %m");
441 if (tcsetattr(0, TCSAFLUSH, &tios) < 0) {
442 syslog(LOG_ERR, "tcsetattr: %m");
445 speed = cfgetispeed(&tios);
448 if (ioctl(0, TIOCSETD, &ldisc) < 0) {
449 syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
452 if (slunit >= 0 && ioctl(0, SLIOCSUNIT, &slunit) < 0) {
453 syslog(LOG_ERR, "ioctl (SLIOCSUNIT): %m");
456 /* find out what unit number we were assigned */
457 if (ioctl(0, SLIOCGUNIT, &unit) < 0) {
458 syslog(LOG_ERR, "ioctl (SLIOCGUNIT): %m");
461 (void) signal(SIGHUP, hup_handler);
462 (void) signal(SIGTERM, hup_handler);
465 (void) signal(SIGURG, hup_handler);
466 if (ioctl(0, SLIOCSKEEPAL, &keepal) < 0) {
467 syslog(LOG_ERR, "ioctl(SLIOCSKEEPAL): %m");
471 if (outfill > 0 && ioctl(0, SLIOCSOUTFILL, &outfill) < 0) {
472 syslog(LOG_ERR, "ioctl(SLIOCSOUTFILL): %m");
476 /* write pid to file */
478 (void) sprintf(ifname, "sl%d", unit);
479 (void) sprintf(pidfilename, "%s%s.pid", _PATH_VARRUN, ifname);
480 if ((pidfile = fopen(pidfilename, "w")) != NULL) {
481 fprintf(pidfile, "%d\n", pid);
482 (void) fclose(pidfile);
484 syslog(LOG_ERR, "Failed to create pid file %s: %m",
489 /* write interface unit number to file */
493 for (n = strlen(devnam); n > 0; n--)
494 if (devnam[n] == '/') {
498 (void) sprintf(iffilename, "%s%s.if", _PATH_VARRUN, &devnam[n]);
499 if ((iffile = fopen(iffilename, "w")) != NULL) {
500 fprintf(iffile, "sl%d\n", unit);
501 (void) fclose(iffile);
503 syslog(LOG_ERR, "Failed to create if file %s: %m", iffilename);
508 syslog(LOG_INFO, "attaching slip unit %d for %s\n", unit, loginname);
509 (void)snprintf(logincmd, sizeof(logincmd), "%s %d %ld %s", loginfile, unit, speed,
512 * aim stdout and errout at /dev/null so logincmd output won't
513 * babble into the slip tty line.
516 if ((fd = open(_PATH_DEVNULL, O_WRONLY)) != 1) {
518 syslog(LOG_ERR, "open %s: %m", _PATH_DEVNULL);
527 * Run login and logout scripts as root (real and effective);
528 * current route(8) is setuid root, and checks the real uid
529 * to see whether changes are allowed (or just "route get").
532 if (s = system(logincmd)) {
533 syslog(LOG_ERR, "%s login failed: exit status %d from %s",
534 loginname, s, loginfile);
538 /* Handle any compression or no-icmp flags. */
541 /* reset uid to users' to allow the user to give a signal. */
543 /* twiddle thumbs until we get a signal */