sliplogin.c revision 1.1.1.2
1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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. 20 * 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 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 static char copyright[] = 36 "@(#) Copyright (c) 1990, 1993\n\ 37 The Regents of the University of California. All rights reserved.\n"; 38 #endif /* not lint */ 39 40 #ifndef lint 41 static char sccsid[] = "@(#)sliplogin.c 8.2 (Berkeley) 2/1/94"; 42 #endif /* not lint */ 43 44 /* 45 * sliplogin.c 46 * [MUST BE RUN SUID, SLOPEN DOES A SUSER()!] 47 * 48 * This program initializes its own tty port to be an async TCP/IP interface. 49 * It sets the line discipline to slip, invokes a shell script to initialize 50 * the network interface, then pauses forever waiting for hangup. 51 * 52 * It is a remote descendant of several similar programs with incestuous ties: 53 * - Kirk Smith's slipconf, modified by Richard Johnsson @ DEC WRL. 54 * - slattach, probably by Rick Adams but touched by countless hordes. 55 * - the original sliplogin for 4.2bsd, Doug Kingston the mover behind it. 56 * 57 * There are two forms of usage: 58 * 59 * "sliplogin" 60 * Invoked simply as "sliplogin", the program looks up the username 61 * in the file /etc/slip.hosts. 62 * If an entry is found, the line on fd0 is configured for SLIP operation 63 * as specified in the file. 64 * 65 * "sliplogin IPhostlogin </dev/ttyb" 66 * Invoked by root with a username, the name is looked up in the 67 * /etc/slip.hosts file and if found fd0 is configured as in case 1. 68 */ 69 70 #include <sys/param.h> 71 #include <sys/socket.h> 72 #include <sys/signal.h> 73 #include <sys/file.h> 74 #include <sys/syslog.h> 75 #include <netdb.h> 76 77 #if BSD >= 199006 78 #define POSIX 79 #endif 80 #ifdef POSIX 81 #include <sys/termios.h> 82 #include <sys/ioctl.h> 83 #include <ttyent.h> 84 #else 85 #include <sgtty.h> 86 #endif 87 #include <net/slip.h> 88 89 #include <stdio.h> 90 #include <errno.h> 91 #include <ctype.h> 92 #include <string.h> 93 #include "pathnames.h" 94 95 int unit; 96 int speed; 97 int uid; 98 char loginargs[BUFSIZ]; 99 char loginfile[MAXPATHLEN]; 100 char loginname[BUFSIZ]; 101 102 void 103 findid(name) 104 char *name; 105 { 106 FILE *fp; 107 static char slopt[5][16]; 108 static char laddr[16]; 109 static char raddr[16]; 110 static char mask[16]; 111 char user[16]; 112 int i, j, n; 113 114 (void)strcpy(loginname, name); 115 if ((fp = fopen(_PATH_ACCESS, "r")) == NULL) { 116 (void)fprintf(stderr, "sliplogin: %s: %s\n", 117 _PATH_ACCESS, strerror(errno)); 118 syslog(LOG_ERR, "%s: %m\n", _PATH_ACCESS); 119 exit(1); 120 } 121 while (fgets(loginargs, sizeof(loginargs) - 1, fp)) { 122 if (ferror(fp)) 123 break; 124 n = sscanf(loginargs, "%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s\n", 125 user, laddr, raddr, mask, slopt[0], slopt[1], 126 slopt[2], slopt[3], slopt[4]); 127 if (user[0] == '#' || isspace(user[0])) 128 continue; 129 if (strcmp(user, name) != 0) 130 continue; 131 132 /* 133 * we've found the guy we're looking for -- see if 134 * there's a login file we can use. First check for 135 * one specific to this host. If none found, try for 136 * a generic one. 137 */ 138 (void)sprintf(loginfile, "%s.%s", _PATH_LOGIN, name); 139 if (access(loginfile, R_OK|X_OK) != 0) { 140 (void)strcpy(loginfile, _PATH_LOGIN); 141 if (access(loginfile, R_OK|X_OK)) { 142 fputs("access denied - no login file\n", 143 stderr); 144 syslog(LOG_ERR, 145 "access denied for %s - no %s\n", 146 name, _PATH_LOGIN); 147 exit(5); 148 } 149 } 150 151 (void) fclose(fp); 152 return; 153 } 154 (void)fprintf(stderr, "SLIP access denied for %s\n", name); 155 syslog(LOG_ERR, "SLIP access denied for %s\n", name); 156 exit(4); 157 /* NOTREACHED */ 158 } 159 160 char * 161 sigstr(s) 162 int s; 163 { 164 static char buf[32]; 165 166 switch (s) { 167 case SIGHUP: return("HUP"); 168 case SIGINT: return("INT"); 169 case SIGQUIT: return("QUIT"); 170 case SIGILL: return("ILL"); 171 case SIGTRAP: return("TRAP"); 172 case SIGIOT: return("IOT"); 173 case SIGEMT: return("EMT"); 174 case SIGFPE: return("FPE"); 175 case SIGKILL: return("KILL"); 176 case SIGBUS: return("BUS"); 177 case SIGSEGV: return("SEGV"); 178 case SIGSYS: return("SYS"); 179 case SIGPIPE: return("PIPE"); 180 case SIGALRM: return("ALRM"); 181 case SIGTERM: return("TERM"); 182 case SIGURG: return("URG"); 183 case SIGSTOP: return("STOP"); 184 case SIGTSTP: return("TSTP"); 185 case SIGCONT: return("CONT"); 186 case SIGCHLD: return("CHLD"); 187 case SIGTTIN: return("TTIN"); 188 case SIGTTOU: return("TTOU"); 189 case SIGIO: return("IO"); 190 case SIGXCPU: return("XCPU"); 191 case SIGXFSZ: return("XFSZ"); 192 case SIGVTALRM: return("VTALRM"); 193 case SIGPROF: return("PROF"); 194 case SIGWINCH: return("WINCH"); 195 #ifdef SIGLOST 196 case SIGLOST: return("LOST"); 197 #endif 198 case SIGUSR1: return("USR1"); 199 case SIGUSR2: return("USR2"); 200 } 201 (void)sprintf(buf, "sig %d", s); 202 return(buf); 203 } 204 205 void 206 hup_handler(s) 207 int s; 208 { 209 char logoutfile[MAXPATHLEN]; 210 211 (void)sprintf(logoutfile, "%s.%s", _PATH_LOGOUT, loginname); 212 if (access(logoutfile, R_OK|X_OK) != 0) 213 (void)strcpy(logoutfile, _PATH_LOGOUT); 214 if (access(logoutfile, R_OK|X_OK) == 0) { 215 char logincmd[2*MAXPATHLEN+32]; 216 217 (void) sprintf(logincmd, "%s %d %d %s", logoutfile, unit, speed, 218 loginargs); 219 (void) system(logincmd); 220 } 221 (void) close(0); 222 syslog(LOG_INFO, "closed %s slip unit %d (%s)\n", loginname, unit, 223 sigstr(s)); 224 exit(1); 225 /* NOTREACHED */ 226 } 227 228 main(argc, argv) 229 int argc; 230 char *argv[]; 231 { 232 int fd, s, ldisc, odisc; 233 char *name; 234 #ifdef POSIX 235 struct termios tios, otios; 236 #else 237 struct sgttyb tty, otty; 238 #endif 239 char logincmd[2*BUFSIZ+32]; 240 extern uid_t getuid(); 241 242 if ((name = strrchr(argv[0], '/')) == NULL) 243 name = argv[0]; 244 s = getdtablesize(); 245 for (fd = 3 ; fd < s ; fd++) 246 (void) close(fd); 247 openlog(name, LOG_PID, LOG_DAEMON); 248 uid = getuid(); 249 if (argc > 1) { 250 findid(argv[1]); 251 252 /* 253 * Disassociate from current controlling terminal, if any, 254 * and ensure that the slip line is our controlling terminal. 255 */ 256 #ifdef POSIX 257 if (fork() > 0) 258 exit(0); 259 if (setsid() != 0) 260 perror("setsid"); 261 #else 262 if ((fd = open("/dev/tty", O_RDONLY, 0)) >= 0) { 263 extern char *ttyname(); 264 265 (void) ioctl(fd, TIOCNOTTY, (caddr_t)0); 266 (void) close(fd); 267 /* open slip tty again to acquire as controlling tty? */ 268 fd = open(ttyname(0), O_RDWR, 0); 269 if (fd >= 0) 270 (void) close(fd); 271 } 272 (void) setpgrp(0, getpid()); 273 #endif 274 if (argc > 2) { 275 if ((fd = open(argv[2], O_RDWR)) == -1) { 276 perror(argv[2]); 277 exit(2); 278 } 279 (void) dup2(fd, 0); 280 if (fd > 2) 281 close(fd); 282 } 283 #ifdef TIOCSCTTY 284 if (ioctl(0, TIOCSCTTY, (caddr_t)0) != 0) 285 perror("ioctl (TIOCSCTTY)"); 286 #endif 287 } else { 288 extern char *getlogin(); 289 290 if ((name = getlogin()) == NULL) { 291 (void) fprintf(stderr, "access denied - no username\n"); 292 syslog(LOG_ERR, "access denied - getlogin returned 0\n"); 293 exit(1); 294 } 295 findid(name); 296 } 297 (void) fchmod(0, 0600); 298 (void) fprintf(stderr, "starting slip login for %s\n", loginname); 299 #ifdef POSIX 300 /* set up the line parameters */ 301 if (tcgetattr(0, &tios) < 0) { 302 syslog(LOG_ERR, "tcgetattr: %m"); 303 exit(1); 304 } 305 otios = tios; 306 cfmakeraw(&tios); 307 tios.c_iflag &= ~IMAXBEL; 308 if (tcsetattr(0, TCSAFLUSH, &tios) < 0) { 309 syslog(LOG_ERR, "tcsetattr: %m"); 310 exit(1); 311 } 312 speed = cfgetispeed(&tios); 313 #else 314 /* set up the line parameters */ 315 if (ioctl(0, TIOCGETP, (caddr_t)&tty) < 0) { 316 syslog(LOG_ERR, "ioctl (TIOCGETP): %m"); 317 exit(1); 318 } 319 otty = tty; 320 speed = tty.sg_ispeed; 321 tty.sg_flags = RAW | ANYP; 322 if (ioctl(0, TIOCSETP, (caddr_t)&tty) < 0) { 323 syslog(LOG_ERR, "ioctl (TIOCSETP): %m"); 324 exit(1); 325 } 326 #endif 327 /* find out what ldisc we started with */ 328 if (ioctl(0, TIOCGETD, (caddr_t)&odisc) < 0) { 329 syslog(LOG_ERR, "ioctl(TIOCGETD) (1): %m"); 330 exit(1); 331 } 332 ldisc = SLIPDISC; 333 if (ioctl(0, TIOCSETD, (caddr_t)&ldisc) < 0) { 334 syslog(LOG_ERR, "ioctl(TIOCSETD): %m"); 335 exit(1); 336 } 337 /* find out what unit number we were assigned */ 338 if (ioctl(0, SLIOCGUNIT, (caddr_t)&unit) < 0) { 339 syslog(LOG_ERR, "ioctl (SLIOCGUNIT): %m"); 340 exit(1); 341 } 342 (void) signal(SIGHUP, hup_handler); 343 (void) signal(SIGTERM, hup_handler); 344 345 syslog(LOG_INFO, "attaching slip unit %d for %s\n", unit, loginname); 346 (void)sprintf(logincmd, "%s %d %d %s", loginfile, unit, speed, 347 loginargs); 348 /* 349 * aim stdout and errout at /dev/null so logincmd output won't 350 * babble into the slip tty line. 351 */ 352 (void) close(1); 353 if ((fd = open(_PATH_DEVNULL, O_WRONLY)) != 1) { 354 if (fd < 0) { 355 syslog(LOG_ERR, "open /dev/null: %m"); 356 exit(1); 357 } 358 (void) dup2(fd, 1); 359 (void) close(fd); 360 } 361 (void) dup2(1, 2); 362 363 /* 364 * Run login and logout scripts as root (real and effective); 365 * current route(8) is setuid root, and checks the real uid 366 * to see whether changes are allowed (or just "route get"). 367 */ 368 (void) setuid(0); 369 if (s = system(logincmd)) { 370 syslog(LOG_ERR, "%s login failed: exit status %d from %s", 371 loginname, s, loginfile); 372 (void) ioctl(0, TIOCSETD, (caddr_t)&odisc); 373 exit(6); 374 } 375 376 /* twiddle thumbs until we get a signal */ 377 while (1) 378 sigpause(0); 379 380 /* NOTREACHED */ 381 } 382
Indexes created Mon Oct 20 11:09:49 GMT 2025