1 /* 2 * Copyright (c) 1983 Regents of the University of California. 3 * All rights reserved. The Berkeley software License Agreement 4 * specifies the terms and conditions for redistribution. 5 */ 6 7 #ifndef lint 8 char copyright[] = 9 "@(#) Copyright (c) 1983 Regents of the University of California.\n\ 10 All rights reserved.\n"; 11 #endif not lint 12 13 #ifndef lint 14 static char sccsid[] = "@(#)rlogind.c 5.10 (Berkeley) 01/07/86"; 15 #endif not lint 16 17 /* 18 * remote login server: 19 * remuser\0 20 * locuser\0 21 * terminal info\0 22 * data 23 */ 24 25 #include <stdio.h> 26 #include <sys/types.h> 27 #include <sys/stat.h> 28 #include <sys/socket.h> 29 #include <sys/wait.h> 30 #include <sys/file.h> 31 32 #include <netinet/in.h> 33 34 #include <errno.h> 35 #include <pwd.h> 36 #include <signal.h> 37 #include <sgtty.h> 38 #include <stdio.h> 39 #include <netdb.h> 40 #include <syslog.h> 41 #include <strings.h> 42 43 # ifndef TIOCPKT_WINDOW 44 # define TIOCPKT_WINDOW 0x80 45 # endif TIOCPKT_WINDOW 46 47 extern errno; 48 int reapchild(); 49 struct passwd *getpwnam(); 50 char *malloc(); 51 52 main(argc, argv) 53 int argc; 54 char **argv; 55 { 56 int on = 1, options = 0, fromlen; 57 struct sockaddr_in from; 58 59 openlog("rlogind", LOG_PID | LOG_AUTH, LOG_AUTH); 60 fromlen = sizeof (from); 61 if (getpeername(0, &from, &fromlen) < 0) { 62 fprintf(stderr, "%s: ", argv[0]); 63 perror("getpeername"); 64 _exit(1); 65 } 66 if (setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof (on)) < 0) { 67 syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m"); 68 } 69 doit(0, &from); 70 } 71 72 int child; 73 int cleanup(); 74 int netf; 75 extern errno; 76 char *line; 77 extern char *inet_ntoa(); 78 79 struct winsize win = { 0, 0, 0, 0 }; 80 81 82 doit(f, fromp) 83 int f; 84 struct sockaddr_in *fromp; 85 { 86 int i, p, t, pid, on = 1; 87 register struct hostent *hp; 88 struct hostent hostent; 89 char c; 90 91 alarm(60); 92 read(f, &c, 1); 93 if (c != 0) 94 exit(1); 95 alarm(0); 96 fromp->sin_port = ntohs((u_short)fromp->sin_port); 97 hp = gethostbyaddr(&fromp->sin_addr, sizeof (struct in_addr), 98 fromp->sin_family); 99 if (hp == 0) { 100 /* 101 * Only the name is used below. 102 */ 103 hp = &hostent; 104 hp->h_name = inet_ntoa(fromp->sin_addr); 105 } 106 if (fromp->sin_family != AF_INET || 107 fromp->sin_port >= IPPORT_RESERVED) 108 fatal(f, "Permission denied"); 109 write(f, "", 1); 110 for (c = 'p'; c <= 's'; c++) { 111 struct stat stb; 112 line = "/dev/ptyXX"; 113 line[strlen("/dev/pty")] = c; 114 line[strlen("/dev/ptyp")] = '0'; 115 if (stat(line, &stb) < 0) 116 break; 117 for (i = 0; i < 16; i++) { 118 line[strlen("/dev/ptyp")] = "0123456789abcdef"[i]; 119 p = open(line, 2); 120 if (p > 0) 121 goto gotpty; 122 } 123 } 124 fatal(f, "Out of ptys"); 125 /*NOTREACHED*/ 126 gotpty: 127 (void) ioctl(p, TIOCSWINSZ, &win); 128 netf = f; 129 line[strlen("/dev/")] = 't'; 130 #ifdef DEBUG 131 { int tt = open("/dev/tty", 2); 132 if (tt > 0) { 133 ioctl(tt, TIOCNOTTY, 0); 134 close(tt); 135 } 136 } 137 #endif 138 t = open(line, 2); 139 if (t < 0) 140 fatalperror(f, line, errno); 141 { struct sgttyb b; 142 gtty(t, &b); b.sg_flags = RAW|ANYP; stty(t, &b); 143 } 144 pid = fork(); 145 if (pid < 0) 146 fatalperror(f, "", errno); 147 if (pid == 0) { 148 close(f), close(p); 149 dup2(t, 0), dup2(t, 1), dup2(t, 2); 150 close(t); 151 execl("/bin/login", "login", "-r", hp->h_name, 0); 152 fatalperror(2, "/bin/login", errno); 153 /*NOTREACHED*/ 154 } 155 close(t); 156 ioctl(f, FIONBIO, &on); 157 ioctl(p, FIONBIO, &on); 158 ioctl(p, TIOCPKT, &on); 159 signal(SIGTSTP, SIG_IGN); 160 signal(SIGCHLD, cleanup); 161 setpgrp(0, 0); 162 protocol(f, p); 163 cleanup(); 164 } 165 166 char magic[2] = { 0377, 0377 }; 167 char oobdata[] = {TIOCPKT_WINDOW}; 168 169 /* 170 * Handle a "control" request (signaled by magic being present) 171 * in the data stream. For now, we are only willing to handle 172 * window size changes. 173 */ 174 control(pty, cp, n) 175 int pty; 176 char *cp; 177 int n; 178 { 179 struct winsize *wp; 180 181 if (n < 4+sizeof (*wp) || cp[2] != 's' || cp[3] != 's') 182 return (0); 183 oobdata[0] &= ~TIOCPKT_WINDOW; /* we know he heard */ 184 wp = (struct winsize *)(cp+4); 185 wp->ws_row = ntohs(wp->ws_row); 186 wp->ws_col = ntohs(wp->ws_col); 187 wp->ws_xpixel = ntohs(wp->ws_xpixel); 188 wp->ws_ypixel = ntohs(wp->ws_ypixel); 189 (void)ioctl(pty, TIOCSWINSZ, wp); 190 return (4+sizeof (*wp)); 191 } 192 193 /* 194 * rlogin "protocol" machine. 195 */ 196 protocol(f, p) 197 int f, p; 198 { 199 char pibuf[1024], fibuf[1024], *pbp, *fbp; 200 register pcc = 0, fcc = 0; 201 int cc; 202 char cntl; 203 204 /* 205 * Must ignore SIGTTOU, otherwise we'll stop 206 * when we try and set slave pty's window shape 207 * (our controlling tty is the master pty). 208 */ 209 (void) signal(SIGTTOU, SIG_IGN); 210 send(f, oobdata, 1, MSG_OOB); /* indicate new rlogin */ 211 for (;;) { 212 int ibits, obits, ebits; 213 214 ibits = 0; 215 obits = 0; 216 if (fcc) 217 obits |= (1<<p); 218 else 219 ibits |= (1<<f); 220 if (pcc >= 0) 221 if (pcc) 222 obits |= (1<<f); 223 else 224 ibits |= (1<<p); 225 ebits = (1<<p); 226 if (select(16, &ibits, &obits, &ebits, 0) < 0) { 227 if (errno == EINTR) 228 continue; 229 fatalperror(f, "select", errno); 230 } 231 if (ibits == 0 && obits == 0 && ebits == 0) { 232 /* shouldn't happen... */ 233 sleep(5); 234 continue; 235 } 236 #define pkcontrol(c) ((c)&(TIOCPKT_FLUSHWRITE|TIOCPKT_NOSTOP|TIOCPKT_DOSTOP)) 237 if (ebits & (1<<p)) { 238 cc = read(p, &cntl, 1); 239 if (cc == 1 && pkcontrol(cntl)) { 240 cntl |= oobdata[0]; 241 send(f, &cntl, 1, MSG_OOB); 242 if (cntl & TIOCPKT_FLUSHWRITE) { 243 pcc = 0; 244 ibits &= ~(1<<p); 245 } 246 } 247 } 248 if (ibits & (1<<f)) { 249 fcc = read(f, fibuf, sizeof (fibuf)); 250 if (fcc < 0 && errno == EWOULDBLOCK) 251 fcc = 0; 252 else { 253 register char *cp; 254 int left, n; 255 256 if (fcc <= 0) 257 break; 258 fbp = fibuf; 259 260 top: 261 for (cp = fibuf; cp < fibuf+fcc-1; cp++) 262 if (cp[0] == magic[0] && 263 cp[1] == magic[1]) { 264 left = fcc - (cp-fibuf); 265 n = control(p, cp, left); 266 if (n) { 267 left -= n; 268 if (left > 0) 269 bcopy(cp+n, cp, left); 270 fcc -= n; 271 goto top; /* n^2 */ 272 } 273 } 274 } 275 } 276 277 if ((obits & (1<<p)) && fcc > 0) { 278 cc = write(p, fbp, fcc); 279 if (cc > 0) { 280 fcc -= cc; 281 fbp += cc; 282 } 283 } 284 285 if (ibits & (1<<p)) { 286 pcc = read(p, pibuf, sizeof (pibuf)); 287 pbp = pibuf; 288 if (pcc < 0 && errno == EWOULDBLOCK) 289 pcc = 0; 290 else if (pcc <= 0) 291 break; 292 else if (pibuf[0] == 0) 293 pbp++, pcc--; 294 else { 295 if (pkcontrol(pibuf[0])) { 296 pibuf[0] |= oobdata[0]; 297 send(f, &pibuf[0], 1, MSG_OOB); 298 } 299 pcc = 0; 300 } 301 } 302 if ((obits & (1<<f)) && pcc > 0) { 303 cc = write(f, pbp, pcc); 304 if (cc < 0 && errno == EWOULDBLOCK) { 305 /* also shouldn't happen */ 306 sleep(5); 307 continue; 308 } 309 if (cc > 0) { 310 pcc -= cc; 311 pbp += cc; 312 } 313 } 314 } 315 } 316 317 cleanup() 318 { 319 320 rmut(); 321 vhangup(); /* XXX */ 322 shutdown(netf, 2); 323 exit(1); 324 } 325 326 fatal(f, msg) 327 int f; 328 char *msg; 329 { 330 char buf[BUFSIZ]; 331 332 buf[0] = '\01'; /* error indicator */ 333 (void) sprintf(buf + 1, "rlogind: %s.\r\n", msg); 334 (void) write(f, buf, strlen(buf)); 335 exit(1); 336 } 337 338 fatalperror(f, msg, errno) 339 int f; 340 char *msg; 341 int errno; 342 { 343 char buf[BUFSIZ]; 344 extern int sys_nerr; 345 extern char *sys_errlist[]; 346 347 if ((unsigned)errno < sys_nerr) 348 (void) sprintf(buf, "%s: %s", msg, sys_errlist[errno]); 349 else 350 (void) sprintf(buf, "%s: Error %d", msg, errno); 351 fatal(f, buf); 352 } 353 354 #include <utmp.h> 355 356 struct utmp wtmp; 357 char wtmpf[] = "/usr/adm/wtmp"; 358 char utmpf[] = "/etc/utmp"; 359 #define SCPYN(a, b) strncpy(a, b, sizeof(a)) 360 #define SCMPN(a, b) strncmp(a, b, sizeof(a)) 361 362 rmut() 363 { 364 register f; 365 int found = 0; 366 struct utmp *u, *utmp; 367 int nutmp; 368 struct stat statbf; 369 370 f = open(utmpf, O_RDWR); 371 if (f >= 0) { 372 fstat(f, &statbf); 373 utmp = (struct utmp *)malloc(statbf.st_size); 374 if (!utmp) 375 syslog(LOG_ERR, "utmp malloc failed"); 376 if (statbf.st_size && utmp) { 377 nutmp = read(f, utmp, statbf.st_size); 378 nutmp /= sizeof(struct utmp); 379 380 for (u = utmp ; u < &utmp[nutmp] ; u++) { 381 if (SCMPN(u->ut_line, line+5) || 382 u->ut_name[0]==0) 383 continue; 384 lseek(f, ((long)u)-((long)utmp), L_SET); 385 SCPYN(u->ut_name, ""); 386 SCPYN(u->ut_host, ""); 387 time(&u->ut_time); 388 write(f, (char *)u, sizeof(wtmp)); 389 found++; 390 } 391 } 392 close(f); 393 } 394 if (found) { 395 f = open(wtmpf, O_WRONLY|O_APPEND); 396 if (f >= 0) { 397 SCPYN(wtmp.ut_line, line+5); 398 SCPYN(wtmp.ut_name, ""); 399 SCPYN(wtmp.ut_host, ""); 400 time(&wtmp.ut_time); 401 write(f, (char *)&wtmp, sizeof(wtmp)); 402 close(f); 403 } 404 } 405 chmod(line, 0666); 406 chown(line, 0, 0); 407 line[strlen("/dev/")] = 'p'; 408 chmod(line, 0666); 409 chown(line, 0, 0); 410 } 411