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 5.9 (Berkeley) 11/08/85"; 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; 202 203 /* 204 * Must ignore SIGTTOU, otherwise we'll stop 205 * when we try and set slave pty's window shape 206 * (our controlling tty is the master pty). 207 */ 208 (void) signal(SIGTTOU, SIG_IGN); 209 send(f, oobdata, 1, MSG_OOB); /* indicate new rlogin */ 210 for (;;) { 211 int ibits = 0, obits = 0; 212 213 if (fcc) 214 obits |= (1<<p); 215 else 216 ibits |= (1<<f); 217 if (pcc >= 0) 218 if (pcc) 219 obits |= (1<<f); 220 else 221 ibits |= (1<<p); 222 if (select(16, &ibits, &obits, 0, 0) < 0) { 223 if (errno == EINTR) 224 continue; 225 fatalperror(f, "select", errno); 226 } 227 if (ibits == 0 && obits == 0) { 228 /* shouldn't happen... */ 229 sleep(5); 230 continue; 231 } 232 if (ibits & (1<<f)) { 233 fcc = read(f, fibuf, sizeof (fibuf)); 234 if (fcc < 0 && errno == EWOULDBLOCK) 235 fcc = 0; 236 else { 237 register char *cp; 238 int left, n; 239 240 if (fcc <= 0) 241 break; 242 fbp = fibuf; 243 244 top: 245 for (cp = fibuf; cp < fibuf+fcc-1; cp++) 246 if (cp[0] == magic[0] && 247 cp[1] == magic[1]) { 248 left = fcc - (cp-fibuf); 249 n = control(p, cp, left); 250 if (n) { 251 left -= n; 252 if (left > 0) 253 bcopy(cp+n, cp, left); 254 fcc -= n; 255 goto top; /* n^2 */ 256 } 257 } 258 } 259 } 260 261 if ((obits & (1<<p)) && fcc > 0) { 262 cc = write(p, fbp, fcc); 263 if (cc > 0) { 264 fcc -= cc; 265 fbp += cc; 266 } 267 } 268 269 if (ibits & (1<<p)) { 270 pcc = read(p, pibuf, sizeof (pibuf)); 271 pbp = pibuf; 272 if (pcc < 0 && errno == EWOULDBLOCK) 273 pcc = 0; 274 else if (pcc <= 0) 275 break; 276 else if (pibuf[0] == 0) 277 pbp++, pcc--; 278 else { 279 #define pkcontrol(c) ((c)&(TIOCPKT_FLUSHWRITE|TIOCPKT_NOSTOP|TIOCPKT_DOSTOP)) 280 if (pkcontrol(pibuf[0])) { 281 pibuf[0] |= oobdata[0]; 282 send(f, &pibuf[0], 1, MSG_OOB); 283 } 284 pcc = 0; 285 } 286 } 287 if ((obits & (1<<f)) && pcc > 0) { 288 cc = write(f, pbp, pcc); 289 if (cc < 0 && errno == EWOULDBLOCK) { 290 /* also shouldn't happen */ 291 sleep(5); 292 continue; 293 } 294 if (cc > 0) { 295 pcc -= cc; 296 pbp += cc; 297 } 298 } 299 } 300 } 301 302 cleanup() 303 { 304 305 rmut(); 306 vhangup(); /* XXX */ 307 shutdown(netf, 2); 308 exit(1); 309 } 310 311 fatal(f, msg) 312 int f; 313 char *msg; 314 { 315 char buf[BUFSIZ]; 316 317 buf[0] = '\01'; /* error indicator */ 318 (void) sprintf(buf + 1, "rlogind: %s.\r\n", msg); 319 (void) write(f, buf, strlen(buf)); 320 exit(1); 321 } 322 323 fatalperror(f, msg, errno) 324 int f; 325 char *msg; 326 int errno; 327 { 328 char buf[BUFSIZ]; 329 extern int sys_nerr; 330 extern char *sys_errlist[]; 331 332 if ((unsigned)errno < sys_nerr) 333 (void) sprintf(buf, "%s: %s", msg, sys_errlist[errno]); 334 else 335 (void) sprintf(buf, "%s: Error %d", msg, errno); 336 fatal(f, buf); 337 } 338 339 #include <utmp.h> 340 341 struct utmp wtmp; 342 char wtmpf[] = "/usr/adm/wtmp"; 343 char utmpf[] = "/etc/utmp"; 344 #define SCPYN(a, b) strncpy(a, b, sizeof(a)) 345 #define SCMPN(a, b) strncmp(a, b, sizeof(a)) 346 347 rmut() 348 { 349 register f; 350 int found = 0; 351 struct utmp *u, *utmp; 352 int nutmp; 353 struct stat statbf; 354 355 f = open(utmpf, O_RDWR); 356 if (f >= 0) { 357 fstat(f, &statbf); 358 utmp = (struct utmp *)malloc(statbf.st_size); 359 if (!utmp) 360 syslog(LOG_ERR, "utmp malloc failed"); 361 if (statbf.st_size && utmp) { 362 nutmp = read(f, utmp, statbf.st_size); 363 nutmp /= sizeof(struct utmp); 364 365 for (u = utmp ; u < &utmp[nutmp] ; u++) { 366 if (SCMPN(u->ut_line, line+5) || 367 u->ut_name[0]==0) 368 continue; 369 lseek(f, ((long)u)-((long)utmp), L_SET); 370 SCPYN(u->ut_name, ""); 371 SCPYN(u->ut_host, ""); 372 time(&u->ut_time); 373 write(f, (char *)u, sizeof(wtmp)); 374 found++; 375 } 376 } 377 close(f); 378 } 379 if (found) { 380 f = open(wtmpf, O_WRONLY|O_APPEND); 381 if (f >= 0) { 382 SCPYN(wtmp.ut_line, line+5); 383 SCPYN(wtmp.ut_name, ""); 384 SCPYN(wtmp.ut_host, ""); 385 time(&wtmp.ut_time); 386 write(f, (char *)&wtmp, sizeof(wtmp)); 387 close(f); 388 } 389 } 390 chmod(line, 0666); 391 chown(line, 0, 0); 392 line[strlen("/dev/")] = 'p'; 393 chmod(line, 0666); 394 chown(line, 0, 0); 395 } 396