1 /*- 2 * Copyright (c) 1983, 1991, 1993, 1994 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 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 * 28 */ 29 30 #include <sys/filio.h> 31 #include <sys/ioccom.h> 32 #include <sys/param.h> 33 #include <sys/stat.h> 34 #include <sys/socket.h> 35 #include <sys/sysctl.h> 36 #include <sys/ucred.h> 37 #include <sys/uio.h> 38 #include <sys/utsname.h> 39 40 #include <ctype.h> 41 #include <err.h> 42 #include <errno.h> 43 #include <fcntl.h> 44 #include <limits.h> 45 #include <pwd.h> 46 #include <signal.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <sysexits.h> 50 #include <syslog.h> 51 #include <unistd.h> 52 53 #include "inetd.h" 54 55 void chargen_dg __P((int, struct servtab *)); 56 void chargen_stream __P((int, struct servtab *)); 57 void daytime_dg __P((int, struct servtab *)); 58 void daytime_stream __P((int, struct servtab *)); 59 void discard_dg __P((int, struct servtab *)); 60 void discard_stream __P((int, struct servtab *)); 61 void echo_dg __P((int, struct servtab *)); 62 void echo_stream __P((int, struct servtab *)); 63 static int getline __P((int, char *, int)); 64 void iderror __P((int, int, int, const char *)); 65 void ident_stream __P((int, struct servtab *)); 66 void initring __P((void)); 67 unsigned long machtime __P((void)); 68 void machtime_dg __P((int, struct servtab *)); 69 void machtime_stream __P((int, struct servtab *)); 70 71 char ring[128]; 72 char *endring; 73 74 75 struct biltin biltins[] = { 76 /* Echo received data */ 77 { "echo", SOCK_STREAM, 1, -1, echo_stream }, 78 { "echo", SOCK_DGRAM, 0, 1, echo_dg }, 79 80 /* Internet /dev/null */ 81 { "discard", SOCK_STREAM, 1, -1, discard_stream }, 82 { "discard", SOCK_DGRAM, 0, 1, discard_dg }, 83 84 /* Return 32 bit time since 1900 */ 85 { "time", SOCK_STREAM, 0, -1, machtime_stream }, 86 { "time", SOCK_DGRAM, 0, 1, machtime_dg }, 87 88 /* Return human-readable time */ 89 { "daytime", SOCK_STREAM, 0, -1, daytime_stream }, 90 { "daytime", SOCK_DGRAM, 0, 1, daytime_dg }, 91 92 /* Familiar character generator */ 93 { "chargen", SOCK_STREAM, 1, -1, chargen_stream }, 94 { "chargen", SOCK_DGRAM, 0, 1, chargen_dg }, 95 96 { "tcpmux", SOCK_STREAM, 1, -1, (bi_fn_t *)tcpmux }, 97 98 { "auth", SOCK_STREAM, 1, -1, ident_stream }, 99 100 { NULL, 0, 0, 0, NULL } 101 }; 102 103 /* 104 * RFC864 Character Generator Protocol. Generates character data without 105 * any regard for input. 106 */ 107 108 void 109 initring() 110 { 111 int i; 112 113 endring = ring; 114 115 for (i = 0; i <= 128; ++i) 116 if (isprint(i)) 117 *endring++ = i; 118 } 119 120 /* ARGSUSED */ 121 void 122 chargen_dg(s, sep) /* Character generator */ 123 int s; 124 struct servtab *sep; 125 { 126 struct sockaddr_storage ss; 127 static char *rs; 128 int len; 129 socklen_t size; 130 char text[LINESIZ+2]; 131 132 if (endring == 0) { 133 initring(); 134 rs = ring; 135 } 136 137 size = sizeof(ss); 138 if (recvfrom(s, text, sizeof(text), 0, 139 (struct sockaddr *)&ss, &size) < 0) 140 return; 141 142 if (check_loop((struct sockaddr *)&ss, sep)) 143 return; 144 145 if ((len = endring - rs) >= LINESIZ) 146 memmove(text, rs, LINESIZ); 147 else { 148 memmove(text, rs, len); 149 memmove(text + len, ring, LINESIZ - len); 150 } 151 if (++rs == endring) 152 rs = ring; 153 text[LINESIZ] = '\r'; 154 text[LINESIZ + 1] = '\n'; 155 (void) sendto(s, text, sizeof(text), 0, (struct sockaddr *)&ss, size); 156 } 157 158 /* ARGSUSED */ 159 void 160 chargen_stream(s, sep) /* Character generator */ 161 int s; 162 struct servtab *sep; 163 { 164 int len; 165 char *rs, text[LINESIZ+2]; 166 167 inetd_setproctitle(sep->se_service, s); 168 169 if (!endring) { 170 initring(); 171 rs = ring; 172 } 173 174 text[LINESIZ] = '\r'; 175 text[LINESIZ + 1] = '\n'; 176 for (rs = ring;;) { 177 if ((len = endring - rs) >= LINESIZ) 178 memmove(text, rs, LINESIZ); 179 else { 180 memmove(text, rs, len); 181 memmove(text + len, ring, LINESIZ - len); 182 } 183 if (++rs == endring) 184 rs = ring; 185 if (write(s, text, sizeof(text)) != sizeof(text)) 186 break; 187 } 188 exit(0); 189 } 190 191 /* 192 * RFC867 Daytime Protocol. Sends the current date and time as an ascii 193 * character string without any regard for input. 194 */ 195 196 /* ARGSUSED */ 197 void 198 daytime_dg(s, sep) /* Return human-readable time of day */ 199 int s; 200 struct servtab *sep; 201 { 202 char buffer[256]; 203 time_t now; 204 struct sockaddr_storage ss; 205 socklen_t size; 206 207 now = time((time_t *) 0); 208 209 size = sizeof(ss); 210 if (recvfrom(s, buffer, sizeof(buffer), 0, 211 (struct sockaddr *)&ss, &size) < 0) 212 return; 213 214 if (check_loop((struct sockaddr *)&ss, sep)) 215 return; 216 217 (void) sprintf(buffer, "%.24s\r\n", ctime(&now)); 218 (void) sendto(s, buffer, strlen(buffer), 0, 219 (struct sockaddr *)&ss, size); 220 } 221 222 /* ARGSUSED */ 223 void 224 daytime_stream(s, sep) /* Return human-readable time of day */ 225 int s; 226 struct servtab *sep; 227 { 228 char buffer[256]; 229 time_t now; 230 231 now = time((time_t *) 0); 232 233 (void) sprintf(buffer, "%.24s\r\n", ctime(&now)); 234 (void) send(s, buffer, strlen(buffer), MSG_EOF); 235 } 236 237 /* 238 * RFC863 Discard Protocol. Any data received is thrown away and no response 239 * is sent. 240 */ 241 242 /* ARGSUSED */ 243 void 244 discard_dg(s, sep) /* Discard service -- ignore data */ 245 int s; 246 struct servtab *sep; 247 { 248 char buffer[BUFSIZE]; 249 250 (void) read(s, buffer, sizeof(buffer)); 251 } 252 253 /* ARGSUSED */ 254 void 255 discard_stream(s, sep) /* Discard service -- ignore data */ 256 int s; 257 struct servtab *sep; 258 { 259 int ret; 260 char buffer[BUFSIZE]; 261 262 inetd_setproctitle(sep->se_service, s); 263 while (1) { 264 while ((ret = read(s, buffer, sizeof(buffer))) > 0) 265 ; 266 if (ret == 0 || errno != EINTR) 267 break; 268 } 269 exit(0); 270 } 271 272 /* 273 * RFC862 Echo Protocol. Any data received is sent back to the sender as 274 * received. 275 */ 276 277 /* ARGSUSED */ 278 void 279 echo_dg(s, sep) /* Echo service -- echo data back */ 280 int s; 281 struct servtab *sep; 282 { 283 char buffer[65536]; /* Should be sizeof(max datagram). */ 284 int i; 285 socklen_t size; 286 struct sockaddr_storage ss; 287 288 size = sizeof(ss); 289 if ((i = recvfrom(s, buffer, sizeof(buffer), 0, 290 (struct sockaddr *)&ss, &size)) < 0) 291 return; 292 293 if (check_loop((struct sockaddr *)&ss, sep)) 294 return; 295 296 (void) sendto(s, buffer, i, 0, (struct sockaddr *)&ss, size); 297 } 298 299 /* ARGSUSED */ 300 void 301 echo_stream(s, sep) /* Echo service -- echo data back */ 302 int s; 303 struct servtab *sep; 304 { 305 char buffer[BUFSIZE]; 306 int i; 307 308 inetd_setproctitle(sep->se_service, s); 309 while ((i = read(s, buffer, sizeof(buffer))) > 0 && 310 write(s, buffer, i) > 0) 311 ; 312 exit(0); 313 } 314 315 /* 316 * RFC1413 Identification Protocol. Given a TCP port number pair, return a 317 * character string which identifies the owner of that connection on the 318 * server's system. Extended to allow for ~/.fakeid support and ~/.noident 319 * support. 320 */ 321 322 /* RFC 1413 says the following are the only errors you can return. */ 323 #define ID_INVALID "INVALID-PORT" /* Port number improperly specified. */ 324 #define ID_NOUSER "NO-USER" /* Port not in use/not identifable. */ 325 #define ID_HIDDEN "HIDDEN-USER" /* Hiden at user's request. */ 326 #define ID_UNKNOWN "UNKNOWN-ERROR" /* Everything else. */ 327 328 /* ARGSUSED */ 329 void 330 iderror(lport, fport, s, er) /* Generic ident_stream error-sending func */ 331 int lport, fport, s; 332 const char *er; 333 { 334 char *p; 335 336 asprintf(&p, "%d , %d : ERROR : %s\r\n", lport, fport, er); 337 if (p == NULL) { 338 syslog(LOG_ERR, "asprintf: %m"); 339 exit(EX_OSERR); 340 } 341 send(s, p, strlen(p), MSG_EOF); 342 free(p); 343 344 exit(0); 345 } 346 347 /* ARGSUSED */ 348 void 349 ident_stream(s, sep) /* Ident service (AKA "auth") */ 350 int s; 351 struct servtab *sep; 352 { 353 struct utsname un; 354 struct stat sb; 355 struct sockaddr_in sin4[2]; 356 #ifdef INET6 357 struct sockaddr_in6 sin6[2]; 358 #endif 359 struct sockaddr_storage ss[2]; 360 struct xucred uc; 361 struct timeval tv = { 362 10, 363 0 364 }, to; 365 struct passwd *pw = NULL; 366 fd_set fdset; 367 char buf[BUFSIZE], *p, **av, *osname = NULL, e; 368 char idbuf[MAXLOGNAME] = ""; /* Big enough to hold uid in decimal. */ 369 socklen_t socklen; 370 ssize_t ssize; 371 size_t size, bufsiz; 372 int c, fflag = 0, nflag = 0, rflag = 0, argc = 0; 373 int gflag = 0, iflag = 0, Fflag = 0, getcredfail = 0, onreadlen; 374 u_short lport, fport; 375 376 inetd_setproctitle(sep->se_service, s); 377 /* 378 * Reset getopt() since we are a fork() but not an exec() from 379 * a parent which used getopt() already. 380 */ 381 optind = 1; 382 optreset = 1; 383 /* 384 * Take the internal argument vector and count it out to make an 385 * argument count for getopt. This can be used for any internal 386 * service to read arguments and use getopt() easily. 387 */ 388 for (av = sep->se_argv; *av; av++) 389 argc++; 390 if (argc) { 391 int sec, usec; 392 size_t i; 393 u_int32_t rnd32; 394 395 while ((c = getopt(argc, sep->se_argv, "d:fFgino:rt:")) != -1) 396 switch (c) { 397 case 'd': 398 if (!gflag) 399 strlcpy(idbuf, optarg, sizeof(idbuf)); 400 break; 401 case 'f': 402 fflag = 1; 403 break; 404 case 'F': 405 fflag = 1; 406 Fflag=1; 407 break; 408 case 'g': 409 gflag = 1; 410 rnd32 = 0; /* Shush, compiler. */ 411 /* 412 * The number of bits in "rnd32" divided 413 * by the number of bits needed per iteration 414 * gives a more optimal way to reload the 415 * random number only when necessary. 416 * 417 * 32 bits from arc4random corrisponds to 418 * about 6 base-36 digits, so we reseed evey 6. 419 */ 420 for (i = 0; i < sizeof(idbuf) - 1; i++) { 421 static const char *const base36 = 422 "0123456789" 423 "abcdefghijklmnopqrstuvwxyz"; 424 if (i % 6 == 0) 425 rnd32 = arc4random(); 426 idbuf[i] = base36[rnd32 % 36]; 427 rnd32 /= 36; 428 } 429 idbuf[i] = '\0'; 430 break; 431 case 'i': 432 iflag = 1; 433 break; 434 case 'n': 435 nflag = 1; 436 break; 437 case 'o': 438 osname = optarg; 439 break; 440 case 'r': 441 rflag = 1; 442 break; 443 case 't': 444 switch (sscanf(optarg, "%d.%d", &sec, &usec)) { 445 case 2: 446 tv.tv_usec = usec; 447 /* FALLTHROUGH */ 448 case 1: 449 tv.tv_sec = sec; 450 break; 451 default: 452 if (debug) 453 warnx("bad -t argument"); 454 break; 455 } 456 break; 457 default: 458 break; 459 } 460 } 461 if (osname == NULL) { 462 if (uname(&un) == -1) 463 iderror(0, 0, s, ID_UNKNOWN); 464 osname = un.sysname; 465 } 466 467 /* 468 * We're going to prepare for and execute reception of a 469 * packet of data from the user. The data is in the format 470 * "local_port , foreign_port\r\n" (with local being the 471 * server's port and foreign being the client's.) 472 */ 473 gettimeofday(&to, NULL); 474 to.tv_sec += tv.tv_sec; 475 to.tv_usec += tv.tv_usec; 476 if (to.tv_usec >= 1000000) { 477 to.tv_usec -= 1000000; 478 to.tv_sec++; 479 } 480 481 size = 0; 482 bufsiz = sizeof(buf) - 1; 483 FD_ZERO(&fdset); 484 while (bufsiz > 0) { 485 gettimeofday(&tv, NULL); 486 tv.tv_sec = to.tv_sec - tv.tv_sec; 487 tv.tv_usec = to.tv_usec - tv.tv_usec; 488 if (tv.tv_usec < 0) { 489 tv.tv_usec += 1000000; 490 tv.tv_sec--; 491 } 492 if (tv.tv_sec < 0) 493 break; 494 FD_SET(s, &fdset); 495 if (select(s + 1, &fdset, NULL, NULL, &tv) == -1) 496 iderror(0, 0, s, ID_UNKNOWN); 497 if (ioctl(s, FIONREAD, &onreadlen) == -1) 498 iderror(0, 0, s, ID_UNKNOWN); 499 if ((size_t)onreadlen > bufsiz) 500 onreadlen = bufsiz; 501 ssize = read(s, &buf[size], (size_t)onreadlen); 502 if (ssize == -1) 503 iderror(0, 0, s, ID_UNKNOWN); 504 else if (ssize == 0) 505 break; 506 bufsiz -= ssize; 507 size += ssize; 508 if (memchr(&buf[size - ssize], '\n', ssize) != NULL) 509 break; 510 } 511 buf[size] = '\0'; 512 /* Read two characters, and check for a delimiting character */ 513 if (sscanf(buf, "%hu , %hu%c", &lport, &fport, &e) != 3 || isdigit(e)) 514 iderror(0, 0, s, ID_INVALID); 515 516 /* Send garbage? */ 517 if (gflag) 518 goto printit; 519 520 /* 521 * If not "real" (-r), send a HIDDEN-USER error for everything. 522 * If -d is used to set a fallback username, this is used to 523 * override it, and the fallback is returned instead. 524 */ 525 if (!rflag) { 526 if (*idbuf == '\0') 527 iderror(lport, fport, s, ID_HIDDEN); 528 goto printit; 529 } 530 531 /* 532 * We take the input and construct an array of two sockaddr_ins 533 * which contain the local address information and foreign 534 * address information, respectively, used to look up the 535 * credentials for the socket (which are returned by the 536 * sysctl "net.inet.tcp.getcred" when we call it.) 537 */ 538 socklen = sizeof(ss[0]); 539 if (getsockname(s, (struct sockaddr *)&ss[0], &socklen) == -1) 540 iderror(lport, fport, s, ID_UNKNOWN); 541 socklen = sizeof(ss[1]); 542 if (getpeername(s, (struct sockaddr *)&ss[1], &socklen) == -1) 543 iderror(lport, fport, s, ID_UNKNOWN); 544 if (ss[0].ss_family != ss[1].ss_family) 545 iderror(lport, fport, s, ID_UNKNOWN); 546 size = sizeof(uc); 547 switch (ss[0].ss_family) { 548 case AF_INET: 549 sin4[0] = *(struct sockaddr_in *)&ss[0]; 550 sin4[0].sin_port = htons(lport); 551 sin4[1] = *(struct sockaddr_in *)&ss[1]; 552 sin4[1].sin_port = htons(fport); 553 if (sysctlbyname("net.inet.tcp.getcred", &uc, &size, sin4, 554 sizeof(sin4)) == -1) 555 getcredfail = errno; 556 break; 557 #ifdef INET6 558 case AF_INET6: 559 sin6[0] = *(struct sockaddr_in6 *)&ss[0]; 560 sin6[0].sin6_port = htons(lport); 561 sin6[1] = *(struct sockaddr_in6 *)&ss[1]; 562 sin6[1].sin6_port = htons(fport); 563 if (sysctlbyname("net.inet6.tcp6.getcred", &uc, &size, sin6, 564 sizeof(sin6)) == -1) 565 getcredfail = errno; 566 break; 567 #endif 568 default: /* should not reach here */ 569 getcredfail = EAFNOSUPPORT; 570 break; 571 } 572 if (getcredfail != 0) { 573 if (*idbuf == '\0') 574 iderror(lport, fport, s, 575 getcredfail == ENOENT ? ID_NOUSER : ID_UNKNOWN); 576 goto printit; 577 } 578 579 /* Look up the pw to get the username and home directory*/ 580 errno = 0; 581 pw = getpwuid(uc.cr_uid); 582 if (pw == NULL) 583 iderror(lport, fport, s, errno == 0 ? ID_NOUSER : ID_UNKNOWN); 584 585 if (iflag) 586 snprintf(idbuf, sizeof(idbuf), "%u", (unsigned)pw->pw_uid); 587 else 588 strlcpy(idbuf, pw->pw_name, sizeof(idbuf)); 589 590 /* 591 * If enabled, we check for a file named ".noident" in the user's 592 * home directory. If found, we return HIDDEN-USER. 593 */ 594 if (nflag) { 595 if (asprintf(&p, "%s/.noident", pw->pw_dir) == -1) 596 iderror(lport, fport, s, ID_UNKNOWN); 597 if (lstat(p, &sb) == 0) { 598 free(p); 599 iderror(lport, fport, s, ID_HIDDEN); 600 } 601 free(p); 602 } 603 604 /* 605 * Here, if enabled, we read a user's ".fakeid" file in their 606 * home directory. It consists of a line containing the name 607 * they want. 608 */ 609 if (fflag) { 610 int fakeid_fd; 611 612 /* 613 * Here we set ourself to effectively be the user, so we don't 614 * open any files we have no permission to open, especially 615 * symbolic links to sensitive root-owned files or devices. 616 */ 617 if (initgroups(pw->pw_name, pw->pw_gid) == -1) 618 iderror(lport, fport, s, ID_UNKNOWN); 619 if (seteuid(pw->pw_uid) == -1) 620 iderror(lport, fport, s, ID_UNKNOWN); 621 /* 622 * We can't stat() here since that would be a race 623 * condition. 624 * Therefore, we open the file we have permissions to open 625 * and if it's not a regular file, we close it and end up 626 * returning the user's real username. 627 */ 628 if (asprintf(&p, "%s/.fakeid", pw->pw_dir) == -1) 629 iderror(lport, fport, s, ID_UNKNOWN); 630 fakeid_fd = open(p, O_RDONLY | O_NONBLOCK); 631 free(p); 632 if (fakeid_fd == -1 || fstat(fakeid_fd, &sb) == -1 || 633 !S_ISREG(sb.st_mode)) 634 goto fakeid_fail; 635 636 if ((ssize = read(fakeid_fd, buf, sizeof(buf) - 1)) < 0) 637 goto fakeid_fail; 638 buf[ssize] = '\0'; 639 640 /* 641 * Usually, the file will have the desired identity 642 * in the form "identity\n". Allow for leading white 643 * space and trailing white space/end of line. 644 */ 645 p = buf; 646 p += strspn(p, " \t"); 647 p[strcspn(p, " \t\r\n")] = '\0'; 648 if (strlen(p) > MAXLOGNAME - 1) /* Too long (including nul)? */ 649 p[MAXLOGNAME - 1] = '\0'; 650 651 /* 652 * If the name is a zero-length string or matches it 653 * the id or name of another user (unless permitted by -F) 654 * then it is invalid. 655 */ 656 if (*p == '\0') 657 goto fakeid_fail; 658 if (!Fflag) { 659 if (iflag) { 660 if (p[strspn(p, "0123456789")] == '\0' && 661 getpwuid(atoi(p)) != NULL) 662 goto fakeid_fail; 663 } else { 664 if (getpwnam(p) != NULL) 665 goto fakeid_fail; 666 } 667 } 668 669 strlcpy(idbuf, p, sizeof(idbuf)); 670 671 fakeid_fail: 672 if (fakeid_fd != -1) 673 close(fakeid_fd); 674 } 675 676 printit: 677 /* Finally, we make and send the reply. */ 678 if (asprintf(&p, "%d , %d : USERID : %s : %s\r\n", lport, fport, osname, 679 idbuf) == -1) { 680 syslog(LOG_ERR, "asprintf: %m"); 681 exit(EX_OSERR); 682 } 683 send(s, p, strlen(p), MSG_EOF); 684 free(p); 685 686 exit(0); 687 } 688 689 /* 690 * RFC738 Time Server. 691 * Return a machine readable date and time, in the form of the 692 * number of seconds since midnight, Jan 1, 1900. Since gettimeofday 693 * returns the number of seconds since midnight, Jan 1, 1970, 694 * we must add 2208988800 seconds to this figure to make up for 695 * some seventy years Bell Labs was asleep. 696 */ 697 698 unsigned long 699 machtime() 700 { 701 struct timeval tv; 702 703 if (gettimeofday(&tv, (struct timezone *)NULL) < 0) { 704 if (debug) 705 warnx("unable to get time of day"); 706 return (0L); 707 } 708 #define OFFSET ((u_long)25567 * 24*60*60) 709 return (htonl((long)(tv.tv_sec + OFFSET))); 710 #undef OFFSET 711 } 712 713 /* ARGSUSED */ 714 void 715 machtime_dg(s, sep) 716 int s; 717 struct servtab *sep; 718 { 719 unsigned long result; 720 struct sockaddr_storage ss; 721 socklen_t size; 722 723 size = sizeof(ss); 724 if (recvfrom(s, (char *)&result, sizeof(result), 0, 725 (struct sockaddr *)&ss, &size) < 0) 726 return; 727 728 if (check_loop((struct sockaddr *)&ss, sep)) 729 return; 730 731 result = machtime(); 732 (void) sendto(s, (char *) &result, sizeof(result), 0, 733 (struct sockaddr *)&ss, size); 734 } 735 736 /* ARGSUSED */ 737 void 738 machtime_stream(s, sep) 739 int s; 740 struct servtab *sep; 741 { 742 unsigned long result; 743 744 result = machtime(); 745 (void) send(s, (char *) &result, sizeof(result), MSG_EOF); 746 } 747 748 /* 749 * RFC1078 TCP Port Service Multiplexer (TCPMUX). Service connections to 750 * services based on the service name sent. 751 * 752 * Based on TCPMUX.C by Mark K. Lottor November 1988 753 * sri-nic::ps:<mkl>tcpmux.c 754 */ 755 756 #define MAX_SERV_LEN (256+2) /* 2 bytes for \r\n */ 757 #define strwrite(fd, buf) (void) write(fd, buf, sizeof(buf)-1) 758 759 static int /* # of characters upto \r,\n or \0 */ 760 getline(fd, buf, len) 761 int fd; 762 char *buf; 763 int len; 764 { 765 int count = 0, n; 766 struct sigaction sa; 767 768 sa.sa_flags = 0; 769 sigemptyset(&sa.sa_mask); 770 sa.sa_handler = SIG_DFL; 771 sigaction(SIGALRM, &sa, (struct sigaction *)0); 772 do { 773 alarm(10); 774 n = read(fd, buf, len-count); 775 alarm(0); 776 if (n == 0) 777 return (count); 778 if (n < 0) 779 return (-1); 780 while (--n >= 0) { 781 if (*buf == '\r' || *buf == '\n' || *buf == '\0') 782 return (count); 783 count++; 784 buf++; 785 } 786 } while (count < len); 787 return (count); 788 } 789 790 struct servtab * 791 tcpmux(s) 792 int s; 793 { 794 struct servtab *sep; 795 char service[MAX_SERV_LEN+1]; 796 int len; 797 798 /* Get requested service name */ 799 if ((len = getline(s, service, MAX_SERV_LEN)) < 0) { 800 strwrite(s, "-Error reading service name\r\n"); 801 return (NULL); 802 } 803 service[len] = '\0'; 804 805 if (debug) 806 warnx("tcpmux: someone wants %s", service); 807 808 /* 809 * Help is a required command, and lists available services, 810 * one per line. 811 */ 812 if (!strcasecmp(service, "help")) { 813 for (sep = servtab; sep; sep = sep->se_next) { 814 if (!ISMUX(sep)) 815 continue; 816 (void)write(s,sep->se_service,strlen(sep->se_service)); 817 strwrite(s, "\r\n"); 818 } 819 return (NULL); 820 } 821 822 /* Try matching a service in inetd.conf with the request */ 823 for (sep = servtab; sep; sep = sep->se_next) { 824 if (!ISMUX(sep)) 825 continue; 826 if (!strcasecmp(service, sep->se_service)) { 827 if (ISMUXPLUS(sep)) { 828 strwrite(s, "+Go\r\n"); 829 } 830 return (sep); 831 } 832 } 833 strwrite(s, "-Service not available\r\n"); 834 return (NULL); 835 } 836