1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 1983, 1991, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 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 static void chargen_dg(int, struct servtab *); 56 static void chargen_stream(int, struct servtab *); 57 static void daytime_dg(int, struct servtab *); 58 static void daytime_stream(int, struct servtab *); 59 static void discard_dg(int, struct servtab *); 60 static void discard_stream(int, struct servtab *); 61 static void echo_dg(int, struct servtab *); 62 static void echo_stream(int, struct servtab *); 63 static int get_line(int, char *, int); 64 static void iderror(int, int, int, const char *); 65 static void ident_stream(int, struct servtab *); 66 static void initring(void); 67 static uint32_t machtime(void); 68 static void machtime_dg(int, struct servtab *); 69 static void machtime_stream(int, struct servtab *); 70 71 static char ring[128]; 72 static char *endring; 73 74 struct biltin biltins[] = { 75 /* Echo received data */ 76 { "echo", SOCK_STREAM, 1, -1, echo_stream }, 77 { "echo", SOCK_DGRAM, 0, 1, echo_dg }, 78 79 /* Internet /dev/null */ 80 { "discard", SOCK_STREAM, 1, -1, discard_stream }, 81 { "discard", SOCK_DGRAM, 0, 1, discard_dg }, 82 83 /* Return 32 bit time since 1900 */ 84 { "time", SOCK_STREAM, 0, -1, machtime_stream }, 85 { "time", SOCK_DGRAM, 0, 1, machtime_dg }, 86 87 /* Return human-readable time */ 88 { "daytime", SOCK_STREAM, 0, -1, daytime_stream }, 89 { "daytime", SOCK_DGRAM, 0, 1, daytime_dg }, 90 91 /* Familiar character generator */ 92 { "chargen", SOCK_STREAM, 1, -1, chargen_stream }, 93 { "chargen", SOCK_DGRAM, 0, 1, chargen_dg }, 94 95 { "tcpmux", SOCK_STREAM, 1, -1, (bi_fn_t *)tcpmux }, 96 97 { "auth", SOCK_STREAM, 1, -1, ident_stream }, 98 99 { NULL, 0, 0, 0, NULL } 100 }; 101 102 /* 103 * RFC864 Character Generator Protocol. Generates character data without 104 * any regard for input. 105 */ 106 107 static void 108 initring(void) 109 { 110 int i; 111 112 endring = ring; 113 114 for (i = 0; i <= 128; ++i) 115 if (isprint(i)) 116 *endring++ = i; 117 } 118 119 /* Character generator 120 * The RFC says that we should send back a random number of 121 * characters chosen from the range 0 to 512. We send LINESIZ+2. 122 */ 123 /* ARGSUSED */ 124 static void 125 chargen_dg(int s, struct servtab *sep) 126 { 127 struct sockaddr_storage ss; 128 static char *rs; 129 int len; 130 socklen_t size; 131 char text[LINESIZ+2]; 132 133 if (endring == NULL) 134 initring(); 135 if (rs == NULL) 136 rs = ring; 137 138 size = sizeof(ss); 139 if (recvfrom(s, text, sizeof(text), 0, 140 (struct sockaddr *)&ss, &size) < 0) 141 return; 142 143 if (check_loop((struct sockaddr *)&ss, sep)) 144 return; 145 146 if ((len = endring - rs) >= LINESIZ) 147 memmove(text, rs, LINESIZ); 148 else { 149 memmove(text, rs, len); 150 memmove(text + len, ring, LINESIZ - len); 151 } 152 if (++rs == endring) 153 rs = ring; 154 text[LINESIZ] = '\r'; 155 text[LINESIZ + 1] = '\n'; 156 (void) sendto(s, text, sizeof(text), 0, (struct sockaddr *)&ss, size); 157 } 158 159 /* Character generator */ 160 /* ARGSUSED */ 161 static void 162 chargen_stream(int s, 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(); 171 172 text[LINESIZ] = '\r'; 173 text[LINESIZ + 1] = '\n'; 174 for (rs = ring;;) { 175 if ((len = endring - rs) >= LINESIZ) 176 memmove(text, rs, LINESIZ); 177 else { 178 memmove(text, rs, len); 179 memmove(text + len, ring, LINESIZ - len); 180 } 181 if (++rs == endring) 182 rs = ring; 183 if (write(s, text, sizeof(text)) != sizeof(text)) 184 break; 185 } 186 exit(0); 187 } 188 189 /* 190 * RFC867 Daytime Protocol. Sends the current date and time as an ascii 191 * character string without any regard for input. 192 */ 193 194 /* Return human-readable time of day */ 195 /* ARGSUSED */ 196 static void 197 daytime_dg(int s, struct servtab *sep) 198 { 199 char buffer[256]; 200 time_t now; 201 struct sockaddr_storage ss; 202 socklen_t size; 203 204 now = time((time_t *) 0); 205 206 size = sizeof(ss); 207 if (recvfrom(s, buffer, sizeof(buffer), 0, 208 (struct sockaddr *)&ss, &size) < 0) 209 return; 210 211 if (check_loop((struct sockaddr *)&ss, sep)) 212 return; 213 214 (void) sprintf(buffer, "%.24s\r\n", ctime(&now)); 215 (void) sendto(s, buffer, strlen(buffer), 0, 216 (struct sockaddr *)&ss, size); 217 } 218 219 /* Return human-readable time of day */ 220 /* ARGSUSED */ 221 static void 222 daytime_stream(int s, struct servtab *sep __unused) 223 { 224 char buffer[256]; 225 time_t now; 226 227 now = time((time_t *) 0); 228 229 (void) sprintf(buffer, "%.24s\r\n", ctime(&now)); 230 (void) send(s, buffer, strlen(buffer), MSG_EOF); 231 } 232 233 /* 234 * RFC863 Discard Protocol. Any data received is thrown away and no response 235 * is sent. 236 */ 237 238 /* Discard service -- ignore data */ 239 /* ARGSUSED */ 240 static void 241 discard_dg(int s, struct servtab *sep __unused) 242 { 243 char buffer[BUFSIZE]; 244 245 (void) read(s, buffer, sizeof(buffer)); 246 } 247 248 /* Discard service -- ignore data */ 249 /* ARGSUSED */ 250 static void 251 discard_stream(int s, struct servtab *sep) 252 { 253 int ret; 254 char buffer[BUFSIZE]; 255 256 inetd_setproctitle(sep->se_service, s); 257 while (1) { 258 while ((ret = read(s, buffer, sizeof(buffer))) > 0) 259 ; 260 if (ret == 0 || errno != EINTR) 261 break; 262 } 263 exit(0); 264 } 265 266 /* 267 * RFC862 Echo Protocol. Any data received is sent back to the sender as 268 * received. 269 */ 270 271 /* Echo service -- echo data back */ 272 /* ARGSUSED */ 273 static void 274 echo_dg(int s, struct servtab *sep) 275 { 276 char buffer[65536]; /* Should be sizeof(max datagram). */ 277 int i; 278 socklen_t size; 279 struct sockaddr_storage ss; 280 281 size = sizeof(ss); 282 if ((i = recvfrom(s, buffer, sizeof(buffer), 0, 283 (struct sockaddr *)&ss, &size)) < 0) 284 return; 285 286 if (check_loop((struct sockaddr *)&ss, sep)) 287 return; 288 289 (void) sendto(s, buffer, i, 0, (struct sockaddr *)&ss, size); 290 } 291 292 /* Echo service -- echo data back */ 293 /* ARGSUSED */ 294 static void 295 echo_stream(int s, struct servtab *sep) 296 { 297 char buffer[BUFSIZE]; 298 int i; 299 300 inetd_setproctitle(sep->se_service, s); 301 while ((i = read(s, buffer, sizeof(buffer))) > 0 && 302 write(s, buffer, i) > 0) 303 ; 304 exit(0); 305 } 306 307 /* 308 * RFC1413 Identification Protocol. Given a TCP port number pair, return a 309 * character string which identifies the owner of that connection on the 310 * server's system. Extended to allow for ~/.fakeid support and ~/.noident 311 * support. 312 */ 313 314 /* RFC 1413 says the following are the only errors you can return. */ 315 #define ID_INVALID "INVALID-PORT" /* Port number improperly specified. */ 316 #define ID_NOUSER "NO-USER" /* Port not in use/not identifiable. */ 317 #define ID_HIDDEN "HIDDEN-USER" /* Hidden at user's request. */ 318 #define ID_UNKNOWN "UNKNOWN-ERROR" /* Everything else. */ 319 320 /* Generic ident_stream error-sending func */ 321 /* ARGSUSED */ 322 static void 323 iderror(int lport, int fport, int s, const char *er) 324 { 325 char *p; 326 327 asprintf(&p, "%d , %d : ERROR : %s\r\n", lport, fport, er); 328 if (p == NULL) { 329 syslog(LOG_ERR, "asprintf: %m"); 330 exit(EX_OSERR); 331 } 332 send(s, p, strlen(p), MSG_EOF); 333 free(p); 334 335 exit(0); 336 } 337 338 /* Ident service (AKA "auth") */ 339 /* ARGSUSED */ 340 static void 341 ident_stream(int s, struct servtab *sep) 342 { 343 struct utsname un; 344 struct stat sb; 345 struct sockaddr_in sin4[2]; 346 #ifdef INET6 347 struct sockaddr_in6 sin6[2]; 348 #endif 349 struct sockaddr_storage ss[2]; 350 struct xucred uc; 351 struct timeval tv = { 352 10, 353 0 354 }, to; 355 struct passwd *pw = NULL; 356 fd_set fdset; 357 char buf[BUFSIZE], *p, **av, *osname = NULL, e; 358 char idbuf[MAXLOGNAME] = ""; /* Big enough to hold uid in decimal. */ 359 socklen_t socklen; 360 ssize_t ssize; 361 size_t size, bufsiz; 362 int c, fflag = 0, nflag = 0, rflag = 0, argc = 0; 363 int gflag = 0, iflag = 0, Fflag = 0, getcredfail = 0, onreadlen; 364 u_short lport, fport; 365 366 inetd_setproctitle(sep->se_service, s); 367 /* 368 * Reset getopt() since we are a fork() but not an exec() from 369 * a parent which used getopt() already. 370 */ 371 optind = 1; 372 optreset = 1; 373 /* 374 * Take the internal argument vector and count it out to make an 375 * argument count for getopt. This can be used for any internal 376 * service to read arguments and use getopt() easily. 377 */ 378 for (av = sep->se_argv; *av; av++) 379 argc++; 380 if (argc) { 381 int sec, usec; 382 size_t i; 383 u_int32_t rnd32; 384 385 while ((c = getopt(argc, sep->se_argv, "d:fFgino:rt:")) != -1) 386 switch (c) { 387 case 'd': 388 if (!gflag) 389 strlcpy(idbuf, optarg, sizeof(idbuf)); 390 break; 391 case 'f': 392 fflag = 1; 393 break; 394 case 'F': 395 fflag = 1; 396 Fflag=1; 397 break; 398 case 'g': 399 gflag = 1; 400 rnd32 = 0; /* Shush, compiler. */ 401 /* 402 * The number of bits in "rnd32" divided 403 * by the number of bits needed per iteration 404 * gives a more optimal way to reload the 405 * random number only when necessary. 406 * 407 * 32 bits from arc4random corresponds to 408 * about 6 base-36 digits, so we reseed every 6. 409 */ 410 for (i = 0; i < sizeof(idbuf) - 1; i++) { 411 static const char *const base36 = 412 "0123456789" 413 "abcdefghijklmnopqrstuvwxyz"; 414 if (i % 6 == 0) 415 rnd32 = arc4random(); 416 idbuf[i] = base36[rnd32 % 36]; 417 rnd32 /= 36; 418 } 419 idbuf[i] = '\0'; 420 break; 421 case 'i': 422 iflag = 1; 423 break; 424 case 'n': 425 nflag = 1; 426 break; 427 case 'o': 428 osname = optarg; 429 break; 430 case 'r': 431 rflag = 1; 432 break; 433 case 't': 434 switch (sscanf(optarg, "%d.%d", &sec, &usec)) { 435 case 2: 436 tv.tv_usec = usec; 437 /* FALLTHROUGH */ 438 case 1: 439 tv.tv_sec = sec; 440 break; 441 default: 442 if (debug) 443 warnx("bad -t argument"); 444 break; 445 } 446 break; 447 default: 448 break; 449 } 450 } 451 if (osname == NULL) { 452 if (uname(&un) == -1) 453 iderror(0, 0, s, ID_UNKNOWN); 454 osname = un.sysname; 455 } 456 457 /* 458 * We're going to prepare for and execute reception of a 459 * packet of data from the user. The data is in the format 460 * "local_port , foreign_port\r\n" (with local being the 461 * server's port and foreign being the client's.) 462 */ 463 gettimeofday(&to, NULL); 464 to.tv_sec += tv.tv_sec; 465 to.tv_usec += tv.tv_usec; 466 if (to.tv_usec >= 1000000) { 467 to.tv_usec -= 1000000; 468 to.tv_sec++; 469 } 470 471 size = 0; 472 bufsiz = sizeof(buf) - 1; 473 FD_ZERO(&fdset); 474 while (bufsiz > 0) { 475 gettimeofday(&tv, NULL); 476 tv.tv_sec = to.tv_sec - tv.tv_sec; 477 tv.tv_usec = to.tv_usec - tv.tv_usec; 478 if (tv.tv_usec < 0) { 479 tv.tv_usec += 1000000; 480 tv.tv_sec--; 481 } 482 if (tv.tv_sec < 0) 483 break; 484 FD_SET(s, &fdset); 485 if (select(s + 1, &fdset, NULL, NULL, &tv) == -1) 486 iderror(0, 0, s, ID_UNKNOWN); 487 if (ioctl(s, FIONREAD, &onreadlen) == -1) 488 iderror(0, 0, s, ID_UNKNOWN); 489 if ((size_t)onreadlen > bufsiz) 490 onreadlen = bufsiz; 491 ssize = read(s, &buf[size], (size_t)onreadlen); 492 if (ssize == -1) 493 iderror(0, 0, s, ID_UNKNOWN); 494 else if (ssize == 0) 495 break; 496 bufsiz -= ssize; 497 size += ssize; 498 if (memchr(&buf[size - ssize], '\n', ssize) != NULL) 499 break; 500 } 501 buf[size] = '\0'; 502 /* Read two characters, and check for a delimiting character */ 503 if (sscanf(buf, "%hu , %hu%c", &lport, &fport, &e) != 3 || isdigit(e)) 504 iderror(0, 0, s, ID_INVALID); 505 506 /* Send garbage? */ 507 if (gflag) 508 goto printit; 509 510 /* 511 * If not "real" (-r), send a HIDDEN-USER error for everything. 512 * If -d is used to set a fallback username, this is used to 513 * override it, and the fallback is returned instead. 514 */ 515 if (!rflag) { 516 if (*idbuf == '\0') 517 iderror(lport, fport, s, ID_HIDDEN); 518 goto printit; 519 } 520 521 /* 522 * We take the input and construct an array of two sockaddr_ins 523 * which contain the local address information and foreign 524 * address information, respectively, used to look up the 525 * credentials for the socket (which are returned by the 526 * sysctl "net.inet.tcp.getcred" when we call it.) 527 */ 528 socklen = sizeof(ss[0]); 529 if (getsockname(s, (struct sockaddr *)&ss[0], &socklen) == -1) 530 iderror(lport, fport, s, ID_UNKNOWN); 531 socklen = sizeof(ss[1]); 532 if (getpeername(s, (struct sockaddr *)&ss[1], &socklen) == -1) 533 iderror(lport, fport, s, ID_UNKNOWN); 534 if (ss[0].ss_family != ss[1].ss_family) 535 iderror(lport, fport, s, ID_UNKNOWN); 536 size = sizeof(uc); 537 switch (ss[0].ss_family) { 538 case AF_INET: 539 sin4[0] = *(struct sockaddr_in *)&ss[0]; 540 sin4[0].sin_port = htons(lport); 541 sin4[1] = *(struct sockaddr_in *)&ss[1]; 542 sin4[1].sin_port = htons(fport); 543 if (sysctlbyname("net.inet.tcp.getcred", &uc, &size, sin4, 544 sizeof(sin4)) == -1) 545 getcredfail = errno; 546 break; 547 #ifdef INET6 548 case AF_INET6: 549 sin6[0] = *(struct sockaddr_in6 *)&ss[0]; 550 sin6[0].sin6_port = htons(lport); 551 sin6[1] = *(struct sockaddr_in6 *)&ss[1]; 552 sin6[1].sin6_port = htons(fport); 553 if (sysctlbyname("net.inet6.tcp6.getcred", &uc, &size, sin6, 554 sizeof(sin6)) == -1) 555 getcredfail = errno; 556 break; 557 #endif 558 default: /* should not reach here */ 559 getcredfail = EAFNOSUPPORT; 560 break; 561 } 562 if (getcredfail != 0 || uc.cr_version != XUCRED_VERSION) { 563 if (*idbuf == '\0') 564 iderror(lport, fport, s, 565 getcredfail == ENOENT ? ID_NOUSER : ID_UNKNOWN); 566 goto printit; 567 } 568 569 /* Look up the pw to get the username and home directory*/ 570 errno = 0; 571 pw = getpwuid(uc.cr_uid); 572 if (pw == NULL) 573 iderror(lport, fport, s, errno == 0 ? ID_NOUSER : ID_UNKNOWN); 574 575 if (iflag) 576 snprintf(idbuf, sizeof(idbuf), "%u", (unsigned)pw->pw_uid); 577 else 578 strlcpy(idbuf, pw->pw_name, sizeof(idbuf)); 579 580 /* 581 * If enabled, we check for a file named ".noident" in the user's 582 * home directory. If found, we return HIDDEN-USER. 583 */ 584 if (nflag) { 585 if (asprintf(&p, "%s/.noident", pw->pw_dir) == -1) 586 iderror(lport, fport, s, ID_UNKNOWN); 587 if (lstat(p, &sb) == 0) { 588 free(p); 589 iderror(lport, fport, s, ID_HIDDEN); 590 } 591 free(p); 592 } 593 594 /* 595 * Here, if enabled, we read a user's ".fakeid" file in their 596 * home directory. It consists of a line containing the name 597 * they want. 598 */ 599 if (fflag) { 600 int fakeid_fd; 601 602 /* 603 * Here we set ourself to effectively be the user, so we don't 604 * open any files we have no permission to open, especially 605 * symbolic links to sensitive root-owned files or devices. 606 */ 607 if (initgroups(pw->pw_name, pw->pw_gid) == -1) 608 iderror(lport, fport, s, ID_UNKNOWN); 609 if (seteuid(pw->pw_uid) == -1) 610 iderror(lport, fport, s, ID_UNKNOWN); 611 /* 612 * We can't stat() here since that would be a race 613 * condition. 614 * Therefore, we open the file we have permissions to open 615 * and if it's not a regular file, we close it and end up 616 * returning the user's real username. 617 */ 618 if (asprintf(&p, "%s/.fakeid", pw->pw_dir) == -1) 619 iderror(lport, fport, s, ID_UNKNOWN); 620 fakeid_fd = open(p, O_RDONLY | O_NONBLOCK); 621 free(p); 622 if (fakeid_fd == -1 || fstat(fakeid_fd, &sb) == -1 || 623 !S_ISREG(sb.st_mode)) 624 goto fakeid_fail; 625 626 if ((ssize = read(fakeid_fd, buf, sizeof(buf) - 1)) < 0) 627 goto fakeid_fail; 628 buf[ssize] = '\0'; 629 630 /* 631 * Usually, the file will have the desired identity 632 * in the form "identity\n". Allow for leading white 633 * space and trailing white space/end of line. 634 */ 635 p = buf; 636 p += strspn(p, " \t"); 637 p[strcspn(p, " \t\r\n")] = '\0'; 638 if (strlen(p) > MAXLOGNAME - 1) /* Too long (including nul)? */ 639 p[MAXLOGNAME - 1] = '\0'; 640 641 /* 642 * If the name is a zero-length string or matches it 643 * the id or name of another user (unless permitted by -F) 644 * then it is invalid. 645 */ 646 if (*p == '\0') 647 goto fakeid_fail; 648 if (!Fflag) { 649 if (iflag) { 650 const char *errstr; 651 uid_t uid; 652 653 uid = strtonum(p, 0, UID_MAX, &errstr); 654 if (errstr != NULL) 655 goto fakeid_fail; 656 657 if (getpwuid(uid) != NULL) 658 goto fakeid_fail; 659 } else { 660 if (getpwnam(p) != NULL) 661 goto fakeid_fail; 662 } 663 } 664 665 strlcpy(idbuf, p, sizeof(idbuf)); 666 667 fakeid_fail: 668 if (fakeid_fd != -1) 669 close(fakeid_fd); 670 } 671 672 printit: 673 /* Finally, we make and send the reply. */ 674 if (asprintf(&p, "%d , %d : USERID : %s : %s\r\n", lport, fport, osname, 675 idbuf) == -1) { 676 syslog(LOG_ERR, "asprintf: %m"); 677 exit(EX_OSERR); 678 } 679 send(s, p, strlen(p), MSG_EOF); 680 free(p); 681 682 exit(0); 683 } 684 685 /* 686 * RFC738/868 Time Server. 687 * Return a machine readable date and time, in the form of the 688 * number of seconds since midnight, Jan 1, 1900. Since gettimeofday 689 * returns the number of seconds since midnight, Jan 1, 1970, 690 * we must add 2208988800 seconds to this figure to make up for 691 * some seventy years Bell Labs was asleep. 692 */ 693 694 static uint32_t 695 machtime(void) 696 { 697 698 #define OFFSET ((uint32_t)25567 * 24*60*60) 699 return (htonl((uint32_t)(time(NULL) + OFFSET))); 700 #undef OFFSET 701 } 702 703 /* ARGSUSED */ 704 static void 705 machtime_dg(int s, struct servtab *sep) 706 { 707 uint32_t result; 708 struct sockaddr_storage ss; 709 socklen_t size; 710 711 size = sizeof(ss); 712 if (recvfrom(s, (char *)&result, sizeof(result), 0, 713 (struct sockaddr *)&ss, &size) < 0) 714 return; 715 716 if (check_loop((struct sockaddr *)&ss, sep)) 717 return; 718 719 result = machtime(); 720 (void) sendto(s, (char *) &result, sizeof(result), 0, 721 (struct sockaddr *)&ss, size); 722 } 723 724 /* ARGSUSED */ 725 static void 726 machtime_stream(int s, struct servtab *sep __unused) 727 { 728 uint32_t result; 729 730 result = machtime(); 731 (void) send(s, (char *) &result, sizeof(result), MSG_EOF); 732 } 733 734 /* 735 * RFC1078 TCP Port Service Multiplexer (TCPMUX). Service connections to 736 * services based on the service name sent. 737 * 738 * Based on TCPMUX.C by Mark K. Lottor November 1988 739 * sri-nic::ps:<mkl>tcpmux.c 740 */ 741 742 #define MAX_SERV_LEN (256+2) /* 2 bytes for \r\n */ 743 #define strwrite(fd, buf) (void) write(fd, buf, sizeof(buf)-1) 744 745 static int /* # of characters up to \r,\n or \0 */ 746 get_line(int fd, char *buf, int len) 747 { 748 int count = 0, n; 749 struct sigaction sa; 750 751 sa.sa_flags = 0; 752 sigemptyset(&sa.sa_mask); 753 sa.sa_handler = SIG_DFL; 754 sigaction(SIGALRM, &sa, (struct sigaction *)0); 755 do { 756 alarm(10); 757 n = read(fd, buf, len-count); 758 alarm(0); 759 if (n == 0) 760 return (count); 761 if (n < 0) 762 return (-1); 763 while (--n >= 0) { 764 if (*buf == '\r' || *buf == '\n' || *buf == '\0') 765 return (count); 766 count++; 767 buf++; 768 } 769 } while (count < len); 770 return (count); 771 } 772 773 struct servtab * 774 tcpmux(int s) 775 { 776 struct servtab *sep; 777 char service[MAX_SERV_LEN+1]; 778 int len; 779 780 /* Get requested service name */ 781 if ((len = get_line(s, service, MAX_SERV_LEN)) < 0) { 782 strwrite(s, "-Error reading service name\r\n"); 783 return (NULL); 784 } 785 service[len] = '\0'; 786 787 if (debug) 788 warnx("tcpmux: someone wants %s", service); 789 790 /* 791 * Help is a required command, and lists available services, 792 * one per line. 793 */ 794 if (!strcasecmp(service, "help")) { 795 for (sep = servtab; sep; sep = sep->se_next) { 796 if (!ISMUX(sep)) 797 continue; 798 (void)write(s,sep->se_service,strlen(sep->se_service)); 799 strwrite(s, "\r\n"); 800 } 801 return (NULL); 802 } 803 804 /* Try matching a service in inetd.conf with the request */ 805 for (sep = servtab; sep; sep = sep->se_next) { 806 if (!ISMUX(sep)) 807 continue; 808 if (!strcasecmp(service, sep->se_service)) { 809 if (ISMUXPLUS(sep)) { 810 strwrite(s, "+Go\r\n"); 811 } 812 return (sep); 813 } 814 } 815 strwrite(s, "-Service not available\r\n"); 816 return (NULL); 817 } 818