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: src/usr.sbin/inetd/builtins.c,v 1.19.2.7 2002/07/22 14:05:56 fanf Exp $ 27 * $DragonFly: src/usr.sbin/inetd/builtins.c,v 1.3 2003/11/03 19:31:37 eirikn Exp $ 28 * 29 */ 30 31 #include <sys/filio.h> 32 #include <sys/ioccom.h> 33 #include <sys/param.h> 34 #include <sys/stat.h> 35 #include <sys/socket.h> 36 #include <sys/sysctl.h> 37 #include <sys/ucred.h> 38 #include <sys/uio.h> 39 #include <sys/utsname.h> 40 41 #include <ctype.h> 42 #include <err.h> 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <limits.h> 46 #include <pwd.h> 47 #include <signal.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <sysexits.h> 51 #include <syslog.h> 52 #include <unistd.h> 53 54 #include "inetd.h" 55 56 void chargen_dg(int, struct servtab *); 57 void chargen_stream(int, struct servtab *); 58 void daytime_dg(int, struct servtab *); 59 void daytime_stream(int, struct servtab *); 60 void discard_dg(int, struct servtab *); 61 void discard_stream(int, struct servtab *); 62 void echo_dg(int, struct servtab *); 63 void echo_stream(int, struct servtab *); 64 static int getline(int, char *, int); 65 void iderror(int, int, int, const char *); 66 void ident_stream(int, struct servtab *); 67 void initring(void); 68 unsigned long machtime(void); 69 void machtime_dg(int, struct servtab *); 70 void machtime_stream(int, struct servtab *); 71 72 char ring[128]; 73 char *endring; 74 75 76 struct biltin biltins[] = { 77 /* Echo received data */ 78 { "echo", SOCK_STREAM, 1, -1, echo_stream }, 79 { "echo", SOCK_DGRAM, 0, 1, echo_dg }, 80 81 /* Internet /dev/null */ 82 { "discard", SOCK_STREAM, 1, -1, discard_stream }, 83 { "discard", SOCK_DGRAM, 0, 1, discard_dg }, 84 85 /* Return 32 bit time since 1900 */ 86 { "time", SOCK_STREAM, 0, -1, machtime_stream }, 87 { "time", SOCK_DGRAM, 0, 1, machtime_dg }, 88 89 /* Return human-readable time */ 90 { "daytime", SOCK_STREAM, 0, -1, daytime_stream }, 91 { "daytime", SOCK_DGRAM, 0, 1, daytime_dg }, 92 93 /* Familiar character generator */ 94 { "chargen", SOCK_STREAM, 1, -1, chargen_stream }, 95 { "chargen", SOCK_DGRAM, 0, 1, chargen_dg }, 96 97 { "tcpmux", SOCK_STREAM, 1, -1, (bi_fn_t *)tcpmux }, 98 99 { "auth", SOCK_STREAM, 1, -1, ident_stream }, 100 101 { NULL, 0, 0, 0, NULL } 102 }; 103 104 /* 105 * RFC864 Character Generator Protocol. Generates character data without 106 * any regard for input. 107 */ 108 109 void 110 initring() 111 { 112 int i; 113 114 endring = ring; 115 116 for (i = 0; i <= 128; ++i) 117 if (isprint(i)) 118 *endring++ = i; 119 } 120 121 /* ARGSUSED */ 122 void 123 chargen_dg(s, sep) /* Character generator */ 124 int s; 125 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 == 0) { 134 initring(); 135 rs = ring; 136 } 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 /* ARGSUSED */ 160 void 161 chargen_stream(s, sep) /* Character generator */ 162 int s; 163 struct servtab *sep; 164 { 165 int len; 166 char *rs, text[LINESIZ+2]; 167 168 inetd_setproctitle(sep->se_service, s); 169 170 if (!endring) { 171 initring(); 172 rs = ring; 173 } 174 175 text[LINESIZ] = '\r'; 176 text[LINESIZ + 1] = '\n'; 177 for (rs = ring;;) { 178 if ((len = endring - rs) >= LINESIZ) 179 memmove(text, rs, LINESIZ); 180 else { 181 memmove(text, rs, len); 182 memmove(text + len, ring, LINESIZ - len); 183 } 184 if (++rs == endring) 185 rs = ring; 186 if (write(s, text, sizeof(text)) != sizeof(text)) 187 break; 188 } 189 exit(0); 190 } 191 192 /* 193 * RFC867 Daytime Protocol. Sends the current date and time as an ascii 194 * character string without any regard for input. 195 */ 196 197 /* ARGSUSED */ 198 void 199 daytime_dg(s, sep) /* Return human-readable time of day */ 200 int s; 201 struct servtab *sep; 202 { 203 char buffer[256]; 204 time_t now; 205 struct sockaddr_storage ss; 206 socklen_t size; 207 208 now = time((time_t *) 0); 209 210 size = sizeof(ss); 211 if (recvfrom(s, buffer, sizeof(buffer), 0, 212 (struct sockaddr *)&ss, &size) < 0) 213 return; 214 215 if (check_loop((struct sockaddr *)&ss, sep)) 216 return; 217 218 (void) sprintf(buffer, "%.24s\r\n", ctime(&now)); 219 (void) sendto(s, buffer, strlen(buffer), 0, 220 (struct sockaddr *)&ss, size); 221 } 222 223 /* ARGSUSED */ 224 void 225 daytime_stream(s, sep) /* Return human-readable time of day */ 226 int s; 227 struct servtab *sep __unused; 228 { 229 char buffer[256]; 230 time_t now; 231 232 now = time((time_t *) 0); 233 234 (void) sprintf(buffer, "%.24s\r\n", ctime(&now)); 235 (void) send(s, buffer, strlen(buffer), MSG_EOF); 236 } 237 238 /* 239 * RFC863 Discard Protocol. Any data received is thrown away and no response 240 * is sent. 241 */ 242 243 /* ARGSUSED */ 244 void 245 discard_dg(s, sep) /* Discard service -- ignore data */ 246 int s; 247 struct servtab *sep __unused; 248 { 249 char buffer[BUFSIZE]; 250 251 (void) read(s, buffer, sizeof(buffer)); 252 } 253 254 /* ARGSUSED */ 255 void 256 discard_stream(s, sep) /* Discard service -- ignore data */ 257 int s; 258 struct servtab *sep; 259 { 260 int ret; 261 char buffer[BUFSIZE]; 262 263 inetd_setproctitle(sep->se_service, s); 264 while (1) { 265 while ((ret = read(s, buffer, sizeof(buffer))) > 0) 266 ; 267 if (ret == 0 || errno != EINTR) 268 break; 269 } 270 exit(0); 271 } 272 273 /* 274 * RFC862 Echo Protocol. Any data received is sent back to the sender as 275 * received. 276 */ 277 278 /* ARGSUSED */ 279 void 280 echo_dg(s, sep) /* Echo service -- echo data back */ 281 int s; 282 struct servtab *sep; 283 { 284 char buffer[65536]; /* Should be sizeof(max datagram). */ 285 int i; 286 socklen_t size; 287 struct sockaddr_storage ss; 288 289 size = sizeof(ss); 290 if ((i = recvfrom(s, buffer, sizeof(buffer), 0, 291 (struct sockaddr *)&ss, &size)) < 0) 292 return; 293 294 if (check_loop((struct sockaddr *)&ss, sep)) 295 return; 296 297 (void) sendto(s, buffer, i, 0, (struct sockaddr *)&ss, size); 298 } 299 300 /* ARGSUSED */ 301 void 302 echo_stream(s, sep) /* Echo service -- echo data back */ 303 int s; 304 struct servtab *sep; 305 { 306 char buffer[BUFSIZE]; 307 int i; 308 309 inetd_setproctitle(sep->se_service, s); 310 while ((i = read(s, buffer, sizeof(buffer))) > 0 && 311 write(s, buffer, i) > 0) 312 ; 313 exit(0); 314 } 315 316 /* 317 * RFC1413 Identification Protocol. Given a TCP port number pair, return a 318 * character string which identifies the owner of that connection on the 319 * server's system. Extended to allow for ~/.fakeid support and ~/.noident 320 * support. 321 */ 322 323 /* RFC 1413 says the following are the only errors you can return. */ 324 #define ID_INVALID "INVALID-PORT" /* Port number improperly specified. */ 325 #define ID_NOUSER "NO-USER" /* Port not in use/not identifable. */ 326 #define ID_HIDDEN "HIDDEN-USER" /* Hiden at user's request. */ 327 #define ID_UNKNOWN "UNKNOWN-ERROR" /* Everything else. */ 328 329 /* ARGSUSED */ 330 void 331 iderror(lport, fport, s, er) /* Generic ident_stream error-sending func */ 332 int lport, fport, s; 333 const char *er; 334 { 335 char *p; 336 337 asprintf(&p, "%d , %d : ERROR : %s\r\n", lport, fport, er); 338 if (p == NULL) { 339 syslog(LOG_ERR, "asprintf: %m"); 340 exit(EX_OSERR); 341 } 342 send(s, p, strlen(p), MSG_EOF); 343 free(p); 344 345 exit(0); 346 } 347 348 /* ARGSUSED */ 349 void 350 ident_stream(s, sep) /* Ident service (AKA "auth") */ 351 int s; 352 struct servtab *sep; 353 { 354 struct utsname un; 355 struct stat sb; 356 struct sockaddr_in sin4[2]; 357 #ifdef INET6 358 struct sockaddr_in6 sin6[2]; 359 #endif 360 struct sockaddr_storage ss[2]; 361 struct ucred uc; 362 struct timeval tv = { 363 10, 364 0 365 }, to; 366 struct passwd *pw = NULL; 367 fd_set fdset; 368 char buf[BUFSIZE], *p, **av, *osname = NULL, e; 369 char idbuf[MAXLOGNAME] = ""; /* Big enough to hold uid in decimal. */ 370 socklen_t socklen; 371 ssize_t ssize; 372 size_t size, bufsiz; 373 int c, fflag = 0, nflag = 0, rflag = 0, argc = 0; 374 int gflag = 0, iflag = 0, Fflag = 0, getcredfail = 0, onreadlen; 375 u_short lport, fport; 376 377 inetd_setproctitle(sep->se_service, s); 378 /* 379 * Reset getopt() since we are a fork() but not an exec() from 380 * a parent which used getopt() already. 381 */ 382 optind = 1; 383 optreset = 1; 384 /* 385 * Take the internal argument vector and count it out to make an 386 * argument count for getopt. This can be used for any internal 387 * service to read arguments and use getopt() easily. 388 */ 389 for (av = sep->se_argv; *av; av++) 390 argc++; 391 if (argc) { 392 int sec, usec; 393 size_t i; 394 u_int32_t rnd32; 395 396 while ((c = getopt(argc, sep->se_argv, "d:fFgino:rt:")) != -1) 397 switch (c) { 398 case 'd': 399 if (!gflag) 400 strlcpy(idbuf, optarg, sizeof(idbuf)); 401 break; 402 case 'f': 403 fflag = 1; 404 break; 405 case 'F': 406 fflag = 1; 407 Fflag=1; 408 break; 409 case 'g': 410 gflag = 1; 411 rnd32 = 0; /* Shush, compiler. */ 412 /* 413 * The number of bits in "rnd32" divided 414 * by the number of bits needed per iteration 415 * gives a more optimal way to reload the 416 * random number only when necessary. 417 * 418 * 32 bits from arc4random corresponds to 419 * about 6 base-36 digits, so we reseed evey 6. 420 */ 421 for (i = 0; i < sizeof(idbuf) - 1; i++) { 422 static const char *const base36 = 423 "0123456789" 424 "abcdefghijklmnopqrstuvwxyz"; 425 if (i % 6 == 0) 426 rnd32 = arc4random(); 427 idbuf[i] = base36[rnd32 % 36]; 428 rnd32 /= 36; 429 } 430 idbuf[i] = '\0'; 431 break; 432 case 'i': 433 iflag = 1; 434 break; 435 case 'n': 436 nflag = 1; 437 break; 438 case 'o': 439 osname = optarg; 440 break; 441 case 'r': 442 rflag = 1; 443 break; 444 case 't': 445 switch (sscanf(optarg, "%d.%d", &sec, &usec)) { 446 case 2: 447 tv.tv_usec = usec; 448 /* FALLTHROUGH */ 449 case 1: 450 tv.tv_sec = sec; 451 break; 452 default: 453 if (debug) 454 warnx("bad -t argument"); 455 break; 456 } 457 break; 458 default: 459 break; 460 } 461 } 462 if (osname == NULL) { 463 if (uname(&un) == -1) 464 iderror(0, 0, s, ID_UNKNOWN); 465 osname = un.sysname; 466 } 467 468 /* 469 * We're going to prepare for and execute reception of a 470 * packet of data from the user. The data is in the format 471 * "local_port , foreign_port\r\n" (with local being the 472 * server's port and foreign being the client's.) 473 */ 474 gettimeofday(&to, NULL); 475 to.tv_sec += tv.tv_sec; 476 to.tv_usec += tv.tv_usec; 477 if (to.tv_usec >= 1000000) { 478 to.tv_usec -= 1000000; 479 to.tv_sec++; 480 } 481 482 size = 0; 483 bufsiz = sizeof(buf) - 1; 484 FD_ZERO(&fdset); 485 while (bufsiz > 0) { 486 gettimeofday(&tv, NULL); 487 tv.tv_sec = to.tv_sec - tv.tv_sec; 488 tv.tv_usec = to.tv_usec - tv.tv_usec; 489 if (tv.tv_usec < 0) { 490 tv.tv_usec += 1000000; 491 tv.tv_sec--; 492 } 493 if (tv.tv_sec < 0) 494 break; 495 FD_SET(s, &fdset); 496 if (select(s + 1, &fdset, NULL, NULL, &tv) == -1) 497 iderror(0, 0, s, ID_UNKNOWN); 498 if (ioctl(s, FIONREAD, &onreadlen) == -1) 499 iderror(0, 0, s, ID_UNKNOWN); 500 if ((size_t)onreadlen > bufsiz) 501 onreadlen = bufsiz; 502 ssize = read(s, &buf[size], (size_t)onreadlen); 503 if (ssize == -1) 504 iderror(0, 0, s, ID_UNKNOWN); 505 else if (ssize == 0) 506 break; 507 bufsiz -= ssize; 508 size += ssize; 509 if (memchr(&buf[size - ssize], '\n', ssize) != NULL) 510 break; 511 } 512 buf[size] = '\0'; 513 /* Read two characters, and check for a delimiting character */ 514 if (sscanf(buf, "%hu , %hu%c", &lport, &fport, &e) != 3 || isdigit(e)) 515 iderror(0, 0, s, ID_INVALID); 516 517 /* Send garbage? */ 518 if (gflag) 519 goto printit; 520 521 /* 522 * If not "real" (-r), send a HIDDEN-USER error for everything. 523 * If -d is used to set a fallback username, this is used to 524 * override it, and the fallback is returned instead. 525 */ 526 if (!rflag) { 527 if (*idbuf == '\0') 528 iderror(lport, fport, s, ID_HIDDEN); 529 goto printit; 530 } 531 532 /* 533 * We take the input and construct an array of two sockaddr_ins 534 * which contain the local address information and foreign 535 * address information, respectively, used to look up the 536 * credentials for the socket (which are returned by the 537 * sysctl "net.inet.tcp.getcred" when we call it.) 538 */ 539 socklen = sizeof(ss[0]); 540 if (getsockname(s, (struct sockaddr *)&ss[0], &socklen) == -1) 541 iderror(lport, fport, s, ID_UNKNOWN); 542 socklen = sizeof(ss[1]); 543 if (getpeername(s, (struct sockaddr *)&ss[1], &socklen) == -1) 544 iderror(lport, fport, s, ID_UNKNOWN); 545 if (ss[0].ss_family != ss[1].ss_family) 546 iderror(lport, fport, s, ID_UNKNOWN); 547 size = sizeof(uc); 548 switch (ss[0].ss_family) { 549 case AF_INET: 550 sin4[0] = *(struct sockaddr_in *)&ss[0]; 551 sin4[0].sin_port = htons(lport); 552 sin4[1] = *(struct sockaddr_in *)&ss[1]; 553 sin4[1].sin_port = htons(fport); 554 if (sysctlbyname("net.inet.tcp.getcred", &uc, &size, sin4, 555 sizeof(sin4)) == -1) 556 getcredfail = errno; 557 break; 558 #ifdef INET6 559 case AF_INET6: 560 sin6[0] = *(struct sockaddr_in6 *)&ss[0]; 561 sin6[0].sin6_port = htons(lport); 562 sin6[1] = *(struct sockaddr_in6 *)&ss[1]; 563 sin6[1].sin6_port = htons(fport); 564 if (sysctlbyname("net.inet6.tcp6.getcred", &uc, &size, sin6, 565 sizeof(sin6)) == -1) 566 getcredfail = errno; 567 break; 568 #endif 569 default: /* should not reach here */ 570 getcredfail = EAFNOSUPPORT; 571 break; 572 } 573 if (getcredfail != 0) { 574 if (*idbuf == '\0') 575 iderror(lport, fport, s, 576 getcredfail == ENOENT ? ID_NOUSER : ID_UNKNOWN); 577 goto printit; 578 } 579 580 /* Look up the pw to get the username and home directory*/ 581 errno = 0; 582 pw = getpwuid(uc.cr_uid); 583 if (pw == NULL) 584 iderror(lport, fport, s, errno == 0 ? ID_NOUSER : ID_UNKNOWN); 585 586 if (iflag) 587 snprintf(idbuf, sizeof(idbuf), "%u", (unsigned)pw->pw_uid); 588 else 589 strlcpy(idbuf, pw->pw_name, sizeof(idbuf)); 590 591 /* 592 * If enabled, we check for a file named ".noident" in the user's 593 * home directory. If found, we return HIDDEN-USER. 594 */ 595 if (nflag) { 596 if (asprintf(&p, "%s/.noident", pw->pw_dir) == -1) 597 iderror(lport, fport, s, ID_UNKNOWN); 598 if (lstat(p, &sb) == 0) { 599 free(p); 600 iderror(lport, fport, s, ID_HIDDEN); 601 } 602 free(p); 603 } 604 605 /* 606 * Here, if enabled, we read a user's ".fakeid" file in their 607 * home directory. It consists of a line containing the name 608 * they want. 609 */ 610 if (fflag) { 611 int fakeid_fd; 612 613 /* 614 * Here we set ourself to effectively be the user, so we don't 615 * open any files we have no permission to open, especially 616 * symbolic links to sensitive root-owned files or devices. 617 */ 618 if (initgroups(pw->pw_name, pw->pw_gid) == -1) 619 iderror(lport, fport, s, ID_UNKNOWN); 620 if (seteuid(pw->pw_uid) == -1) 621 iderror(lport, fport, s, ID_UNKNOWN); 622 /* 623 * We can't stat() here since that would be a race 624 * condition. 625 * Therefore, we open the file we have permissions to open 626 * and if it's not a regular file, we close it and end up 627 * returning the user's real username. 628 */ 629 if (asprintf(&p, "%s/.fakeid", pw->pw_dir) == -1) 630 iderror(lport, fport, s, ID_UNKNOWN); 631 fakeid_fd = open(p, O_RDONLY | O_NONBLOCK); 632 free(p); 633 if (fakeid_fd == -1 || fstat(fakeid_fd, &sb) == -1 || 634 !S_ISREG(sb.st_mode)) 635 goto fakeid_fail; 636 637 if ((ssize = read(fakeid_fd, buf, sizeof(buf) - 1)) < 0) 638 goto fakeid_fail; 639 buf[ssize] = '\0'; 640 641 /* 642 * Usually, the file will have the desired identity 643 * in the form "identity\n". Allow for leading white 644 * space and trailing white space/end of line. 645 */ 646 p = buf; 647 p += strspn(p, " \t"); 648 p[strcspn(p, " \t\r\n")] = '\0'; 649 if (strlen(p) > MAXLOGNAME - 1) /* Too long (including nul)? */ 650 p[MAXLOGNAME - 1] = '\0'; 651 652 /* 653 * If the name is a zero-length string or matches it 654 * the id or name of another user (unless permitted by -F) 655 * then it is invalid. 656 */ 657 if (*p == '\0') 658 goto fakeid_fail; 659 if (!Fflag) { 660 if (iflag) { 661 if (p[strspn(p, "0123456789")] == '\0' && 662 getpwuid(atoi(p)) != NULL) 663 goto fakeid_fail; 664 } else { 665 if (getpwnam(p) != NULL) 666 goto fakeid_fail; 667 } 668 } 669 670 strlcpy(idbuf, p, sizeof(idbuf)); 671 672 fakeid_fail: 673 if (fakeid_fd != -1) 674 close(fakeid_fd); 675 } 676 677 printit: 678 /* Finally, we make and send the reply. */ 679 if (asprintf(&p, "%d , %d : USERID : %s : %s\r\n", lport, fport, osname, 680 idbuf) == -1) { 681 syslog(LOG_ERR, "asprintf: %m"); 682 exit(EX_OSERR); 683 } 684 send(s, p, strlen(p), MSG_EOF); 685 free(p); 686 687 exit(0); 688 } 689 690 /* 691 * RFC738 Time Server. 692 * Return a machine readable date and time, in the form of the 693 * number of seconds since midnight, Jan 1, 1900. Since gettimeofday 694 * returns the number of seconds since midnight, Jan 1, 1970, 695 * we must add 2208988800 seconds to this figure to make up for 696 * some seventy years Bell Labs was asleep. 697 */ 698 699 unsigned long 700 machtime() 701 { 702 struct timeval tv; 703 704 if (gettimeofday(&tv, (struct timezone *)NULL) < 0) { 705 if (debug) 706 warnx("unable to get time of day"); 707 return (0L); 708 } 709 #define OFFSET ((u_long)25567 * 24*60*60) 710 return (htonl((long)(tv.tv_sec + OFFSET))); 711 #undef OFFSET 712 } 713 714 /* ARGSUSED */ 715 void 716 machtime_dg(s, sep) 717 int s; 718 struct servtab *sep; 719 { 720 unsigned long result; 721 struct sockaddr_storage ss; 722 socklen_t size; 723 724 size = sizeof(ss); 725 if (recvfrom(s, (char *)&result, sizeof(result), 0, 726 (struct sockaddr *)&ss, &size) < 0) 727 return; 728 729 if (check_loop((struct sockaddr *)&ss, sep)) 730 return; 731 732 result = machtime(); 733 (void) sendto(s, (char *) &result, sizeof(result), 0, 734 (struct sockaddr *)&ss, size); 735 } 736 737 /* ARGSUSED */ 738 void 739 machtime_stream(s, sep) 740 int s; 741 struct servtab *sep __unused; 742 { 743 unsigned long result; 744 745 result = machtime(); 746 (void) send(s, (char *) &result, sizeof(result), MSG_EOF); 747 } 748 749 /* 750 * RFC1078 TCP Port Service Multiplexer (TCPMUX). Service connections to 751 * services based on the service name sent. 752 * 753 * Based on TCPMUX.C by Mark K. Lottor November 1988 754 * sri-nic::ps:<mkl>tcpmux.c 755 */ 756 757 #define MAX_SERV_LEN (256+2) /* 2 bytes for \r\n */ 758 #define strwrite(fd, buf) (void) write(fd, buf, sizeof(buf)-1) 759 760 static int /* # of characters upto \r,\n or \0 */ 761 getline(fd, buf, len) 762 int fd; 763 char *buf; 764 int len; 765 { 766 int count = 0, n; 767 struct sigaction sa; 768 769 sa.sa_flags = 0; 770 sigemptyset(&sa.sa_mask); 771 sa.sa_handler = SIG_DFL; 772 sigaction(SIGALRM, &sa, (struct sigaction *)0); 773 do { 774 alarm(10); 775 n = read(fd, buf, len-count); 776 alarm(0); 777 if (n == 0) 778 return (count); 779 if (n < 0) 780 return (-1); 781 while (--n >= 0) { 782 if (*buf == '\r' || *buf == '\n' || *buf == '\0') 783 return (count); 784 count++; 785 buf++; 786 } 787 } while (count < len); 788 return (count); 789 } 790 791 struct servtab * 792 tcpmux(s) 793 int s; 794 { 795 struct servtab *sep; 796 char service[MAX_SERV_LEN+1]; 797 int len; 798 799 /* Get requested service name */ 800 if ((len = getline(s, service, MAX_SERV_LEN)) < 0) { 801 strwrite(s, "-Error reading service name\r\n"); 802 return (NULL); 803 } 804 service[len] = '\0'; 805 806 if (debug) 807 warnx("tcpmux: someone wants %s", service); 808 809 /* 810 * Help is a required command, and lists available services, 811 * one per line. 812 */ 813 if (!strcasecmp(service, "help")) { 814 for (sep = servtab; sep; sep = sep->se_next) { 815 if (!ISMUX(sep)) 816 continue; 817 (void)write(s,sep->se_service,strlen(sep->se_service)); 818 strwrite(s, "\r\n"); 819 } 820 return (NULL); 821 } 822 823 /* Try matching a service in inetd.conf with the request */ 824 for (sep = servtab; sep; sep = sep->se_next) { 825 if (!ISMUX(sep)) 826 continue; 827 if (!strcasecmp(service, sep->se_service)) { 828 if (ISMUXPLUS(sep)) { 829 strwrite(s, "+Go\r\n"); 830 } 831 return (sep); 832 } 833 } 834 strwrite(s, "-Service not available\r\n"); 835 return (NULL); 836 } 837