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 <limits.h> 44 #include <pwd.h> 45 #include <signal.h> 46 #include <stdlib.h> 47 #include <string.h> 48 #include <sysexits.h> 49 #include <syslog.h> 50 #include <unistd.h> 51 52 #include "inetd.h" 53 54 extern int debug; 55 extern struct servtab *servtab; 56 57 char ring[128]; 58 char *endring; 59 60 int check_loop __P((struct sockaddr *, struct servtab *sep)); 61 void inetd_setproctitle __P((char *, int)); 62 63 struct biltin biltins[] = { 64 /* Echo received data */ 65 { "echo", SOCK_STREAM, 1, -1, echo_stream }, 66 { "echo", SOCK_DGRAM, 0, 1, echo_dg }, 67 68 /* Internet /dev/null */ 69 { "discard", SOCK_STREAM, 1, -1, discard_stream }, 70 { "discard", SOCK_DGRAM, 0, 1, discard_dg }, 71 72 /* Return 32 bit time since 1970 */ 73 { "time", SOCK_STREAM, 0, -1, machtime_stream }, 74 { "time", SOCK_DGRAM, 0, 1, machtime_dg }, 75 76 /* Return human-readable time */ 77 { "daytime", SOCK_STREAM, 0, -1, daytime_stream }, 78 { "daytime", SOCK_DGRAM, 0, 1, daytime_dg }, 79 80 /* Familiar character generator */ 81 { "chargen", SOCK_STREAM, 1, -1, chargen_stream }, 82 { "chargen", SOCK_DGRAM, 0, 1, chargen_dg }, 83 84 { "tcpmux", SOCK_STREAM, 1, -1, (void (*)())tcpmux }, 85 86 { "auth", SOCK_STREAM, 1, -1, ident_stream }, 87 88 { NULL } 89 }; 90 91 /* 92 * RFC864 Character Generator Protocol. Generates character data without 93 * any regard for input. 94 */ 95 96 void 97 initring() 98 { 99 int i; 100 101 endring = ring; 102 103 for (i = 0; i <= 128; ++i) 104 if (isprint(i)) 105 *endring++ = i; 106 } 107 108 /* ARGSUSED */ 109 void 110 chargen_dg(s, sep) /* Character generator */ 111 int s; 112 struct servtab *sep; 113 { 114 struct sockaddr_storage ss; 115 static char *rs; 116 int len; 117 socklen_t size; 118 char text[LINESIZ+2]; 119 120 if (endring == 0) { 121 initring(); 122 rs = ring; 123 } 124 125 size = sizeof(ss); 126 if (recvfrom(s, text, sizeof(text), 0, 127 (struct sockaddr *)&ss, &size) < 0) 128 return; 129 130 if (check_loop((struct sockaddr *)&ss, sep)) 131 return; 132 133 if ((len = endring - rs) >= LINESIZ) 134 memmove(text, rs, LINESIZ); 135 else { 136 memmove(text, rs, len); 137 memmove(text + len, ring, LINESIZ - len); 138 } 139 if (++rs == endring) 140 rs = ring; 141 text[LINESIZ] = '\r'; 142 text[LINESIZ + 1] = '\n'; 143 (void) sendto(s, text, sizeof(text), 0, (struct sockaddr *)&ss, size); 144 } 145 146 /* ARGSUSED */ 147 void 148 chargen_stream(s, sep) /* Character generator */ 149 int s; 150 struct servtab *sep; 151 { 152 int len; 153 char *rs, text[LINESIZ+2]; 154 155 inetd_setproctitle(sep->se_service, s); 156 157 if (!endring) { 158 initring(); 159 rs = ring; 160 } 161 162 text[LINESIZ] = '\r'; 163 text[LINESIZ + 1] = '\n'; 164 for (rs = ring;;) { 165 if ((len = endring - rs) >= LINESIZ) 166 memmove(text, rs, LINESIZ); 167 else { 168 memmove(text, rs, len); 169 memmove(text + len, ring, LINESIZ - len); 170 } 171 if (++rs == endring) 172 rs = ring; 173 if (write(s, text, sizeof(text)) != sizeof(text)) 174 break; 175 } 176 exit(0); 177 } 178 179 /* 180 * RFC867 Daytime Protocol. Sends the current date and time as an ascii 181 * character string without any regard for input. 182 */ 183 184 /* ARGSUSED */ 185 void 186 daytime_dg(s, sep) /* Return human-readable time of day */ 187 int s; 188 struct servtab *sep; 189 { 190 char buffer[256]; 191 time_t clock; 192 struct sockaddr_storage ss; 193 socklen_t size; 194 195 clock = time((time_t *) 0); 196 197 size = sizeof(ss); 198 if (recvfrom(s, buffer, sizeof(buffer), 0, 199 (struct sockaddr *)&ss, &size) < 0) 200 return; 201 202 if (check_loop((struct sockaddr *)&ss, sep)) 203 return; 204 205 (void) sprintf(buffer, "%.24s\r\n", ctime(&clock)); 206 (void) sendto(s, buffer, strlen(buffer), 0, 207 (struct sockaddr *)&ss, size); 208 } 209 210 /* ARGSUSED */ 211 void 212 daytime_stream(s, sep) /* Return human-readable time of day */ 213 int s; 214 struct servtab *sep; 215 { 216 char buffer[256]; 217 time_t clock; 218 219 clock = time((time_t *) 0); 220 221 (void) sprintf(buffer, "%.24s\r\n", ctime(&clock)); 222 (void) send(s, buffer, strlen(buffer), MSG_EOF); 223 } 224 225 /* 226 * RFC863 Discard Protocol. Any data received is thrown away and no response 227 * is sent. 228 */ 229 230 /* ARGSUSED */ 231 void 232 discard_dg(s, sep) /* Discard service -- ignore data */ 233 int s; 234 struct servtab *sep; 235 { 236 char buffer[BUFSIZE]; 237 238 (void) read(s, buffer, sizeof(buffer)); 239 } 240 241 /* ARGSUSED */ 242 void 243 discard_stream(s, sep) /* Discard service -- ignore data */ 244 int s; 245 struct servtab *sep; 246 { 247 int ret; 248 char buffer[BUFSIZE]; 249 250 inetd_setproctitle(sep->se_service, s); 251 while (1) { 252 while ((ret = read(s, buffer, sizeof(buffer))) > 0) 253 ; 254 if (ret == 0 || errno != EINTR) 255 break; 256 } 257 exit(0); 258 } 259 260 /* 261 * RFC862 Echo Protocol. Any data received is sent back to the sender as 262 * received. 263 */ 264 265 /* ARGSUSED */ 266 void 267 echo_dg(s, sep) /* Echo service -- echo data back */ 268 int s; 269 struct servtab *sep; 270 { 271 char buffer[BUFSIZE]; 272 int i; 273 socklen_t size; 274 struct sockaddr_storage ss; 275 276 size = sizeof(ss); 277 if ((i = recvfrom(s, buffer, sizeof(buffer), 0, 278 (struct sockaddr *)&ss, &size)) < 0) 279 return; 280 281 if (check_loop((struct sockaddr *)&ss, sep)) 282 return; 283 284 (void) sendto(s, buffer, i, 0, (struct sockaddr *)&ss, size); 285 } 286 287 /* ARGSUSED */ 288 void 289 echo_stream(s, sep) /* Echo service -- echo data back */ 290 int s; 291 struct servtab *sep; 292 { 293 char buffer[BUFSIZE]; 294 int i; 295 296 inetd_setproctitle(sep->se_service, s); 297 while ((i = read(s, buffer, sizeof(buffer))) > 0 && 298 write(s, buffer, i) > 0) 299 ; 300 exit(0); 301 } 302 303 /* 304 * RFC1413 Identification Protocol. Given a TCP port number pair, return a 305 * character string which identifies the owner of that connection on the 306 * server's system. Extended to allow for ~/.fakeid support and ~/.noident 307 * support. 308 */ 309 310 /* ARGSUSED */ 311 void 312 iderror(lport, fport, s, er) /* Generic ident_stream error-sending func */ 313 int lport, fport, s, er; 314 { 315 char *p; 316 317 asprintf(&p, "%d , %d : ERROR : %s\r\n", lport, fport, 318 er == -1 ? "HIDDEN-USER" : er ? strerror(er) : "UNKNOWN-ERROR"); 319 if (p == NULL) { 320 syslog(LOG_ERR, "asprintf: %m"); 321 exit(EX_OSERR); 322 } 323 send(s, p, strlen(p), MSG_EOF); 324 free(p); 325 326 exit(0); 327 } 328 329 /* ARGSUSED */ 330 void 331 ident_stream(s, sep) /* Ident service (AKA "auth") */ 332 int s; 333 struct servtab *sep; 334 { 335 struct utsname un; 336 struct stat sb; 337 struct sockaddr_in sin[2]; 338 #ifdef INET6 339 struct sockaddr_in6 sin6[2]; 340 #endif 341 struct sockaddr_storage ss[2]; 342 struct ucred uc; 343 struct timeval tv = { 344 10, 345 0 346 }, to; 347 struct passwd *pw = NULL; 348 fd_set fdset; 349 char buf[BUFSIZE], *cp = NULL, *p, **av, *osname = NULL, garbage[7], e; 350 char *fallback = NULL; 351 socklen_t socklen; 352 ssize_t ssize; 353 size_t size, bufsiz; 354 int c, fflag = 0, nflag = 0, rflag = 0, argc = 0, usedfallback = 0; 355 int gflag = 0, getcredfail = 0, onreadlen; 356 u_short lport, fport; 357 358 inetd_setproctitle(sep->se_service, s); 359 /* 360 * Reset getopt() since we are a fork() but not an exec() from 361 * a parent which used getopt() already. 362 */ 363 optind = 1; 364 optreset = 1; 365 /* 366 * Take the internal argument vector and count it out to make an 367 * argument count for getopt. This can be used for any internal 368 * service to read arguments and use getopt() easily. 369 */ 370 for (av = sep->se_argv; *av; av++) 371 argc++; 372 if (argc) { 373 int sec, usec; 374 size_t i; 375 u_int32_t random; 376 377 while ((c = getopt(argc, sep->se_argv, "d:fgno:rt:")) != -1) 378 switch (c) { 379 case 'd': 380 fallback = optarg; 381 break; 382 case 'f': 383 fflag = 1; 384 break; 385 case 'g': 386 gflag = 1; 387 random = 0; /* Shush, compiler. */ 388 /* 389 * The number of bits in "random" divided 390 * by the number of bits needed per iteration 391 * gives a more optimal way to reload the 392 * random number only when necessary. 393 * 394 * I'm using base-36, so I need at least 6 395 * bits; round it up to 8 bits to make it 396 * easier. 397 */ 398 for (i = 0; i < sizeof(garbage) - 1; i++) { 399 const char *const base36 = 400 "0123456789" 401 "abcdefghijklmnopqrstuvwxyz"; 402 if (i % (sizeof(random) * 8 / 8) == 0) 403 random = arc4random(); 404 garbage[i] = 405 base36[(random & 0xff) % 36]; 406 random >>= 8; 407 } 408 garbage[i] = '\0'; 409 break; 410 case 'n': 411 nflag = 1; 412 break; 413 case 'o': 414 osname = optarg; 415 break; 416 case 'r': 417 rflag = 1; 418 break; 419 case 't': 420 switch (sscanf(optarg, "%d.%d", &sec, &usec)) { 421 case 2: 422 tv.tv_usec = usec; 423 case 1: 424 tv.tv_sec = sec; 425 break; 426 default: 427 if (debug) 428 warnx("bad -t argument"); 429 break; 430 } 431 break; 432 default: 433 break; 434 } 435 } 436 if (osname == NULL) { 437 if (uname(&un) == -1) 438 iderror(0, 0, s, errno); 439 osname = un.sysname; 440 } 441 socklen = sizeof(ss[0]); 442 if (getsockname(s, (struct sockaddr *)&ss[0], &socklen) == -1) 443 iderror(0, 0, s, errno); 444 socklen = sizeof(ss[1]); 445 if (getpeername(s, (struct sockaddr *)&ss[1], &socklen) == -1) 446 iderror(0, 0, s, errno); 447 /* 448 * We're going to prepare for and execute reception of a 449 * packet of data from the user. The data is in the format 450 * "local_port , foreign_port\r\n" (with local being the 451 * server's port and foreign being the client's.) 452 */ 453 gettimeofday(&to, NULL); 454 to.tv_sec += tv.tv_sec; 455 if ((to.tv_usec += tv.tv_usec) >= 1000000) { 456 to.tv_usec -= 1000000; 457 to.tv_sec++; 458 } 459 460 size = 0; 461 bufsiz = sizeof(buf) - 1; 462 FD_ZERO(&fdset); 463 while (bufsiz > 0 && (size == 0 || buf[size - 1] != '\n')) { 464 gettimeofday(&tv, NULL); 465 tv.tv_sec = to.tv_sec - tv.tv_sec; 466 tv.tv_usec = to.tv_usec - tv.tv_usec; 467 if (tv.tv_usec < 0) { 468 tv.tv_usec += 1000000; 469 tv.tv_sec--; 470 } 471 if (tv.tv_sec < 0) 472 break; 473 FD_SET(s, &fdset); 474 if (select(s + 1, &fdset, NULL, NULL, &tv) == -1) 475 iderror(0, 0, s, errno); 476 if (ioctl(s, FIONREAD, &onreadlen) == -1) 477 iderror(0, 0, s, errno); 478 if (onreadlen > bufsiz) 479 onreadlen = bufsiz; 480 ssize = read(s, &buf[size], (size_t)onreadlen); 481 if (ssize == -1) 482 iderror(0, 0, s, errno); 483 bufsiz -= ssize; 484 size += ssize; 485 } 486 buf[size] = '\0'; 487 /* Read two characters, and check for a delimiting character */ 488 if (sscanf(buf, "%hu , %hu%c", &lport, &fport, &e) != 3 || isdigit(e)) 489 iderror(0, 0, s, 0); 490 if (gflag) { 491 cp = garbage; 492 goto printit; 493 } 494 495 /* 496 * If not "real" (-r), send a HIDDEN-USER error for everything. 497 * If -d is used to set a fallback username, this is used to 498 * override it, and the fallback is returned instead. 499 */ 500 if (!rflag) { 501 if (fallback == NULL) 502 iderror(lport, fport, s, -1); 503 else { 504 cp = fallback; 505 goto printit; 506 } 507 } 508 509 /* 510 * We take the input and construct an array of two sockaddr_ins 511 * which contain the local address information and foreign 512 * address information, respectively, used to look up the 513 * credentials for the socket (which are returned by the 514 * sysctl "net.inet.tcp.getcred" when we call it.) The 515 * arrays have been filled in above via get{peer,sock}name(), 516 * so right here we are only setting the ports. 517 */ 518 if (ss[0].ss_family != ss[1].ss_family) 519 iderror(lport, fport, s, errno); 520 size = sizeof(uc); 521 switch (ss[0].ss_family) { 522 case AF_INET: 523 sin[0] = *(struct sockaddr_in *)&ss[0]; 524 sin[0].sin_port = htons(lport); 525 sin[1] = *(struct sockaddr_in *)&ss[1]; 526 sin[1].sin_port = htons(fport); 527 if (sysctlbyname("net.inet.tcp.getcred", &uc, &size, sin, 528 sizeof(sin)) == -1) 529 getcredfail = 1; 530 break; 531 #ifdef INET6 532 case AF_INET6: 533 sin6[0] = *(struct sockaddr_in6 *)&ss[0]; 534 sin6[0].sin6_port = htons(lport); 535 sin6[1] = *(struct sockaddr_in6 *)&ss[1]; 536 sin6[1].sin6_port = htons(fport); 537 if (sysctlbyname("net.inet6.tcp6.getcred", &uc, &size, sin6, 538 sizeof(sin6)) == -1) 539 getcredfail = 1; 540 break; 541 #endif 542 default: /* should not reach here */ 543 getcredfail = 1; 544 break; 545 } 546 if (getcredfail != 0) { 547 if (fallback == NULL) /* Use a default, if asked to */ 548 iderror(lport, fport, s, errno); 549 usedfallback = 1; 550 } else { 551 /* Look up the pw to get the username */ 552 pw = getpwuid(uc.cr_uid); 553 } 554 if (pw == NULL && !usedfallback) /* No such user... */ 555 iderror(lport, fport, s, errno); 556 /* 557 * If enabled, we check for a file named ".noident" in the user's 558 * home directory. If found, we return HIDDEN-USER. 559 */ 560 if (nflag && !usedfallback) { 561 if (asprintf(&p, "%s/.noident", pw->pw_dir) == -1) 562 iderror(lport, fport, s, errno); 563 if (lstat(p, &sb) == 0) { 564 free(p); 565 iderror(lport, fport, s, -1); 566 } 567 free(p); 568 } 569 /* 570 * Here, if enabled, we read a user's ".fakeid" file in their 571 * home directory. It consists of a line containing the name 572 * they want. 573 */ 574 if (fflag && !usedfallback) { 575 FILE *fakeid = NULL; 576 577 if (asprintf(&p, "%s/.fakeid", pw->pw_dir) == -1) 578 iderror(lport, fport, s, errno); 579 /* 580 * Here we set ourself to effectively be the user, so we don't 581 * open any files we have no permission to open, especially 582 * symbolic links to sensitive root-owned files or devices. 583 */ 584 seteuid(pw->pw_uid); 585 setegid(pw->pw_gid); 586 /* 587 * If we were to lstat() here, it would do no good, since it 588 * would introduce a race condition and could be defeated. 589 * Therefore, we open the file we have permissions to open 590 * and if it's not a regular file, we close it and end up 591 * returning the user's real username. 592 */ 593 fakeid = fopen(p, "r"); 594 free(p); 595 if (fakeid != NULL && 596 fstat(fileno(fakeid), &sb) != -1 && S_ISREG(sb.st_mode)) { 597 buf[sizeof(buf) - 1] = '\0'; 598 if (fgets(buf, sizeof(buf), fakeid) == NULL) { 599 cp = pw->pw_name; 600 fclose(fakeid); 601 goto printit; 602 } 603 fclose(fakeid); 604 /* 605 * Usually, the file will have the desired identity 606 * in the form "identity\n", so we use strtok() to 607 * end the string (which fgets() doesn't do.) 608 */ 609 buf[strcspn(buf, "\r\n")] = '\0'; 610 cp = buf; 611 /* Allow for beginning white space... */ 612 while (isspace(*cp)) 613 cp++; 614 /* ...and ending white space. */ 615 cp[strcspn(cp, " \t")] = '\0'; 616 /* User names of >16 characters are invalid */ 617 if (strlen(cp) > 16) 618 cp[16] = '\0'; 619 /* 620 * If the name is a zero-length string or matches 621 * the name of another user, it's invalid, so 622 * we will return their real identity instead. 623 */ 624 625 if (!*cp || getpwnam(cp)) 626 cp = getpwuid(uc.cr_uid)->pw_name; 627 } else 628 cp = pw->pw_name; 629 } else if (!usedfallback) 630 cp = pw->pw_name; 631 else 632 cp = fallback; 633 printit: 634 /* Finally, we make and send the reply. */ 635 if (asprintf(&p, "%d , %d : USERID : %s : %s\r\n", lport, fport, osname, 636 cp) == -1) { 637 syslog(LOG_ERR, "asprintf: %m"); 638 exit(EX_OSERR); 639 } 640 send(s, p, strlen(p), MSG_EOF); 641 free(p); 642 643 exit(0); 644 } 645 646 /* 647 * RFC738 Time Server. 648 * Return a machine readable date and time, in the form of the 649 * number of seconds since midnight, Jan 1, 1900. Since gettimeofday 650 * returns the number of seconds since midnight, Jan 1, 1970, 651 * we must add 2208988800 seconds to this figure to make up for 652 * some seventy years Bell Labs was asleep. 653 */ 654 655 unsigned long 656 machtime() 657 { 658 struct timeval tv; 659 660 if (gettimeofday(&tv, (struct timezone *)NULL) < 0) { 661 if (debug) 662 warnx("unable to get time of day"); 663 return (0L); 664 } 665 #define OFFSET ((u_long)25567 * 24*60*60) 666 return (htonl((long)(tv.tv_sec + OFFSET))); 667 #undef OFFSET 668 } 669 670 /* ARGSUSED */ 671 void 672 machtime_dg(s, sep) 673 int s; 674 struct servtab *sep; 675 { 676 unsigned long result; 677 struct sockaddr_storage ss; 678 socklen_t size; 679 680 size = sizeof(ss); 681 if (recvfrom(s, (char *)&result, sizeof(result), 0, 682 (struct sockaddr *)&ss, &size) < 0) 683 return; 684 685 if (check_loop((struct sockaddr *)&ss, sep)) 686 return; 687 688 result = machtime(); 689 (void) sendto(s, (char *) &result, sizeof(result), 0, 690 (struct sockaddr *)&ss, size); 691 } 692 693 /* ARGSUSED */ 694 void 695 machtime_stream(s, sep) 696 int s; 697 struct servtab *sep; 698 { 699 unsigned long result; 700 701 result = machtime(); 702 (void) send(s, (char *) &result, sizeof(result), MSG_EOF); 703 } 704 705 /* 706 * RFC1078 TCP Port Service Multiplexer (TCPMUX). Service connections to 707 * services based on the service name sent. 708 * 709 * Based on TCPMUX.C by Mark K. Lottor November 1988 710 * sri-nic::ps:<mkl>tcpmux.c 711 */ 712 713 #define MAX_SERV_LEN (256+2) /* 2 bytes for \r\n */ 714 #define strwrite(fd, buf) (void) write(fd, buf, sizeof(buf)-1) 715 716 static int /* # of characters upto \r,\n or \0 */ 717 getline(fd, buf, len) 718 int fd; 719 char *buf; 720 int len; 721 { 722 int count = 0, n; 723 struct sigaction sa; 724 725 sa.sa_flags = 0; 726 sigemptyset(&sa.sa_mask); 727 sa.sa_handler = SIG_DFL; 728 sigaction(SIGALRM, &sa, (struct sigaction *)0); 729 do { 730 alarm(10); 731 n = read(fd, buf, len-count); 732 alarm(0); 733 if (n == 0) 734 return (count); 735 if (n < 0) 736 return (-1); 737 while (--n >= 0) { 738 if (*buf == '\r' || *buf == '\n' || *buf == '\0') 739 return (count); 740 count++; 741 buf++; 742 } 743 } while (count < len); 744 return (count); 745 } 746 747 struct servtab * 748 tcpmux(s) 749 int s; 750 { 751 struct servtab *sep; 752 char service[MAX_SERV_LEN+1]; 753 int len; 754 755 /* Get requested service name */ 756 if ((len = getline(s, service, MAX_SERV_LEN)) < 0) { 757 strwrite(s, "-Error reading service name\r\n"); 758 return (NULL); 759 } 760 service[len] = '\0'; 761 762 if (debug) 763 warnx("tcpmux: someone wants %s", service); 764 765 /* 766 * Help is a required command, and lists available services, 767 * one per line. 768 */ 769 if (!strcasecmp(service, "help")) { 770 for (sep = servtab; sep; sep = sep->se_next) { 771 if (!ISMUX(sep)) 772 continue; 773 (void)write(s,sep->se_service,strlen(sep->se_service)); 774 strwrite(s, "\r\n"); 775 } 776 return (NULL); 777 } 778 779 /* Try matching a service in inetd.conf with the request */ 780 for (sep = servtab; sep; sep = sep->se_next) { 781 if (!ISMUX(sep)) 782 continue; 783 if (!strcasecmp(service, sep->se_service)) { 784 if (ISMUXPLUS(sep)) { 785 strwrite(s, "+Go\r\n"); 786 } 787 return (sep); 788 } 789 } 790 strwrite(s, "-Service not available\r\n"); 791 return (NULL); 792 } 793