1/* vi: set sw=4 ts=4: */ 2/* $Slackware: inetd.c 1.79s 2001/02/06 13:18:00 volkerdi Exp $ */ 3/* $OpenBSD: inetd.c,v 1.79 2001/01/30 08:30:57 deraadt Exp $ */ 4/* $NetBSD: inetd.c,v 1.11 1996/02/22 11:14:41 mycroft Exp $ */ 5/* Busybox port by Vladimir Oleynik (C) 2001-2005 <dzo@simtreas.ru> */ 6/* 7 * Copyright (c) 1983,1991 The Regents of the University of California. 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39/* Inetd - Internet super-server 40 * 41 * This program invokes all internet services as needed. 42 * connection-oriented services are invoked each time a 43 * connection is made, by creating a process. This process 44 * is passed the connection as file descriptor 0 and is 45 * expected to do a getpeername to find out the source host 46 * and port. 47 * 48 * Datagram oriented services are invoked when a datagram 49 * arrives; a process is created and passed a pending message 50 * on file descriptor 0. Datagram servers may either connect 51 * to their peer, freeing up the original socket for inetd 52 * to receive further messages on, or "take over the socket", 53 * processing all arriving datagrams and, eventually, timing 54 * out. The first type of server is said to be "multi-threaded"; 55 * the second type of server "single-threaded". 56 * 57 * Inetd uses a configuration file which is read at startup 58 * and, possibly, at some later time in response to a hangup signal. 59 * The configuration file is "free format" with fields given in the 60 * order shown below. Continuation lines for an entry must begin with 61 * a space or tab. All fields must be present in each entry. 62 * 63 * service name must be in /etc/services 64 * socket type stream/dgram/raw/rdm/seqpacket 65 * protocol must be in /etc/protocols 66 * wait/nowait[.max] single-threaded/multi-threaded, max # 67 * user[.group] or user[:group] user/group to run daemon as 68 * server program full path name 69 * server program arguments maximum of MAXARGS (20) 70 * 71 * For RPC services 72 * service name/version must be in /etc/rpc 73 * socket type stream/dgram/raw/rdm/seqpacket 74 * protocol must be in /etc/protocols 75 * wait/nowait[.max] single-threaded/multi-threaded 76 * user[.group] or user[:group] user to run daemon as 77 * server program full path name 78 * server program arguments maximum of MAXARGS (20) 79 * 80 * For non-RPC services, the "service name" can be of the form 81 * hostaddress:servicename, in which case the hostaddress is used 82 * as the host portion of the address to listen on. If hostaddress 83 * consists of a single `*' character, INADDR_ANY is used. 84 * 85 * A line can also consist of just 86 * hostaddress: 87 * where hostaddress is as in the preceding paragraph. Such a line must 88 * have no further fields; the specified hostaddress is remembered and 89 * used for all further lines that have no hostaddress specified, 90 * until the next such line (or EOF). (This is why * is provided to 91 * allow explicit specification of INADDR_ANY.) A line 92 * *: 93 * is implicitly in effect at the beginning of the file. 94 * 95 * The hostaddress specifier may (and often will) contain dots; 96 * the service name must not. 97 * 98 * For RPC services, host-address specifiers are accepted and will 99 * work to some extent; however, because of limitations in the 100 * portmapper interface, it will not work to try to give more than 101 * one line for any given RPC service, even if the host-address 102 * specifiers are different. 103 * 104 * Comment lines are indicated by a `#' in column 1. 105 */ 106 107/* inetd rules for passing file descriptors to children 108 * (http://www.freebsd.org/cgi/man.cgi?query=inetd): 109 * 110 * The wait/nowait entry specifies whether the server that is invoked by 111 * inetd will take over the socket associated with the service access point, 112 * and thus whether inetd should wait for the server to exit before listen- 113 * ing for new service requests. Datagram servers must use "wait", as 114 * they are always invoked with the original datagram socket bound to the 115 * specified service address. These servers must read at least one datagram 116 * from the socket before exiting. If a datagram server connects to its 117 * peer, freeing the socket so inetd can receive further messages on the 118 * socket, it is said to be a "multi-threaded" server; it should read one 119 * datagram from the socket and create a new socket connected to the peer. 120 * It should fork, and the parent should then exit to allow inetd to check 121 * for new service requests to spawn new servers. Datagram servers which 122 * process all incoming datagrams on a socket and eventually time out are 123 * said to be "single-threaded". The comsat(8), (biff(1)) and talkd(8) 124 * utilities are both examples of the latter type of datagram server. The 125 * tftpd(8) utility is an example of a multi-threaded datagram server. 126 * 127 * Servers using stream sockets generally are multi-threaded and use the 128 * "nowait" entry. Connection requests for these services are accepted by 129 * inetd, and the server is given only the newly-accepted socket connected 130 * to a client of the service. Most stream-based services operate in this 131 * manner. Stream-based servers that use "wait" are started with the lis- 132 * tening service socket, and must accept at least one connection request 133 * before exiting. Such a server would normally accept and process incoming 134 * connection requests until a timeout. 135 */ 136 137/* Here's the scoop concerning the user[.:]group feature: 138 * 139 * 1) set-group-option off. 140 * 141 * a) user = root: NO setuid() or setgid() is done 142 * 143 * b) other: setgid(primary group as found in passwd) 144 * initgroups(name, primary group) 145 * setuid() 146 * 147 * 2) set-group-option on. 148 * 149 * a) user = root: setgid(specified group) 150 * NO initgroups() 151 * NO setuid() 152 * 153 * b) other: setgid(specified group) 154 * initgroups(name, specified group) 155 * setuid() 156 */ 157 158#include "libbb.h" 159#include <syslog.h> 160#include <sys/un.h> 161 162//#define ENABLE_FEATURE_INETD_RPC 1 163//#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO 1 164//#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD 1 165//#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME 1 166//#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME 1 167//#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 1 168//#define ENABLE_FEATURE_IPV6 1 169 170#if ENABLE_FEATURE_INETD_RPC 171#include <rpc/rpc.h> 172#include <rpc/pmap_clnt.h> 173#endif 174 175extern char **environ; 176 177 178#define _PATH_INETDPID "/var/run/inetd.pid" 179 180#define CNT_INTVL 60 /* servers in CNT_INTVL sec. */ 181#define RETRYTIME (60*10) /* retry after bind or server fail */ 182 183#ifndef RLIMIT_NOFILE 184#define RLIMIT_NOFILE RLIMIT_OFILE 185#endif 186 187#ifndef OPEN_MAX 188#define OPEN_MAX 64 189#endif 190 191/* Reserve some descriptors, 3 stdio + at least: 1 log, 1 conf. file */ 192#define FD_MARGIN 8 193static rlim_t rlim_ofile_cur = OPEN_MAX; 194static struct rlimit rlim_ofile; 195 196 197/* Check unsupporting builtin */ 198#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO || \ 199 ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD || \ 200 ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME || \ 201 ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME || \ 202 ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 203# define INETD_FEATURE_ENABLED 204#endif 205 206#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO || \ 207 ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD || \ 208 ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 209# define INETD_SETPROCTITLE 210#endif 211 212typedef struct servtab { 213 char *se_hostaddr; /* host address to listen on */ 214 char *se_service; /* name of service */ 215 int se_socktype; /* type of socket to use */ 216 int se_family; /* address family */ 217 char *se_proto; /* protocol used */ 218#if ENABLE_FEATURE_INETD_RPC 219 int se_rpcprog; /* rpc program number */ 220 int se_rpcversl; /* rpc program lowest version */ 221 int se_rpcversh; /* rpc program highest version */ 222#define isrpcservice(sep) ((sep)->se_rpcversl != 0) 223#else 224#define isrpcservice(sep) 0 225#endif 226 pid_t se_wait; /* single threaded server */ 227 short se_checked; /* looked at during merge */ 228 char *se_user; /* user name to run as */ 229 char *se_group; /* group name to run as */ 230#ifdef INETD_FEATURE_ENABLED 231 const struct builtin *se_bi; /* if built-in, description */ 232#endif 233 char *se_server; /* server program */ 234#define MAXARGV 20 235 char *se_argv[MAXARGV + 1]; /* program arguments */ 236 int se_fd; /* open descriptor */ 237 union { 238 struct sockaddr se_un_ctrladdr; 239 struct sockaddr_in se_un_ctrladdr_in; 240#if ENABLE_FEATURE_IPV6 241 struct sockaddr_in6 se_un_ctrladdr_in6; 242#endif 243 struct sockaddr_un se_un_ctrladdr_un; 244 } se_un; /* bound address */ 245#define se_ctrladdr se_un.se_un_ctrladdr 246#define se_ctrladdr_in se_un.se_un_ctrladdr_in 247#define se_ctrladdr_in6 se_un.se_un_ctrladdr_in6 248#define se_ctrladdr_un se_un.se_un_ctrladdr_un 249 int se_ctrladdr_size; 250 int se_max; /* max # of instances of this service */ 251 int se_count; /* number started since se_time */ 252 struct timeval se_time; /* start of se_count */ 253 struct servtab *se_next; 254} servtab_t; 255 256static servtab_t *servtab; 257 258#ifdef INETD_FEATURE_ENABLED 259struct builtin { 260 const char *bi_service; /* internally provided service name */ 261 int bi_socktype; /* type of socket supported */ 262 short bi_fork; /* 1 if should fork before call */ 263 short bi_wait; /* 1 if should wait for child */ 264 void (*bi_fn) (int, servtab_t *); 265}; 266 267 /* Echo received data */ 268#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO 269static void echo_stream(int, servtab_t *); 270static void echo_dg(int, servtab_t *); 271#endif 272 /* Internet /dev/null */ 273#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD 274static void discard_stream(int, servtab_t *); 275static void discard_dg(int, servtab_t *); 276#endif 277 /* Return 32 bit time since 1900 */ 278#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME 279static void machtime_stream(int, servtab_t *); 280static void machtime_dg(int, servtab_t *); 281#endif 282 /* Return human-readable time */ 283#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME 284static void daytime_stream(int, servtab_t *); 285static void daytime_dg(int, servtab_t *); 286#endif 287 /* Familiar character generator */ 288#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 289static void chargen_stream(int, servtab_t *); 290static void chargen_dg(int, servtab_t *); 291#endif 292 293static const struct builtin builtins[] = { 294#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO 295 /* Echo received data */ 296 {"echo", SOCK_STREAM, 1, 0, echo_stream,}, 297 {"echo", SOCK_DGRAM, 0, 0, echo_dg,}, 298#endif 299#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD 300 /* Internet /dev/null */ 301 {"discard", SOCK_STREAM, 1, 0, discard_stream,}, 302 {"discard", SOCK_DGRAM, 0, 0, discard_dg,}, 303#endif 304#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME 305 /* Return 32 bit time since 1900 */ 306 {"time", SOCK_STREAM, 0, 0, machtime_stream,}, 307 {"time", SOCK_DGRAM, 0, 0, machtime_dg,}, 308#endif 309#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME 310 /* Return human-readable time */ 311 {"daytime", SOCK_STREAM, 0, 0, daytime_stream,}, 312 {"daytime", SOCK_DGRAM, 0, 0, daytime_dg,}, 313#endif 314#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 315 /* Familiar character generator */ 316 {"chargen", SOCK_STREAM, 1, 0, chargen_stream,}, 317 {"chargen", SOCK_DGRAM, 0, 0, chargen_dg,}, 318#endif 319 {NULL, 0, 0, 0, NULL} 320}; 321#endif /* INETD_FEATURE_ENABLED */ 322 323static int global_queuelen = 128; 324static int nsock, maxsock; 325static fd_set allsock; 326static int toomany; 327static int timingout; 328static struct servent *sp; 329static uid_t uid; 330 331static const char *config_filename = "/etc/inetd.conf"; 332 333static FILE *fconfig; 334static char *defhost; 335 336/* xstrdup(NULL) returns NULL, but this one 337 * will return newly-allocated "" if called with NULL arg 338 * TODO: audit whether this makes any real difference 339 */ 340static char *xxstrdup(char *cp) 341{ 342 return xstrdup(cp ? cp : ""); 343} 344 345static int setconfig(void) 346{ 347 free(defhost); 348 defhost = xstrdup("*"); 349 if (fconfig != NULL) { 350 fseek(fconfig, 0L, SEEK_SET); 351 return 1; 352 } 353 fconfig = fopen(config_filename, "r"); 354 return (fconfig != NULL); 355} 356 357static void endconfig(void) 358{ 359 if (fconfig) { 360 (void) fclose(fconfig); 361 fconfig = NULL; 362 } 363 free(defhost); 364 defhost = 0; 365} 366 367#if ENABLE_FEATURE_INETD_RPC 368static void register_rpc(servtab_t *sep) 369{ 370 int n; 371 struct sockaddr_in ir_sin; 372 struct protoent *pp; 373 socklen_t size; 374 375 if ((pp = getprotobyname(sep->se_proto + 4)) == NULL) { 376 bb_perror_msg("%s: getproto", sep->se_proto); 377 return; 378 } 379 size = sizeof ir_sin; 380 if (getsockname(sep->se_fd, (struct sockaddr *) &ir_sin, &size) < 0) { 381 bb_perror_msg("%s/%s: getsockname", 382 sep->se_service, sep->se_proto); 383 return; 384 } 385 386 for (n = sep->se_rpcversl; n <= sep->se_rpcversh; n++) { 387 (void) pmap_unset(sep->se_rpcprog, n); 388 if (!pmap_set(sep->se_rpcprog, n, pp->p_proto, ntohs(ir_sin.sin_port))) 389 bb_perror_msg("%s %s: pmap_set: %u %u %u %u", 390 sep->se_service, sep->se_proto, 391 sep->se_rpcprog, n, pp->p_proto, ntohs(ir_sin.sin_port)); 392 } 393} 394 395static void unregister_rpc(servtab_t *sep) 396{ 397 int n; 398 399 for (n = sep->se_rpcversl; n <= sep->se_rpcversh; n++) { 400 if (!pmap_unset(sep->se_rpcprog, n)) 401 bb_error_msg("pmap_unset(%u, %u)", sep->se_rpcprog, n); 402 } 403} 404#endif /* FEATURE_INETD_RPC */ 405 406static void freeconfig(servtab_t *cp) 407{ 408 int i; 409 410 free(cp->se_hostaddr); 411 free(cp->se_service); 412 free(cp->se_proto); 413 free(cp->se_user); 414 free(cp->se_group); 415 free(cp->se_server); 416 for (i = 0; i < MAXARGV; i++) 417 free(cp->se_argv[i]); 418} 419 420static int bump_nofile(void) 421{ 422#define FD_CHUNK 32 423 424 struct rlimit rl; 425 426 if (getrlimit(RLIMIT_NOFILE, &rl) < 0) { 427 bb_perror_msg("getrlimit"); 428 return -1; 429 } 430 rl.rlim_cur = MIN(rl.rlim_max, rl.rlim_cur + FD_CHUNK); 431 rl.rlim_cur = MIN(FD_SETSIZE, rl.rlim_cur + FD_CHUNK); 432 if (rl.rlim_cur <= rlim_ofile_cur) { 433 bb_error_msg("bump_nofile: cannot extend file limit, max = %d", 434 (int) rl.rlim_cur); 435 return -1; 436 } 437 438 if (setrlimit(RLIMIT_NOFILE, &rl) < 0) { 439 bb_perror_msg("setrlimit"); 440 return -1; 441 } 442 443 rlim_ofile_cur = rl.rlim_cur; 444 return 0; 445} 446 447static void setup(servtab_t *sep) 448{ 449 int r; 450 451 sep->se_fd = socket(sep->se_family, sep->se_socktype, 0); 452 if (sep->se_fd < 0) { 453 bb_perror_msg("%s/%s: socket", sep->se_service, sep->se_proto); 454 return; 455 } 456 setsockopt_reuseaddr(sep->se_fd); 457 458#if ENABLE_FEATURE_INETD_RPC 459 if (isrpcservice(sep)) { 460 struct passwd *pwd; 461 462 /* 463 * for RPC services, attempt to use a reserved port 464 * if they are going to be running as root. 465 * 466 * Also, zero out the port for all RPC services; let bind() 467 * find one. 468 */ 469 sep->se_ctrladdr_in.sin_port = 0; 470 if (sep->se_user && (pwd = getpwnam(sep->se_user)) && 471 pwd->pw_uid == 0 && uid == 0) 472 r = bindresvport(sep->se_fd, &sep->se_ctrladdr_in); 473 else { 474 r = bind(sep->se_fd, &sep->se_ctrladdr, sep->se_ctrladdr_size); 475 if (r == 0) { 476 socklen_t len = sep->se_ctrladdr_size; 477 int saveerrno = errno; 478 479 /* update se_ctrladdr_in.sin_port */ 480 r = getsockname(sep->se_fd, &sep->se_ctrladdr, &len); 481 if (r <= 0) 482 errno = saveerrno; 483 } 484 } 485 } else 486#endif 487 r = bind(sep->se_fd, &sep->se_ctrladdr, sep->se_ctrladdr_size); 488 if (r < 0) { 489 bb_perror_msg("%s/%s (%d): bind", 490 sep->se_service, sep->se_proto, sep->se_ctrladdr.sa_family); 491 close(sep->se_fd); 492 sep->se_fd = -1; 493 if (!timingout) { 494 timingout = 1; 495 alarm(RETRYTIME); 496 } 497 return; 498 } 499 if (sep->se_socktype == SOCK_STREAM) 500 listen(sep->se_fd, global_queuelen); 501 502 FD_SET(sep->se_fd, &allsock); 503 nsock++; 504 if (sep->se_fd > maxsock) { 505 maxsock = sep->se_fd; 506 if ((rlim_t)maxsock > rlim_ofile_cur - FD_MARGIN) 507 bump_nofile(); 508 } 509} 510 511static char *nextline(void) 512{ 513#define line bb_common_bufsiz1 514 515 char *cp; 516 FILE *fd = fconfig; 517 518 if (fgets(line, sizeof(line), fd) == NULL) 519 return NULL; 520 cp = strchr(line, '\n'); 521 if (cp) 522 *cp = '\0'; 523 return line; 524} 525 526static char *skip(char **cpp) /* int report; */ 527{ 528 char *cp = *cpp; 529 char *start; 530 531/* erp: */ 532 if (*cpp == NULL) { 533 /* if (report) */ 534 /* bb_error_msg("syntax error in inetd config file"); */ 535 return NULL; 536 } 537 538 again: 539 while (*cp == ' ' || *cp == '\t') 540 cp++; 541 if (*cp == '\0') { 542 int c; 543 544 c = getc(fconfig); 545 ungetc(c, fconfig); 546 if (c == ' ' || c == '\t') { 547 cp = nextline(); 548 if (cp) 549 goto again; 550 } 551 *cpp = NULL; 552 /* goto erp; */ 553 return NULL; 554 } 555 start = cp; 556 while (*cp && *cp != ' ' && *cp != '\t') 557 cp++; 558 if (*cp != '\0') 559 *cp++ = '\0'; 560 /* if ((*cpp = cp) == NULL) */ 561 /* goto erp; */ 562 563 *cpp = cp; 564 return start; 565} 566 567static servtab_t *new_servtab(void) 568{ 569 return xmalloc(sizeof(servtab_t)); 570} 571 572static servtab_t *dupconfig(servtab_t *sep) 573{ 574 servtab_t *newtab; 575 int argc; 576 577 newtab = new_servtab(); 578 memset(newtab, 0, sizeof(servtab_t)); 579 newtab->se_service = xstrdup(sep->se_service); 580 newtab->se_socktype = sep->se_socktype; 581 newtab->se_family = sep->se_family; 582 newtab->se_proto = xstrdup(sep->se_proto); 583#if ENABLE_FEATURE_INETD_RPC 584 newtab->se_rpcprog = sep->se_rpcprog; 585 newtab->se_rpcversl = sep->se_rpcversl; 586 newtab->se_rpcversh = sep->se_rpcversh; 587#endif 588 newtab->se_wait = sep->se_wait; 589 newtab->se_user = xstrdup(sep->se_user); 590 newtab->se_group = xstrdup(sep->se_group); 591#ifdef INETD_FEATURE_ENABLED 592 newtab->se_bi = sep->se_bi; 593#endif 594 newtab->se_server = xstrdup(sep->se_server); 595 596 for (argc = 0; argc <= MAXARGV; argc++) 597 newtab->se_argv[argc] = xstrdup(sep->se_argv[argc]); 598 newtab->se_max = sep->se_max; 599 600 return newtab; 601} 602 603static servtab_t *getconfigent(void) 604{ 605 servtab_t *sep; 606 int argc; 607 char *cp, *arg; 608 char *hostdelim; 609 servtab_t *nsep; 610 servtab_t *psep; 611 612 sep = new_servtab(); 613 614 /* memset(sep, 0, sizeof *sep); */ 615 more: 616 /* freeconfig(sep); */ 617 618 while ((cp = nextline()) && *cp == '#') /* skip comment line */; 619 if (cp == NULL) { 620 /* free(sep); */ 621 return NULL; 622 } 623 624 memset((char *) sep, 0, sizeof *sep); 625 arg = skip(&cp); 626 if (arg == NULL) { 627 /* A blank line. */ 628 goto more; 629 } 630 631 /* Check for a host name. */ 632 hostdelim = strrchr(arg, ':'); 633 if (hostdelim) { 634 *hostdelim = '\0'; 635 sep->se_hostaddr = xstrdup(arg); 636 arg = hostdelim + 1; 637 /* 638 * If the line is of the form `host:', then just change the 639 * default host for the following lines. 640 */ 641 if (*arg == '\0') { 642 arg = skip(&cp); 643 if (cp == NULL) { 644 free(defhost); 645 defhost = sep->se_hostaddr; 646 goto more; 647 } 648 } 649 } else 650 sep->se_hostaddr = xxstrdup(defhost); 651 652 sep->se_service = xxstrdup(arg); 653 arg = skip(&cp); 654 655 if (strcmp(arg, "stream") == 0) 656 sep->se_socktype = SOCK_STREAM; 657 else if (strcmp(arg, "dgram") == 0) 658 sep->se_socktype = SOCK_DGRAM; 659 else if (strcmp(arg, "rdm") == 0) 660 sep->se_socktype = SOCK_RDM; 661 else if (strcmp(arg, "seqpacket") == 0) 662 sep->se_socktype = SOCK_SEQPACKET; 663 else if (strcmp(arg, "raw") == 0) 664 sep->se_socktype = SOCK_RAW; 665 else 666 sep->se_socktype = -1; 667 668 sep->se_proto = xxstrdup(skip(&cp)); 669 670 if (strcmp(sep->se_proto, "unix") == 0) { 671 sep->se_family = AF_UNIX; 672 } else { 673 sep->se_family = AF_INET; 674 if (sep->se_proto[strlen(sep->se_proto) - 1] == '6') 675#if ENABLE_FEATURE_IPV6 676 sep->se_family = AF_INET6; 677#else 678 bb_error_msg("%s: IPV6 not supported", sep->se_proto); 679#endif 680 if (strncmp(sep->se_proto, "rpc/", 4) == 0) { 681#if ENABLE_FEATURE_INETD_RPC 682 char *p, *ccp; 683 long l; 684 685 p = strchr(sep->se_service, '/'); 686 if (p == 0) { 687 bb_error_msg("%s: no rpc version", sep->se_service); 688 goto more; 689 } 690 *p++ = '\0'; 691 l = strtol(p, &ccp, 0); 692 if (ccp == p || l < 0 || l > INT_MAX) { 693 badafterall: 694 bb_error_msg("%s/%s: bad rpc version", sep->se_service, p); 695 goto more; 696 } 697 sep->se_rpcversl = sep->se_rpcversh = l; 698 if (*ccp == '-') { 699 p = ccp + 1; 700 l = strtol(p, &ccp, 0); 701 if (ccp == p || l < 0 || l > INT_MAX || l < sep->se_rpcversl || *ccp) 702 goto badafterall; 703 sep->se_rpcversh = l; 704 } else if (*ccp != '\0') 705 goto badafterall; 706#else 707 bb_error_msg("%s: rpc services not supported", sep->se_service); 708#endif 709 } 710 } 711 arg = skip(&cp); 712 if (arg == NULL) 713 goto more; 714 715 { 716 char *s = strchr(arg, '.'); 717 if (s) { 718 *s++ = '\0'; 719 sep->se_max = xatoi(s); 720 } else 721 sep->se_max = toomany; 722 } 723 sep->se_wait = strcmp(arg, "wait") == 0; 724 /* if ((arg = skip(&cp, 1)) == NULL) */ 725 /* goto more; */ 726 sep->se_user = xxstrdup(skip(&cp)); 727 arg = strchr(sep->se_user, '.'); 728 if (arg == NULL) 729 arg = strchr(sep->se_user, ':'); 730 if (arg) { 731 *arg++ = '\0'; 732 sep->se_group = xstrdup(arg); 733 } 734 /* if ((arg = skip(&cp, 1)) == NULL) */ 735 /* goto more; */ 736 737 sep->se_server = xxstrdup(skip(&cp)); 738 if (strcmp(sep->se_server, "internal") == 0) { 739#ifdef INETD_FEATURE_ENABLED 740 const struct builtin *bi; 741 742 for (bi = builtins; bi->bi_service; bi++) 743 if (bi->bi_socktype == sep->se_socktype && 744 strcmp(bi->bi_service, sep->se_service) == 0) 745 break; 746 if (bi->bi_service == 0) { 747 bb_error_msg("internal service %s unknown", sep->se_service); 748 goto more; 749 } 750 sep->se_bi = bi; 751 sep->se_wait = bi->bi_wait; 752#else 753 bb_perror_msg("internal service %s unknown", sep->se_service); 754 goto more; 755#endif 756 } 757#ifdef INETD_FEATURE_ENABLED 758 else 759 sep->se_bi = NULL; 760#endif 761 argc = 0; 762 for (arg = skip(&cp); cp; arg = skip(&cp)) { 763 if (argc < MAXARGV) 764 sep->se_argv[argc++] = xxstrdup(arg); 765 } 766 while (argc <= MAXARGV) 767 sep->se_argv[argc++] = NULL; 768 769 /* 770 * Now that we've processed the entire line, check if the hostname 771 * specifier was a comma separated list of hostnames. If so 772 * we'll make new entries for each address. 773 */ 774 while ((hostdelim = strrchr(sep->se_hostaddr, ',')) != NULL) { 775 nsep = dupconfig(sep); 776 777 /* 778 * NULL terminate the hostname field of the existing entry, 779 * and make a dup for the new entry. 780 */ 781 *hostdelim++ = '\0'; 782 nsep->se_hostaddr = xstrdup(hostdelim); 783 784 nsep->se_next = sep->se_next; 785 sep->se_next = nsep; 786 } 787 788 nsep = sep; 789 while (nsep != NULL) { 790 nsep->se_checked = 1; 791 if (nsep->se_family == AF_INET) { 792 if (LONE_CHAR(nsep->se_hostaddr, '*')) 793 nsep->se_ctrladdr_in.sin_addr.s_addr = INADDR_ANY; 794 else if (!inet_aton(nsep->se_hostaddr, &nsep->se_ctrladdr_in.sin_addr)) { 795 struct hostent *hp; 796 797 hp = gethostbyname(nsep->se_hostaddr); 798 if (hp == 0) { 799 bb_error_msg("%s: unknown host", nsep->se_hostaddr); 800 nsep->se_checked = 0; 801 goto skip; 802 } else if (hp->h_addrtype != AF_INET) { 803 bb_error_msg("%s: address isn't an Internet " 804 "address", nsep->se_hostaddr); 805 nsep->se_checked = 0; 806 goto skip; 807 } else { 808 int i = 1; 809 810 memmove(&nsep->se_ctrladdr_in.sin_addr, 811 hp->h_addr_list[0], sizeof(struct in_addr)); 812 while (hp->h_addr_list[i] != NULL) { 813 psep = dupconfig(nsep); 814 psep->se_hostaddr = xxstrdup(nsep->se_hostaddr); 815 psep->se_checked = 1; 816 memmove(&psep->se_ctrladdr_in.sin_addr, 817 hp->h_addr_list[i], sizeof(struct in_addr)); 818 psep->se_ctrladdr_size = sizeof(psep->se_ctrladdr_in); 819 i++; 820 /* Prepend to list, don't want to look up */ 821 /* its hostname again. */ 822 psep->se_next = sep; 823 sep = psep; 824 } 825 } 826 } 827 } 828 skip: 829 nsep = nsep->se_next; 830 } 831 832 /* 833 * Finally, free any entries which failed the gethostbyname 834 * check. 835 */ 836 psep = NULL; 837 nsep = sep; 838 while (nsep != NULL) { 839 servtab_t *tsep; 840 841 if (nsep->se_checked == 0) { 842 tsep = nsep; 843 if (psep == NULL) { 844 sep = nsep->se_next; 845 nsep = sep; 846 } else { 847 nsep = nsep->se_next; 848 psep->se_next = nsep; 849 } 850 freeconfig(tsep); 851 } else { 852 nsep->se_checked = 0; 853 psep = nsep; 854 nsep = nsep->se_next; 855 } 856 } 857 858 return sep; 859} 860 861#define Block_Using_Signals(m) do { \ 862 sigemptyset(&m); \ 863 sigaddset(&m, SIGCHLD); \ 864 sigaddset(&m, SIGHUP); \ 865 sigaddset(&m, SIGALRM); \ 866 sigprocmask(SIG_BLOCK, &m, NULL); \ 867} while (0) 868 869static servtab_t *enter(servtab_t *cp) 870{ 871 servtab_t *sep; 872 sigset_t omask; 873 874 sep = new_servtab(); 875 *sep = *cp; 876 sep->se_fd = -1; 877#if ENABLE_FEATURE_INETD_RPC 878 sep->se_rpcprog = -1; 879#endif 880 Block_Using_Signals(omask); 881 sep->se_next = servtab; 882 servtab = sep; 883 sigprocmask(SIG_UNBLOCK, &omask, NULL); 884 return sep; 885} 886 887static int matchconf(servtab_t *old, servtab_t *new) 888{ 889 if (strcmp(old->se_service, new->se_service) != 0) 890 return 0; 891 892 if (strcmp(old->se_hostaddr, new->se_hostaddr) != 0) 893 return 0; 894 895 if (strcmp(old->se_proto, new->se_proto) != 0) 896 return 0; 897 898 /* 899 * If the new servtab is bound to a specific address, check that the 900 * old servtab is bound to the same entry. If the new service is not 901 * bound to a specific address then the check of se_hostaddr above 902 * is sufficient. 903 */ 904 905 if (old->se_family == AF_INET && new->se_family == AF_INET && 906 memcmp(&old->se_ctrladdr_in.sin_addr, 907 &new->se_ctrladdr_in.sin_addr, 908 sizeof(new->se_ctrladdr_in.sin_addr)) != 0) 909 return 0; 910 911#if ENABLE_FEATURE_IPV6 912 if (old->se_family == AF_INET6 && new->se_family == AF_INET6 && 913 memcmp(&old->se_ctrladdr_in6.sin6_addr, 914 &new->se_ctrladdr_in6.sin6_addr, 915 sizeof(new->se_ctrladdr_in6.sin6_addr)) != 0) 916 return 0; 917#endif 918 return 1; 919} 920 921static void config(int sig ATTRIBUTE_UNUSED) 922{ 923 servtab_t *sep, *cp, **sepp; 924 sigset_t omask; 925 size_t n; 926 char protoname[10]; 927 928 if (!setconfig()) { 929 bb_perror_msg("%s", config_filename); 930 return; 931 } 932 for (sep = servtab; sep; sep = sep->se_next) 933 sep->se_checked = 0; 934 cp = getconfigent(); 935 while (cp != NULL) { 936 for (sep = servtab; sep; sep = sep->se_next) 937 if (matchconf(sep, cp)) 938 break; 939 940 if (sep != 0) { 941 int i; 942 943#define SWAP(type, a, b) do {type c=(type)a; a=(type)b; b=(type)c;} while (0) 944 945 Block_Using_Signals(omask); 946 /* 947 * sep->se_wait may be holding the pid of a daemon 948 * that we're waiting for. If so, don't overwrite 949 * it unless the config file explicitly says don't 950 * wait. 951 */ 952 if ( 953#ifdef INETD_FEATURE_ENABLED 954 cp->se_bi == 0 && 955#endif 956 (sep->se_wait == 1 || cp->se_wait == 0)) 957 sep->se_wait = cp->se_wait; 958 SWAP(int, cp->se_max, sep->se_max); 959 SWAP(char *, sep->se_user, cp->se_user); 960 SWAP(char *, sep->se_group, cp->se_group); 961 SWAP(char *, sep->se_server, cp->se_server); 962 for (i = 0; i < MAXARGV; i++) 963 SWAP(char *, sep->se_argv[i], cp->se_argv[i]); 964#undef SWAP 965 966#if ENABLE_FEATURE_INETD_RPC 967 if (isrpcservice(sep)) 968 unregister_rpc(sep); 969 sep->se_rpcversl = cp->se_rpcversl; 970 sep->se_rpcversh = cp->se_rpcversh; 971#endif 972 sigprocmask(SIG_UNBLOCK, &omask, NULL); 973 freeconfig(cp); 974 } else { 975 sep = enter(cp); 976 } 977 sep->se_checked = 1; 978 979 switch (sep->se_family) { 980 case AF_UNIX: 981 if (sep->se_fd != -1) 982 break; 983 (void) unlink(sep->se_service); 984 n = strlen(sep->se_service); 985 if (n > sizeof sep->se_ctrladdr_un.sun_path - 1) 986 n = sizeof sep->se_ctrladdr_un.sun_path - 1; 987 safe_strncpy(sep->se_ctrladdr_un.sun_path, sep->se_service, n + 1); 988 sep->se_ctrladdr_un.sun_family = AF_UNIX; 989 sep->se_ctrladdr_size = n + sizeof sep->se_ctrladdr_un.sun_family; 990 setup(sep); 991 break; 992 case AF_INET: 993 sep->se_ctrladdr_in.sin_family = AF_INET; 994 /* se_ctrladdr_in was set in getconfigent */ 995 sep->se_ctrladdr_size = sizeof sep->se_ctrladdr_in; 996 997#if ENABLE_FEATURE_INETD_RPC 998 if (isrpcservice(sep)) { 999 struct rpcent *rp; 1000 sep->se_rpcprog = atoi(sep->se_service); 1001 if (sep->se_rpcprog == 0) { 1002 rp = getrpcbyname(sep->se_service); 1003 if (rp == 0) { 1004 bb_error_msg("%s: unknown rpc service", sep->se_service); 1005 goto serv_unknown; 1006 } 1007 sep->se_rpcprog = rp->r_number; 1008 } 1009 if (sep->se_fd == -1) 1010 setup(sep); 1011 if (sep->se_fd != -1) 1012 register_rpc(sep); 1013 } else 1014#endif 1015 { 1016 uint16_t port = htons(atoi(sep->se_service)); 1017 if (!port) { 1018 strncpy(protoname, sep->se_proto, sizeof(protoname)); 1019 if (isdigit(protoname[strlen(protoname) - 1])) 1020 protoname[strlen(protoname) - 1] = '\0'; 1021 sp = getservbyname(sep->se_service, protoname); 1022 if (sp == 0) { 1023 bb_error_msg("%s/%s: unknown service", 1024 sep->se_service, sep->se_proto); 1025 goto serv_unknown; 1026 } 1027 port = sp->s_port; 1028 } 1029 if (port != sep->se_ctrladdr_in.sin_port) { 1030 sep->se_ctrladdr_in.sin_port = port; 1031 if (sep->se_fd != -1) { 1032 FD_CLR(sep->se_fd, &allsock); 1033 nsock--; 1034 (void) close(sep->se_fd); 1035 } 1036 sep->se_fd = -1; 1037 } 1038 if (sep->se_fd == -1) 1039 setup(sep); 1040 } 1041 break; 1042#if ENABLE_FEATURE_IPV6 1043 case AF_INET6: 1044 sep->se_ctrladdr_in6.sin6_family = AF_INET6; 1045 /* se_ctrladdr_in was set in getconfigent */ 1046 sep->se_ctrladdr_size = sizeof sep->se_ctrladdr_in6; 1047 1048#if ENABLE_FEATURE_INETD_RPC 1049 if (isrpcservice(sep)) { 1050 struct rpcent *rp; 1051 1052 sep->se_rpcprog = atoi(sep->se_service); 1053 if (sep->se_rpcprog == 0) { 1054 rp = getrpcbyname(sep->se_service); 1055 if (rp == 0) { 1056 bb_error_msg("%s: unknown rpc service", sep->se_service); 1057 goto serv_unknown; 1058 } 1059 sep->se_rpcprog = rp->r_number; 1060 } 1061 if (sep->se_fd == -1) 1062 setup(sep); 1063 if (sep->se_fd != -1) 1064 register_rpc(sep); 1065 } else 1066#endif 1067 { 1068 uint16_t port = htons(atoi(sep->se_service)); 1069 1070 if (!port) { 1071 strncpy(protoname, sep->se_proto, sizeof(protoname)); 1072 if (isdigit(protoname[strlen(protoname) - 1])) 1073 protoname[strlen(protoname) - 1] = '\0'; 1074 sp = getservbyname(sep->se_service, protoname); 1075 if (sp == 0) { 1076 bb_error_msg("%s/%s: unknown service", 1077 sep->se_service, sep->se_proto); 1078 goto serv_unknown; 1079 } 1080 port = sp->s_port; 1081 } 1082 if (port != sep->se_ctrladdr_in6.sin6_port) { 1083 sep->se_ctrladdr_in6.sin6_port = port; 1084 if (sep->se_fd != -1) { 1085 FD_CLR(sep->se_fd, &allsock); 1086 nsock--; 1087 (void) close(sep->se_fd); 1088 } 1089 sep->se_fd = -1; 1090 } 1091 if (sep->se_fd == -1) 1092 setup(sep); 1093 } 1094 break; 1095#endif /* FEATURE_IPV6 */ 1096 } 1097 serv_unknown: 1098 if (cp->se_next != NULL) { 1099 servtab_t *tmp = cp; 1100 1101 cp = cp->se_next; 1102 free(tmp); 1103 } else { 1104 free(cp); 1105 cp = getconfigent(); 1106 } 1107 } 1108 endconfig(); 1109 /* 1110 * Purge anything not looked at above. 1111 */ 1112 Block_Using_Signals(omask); 1113 sepp = &servtab; 1114 while ((sep = *sepp)) { 1115 if (sep->se_checked) { 1116 sepp = &sep->se_next; 1117 continue; 1118 } 1119 *sepp = sep->se_next; 1120 if (sep->se_fd != -1) { 1121 FD_CLR(sep->se_fd, &allsock); 1122 nsock--; 1123 (void) close(sep->se_fd); 1124 } 1125#if ENABLE_FEATURE_INETD_RPC 1126 if (isrpcservice(sep)) 1127 unregister_rpc(sep); 1128#endif 1129 if (sep->se_family == AF_UNIX) 1130 (void) unlink(sep->se_service); 1131 freeconfig(sep); 1132 free(sep); 1133 } 1134 sigprocmask(SIG_UNBLOCK, &omask, NULL); 1135} 1136 1137 1138static void reapchild(int sig ATTRIBUTE_UNUSED) 1139{ 1140 pid_t pid; 1141 int save_errno = errno, status; 1142 servtab_t *sep; 1143 1144 for (;;) { 1145 pid = wait3(&status, WNOHANG, NULL); 1146 if (pid <= 0) 1147 break; 1148 for (sep = servtab; sep; sep = sep->se_next) 1149 if (sep->se_wait == pid) { 1150 if (WIFEXITED(status) && WEXITSTATUS(status)) 1151 bb_error_msg("%s: exit status 0x%x", 1152 sep->se_server, WEXITSTATUS(status)); 1153 else if (WIFSIGNALED(status)) 1154 bb_error_msg("%s: exit signal 0x%x", 1155 sep->se_server, WTERMSIG(status)); 1156 sep->se_wait = 1; 1157 FD_SET(sep->se_fd, &allsock); 1158 nsock++; 1159 } 1160 } 1161 errno = save_errno; 1162} 1163 1164static void retry(int sig ATTRIBUTE_UNUSED) 1165{ 1166 servtab_t *sep; 1167 1168 timingout = 0; 1169 for (sep = servtab; sep; sep = sep->se_next) { 1170 if (sep->se_fd == -1) { 1171 switch (sep->se_family) { 1172 case AF_UNIX: 1173 case AF_INET: 1174#if ENABLE_FEATURE_IPV6 1175 case AF_INET6: 1176#endif 1177 setup(sep); 1178#if ENABLE_FEATURE_INETD_RPC 1179 if (sep->se_fd != -1 && isrpcservice(sep)) 1180 register_rpc(sep); 1181#endif 1182 break; 1183 } 1184 } 1185 } 1186} 1187 1188static void goaway(int sig ATTRIBUTE_UNUSED) 1189{ 1190 servtab_t *sep; 1191 1192 for (sep = servtab; sep; sep = sep->se_next) { 1193 if (sep->se_fd == -1) 1194 continue; 1195 1196 switch (sep->se_family) { 1197 case AF_UNIX: 1198 (void) unlink(sep->se_service); 1199 break; 1200 case AF_INET: 1201#if ENABLE_FEATURE_IPV6 1202 case AF_INET6: 1203#endif 1204#if ENABLE_FEATURE_INETD_RPC 1205 if (sep->se_wait == 1 && isrpcservice(sep)) 1206 unregister_rpc(sep); 1207#endif 1208 break; 1209 } 1210 (void) close(sep->se_fd); 1211 } 1212 remove_pidfile(_PATH_INETDPID); 1213 exit(0); 1214} 1215 1216 1217#ifdef INETD_SETPROCTITLE 1218static char **Argv; 1219static char *LastArg; 1220 1221static void 1222inetd_setproctitle(char *a, int s) 1223{ 1224 socklen_t size; 1225 char *cp; 1226 struct sockaddr_in prt_sin; 1227 char buf[80]; 1228 1229 cp = Argv[0]; 1230 size = sizeof(prt_sin); 1231 (void) snprintf(buf, sizeof buf, "-%s", a); 1232 if (getpeername(s, (struct sockaddr *) &prt_sin, &size) == 0) { 1233 char *sa = inet_ntoa(prt_sin.sin_addr); 1234 1235 buf[sizeof(buf) - 1 - strlen(sa) - 3] = '\0'; 1236 strcat(buf, " ["); 1237 strcat(buf, sa); 1238 strcat(buf, "]"); 1239 } 1240 strncpy(cp, buf, LastArg - cp); 1241 cp += strlen(cp); 1242 while (cp < LastArg) 1243 *cp++ = ' '; 1244} 1245#endif 1246 1247 1248int inetd_main(int argc, char **argv); 1249int inetd_main(int argc, char **argv) 1250{ 1251 servtab_t *sep; 1252 struct passwd *pwd; 1253 struct group *grp = NULL; 1254 int tmpint; 1255 struct sigaction sa, sapipe; 1256 int opt; 1257 pid_t pid; 1258 char buf[50]; 1259 char *stoomany; 1260 sigset_t omask, wait_mask; 1261 1262#ifdef INETD_SETPROCTITLE 1263 char **envp = environ; 1264 1265 Argv = argv; 1266 if (envp == 0 || *envp == 0) 1267 envp = argv; 1268 while (*envp) 1269 envp++; 1270 LastArg = envp[-1] + strlen(envp[-1]); 1271#endif 1272 1273 uid = getuid(); 1274 if (uid != 0) 1275 config_filename = NULL; 1276 1277 opt = getopt32(argv, "R:f", &stoomany); 1278 if (opt & 1) 1279 toomany = xatoi_u(stoomany); 1280 argv += optind; 1281 argc -= optind; 1282 if (argc) 1283 config_filename = argv[0]; 1284 if (config_filename == NULL) 1285 bb_error_msg_and_die("non-root must specify a config file"); 1286 1287 if (!(opt & 2)) 1288 bb_daemonize_or_rexec(0, argv - optind); 1289 else 1290 bb_sanitize_stdio(); 1291 openlog(applet_name, LOG_PID | LOG_NOWAIT, LOG_DAEMON); 1292 logmode = LOGMODE_SYSLOG; 1293 1294 if (uid == 0) { 1295 /* If run by hand, ensure groups vector gets trashed */ 1296 gid_t gid = getgid(); 1297 setgroups(1, &gid); 1298 } 1299 1300 write_pidfile(_PATH_INETDPID); 1301 1302 if (getrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0) { 1303 bb_perror_msg("getrlimit"); 1304 } else { 1305 rlim_ofile_cur = rlim_ofile.rlim_cur; 1306 if (rlim_ofile_cur == RLIM_INFINITY) /* ! */ 1307 rlim_ofile_cur = OPEN_MAX; 1308 } 1309 1310 memset((char *) &sa, 0, sizeof(sa)); 1311 sigemptyset(&sa.sa_mask); 1312 sigaddset(&sa.sa_mask, SIGALRM); 1313 sigaddset(&sa.sa_mask, SIGCHLD); 1314 sigaddset(&sa.sa_mask, SIGHUP); 1315 sa.sa_handler = retry; 1316 sigaction(SIGALRM, &sa, NULL); 1317 config(SIGHUP); 1318 sa.sa_handler = config; 1319 sigaction(SIGHUP, &sa, NULL); 1320 sa.sa_handler = reapchild; 1321 sigaction(SIGCHLD, &sa, NULL); 1322 sa.sa_handler = goaway; 1323 sigaction(SIGTERM, &sa, NULL); 1324 sa.sa_handler = goaway; 1325 sigaction(SIGINT, &sa, NULL); 1326 sa.sa_handler = SIG_IGN; 1327 sigaction(SIGPIPE, &sa, &sapipe); 1328 memset(&wait_mask, 0, sizeof(wait_mask)); 1329 { 1330 /* space for daemons to overwrite environment for ps */ 1331#define DUMMYSIZE 100 1332 char dummy[DUMMYSIZE]; 1333 1334 (void) memset(dummy, 'x', DUMMYSIZE - 1); 1335 dummy[DUMMYSIZE - 1] = '\0'; 1336 1337 (void) setenv("inetd_dummy", dummy, 1); 1338 } 1339 1340 for (;;) { 1341 int n, ctrl = -1; 1342 fd_set readable; 1343 1344 if (nsock == 0) { 1345 Block_Using_Signals(omask); 1346 while (nsock == 0) 1347 sigsuspend(&wait_mask); 1348 sigprocmask(SIG_UNBLOCK, &omask, NULL); 1349 } 1350 1351 readable = allsock; 1352 n = select(maxsock + 1, &readable, NULL, NULL, NULL); 1353 if (n <= 0) { 1354 if (n < 0 && errno != EINTR) { 1355 bb_perror_msg("select"); 1356 sleep(1); 1357 } 1358 continue; 1359 } 1360 1361 for (sep = servtab; n && sep; sep = sep->se_next) { 1362 if (sep->se_fd == -1 || !FD_ISSET(sep->se_fd, &readable)) 1363 continue; 1364 1365 n--; 1366 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) { 1367 ctrl = accept(sep->se_fd, NULL, NULL); 1368 if (ctrl < 0) { 1369 if (errno == EINTR) 1370 continue; 1371 bb_perror_msg("accept (for %s)", sep->se_service); 1372 continue; 1373 } 1374 if (sep->se_family == AF_INET && sep->se_socktype == SOCK_STREAM) { 1375 struct sockaddr_in peer; 1376 socklen_t plen = sizeof(peer); 1377 1378 if (getpeername(ctrl, (struct sockaddr *) &peer, &plen) < 0) { 1379 bb_error_msg("cannot getpeername"); 1380 close(ctrl); 1381 continue; 1382 } 1383 if (ntohs(peer.sin_port) == 20) { 1384 close(ctrl); 1385 continue; 1386 } 1387 } 1388 } else 1389 ctrl = sep->se_fd; 1390 1391 Block_Using_Signals(omask); 1392 pid = 0; 1393#ifdef INETD_FEATURE_ENABLED 1394 if (sep->se_bi == 0 || sep->se_bi->bi_fork) 1395#endif 1396 { 1397 if (sep->se_count++ == 0) 1398 (void) gettimeofday(&sep->se_time, NULL); 1399 else if (toomany > 0 && sep->se_count >= sep->se_max) { 1400 struct timeval now; 1401 1402 (void) gettimeofday(&now, NULL); 1403 if (now.tv_sec - sep->se_time.tv_sec > CNT_INTVL) { 1404 sep->se_time = now; 1405 sep->se_count = 1; 1406 } else { 1407 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) 1408 close(ctrl); 1409 if (sep->se_family == AF_INET && 1410 ntohs(sep->se_ctrladdr_in.sin_port) >= IPPORT_RESERVED) { 1411 /* 1412 * Cannot close it -- there are 1413 * thieves on the system. 1414 * Simply ignore the connection. 1415 */ 1416 --sep->se_count; 1417 continue; 1418 } 1419 bb_error_msg("%s/%s server failing (looping), service terminated", 1420 sep->se_service, sep->se_proto); 1421 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) 1422 close(ctrl); 1423 FD_CLR(sep->se_fd, &allsock); 1424 (void) close(sep->se_fd); 1425 sep->se_fd = -1; 1426 sep->se_count = 0; 1427 nsock--; 1428 sigprocmask(SIG_UNBLOCK, &omask, NULL); 1429 if (!timingout) { 1430 timingout = 1; 1431 alarm(RETRYTIME); 1432 } 1433 continue; 1434 } 1435 } 1436 pid = fork(); 1437 } 1438 if (pid < 0) { 1439 bb_perror_msg("fork"); 1440 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) 1441 close(ctrl); 1442 sigprocmask(SIG_UNBLOCK, &omask, NULL); 1443 sleep(1); 1444 continue; 1445 } 1446 if (pid && sep->se_wait) { 1447 sep->se_wait = pid; 1448 FD_CLR(sep->se_fd, &allsock); 1449 nsock--; 1450 } 1451 sigprocmask(SIG_UNBLOCK, &omask, NULL); 1452 if (pid == 0) { 1453#ifdef INETD_FEATURE_ENABLED 1454 if (sep->se_bi) { 1455 (*sep->se_bi->bi_fn)(ctrl, sep); 1456 } else 1457#endif 1458 { 1459 pwd = getpwnam(sep->se_user); 1460 if (pwd == NULL) { 1461 bb_error_msg("getpwnam: %s: no such user", sep->se_user); 1462 goto do_exit1; 1463 } 1464 if (setsid() < 0) 1465 bb_perror_msg("%s: setsid", sep->se_service); 1466 if (sep->se_group && (grp = getgrnam(sep->se_group)) == NULL) { 1467 bb_error_msg("getgrnam: %s: no such group", sep->se_group); 1468 goto do_exit1; 1469 } 1470 if (uid != 0) { 1471 /* a user running private inetd */ 1472 if (uid != pwd->pw_uid) 1473 _exit(1); 1474 } else if (pwd->pw_uid) { 1475 if (sep->se_group) 1476 pwd->pw_gid = grp->gr_gid; 1477 xsetgid((gid_t) pwd->pw_gid); 1478 initgroups(pwd->pw_name, pwd->pw_gid); 1479 xsetuid((uid_t) pwd->pw_uid); 1480 } else if (sep->se_group) { 1481 xsetgid(grp->gr_gid); 1482 setgroups(1, &grp->gr_gid); 1483 } 1484 dup2(ctrl, 0); 1485 if (ctrl) close(ctrl); 1486 dup2(0, 1); 1487 dup2(0, 2); 1488 if (rlim_ofile.rlim_cur != rlim_ofile_cur) 1489 if (setrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0) 1490 bb_perror_msg("setrlimit"); 1491 closelog(); 1492 for (tmpint = rlim_ofile_cur - 1; --tmpint > 2;) 1493 (void) close(tmpint); 1494 sigaction(SIGPIPE, &sapipe, NULL); 1495 execv(sep->se_server, sep->se_argv); 1496 bb_perror_msg("execv %s", sep->se_server); 1497 do_exit1: 1498 if (sep->se_socktype != SOCK_STREAM) 1499 recv(0, buf, sizeof(buf), 0); 1500 _exit(1); 1501 } 1502 } 1503 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) 1504 close(ctrl); 1505 } /* for (sep = servtab...) */ 1506 } /* for (;;) */ 1507} 1508 1509/* 1510 * Internet services provided internally by inetd: 1511 */ 1512#define BUFSIZE 4096 1513 1514#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO || \ 1515 ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN || \ 1516 ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME 1517static int dg_badinput(struct sockaddr_in *dg_sin) 1518{ 1519 if (ntohs(dg_sin->sin_port) < IPPORT_RESERVED) 1520 return 1; 1521 if (dg_sin->sin_addr.s_addr == htonl(INADDR_BROADCAST)) 1522 return 1; 1523 return 0; 1524} 1525#endif 1526 1527#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO 1528/* Echo service -- echo data back */ 1529/* ARGSUSED */ 1530static void 1531echo_stream(int s, servtab_t *sep) 1532{ 1533 char buffer[BUFSIZE]; 1534 int i; 1535 1536 inetd_setproctitle(sep->se_service, s); 1537 while (1) { 1538 i = read(s, buffer, sizeof(buffer)); 1539 if (i <= 0) break; 1540 if (write(s, buffer, i) <= 0) break; 1541 } 1542 exit(0); 1543} 1544 1545/* Echo service -- echo data back */ 1546/* ARGSUSED */ 1547static void 1548echo_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED) 1549{ 1550 char buffer[BUFSIZE]; 1551 int i; 1552 socklen_t size; 1553 /* struct sockaddr_storage ss; */ 1554 struct sockaddr sa; 1555 1556 size = sizeof(sa); 1557 i = recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size); 1558 if (i < 0) 1559 return; 1560 if (dg_badinput((struct sockaddr_in *) &sa)) 1561 return; 1562 (void) sendto(s, buffer, i, 0, &sa, sizeof(sa)); 1563} 1564#endif /* FEATURE_INETD_SUPPORT_BUILTIN_ECHO */ 1565 1566#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD 1567/* Discard service -- ignore data */ 1568/* ARGSUSED */ 1569static void 1570discard_stream(int s, servtab_t *sep) 1571{ 1572 char buffer[BUFSIZE]; 1573 1574 inetd_setproctitle(sep->se_service, s); 1575 while (1) { 1576 errno = 0; 1577 if (read(s, buffer, sizeof(buffer)) <= 0 && errno != EINTR) 1578 exit(0); 1579 } 1580} 1581 1582/* Discard service -- ignore data */ 1583/* ARGSUSED */ 1584static void 1585discard_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED) 1586{ 1587 char buffer[BUFSIZE]; 1588 1589 (void) read(s, buffer, sizeof(buffer)); 1590} 1591#endif /* FEATURE_INETD_SUPPORT_BUILTIN_DISCARD */ 1592 1593 1594#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 1595#define LINESIZ 72 1596static char ring[128]; 1597static char *endring; 1598 1599static void 1600initring(void) 1601{ 1602 int i; 1603 1604 endring = ring; 1605 1606 for (i = 0; i <= 128; ++i) 1607 if (isprint(i)) 1608 *endring++ = i; 1609} 1610 1611/* Character generator */ 1612/* ARGSUSED */ 1613static void 1614chargen_stream(int s, servtab_t *sep) 1615{ 1616 char *rs; 1617 int len; 1618 char text[LINESIZ + 2]; 1619 1620 inetd_setproctitle(sep->se_service, s); 1621 1622 if (!endring) { 1623 initring(); 1624 rs = ring; 1625 } 1626 1627 text[LINESIZ] = '\r'; 1628 text[LINESIZ + 1] = '\n'; 1629 rs = ring; 1630 for (;;) { 1631 len = endring - rs; 1632 if (len >= LINESIZ) 1633 memmove(text, rs, LINESIZ); 1634 else { 1635 memmove(text, rs, len); 1636 memmove(text + len, ring, LINESIZ - len); 1637 } 1638 if (++rs == endring) 1639 rs = ring; 1640 if (write(s, text, sizeof(text)) != sizeof(text)) 1641 break; 1642 } 1643 exit(0); 1644} 1645 1646/* Character generator */ 1647/* ARGSUSED */ 1648static void 1649chargen_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED) 1650{ 1651 /* struct sockaddr_storage ss; */ 1652 struct sockaddr sa; 1653 static char *rs; 1654 int len; 1655 char text[LINESIZ + 2]; 1656 socklen_t size; 1657 1658 if (endring == 0) { 1659 initring(); 1660 rs = ring; 1661 } 1662 1663 size = sizeof(sa); 1664 if (recvfrom(s, text, sizeof(text), 0, &sa, &size) < 0) 1665 return; 1666 if (dg_badinput((struct sockaddr_in *) &sa)) 1667 return; 1668 1669 if ((len = endring - rs) >= LINESIZ) 1670 memmove(text, rs, LINESIZ); 1671 else { 1672 memmove(text, rs, len); 1673 memmove(text + len, ring, LINESIZ - len); 1674 } 1675 if (++rs == endring) 1676 rs = ring; 1677 text[LINESIZ] = '\r'; 1678 text[LINESIZ + 1] = '\n'; 1679 (void) sendto(s, text, sizeof(text), 0, &sa, sizeof(sa)); 1680} 1681#endif /* FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN */ 1682 1683 1684#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME 1685/* 1686 * Return a machine readable date and time, in the form of the 1687 * number of seconds since midnight, Jan 1, 1900. Since gettimeofday 1688 * returns the number of seconds since midnight, Jan 1, 1970, 1689 * we must add 2208988800 seconds to this figure to make up for 1690 * some seventy years Bell Labs was asleep. 1691 */ 1692 1693static unsigned machtime(void) 1694{ 1695 struct timeval tv; 1696 1697 if (gettimeofday(&tv, NULL) < 0) { 1698 fprintf(stderr, "Unable to get time of day\n"); 1699 return 0L; 1700 } 1701 return htonl((unsigned) tv.tv_sec + 2208988800UL); 1702} 1703 1704/* ARGSUSED */ 1705static void 1706machtime_stream(int s, servtab_t *sep ATTRIBUTE_UNUSED) 1707{ 1708 unsigned result; 1709 1710 result = machtime(); 1711 (void) write(s, (char *) &result, sizeof(result)); 1712} 1713 1714/* ARGSUSED */ 1715static void 1716machtime_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED) 1717{ 1718 unsigned result; 1719 /* struct sockaddr_storage ss; */ 1720 struct sockaddr sa; 1721 struct sockaddr_in *dg_sin; 1722 socklen_t size; 1723 1724 size = sizeof(sa); 1725 if (recvfrom(s, (char *) &result, sizeof(result), 0, &sa, &size) < 0) 1726 return; 1727 /* if (dg_badinput((struct sockaddr *)&ss)) */ 1728 dg_sin = (struct sockaddr_in *) &sa; 1729 if (dg_sin->sin_addr.s_addr == htonl(INADDR_BROADCAST) || 1730 ntohs(dg_sin->sin_port) < IPPORT_RESERVED / 2) 1731 return; 1732 result = machtime(); 1733 (void) sendto(s, (char *) &result, sizeof(result), 0, &sa, sizeof(sa)); 1734} 1735#endif /* FEATURE_INETD_SUPPORT_BUILTIN_TIME */ 1736 1737 1738#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME 1739/* Return human-readable time of day */ 1740/* ARGSUSED */ 1741static void daytime_stream(int s, servtab_t *sep ATTRIBUTE_UNUSED) 1742{ 1743 char buffer[32]; 1744 time_t t; 1745 1746 t = time(NULL); 1747 1748// fdprintf instead? 1749 (void) sprintf(buffer, "%.24s\r\n", ctime(&t)); 1750 (void) write(s, buffer, strlen(buffer)); 1751} 1752 1753/* Return human-readable time of day */ 1754/* ARGSUSED */ 1755void 1756daytime_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED) 1757{ 1758 char buffer[256]; 1759 time_t t; 1760 /* struct sockaddr_storage ss; */ 1761 struct sockaddr sa; 1762 socklen_t size; 1763 1764 t = time(NULL); 1765 1766 size = sizeof(sa); 1767 if (recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size) < 0) 1768 return; 1769 if (dg_badinput((struct sockaddr_in *) &sa)) 1770 return; 1771 (void) sprintf(buffer, "%.24s\r\n", ctime(&t)); 1772 (void) sendto(s, buffer, strlen(buffer), 0, &sa, sizeof(sa)); 1773} 1774#endif /* FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME */ 1775