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 /* IPv6 support, many bug fixes by Denys Vlasenko (c) 2008 */
8 * Copyright (c) 1983,1991 The Regents of the University of California.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the University of
22 * California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40 /* Inetd - Internet super-server
42 * This program invokes configured services when a connection
43 * from a peer is established or a datagram arrives.
44 * Connection-oriented services are invoked each time a
45 * connection is made, by creating a process. This process
46 * is passed the connection as file descriptor 0 and is
47 * expected to do a getpeername to find out peer's host
49 * Datagram oriented services are invoked when a datagram
50 * arrives; a process is created and passed a pending message
51 * on file descriptor 0. peer's address can be obtained
54 * Inetd uses a configuration file which is read at startup
55 * and, possibly, at some later time in response to a hangup signal.
56 * The configuration file is "free format" with fields given in the
57 * order shown below. Continuation lines for an entry must begin with
58 * a space or tab. All fields must be present in each entry.
60 * service_name must be in /etc/services
61 * socket_type stream/dgram/raw/rdm/seqpacket
62 * protocol must be in /etc/protocols
63 * (usually "tcp" or "udp")
64 * wait/nowait[.max] single-threaded/multi-threaded, max #
65 * user[.group] or user[:group] user/group to run daemon as
66 * server_program full path name
67 * server_program_arguments maximum of MAXARGS (20)
70 * service_name/version must be in /etc/rpc
71 * socket_type stream/dgram/raw/rdm/seqpacket
72 * rpc/protocol "rpc/tcp" etc
73 * wait/nowait[.max] single-threaded/multi-threaded
74 * user[.group] or user[:group] user to run daemon as
75 * server_program full path name
76 * server_program_arguments maximum of MAXARGS (20)
78 * For non-RPC services, the "service name" can be of the form
79 * hostaddress:servicename, in which case the hostaddress is used
80 * as the host portion of the address to listen on. If hostaddress
81 * consists of a single '*' character, INADDR_ANY is used.
83 * A line can also consist of just
85 * where hostaddress is as in the preceding paragraph. Such a line must
86 * have no further fields; the specified hostaddress is remembered and
87 * used for all further lines that have no hostaddress specified,
88 * until the next such line (or EOF). (This is why * is provided to
89 * allow explicit specification of INADDR_ANY.) A line
91 * is implicitly in effect at the beginning of the file.
93 * The hostaddress specifier may (and often will) contain dots;
94 * the service name must not.
96 * For RPC services, host-address specifiers are accepted and will
97 * work to some extent; however, because of limitations in the
98 * portmapper interface, it will not work to try to give more than
99 * one line for any given RPC service, even if the host-address
100 * specifiers are different.
102 * Comment lines are indicated by a '#' in column 1.
105 /* inetd rules for passing file descriptors to children
106 * (http://www.freebsd.org/cgi/man.cgi?query=inetd):
108 * The wait/nowait entry specifies whether the server that is invoked by
109 * inetd will take over the socket associated with the service access point,
110 * and thus whether inetd should wait for the server to exit before listen-
111 * ing for new service requests. Datagram servers must use "wait", as
112 * they are always invoked with the original datagram socket bound to the
113 * specified service address. These servers must read at least one datagram
114 * from the socket before exiting. If a datagram server connects to its
115 * peer, freeing the socket so inetd can receive further messages on the
116 * socket, it is said to be a "multi-threaded" server; it should read one
117 * datagram from the socket and create a new socket connected to the peer.
118 * It should fork, and the parent should then exit to allow inetd to check
119 * for new service requests to spawn new servers. Datagram servers which
120 * process all incoming datagrams on a socket and eventually time out are
121 * said to be "single-threaded". The comsat(8), biff(1) and talkd(8)
122 * utilities are both examples of the latter type of datagram server. The
123 * tftpd(8) utility is an example of a multi-threaded datagram server.
125 * Servers using stream sockets generally are multi-threaded and use the
126 * "nowait" entry. Connection requests for these services are accepted by
127 * inetd, and the server is given only the newly-accepted socket connected
128 * to a client of the service. Most stream-based services operate in this
129 * manner. Stream-based servers that use "wait" are started with the lis-
130 * tening service socket, and must accept at least one connection request
131 * before exiting. Such a server would normally accept and process incoming
132 * connection requests until a timeout.
135 /* Despite of above doc saying that dgram services must use "wait",
136 * "udp nowait" servers are implemented in busyboxed inetd.
137 * IPv6 addresses are also implemented. However, they may look ugly -
138 * ":::service..." means "address '::' (IPv6 wildcard addr)":"service"...
139 * You have to put "tcp6"/"udp6" in protocol field to select IPv6.
142 /* Here's the scoop concerning the user[:group] feature:
143 * 1) group is not specified:
144 * a) user = root: NO setuid() or setgid() is done
145 * b) other: initgroups(name, primary group)
146 * setgid(primary group as found in passwd)
148 * 2) group is specified:
149 * a) user = root: setgid(specified group)
152 * b) other: initgroups(name, specified group)
153 * setgid(specified group)
157 //usage:#define inetd_trivial_usage
158 //usage: "[-fe] [-q N] [-R N] [CONFFILE]"
159 //usage:#define inetd_full_usage "\n\n"
160 //usage: "Listen for network connections and launch programs\n"
161 //usage: "\n -f Run in foreground"
162 //usage: "\n -e Log to stderr"
163 //usage: "\n -q N Socket listen queue (default: 128)"
164 //usage: "\n -R N Pause services after N connects/min"
165 //usage: "\n (default: 0 - disabled)"
168 #include <sys/resource.h> /* setrlimit */
169 #include <sys/socket.h> /* un.h may need this */
173 #include "common_bufsiz.h"
175 #if ENABLE_FEATURE_INETD_RPC
176 # if defined(__UCLIBC__) && ! defined(__UCLIBC_HAS_RPC__)
177 # error "You need to build uClibc with UCLIBC_HAS_RPC for NFS support"
179 # include <rpc/rpc.h>
180 # include <rpc/pmap_clnt.h>
184 /* stream version of chargen is forking but not execing,
185 * can't do that (easily) on NOMMU */
186 #undef ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
187 #define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 0
190 #define CNT_INTERVAL 60 /* servers in CNT_INTERVAL sec. */
191 #define RETRYTIME 60 /* retry after bind or server fail */
193 // TODO: explain, or get rid of setrlimit games
195 #ifndef RLIMIT_NOFILE
196 #define RLIMIT_NOFILE RLIMIT_OFILE
203 /* Reserve some descriptors, 3 stdio + at least: 1 log, 1 conf. file */
206 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD \
207 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO \
208 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN \
209 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME \
210 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
211 # define INETD_BUILTINS_ENABLED
214 typedef struct servtab_t {
215 /* The most frequently referenced one: */
216 int se_fd; /* open descriptor */
217 /* NB: 'biggest fields last' saves on code size (~250 bytes) */
218 /* [addr:]service socktype proto wait user[:group] prog [args] */
219 char *se_local_hostname; /* addr to listen on */
220 char *se_service; /* "80" or "www" or "mount/2[-3]" */
221 /* socktype is in se_socktype */ /* "stream" "dgram" "raw" "rdm" "seqpacket" */
222 char *se_proto; /* "unix" or "[rpc/]tcp[6]" */
223 #if ENABLE_FEATURE_INETD_RPC
224 int se_rpcprog; /* rpc program number */
225 int se_rpcver_lo; /* rpc program lowest version */
226 int se_rpcver_hi; /* rpc program highest version */
227 #define is_rpc_service(sep) ((sep)->se_rpcver_lo != 0)
229 #define is_rpc_service(sep) 0
231 pid_t se_wait; /* 0:"nowait", 1:"wait", >1:"wait" */
232 /* and waiting for this pid */
233 socktype_t se_socktype; /* SOCK_STREAM/DGRAM/RDM/... */
234 family_t se_family; /* AF_UNIX/INET[6] */
235 /* se_proto_no is used by RPC code only... hmm */
236 smallint se_proto_no; /* IPPROTO_TCP/UDP, n/a for AF_UNIX */
237 smallint se_checked; /* looked at during merge */
238 unsigned se_max; /* allowed instances per minute */
239 unsigned se_count; /* number started since se_time */
240 unsigned se_time; /* when we started counting */
241 char *se_user; /* user name to run as */
242 char *se_group; /* group name to run as, can be NULL */
243 #ifdef INETD_BUILTINS_ENABLED
244 const struct builtin *se_builtin; /* if built-in, description */
246 struct servtab_t *se_next;
247 len_and_sockaddr *se_lsa;
248 char *se_program; /* server program */
250 char *se_argv[MAXARGV + 1]; /* program arguments */
253 #ifdef INETD_BUILTINS_ENABLED
254 /* Echo received data */
255 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
256 static void FAST_FUNC echo_stream(int, servtab_t *);
257 static void FAST_FUNC echo_dg(int, servtab_t *);
259 /* Internet /dev/null */
260 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
261 static void FAST_FUNC discard_stream(int, servtab_t *);
262 static void FAST_FUNC discard_dg(int, servtab_t *);
264 /* Return 32 bit time since 1900 */
265 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
266 static void FAST_FUNC machtime_stream(int, servtab_t *);
267 static void FAST_FUNC machtime_dg(int, servtab_t *);
269 /* Return human-readable time */
270 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
271 static void FAST_FUNC daytime_stream(int, servtab_t *);
272 static void FAST_FUNC daytime_dg(int, servtab_t *);
274 /* Familiar character generator */
275 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
276 static void FAST_FUNC chargen_stream(int, servtab_t *);
277 static void FAST_FUNC chargen_dg(int, servtab_t *);
281 /* NB: not necessarily NUL terminated */
282 char bi_service7[7]; /* internally provided service name */
283 uint8_t bi_fork; /* 1 if stream fn should run in child */
284 void (*bi_stream_fn)(int, servtab_t *) FAST_FUNC;
285 void (*bi_dgram_fn)(int, servtab_t *) FAST_FUNC;
288 static const struct builtin builtins[] = {
289 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
290 { "echo", 1, echo_stream, echo_dg },
292 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
293 { "discard", 1, discard_stream, discard_dg },
295 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
296 { "chargen", 1, chargen_stream, chargen_dg },
298 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
299 { "time", 0, machtime_stream, machtime_dg },
301 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
302 { "daytime", 0, daytime_stream, daytime_dg },
305 #endif /* INETD_BUILTINS_ENABLED */
308 rlim_t rlim_ofile_cur;
309 struct rlimit rlim_ofile;
310 servtab_t *serv_list;
312 int maxsock; /* max fd# in allsock, -1: unknown */
313 /* whenever maxsock grows, prev_maxsock is set to new maxsock,
314 * but if maxsock is set to -1, prev_maxsock is not changed */
316 unsigned max_concurrency;
317 smallint alarm_armed;
318 uid_t real_uid; /* user ID who ran us */
319 const char *config_filename;
321 char *default_local_hostname;
322 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
328 /* Used in next_line(), and as scratch read buffer */
329 char line[256]; /* _at least_ 256, see LINE_SIZE */
331 #define G (*(struct globals*)bb_common_bufsiz1)
332 enum { LINE_SIZE = COMMON_BUFSIZE - offsetof(struct globals, line) };
333 #define rlim_ofile_cur (G.rlim_ofile_cur )
334 #define rlim_ofile (G.rlim_ofile )
335 #define serv_list (G.serv_list )
336 #define global_queuelen (G.global_queuelen)
337 #define maxsock (G.maxsock )
338 #define prev_maxsock (G.prev_maxsock )
339 #define max_concurrency (G.max_concurrency)
340 #define alarm_armed (G.alarm_armed )
341 #define real_uid (G.real_uid )
342 #define config_filename (G.config_filename)
343 #define parser (G.parser )
344 #define default_local_hostname (G.default_local_hostname)
345 #define first_ps_byte (G.first_ps_byte )
346 #define last_ps_byte (G.last_ps_byte )
347 #define end_ring (G.end_ring )
348 #define ring_pos (G.ring_pos )
349 #define ring (G.ring )
350 #define allsock (G.allsock )
351 #define line (G.line )
352 #define INIT_G() do { \
353 BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
354 rlim_ofile_cur = OPEN_MAX; \
355 global_queuelen = 128; \
356 config_filename = "/etc/inetd.conf"; \
360 # define dbg(...) ((void)0)
364 int dbg_fd = open("inetd_debug.log", O_WRONLY | O_CREAT | O_APPEND, 0666); \
366 fdprintf(dbg_fd, "%d: ", getpid()); \
367 fdprintf(dbg_fd, __VA_ARGS__); \
373 static void maybe_close(int fd)
377 dbg("closed fd:%d\n", fd);
381 // TODO: move to libbb?
382 static len_and_sockaddr *xzalloc_lsa(int family)
384 len_and_sockaddr *lsa;
387 sz = sizeof(struct sockaddr_in);
388 if (family == AF_UNIX)
389 sz = sizeof(struct sockaddr_un);
390 #if ENABLE_FEATURE_IPV6
391 if (family == AF_INET6)
392 sz = sizeof(struct sockaddr_in6);
394 lsa = xzalloc(LSA_LEN_SIZE + sz);
396 lsa->u.sa.sa_family = family;
400 static void rearm_alarm(void)
408 static void block_CHLD_HUP_ALRM(sigset_t *m)
411 sigaddset(m, SIGCHLD);
412 sigaddset(m, SIGHUP);
413 sigaddset(m, SIGALRM);
414 sigprocmask(SIG_BLOCK, m, m); /* old sigmask is stored in m */
417 static void restore_sigmask(sigset_t *m)
419 sigprocmask(SIG_SETMASK, m, NULL);
422 #if ENABLE_FEATURE_INETD_RPC
423 static void register_rpc(servtab_t *sep)
426 struct sockaddr_in ir_sin;
429 size = sizeof(ir_sin);
430 if (getsockname(sep->se_fd, (struct sockaddr *) &ir_sin, &size) < 0) {
431 bb_perror_msg("getsockname");
435 for (n = sep->se_rpcver_lo; n <= sep->se_rpcver_hi; n++) {
436 pmap_unset(sep->se_rpcprog, n);
437 if (!pmap_set(sep->se_rpcprog, n, sep->se_proto_no, ntohs(ir_sin.sin_port)))
438 bb_perror_msg("%s %s: pmap_set(%u,%u,%u,%u)",
439 sep->se_service, sep->se_proto,
440 sep->se_rpcprog, n, sep->se_proto_no, ntohs(ir_sin.sin_port));
444 static void unregister_rpc(servtab_t *sep)
448 for (n = sep->se_rpcver_lo; n <= sep->se_rpcver_hi; n++) {
449 if (!pmap_unset(sep->se_rpcprog, n))
450 bb_perror_msg("pmap_unset(%u,%u)", sep->se_rpcprog, n);
453 #endif /* FEATURE_INETD_RPC */
455 static void bump_nofile(void)
457 enum { FD_CHUNK = 32 };
460 /* Never fails under Linux (except if you pass it bad arguments) */
461 getrlimit(RLIMIT_NOFILE, &rl);
462 rl.rlim_cur = MIN(rl.rlim_max, rl.rlim_cur + FD_CHUNK);
463 rl.rlim_cur = MIN(FD_SETSIZE, rl.rlim_cur + FD_CHUNK);
464 if (rl.rlim_cur <= rlim_ofile_cur) {
465 bb_error_msg("can't extend file limit, max = %d",
470 if (setrlimit(RLIMIT_NOFILE, &rl) < 0) {
471 bb_perror_msg("setrlimit");
475 rlim_ofile_cur = rl.rlim_cur;
478 static void remove_fd_from_set(int fd)
481 FD_CLR(fd, &allsock);
482 dbg("stopped listening on fd:%d\n", fd);
484 dbg("maxsock:%d\n", maxsock);
488 static void add_fd_to_set(int fd)
491 FD_SET(fd, &allsock);
492 dbg("started listening on fd:%d\n", fd);
493 if (maxsock >= 0 && fd > maxsock) {
494 prev_maxsock = maxsock = fd;
495 dbg("maxsock:%d\n", maxsock);
496 if ((rlim_t)fd > rlim_ofile_cur - FD_MARGIN)
502 static void recalculate_maxsock(void)
506 /* We may have no services, in this case maxsock should still be >= 0
507 * (code elsewhere is not happy with maxsock == -1) */
509 while (fd <= prev_maxsock) {
510 if (FD_ISSET(fd, &allsock))
514 dbg("recalculated maxsock:%d\n", maxsock);
515 prev_maxsock = maxsock;
516 if ((rlim_t)maxsock > rlim_ofile_cur - FD_MARGIN)
520 static void prepare_socket_fd(servtab_t *sep)
524 fd = socket(sep->se_family, sep->se_socktype, 0);
526 bb_perror_msg("socket");
529 setsockopt_reuseaddr(fd);
531 #if ENABLE_FEATURE_INETD_RPC
532 if (is_rpc_service(sep)) {
535 /* zero out the port for all RPC services; let bind()
537 set_nport(&sep->se_lsa->u.sa, 0);
539 /* for RPC services, attempt to use a reserved port
540 * if they are going to be running as root. */
541 if (real_uid == 0 && sep->se_family == AF_INET
542 && (pwd = getpwnam(sep->se_user)) != NULL
545 r = bindresvport(fd, &sep->se_lsa->u.sin);
547 r = bind(fd, &sep->se_lsa->u.sa, sep->se_lsa->len);
550 int saveerrno = errno;
551 /* update lsa with port# */
552 getsockname(fd, &sep->se_lsa->u.sa, &sep->se_lsa->len);
558 if (sep->se_family == AF_UNIX) {
559 struct sockaddr_un *sun;
560 sun = (struct sockaddr_un*)&(sep->se_lsa->u.sa);
561 unlink(sun->sun_path);
563 r = bind(fd, &sep->se_lsa->u.sa, sep->se_lsa->len);
566 bb_perror_msg("%s/%s: bind",
567 sep->se_service, sep->se_proto);
573 if (sep->se_socktype == SOCK_STREAM) {
574 listen(fd, global_queuelen);
575 dbg("new sep->se_fd:%d (stream)\n", fd);
577 dbg("new sep->se_fd:%d (!stream)\n", fd);
584 static int reopen_config_file(void)
586 free(default_local_hostname);
587 default_local_hostname = xstrdup("*");
589 config_close(parser);
590 parser = config_open(config_filename);
591 return (parser != NULL);
594 static void close_config_file(void)
597 config_close(parser);
602 static void free_servtab_strings(servtab_t *cp)
606 free(cp->se_local_hostname);
607 free(cp->se_service);
611 free(cp->se_lsa); /* not a string in fact */
612 free(cp->se_program);
613 for (i = 0; i < MAXARGV; i++)
614 free(cp->se_argv[i]);
617 static servtab_t *new_servtab(void)
619 servtab_t *newtab = xzalloc(sizeof(servtab_t));
620 newtab->se_fd = -1; /* paranoia */
624 static servtab_t *dup_servtab(servtab_t *sep)
629 newtab = new_servtab();
630 *newtab = *sep; /* struct copy */
631 /* deep-copying strings */
632 newtab->se_service = xstrdup(newtab->se_service);
633 newtab->se_proto = xstrdup(newtab->se_proto);
634 newtab->se_user = xstrdup(newtab->se_user);
635 newtab->se_group = xstrdup(newtab->se_group);
636 newtab->se_program = xstrdup(newtab->se_program);
637 for (argc = 0; argc <= MAXARGV; argc++)
638 newtab->se_argv[argc] = xstrdup(newtab->se_argv[argc]);
639 /* NB: se_fd, se_hostaddr and se_next are always
640 * overwrittend by callers, so we don't bother resetting them
641 * to NULL/0/-1 etc */
646 /* gcc generates much more code if this is inlined */
647 static NOINLINE servtab_t *parse_one_line(void)
650 char *token[6+MAXARGV];
658 argc = config_read(parser, token, 6+MAXARGV, 1, "# \t", PARSE_NORMAL);
664 /* [host:]service socktype proto wait user[:group] prog [args] */
665 /* Check for "host:...." line */
667 hostdelim = strrchr(arg, ':');
670 sep->se_local_hostname = xstrdup(arg);
672 if (*arg == '\0' && argc == 1) {
673 /* Line has just "host:", change the
674 * default host for the following lines. */
675 free(default_local_hostname);
676 default_local_hostname = sep->se_local_hostname;
677 /*sep->se_local_hostname = NULL; - redundant */
678 /* (we'll overwrite this field anyway) */
682 sep->se_local_hostname = xstrdup(default_local_hostname);
684 /* service socktype proto wait user[:group] prog [args] */
685 sep->se_service = xstrdup(arg);
687 /* socktype proto wait user[:group] prog [args] */
690 bb_error_msg("parse error on line %u, line is ignored",
692 /* Just "goto more" can make sep to carry over e.g.
693 * "rpc"-ness (by having se_rpcver_lo != 0).
694 * We will be more paranoid: */
695 free_servtab_strings(sep);
701 static const int8_t SOCK_xxx[] ALIGN1 = {
703 SOCK_STREAM, SOCK_DGRAM, SOCK_RDM,
704 SOCK_SEQPACKET, SOCK_RAW
706 sep->se_socktype = SOCK_xxx[1 + index_in_strings(
707 "stream""\0" "dgram""\0" "rdm""\0"
708 "seqpacket""\0" "raw""\0"
712 /* {unix,[rpc/]{tcp,udp}[6]} wait user[:group] prog [args] */
713 sep->se_proto = arg = xstrdup(token[2]);
714 if (strcmp(arg, "unix") == 0) {
715 sep->se_family = AF_UNIX;
718 sep->se_family = AF_INET;
719 six = last_char_is(arg, '6');
721 #if ENABLE_FEATURE_IPV6
723 sep->se_family = AF_INET6;
725 bb_error_msg("%s: no support for IPv6", sep->se_proto);
729 if (is_prefixed_with(arg, "rpc/")) {
730 #if ENABLE_FEATURE_INETD_RPC
733 p = strchr(sep->se_service, '/');
735 bb_error_msg("no rpc version: '%s'", sep->se_service);
739 n = bb_strtou(p, &p, 10);
742 bb_error_msg("bad rpc version");
745 sep->se_rpcver_lo = sep->se_rpcver_hi = n;
748 n = bb_strtou(p, &p, 10);
749 if (n > INT_MAX || (int)n < sep->se_rpcver_lo)
751 sep->se_rpcver_hi = n;
756 bb_error_msg("no support for rpc services");
760 /* we don't really need getprotobyname()! */
761 if (strcmp(arg, "tcp") == 0)
762 sep->se_proto_no = IPPROTO_TCP; /* = 6 */
763 if (strcmp(arg, "udp") == 0)
764 sep->se_proto_no = IPPROTO_UDP; /* = 17 */
767 if (!sep->se_proto_no) /* not tcp/udp?? */
771 /* [no]wait[.max] user[:group] prog [args] */
773 sep->se_max = max_concurrency;
774 p = strchr(arg, '.');
777 sep->se_max = bb_strtou(p, NULL, 10);
781 sep->se_wait = (arg[0] != 'n' || arg[1] != 'o');
782 if (!sep->se_wait) /* "no" seen */
784 if (strcmp(arg, "wait") != 0)
787 /* user[:group] prog [args] */
788 sep->se_user = xstrdup(token[4]);
789 arg = strchr(sep->se_user, '.');
791 arg = strchr(sep->se_user, ':');
794 sep->se_group = xstrdup(arg);
798 sep->se_program = xstrdup(token[5]);
799 #ifdef INETD_BUILTINS_ENABLED
800 if (strcmp(sep->se_program, "internal") == 0
801 && strlen(sep->se_service) <= 7
802 && (sep->se_socktype == SOCK_STREAM
803 || sep->se_socktype == SOCK_DGRAM)
806 for (i = 0; i < ARRAY_SIZE(builtins); i++)
807 if (strncmp(builtins[i].bi_service7, sep->se_service, 7) == 0)
809 bb_error_msg("unknown internal service %s", sep->se_service);
812 sep->se_builtin = &builtins[i];
813 /* stream builtins must be "nowait", dgram must be "wait" */
814 if (sep->se_wait != (sep->se_socktype == SOCK_DGRAM))
819 while (argc < MAXARGV && (arg = token[6+argc]) != NULL)
820 sep->se_argv[argc++] = xstrdup(arg);
821 /* Some inetd.conf files have no argv's, not even argv[0].
823 * (Technically, programs can be execed with argv[0] = NULL,
824 * but many programs do not like that at all) */
826 sep->se_argv[0] = xstrdup(sep->se_program);
828 /* catch mixups. "<service> stream udp ..." == wtf */
829 if (sep->se_socktype == SOCK_STREAM) {
830 if (sep->se_proto_no == IPPROTO_UDP)
833 if (sep->se_socktype == SOCK_DGRAM) {
834 if (sep->se_proto_no == IPPROTO_TCP)
839 // "ENTRY[%s][%s][%s][%d][%d][%d][%d][%d][%s][%s][%s]",
840 // sep->se_local_hostname, sep->se_service, sep->se_proto, sep->se_wait, sep->se_proto_no,
841 // sep->se_max, sep->se_count, sep->se_time, sep->se_user, sep->se_group, sep->se_program);
843 /* check if the hostname specifier is a comma separated list
844 * of hostnames. we'll make new entries for each address. */
845 while ((hostdelim = strrchr(sep->se_local_hostname, ',')) != NULL) {
846 nsep = dup_servtab(sep);
847 /* NUL terminate the hostname field of the existing entry,
848 * and make a dup for the new entry. */
850 nsep->se_local_hostname = xstrdup(hostdelim);
851 nsep->se_next = sep->se_next;
855 /* was doing it here: */
856 /* DNS resolution, create copies for each IP address */
857 /* IPv6-ization destroyed it :( */
862 static servtab_t *insert_in_servlist(servtab_t *cp)
868 *sep = *cp; /* struct copy */
870 #if ENABLE_FEATURE_INETD_RPC
871 sep->se_rpcprog = -1;
873 block_CHLD_HUP_ALRM(&omask);
874 sep->se_next = serv_list;
876 restore_sigmask(&omask);
880 static int same_serv_addr_proto(servtab_t *old, servtab_t *new)
882 if (strcmp(old->se_local_hostname, new->se_local_hostname) != 0)
884 if (strcmp(old->se_service, new->se_service) != 0)
886 if (strcmp(old->se_proto, new->se_proto) != 0)
891 static void reread_config_file(int sig UNUSED_PARAM)
893 servtab_t *sep, *cp, **sepp;
894 len_and_sockaddr *lsa;
898 int save_errno = errno;
900 if (!reopen_config_file())
902 for (sep = serv_list; sep; sep = sep->se_next)
909 cp = parse_one_line();
913 for (sep = serv_list; sep; sep = sep->se_next)
914 if (same_serv_addr_proto(sep, cp))
916 /* not an "equal" servtab */
917 sep = insert_in_servlist(cp);
923 block_CHLD_HUP_ALRM(&omask);
924 #if ENABLE_FEATURE_INETD_RPC
925 if (is_rpc_service(sep))
927 sep->se_rpcver_lo = cp->se_rpcver_lo;
928 sep->se_rpcver_hi = cp->se_rpcver_hi;
930 if (cp->se_wait == 0) {
931 /* New config says "nowait". If old one
932 * was "wait", we currently may be waiting
933 * for a child (and not accepting connects).
934 * Stop waiting, start listening again.
935 * (if it's not true, this op is harmless) */
936 add_fd_to_set(sep->se_fd);
938 sep->se_wait = cp->se_wait;
939 sep->se_max = cp->se_max;
940 /* string fields need more love - we don't want to leak them */
941 #define SWAP(type, a, b) do { type c = (type)a; a = (type)b; b = (type)c; } while (0)
942 SWAP(char*, sep->se_user, cp->se_user);
943 SWAP(char*, sep->se_group, cp->se_group);
944 SWAP(char*, sep->se_program, cp->se_program);
945 for (i = 0; i < MAXARGV; i++)
946 SWAP(char*, sep->se_argv[i], cp->se_argv[i]);
948 restore_sigmask(&omask);
949 free_servtab_strings(cp);
952 /* cp->string_fields are consumed by insert_in_servlist()
953 * or freed at this point, cp itself is not yet freed. */
956 /* create new len_and_sockaddr */
957 switch (sep->se_family) {
958 struct sockaddr_un *sun;
960 lsa = xzalloc_lsa(AF_UNIX);
961 sun = (struct sockaddr_un*)&lsa->u.sa;
962 safe_strncpy(sun->sun_path, sep->se_service, sizeof(sun->sun_path));
965 default: /* case AF_INET, case AF_INET6 */
966 n = bb_strtou(sep->se_service, NULL, 10);
967 #if ENABLE_FEATURE_INETD_RPC
968 if (is_rpc_service(sep)) {
970 if (errno) { /* se_service is not numeric */
971 struct rpcent *rp = getrpcbyname(sep->se_service);
973 bb_error_msg("%s: unknown rpc service", sep->se_service);
976 sep->se_rpcprog = rp->r_number;
978 if (sep->se_fd == -1)
979 prepare_socket_fd(sep);
980 if (sep->se_fd != -1)
985 /* what port to listen on? */
987 if (errno || n > 0xffff) { /* se_service is not numeric */
990 /* can result only in "tcp" or "udp": */
991 safe_strncpy(protoname, sep->se_proto, 4);
992 sp = getservbyname(sep->se_service, protoname);
994 bb_error_msg("%s/%s: unknown service",
995 sep->se_service, sep->se_proto);
1000 if (LONE_CHAR(sep->se_local_hostname, '*')) {
1001 lsa = xzalloc_lsa(sep->se_family);
1002 set_nport(&lsa->u.sa, port);
1004 lsa = host_and_af2sockaddr(sep->se_local_hostname,
1005 ntohs(port), sep->se_family);
1007 bb_error_msg("%s/%s: unknown host '%s'",
1008 sep->se_service, sep->se_proto,
1009 sep->se_local_hostname);
1014 } /* end of "switch (sep->se_family)" */
1016 /* did lsa change? Then close/open */
1017 if (sep->se_lsa == NULL
1018 || lsa->len != sep->se_lsa->len
1019 || memcmp(&lsa->u.sa, &sep->se_lsa->u.sa, lsa->len) != 0
1021 remove_fd_from_set(sep->se_fd);
1022 maybe_close(sep->se_fd);
1029 if (sep->se_fd == -1)
1030 prepare_socket_fd(sep);
1035 } /* end of "while (1) parse lines" */
1036 close_config_file();
1038 /* Purge anything not looked at above - these are stale entries,
1039 * new config file doesnt have them. */
1040 block_CHLD_HUP_ALRM(&omask);
1042 while ((sep = *sepp) != NULL) {
1043 if (sep->se_checked) {
1044 sepp = &sep->se_next;
1047 *sepp = sep->se_next;
1048 remove_fd_from_set(sep->se_fd);
1049 maybe_close(sep->se_fd);
1050 #if ENABLE_FEATURE_INETD_RPC
1051 if (is_rpc_service(sep))
1052 unregister_rpc(sep);
1054 if (sep->se_family == AF_UNIX)
1055 unlink(sep->se_service);
1056 free_servtab_strings(sep);
1059 restore_sigmask(&omask);
1064 static void reap_child(int sig UNUSED_PARAM)
1069 int save_errno = errno;
1072 pid = wait_any_nohang(&status);
1075 for (sep = serv_list; sep; sep = sep->se_next) {
1076 if (sep->se_wait != pid)
1078 /* One of our "wait" services */
1079 if (WIFEXITED(status) && WEXITSTATUS(status))
1080 bb_error_msg("%s: exit status %u",
1081 sep->se_program, WEXITSTATUS(status));
1082 else if (WIFSIGNALED(status))
1083 bb_error_msg("%s: exit signal %u",
1084 sep->se_program, WTERMSIG(status));
1086 add_fd_to_set(sep->se_fd);
1093 static void retry_network_setup(int sig UNUSED_PARAM)
1095 int save_errno = errno;
1099 for (sep = serv_list; sep; sep = sep->se_next) {
1100 if (sep->se_fd == -1) {
1101 prepare_socket_fd(sep);
1102 #if ENABLE_FEATURE_INETD_RPC
1103 if (sep->se_fd != -1 && is_rpc_service(sep))
1111 static void clean_up_and_exit(int sig UNUSED_PARAM)
1115 /* XXX signal race walking sep list */
1116 for (sep = serv_list; sep; sep = sep->se_next) {
1117 if (sep->se_fd == -1)
1120 switch (sep->se_family) {
1122 unlink(sep->se_service);
1124 default: /* case AF_INET, AF_INET6 */
1125 #if ENABLE_FEATURE_INETD_RPC
1126 if (sep->se_wait == 1 && is_rpc_service(sep))
1127 unregister_rpc(sep); /* XXX signal race */
1131 if (ENABLE_FEATURE_CLEAN_UP)
1134 remove_pidfile(CONFIG_PID_FILE_PATH "/inetd.pid");
1138 int inetd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1139 int inetd_main(int argc UNUSED_PARAM, char **argv)
1141 struct sigaction sa, saved_pipe_handler;
1142 servtab_t *sep, *sep2;
1144 struct group *grp = grp; /* for compiler */
1151 real_uid = getuid();
1152 if (real_uid != 0) /* run by non-root user */
1153 config_filename = NULL;
1155 opt_complementary = "R+:q+"; /* -q N, -R N */
1156 opt = getopt32(argv, "R:feq:", &max_concurrency, &global_queuelen);
1160 config_filename = argv[0];
1161 if (config_filename == NULL)
1162 bb_error_msg_and_die("non-root must specify config file");
1164 bb_daemonize_or_rexec(0, argv - optind);
1166 bb_sanitize_stdio();
1168 /* LOG_NDELAY: connect to syslog daemon NOW.
1169 * Otherwise, we may open syslog socket
1170 * in vforked child, making opened fds and syslog()
1171 * internal state inconsistent.
1172 * This was observed to leak file descriptors. */
1173 openlog(applet_name, LOG_PID | LOG_NDELAY, LOG_DAEMON);
1174 logmode = LOGMODE_SYSLOG;
1177 if (real_uid == 0) {
1178 /* run by root, ensure groups vector gets trashed */
1179 gid_t gid = getgid();
1183 write_pidfile(CONFIG_PID_FILE_PATH "/inetd.pid");
1185 /* never fails under Linux (except if you pass it bad arguments) */
1186 getrlimit(RLIMIT_NOFILE, &rlim_ofile);
1187 rlim_ofile_cur = rlim_ofile.rlim_cur;
1188 if (rlim_ofile_cur == RLIM_INFINITY) /* ! */
1189 rlim_ofile_cur = OPEN_MAX;
1191 memset(&sa, 0, sizeof(sa));
1192 /*sigemptyset(&sa.sa_mask); - memset did it */
1193 sigaddset(&sa.sa_mask, SIGALRM);
1194 sigaddset(&sa.sa_mask, SIGCHLD);
1195 sigaddset(&sa.sa_mask, SIGHUP);
1196 //FIXME: explain why no SA_RESTART
1197 //FIXME: retry_network_setup is unsafe to run in signal handler (many reasons)!
1198 sa.sa_handler = retry_network_setup;
1199 sigaction_set(SIGALRM, &sa);
1200 //FIXME: reread_config_file is unsafe to run in signal handler(many reasons)!
1201 sa.sa_handler = reread_config_file;
1202 sigaction_set(SIGHUP, &sa);
1203 //FIXME: reap_child is unsafe to run in signal handler (uses stdio)!
1204 sa.sa_handler = reap_child;
1205 sigaction_set(SIGCHLD, &sa);
1206 //FIXME: clean_up_and_exit is unsafe to run in signal handler (uses stdio)!
1207 sa.sa_handler = clean_up_and_exit;
1208 sigaction_set(SIGTERM, &sa);
1209 sa.sa_handler = clean_up_and_exit;
1210 sigaction_set(SIGINT, &sa);
1211 sa.sa_handler = SIG_IGN;
1212 sigaction(SIGPIPE, &sa, &saved_pipe_handler);
1214 reread_config_file(SIGHUP); /* load config from file */
1218 int ctrl, accepted_fd, new_udp_fd;
1222 recalculate_maxsock();
1224 readable = allsock; /* struct copy */
1225 /* if there are no fds to wait on, we will block
1226 * until signal wakes us up (maxsock == 0, but readable
1227 * never contains fds 0 and 1...) */
1228 ready_fd_cnt = select(maxsock + 1, &readable, NULL, NULL, NULL);
1229 if (ready_fd_cnt < 0) {
1230 if (errno != EINTR) {
1231 bb_perror_msg("select");
1236 dbg("ready_fd_cnt:%d\n", ready_fd_cnt);
1238 for (sep = serv_list; ready_fd_cnt && sep; sep = sep->se_next) {
1239 if (sep->se_fd == -1 || !FD_ISSET(sep->se_fd, &readable))
1242 dbg("ready fd:%d\n", sep->se_fd);
1247 if (!sep->se_wait) {
1248 if (sep->se_socktype == SOCK_STREAM) {
1249 ctrl = accepted_fd = accept(sep->se_fd, NULL, NULL);
1250 dbg("accepted_fd:%d\n", accepted_fd);
1253 bb_perror_msg("accept (for %s)", sep->se_service);
1258 if (sep->se_socktype == SOCK_DGRAM
1259 && sep->se_family != AF_UNIX
1261 /* How udp "nowait" works:
1262 * child peeks at (received and buffered by kernel) UDP packet,
1263 * performs connect() on the socket so that it is linked only
1264 * to this peer. But this also affects parent, because descriptors
1265 * are shared after fork() a-la dup(). When parent performs
1266 * select(), it will see this descriptor connected to the peer (!)
1267 * and still readable, will act on it and mess things up
1268 * (can create many copies of same child, etc).
1269 * Parent must create and use new socket instead. */
1270 new_udp_fd = socket(sep->se_family, SOCK_DGRAM, 0);
1271 dbg("new_udp_fd:%d\n", new_udp_fd);
1272 if (new_udp_fd < 0) { /* error: eat packet, forget about it */
1274 recv(sep->se_fd, line, LINE_SIZE, MSG_DONTWAIT);
1277 setsockopt_reuseaddr(new_udp_fd);
1278 /* TODO: better do bind after fork in parent,
1279 * so that we don't have two wildcard bound sockets
1280 * even for a brief moment? */
1281 if (bind(new_udp_fd, &sep->se_lsa->u.sa, sep->se_lsa->len) < 0) {
1282 dbg("bind(new_udp_fd) failed\n");
1286 dbg("bind(new_udp_fd) succeeded\n");
1290 block_CHLD_HUP_ALRM(&omask);
1292 #ifdef INETD_BUILTINS_ENABLED
1293 /* do we need to fork? */
1294 if (sep->se_builtin == NULL
1295 || (sep->se_socktype == SOCK_STREAM
1296 && sep->se_builtin->bi_fork))
1299 if (sep->se_max != 0) {
1300 if (++sep->se_count == 1)
1301 sep->se_time = monotonic_sec();
1302 else if (sep->se_count >= sep->se_max) {
1303 unsigned now = monotonic_sec();
1304 /* did we accumulate se_max connects too quickly? */
1305 if (now - sep->se_time <= CNT_INTERVAL) {
1306 bb_error_msg("%s/%s: too many connections, pausing",
1307 sep->se_service, sep->se_proto);
1308 remove_fd_from_set(sep->se_fd);
1312 rearm_alarm(); /* will revive it in RETRYTIME sec */
1313 restore_sigmask(&omask);
1314 maybe_close(new_udp_fd);
1315 maybe_close(accepted_fd);
1316 continue; /* -> check next fd in fd set */
1321 /* on NOMMU, streamed chargen
1322 * builtin wouldn't work, but it is
1323 * not allowed on NOMMU (ifdefed out) */
1324 #ifdef INETD_BUILTINS_ENABLED
1325 if (BB_MMU && sep->se_builtin)
1331 if (pid < 0) { /* fork error */
1332 bb_perror_msg("vfork"+1);
1334 restore_sigmask(&omask);
1335 maybe_close(new_udp_fd);
1336 maybe_close(accepted_fd);
1337 continue; /* -> check next fd in fd set */
1340 pid--; /* -1: "we did fork and we are child" */
1342 /* if pid == 0 here, we didn't fork */
1344 if (pid > 0) { /* parent */
1346 /* wait: we passed socket to child,
1347 * will wait for child to terminate */
1349 remove_fd_from_set(sep->se_fd);
1351 if (new_udp_fd >= 0) {
1352 /* udp nowait: child connected the socket,
1353 * we created and will use new, unconnected one */
1354 xmove_fd(new_udp_fd, sep->se_fd);
1355 dbg("moved new_udp_fd:%d to sep->se_fd:%d\n", new_udp_fd, sep->se_fd);
1357 restore_sigmask(&omask);
1358 maybe_close(accepted_fd);
1359 continue; /* -> check next fd in fd set */
1362 /* we are either child or didn't fork at all */
1363 #ifdef INETD_BUILTINS_ENABLED
1364 if (sep->se_builtin) {
1365 if (pid) { /* "pid" is -1: we did fork */
1366 close(sep->se_fd); /* listening socket */
1367 dbg("closed sep->se_fd:%d\n", sep->se_fd);
1368 logmode = LOGMODE_NONE; /* make xwrite etc silent */
1370 restore_sigmask(&omask);
1371 if (sep->se_socktype == SOCK_STREAM)
1372 sep->se_builtin->bi_stream_fn(ctrl, sep);
1374 sep->se_builtin->bi_dgram_fn(ctrl, sep);
1375 if (pid) /* we did fork */
1376 _exit(EXIT_FAILURE);
1377 maybe_close(accepted_fd);
1378 continue; /* -> check next fd in fd set */
1384 if (new_udp_fd >= 0) {
1385 len_and_sockaddr *lsa;
1389 dbg("closed new_udp_fd:%d\n", new_udp_fd);
1390 lsa = xzalloc_lsa(sep->se_family);
1391 /* peek at the packet and remember peer addr */
1392 r = recvfrom(ctrl, NULL, 0, MSG_PEEK|MSG_DONTWAIT,
1393 &lsa->u.sa, &lsa->len);
1396 /* make this socket "connected" to peer addr:
1397 * only packets from this peer will be recv'ed,
1398 * and bare write()/send() will work on it */
1399 connect(ctrl, &lsa->u.sa, lsa->len);
1400 dbg("connected ctrl:%d to remote peer\n", ctrl);
1403 /* prepare env and exec program */
1404 pwd = getpwnam(sep->se_user);
1406 bb_error_msg("%s: no such %s", sep->se_user, "user");
1409 if (sep->se_group && (grp = getgrnam(sep->se_group)) == NULL) {
1410 bb_error_msg("%s: no such %s", sep->se_group, "group");
1413 if (real_uid != 0 && real_uid != pwd->pw_uid) {
1414 /* a user running private inetd */
1415 bb_error_msg("non-root must run services as himself");
1418 if (pwd->pw_uid != 0) {
1420 pwd->pw_gid = grp->gr_gid;
1421 /* initgroups, setgid, setuid: */
1422 change_identity(pwd);
1423 } else if (sep->se_group) {
1424 xsetgid(grp->gr_gid);
1425 setgroups(1, &grp->gr_gid);
1427 if (rlim_ofile.rlim_cur != rlim_ofile_cur)
1428 if (setrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0)
1429 bb_perror_msg("setrlimit");
1431 /* closelog(); - WRONG. we are after vfork,
1432 * this may confuse syslog() internal state.
1433 * Let's hope libc sets syslog fd to CLOEXEC...
1435 xmove_fd(ctrl, STDIN_FILENO);
1436 xdup2(STDIN_FILENO, STDOUT_FILENO);
1437 dbg("moved ctrl:%d to fd 0,1[,2]\n", ctrl);
1438 /* manpages of inetd I managed to find either say
1439 * that stderr is also redirected to the network,
1440 * or do not talk about redirection at all (!) */
1441 if (!sep->se_wait) /* only for usual "tcp nowait" */
1442 xdup2(STDIN_FILENO, STDERR_FILENO);
1443 /* NB: among others, this loop closes listening sockets
1444 * for nowait stream children */
1445 for (sep2 = serv_list; sep2; sep2 = sep2->se_next)
1446 if (sep2->se_fd != ctrl)
1447 maybe_close(sep2->se_fd);
1448 sigaction_set(SIGPIPE, &saved_pipe_handler);
1449 restore_sigmask(&omask);
1450 dbg("execing:'%s'\n", sep->se_program);
1451 BB_EXECVP(sep->se_program, sep->se_argv);
1452 bb_perror_msg("can't execute '%s'", sep->se_program);
1454 /* eat packet in udp case */
1455 if (sep->se_socktype != SOCK_STREAM)
1456 recv(0, line, LINE_SIZE, MSG_DONTWAIT);
1457 _exit(EXIT_FAILURE);
1458 } /* for (sep = servtab...) */
1463 static const char *const cat_args[] = { "cat", NULL };
1467 * Internet services provided internally by inetd:
1469 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
1470 /* Echo service -- echo data back. */
1472 static void FAST_FUNC echo_stream(int s, servtab_t *sep UNUSED_PARAM)
1476 ssize_t sz = safe_read(s, line, LINE_SIZE);
1479 xwrite(s, line, sz);
1482 /* We are after vfork here! */
1483 /* move network socket to stdin/stdout */
1484 xmove_fd(s, STDIN_FILENO);
1485 xdup2(STDIN_FILENO, STDOUT_FILENO);
1486 /* no error messages please... */
1487 close(STDERR_FILENO);
1488 xopen(bb_dev_null, O_WRONLY);
1489 BB_EXECVP("cat", (char**)cat_args);
1490 /* on failure we return to main, which does exit(EXIT_FAILURE) */
1493 static void FAST_FUNC echo_dg(int s, servtab_t *sep)
1495 enum { BUFSIZE = 12*1024 }; /* for jumbo sized packets! :) */
1496 char *buf = xmalloc(BUFSIZE); /* too big for stack */
1498 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1500 lsa->len = sep->se_lsa->len;
1501 /* dgram builtins are non-forking - DONT BLOCK! */
1502 sz = recvfrom(s, buf, BUFSIZE, MSG_DONTWAIT, &lsa->u.sa, &lsa->len);
1504 sendto(s, buf, sz, 0, &lsa->u.sa, lsa->len);
1507 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_ECHO */
1510 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
1511 /* Discard service -- ignore data. */
1513 static void FAST_FUNC discard_stream(int s, servtab_t *sep UNUSED_PARAM)
1516 while (safe_read(s, line, LINE_SIZE) > 0)
1519 /* We are after vfork here! */
1520 /* move network socket to stdin */
1521 xmove_fd(s, STDIN_FILENO);
1522 /* discard output */
1523 close(STDOUT_FILENO);
1524 xopen(bb_dev_null, O_WRONLY);
1525 /* no error messages please... */
1526 xdup2(STDOUT_FILENO, STDERR_FILENO);
1527 BB_EXECVP("cat", (char**)cat_args);
1528 /* on failure we return to main, which does exit(EXIT_FAILURE) */
1532 static void FAST_FUNC discard_dg(int s, servtab_t *sep UNUSED_PARAM)
1534 /* dgram builtins are non-forking - DONT BLOCK! */
1535 recv(s, line, LINE_SIZE, MSG_DONTWAIT);
1537 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_DISCARD */
1540 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
1542 static void init_ring(void)
1547 for (i = ' '; i < 127; i++)
1550 /* Character generator. MMU arches only. */
1552 static void FAST_FUNC chargen_stream(int s, servtab_t *sep UNUSED_PARAM)
1556 char text[LINESIZ + 2];
1563 text[LINESIZ] = '\r';
1564 text[LINESIZ + 1] = '\n';
1567 len = end_ring - rs;
1569 memmove(text, rs, LINESIZ);
1571 memmove(text, rs, len);
1572 memmove(text + len, ring, LINESIZ - len);
1574 if (++rs == end_ring)
1576 xwrite(s, text, sizeof(text));
1580 static void FAST_FUNC chargen_dg(int s, servtab_t *sep)
1583 char text[LINESIZ + 2];
1584 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1586 /* Eat UDP packet which started it all */
1587 /* dgram builtins are non-forking - DONT BLOCK! */
1588 lsa->len = sep->se_lsa->len;
1589 if (recvfrom(s, text, sizeof(text), MSG_DONTWAIT, &lsa->u.sa, &lsa->len) < 0)
1597 len = end_ring - ring_pos;
1599 memmove(text, ring_pos, LINESIZ);
1601 memmove(text, ring_pos, len);
1602 memmove(text + len, ring, LINESIZ - len);
1604 if (++ring_pos == end_ring)
1606 text[LINESIZ] = '\r';
1607 text[LINESIZ + 1] = '\n';
1608 sendto(s, text, sizeof(text), 0, &lsa->u.sa, lsa->len);
1610 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN */
1613 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
1615 * Return a machine readable date and time, in the form of the
1616 * number of seconds since midnight, Jan 1, 1900. Since gettimeofday
1617 * returns the number of seconds since midnight, Jan 1, 1970,
1618 * we must add 2208988800 seconds to this figure to make up for
1619 * some seventy years Bell Labs was asleep.
1621 static uint32_t machtime(void)
1625 gettimeofday(&tv, NULL);
1626 return htonl((uint32_t)(tv.tv_sec + 2208988800));
1629 static void FAST_FUNC machtime_stream(int s, servtab_t *sep UNUSED_PARAM)
1633 result = machtime();
1634 full_write(s, &result, sizeof(result));
1636 static void FAST_FUNC machtime_dg(int s, servtab_t *sep)
1639 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1641 lsa->len = sep->se_lsa->len;
1642 if (recvfrom(s, line, LINE_SIZE, MSG_DONTWAIT, &lsa->u.sa, &lsa->len) < 0)
1645 result = machtime();
1646 sendto(s, &result, sizeof(result), 0, &lsa->u.sa, lsa->len);
1648 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_TIME */
1651 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
1652 /* Return human-readable time of day */
1654 static void FAST_FUNC daytime_stream(int s, servtab_t *sep UNUSED_PARAM)
1659 fdprintf(s, "%.24s\r\n", ctime(&t));
1661 static void FAST_FUNC daytime_dg(int s, servtab_t *sep)
1664 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1666 lsa->len = sep->se_lsa->len;
1667 if (recvfrom(s, line, LINE_SIZE, MSG_DONTWAIT, &lsa->u.sa, &lsa->len) < 0)
1671 sprintf(line, "%.24s\r\n", ctime(&t));
1672 sendto(s, line, strlen(line), 0, &lsa->u.sa, lsa->len);
1674 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME */