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)
156 //config:config INETD
157 //config: bool "inetd"
159 //config: select FEATURE_SYSLOG
161 //config: Internet superserver daemon
163 //config:config FEATURE_INETD_SUPPORT_BUILTIN_ECHO
164 //config: bool "Support echo service"
166 //config: depends on INETD
168 //config: Echo received data internal inetd service
170 //config:config FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
171 //config: bool "Support discard service"
173 //config: depends on INETD
175 //config: Internet /dev/null internal inetd service
177 //config:config FEATURE_INETD_SUPPORT_BUILTIN_TIME
178 //config: bool "Support time service"
180 //config: depends on INETD
182 //config: Return 32 bit time since 1900 internal inetd service
184 //config:config FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
185 //config: bool "Support daytime service"
187 //config: depends on INETD
189 //config: Return human-readable time internal inetd service
191 //config:config FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
192 //config: bool "Support chargen service"
194 //config: depends on INETD
196 //config: Familiar character generator internal inetd service
198 //config:config FEATURE_INETD_RPC
199 //config: bool "Support RPC services"
200 //config: default n # very rarely used, and needs Sun RPC support in libc
201 //config: depends on INETD
202 //config: select FEATURE_HAVE_RPC
204 //config: Support Sun-RPC based services
206 //applet:IF_INETD(APPLET(inetd, BB_DIR_USR_SBIN, BB_SUID_DROP))
208 //kbuild:lib-$(CONFIG_INETD) += inetd.o
210 //usage:#define inetd_trivial_usage
211 //usage: "[-fe] [-q N] [-R N] [CONFFILE]"
212 //usage:#define inetd_full_usage "\n\n"
213 //usage: "Listen for network connections and launch programs\n"
214 //usage: "\n -f Run in foreground"
215 //usage: "\n -e Log to stderr"
216 //usage: "\n -q N Socket listen queue (default 128)"
217 //usage: "\n -R N Pause services after N connects/min"
218 //usage: "\n (default 0 - disabled)"
221 #include <sys/resource.h> /* setrlimit */
222 #include <sys/socket.h> /* un.h may need this */
226 #include "common_bufsiz.h"
228 #if ENABLE_FEATURE_INETD_RPC
229 # if defined(__UCLIBC__) && ! defined(__UCLIBC_HAS_RPC__)
230 # warning "You probably need to build uClibc with UCLIBC_HAS_RPC for NFS support"
231 /* not #error, since user may be using e.g. libtirpc instead */
233 # include <rpc/rpc.h>
234 # include <rpc/pmap_clnt.h>
238 /* stream version of chargen is forking but not execing,
239 * can't do that (easily) on NOMMU */
240 #undef ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
241 #define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 0
244 #define CNT_INTERVAL 60 /* servers in CNT_INTERVAL sec. */
245 #define RETRYTIME 60 /* retry after bind or server fail */
247 // TODO: explain, or get rid of setrlimit games
249 #ifndef RLIMIT_NOFILE
250 #define RLIMIT_NOFILE RLIMIT_OFILE
257 /* Reserve some descriptors, 3 stdio + at least: 1 log, 1 conf. file */
260 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD \
261 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO \
262 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN \
263 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME \
264 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
265 # define INETD_BUILTINS_ENABLED
268 typedef struct servtab_t {
269 /* The most frequently referenced one: */
270 int se_fd; /* open descriptor */
271 /* NB: 'biggest fields last' saves on code size (~250 bytes) */
272 /* [addr:]service socktype proto wait user[:group] prog [args] */
273 char *se_local_hostname; /* addr to listen on */
274 char *se_service; /* "80" or "www" or "mount/2[-3]" */
275 /* socktype is in se_socktype */ /* "stream" "dgram" "raw" "rdm" "seqpacket" */
276 char *se_proto; /* "unix" or "[rpc/]tcp[6]" */
277 #if ENABLE_FEATURE_INETD_RPC
278 int se_rpcprog; /* rpc program number */
279 int se_rpcver_lo; /* rpc program lowest version */
280 int se_rpcver_hi; /* rpc program highest version */
281 #define is_rpc_service(sep) ((sep)->se_rpcver_lo != 0)
283 #define is_rpc_service(sep) 0
285 pid_t se_wait; /* 0:"nowait", 1:"wait", >1:"wait" */
286 /* and waiting for this pid */
287 socktype_t se_socktype; /* SOCK_STREAM/DGRAM/RDM/... */
288 family_t se_family; /* AF_UNIX/INET[6] */
289 /* se_proto_no is used by RPC code only... hmm */
290 smallint se_proto_no; /* IPPROTO_TCP/UDP, n/a for AF_UNIX */
291 smallint se_checked; /* looked at during merge */
292 unsigned se_max; /* allowed instances per minute */
293 unsigned se_count; /* number started since se_time */
294 unsigned se_time; /* when we started counting */
295 char *se_user; /* user name to run as */
296 char *se_group; /* group name to run as, can be NULL */
297 #ifdef INETD_BUILTINS_ENABLED
298 const struct builtin *se_builtin; /* if built-in, description */
300 struct servtab_t *se_next;
301 len_and_sockaddr *se_lsa;
302 char *se_program; /* server program */
304 char *se_argv[MAXARGV + 1]; /* program arguments */
307 #ifdef INETD_BUILTINS_ENABLED
308 /* Echo received data */
309 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
310 static void FAST_FUNC echo_stream(int, servtab_t *);
311 static void FAST_FUNC echo_dg(int, servtab_t *);
313 /* Internet /dev/null */
314 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
315 static void FAST_FUNC discard_stream(int, servtab_t *);
316 static void FAST_FUNC discard_dg(int, servtab_t *);
318 /* Return 32 bit time since 1900 */
319 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
320 static void FAST_FUNC machtime_stream(int, servtab_t *);
321 static void FAST_FUNC machtime_dg(int, servtab_t *);
323 /* Return human-readable time */
324 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
325 static void FAST_FUNC daytime_stream(int, servtab_t *);
326 static void FAST_FUNC daytime_dg(int, servtab_t *);
328 /* Familiar character generator */
329 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
330 static void FAST_FUNC chargen_stream(int, servtab_t *);
331 static void FAST_FUNC chargen_dg(int, servtab_t *);
335 /* NB: not necessarily NUL terminated */
336 char bi_service7[7]; /* internally provided service name */
337 uint8_t bi_fork; /* 1 if stream fn should run in child */
338 void (*bi_stream_fn)(int, servtab_t *) FAST_FUNC;
339 void (*bi_dgram_fn)(int, servtab_t *) FAST_FUNC;
342 static const struct builtin builtins[] = {
343 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
344 { "echo", 1, echo_stream, echo_dg },
346 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
347 { "discard", 1, discard_stream, discard_dg },
349 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
350 { "chargen", 1, chargen_stream, chargen_dg },
352 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
353 { "time", 0, machtime_stream, machtime_dg },
355 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
356 { "daytime", 0, daytime_stream, daytime_dg },
359 #endif /* INETD_BUILTINS_ENABLED */
362 rlim_t rlim_ofile_cur;
363 struct rlimit rlim_ofile;
364 servtab_t *serv_list;
366 int maxsock; /* max fd# in allsock, -1: unknown */
367 /* whenever maxsock grows, prev_maxsock is set to new maxsock,
368 * but if maxsock is set to -1, prev_maxsock is not changed */
370 unsigned max_concurrency;
371 smallint alarm_armed;
372 uid_t real_uid; /* user ID who ran us */
373 const char *config_filename;
375 char *default_local_hostname;
376 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
382 /* Used in next_line(), and as scratch read buffer */
383 char line[256]; /* _at least_ 256, see LINE_SIZE */
385 #define G (*(struct globals*)bb_common_bufsiz1)
386 enum { LINE_SIZE = COMMON_BUFSIZE - offsetof(struct globals, line) };
387 #define rlim_ofile_cur (G.rlim_ofile_cur )
388 #define rlim_ofile (G.rlim_ofile )
389 #define serv_list (G.serv_list )
390 #define global_queuelen (G.global_queuelen)
391 #define maxsock (G.maxsock )
392 #define prev_maxsock (G.prev_maxsock )
393 #define max_concurrency (G.max_concurrency)
394 #define alarm_armed (G.alarm_armed )
395 #define real_uid (G.real_uid )
396 #define config_filename (G.config_filename)
397 #define parser (G.parser )
398 #define default_local_hostname (G.default_local_hostname)
399 #define first_ps_byte (G.first_ps_byte )
400 #define last_ps_byte (G.last_ps_byte )
401 #define end_ring (G.end_ring )
402 #define ring_pos (G.ring_pos )
403 #define ring (G.ring )
404 #define allsock (G.allsock )
405 #define line (G.line )
406 #define INIT_G() do { \
407 setup_common_bufsiz(); \
408 BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
409 rlim_ofile_cur = OPEN_MAX; \
410 global_queuelen = 128; \
411 config_filename = "/etc/inetd.conf"; \
415 # define dbg(...) ((void)0)
419 int dbg_fd = open("inetd_debug.log", O_WRONLY | O_CREAT | O_APPEND, 0666); \
421 fdprintf(dbg_fd, "%d: ", getpid()); \
422 fdprintf(dbg_fd, __VA_ARGS__); \
428 static void maybe_close(int fd)
432 dbg("closed fd:%d\n", fd);
436 // TODO: move to libbb?
437 static len_and_sockaddr *xzalloc_lsa(int family)
439 len_and_sockaddr *lsa;
442 sz = sizeof(struct sockaddr_in);
443 if (family == AF_UNIX)
444 sz = sizeof(struct sockaddr_un);
445 #if ENABLE_FEATURE_IPV6
446 if (family == AF_INET6)
447 sz = sizeof(struct sockaddr_in6);
449 lsa = xzalloc(LSA_LEN_SIZE + sz);
451 lsa->u.sa.sa_family = family;
455 static void rearm_alarm(void)
463 static void block_CHLD_HUP_ALRM(sigset_t *m)
466 sigaddset(m, SIGCHLD);
467 sigaddset(m, SIGHUP);
468 sigaddset(m, SIGALRM);
469 sigprocmask(SIG_BLOCK, m, m); /* old sigmask is stored in m */
472 static void restore_sigmask(sigset_t *m)
474 sigprocmask(SIG_SETMASK, m, NULL);
477 #if ENABLE_FEATURE_INETD_RPC
478 static void register_rpc(servtab_t *sep)
481 struct sockaddr_in ir_sin;
484 size = sizeof(ir_sin);
485 if (getsockname(sep->se_fd, (struct sockaddr *) &ir_sin, &size) < 0) {
486 bb_perror_msg("getsockname");
490 for (n = sep->se_rpcver_lo; n <= sep->se_rpcver_hi; n++) {
491 pmap_unset(sep->se_rpcprog, n);
492 if (!pmap_set(sep->se_rpcprog, n, sep->se_proto_no, ntohs(ir_sin.sin_port)))
493 bb_perror_msg("%s %s: pmap_set(%u,%u,%u,%u)",
494 sep->se_service, sep->se_proto,
495 sep->se_rpcprog, n, sep->se_proto_no, ntohs(ir_sin.sin_port));
499 static void unregister_rpc(servtab_t *sep)
503 for (n = sep->se_rpcver_lo; n <= sep->se_rpcver_hi; n++) {
504 if (!pmap_unset(sep->se_rpcprog, n))
505 bb_perror_msg("pmap_unset(%u,%u)", sep->se_rpcprog, n);
508 #endif /* FEATURE_INETD_RPC */
510 static void bump_nofile(void)
512 enum { FD_CHUNK = 32 };
515 /* Never fails under Linux (except if you pass it bad arguments) */
516 getrlimit(RLIMIT_NOFILE, &rl);
517 rl.rlim_cur = MIN(rl.rlim_max, rl.rlim_cur + FD_CHUNK);
518 rl.rlim_cur = MIN(FD_SETSIZE, rl.rlim_cur + FD_CHUNK);
519 if (rl.rlim_cur <= rlim_ofile_cur) {
520 bb_error_msg("can't extend file limit, max = %d",
525 if (setrlimit(RLIMIT_NOFILE, &rl) < 0) {
526 bb_perror_msg("setrlimit");
530 rlim_ofile_cur = rl.rlim_cur;
533 static void remove_fd_from_set(int fd)
536 FD_CLR(fd, &allsock);
537 dbg("stopped listening on fd:%d\n", fd);
539 dbg("maxsock:%d\n", maxsock);
543 static void add_fd_to_set(int fd)
546 FD_SET(fd, &allsock);
547 dbg("started listening on fd:%d\n", fd);
548 if (maxsock >= 0 && fd > maxsock) {
549 prev_maxsock = maxsock = fd;
550 dbg("maxsock:%d\n", maxsock);
551 if ((rlim_t)fd > rlim_ofile_cur - FD_MARGIN)
557 static void recalculate_maxsock(void)
561 /* We may have no services, in this case maxsock should still be >= 0
562 * (code elsewhere is not happy with maxsock == -1) */
564 while (fd <= prev_maxsock) {
565 if (FD_ISSET(fd, &allsock))
569 dbg("recalculated maxsock:%d\n", maxsock);
570 prev_maxsock = maxsock;
571 if ((rlim_t)maxsock > rlim_ofile_cur - FD_MARGIN)
575 static void prepare_socket_fd(servtab_t *sep)
579 fd = socket(sep->se_family, sep->se_socktype, 0);
581 bb_perror_msg("socket");
584 setsockopt_reuseaddr(fd);
586 #if ENABLE_FEATURE_INETD_RPC
587 if (is_rpc_service(sep)) {
590 /* zero out the port for all RPC services; let bind()
592 set_nport(&sep->se_lsa->u.sa, 0);
594 /* for RPC services, attempt to use a reserved port
595 * if they are going to be running as root. */
596 if (real_uid == 0 && sep->se_family == AF_INET
597 && (pwd = getpwnam(sep->se_user)) != NULL
600 r = bindresvport(fd, &sep->se_lsa->u.sin);
602 r = bind(fd, &sep->se_lsa->u.sa, sep->se_lsa->len);
605 int saveerrno = errno;
606 /* update lsa with port# */
607 getsockname(fd, &sep->se_lsa->u.sa, &sep->se_lsa->len);
613 if (sep->se_family == AF_UNIX) {
614 struct sockaddr_un *sun;
615 sun = (struct sockaddr_un*)&(sep->se_lsa->u.sa);
616 unlink(sun->sun_path);
618 r = bind(fd, &sep->se_lsa->u.sa, sep->se_lsa->len);
621 bb_perror_msg("%s/%s: bind",
622 sep->se_service, sep->se_proto);
628 if (sep->se_socktype == SOCK_STREAM) {
629 listen(fd, global_queuelen);
630 dbg("new sep->se_fd:%d (stream)\n", fd);
632 dbg("new sep->se_fd:%d (!stream)\n", fd);
639 static int reopen_config_file(void)
641 free(default_local_hostname);
642 default_local_hostname = xstrdup("*");
644 config_close(parser);
645 parser = config_open(config_filename);
646 return (parser != NULL);
649 static void close_config_file(void)
652 config_close(parser);
657 static void free_servtab_strings(servtab_t *cp)
661 free(cp->se_local_hostname);
662 free(cp->se_service);
666 free(cp->se_lsa); /* not a string in fact */
667 free(cp->se_program);
668 for (i = 0; i < MAXARGV; i++)
669 free(cp->se_argv[i]);
672 static servtab_t *new_servtab(void)
674 servtab_t *newtab = xzalloc(sizeof(servtab_t));
675 newtab->se_fd = -1; /* paranoia */
679 static servtab_t *dup_servtab(servtab_t *sep)
684 newtab = new_servtab();
685 *newtab = *sep; /* struct copy */
686 /* deep-copying strings */
687 newtab->se_service = xstrdup(newtab->se_service);
688 newtab->se_proto = xstrdup(newtab->se_proto);
689 newtab->se_user = xstrdup(newtab->se_user);
690 newtab->se_group = xstrdup(newtab->se_group);
691 newtab->se_program = xstrdup(newtab->se_program);
692 for (argc = 0; argc <= MAXARGV; argc++)
693 newtab->se_argv[argc] = xstrdup(newtab->se_argv[argc]);
694 /* NB: se_fd, se_hostaddr and se_next are always
695 * overwrittend by callers, so we don't bother resetting them
696 * to NULL/0/-1 etc */
701 /* gcc generates much more code if this is inlined */
702 static NOINLINE servtab_t *parse_one_line(void)
705 char *token[6+MAXARGV];
713 argc = config_read(parser, token, 6+MAXARGV, 1, "# \t", PARSE_NORMAL);
719 /* [host:]service socktype proto wait user[:group] prog [args] */
720 /* Check for "host:...." line */
722 hostdelim = strrchr(arg, ':');
725 sep->se_local_hostname = xstrdup(arg);
727 if (*arg == '\0' && argc == 1) {
728 /* Line has just "host:", change the
729 * default host for the following lines. */
730 free(default_local_hostname);
731 default_local_hostname = sep->se_local_hostname;
732 /*sep->se_local_hostname = NULL; - redundant */
733 /* (we'll overwrite this field anyway) */
737 sep->se_local_hostname = xstrdup(default_local_hostname);
739 /* service socktype proto wait user[:group] prog [args] */
740 sep->se_service = xstrdup(arg);
742 /* socktype proto wait user[:group] prog [args] */
745 bb_error_msg("parse error on line %u, line is ignored",
747 /* Just "goto more" can make sep to carry over e.g.
748 * "rpc"-ness (by having se_rpcver_lo != 0).
749 * We will be more paranoid: */
750 free_servtab_strings(sep);
756 static const int8_t SOCK_xxx[] ALIGN1 = {
758 SOCK_STREAM, SOCK_DGRAM, SOCK_RDM,
759 SOCK_SEQPACKET, SOCK_RAW
761 sep->se_socktype = SOCK_xxx[1 + index_in_strings(
762 "stream""\0" "dgram""\0" "rdm""\0"
763 "seqpacket""\0" "raw""\0"
767 /* {unix,[rpc/]{tcp,udp}[6]} wait user[:group] prog [args] */
768 sep->se_proto = arg = xstrdup(token[2]);
769 if (strcmp(arg, "unix") == 0) {
770 sep->se_family = AF_UNIX;
773 sep->se_family = AF_INET;
774 six = last_char_is(arg, '6');
776 #if ENABLE_FEATURE_IPV6
778 sep->se_family = AF_INET6;
780 bb_error_msg("%s: no support for IPv6", sep->se_proto);
784 if (is_prefixed_with(arg, "rpc/")) {
785 #if ENABLE_FEATURE_INETD_RPC
788 p = strchr(sep->se_service, '/');
790 bb_error_msg("no rpc version: '%s'", sep->se_service);
794 n = bb_strtou(p, &p, 10);
797 bb_error_msg("bad rpc version");
800 sep->se_rpcver_lo = sep->se_rpcver_hi = n;
803 n = bb_strtou(p, &p, 10);
804 if (n > INT_MAX || (int)n < sep->se_rpcver_lo)
806 sep->se_rpcver_hi = n;
811 bb_error_msg("no support for rpc services");
815 /* we don't really need getprotobyname()! */
816 if (strcmp(arg, "tcp") == 0)
817 sep->se_proto_no = IPPROTO_TCP; /* = 6 */
818 if (strcmp(arg, "udp") == 0)
819 sep->se_proto_no = IPPROTO_UDP; /* = 17 */
822 if (!sep->se_proto_no) /* not tcp/udp?? */
826 /* [no]wait[.max] user[:group] prog [args] */
828 sep->se_max = max_concurrency;
829 p = strchr(arg, '.');
832 sep->se_max = bb_strtou(p, NULL, 10);
836 sep->se_wait = (arg[0] != 'n' || arg[1] != 'o');
837 if (!sep->se_wait) /* "no" seen */
839 if (strcmp(arg, "wait") != 0)
842 /* user[:group] prog [args] */
843 sep->se_user = xstrdup(token[4]);
844 arg = strchr(sep->se_user, '.');
846 arg = strchr(sep->se_user, ':');
849 sep->se_group = xstrdup(arg);
853 sep->se_program = xstrdup(token[5]);
854 #ifdef INETD_BUILTINS_ENABLED
855 if (strcmp(sep->se_program, "internal") == 0
856 && strlen(sep->se_service) <= 7
857 && (sep->se_socktype == SOCK_STREAM
858 || sep->se_socktype == SOCK_DGRAM)
861 for (i = 0; i < ARRAY_SIZE(builtins); i++)
862 if (strncmp(builtins[i].bi_service7, sep->se_service, 7) == 0)
864 bb_error_msg("unknown internal service %s", sep->se_service);
867 sep->se_builtin = &builtins[i];
868 /* stream builtins must be "nowait", dgram must be "wait" */
869 if (sep->se_wait != (sep->se_socktype == SOCK_DGRAM))
874 while (argc < MAXARGV && (arg = token[6+argc]) != NULL)
875 sep->se_argv[argc++] = xstrdup(arg);
876 /* Some inetd.conf files have no argv's, not even argv[0].
878 * (Technically, programs can be execed with argv[0] = NULL,
879 * but many programs do not like that at all) */
881 sep->se_argv[0] = xstrdup(sep->se_program);
883 /* catch mixups. "<service> stream udp ..." == wtf */
884 if (sep->se_socktype == SOCK_STREAM) {
885 if (sep->se_proto_no == IPPROTO_UDP)
888 if (sep->se_socktype == SOCK_DGRAM) {
889 if (sep->se_proto_no == IPPROTO_TCP)
894 // "ENTRY[%s][%s][%s][%d][%d][%d][%d][%d][%s][%s][%s]",
895 // sep->se_local_hostname, sep->se_service, sep->se_proto, sep->se_wait, sep->se_proto_no,
896 // sep->se_max, sep->se_count, sep->se_time, sep->se_user, sep->se_group, sep->se_program);
898 /* check if the hostname specifier is a comma separated list
899 * of hostnames. we'll make new entries for each address. */
900 while ((hostdelim = strrchr(sep->se_local_hostname, ',')) != NULL) {
901 nsep = dup_servtab(sep);
902 /* NUL terminate the hostname field of the existing entry,
903 * and make a dup for the new entry. */
905 nsep->se_local_hostname = xstrdup(hostdelim);
906 nsep->se_next = sep->se_next;
910 /* was doing it here: */
911 /* DNS resolution, create copies for each IP address */
912 /* IPv6-ization destroyed it :( */
917 static servtab_t *insert_in_servlist(servtab_t *cp)
923 *sep = *cp; /* struct copy */
925 #if ENABLE_FEATURE_INETD_RPC
926 sep->se_rpcprog = -1;
928 block_CHLD_HUP_ALRM(&omask);
929 sep->se_next = serv_list;
931 restore_sigmask(&omask);
935 static int same_serv_addr_proto(servtab_t *old, servtab_t *new)
937 if (strcmp(old->se_local_hostname, new->se_local_hostname) != 0)
939 if (strcmp(old->se_service, new->se_service) != 0)
941 if (strcmp(old->se_proto, new->se_proto) != 0)
946 static void reread_config_file(int sig UNUSED_PARAM)
948 servtab_t *sep, *cp, **sepp;
949 len_and_sockaddr *lsa;
953 int save_errno = errno;
955 if (!reopen_config_file())
957 for (sep = serv_list; sep; sep = sep->se_next)
964 cp = parse_one_line();
968 for (sep = serv_list; sep; sep = sep->se_next)
969 if (same_serv_addr_proto(sep, cp))
971 /* not an "equal" servtab */
972 sep = insert_in_servlist(cp);
978 block_CHLD_HUP_ALRM(&omask);
979 #if ENABLE_FEATURE_INETD_RPC
980 if (is_rpc_service(sep))
982 sep->se_rpcver_lo = cp->se_rpcver_lo;
983 sep->se_rpcver_hi = cp->se_rpcver_hi;
985 if (cp->se_wait == 0) {
986 /* New config says "nowait". If old one
987 * was "wait", we currently may be waiting
988 * for a child (and not accepting connects).
989 * Stop waiting, start listening again.
990 * (if it's not true, this op is harmless) */
991 add_fd_to_set(sep->se_fd);
993 sep->se_wait = cp->se_wait;
994 sep->se_max = cp->se_max;
995 /* string fields need more love - we don't want to leak them */
996 #define SWAP(type, a, b) do { type c = (type)a; a = (type)b; b = (type)c; } while (0)
997 SWAP(char*, sep->se_user, cp->se_user);
998 SWAP(char*, sep->se_group, cp->se_group);
999 SWAP(char*, sep->se_program, cp->se_program);
1000 for (i = 0; i < MAXARGV; i++)
1001 SWAP(char*, sep->se_argv[i], cp->se_argv[i]);
1003 restore_sigmask(&omask);
1004 free_servtab_strings(cp);
1007 /* cp->string_fields are consumed by insert_in_servlist()
1008 * or freed at this point, cp itself is not yet freed. */
1009 sep->se_checked = 1;
1011 /* create new len_and_sockaddr */
1012 switch (sep->se_family) {
1013 struct sockaddr_un *sun;
1015 lsa = xzalloc_lsa(AF_UNIX);
1016 sun = (struct sockaddr_un*)&lsa->u.sa;
1017 safe_strncpy(sun->sun_path, sep->se_service, sizeof(sun->sun_path));
1020 default: /* case AF_INET, case AF_INET6 */
1021 n = bb_strtou(sep->se_service, NULL, 10);
1022 #if ENABLE_FEATURE_INETD_RPC
1023 if (is_rpc_service(sep)) {
1024 sep->se_rpcprog = n;
1025 if (errno) { /* se_service is not numeric */
1026 struct rpcent *rp = getrpcbyname(sep->se_service);
1028 bb_error_msg("%s: unknown rpc service", sep->se_service);
1031 sep->se_rpcprog = rp->r_number;
1033 if (sep->se_fd == -1)
1034 prepare_socket_fd(sep);
1035 if (sep->se_fd != -1)
1040 /* what port to listen on? */
1042 if (errno || n > 0xffff) { /* se_service is not numeric */
1045 /* can result only in "tcp" or "udp": */
1046 safe_strncpy(protoname, sep->se_proto, 4);
1047 sp = getservbyname(sep->se_service, protoname);
1049 bb_error_msg("%s/%s: unknown service",
1050 sep->se_service, sep->se_proto);
1055 if (LONE_CHAR(sep->se_local_hostname, '*')) {
1056 lsa = xzalloc_lsa(sep->se_family);
1057 set_nport(&lsa->u.sa, port);
1059 lsa = host_and_af2sockaddr(sep->se_local_hostname,
1060 ntohs(port), sep->se_family);
1062 bb_error_msg("%s/%s: unknown host '%s'",
1063 sep->se_service, sep->se_proto,
1064 sep->se_local_hostname);
1069 } /* end of "switch (sep->se_family)" */
1071 /* did lsa change? Then close/open */
1072 if (sep->se_lsa == NULL
1073 || lsa->len != sep->se_lsa->len
1074 || memcmp(&lsa->u.sa, &sep->se_lsa->u.sa, lsa->len) != 0
1076 remove_fd_from_set(sep->se_fd);
1077 maybe_close(sep->se_fd);
1084 if (sep->se_fd == -1)
1085 prepare_socket_fd(sep);
1090 } /* end of "while (1) parse lines" */
1091 close_config_file();
1093 /* Purge anything not looked at above - these are stale entries,
1094 * new config file doesnt have them. */
1095 block_CHLD_HUP_ALRM(&omask);
1097 while ((sep = *sepp) != NULL) {
1098 if (sep->se_checked) {
1099 sepp = &sep->se_next;
1102 *sepp = sep->se_next;
1103 remove_fd_from_set(sep->se_fd);
1104 maybe_close(sep->se_fd);
1105 #if ENABLE_FEATURE_INETD_RPC
1106 if (is_rpc_service(sep))
1107 unregister_rpc(sep);
1109 if (sep->se_family == AF_UNIX)
1110 unlink(sep->se_service);
1111 free_servtab_strings(sep);
1114 restore_sigmask(&omask);
1119 static void reap_child(int sig UNUSED_PARAM)
1124 int save_errno = errno;
1127 pid = wait_any_nohang(&status);
1130 for (sep = serv_list; sep; sep = sep->se_next) {
1131 if (sep->se_wait != pid)
1133 /* One of our "wait" services */
1134 if (WIFEXITED(status) && WEXITSTATUS(status))
1135 bb_error_msg("%s: exit status %u",
1136 sep->se_program, WEXITSTATUS(status));
1137 else if (WIFSIGNALED(status))
1138 bb_error_msg("%s: exit signal %u",
1139 sep->se_program, WTERMSIG(status));
1141 add_fd_to_set(sep->se_fd);
1148 static void retry_network_setup(int sig UNUSED_PARAM)
1150 int save_errno = errno;
1154 for (sep = serv_list; sep; sep = sep->se_next) {
1155 if (sep->se_fd == -1) {
1156 prepare_socket_fd(sep);
1157 #if ENABLE_FEATURE_INETD_RPC
1158 if (sep->se_fd != -1 && is_rpc_service(sep))
1166 static void clean_up_and_exit(int sig UNUSED_PARAM)
1170 /* XXX signal race walking sep list */
1171 for (sep = serv_list; sep; sep = sep->se_next) {
1172 if (sep->se_fd == -1)
1175 switch (sep->se_family) {
1177 unlink(sep->se_service);
1179 default: /* case AF_INET, AF_INET6 */
1180 #if ENABLE_FEATURE_INETD_RPC
1181 if (sep->se_wait == 1 && is_rpc_service(sep))
1182 unregister_rpc(sep); /* XXX signal race */
1186 if (ENABLE_FEATURE_CLEAN_UP)
1189 remove_pidfile(CONFIG_PID_FILE_PATH "/inetd.pid");
1193 int inetd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1194 int inetd_main(int argc UNUSED_PARAM, char **argv)
1196 struct sigaction sa, saved_pipe_handler;
1197 servtab_t *sep, *sep2;
1199 struct group *grp = grp; /* for compiler */
1206 real_uid = getuid();
1207 if (real_uid != 0) /* run by non-root user */
1208 config_filename = NULL;
1211 opt = getopt32(argv, "R:+feq:+", &max_concurrency, &global_queuelen);
1215 config_filename = argv[0];
1216 if (config_filename == NULL)
1217 bb_error_msg_and_die("non-root must specify config file");
1219 bb_daemonize_or_rexec(0, argv - optind);
1221 bb_sanitize_stdio();
1223 /* LOG_NDELAY: connect to syslog daemon NOW.
1224 * Otherwise, we may open syslog socket
1225 * in vforked child, making opened fds and syslog()
1226 * internal state inconsistent.
1227 * This was observed to leak file descriptors. */
1228 openlog(applet_name, LOG_PID | LOG_NDELAY, LOG_DAEMON);
1229 logmode = LOGMODE_SYSLOG;
1232 if (real_uid == 0) {
1233 /* run by root, ensure groups vector gets trashed */
1234 gid_t gid = getgid();
1238 write_pidfile(CONFIG_PID_FILE_PATH "/inetd.pid");
1240 /* never fails under Linux (except if you pass it bad arguments) */
1241 getrlimit(RLIMIT_NOFILE, &rlim_ofile);
1242 rlim_ofile_cur = rlim_ofile.rlim_cur;
1243 if (rlim_ofile_cur == RLIM_INFINITY) /* ! */
1244 rlim_ofile_cur = OPEN_MAX;
1246 memset(&sa, 0, sizeof(sa));
1247 /*sigemptyset(&sa.sa_mask); - memset did it */
1248 sigaddset(&sa.sa_mask, SIGALRM);
1249 sigaddset(&sa.sa_mask, SIGCHLD);
1250 sigaddset(&sa.sa_mask, SIGHUP);
1251 //FIXME: explain why no SA_RESTART
1252 //FIXME: retry_network_setup is unsafe to run in signal handler (many reasons)!
1253 sa.sa_handler = retry_network_setup;
1254 sigaction_set(SIGALRM, &sa);
1255 //FIXME: reread_config_file is unsafe to run in signal handler(many reasons)!
1256 sa.sa_handler = reread_config_file;
1257 sigaction_set(SIGHUP, &sa);
1258 //FIXME: reap_child is unsafe to run in signal handler (uses stdio)!
1259 sa.sa_handler = reap_child;
1260 sigaction_set(SIGCHLD, &sa);
1261 //FIXME: clean_up_and_exit is unsafe to run in signal handler (uses stdio)!
1262 sa.sa_handler = clean_up_and_exit;
1263 sigaction_set(SIGTERM, &sa);
1264 sa.sa_handler = clean_up_and_exit;
1265 sigaction_set(SIGINT, &sa);
1266 sa.sa_handler = SIG_IGN;
1267 sigaction(SIGPIPE, &sa, &saved_pipe_handler);
1269 reread_config_file(SIGHUP); /* load config from file */
1273 int ctrl, accepted_fd, new_udp_fd;
1277 recalculate_maxsock();
1279 readable = allsock; /* struct copy */
1280 /* if there are no fds to wait on, we will block
1281 * until signal wakes us up (maxsock == 0, but readable
1282 * never contains fds 0 and 1...) */
1283 ready_fd_cnt = select(maxsock + 1, &readable, NULL, NULL, NULL);
1284 if (ready_fd_cnt < 0) {
1285 if (errno != EINTR) {
1286 bb_perror_msg("select");
1291 dbg("ready_fd_cnt:%d\n", ready_fd_cnt);
1293 for (sep = serv_list; ready_fd_cnt && sep; sep = sep->se_next) {
1294 if (sep->se_fd == -1 || !FD_ISSET(sep->se_fd, &readable))
1297 dbg("ready fd:%d\n", sep->se_fd);
1302 if (!sep->se_wait) {
1303 if (sep->se_socktype == SOCK_STREAM) {
1304 ctrl = accepted_fd = accept(sep->se_fd, NULL, NULL);
1305 dbg("accepted_fd:%d\n", accepted_fd);
1308 bb_perror_msg("accept (for %s)", sep->se_service);
1313 if (sep->se_socktype == SOCK_DGRAM
1314 && sep->se_family != AF_UNIX
1316 /* How udp "nowait" works:
1317 * child peeks at (received and buffered by kernel) UDP packet,
1318 * performs connect() on the socket so that it is linked only
1319 * to this peer. But this also affects parent, because descriptors
1320 * are shared after fork() a-la dup(). When parent performs
1321 * select(), it will see this descriptor connected to the peer (!)
1322 * and still readable, will act on it and mess things up
1323 * (can create many copies of same child, etc).
1324 * Parent must create and use new socket instead. */
1325 new_udp_fd = socket(sep->se_family, SOCK_DGRAM, 0);
1326 dbg("new_udp_fd:%d\n", new_udp_fd);
1327 if (new_udp_fd < 0) { /* error: eat packet, forget about it */
1329 recv(sep->se_fd, line, LINE_SIZE, MSG_DONTWAIT);
1332 setsockopt_reuseaddr(new_udp_fd);
1333 /* TODO: better do bind after fork in parent,
1334 * so that we don't have two wildcard bound sockets
1335 * even for a brief moment? */
1336 if (bind(new_udp_fd, &sep->se_lsa->u.sa, sep->se_lsa->len) < 0) {
1337 dbg("bind(new_udp_fd) failed\n");
1341 dbg("bind(new_udp_fd) succeeded\n");
1345 block_CHLD_HUP_ALRM(&omask);
1347 #ifdef INETD_BUILTINS_ENABLED
1348 /* do we need to fork? */
1349 if (sep->se_builtin == NULL
1350 || (sep->se_socktype == SOCK_STREAM
1351 && sep->se_builtin->bi_fork))
1354 if (sep->se_max != 0) {
1355 if (++sep->se_count == 1)
1356 sep->se_time = monotonic_sec();
1357 else if (sep->se_count >= sep->se_max) {
1358 unsigned now = monotonic_sec();
1359 /* did we accumulate se_max connects too quickly? */
1360 if (now - sep->se_time <= CNT_INTERVAL) {
1361 bb_error_msg("%s/%s: too many connections, pausing",
1362 sep->se_service, sep->se_proto);
1363 remove_fd_from_set(sep->se_fd);
1367 rearm_alarm(); /* will revive it in RETRYTIME sec */
1368 restore_sigmask(&omask);
1369 maybe_close(new_udp_fd);
1370 maybe_close(accepted_fd);
1371 continue; /* -> check next fd in fd set */
1376 /* on NOMMU, streamed chargen
1377 * builtin wouldn't work, but it is
1378 * not allowed on NOMMU (ifdefed out) */
1379 #ifdef INETD_BUILTINS_ENABLED
1380 if (BB_MMU && sep->se_builtin)
1386 if (pid < 0) { /* fork error */
1387 bb_perror_msg("vfork"+1);
1389 restore_sigmask(&omask);
1390 maybe_close(new_udp_fd);
1391 maybe_close(accepted_fd);
1392 continue; /* -> check next fd in fd set */
1395 pid--; /* -1: "we did fork and we are child" */
1397 /* if pid == 0 here, we didn't fork */
1399 if (pid > 0) { /* parent */
1401 /* wait: we passed socket to child,
1402 * will wait for child to terminate */
1404 remove_fd_from_set(sep->se_fd);
1406 if (new_udp_fd >= 0) {
1407 /* udp nowait: child connected the socket,
1408 * we created and will use new, unconnected one */
1409 xmove_fd(new_udp_fd, sep->se_fd);
1410 dbg("moved new_udp_fd:%d to sep->se_fd:%d\n", new_udp_fd, sep->se_fd);
1412 restore_sigmask(&omask);
1413 maybe_close(accepted_fd);
1414 continue; /* -> check next fd in fd set */
1417 /* we are either child or didn't fork at all */
1418 #ifdef INETD_BUILTINS_ENABLED
1419 if (sep->se_builtin) {
1420 if (pid) { /* "pid" is -1: we did fork */
1421 close(sep->se_fd); /* listening socket */
1422 dbg("closed sep->se_fd:%d\n", sep->se_fd);
1423 logmode = LOGMODE_NONE; /* make xwrite etc silent */
1425 restore_sigmask(&omask);
1426 if (sep->se_socktype == SOCK_STREAM)
1427 sep->se_builtin->bi_stream_fn(ctrl, sep);
1429 sep->se_builtin->bi_dgram_fn(ctrl, sep);
1430 if (pid) /* we did fork */
1431 _exit(EXIT_FAILURE);
1432 maybe_close(accepted_fd);
1433 continue; /* -> check next fd in fd set */
1439 if (new_udp_fd >= 0) {
1440 len_and_sockaddr *lsa;
1444 dbg("closed new_udp_fd:%d\n", new_udp_fd);
1445 lsa = xzalloc_lsa(sep->se_family);
1446 /* peek at the packet and remember peer addr */
1447 r = recvfrom(ctrl, NULL, 0, MSG_PEEK|MSG_DONTWAIT,
1448 &lsa->u.sa, &lsa->len);
1451 /* make this socket "connected" to peer addr:
1452 * only packets from this peer will be recv'ed,
1453 * and bare write()/send() will work on it */
1454 connect(ctrl, &lsa->u.sa, lsa->len);
1455 dbg("connected ctrl:%d to remote peer\n", ctrl);
1458 /* prepare env and exec program */
1459 pwd = getpwnam(sep->se_user);
1461 bb_error_msg("%s: no such %s", sep->se_user, "user");
1464 if (sep->se_group && (grp = getgrnam(sep->se_group)) == NULL) {
1465 bb_error_msg("%s: no such %s", sep->se_group, "group");
1468 if (real_uid != 0 && real_uid != pwd->pw_uid) {
1469 /* a user running private inetd */
1470 bb_error_msg("non-root must run services as himself");
1473 if (pwd->pw_uid != 0) {
1475 pwd->pw_gid = grp->gr_gid;
1476 /* initgroups, setgid, setuid: */
1477 change_identity(pwd);
1478 } else if (sep->se_group) {
1479 xsetgid(grp->gr_gid);
1480 setgroups(1, &grp->gr_gid);
1482 if (rlim_ofile.rlim_cur != rlim_ofile_cur)
1483 if (setrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0)
1484 bb_perror_msg("setrlimit");
1486 /* closelog(); - WRONG. we are after vfork,
1487 * this may confuse syslog() internal state.
1488 * Let's hope libc sets syslog fd to CLOEXEC...
1490 xmove_fd(ctrl, STDIN_FILENO);
1491 xdup2(STDIN_FILENO, STDOUT_FILENO);
1492 dbg("moved ctrl:%d to fd 0,1[,2]\n", ctrl);
1493 /* manpages of inetd I managed to find either say
1494 * that stderr is also redirected to the network,
1495 * or do not talk about redirection at all (!) */
1496 if (!sep->se_wait) /* only for usual "tcp nowait" */
1497 xdup2(STDIN_FILENO, STDERR_FILENO);
1498 /* NB: among others, this loop closes listening sockets
1499 * for nowait stream children */
1500 for (sep2 = serv_list; sep2; sep2 = sep2->se_next)
1501 if (sep2->se_fd != ctrl)
1502 maybe_close(sep2->se_fd);
1503 sigaction_set(SIGPIPE, &saved_pipe_handler);
1504 restore_sigmask(&omask);
1505 dbg("execing:'%s'\n", sep->se_program);
1506 BB_EXECVP(sep->se_program, sep->se_argv);
1507 bb_perror_msg("can't execute '%s'", sep->se_program);
1509 /* eat packet in udp case */
1510 if (sep->se_socktype != SOCK_STREAM)
1511 recv(0, line, LINE_SIZE, MSG_DONTWAIT);
1512 _exit(EXIT_FAILURE);
1513 } /* for (sep = servtab...) */
1517 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO \
1518 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
1520 static const char *const cat_args[] = { "cat", NULL };
1525 * Internet services provided internally by inetd:
1527 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
1528 /* Echo service -- echo data back. */
1530 static void FAST_FUNC echo_stream(int s, servtab_t *sep UNUSED_PARAM)
1534 ssize_t sz = safe_read(s, line, LINE_SIZE);
1537 xwrite(s, line, sz);
1540 /* We are after vfork here! */
1541 /* move network socket to stdin/stdout */
1542 xmove_fd(s, STDIN_FILENO);
1543 xdup2(STDIN_FILENO, STDOUT_FILENO);
1544 /* no error messages please... */
1545 close(STDERR_FILENO);
1546 xopen(bb_dev_null, O_WRONLY);
1547 BB_EXECVP("cat", (char**)cat_args);
1548 /* on failure we return to main, which does exit(EXIT_FAILURE) */
1551 static void FAST_FUNC echo_dg(int s, servtab_t *sep)
1553 enum { BUFSIZE = 12*1024 }; /* for jumbo sized packets! :) */
1554 char *buf = xmalloc(BUFSIZE); /* too big for stack */
1556 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1558 lsa->len = sep->se_lsa->len;
1559 /* dgram builtins are non-forking - DONT BLOCK! */
1560 sz = recvfrom(s, buf, BUFSIZE, MSG_DONTWAIT, &lsa->u.sa, &lsa->len);
1562 sendto(s, buf, sz, 0, &lsa->u.sa, lsa->len);
1565 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_ECHO */
1568 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
1569 /* Discard service -- ignore data. */
1571 static void FAST_FUNC discard_stream(int s, servtab_t *sep UNUSED_PARAM)
1574 while (safe_read(s, line, LINE_SIZE) > 0)
1577 /* We are after vfork here! */
1578 /* move network socket to stdin */
1579 xmove_fd(s, STDIN_FILENO);
1580 /* discard output */
1581 close(STDOUT_FILENO);
1582 xopen(bb_dev_null, O_WRONLY);
1583 /* no error messages please... */
1584 xdup2(STDOUT_FILENO, STDERR_FILENO);
1585 BB_EXECVP("cat", (char**)cat_args);
1586 /* on failure we return to main, which does exit(EXIT_FAILURE) */
1590 static void FAST_FUNC discard_dg(int s, servtab_t *sep UNUSED_PARAM)
1592 /* dgram builtins are non-forking - DONT BLOCK! */
1593 recv(s, line, LINE_SIZE, MSG_DONTWAIT);
1595 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_DISCARD */
1598 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
1600 static void init_ring(void)
1605 for (i = ' '; i < 127; i++)
1608 /* Character generator. MMU arches only. */
1610 static void FAST_FUNC chargen_stream(int s, servtab_t *sep UNUSED_PARAM)
1614 char text[LINESIZ + 2];
1621 text[LINESIZ] = '\r';
1622 text[LINESIZ + 1] = '\n';
1625 len = end_ring - rs;
1627 memmove(text, rs, LINESIZ);
1629 memmove(text, rs, len);
1630 memmove(text + len, ring, LINESIZ - len);
1632 if (++rs == end_ring)
1634 xwrite(s, text, sizeof(text));
1638 static void FAST_FUNC chargen_dg(int s, servtab_t *sep)
1641 char text[LINESIZ + 2];
1642 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1644 /* Eat UDP packet which started it all */
1645 /* dgram builtins are non-forking - DONT BLOCK! */
1646 lsa->len = sep->se_lsa->len;
1647 if (recvfrom(s, text, sizeof(text), MSG_DONTWAIT, &lsa->u.sa, &lsa->len) < 0)
1655 len = end_ring - ring_pos;
1657 memmove(text, ring_pos, LINESIZ);
1659 memmove(text, ring_pos, len);
1660 memmove(text + len, ring, LINESIZ - len);
1662 if (++ring_pos == end_ring)
1664 text[LINESIZ] = '\r';
1665 text[LINESIZ + 1] = '\n';
1666 sendto(s, text, sizeof(text), 0, &lsa->u.sa, lsa->len);
1668 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN */
1671 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
1673 * Return a machine readable date and time, in the form of the
1674 * number of seconds since midnight, Jan 1, 1900. Since gettimeofday
1675 * returns the number of seconds since midnight, Jan 1, 1970,
1676 * we must add 2208988800 seconds to this figure to make up for
1677 * some seventy years Bell Labs was asleep.
1679 static uint32_t machtime(void)
1683 gettimeofday(&tv, NULL);
1684 return htonl((uint32_t)(tv.tv_sec + 2208988800U));
1687 static void FAST_FUNC machtime_stream(int s, servtab_t *sep UNUSED_PARAM)
1691 result = machtime();
1692 full_write(s, &result, sizeof(result));
1694 static void FAST_FUNC machtime_dg(int s, servtab_t *sep)
1697 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1699 lsa->len = sep->se_lsa->len;
1700 if (recvfrom(s, line, LINE_SIZE, MSG_DONTWAIT, &lsa->u.sa, &lsa->len) < 0)
1703 result = machtime();
1704 sendto(s, &result, sizeof(result), 0, &lsa->u.sa, lsa->len);
1706 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_TIME */
1709 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
1710 /* Return human-readable time of day */
1712 static void FAST_FUNC daytime_stream(int s, servtab_t *sep UNUSED_PARAM)
1717 fdprintf(s, "%.24s\r\n", ctime(&t));
1719 static void FAST_FUNC daytime_dg(int s, servtab_t *sep)
1722 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1724 lsa->len = sep->se_lsa->len;
1725 if (recvfrom(s, line, LINE_SIZE, MSG_DONTWAIT, &lsa->u.sa, &lsa->len) < 0)
1729 sprintf(line, "%.24s\r\n", ctime(&t));
1730 sendto(s, line, strlen(line), 0, &lsa->u.sa, lsa->len);
1732 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME */