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 # error "You need to build uClibc with UCLIBC_HAS_RPC for NFS support"
232 # include <rpc/rpc.h>
233 # include <rpc/pmap_clnt.h>
237 /* stream version of chargen is forking but not execing,
238 * can't do that (easily) on NOMMU */
239 #undef ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
240 #define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 0
243 #define CNT_INTERVAL 60 /* servers in CNT_INTERVAL sec. */
244 #define RETRYTIME 60 /* retry after bind or server fail */
246 // TODO: explain, or get rid of setrlimit games
248 #ifndef RLIMIT_NOFILE
249 #define RLIMIT_NOFILE RLIMIT_OFILE
256 /* Reserve some descriptors, 3 stdio + at least: 1 log, 1 conf. file */
259 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD \
260 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO \
261 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN \
262 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME \
263 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
264 # define INETD_BUILTINS_ENABLED
267 typedef struct servtab_t {
268 /* The most frequently referenced one: */
269 int se_fd; /* open descriptor */
270 /* NB: 'biggest fields last' saves on code size (~250 bytes) */
271 /* [addr:]service socktype proto wait user[:group] prog [args] */
272 char *se_local_hostname; /* addr to listen on */
273 char *se_service; /* "80" or "www" or "mount/2[-3]" */
274 /* socktype is in se_socktype */ /* "stream" "dgram" "raw" "rdm" "seqpacket" */
275 char *se_proto; /* "unix" or "[rpc/]tcp[6]" */
276 #if ENABLE_FEATURE_INETD_RPC
277 int se_rpcprog; /* rpc program number */
278 int se_rpcver_lo; /* rpc program lowest version */
279 int se_rpcver_hi; /* rpc program highest version */
280 #define is_rpc_service(sep) ((sep)->se_rpcver_lo != 0)
282 #define is_rpc_service(sep) 0
284 pid_t se_wait; /* 0:"nowait", 1:"wait", >1:"wait" */
285 /* and waiting for this pid */
286 socktype_t se_socktype; /* SOCK_STREAM/DGRAM/RDM/... */
287 family_t se_family; /* AF_UNIX/INET[6] */
288 /* se_proto_no is used by RPC code only... hmm */
289 smallint se_proto_no; /* IPPROTO_TCP/UDP, n/a for AF_UNIX */
290 smallint se_checked; /* looked at during merge */
291 unsigned se_max; /* allowed instances per minute */
292 unsigned se_count; /* number started since se_time */
293 unsigned se_time; /* when we started counting */
294 char *se_user; /* user name to run as */
295 char *se_group; /* group name to run as, can be NULL */
296 #ifdef INETD_BUILTINS_ENABLED
297 const struct builtin *se_builtin; /* if built-in, description */
299 struct servtab_t *se_next;
300 len_and_sockaddr *se_lsa;
301 char *se_program; /* server program */
303 char *se_argv[MAXARGV + 1]; /* program arguments */
306 #ifdef INETD_BUILTINS_ENABLED
307 /* Echo received data */
308 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
309 static void FAST_FUNC echo_stream(int, servtab_t *);
310 static void FAST_FUNC echo_dg(int, servtab_t *);
312 /* Internet /dev/null */
313 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
314 static void FAST_FUNC discard_stream(int, servtab_t *);
315 static void FAST_FUNC discard_dg(int, servtab_t *);
317 /* Return 32 bit time since 1900 */
318 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
319 static void FAST_FUNC machtime_stream(int, servtab_t *);
320 static void FAST_FUNC machtime_dg(int, servtab_t *);
322 /* Return human-readable time */
323 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
324 static void FAST_FUNC daytime_stream(int, servtab_t *);
325 static void FAST_FUNC daytime_dg(int, servtab_t *);
327 /* Familiar character generator */
328 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
329 static void FAST_FUNC chargen_stream(int, servtab_t *);
330 static void FAST_FUNC chargen_dg(int, servtab_t *);
334 /* NB: not necessarily NUL terminated */
335 char bi_service7[7]; /* internally provided service name */
336 uint8_t bi_fork; /* 1 if stream fn should run in child */
337 void (*bi_stream_fn)(int, servtab_t *) FAST_FUNC;
338 void (*bi_dgram_fn)(int, servtab_t *) FAST_FUNC;
341 static const struct builtin builtins[] = {
342 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
343 { "echo", 1, echo_stream, echo_dg },
345 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
346 { "discard", 1, discard_stream, discard_dg },
348 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
349 { "chargen", 1, chargen_stream, chargen_dg },
351 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
352 { "time", 0, machtime_stream, machtime_dg },
354 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
355 { "daytime", 0, daytime_stream, daytime_dg },
358 #endif /* INETD_BUILTINS_ENABLED */
361 rlim_t rlim_ofile_cur;
362 struct rlimit rlim_ofile;
363 servtab_t *serv_list;
365 int maxsock; /* max fd# in allsock, -1: unknown */
366 /* whenever maxsock grows, prev_maxsock is set to new maxsock,
367 * but if maxsock is set to -1, prev_maxsock is not changed */
369 unsigned max_concurrency;
370 smallint alarm_armed;
371 uid_t real_uid; /* user ID who ran us */
372 const char *config_filename;
374 char *default_local_hostname;
375 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
381 /* Used in next_line(), and as scratch read buffer */
382 char line[256]; /* _at least_ 256, see LINE_SIZE */
384 #define G (*(struct globals*)bb_common_bufsiz1)
385 enum { LINE_SIZE = COMMON_BUFSIZE - offsetof(struct globals, line) };
386 #define rlim_ofile_cur (G.rlim_ofile_cur )
387 #define rlim_ofile (G.rlim_ofile )
388 #define serv_list (G.serv_list )
389 #define global_queuelen (G.global_queuelen)
390 #define maxsock (G.maxsock )
391 #define prev_maxsock (G.prev_maxsock )
392 #define max_concurrency (G.max_concurrency)
393 #define alarm_armed (G.alarm_armed )
394 #define real_uid (G.real_uid )
395 #define config_filename (G.config_filename)
396 #define parser (G.parser )
397 #define default_local_hostname (G.default_local_hostname)
398 #define first_ps_byte (G.first_ps_byte )
399 #define last_ps_byte (G.last_ps_byte )
400 #define end_ring (G.end_ring )
401 #define ring_pos (G.ring_pos )
402 #define ring (G.ring )
403 #define allsock (G.allsock )
404 #define line (G.line )
405 #define INIT_G() do { \
406 setup_common_bufsiz(); \
407 BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
408 rlim_ofile_cur = OPEN_MAX; \
409 global_queuelen = 128; \
410 config_filename = "/etc/inetd.conf"; \
414 # define dbg(...) ((void)0)
418 int dbg_fd = open("inetd_debug.log", O_WRONLY | O_CREAT | O_APPEND, 0666); \
420 fdprintf(dbg_fd, "%d: ", getpid()); \
421 fdprintf(dbg_fd, __VA_ARGS__); \
427 static void maybe_close(int fd)
431 dbg("closed fd:%d\n", fd);
435 // TODO: move to libbb?
436 static len_and_sockaddr *xzalloc_lsa(int family)
438 len_and_sockaddr *lsa;
441 sz = sizeof(struct sockaddr_in);
442 if (family == AF_UNIX)
443 sz = sizeof(struct sockaddr_un);
444 #if ENABLE_FEATURE_IPV6
445 if (family == AF_INET6)
446 sz = sizeof(struct sockaddr_in6);
448 lsa = xzalloc(LSA_LEN_SIZE + sz);
450 lsa->u.sa.sa_family = family;
454 static void rearm_alarm(void)
462 static void block_CHLD_HUP_ALRM(sigset_t *m)
465 sigaddset(m, SIGCHLD);
466 sigaddset(m, SIGHUP);
467 sigaddset(m, SIGALRM);
468 sigprocmask(SIG_BLOCK, m, m); /* old sigmask is stored in m */
471 static void restore_sigmask(sigset_t *m)
473 sigprocmask(SIG_SETMASK, m, NULL);
476 #if ENABLE_FEATURE_INETD_RPC
477 static void register_rpc(servtab_t *sep)
480 struct sockaddr_in ir_sin;
483 size = sizeof(ir_sin);
484 if (getsockname(sep->se_fd, (struct sockaddr *) &ir_sin, &size) < 0) {
485 bb_perror_msg("getsockname");
489 for (n = sep->se_rpcver_lo; n <= sep->se_rpcver_hi; n++) {
490 pmap_unset(sep->se_rpcprog, n);
491 if (!pmap_set(sep->se_rpcprog, n, sep->se_proto_no, ntohs(ir_sin.sin_port)))
492 bb_perror_msg("%s %s: pmap_set(%u,%u,%u,%u)",
493 sep->se_service, sep->se_proto,
494 sep->se_rpcprog, n, sep->se_proto_no, ntohs(ir_sin.sin_port));
498 static void unregister_rpc(servtab_t *sep)
502 for (n = sep->se_rpcver_lo; n <= sep->se_rpcver_hi; n++) {
503 if (!pmap_unset(sep->se_rpcprog, n))
504 bb_perror_msg("pmap_unset(%u,%u)", sep->se_rpcprog, n);
507 #endif /* FEATURE_INETD_RPC */
509 static void bump_nofile(void)
511 enum { FD_CHUNK = 32 };
514 /* Never fails under Linux (except if you pass it bad arguments) */
515 getrlimit(RLIMIT_NOFILE, &rl);
516 rl.rlim_cur = MIN(rl.rlim_max, rl.rlim_cur + FD_CHUNK);
517 rl.rlim_cur = MIN(FD_SETSIZE, rl.rlim_cur + FD_CHUNK);
518 if (rl.rlim_cur <= rlim_ofile_cur) {
519 bb_error_msg("can't extend file limit, max = %d",
524 if (setrlimit(RLIMIT_NOFILE, &rl) < 0) {
525 bb_perror_msg("setrlimit");
529 rlim_ofile_cur = rl.rlim_cur;
532 static void remove_fd_from_set(int fd)
535 FD_CLR(fd, &allsock);
536 dbg("stopped listening on fd:%d\n", fd);
538 dbg("maxsock:%d\n", maxsock);
542 static void add_fd_to_set(int fd)
545 FD_SET(fd, &allsock);
546 dbg("started listening on fd:%d\n", fd);
547 if (maxsock >= 0 && fd > maxsock) {
548 prev_maxsock = maxsock = fd;
549 dbg("maxsock:%d\n", maxsock);
550 if ((rlim_t)fd > rlim_ofile_cur - FD_MARGIN)
556 static void recalculate_maxsock(void)
560 /* We may have no services, in this case maxsock should still be >= 0
561 * (code elsewhere is not happy with maxsock == -1) */
563 while (fd <= prev_maxsock) {
564 if (FD_ISSET(fd, &allsock))
568 dbg("recalculated maxsock:%d\n", maxsock);
569 prev_maxsock = maxsock;
570 if ((rlim_t)maxsock > rlim_ofile_cur - FD_MARGIN)
574 static void prepare_socket_fd(servtab_t *sep)
578 fd = socket(sep->se_family, sep->se_socktype, 0);
580 bb_perror_msg("socket");
583 setsockopt_reuseaddr(fd);
585 #if ENABLE_FEATURE_INETD_RPC
586 if (is_rpc_service(sep)) {
589 /* zero out the port for all RPC services; let bind()
591 set_nport(&sep->se_lsa->u.sa, 0);
593 /* for RPC services, attempt to use a reserved port
594 * if they are going to be running as root. */
595 if (real_uid == 0 && sep->se_family == AF_INET
596 && (pwd = getpwnam(sep->se_user)) != NULL
599 r = bindresvport(fd, &sep->se_lsa->u.sin);
601 r = bind(fd, &sep->se_lsa->u.sa, sep->se_lsa->len);
604 int saveerrno = errno;
605 /* update lsa with port# */
606 getsockname(fd, &sep->se_lsa->u.sa, &sep->se_lsa->len);
612 if (sep->se_family == AF_UNIX) {
613 struct sockaddr_un *sun;
614 sun = (struct sockaddr_un*)&(sep->se_lsa->u.sa);
615 unlink(sun->sun_path);
617 r = bind(fd, &sep->se_lsa->u.sa, sep->se_lsa->len);
620 bb_perror_msg("%s/%s: bind",
621 sep->se_service, sep->se_proto);
627 if (sep->se_socktype == SOCK_STREAM) {
628 listen(fd, global_queuelen);
629 dbg("new sep->se_fd:%d (stream)\n", fd);
631 dbg("new sep->se_fd:%d (!stream)\n", fd);
638 static int reopen_config_file(void)
640 free(default_local_hostname);
641 default_local_hostname = xstrdup("*");
643 config_close(parser);
644 parser = config_open(config_filename);
645 return (parser != NULL);
648 static void close_config_file(void)
651 config_close(parser);
656 static void free_servtab_strings(servtab_t *cp)
660 free(cp->se_local_hostname);
661 free(cp->se_service);
665 free(cp->se_lsa); /* not a string in fact */
666 free(cp->se_program);
667 for (i = 0; i < MAXARGV; i++)
668 free(cp->se_argv[i]);
671 static servtab_t *new_servtab(void)
673 servtab_t *newtab = xzalloc(sizeof(servtab_t));
674 newtab->se_fd = -1; /* paranoia */
678 static servtab_t *dup_servtab(servtab_t *sep)
683 newtab = new_servtab();
684 *newtab = *sep; /* struct copy */
685 /* deep-copying strings */
686 newtab->se_service = xstrdup(newtab->se_service);
687 newtab->se_proto = xstrdup(newtab->se_proto);
688 newtab->se_user = xstrdup(newtab->se_user);
689 newtab->se_group = xstrdup(newtab->se_group);
690 newtab->se_program = xstrdup(newtab->se_program);
691 for (argc = 0; argc <= MAXARGV; argc++)
692 newtab->se_argv[argc] = xstrdup(newtab->se_argv[argc]);
693 /* NB: se_fd, se_hostaddr and se_next are always
694 * overwrittend by callers, so we don't bother resetting them
695 * to NULL/0/-1 etc */
700 /* gcc generates much more code if this is inlined */
701 static NOINLINE servtab_t *parse_one_line(void)
704 char *token[6+MAXARGV];
712 argc = config_read(parser, token, 6+MAXARGV, 1, "# \t", PARSE_NORMAL);
718 /* [host:]service socktype proto wait user[:group] prog [args] */
719 /* Check for "host:...." line */
721 hostdelim = strrchr(arg, ':');
724 sep->se_local_hostname = xstrdup(arg);
726 if (*arg == '\0' && argc == 1) {
727 /* Line has just "host:", change the
728 * default host for the following lines. */
729 free(default_local_hostname);
730 default_local_hostname = sep->se_local_hostname;
731 /*sep->se_local_hostname = NULL; - redundant */
732 /* (we'll overwrite this field anyway) */
736 sep->se_local_hostname = xstrdup(default_local_hostname);
738 /* service socktype proto wait user[:group] prog [args] */
739 sep->se_service = xstrdup(arg);
741 /* socktype proto wait user[:group] prog [args] */
744 bb_error_msg("parse error on line %u, line is ignored",
746 /* Just "goto more" can make sep to carry over e.g.
747 * "rpc"-ness (by having se_rpcver_lo != 0).
748 * We will be more paranoid: */
749 free_servtab_strings(sep);
755 static const int8_t SOCK_xxx[] ALIGN1 = {
757 SOCK_STREAM, SOCK_DGRAM, SOCK_RDM,
758 SOCK_SEQPACKET, SOCK_RAW
760 sep->se_socktype = SOCK_xxx[1 + index_in_strings(
761 "stream""\0" "dgram""\0" "rdm""\0"
762 "seqpacket""\0" "raw""\0"
766 /* {unix,[rpc/]{tcp,udp}[6]} wait user[:group] prog [args] */
767 sep->se_proto = arg = xstrdup(token[2]);
768 if (strcmp(arg, "unix") == 0) {
769 sep->se_family = AF_UNIX;
772 sep->se_family = AF_INET;
773 six = last_char_is(arg, '6');
775 #if ENABLE_FEATURE_IPV6
777 sep->se_family = AF_INET6;
779 bb_error_msg("%s: no support for IPv6", sep->se_proto);
783 if (is_prefixed_with(arg, "rpc/")) {
784 #if ENABLE_FEATURE_INETD_RPC
787 p = strchr(sep->se_service, '/');
789 bb_error_msg("no rpc version: '%s'", sep->se_service);
793 n = bb_strtou(p, &p, 10);
796 bb_error_msg("bad rpc version");
799 sep->se_rpcver_lo = sep->se_rpcver_hi = n;
802 n = bb_strtou(p, &p, 10);
803 if (n > INT_MAX || (int)n < sep->se_rpcver_lo)
805 sep->se_rpcver_hi = n;
810 bb_error_msg("no support for rpc services");
814 /* we don't really need getprotobyname()! */
815 if (strcmp(arg, "tcp") == 0)
816 sep->se_proto_no = IPPROTO_TCP; /* = 6 */
817 if (strcmp(arg, "udp") == 0)
818 sep->se_proto_no = IPPROTO_UDP; /* = 17 */
821 if (!sep->se_proto_no) /* not tcp/udp?? */
825 /* [no]wait[.max] user[:group] prog [args] */
827 sep->se_max = max_concurrency;
828 p = strchr(arg, '.');
831 sep->se_max = bb_strtou(p, NULL, 10);
835 sep->se_wait = (arg[0] != 'n' || arg[1] != 'o');
836 if (!sep->se_wait) /* "no" seen */
838 if (strcmp(arg, "wait") != 0)
841 /* user[:group] prog [args] */
842 sep->se_user = xstrdup(token[4]);
843 arg = strchr(sep->se_user, '.');
845 arg = strchr(sep->se_user, ':');
848 sep->se_group = xstrdup(arg);
852 sep->se_program = xstrdup(token[5]);
853 #ifdef INETD_BUILTINS_ENABLED
854 if (strcmp(sep->se_program, "internal") == 0
855 && strlen(sep->se_service) <= 7
856 && (sep->se_socktype == SOCK_STREAM
857 || sep->se_socktype == SOCK_DGRAM)
860 for (i = 0; i < ARRAY_SIZE(builtins); i++)
861 if (strncmp(builtins[i].bi_service7, sep->se_service, 7) == 0)
863 bb_error_msg("unknown internal service %s", sep->se_service);
866 sep->se_builtin = &builtins[i];
867 /* stream builtins must be "nowait", dgram must be "wait" */
868 if (sep->se_wait != (sep->se_socktype == SOCK_DGRAM))
873 while (argc < MAXARGV && (arg = token[6+argc]) != NULL)
874 sep->se_argv[argc++] = xstrdup(arg);
875 /* Some inetd.conf files have no argv's, not even argv[0].
877 * (Technically, programs can be execed with argv[0] = NULL,
878 * but many programs do not like that at all) */
880 sep->se_argv[0] = xstrdup(sep->se_program);
882 /* catch mixups. "<service> stream udp ..." == wtf */
883 if (sep->se_socktype == SOCK_STREAM) {
884 if (sep->se_proto_no == IPPROTO_UDP)
887 if (sep->se_socktype == SOCK_DGRAM) {
888 if (sep->se_proto_no == IPPROTO_TCP)
893 // "ENTRY[%s][%s][%s][%d][%d][%d][%d][%d][%s][%s][%s]",
894 // sep->se_local_hostname, sep->se_service, sep->se_proto, sep->se_wait, sep->se_proto_no,
895 // sep->se_max, sep->se_count, sep->se_time, sep->se_user, sep->se_group, sep->se_program);
897 /* check if the hostname specifier is a comma separated list
898 * of hostnames. we'll make new entries for each address. */
899 while ((hostdelim = strrchr(sep->se_local_hostname, ',')) != NULL) {
900 nsep = dup_servtab(sep);
901 /* NUL terminate the hostname field of the existing entry,
902 * and make a dup for the new entry. */
904 nsep->se_local_hostname = xstrdup(hostdelim);
905 nsep->se_next = sep->se_next;
909 /* was doing it here: */
910 /* DNS resolution, create copies for each IP address */
911 /* IPv6-ization destroyed it :( */
916 static servtab_t *insert_in_servlist(servtab_t *cp)
922 *sep = *cp; /* struct copy */
924 #if ENABLE_FEATURE_INETD_RPC
925 sep->se_rpcprog = -1;
927 block_CHLD_HUP_ALRM(&omask);
928 sep->se_next = serv_list;
930 restore_sigmask(&omask);
934 static int same_serv_addr_proto(servtab_t *old, servtab_t *new)
936 if (strcmp(old->se_local_hostname, new->se_local_hostname) != 0)
938 if (strcmp(old->se_service, new->se_service) != 0)
940 if (strcmp(old->se_proto, new->se_proto) != 0)
945 static void reread_config_file(int sig UNUSED_PARAM)
947 servtab_t *sep, *cp, **sepp;
948 len_and_sockaddr *lsa;
952 int save_errno = errno;
954 if (!reopen_config_file())
956 for (sep = serv_list; sep; sep = sep->se_next)
963 cp = parse_one_line();
967 for (sep = serv_list; sep; sep = sep->se_next)
968 if (same_serv_addr_proto(sep, cp))
970 /* not an "equal" servtab */
971 sep = insert_in_servlist(cp);
977 block_CHLD_HUP_ALRM(&omask);
978 #if ENABLE_FEATURE_INETD_RPC
979 if (is_rpc_service(sep))
981 sep->se_rpcver_lo = cp->se_rpcver_lo;
982 sep->se_rpcver_hi = cp->se_rpcver_hi;
984 if (cp->se_wait == 0) {
985 /* New config says "nowait". If old one
986 * was "wait", we currently may be waiting
987 * for a child (and not accepting connects).
988 * Stop waiting, start listening again.
989 * (if it's not true, this op is harmless) */
990 add_fd_to_set(sep->se_fd);
992 sep->se_wait = cp->se_wait;
993 sep->se_max = cp->se_max;
994 /* string fields need more love - we don't want to leak them */
995 #define SWAP(type, a, b) do { type c = (type)a; a = (type)b; b = (type)c; } while (0)
996 SWAP(char*, sep->se_user, cp->se_user);
997 SWAP(char*, sep->se_group, cp->se_group);
998 SWAP(char*, sep->se_program, cp->se_program);
999 for (i = 0; i < MAXARGV; i++)
1000 SWAP(char*, sep->se_argv[i], cp->se_argv[i]);
1002 restore_sigmask(&omask);
1003 free_servtab_strings(cp);
1006 /* cp->string_fields are consumed by insert_in_servlist()
1007 * or freed at this point, cp itself is not yet freed. */
1008 sep->se_checked = 1;
1010 /* create new len_and_sockaddr */
1011 switch (sep->se_family) {
1012 struct sockaddr_un *sun;
1014 lsa = xzalloc_lsa(AF_UNIX);
1015 sun = (struct sockaddr_un*)&lsa->u.sa;
1016 safe_strncpy(sun->sun_path, sep->se_service, sizeof(sun->sun_path));
1019 default: /* case AF_INET, case AF_INET6 */
1020 n = bb_strtou(sep->se_service, NULL, 10);
1021 #if ENABLE_FEATURE_INETD_RPC
1022 if (is_rpc_service(sep)) {
1023 sep->se_rpcprog = n;
1024 if (errno) { /* se_service is not numeric */
1025 struct rpcent *rp = getrpcbyname(sep->se_service);
1027 bb_error_msg("%s: unknown rpc service", sep->se_service);
1030 sep->se_rpcprog = rp->r_number;
1032 if (sep->se_fd == -1)
1033 prepare_socket_fd(sep);
1034 if (sep->se_fd != -1)
1039 /* what port to listen on? */
1041 if (errno || n > 0xffff) { /* se_service is not numeric */
1044 /* can result only in "tcp" or "udp": */
1045 safe_strncpy(protoname, sep->se_proto, 4);
1046 sp = getservbyname(sep->se_service, protoname);
1048 bb_error_msg("%s/%s: unknown service",
1049 sep->se_service, sep->se_proto);
1054 if (LONE_CHAR(sep->se_local_hostname, '*')) {
1055 lsa = xzalloc_lsa(sep->se_family);
1056 set_nport(&lsa->u.sa, port);
1058 lsa = host_and_af2sockaddr(sep->se_local_hostname,
1059 ntohs(port), sep->se_family);
1061 bb_error_msg("%s/%s: unknown host '%s'",
1062 sep->se_service, sep->se_proto,
1063 sep->se_local_hostname);
1068 } /* end of "switch (sep->se_family)" */
1070 /* did lsa change? Then close/open */
1071 if (sep->se_lsa == NULL
1072 || lsa->len != sep->se_lsa->len
1073 || memcmp(&lsa->u.sa, &sep->se_lsa->u.sa, lsa->len) != 0
1075 remove_fd_from_set(sep->se_fd);
1076 maybe_close(sep->se_fd);
1083 if (sep->se_fd == -1)
1084 prepare_socket_fd(sep);
1089 } /* end of "while (1) parse lines" */
1090 close_config_file();
1092 /* Purge anything not looked at above - these are stale entries,
1093 * new config file doesnt have them. */
1094 block_CHLD_HUP_ALRM(&omask);
1096 while ((sep = *sepp) != NULL) {
1097 if (sep->se_checked) {
1098 sepp = &sep->se_next;
1101 *sepp = sep->se_next;
1102 remove_fd_from_set(sep->se_fd);
1103 maybe_close(sep->se_fd);
1104 #if ENABLE_FEATURE_INETD_RPC
1105 if (is_rpc_service(sep))
1106 unregister_rpc(sep);
1108 if (sep->se_family == AF_UNIX)
1109 unlink(sep->se_service);
1110 free_servtab_strings(sep);
1113 restore_sigmask(&omask);
1118 static void reap_child(int sig UNUSED_PARAM)
1123 int save_errno = errno;
1126 pid = wait_any_nohang(&status);
1129 for (sep = serv_list; sep; sep = sep->se_next) {
1130 if (sep->se_wait != pid)
1132 /* One of our "wait" services */
1133 if (WIFEXITED(status) && WEXITSTATUS(status))
1134 bb_error_msg("%s: exit status %u",
1135 sep->se_program, WEXITSTATUS(status));
1136 else if (WIFSIGNALED(status))
1137 bb_error_msg("%s: exit signal %u",
1138 sep->se_program, WTERMSIG(status));
1140 add_fd_to_set(sep->se_fd);
1147 static void retry_network_setup(int sig UNUSED_PARAM)
1149 int save_errno = errno;
1153 for (sep = serv_list; sep; sep = sep->se_next) {
1154 if (sep->se_fd == -1) {
1155 prepare_socket_fd(sep);
1156 #if ENABLE_FEATURE_INETD_RPC
1157 if (sep->se_fd != -1 && is_rpc_service(sep))
1165 static void clean_up_and_exit(int sig UNUSED_PARAM)
1169 /* XXX signal race walking sep list */
1170 for (sep = serv_list; sep; sep = sep->se_next) {
1171 if (sep->se_fd == -1)
1174 switch (sep->se_family) {
1176 unlink(sep->se_service);
1178 default: /* case AF_INET, AF_INET6 */
1179 #if ENABLE_FEATURE_INETD_RPC
1180 if (sep->se_wait == 1 && is_rpc_service(sep))
1181 unregister_rpc(sep); /* XXX signal race */
1185 if (ENABLE_FEATURE_CLEAN_UP)
1188 remove_pidfile(CONFIG_PID_FILE_PATH "/inetd.pid");
1192 int inetd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1193 int inetd_main(int argc UNUSED_PARAM, char **argv)
1195 struct sigaction sa, saved_pipe_handler;
1196 servtab_t *sep, *sep2;
1198 struct group *grp = grp; /* for compiler */
1205 real_uid = getuid();
1206 if (real_uid != 0) /* run by non-root user */
1207 config_filename = NULL;
1210 opt = getopt32(argv, "R:+feq:+", &max_concurrency, &global_queuelen);
1214 config_filename = argv[0];
1215 if (config_filename == NULL)
1216 bb_error_msg_and_die("non-root must specify config file");
1218 bb_daemonize_or_rexec(0, argv - optind);
1220 bb_sanitize_stdio();
1222 /* LOG_NDELAY: connect to syslog daemon NOW.
1223 * Otherwise, we may open syslog socket
1224 * in vforked child, making opened fds and syslog()
1225 * internal state inconsistent.
1226 * This was observed to leak file descriptors. */
1227 openlog(applet_name, LOG_PID | LOG_NDELAY, LOG_DAEMON);
1228 logmode = LOGMODE_SYSLOG;
1231 if (real_uid == 0) {
1232 /* run by root, ensure groups vector gets trashed */
1233 gid_t gid = getgid();
1237 write_pidfile(CONFIG_PID_FILE_PATH "/inetd.pid");
1239 /* never fails under Linux (except if you pass it bad arguments) */
1240 getrlimit(RLIMIT_NOFILE, &rlim_ofile);
1241 rlim_ofile_cur = rlim_ofile.rlim_cur;
1242 if (rlim_ofile_cur == RLIM_INFINITY) /* ! */
1243 rlim_ofile_cur = OPEN_MAX;
1245 memset(&sa, 0, sizeof(sa));
1246 /*sigemptyset(&sa.sa_mask); - memset did it */
1247 sigaddset(&sa.sa_mask, SIGALRM);
1248 sigaddset(&sa.sa_mask, SIGCHLD);
1249 sigaddset(&sa.sa_mask, SIGHUP);
1250 //FIXME: explain why no SA_RESTART
1251 //FIXME: retry_network_setup is unsafe to run in signal handler (many reasons)!
1252 sa.sa_handler = retry_network_setup;
1253 sigaction_set(SIGALRM, &sa);
1254 //FIXME: reread_config_file is unsafe to run in signal handler(many reasons)!
1255 sa.sa_handler = reread_config_file;
1256 sigaction_set(SIGHUP, &sa);
1257 //FIXME: reap_child is unsafe to run in signal handler (uses stdio)!
1258 sa.sa_handler = reap_child;
1259 sigaction_set(SIGCHLD, &sa);
1260 //FIXME: clean_up_and_exit is unsafe to run in signal handler (uses stdio)!
1261 sa.sa_handler = clean_up_and_exit;
1262 sigaction_set(SIGTERM, &sa);
1263 sa.sa_handler = clean_up_and_exit;
1264 sigaction_set(SIGINT, &sa);
1265 sa.sa_handler = SIG_IGN;
1266 sigaction(SIGPIPE, &sa, &saved_pipe_handler);
1268 reread_config_file(SIGHUP); /* load config from file */
1272 int ctrl, accepted_fd, new_udp_fd;
1276 recalculate_maxsock();
1278 readable = allsock; /* struct copy */
1279 /* if there are no fds to wait on, we will block
1280 * until signal wakes us up (maxsock == 0, but readable
1281 * never contains fds 0 and 1...) */
1282 ready_fd_cnt = select(maxsock + 1, &readable, NULL, NULL, NULL);
1283 if (ready_fd_cnt < 0) {
1284 if (errno != EINTR) {
1285 bb_perror_msg("select");
1290 dbg("ready_fd_cnt:%d\n", ready_fd_cnt);
1292 for (sep = serv_list; ready_fd_cnt && sep; sep = sep->se_next) {
1293 if (sep->se_fd == -1 || !FD_ISSET(sep->se_fd, &readable))
1296 dbg("ready fd:%d\n", sep->se_fd);
1301 if (!sep->se_wait) {
1302 if (sep->se_socktype == SOCK_STREAM) {
1303 ctrl = accepted_fd = accept(sep->se_fd, NULL, NULL);
1304 dbg("accepted_fd:%d\n", accepted_fd);
1307 bb_perror_msg("accept (for %s)", sep->se_service);
1312 if (sep->se_socktype == SOCK_DGRAM
1313 && sep->se_family != AF_UNIX
1315 /* How udp "nowait" works:
1316 * child peeks at (received and buffered by kernel) UDP packet,
1317 * performs connect() on the socket so that it is linked only
1318 * to this peer. But this also affects parent, because descriptors
1319 * are shared after fork() a-la dup(). When parent performs
1320 * select(), it will see this descriptor connected to the peer (!)
1321 * and still readable, will act on it and mess things up
1322 * (can create many copies of same child, etc).
1323 * Parent must create and use new socket instead. */
1324 new_udp_fd = socket(sep->se_family, SOCK_DGRAM, 0);
1325 dbg("new_udp_fd:%d\n", new_udp_fd);
1326 if (new_udp_fd < 0) { /* error: eat packet, forget about it */
1328 recv(sep->se_fd, line, LINE_SIZE, MSG_DONTWAIT);
1331 setsockopt_reuseaddr(new_udp_fd);
1332 /* TODO: better do bind after fork in parent,
1333 * so that we don't have two wildcard bound sockets
1334 * even for a brief moment? */
1335 if (bind(new_udp_fd, &sep->se_lsa->u.sa, sep->se_lsa->len) < 0) {
1336 dbg("bind(new_udp_fd) failed\n");
1340 dbg("bind(new_udp_fd) succeeded\n");
1344 block_CHLD_HUP_ALRM(&omask);
1346 #ifdef INETD_BUILTINS_ENABLED
1347 /* do we need to fork? */
1348 if (sep->se_builtin == NULL
1349 || (sep->se_socktype == SOCK_STREAM
1350 && sep->se_builtin->bi_fork))
1353 if (sep->se_max != 0) {
1354 if (++sep->se_count == 1)
1355 sep->se_time = monotonic_sec();
1356 else if (sep->se_count >= sep->se_max) {
1357 unsigned now = monotonic_sec();
1358 /* did we accumulate se_max connects too quickly? */
1359 if (now - sep->se_time <= CNT_INTERVAL) {
1360 bb_error_msg("%s/%s: too many connections, pausing",
1361 sep->se_service, sep->se_proto);
1362 remove_fd_from_set(sep->se_fd);
1366 rearm_alarm(); /* will revive it in RETRYTIME sec */
1367 restore_sigmask(&omask);
1368 maybe_close(new_udp_fd);
1369 maybe_close(accepted_fd);
1370 continue; /* -> check next fd in fd set */
1375 /* on NOMMU, streamed chargen
1376 * builtin wouldn't work, but it is
1377 * not allowed on NOMMU (ifdefed out) */
1378 #ifdef INETD_BUILTINS_ENABLED
1379 if (BB_MMU && sep->se_builtin)
1385 if (pid < 0) { /* fork error */
1386 bb_perror_msg("vfork"+1);
1388 restore_sigmask(&omask);
1389 maybe_close(new_udp_fd);
1390 maybe_close(accepted_fd);
1391 continue; /* -> check next fd in fd set */
1394 pid--; /* -1: "we did fork and we are child" */
1396 /* if pid == 0 here, we didn't fork */
1398 if (pid > 0) { /* parent */
1400 /* wait: we passed socket to child,
1401 * will wait for child to terminate */
1403 remove_fd_from_set(sep->se_fd);
1405 if (new_udp_fd >= 0) {
1406 /* udp nowait: child connected the socket,
1407 * we created and will use new, unconnected one */
1408 xmove_fd(new_udp_fd, sep->se_fd);
1409 dbg("moved new_udp_fd:%d to sep->se_fd:%d\n", new_udp_fd, sep->se_fd);
1411 restore_sigmask(&omask);
1412 maybe_close(accepted_fd);
1413 continue; /* -> check next fd in fd set */
1416 /* we are either child or didn't fork at all */
1417 #ifdef INETD_BUILTINS_ENABLED
1418 if (sep->se_builtin) {
1419 if (pid) { /* "pid" is -1: we did fork */
1420 close(sep->se_fd); /* listening socket */
1421 dbg("closed sep->se_fd:%d\n", sep->se_fd);
1422 logmode = LOGMODE_NONE; /* make xwrite etc silent */
1424 restore_sigmask(&omask);
1425 if (sep->se_socktype == SOCK_STREAM)
1426 sep->se_builtin->bi_stream_fn(ctrl, sep);
1428 sep->se_builtin->bi_dgram_fn(ctrl, sep);
1429 if (pid) /* we did fork */
1430 _exit(EXIT_FAILURE);
1431 maybe_close(accepted_fd);
1432 continue; /* -> check next fd in fd set */
1438 if (new_udp_fd >= 0) {
1439 len_and_sockaddr *lsa;
1443 dbg("closed new_udp_fd:%d\n", new_udp_fd);
1444 lsa = xzalloc_lsa(sep->se_family);
1445 /* peek at the packet and remember peer addr */
1446 r = recvfrom(ctrl, NULL, 0, MSG_PEEK|MSG_DONTWAIT,
1447 &lsa->u.sa, &lsa->len);
1450 /* make this socket "connected" to peer addr:
1451 * only packets from this peer will be recv'ed,
1452 * and bare write()/send() will work on it */
1453 connect(ctrl, &lsa->u.sa, lsa->len);
1454 dbg("connected ctrl:%d to remote peer\n", ctrl);
1457 /* prepare env and exec program */
1458 pwd = getpwnam(sep->se_user);
1460 bb_error_msg("%s: no such %s", sep->se_user, "user");
1463 if (sep->se_group && (grp = getgrnam(sep->se_group)) == NULL) {
1464 bb_error_msg("%s: no such %s", sep->se_group, "group");
1467 if (real_uid != 0 && real_uid != pwd->pw_uid) {
1468 /* a user running private inetd */
1469 bb_error_msg("non-root must run services as himself");
1472 if (pwd->pw_uid != 0) {
1474 pwd->pw_gid = grp->gr_gid;
1475 /* initgroups, setgid, setuid: */
1476 change_identity(pwd);
1477 } else if (sep->se_group) {
1478 xsetgid(grp->gr_gid);
1479 setgroups(1, &grp->gr_gid);
1481 if (rlim_ofile.rlim_cur != rlim_ofile_cur)
1482 if (setrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0)
1483 bb_perror_msg("setrlimit");
1485 /* closelog(); - WRONG. we are after vfork,
1486 * this may confuse syslog() internal state.
1487 * Let's hope libc sets syslog fd to CLOEXEC...
1489 xmove_fd(ctrl, STDIN_FILENO);
1490 xdup2(STDIN_FILENO, STDOUT_FILENO);
1491 dbg("moved ctrl:%d to fd 0,1[,2]\n", ctrl);
1492 /* manpages of inetd I managed to find either say
1493 * that stderr is also redirected to the network,
1494 * or do not talk about redirection at all (!) */
1495 if (!sep->se_wait) /* only for usual "tcp nowait" */
1496 xdup2(STDIN_FILENO, STDERR_FILENO);
1497 /* NB: among others, this loop closes listening sockets
1498 * for nowait stream children */
1499 for (sep2 = serv_list; sep2; sep2 = sep2->se_next)
1500 if (sep2->se_fd != ctrl)
1501 maybe_close(sep2->se_fd);
1502 sigaction_set(SIGPIPE, &saved_pipe_handler);
1503 restore_sigmask(&omask);
1504 dbg("execing:'%s'\n", sep->se_program);
1505 BB_EXECVP(sep->se_program, sep->se_argv);
1506 bb_perror_msg("can't execute '%s'", sep->se_program);
1508 /* eat packet in udp case */
1509 if (sep->se_socktype != SOCK_STREAM)
1510 recv(0, line, LINE_SIZE, MSG_DONTWAIT);
1511 _exit(EXIT_FAILURE);
1512 } /* for (sep = servtab...) */
1517 static const char *const cat_args[] = { "cat", NULL };
1521 * Internet services provided internally by inetd:
1523 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
1524 /* Echo service -- echo data back. */
1526 static void FAST_FUNC echo_stream(int s, servtab_t *sep UNUSED_PARAM)
1530 ssize_t sz = safe_read(s, line, LINE_SIZE);
1533 xwrite(s, line, sz);
1536 /* We are after vfork here! */
1537 /* move network socket to stdin/stdout */
1538 xmove_fd(s, STDIN_FILENO);
1539 xdup2(STDIN_FILENO, STDOUT_FILENO);
1540 /* no error messages please... */
1541 close(STDERR_FILENO);
1542 xopen(bb_dev_null, O_WRONLY);
1543 BB_EXECVP("cat", (char**)cat_args);
1544 /* on failure we return to main, which does exit(EXIT_FAILURE) */
1547 static void FAST_FUNC echo_dg(int s, servtab_t *sep)
1549 enum { BUFSIZE = 12*1024 }; /* for jumbo sized packets! :) */
1550 char *buf = xmalloc(BUFSIZE); /* too big for stack */
1552 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1554 lsa->len = sep->se_lsa->len;
1555 /* dgram builtins are non-forking - DONT BLOCK! */
1556 sz = recvfrom(s, buf, BUFSIZE, MSG_DONTWAIT, &lsa->u.sa, &lsa->len);
1558 sendto(s, buf, sz, 0, &lsa->u.sa, lsa->len);
1561 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_ECHO */
1564 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
1565 /* Discard service -- ignore data. */
1567 static void FAST_FUNC discard_stream(int s, servtab_t *sep UNUSED_PARAM)
1570 while (safe_read(s, line, LINE_SIZE) > 0)
1573 /* We are after vfork here! */
1574 /* move network socket to stdin */
1575 xmove_fd(s, STDIN_FILENO);
1576 /* discard output */
1577 close(STDOUT_FILENO);
1578 xopen(bb_dev_null, O_WRONLY);
1579 /* no error messages please... */
1580 xdup2(STDOUT_FILENO, STDERR_FILENO);
1581 BB_EXECVP("cat", (char**)cat_args);
1582 /* on failure we return to main, which does exit(EXIT_FAILURE) */
1586 static void FAST_FUNC discard_dg(int s, servtab_t *sep UNUSED_PARAM)
1588 /* dgram builtins are non-forking - DONT BLOCK! */
1589 recv(s, line, LINE_SIZE, MSG_DONTWAIT);
1591 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_DISCARD */
1594 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
1596 static void init_ring(void)
1601 for (i = ' '; i < 127; i++)
1604 /* Character generator. MMU arches only. */
1606 static void FAST_FUNC chargen_stream(int s, servtab_t *sep UNUSED_PARAM)
1610 char text[LINESIZ + 2];
1617 text[LINESIZ] = '\r';
1618 text[LINESIZ + 1] = '\n';
1621 len = end_ring - rs;
1623 memmove(text, rs, LINESIZ);
1625 memmove(text, rs, len);
1626 memmove(text + len, ring, LINESIZ - len);
1628 if (++rs == end_ring)
1630 xwrite(s, text, sizeof(text));
1634 static void FAST_FUNC chargen_dg(int s, servtab_t *sep)
1637 char text[LINESIZ + 2];
1638 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1640 /* Eat UDP packet which started it all */
1641 /* dgram builtins are non-forking - DONT BLOCK! */
1642 lsa->len = sep->se_lsa->len;
1643 if (recvfrom(s, text, sizeof(text), MSG_DONTWAIT, &lsa->u.sa, &lsa->len) < 0)
1651 len = end_ring - ring_pos;
1653 memmove(text, ring_pos, LINESIZ);
1655 memmove(text, ring_pos, len);
1656 memmove(text + len, ring, LINESIZ - len);
1658 if (++ring_pos == end_ring)
1660 text[LINESIZ] = '\r';
1661 text[LINESIZ + 1] = '\n';
1662 sendto(s, text, sizeof(text), 0, &lsa->u.sa, lsa->len);
1664 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN */
1667 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
1669 * Return a machine readable date and time, in the form of the
1670 * number of seconds since midnight, Jan 1, 1900. Since gettimeofday
1671 * returns the number of seconds since midnight, Jan 1, 1970,
1672 * we must add 2208988800 seconds to this figure to make up for
1673 * some seventy years Bell Labs was asleep.
1675 static uint32_t machtime(void)
1679 gettimeofday(&tv, NULL);
1680 return htonl((uint32_t)(tv.tv_sec + 2208988800U));
1683 static void FAST_FUNC machtime_stream(int s, servtab_t *sep UNUSED_PARAM)
1687 result = machtime();
1688 full_write(s, &result, sizeof(result));
1690 static void FAST_FUNC machtime_dg(int s, servtab_t *sep)
1693 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1695 lsa->len = sep->se_lsa->len;
1696 if (recvfrom(s, line, LINE_SIZE, MSG_DONTWAIT, &lsa->u.sa, &lsa->len) < 0)
1699 result = machtime();
1700 sendto(s, &result, sizeof(result), 0, &lsa->u.sa, lsa->len);
1702 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_TIME */
1705 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
1706 /* Return human-readable time of day */
1708 static void FAST_FUNC daytime_stream(int s, servtab_t *sep UNUSED_PARAM)
1713 fdprintf(s, "%.24s\r\n", ctime(&t));
1715 static void FAST_FUNC daytime_dg(int s, servtab_t *sep)
1718 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1720 lsa->len = sep->se_lsa->len;
1721 if (recvfrom(s, line, LINE_SIZE, MSG_DONTWAIT, &lsa->u.sa, &lsa->len) < 0)
1725 sprintf(line, "%.24s\r\n", ctime(&t));
1726 sendto(s, line, strlen(line), 0, &lsa->u.sa, lsa->len);
1728 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME */