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 (18 kb)"
159 //config: select FEATURE_SYSLOG
161 //config: Internet superserver daemon
163 //config:config FEATURE_INETD_SUPPORT_BUILTIN_ECHO
164 //config: bool "Support echo service on port 7"
166 //config: depends on INETD
168 //config: Internal service which echoes data back.
169 //config: Activated by configuration lines like these:
170 //config: echo stream tcp nowait root internal
171 //config: echo dgram udp wait root internal
173 //config:config FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
174 //config: bool "Support discard service on port 8"
176 //config: depends on INETD
178 //config: Internal service which discards all input.
179 //config: Activated by configuration lines like these:
180 //config: discard stream tcp nowait root internal
181 //config: discard dgram udp wait root internal
183 //config:config FEATURE_INETD_SUPPORT_BUILTIN_TIME
184 //config: bool "Support time service on port 37"
186 //config: depends on INETD
188 //config: Internal service which returns big-endian 32-bit number
189 //config: of seconds passed since 1900-01-01. The number wraps around
190 //config: on overflow.
191 //config: Activated by configuration lines like these:
192 //config: time stream tcp nowait root internal
193 //config: time dgram udp wait root internal
195 //config:config FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
196 //config: bool "Support daytime service on port 13"
198 //config: depends on INETD
200 //config: Internal service which returns human-readable time.
201 //config: Activated by configuration lines like these:
202 //config: daytime stream tcp nowait root internal
203 //config: daytime dgram udp wait root internal
205 //config:config FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
206 //config: bool "Support chargen service on port 19"
208 //config: depends on INETD
210 //config: Internal service which generates endless stream
211 //config: of all ASCII chars beetween space and char 126.
212 //config: Activated by configuration lines like these:
213 //config: chargen stream tcp nowait root internal
214 //config: chargen dgram udp wait root internal
216 //config:config FEATURE_INETD_RPC
217 //config: bool "Support RPC services"
218 //config: default n # very rarely used, and needs Sun RPC support in libc
219 //config: depends on INETD
220 //config: select FEATURE_HAVE_RPC
222 //config: Support Sun-RPC based services
224 //applet:IF_INETD(APPLET(inetd, BB_DIR_USR_SBIN, BB_SUID_DROP))
226 //kbuild:lib-$(CONFIG_INETD) += inetd.o
228 //usage:#define inetd_trivial_usage
229 //usage: "[-fe] [-q N] [-R N] [CONFFILE]"
230 //usage:#define inetd_full_usage "\n\n"
231 //usage: "Listen for network connections and launch programs\n"
232 //usage: "\n -f Run in foreground"
233 //usage: "\n -e Log to stderr"
234 //usage: "\n -q N Socket listen queue (default 128)"
235 //usage: "\n -R N Pause services after N connects/min"
236 //usage: "\n (default 0 - disabled)"
237 //usage: "\n Default CONFFILE is /etc/inetd.conf"
240 #include <sys/resource.h> /* setrlimit */
241 #include <sys/socket.h> /* un.h may need this */
245 #include "common_bufsiz.h"
247 #if ENABLE_FEATURE_INETD_RPC
248 # if defined(__UCLIBC__) && ! defined(__UCLIBC_HAS_RPC__)
249 # warning "You probably need to build uClibc with UCLIBC_HAS_RPC for NFS support"
250 /* not #error, since user may be using e.g. libtirpc instead */
252 # include <rpc/rpc.h>
253 # include <rpc/pmap_clnt.h>
257 /* stream version of chargen is forking but not execing,
258 * can't do that (easily) on NOMMU */
259 #undef ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
260 #define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 0
263 #define CNT_INTERVAL 60 /* servers in CNT_INTERVAL sec. */
264 #define RETRYTIME 60 /* retry after bind or server fail */
266 // TODO: explain, or get rid of setrlimit games
268 #ifndef RLIMIT_NOFILE
269 #define RLIMIT_NOFILE RLIMIT_OFILE
276 /* Reserve some descriptors, 3 stdio + at least: 1 log, 1 conf. file */
279 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD \
280 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO \
281 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN \
282 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME \
283 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
284 # define INETD_BUILTINS_ENABLED
287 typedef struct servtab_t {
288 /* The most frequently referenced one: */
289 int se_fd; /* open descriptor */
290 /* NB: 'biggest fields last' saves on code size (~250 bytes) */
291 /* [addr:]service socktype proto wait user[:group] prog [args] */
292 char *se_local_hostname; /* addr to listen on */
293 char *se_service; /* "80" or "www" or "mount/2[-3]" */
294 /* socktype is in se_socktype */ /* "stream" "dgram" "raw" "rdm" "seqpacket" */
295 char *se_proto; /* "unix" or "[rpc/]tcp[6]" */
296 #if ENABLE_FEATURE_INETD_RPC
297 int se_rpcprog; /* rpc program number */
298 int se_rpcver_lo; /* rpc program lowest version */
299 int se_rpcver_hi; /* rpc program highest version */
300 #define is_rpc_service(sep) ((sep)->se_rpcver_lo != 0)
302 #define is_rpc_service(sep) 0
304 pid_t se_wait; /* 0:"nowait", 1:"wait", >1:"wait" */
305 /* and waiting for this pid */
306 socktype_t se_socktype; /* SOCK_STREAM/DGRAM/RDM/... */
307 family_t se_family; /* AF_UNIX/INET[6] */
308 /* se_proto_no is used by RPC code only... hmm */
309 smallint se_proto_no; /* IPPROTO_TCP/UDP, n/a for AF_UNIX */
310 smallint se_checked; /* looked at during merge */
311 unsigned se_max; /* allowed instances per minute */
312 unsigned se_count; /* number started since se_time */
313 unsigned se_time; /* when we started counting */
314 char *se_user; /* user name to run as */
315 char *se_group; /* group name to run as, can be NULL */
316 #ifdef INETD_BUILTINS_ENABLED
317 const struct builtin *se_builtin; /* if built-in, description */
319 struct servtab_t *se_next;
320 len_and_sockaddr *se_lsa;
321 char *se_program; /* server program */
323 char *se_argv[MAXARGV + 1]; /* program arguments */
326 #ifdef INETD_BUILTINS_ENABLED
327 /* Echo received data */
328 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
329 static void FAST_FUNC echo_stream(int, servtab_t *);
330 static void FAST_FUNC echo_dg(int, servtab_t *);
332 /* Internet /dev/null */
333 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
334 static void FAST_FUNC discard_stream(int, servtab_t *);
335 static void FAST_FUNC discard_dg(int, servtab_t *);
337 /* Return 32 bit time since 1900 */
338 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
339 static void FAST_FUNC machtime_stream(int, servtab_t *);
340 static void FAST_FUNC machtime_dg(int, servtab_t *);
342 /* Return human-readable time */
343 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
344 static void FAST_FUNC daytime_stream(int, servtab_t *);
345 static void FAST_FUNC daytime_dg(int, servtab_t *);
347 /* Familiar character generator */
348 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
349 static void FAST_FUNC chargen_stream(int, servtab_t *);
350 static void FAST_FUNC chargen_dg(int, servtab_t *);
354 /* NB: not necessarily NUL terminated */
355 char bi_service7[7]; /* internally provided service name */
356 uint8_t bi_fork; /* 1 if stream fn should run in child */
357 void (*bi_stream_fn)(int, servtab_t *) FAST_FUNC;
358 void (*bi_dgram_fn)(int, servtab_t *) FAST_FUNC;
361 static const struct builtin builtins[] = {
362 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
363 { "echo", 1, echo_stream, echo_dg },
365 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
366 { "discard", 1, discard_stream, discard_dg },
368 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
369 { "chargen", 1, chargen_stream, chargen_dg },
371 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
372 { "time", 0, machtime_stream, machtime_dg },
374 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
375 { "daytime", 0, daytime_stream, daytime_dg },
378 #endif /* INETD_BUILTINS_ENABLED */
381 rlim_t rlim_ofile_cur;
382 struct rlimit rlim_ofile;
383 servtab_t *serv_list;
385 int maxsock; /* max fd# in allsock, -1: unknown */
386 /* whenever maxsock grows, prev_maxsock is set to new maxsock,
387 * but if maxsock is set to -1, prev_maxsock is not changed */
389 unsigned max_concurrency;
390 smallint alarm_armed;
391 uid_t real_uid; /* user ID who ran us */
392 const char *config_filename;
394 char *default_local_hostname;
395 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
401 /* Used in next_line(), and as scratch read buffer */
402 char line[256]; /* _at least_ 256, see LINE_SIZE */
404 #define G (*(struct globals*)bb_common_bufsiz1)
405 enum { LINE_SIZE = COMMON_BUFSIZE - offsetof(struct globals, line) };
406 #define rlim_ofile_cur (G.rlim_ofile_cur )
407 #define rlim_ofile (G.rlim_ofile )
408 #define serv_list (G.serv_list )
409 #define global_queuelen (G.global_queuelen)
410 #define maxsock (G.maxsock )
411 #define prev_maxsock (G.prev_maxsock )
412 #define max_concurrency (G.max_concurrency)
413 #define alarm_armed (G.alarm_armed )
414 #define real_uid (G.real_uid )
415 #define config_filename (G.config_filename)
416 #define parser (G.parser )
417 #define default_local_hostname (G.default_local_hostname)
418 #define first_ps_byte (G.first_ps_byte )
419 #define last_ps_byte (G.last_ps_byte )
420 #define end_ring (G.end_ring )
421 #define ring_pos (G.ring_pos )
422 #define ring (G.ring )
423 #define allsock (G.allsock )
424 #define line (G.line )
425 #define INIT_G() do { \
426 setup_common_bufsiz(); \
427 BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
428 rlim_ofile_cur = OPEN_MAX; \
429 global_queuelen = 128; \
430 config_filename = "/etc/inetd.conf"; \
434 # define dbg(...) ((void)0)
438 int dbg_fd = open("inetd_debug.log", O_WRONLY | O_CREAT | O_APPEND, 0666); \
440 fdprintf(dbg_fd, "%d: ", getpid()); \
441 fdprintf(dbg_fd, __VA_ARGS__); \
447 static void maybe_close(int fd)
451 dbg("closed fd:%d\n", fd);
455 // TODO: move to libbb?
456 static len_and_sockaddr *xzalloc_lsa(int family)
458 len_and_sockaddr *lsa;
461 sz = sizeof(struct sockaddr_in);
462 if (family == AF_UNIX)
463 sz = sizeof(struct sockaddr_un);
464 #if ENABLE_FEATURE_IPV6
465 if (family == AF_INET6)
466 sz = sizeof(struct sockaddr_in6);
468 lsa = xzalloc(LSA_LEN_SIZE + sz);
470 lsa->u.sa.sa_family = family;
474 static void rearm_alarm(void)
482 static void block_CHLD_HUP_ALRM(sigset_t *m)
485 sigaddset(m, SIGCHLD);
486 sigaddset(m, SIGHUP);
487 sigaddset(m, SIGALRM);
488 sigprocmask(SIG_BLOCK, m, m); /* old sigmask is stored in m */
491 static void restore_sigmask(sigset_t *m)
493 sigprocmask(SIG_SETMASK, m, NULL);
496 #if ENABLE_FEATURE_INETD_RPC
497 static void register_rpc(servtab_t *sep)
500 struct sockaddr_in ir_sin;
503 size = sizeof(ir_sin);
504 if (getsockname(sep->se_fd, (struct sockaddr *) &ir_sin, &size) < 0) {
505 bb_perror_msg("getsockname");
509 for (n = sep->se_rpcver_lo; n <= sep->se_rpcver_hi; n++) {
510 pmap_unset(sep->se_rpcprog, n);
511 if (!pmap_set(sep->se_rpcprog, n, sep->se_proto_no, ntohs(ir_sin.sin_port)))
512 bb_perror_msg("%s %s: pmap_set(%u,%u,%u,%u)",
513 sep->se_service, sep->se_proto,
514 sep->se_rpcprog, n, sep->se_proto_no, ntohs(ir_sin.sin_port));
518 static void unregister_rpc(servtab_t *sep)
522 for (n = sep->se_rpcver_lo; n <= sep->se_rpcver_hi; n++) {
523 if (!pmap_unset(sep->se_rpcprog, n))
524 bb_perror_msg("pmap_unset(%u,%u)", sep->se_rpcprog, n);
527 #endif /* FEATURE_INETD_RPC */
529 static void bump_nofile(void)
531 enum { FD_CHUNK = 32 };
534 /* Never fails under Linux (except if you pass it bad arguments) */
535 getrlimit(RLIMIT_NOFILE, &rl);
536 rl.rlim_cur = MIN(rl.rlim_max, rl.rlim_cur + FD_CHUNK);
537 rl.rlim_cur = MIN(FD_SETSIZE, rl.rlim_cur + FD_CHUNK);
538 if (rl.rlim_cur <= rlim_ofile_cur) {
539 bb_error_msg("can't extend file limit, max = %d",
544 if (setrlimit(RLIMIT_NOFILE, &rl) < 0) {
545 bb_perror_msg("setrlimit");
549 rlim_ofile_cur = rl.rlim_cur;
552 static void remove_fd_from_set(int fd)
555 FD_CLR(fd, &allsock);
556 dbg("stopped listening on fd:%d\n", fd);
558 dbg("maxsock:%d\n", maxsock);
562 static void add_fd_to_set(int fd)
565 FD_SET(fd, &allsock);
566 dbg("started listening on fd:%d\n", fd);
567 if (maxsock >= 0 && fd > maxsock) {
568 prev_maxsock = maxsock = fd;
569 dbg("maxsock:%d\n", maxsock);
570 if ((rlim_t)fd > rlim_ofile_cur - FD_MARGIN)
576 static void recalculate_maxsock(void)
580 /* We may have no services, in this case maxsock should still be >= 0
581 * (code elsewhere is not happy with maxsock == -1) */
583 while (fd <= prev_maxsock) {
584 if (FD_ISSET(fd, &allsock))
588 dbg("recalculated maxsock:%d\n", maxsock);
589 prev_maxsock = maxsock;
590 if ((rlim_t)maxsock > rlim_ofile_cur - FD_MARGIN)
594 static void prepare_socket_fd(servtab_t *sep)
598 fd = socket(sep->se_family, sep->se_socktype, 0);
600 bb_perror_msg("socket");
603 setsockopt_reuseaddr(fd);
605 #if ENABLE_FEATURE_INETD_RPC
606 if (is_rpc_service(sep)) {
609 /* zero out the port for all RPC services; let bind()
611 set_nport(&sep->se_lsa->u.sa, 0);
613 /* for RPC services, attempt to use a reserved port
614 * if they are going to be running as root. */
615 if (real_uid == 0 && sep->se_family == AF_INET
616 && (pwd = getpwnam(sep->se_user)) != NULL
619 r = bindresvport(fd, &sep->se_lsa->u.sin);
621 r = bind(fd, &sep->se_lsa->u.sa, sep->se_lsa->len);
624 int saveerrno = errno;
625 /* update lsa with port# */
626 getsockname(fd, &sep->se_lsa->u.sa, &sep->se_lsa->len);
632 if (sep->se_family == AF_UNIX) {
633 struct sockaddr_un *sun;
634 sun = (struct sockaddr_un*)&(sep->se_lsa->u.sa);
635 unlink(sun->sun_path);
637 r = bind(fd, &sep->se_lsa->u.sa, sep->se_lsa->len);
640 bb_perror_msg("%s/%s: bind",
641 sep->se_service, sep->se_proto);
647 if (sep->se_socktype == SOCK_STREAM) {
648 listen(fd, global_queuelen);
649 dbg("new sep->se_fd:%d (stream)\n", fd);
651 dbg("new sep->se_fd:%d (!stream)\n", fd);
658 static int reopen_config_file(void)
660 free(default_local_hostname);
661 default_local_hostname = xstrdup("*");
663 config_close(parser);
664 parser = config_open(config_filename);
665 return (parser != NULL);
668 static void close_config_file(void)
671 config_close(parser);
676 static void free_servtab_strings(servtab_t *cp)
680 free(cp->se_local_hostname);
681 free(cp->se_service);
685 free(cp->se_lsa); /* not a string in fact */
686 free(cp->se_program);
687 for (i = 0; i < MAXARGV; i++)
688 free(cp->se_argv[i]);
691 static servtab_t *new_servtab(void)
693 servtab_t *newtab = xzalloc(sizeof(servtab_t));
694 newtab->se_fd = -1; /* paranoia */
698 static servtab_t *dup_servtab(servtab_t *sep)
703 newtab = new_servtab();
704 *newtab = *sep; /* struct copy */
705 /* deep-copying strings */
706 newtab->se_service = xstrdup(newtab->se_service);
707 newtab->se_proto = xstrdup(newtab->se_proto);
708 newtab->se_user = xstrdup(newtab->se_user);
709 newtab->se_group = xstrdup(newtab->se_group);
710 newtab->se_program = xstrdup(newtab->se_program);
711 for (argc = 0; argc <= MAXARGV; argc++)
712 newtab->se_argv[argc] = xstrdup(newtab->se_argv[argc]);
713 /* NB: se_fd, se_hostaddr and se_next are always
714 * overwrittend by callers, so we don't bother resetting them
715 * to NULL/0/-1 etc */
720 /* gcc generates much more code if this is inlined */
721 static NOINLINE servtab_t *parse_one_line(void)
724 char *token[6+MAXARGV];
732 argc = config_read(parser, token, 6+MAXARGV, 1, "# \t", PARSE_NORMAL);
738 /* [host:]service socktype proto wait user[:group] prog [args] */
739 /* Check for "host:...." line */
741 hostdelim = strrchr(arg, ':');
744 sep->se_local_hostname = xstrdup(arg);
746 if (*arg == '\0' && argc == 1) {
747 /* Line has just "host:", change the
748 * default host for the following lines. */
749 free(default_local_hostname);
750 default_local_hostname = sep->se_local_hostname;
751 /*sep->se_local_hostname = NULL; - redundant */
752 /* (we'll overwrite this field anyway) */
756 sep->se_local_hostname = xstrdup(default_local_hostname);
758 /* service socktype proto wait user[:group] prog [args] */
759 sep->se_service = xstrdup(arg);
761 /* socktype proto wait user[:group] prog [args] */
764 bb_error_msg("parse error on line %u, line is ignored",
766 /* Just "goto more" can make sep to carry over e.g.
767 * "rpc"-ness (by having se_rpcver_lo != 0).
768 * We will be more paranoid: */
769 free_servtab_strings(sep);
775 static const int8_t SOCK_xxx[] ALIGN1 = {
777 SOCK_STREAM, SOCK_DGRAM, SOCK_RDM,
778 SOCK_SEQPACKET, SOCK_RAW
780 sep->se_socktype = SOCK_xxx[1 + index_in_strings(
781 "stream""\0" "dgram""\0" "rdm""\0"
782 "seqpacket""\0" "raw""\0"
786 /* {unix,[rpc/]{tcp,udp}[6]} wait user[:group] prog [args] */
787 sep->se_proto = arg = xstrdup(token[2]);
788 if (strcmp(arg, "unix") == 0) {
789 sep->se_family = AF_UNIX;
792 sep->se_family = AF_INET;
793 six = last_char_is(arg, '6');
795 #if ENABLE_FEATURE_IPV6
797 sep->se_family = AF_INET6;
799 bb_error_msg("%s: no support for IPv6", sep->se_proto);
803 if (is_prefixed_with(arg, "rpc/")) {
804 #if ENABLE_FEATURE_INETD_RPC
807 p = strchr(sep->se_service, '/');
809 bb_error_msg("no rpc version: '%s'", sep->se_service);
813 n = bb_strtou(p, &p, 10);
816 bb_error_msg("bad rpc version");
819 sep->se_rpcver_lo = sep->se_rpcver_hi = n;
822 n = bb_strtou(p, &p, 10);
823 if (n > INT_MAX || (int)n < sep->se_rpcver_lo)
825 sep->se_rpcver_hi = n;
830 bb_error_msg("no support for rpc services");
834 /* we don't really need getprotobyname()! */
835 if (strcmp(arg, "tcp") == 0)
836 sep->se_proto_no = IPPROTO_TCP; /* = 6 */
837 if (strcmp(arg, "udp") == 0)
838 sep->se_proto_no = IPPROTO_UDP; /* = 17 */
841 if (!sep->se_proto_no) /* not tcp/udp?? */
845 /* [no]wait[.max] user[:group] prog [args] */
847 sep->se_max = max_concurrency;
848 p = strchr(arg, '.');
851 sep->se_max = bb_strtou(p, NULL, 10);
855 sep->se_wait = (arg[0] != 'n' || arg[1] != 'o');
856 if (!sep->se_wait) /* "no" seen */
858 if (strcmp(arg, "wait") != 0)
861 /* user[:group] prog [args] */
862 sep->se_user = xstrdup(token[4]);
863 arg = strchr(sep->se_user, '.');
865 arg = strchr(sep->se_user, ':');
868 sep->se_group = xstrdup(arg);
872 sep->se_program = xstrdup(token[5]);
873 #ifdef INETD_BUILTINS_ENABLED
874 if (strcmp(sep->se_program, "internal") == 0
875 && strlen(sep->se_service) <= 7
876 && (sep->se_socktype == SOCK_STREAM
877 || sep->se_socktype == SOCK_DGRAM)
880 for (i = 0; i < ARRAY_SIZE(builtins); i++)
881 if (strncmp(builtins[i].bi_service7, sep->se_service, 7) == 0)
883 bb_error_msg("unknown internal service %s", sep->se_service);
886 sep->se_builtin = &builtins[i];
887 /* stream builtins must be "nowait", dgram must be "wait" */
888 if (sep->se_wait != (sep->se_socktype == SOCK_DGRAM))
893 while (argc < MAXARGV && (arg = token[6+argc]) != NULL)
894 sep->se_argv[argc++] = xstrdup(arg);
895 /* Some inetd.conf files have no argv's, not even argv[0].
897 * (Technically, programs can be execed with argv[0] = NULL,
898 * but many programs do not like that at all) */
900 sep->se_argv[0] = xstrdup(sep->se_program);
902 /* catch mixups. "<service> stream udp ..." == wtf */
903 if (sep->se_socktype == SOCK_STREAM) {
904 if (sep->se_proto_no == IPPROTO_UDP)
907 if (sep->se_socktype == SOCK_DGRAM) {
908 if (sep->se_proto_no == IPPROTO_TCP)
913 // "ENTRY[%s][%s][%s][%d][%d][%d][%d][%d][%s][%s][%s]",
914 // sep->se_local_hostname, sep->se_service, sep->se_proto, sep->se_wait, sep->se_proto_no,
915 // sep->se_max, sep->se_count, sep->se_time, sep->se_user, sep->se_group, sep->se_program);
917 /* check if the hostname specifier is a comma separated list
918 * of hostnames. we'll make new entries for each address. */
919 while ((hostdelim = strrchr(sep->se_local_hostname, ',')) != NULL) {
920 nsep = dup_servtab(sep);
921 /* NUL terminate the hostname field of the existing entry,
922 * and make a dup for the new entry. */
924 nsep->se_local_hostname = xstrdup(hostdelim);
925 nsep->se_next = sep->se_next;
929 /* was doing it here: */
930 /* DNS resolution, create copies for each IP address */
931 /* IPv6-ization destroyed it :( */
936 static servtab_t *insert_in_servlist(servtab_t *cp)
942 *sep = *cp; /* struct copy */
944 #if ENABLE_FEATURE_INETD_RPC
945 sep->se_rpcprog = -1;
947 block_CHLD_HUP_ALRM(&omask);
948 sep->se_next = serv_list;
950 restore_sigmask(&omask);
954 static int same_serv_addr_proto(servtab_t *old, servtab_t *new)
956 if (strcmp(old->se_local_hostname, new->se_local_hostname) != 0)
958 if (strcmp(old->se_service, new->se_service) != 0)
960 if (strcmp(old->se_proto, new->se_proto) != 0)
965 static void reread_config_file(int sig UNUSED_PARAM)
967 servtab_t *sep, *cp, **sepp;
968 len_and_sockaddr *lsa;
972 int save_errno = errno;
974 if (!reopen_config_file())
976 for (sep = serv_list; sep; sep = sep->se_next)
983 cp = parse_one_line();
987 for (sep = serv_list; sep; sep = sep->se_next)
988 if (same_serv_addr_proto(sep, cp))
990 /* not an "equal" servtab */
991 sep = insert_in_servlist(cp);
997 block_CHLD_HUP_ALRM(&omask);
998 #if ENABLE_FEATURE_INETD_RPC
999 if (is_rpc_service(sep))
1000 unregister_rpc(sep);
1001 sep->se_rpcver_lo = cp->se_rpcver_lo;
1002 sep->se_rpcver_hi = cp->se_rpcver_hi;
1004 if (cp->se_wait == 0) {
1005 /* New config says "nowait". If old one
1006 * was "wait", we currently may be waiting
1007 * for a child (and not accepting connects).
1008 * Stop waiting, start listening again.
1009 * (if it's not true, this op is harmless) */
1010 add_fd_to_set(sep->se_fd);
1012 sep->se_wait = cp->se_wait;
1013 sep->se_max = cp->se_max;
1014 /* string fields need more love - we don't want to leak them */
1015 #define SWAP(type, a, b) do { type c = (type)a; a = (type)b; b = (type)c; } while (0)
1016 SWAP(char*, sep->se_user, cp->se_user);
1017 SWAP(char*, sep->se_group, cp->se_group);
1018 SWAP(char*, sep->se_program, cp->se_program);
1019 for (i = 0; i < MAXARGV; i++)
1020 SWAP(char*, sep->se_argv[i], cp->se_argv[i]);
1022 restore_sigmask(&omask);
1023 free_servtab_strings(cp);
1026 /* cp->string_fields are consumed by insert_in_servlist()
1027 * or freed at this point, cp itself is not yet freed. */
1028 sep->se_checked = 1;
1030 /* create new len_and_sockaddr */
1031 switch (sep->se_family) {
1032 struct sockaddr_un *sun;
1034 lsa = xzalloc_lsa(AF_UNIX);
1035 sun = (struct sockaddr_un*)&lsa->u.sa;
1036 safe_strncpy(sun->sun_path, sep->se_service, sizeof(sun->sun_path));
1039 default: /* case AF_INET, case AF_INET6 */
1040 n = bb_strtou(sep->se_service, NULL, 10);
1041 #if ENABLE_FEATURE_INETD_RPC
1042 if (is_rpc_service(sep)) {
1043 sep->se_rpcprog = n;
1044 if (errno) { /* se_service is not numeric */
1045 struct rpcent *rp = getrpcbyname(sep->se_service);
1047 bb_error_msg("%s: unknown rpc service", sep->se_service);
1050 sep->se_rpcprog = rp->r_number;
1052 if (sep->se_fd == -1)
1053 prepare_socket_fd(sep);
1054 if (sep->se_fd != -1)
1059 /* what port to listen on? */
1061 if (errno || n > 0xffff) { /* se_service is not numeric */
1064 /* can result only in "tcp" or "udp": */
1065 safe_strncpy(protoname, sep->se_proto, 4);
1066 sp = getservbyname(sep->se_service, protoname);
1068 bb_error_msg("%s/%s: unknown service",
1069 sep->se_service, sep->se_proto);
1074 if (LONE_CHAR(sep->se_local_hostname, '*')) {
1075 lsa = xzalloc_lsa(sep->se_family);
1076 set_nport(&lsa->u.sa, port);
1078 lsa = host_and_af2sockaddr(sep->se_local_hostname,
1079 ntohs(port), sep->se_family);
1081 bb_error_msg("%s/%s: unknown host '%s'",
1082 sep->se_service, sep->se_proto,
1083 sep->se_local_hostname);
1088 } /* end of "switch (sep->se_family)" */
1090 /* did lsa change? Then close/open */
1091 if (sep->se_lsa == NULL
1092 || lsa->len != sep->se_lsa->len
1093 || memcmp(&lsa->u.sa, &sep->se_lsa->u.sa, lsa->len) != 0
1095 remove_fd_from_set(sep->se_fd);
1096 maybe_close(sep->se_fd);
1103 if (sep->se_fd == -1)
1104 prepare_socket_fd(sep);
1109 } /* end of "while (1) parse lines" */
1110 close_config_file();
1112 /* Purge anything not looked at above - these are stale entries,
1113 * new config file doesnt have them. */
1114 block_CHLD_HUP_ALRM(&omask);
1116 while ((sep = *sepp) != NULL) {
1117 if (sep->se_checked) {
1118 sepp = &sep->se_next;
1121 *sepp = sep->se_next;
1122 remove_fd_from_set(sep->se_fd);
1123 maybe_close(sep->se_fd);
1124 #if ENABLE_FEATURE_INETD_RPC
1125 if (is_rpc_service(sep))
1126 unregister_rpc(sep);
1128 if (sep->se_family == AF_UNIX)
1129 unlink(sep->se_service);
1130 free_servtab_strings(sep);
1133 restore_sigmask(&omask);
1138 static void reap_child(int sig UNUSED_PARAM)
1143 int save_errno = errno;
1146 pid = wait_any_nohang(&status);
1149 for (sep = serv_list; sep; sep = sep->se_next) {
1150 if (sep->se_wait != pid)
1152 /* One of our "wait" services */
1153 if (WIFEXITED(status) && WEXITSTATUS(status))
1154 bb_error_msg("%s: exit status %u",
1155 sep->se_program, WEXITSTATUS(status));
1156 else if (WIFSIGNALED(status))
1157 bb_error_msg("%s: exit signal %u",
1158 sep->se_program, WTERMSIG(status));
1160 add_fd_to_set(sep->se_fd);
1167 static void retry_network_setup(int sig UNUSED_PARAM)
1169 int save_errno = errno;
1173 for (sep = serv_list; sep; sep = sep->se_next) {
1174 if (sep->se_fd == -1) {
1175 prepare_socket_fd(sep);
1176 #if ENABLE_FEATURE_INETD_RPC
1177 if (sep->se_fd != -1 && is_rpc_service(sep))
1185 static void clean_up_and_exit(int sig UNUSED_PARAM)
1189 /* XXX signal race walking sep list */
1190 for (sep = serv_list; sep; sep = sep->se_next) {
1191 if (sep->se_fd == -1)
1194 switch (sep->se_family) {
1196 unlink(sep->se_service);
1198 default: /* case AF_INET, AF_INET6 */
1199 #if ENABLE_FEATURE_INETD_RPC
1200 if (sep->se_wait == 1 && is_rpc_service(sep))
1201 unregister_rpc(sep); /* XXX signal race */
1205 if (ENABLE_FEATURE_CLEAN_UP)
1208 remove_pidfile(CONFIG_PID_FILE_PATH "/inetd.pid");
1212 int inetd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1213 int inetd_main(int argc UNUSED_PARAM, char **argv)
1215 struct sigaction sa, saved_pipe_handler;
1216 servtab_t *sep, *sep2;
1218 struct group *grp = grp; /* for compiler */
1225 real_uid = getuid();
1226 if (real_uid != 0) /* run by non-root user */
1227 config_filename = NULL;
1230 opt = getopt32(argv, "R:+feq:+", &max_concurrency, &global_queuelen);
1234 config_filename = argv[0];
1235 if (config_filename == NULL)
1236 bb_error_msg_and_die("non-root must specify config file");
1238 bb_daemonize_or_rexec(0, argv - optind);
1240 bb_sanitize_stdio();
1242 /* LOG_NDELAY: connect to syslog daemon NOW.
1243 * Otherwise, we may open syslog socket
1244 * in vforked child, making opened fds and syslog()
1245 * internal state inconsistent.
1246 * This was observed to leak file descriptors. */
1247 openlog(applet_name, LOG_PID | LOG_NDELAY, LOG_DAEMON);
1248 logmode = LOGMODE_SYSLOG;
1251 if (real_uid == 0) {
1252 /* run by root, ensure groups vector gets trashed */
1253 gid_t gid = getgid();
1257 write_pidfile(CONFIG_PID_FILE_PATH "/inetd.pid");
1259 /* never fails under Linux (except if you pass it bad arguments) */
1260 getrlimit(RLIMIT_NOFILE, &rlim_ofile);
1261 rlim_ofile_cur = rlim_ofile.rlim_cur;
1262 if (rlim_ofile_cur == RLIM_INFINITY) /* ! */
1263 rlim_ofile_cur = OPEN_MAX;
1265 memset(&sa, 0, sizeof(sa));
1266 /*sigemptyset(&sa.sa_mask); - memset did it */
1267 sigaddset(&sa.sa_mask, SIGALRM);
1268 sigaddset(&sa.sa_mask, SIGCHLD);
1269 sigaddset(&sa.sa_mask, SIGHUP);
1270 //FIXME: explain why no SA_RESTART
1271 //FIXME: retry_network_setup is unsafe to run in signal handler (many reasons)!
1272 sa.sa_handler = retry_network_setup;
1273 sigaction_set(SIGALRM, &sa);
1274 //FIXME: reread_config_file is unsafe to run in signal handler(many reasons)!
1275 sa.sa_handler = reread_config_file;
1276 sigaction_set(SIGHUP, &sa);
1277 //FIXME: reap_child is unsafe to run in signal handler (uses stdio)!
1278 sa.sa_handler = reap_child;
1279 sigaction_set(SIGCHLD, &sa);
1280 //FIXME: clean_up_and_exit is unsafe to run in signal handler (uses stdio)!
1281 sa.sa_handler = clean_up_and_exit;
1282 sigaction_set(SIGTERM, &sa);
1283 sa.sa_handler = clean_up_and_exit;
1284 sigaction_set(SIGINT, &sa);
1285 sa.sa_handler = SIG_IGN;
1286 sigaction(SIGPIPE, &sa, &saved_pipe_handler);
1288 reread_config_file(SIGHUP); /* load config from file */
1292 int ctrl, accepted_fd, new_udp_fd;
1296 recalculate_maxsock();
1298 readable = allsock; /* struct copy */
1299 /* if there are no fds to wait on, we will block
1300 * until signal wakes us up (maxsock == 0, but readable
1301 * never contains fds 0 and 1...) */
1302 ready_fd_cnt = select(maxsock + 1, &readable, NULL, NULL, NULL);
1303 if (ready_fd_cnt < 0) {
1304 if (errno != EINTR) {
1305 bb_perror_msg("select");
1310 dbg("ready_fd_cnt:%d\n", ready_fd_cnt);
1312 for (sep = serv_list; ready_fd_cnt && sep; sep = sep->se_next) {
1313 if (sep->se_fd == -1 || !FD_ISSET(sep->se_fd, &readable))
1316 dbg("ready fd:%d\n", sep->se_fd);
1321 if (!sep->se_wait) {
1322 if (sep->se_socktype == SOCK_STREAM) {
1323 ctrl = accepted_fd = accept(sep->se_fd, NULL, NULL);
1324 dbg("accepted_fd:%d\n", accepted_fd);
1327 bb_perror_msg("accept (for %s)", sep->se_service);
1332 if (sep->se_socktype == SOCK_DGRAM
1333 && sep->se_family != AF_UNIX
1335 /* How udp "nowait" works:
1336 * child peeks at (received and buffered by kernel) UDP packet,
1337 * performs connect() on the socket so that it is linked only
1338 * to this peer. But this also affects parent, because descriptors
1339 * are shared after fork() a-la dup(). When parent performs
1340 * select(), it will see this descriptor connected to the peer (!)
1341 * and still readable, will act on it and mess things up
1342 * (can create many copies of same child, etc).
1343 * Parent must create and use new socket instead. */
1344 new_udp_fd = socket(sep->se_family, SOCK_DGRAM, 0);
1345 dbg("new_udp_fd:%d\n", new_udp_fd);
1346 if (new_udp_fd < 0) { /* error: eat packet, forget about it */
1348 recv(sep->se_fd, line, LINE_SIZE, MSG_DONTWAIT);
1351 setsockopt_reuseaddr(new_udp_fd);
1352 /* TODO: better do bind after fork in parent,
1353 * so that we don't have two wildcard bound sockets
1354 * even for a brief moment? */
1355 if (bind(new_udp_fd, &sep->se_lsa->u.sa, sep->se_lsa->len) < 0) {
1356 dbg("bind(new_udp_fd) failed\n");
1360 dbg("bind(new_udp_fd) succeeded\n");
1364 block_CHLD_HUP_ALRM(&omask);
1366 #ifdef INETD_BUILTINS_ENABLED
1367 /* do we need to fork? */
1368 if (sep->se_builtin == NULL
1369 || (sep->se_socktype == SOCK_STREAM
1370 && sep->se_builtin->bi_fork))
1373 if (sep->se_max != 0) {
1374 if (++sep->se_count == 1)
1375 sep->se_time = monotonic_sec();
1376 else if (sep->se_count >= sep->se_max) {
1377 unsigned now = monotonic_sec();
1378 /* did we accumulate se_max connects too quickly? */
1379 if (now - sep->se_time <= CNT_INTERVAL) {
1380 bb_error_msg("%s/%s: too many connections, pausing",
1381 sep->se_service, sep->se_proto);
1382 remove_fd_from_set(sep->se_fd);
1386 rearm_alarm(); /* will revive it in RETRYTIME sec */
1387 restore_sigmask(&omask);
1388 maybe_close(new_udp_fd);
1389 maybe_close(accepted_fd);
1390 continue; /* -> check next fd in fd set */
1395 /* on NOMMU, streamed chargen
1396 * builtin wouldn't work, but it is
1397 * not allowed on NOMMU (ifdefed out) */
1398 #ifdef INETD_BUILTINS_ENABLED
1399 if (BB_MMU && sep->se_builtin)
1405 if (pid < 0) { /* fork error */
1406 bb_perror_msg("vfork"+1);
1408 restore_sigmask(&omask);
1409 maybe_close(new_udp_fd);
1410 maybe_close(accepted_fd);
1411 continue; /* -> check next fd in fd set */
1414 pid--; /* -1: "we did fork and we are child" */
1416 /* if pid == 0 here, we didn't fork */
1418 if (pid > 0) { /* parent */
1420 /* wait: we passed socket to child,
1421 * will wait for child to terminate */
1423 remove_fd_from_set(sep->se_fd);
1425 if (new_udp_fd >= 0) {
1426 /* udp nowait: child connected the socket,
1427 * we created and will use new, unconnected one */
1428 xmove_fd(new_udp_fd, sep->se_fd);
1429 dbg("moved new_udp_fd:%d to sep->se_fd:%d\n", new_udp_fd, sep->se_fd);
1431 restore_sigmask(&omask);
1432 maybe_close(accepted_fd);
1433 continue; /* -> check next fd in fd set */
1436 /* we are either child or didn't fork at all */
1437 #ifdef INETD_BUILTINS_ENABLED
1438 if (sep->se_builtin) {
1439 if (pid) { /* "pid" is -1: we did fork */
1440 close(sep->se_fd); /* listening socket */
1441 dbg("closed sep->se_fd:%d\n", sep->se_fd);
1442 logmode = LOGMODE_NONE; /* make xwrite etc silent */
1444 restore_sigmask(&omask);
1445 if (sep->se_socktype == SOCK_STREAM)
1446 sep->se_builtin->bi_stream_fn(ctrl, sep);
1448 sep->se_builtin->bi_dgram_fn(ctrl, sep);
1449 if (pid) /* we did fork */
1450 _exit(EXIT_FAILURE);
1451 maybe_close(accepted_fd);
1452 continue; /* -> check next fd in fd set */
1458 if (new_udp_fd >= 0) {
1459 len_and_sockaddr *lsa;
1463 dbg("closed new_udp_fd:%d\n", new_udp_fd);
1464 lsa = xzalloc_lsa(sep->se_family);
1465 /* peek at the packet and remember peer addr */
1466 r = recvfrom(ctrl, NULL, 0, MSG_PEEK|MSG_DONTWAIT,
1467 &lsa->u.sa, &lsa->len);
1470 /* make this socket "connected" to peer addr:
1471 * only packets from this peer will be recv'ed,
1472 * and bare write()/send() will work on it */
1473 connect(ctrl, &lsa->u.sa, lsa->len);
1474 dbg("connected ctrl:%d to remote peer\n", ctrl);
1477 /* prepare env and exec program */
1478 pwd = getpwnam(sep->se_user);
1480 bb_error_msg("%s: no such %s", sep->se_user, "user");
1483 if (sep->se_group && (grp = getgrnam(sep->se_group)) == NULL) {
1484 bb_error_msg("%s: no such %s", sep->se_group, "group");
1487 if (real_uid != 0 && real_uid != pwd->pw_uid) {
1488 /* a user running private inetd */
1489 bb_error_msg("non-root must run services as himself");
1492 if (pwd->pw_uid != 0) {
1494 pwd->pw_gid = grp->gr_gid;
1495 /* initgroups, setgid, setuid: */
1496 change_identity(pwd);
1497 } else if (sep->se_group) {
1498 xsetgid(grp->gr_gid);
1499 setgroups(1, &grp->gr_gid);
1501 if (rlim_ofile.rlim_cur != rlim_ofile_cur)
1502 if (setrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0)
1503 bb_perror_msg("setrlimit");
1505 /* closelog(); - WRONG. we are after vfork,
1506 * this may confuse syslog() internal state.
1507 * Let's hope libc sets syslog fd to CLOEXEC...
1509 xmove_fd(ctrl, STDIN_FILENO);
1510 xdup2(STDIN_FILENO, STDOUT_FILENO);
1511 dbg("moved ctrl:%d to fd 0,1[,2]\n", ctrl);
1512 /* manpages of inetd I managed to find either say
1513 * that stderr is also redirected to the network,
1514 * or do not talk about redirection at all (!) */
1515 if (!sep->se_wait) /* only for usual "tcp nowait" */
1516 xdup2(STDIN_FILENO, STDERR_FILENO);
1517 /* NB: among others, this loop closes listening sockets
1518 * for nowait stream children */
1519 for (sep2 = serv_list; sep2; sep2 = sep2->se_next)
1520 if (sep2->se_fd != ctrl)
1521 maybe_close(sep2->se_fd);
1522 sigaction_set(SIGPIPE, &saved_pipe_handler);
1523 restore_sigmask(&omask);
1524 dbg("execing:'%s'\n", sep->se_program);
1525 BB_EXECVP(sep->se_program, sep->se_argv);
1526 bb_perror_msg("can't execute '%s'", sep->se_program);
1528 /* eat packet in udp case */
1529 if (sep->se_socktype != SOCK_STREAM)
1530 recv(0, line, LINE_SIZE, MSG_DONTWAIT);
1531 _exit(EXIT_FAILURE);
1532 } /* for (sep = servtab...) */
1536 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO \
1537 || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
1539 static const char *const cat_args[] = { "cat", NULL };
1544 * Internet services provided internally by inetd:
1546 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
1547 /* Echo service -- echo data back. */
1549 static void FAST_FUNC echo_stream(int s, servtab_t *sep UNUSED_PARAM)
1553 ssize_t sz = safe_read(s, line, LINE_SIZE);
1556 xwrite(s, line, sz);
1559 /* We are after vfork here! */
1560 /* move network socket to stdin/stdout */
1561 xmove_fd(s, STDIN_FILENO);
1562 xdup2(STDIN_FILENO, STDOUT_FILENO);
1563 /* no error messages please... */
1564 close(STDERR_FILENO);
1565 xopen(bb_dev_null, O_WRONLY);
1566 BB_EXECVP("cat", (char**)cat_args);
1567 /* on failure we return to main, which does exit(EXIT_FAILURE) */
1570 static void FAST_FUNC echo_dg(int s, servtab_t *sep)
1572 enum { BUFSIZE = 12*1024 }; /* for jumbo sized packets! :) */
1573 char *buf = xmalloc(BUFSIZE); /* too big for stack */
1575 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1577 lsa->len = sep->se_lsa->len;
1578 /* dgram builtins are non-forking - DONT BLOCK! */
1579 sz = recvfrom(s, buf, BUFSIZE, MSG_DONTWAIT, &lsa->u.sa, &lsa->len);
1581 sendto(s, buf, sz, 0, &lsa->u.sa, lsa->len);
1584 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_ECHO */
1587 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
1588 /* Discard service -- ignore data. */
1590 static void FAST_FUNC discard_stream(int s, servtab_t *sep UNUSED_PARAM)
1593 while (safe_read(s, line, LINE_SIZE) > 0)
1596 /* We are after vfork here! */
1597 /* move network socket to stdin */
1598 xmove_fd(s, STDIN_FILENO);
1599 /* discard output */
1600 close(STDOUT_FILENO);
1601 xopen(bb_dev_null, O_WRONLY);
1602 /* no error messages please... */
1603 xdup2(STDOUT_FILENO, STDERR_FILENO);
1604 BB_EXECVP("cat", (char**)cat_args);
1605 /* on failure we return to main, which does exit(EXIT_FAILURE) */
1609 static void FAST_FUNC discard_dg(int s, servtab_t *sep UNUSED_PARAM)
1611 /* dgram builtins are non-forking - DONT BLOCK! */
1612 recv(s, line, LINE_SIZE, MSG_DONTWAIT);
1614 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_DISCARD */
1617 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
1619 static void init_ring(void)
1624 for (i = ' '; i < 127; i++)
1627 /* Character generator. MMU arches only. */
1629 static void FAST_FUNC chargen_stream(int s, servtab_t *sep UNUSED_PARAM)
1633 char text[LINESIZ + 2];
1640 text[LINESIZ] = '\r';
1641 text[LINESIZ + 1] = '\n';
1644 len = end_ring - rs;
1646 memmove(text, rs, LINESIZ);
1648 memmove(text, rs, len);
1649 memmove(text + len, ring, LINESIZ - len);
1651 if (++rs == end_ring)
1653 xwrite(s, text, sizeof(text));
1657 static void FAST_FUNC chargen_dg(int s, servtab_t *sep)
1660 char text[LINESIZ + 2];
1661 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1663 /* Eat UDP packet which started it all */
1664 /* dgram builtins are non-forking - DONT BLOCK! */
1665 lsa->len = sep->se_lsa->len;
1666 if (recvfrom(s, text, sizeof(text), MSG_DONTWAIT, &lsa->u.sa, &lsa->len) < 0)
1674 len = end_ring - ring_pos;
1676 memmove(text, ring_pos, LINESIZ);
1678 memmove(text, ring_pos, len);
1679 memmove(text + len, ring, LINESIZ - len);
1681 if (++ring_pos == end_ring)
1683 text[LINESIZ] = '\r';
1684 text[LINESIZ + 1] = '\n';
1685 sendto(s, text, sizeof(text), 0, &lsa->u.sa, lsa->len);
1687 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN */
1690 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
1692 * Return a machine readable date and time, in the form of the
1693 * number of seconds since midnight, Jan 1, 1900. Since gettimeofday
1694 * returns the number of seconds since midnight, Jan 1, 1970,
1695 * we must add 2208988800 seconds to this figure to make up for
1696 * some seventy years Bell Labs was asleep.
1698 static uint32_t machtime(void)
1702 gettimeofday(&tv, NULL);
1703 return htonl((uint32_t)(tv.tv_sec + 2208988800U));
1706 static void FAST_FUNC machtime_stream(int s, servtab_t *sep UNUSED_PARAM)
1710 result = machtime();
1711 full_write(s, &result, sizeof(result));
1713 static void FAST_FUNC machtime_dg(int s, servtab_t *sep)
1716 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1718 lsa->len = sep->se_lsa->len;
1719 if (recvfrom(s, line, LINE_SIZE, MSG_DONTWAIT, &lsa->u.sa, &lsa->len) < 0)
1722 result = machtime();
1723 sendto(s, &result, sizeof(result), 0, &lsa->u.sa, lsa->len);
1725 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_TIME */
1728 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
1729 /* Return human-readable time of day */
1731 static void FAST_FUNC daytime_stream(int s, servtab_t *sep UNUSED_PARAM)
1736 fdprintf(s, "%.24s\r\n", ctime(&t));
1738 static void FAST_FUNC daytime_dg(int s, servtab_t *sep)
1741 len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
1743 lsa->len = sep->se_lsa->len;
1744 if (recvfrom(s, line, LINE_SIZE, MSG_DONTWAIT, &lsa->u.sa, &lsa->len) < 0)
1748 sprintf(line, "%.24s\r\n", ctime(&t));
1749 sendto(s, line, strlen(line), 0, &lsa->u.sa, lsa->len);
1751 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME */