networking/inetd.c

   1 /* vi: set sw=4 ts=4: */
   2 /*      $Slackware: inetd.c 1.79s 2001/02/06 13:18:00 volkerdi Exp $    */
   3 /*      $OpenBSD: inetd.c,v 1.79 2001/01/30 08:30:57 deraadt Exp $      */
   4 /*      $NetBSD: inetd.c,v 1.11 1996/02/22 11:14:41 mycroft Exp $       */
   5 /* Busybox port by Vladimir Oleynik (C) 2001-2005 <dzo@simtreas.ru>     */
   6 /*
   7  * Copyright (c) 1983,1991 The Regents of the University of California.
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  */
  38
  39 /* Inetd - Internet super-server
  40  *
  41  * This program invokes all internet services as needed.
  42  * connection-oriented services are invoked each time a
  43  * connection is made, by creating a process.  This process
  44  * is passed the connection as file descriptor 0 and is
  45  * expected to do a getpeername to find out the source host
  46  * and port.
  47  *
  48  * Datagram oriented services are invoked when a datagram
  49  * arrives; a process is created and passed a pending message
  50  * on file descriptor 0.  Datagram servers may either connect
  51  * to their peer, freeing up the original socket for inetd
  52  * to receive further messages on, or "take over the socket",
  53  * processing all arriving datagrams and, eventually, timing
  54  * out.  The first type of server is said to be "multi-threaded";
  55  * the second type of server "single-threaded".
  56  *
  57  * Inetd uses a configuration file which is read at startup
  58  * and, possibly, at some later time in response to a hangup signal.
  59  * The configuration file is "free format" with fields given in the
  60  * order shown below.  Continuation lines for an entry must begin with
  61  * a space or tab.  All fields must be present in each entry.
  62  *
  63  *      service name                    must be in /etc/services
  64  *      socket type                     stream/dgram/raw/rdm/seqpacket
  65  *      protocol                        must be in /etc/protocols
  66  *      wait/nowait[.max]               single-threaded/multi-threaded, max #
  67  *      user[.group] or user[:group]    user/group to run daemon as
  68  *      server program                  full path name
  69  *      server program arguments        maximum of MAXARGS (20)
  70  *
  71  * For RPC services
  72  *      service name/version            must be in /etc/rpc
  73  *      socket type                     stream/dgram/raw/rdm/seqpacket
  74  *      protocol                        must be in /etc/protocols
  75  *      wait/nowait[.max]               single-threaded/multi-threaded
  76  *      user[.group] or user[:group]    user to run daemon as
  77  *      server program                  full path name
  78  *      server program arguments        maximum of MAXARGS (20)
  79  *
  80  * For non-RPC services, the "service name" can be of the form
  81  * hostaddress:servicename, in which case the hostaddress is used
  82  * as the host portion of the address to listen on.  If hostaddress
  83  * consists of a single `*' character, INADDR_ANY is used.
  84  *
  85  * A line can also consist of just
  86  *      hostaddress:
  87  * where hostaddress is as in the preceding paragraph.  Such a line must
  88  * have no further fields; the specified hostaddress is remembered and
  89  * used for all further lines that have no hostaddress specified,
  90  * until the next such line (or EOF).  (This is why * is provided to
  91  * allow explicit specification of INADDR_ANY.)  A line
  92  *      *:
  93  * is implicitly in effect at the beginning of the file.
  94  *
  95  * The hostaddress specifier may (and often will) contain dots;
  96  * the service name must not.
  97  *
  98  * For RPC services, host-address specifiers are accepted and will
  99  * work to some extent; however, because of limitations in the
 100  * portmapper interface, it will not work to try to give more than
 101  * one line for any given RPC service, even if the host-address
 102  * specifiers are different.
 103  *
 104  * Comment lines are indicated by a `#' in column 1.
 105  */
 106
 107 /* inetd rules for passing file descriptors to children
 108  * (http://www.freebsd.org/cgi/man.cgi?query=inetd):
 109  *
 110  * The wait/nowait entry specifies whether the server that is invoked by
 111  * inetd will take over the socket associated with the service access point,
 112  * and thus whether inetd should wait for the server to exit before listen-
 113  * ing for new service requests.  Datagram servers must use "wait", as
 114  * they are always invoked with the original datagram socket bound to the
 115  * specified service address.  These servers must read at least one datagram
 116  * from the socket before exiting.  If a datagram server connects to its
 117  * peer, freeing the socket so inetd can receive further messages on the
 118  * socket, it is said to be a "multi-threaded" server; it should read one
 119  * datagram from the socket and create a new socket connected to the peer.
 120  * It should fork, and the parent should then exit to allow inetd to check
 121  * for new service requests to spawn new servers.  Datagram servers which
 122  * process all incoming datagrams on a socket and eventually time out are
 123  * said to be "single-threaded".  The comsat(8), (biff(1)) and talkd(8)
 124  * utilities are both examples of the latter type of datagram server.  The
 125  * tftpd(8) utility is an example of a multi-threaded datagram server.
 126  *
 127  * Servers using stream sockets generally are multi-threaded and use the
 128  * "nowait" entry. Connection requests for these services are accepted by
 129  * inetd, and the server is given only the newly-accepted socket connected
 130  * to a client of the service.  Most stream-based services operate in this
 131  * manner.  Stream-based servers that use "wait" are started with the lis-
 132  * tening service socket, and must accept at least one connection request
 133  * before exiting.  Such a server would normally accept and process incoming
 134  * connection requests until a timeout.
 135  */
 136
 137 /* Here's the scoop concerning the user[.:]group feature:
 138  *
 139  * 1) set-group-option off.
 140  *
 141  *      a) user = root: NO setuid() or setgid() is done
 142  *
 143  *      b) other:       setgid(primary group as found in passwd)
 144  *                      initgroups(name, primary group)
 145  *                      setuid()
 146  *
 147  * 2) set-group-option on.
 148  *
 149  *      a) user = root: setgid(specified group)
 150  *                      NO initgroups()
 151  *                      NO setuid()
 152  *
 153  *      b) other:       setgid(specified group)
 154  *                      initgroups(name, specified group)
 155  *                      setuid()
 156  */
 157
 158 #include "libbb.h"
 159 #include <syslog.h>
 160 #include <sys/un.h>
 161
 162 //#define ENABLE_FEATURE_INETD_RPC 1
 163 //#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO 1
 164 //#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD 1
 165 //#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME 1
 166 //#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME 1
 167 //#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 1
 168 //#define ENABLE_FEATURE_IPV6 1
 169
 170 #if ENABLE_FEATURE_INETD_RPC
 171 #include <rpc/rpc.h>
 172 #include <rpc/pmap_clnt.h>
 173 #endif
 174
 175 extern char **environ;
 176
 177
 178 #define _PATH_INETDPID  "/var/run/inetd.pid"
 179
 180 #define CNT_INTVL       60              /* servers in CNT_INTVL sec. */
 181 #define RETRYTIME       (60*10)         /* retry after bind or server fail */
 182
 183 #ifndef RLIMIT_NOFILE
 184 #define RLIMIT_NOFILE   RLIMIT_OFILE
 185 #endif
 186
 187 #ifndef OPEN_MAX
 188 #define OPEN_MAX        64
 189 #endif
 190
 191 /* Reserve some descriptors, 3 stdio + at least: 1 log, 1 conf. file */
 192 #define FD_MARGIN       8
 193
 194 /* Check unsupporting builtin */
 195 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO || \
 196         ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD || \
 197         ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME || \
 198         ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME || \
 199         ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
 200 # define INETD_FEATURE_ENABLED
 201 #endif
 202
 203 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO || \
 204         ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD || \
 205         ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
 206 # define INETD_SETPROCTITLE
 207 #endif
 208
 209 typedef int8_t socktype_t;
 210 typedef int8_t family_t;
 211 struct BUG_too_small {
 212         char BUG_socktype_t_too_small[(0
 213                         | SOCK_STREAM
 214                         | SOCK_DGRAM
 215                         | SOCK_RDM
 216                         | SOCK_SEQPACKET
 217                         | SOCK_RAW) <= 127 ? 1 : -1];
 218         char BUG_family_t_too_small[(0
 219                         | AF_INET
 220                         | AF_INET6
 221                         | AF_UNIX) <= 127 ? 1 : -1];
 222 };
 223
 224 typedef struct servtab_t {
 225         /* The most frequently referenced one: */
 226         int se_fd;                            /* open descriptor */
 227         /* NB: 'biggest fields last' saves on code size (~250 bytes) */
 228         char *se_hostaddr;                    /* host address to listen on */
 229         char *se_service;                     /* name of service */
 230         char *se_proto;                       /* protocol used */
 231 #if ENABLE_FEATURE_INETD_RPC
 232         int se_rpcprog;                       /* rpc program number */
 233         int se_rpcversl;                      /* rpc program lowest version */
 234         int se_rpcversh;                      /* rpc program highest version */
 235 #define isrpcservice(sep)       ((sep)->se_rpcversl != 0)
 236 #else
 237 #define isrpcservice(sep)       0
 238 #endif
 239         pid_t se_wait;                        /* single threaded server */
 240         socktype_t se_socktype;               /* type of socket to use */
 241         family_t se_family;                   /* address family */
 242         smallint se_checked;                  /* looked at during merge */
 243         char *se_user;                        /* user name to run as */
 244         char *se_group;                       /* group name to run as */
 245 #ifdef INETD_FEATURE_ENABLED
 246         const struct builtin *se_bi;          /* if built-in, description */
 247 #endif
 248         int se_ctrladdr_size;
 249         int se_max;                           /* max # of instances of this service */
 250         int se_count;                         /* number started since se_time */
 251         struct servtab_t *se_next;
 252         struct timeval se_time;               /* start of se_count */
 253         char *se_server;                      /* server program */
 254 #define MAXARGV 20
 255         char *se_argv[MAXARGV + 1];           /* program arguments */
 256         union {
 257                 struct sockaddr se_un_ctrladdr;
 258                 struct sockaddr_in se_un_ctrladdr_in;
 259 #if ENABLE_FEATURE_IPV6
 260                 struct sockaddr_in6 se_un_ctrladdr_in6;
 261 #endif
 262                 struct sockaddr_un se_un_ctrladdr_un;
 263         } se_un;                              /* bound address */
 264 #define se_ctrladdr     se_un.se_un_ctrladdr
 265 #define se_ctrladdr_in  se_un.se_un_ctrladdr_in
 266 #define se_ctrladdr_in6 se_un.se_un_ctrladdr_in6
 267 #define se_ctrladdr_un  se_un.se_un_ctrladdr_un
 268 } servtab_t;
 269
 270 #ifdef INETD_FEATURE_ENABLED
 271 struct builtin {
 272         const char *bi_service;               /* internally provided service name */
 273         socktype_t bi_socktype;               /* type of socket supported */
 274         uint8_t bi_fork;                      /* 1 if should fork before call */
 275 // Commented since it is always 0
 276 //      uint8_t bi_wait;                      /* 1 if should wait for child */
 277         void (*bi_fn) (int, servtab_t *);
 278 };
 279
 280                 /* Echo received data */
 281 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
 282 static void echo_stream(int, servtab_t *);
 283 static void echo_dg(int, servtab_t *);
 284 #endif
 285                 /* Internet /dev/null */
 286 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
 287 static void discard_stream(int, servtab_t *);
 288 static void discard_dg(int, servtab_t *);
 289 #endif
 290                 /* Return 32 bit time since 1900 */
 291 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
 292 static void machtime_stream(int, servtab_t *);
 293 static void machtime_dg(int, servtab_t *);
 294 #endif
 295                 /* Return human-readable time */
 296 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
 297 static void daytime_stream(int, servtab_t *);
 298 static void daytime_dg(int, servtab_t *);
 299 #endif
 300                 /* Familiar character generator */
 301 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
 302 static void chargen_stream(int, servtab_t *);
 303 static void chargen_dg(int, servtab_t *);
 304 #endif
 305
 306 static const struct builtin builtins[] = {
 307 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
 308         /* Echo received data */
 309         {"echo", SOCK_STREAM, 1, echo_stream,},
 310         {"echo", SOCK_DGRAM, 0, echo_dg,},
 311 #endif
 312 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
 313         /* Internet /dev/null */
 314         {"discard", SOCK_STREAM, 1, discard_stream,},
 315         {"discard", SOCK_DGRAM, 0, discard_dg,},
 316 #endif
 317 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
 318         /* Return 32 bit time since 1900 */
 319         {"time", SOCK_STREAM, 0, machtime_stream,},
 320         {"time", SOCK_DGRAM, 0, machtime_dg,},
 321 #endif
 322 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
 323         /* Return human-readable time */
 324         {"daytime", SOCK_STREAM, 0, daytime_stream,},
 325         {"daytime", SOCK_DGRAM, 0, daytime_dg,},
 326 #endif
 327 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
 328         /* Familiar character generator */
 329         {"chargen", SOCK_STREAM, 1, chargen_stream,},
 330         {"chargen", SOCK_DGRAM, 0, chargen_dg,},
 331 #endif
 332         { /* zero filled */ }
 333 };
 334 #endif /* INETD_FEATURE_ENABLED */
 335
 336 struct globals {
 337         rlim_t rlim_ofile_cur;
 338         struct rlimit rlim_ofile;
 339         servtab_t *servtab;
 340         int global_queuelen;
 341         int nsock;
 342         int maxsock;
 343         int toomany;
 344         int timingout;
 345         struct servent *sp;
 346         uid_t uid;
 347         const char *config_filename;
 348         FILE *fconfig;
 349         char *defhost;
 350 #ifdef INETD_SETPROCTITLE
 351         char **Argv;
 352         char *LastArg;
 353 #endif
 354 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
 355         char *endring;
 356         char *ringpos;
 357         char ring[128];
 358 #endif
 359         fd_set allsock;
 360         /* Used only in nextline() */
 361         char line[80];          /* at least 80, see LINE_SIZE */
 362 };
 363 #define G (*(struct globals*)&bb_common_bufsiz1)
 364 enum { LINE_SIZE = COMMON_BUFSIZE - offsetof(struct globals, line) };
 365 struct BUG_G_too_big {
 366         char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
 367 };
 368 #define rlim_ofile_cur  (G.rlim_ofile_cur )
 369 #define rlim_ofile      (G.rlim_ofile     )
 370 #define servtab         (G.servtab        )
 371 #define global_queuelen (G.global_queuelen)
 372 #define nsock           (G.nsock          )
 373 #define maxsock         (G.maxsock        )
 374 #define toomany         (G.toomany        )
 375 #define timingout       (G.timingout      )
 376 #define sp              (G.sp             )
 377 #define uid             (G.uid            )
 378 #define config_filename (G.config_filename)
 379 #define fconfig         (G.fconfig        )
 380 #define defhost         (G.defhost        )
 381 #define Argv            (G.Argv           )
 382 #define LastArg         (G.LastArg        )
 383 #define endring         (G.endring        )
 384 #define ringpos         (G.ringpos        )
 385 #define ring            (G.ring           )
 386 #define allsock         (G.allsock        )
 387 #define line            (G.line           )
 388 #define INIT_G() do { \
 389         rlim_ofile_cur = OPEN_MAX; \
 390         global_queuelen = 128; \
 391         config_filename = "/etc/inetd.conf"; \
 392 } while (0)
 393
 394 /* xstrdup(NULL) returns NULL, but this one
 395  * will return newly-allocated "" if called with NULL arg
 396  * TODO: audit whether this makes any real difference
 397  */
 398 static char *xxstrdup(char *cp)
 399 {
 400         return xstrdup(cp ? cp : "");
 401 }
 402
 403 static int setconfig(void)
 404 {
 405         free(defhost);
 406         defhost = xstrdup("*");
 407         if (fconfig != NULL) {
 408                 fseek(fconfig, 0L, SEEK_SET);
 409                 return 1;
 410         }
 411         fconfig = fopen(config_filename, "r");
 412         return (fconfig != NULL);
 413 }
 414
 415 static void endconfig(void)
 416 {
 417         if (fconfig) {
 418                 (void) fclose(fconfig);
 419                 fconfig = NULL;
 420         }
 421         free(defhost);
 422         defhost = 0;
 423 }
 424
 425 #if ENABLE_FEATURE_INETD_RPC
 426 static void register_rpc(servtab_t *sep)
 427 {
 428         int n;
 429         struct sockaddr_in ir_sin;
 430         struct protoent *pp;
 431         socklen_t size;
 432
 433         pp = getprotobyname(sep->se_proto + 4);
 434         if (pp == NULL) {
 435                 bb_perror_msg("%s: getproto", sep->se_proto);
 436                 return;
 437         }
 438         size = sizeof ir_sin;
 439         if (getsockname(sep->se_fd, (struct sockaddr *) &ir_sin, &size) < 0) {
 440                 bb_perror_msg("%s/%s: getsockname",
 441                                 sep->se_service, sep->se_proto);
 442                 return;
 443         }
 444
 445         for (n = sep->se_rpcversl; n <= sep->se_rpcversh; n++) {
 446                 (void) pmap_unset(sep->se_rpcprog, n);
 447                 if (!pmap_set(sep->se_rpcprog, n, pp->p_proto, ntohs(ir_sin.sin_port)))
 448                         bb_perror_msg("%s %s: pmap_set: %u %u %u %u",
 449                                         sep->se_service, sep->se_proto,
 450                                         sep->se_rpcprog, n, pp->p_proto, ntohs(ir_sin.sin_port));
 451         }
 452 }
 453
 454 static void unregister_rpc(servtab_t *sep)
 455 {
 456         int n;
 457
 458         for (n = sep->se_rpcversl; n <= sep->se_rpcversh; n++) {
 459                 if (!pmap_unset(sep->se_rpcprog, n))
 460                         bb_error_msg("pmap_unset(%u, %u)", sep->se_rpcprog, n);
 461         }
 462 }
 463 #endif /* FEATURE_INETD_RPC */
 464
 465 static void freeconfig(servtab_t *cp)
 466 {
 467         int i;
 468
 469         free(cp->se_hostaddr);
 470         free(cp->se_service);
 471         free(cp->se_proto);
 472         free(cp->se_user);
 473         free(cp->se_group);
 474         free(cp->se_server);
 475         for (i = 0; i < MAXARGV; i++)
 476                 free(cp->se_argv[i]);
 477 }
 478
 479 static int bump_nofile(void)
 480 {
 481 #define FD_CHUNK        32
 482
 483         struct rlimit rl;
 484
 485         if (getrlimit(RLIMIT_NOFILE, &rl) < 0) {
 486                 bb_perror_msg("getrlimit");
 487                 return -1;
 488         }
 489         rl.rlim_cur = MIN(rl.rlim_max, rl.rlim_cur + FD_CHUNK);
 490         rl.rlim_cur = MIN(FD_SETSIZE, rl.rlim_cur + FD_CHUNK);
 491         if (rl.rlim_cur <= rlim_ofile_cur) {
 492                 bb_error_msg("bump_nofile: cannot extend file limit, max = %d",
 493                                                 (int) rl.rlim_cur);
 494                 return -1;
 495         }
 496
 497         if (setrlimit(RLIMIT_NOFILE, &rl) < 0) {
 498                 bb_perror_msg("setrlimit");
 499                 return -1;
 500         }
 501
 502         rlim_ofile_cur = rl.rlim_cur;
 503         return 0;
 504 }
 505
 506 static void setup(servtab_t *sep)
 507 {
 508         int r;
 509
 510         sep->se_fd = socket(sep->se_family, sep->se_socktype, 0);
 511         if (sep->se_fd < 0) {
 512                 bb_perror_msg("%s/%s: socket", sep->se_service, sep->se_proto);
 513                 return;
 514         }
 515         setsockopt_reuseaddr(sep->se_fd);
 516
 517 #if ENABLE_FEATURE_INETD_RPC
 518         if (isrpcservice(sep)) {
 519                 struct passwd *pwd;
 520
 521                 /*
 522                  * for RPC services, attempt to use a reserved port
 523                  * if they are going to be running as root.
 524                  *
 525                  * Also, zero out the port for all RPC services; let bind()
 526                  * find one.
 527                  */
 528                 sep->se_ctrladdr_in.sin_port = 0;
 529                 if (sep->se_user && (pwd = getpwnam(sep->se_user)) &&
 530                                 pwd->pw_uid == 0 && uid == 0)
 531                         r = bindresvport(sep->se_fd, &sep->se_ctrladdr_in);
 532                 else {
 533                         r = bind(sep->se_fd, &sep->se_ctrladdr, sep->se_ctrladdr_size);
 534                         if (r == 0) {
 535                                 socklen_t len = sep->se_ctrladdr_size;
 536                                 int saveerrno = errno;
 537
 538                                 /* update se_ctrladdr_in.sin_port */
 539                                 r = getsockname(sep->se_fd, &sep->se_ctrladdr, &len);
 540                                 if (r <= 0)
 541                                         errno = saveerrno;
 542                         }
 543                 }
 544         } else
 545 #endif
 546                 r = bind(sep->se_fd, &sep->se_ctrladdr, sep->se_ctrladdr_size);
 547         if (r < 0) {
 548                 bb_perror_msg("%s/%s (%d): bind",
 549                                 sep->se_service, sep->se_proto, sep->se_ctrladdr.sa_family);
 550                 close(sep->se_fd);
 551                 sep->se_fd = -1;
 552                 if (!timingout) {
 553                         timingout = 1;
 554                         alarm(RETRYTIME);
 555                 }
 556                 return;
 557         }
 558         if (sep->se_socktype == SOCK_STREAM)
 559                 listen(sep->se_fd, global_queuelen);
 560
 561         FD_SET(sep->se_fd, &allsock);
 562         nsock++;
 563         if (sep->se_fd > maxsock) {
 564                 maxsock = sep->se_fd;
 565                 if ((rlim_t)maxsock > rlim_ofile_cur - FD_MARGIN)
 566                         bump_nofile();
 567         }
 568 }
 569
 570 static char *nextline(void)
 571 {
 572         char *cp;
 573
 574         if (fgets(line, LINE_SIZE, fconfig) == NULL)
 575                 return NULL;
 576         cp = strchr(line, '\n');
 577         if (cp)
 578                 *cp = '\0';
 579         return line;
 580 }
 581
 582 static char *skip(char **cpp) /* int report; */
 583 {
 584         char *cp = *cpp;
 585         char *start;
 586
 587 /* erp: */
 588         if (cp == NULL) {
 589                 /* if (report) */
 590                 /* bb_error_msg("syntax error in inetd config file"); */
 591                 return NULL;
 592         }
 593
 594  again:
 595         while (*cp == ' ' || *cp == '\t')
 596                 cp++;
 597         if (*cp == '\0') {
 598                 int c = getc(fconfig);
 599                 ungetc(c, fconfig);
 600                 if (c == ' ' || c == '\t') {
 601                         cp = nextline();
 602                         if (cp)
 603                                 goto again;
 604                 }
 605                 *cpp = NULL;
 606                 return NULL;
 607         }
 608         start = cp;
 609         while (*cp && *cp != ' ' && *cp != '\t')
 610                 cp++;
 611         if (*cp != '\0')
 612                 *cp++ = '\0';
 613
 614         *cpp = cp;
 615         return start;
 616 }
 617
 618 static servtab_t *new_servtab(void)
 619 {
 620         return xzalloc(sizeof(servtab_t));
 621 }
 622
 623 static servtab_t *dupconfig(servtab_t *sep)
 624 {
 625         servtab_t *newtab;
 626         int argc;
 627
 628         newtab = new_servtab();
 629         newtab->se_service = xstrdup(sep->se_service);
 630         newtab->se_socktype = sep->se_socktype;
 631         newtab->se_family = sep->se_family;
 632         newtab->se_proto = xstrdup(sep->se_proto);
 633 #if ENABLE_FEATURE_INETD_RPC
 634         newtab->se_rpcprog = sep->se_rpcprog;
 635         newtab->se_rpcversl = sep->se_rpcversl;
 636         newtab->se_rpcversh = sep->se_rpcversh;
 637 #endif
 638         newtab->se_wait = sep->se_wait;
 639         newtab->se_user = xstrdup(sep->se_user);
 640         newtab->se_group = xstrdup(sep->se_group);
 641 #ifdef INETD_FEATURE_ENABLED
 642         newtab->se_bi = sep->se_bi;
 643 #endif
 644         newtab->se_server = xstrdup(sep->se_server);
 645
 646         for (argc = 0; argc <= MAXARGV; argc++)
 647                 newtab->se_argv[argc] = xstrdup(sep->se_argv[argc]);
 648         newtab->se_max = sep->se_max;
 649
 650         return newtab;
 651 }
 652
 653 static servtab_t *getconfigent(void)
 654 {
 655         servtab_t *sep;
 656         int argc;
 657         char *cp, *arg;
 658         char *hostdelim;
 659         servtab_t *nsep;
 660         servtab_t *psep;
 661
 662         sep = new_servtab();
 663
 664  more:
 665         while ((cp = nextline()) && *cp == '#')
 666                 continue; /* skip comment lines */
 667         if (cp == NULL) {
 668                 free(sep);
 669                 return NULL;
 670         }
 671
 672         arg = skip(&cp);
 673         if (arg == NULL) {
 674                 /* A blank line. */
 675                 goto more;
 676         }
 677
 678         /* Check for a host name. */
 679         hostdelim = strrchr(arg, ':');
 680         if (hostdelim) {
 681                 *hostdelim = '\0';
 682                 sep->se_hostaddr = xstrdup(arg);
 683                 arg = hostdelim + 1;
 684                 /*
 685                  * If the line is of the form `host:', then just change the
 686                  * default host for the following lines.
 687                  */
 688                 if (*arg == '\0') {
 689                         arg = skip(&cp);
 690                         if (cp == NULL) {
 691                                 free(defhost);
 692                                 defhost = sep->se_hostaddr;
 693                                 goto more;
 694                         }
 695                 }
 696         } else
 697                 sep->se_hostaddr = xxstrdup(defhost);
 698
 699         sep->se_service = xxstrdup(arg);
 700         arg = skip(&cp);
 701
 702         {
 703                 static int8_t SOCK_xxx[] ALIGN1 = {
 704                         -1,
 705                         SOCK_STREAM, SOCK_DGRAM, SOCK_RDM,
 706                         SOCK_SEQPACKET, SOCK_RAW
 707                 };
 708                 sep->se_socktype = SOCK_xxx[1 + index_in_strings(
 709                         "stream""\0" "dgram""\0" "rdm""\0"
 710                         "seqpacket""\0" "raw""\0"
 711                         , arg)];
 712         }
 713
 714         sep->se_proto = xxstrdup(skip(&cp));
 715
 716         if (strcmp(sep->se_proto, "unix") == 0) {
 717                 sep->se_family = AF_UNIX;
 718         } else {
 719                 sep->se_family = AF_INET;
 720                 if (sep->se_proto[strlen(sep->se_proto) - 1] == '6')
 721 #if ENABLE_FEATURE_IPV6
 722                         sep->se_family = AF_INET6;
 723 #else
 724                         bb_error_msg("%s: IPV6 not supported", sep->se_proto);
 725 #endif
 726                 if (strncmp(sep->se_proto, "rpc/", 4) == 0) {
 727 #if ENABLE_FEATURE_INETD_RPC
 728                         char *p, *ccp;
 729                         long l;
 730
 731                         p = strchr(sep->se_service, '/');
 732                         if (p == 0) {
 733                                 bb_error_msg("%s: no rpc version", sep->se_service);
 734                                 goto more;
 735                         }
 736                         *p++ = '\0';
 737                         l = strtol(p, &ccp, 0);
 738                         if (ccp == p || l < 0 || l > INT_MAX) {
 739  badafterall:
 740                                 bb_error_msg("%s/%s: bad rpc version", sep->se_service, p);
 741                                 goto more;
 742                         }
 743                         sep->se_rpcversl = sep->se_rpcversh = l;
 744                         if (*ccp == '-') {
 745                                 p = ccp + 1;
 746                                 l = strtol(p, &ccp, 0);
 747                                 if (ccp == p || l < 0 || l > INT_MAX || l < sep->se_rpcversl || *ccp)
 748                                         goto badafterall;
 749                                 sep->se_rpcversh = l;
 750                         } else if (*ccp != '\0')
 751                                 goto badafterall;
 752 #else
 753                         bb_error_msg("%s: rpc services not supported", sep->se_service);
 754 #endif
 755                 }
 756         }
 757         arg = skip(&cp);
 758         if (arg == NULL)
 759                 goto more;
 760
 761         {
 762                 char *s = strchr(arg, '.');
 763                 if (s) {
 764                         *s++ = '\0';
 765                         sep->se_max = xatoi(s);
 766                 } else
 767                         sep->se_max = toomany;
 768         }
 769         sep->se_wait = (strcmp(arg, "wait") == 0);
 770         sep->se_user = xxstrdup(skip(&cp));
 771         arg = strchr(sep->se_user, '.');
 772         if (arg == NULL)
 773                 arg = strchr(sep->se_user, ':');
 774         if (arg) {
 775                 *arg++ = '\0';
 776                 sep->se_group = xstrdup(arg);
 777         }
 778
 779         sep->se_server = xxstrdup(skip(&cp));
 780 #ifdef INETD_FEATURE_ENABLED
 781         /* sep->se_bi = NULL; - done by new_servtab() */
 782         if (strcmp(sep->se_server, "internal") == 0) {
 783                 const struct builtin *bi;
 784
 785                 for (bi = builtins; bi->bi_service; bi++)
 786                         if (bi->bi_socktype == sep->se_socktype
 787                          && strcmp(bi->bi_service, sep->se_service) == 0)
 788                                 break;
 789                 if (bi->bi_service == 0) {
 790                         bb_error_msg("internal service %s unknown", sep->se_service);
 791                         goto more;
 792                 }
 793                 sep->se_bi = bi;
 794                 sep->se_wait = 0; /* = bi->bi_wait; - always 0 */
 795         }
 796 #endif
 797         argc = 0;
 798         while ((arg = skip(&cp)) != NULL && argc < MAXARGV) {
 799                 sep->se_argv[argc++] = xxstrdup(arg);
 800         }
 801         /* while (argc <= MAXARGV) */
 802         /*      sep->se_argv[argc++] = NULL; - done by new_servtab() */
 803
 804         /*
 805          * Now that we've processed the entire line, check if the hostname
 806          * specifier was a comma separated list of hostnames. If so
 807          * we'll make new entries for each address.
 808          */
 809         while ((hostdelim = strrchr(sep->se_hostaddr, ',')) != NULL) {
 810                 nsep = dupconfig(sep);
 811
 812                 /*
 813                  * NULL terminate the hostname field of the existing entry,
 814                  * and make a dup for the new entry.
 815                  */
 816                 *hostdelim++ = '\0';
 817                 nsep->se_hostaddr = xstrdup(hostdelim);
 818
 819                 nsep->se_next = sep->se_next;
 820                 sep->se_next = nsep;
 821         }
 822
 823         nsep = sep;
 824         while (nsep != NULL) {
 825                 nsep->se_checked = 1;
 826                 if (nsep->se_family == AF_INET) {
 827                         if (LONE_CHAR(nsep->se_hostaddr, '*'))
 828                                 nsep->se_ctrladdr_in.sin_addr.s_addr = INADDR_ANY;
 829                         else if (!inet_aton(nsep->se_hostaddr, &nsep->se_ctrladdr_in.sin_addr)) {
 830                                 int i;
 831                                 struct hostent *hp;
 832
 833                                 hp = gethostbyname(nsep->se_hostaddr);
 834                                 if (hp == NULL) {
 835                                         bb_error_msg("%s: unknown host", nsep->se_hostaddr);
 836                                         nsep->se_checked = 0;
 837                                         goto skip;
 838                                 }
 839                                 if (hp->h_addrtype != AF_INET) {
 840                                         bb_error_msg("%s: address isn't an Internet "
 841                                                                   "address", nsep->se_hostaddr);
 842                                         nsep->se_checked = 0;
 843                                         goto skip;
 844                                 }
 845                                 i = 1;
 846                                 memmove(&nsep->se_ctrladdr_in.sin_addr,
 847                                                            hp->h_addr_list[0], sizeof(struct in_addr));
 848                                 while (hp->h_addr_list[i] != NULL) {
 849                                         psep = dupconfig(nsep);
 850                                         psep->se_hostaddr = xxstrdup(nsep->se_hostaddr);
 851                                         psep->se_checked = 1;
 852                                         memmove(&psep->se_ctrladdr_in.sin_addr,
 853                                                              hp->h_addr_list[i], sizeof(struct in_addr));
 854                                         psep->se_ctrladdr_size = sizeof(psep->se_ctrladdr_in);
 855                                         i++;
 856                                         /* Prepend to list, don't want to look up */
 857                                         /* its hostname again. */
 858                                         psep->se_next = sep;
 859                                         sep = psep;
 860                                 }
 861                         }
 862                 }
 863 /* XXX BUG?: is this skip: label supposed to remain? */
 864  skip:
 865                 nsep = nsep->se_next;
 866         }
 867
 868         /*
 869          * Finally, free any entries which failed the gethostbyname
 870          * check.
 871          */
 872         psep = NULL;
 873         nsep = sep;
 874         while (nsep != NULL) {
 875                 servtab_t *tsep;
 876
 877                 if (nsep->se_checked == 0) {
 878                         tsep = nsep;
 879                         if (psep == NULL) {
 880                                 sep = nsep->se_next;
 881                                 nsep = sep;
 882                         } else {
 883                                 nsep = nsep->se_next;
 884                                 psep->se_next = nsep;
 885                         }
 886                         freeconfig(tsep);
 887                 } else {
 888                         nsep->se_checked = 0;
 889                         psep = nsep;
 890                         nsep = nsep->se_next;
 891                 }
 892         }
 893
 894         return sep;
 895 }
 896
 897 #define Block_Using_Signals(m) do { \
 898         sigemptyset(&m); \
 899         sigaddset(&m, SIGCHLD); \
 900         sigaddset(&m, SIGHUP); \
 901         sigaddset(&m, SIGALRM); \
 902         sigprocmask(SIG_BLOCK, &m, NULL); \
 903 } while (0)
 904
 905 static servtab_t *enter(servtab_t *cp)
 906 {
 907         servtab_t *sep;
 908         sigset_t omask;
 909
 910         sep = new_servtab();
 911         *sep = *cp;
 912         sep->se_fd = -1;
 913 #if ENABLE_FEATURE_INETD_RPC
 914         sep->se_rpcprog = -1;
 915 #endif
 916         Block_Using_Signals(omask);
 917         sep->se_next = servtab;
 918         servtab = sep;
 919         sigprocmask(SIG_UNBLOCK, &omask, NULL);
 920         return sep;
 921 }
 922
 923 static int matchconf(servtab_t *old, servtab_t *new)
 924 {
 925         if (strcmp(old->se_service, new->se_service) != 0)
 926                 return 0;
 927
 928         if (strcmp(old->se_hostaddr, new->se_hostaddr) != 0)
 929                 return 0;
 930
 931         if (strcmp(old->se_proto, new->se_proto) != 0)
 932                 return 0;
 933
 934         /*
 935          * If the new servtab is bound to a specific address, check that the
 936          * old servtab is bound to the same entry. If the new service is not
 937          * bound to a specific address then the check of se_hostaddr above
 938          * is sufficient.
 939          */
 940
 941         if (old->se_family == AF_INET && new->se_family == AF_INET &&
 942                         memcmp(&old->se_ctrladdr_in.sin_addr,
 943                                         &new->se_ctrladdr_in.sin_addr,
 944                                         sizeof(new->se_ctrladdr_in.sin_addr)) != 0)
 945                 return 0;
 946
 947 #if ENABLE_FEATURE_IPV6
 948         if (old->se_family == AF_INET6 && new->se_family == AF_INET6 &&
 949                         memcmp(&old->se_ctrladdr_in6.sin6_addr,
 950                                         &new->se_ctrladdr_in6.sin6_addr,
 951                                         sizeof(new->se_ctrladdr_in6.sin6_addr)) != 0)
 952                 return 0;
 953 #endif
 954         return 1;
 955 }
 956
 957 static void config(int sig ATTRIBUTE_UNUSED)
 958 {
 959         servtab_t *sep, *cp, **sepp;
 960         sigset_t omask;
 961         size_t n;
 962         char protoname[10];
 963
 964         if (!setconfig()) {
 965                 bb_simple_perror_msg(config_filename);
 966                 return;
 967         }
 968         for (sep = servtab; sep; sep = sep->se_next)
 969                 sep->se_checked = 0;
 970         cp = getconfigent();
 971         while (cp != NULL) {
 972                 for (sep = servtab; sep; sep = sep->se_next)
 973                         if (matchconf(sep, cp))
 974                                 break;
 975
 976                 if (sep != 0) {
 977                         int i;
 978
 979 #define SWAP(type, a, b) do {type c=(type)a; a=(type)b; b=(type)c;} while (0)
 980
 981                         Block_Using_Signals(omask);
 982                         /*
 983                          * sep->se_wait may be holding the pid of a daemon
 984                          * that we're waiting for.  If so, don't overwrite
 985                          * it unless the config file explicitly says don't
 986                          * wait.
 987                          */
 988                         if (
 989 #ifdef INETD_FEATURE_ENABLED
 990                                 cp->se_bi == 0 &&
 991 #endif
 992                                 (sep->se_wait == 1 || cp->se_wait == 0))
 993                                 sep->se_wait = cp->se_wait;
 994                         SWAP(int, cp->se_max, sep->se_max);
 995                         SWAP(char *, sep->se_user, cp->se_user);
 996                         SWAP(char *, sep->se_group, cp->se_group);
 997                         SWAP(char *, sep->se_server, cp->se_server);
 998                         for (i = 0; i < MAXARGV; i++)
 999                                 SWAP(char *, sep->se_argv[i], cp->se_argv[i]);
1000 #undef SWAP
1001
1002 #if ENABLE_FEATURE_INETD_RPC
1003                         if (isrpcservice(sep))
1004                                 unregister_rpc(sep);
1005                         sep->se_rpcversl = cp->se_rpcversl;
1006                         sep->se_rpcversh = cp->se_rpcversh;
1007 #endif
1008                         sigprocmask(SIG_UNBLOCK, &omask, NULL);
1009                         freeconfig(cp);
1010                 } else {
1011                         sep = enter(cp);
1012                 }
1013                 sep->se_checked = 1;
1014
1015                 switch (sep->se_family) {
1016                 case AF_UNIX:
1017                         if (sep->se_fd != -1)
1018                                 break;
1019                         (void) unlink(sep->se_service);
1020                         n = strlen(sep->se_service);
1021                         if (n > sizeof sep->se_ctrladdr_un.sun_path - 1)
1022                                 n = sizeof sep->se_ctrladdr_un.sun_path - 1;
1023                         safe_strncpy(sep->se_ctrladdr_un.sun_path, sep->se_service, n + 1);
1024                         sep->se_ctrladdr_un.sun_family = AF_UNIX;
1025                         sep->se_ctrladdr_size = n + sizeof sep->se_ctrladdr_un.sun_family;
1026                         setup(sep);
1027                         break;
1028                 case AF_INET:
1029                         sep->se_ctrladdr_in.sin_family = AF_INET;
1030                         /* se_ctrladdr_in was set in getconfigent */
1031                         sep->se_ctrladdr_size = sizeof sep->se_ctrladdr_in;
1032
1033 #if ENABLE_FEATURE_INETD_RPC
1034                         if (isrpcservice(sep)) {
1035                                 struct rpcent *rp;
1036                                 // FIXME: atoi_or_else(str, 0) would be handy here
1037                                 sep->se_rpcprog = atoi(sep->se_service);
1038                                 if (sep->se_rpcprog == 0) {
1039                                         rp = getrpcbyname(sep->se_service);
1040                                         if (rp == 0) {
1041                                                 bb_error_msg("%s: unknown rpc service", sep->se_service);
1042                                                 goto serv_unknown;
1043                                         }
1044                                         sep->se_rpcprog = rp->r_number;
1045                                 }
1046                                 if (sep->se_fd == -1)
1047                                         setup(sep);
1048                                 if (sep->se_fd != -1)
1049                                         register_rpc(sep);
1050                         } else
1051 #endif
1052                         {
1053                                 uint16_t port = htons(atoi(sep->se_service));
1054                                 // FIXME: atoi_or_else(str, 0) would be handy here
1055                                 if (!port) {
1056                                          /*XXX*/ strncpy(protoname, sep->se_proto, sizeof(protoname));
1057                                         if (isdigit(protoname[strlen(protoname) - 1]))
1058                                                 protoname[strlen(protoname) - 1] = '\0';
1059                                         sp = getservbyname(sep->se_service, protoname);
1060                                         if (sp == 0) {
1061                                                 bb_error_msg("%s/%s: unknown service",
1062                                                                 sep->se_service, sep->se_proto);
1063                                                 goto serv_unknown;
1064                                         }
1065                                         port = sp->s_port;
1066                                 }
1067                                 if (port != sep->se_ctrladdr_in.sin_port) {
1068                                         sep->se_ctrladdr_in.sin_port = port;
1069                                         if (sep->se_fd != -1) {
1070                                                 FD_CLR(sep->se_fd, &allsock);
1071                                                 nsock--;
1072                                                 (void) close(sep->se_fd);
1073                                         }
1074                                         sep->se_fd = -1;
1075                                 }
1076                                 if (sep->se_fd == -1)
1077                                         setup(sep);
1078                         }
1079                         break;
1080 #if ENABLE_FEATURE_IPV6
1081                 case AF_INET6:
1082                         sep->se_ctrladdr_in6.sin6_family = AF_INET6;
1083                         /* se_ctrladdr_in was set in getconfigent */
1084                         sep->se_ctrladdr_size = sizeof sep->se_ctrladdr_in6;
1085
1086 #if ENABLE_FEATURE_INETD_RPC
1087                         if (isrpcservice(sep)) {
1088                                 struct rpcent *rp;
1089
1090                                 sep->se_rpcprog = atoi(sep->se_service);
1091                                 if (sep->se_rpcprog == 0) {
1092                                         rp = getrpcbyname(sep->se_service);
1093                                         if (rp == 0) {
1094                                                 bb_error_msg("%s: unknown rpc service", sep->se_service);
1095                                                 goto serv_unknown;
1096                                         }
1097                                         sep->se_rpcprog = rp->r_number;
1098                                 }
1099                                 if (sep->se_fd == -1)
1100                                         setup(sep);
1101                                 if (sep->se_fd != -1)
1102                                         register_rpc(sep);
1103                         } else
1104 #endif
1105                         {
1106                                 uint16_t port = htons(atoi(sep->se_service));
1107
1108                                 if (!port) {
1109                                          /*XXX*/ strncpy(protoname, sep->se_proto, sizeof(protoname));
1110                                         if (isdigit(protoname[strlen(protoname) - 1]))
1111                                                 protoname[strlen(protoname) - 1] = '\0';
1112                                         sp = getservbyname(sep->se_service, protoname);
1113                                         if (sp == 0) {
1114                                                 bb_error_msg("%s/%s: unknown service",
1115                                                                 sep->se_service, sep->se_proto);
1116                                                 goto serv_unknown;
1117                                         }
1118                                         port = sp->s_port;
1119                                 }
1120                                 if (port != sep->se_ctrladdr_in6.sin6_port) {
1121                                         sep->se_ctrladdr_in6.sin6_port = port;
1122                                         if (sep->se_fd != -1) {
1123                                                 FD_CLR(sep->se_fd, &allsock);
1124                                                 nsock--;
1125                                                 (void) close(sep->se_fd);
1126                                         }
1127                                         sep->se_fd = -1;
1128                                 }
1129                                 if (sep->se_fd == -1)
1130                                         setup(sep);
1131                         }
1132                         break;
1133 #endif /* FEATURE_IPV6 */
1134                 }
1135  serv_unknown:
1136                 if (cp->se_next != NULL) {
1137                         servtab_t *tmp = cp;
1138
1139                         cp = cp->se_next;
1140                         free(tmp);
1141                 } else {
1142                         free(cp);
1143                         cp = getconfigent();
1144                 }
1145         }
1146         endconfig();
1147         /*
1148          * Purge anything not looked at above.
1149          */
1150         Block_Using_Signals(omask);
1151         sepp = &servtab;
1152         while ((sep = *sepp)) {
1153                 if (sep->se_checked) {
1154                         sepp = &sep->se_next;
1155                         continue;
1156                 }
1157                 *sepp = sep->se_next;
1158                 if (sep->se_fd != -1) {
1159                         FD_CLR(sep->se_fd, &allsock);
1160                         nsock--;
1161                         (void) close(sep->se_fd);
1162                 }
1163 #if ENABLE_FEATURE_INETD_RPC
1164                 if (isrpcservice(sep))
1165                         unregister_rpc(sep);
1166 #endif
1167                 if (sep->se_family == AF_UNIX)
1168                         (void) unlink(sep->se_service);
1169                 freeconfig(sep);
1170                 free(sep);
1171         }
1172         sigprocmask(SIG_UNBLOCK, &omask, NULL);
1173 }
1174
1175
1176 static void reapchild(int sig ATTRIBUTE_UNUSED)
1177 {
1178         pid_t pid;
1179         int save_errno = errno, status;
1180         servtab_t *sep;
1181
1182         for (;;) {
1183                 pid = wait3(&status, WNOHANG, NULL);
1184                 if (pid <= 0)
1185                         break;
1186                 for (sep = servtab; sep; sep = sep->se_next)
1187                         if (sep->se_wait == pid) {
1188                                 if (WIFEXITED(status) && WEXITSTATUS(status))
1189                                         bb_error_msg("%s: exit status 0x%x",
1190                                                         sep->se_server, WEXITSTATUS(status));
1191                                 else if (WIFSIGNALED(status))
1192                                         bb_error_msg("%s: exit signal 0x%x",
1193                                                         sep->se_server, WTERMSIG(status));
1194                                 sep->se_wait = 1;
1195                                 FD_SET(sep->se_fd, &allsock);
1196                                 nsock++;
1197                         }
1198         }
1199         errno = save_errno;
1200 }
1201
1202 static void retry(int sig ATTRIBUTE_UNUSED)
1203 {
1204         servtab_t *sep;
1205
1206         timingout = 0;
1207         for (sep = servtab; sep; sep = sep->se_next) {
1208                 if (sep->se_fd == -1) {
1209                         switch (sep->se_family) {
1210                         case AF_UNIX:
1211                         case AF_INET:
1212 #if ENABLE_FEATURE_IPV6
1213                         case AF_INET6:
1214 #endif
1215                                 setup(sep);
1216 #if ENABLE_FEATURE_INETD_RPC
1217                                 if (sep->se_fd != -1 && isrpcservice(sep))
1218                                         register_rpc(sep);
1219 #endif
1220                                 break;
1221                         }
1222                 }
1223         }
1224 }
1225
1226 static void goaway(int sig ATTRIBUTE_UNUSED)
1227 {
1228         servtab_t *sep;
1229
1230         /* XXX signal race walking sep list */
1231         for (sep = servtab; sep; sep = sep->se_next) {
1232                 if (sep->se_fd == -1)
1233                         continue;
1234
1235                 switch (sep->se_family) {
1236                 case AF_UNIX:
1237                         (void) unlink(sep->se_service);
1238                         break;
1239                 case AF_INET:
1240 #if ENABLE_FEATURE_IPV6
1241                 case AF_INET6:
1242 #endif
1243 #if ENABLE_FEATURE_INETD_RPC
1244                         if (sep->se_wait == 1 && isrpcservice(sep))
1245                                 unregister_rpc(sep);   /* XXX signal race */
1246 #endif
1247                         break;
1248                 }
1249                 (void) close(sep->se_fd);
1250         }
1251         remove_pidfile(_PATH_INETDPID);
1252         exit(0);
1253 }
1254
1255
1256 #ifdef INETD_SETPROCTITLE
1257
1258 static void
1259 inetd_setproctitle(char *a, int s)
1260 {
1261         socklen_t size;
1262         char *cp;
1263         struct sockaddr_in prt_sin;
1264         char buf[80];
1265
1266         cp = Argv[0];
1267         size = sizeof(prt_sin);
1268         (void) snprintf(buf, sizeof buf, "-%s", a);
1269         if (getpeername(s, (struct sockaddr *) &prt_sin, &size) == 0) {
1270                 char *sa = inet_ntoa(prt_sin.sin_addr);
1271
1272                 buf[sizeof(buf) - 1 - strlen(sa) - 3] = '\0';
1273                 strcat(buf, " [");
1274                 strcat(buf, sa);
1275                 strcat(buf, "]");
1276         }
1277         strncpy(cp, buf, LastArg - cp);
1278         cp += strlen(cp);
1279         while (cp < LastArg)
1280                 *cp++ = ' ';
1281 }
1282 #endif
1283
1284
1285 int inetd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1286 int inetd_main(int argc, char **argv)
1287 {
1288         servtab_t *sep;
1289         struct passwd *pwd;
1290         struct group *grp = NULL;
1291         int tmpint;
1292         struct sigaction sa, sapipe;
1293         int opt;
1294         pid_t pid;
1295         char buf[50];
1296         char *stoomany;
1297         sigset_t omask, wait_mask;
1298 #ifdef INETD_SETPROCTITLE
1299         char **envp;
1300 #endif
1301
1302         INIT_G();
1303
1304 #ifdef INETD_SETPROCTITLE
1305         envp = environ;
1306         Argv = argv;
1307         if (envp == 0 || *envp == 0)
1308                 envp = argv;
1309         while (*envp)
1310                 envp++;
1311         LastArg = envp[-1] + strlen(envp[-1]);
1312 #endif
1313
1314         uid = getuid();
1315         if (uid != 0)
1316                 config_filename = NULL;
1317
1318         opt = getopt32(argv, "R:f", &stoomany);
1319         if (opt & 1)
1320                 toomany = xatoi_u(stoomany);
1321         argv += optind;
1322         argc -= optind;
1323         if (argc)
1324                 config_filename = argv[0];
1325         if (config_filename == NULL)
1326                 bb_error_msg_and_die("non-root must specify a config file");
1327
1328         if (!(opt & 2))
1329                 bb_daemonize_or_rexec(0, argv - optind);
1330         else
1331                 bb_sanitize_stdio();
1332         openlog(applet_name, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
1333         logmode = LOGMODE_SYSLOG;
1334
1335         if (uid == 0) {
1336                 /* If run by hand, ensure groups vector gets trashed */
1337                 gid_t gid = getgid();
1338                 setgroups(1, &gid);
1339         }
1340
1341         write_pidfile(_PATH_INETDPID);
1342
1343         if (getrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0) {
1344                 bb_perror_msg("getrlimit");
1345         } else {
1346                 rlim_ofile_cur = rlim_ofile.rlim_cur;
1347                 if (rlim_ofile_cur == RLIM_INFINITY)    /* ! */
1348                         rlim_ofile_cur = OPEN_MAX;
1349         }
1350
1351         memset((char *) &sa, 0, sizeof(sa));
1352         sigemptyset(&sa.sa_mask);
1353         sigaddset(&sa.sa_mask, SIGALRM);
1354         sigaddset(&sa.sa_mask, SIGCHLD);
1355         sigaddset(&sa.sa_mask, SIGHUP);
1356         sa.sa_handler = retry;
1357         sigaction(SIGALRM, &sa, NULL);
1358         config(SIGHUP);
1359         sa.sa_handler = config;
1360         sigaction(SIGHUP, &sa, NULL);
1361         sa.sa_handler = reapchild;
1362         sigaction(SIGCHLD, &sa, NULL);
1363         sa.sa_handler = goaway;
1364         sigaction(SIGTERM, &sa, NULL);
1365         sa.sa_handler = goaway;
1366         sigaction(SIGINT, &sa, NULL);
1367         sa.sa_handler = SIG_IGN;
1368         sigaction(SIGPIPE, &sa, &sapipe);
1369         memset(&wait_mask, 0, sizeof(wait_mask));
1370         {
1371                 /* space for daemons to overwrite environment for ps */
1372 #define DUMMYSIZE       100
1373                 char dummy[DUMMYSIZE];
1374
1375                 (void) memset(dummy, 'x', DUMMYSIZE - 1);
1376                 dummy[DUMMYSIZE - 1] = '\0';
1377
1378                 (void) setenv("inetd_dummy", dummy, 1);
1379         }
1380
1381         for (;;) {
1382                 int n, ctrl = -1;
1383                 fd_set readable;
1384
1385                 if (nsock == 0) {
1386                         Block_Using_Signals(omask);
1387                         while (nsock == 0)
1388                                 sigsuspend(&wait_mask);
1389                         sigprocmask(SIG_UNBLOCK, &omask, NULL);
1390                 }
1391
1392                 readable = allsock;
1393                 n = select(maxsock + 1, &readable, NULL, NULL, NULL);
1394                 if (n <= 0) {
1395                         if (n < 0 && errno != EINTR) {
1396                                 bb_perror_msg("select");
1397                                 sleep(1);
1398                         }
1399                         continue;
1400                 }
1401
1402                 for (sep = servtab; n && sep; sep = sep->se_next) {
1403                         if (sep->se_fd == -1 || !FD_ISSET(sep->se_fd, &readable))
1404                                 continue;
1405
1406                         n--;
1407                         if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) {
1408                                 ctrl = accept(sep->se_fd, NULL, NULL);
1409                                 if (ctrl < 0) {
1410                                         if (errno == EINTR)
1411                                                 continue;
1412                                         bb_perror_msg("accept (for %s)", sep->se_service);
1413                                         continue;
1414                                 }
1415                                 if (sep->se_family == AF_INET && sep->se_socktype == SOCK_STREAM) {
1416                                         struct sockaddr_in peer;
1417                                         socklen_t plen = sizeof(peer);
1418
1419                                         if (getpeername(ctrl, (struct sockaddr *) &peer, &plen) < 0) {
1420                                                 bb_error_msg("cannot getpeername");
1421                                                 close(ctrl);
1422                                                 continue;
1423                                         }
1424                                         if (ntohs(peer.sin_port) == 20) {
1425                                                 /* XXX ftp bounce */
1426                                                 close(ctrl);
1427                                                 continue;
1428                                         }
1429                                 }
1430                         } else
1431                                 ctrl = sep->se_fd;
1432
1433                         Block_Using_Signals(omask);
1434                         pid = 0;
1435 #ifdef INETD_FEATURE_ENABLED
1436                         if (sep->se_bi == 0 || sep->se_bi->bi_fork)
1437 #endif
1438                         {
1439                                 if (sep->se_count++ == 0)
1440                                         (void) gettimeofday(&sep->se_time, NULL);
1441                                 else if (toomany > 0 && sep->se_count >= sep->se_max) {
1442                                         struct timeval now;
1443
1444                                         (void) gettimeofday(&now, NULL);
1445                                         if (now.tv_sec - sep->se_time.tv_sec > CNT_INTVL) {
1446                                                 sep->se_time = now;
1447                                                 sep->se_count = 1;
1448                                         } else {
1449                                                 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
1450                                                         close(ctrl);
1451                                                 if (sep->se_family == AF_INET &&
1452                                                           ntohs(sep->se_ctrladdr_in.sin_port) >= IPPORT_RESERVED) {
1453                                                         /*
1454                                                          * Cannot close it -- there are
1455                                                          * thieves on the system.
1456                                                          * Simply ignore the connection.
1457                                                          */
1458                                                         --sep->se_count;
1459                                                         continue;
1460                                                 }
1461                                                 bb_error_msg("%s/%s server failing (looping), service terminated",
1462                                                               sep->se_service, sep->se_proto);
1463                                                 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
1464                                                         close(ctrl);
1465                                                 FD_CLR(sep->se_fd, &allsock);
1466                                                 (void) close(sep->se_fd);
1467                                                 sep->se_fd = -1;
1468                                                 sep->se_count = 0;
1469                                                 nsock--;
1470                                                 sigprocmask(SIG_UNBLOCK, &omask, NULL);
1471                                                 if (!timingout) {
1472                                                         timingout = 1;
1473                                                         alarm(RETRYTIME);
1474                                                 }
1475                                                 continue;
1476                                         }
1477                                 }
1478                                 pid = fork();
1479                         }
1480                         if (pid < 0) {
1481                                 bb_perror_msg("fork");
1482                                 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
1483                                         close(ctrl);
1484                                 sigprocmask(SIG_UNBLOCK, &omask, NULL);
1485                                 sleep(1);
1486                                 continue;
1487                         }
1488                         if (pid && sep->se_wait) {
1489                                 sep->se_wait = pid;
1490                                 FD_CLR(sep->se_fd, &allsock);
1491                                 nsock--;
1492                         }
1493                         sigprocmask(SIG_UNBLOCK, &omask, NULL);
1494                         if (pid == 0) {
1495 #ifdef INETD_FEATURE_ENABLED
1496                                 if (sep->se_bi) {
1497                                         (*sep->se_bi->bi_fn)(ctrl, sep);
1498                                 } else
1499 #endif
1500                                 {
1501                                         pwd = getpwnam(sep->se_user);
1502                                         if (pwd == NULL) {
1503                                                 bb_error_msg("getpwnam: %s: no such user", sep->se_user);
1504                                                 goto do_exit1;
1505                                         }
1506                                         if (setsid() < 0)
1507                                                 bb_perror_msg("%s: setsid", sep->se_service);
1508                                         if (sep->se_group && (grp = getgrnam(sep->se_group)) == NULL) {
1509                                                 bb_error_msg("getgrnam: %s: no such group", sep->se_group);
1510                                                 goto do_exit1;
1511                                         }
1512                                         if (uid != 0) {
1513                                                 /* a user running private inetd */
1514                                                 if (uid != pwd->pw_uid)
1515                                                         _exit(1);
1516                                         } else if (pwd->pw_uid) {
1517                                                 if (sep->se_group)
1518                                                         pwd->pw_gid = grp->gr_gid;
1519                                                 xsetgid((gid_t) pwd->pw_gid);
1520                                                 initgroups(pwd->pw_name, pwd->pw_gid);
1521                                                 xsetuid((uid_t) pwd->pw_uid);
1522                                         } else if (sep->se_group) {
1523                                                 xsetgid(grp->gr_gid);
1524                                                 setgroups(1, &grp->gr_gid);
1525                                         }
1526                                         dup2(ctrl, 0);
1527                                         if (ctrl) close(ctrl);
1528                                         dup2(0, 1);
1529                                         dup2(0, 2);
1530                                         if (rlim_ofile.rlim_cur != rlim_ofile_cur)
1531                                                 if (setrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0)
1532                                                         bb_perror_msg("setrlimit");
1533                                         closelog();
1534                                         for (tmpint = rlim_ofile_cur - 1; --tmpint > 2;)
1535                                                 (void) close(tmpint);
1536                                         sigaction(SIGPIPE, &sapipe, NULL);
1537                                         execv(sep->se_server, sep->se_argv);
1538                                         bb_perror_msg("execv %s", sep->se_server);
1539  do_exit1:
1540                                         if (sep->se_socktype != SOCK_STREAM)
1541                                                 recv(0, buf, sizeof(buf), 0);
1542                                         _exit(1);
1543                                 }
1544                         }
1545                         if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
1546                                 close(ctrl);
1547                 } /* for (sep = servtab...) */
1548         } /* for (;;) */
1549 }
1550
1551 /*
1552  * Internet services provided internally by inetd:
1553  */
1554 #define BUFSIZE 4096
1555
1556 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO || \
1557         ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN || \
1558         ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
1559 static int dg_badinput(struct sockaddr_in *dg_sin)
1560 {
1561         if (ntohs(dg_sin->sin_port) < IPPORT_RESERVED)
1562                 return 1;
1563         if (dg_sin->sin_addr.s_addr == htonl(INADDR_BROADCAST))
1564                 return 1;
1565         /* XXX compare against broadcast addresses in SIOCGIFCONF list? */
1566         return 0;
1567 }
1568 #endif
1569
1570 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
1571 /* Echo service -- echo data back */
1572 /* ARGSUSED */
1573 static void
1574 echo_stream(int s, servtab_t *sep)
1575 {
1576         char buffer[BUFSIZE];
1577         int i;
1578
1579         inetd_setproctitle(sep->se_service, s);
1580         while (1) {
1581                 i = read(s, buffer, sizeof(buffer));
1582                 if (i <= 0) break;
1583                 /* FIXME: this isnt correct - safe_write()? */
1584                 if (write(s, buffer, i) <= 0) break;
1585         }
1586         exit(0);
1587 }
1588
1589 /* Echo service -- echo data back */
1590 /* ARGSUSED */
1591 static void
1592 echo_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1593 {
1594         char buffer[BUFSIZE];
1595         int i;
1596         socklen_t size;
1597         /* struct sockaddr_storage ss; */
1598         struct sockaddr sa;
1599
1600         size = sizeof(sa);
1601         i = recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size);
1602         if (i < 0)
1603                 return;
1604         if (dg_badinput((struct sockaddr_in *) &sa))
1605                 return;
1606         (void) sendto(s, buffer, i, 0, &sa, sizeof(sa));
1607 }
1608 #endif  /* FEATURE_INETD_SUPPORT_BUILTIN_ECHO */
1609
1610 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
1611 /* Discard service -- ignore data */
1612 /* ARGSUSED */
1613 static void
1614 discard_stream(int s, servtab_t *sep)
1615 {
1616         char buffer[BUFSIZE];
1617
1618         inetd_setproctitle(sep->se_service, s);
1619         while (1) {
1620                 if (safe_read(s, buffer, sizeof(buffer)) <= 0)
1621                         exit(0);
1622         }
1623 }
1624
1625 /* Discard service -- ignore data */
1626 /* ARGSUSED */
1627 static void
1628 discard_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1629 {
1630         char buffer[BUFSIZE];
1631
1632         (void) read(s, buffer, sizeof(buffer));
1633 }
1634 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_DISCARD */
1635
1636
1637 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
1638 #define LINESIZ 72
1639
1640 static void
1641 initring(void)
1642 {
1643         int i;
1644
1645         endring = ring;
1646         for (i = 0; i <= 128; ++i)
1647                 if (isprint(i))
1648                         *endring++ = i;
1649 }
1650
1651 /* Character generator */
1652 /* ARGSUSED */
1653 static void
1654 chargen_stream(int s, servtab_t *sep)
1655 {
1656         char *rs;
1657         int len;
1658         char text[LINESIZ + 2];
1659
1660         inetd_setproctitle(sep->se_service, s);
1661
1662         if (!endring) {
1663                 initring();
1664                 rs = ring;
1665         }
1666
1667         text[LINESIZ] = '\r';
1668         text[LINESIZ + 1] = '\n';
1669         rs = ring;
1670         for (;;) {
1671                 len = endring - rs;
1672                 if (len >= LINESIZ)
1673                         memmove(text, rs, LINESIZ);
1674                 else {
1675                         memmove(text, rs, len);
1676                         memmove(text + len, ring, LINESIZ - len);
1677                 }
1678                 if (++rs == endring)
1679                         rs = ring;
1680                 if (write(s, text, sizeof(text)) != sizeof(text))
1681                         break;
1682         }
1683         exit(0);
1684 }
1685
1686 /* Character generator */
1687 /* ARGSUSED */
1688 static void
1689 chargen_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1690 {
1691         /* struct sockaddr_storage ss; */
1692         struct sockaddr sa;
1693         int len;
1694         char text[LINESIZ + 2];
1695         socklen_t size;
1696
1697         if (!endring) {
1698                 initring();
1699                 ringpos = ring;
1700         }
1701
1702         size = sizeof(sa);
1703         if (recvfrom(s, text, sizeof(text), 0, &sa, &size) < 0)
1704                 return;
1705         if (dg_badinput((struct sockaddr_in *) &sa))
1706                 return;
1707
1708         len = endring - ringpos;
1709         if (len >= LINESIZ)
1710                 memmove(text, ringpos, LINESIZ);
1711         else {
1712                 memmove(text, ringpos, len);
1713                 memmove(text + len, ring, LINESIZ - len);
1714         }
1715         if (++ringpos == endring)
1716                 ringpos = ring;
1717         text[LINESIZ] = '\r';
1718         text[LINESIZ + 1] = '\n';
1719         (void) sendto(s, text, sizeof(text), 0, &sa, sizeof(sa));
1720 }
1721 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN */
1722
1723
1724 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
1725 /*
1726  * Return a machine readable date and time, in the form of the
1727  * number of seconds since midnight, Jan 1, 1900.  Since gettimeofday
1728  * returns the number of seconds since midnight, Jan 1, 1970,
1729  * we must add 2208988800 seconds to this figure to make up for
1730  * some seventy years Bell Labs was asleep.
1731  */
1732
1733 static unsigned machtime(void)
1734 {
1735         struct timeval tv;
1736
1737         if (gettimeofday(&tv, NULL) < 0) {
1738                 fprintf(stderr, "Unable to get time of day\n");
1739                 return 0L;
1740         }
1741         return htonl((unsigned) tv.tv_sec + 2208988800UL);
1742 }
1743
1744 /* ARGSUSED */
1745 static void
1746 machtime_stream(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1747 {
1748         unsigned result;
1749
1750         result = machtime();
1751         (void) write(s, (char *) &result, sizeof(result));
1752 }
1753
1754 /* ARGSUSED */
1755 static void
1756 machtime_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1757 {
1758         unsigned result;
1759         /* struct sockaddr_storage ss; */
1760         struct sockaddr sa;
1761         struct sockaddr_in *dg_sin;
1762         socklen_t size;
1763
1764         size = sizeof(sa);
1765         if (recvfrom(s, (char *) &result, sizeof(result), 0, &sa, &size) < 0)
1766                 return;
1767         /* if (dg_badinput((struct sockaddr *)&ss)) */
1768         dg_sin = (struct sockaddr_in *) &sa;
1769         if (dg_sin->sin_addr.s_addr == htonl(INADDR_BROADCAST) ||
1770                         ntohs(dg_sin->sin_port) < IPPORT_RESERVED / 2)
1771                 return;
1772         result = machtime();
1773         (void) sendto(s, (char *) &result, sizeof(result), 0, &sa, sizeof(sa));
1774 }
1775 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_TIME */
1776
1777
1778 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
1779 /* Return human-readable time of day */
1780 /* ARGSUSED */
1781 static void daytime_stream(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1782 {
1783         char buffer[32];
1784         time_t t;
1785
1786         t = time(NULL);
1787
1788 // fdprintf instead?
1789         (void) sprintf(buffer, "%.24s\r\n", ctime(&t));
1790         (void) write(s, buffer, strlen(buffer));
1791 }
1792
1793 /* Return human-readable time of day */
1794 /* ARGSUSED */
1795 void
1796 daytime_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1797 {
1798         char buffer[256];
1799         time_t t;
1800         /* struct sockaddr_storage ss; */
1801         struct sockaddr sa;
1802         socklen_t size;
1803
1804         t = time(NULL);
1805
1806         size = sizeof(sa);
1807         if (recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size) < 0)
1808                 return;
1809         if (dg_badinput((struct sockaddr_in *) &sa))
1810                 return;
1811         (void) sprintf(buffer, "%.24s\r\n", ctime(&t));
1812         (void) sendto(s, buffer, strlen(buffer), 0, &sa, sizeof(sa));
1813 }
1814 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME */