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         FILE *fd = fconfig;
 574
 575         if (fgets(line, LINE_SIZE, fd) == NULL)
 576                 return NULL;
 577         cp = strchr(line, '\n');
 578         if (cp)
 579                 *cp = '\0';
 580         return line;
 581 }
 582
 583 static char *skip(char **cpp) /* int report; */
 584 {
 585         char *cp = *cpp;
 586         char *start;
 587
 588 /* erp: */
 589         if (*cpp == NULL) {
 590                 /* if (report) */
 591                 /* bb_error_msg("syntax error in inetd config file"); */
 592                 return NULL;
 593         }
 594
 595  again:
 596         while (*cp == ' ' || *cp == '\t')
 597                 cp++;
 598         if (*cp == '\0') {
 599                 int c;
 600
 601                 c = getc(fconfig);
 602                 ungetc(c, fconfig);
 603                 if (c == ' ' || c == '\t') {
 604                         cp = nextline();
 605                         if (cp)
 606                                 goto again;
 607                 }
 608                 *cpp = NULL;
 609                 /* goto erp; */
 610                 return NULL;
 611         }
 612         start = cp;
 613         while (*cp && *cp != ' ' && *cp != '\t')
 614                 cp++;
 615         if (*cp != '\0')
 616                 *cp++ = '\0';
 617         /* if ((*cpp = cp) == NULL) */
 618         /* goto erp; */
 619
 620         *cpp = cp;
 621         return start;
 622 }
 623
 624 static servtab_t *new_servtab(void)
 625 {
 626         return xmalloc(sizeof(servtab_t));
 627 }
 628
 629 static servtab_t *dupconfig(servtab_t *sep)
 630 {
 631         servtab_t *newtab;
 632         int argc;
 633
 634         newtab = new_servtab();
 635         memset(newtab, 0, sizeof(servtab_t));
 636         newtab->se_service = xstrdup(sep->se_service);
 637         newtab->se_socktype = sep->se_socktype;
 638         newtab->se_family = sep->se_family;
 639         newtab->se_proto = xstrdup(sep->se_proto);
 640 #if ENABLE_FEATURE_INETD_RPC
 641         newtab->se_rpcprog = sep->se_rpcprog;
 642         newtab->se_rpcversl = sep->se_rpcversl;
 643         newtab->se_rpcversh = sep->se_rpcversh;
 644 #endif
 645         newtab->se_wait = sep->se_wait;
 646         newtab->se_user = xstrdup(sep->se_user);
 647         newtab->se_group = xstrdup(sep->se_group);
 648 #ifdef INETD_FEATURE_ENABLED
 649         newtab->se_bi = sep->se_bi;
 650 #endif
 651         newtab->se_server = xstrdup(sep->se_server);
 652
 653         for (argc = 0; argc <= MAXARGV; argc++)
 654                 newtab->se_argv[argc] = xstrdup(sep->se_argv[argc]);
 655         newtab->se_max = sep->se_max;
 656
 657         return newtab;
 658 }
 659
 660 static servtab_t *getconfigent(void)
 661 {
 662         servtab_t *sep;
 663         int argc;
 664         char *cp, *arg;
 665         char *hostdelim;
 666         servtab_t *nsep;
 667         servtab_t *psep;
 668
 669         sep = new_servtab();
 670
 671         /* memset(sep, 0, sizeof *sep); */
 672  more:
 673         /* freeconfig(sep); */
 674
 675         while ((cp = nextline()) && *cp == '#') /* skip comment line */;
 676         if (cp == NULL) {
 677                 /* free(sep); */
 678                 return NULL;
 679         }
 680
 681         memset((char *) sep, 0, sizeof *sep);
 682         arg = skip(&cp);
 683         if (arg == NULL) {
 684                 /* A blank line. */
 685                 goto more;
 686         }
 687
 688         /* Check for a host name. */
 689         hostdelim = strrchr(arg, ':');
 690         if (hostdelim) {
 691                 *hostdelim = '\0';
 692                 sep->se_hostaddr = xstrdup(arg);
 693                 arg = hostdelim + 1;
 694                 /*
 695                  * If the line is of the form `host:', then just change the
 696                  * default host for the following lines.
 697                  */
 698                 if (*arg == '\0') {
 699                         arg = skip(&cp);
 700                         if (cp == NULL) {
 701                                 free(defhost);
 702                                 defhost = sep->se_hostaddr;
 703                                 goto more;
 704                         }
 705                 }
 706         } else
 707                 sep->se_hostaddr = xxstrdup(defhost);
 708
 709         sep->se_service = xxstrdup(arg);
 710         arg = skip(&cp);
 711
 712         {
 713                 static int8_t SOCK_xxx[] ALIGN1 = {
 714                         -1,
 715                         SOCK_STREAM, SOCK_DGRAM, SOCK_RDM,
 716                         SOCK_SEQPACKET, SOCK_RAW
 717                 };
 718                 sep->se_socktype = SOCK_xxx[1 + index_in_strings(
 719                         "stream""\0" "dgram""\0" "rdm""\0"
 720                         "seqpacket""\0" "raw""\0"
 721                         , arg)];
 722         }
 723
 724         sep->se_proto = xxstrdup(skip(&cp));
 725
 726         if (strcmp(sep->se_proto, "unix") == 0) {
 727                 sep->se_family = AF_UNIX;
 728         } else {
 729                 sep->se_family = AF_INET;
 730                 if (sep->se_proto[strlen(sep->se_proto) - 1] == '6')
 731 #if ENABLE_FEATURE_IPV6
 732                         sep->se_family = AF_INET6;
 733 #else
 734                         bb_error_msg("%s: IPV6 not supported", sep->se_proto);
 735 #endif
 736                 if (strncmp(sep->se_proto, "rpc/", 4) == 0) {
 737 #if ENABLE_FEATURE_INETD_RPC
 738                         char *p, *ccp;
 739                         long l;
 740
 741                         p = strchr(sep->se_service, '/');
 742                         if (p == 0) {
 743                                 bb_error_msg("%s: no rpc version", sep->se_service);
 744                                 goto more;
 745                         }
 746                         *p++ = '\0';
 747                         l = strtol(p, &ccp, 0);
 748                         if (ccp == p || l < 0 || l > INT_MAX) {
 749  badafterall:
 750                                 bb_error_msg("%s/%s: bad rpc version", sep->se_service, p);
 751                                 goto more;
 752                         }
 753                         sep->se_rpcversl = sep->se_rpcversh = l;
 754                         if (*ccp == '-') {
 755                                 p = ccp + 1;
 756                                 l = strtol(p, &ccp, 0);
 757                                 if (ccp == p || l < 0 || l > INT_MAX || l < sep->se_rpcversl || *ccp)
 758                                         goto badafterall;
 759                                 sep->se_rpcversh = l;
 760                         } else if (*ccp != '\0')
 761                                 goto badafterall;
 762 #else
 763                         bb_error_msg("%s: rpc services not supported", sep->se_service);
 764 #endif
 765                 }
 766         }
 767         arg = skip(&cp);
 768         if (arg == NULL)
 769                 goto more;
 770
 771         {
 772                 char *s = strchr(arg, '.');
 773                 if (s) {
 774                         *s++ = '\0';
 775                         sep->se_max = xatoi(s);
 776                 } else
 777                         sep->se_max = toomany;
 778         }
 779         sep->se_wait = strcmp(arg, "wait") == 0;
 780         /* if ((arg = skip(&cp, 1)) == NULL) */
 781         /* goto more; */
 782         sep->se_user = xxstrdup(skip(&cp));
 783         arg = strchr(sep->se_user, '.');
 784         if (arg == NULL)
 785                 arg = strchr(sep->se_user, ':');
 786         if (arg) {
 787                 *arg++ = '\0';
 788                 sep->se_group = xstrdup(arg);
 789         }
 790
 791         arg = skip(&cp);
 792         sep->se_server = xxstrdup(arg);
 793         if (strcmp(sep->se_server, "internal") == 0) {
 794 #ifdef INETD_FEATURE_ENABLED
 795                 const struct builtin *bi;
 796
 797                 for (bi = builtins; bi->bi_service; bi++)
 798                         if (bi->bi_socktype == sep->se_socktype
 799                          && strcmp(bi->bi_service, sep->se_service) == 0)
 800                                 break;
 801                 if (bi->bi_service == 0) {
 802                         bb_error_msg("internal service %s unknown", sep->se_service);
 803                         goto more;
 804                 }
 805                 sep->se_bi = bi;
 806                 sep->se_wait = 0; /* = bi->bi_wait; - always 0 */
 807 #else
 808                 bb_perror_msg("internal service %s unknown", sep->se_service);
 809                 goto more;
 810 #endif
 811         }
 812 #ifdef INETD_FEATURE_ENABLED
 813                 else
 814                 sep->se_bi = NULL;
 815 #endif
 816         argc = 0;
 817         for (; cp; arg = skip(&cp)) {
 818                 if (argc < MAXARGV)
 819                         sep->se_argv[argc++] = xxstrdup(arg);
 820         }
 821         while (argc <= MAXARGV)
 822                 sep->se_argv[argc++] = NULL;
 823
 824         /*
 825          * Now that we've processed the entire line, check if the hostname
 826          * specifier was a comma separated list of hostnames. If so
 827          * we'll make new entries for each address.
 828          */
 829         while ((hostdelim = strrchr(sep->se_hostaddr, ',')) != NULL) {
 830                 nsep = dupconfig(sep);
 831
 832                 /*
 833                  * NULL terminate the hostname field of the existing entry,
 834                  * and make a dup for the new entry.
 835                  */
 836                 *hostdelim++ = '\0';
 837                 nsep->se_hostaddr = xstrdup(hostdelim);
 838
 839                 nsep->se_next = sep->se_next;
 840                 sep->se_next = nsep;
 841         }
 842
 843         nsep = sep;
 844         while (nsep != NULL) {
 845                 nsep->se_checked = 1;
 846                 if (nsep->se_family == AF_INET) {
 847                         if (LONE_CHAR(nsep->se_hostaddr, '*'))
 848                                 nsep->se_ctrladdr_in.sin_addr.s_addr = INADDR_ANY;
 849                         else if (!inet_aton(nsep->se_hostaddr, &nsep->se_ctrladdr_in.sin_addr)) {
 850                                 int i;
 851                                 struct hostent *hp;
 852
 853                                 hp = gethostbyname(nsep->se_hostaddr);
 854                                 if (hp == NULL) {
 855                                         bb_error_msg("%s: unknown host", nsep->se_hostaddr);
 856                                         nsep->se_checked = 0;
 857                                         goto skip;
 858                                 }
 859                                 if (hp->h_addrtype != AF_INET) {
 860                                         bb_error_msg("%s: address isn't an Internet "
 861                                                                   "address", nsep->se_hostaddr);
 862                                         nsep->se_checked = 0;
 863                                         goto skip;
 864                                 }
 865                                 i = 1;
 866                                 memmove(&nsep->se_ctrladdr_in.sin_addr,
 867                                                            hp->h_addr_list[0], sizeof(struct in_addr));
 868                                 while (hp->h_addr_list[i] != NULL) {
 869                                         psep = dupconfig(nsep);
 870                                         psep->se_hostaddr = xxstrdup(nsep->se_hostaddr);
 871                                         psep->se_checked = 1;
 872                                         memmove(&psep->se_ctrladdr_in.sin_addr,
 873                                                              hp->h_addr_list[i], sizeof(struct in_addr));
 874                                         psep->se_ctrladdr_size = sizeof(psep->se_ctrladdr_in);
 875                                         i++;
 876                                         /* Prepend to list, don't want to look up */
 877                                         /* its hostname again. */
 878                                         psep->se_next = sep;
 879                                         sep = psep;
 880                                 }
 881                         }
 882                 }
 883 /* XXX BUG?: is this skip: label supposed to remain? */
 884  skip:
 885                 nsep = nsep->se_next;
 886         }
 887
 888         /*
 889          * Finally, free any entries which failed the gethostbyname
 890          * check.
 891          */
 892         psep = NULL;
 893         nsep = sep;
 894         while (nsep != NULL) {
 895                 servtab_t *tsep;
 896
 897                 if (nsep->se_checked == 0) {
 898                         tsep = nsep;
 899                         if (psep == NULL) {
 900                                 sep = nsep->se_next;
 901                                 nsep = sep;
 902                         } else {
 903                                 nsep = nsep->se_next;
 904                                 psep->se_next = nsep;
 905                         }
 906                         freeconfig(tsep);
 907                 } else {
 908                         nsep->se_checked = 0;
 909                         psep = nsep;
 910                         nsep = nsep->se_next;
 911                 }
 912         }
 913
 914         return sep;
 915 }
 916
 917 #define Block_Using_Signals(m) do { \
 918         sigemptyset(&m); \
 919         sigaddset(&m, SIGCHLD); \
 920         sigaddset(&m, SIGHUP); \
 921         sigaddset(&m, SIGALRM); \
 922         sigprocmask(SIG_BLOCK, &m, NULL); \
 923 } while (0)
 924
 925 static servtab_t *enter(servtab_t *cp)
 926 {
 927         servtab_t *sep;
 928         sigset_t omask;
 929
 930         sep = new_servtab();
 931         *sep = *cp;
 932         sep->se_fd = -1;
 933 #if ENABLE_FEATURE_INETD_RPC
 934         sep->se_rpcprog = -1;
 935 #endif
 936         Block_Using_Signals(omask);
 937         sep->se_next = servtab;
 938         servtab = sep;
 939         sigprocmask(SIG_UNBLOCK, &omask, NULL);
 940         return sep;
 941 }
 942
 943 static int matchconf(servtab_t *old, servtab_t *new)
 944 {
 945         if (strcmp(old->se_service, new->se_service) != 0)
 946                 return 0;
 947
 948         if (strcmp(old->se_hostaddr, new->se_hostaddr) != 0)
 949                 return 0;
 950
 951         if (strcmp(old->se_proto, new->se_proto) != 0)
 952                 return 0;
 953
 954         /*
 955          * If the new servtab is bound to a specific address, check that the
 956          * old servtab is bound to the same entry. If the new service is not
 957          * bound to a specific address then the check of se_hostaddr above
 958          * is sufficient.
 959          */
 960
 961         if (old->se_family == AF_INET && new->se_family == AF_INET &&
 962                         memcmp(&old->se_ctrladdr_in.sin_addr,
 963                                         &new->se_ctrladdr_in.sin_addr,
 964                                         sizeof(new->se_ctrladdr_in.sin_addr)) != 0)
 965                 return 0;
 966
 967 #if ENABLE_FEATURE_IPV6
 968         if (old->se_family == AF_INET6 && new->se_family == AF_INET6 &&
 969                         memcmp(&old->se_ctrladdr_in6.sin6_addr,
 970                                         &new->se_ctrladdr_in6.sin6_addr,
 971                                         sizeof(new->se_ctrladdr_in6.sin6_addr)) != 0)
 972                 return 0;
 973 #endif
 974         return 1;
 975 }
 976
 977 static void config(int sig ATTRIBUTE_UNUSED)
 978 {
 979         servtab_t *sep, *cp, **sepp;
 980         sigset_t omask;
 981         size_t n;
 982         char protoname[10];
 983
 984         if (!setconfig()) {
 985                 bb_simple_perror_msg(config_filename);
 986                 return;
 987         }
 988         for (sep = servtab; sep; sep = sep->se_next)
 989                 sep->se_checked = 0;
 990         cp = getconfigent();
 991         while (cp != NULL) {
 992                 for (sep = servtab; sep; sep = sep->se_next)
 993                         if (matchconf(sep, cp))
 994                                 break;
 995
 996                 if (sep != 0) {
 997                         int i;
 998
 999 #define SWAP(type, a, b) do {type c=(type)a; a=(type)b; b=(type)c;} while (0)
1000
1001                         Block_Using_Signals(omask);
1002                         /*
1003                          * sep->se_wait may be holding the pid of a daemon
1004                          * that we're waiting for.  If so, don't overwrite
1005                          * it unless the config file explicitly says don't
1006                          * wait.
1007                          */
1008                         if (
1009 #ifdef INETD_FEATURE_ENABLED
1010                                 cp->se_bi == 0 &&
1011 #endif
1012                                 (sep->se_wait == 1 || cp->se_wait == 0))
1013                                 sep->se_wait = cp->se_wait;
1014                         SWAP(int, cp->se_max, sep->se_max);
1015                         SWAP(char *, sep->se_user, cp->se_user);
1016                         SWAP(char *, sep->se_group, cp->se_group);
1017                         SWAP(char *, sep->se_server, cp->se_server);
1018                         for (i = 0; i < MAXARGV; i++)
1019                                 SWAP(char *, sep->se_argv[i], cp->se_argv[i]);
1020 #undef SWAP
1021
1022 #if ENABLE_FEATURE_INETD_RPC
1023                         if (isrpcservice(sep))
1024                                 unregister_rpc(sep);
1025                         sep->se_rpcversl = cp->se_rpcversl;
1026                         sep->se_rpcversh = cp->se_rpcversh;
1027 #endif
1028                         sigprocmask(SIG_UNBLOCK, &omask, NULL);
1029                         freeconfig(cp);
1030                 } else {
1031                         sep = enter(cp);
1032                 }
1033                 sep->se_checked = 1;
1034
1035                 switch (sep->se_family) {
1036                 case AF_UNIX:
1037                         if (sep->se_fd != -1)
1038                                 break;
1039                         (void) unlink(sep->se_service);
1040                         n = strlen(sep->se_service);
1041                         if (n > sizeof sep->se_ctrladdr_un.sun_path - 1)
1042                                 n = sizeof sep->se_ctrladdr_un.sun_path - 1;
1043                         safe_strncpy(sep->se_ctrladdr_un.sun_path, sep->se_service, n + 1);
1044                         sep->se_ctrladdr_un.sun_family = AF_UNIX;
1045                         sep->se_ctrladdr_size = n + sizeof sep->se_ctrladdr_un.sun_family;
1046                         setup(sep);
1047                         break;
1048                 case AF_INET:
1049                         sep->se_ctrladdr_in.sin_family = AF_INET;
1050                         /* se_ctrladdr_in was set in getconfigent */
1051                         sep->se_ctrladdr_size = sizeof sep->se_ctrladdr_in;
1052
1053 #if ENABLE_FEATURE_INETD_RPC
1054                         if (isrpcservice(sep)) {
1055                                 struct rpcent *rp;
1056                                 // FIXME: atoi_or_else(str, 0) would be handy here
1057                                 sep->se_rpcprog = atoi(sep->se_service);
1058                                 if (sep->se_rpcprog == 0) {
1059                                         rp = getrpcbyname(sep->se_service);
1060                                         if (rp == 0) {
1061                                                 bb_error_msg("%s: unknown rpc service", sep->se_service);
1062                                                 goto serv_unknown;
1063                                         }
1064                                         sep->se_rpcprog = rp->r_number;
1065                                 }
1066                                 if (sep->se_fd == -1)
1067                                         setup(sep);
1068                                 if (sep->se_fd != -1)
1069                                         register_rpc(sep);
1070                         } else
1071 #endif
1072                         {
1073                                 uint16_t port = htons(atoi(sep->se_service));
1074                                 // FIXME: atoi_or_else(str, 0) would be handy here
1075                                 if (!port) {
1076                                          /*XXX*/ strncpy(protoname, sep->se_proto, sizeof(protoname));
1077                                         if (isdigit(protoname[strlen(protoname) - 1]))
1078                                                 protoname[strlen(protoname) - 1] = '\0';
1079                                         sp = getservbyname(sep->se_service, protoname);
1080                                         if (sp == 0) {
1081                                                 bb_error_msg("%s/%s: unknown service",
1082                                                                 sep->se_service, sep->se_proto);
1083                                                 goto serv_unknown;
1084                                         }
1085                                         port = sp->s_port;
1086                                 }
1087                                 if (port != sep->se_ctrladdr_in.sin_port) {
1088                                         sep->se_ctrladdr_in.sin_port = port;
1089                                         if (sep->se_fd != -1) {
1090                                                 FD_CLR(sep->se_fd, &allsock);
1091                                                 nsock--;
1092                                                 (void) close(sep->se_fd);
1093                                         }
1094                                         sep->se_fd = -1;
1095                                 }
1096                                 if (sep->se_fd == -1)
1097                                         setup(sep);
1098                         }
1099                         break;
1100 #if ENABLE_FEATURE_IPV6
1101                 case AF_INET6:
1102                         sep->se_ctrladdr_in6.sin6_family = AF_INET6;
1103                         /* se_ctrladdr_in was set in getconfigent */
1104                         sep->se_ctrladdr_size = sizeof sep->se_ctrladdr_in6;
1105
1106 #if ENABLE_FEATURE_INETD_RPC
1107                         if (isrpcservice(sep)) {
1108                                 struct rpcent *rp;
1109
1110                                 sep->se_rpcprog = atoi(sep->se_service);
1111                                 if (sep->se_rpcprog == 0) {
1112                                         rp = getrpcbyname(sep->se_service);
1113                                         if (rp == 0) {
1114                                                 bb_error_msg("%s: unknown rpc service", sep->se_service);
1115                                                 goto serv_unknown;
1116                                         }
1117                                         sep->se_rpcprog = rp->r_number;
1118                                 }
1119                                 if (sep->se_fd == -1)
1120                                         setup(sep);
1121                                 if (sep->se_fd != -1)
1122                                         register_rpc(sep);
1123                         } else
1124 #endif
1125                         {
1126                                 uint16_t port = htons(atoi(sep->se_service));
1127
1128                                 if (!port) {
1129                                          /*XXX*/ strncpy(protoname, sep->se_proto, sizeof(protoname));
1130                                         if (isdigit(protoname[strlen(protoname) - 1]))
1131                                                 protoname[strlen(protoname) - 1] = '\0';
1132                                         sp = getservbyname(sep->se_service, protoname);
1133                                         if (sp == 0) {
1134                                                 bb_error_msg("%s/%s: unknown service",
1135                                                                 sep->se_service, sep->se_proto);
1136                                                 goto serv_unknown;
1137                                         }
1138                                         port = sp->s_port;
1139                                 }
1140                                 if (port != sep->se_ctrladdr_in6.sin6_port) {
1141                                         sep->se_ctrladdr_in6.sin6_port = port;
1142                                         if (sep->se_fd != -1) {
1143                                                 FD_CLR(sep->se_fd, &allsock);
1144                                                 nsock--;
1145                                                 (void) close(sep->se_fd);
1146                                         }
1147                                         sep->se_fd = -1;
1148                                 }
1149                                 if (sep->se_fd == -1)
1150                                         setup(sep);
1151                         }
1152                         break;
1153 #endif /* FEATURE_IPV6 */
1154                 }
1155  serv_unknown:
1156                 if (cp->se_next != NULL) {
1157                         servtab_t *tmp = cp;
1158
1159                         cp = cp->se_next;
1160                         free(tmp);
1161                 } else {
1162                         free(cp);
1163                         cp = getconfigent();
1164                 }
1165         }
1166         endconfig();
1167         /*
1168          * Purge anything not looked at above.
1169          */
1170         Block_Using_Signals(omask);
1171         sepp = &servtab;
1172         while ((sep = *sepp)) {
1173                 if (sep->se_checked) {
1174                         sepp = &sep->se_next;
1175                         continue;
1176                 }
1177                 *sepp = sep->se_next;
1178                 if (sep->se_fd != -1) {
1179                         FD_CLR(sep->se_fd, &allsock);
1180                         nsock--;
1181                         (void) close(sep->se_fd);
1182                 }
1183 #if ENABLE_FEATURE_INETD_RPC
1184                 if (isrpcservice(sep))
1185                         unregister_rpc(sep);
1186 #endif
1187                 if (sep->se_family == AF_UNIX)
1188                         (void) unlink(sep->se_service);
1189                 freeconfig(sep);
1190                 free(sep);
1191         }
1192         sigprocmask(SIG_UNBLOCK, &omask, NULL);
1193 }
1194
1195
1196 static void reapchild(int sig ATTRIBUTE_UNUSED)
1197 {
1198         pid_t pid;
1199         int save_errno = errno, status;
1200         servtab_t *sep;
1201
1202         for (;;) {
1203                 pid = wait3(&status, WNOHANG, NULL);
1204                 if (pid <= 0)
1205                         break;
1206                 for (sep = servtab; sep; sep = sep->se_next)
1207                         if (sep->se_wait == pid) {
1208                                 if (WIFEXITED(status) && WEXITSTATUS(status))
1209                                         bb_error_msg("%s: exit status 0x%x",
1210                                                         sep->se_server, WEXITSTATUS(status));
1211                                 else if (WIFSIGNALED(status))
1212                                         bb_error_msg("%s: exit signal 0x%x",
1213                                                         sep->se_server, WTERMSIG(status));
1214                                 sep->se_wait = 1;
1215                                 FD_SET(sep->se_fd, &allsock);
1216                                 nsock++;
1217                         }
1218         }
1219         errno = save_errno;
1220 }
1221
1222 static void retry(int sig ATTRIBUTE_UNUSED)
1223 {
1224         servtab_t *sep;
1225
1226         timingout = 0;
1227         for (sep = servtab; sep; sep = sep->se_next) {
1228                 if (sep->se_fd == -1) {
1229                         switch (sep->se_family) {
1230                         case AF_UNIX:
1231                         case AF_INET:
1232 #if ENABLE_FEATURE_IPV6
1233                         case AF_INET6:
1234 #endif
1235                                 setup(sep);
1236 #if ENABLE_FEATURE_INETD_RPC
1237                                 if (sep->se_fd != -1 && isrpcservice(sep))
1238                                         register_rpc(sep);
1239 #endif
1240                                 break;
1241                         }
1242                 }
1243         }
1244 }
1245
1246 static void goaway(int sig ATTRIBUTE_UNUSED)
1247 {
1248         servtab_t *sep;
1249
1250         /* XXX signal race walking sep list */
1251         for (sep = servtab; sep; sep = sep->se_next) {
1252                 if (sep->se_fd == -1)
1253                         continue;
1254
1255                 switch (sep->se_family) {
1256                 case AF_UNIX:
1257                         (void) unlink(sep->se_service);
1258                         break;
1259                 case AF_INET:
1260 #if ENABLE_FEATURE_IPV6
1261                 case AF_INET6:
1262 #endif
1263 #if ENABLE_FEATURE_INETD_RPC
1264                         if (sep->se_wait == 1 && isrpcservice(sep))
1265                                 unregister_rpc(sep);   /* XXX signal race */
1266 #endif
1267                         break;
1268                 }
1269                 (void) close(sep->se_fd);
1270         }
1271         remove_pidfile(_PATH_INETDPID);
1272         exit(0);
1273 }
1274
1275
1276 #ifdef INETD_SETPROCTITLE
1277
1278 static void
1279 inetd_setproctitle(char *a, int s)
1280 {
1281         socklen_t size;
1282         char *cp;
1283         struct sockaddr_in prt_sin;
1284         char buf[80];
1285
1286         cp = Argv[0];
1287         size = sizeof(prt_sin);
1288         (void) snprintf(buf, sizeof buf, "-%s", a);
1289         if (getpeername(s, (struct sockaddr *) &prt_sin, &size) == 0) {
1290                 char *sa = inet_ntoa(prt_sin.sin_addr);
1291
1292                 buf[sizeof(buf) - 1 - strlen(sa) - 3] = '\0';
1293                 strcat(buf, " [");
1294                 strcat(buf, sa);
1295                 strcat(buf, "]");
1296         }
1297         strncpy(cp, buf, LastArg - cp);
1298         cp += strlen(cp);
1299         while (cp < LastArg)
1300                 *cp++ = ' ';
1301 }
1302 #endif
1303
1304
1305 int inetd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1306 int inetd_main(int argc, char **argv)
1307 {
1308         servtab_t *sep;
1309         struct passwd *pwd;
1310         struct group *grp = NULL;
1311         int tmpint;
1312         struct sigaction sa, sapipe;
1313         int opt;
1314         pid_t pid;
1315         char buf[50];
1316         char *stoomany;
1317         sigset_t omask, wait_mask;
1318 #ifdef INETD_SETPROCTITLE
1319         char **envp;
1320 #endif
1321
1322         INIT_G();
1323
1324 #ifdef INETD_SETPROCTITLE
1325         envp = environ;
1326         Argv = argv;
1327         if (envp == 0 || *envp == 0)
1328                 envp = argv;
1329         while (*envp)
1330                 envp++;
1331         LastArg = envp[-1] + strlen(envp[-1]);
1332 #endif
1333
1334         uid = getuid();
1335         if (uid != 0)
1336                 config_filename = NULL;
1337
1338         opt = getopt32(argv, "R:f", &stoomany);
1339         if (opt & 1)
1340                 toomany = xatoi_u(stoomany);
1341         argv += optind;
1342         argc -= optind;
1343         if (argc)
1344                 config_filename = argv[0];
1345         if (config_filename == NULL)
1346                 bb_error_msg_and_die("non-root must specify a config file");
1347
1348         if (!(opt & 2))
1349                 bb_daemonize_or_rexec(0, argv - optind);
1350         else
1351                 bb_sanitize_stdio();
1352         openlog(applet_name, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
1353         logmode = LOGMODE_SYSLOG;
1354
1355         if (uid == 0) {
1356                 /* If run by hand, ensure groups vector gets trashed */
1357                 gid_t gid = getgid();
1358                 setgroups(1, &gid);
1359         }
1360
1361         write_pidfile(_PATH_INETDPID);
1362
1363         if (getrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0) {
1364                 bb_perror_msg("getrlimit");
1365         } else {
1366                 rlim_ofile_cur = rlim_ofile.rlim_cur;
1367                 if (rlim_ofile_cur == RLIM_INFINITY)    /* ! */
1368                         rlim_ofile_cur = OPEN_MAX;
1369         }
1370
1371         memset((char *) &sa, 0, sizeof(sa));
1372         sigemptyset(&sa.sa_mask);
1373         sigaddset(&sa.sa_mask, SIGALRM);
1374         sigaddset(&sa.sa_mask, SIGCHLD);
1375         sigaddset(&sa.sa_mask, SIGHUP);
1376         sa.sa_handler = retry;
1377         sigaction(SIGALRM, &sa, NULL);
1378         config(SIGHUP);
1379         sa.sa_handler = config;
1380         sigaction(SIGHUP, &sa, NULL);
1381         sa.sa_handler = reapchild;
1382         sigaction(SIGCHLD, &sa, NULL);
1383         sa.sa_handler = goaway;
1384         sigaction(SIGTERM, &sa, NULL);
1385         sa.sa_handler = goaway;
1386         sigaction(SIGINT, &sa, NULL);
1387         sa.sa_handler = SIG_IGN;
1388         sigaction(SIGPIPE, &sa, &sapipe);
1389         memset(&wait_mask, 0, sizeof(wait_mask));
1390         {
1391                 /* space for daemons to overwrite environment for ps */
1392 #define DUMMYSIZE       100
1393                 char dummy[DUMMYSIZE];
1394
1395                 (void) memset(dummy, 'x', DUMMYSIZE - 1);
1396                 dummy[DUMMYSIZE - 1] = '\0';
1397
1398                 (void) setenv("inetd_dummy", dummy, 1);
1399         }
1400
1401         for (;;) {
1402                 int n, ctrl = -1;
1403                 fd_set readable;
1404
1405                 if (nsock == 0) {
1406                         Block_Using_Signals(omask);
1407                         while (nsock == 0)
1408                                 sigsuspend(&wait_mask);
1409                         sigprocmask(SIG_UNBLOCK, &omask, NULL);
1410                 }
1411
1412                 readable = allsock;
1413                 n = select(maxsock + 1, &readable, NULL, NULL, NULL);
1414                 if (n <= 0) {
1415                         if (n < 0 && errno != EINTR) {
1416                                 bb_perror_msg("select");
1417                                 sleep(1);
1418                         }
1419                         continue;
1420                 }
1421
1422                 for (sep = servtab; n && sep; sep = sep->se_next) {
1423                         if (sep->se_fd == -1 || !FD_ISSET(sep->se_fd, &readable))
1424                                 continue;
1425
1426                         n--;
1427                         if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) {
1428                                 ctrl = accept(sep->se_fd, NULL, NULL);
1429                                 if (ctrl < 0) {
1430                                         if (errno == EINTR)
1431                                                 continue;
1432                                         bb_perror_msg("accept (for %s)", sep->se_service);
1433                                         continue;
1434                                 }
1435                                 if (sep->se_family == AF_INET && sep->se_socktype == SOCK_STREAM) {
1436                                         struct sockaddr_in peer;
1437                                         socklen_t plen = sizeof(peer);
1438
1439                                         if (getpeername(ctrl, (struct sockaddr *) &peer, &plen) < 0) {
1440                                                 bb_error_msg("cannot getpeername");
1441                                                 close(ctrl);
1442                                                 continue;
1443                                         }
1444                                         if (ntohs(peer.sin_port) == 20) {
1445                                                 /* XXX ftp bounce */
1446                                                 close(ctrl);
1447                                                 continue;
1448                                         }
1449                                 }
1450                         } else
1451                                 ctrl = sep->se_fd;
1452
1453                         Block_Using_Signals(omask);
1454                         pid = 0;
1455 #ifdef INETD_FEATURE_ENABLED
1456                         if (sep->se_bi == 0 || sep->se_bi->bi_fork)
1457 #endif
1458                         {
1459                                 if (sep->se_count++ == 0)
1460                                         (void) gettimeofday(&sep->se_time, NULL);
1461                                 else if (toomany > 0 && sep->se_count >= sep->se_max) {
1462                                         struct timeval now;
1463
1464                                         (void) gettimeofday(&now, NULL);
1465                                         if (now.tv_sec - sep->se_time.tv_sec > CNT_INTVL) {
1466                                                 sep->se_time = now;
1467                                                 sep->se_count = 1;
1468                                         } else {
1469                                                 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
1470                                                         close(ctrl);
1471                                                 if (sep->se_family == AF_INET &&
1472                                                           ntohs(sep->se_ctrladdr_in.sin_port) >= IPPORT_RESERVED) {
1473                                                         /*
1474                                                          * Cannot close it -- there are
1475                                                          * thieves on the system.
1476                                                          * Simply ignore the connection.
1477                                                          */
1478                                                         --sep->se_count;
1479                                                         continue;
1480                                                 }
1481                                                 bb_error_msg("%s/%s server failing (looping), service terminated",
1482                                                               sep->se_service, sep->se_proto);
1483                                                 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
1484                                                         close(ctrl);
1485                                                 FD_CLR(sep->se_fd, &allsock);
1486                                                 (void) close(sep->se_fd);
1487                                                 sep->se_fd = -1;
1488                                                 sep->se_count = 0;
1489                                                 nsock--;
1490                                                 sigprocmask(SIG_UNBLOCK, &omask, NULL);
1491                                                 if (!timingout) {
1492                                                         timingout = 1;
1493                                                         alarm(RETRYTIME);
1494                                                 }
1495                                                 continue;
1496                                         }
1497                                 }
1498                                 pid = fork();
1499                         }
1500                         if (pid < 0) {
1501                                 bb_perror_msg("fork");
1502                                 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
1503                                         close(ctrl);
1504                                 sigprocmask(SIG_UNBLOCK, &omask, NULL);
1505                                 sleep(1);
1506                                 continue;
1507                         }
1508                         if (pid && sep->se_wait) {
1509                                 sep->se_wait = pid;
1510                                 FD_CLR(sep->se_fd, &allsock);
1511                                 nsock--;
1512                         }
1513                         sigprocmask(SIG_UNBLOCK, &omask, NULL);
1514                         if (pid == 0) {
1515 #ifdef INETD_FEATURE_ENABLED
1516                                 if (sep->se_bi) {
1517                                         (*sep->se_bi->bi_fn)(ctrl, sep);
1518                                 } else
1519 #endif
1520                                 {
1521                                         pwd = getpwnam(sep->se_user);
1522                                         if (pwd == NULL) {
1523                                                 bb_error_msg("getpwnam: %s: no such user", sep->se_user);
1524                                                 goto do_exit1;
1525                                         }
1526                                         if (setsid() < 0)
1527                                                 bb_perror_msg("%s: setsid", sep->se_service);
1528                                         if (sep->se_group && (grp = getgrnam(sep->se_group)) == NULL) {
1529                                                 bb_error_msg("getgrnam: %s: no such group", sep->se_group);
1530                                                 goto do_exit1;
1531                                         }
1532                                         if (uid != 0) {
1533                                                 /* a user running private inetd */
1534                                                 if (uid != pwd->pw_uid)
1535                                                         _exit(1);
1536                                         } else if (pwd->pw_uid) {
1537                                                 if (sep->se_group)
1538                                                         pwd->pw_gid = grp->gr_gid;
1539                                                 xsetgid((gid_t) pwd->pw_gid);
1540                                                 initgroups(pwd->pw_name, pwd->pw_gid);
1541                                                 xsetuid((uid_t) pwd->pw_uid);
1542                                         } else if (sep->se_group) {
1543                                                 xsetgid(grp->gr_gid);
1544                                                 setgroups(1, &grp->gr_gid);
1545                                         }
1546                                         dup2(ctrl, 0);
1547                                         if (ctrl) close(ctrl);
1548                                         dup2(0, 1);
1549                                         dup2(0, 2);
1550                                         if (rlim_ofile.rlim_cur != rlim_ofile_cur)
1551                                                 if (setrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0)
1552                                                         bb_perror_msg("setrlimit");
1553                                         closelog();
1554                                         for (tmpint = rlim_ofile_cur - 1; --tmpint > 2;)
1555                                                 (void) close(tmpint);
1556                                         sigaction(SIGPIPE, &sapipe, NULL);
1557                                         execv(sep->se_server, sep->se_argv);
1558                                         bb_perror_msg("execv %s", sep->se_server);
1559  do_exit1:
1560                                         if (sep->se_socktype != SOCK_STREAM)
1561                                                 recv(0, buf, sizeof(buf), 0);
1562                                         _exit(1);
1563                                 }
1564                         }
1565                         if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
1566                                 close(ctrl);
1567                 } /* for (sep = servtab...) */
1568         } /* for (;;) */
1569 }
1570
1571 /*
1572  * Internet services provided internally by inetd:
1573  */
1574 #define BUFSIZE 4096
1575
1576 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO || \
1577         ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN || \
1578         ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
1579 static int dg_badinput(struct sockaddr_in *dg_sin)
1580 {
1581         if (ntohs(dg_sin->sin_port) < IPPORT_RESERVED)
1582                 return 1;
1583         if (dg_sin->sin_addr.s_addr == htonl(INADDR_BROADCAST))
1584                 return 1;
1585         /* XXX compare against broadcast addresses in SIOCGIFCONF list? */
1586         return 0;
1587 }
1588 #endif
1589
1590 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
1591 /* Echo service -- echo data back */
1592 /* ARGSUSED */
1593 static void
1594 echo_stream(int s, servtab_t *sep)
1595 {
1596         char buffer[BUFSIZE];
1597         int i;
1598
1599         inetd_setproctitle(sep->se_service, s);
1600         while (1) {
1601                 i = read(s, buffer, sizeof(buffer));
1602                 if (i <= 0) break;
1603                 /* FIXME: this isnt correct - safe_write()? */
1604                 if (write(s, buffer, i) <= 0) break;
1605         }
1606         exit(0);
1607 }
1608
1609 /* Echo service -- echo data back */
1610 /* ARGSUSED */
1611 static void
1612 echo_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1613 {
1614         char buffer[BUFSIZE];
1615         int i;
1616         socklen_t size;
1617         /* struct sockaddr_storage ss; */
1618         struct sockaddr sa;
1619
1620         size = sizeof(sa);
1621         i = recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size);
1622         if (i < 0)
1623                 return;
1624         if (dg_badinput((struct sockaddr_in *) &sa))
1625                 return;
1626         (void) sendto(s, buffer, i, 0, &sa, sizeof(sa));
1627 }
1628 #endif  /* FEATURE_INETD_SUPPORT_BUILTIN_ECHO */
1629
1630 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
1631 /* Discard service -- ignore data */
1632 /* ARGSUSED */
1633 static void
1634 discard_stream(int s, servtab_t *sep)
1635 {
1636         char buffer[BUFSIZE];
1637
1638         inetd_setproctitle(sep->se_service, s);
1639         while (1) {
1640                 if (safe_read(s, buffer, sizeof(buffer)) <= 0)
1641                         exit(0);
1642         }
1643 }
1644
1645 /* Discard service -- ignore data */
1646 /* ARGSUSED */
1647 static void
1648 discard_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1649 {
1650         char buffer[BUFSIZE];
1651
1652         (void) read(s, buffer, sizeof(buffer));
1653 }
1654 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_DISCARD */
1655
1656
1657 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
1658 #define LINESIZ 72
1659
1660 static void
1661 initring(void)
1662 {
1663         int i;
1664
1665         endring = ring;
1666         for (i = 0; i <= 128; ++i)
1667                 if (isprint(i))
1668                         *endring++ = i;
1669 }
1670
1671 /* Character generator */
1672 /* ARGSUSED */
1673 static void
1674 chargen_stream(int s, servtab_t *sep)
1675 {
1676         char *rs;
1677         int len;
1678         char text[LINESIZ + 2];
1679
1680         inetd_setproctitle(sep->se_service, s);
1681
1682         if (!endring) {
1683                 initring();
1684                 rs = ring;
1685         }
1686
1687         text[LINESIZ] = '\r';
1688         text[LINESIZ + 1] = '\n';
1689         rs = ring;
1690         for (;;) {
1691                 len = endring - rs;
1692                 if (len >= LINESIZ)
1693                         memmove(text, rs, LINESIZ);
1694                 else {
1695                         memmove(text, rs, len);
1696                         memmove(text + len, ring, LINESIZ - len);
1697                 }
1698                 if (++rs == endring)
1699                         rs = ring;
1700                 if (write(s, text, sizeof(text)) != sizeof(text))
1701                         break;
1702         }
1703         exit(0);
1704 }
1705
1706 /* Character generator */
1707 /* ARGSUSED */
1708 static void
1709 chargen_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1710 {
1711         /* struct sockaddr_storage ss; */
1712         struct sockaddr sa;
1713         int len;
1714         char text[LINESIZ + 2];
1715         socklen_t size;
1716
1717         if (!endring) {
1718                 initring();
1719                 ringpos = ring;
1720         }
1721
1722         size = sizeof(sa);
1723         if (recvfrom(s, text, sizeof(text), 0, &sa, &size) < 0)
1724                 return;
1725         if (dg_badinput((struct sockaddr_in *) &sa))
1726                 return;
1727
1728         len = endring - ringpos;
1729         if (len >= LINESIZ)
1730                 memmove(text, ringpos, LINESIZ);
1731         else {
1732                 memmove(text, ringpos, len);
1733                 memmove(text + len, ring, LINESIZ - len);
1734         }
1735         if (++ringpos == endring)
1736                 ringpos = ring;
1737         text[LINESIZ] = '\r';
1738         text[LINESIZ + 1] = '\n';
1739         (void) sendto(s, text, sizeof(text), 0, &sa, sizeof(sa));
1740 }
1741 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN */
1742
1743
1744 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
1745 /*
1746  * Return a machine readable date and time, in the form of the
1747  * number of seconds since midnight, Jan 1, 1900.  Since gettimeofday
1748  * returns the number of seconds since midnight, Jan 1, 1970,
1749  * we must add 2208988800 seconds to this figure to make up for
1750  * some seventy years Bell Labs was asleep.
1751  */
1752
1753 static unsigned machtime(void)
1754 {
1755         struct timeval tv;
1756
1757         if (gettimeofday(&tv, NULL) < 0) {
1758                 fprintf(stderr, "Unable to get time of day\n");
1759                 return 0L;
1760         }
1761         return htonl((unsigned) tv.tv_sec + 2208988800UL);
1762 }
1763
1764 /* ARGSUSED */
1765 static void
1766 machtime_stream(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1767 {
1768         unsigned result;
1769
1770         result = machtime();
1771         (void) write(s, (char *) &result, sizeof(result));
1772 }
1773
1774 /* ARGSUSED */
1775 static void
1776 machtime_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1777 {
1778         unsigned result;
1779         /* struct sockaddr_storage ss; */
1780         struct sockaddr sa;
1781         struct sockaddr_in *dg_sin;
1782         socklen_t size;
1783
1784         size = sizeof(sa);
1785         if (recvfrom(s, (char *) &result, sizeof(result), 0, &sa, &size) < 0)
1786                 return;
1787         /* if (dg_badinput((struct sockaddr *)&ss)) */
1788         dg_sin = (struct sockaddr_in *) &sa;
1789         if (dg_sin->sin_addr.s_addr == htonl(INADDR_BROADCAST) ||
1790                         ntohs(dg_sin->sin_port) < IPPORT_RESERVED / 2)
1791                 return;
1792         result = machtime();
1793         (void) sendto(s, (char *) &result, sizeof(result), 0, &sa, sizeof(sa));
1794 }
1795 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_TIME */
1796
1797
1798 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
1799 /* Return human-readable time of day */
1800 /* ARGSUSED */
1801 static void daytime_stream(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1802 {
1803         char buffer[32];
1804         time_t t;
1805
1806         t = time(NULL);
1807
1808 // fdprintf instead?
1809         (void) sprintf(buffer, "%.24s\r\n", ctime(&t));
1810         (void) write(s, buffer, strlen(buffer));
1811 }
1812
1813 /* Return human-readable time of day */
1814 /* ARGSUSED */
1815 void
1816 daytime_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1817 {
1818         char buffer[256];
1819         time_t t;
1820         /* struct sockaddr_storage ss; */
1821         struct sockaddr sa;
1822         socklen_t size;
1823
1824         t = time(NULL);
1825
1826         size = sizeof(sa);
1827         if (recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size) < 0)
1828                 return;
1829         if (dg_badinput((struct sockaddr_in *) &sa))
1830                 return;
1831         (void) sprintf(buffer, "%.24s\r\n", ctime(&t));
1832         (void) sendto(s, buffer, strlen(buffer), 0, &sa, sizeof(sa));
1833 }
1834 #endif /* FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME */