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 /*
  40  * Inetd - Internet super-server
  41  *
  42  * This program invokes all internet services as needed.
  43  * connection-oriented services are invoked each time a
  44  * connection is made, by creating a process.  This process
  45  * is passed the connection as file descriptor 0 and is
  46  * expected to do a getpeername to find out the source host
  47  * and port.
  48  *
  49  * Datagram oriented services are invoked when a datagram
  50  * arrives; a process is created and passed a pending message
  51  * on file descriptor 0.  Datagram servers may either connect
  52  * to their peer, freeing up the original socket for inetd
  53  * to receive further messages on, or ``take over the socket'',
  54  * processing all arriving datagrams and, eventually, timing
  55  * out.  The first type of server is said to be ``multi-threaded'';
  56  * the second type of server ``single-threaded''.
  57  *
  58  * Inetd uses a configuration file which is read at startup
  59  * and, possibly, at some later time in response to a hangup signal.
  60  * The configuration file is ``free format'' with fields given in the
  61  * order shown below.  Continuation lines for an entry must begin with
  62  * a space or tab.  All fields must be present in each entry.
  63  *
  64  *      service name                    must be in /etc/services
  65  *      socket type                     stream/dgram/raw/rdm/seqpacket
  66  *      protocol                        must be in /etc/protocols
  67  *      wait/nowait[.max]               single-threaded/multi-threaded, max #
  68  *      user[.group] or user[:group]    user/group to run daemon as
  69  *      server program                  full path name
  70  *      server program arguments        maximum of MAXARGS (20)
  71  *
  72  * For RPC services
  73  *      service name/version            must be in /etc/rpc
  74  *      socket type                     stream/dgram/raw/rdm/seqpacket
  75  *      protocol                        must be in /etc/protocols
  76  *      wait/nowait[.max]               single-threaded/multi-threaded
  77  *      user[.group] or user[:group]    user to run daemon as
  78  *      server program                  full path name
  79  *      server program arguments        maximum of MAXARGS (20)
  80  *
  81  * For non-RPC services, the "service name" can be of the form
  82  * hostaddress:servicename, in which case the hostaddress is used
  83  * as the host portion of the address to listen on.  If hostaddress
  84  * consists of a single `*' character, INADDR_ANY is used.
  85  *
  86  * A line can also consist of just
  87  *      hostaddress:
  88  * where hostaddress is as in the preceding paragraph.  Such a line must
  89  * have no further fields; the specified hostaddress is remembered and
  90  * used for all further lines that have no hostaddress specified,
  91  * until the next such line (or EOF).  (This is why * is provided to
  92  * allow explicit specification of INADDR_ANY.)  A line
  93  *      *:
  94  * is implicitly in effect at the beginning of the file.
  95  *
  96  * The hostaddress specifier may (and often will) contain dots;
  97  * the service name must not.
  98  *
  99  * For RPC services, host-address specifiers are accepted and will
 100  * work to some extent; however, because of limitations in the
 101  * portmapper interface, it will not work to try to give more than
 102  * one line for any given RPC service, even if the host-address
 103  * specifiers are different.
 104  *
 105  * Comment lines are indicated by a `#' in column 1.
 106  */
 107
 108 /*
 109  * Here's the scoop concerning the user[.:]group feature:
 110  *
 111  * 1) set-group-option off.
 112  *
 113  *      a) user = root: NO setuid() or setgid() is done
 114  *
 115  *      b) other:       setgid(primary group as found in passwd)
 116  *                      initgroups(name, primary group)
 117  *                      setuid()
 118  *
 119  * 2) set-group-option on.
 120  *
 121  *      a) user = root: setgid(specified group)
 122  *                      NO initgroups()
 123  *                      NO setuid()
 124  *
 125  *      b) other:       setgid(specified group)
 126  *                      initgroups(name, specified group)
 127  *                      setuid()
 128  *
 129  */
 130
 131 #include "busybox.h"
 132 #include <syslog.h>
 133 #include <sys/un.h>
 134
 135 //#define CONFIG_FEATURE_INETD_RPC
 136 //#define CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
 137 //#define CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
 138 //#define CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_TIME
 139 //#define CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
 140 //#define CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
 141 //#define CONFIG_FEATURE_IPV6
 142
 143 #ifdef CONFIG_FEATURE_INETD_RPC
 144 #include <rpc/rpc.h>
 145 #include <rpc/pmap_clnt.h>
 146 #endif
 147
 148 #define _PATH_INETDCONF "/etc/inetd.conf"
 149 #define _PATH_INETDPID  "/var/run/inetd.pid"
 150
 151
 152 #define TOOMANY         0               /* don't start more than TOOMANY */
 153
 154 #define CNT_INTVL       60              /* servers in CNT_INTVL sec. */
 155 #define RETRYTIME       (60*10)         /* retry after bind or server fail */
 156
 157 #ifndef RLIMIT_NOFILE
 158 #define RLIMIT_NOFILE   RLIMIT_OFILE
 159 #endif
 160
 161 #ifndef OPEN_MAX
 162 #define OPEN_MAX        64
 163 #endif
 164
 165 /* Reserve some descriptors, 3 stdio + at least: 1 log, 1 conf. file */
 166 #define FD_MARGIN       (8)
 167 static rlim_t rlim_ofile_cur = OPEN_MAX;
 168 static struct rlimit rlim_ofile;
 169
 170
 171 /* Check unsupporting builtin */
 172 #if defined CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_ECHO || \
 173                 defined CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD || \
 174                 defined CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_TIME || \
 175                 defined CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME || \
 176                 defined CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
 177 # define INETD_FEATURE_ENABLED
 178 #endif
 179
 180 #if defined CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_ECHO || \
 181                 defined CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD || \
 182                 defined CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
 183 # define INETD_SETPROCTITLE
 184 #endif
 185
 186 typedef struct servtab {
 187         char *se_hostaddr;                    /* host address to listen on */
 188         char *se_service;                     /* name of service */
 189         int se_socktype;                      /* type of socket to use */
 190         int se_family;                        /* address family */
 191         char *se_proto;                       /* protocol used */
 192 #ifdef CONFIG_FEATURE_INETD_RPC
 193         int se_rpcprog;                       /* rpc program number */
 194         int se_rpcversl;                      /* rpc program lowest version */
 195         int se_rpcversh;                      /* rpc program highest version */
 196 #define isrpcservice(sep)       ((sep)->se_rpcversl != 0)
 197 #else
 198 #define isrpcservice(sep)       0
 199 #endif
 200         pid_t se_wait;                        /* single threaded server */
 201         short se_checked;                     /* looked at during merge */
 202         char *se_user;                        /* user name to run as */
 203         char *se_group;                       /* group name to run as */
 204 #ifdef INETD_FEATURE_ENABLED
 205         const struct builtin *se_bi;          /* if built-in, description */
 206 #endif
 207         char *se_server;                      /* server program */
 208 #define MAXARGV 20
 209         char *se_argv[MAXARGV + 1];           /* program arguments */
 210         int se_fd;                            /* open descriptor */
 211         union {
 212                 struct sockaddr se_un_ctrladdr;
 213                 struct sockaddr_in se_un_ctrladdr_in;
 214 #ifdef CONFIG_FEATURE_IPV6
 215                 struct sockaddr_in6 se_un_ctrladdr_in6;
 216 #endif
 217                 struct sockaddr_un se_un_ctrladdr_un;
 218         } se_un;                              /* bound address */
 219 #define se_ctrladdr     se_un.se_un_ctrladdr
 220 #define se_ctrladdr_in  se_un.se_un_ctrladdr_in
 221 #define se_ctrladdr_in6 se_un.se_un_ctrladdr_in6
 222 #define se_ctrladdr_un  se_un.se_un_ctrladdr_un
 223         int se_ctrladdr_size;
 224         int se_max;                           /* max # of instances of this service */
 225         int se_count;                         /* number started since se_time */
 226         struct timeval se_time;               /* start of se_count */
 227         struct servtab *se_next;
 228 } servtab_t;
 229
 230 static servtab_t *servtab;
 231
 232 #ifdef INETD_FEATURE_ENABLED
 233 struct builtin {
 234         const char *bi_service;               /* internally provided service name */
 235         int bi_socktype;                      /* type of socket supported */
 236         short bi_fork;                        /* 1 if should fork before call */
 237         short bi_wait;                        /* 1 if should wait for child */
 238         void (*bi_fn) (int, servtab_t *);
 239 };
 240
 241                 /* Echo received data */
 242 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
 243 static void echo_stream(int, servtab_t *);
 244 static void echo_dg(int, servtab_t *);
 245 #endif
 246                 /* Internet /dev/null */
 247 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
 248 static void discard_stream(int, servtab_t *);
 249 static void discard_dg(int, servtab_t *);
 250 #endif
 251                 /* Return 32 bit time since 1900 */
 252 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_TIME
 253 static void machtime_stream(int, servtab_t *);
 254 static void machtime_dg(int, servtab_t *);
 255 #endif
 256                 /* Return human-readable time */
 257 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
 258 static void daytime_stream(int, servtab_t *);
 259 static void daytime_dg(int, servtab_t *);
 260 #endif
 261                 /* Familiar character generator */
 262 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
 263 static void chargen_stream(int, servtab_t *);
 264 static void chargen_dg(int, servtab_t *);
 265 #endif
 266
 267 static const struct builtin builtins[] = {
 268 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
 269         /* Echo received data */
 270         {"echo", SOCK_STREAM, 1, 0, echo_stream,},
 271         {"echo", SOCK_DGRAM, 0, 0, echo_dg,},
 272 #endif
 273 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
 274         /* Internet /dev/null */
 275         {"discard", SOCK_STREAM, 1, 0, discard_stream,},
 276         {"discard", SOCK_DGRAM, 0, 0, discard_dg,},
 277 #endif
 278 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_TIME
 279         /* Return 32 bit time since 1900 */
 280         {"time", SOCK_STREAM, 0, 0, machtime_stream,},
 281         {"time", SOCK_DGRAM, 0, 0, machtime_dg,},
 282 #endif
 283 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
 284         /* Return human-readable time */
 285         {"daytime", SOCK_STREAM, 0, 0, daytime_stream,},
 286         {"daytime", SOCK_DGRAM, 0, 0, daytime_dg,},
 287 #endif
 288 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
 289         /* Familiar character generator */
 290         {"chargen", SOCK_STREAM, 1, 0, chargen_stream,},
 291         {"chargen", SOCK_DGRAM, 0, 0, chargen_dg,},
 292 #endif
 293         {NULL, 0, 0, 0, NULL}
 294 };
 295 #endif /* INETD_FEATURE_ENABLED */
 296
 297 static int global_queuelen = 128;
 298 static int nsock, maxsock;
 299 static fd_set allsock;
 300 static int toomany = TOOMANY;
 301 static int timingout;
 302 static struct servent *sp;
 303 static uid_t uid;
 304
 305 static char *CONFIG = _PATH_INETDCONF;
 306
 307 static FILE *fconfig;
 308 static char line[1024];
 309 static char *defhost;
 310
 311 /* xstrdup(NULL) returns NULL, but this one
 312  * will return newly-allocated "" if called with NULL arg
 313  * TODO: audit whether this makes any real difference
 314  */
 315 static char *xxstrdup(char *cp)
 316 {
 317         return xstrdup(cp ? cp : "");
 318 }
 319
 320 static int setconfig(void)
 321 {
 322         free(defhost);
 323         defhost = xstrdup("*");
 324         if (fconfig != NULL) {
 325                 fseek(fconfig, 0L, SEEK_SET);
 326                 return 1;
 327         }
 328         fconfig = fopen(CONFIG, "r");
 329         return (fconfig != NULL);
 330 }
 331
 332 static void endconfig(void)
 333 {
 334         if (fconfig) {
 335                 (void) fclose(fconfig);
 336                 fconfig = NULL;
 337         }
 338         free(defhost);
 339         defhost = 0;
 340 }
 341
 342 #ifdef CONFIG_FEATURE_INETD_RPC
 343 static void register_rpc(servtab_t *sep)
 344 {
 345         int n;
 346         struct sockaddr_in ir_sin;
 347         struct protoent *pp;
 348         socklen_t size;
 349
 350         if ((pp = getprotobyname(sep->se_proto + 4)) == NULL) {
 351                 bb_perror_msg("%s: getproto", sep->se_proto);
 352                 return;
 353         }
 354         size = sizeof ir_sin;
 355         if (getsockname(sep->se_fd, (struct sockaddr *) &ir_sin, &size) < 0) {
 356                 bb_perror_msg("%s/%s: getsockname",
 357                                 sep->se_service, sep->se_proto);
 358                 return;
 359         }
 360
 361         for (n = sep->se_rpcversl; n <= sep->se_rpcversh; n++) {
 362                 (void) pmap_unset(sep->se_rpcprog, n);
 363                 if (!pmap_set(sep->se_rpcprog, n, pp->p_proto, ntohs(ir_sin.sin_port)))
 364                         bb_perror_msg("%s %s: pmap_set: %u %u %u %u",
 365                                         sep->se_service, sep->se_proto,
 366                                         sep->se_rpcprog, n, pp->p_proto, ntohs(ir_sin.sin_port));
 367         }
 368 }
 369
 370 static void unregister_rpc(servtab_t *sep)
 371 {
 372         int n;
 373
 374         for (n = sep->se_rpcversl; n <= sep->se_rpcversh; n++) {
 375                 if (!pmap_unset(sep->se_rpcprog, n))
 376                         bb_error_msg("pmap_unset(%u, %u)", sep->se_rpcprog, n);
 377         }
 378 }
 379 #endif /* CONFIG_FEATURE_INETD_RPC */
 380
 381 static void freeconfig(servtab_t *cp)
 382 {
 383         int i;
 384
 385         free(cp->se_hostaddr);
 386         free(cp->se_service);
 387         free(cp->se_proto);
 388         free(cp->se_user);
 389         free(cp->se_group);
 390         free(cp->se_server);
 391         for (i = 0; i < MAXARGV; i++)
 392                 free(cp->se_argv[i]);
 393 }
 394
 395 static int bump_nofile (void)
 396 {
 397 #define FD_CHUNK        32
 398
 399         struct rlimit rl;
 400
 401         if (getrlimit (RLIMIT_NOFILE, &rl) < 0) {
 402                 bb_perror_msg("getrlimit");
 403                 return -1;
 404         }
 405         rl.rlim_cur = MIN(rl.rlim_max, rl.rlim_cur + FD_CHUNK);
 406         rl.rlim_cur = MIN(FD_SETSIZE, rl.rlim_cur + FD_CHUNK);
 407         if (rl.rlim_cur <= rlim_ofile_cur) {
 408                 bb_error_msg("bump_nofile: cannot extend file limit, max = %d",
 409                                                 (int) rl.rlim_cur);
 410                 return -1;
 411         }
 412
 413         if (setrlimit(RLIMIT_NOFILE, &rl) < 0) {
 414                 bb_perror_msg("setrlimit");
 415                 return -1;
 416         }
 417
 418         rlim_ofile_cur = rl.rlim_cur;
 419         return 0;
 420 }
 421
 422 static void setup(servtab_t *sep)
 423 {
 424         int on = 1;
 425         int r;
 426
 427         sep->se_fd = socket(sep->se_family, sep->se_socktype, 0);
 428         if (sep->se_fd < 0) {
 429                 bb_perror_msg("%s/%s: socket", sep->se_service, sep->se_proto);
 430                 return;
 431         }
 432 #define turnon(fd, opt) \
 433 setsockopt(fd, SOL_SOCKET, opt, (char *)&on, sizeof(on))
 434         if (turnon(sep->se_fd, SO_REUSEADDR) < 0)
 435                 bb_perror_msg("setsockopt(SO_REUSEADDR)");
 436 #undef turnon
 437
 438 #ifdef CONFIG_FEATURE_INETD_RPC
 439         if (isrpcservice(sep)) {
 440                 struct passwd *pwd;
 441
 442                 /*
 443                  * for RPC services, attempt to use a reserved port
 444                  * if they are going to be running as root.
 445                  *
 446                  * Also, zero out the port for all RPC services; let bind()
 447                  * find one.
 448                  */
 449                 sep->se_ctrladdr_in.sin_port = 0;
 450                 if (sep->se_user && (pwd = getpwnam(sep->se_user)) &&
 451                                 pwd->pw_uid == 0 && uid == 0)
 452                         r = bindresvport(sep->se_fd, &sep->se_ctrladdr_in);
 453                 else {
 454                         r = bind(sep->se_fd, &sep->se_ctrladdr, sep->se_ctrladdr_size);
 455                         if (r == 0) {
 456                                 socklen_t len = sep->se_ctrladdr_size;
 457                                 int saveerrno = errno;
 458
 459                                 /* update se_ctrladdr_in.sin_port */
 460                                 r = getsockname(sep->se_fd, &sep->se_ctrladdr, &len);
 461                                 if (r <= 0)
 462                                         errno = saveerrno;
 463                         }
 464                 }
 465         } else
 466 #endif
 467                 r = bind(sep->se_fd, &sep->se_ctrladdr, sep->se_ctrladdr_size);
 468         if (r < 0) {
 469                 bb_perror_msg("%s/%s (%d): bind",
 470                                 sep->se_service, sep->se_proto, sep->se_ctrladdr.sa_family);
 471                 close(sep->se_fd);
 472                 sep->se_fd = -1;
 473                 if (!timingout) {
 474                         timingout = 1;
 475                         alarm(RETRYTIME);
 476                 }
 477                 return;
 478         }
 479         if (sep->se_socktype == SOCK_STREAM)
 480                 listen(sep->se_fd, global_queuelen);
 481
 482         FD_SET(sep->se_fd, &allsock);
 483         nsock++;
 484         if (sep->se_fd > maxsock) {
 485                 maxsock = sep->se_fd;
 486                 if ((rlim_t)maxsock > rlim_ofile_cur - FD_MARGIN)
 487                         bump_nofile();
 488         }
 489 }
 490
 491 static char *nextline(void)
 492 {
 493         char *cp;
 494         FILE *fd = fconfig;
 495
 496         if (fgets(line, sizeof(line), fd) == NULL)
 497                 return NULL;
 498         cp = strchr(line, '\n');
 499         if (cp)
 500                 *cp = '\0';
 501         return line;
 502 }
 503
 504 static char *skip(char **cpp) /* int report; */
 505 {
 506         char *cp = *cpp;
 507         char *start;
 508
 509 /* erp: */
 510         if (*cpp == NULL) {
 511                 /* if (report) */
 512                 /* bb_error_msg("syntax error in inetd config file"); */
 513                 return NULL;
 514         }
 515
 516 again:
 517         while (*cp == ' ' || *cp == '\t')
 518                 cp++;
 519         if (*cp == '\0') {
 520                 int c;
 521
 522                 c = getc(fconfig);
 523                 (void) ungetc(c, fconfig);
 524                 if (c == ' ' || c == '\t')
 525                         if ((cp = nextline()))
 526                                 goto again;
 527                 *cpp = NULL;
 528                 /* goto erp; */
 529                 return NULL;
 530         }
 531         start = cp;
 532         while (*cp && *cp != ' ' && *cp != '\t')
 533                 cp++;
 534         if (*cp != '\0')
 535                 *cp++ = '\0';
 536         /* if ((*cpp = cp) == NULL) */
 537         /* goto erp; */
 538
 539         *cpp = cp;
 540         return start;
 541 }
 542
 543 static servtab_t *new_servtab(void)
 544 {
 545         return xmalloc(sizeof(servtab_t));
 546 }
 547
 548 static servtab_t *dupconfig(servtab_t *sep)
 549 {
 550         servtab_t *newtab;
 551         int argc;
 552
 553         newtab = new_servtab();
 554         memset(newtab, 0, sizeof(servtab_t));
 555         newtab->se_service = xstrdup(sep->se_service);
 556         newtab->se_socktype = sep->se_socktype;
 557         newtab->se_family = sep->se_family;
 558         newtab->se_proto = xstrdup(sep->se_proto);
 559 #ifdef CONFIG_FEATURE_INETD_RPC
 560         newtab->se_rpcprog = sep->se_rpcprog;
 561         newtab->se_rpcversl = sep->se_rpcversl;
 562         newtab->se_rpcversh = sep->se_rpcversh;
 563 #endif
 564         newtab->se_wait = sep->se_wait;
 565         newtab->se_user = xstrdup(sep->se_user);
 566         newtab->se_group = xstrdup(sep->se_group);
 567 #ifdef INETD_FEATURE_ENABLED
 568         newtab->se_bi = sep->se_bi;
 569 #endif
 570         newtab->se_server = xstrdup(sep->se_server);
 571
 572         for (argc = 0; argc <= MAXARGV; argc++)
 573                 newtab->se_argv[argc] = xstrdup(sep->se_argv[argc]);
 574         newtab->se_max = sep->se_max;
 575
 576         return newtab;
 577 }
 578
 579 static servtab_t *getconfigent(void)
 580 {
 581         servtab_t *sep;
 582         int argc;
 583         char *cp, *arg;
 584         char *hostdelim;
 585         servtab_t *nsep;
 586         servtab_t *psep;
 587
 588         sep = new_servtab();
 589
 590         /* memset(sep, 0, sizeof *sep); */
 591 more:
 592         /* freeconfig(sep); */
 593
 594         while ((cp = nextline()) && *cp == '#');
 595         if (cp == NULL) {
 596                 /* free(sep); */
 597                 return NULL;
 598         }
 599
 600         memset((char *) sep, 0, sizeof *sep);
 601         arg = skip(&cp);
 602         if (arg == NULL) {
 603                 /* A blank line. */
 604                 goto more;
 605         }
 606
 607         /* Check for a host name. */
 608         hostdelim = strrchr(arg, ':');
 609         if (hostdelim) {
 610                 *hostdelim = '\0';
 611                 sep->se_hostaddr = xstrdup(arg);
 612                 arg = hostdelim + 1;
 613                 /*
 614                  * If the line is of the form `host:', then just change the
 615                  * default host for the following lines.
 616                  */
 617                 if (*arg == '\0') {
 618                         arg = skip(&cp);
 619                         if (cp == NULL) {
 620                                 free(defhost);
 621                                 defhost = sep->se_hostaddr;
 622                                 goto more;
 623                         }
 624                 }
 625         } else
 626                 sep->se_hostaddr = xxstrdup(defhost);
 627
 628         sep->se_service = xxstrdup(arg);
 629         arg = skip(&cp);
 630
 631         if (strcmp(arg, "stream") == 0)
 632                 sep->se_socktype = SOCK_STREAM;
 633         else if (strcmp(arg, "dgram") == 0)
 634                 sep->se_socktype = SOCK_DGRAM;
 635         else if (strcmp(arg, "rdm") == 0)
 636                 sep->se_socktype = SOCK_RDM;
 637         else if (strcmp(arg, "seqpacket") == 0)
 638                 sep->se_socktype = SOCK_SEQPACKET;
 639         else if (strcmp(arg, "raw") == 0)
 640                 sep->se_socktype = SOCK_RAW;
 641         else
 642                 sep->se_socktype = -1;
 643
 644         sep->se_proto = xxstrdup(skip(&cp));
 645
 646         if (strcmp(sep->se_proto, "unix") == 0) {
 647                 sep->se_family = AF_UNIX;
 648         } else {
 649                 sep->se_family = AF_INET;
 650                 if (sep->se_proto[strlen(sep->se_proto) - 1] == '6')
 651 #ifdef CONFIG_FEATURE_IPV6
 652                         sep->se_family = AF_INET6;
 653 #else
 654                         bb_error_msg("%s: IPV6 not supported", sep->se_proto);
 655 #endif
 656                 if (strncmp(sep->se_proto, "rpc/", 4) == 0) {
 657 #ifdef CONFIG_FEATURE_INETD_RPC
 658                         char *p, *ccp;
 659                         long l;
 660
 661                         p = strchr(sep->se_service, '/');
 662                         if (p == 0) {
 663                                 bb_error_msg("%s: no rpc version", sep->se_service);
 664                                 goto more;
 665                         }
 666                         *p++ = '\0';
 667                         l = strtol(p, &ccp, 0);
 668                         if (ccp == p || l < 0 || l > INT_MAX) {
 669                         badafterall:
 670                                 bb_error_msg("%s/%s: bad rpc version", sep->se_service, p);
 671                                 goto more;
 672                         }
 673                         sep->se_rpcversl = sep->se_rpcversh = l;
 674                         if (*ccp == '-') {
 675                                 p = ccp + 1;
 676                                 l = strtol(p, &ccp, 0);
 677                                 if (ccp == p || l < 0 || l > INT_MAX || l < sep->se_rpcversl || *ccp)
 678                                         goto badafterall;
 679                                 sep->se_rpcversh = l;
 680                         } else if (*ccp != '\0')
 681                                 goto badafterall;
 682 #else
 683                 bb_error_msg("%s: rpc services not supported", sep->se_service);
 684 #endif
 685                 }
 686         }
 687         arg = skip(&cp);
 688         if (arg == NULL)
 689                 goto more;
 690
 691         {
 692                 char *s = strchr(arg, '.');
 693                 if (s) {
 694                         *s++ = '\0';
 695                         sep->se_max = atoi(s);
 696                 } else
 697                         sep->se_max = toomany;
 698         }
 699         sep->se_wait = strcmp(arg, "wait") == 0;
 700         /* if ((arg = skip(&cp, 1)) == NULL) */
 701         /* goto more; */
 702         sep->se_user = xxstrdup(skip(&cp));
 703         arg = strchr(sep->se_user, '.');
 704         if (arg == NULL)
 705                 arg = strchr(sep->se_user, ':');
 706         if (arg) {
 707                 *arg++ = '\0';
 708                 sep->se_group = xstrdup(arg);
 709         }
 710         /* if ((arg = skip(&cp, 1)) == NULL) */
 711         /* goto more; */
 712
 713         sep->se_server = xxstrdup(skip(&cp));
 714         if (strcmp(sep->se_server, "internal") == 0) {
 715 #ifdef INETD_FEATURE_ENABLED
 716                 const struct builtin *bi;
 717
 718                 for (bi = builtins; bi->bi_service; bi++)
 719                         if (bi->bi_socktype == sep->se_socktype &&
 720                                         strcmp(bi->bi_service, sep->se_service) == 0)
 721                                 break;
 722                 if (bi->bi_service == 0) {
 723                         bb_error_msg("internal service %s unknown", sep->se_service);
 724                         goto more;
 725                 }
 726                 sep->se_bi = bi;
 727                 sep->se_wait = bi->bi_wait;
 728 #else
 729                 bb_perror_msg("internal service %s unknown", sep->se_service);
 730                 goto more;
 731 #endif
 732         }
 733 #ifdef INETD_FEATURE_ENABLED
 734                 else
 735                 sep->se_bi = NULL;
 736 #endif
 737         argc = 0;
 738         for (arg = skip(&cp); cp; arg = skip(&cp)) {
 739                 if (argc < MAXARGV)
 740                         sep->se_argv[argc++] = xxstrdup(arg);
 741         }
 742         while (argc <= MAXARGV)
 743                 sep->se_argv[argc++] = NULL;
 744
 745         /*
 746          * Now that we've processed the entire line, check if the hostname
 747          * specifier was a comma separated list of hostnames. If so
 748          * we'll make new entries for each address.
 749          */
 750         while ((hostdelim = strrchr(sep->se_hostaddr, ',')) != NULL) {
 751                 nsep = dupconfig(sep);
 752
 753                 /*
 754                  * NULL terminate the hostname field of the existing entry,
 755                  * and make a dup for the new entry.
 756                  */
 757                 *hostdelim++ = '\0';
 758                 nsep->se_hostaddr = xstrdup(hostdelim);
 759
 760                 nsep->se_next = sep->se_next;
 761                 sep->se_next = nsep;
 762         }
 763
 764         nsep = sep;
 765         while (nsep != NULL) {
 766                 nsep->se_checked = 1;
 767                 if (nsep->se_family == AF_INET) {
 768                         if (!strcmp(nsep->se_hostaddr, "*"))
 769                                 nsep->se_ctrladdr_in.sin_addr.s_addr = INADDR_ANY;
 770                         else if (!inet_aton(nsep->se_hostaddr, &nsep->se_ctrladdr_in.sin_addr)) {
 771                                 struct hostent *hp;
 772
 773                                 hp = gethostbyname(nsep->se_hostaddr);
 774                                 if (hp == 0) {
 775                                         bb_error_msg("%s: unknown host", nsep->se_hostaddr);
 776                                         nsep->se_checked = 0;
 777                                         goto skip;
 778                                 } else if (hp->h_addrtype != AF_INET) {
 779                                         bb_error_msg("%s: address isn't an Internet "
 780                                                                   "address", nsep->se_hostaddr);
 781                                         nsep->se_checked = 0;
 782                                         goto skip;
 783                                 } else {
 784                                         int i = 1;
 785
 786                                         memmove(&nsep->se_ctrladdr_in.sin_addr,
 787                                                                    hp->h_addr_list[0], sizeof(struct in_addr));
 788                                         while (hp->h_addr_list[i] != NULL) {
 789                                                 psep = dupconfig(nsep);
 790                                                 psep->se_hostaddr = xxstrdup(nsep->se_hostaddr);
 791                                                 psep->se_checked = 1;
 792                                                 memmove(&psep->se_ctrladdr_in.sin_addr,
 793                                                                      hp->h_addr_list[i], sizeof(struct in_addr));
 794                                                 psep->se_ctrladdr_size = sizeof(psep->se_ctrladdr_in);
 795                                                 i++;
 796                                                 /* Prepend to list, don't want to look up */
 797                                                 /* its hostname again. */
 798                                                 psep->se_next = sep;
 799                                                 sep = psep;
 800                                         }
 801                                 }
 802                         }
 803                 }
 804 /* XXX BUG?: is this skip: label supposed to remain? */
 805         skip:
 806                 nsep = nsep->se_next;
 807         }
 808
 809         /*
 810          * Finally, free any entries which failed the gethostbyname
 811          * check.
 812          */
 813         psep = NULL;
 814         nsep = sep;
 815         while (nsep != NULL) {
 816                 servtab_t *tsep;
 817
 818                 if (nsep->se_checked == 0) {
 819                         tsep = nsep;
 820                         if (psep == NULL) {
 821                                 sep = nsep->se_next;
 822                                 nsep = sep;
 823                         } else {
 824                                 nsep = nsep->se_next;
 825                                 psep->se_next = nsep;
 826                         }
 827                         freeconfig(tsep);
 828                 } else {
 829                         nsep->se_checked = 0;
 830                         psep = nsep;
 831                         nsep = nsep->se_next;
 832                 }
 833         }
 834
 835         return sep;
 836 }
 837
 838 #define Block_Using_Signals(m) do { \
 839         sigemptyset(&m); \
 840         sigaddset(&m, SIGCHLD); \
 841         sigaddset(&m, SIGHUP); \
 842         sigaddset(&m, SIGALRM); \
 843         sigprocmask(SIG_BLOCK, &m, NULL); \
 844 } while(0)
 845
 846 static servtab_t *enter(servtab_t *cp)
 847 {
 848         servtab_t *sep;
 849         sigset_t omask;
 850
 851         sep = new_servtab();
 852         *sep = *cp;
 853         sep->se_fd = -1;
 854 #ifdef CONFIG_FEATURE_INETD_RPC
 855         sep->se_rpcprog = -1;
 856 #endif
 857         Block_Using_Signals(omask);
 858         sep->se_next = servtab;
 859         servtab = sep;
 860         sigprocmask(SIG_UNBLOCK, &omask, NULL);
 861         return sep;
 862 }
 863
 864 static int matchconf(servtab_t *old, servtab_t *new)
 865 {
 866         if (strcmp(old->se_service, new->se_service) != 0)
 867                 return 0;
 868
 869         if (strcmp(old->se_hostaddr, new->se_hostaddr) != 0)
 870                 return 0;
 871
 872         if (strcmp(old->se_proto, new->se_proto) != 0)
 873                 return 0;
 874
 875         /*
 876          * If the new servtab is bound to a specific address, check that the
 877          * old servtab is bound to the same entry. If the new service is not
 878          * bound to a specific address then the check of se_hostaddr above
 879          * is sufficient.
 880          */
 881
 882         if (old->se_family == AF_INET && new->se_family == AF_INET &&
 883                         memcmp(&old->se_ctrladdr_in.sin_addr,
 884                                         &new->se_ctrladdr_in.sin_addr,
 885                                         sizeof(new->se_ctrladdr_in.sin_addr)) != 0)
 886                 return 0;
 887
 888 #ifdef CONFIG_FEATURE_IPV6
 889         if (old->se_family == AF_INET6 && new->se_family == AF_INET6 &&
 890                         memcmp(&old->se_ctrladdr_in6.sin6_addr,
 891                                         &new->se_ctrladdr_in6.sin6_addr,
 892                                         sizeof(new->se_ctrladdr_in6.sin6_addr)) != 0)
 893                 return 0;
 894 #endif
 895         return 1;
 896 }
 897
 898 static void config(int sig ATTRIBUTE_UNUSED)
 899 {
 900         servtab_t *sep, *cp, **sepp;
 901         sigset_t omask;
 902         size_t n;
 903         char protoname[10];
 904
 905         if (!setconfig()) {
 906                 bb_perror_msg("%s", CONFIG);
 907                 return;
 908         }
 909         for (sep = servtab; sep; sep = sep->se_next)
 910                 sep->se_checked = 0;
 911         cp = getconfigent();
 912         while (cp != NULL) {
 913                 for (sep = servtab; sep; sep = sep->se_next)
 914                         if (matchconf(sep, cp))
 915                                 break;
 916
 917                 if (sep != 0) {
 918                         int i;
 919
 920 #define SWAP(type, a, b) do {type c=(type)a; a=(type)b; b=(type)c;} while (0)
 921
 922                         Block_Using_Signals(omask);
 923                         /*
 924                          * sep->se_wait may be holding the pid of a daemon
 925                          * that we're waiting for.  If so, don't overwrite
 926                          * it unless the config file explicitly says don't
 927                          * wait.
 928                          */
 929                         if (
 930 #ifdef INETD_FEATURE_ENABLED
 931                                          cp->se_bi == 0 &&
 932 #endif
 933                                 (sep->se_wait == 1 || cp->se_wait == 0))
 934                                 sep->se_wait = cp->se_wait;
 935                         SWAP(int, cp->se_max, sep->se_max);
 936                         SWAP(char *, sep->se_user, cp->se_user);
 937                         SWAP(char *, sep->se_group, cp->se_group);
 938                         SWAP(char *, sep->se_server, cp->se_server);
 939                         for (i = 0; i < MAXARGV; i++)
 940                                 SWAP(char *, sep->se_argv[i], cp->se_argv[i]);
 941 #undef SWAP
 942
 943 #ifdef CONFIG_FEATURE_INETD_RPC
 944                         if (isrpcservice(sep))
 945                                 unregister_rpc(sep);
 946                         sep->se_rpcversl = cp->se_rpcversl;
 947                         sep->se_rpcversh = cp->se_rpcversh;
 948 #endif
 949                         sigprocmask(SIG_UNBLOCK, &omask, NULL);
 950                         freeconfig(cp);
 951                 } else {
 952                         sep = enter(cp);
 953                 }
 954                 sep->se_checked = 1;
 955
 956                 switch (sep->se_family) {
 957                 case AF_UNIX:
 958                         if (sep->se_fd != -1)
 959                                 break;
 960                         (void) unlink(sep->se_service);
 961                         n = strlen(sep->se_service);
 962                         if (n > sizeof sep->se_ctrladdr_un.sun_path - 1)
 963                                 n = sizeof sep->se_ctrladdr_un.sun_path - 1;
 964                         safe_strncpy(sep->se_ctrladdr_un.sun_path, sep->se_service, n + 1);
 965                         sep->se_ctrladdr_un.sun_family = AF_UNIX;
 966                         sep->se_ctrladdr_size = n + sizeof sep->se_ctrladdr_un.sun_family;
 967                         setup(sep);
 968                         break;
 969                 case AF_INET:
 970                         sep->se_ctrladdr_in.sin_family = AF_INET;
 971                         /* se_ctrladdr_in was set in getconfigent */
 972                         sep->se_ctrladdr_size = sizeof sep->se_ctrladdr_in;
 973
 974 #ifdef CONFIG_FEATURE_INETD_RPC
 975                         if (isrpcservice(sep)) {
 976                                 struct rpcent *rp;
 977
 978                                 sep->se_rpcprog = atoi(sep->se_service);
 979                                 if (sep->se_rpcprog == 0) {
 980                                         rp = getrpcbyname(sep->se_service);
 981                                         if (rp == 0) {
 982                                                 bb_error_msg("%s: unknown rpc service", sep->se_service);
 983                                                 goto serv_unknown;
 984                                         }
 985                                         sep->se_rpcprog = rp->r_number;
 986                                 }
 987                                 if (sep->se_fd == -1)
 988                                         setup(sep);
 989                                 if (sep->se_fd != -1)
 990                                         register_rpc(sep);
 991                         } else
 992 #endif
 993                                  {
 994                                 u_short port = htons(atoi(sep->se_service));
 995
 996                                 if (!port) {
 997                                          /*XXX*/ strncpy(protoname, sep->se_proto, sizeof(protoname));
 998                                         if (isdigit(protoname[strlen(protoname) - 1]))
 999                                                 protoname[strlen(protoname) - 1] = '\0';
1000                                         sp = getservbyname(sep->se_service, protoname);
1001                                         if (sp == 0) {
1002                                                 bb_error_msg("%s/%s: unknown service",
1003                                                                 sep->se_service, sep->se_proto);
1004                                                 goto serv_unknown;
1005                                         }
1006                                         port = sp->s_port;
1007                                 }
1008                                 if (port != sep->se_ctrladdr_in.sin_port) {
1009                                         sep->se_ctrladdr_in.sin_port = port;
1010                                         if (sep->se_fd != -1) {
1011                                                 FD_CLR(sep->se_fd, &allsock);
1012                                                 nsock--;
1013                                                 (void) close(sep->se_fd);
1014                                         }
1015                                         sep->se_fd = -1;
1016                                 }
1017                                 if (sep->se_fd == -1)
1018                                         setup(sep);
1019                         }
1020                         break;
1021 #ifdef CONFIG_FEATURE_IPV6
1022                 case AF_INET6:
1023                         sep->se_ctrladdr_in6.sin6_family = AF_INET6;
1024                         /* se_ctrladdr_in was set in getconfigent */
1025                         sep->se_ctrladdr_size = sizeof sep->se_ctrladdr_in6;
1026
1027 #ifdef CONFIG_FEATURE_INETD_RPC
1028                         if (isrpcservice(sep)) {
1029                                 struct rpcent *rp;
1030
1031                                 sep->se_rpcprog = atoi(sep->se_service);
1032                                 if (sep->se_rpcprog == 0) {
1033                                         rp = getrpcbyname(sep->se_service);
1034                                         if (rp == 0) {
1035                                                 bb_error_msg("%s: unknown rpc service", sep->se_service);
1036                                                 goto serv_unknown;
1037                                         }
1038                                         sep->se_rpcprog = rp->r_number;
1039                                 }
1040                                 if (sep->se_fd == -1)
1041                                         setup(sep);
1042                                 if (sep->se_fd != -1)
1043                                         register_rpc(sep);
1044                         } else
1045 #endif
1046                                 {
1047                                 u_short port = htons(atoi(sep->se_service));
1048
1049                                 if (!port) {
1050                                          /*XXX*/ strncpy(protoname, sep->se_proto, sizeof(protoname));
1051                                         if (isdigit(protoname[strlen(protoname) - 1]))
1052                                                 protoname[strlen(protoname) - 1] = '\0';
1053                                         sp = getservbyname(sep->se_service, protoname);
1054                                         if (sp == 0) {
1055                                                 bb_error_msg("%s/%s: unknown service",
1056                                                                 sep->se_service, sep->se_proto);
1057                                                 goto serv_unknown;
1058                                         }
1059                                         port = sp->s_port;
1060                                 }
1061                                 if (port != sep->se_ctrladdr_in6.sin6_port) {
1062                                         sep->se_ctrladdr_in6.sin6_port = port;
1063                                         if (sep->se_fd != -1) {
1064                                                 FD_CLR(sep->se_fd, &allsock);
1065                                                 nsock--;
1066                                                 (void) close(sep->se_fd);
1067                                         }
1068                                         sep->se_fd = -1;
1069                                 }
1070                                 if (sep->se_fd == -1)
1071                                         setup(sep);
1072                         }
1073                         break;
1074 #endif /* CONFIG_FEATURE_IPV6 */
1075                 }
1076         serv_unknown:
1077                 if (cp->se_next != NULL) {
1078                         servtab_t *tmp = cp;
1079
1080                         cp = cp->se_next;
1081                         free(tmp);
1082                 } else {
1083                         free(cp);
1084                         cp = getconfigent();
1085                 }
1086         }
1087         endconfig();
1088         /*
1089          * Purge anything not looked at above.
1090          */
1091         Block_Using_Signals(omask);
1092         sepp = &servtab;
1093         while ((sep = *sepp)) {
1094                 if (sep->se_checked) {
1095                         sepp = &sep->se_next;
1096                         continue;
1097                 }
1098                 *sepp = sep->se_next;
1099                 if (sep->se_fd != -1) {
1100                         FD_CLR(sep->se_fd, &allsock);
1101                         nsock--;
1102                         (void) close(sep->se_fd);
1103                 }
1104 #ifdef CONFIG_FEATURE_INETD_RPC
1105                 if (isrpcservice(sep))
1106                         unregister_rpc(sep);
1107 #endif
1108                 if (sep->se_family == AF_UNIX)
1109                         (void) unlink(sep->se_service);
1110                 freeconfig(sep);
1111                 free(sep);
1112         }
1113         sigprocmask(SIG_UNBLOCK, &omask, NULL);
1114 }
1115
1116
1117 static void reapchild(int sig ATTRIBUTE_UNUSED)
1118 {
1119         pid_t pid;
1120         int save_errno = errno, status;
1121         servtab_t *sep;
1122
1123         for (;;) {
1124                 pid = wait3(&status, WNOHANG, NULL);
1125                 if (pid <= 0)
1126                         break;
1127                 for (sep = servtab; sep; sep = sep->se_next)
1128                         if (sep->se_wait == pid) {
1129                                 if (WIFEXITED(status) && WEXITSTATUS(status))
1130                                         bb_error_msg("%s: exit status 0x%x",
1131                                                         sep->se_server, WEXITSTATUS(status));
1132                                 else if (WIFSIGNALED(status))
1133                                         bb_error_msg("%s: exit signal 0x%x",
1134                                                         sep->se_server, WTERMSIG(status));
1135                                 sep->se_wait = 1;
1136                                 FD_SET(sep->se_fd, &allsock);
1137                                 nsock++;
1138                         }
1139         }
1140         errno = save_errno;
1141 }
1142
1143 static void retry(int sig ATTRIBUTE_UNUSED)
1144 {
1145         servtab_t *sep;
1146
1147         timingout = 0;
1148         for (sep = servtab; sep; sep = sep->se_next) {
1149                 if (sep->se_fd == -1) {
1150                         switch (sep->se_family) {
1151                         case AF_UNIX:
1152                         case AF_INET:
1153 #ifdef CONFIG_FEATURE_IPV6
1154                         case AF_INET6:
1155 #endif
1156                                 setup(sep);
1157 #ifdef CONFIG_FEATURE_INETD_RPC
1158                                 if (sep->se_fd != -1 && isrpcservice(sep))
1159                                         register_rpc(sep);
1160 #endif
1161                                 break;
1162                         }
1163                 }
1164         }
1165 }
1166
1167 static void goaway(int sig ATTRIBUTE_UNUSED)
1168 {
1169         servtab_t *sep;
1170
1171         /* XXX signal race walking sep list */
1172         for (sep = servtab; sep; sep = sep->se_next) {
1173                 if (sep->se_fd == -1)
1174                         continue;
1175
1176                 switch (sep->se_family) {
1177                 case AF_UNIX:
1178                         (void) unlink(sep->se_service);
1179                         break;
1180                 case AF_INET:
1181 #ifdef CONFIG_FEATURE_IPV6
1182                 case AF_INET6:
1183 #endif
1184 #ifdef CONFIG_FEATURE_INETD_RPC
1185                         if (sep->se_wait == 1 && isrpcservice(sep))
1186                                 unregister_rpc(sep);   /* XXX signal race */
1187 #endif
1188                         break;
1189                 }
1190                 (void) close(sep->se_fd);
1191         }
1192         (void) unlink(_PATH_INETDPID);
1193         exit(0);
1194 }
1195
1196
1197 #ifdef INETD_SETPROCTITLE
1198 static char **Argv;
1199 static char *LastArg;
1200
1201 static void
1202 inetd_setproctitle(char *a, int s)
1203 {
1204         socklen_t size;
1205         char *cp;
1206         struct sockaddr_in prt_sin;
1207         char buf[80];
1208
1209         cp = Argv[0];
1210         size = sizeof(prt_sin);
1211         (void) snprintf(buf, sizeof buf, "-%s", a);
1212         if (getpeername(s, (struct sockaddr *) &prt_sin, &size) == 0) {
1213                 char *sa = inet_ntoa(prt_sin.sin_addr);
1214
1215                 buf[sizeof(buf) - 1 - strlen(sa) - 3] = '\0';
1216                 strcat(buf, " [");
1217                 strcat(buf, sa);
1218                 strcat(buf, "]");
1219         }
1220         strncpy(cp, buf, LastArg - cp);
1221         cp += strlen(cp);
1222         while (cp < LastArg)
1223                 *cp++ = ' ';
1224 }
1225 #endif
1226
1227
1228 int
1229 inetd_main(int argc, char *argv[])
1230 {
1231         servtab_t *sep;
1232         struct passwd *pwd;
1233         struct group *grp = NULL;
1234         int tmpint;
1235         struct sigaction sa, sapipe;
1236         int opt;
1237         pid_t pid;
1238         char buf[50];
1239         char *stoomany;
1240         sigset_t omask, wait_mask;
1241
1242 #ifdef INETD_SETPROCTITLE
1243         extern char **environ;
1244         char **envp = environ;
1245
1246         Argv = argv;
1247         if (envp == 0 || *envp == 0)
1248                 envp = argv;
1249         while (*envp)
1250                 envp++;
1251         LastArg = envp[-1] + strlen(envp[-1]);
1252 #endif
1253
1254         openlog(bb_applet_name, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
1255
1256         opt = bb_getopt_ulflags(argc, argv, "R:f", &stoomany);
1257         if(opt & 1) {
1258                 char *e;
1259
1260                 toomany = strtoul(stoomany, &e, 0);
1261                 if (!(toomany >= 0 && *e == '\0')) {
1262                                 toomany = TOOMANY;
1263                                 bb_perror_msg("-R %s: bad value for service invocation rate", stoomany);
1264                 }
1265         }
1266         argc -= optind;
1267         argv += optind;
1268
1269         uid = getuid();
1270         if (uid != 0)
1271                 CONFIG = NULL;
1272         if (argc > 0)
1273                 CONFIG = argv[0];
1274         if (CONFIG == NULL)
1275                 bb_error_msg_and_die("non-root must specify a config file");
1276
1277         if (!(opt & 2)) {
1278 #ifdef BB_NOMMU
1279                 /* reexec for vfork() do continue parent */
1280                 vfork_daemon_rexec(0, 0, argc, argv, "-f");
1281 #else
1282                 xdaemon(0, 0);
1283 #endif
1284         } else {
1285                 setsid();
1286         }
1287         logmode = LOGMODE_SYSLOG;
1288
1289         if (uid == 0) {
1290                 gid_t gid = getgid();
1291
1292                 /* If run by hand, ensure groups vector gets trashed */
1293                 setgroups(1, &gid);
1294         }
1295
1296         {
1297                 FILE *fp = fopen(_PATH_INETDPID, "w");
1298
1299                 if (fp != NULL) {
1300                         fprintf(fp, "%u\n", getpid());
1301                         (void) fclose(fp);
1302                 }
1303         }
1304
1305         if (getrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0) {
1306                 bb_perror_msg("getrlimit");
1307         } else {
1308                 rlim_ofile_cur = rlim_ofile.rlim_cur;
1309                 if (rlim_ofile_cur == RLIM_INFINITY)    /* ! */
1310                         rlim_ofile_cur = OPEN_MAX;
1311         }
1312
1313         memset((char *) &sa, 0, sizeof(sa));
1314         sigemptyset(&sa.sa_mask);
1315         sigaddset(&sa.sa_mask, SIGALRM);
1316         sigaddset(&sa.sa_mask, SIGCHLD);
1317         sigaddset(&sa.sa_mask, SIGHUP);
1318         sa.sa_handler = retry;
1319         sigaction(SIGALRM, &sa, NULL);
1320         /* doconfig(); */
1321         config(SIGHUP);
1322         sa.sa_handler = config;
1323         sigaction(SIGHUP, &sa, NULL);
1324         sa.sa_handler = reapchild;
1325         sigaction(SIGCHLD, &sa, NULL);
1326         sa.sa_handler = goaway;
1327         sigaction(SIGTERM, &sa, NULL);
1328         sa.sa_handler = goaway;
1329         sigaction(SIGINT, &sa, NULL);
1330         sa.sa_handler = SIG_IGN;
1331         sigaction(SIGPIPE, &sa, &sapipe);
1332         memset(&wait_mask, 0, sizeof(wait_mask));
1333         {
1334                 /* space for daemons to overwrite environment for ps */
1335 #define DUMMYSIZE       100
1336                 char dummy[DUMMYSIZE];
1337
1338                 (void) memset(dummy, 'x', DUMMYSIZE - 1);
1339                 dummy[DUMMYSIZE - 1] = '\0';
1340
1341                 (void) setenv("inetd_dummy", dummy, 1);
1342         }
1343
1344         for (;;) {
1345                 int n, ctrl = -1;
1346                 fd_set readable;
1347
1348                 if (nsock == 0) {
1349                         Block_Using_Signals(omask);
1350                         while (nsock == 0)
1351                                 sigsuspend(&wait_mask);
1352                         sigprocmask(SIG_UNBLOCK, &omask, NULL);
1353                 }
1354
1355                 readable = allsock;
1356                 n = select(maxsock + 1, &readable, NULL, NULL, NULL);
1357                 if (n <= 0) {
1358                         if (n < 0 && errno != EINTR) {
1359                                 bb_perror_msg("select");
1360                                 sleep(1);
1361                         }
1362                         continue;
1363                 }
1364
1365                 for (sep = servtab; n && sep; sep = sep->se_next) {
1366                         if (sep->se_fd == -1 || !FD_ISSET(sep->se_fd, &readable))
1367                                 continue;
1368
1369                         n--;
1370                         if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) {
1371                                 ctrl = accept(sep->se_fd, NULL, NULL);
1372                                 if (ctrl < 0) {
1373                                         if (errno == EINTR)
1374                                                 continue;
1375                                         bb_perror_msg("accept (for %s)", sep->se_service);
1376                                         continue;
1377                                 }
1378                                 if (sep->se_family == AF_INET && sep->se_socktype == SOCK_STREAM) {
1379                                         struct sockaddr_in peer;
1380                                         socklen_t plen = sizeof(peer);
1381
1382                                         if (getpeername(ctrl, (struct sockaddr *) &peer, &plen) < 0) {
1383                                                 bb_error_msg("could not getpeername");
1384                                                 close(ctrl);
1385                                                 continue;
1386                                         }
1387                                         if (ntohs(peer.sin_port) == 20) {
1388                                                 /* XXX ftp bounce */
1389                                                 close(ctrl);
1390                                                 continue;
1391                                         }
1392                                 }
1393                         } else
1394                                 ctrl = sep->se_fd;
1395
1396                         Block_Using_Signals(omask);
1397                         pid = 0;
1398 #ifdef INETD_FEATURE_ENABLED
1399                         if (sep->se_bi == 0 || sep->se_bi->bi_fork)
1400 #endif
1401                         {
1402                                 if (sep->se_count++ == 0)
1403                                         (void) gettimeofday(&sep->se_time, NULL);
1404                                 else if (toomany > 0 && sep->se_count >= sep->se_max) {
1405                                         struct timeval now;
1406
1407                                         (void) gettimeofday(&now, NULL);
1408                                         if (now.tv_sec - sep->se_time.tv_sec > CNT_INTVL) {
1409                                                 sep->se_time = now;
1410                                                 sep->se_count = 1;
1411                                         } else {
1412                                                 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
1413                                                         close(ctrl);
1414                                                 if (sep->se_family == AF_INET &&
1415                                                           ntohs(sep->se_ctrladdr_in.sin_port) >= IPPORT_RESERVED) {
1416                                                         /*
1417                                                          * Cannot close it -- there are
1418                                                          * thieves on the system.
1419                                                          * Simply ignore the connection.
1420                                                          */
1421                                                         --sep->se_count;
1422                                                         continue;
1423                                                 }
1424                                                 bb_error_msg("%s/%s server failing (looping), service terminated",
1425                                                               sep->se_service, sep->se_proto);
1426                                                 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
1427                                                         close(ctrl);
1428                                                 FD_CLR(sep->se_fd, &allsock);
1429                                                 (void) close(sep->se_fd);
1430                                                 sep->se_fd = -1;
1431                                                 sep->se_count = 0;
1432                                                 nsock--;
1433                                                 sigprocmask(SIG_UNBLOCK, &omask, NULL);
1434                                                 if (!timingout) {
1435                                                         timingout = 1;
1436                                                         alarm(RETRYTIME);
1437                                                 }
1438                                                 continue;
1439                                         }
1440                                 }
1441                                 pid = fork();
1442                         }
1443                         if (pid < 0) {
1444                                 bb_perror_msg("fork");
1445                                 if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
1446                                         close(ctrl);
1447                                 sigprocmask(SIG_UNBLOCK, &omask, NULL);
1448                                 sleep(1);
1449                                 continue;
1450                         }
1451                         if (pid && sep->se_wait) {
1452                                 sep->se_wait = pid;
1453                                 FD_CLR(sep->se_fd, &allsock);
1454                                 nsock--;
1455                         }
1456                         sigprocmask(SIG_UNBLOCK, &omask, NULL);
1457                         if (pid == 0) {
1458 #ifdef INETD_FEATURE_ENABLED
1459                                 if (sep->se_bi) {
1460                                         (*sep->se_bi->bi_fn)(ctrl, sep);
1461                                 } else
1462 #endif
1463                                         {
1464                                         pwd = getpwnam(sep->se_user);
1465                                         if (pwd == NULL) {
1466                                                 bb_error_msg("getpwnam: %s: no such user", sep->se_user);
1467                                                 goto do_exit1;
1468                                         }
1469                                         if (setsid() < 0)
1470                                                 bb_perror_msg("%s: setsid", sep->se_service);
1471                                         if (sep->se_group && (grp = getgrnam(sep->se_group)) == NULL) {
1472                                                 bb_error_msg("getgrnam: %s: no such group", sep->se_group);
1473                                                 goto do_exit1;
1474                                         }
1475                                         if (uid != 0) {
1476                                                 /* a user running private inetd */
1477                                                 if (uid != pwd->pw_uid)
1478                                                         _exit(1);
1479                                         } else if (pwd->pw_uid) {
1480                                                 if (sep->se_group)
1481                                                         pwd->pw_gid = grp->gr_gid;
1482                                                 xsetgid((gid_t) pwd->pw_gid);
1483                                                 initgroups(pwd->pw_name, pwd->pw_gid);
1484                                                 xsetuid((uid_t) pwd->pw_uid);
1485                                         } else if (sep->se_group) {
1486                                                 xsetgid(grp->gr_gid);
1487                                                 setgroups(1, &grp->gr_gid);
1488                                         }
1489                                         dup2(ctrl, 0);
1490                                         if (ctrl) close(ctrl);
1491                                         dup2(0, 1);
1492                                         dup2(0, 2);
1493                                         if (rlim_ofile.rlim_cur != rlim_ofile_cur)
1494                                                 if (setrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0)
1495                                                         bb_perror_msg("setrlimit");
1496                                         closelog();
1497                                         for (tmpint = rlim_ofile_cur - 1; --tmpint > 2;)
1498                                                 (void) close(tmpint);
1499                                         sigaction(SIGPIPE, &sapipe, NULL);
1500                                         execv(sep->se_server, sep->se_argv);
1501                                         bb_perror_msg("execv %s", sep->se_server);
1502 do_exit1:
1503                                         if (sep->se_socktype != SOCK_STREAM)
1504                                                 recv(0, buf, sizeof(buf), 0);
1505                                         _exit(1);
1506                                 }
1507                         }
1508                         if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
1509                                 close(ctrl);
1510                 } /* for (sep = servtab...) */
1511         } /* for(;;) */
1512 }
1513
1514 /*
1515  * Internet services provided internally by inetd:
1516  */
1517 #define BUFSIZE 4096
1518
1519 #if defined(CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_ECHO) || \
1520                 defined(CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN) || \
1521                 defined(CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME)
1522 static int dg_badinput(struct sockaddr_in *dg_sin)
1523 {
1524         if (ntohs(dg_sin->sin_port) < IPPORT_RESERVED)
1525                 return 1;
1526         if (dg_sin->sin_addr.s_addr == htonl(INADDR_BROADCAST))
1527                 return 1;
1528         /* XXX compare against broadcast addresses in SIOCGIFCONF list? */
1529         return 0;
1530 }
1531 #endif
1532
1533 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
1534 /* Echo service -- echo data back */
1535 /* ARGSUSED */
1536 static void
1537 echo_stream(int s, servtab_t *sep)
1538 {
1539         char buffer[BUFSIZE];
1540         int i;
1541
1542         inetd_setproctitle(sep->se_service, s);
1543         while (1) {
1544                 i = read(s, buffer, sizeof(buffer));
1545                 if (i <= 0) break;
1546                 /* FIXME: this isnt correct - safe_write()? */
1547                 if (write(s, buffer, i) <= 0) break;
1548         }
1549         exit(0);
1550 }
1551
1552 /* Echo service -- echo data back */
1553 /* ARGSUSED */
1554 static void
1555 echo_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1556 {
1557         char buffer[BUFSIZE];
1558         int i;
1559         socklen_t size;
1560         /* struct sockaddr_storage ss; */
1561         struct sockaddr sa;
1562
1563         size = sizeof(sa);
1564         i = recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size);
1565         if (i < 0)
1566                 return;
1567         if (dg_badinput((struct sockaddr_in *) &sa))
1568                 return;
1569         (void) sendto(s, buffer, i, 0, &sa, sizeof(sa));
1570 }
1571 #endif  /* CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_ECHO */
1572
1573 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
1574 /* Discard service -- ignore data */
1575 /* ARGSUSED */
1576 static void
1577 discard_stream(int s, servtab_t *sep)
1578 {
1579         char buffer[BUFSIZE];
1580
1581         inetd_setproctitle(sep->se_service, s);
1582         while (1) {
1583                 errno = 0;
1584                 if (read(s, buffer, sizeof(buffer)) <= 0 && errno != EINTR)
1585                         exit(0);
1586         }
1587 }
1588
1589 /* Discard service -- ignore data */
1590 /* ARGSUSED */
1591 static void
1592 discard_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1593 {
1594         char buffer[BUFSIZE];
1595
1596         (void) read(s, buffer, sizeof(buffer));
1597 }
1598 #endif /* CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD */
1599
1600
1601 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
1602 #define LINESIZ 72
1603 static char ring[128];
1604 static char *endring;
1605
1606 static void
1607 initring(void)
1608 {
1609         int i;
1610
1611         endring = ring;
1612
1613         for (i = 0; i <= 128; ++i)
1614                 if (isprint(i))
1615                         *endring++ = i;
1616 }
1617
1618 /* Character generator */
1619 /* ARGSUSED */
1620 static void
1621 chargen_stream(int s, servtab_t *sep)
1622 {
1623         char *rs;
1624         int len;
1625         char text[LINESIZ + 2];
1626
1627         inetd_setproctitle(sep->se_service, s);
1628
1629         if (!endring) {
1630                 initring();
1631                 rs = ring;
1632         }
1633
1634         text[LINESIZ] = '\r';
1635         text[LINESIZ + 1] = '\n';
1636         rs = ring;
1637         for (;;) {
1638                 len = endring - rs;
1639                 if (len >= LINESIZ)
1640                         memmove(text, rs, LINESIZ);
1641                 else {
1642                         memmove(text, rs, len);
1643                         memmove(text + len, ring, LINESIZ - len);
1644                 }
1645                 if (++rs == endring)
1646                         rs = ring;
1647                 if (write(s, text, sizeof(text)) != sizeof(text))
1648                         break;
1649         }
1650         exit(0);
1651 }
1652
1653 /* Character generator */
1654 /* ARGSUSED */
1655 static void
1656 chargen_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1657 {
1658         /* struct sockaddr_storage ss; */
1659         struct sockaddr sa;
1660         static char *rs;
1661         int len;
1662         char text[LINESIZ + 2];
1663         socklen_t size;
1664
1665         if (endring == 0) {
1666                 initring();
1667                 rs = ring;
1668         }
1669
1670         size = sizeof(sa);
1671         if (recvfrom(s, text, sizeof(text), 0, &sa, &size) < 0)
1672                 return;
1673         if (dg_badinput((struct sockaddr_in *) &sa))
1674                 return;
1675
1676         if ((len = endring - rs) >= LINESIZ)
1677                 memmove(text, rs, LINESIZ);
1678         else {
1679                 memmove(text, rs, len);
1680                 memmove(text + len, ring, LINESIZ - len);
1681         }
1682         if (++rs == endring)
1683                 rs = ring;
1684         text[LINESIZ] = '\r';
1685         text[LINESIZ + 1] = '\n';
1686         (void) sendto(s, text, sizeof(text), 0, &sa, sizeof(sa));
1687 }
1688 #endif /* CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN */
1689
1690
1691 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_TIME
1692 /*
1693  * Return a machine readable date and time, in the form of the
1694  * number of seconds since midnight, Jan 1, 1900.  Since gettimeofday
1695  * returns the number of seconds since midnight, Jan 1, 1970,
1696  * we must add 2208988800 seconds to this figure to make up for
1697  * some seventy years Bell Labs was asleep.
1698  */
1699
1700 static u_int machtime(void)
1701 {
1702         struct timeval tv;
1703
1704         if (gettimeofday(&tv, NULL) < 0) {
1705                 fprintf(stderr, "Unable to get time of day\n");
1706                 return 0L;
1707         }
1708         return htonl((u_int) tv.tv_sec + 2208988800UL);
1709 }
1710
1711 /* ARGSUSED */
1712 static void
1713 machtime_stream(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1714 {
1715         u_int result;
1716
1717         result = machtime();
1718         (void) write(s, (char *) &result, sizeof(result));
1719 }
1720
1721 /* ARGSUSED */
1722 static void
1723 machtime_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1724 {
1725         u_int result;
1726         /* struct sockaddr_storage ss; */
1727         struct sockaddr sa;
1728         struct sockaddr_in *dg_sin;
1729         socklen_t size;
1730
1731         size = sizeof(sa);
1732         if (recvfrom(s, (char *) &result, sizeof(result), 0, &sa, &size) < 0)
1733                 return;
1734         /* if (dg_badinput((struct sockaddr *)&ss)) */
1735         dg_sin = (struct sockaddr_in *) &sa;
1736         if (dg_sin->sin_addr.s_addr == htonl(INADDR_BROADCAST) ||
1737                         ntohs(dg_sin->sin_port) < IPPORT_RESERVED / 2)
1738                 return;
1739         result = machtime();
1740         (void) sendto(s, (char *) &result, sizeof(result), 0, &sa, sizeof(sa));
1741 }
1742 #endif /* CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_TIME */
1743
1744
1745 #ifdef CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
1746 /* Return human-readable time of day */
1747 /* ARGSUSED */
1748 static void daytime_stream(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1749 {
1750         char buffer[256];
1751         time_t t;
1752
1753         t = time(NULL);
1754
1755         (void) sprintf(buffer, "%.24s\r\n", ctime(&t));
1756         (void) write(s, buffer, strlen(buffer));
1757 }
1758
1759 /* Return human-readable time of day */
1760 /* ARGSUSED */
1761 void
1762 daytime_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
1763 {
1764         char buffer[256];
1765         time_t t;
1766         /* struct sockaddr_storage ss; */
1767         struct sockaddr sa;
1768         socklen_t size;
1769
1770         t = time(NULL);
1771
1772         size = sizeof(sa);
1773         if (recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size) < 0)
1774                 return;
1775         if (dg_badinput((struct sockaddr_in *) &sa))
1776                 return;
1777         (void) sprintf(buffer, "%.24s\r\n", ctime(&t));
1778         (void) sendto(s, buffer, strlen(buffer), 0, &sa, sizeof(sa));
1779 }
1780 #endif /* CONFIG_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME */