scheduler/listen.c

   1 /*
   2  * "$Id: listen.c 5083 2006-02-06 02:57:43Z mike $"
   3  *
   4  *   Server listening routines for the Common UNIX Printing System (CUPS)
   5  *   scheduler.
   6  *
   7  *   Copyright 1997-2006 by Easy Software Products, all rights reserved.
   8  *
   9  *   These coded instructions, statements, and computer programs are the
  10  *   property of Easy Software Products and are protected by Federal
  11  *   copyright law.  Distribution and use rights are outlined in the file
  12  *   "LICENSE.txt" which should have been included with this file.  If this
  13  *   file is missing or damaged please contact Easy Software Products
  14  *   at:
  15  *
  16  *       Attn: CUPS Licensing Information
  17  *       Easy Software Products
  18  *       44141 Airport View Drive, Suite 204
  19  *       Hollywood, Maryland 20636 USA
  20  *
  21  *       Voice: (301) 373-9600
  22  *       EMail: cups-info@cups.org
  23  *         WWW: http://www.cups.org
  24  *
  25  * Contents:
  26  *
  27  *   cupsdDeleteAllListeners() - Delete all listeners.
  28  *   cupsdPauseListening()     - Clear input polling on all listening sockets...
  29  *   cupsdResumeListening()    - Set input polling on all listening sockets...
  30  *   cupsdStartListening()     - Create all listening sockets...
  31  *   cupsdStopListening()      - Close all listening sockets...
  32  */
  33
  34 /*
  35  * Include necessary headers...
  36  */
  37
  38 #include "cupsd.h"
  39
  40
  41 /*
  42  * Make sure the IPV6_V6ONLY is defined on Linux - older versions of
  43  * glibc don't define it even if the kernel supports it...
  44  */
  45
  46 #if defined(__linux) && !defined(IPV6_V6ONLY)
  47 #  define IPV6_V6ONLY 26
  48 #endif /* __linux && !IPV6_V6ONLY */
  49
  50
  51 /*
  52  * 'cupsdDeleteAllListeners()' - Delete all listeners.
  53  */
  54
  55 void
  56 cupsdDeleteAllListeners(void)
  57 {
  58   cupsd_listener_t      *lis;           /* Current listening socket */
  59
  60
  61   for (lis = (cupsd_listener_t *)cupsArrayFirst(Listeners);
  62        lis;
  63        lis = (cupsd_listener_t *)cupsArrayNext(Listeners))
  64     free(lis);
  65
  66   cupsArrayDelete(Listeners);
  67   Listeners = NULL;
  68 }
  69
  70
  71 /*
  72  * 'cupsdPauseListening()' - Clear input polling on all listening sockets...
  73  */
  74
  75 void
  76 cupsdPauseListening(void)
  77 {
  78   cupsd_listener_t      *lis;           /* Current listening socket */
  79
  80
  81   if (cupsArrayCount(Listeners) < 1)
  82     return;
  83
  84   if (cupsArrayCount(Clients) == MaxClients)
  85     cupsdLogMessage(CUPSD_LOG_WARN,
  86                     "Max clients reached, holding new connections...");
  87
  88   cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdPauseListening: Clearing input bits...");
  89
  90   for (lis = (cupsd_listener_t *)cupsArrayFirst(Listeners);
  91        lis;
  92        lis = (cupsd_listener_t *)cupsArrayNext(Listeners))
  93     if (lis->fd >= 0)
  94     {
  95       cupsdLogMessage(CUPSD_LOG_DEBUG2,
  96                       "cupsdPauseListening: Removing fd %d from InputSet...",
  97                       lis->fd);
  98
  99       FD_CLR(lis->fd, InputSet);
 100     }
 101 }
 102
 103
 104 /*
 105  * 'cupsdResumeListening()' - Set input polling on all listening sockets...
 106  */
 107
 108 void
 109 cupsdResumeListening(void)
 110 {
 111   cupsd_listener_t      *lis;           /* Current listening socket */
 112
 113
 114   if (cupsArrayCount(Listeners) < 1)
 115     return;
 116
 117   if (cupsArrayCount(Clients) >= (MaxClients - 1))
 118     cupsdLogMessage(CUPSD_LOG_WARN, "Resuming new connection processing...");
 119
 120   cupsdLogMessage(CUPSD_LOG_DEBUG2,
 121                   "cupsdResumeListening: Setting input bits...");
 122
 123   for (lis = (cupsd_listener_t *)cupsArrayFirst(Listeners);
 124        lis;
 125        lis = (cupsd_listener_t *)cupsArrayNext(Listeners))
 126     if (lis->fd >= 0)
 127     {
 128       cupsdLogMessage(CUPSD_LOG_DEBUG2,
 129                       "cupsdResumeListening: Adding fd %d to InputSet...",
 130                       lis->fd);
 131       FD_SET(lis->fd, InputSet);
 132     }
 133 }
 134
 135
 136 /*
 137  * 'cupsdStartListening()' - Create all listening sockets...
 138  */
 139
 140 void
 141 cupsdStartListening(void)
 142 {
 143   int                   status;         /* Bind result */
 144   int                   p,              /* Port number */
 145                         val;            /* Parameter value */
 146   cupsd_listener_t      *lis;           /* Current listening socket */
 147   char                  s[256];         /* String addresss */
 148   const char            *have_domain;   /* Have a domain socket? */
 149   static const char * const encryptions[] =
 150                 {                       /* Encryption values */
 151                   "IfRequested",
 152                   "Never",
 153                   "Required",
 154                   "Always"
 155                 };
 156
 157
 158   cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdStartListening: %d Listeners",
 159                   cupsArrayCount(Listeners));
 160
 161  /*
 162   * Get the server's IP address...
 163   */
 164
 165   if (ServerAddrs)
 166     httpAddrFreeList(ServerAddrs);
 167
 168   if ((ServerAddrs = httpAddrGetList(ServerName, AF_UNSPEC, NULL)) == NULL)
 169     cupsdLogMessage(CUPSD_LOG_ERROR,
 170                     "Unable to find IP address for server name \"%s\"!\n",
 171                     ServerName);
 172
 173  /*
 174   * Setup socket listeners...
 175   */
 176
 177   for (lis = (cupsd_listener_t *)cupsArrayFirst(Listeners), LocalPort = 0,
 178            have_domain = NULL;
 179        lis;
 180        lis = (cupsd_listener_t *)cupsArrayNext(Listeners))
 181   {
 182     httpAddrString(&(lis->address), s, sizeof(s));
 183
 184 #ifdef AF_INET6
 185     if (lis->address.addr.sa_family == AF_INET6)
 186       p = ntohs(lis->address.ipv6.sin6_port);
 187     else
 188 #endif /* AF_INET6 */
 189 #ifdef AF_LOCAL
 190     if (lis->address.addr.sa_family == AF_LOCAL)
 191       p = 0;
 192     else
 193 #endif /* AF_LOCAL */
 194     p = ntohs(lis->address.ipv4.sin_port);
 195
 196    /*
 197     * If needed, create a socket for listening...
 198     */
 199
 200     if (lis->fd == -1)
 201     {
 202      /*
 203       * Create a socket for listening...
 204       */
 205
 206       lis->fd = socket(lis->address.addr.sa_family, SOCK_STREAM, 0);
 207
 208       if (lis->fd == -1)
 209       {
 210         cupsdLogMessage(CUPSD_LOG_ERROR,
 211                         "Unable to open listen socket for address %s:%d - %s.",
 212                         s, p, strerror(errno));
 213         continue;
 214       }
 215
 216      /*
 217       * Set things up to reuse the local address for this port.
 218       */
 219
 220       val = 1;
 221 #ifdef __sun
 222       setsockopt(lis->fd, SOL_SOCKET, SO_REUSEADDR, (char *)&val, sizeof(val));
 223 #else
 224       setsockopt(lis->fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 225 #endif /* __sun */
 226
 227      /*
 228       * Bind to the port we found...
 229       */
 230
 231 #ifdef AF_INET6
 232       if (lis->address.addr.sa_family == AF_INET6)
 233       {
 234 #  ifdef IPV6_V6ONLY
 235        /*
 236         * Accept only IPv6 connections on this socket, to avoid
 237         * potential security issues and to make all platforms behave
 238         * the same.
 239         */
 240
 241         val = 1;
 242 #    ifdef __sun
 243         setsockopt(lis->fd, IPPROTO_IPV6, IPV6_V6ONLY, (char *)&val, sizeof(val));
 244 #    else
 245         setsockopt(lis->fd, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
 246 #    endif /* __sun */
 247 #  endif /* IPV6_V6ONLY */
 248
 249         status = bind(lis->fd, (struct sockaddr *)&(lis->address),
 250                       httpAddrLength(&(lis->address)));
 251       }
 252       else
 253 #endif /* AF_INET6 */
 254 #ifdef AF_LOCAL
 255       if (lis->address.addr.sa_family == AF_LOCAL)
 256       {
 257         mode_t  mask;                   /* Umask setting */
 258
 259
 260        /*
 261         * Remove any existing domain socket file...
 262         */
 263
 264         unlink(lis->address.un.sun_path);
 265
 266        /*
 267         * Save the curent umask and set it to 0...
 268         */
 269
 270         mask = umask(0);
 271
 272        /*
 273         * Bind the domain socket...
 274         */
 275
 276         status = bind(lis->fd, (struct sockaddr *)&(lis->address),
 277                       httpAddrLength(&(lis->address)));
 278
 279        /*
 280         * Restore the umask...
 281         */
 282
 283         umask(mask);
 284       }
 285       else
 286 #endif /* AF_LOCAL */
 287       status = bind(lis->fd, (struct sockaddr *)&(lis->address),
 288                     sizeof(lis->address.ipv4));
 289
 290       if (status < 0)
 291       {
 292         cupsdLogMessage(CUPSD_LOG_ERROR,
 293                         "Unable to bind socket for address %s:%d - %s.",
 294                         s, p, strerror(errno));
 295         close(lis->fd);
 296         lis->fd = -1;
 297         continue;
 298       }
 299
 300      /*
 301       * Listen for new clients.
 302       */
 303
 304       if (listen(lis->fd, ListenBackLog) < 0)
 305       {
 306         cupsdLogMessage(CUPSD_LOG_ERROR,
 307                         "Unable to listen for clients on address %s:%d - %s.",
 308                         s, p, strerror(errno));
 309         exit(errno);
 310       }
 311     }
 312
 313     fcntl(lis->fd, F_SETFD, fcntl(lis->fd, F_GETFD) | FD_CLOEXEC);
 314
 315     if (p)
 316       cupsdLogMessage(CUPSD_LOG_INFO, "Listening to %s:%d on fd %d...",
 317                       s, p, lis->fd);
 318     else
 319     {
 320       cupsdLogMessage(CUPSD_LOG_INFO, "Listening to %s on fd %d...",
 321                       s, lis->fd);
 322
 323       if (chmod(s, 0140777))
 324         cupsdLogMessage(CUPSD_LOG_ERROR,
 325                         "Unable to change permisssions on domain socket "
 326                         "\"%s\" - %s", s, strerror(errno));
 327     }
 328
 329    /*
 330     * Save the first port that is bound to the local loopback or
 331     * "any" address...
 332     */
 333
 334     if (!LocalPort && p > 0 &&
 335         (httpAddrLocalhost(&(lis->address)) ||
 336          httpAddrAny(&(lis->address))))
 337     {
 338       LocalPort       = p;
 339       LocalEncryption = lis->encryption;
 340     }
 341
 342 #ifdef AF_LOCAL
 343     if (lis->address.addr.sa_family == AF_LOCAL && !have_domain)
 344       have_domain = lis->address.un.sun_path;
 345 #endif /* AF_LOCAL */
 346   }
 347
 348  /*
 349   * Make sure that we are listening on localhost!
 350   */
 351
 352   if (!LocalPort && !have_domain)
 353   {
 354     cupsdLogMessage(CUPSD_LOG_EMERG,
 355                     "No Listen or Port lines were found to allow access via localhost!");
 356
 357    /*
 358     * Commit suicide...
 359     */
 360
 361     cupsdEndProcess(getpid(), 0);
 362   }
 363
 364  /*
 365   * Set the CUPS_SERVER, IPP_PORT, and CUPS_ENCRYPTION variables based on
 366   * the listeners...
 367   */
 368
 369   if (have_domain)
 370   {
 371    /*
 372     * Use domain sockets for the local connection...
 373     */
 374
 375     cupsdSetEnv("CUPS_SERVER", have_domain);
 376   }
 377   else
 378   {
 379    /*
 380     * Use the default local loopback address for the server...
 381     */
 382
 383     cupsdSetEnv("CUPS_SERVER", "localhost");
 384   }
 385
 386   cupsdSetEnv("CUPS_ENCRYPTION", encryptions[LocalEncryption]);
 387   cupsdSetEnvf("IPP_PORT", "%d", LocalPort);
 388
 389  /*
 390   * Resume listening for connections...
 391   */
 392
 393   cupsdResumeListening();
 394 }
 395
 396
 397 /*
 398  * 'cupsdStopListening()' - Close all listening sockets...
 399  */
 400
 401 void
 402 cupsdStopListening(void)
 403 {
 404   cupsd_listener_t      *lis;           /* Current listening socket */
 405
 406
 407   cupsdLogMessage(CUPSD_LOG_DEBUG2,
 408                   "cupsdStopListening: closing all listen sockets.");
 409
 410   cupsdPauseListening();
 411
 412   for (lis = (cupsd_listener_t *)cupsArrayFirst(Listeners);
 413        lis;
 414        lis = (cupsd_listener_t *)cupsArrayNext(Listeners))
 415   {
 416     if (lis->fd != -1)
 417     {
 418 #ifdef WIN32
 419       closesocket(lis->fd);
 420 #else
 421       close(lis->fd);
 422 #endif /* WIN32 */
 423
 424 #ifdef AF_LOCAL
 425      /*
 426       * Remove domain sockets...
 427       */
 428
 429 #  ifdef HAVE_LAUNCH_H
 430       if (lis->address.addr.sa_family == AF_LOCAL && !Launchd)
 431 #  else
 432       if (lis->address.addr.sa_family == AF_LOCAL)
 433 #  endif /* HAVE_LAUNCH_H */
 434         unlink(lis->address.un.sun_path);
 435 #endif /* AF_LOCAL */
 436     }
 437   }
 438 }
 439
 440
 441 /*
 442  * End of "$Id: listen.c 5083 2006-02-06 02:57:43Z mike $".
 443  */