1: /* _hurd_socket_server - Find the server for a socket domain.
    2:    Copyright (C) 1991,92,93,94,95,97,99 Free Software Foundation, Inc.
    3:    This file is part of the GNU C Library.
    4: 
    5:    The GNU C Library is free software; you can redistribute it and/or
    6:    modify it under the terms of the GNU Lesser General Public
    7:    License as published by the Free Software Foundation; either
    8:    version 2.1 of the License, or (at your option) any later version.
    9: 
   10:    The GNU C Library is distributed in the hope that it will be useful,
   11:    but WITHOUT ANY WARRANTY; without even the implied warranty of
   12:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   13:    Lesser General Public License for more details.
   14: 
   15:    You should have received a copy of the GNU Lesser General Public
   16:    License along with the GNU C Library; if not, write to the Free
   17:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   18:    02111-1307 USA.  */
   19: 
   20: #include <hurd.h>
   21: #include <sys/socket.h>
   22: #include <stdlib.h>
   23: #include <string.h>
   24: #include <hurd/paths.h>
   25: #include <stdio.h>
   26: #include "stdio-common/_itoa.h"
   27: #include <cthreads.h>           /* For `struct mutex'.  */
   28: #include "hurdmalloc.h"         /* XXX */
   29: 
   30: static struct mutex lock;
   31: 
   32: static file_t *servers;
   33: static int max_domain = -1;
   34: 
   35: /* Return a port to the socket server for DOMAIN.
   36:    Socket servers translate nodes in the directory _SERVERS_SOCKET
   37:    (canonically /servers/socket).  These naming point nodes are named
   38:    by the simplest decimal representation of the socket domain number,
   39:    for example "/servers/socket/3".
   40: 
   41:    Socket servers are assumed not to change very often.
   42:    The library keeps all the server socket ports it has ever looked up,
   43:    and does not look them up in /servers/socket more than once.  */
   44: 
   45: socket_t
   46: _hurd_socket_server (int domain, int dead)
   47: {
   48:   socket_t server;
   49: 
   50:   HURD_CRITICAL_BEGIN;
   51:   __mutex_lock (&lock);
   52: 
   53:   if (domain > max_domain)
   54:     {
   55:       error_t save = errno;
   56:       file_t *new = realloc (servers, (domain + 1) * sizeof (file_t));
   57:       if (new != NULL)
   58:         {
   59:           do
   60:             new[++max_domain] = MACH_PORT_NULL;
   61:           while (max_domain < domain);
   62:           servers = new;
   63:         }
   64:       else
   65:         /* No space to cache the port; we will just fetch it anew below.  */
   66:         errno = save;
   67:     }
   68: 
   69:   if (dead && domain <= max_domain)
   70:     {
   71:       /* The user says the port we returned earlier (now in SERVERS[DOMAIN])
   72:          was dead.  Clear the cache and fetch a new one below.  */
   73:       __mach_port_deallocate (__mach_task_self (), servers[domain]);
   74:       servers[domain] = MACH_PORT_NULL;
   75:     }
   76: 
   77:   if (domain > max_domain || servers[domain] == MACH_PORT_NULL)
   78:     {
   79:       char name[sizeof (_SERVERS_SOCKET) + 100];
   80:       char *np = &name[sizeof (name)];
   81:       *--np = '\0';
   82:       np = _itoa (domain, np, 10, 0);
   83:       *--np = '/';
   84:       np -= sizeof (_SERVERS_SOCKET) - 1;
   85:       memcpy (np, _SERVERS_SOCKET, sizeof (_SERVERS_SOCKET) - 1);
   86:       server = __file_name_lookup (np, 0, 0);
   87:       if (domain <= max_domain)
   88:         servers[domain] = server;
   89:     }
   90:   else
   91:     server = servers[domain];
   92: 
   93:   if (server == MACH_PORT_NULL && errno == ENOENT)
   94:     /* If the server node is absent, we don't support that protocol.  */
   95:     errno = EPFNOSUPPORT;
   96: 
   97:   __mutex_unlock (&lock);
   98:   HURD_CRITICAL_END;
   99: 
  100:   return server;
  101: }
  102: ^L
  103: static void
  104: init (void)
  105: {
  106:   int i;
  107: 
  108:   __mutex_init (&lock);
  109: 
  110:   for (i = 0; i < max_domain; ++i)
  111:     servers[i] = MACH_PORT_NULL;
  112: 
  113:   (void) &init;                 /* Avoid "defined but not used" warning.  */
  114: }
  115: text_set_element (_hurd_preinit_hook, init);