nis/nis_util.c

   1 /* Copyright (c) 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 1997.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <string.h>
  21 #include <rpcsvc/nis.h>
  22 #include "nis_intern.h"
  23
  24 fd_result *
  25 __nis_finddirectory (directory_obj *dir, const_nis_name name)
  26 {
  27   nis_error status;
  28   fd_args fd_args;
  29   fd_result *fd_res;
  30
  31   fd_args.dir_name = strdup (name);
  32   fd_args.requester = nis_local_host();
  33   fd_res = calloc (1, sizeof (fd_result));
  34
  35   if ((status = __do_niscall2 (dir->do_servers.do_servers_val,
  36                                dir->do_servers.do_servers_len,
  37                                NIS_FINDDIRECTORY, (xdrproc_t) xdr_fd_args,
  38                                (caddr_t) &fd_args, (xdrproc_t) xdr_fd_result,
  39                                (caddr_t) fd_res,
  40                                NO_AUTHINFO|USE_DGRAM, NULL)) != NIS_SUCCESS)
  41     fd_res->status = status;
  42
  43   return fd_res;
  44 }
  45
  46 /* This is from libc/db/hash/hash_func.c, hash3 is static there */
  47 /*
  48  * This is INCREDIBLY ugly, but fast.  We break the string up into 8 byte
  49  * units.  On the first time through the loop we get the "leftover bytes"
  50  * (strlen % 8).  On every other iteration, we perform 8 HASHC's so we handle
  51  * all 8 bytes.  Essentially, this saves us 7 cmp & branch instructions.  If
  52  * this routine is heavily used enough, it's worth the ugly coding.
  53  *
  54  * OZ's original sdbm hash
  55  */
  56 unsigned long
  57 __nis_hash (const void *keyarg, register size_t len)
  58 {
  59   register const u_char *key;
  60   register size_t loop;
  61   register u_int32_t h;
  62
  63 #define HASHC   h = *key++ + 65599 * h
  64
  65   h = 0;
  66   key = keyarg;
  67   if (len > 0)
  68     {
  69       loop = (len + 8 - 1) >> 3;
  70       switch (len & (8 - 1))
  71         {
  72         case 0:
  73           do {
  74             HASHC;
  75             /* FALLTHROUGH */
  76           case 7:
  77             HASHC;
  78             /* FALLTHROUGH */
  79           case 6:
  80             HASHC;
  81             /* FALLTHROUGH */
  82           case 5:
  83             HASHC;
  84             /* FALLTHROUGH */
  85           case 4:
  86             HASHC;
  87             /* FALLTHROUGH */
  88           case 3:
  89             HASHC;
  90             /* FALLTHROUGH */
  91           case 2:
  92             HASHC;
  93             /* FALLTHROUGH */
  94           case 1:
  95             HASHC;
  96           } while (--loop);
  97         }
  98     }
  99   return (h);
 100 }