nis/nss_nis/nis-alias.c

   1 /* Copyright (C) 1996-2002, 2003, 2006 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 1996.
   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 <nss.h>
  21 #include <ctype.h>
  22 #include <errno.h>
  23 #include <string.h>
  24 #include <aliases.h>
  25 #include <bits/libc-lock.h>
  26 #include <rpcsvc/yp.h>
  27 #include <rpcsvc/ypclnt.h>
  28
  29 #include "nss-nis.h"
  30
  31 __libc_lock_define_initialized (static, lock)
  32
  33 static bool_t new_start = 1;
  34 static char *oldkey;
  35 static int oldkeylen;
  36
  37 static int
  38 _nss_nis_parse_aliasent (const char *key, char *alias, struct aliasent *result,
  39                          char *buffer, size_t buflen, int *errnop)
  40 {
  41   char *first_unused = buffer + strlen (alias) + 1;
  42   size_t room_left =
  43     buflen - (buflen % __alignof__ (char *)) - strlen (alias) - 2;
  44   char *line;
  45   char *cp;
  46
  47   result->alias_members_len = 0;
  48   *first_unused = '\0';
  49   first_unused++;
  50   strcpy (first_unused, key);
  51
  52   if (first_unused[room_left - 1] != '\0')
  53     {
  54       /* The line is too long for our buffer.  */
  55     no_more_room:
  56       *errnop = ERANGE;
  57       return -1;
  58     }
  59
  60   result->alias_name = first_unused;
  61
  62   /* Terminate the line for any case.  */
  63   cp = strpbrk (alias, "#\n");
  64   if (cp != NULL)
  65     *cp = '\0';
  66
  67   first_unused += strlen (result->alias_name) + 1;
  68   /* Adjust the pointer so it is aligned for
  69      storing pointers.  */
  70   first_unused += __alignof__ (char *) - 1;
  71   first_unused -= ((first_unused - (char *) 0) % __alignof__ (char *));
  72   result->alias_members = (char **) first_unused;
  73
  74   line = alias;
  75
  76   while (*line != '\0')
  77     {
  78       /* Skip leading blanks.  */
  79       while (isspace (*line))
  80         line++;
  81
  82       if (*line == '\0')
  83         break;
  84
  85       if (room_left < sizeof (char *))
  86           goto no_more_room;
  87       room_left -= sizeof (char *);
  88       result->alias_members[result->alias_members_len] = line;
  89
  90       while (*line != '\0' && *line != ',')
  91         line++;
  92
  93       if (line != result->alias_members[result->alias_members_len])
  94         {
  95           *line = '\0';
  96           line++;
  97           result->alias_members_len++;
  98         }
  99     }
 100   return result->alias_members_len == 0 ? 0 : 1;
 101 }
 102
 103 enum nss_status
 104 _nss_nis_setaliasent (void)
 105 {
 106   __libc_lock_lock (lock);
 107
 108   new_start = 1;
 109   if (oldkey != NULL)
 110     {
 111       free (oldkey);
 112       oldkey = NULL;
 113       oldkeylen = 0;
 114     }
 115
 116   __libc_lock_unlock (lock);
 117
 118   return NSS_STATUS_SUCCESS;
 119 }
 120 /* The 'endaliasent' function is identical.  */
 121 strong_alias (_nss_nis_setaliasent, _nss_nis_endaliasent)
 122
 123 static enum nss_status
 124 internal_nis_getaliasent_r (struct aliasent *alias, char *buffer,
 125                             size_t buflen, int *errnop)
 126 {
 127   char *domain;
 128
 129   if (__builtin_expect (yp_get_default_domain (&domain), 0))
 130     return NSS_STATUS_UNAVAIL;
 131
 132   alias->alias_local = 0;
 133
 134   /* Get the next entry until we found a correct one. */
 135   int parse_res;
 136   do
 137     {
 138       char *result;
 139       int len;
 140       char *outkey;
 141       int keylen;
 142       int yperr;
 143
 144       if (new_start)
 145         yperr = yp_first (domain, "mail.aliases", &outkey, &keylen, &result,
 146                           &len);
 147       else
 148         yperr = yp_next (domain, "mail.aliases", oldkey, oldkeylen, &outkey,
 149                          &keylen, &result, &len);
 150
 151       if (__builtin_expect (yperr != YPERR_SUCCESS, 0))
 152         {
 153           enum nss_status retval = yperr2nss (yperr);
 154
 155           if (retval == NSS_STATUS_TRYAGAIN)
 156             *errnop = errno;
 157           return retval;
 158         }
 159
 160       if (__builtin_expect ((size_t) (len + 1) > buflen, 0))
 161         {
 162           free (result);
 163           *errnop = ERANGE;
 164           return NSS_STATUS_TRYAGAIN;
 165         }
 166       char *p = strncpy (buffer, result, len);
 167       buffer[len] = '\0';
 168       while (isspace (*p))
 169         ++p;
 170       free (result);
 171
 172       parse_res = _nss_nis_parse_aliasent (outkey, p, alias, buffer,
 173                                            buflen, errnop);
 174       if (__builtin_expect (parse_res == -1, 0))
 175         {
 176           free (outkey);
 177           *errnop = ERANGE;
 178           return NSS_STATUS_TRYAGAIN;
 179         }
 180
 181       free (oldkey);
 182       oldkey = outkey;
 183       oldkeylen = keylen;
 184       new_start = 0;
 185     }
 186   while (!parse_res);
 187
 188   return NSS_STATUS_SUCCESS;
 189 }
 190
 191 enum nss_status
 192 _nss_nis_getaliasent_r (struct aliasent *alias, char *buffer, size_t buflen,
 193                         int *errnop)
 194 {
 195   enum nss_status status;
 196
 197   __libc_lock_lock (lock);
 198
 199   status = internal_nis_getaliasent_r (alias, buffer, buflen, errnop);
 200
 201   __libc_lock_unlock (lock);
 202
 203   return status;
 204 }
 205
 206 enum nss_status
 207 _nss_nis_getaliasbyname_r (const char *name, struct aliasent *alias,
 208                            char *buffer, size_t buflen, int *errnop)
 209 {
 210   if (name == NULL)
 211     {
 212       *errnop = EINVAL;
 213       return NSS_STATUS_UNAVAIL;
 214     }
 215
 216   size_t namlen = strlen (name);
 217   char name2[namlen + 1];
 218
 219   char *domain;
 220   if (__builtin_expect (yp_get_default_domain (&domain), 0))
 221     return NSS_STATUS_UNAVAIL;
 222
 223   /* Convert name to lowercase.  */
 224   size_t i;
 225   for (i = 0; i < namlen; ++i)
 226     name2[i] = _tolower (name[i]);
 227   name2[i] = '\0';
 228
 229   char *result;
 230   int len;
 231   int yperr = yp_match (domain, "mail.aliases", name2, namlen, &result, &len);
 232
 233   if (__builtin_expect (yperr != YPERR_SUCCESS, 0))
 234     {
 235       enum nss_status retval = yperr2nss (yperr);
 236
 237       if (retval == NSS_STATUS_TRYAGAIN)
 238         *errnop = errno;
 239       return retval;
 240     }
 241
 242   if (__builtin_expect ((size_t) (len + 1) > buflen, 0))
 243     {
 244       free (result);
 245       *errnop = ERANGE;
 246       return NSS_STATUS_TRYAGAIN;
 247     }
 248
 249   char *p = strncpy (buffer, result, len);
 250   buffer[len] = '\0';
 251   while (isspace (*p))
 252     ++p;
 253   free (result);
 254
 255   alias->alias_local = 0;
 256   int parse_res = _nss_nis_parse_aliasent (name, p, alias, buffer, buflen,
 257                                            errnop);
 258   if (__builtin_expect (parse_res < 1, 0))
 259     {
 260       if (parse_res == -1)
 261         return NSS_STATUS_TRYAGAIN;
 262       else
 263         return NSS_STATUS_NOTFOUND;
 264     }
 265
 266   return NSS_STATUS_SUCCESS;
 267 }