nis/nis_subr.c

   1 /* Copyright (c) 1997-2021 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 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, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <string.h>
  21 #include <rpcsvc/nis.h>
  22 #include <shlib-compat.h>
  23
  24 nis_name
  25 nis_leaf_of (const_nis_name name)
  26 {
  27   static char result[NIS_MAXNAMELEN + 1];
  28
  29   return nis_leaf_of_r (name, result, NIS_MAXNAMELEN);
  30 }
  31 libnsl_hidden_nolink_def (nis_leaf_of, GLIBC_2_1)
  32
  33 nis_name
  34 nis_leaf_of_r (const_nis_name name, char *buffer, size_t buflen)
  35 {
  36   size_t i = 0;
  37
  38   buffer[0] = '\0';
  39
  40   while (name[i] != '.' && name[i] != '\0')
  41     i++;
  42
  43   if (__glibc_unlikely (i >= buflen))
  44     {
  45       __set_errno (ERANGE);
  46       return NULL;
  47     }
  48
  49   *((char *) __mempcpy (buffer, name, i)) = '\0';
  50
  51   return buffer;
  52 }
  53 libnsl_hidden_nolink_def (nis_leaf_of_r, GLIBC_2_1)
  54
  55 nis_name
  56 nis_name_of (const_nis_name name)
  57 {
  58   static char result[NIS_MAXNAMELEN + 1];
  59
  60   return nis_name_of_r (name, result, NIS_MAXNAMELEN);
  61 }
  62 libnsl_hidden_nolink_def (nis_name_of, GLIBC_2_1)
  63
  64 nis_name
  65 nis_name_of_r (const_nis_name name, char *buffer, size_t buflen)
  66 {
  67   char *local_domain;
  68   int diff;
  69
  70   local_domain = nis_local_directory ();
  71
  72   diff = strlen (name) - strlen (local_domain);
  73   if (diff <= 0)
  74     return NULL;
  75
  76   if (strcmp (&name[diff], local_domain) != 0)
  77     return NULL;
  78
  79   if ((size_t) diff >= buflen)
  80     {
  81       __set_errno (ERANGE);
  82       return NULL;
  83     }
  84
  85   *((char *) __mempcpy (buffer, name, diff - 1)) = '\0';
  86
  87   if (diff - 1 == 0)
  88     return NULL;
  89
  90   return buffer;
  91 }
  92 libnsl_hidden_nolink_def (nis_name_of_r, GLIBC_2_1)
  93
  94 static __always_inline int
  95 count_dots (const_nis_name str)
  96 {
  97   int count = 0;
  98
  99   for (size_t i = 0; str[i] != '\0'; ++i)
 100     if (str[i] == '.')
 101       ++count;
 102
 103   return count;
 104 }
 105
 106 /* If we run out of memory, we don't give already allocated memory
 107    free. The overhead for bringing getnames back in a safe state to
 108    free it is to big. */
 109 nis_name *
 110 nis_getnames (const_nis_name name)
 111 {
 112   const char *local_domain = nis_local_directory ();
 113   size_t local_domain_len = strlen (local_domain);
 114   size_t name_len = strlen (name);
 115   char *path;
 116   int pos = 0;
 117   char *saveptr = NULL;
 118   int have_point;
 119   const char *cp;
 120   const char *cp2;
 121
 122   int count = 2;
 123   nis_name *getnames = malloc ((count + 1) * sizeof (char *));
 124   if (__glibc_unlikely (getnames == NULL))
 125       return NULL;
 126
 127   /* Do we have a fully qualified NIS+ name ? If yes, give it back */
 128   if (name[name_len - 1] == '.')
 129     {
 130       if ((getnames[0] = strdup (name)) == NULL)
 131         {
 132         free_null:
 133           while (pos-- > 0)
 134             free (getnames[pos]);
 135           free (getnames);
 136           return NULL;
 137         }
 138
 139       getnames[1] = NULL;
 140
 141       return getnames;
 142     }
 143
 144   /* If the passed NAME is shared a suffix (the latter of course with
 145      a final dot) with each other we pass back NAME with a final
 146      dot.  */
 147   if (local_domain_len > 2)
 148     {
 149       have_point = 0;
 150       cp = &local_domain[local_domain_len - 2];
 151       cp2 = &name[name_len - 1];
 152
 153       while (*cp == *cp2)
 154         {
 155           if (*cp == '.')
 156             have_point = 1;
 157           --cp;
 158           --cp2;
 159           if (cp < local_domain)
 160             {
 161               have_point = cp2 < name || *cp2 == '.';
 162               break;
 163             }
 164           if (cp2 < name)
 165             {
 166               have_point = *cp == '.';
 167               break;
 168             }
 169         }
 170
 171       if (have_point)
 172         {
 173           getnames[0] = malloc (name_len + 2);
 174           if (getnames[0] == NULL)
 175             goto free_null;
 176
 177           strcpy (stpcpy (getnames[0], name), ".");
 178           ++pos;
 179         }
 180     }
 181
 182   /* Get the search path, where we have to search "name" */
 183   path = getenv ("NIS_PATH");
 184   if (path == NULL)
 185     path = strdupa ("$");
 186   else
 187     path = strdupa (path);
 188
 189   have_point = strchr (name, '.') != NULL;
 190
 191   cp = __strtok_r (path, ":", &saveptr);
 192   while (cp)
 193     {
 194       if (strcmp (cp, "$") == 0)
 195         {
 196           const char *cptr = local_domain;
 197           char *tmp;
 198
 199           while (*cptr != '\0' && count_dots (cptr) >= 2)
 200             {
 201               if (pos >= count)
 202                 {
 203                   count += 5;
 204                   nis_name *newp = realloc (getnames,
 205                                             (count + 1) * sizeof (char *));
 206                   if (__glibc_unlikely (newp == NULL))
 207                     goto free_null;
 208                   getnames = newp;
 209                 }
 210               tmp = malloc (strlen (cptr) + local_domain_len + name_len + 2);
 211               if (__glibc_unlikely (tmp == NULL))
 212                 goto free_null;
 213
 214               getnames[pos] = tmp;
 215               tmp = stpcpy (tmp, name);
 216               *tmp++ = '.';
 217               if (cptr[1] != '\0')
 218                 stpcpy (tmp, cptr);
 219               else
 220                 ++cptr;
 221
 222               ++pos;
 223
 224               while (*cptr != '.' && *cptr != '\0')
 225                 ++cptr;
 226               if (cptr[0] != '\0' && cptr[1] != '\0')
 227                 /* If we have only ".", don't remove the "." */
 228                 ++cptr;
 229             }
 230         }
 231       else
 232         {
 233           char *tmp;
 234           size_t cplen = strlen (cp);
 235
 236           if (cp[cplen - 1] == '$')
 237             {
 238               char *p;
 239
 240               tmp = malloc (cplen + local_domain_len + name_len + 2);
 241               if (__glibc_unlikely (tmp == NULL))
 242                 goto free_null;
 243
 244               p = __stpcpy (tmp, name);
 245               *p++ = '.';
 246               p = __mempcpy (p, cp, cplen);
 247               --p;
 248               if (p[-1] != '.')
 249                 *p++ = '.';
 250               __stpcpy (p, local_domain);
 251             }
 252           else
 253             {
 254               char *p;
 255
 256               tmp = malloc (cplen + name_len + 3);
 257               if (__glibc_unlikely (tmp == NULL))
 258                 goto free_null;
 259
 260               p = __mempcpy (tmp, name, name_len);
 261               *p++ = '.';
 262               p = __mempcpy (p, cp, cplen);
 263               if (p[-1] != '.')
 264                 *p++ = '.';
 265               *p = '\0';
 266             }
 267
 268           if (pos >= count)
 269             {
 270               count += 5;
 271               nis_name *newp = realloc (getnames,
 272                                         (count + 1) * sizeof (char *));
 273               if (__glibc_unlikely (newp == NULL))
 274                 goto free_null;
 275               getnames = newp;
 276             }
 277           getnames[pos] = tmp;
 278           ++pos;
 279         }
 280       cp = __strtok_r (NULL, ":", &saveptr);
 281     }
 282
 283   if (pos == 0
 284       && __asprintf (&getnames[pos++], "%s%s%s%s",
 285                      name, name[name_len - 1] == '.' ? "" : ".",
 286                      local_domain,
 287                      local_domain[local_domain_len - 1] == '.' ? "" : ".") < 0)
 288     goto free_null;
 289
 290   getnames[pos] = NULL;
 291
 292   return getnames;
 293 }
 294 libnsl_hidden_nolink_def (nis_getnames, GLIBC_2_1)
 295
 296 void
 297 nis_freenames (nis_name *names)
 298 {
 299   int i = 0;
 300
 301   while (names[i] != NULL)
 302     {
 303       free (names[i]);
 304       ++i;
 305     }
 306
 307   free (names);
 308 }
 309 libnsl_hidden_nolink_def  (nis_freenames, GLIBC_2_1)
 310
 311 name_pos
 312 nis_dir_cmp (const_nis_name n1, const_nis_name n2)
 313 {
 314   int len1, len2;
 315
 316   len1 = strlen (n1);
 317   len2 = strlen (n2);
 318
 319   if (len1 == len2)
 320     {
 321       if (strcmp (n1, n2) == 0)
 322         return SAME_NAME;
 323       else
 324         return NOT_SEQUENTIAL;
 325     }
 326
 327   if (len1 < len2)
 328     {
 329       if (n2[len2 - len1 - 1] != '.')
 330         return NOT_SEQUENTIAL;
 331       else if (strcmp (&n2[len2 - len1], n1) == 0)
 332         return HIGHER_NAME;
 333       else
 334         return NOT_SEQUENTIAL;
 335     }
 336   else
 337     {
 338       if (n1[len1 - len2 - 1] != '.')
 339         return NOT_SEQUENTIAL;
 340       else if (strcmp (&n1[len1 - len2], n2) == 0)
 341         return LOWER_NAME;
 342       else
 343         return NOT_SEQUENTIAL;
 344
 345     }
 346 }
 347 libnsl_hidden_nolink_def (nis_dir_cmp, GLIBC_2_1)
 348
 349 void
 350 nis_destroy_object (nis_object *obj)
 351 {
 352   nis_free_object (obj);
 353 }
 354 libnsl_hidden_nolink_def (nis_destroy_object, GLIBC_2_1)