hurd/hurdlookup.c

   1 /* Copyright (C) 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <hurd.h>
  20 #include <hurd/lookup.h>
  21 #include <string.h>
  22 #include <limits.h>
  23 #include <fcntl.h>
  24 #include "stdio-common/_itoa.h"
  25 #include <hurd/term.h>
  26
  27
  28 /* Translate the error from dir_lookup into the error the user sees.  */
  29 static inline error_t
  30 lookup_error (error_t error)
  31 {
  32   switch (error)
  33     {
  34     case EOPNOTSUPP:
  35     case MIG_BAD_ID:
  36       /* These indicate that the server does not understand dir_lookup
  37          at all.  If it were a directory, it would, by definition.  */
  38       return ENOTDIR;
  39     default:
  40       return error;
  41     }
  42 }
  43
  44 error_t
  45 __hurd_file_name_lookup (error_t (*use_init_port)
  46                            (int which, error_t (*operate) (file_t)),
  47                          file_t (*get_dtable_port) (int fd),
  48                          const char *file_name, int flags, mode_t mode,
  49                          file_t *result)
  50 {
  51   error_t err;
  52   enum retry_type doretry;
  53   char retryname[1024];         /* XXX string_t LOSES! */
  54
  55   error_t lookup (mach_port_t startdir)
  56     {
  57       while (file_name[0] == '/')
  58         file_name++;
  59
  60       return lookup_error (__dir_lookup (startdir, file_name, flags, mode,
  61                                          &doretry, retryname, result));
  62     }
  63
  64   err = (*use_init_port) (file_name[0] == '/'
  65                           ? INIT_PORT_CRDIR : INIT_PORT_CWDIR,
  66                           &lookup);
  67   if (! err)
  68     err = __hurd_file_name_lookup_retry (use_init_port, get_dtable_port,
  69                                          doretry, retryname, flags, mode,
  70                                          result);
  71
  72   return err;
  73 }
  74 weak_alias (__hurd_file_name_lookup, hurd_file_name_lookup)
  75
  76 error_t
  77 __hurd_file_name_lookup_retry (error_t (*use_init_port)
  78                                  (int which, error_t (*operate) (file_t)),
  79                                file_t (*get_dtable_port) (int fd),
  80                                enum retry_type doretry,
  81                                char retryname[1024],
  82                                int flags, mode_t mode,
  83                                file_t *result)
  84 {
  85   error_t err;
  86   char *file_name;
  87   int nloops;
  88
  89   error_t lookup (file_t startdir)
  90     {
  91       while (file_name[0] == '/')
  92         file_name++;
  93
  94       return lookup_error (__dir_lookup (startdir, file_name, flags, mode,
  95                                          &doretry, retryname, result));
  96     }
  97   error_t reauthenticate (file_t unauth)
  98     {
  99       error_t err;
 100       mach_port_t ref = __mach_reply_port ();
 101       error_t reauth (auth_t auth)
 102         {
 103           return __auth_user_authenticate (auth, unauth, ref,
 104                                            MACH_MSG_TYPE_MAKE_SEND,
 105                                            result);
 106         }
 107       err = __io_reauthenticate (unauth, ref, MACH_MSG_TYPE_MAKE_SEND);
 108       if (! err)
 109         err = (*use_init_port) (INIT_PORT_AUTH, &reauth);
 110       __mach_port_destroy (__mach_task_self (), ref);
 111       __mach_port_deallocate (__mach_task_self (), unauth);
 112       return err;
 113     }
 114
 115   nloops = 0;
 116   err = 0;
 117   do
 118     {
 119       file_t startdir = MACH_PORT_NULL;
 120       int dirport = INIT_PORT_CWDIR;
 121
 122       switch (doretry)
 123         {
 124         case FS_RETRY_REAUTH:
 125           if (err = reauthenticate (*result))
 126             return err;
 127           /* Fall through.  */
 128
 129         case FS_RETRY_NORMAL:
 130 #ifdef SYMLOOP_MAX
 131           if (nloops++ >= SYMLOOP_MAX)
 132             return ELOOP;
 133 #endif
 134
 135           /* An empty RETRYNAME indicates we have the final port.  */
 136           if (retryname[0] == '\0')
 137             {
 138               /* We got a successful translation.  Now apply any open-time
 139                  action flags we were passed.  */
 140               if (flags & O_EXLOCK)
 141                 ;               /* XXX */
 142               if (!err && (flags & O_SHLOCK))
 143                 ;               /* XXX */
 144               if (!err && (flags & O_TRUNC))
 145                 err = __file_set_size (*result, 0);
 146
 147               if (err)
 148                 __mach_port_deallocate (__mach_task_self (), *result);
 149               return err;
 150             }
 151
 152           startdir = *result;
 153           file_name = retryname;
 154           break;
 155
 156         case FS_RETRY_MAGICAL:
 157           switch (retryname[0])
 158             {
 159             case '/':
 160               dirport = INIT_PORT_CRDIR;
 161               if (*result != MACH_PORT_NULL)
 162                 __mach_port_deallocate (__mach_task_self (), *result);
 163               file_name = &retryname[1];
 164               break;
 165
 166             case 'f':
 167               if (retryname[1] == 'd' && retryname[2] == '/')
 168                 {
 169                   int fd;
 170                   char *end;
 171                   int save = errno;
 172                   errno = 0;
 173                   fd = (int) strtol (&retryname[3], &end, 10);
 174                   if (end == NULL || errno || /* Malformed number.  */
 175                       /* Check for excess text after the number.  A slash
 176                          is valid; it ends the component.  Anything else
 177                          does not name a numeric file descriptor.  */
 178                       (*end != '/' && *end != '\0'))
 179                     {
 180                       errno = save;
 181                       return ENOENT;
 182                     }
 183                   if (! get_dtable_port)
 184                     err = EGRATUITOUS;
 185                   else
 186                     {
 187                       *result = (*get_dtable_port) (fd);
 188                       if (*result == MACH_PORT_NULL)
 189                         {
 190                           /* If the name was a proper number, but the file
 191                              descriptor does not exist, we return EBADF instead
 192                              of ENOENT.  */
 193                           err = errno;
 194                           errno = save;
 195                         }
 196                     }
 197                   errno = save;
 198                   if (err)
 199                     return err;
 200                   if (*end == '\0')
 201                     return 0;
 202                   else
 203                     {
 204                       /* Do a normal retry on the remaining components.  */
 205                       startdir = *result;
 206                       file_name = end + 1; /* Skip the slash.  */
 207                       break;
 208                     }
 209                 }
 210               else
 211                 goto bad_magic;
 212               break;
 213
 214             case 'm':
 215               if (retryname[1] == 'a' && retryname[2] == 'c' &&
 216                   retryname[3] == 'h' && retryname[4] == 't' &&
 217                   retryname[5] == 'y' && retryname[6] == 'p' &&
 218                   retryname[7] == 'e')
 219                 {
 220                   error_t err;
 221                   struct host_basic_info hostinfo;
 222                   mach_msg_type_number_t hostinfocnt = HOST_BASIC_INFO_COUNT;
 223                   char *p;
 224                   /* XXX want client's host */
 225                   if (err = __host_info (__mach_host_self (), HOST_BASIC_INFO,
 226                                          (natural_t *) &hostinfo,
 227                                          &hostinfocnt))
 228                     return err;
 229                   if (hostinfocnt != HOST_BASIC_INFO_COUNT)
 230                     return EGRATUITOUS;
 231                   p = _itoa (hostinfo.cpu_subtype, &retryname[8], 10, 0);
 232                   *--p = '/';
 233                   p = _itoa (hostinfo.cpu_type, &retryname[8], 10, 0);
 234                   if (p < retryname)
 235                     abort ();   /* XXX write this right if this ever happens */
 236                   if (p > retryname)
 237                     strcpy (retryname, p);
 238                   startdir = *result;
 239                 }
 240               else
 241                 goto bad_magic;
 242               break;
 243
 244             case 't':
 245               if (retryname[1] == 't' && retryname[2] == 'y')
 246                 switch (retryname[3])
 247                   {
 248                     error_t opentty (file_t *result)
 249                       {
 250                         error_t err;
 251                         error_t ctty_open (file_t port)
 252                           {
 253                             if (port == MACH_PORT_NULL)
 254                               return ENXIO; /* No controlling terminal.  */
 255                             return __termctty_open_terminal (port,
 256                                                              flags,
 257                                                              result);
 258                           }
 259                         err = (*use_init_port) (INIT_PORT_CTTYID, &ctty_open);
 260                         if (! err)
 261                           err = reauthenticate (*result);
 262                         return err;
 263                       }
 264
 265                   case '\0':
 266                     return opentty (result);
 267                   case '/':
 268                     if (err = opentty (&startdir))
 269                       return err;
 270                     strcpy (retryname, &retryname[4]);
 271                     break;
 272                   default:
 273                     goto bad_magic;
 274                   }
 275               else
 276                 goto bad_magic;
 277               break;
 278
 279             default:
 280             bad_magic:
 281               return EGRATUITOUS;
 282             }
 283           break;
 284
 285         default:
 286           return EGRATUITOUS;
 287         }
 288
 289       if (startdir != MACH_PORT_NULL)
 290         {
 291           err = lookup (startdir);
 292           __mach_port_deallocate (__mach_task_self (), startdir);
 293           startdir = MACH_PORT_NULL;
 294         }
 295       else
 296         err = (*use_init_port) (dirport, &lookup);
 297     } while (! err);
 298
 299   return err;
 300 }
 301 weak_alias (__hurd_file_name_lookup_retry, hurd_file_name_lookup_retry)
 302
 303 error_t
 304 __hurd_file_name_split (error_t (*use_init_port)
 305                           (int which, error_t (*operate) (file_t)),
 306                         file_t (*get_dtable_port) (int fd),
 307                         const char *file_name,
 308                         file_t *dir, char **name)
 309 {
 310   error_t addref (file_t crdir)
 311     {
 312       *dir = crdir;
 313       return __mach_port_mod_refs (__mach_task_self (),
 314                                    crdir, MACH_PORT_RIGHT_SEND, +1);
 315     }
 316
 317   const char *lastslash = strrchr (file_name, '/');
 318
 319   if (lastslash != NULL)
 320     {
 321       if (lastslash == file_name)
 322         {
 323           /* "/foobar" => crdir + "foobar".  */
 324           *name = (char *) file_name + 1;
 325           return (*use_init_port) (INIT_PORT_CRDIR, &addref);
 326         }
 327       else
 328         {
 329           /* "/dir1/dir2/.../file".  */
 330           char dirname[lastslash - file_name + 1];
 331           memcpy (dirname, file_name, lastslash - file_name);
 332           dirname[lastslash - file_name] = '\0';
 333           *name = (char *) lastslash + 1;
 334           return __hurd_file_name_lookup (use_init_port, get_dtable_port,
 335                                           dirname, 0, 0, dir);
 336         }
 337     }
 338   else
 339     {
 340       /* "foobar" => cwdir + "foobar".  */
 341       *name = (char *) file_name;
 342       return (*use_init_port) (INIT_PORT_CWDIR, &addref);
 343     }
 344 }
 345 weak_alias (__hurd_file_name_split, hurd_file_name_split)
 346
 347 \f
 348 file_t
 349 __file_name_lookup (const char *file_name, int flags, mode_t mode)
 350 {
 351   error_t err;
 352   file_t result;
 353
 354   err = __hurd_file_name_lookup (&_hurd_ports_use, &__getdport,
 355                                  file_name, flags, mode,
 356                                  &result);
 357
 358   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
 359 }
 360 weak_alias (__file_name_lookup, file_name_lookup)
 361
 362
 363 file_t
 364 __file_name_split (const char *file_name, char **name)
 365 {
 366   error_t err;
 367   file_t result;
 368
 369   err = __hurd_file_name_split (&_hurd_ports_use, &__getdport,
 370                                 file_name, &result, name);
 371
 372   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
 373 }
 374 weak_alias (__file_name_split, file_name_split)
 375
 376
 377 file_t
 378 __file_name_lookup_under (file_t startdir,
 379                           const char *file_name, int flags, mode_t mode)
 380 {
 381   error_t err;
 382   file_t result;
 383
 384   error_t use_init_port (int which, error_t (*operate) (mach_port_t))
 385     {
 386       return (which == INIT_PORT_CWDIR ? (*operate) (startdir) :
 387               _hurd_ports_use (which, operate));
 388     }
 389
 390   err = __hurd_file_name_lookup (&use_init_port, &__getdport,
 391                                  file_name, flags, mode,
 392                                  &result);
 393
 394   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
 395 }
 396 weak_alias (__file_name_lookup_under, file_name_lookup_under)