hurd/hurdlookup.c

   1 /* Copyright (C) 1992, 1993, 1994, 1995, 1996 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, 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               /* If reauth'd, we must do one more retry on "" to give the new
 138                  translator a chance to make a new port for us.  */
 139               doretry == FS_RETRY_NORMAL)
 140             {
 141               /* We got a successful translation.  Now apply any open-time
 142                  action flags we were passed.  */
 143               if (flags & O_EXLOCK)
 144                 ;               /* XXX */
 145               if (!err && (flags & O_SHLOCK))
 146                 ;               /* XXX */
 147               if (!err && (flags & O_TRUNC))
 148                 err = __file_set_size (*result, 0);
 149
 150               if (err)
 151                 __mach_port_deallocate (__mach_task_self (), *result);
 152               return err;
 153             }
 154
 155           startdir = *result;
 156           file_name = retryname;
 157           break;
 158
 159         case FS_RETRY_MAGICAL:
 160           switch (retryname[0])
 161             {
 162             case '/':
 163               dirport = INIT_PORT_CRDIR;
 164               if (*result != MACH_PORT_NULL)
 165                 __mach_port_deallocate (__mach_task_self (), *result);
 166               file_name = &retryname[1];
 167               break;
 168
 169             case 'f':
 170               if (retryname[1] == 'd' && retryname[2] == '/')
 171                 {
 172                   int fd;
 173                   char *end;
 174                   int save = errno;
 175                   errno = 0;
 176                   fd = (int) strtol (&retryname[3], &end, 10);
 177                   if (end == NULL || errno || /* Malformed number.  */
 178                       /* Check for excess text after the number.  A slash
 179                          is valid; it ends the component.  Anything else
 180                          does not name a numeric file descriptor.  */
 181                       (*end != '/' && *end != '\0'))
 182                     {
 183                       errno = save;
 184                       return ENOENT;
 185                     }
 186                   if (! get_dtable_port)
 187                     err = EGRATUITOUS;
 188                   else
 189                     {
 190                       *result = (*get_dtable_port) (fd);
 191                       if (*result == MACH_PORT_NULL)
 192                         {
 193                           /* If the name was a proper number, but the file
 194                              descriptor does not exist, we return EBADF instead
 195                              of ENOENT.  */
 196                           err = errno;
 197                           errno = save;
 198                         }
 199                     }
 200                   errno = save;
 201                   if (err)
 202                     return err;
 203                   if (*end == '\0')
 204                     return 0;
 205                   else
 206                     {
 207                       /* Do a normal retry on the remaining components.  */
 208                       startdir = *result;
 209                       file_name = end + 1; /* Skip the slash.  */
 210                       break;
 211                     }
 212                 }
 213               else
 214                 goto bad_magic;
 215               break;
 216
 217             case 'm':
 218               if (retryname[1] == 'a' && retryname[2] == 'c' &&
 219                   retryname[3] == 'h' && retryname[4] == 't' &&
 220                   retryname[5] == 'y' && retryname[6] == 'p' &&
 221                   retryname[7] == 'e')
 222                 {
 223                   error_t err;
 224                   struct host_basic_info hostinfo;
 225                   mach_msg_type_number_t hostinfocnt = HOST_BASIC_INFO_COUNT;
 226                   char *p;
 227                   /* XXX want client's host */
 228                   if (err = __host_info (__mach_host_self (), HOST_BASIC_INFO,
 229                                          (natural_t *) &hostinfo,
 230                                          &hostinfocnt))
 231                     return err;
 232                   if (hostinfocnt != HOST_BASIC_INFO_COUNT)
 233                     return EGRATUITOUS;
 234                   p = _itoa (hostinfo.cpu_subtype, &retryname[8], 10, 0);
 235                   *--p = '/';
 236                   p = _itoa (hostinfo.cpu_type, &retryname[8], 10, 0);
 237                   if (p < retryname)
 238                     abort ();   /* XXX write this right if this ever happens */
 239                   if (p > retryname)
 240                     strcpy (retryname, p);
 241                   startdir = *result;
 242                 }
 243               else
 244                 goto bad_magic;
 245               break;
 246
 247             case 't':
 248               if (retryname[1] == 't' && retryname[2] == 'y')
 249                 switch (retryname[3])
 250                   {
 251                     error_t opentty (file_t *result)
 252                       {
 253                         error_t err;
 254                         error_t ctty_open (file_t port)
 255                           {
 256                             if (port == MACH_PORT_NULL)
 257                               return ENXIO; /* No controlling terminal.  */
 258                             return __termctty_open_terminal (port,
 259                                                              flags,
 260                                                              result);
 261                           }
 262                         err = (*use_init_port) (INIT_PORT_CTTYID, &ctty_open);
 263                         if (! err)
 264                           err = reauthenticate (*result);
 265                         return err;
 266                       }
 267
 268                   case '\0':
 269                     return opentty (result);
 270                   case '/':
 271                     if (err = opentty (&startdir))
 272                       return err;
 273                     strcpy (retryname, &retryname[4]);
 274                     break;
 275                   default:
 276                     goto bad_magic;
 277                   }
 278               else
 279                 goto bad_magic;
 280               break;
 281
 282             default:
 283             bad_magic:
 284               return EGRATUITOUS;
 285             }
 286           break;
 287
 288         default:
 289           return EGRATUITOUS;
 290         }
 291
 292       if (startdir != MACH_PORT_NULL)
 293         {
 294           err = lookup (startdir);
 295           __mach_port_deallocate (__mach_task_self (), startdir);
 296           startdir = MACH_PORT_NULL;
 297         }
 298       else
 299         err = (*use_init_port) (dirport, &lookup);
 300     } while (! err);
 301
 302   return err;
 303 }
 304 weak_alias (__hurd_file_name_lookup_retry, hurd_file_name_lookup_retry)
 305
 306 error_t
 307 __hurd_file_name_split (error_t (*use_init_port)
 308                           (int which, error_t (*operate) (file_t)),
 309                         file_t (*get_dtable_port) (int fd),
 310                         const char *file_name,
 311                         file_t *dir, char **name)
 312 {
 313   error_t addref (file_t crdir)
 314     {
 315       *dir = crdir;
 316       return __mach_port_mod_refs (__mach_task_self (),
 317                                    crdir, MACH_PORT_RIGHT_SEND, +1);
 318     }
 319
 320   const char *lastslash = strrchr (file_name, '/');
 321
 322   if (lastslash != NULL)
 323     {
 324       if (lastslash == file_name)
 325         {
 326           /* "/foobar" => crdir + "foobar".  */
 327           *name = (char *) file_name + 1;
 328           return (*use_init_port) (INIT_PORT_CRDIR, &addref);
 329         }
 330       else
 331         {
 332           /* "/dir1/dir2/.../file".  */
 333           char dirname[lastslash - file_name + 1];
 334           memcpy (dirname, file_name, lastslash - file_name);
 335           dirname[lastslash - file_name] = '\0';
 336           *name = (char *) lastslash + 1;
 337           return __hurd_file_name_lookup (use_init_port, get_dtable_port,
 338                                           dirname, 0, 0, dir);
 339         }
 340     }
 341   else
 342     {
 343       /* "foobar" => cwdir + "foobar".  */
 344       *name = (char *) file_name;
 345       return (*use_init_port) (INIT_PORT_CWDIR, &addref);
 346     }
 347 }
 348 weak_alias (__hurd_file_name_split, hurd_file_name_split)
 349
 350 \f
 351 file_t
 352 __file_name_lookup (const char *file_name, int flags, mode_t mode)
 353 {
 354   error_t err;
 355   file_t result;
 356
 357   err = __hurd_file_name_lookup (&_hurd_ports_use, &__getdport,
 358                                  file_name, flags, mode & ~_hurd_umask,
 359                                  &result);
 360
 361   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
 362 }
 363 weak_alias (__file_name_lookup, file_name_lookup)
 364
 365
 366 file_t
 367 __file_name_split (const char *file_name, char **name)
 368 {
 369   error_t err;
 370   file_t result;
 371
 372   err = __hurd_file_name_split (&_hurd_ports_use, &__getdport,
 373                                 file_name, &result, name);
 374
 375   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
 376 }
 377 weak_alias (__file_name_split, file_name_split)
 378
 379
 380 file_t
 381 __file_name_lookup_under (file_t startdir,
 382                           const char *file_name, int flags, mode_t mode)
 383 {
 384   error_t err;
 385   file_t result;
 386
 387   error_t use_init_port (int which, error_t (*operate) (mach_port_t))
 388     {
 389       return (which == INIT_PORT_CWDIR ? (*operate) (startdir) :
 390               _hurd_ports_use (which, operate));
 391     }
 392
 393   err = __hurd_file_name_lookup (&use_init_port, &__getdport,
 394                                  file_name, flags, mode & ~_hurd_umask,
 395                                  &result);
 396
 397   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
 398 }
 399 weak_alias (__file_name_lookup_under, file_name_lookup_under)