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                          error_t (*lookup)
  49                            (file_t dir, char *name, int flags, mode_t mode,
  50                             retry_type *do_retry, string_t retry_name,
  51                             mach_port_t *result),
  52                          const char *file_name, int flags, mode_t mode,
  53                          file_t *result)
  54 {
  55   error_t err;
  56   enum retry_type doretry;
  57   char retryname[1024];         /* XXX string_t LOSES! */
  58
  59   error_t lookup_op (mach_port_t startdir)
  60     {
  61       while (file_name[0] == '/')
  62         file_name++;
  63
  64       return lookup_error ((*lookup) (startdir, file_name, flags, mode,
  65                                       &doretry, retryname, result));
  66     }
  67
  68   if (! lookup)
  69     lookup = __dir_lookup;
  70
  71   err = (*use_init_port) (file_name[0] == '/'
  72                           ? INIT_PORT_CRDIR : INIT_PORT_CWDIR,
  73                           &lookup_op);
  74   if (! err)
  75     err = __hurd_file_name_lookup_retry (use_init_port, get_dtable_port, lookup,
  76                                          doretry, retryname, flags, mode,
  77                                          result);
  78
  79   return err;
  80 }
  81 weak_alias (__hurd_file_name_lookup, hurd_file_name_lookup)
  82
  83 error_t
  84 __hurd_file_name_lookup_retry (error_t (*use_init_port)
  85                                  (int which, error_t (*operate) (file_t)),
  86                                file_t (*get_dtable_port) (int fd),
  87                                error_t (*lookup)
  88                                  (file_t dir, char *name, int flags, mode_t mode,
  89                                   retry_type *do_retry, string_t retry_name,
  90                                   mach_port_t *result),
  91                                enum retry_type doretry,
  92                                char retryname[1024],
  93                                int flags, mode_t mode,
  94                                file_t *result)
  95 {
  96   error_t err;
  97   char *file_name;
  98   int nloops;
  99
 100   error_t lookup_op (file_t startdir)
 101     {
 102       while (file_name[0] == '/')
 103         file_name++;
 104
 105       return lookup_error ((*lookup) (startdir, file_name, flags, mode,
 106                                       &doretry, retryname, result));
 107     }
 108   error_t reauthenticate (file_t unauth)
 109     {
 110       error_t err;
 111       mach_port_t ref = __mach_reply_port ();
 112       error_t reauth (auth_t auth)
 113         {
 114           return __auth_user_authenticate (auth, ref,
 115                                            MACH_MSG_TYPE_MAKE_SEND,
 116                                            result);
 117         }
 118       err = __io_reauthenticate (unauth, ref, MACH_MSG_TYPE_MAKE_SEND);
 119       if (! err)
 120         err = (*use_init_port) (INIT_PORT_AUTH, &reauth);
 121       __mach_port_destroy (__mach_task_self (), ref);
 122       __mach_port_deallocate (__mach_task_self (), unauth);
 123       return err;
 124     }
 125
 126   if (! lookup)
 127     lookup = __dir_lookup;
 128
 129   nloops = 0;
 130   err = 0;
 131   do
 132     {
 133       file_t startdir = MACH_PORT_NULL;
 134       int dirport = INIT_PORT_CWDIR;
 135
 136       switch (doretry)
 137         {
 138         case FS_RETRY_REAUTH:
 139           if (err = reauthenticate (*result))
 140             return err;
 141           /* Fall through.  */
 142
 143         case FS_RETRY_NORMAL:
 144 #ifdef SYMLOOP_MAX
 145           if (nloops++ >= SYMLOOP_MAX)
 146             return ELOOP;
 147 #endif
 148
 149           /* An empty RETRYNAME indicates we have the final port.  */
 150           if (retryname[0] == '\0' &&
 151               /* If reauth'd, we must do one more retry on "" to give the new
 152                  translator a chance to make a new port for us.  */
 153               doretry == FS_RETRY_NORMAL)
 154             {
 155               /* We got a successful translation.  Now apply any open-time
 156                  action flags we were passed.  */
 157               if (flags & O_EXLOCK)
 158                 ;               /* XXX */
 159               if (!err && (flags & O_SHLOCK))
 160                 ;               /* XXX */
 161               if (!err && (flags & O_TRUNC))
 162                 err = __file_set_size (*result, 0);
 163
 164               if (err)
 165                 __mach_port_deallocate (__mach_task_self (), *result);
 166               return err;
 167             }
 168
 169           startdir = *result;
 170           file_name = retryname;
 171           break;
 172
 173         case FS_RETRY_MAGICAL:
 174           switch (retryname[0])
 175             {
 176             case '/':
 177               dirport = INIT_PORT_CRDIR;
 178               if (*result != MACH_PORT_NULL)
 179                 __mach_port_deallocate (__mach_task_self (), *result);
 180               file_name = &retryname[1];
 181               break;
 182
 183             case 'f':
 184               if (retryname[1] == 'd' && retryname[2] == '/')
 185                 {
 186                   int fd;
 187                   char *end;
 188                   int save = errno;
 189                   errno = 0;
 190                   fd = (int) strtol (&retryname[3], &end, 10);
 191                   if (end == NULL || errno || /* Malformed number.  */
 192                       /* Check for excess text after the number.  A slash
 193                          is valid; it ends the component.  Anything else
 194                          does not name a numeric file descriptor.  */
 195                       (*end != '/' && *end != '\0'))
 196                     {
 197                       errno = save;
 198                       return ENOENT;
 199                     }
 200                   if (! get_dtable_port)
 201                     err = EGRATUITOUS;
 202                   else
 203                     {
 204                       *result = (*get_dtable_port) (fd);
 205                       if (*result == MACH_PORT_NULL)
 206                         {
 207                           /* If the name was a proper number, but the file
 208                              descriptor does not exist, we return EBADF instead
 209                              of ENOENT.  */
 210                           err = errno;
 211                           errno = save;
 212                         }
 213                     }
 214                   errno = save;
 215                   if (err)
 216                     return err;
 217                   if (*end == '\0')
 218                     return 0;
 219                   else
 220                     {
 221                       /* Do a normal retry on the remaining components.  */
 222                       startdir = *result;
 223                       file_name = end + 1; /* Skip the slash.  */
 224                       break;
 225                     }
 226                 }
 227               else
 228                 goto bad_magic;
 229               break;
 230
 231             case 'm':
 232               if (retryname[1] == 'a' && retryname[2] == 'c' &&
 233                   retryname[3] == 'h' && retryname[4] == 't' &&
 234                   retryname[5] == 'y' && retryname[6] == 'p' &&
 235                   retryname[7] == 'e')
 236                 {
 237                   error_t err;
 238                   struct host_basic_info hostinfo;
 239                   mach_msg_type_number_t hostinfocnt = HOST_BASIC_INFO_COUNT;
 240                   char *p;
 241                   /* XXX want client's host */
 242                   if (err = __host_info (__mach_host_self (), HOST_BASIC_INFO,
 243                                          (natural_t *) &hostinfo,
 244                                          &hostinfocnt))
 245                     return err;
 246                   if (hostinfocnt != HOST_BASIC_INFO_COUNT)
 247                     return EGRATUITOUS;
 248                   p = _itoa (hostinfo.cpu_subtype, &retryname[8], 10, 0);
 249                   *--p = '/';
 250                   p = _itoa (hostinfo.cpu_type, &retryname[8], 10, 0);
 251                   if (p < retryname)
 252                     abort ();   /* XXX write this right if this ever happens */
 253                   if (p > retryname)
 254                     strcpy (retryname, p);
 255                   startdir = *result;
 256                 }
 257               else
 258                 goto bad_magic;
 259               break;
 260
 261             case 't':
 262               if (retryname[1] == 't' && retryname[2] == 'y')
 263                 switch (retryname[3])
 264                   {
 265                     error_t opentty (file_t *result)
 266                       {
 267                         error_t err;
 268                         error_t ctty_open (file_t port)
 269                           {
 270                             if (port == MACH_PORT_NULL)
 271                               return ENXIO; /* No controlling terminal.  */
 272                             return __termctty_open_terminal (port,
 273                                                              flags,
 274                                                              result);
 275                           }
 276                         err = (*use_init_port) (INIT_PORT_CTTYID, &ctty_open);
 277                         if (! err)
 278                           err = reauthenticate (*result);
 279                         return err;
 280                       }
 281
 282                   case '\0':
 283                     return opentty (result);
 284                   case '/':
 285                     if (err = opentty (&startdir))
 286                       return err;
 287                     strcpy (retryname, &retryname[4]);
 288                     break;
 289                   default:
 290                     goto bad_magic;
 291                   }
 292               else
 293                 goto bad_magic;
 294               break;
 295
 296             default:
 297             bad_magic:
 298               return EGRATUITOUS;
 299             }
 300           break;
 301
 302         default:
 303           return EGRATUITOUS;
 304         }
 305
 306       if (startdir != MACH_PORT_NULL)
 307         {
 308           err = lookup_op (startdir);
 309           __mach_port_deallocate (__mach_task_self (), startdir);
 310           startdir = MACH_PORT_NULL;
 311         }
 312       else
 313         err = (*use_init_port) (dirport, &lookup_op);
 314     } while (! err);
 315
 316   return err;
 317 }
 318 weak_alias (__hurd_file_name_lookup_retry, hurd_file_name_lookup_retry)
 319
 320 error_t
 321 __hurd_file_name_split (error_t (*use_init_port)
 322                           (int which, error_t (*operate) (file_t)),
 323                         file_t (*get_dtable_port) (int fd),
 324                         error_t (*lookup)
 325                           (file_t dir, char *name, int flags, mode_t mode,
 326                            retry_type *do_retry, string_t retry_name,
 327                            mach_port_t *result),
 328                         const char *file_name,
 329                         file_t *dir, char **name)
 330 {
 331   error_t addref (file_t crdir)
 332     {
 333       *dir = crdir;
 334       return __mach_port_mod_refs (__mach_task_self (),
 335                                    crdir, MACH_PORT_RIGHT_SEND, +1);
 336     }
 337
 338   const char *lastslash = strrchr (file_name, '/');
 339
 340   if (lastslash != NULL)
 341     {
 342       if (lastslash == file_name)
 343         {
 344           /* "/foobar" => crdir + "foobar".  */
 345           *name = (char *) file_name + 1;
 346           return (*use_init_port) (INIT_PORT_CRDIR, &addref);
 347         }
 348       else
 349         {
 350           /* "/dir1/dir2/.../file".  */
 351           char dirname[lastslash - file_name + 1];
 352           memcpy (dirname, file_name, lastslash - file_name);
 353           dirname[lastslash - file_name] = '\0';
 354           *name = (char *) lastslash + 1;
 355           return
 356             __hurd_file_name_lookup (use_init_port, get_dtable_port, lookup,
 357                                      dirname, 0, 0, dir);
 358         }
 359     }
 360   else
 361     {
 362       /* "foobar" => cwdir + "foobar".  */
 363       *name = (char *) file_name;
 364       return (*use_init_port) (INIT_PORT_CWDIR, &addref);
 365     }
 366 }
 367 weak_alias (__hurd_file_name_split, hurd_file_name_split)
 368
 369 \f
 370 file_t
 371 __file_name_lookup (const char *file_name, int flags, mode_t mode)
 372 {
 373   error_t err;
 374   file_t result;
 375
 376   err = __hurd_file_name_lookup (&_hurd_ports_use, &__getdport, 0,
 377                                  file_name, flags, mode & ~_hurd_umask,
 378                                  &result);
 379
 380   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
 381 }
 382 weak_alias (__file_name_lookup, file_name_lookup)
 383
 384
 385 file_t
 386 __file_name_split (const char *file_name, char **name)
 387 {
 388   error_t err;
 389   file_t result;
 390
 391   err = __hurd_file_name_split (&_hurd_ports_use, &__getdport, 0,
 392                                 file_name, &result, name);
 393
 394   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
 395 }
 396 weak_alias (__file_name_split, file_name_split)
 397
 398
 399 file_t
 400 __file_name_lookup_under (file_t startdir,
 401                           const char *file_name, int flags, mode_t mode)
 402 {
 403   error_t err;
 404   file_t result;
 405
 406   error_t use_init_port (int which, error_t (*operate) (mach_port_t))
 407     {
 408       return (which == INIT_PORT_CWDIR ? (*operate) (startdir) :
 409               _hurd_ports_use (which, operate));
 410     }
 411
 412   err = __hurd_file_name_lookup (&use_init_port, &__getdport, 0,
 413                                  file_name, flags, mode & ~_hurd_umask,
 414                                  &result);
 415
 416   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
 417 }
 418 weak_alias (__file_name_lookup_under, file_name_lookup_under)