hurd/hurdlookup.c

   1 /* Copyright (C) 1992, 93, 94, 95, 96, 97 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 not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, 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_TRUNC)
 158                 err = __file_set_size (*result, 0);
 159
 160               if (err)
 161                 __mach_port_deallocate (__mach_task_self (), *result);
 162               return err;
 163             }
 164
 165           startdir = *result;
 166           file_name = retryname;
 167           break;
 168
 169         case FS_RETRY_MAGICAL:
 170           switch (retryname[0])
 171             {
 172             case '/':
 173               dirport = INIT_PORT_CRDIR;
 174               if (*result != MACH_PORT_NULL)
 175                 __mach_port_deallocate (__mach_task_self (), *result);
 176               file_name = &retryname[1];
 177               break;
 178
 179             case 'f':
 180               if (retryname[1] == 'd' && retryname[2] == '/')
 181                 {
 182                   int fd;
 183                   char *end;
 184                   int save = errno;
 185                   errno = 0;
 186                   fd = (int) strtol (&retryname[3], &end, 10);
 187                   if (end == NULL || errno || /* Malformed number.  */
 188                       /* Check for excess text after the number.  A slash
 189                          is valid; it ends the component.  Anything else
 190                          does not name a numeric file descriptor.  */
 191                       (*end != '/' && *end != '\0'))
 192                     {
 193                       errno = save;
 194                       return ENOENT;
 195                     }
 196                   if (! get_dtable_port)
 197                     err = EGRATUITOUS;
 198                   else
 199                     {
 200                       *result = (*get_dtable_port) (fd);
 201                       if (*result == MACH_PORT_NULL)
 202                         {
 203                           /* If the name was a proper number, but the file
 204                              descriptor does not exist, we return EBADF instead
 205                              of ENOENT.  */
 206                           err = errno;
 207                           errno = save;
 208                         }
 209                     }
 210                   errno = save;
 211                   if (err)
 212                     return err;
 213                   if (*end == '\0')
 214                     return 0;
 215                   else
 216                     {
 217                       /* Do a normal retry on the remaining components.  */
 218                       startdir = *result;
 219                       file_name = end + 1; /* Skip the slash.  */
 220                       break;
 221                     }
 222                 }
 223               else
 224                 goto bad_magic;
 225               break;
 226
 227             case 'm':
 228               if (retryname[1] == 'a' && retryname[2] == 'c' &&
 229                   retryname[3] == 'h' && retryname[4] == 't' &&
 230                   retryname[5] == 'y' && retryname[6] == 'p' &&
 231                   retryname[7] == 'e')
 232                 {
 233                   error_t err;
 234                   struct host_basic_info hostinfo;
 235                   mach_msg_type_number_t hostinfocnt = HOST_BASIC_INFO_COUNT;
 236                   char *p;
 237                   /* XXX want client's host */
 238                   if (err = __host_info (__mach_host_self (), HOST_BASIC_INFO,
 239                                          (natural_t *) &hostinfo,
 240                                          &hostinfocnt))
 241                     return err;
 242                   if (hostinfocnt != HOST_BASIC_INFO_COUNT)
 243                     return EGRATUITOUS;
 244                   p = _itoa (hostinfo.cpu_subtype, &retryname[8], 10, 0);
 245                   *--p = '/';
 246                   p = _itoa (hostinfo.cpu_type, &retryname[8], 10, 0);
 247                   if (p < retryname)
 248                     abort ();   /* XXX write this right if this ever happens */
 249                   if (p > retryname)
 250                     strcpy (retryname, p);
 251                   startdir = *result;
 252                 }
 253               else
 254                 goto bad_magic;
 255               break;
 256
 257             case 't':
 258               if (retryname[1] == 't' && retryname[2] == 'y')
 259                 switch (retryname[3])
 260                   {
 261                     error_t opentty (file_t *result)
 262                       {
 263                         error_t err;
 264                         error_t ctty_open (file_t port)
 265                           {
 266                             if (port == MACH_PORT_NULL)
 267                               return ENXIO; /* No controlling terminal.  */
 268                             return __termctty_open_terminal (port,
 269                                                              flags,
 270                                                              result);
 271                           }
 272                         err = (*use_init_port) (INIT_PORT_CTTYID, &ctty_open);
 273                         if (! err)
 274                           err = reauthenticate (*result);
 275                         return err;
 276                       }
 277
 278                   case '\0':
 279                     return opentty (result);
 280                   case '/':
 281                     if (err = opentty (&startdir))
 282                       return err;
 283                     strcpy (retryname, &retryname[4]);
 284                     break;
 285                   default:
 286                     goto bad_magic;
 287                   }
 288               else
 289                 goto bad_magic;
 290               break;
 291
 292             default:
 293             bad_magic:
 294               return EGRATUITOUS;
 295             }
 296           break;
 297
 298         default:
 299           return EGRATUITOUS;
 300         }
 301
 302       if (startdir != MACH_PORT_NULL)
 303         {
 304           err = lookup_op (startdir);
 305           __mach_port_deallocate (__mach_task_self (), startdir);
 306           startdir = MACH_PORT_NULL;
 307         }
 308       else
 309         err = (*use_init_port) (dirport, &lookup_op);
 310     } while (! err);
 311
 312   return err;
 313 }
 314 weak_alias (__hurd_file_name_lookup_retry, hurd_file_name_lookup_retry)
 315
 316 error_t
 317 __hurd_file_name_split (error_t (*use_init_port)
 318                           (int which, error_t (*operate) (file_t)),
 319                         file_t (*get_dtable_port) (int fd),
 320                         error_t (*lookup)
 321                           (file_t dir, char *name, int flags, mode_t mode,
 322                            retry_type *do_retry, string_t retry_name,
 323                            mach_port_t *result),
 324                         const char *file_name,
 325                         file_t *dir, char **name)
 326 {
 327   error_t addref (file_t crdir)
 328     {
 329       *dir = crdir;
 330       return __mach_port_mod_refs (__mach_task_self (),
 331                                    crdir, MACH_PORT_RIGHT_SEND, +1);
 332     }
 333
 334   const char *lastslash = strrchr (file_name, '/');
 335
 336   if (lastslash != NULL)
 337     {
 338       if (lastslash == file_name)
 339         {
 340           /* "/foobar" => crdir + "foobar".  */
 341           *name = (char *) file_name + 1;
 342           return (*use_init_port) (INIT_PORT_CRDIR, &addref);
 343         }
 344       else
 345         {
 346           /* "/dir1/dir2/.../file".  */
 347           char dirname[lastslash - file_name + 1];
 348           memcpy (dirname, file_name, lastslash - file_name);
 349           dirname[lastslash - file_name] = '\0';
 350           *name = (char *) lastslash + 1;
 351           return
 352             __hurd_file_name_lookup (use_init_port, get_dtable_port, lookup,
 353                                      dirname, 0, 0, dir);
 354         }
 355     }
 356   else
 357     {
 358       /* "foobar" => cwdir + "foobar".  */
 359       *name = (char *) file_name;
 360       return (*use_init_port) (INIT_PORT_CWDIR, &addref);
 361     }
 362 }
 363 weak_alias (__hurd_file_name_split, hurd_file_name_split)
 364
 365 \f
 366 file_t
 367 __file_name_lookup (const char *file_name, int flags, mode_t mode)
 368 {
 369   error_t err;
 370   file_t result;
 371
 372   err = __hurd_file_name_lookup (&_hurd_ports_use, &__getdport, 0,
 373                                  file_name, flags, mode & ~_hurd_umask,
 374                                  &result);
 375
 376   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
 377 }
 378 weak_alias (__file_name_lookup, file_name_lookup)
 379
 380
 381 file_t
 382 __file_name_split (const char *file_name, char **name)
 383 {
 384   error_t err;
 385   file_t result;
 386
 387   err = __hurd_file_name_split (&_hurd_ports_use, &__getdport, 0,
 388                                 file_name, &result, name);
 389
 390   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
 391 }
 392 weak_alias (__file_name_split, file_name_split)
 393
 394
 395 file_t
 396 __file_name_lookup_under (file_t startdir,
 397                           const char *file_name, int flags, mode_t mode)
 398 {
 399   error_t err;
 400   file_t result;
 401
 402   error_t use_init_port (int which, error_t (*operate) (mach_port_t))
 403     {
 404       return (which == INIT_PORT_CWDIR ? (*operate) (startdir) :
 405               _hurd_ports_use (which, operate));
 406     }
 407
 408   err = __hurd_file_name_lookup (&use_init_port, &__getdport, 0,
 409                                  file_name, flags, mode & ~_hurd_umask,
 410                                  &result);
 411
 412   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
 413 }
 414 weak_alias (__file_name_lookup_under, file_name_lookup_under)