1: /* Copyright (C) 1992,1993,1994,1995,1996,1997,1999,2001,2004,2006
    2:         Free Software Foundation, Inc.
    3:    This file is part of the GNU C Library.
    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, write to the Free
   17:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   18:    02111-1307 USA.  */
   19: 
   20: #include <hurd.h>
   21: #include <hurd/lookup.h>
   22: #include <string.h>
   23: #include <fcntl.h>
   24: 
   25: 
   26: /* Translate the error from dir_lookup into the error the user sees.  */
   27: static inline error_t
   28: lookup_error (error_t error)
   29: {
   30:   switch (error)
   31:     {
   32:     case EOPNOTSUPP:
   33:     case MIG_BAD_ID:
   34:       /* These indicate that the server does not understand dir_lookup
   35:          at all.  If it were a directory, it would, by definition.  */
   36:       return ENOTDIR;
   37:     default:
   38:       return error;
   39:     }
   40: }
   41: 
   42: error_t
   43: __hurd_file_name_lookup (error_t (*use_init_port)
   44:                            (int which, error_t (*operate) (file_t)),
   45:                          file_t (*get_dtable_port) (int fd),
   46:                          error_t (*lookup)
   47:                            (file_t dir, char *name, int flags, mode_t mode,
   48:                             retry_type *do_retry, string_t retry_name,
   49:                             mach_port_t *result),
   50:                          const char *file_name, int flags, mode_t mode,
   51:                          file_t *result)
   52: {
   53:   error_t err;
   54:   enum retry_type doretry;
   55:   char retryname[1024];         /* XXX string_t LOSES! */
   56:   int startport;
   57: 
   58:   error_t lookup_op (mach_port_t startdir)
   59:     {
   60:       return lookup_error ((*lookup) (startdir, file_name, flags, mode,
   61:                                       &doretry, retryname, result));
   62:     }
   63: 
   64:   if (! lookup)
   65:     lookup = __dir_lookup;
   66: 
   67:   if (file_name[0] == '\0')
   68:     return ENOENT;
   69: 
   70:   startport = (file_name[0] == '/') ? INIT_PORT_CRDIR : INIT_PORT_CWDIR;
   71:   while (file_name[0] == '/')
   72:     file_name++;
   73: 
   74:   if (flags & O_NOFOLLOW)       /* See lookup-retry.c about O_NOFOLLOW.  */
   75:     flags |= O_NOTRANS;
   76: 
   77:   if (flags & O_DIRECTORY)
   78:     {
   79:       /* The caller wants to require that the file we look up is a directory.
   80:          We can do this without an extra RPC by appending a trailing slash
   81:          to the file name we look up.  */
   82:       size_t len = strlen (file_name);
   83:       if (len == 0)
   84:         file_name = "/";
   85:       else if (file_name[len - 1] != '/')
   86:         {
   87:           char *n = alloca (len + 2);
   88:           memcpy (n, file_name, len);
   89:           n[len] = '/';
   90:           n[len + 1] = '\0';
   91:           file_name = n;
   92:         }
   93:     }
   94: 
   95:   err = (*use_init_port) (startport, &lookup_op);
   96:   if (! err)
   97:     err = __hurd_file_name_lookup_retry (use_init_port, get_dtable_port,
   98:                                          lookup, doretry, retryname,
   99:                                          flags, mode, result);
  100: 
  101:   return err;
  102: }
  103: weak_alias (__hurd_file_name_lookup, hurd_file_name_lookup)
  104: 
  105: error_t
  106: __hurd_file_name_split (error_t (*use_init_port)
  107:                           (int which, error_t (*operate) (file_t)),
  108:                         file_t (*get_dtable_port) (int fd),
  109:                         error_t (*lookup)
  110:                           (file_t dir, char *name, int flags, mode_t mode,
  111:                            retry_type *do_retry, string_t retry_name,
  112:                            mach_port_t *result),
  113:                         const char *file_name,
  114:                         file_t *dir, char **name)
  115: {
  116:   error_t addref (file_t crdir)
  117:     {
  118:       *dir = crdir;
  119:       return __mach_port_mod_refs (__mach_task_self (),
  120:                                    crdir, MACH_PORT_RIGHT_SEND, +1);
  121:     }
  122: 
  123:   const char *lastslash = strrchr (file_name, '/');
  124: 
  125:   if (lastslash != NULL)
  126:     {
  127:       if (lastslash == file_name)
  128:         {
  129:           /* "/foobar" => crdir + "foobar".  */
  130:           *name = (char *) file_name + 1;
  131:           return (*use_init_port) (INIT_PORT_CRDIR, &addref);
  132:         }
  133:       else
  134:         {
  135:           /* "/dir1/dir2/.../file".  */
  136:           char dirname[lastslash - file_name + 1];
  137:           memcpy (dirname, file_name, lastslash - file_name);
  138:           dirname[lastslash - file_name] = '\0';
  139:           *name = (char *) lastslash + 1;
  140:           return
  141:             __hurd_file_name_lookup (use_init_port, get_dtable_port, lookup,
  142:                                      dirname, 0, 0, dir);
  143:         }
  144:     }
  145:   else if (file_name[0] == '\0')
  146:     return ENOENT;
  147:   else
  148:     {
  149:       /* "foobar" => cwdir + "foobar".  */
  150:       *name = (char *) file_name;
  151:       return (*use_init_port) (INIT_PORT_CWDIR, &addref);
  152:     }
  153: }
  154: weak_alias (__hurd_file_name_split, hurd_file_name_split)
  155: 
  156: /* This is the same as hurd_file_name_split, except that it ignores
  157:    trailing slashes (so *NAME is never "").  */
  158: error_t
  159: __hurd_directory_name_split (error_t (*use_init_port)
  160:                              (int which, error_t (*operate) (file_t)),
  161:                              file_t (*get_dtable_port) (int fd),
  162:                              error_t (*lookup)
  163:                              (file_t dir, char *name, int flags, mode_t mode,
  164:                               retry_type *do_retry, string_t retry_name,
  165:                               mach_port_t *result),
  166:                              const char *file_name,
  167:                              file_t *dir, char **name)
  168: {
  169:   error_t addref (file_t crdir)
  170:     {
  171:       *dir = crdir;
  172:       return __mach_port_mod_refs (__mach_task_self (),
  173:                                    crdir, MACH_PORT_RIGHT_SEND, +1);
  174:     }
  175: 
  176:   const char *lastslash = strrchr (file_name, '/');
  177: 
  178:   if (lastslash != NULL && lastslash[1] == '\0')
  179:     {
  180:       /* Trailing slash doesn't count.  Look back further.  */
  181: 
  182:       /* Back up over all trailing slashes.  */
  183:       while (lastslash > file_name && *lastslash == '/')
  184:         --lastslash;
  185: 
  186:       /* Find the last one earlier in the string, before the trailing ones.  */
  187:       lastslash = __memrchr (file_name, '/', lastslash - file_name);
  188:     }
  189: 
  190:   if (lastslash != NULL)
  191:     {
  192:       if (lastslash == file_name)
  193:         {
  194:           /* "/foobar" => crdir + "foobar".  */
  195:           *name = (char *) file_name + 1;
  196:           return (*use_init_port) (INIT_PORT_CRDIR, &addref);
  197:         }
  198:       else
  199:         {
  200:           /* "/dir1/dir2/.../file".  */
  201:           char dirname[lastslash - file_name + 1];
  202:           memcpy (dirname, file_name, lastslash - file_name);
  203:           dirname[lastslash - file_name] = '\0';
  204:           *name = (char *) lastslash + 1;
  205:           return
  206:             __hurd_file_name_lookup (use_init_port, get_dtable_port, lookup,
  207:                                      dirname, 0, 0, dir);
  208:         }
  209:     }
  210:   else if (file_name[0] == '\0')
  211:     return ENOENT;
  212:   else
  213:     {
  214:       /* "foobar" => cwdir + "foobar".  */
  215:       *name = (char *) file_name;
  216:       return (*use_init_port) (INIT_PORT_CWDIR, &addref);
  217:     }
  218: }
  219: weak_alias (__hurd_directory_name_split, hurd_directory_name_split)
  220: 
  221: ^L
  222: file_t
  223: __file_name_lookup (const char *file_name, int flags, mode_t mode)
  224: {
  225:   error_t err;
  226:   file_t result;
  227: 
  228:   err = __hurd_file_name_lookup (&_hurd_ports_use, &__getdport, 0,
  229:                                  file_name, flags, mode & ~_hurd_umask,
  230:                                  &result);
  231: 
  232:   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
  233: }
  234: weak_alias (__file_name_lookup, file_name_lookup)
  235: 
  236: 
  237: file_t
  238: __file_name_split (const char *file_name, char **name)
  239: {
  240:   error_t err;
  241:   file_t result;
  242: 
  243:   err = __hurd_file_name_split (&_hurd_ports_use, &__getdport, 0,
  244:                                 file_name, &result, name);
  245: 
  246:   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
  247: }
  248: weak_alias (__file_name_split, file_name_split)
  249: 
  250: file_t
  251: __directory_name_split (const char *directory_name, char **name)
  252: {
  253:   error_t err;
  254:   file_t result;
  255: 
  256:   err = __hurd_directory_name_split (&_hurd_ports_use, &__getdport, 0,
  257:                                      directory_name, &result, name);
  258: 
  259:   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
  260: }
  261: weak_alias (__directory_name_split, directory_name_split)
  262: 
  263: 
  264: file_t
  265: __file_name_lookup_under (file_t startdir,
  266:                           const char *file_name, int flags, mode_t mode)
  267: {
  268:   error_t err;
  269:   file_t result;
  270: 
  271:   error_t use_init_port (int which, error_t (*operate) (mach_port_t))
  272:     {
  273:       return (which == INIT_PORT_CWDIR ? (*operate) (startdir) :
  274:               _hurd_ports_use (which, operate));
  275:     }
  276: 
  277:   err = __hurd_file_name_lookup (&use_init_port, &__getdport, 0,
  278:                                  file_name, flags, mode & ~_hurd_umask,
  279:                                  &result);
  280: 
  281:   return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
  282: }
  283: weak_alias (__file_name_lookup_under, file_name_lookup_under)