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570 lines
15 KiB
C
570 lines
15 KiB
C
/* Copyright (C) 1992, 93, 94, 95, 96, 97, 99 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <hurd.h>
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#include <hurd/lookup.h>
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#include <string.h>
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#include <limits.h>
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#include <fcntl.h>
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#include "stdio-common/_itoa.h"
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#include <hurd/term.h>
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#include <hurd/paths.h>
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/* Translate the error from dir_lookup into the error the user sees. */
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static inline error_t
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lookup_error (error_t error)
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{
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switch (error)
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{
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case EOPNOTSUPP:
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case MIG_BAD_ID:
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/* These indicate that the server does not understand dir_lookup
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at all. If it were a directory, it would, by definition. */
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return ENOTDIR;
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default:
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return error;
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}
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}
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error_t
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__hurd_file_name_lookup (error_t (*use_init_port)
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(int which, error_t (*operate) (file_t)),
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file_t (*get_dtable_port) (int fd),
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error_t (*lookup)
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(file_t dir, char *name, int flags, mode_t mode,
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retry_type *do_retry, string_t retry_name,
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mach_port_t *result),
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const char *file_name, int flags, mode_t mode,
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file_t *result)
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{
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error_t err;
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enum retry_type doretry;
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char retryname[1024]; /* XXX string_t LOSES! */
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int startport;
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error_t lookup_op (mach_port_t startdir)
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{
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return lookup_error ((*lookup) (startdir, file_name, flags, mode,
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&doretry, retryname, result));
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}
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if (! lookup)
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lookup = __dir_lookup;
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startport = (file_name[0] == '/') ? INIT_PORT_CRDIR : INIT_PORT_CWDIR;
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while (file_name[0] == '/')
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file_name++;
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if (flags & O_NOFOLLOW) /* See comments below about O_NOFOLLOW. */
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flags |= O_NOTRANS;
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if (flags & O_DIRECTORY)
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{
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/* The caller wants to require that the file we look up is a directory.
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We can do this without an extra RPC by appending a trailing slash
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to the file name we look up. */
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size_t len = strlen (file_name);
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if (len == 0)
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file_name = "/";
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else if (file_name[len - 1] != '/')
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{
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char *n = alloca (len + 2);
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memcpy (n, file_name, len);
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n[len] = '/';
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n[len + 1] = '\0';
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file_name = n;
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}
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}
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err = (*use_init_port) (startport, &lookup_op);
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if (! err)
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err = __hurd_file_name_lookup_retry (use_init_port, get_dtable_port,
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lookup, doretry, retryname,
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flags, mode, result);
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return err;
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}
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weak_alias (__hurd_file_name_lookup, hurd_file_name_lookup)
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error_t
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__hurd_file_name_lookup_retry (error_t (*use_init_port)
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(int which, error_t (*operate) (file_t)),
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file_t (*get_dtable_port) (int fd),
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error_t (*lookup)
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(file_t dir, char *name,
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int flags, mode_t mode,
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retry_type *do_retry, string_t retry_name,
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mach_port_t *result),
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enum retry_type doretry,
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char retryname[1024],
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int flags, mode_t mode,
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file_t *result)
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{
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error_t err;
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char *file_name;
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int nloops;
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error_t lookup_op (file_t startdir)
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{
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while (file_name[0] == '/')
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file_name++;
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return lookup_error ((*lookup) (startdir, file_name, flags, mode,
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&doretry, retryname, result));
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}
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error_t reauthenticate (file_t unauth)
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{
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error_t err;
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mach_port_t ref = __mach_reply_port ();
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error_t reauth (auth_t auth)
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{
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return __auth_user_authenticate (auth, ref,
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MACH_MSG_TYPE_MAKE_SEND,
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result);
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}
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err = __io_reauthenticate (unauth, ref, MACH_MSG_TYPE_MAKE_SEND);
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if (! err)
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err = (*use_init_port) (INIT_PORT_AUTH, &reauth);
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__mach_port_destroy (__mach_task_self (), ref);
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__mach_port_deallocate (__mach_task_self (), unauth);
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return err;
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}
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if (! lookup)
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lookup = __dir_lookup;
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nloops = 0;
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err = 0;
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do
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{
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file_t startdir = MACH_PORT_NULL;
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int dirport = INIT_PORT_CWDIR;
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switch (doretry)
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{
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case FS_RETRY_REAUTH:
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if (err = reauthenticate (*result))
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return err;
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/* Fall through. */
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case FS_RETRY_NORMAL:
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#ifdef SYMLOOP_MAX
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if (nloops++ >= SYMLOOP_MAX)
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return ELOOP;
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#endif
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/* An empty RETRYNAME indicates we have the final port. */
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if (retryname[0] == '\0' &&
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/* If reauth'd, we must do one more retry on "" to give the new
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translator a chance to make a new port for us. */
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doretry == FS_RETRY_NORMAL)
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{
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if (flags & O_NOFOLLOW)
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{
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/* In Linux, O_NOFOLLOW means to reject symlinks. If we
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did an O_NOLINK lookup above and io_stat here to check
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for S_IFLNK, a translator like firmlink could easily
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spoof this check by not showing S_IFLNK, but in fact
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redirecting the lookup to some other name
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(i.e. opening the very same holes a symlink would).
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Instead we do an O_NOTRANS lookup above, and stat the
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underlying node: if it has a translator set, and its
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owner is not root (st_uid 0) then we reject it.
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Since the motivation for this feature is security, and
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that security presumes we trust the containing
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directory, this check approximates the security of
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refusing symlinks while accepting mount points.
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Note that we actually permit something Linux doesn't:
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we follow root-owned symlinks; if that is deemed
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undesireable, we can add a final check for that
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one exception to our general translator-based rule. */
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struct stat st;
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err = __io_stat (*result, &st);
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if (!err
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&& (st.st_mode & (S_IPTRANS|S_IATRANS)))
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{
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if (st.st_uid != 0)
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err = ENOENT;
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else if (st.st_mode & S_IPTRANS)
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{
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char buf[1024];
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char *trans = buf;
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size_t translen = sizeof buf;
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err = __file_get_translator (*result,
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&trans, &translen);
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if (!err
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&& translen > sizeof _HURD_SYMLINK
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&& !memcmp (trans,
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_HURD_SYMLINK, sizeof _HURD_SYMLINK))
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err = ENOENT;
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}
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}
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}
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/* We got a successful translation. Now apply any open-time
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action flags we were passed. */
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if (!err && (flags & O_TRUNC)) /* Asked to truncate the file. */
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err = __file_set_size (*result, 0);
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if (err)
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__mach_port_deallocate (__mach_task_self (), *result);
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return err;
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}
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startdir = *result;
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file_name = retryname;
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break;
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case FS_RETRY_MAGICAL:
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switch (retryname[0])
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{
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case '/':
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dirport = INIT_PORT_CRDIR;
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if (*result != MACH_PORT_NULL)
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__mach_port_deallocate (__mach_task_self (), *result);
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file_name = &retryname[1];
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break;
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case 'f':
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if (retryname[1] == 'd' && retryname[2] == '/')
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{
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int fd;
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char *end;
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int save = errno;
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errno = 0;
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fd = (int) strtol (&retryname[3], &end, 10);
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if (end == NULL || errno || /* Malformed number. */
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/* Check for excess text after the number. A slash
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is valid; it ends the component. Anything else
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does not name a numeric file descriptor. */
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(*end != '/' && *end != '\0'))
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{
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errno = save;
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return ENOENT;
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}
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if (! get_dtable_port)
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err = EGRATUITOUS;
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else
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{
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*result = (*get_dtable_port) (fd);
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if (*result == MACH_PORT_NULL)
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{
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/* If the name was a proper number, but the file
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descriptor does not exist, we return EBADF instead
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of ENOENT. */
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err = errno;
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errno = save;
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}
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}
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errno = save;
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if (err)
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return err;
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if (*end == '\0')
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return 0;
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else
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{
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/* Do a normal retry on the remaining components. */
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startdir = *result;
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file_name = end + 1; /* Skip the slash. */
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break;
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}
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}
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else
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goto bad_magic;
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break;
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case 'm':
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if (retryname[1] == 'a' && retryname[2] == 'c' &&
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retryname[3] == 'h' && retryname[4] == 't' &&
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retryname[5] == 'y' && retryname[6] == 'p' &&
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retryname[7] == 'e')
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{
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error_t err;
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struct host_basic_info hostinfo;
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mach_msg_type_number_t hostinfocnt = HOST_BASIC_INFO_COUNT;
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char *p;
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/* XXX want client's host */
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if (err = __host_info (__mach_host_self (), HOST_BASIC_INFO,
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(natural_t *) &hostinfo,
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&hostinfocnt))
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return err;
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if (hostinfocnt != HOST_BASIC_INFO_COUNT)
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return EGRATUITOUS;
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p = _itoa (hostinfo.cpu_subtype, &retryname[8], 10, 0);
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*--p = '/';
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p = _itoa (hostinfo.cpu_type, &retryname[8], 10, 0);
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if (p < retryname)
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abort (); /* XXX write this right if this ever happens */
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if (p > retryname)
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strcpy (retryname, p);
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startdir = *result;
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}
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else
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goto bad_magic;
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break;
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case 't':
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if (retryname[1] == 't' && retryname[2] == 'y')
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switch (retryname[3])
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{
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error_t opentty (file_t *result)
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{
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error_t err;
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error_t ctty_open (file_t port)
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{
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if (port == MACH_PORT_NULL)
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return ENXIO; /* No controlling terminal. */
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return __termctty_open_terminal (port,
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flags,
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result);
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}
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err = (*use_init_port) (INIT_PORT_CTTYID, &ctty_open);
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if (! err)
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err = reauthenticate (*result);
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return err;
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}
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case '\0':
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return opentty (result);
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case '/':
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if (err = opentty (&startdir))
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return err;
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strcpy (retryname, &retryname[4]);
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break;
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default:
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goto bad_magic;
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}
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else
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goto bad_magic;
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break;
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default:
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bad_magic:
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return EGRATUITOUS;
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}
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break;
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default:
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return EGRATUITOUS;
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}
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if (startdir != MACH_PORT_NULL)
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{
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err = lookup_op (startdir);
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__mach_port_deallocate (__mach_task_self (), startdir);
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startdir = MACH_PORT_NULL;
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}
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else
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err = (*use_init_port) (dirport, &lookup_op);
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} while (! err);
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return err;
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}
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weak_alias (__hurd_file_name_lookup_retry, hurd_file_name_lookup_retry)
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error_t
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__hurd_file_name_split (error_t (*use_init_port)
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(int which, error_t (*operate) (file_t)),
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file_t (*get_dtable_port) (int fd),
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error_t (*lookup)
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(file_t dir, char *name, int flags, mode_t mode,
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retry_type *do_retry, string_t retry_name,
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mach_port_t *result),
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const char *file_name,
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file_t *dir, char **name)
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{
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error_t addref (file_t crdir)
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{
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*dir = crdir;
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return __mach_port_mod_refs (__mach_task_self (),
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crdir, MACH_PORT_RIGHT_SEND, +1);
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}
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const char *lastslash = strrchr (file_name, '/');
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if (lastslash != NULL)
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{
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if (lastslash == file_name)
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{
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/* "/foobar" => crdir + "foobar". */
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*name = (char *) file_name + 1;
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return (*use_init_port) (INIT_PORT_CRDIR, &addref);
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}
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else
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{
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/* "/dir1/dir2/.../file". */
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char dirname[lastslash - file_name + 1];
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memcpy (dirname, file_name, lastslash - file_name);
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dirname[lastslash - file_name] = '\0';
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*name = (char *) lastslash + 1;
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return
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__hurd_file_name_lookup (use_init_port, get_dtable_port, lookup,
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dirname, 0, 0, dir);
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}
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}
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else
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{
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/* "foobar" => cwdir + "foobar". */
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*name = (char *) file_name;
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return (*use_init_port) (INIT_PORT_CWDIR, &addref);
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}
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}
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weak_alias (__hurd_file_name_split, hurd_file_name_split)
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/* This is the same as hurd_file_name_split, except that it ignores
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trailing slashes (so *NAME is never ""). */
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error_t
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__hurd_directory_name_split (error_t (*use_init_port)
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(int which, error_t (*operate) (file_t)),
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file_t (*get_dtable_port) (int fd),
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error_t (*lookup)
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(file_t dir, char *name, int flags, mode_t mode,
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retry_type *do_retry, string_t retry_name,
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mach_port_t *result),
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const char *file_name,
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file_t *dir, char **name)
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{
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error_t addref (file_t crdir)
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{
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*dir = crdir;
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return __mach_port_mod_refs (__mach_task_self (),
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crdir, MACH_PORT_RIGHT_SEND, +1);
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}
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const char *lastslash = strrchr (file_name, '/');
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if (lastslash != NULL && lastslash[1] == '\0')
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{
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/* Trailing slash doesn't count. Look back further. */
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/* Back up over all trailing slashes. */
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while (lastslash > file_name && *lastslash == '/')
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--lastslash;
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/* Find the last one earlier in the string, before the trailing ones. */
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#if __GLIBC__ > 2 || __GLIBC_MINOR__ >= 2
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lastslash = __memrchr (file_name, '/', lastslash - file_name);
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#else
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/* Keep backing up, looking for a slash. */
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do
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if (lastslash == file_name)
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{
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/* Hit the start with no slash. */
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lastslash = NULL;
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break;
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}
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while (*lastslash-- != '/');
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#endif
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}
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if (lastslash != NULL)
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{
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if (lastslash == file_name)
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{
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/* "/foobar" => crdir + "foobar". */
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*name = (char *) file_name + 1;
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return (*use_init_port) (INIT_PORT_CRDIR, &addref);
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}
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else
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{
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/* "/dir1/dir2/.../file". */
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char dirname[lastslash - file_name + 1];
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memcpy (dirname, file_name, lastslash - file_name);
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dirname[lastslash - file_name] = '\0';
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*name = (char *) lastslash + 1;
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return
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__hurd_file_name_lookup (use_init_port, get_dtable_port, lookup,
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dirname, 0, 0, dir);
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}
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}
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else
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{
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/* "foobar" => cwdir + "foobar". */
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*name = (char *) file_name;
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return (*use_init_port) (INIT_PORT_CWDIR, &addref);
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}
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}
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weak_alias (__hurd_directory_name_split, hurd_directory_name_split)
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file_t
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__file_name_lookup (const char *file_name, int flags, mode_t mode)
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{
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error_t err;
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file_t result;
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err = __hurd_file_name_lookup (&_hurd_ports_use, &__getdport, 0,
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file_name, flags, mode & ~_hurd_umask,
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&result);
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|
||
return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
|
||
}
|
||
weak_alias (__file_name_lookup, file_name_lookup)
|
||
|
||
|
||
file_t
|
||
__file_name_split (const char *file_name, char **name)
|
||
{
|
||
error_t err;
|
||
file_t result;
|
||
|
||
err = __hurd_file_name_split (&_hurd_ports_use, &__getdport, 0,
|
||
file_name, &result, name);
|
||
|
||
return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
|
||
}
|
||
weak_alias (__file_name_split, file_name_split)
|
||
|
||
file_t
|
||
__directory_name_split (const char *directory_name, char **name)
|
||
{
|
||
error_t err;
|
||
file_t result;
|
||
|
||
err = __hurd_directory_name_split (&_hurd_ports_use, &__getdport, 0,
|
||
directory_name, &result, name);
|
||
|
||
return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
|
||
}
|
||
weak_alias (__directory_name_split, directory_name_split)
|
||
|
||
|
||
file_t
|
||
__file_name_lookup_under (file_t startdir,
|
||
const char *file_name, int flags, mode_t mode)
|
||
{
|
||
error_t err;
|
||
file_t result;
|
||
|
||
error_t use_init_port (int which, error_t (*operate) (mach_port_t))
|
||
{
|
||
return (which == INIT_PORT_CWDIR ? (*operate) (startdir) :
|
||
_hurd_ports_use (which, operate));
|
||
}
|
||
|
||
err = __hurd_file_name_lookup (&use_init_port, &__getdport, 0,
|
||
file_name, flags, mode & ~_hurd_umask,
|
||
&result);
|
||
|
||
return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
|
||
}
|
||
weak_alias (__file_name_lookup_under, file_name_lookup_under)
|