+/* Support for *xattr interfaces on GNU/Hurd.
+ Copyright (C) 2006 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <hurd.h>
+#include <hurd/xattr.h>
+#include <string.h>
+#include <sys/mman.h>
+
+/* Right now we support only a fixed set of xattr names for Hurd features.
+ There are no RPC interfaces for free-form xattr names and values.
+
+ Name Value encoding
+ ---- ----- --------
+ gnu.author empty if st_author==st_uid
+ uid_t giving st_author value
+ gnu.translator empty if no passive translator
+ translator and arguments: "/hurd/foo\0arg1\0arg2\0"
+*/
+
+error_t
+_hurd_xattr_get (io_t port, const char *name, void *value, size_t *size)
+{
+ if (strncmp (name, "gnu.", 4))
+ return EOPNOTSUPP;
+ name += 4;
+
+ if (!strcmp (name, "author"))
+ {
+ struct stat64 st;
+ error_t err = __io_stat (port, &st);
+ if (err)
+ return err;
+ if (st.st_author == st.st_uid)
+ *size = 0;
+ else if (value)
+ {
+ if (*size < sizeof st.st_author)
+ return ERANGE;
+ memcpy (value, &st.st_author, sizeof st.st_author);
+ }
+ *size = sizeof st.st_author;
+ return 0;
+ }
+
+ if (!strcmp (name, "translator"))
+ {
+ char *buf = value;
+ size_t bufsz = value ? *size : 0;
+ error_t err = __file_get_translator (port, &buf, &bufsz);
+ if (err)
+ return err;
+ if (value != NULL && *size < bufsz)
+ {
+ if (buf != value)
+ munmap (buf, bufsz);
+ return -ERANGE;
+ }
+ if (buf != value && bufsz > 0)
+ {
+ if (value != NULL)
+ memcpy (value, buf, bufsz);
+ munmap (buf, bufsz);
+ }
+ *size = bufsz;
+ return 0;
+ }
+
+ return EOPNOTSUPP;
+}
+
+error_t
+_hurd_xattr_set (io_t port, const char *name, const void *value, size_t size,
+ int flags)
+{
+ if (strncmp (name, "gnu.", 4))
+ return EOPNOTSUPP;
+ name += 4;
+
+ if (!strcmp (name, "author"))
+ switch (size)
+ {
+ default:
+ return EINVAL;
+ case 0: /* "Clear" author by setting to st_uid. */
+ {
+ struct stat64 st;
+ error_t err = __io_stat (port, &st);
+ if (err)
+ return err;
+ if (st.st_author == st.st_uid)
+ {
+ /* Nothing to do. */
+ if (flags & XATTR_REPLACE)
+ return ENODATA;
+ return 0;
+ }
+ if (flags & XATTR_CREATE)
+ return EEXIST;
+ return __file_chauthor (port, st.st_uid);
+ }
+ case sizeof (uid_t): /* Set the author. */
+ {
+ uid_t id;
+ memcpy (&id, value, sizeof id);
+ if (flags & (XATTR_CREATE|XATTR_REPLACE))
+ {
+ struct stat64 st;
+ error_t err = __io_stat (port, &st);
+ if (err)
+ return err;
+ if (st.st_author == st.st_uid)
+ {
+ if (flags & XATTR_REPLACE)
+ return ENODATA;
+ }
+ else if (flags & XATTR_CREATE)
+ return EEXIST;
+ if (st.st_author == id)
+ /* Nothing to do. */
+ return 0;
+ }
+ return __file_chauthor (port, id);
+ }
+ }
+
+ if (!strcmp (name, "translator"))
+ {
+ if (flags & XATTR_REPLACE)
+ {
+ /* Must make sure it's already there. */
+ char *buf = NULL;
+ size_t bufsz = 0;
+ error_t err = __file_get_translator (port, &buf, &bufsz);
+ if (err)
+ return err;
+ if (bufsz > 0)
+ {
+ munmap (buf, bufsz);
+ return ENODATA;
+ }
+ }
+ return __file_set_translator (port,
+ FS_TRANS_SET | ((flags & XATTR_CREATE)
+ ? FS_TRANS_EXCL : 0), 0, 0,
+ value, size,
+ MACH_PORT_NULL, MACH_MSG_TYPE_COPY_SEND);
+ }
+
+ return EOPNOTSUPP;
+}
+
+error_t
+_hurd_xattr_remove (io_t port, const char *name)
+{
+ return _hurd_xattr_set (port, name, NULL, 0, XATTR_REPLACE);
+}
+
+error_t
+_hurd_xattr_list (io_t port, void *buffer, size_t *size)
+{
+ size_t total = 0;
+ char *bufp = buffer;
+ inline void add (const char *name, size_t len)
+ {
+ total += len;
+ if (bufp != NULL && total <= *size)
+ bufp = __mempcpy (bufp, name, len);
+ }
+#define add(s) add (s, sizeof s)
+
+ struct stat64 st;
+ error_t err = __io_stat (port, &st);
+ if (err)
+ return err;
+
+ if (st.st_author != st.st_uid)
+ add ("gnu.author");
+ if (st.st_mode & S_IPTRANS)
+ add ("gnu.translator");
+
+ if (buffer != NULL && total > *size)
+ return ERANGE;
+ *size = total;
+ return 0;
+}