aboutsummaryrefslogtreecommitdiff
blob: 5a694ab11f227d14426b5df59f45a9c2f05a2efd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
/* Support for *xattr interfaces on GNU/Hurd.
   Copyright (C) 2006-2016 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, see
   <http://www.gnu.org/licenses/>.  */

#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;
}