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c5780b5f | 1 | /* Support for *xattr interfaces on GNU/Hurd. |
04277e02 | 2 | Copyright (C) 2006-2019 Free Software Foundation, Inc. |
c5780b5f RM |
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 | |
59ba27a6 | 16 | License along with the GNU C Library; if not, see |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
c5780b5f RM |
18 | |
19 | #include <hurd.h> | |
20 | #include <hurd/xattr.h> | |
21 | #include <string.h> | |
22 | #include <sys/mman.h> | |
23 | ||
24 | /* Right now we support only a fixed set of xattr names for Hurd features. | |
25 | There are no RPC interfaces for free-form xattr names and values. | |
26 | ||
27 | Name Value encoding | |
28 | ---- ----- -------- | |
29 | gnu.author empty if st_author==st_uid | |
30 | uid_t giving st_author value | |
31 | gnu.translator empty if no passive translator | |
350635a5 | 32 | translator and arguments: "/hurd/foo\0arg1\0arg2\0" |
c5780b5f RM |
33 | */ |
34 | ||
35 | error_t | |
36 | _hurd_xattr_get (io_t port, const char *name, void *value, size_t *size) | |
37 | { | |
38 | if (strncmp (name, "gnu.", 4)) | |
39 | return EOPNOTSUPP; | |
40 | name += 4; | |
41 | ||
42 | if (!strcmp (name, "author")) | |
43 | { | |
44 | struct stat64 st; | |
45 | error_t err = __io_stat (port, &st); | |
46 | if (err) | |
47 | return err; | |
48 | if (st.st_author == st.st_uid) | |
49 | *size = 0; | |
50 | else if (value) | |
51 | { | |
52 | if (*size < sizeof st.st_author) | |
53 | return ERANGE; | |
54 | memcpy (value, &st.st_author, sizeof st.st_author); | |
55 | } | |
56 | *size = sizeof st.st_author; | |
57 | return 0; | |
58 | } | |
59 | ||
60 | if (!strcmp (name, "translator")) | |
61 | { | |
62 | char *buf = value; | |
63 | size_t bufsz = value ? *size : 0; | |
64 | error_t err = __file_get_translator (port, &buf, &bufsz); | |
65 | if (err) | |
66 | return err; | |
67 | if (value != NULL && *size < bufsz) | |
68 | { | |
69 | if (buf != value) | |
dba2bdbe | 70 | __munmap (buf, bufsz); |
c5780b5f RM |
71 | return -ERANGE; |
72 | } | |
73 | if (buf != value && bufsz > 0) | |
74 | { | |
75 | if (value != NULL) | |
76 | memcpy (value, buf, bufsz); | |
dba2bdbe | 77 | __munmap (buf, bufsz); |
c5780b5f RM |
78 | } |
79 | *size = bufsz; | |
80 | return 0; | |
81 | } | |
82 | ||
83 | return EOPNOTSUPP; | |
84 | } | |
85 | ||
86 | error_t | |
87 | _hurd_xattr_set (io_t port, const char *name, const void *value, size_t size, | |
88 | int flags) | |
89 | { | |
90 | if (strncmp (name, "gnu.", 4)) | |
91 | return EOPNOTSUPP; | |
92 | name += 4; | |
93 | ||
94 | if (!strcmp (name, "author")) | |
95 | switch (size) | |
96 | { | |
97 | default: | |
98 | return EINVAL; | |
99 | case 0: /* "Clear" author by setting to st_uid. */ | |
100 | { | |
101 | struct stat64 st; | |
102 | error_t err = __io_stat (port, &st); | |
103 | if (err) | |
104 | return err; | |
105 | if (st.st_author == st.st_uid) | |
106 | { | |
107 | /* Nothing to do. */ | |
108 | if (flags & XATTR_REPLACE) | |
109 | return ENODATA; | |
110 | return 0; | |
111 | } | |
112 | if (flags & XATTR_CREATE) | |
113 | return EEXIST; | |
114 | return __file_chauthor (port, st.st_uid); | |
115 | } | |
116 | case sizeof (uid_t): /* Set the author. */ | |
117 | { | |
118 | uid_t id; | |
119 | memcpy (&id, value, sizeof id); | |
120 | if (flags & (XATTR_CREATE|XATTR_REPLACE)) | |
121 | { | |
122 | struct stat64 st; | |
123 | error_t err = __io_stat (port, &st); | |
124 | if (err) | |
125 | return err; | |
126 | if (st.st_author == st.st_uid) | |
127 | { | |
128 | if (flags & XATTR_REPLACE) | |
129 | return ENODATA; | |
130 | } | |
131 | else if (flags & XATTR_CREATE) | |
132 | return EEXIST; | |
133 | if (st.st_author == id) | |
134 | /* Nothing to do. */ | |
135 | return 0; | |
136 | } | |
137 | return __file_chauthor (port, id); | |
138 | } | |
139 | } | |
140 | ||
141 | if (!strcmp (name, "translator")) | |
142 | { | |
143 | if (flags & XATTR_REPLACE) | |
144 | { | |
145 | /* Must make sure it's already there. */ | |
146 | char *buf = NULL; | |
147 | size_t bufsz = 0; | |
148 | error_t err = __file_get_translator (port, &buf, &bufsz); | |
149 | if (err) | |
150 | return err; | |
151 | if (bufsz > 0) | |
152 | { | |
dba2bdbe | 153 | __munmap (buf, bufsz); |
c5780b5f RM |
154 | return ENODATA; |
155 | } | |
156 | } | |
157 | return __file_set_translator (port, | |
158 | FS_TRANS_SET | ((flags & XATTR_CREATE) | |
159 | ? FS_TRANS_EXCL : 0), 0, 0, | |
160 | value, size, | |
161 | MACH_PORT_NULL, MACH_MSG_TYPE_COPY_SEND); | |
162 | } | |
163 | ||
164 | return EOPNOTSUPP; | |
165 | } | |
166 | ||
167 | error_t | |
168 | _hurd_xattr_remove (io_t port, const char *name) | |
169 | { | |
170 | return _hurd_xattr_set (port, name, NULL, 0, XATTR_REPLACE); | |
171 | } | |
172 | ||
173 | error_t | |
174 | _hurd_xattr_list (io_t port, void *buffer, size_t *size) | |
175 | { | |
176 | size_t total = 0; | |
177 | char *bufp = buffer; | |
178 | inline void add (const char *name, size_t len) | |
179 | { | |
180 | total += len; | |
181 | if (bufp != NULL && total <= *size) | |
182 | bufp = __mempcpy (bufp, name, len); | |
183 | } | |
184 | #define add(s) add (s, sizeof s) | |
185 | ||
186 | struct stat64 st; | |
187 | error_t err = __io_stat (port, &st); | |
188 | if (err) | |
189 | return err; | |
190 | ||
191 | if (st.st_author != st.st_uid) | |
192 | add ("gnu.author"); | |
193 | if (st.st_mode & S_IPTRANS) | |
194 | add ("gnu.translator"); | |
195 | ||
196 | if (buffer != NULL && total > *size) | |
197 | return ERANGE; | |
198 | *size = total; | |
199 | return 0; | |
200 | } |