xref: /freebsd/sys/compat/linux/linux_xattr.c (revision 7ef62cebc2f965b0f640263e179276928885e33d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2023 Dmitry Chagin <dchagin@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/extattr.h>
33 #include <sys/fcntl.h>
34 #include <sys/namei.h>
35 #include <sys/proc.h>
36 #include <sys/syscallsubr.h>
37 
38 #ifdef COMPAT_LINUX32
39 #include <machine/../linux32/linux.h>
40 #include <machine/../linux32/linux32_proto.h>
41 #else
42 #include <machine/../linux/linux.h>
43 #include <machine/../linux/linux_proto.h>
44 #endif
45 
46 #include <compat/linux/linux_util.h>
47 
48 #define	LINUX_XATTR_SIZE_MAX	65536
49 #define	LINUX_XATTR_LIST_MAX	65536
50 #define	LINUX_XATTR_NAME_MAX	255
51 
52 #define	LINUX_XATTR_CREATE	0x1
53 #define	LINUX_XATTR_REPLACE	0x2
54 #define	LINUX_XATTR_FLAGS	LINUX_XATTR_CREATE|LINUX_XATTR_REPLACE
55 
56 struct listxattr_args {
57 	int		fd;
58 	const char	*path;
59 	char		*list;
60 	l_size_t	size;
61 	int		follow;
62 };
63 
64 struct setxattr_args {
65 	int		fd;
66 	const char	*path;
67 	const char	*name;
68 	void 		*value;
69 	l_size_t	size;
70 	l_int		flags;
71 	int		follow;
72 };
73 
74 static char *extattr_namespace_names[] = EXTATTR_NAMESPACE_NAMES;
75 
76 
77 static int
78 xatrr_to_extattr(const char *uattrname, int *attrnamespace, char *attrname)
79 {
80 	char uname[LINUX_XATTR_NAME_MAX + 1], *dot;
81 	size_t len, cplen;
82 	int error;
83 
84 	error = copyinstr(uattrname, uname, sizeof(uname), &cplen);
85 	if (error != 0)
86 		return (error);
87 	if (cplen == sizeof(uname))
88 		return (ERANGE);
89 	dot = strchr(uname, '.');
90 	if (dot == NULL)
91 		return (ENOTSUP);
92 	*dot = '\0';
93 	for (*attrnamespace = EXTATTR_NAMESPACE_USER;
94 	    *attrnamespace < nitems(extattr_namespace_names);
95 	    (*attrnamespace)++) {
96 		if (bcmp(uname, extattr_namespace_names[*attrnamespace],
97 		    dot - uname + 1) == 0) {
98 			dot++;
99 			len = strlen(dot) + 1;
100 			bcopy(dot, attrname, len);
101 			return (0);
102 		}
103 	}
104 	return (ENOTSUP);
105 }
106 
107 static int
108 listxattr(struct thread *td, struct listxattr_args *args)
109 {
110 	char attrname[LINUX_XATTR_NAME_MAX + 1];
111 	char *data, *prefix, *key;
112 	struct uio auio;
113 	struct iovec aiov;
114 	unsigned char keylen;
115 	size_t sz, cnt, rs, prefixlen, pairlen;
116 	int attrnamespace, error;
117 
118 	if (args->size != 0)
119 		sz = min(LINUX_XATTR_LIST_MAX, args->size);
120 	else
121 		sz = LINUX_XATTR_LIST_MAX;
122 
123 	data = malloc(sz, M_LINUX, M_WAITOK);
124 	auio.uio_iov = &aiov;
125 	auio.uio_iovcnt = 1;
126 	auio.uio_rw = UIO_READ;
127 	auio.uio_segflg = UIO_SYSSPACE;
128 	auio.uio_td = td;
129 	cnt = 0;
130 	for (attrnamespace = EXTATTR_NAMESPACE_USER;
131 	    attrnamespace < nitems(extattr_namespace_names);
132 	    attrnamespace++) {
133 		aiov.iov_base = data;
134 		aiov.iov_len = sz;
135 		auio.uio_resid = sz;
136 		auio.uio_offset = 0;
137 
138 		if (args->path != NULL)
139 			error = kern_extattr_list_path(td, args->path,
140 			    attrnamespace, &auio, args->follow, UIO_USERSPACE);
141 		else
142 			error = kern_extattr_list_fd(td, args->fd,
143 			    attrnamespace, &auio);
144 		rs = sz - auio.uio_resid;
145 		if (error != 0 || rs == 0)
146 			continue;
147 		prefix = extattr_namespace_names[attrnamespace];
148 		prefixlen = strlen(prefix);
149 		key = data;
150 		while (rs > 0) {
151 			keylen = (unsigned char)key[0];
152 			pairlen = prefixlen + 1 + keylen + 1;
153 			if (cnt + pairlen > LINUX_XATTR_LIST_MAX) {
154 				error = E2BIG;
155 				break;
156 			}
157 			if ((args->list != NULL && cnt > args->size) ||
158 			    pairlen >= sizeof(attrname)) {
159 				error = ERANGE;
160 				break;
161 			}
162 			++key;
163 			if (args->list != NULL) {
164 				sprintf(attrname, "%s.%.*s", prefix, keylen, key);
165 				error = copyout(attrname, args->list, pairlen);
166 				if (error != 0)
167 					break;
168 				args->list += pairlen;
169 			}
170 			cnt += pairlen;
171 			key += keylen;
172 			rs -= (keylen + 1);
173 		}
174 	}
175 	if (error == 0)
176 		td->td_retval[0] = cnt;
177 	free(data, M_LINUX);
178 	return (error);
179 }
180 
181 int
182 linux_listxattr(struct thread *td, struct linux_listxattr_args *args)
183 {
184 	struct listxattr_args eargs = {
185 		.fd = -1,
186 		.path = args->path,
187 		.list = args->list,
188 		.size = args->size,
189 		.follow = FOLLOW,
190 	};
191 
192 	return (listxattr(td, &eargs));
193 }
194 
195 int
196 linux_llistxattr(struct thread *td, struct linux_llistxattr_args *args)
197 {
198 	struct listxattr_args eargs = {
199 		.fd = -1,
200 		.path = args->path,
201 		.list = args->list,
202 		.size = args->size,
203 		.follow = NOFOLLOW,
204 	};
205 
206 	return (listxattr(td, &eargs));
207 }
208 
209 int
210 linux_flistxattr(struct thread *td, struct linux_flistxattr_args *args)
211 {
212 	struct listxattr_args eargs = {
213 		.fd = args->fd,
214 		.path = NULL,
215 		.list = args->list,
216 		.size = args->size,
217 		.follow = 0,
218 	};
219 
220 	return (listxattr(td, &eargs));
221 }
222 
223 static int
224 linux_path_removexattr(struct thread *td, const char *upath, const char *uname,
225     int follow)
226 {
227 	char attrname[LINUX_XATTR_NAME_MAX + 1];
228 	int attrnamespace, error;
229 
230 	error = xatrr_to_extattr(uname, &attrnamespace, attrname);
231 	if (error != 0)
232 		return (error);
233 
234 	return (kern_extattr_delete_path(td, upath, attrnamespace,
235 	    attrname, follow, UIO_USERSPACE));
236 }
237 
238 int
239 linux_removexattr(struct thread *td, struct linux_removexattr_args *args)
240 {
241 
242 	return (linux_path_removexattr(td, args->path, args->name,
243 	    FOLLOW));
244 }
245 
246 int
247 linux_lremovexattr(struct thread *td, struct linux_lremovexattr_args *args)
248 {
249 
250 	return (linux_path_removexattr(td, args->path, args->name,
251 	    NOFOLLOW));
252 }
253 
254 int
255 linux_fremovexattr(struct thread *td, struct linux_fremovexattr_args *args)
256 {
257 	char attrname[LINUX_XATTR_NAME_MAX + 1];
258 	int attrnamespace, error;
259 
260 	error = xatrr_to_extattr(args->name, &attrnamespace, attrname);
261 	if (error != 0)
262 		return (error);
263 	return (kern_extattr_delete_fd(td, args->fd, attrnamespace,
264 	    attrname));
265 }
266 
267 static int
268 linux_path_getxattr(struct thread *td, const char *upath, const char *uname,
269     void *value, l_size_t size, int follow)
270 {
271 	char attrname[LINUX_XATTR_NAME_MAX + 1];
272 	int attrnamespace, error;
273 
274 	error = xatrr_to_extattr(uname, &attrnamespace, attrname);
275 	if (error != 0)
276 		return (error);
277 
278 	return (kern_extattr_get_path(td, upath, attrnamespace,
279 	    attrname, value, size, follow, UIO_USERSPACE));
280 }
281 
282 int
283 linux_getxattr(struct thread *td, struct linux_getxattr_args *args)
284 {
285 
286 	return (linux_path_getxattr(td, args->path, args->name,
287 	    args->value, args->size, FOLLOW));
288 }
289 
290 int
291 linux_lgetxattr(struct thread *td, struct linux_lgetxattr_args *args)
292 {
293 
294 	return (linux_path_getxattr(td, args->path, args->name,
295 	    args->value, args->size, NOFOLLOW));
296 }
297 
298 int
299 linux_fgetxattr(struct thread *td, struct linux_fgetxattr_args *args)
300 {
301 	char attrname[LINUX_XATTR_NAME_MAX + 1];
302 	int attrnamespace, error;
303 
304 	error = xatrr_to_extattr(args->name, &attrnamespace, attrname);
305 	if (error != 0)
306 		return (error);
307 	return (kern_extattr_get_fd(td, args->fd, attrnamespace,
308 	    attrname, args->value, args->size));
309 }
310 
311 static int
312 setxattr(struct thread *td, struct setxattr_args *args)
313 {
314 	char attrname[LINUX_XATTR_NAME_MAX + 1];
315 	int attrnamespace, error;
316 
317 	if ((args->flags & ~(LINUX_XATTR_FLAGS)) != 0 ||
318 	    args->flags == (LINUX_XATTR_FLAGS))
319 		return (EINVAL);
320 	error = xatrr_to_extattr(args->name, &attrnamespace, attrname);
321 	if (error != 0)
322 		return (error);
323 
324 	if ((args->flags & (LINUX_XATTR_FLAGS)) != 0 ) {
325 		if (args->path != NULL)
326 			error = kern_extattr_get_path(td, args->path,
327 			    attrnamespace, attrname, NULL, args->size,
328 			    args->follow, UIO_USERSPACE);
329 		else
330 			error = kern_extattr_get_fd(td, args->fd,
331 			    attrnamespace, attrname, NULL, args->size);
332 		if ((args->flags & LINUX_XATTR_CREATE) != 0) {
333 			if (error == 0)
334 				error = EEXIST;
335 			else if (error == ENOATTR)
336 				error = 0;
337 		}
338 		if (error != 0)
339 			goto out;
340 	}
341 	if (args->path != NULL)
342 		error = kern_extattr_set_path(td, args->path, attrnamespace,
343 		    attrname, args->value, args->size, args->follow,
344 		    UIO_USERSPACE);
345 	else
346 		error = kern_extattr_set_fd(td, args->fd, attrnamespace,
347 		    attrname, args->value, args->size);
348 out:
349 	td->td_retval[0] = 0;
350 	return (error);
351 }
352 
353 int
354 linux_setxattr(struct thread *td, struct linux_setxattr_args *args)
355 {
356 	struct setxattr_args eargs = {
357 		.fd = -1,
358 		.path = args->path,
359 		.name = args->name,
360 		.value = args->value,
361 		.size = args->size,
362 		.flags = args->flags,
363 		.follow = FOLLOW,
364 	};
365 
366 	return (setxattr(td, &eargs));
367 }
368 
369 int
370 linux_lsetxattr(struct thread *td, struct linux_lsetxattr_args *args)
371 {
372 	struct setxattr_args eargs = {
373 		.fd = -1,
374 		.path = args->path,
375 		.name = args->name,
376 		.value = args->value,
377 		.size = args->size,
378 		.flags = args->flags,
379 		.follow = NOFOLLOW,
380 	};
381 
382 	return (setxattr(td, &eargs));
383 }
384 
385 int
386 linux_fsetxattr(struct thread *td, struct linux_fsetxattr_args *args)
387 {
388 	struct setxattr_args eargs = {
389 		.fd = args->fd,
390 		.path = NULL,
391 		.name = args->name,
392 		.value = args->value,
393 		.size = args->size,
394 		.flags = args->flags,
395 		.follow = 0,
396 	};
397 
398 	return (setxattr(td, &eargs));
399 }
400