xref: /openbmc/linux/fs/smb/client/reparse.c (revision 003d2996)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2024 Paulo Alcantara <pc@manguebit.com>
4  */
5 
6 #include <linux/fs.h>
7 #include <linux/stat.h>
8 #include <linux/slab.h>
9 #include "cifsglob.h"
10 #include "smb2proto.h"
11 #include "cifsproto.h"
12 #include "cifs_unicode.h"
13 #include "cifs_debug.h"
14 #include "fs_context.h"
15 #include "reparse.h"
16 
17 static int detect_directory_symlink_target(struct cifs_sb_info *cifs_sb,
18 					   const unsigned int xid,
19 					   const char *full_path,
20 					   const char *symname,
21 					   bool *directory);
22 
23 int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,
24 				struct dentry *dentry, struct cifs_tcon *tcon,
25 				const char *full_path, const char *symname)
26 {
27 	struct reparse_symlink_data_buffer *buf = NULL;
28 	struct cifs_open_info_data data;
29 	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
30 	struct inode *new;
31 	struct kvec iov;
32 	__le16 *path;
33 	bool directory;
34 	char *sym, sep = CIFS_DIR_SEP(cifs_sb);
35 	u16 len, plen;
36 	int rc = 0;
37 
38 	sym = kstrdup(symname, GFP_KERNEL);
39 	if (!sym)
40 		return -ENOMEM;
41 
42 	data = (struct cifs_open_info_data) {
43 		.reparse_point = true,
44 		.reparse = { .tag = IO_REPARSE_TAG_SYMLINK, },
45 		.symlink_target = sym,
46 	};
47 
48 	convert_delimiter(sym, sep);
49 	path = cifs_convert_path_to_utf16(sym, cifs_sb);
50 	if (!path) {
51 		rc = -ENOMEM;
52 		goto out;
53 	}
54 
55 	/*
56 	 * SMB distinguish between symlink to directory and symlink to file.
57 	 * They cannot be exchanged (symlink of file type which points to
58 	 * directory cannot be resolved and vice-versa). Try to detect if
59 	 * the symlink target could be a directory or not. When detection
60 	 * fails then treat symlink as a file (non-directory) symlink.
61 	 */
62 	directory = false;
63 	rc = detect_directory_symlink_target(cifs_sb, xid, full_path, symname, &directory);
64 	if (rc < 0)
65 		goto out;
66 
67 	plen = 2 * UniStrnlen((wchar_t *)path, PATH_MAX);
68 	len = sizeof(*buf) + plen * 2;
69 	buf = kzalloc(len, GFP_KERNEL);
70 	if (!buf) {
71 		rc = -ENOMEM;
72 		goto out;
73 	}
74 
75 	buf->ReparseTag = cpu_to_le32(IO_REPARSE_TAG_SYMLINK);
76 	buf->ReparseDataLength = cpu_to_le16(len - sizeof(struct reparse_data_buffer));
77 	buf->SubstituteNameOffset = cpu_to_le16(plen);
78 	buf->SubstituteNameLength = cpu_to_le16(plen);
79 	memcpy(&buf->PathBuffer[plen], path, plen);
80 	buf->PrintNameOffset = 0;
81 	buf->PrintNameLength = cpu_to_le16(plen);
82 	memcpy(buf->PathBuffer, path, plen);
83 	buf->Flags = cpu_to_le32(*symname != '/' ? SYMLINK_FLAG_RELATIVE : 0);
84 	if (*sym != sep)
85 		buf->Flags = cpu_to_le32(SYMLINK_FLAG_RELATIVE);
86 
87 	convert_delimiter(sym, '/');
88 	iov.iov_base = buf;
89 	iov.iov_len = len;
90 	new = smb2_get_reparse_inode(&data, inode->i_sb, xid,
91 				     tcon, full_path, directory,
92 				     &iov, NULL);
93 	if (!IS_ERR(new))
94 		d_instantiate(dentry, new);
95 	else
96 		rc = PTR_ERR(new);
97 out:
98 	kfree(path);
99 	cifs_free_open_info(&data);
100 	kfree(buf);
101 	return rc;
102 }
103 
104 static int detect_directory_symlink_target(struct cifs_sb_info *cifs_sb,
105 					   const unsigned int xid,
106 					   const char *full_path,
107 					   const char *symname,
108 					   bool *directory)
109 {
110 	char sep = CIFS_DIR_SEP(cifs_sb);
111 	struct cifs_open_parms oparms;
112 	struct tcon_link *tlink;
113 	struct cifs_tcon *tcon;
114 	const char *basename;
115 	struct cifs_fid fid;
116 	char *resolved_path;
117 	int full_path_len;
118 	int basename_len;
119 	int symname_len;
120 	char *path_sep;
121 	__u32 oplock;
122 	int open_rc;
123 
124 	/*
125 	 * First do some simple check. If the original Linux symlink target ends
126 	 * with slash, or last path component is dot or dot-dot then it is for
127 	 * sure symlink to the directory.
128 	 */
129 	basename = kbasename(symname);
130 	basename_len = strlen(basename);
131 	if (basename_len == 0 || /* symname ends with slash */
132 	    (basename_len == 1 && basename[0] == '.') || /* last component is "." */
133 	    (basename_len == 2 && basename[0] == '.' && basename[1] == '.')) { /* or ".." */
134 		*directory = true;
135 		return 0;
136 	}
137 
138 	/*
139 	 * For absolute symlinks it is not possible to determinate
140 	 * if it should point to directory or file.
141 	 */
142 	if (symname[0] == '/') {
143 		cifs_dbg(FYI,
144 			 "%s: cannot determinate if the symlink target path '%s' "
145 			 "is directory or not, creating '%s' as file symlink\n",
146 			 __func__, symname, full_path);
147 		return 0;
148 	}
149 
150 	/*
151 	 * If it was not detected as directory yet and the symlink is relative
152 	 * then try to resolve the path on the SMB server, check if the path
153 	 * exists and determinate if it is a directory or not.
154 	 */
155 
156 	full_path_len = strlen(full_path);
157 	symname_len = strlen(symname);
158 
159 	tlink = cifs_sb_tlink(cifs_sb);
160 	if (IS_ERR(tlink))
161 		return PTR_ERR(tlink);
162 
163 	resolved_path = kzalloc(full_path_len + symname_len + 1, GFP_KERNEL);
164 	if (!resolved_path) {
165 		cifs_put_tlink(tlink);
166 		return -ENOMEM;
167 	}
168 
169 	/*
170 	 * Compose the resolved SMB symlink path from the SMB full path
171 	 * and Linux target symlink path.
172 	 */
173 	memcpy(resolved_path, full_path, full_path_len+1);
174 	path_sep = strrchr(resolved_path, sep);
175 	if (path_sep)
176 		path_sep++;
177 	else
178 		path_sep = resolved_path;
179 	memcpy(path_sep, symname, symname_len+1);
180 	if (sep == '\\')
181 		convert_delimiter(path_sep, sep);
182 
183 	tcon = tlink_tcon(tlink);
184 	oparms = CIFS_OPARMS(cifs_sb, tcon, resolved_path,
185 			     FILE_READ_ATTRIBUTES, FILE_OPEN, 0, ACL_NO_MODE);
186 	oparms.fid = &fid;
187 
188 	/* Try to open as a directory (NOT_FILE) */
189 	oplock = 0;
190 	oparms.create_options = cifs_create_options(cifs_sb,
191 						    CREATE_NOT_FILE | OPEN_REPARSE_POINT);
192 	open_rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, NULL);
193 	if (open_rc == 0) {
194 		/* Successful open means that the target path is definitely a directory. */
195 		*directory = true;
196 		tcon->ses->server->ops->close(xid, tcon, &fid);
197 	} else if (open_rc == -ENOTDIR) {
198 		/* -ENOTDIR means that the target path is definitely a file. */
199 		*directory = false;
200 	} else if (open_rc == -ENOENT) {
201 		/* -ENOENT means that the target path does not exist. */
202 		cifs_dbg(FYI,
203 			 "%s: symlink target path '%s' does not exist, "
204 			 "creating '%s' as file symlink\n",
205 			 __func__, symname, full_path);
206 	} else {
207 		/* Try to open as a file (NOT_DIR) */
208 		oplock = 0;
209 		oparms.create_options = cifs_create_options(cifs_sb,
210 							    CREATE_NOT_DIR | OPEN_REPARSE_POINT);
211 		open_rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, NULL);
212 		if (open_rc == 0) {
213 			/* Successful open means that the target path is definitely a file. */
214 			*directory = false;
215 			tcon->ses->server->ops->close(xid, tcon, &fid);
216 		} else if (open_rc == -EISDIR) {
217 			/* -EISDIR means that the target path is definitely a directory. */
218 			*directory = true;
219 		} else {
220 			/*
221 			 * This code branch is called when we do not have a permission to
222 			 * open the resolved_path or some other client/process denied
223 			 * opening the resolved_path.
224 			 *
225 			 * TODO: Try to use ops->query_dir_first on the parent directory
226 			 * of resolved_path, search for basename of resolved_path and
227 			 * check if the ATTR_DIRECTORY is set in fi.Attributes. In some
228 			 * case this could work also when opening of the path is denied.
229 			 */
230 			cifs_dbg(FYI,
231 				 "%s: cannot determinate if the symlink target path '%s' "
232 				 "is directory or not, creating '%s' as file symlink\n",
233 				 __func__, symname, full_path);
234 		}
235 	}
236 
237 	kfree(resolved_path);
238 	cifs_put_tlink(tlink);
239 	return 0;
240 }
241 
242 static int nfs_set_reparse_buf(struct reparse_posix_data *buf,
243 			       mode_t mode, dev_t dev,
244 			       struct kvec *iov)
245 {
246 	u64 type;
247 	u16 len, dlen;
248 
249 	len = sizeof(*buf);
250 
251 	switch ((type = reparse_mode_nfs_type(mode))) {
252 	case NFS_SPECFILE_BLK:
253 	case NFS_SPECFILE_CHR:
254 		dlen = sizeof(__le64);
255 		break;
256 	case NFS_SPECFILE_FIFO:
257 	case NFS_SPECFILE_SOCK:
258 		dlen = 0;
259 		break;
260 	default:
261 		return -EOPNOTSUPP;
262 	}
263 
264 	buf->ReparseTag = cpu_to_le32(IO_REPARSE_TAG_NFS);
265 	buf->Reserved = 0;
266 	buf->InodeType = cpu_to_le64(type);
267 	buf->ReparseDataLength = cpu_to_le16(len + dlen -
268 					     sizeof(struct reparse_data_buffer));
269 	*(__le64 *)buf->DataBuffer = cpu_to_le64(((u64)MINOR(dev) << 32) |
270 						 MAJOR(dev));
271 	iov->iov_base = buf;
272 	iov->iov_len = len + dlen;
273 	return 0;
274 }
275 
276 static int mknod_nfs(unsigned int xid, struct inode *inode,
277 		     struct dentry *dentry, struct cifs_tcon *tcon,
278 		     const char *full_path, umode_t mode, dev_t dev)
279 {
280 	struct cifs_open_info_data data;
281 	struct reparse_posix_data *p;
282 	struct inode *new;
283 	struct kvec iov;
284 	__u8 buf[sizeof(*p) + sizeof(__le64)];
285 	int rc;
286 
287 	p = (struct reparse_posix_data *)buf;
288 	rc = nfs_set_reparse_buf(p, mode, dev, &iov);
289 	if (rc)
290 		return rc;
291 
292 	data = (struct cifs_open_info_data) {
293 		.reparse_point = true,
294 		.reparse = { .tag = IO_REPARSE_TAG_NFS, .posix = p, },
295 	};
296 
297 	new = smb2_get_reparse_inode(&data, inode->i_sb, xid,
298 				     tcon, full_path, false, &iov, NULL);
299 	if (!IS_ERR(new))
300 		d_instantiate(dentry, new);
301 	else
302 		rc = PTR_ERR(new);
303 	cifs_free_open_info(&data);
304 	return rc;
305 }
306 
307 static int wsl_set_reparse_buf(struct reparse_data_buffer *buf,
308 			       mode_t mode, struct kvec *iov)
309 {
310 	u32 tag;
311 
312 	switch ((tag = reparse_mode_wsl_tag(mode))) {
313 	case IO_REPARSE_TAG_LX_BLK:
314 	case IO_REPARSE_TAG_LX_CHR:
315 	case IO_REPARSE_TAG_LX_FIFO:
316 	case IO_REPARSE_TAG_AF_UNIX:
317 		break;
318 	default:
319 		return -EOPNOTSUPP;
320 	}
321 
322 	buf->ReparseTag = cpu_to_le32(tag);
323 	buf->Reserved = 0;
324 	buf->ReparseDataLength = 0;
325 	iov->iov_base = buf;
326 	iov->iov_len = sizeof(*buf);
327 	return 0;
328 }
329 
330 static struct smb2_create_ea_ctx *ea_create_context(u32 dlen, size_t *cc_len)
331 {
332 	struct smb2_create_ea_ctx *cc;
333 
334 	*cc_len = round_up(sizeof(*cc) + dlen, 8);
335 	cc = kzalloc(*cc_len, GFP_KERNEL);
336 	if (!cc)
337 		return ERR_PTR(-ENOMEM);
338 
339 	cc->ctx.NameOffset = cpu_to_le16(offsetof(struct smb2_create_ea_ctx,
340 						  name));
341 	cc->ctx.NameLength = cpu_to_le16(4);
342 	memcpy(cc->name, SMB2_CREATE_EA_BUFFER, strlen(SMB2_CREATE_EA_BUFFER));
343 	cc->ctx.DataOffset = cpu_to_le16(offsetof(struct smb2_create_ea_ctx, ea));
344 	cc->ctx.DataLength = cpu_to_le32(dlen);
345 	return cc;
346 }
347 
348 struct wsl_xattr {
349 	const char	*name;
350 	__le64		value;
351 	u16		size;
352 	u32		next;
353 };
354 
355 static int wsl_set_xattrs(struct inode *inode, umode_t _mode,
356 			  dev_t _dev, struct kvec *iov)
357 {
358 	struct smb2_file_full_ea_info *ea;
359 	struct smb2_create_ea_ctx *cc;
360 	struct smb3_fs_context *ctx = CIFS_SB(inode->i_sb)->ctx;
361 	__le64 uid = cpu_to_le64(from_kuid(current_user_ns(), ctx->linux_uid));
362 	__le64 gid = cpu_to_le64(from_kgid(current_user_ns(), ctx->linux_gid));
363 	__le64 dev = cpu_to_le64(((u64)MINOR(_dev) << 32) | MAJOR(_dev));
364 	__le64 mode = cpu_to_le64(_mode);
365 	struct wsl_xattr xattrs[] = {
366 		{ .name = SMB2_WSL_XATTR_UID,  .value = uid,  .size = SMB2_WSL_XATTR_UID_SIZE, },
367 		{ .name = SMB2_WSL_XATTR_GID,  .value = gid,  .size = SMB2_WSL_XATTR_GID_SIZE, },
368 		{ .name = SMB2_WSL_XATTR_MODE, .value = mode, .size = SMB2_WSL_XATTR_MODE_SIZE, },
369 		{ .name = SMB2_WSL_XATTR_DEV,  .value = dev, .size = SMB2_WSL_XATTR_DEV_SIZE, },
370 	};
371 	size_t cc_len;
372 	u32 dlen = 0, next = 0;
373 	int i, num_xattrs;
374 	u8 name_size = SMB2_WSL_XATTR_NAME_LEN + 1;
375 
376 	memset(iov, 0, sizeof(*iov));
377 
378 	/* Exclude $LXDEV xattr for sockets and fifos */
379 	if (S_ISSOCK(_mode) || S_ISFIFO(_mode))
380 		num_xattrs = ARRAY_SIZE(xattrs) - 1;
381 	else
382 		num_xattrs = ARRAY_SIZE(xattrs);
383 
384 	for (i = 0; i < num_xattrs; i++) {
385 		xattrs[i].next = ALIGN(sizeof(*ea) + name_size +
386 				       xattrs[i].size, 4);
387 		dlen += xattrs[i].next;
388 	}
389 
390 	cc = ea_create_context(dlen, &cc_len);
391 	if (IS_ERR(cc))
392 		return PTR_ERR(cc);
393 
394 	ea = &cc->ea;
395 	for (i = 0; i < num_xattrs; i++) {
396 		ea = (void *)((u8 *)ea + next);
397 		next = xattrs[i].next;
398 		ea->next_entry_offset = cpu_to_le32(next);
399 
400 		ea->ea_name_length = name_size - 1;
401 		ea->ea_value_length = cpu_to_le16(xattrs[i].size);
402 		memcpy(ea->ea_data, xattrs[i].name, name_size);
403 		memcpy(&ea->ea_data[name_size],
404 		       &xattrs[i].value, xattrs[i].size);
405 	}
406 	ea->next_entry_offset = 0;
407 
408 	iov->iov_base = cc;
409 	iov->iov_len = cc_len;
410 	return 0;
411 }
412 
413 static int mknod_wsl(unsigned int xid, struct inode *inode,
414 		     struct dentry *dentry, struct cifs_tcon *tcon,
415 		     const char *full_path, umode_t mode, dev_t dev)
416 {
417 	struct cifs_open_info_data data;
418 	struct reparse_data_buffer buf;
419 	struct smb2_create_ea_ctx *cc;
420 	struct inode *new;
421 	unsigned int len;
422 	struct kvec reparse_iov, xattr_iov;
423 	int rc;
424 
425 	rc = wsl_set_reparse_buf(&buf, mode, &reparse_iov);
426 	if (rc)
427 		return rc;
428 
429 	rc = wsl_set_xattrs(inode, mode, dev, &xattr_iov);
430 	if (rc)
431 		return rc;
432 
433 	data = (struct cifs_open_info_data) {
434 		.reparse_point = true,
435 		.reparse = { .tag = le32_to_cpu(buf.ReparseTag), .buf = &buf, },
436 	};
437 
438 	cc = xattr_iov.iov_base;
439 	len = le32_to_cpu(cc->ctx.DataLength);
440 	memcpy(data.wsl.eas, &cc->ea, len);
441 	data.wsl.eas_len = len;
442 
443 	new = smb2_get_reparse_inode(&data, inode->i_sb,
444 				     xid, tcon, full_path, false,
445 				     &reparse_iov, &xattr_iov);
446 	if (!IS_ERR(new))
447 		d_instantiate(dentry, new);
448 	else
449 		rc = PTR_ERR(new);
450 	cifs_free_open_info(&data);
451 	kfree(xattr_iov.iov_base);
452 	return rc;
453 }
454 
455 int smb2_mknod_reparse(unsigned int xid, struct inode *inode,
456 		       struct dentry *dentry, struct cifs_tcon *tcon,
457 		       const char *full_path, umode_t mode, dev_t dev)
458 {
459 	struct smb3_fs_context *ctx = CIFS_SB(inode->i_sb)->ctx;
460 	int rc = -EOPNOTSUPP;
461 
462 	switch (ctx->reparse_type) {
463 	case CIFS_REPARSE_TYPE_NFS:
464 		rc = mknod_nfs(xid, inode, dentry, tcon, full_path, mode, dev);
465 		break;
466 	case CIFS_REPARSE_TYPE_WSL:
467 		rc = mknod_wsl(xid, inode, dentry, tcon, full_path, mode, dev);
468 		break;
469 	}
470 	return rc;
471 }
472 
473 /* See MS-FSCC 2.1.2.6 for the 'NFS' style reparse tags */
474 static int parse_reparse_posix(struct reparse_posix_data *buf,
475 			       struct cifs_sb_info *cifs_sb,
476 			       struct cifs_open_info_data *data)
477 {
478 	unsigned int len;
479 	u64 type;
480 
481 	len = le16_to_cpu(buf->ReparseDataLength);
482 	if (len < sizeof(buf->InodeType)) {
483 		cifs_dbg(VFS, "srv returned malformed nfs buffer\n");
484 		return -EIO;
485 	}
486 
487 	len -= sizeof(buf->InodeType);
488 
489 	switch ((type = le64_to_cpu(buf->InodeType))) {
490 	case NFS_SPECFILE_LNK:
491 		if (len == 0 || (len % 2)) {
492 			cifs_dbg(VFS, "srv returned malformed nfs symlink buffer\n");
493 			return -EIO;
494 		}
495 		/*
496 		 * Check that buffer does not contain UTF-16 null codepoint
497 		 * because Linux cannot process symlink with null byte.
498 		 */
499 		if (UniStrnlen((wchar_t *)buf->DataBuffer, len/2) != len/2) {
500 			cifs_dbg(VFS, "srv returned null byte in nfs symlink target location\n");
501 			return -EIO;
502 		}
503 		data->symlink_target = cifs_strndup_from_utf16(buf->DataBuffer,
504 							       len, true,
505 							       cifs_sb->local_nls);
506 		if (!data->symlink_target)
507 			return -ENOMEM;
508 		cifs_dbg(FYI, "%s: target path: %s\n",
509 			 __func__, data->symlink_target);
510 		break;
511 	case NFS_SPECFILE_CHR:
512 	case NFS_SPECFILE_BLK:
513 		/* DataBuffer for block and char devices contains two 32-bit numbers */
514 		if (len != 8) {
515 			cifs_dbg(VFS, "srv returned malformed nfs buffer for type: 0x%llx\n", type);
516 			return -EIO;
517 		}
518 		break;
519 	case NFS_SPECFILE_FIFO:
520 	case NFS_SPECFILE_SOCK:
521 		/* DataBuffer for fifos and sockets is empty */
522 		if (len != 0) {
523 			cifs_dbg(VFS, "srv returned malformed nfs buffer for type: 0x%llx\n", type);
524 			return -EIO;
525 		}
526 		break;
527 	default:
528 		cifs_dbg(VFS, "%s: unhandled inode type: 0x%llx\n",
529 			 __func__, type);
530 		return -EOPNOTSUPP;
531 	}
532 	return 0;
533 }
534 
535 static int parse_reparse_symlink(struct reparse_symlink_data_buffer *sym,
536 				 u32 plen, bool unicode,
537 				 struct cifs_sb_info *cifs_sb,
538 				 struct cifs_open_info_data *data)
539 {
540 	unsigned int len;
541 	unsigned int offs;
542 
543 	/* We handle Symbolic Link reparse tag here. See: MS-FSCC 2.1.2.4 */
544 
545 	offs = le16_to_cpu(sym->SubstituteNameOffset);
546 	len = le16_to_cpu(sym->SubstituteNameLength);
547 	if (offs + 20 > plen || offs + len + 20 > plen) {
548 		cifs_dbg(VFS, "srv returned malformed symlink buffer\n");
549 		return -EIO;
550 	}
551 
552 	data->symlink_target = cifs_strndup_from_utf16(sym->PathBuffer + offs,
553 						       len, unicode,
554 						       cifs_sb->local_nls);
555 	if (!data->symlink_target)
556 		return -ENOMEM;
557 
558 	convert_delimiter(data->symlink_target, '/');
559 	cifs_dbg(FYI, "%s: target path: %s\n", __func__, data->symlink_target);
560 
561 	return 0;
562 }
563 
564 int parse_reparse_point(struct reparse_data_buffer *buf,
565 			u32 plen, struct cifs_sb_info *cifs_sb,
566 			bool unicode, struct cifs_open_info_data *data)
567 {
568 	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
569 
570 	data->reparse.buf = buf;
571 
572 	/* See MS-FSCC 2.1.2 */
573 	switch (le32_to_cpu(buf->ReparseTag)) {
574 	case IO_REPARSE_TAG_NFS:
575 		return parse_reparse_posix((struct reparse_posix_data *)buf,
576 					   cifs_sb, data);
577 	case IO_REPARSE_TAG_SYMLINK:
578 		return parse_reparse_symlink(
579 			(struct reparse_symlink_data_buffer *)buf,
580 			plen, unicode, cifs_sb, data);
581 	case IO_REPARSE_TAG_LX_SYMLINK:
582 	case IO_REPARSE_TAG_AF_UNIX:
583 	case IO_REPARSE_TAG_LX_FIFO:
584 	case IO_REPARSE_TAG_LX_CHR:
585 	case IO_REPARSE_TAG_LX_BLK:
586 		break;
587 	default:
588 		cifs_tcon_dbg(VFS | ONCE, "unhandled reparse tag: 0x%08x\n",
589 			      le32_to_cpu(buf->ReparseTag));
590 		break;
591 	}
592 	return 0;
593 }
594 
595 int smb2_parse_reparse_point(struct cifs_sb_info *cifs_sb,
596 			     struct kvec *rsp_iov,
597 			     struct cifs_open_info_data *data)
598 {
599 	struct reparse_data_buffer *buf;
600 	struct smb2_ioctl_rsp *io = rsp_iov->iov_base;
601 	u32 plen = le32_to_cpu(io->OutputCount);
602 
603 	buf = (struct reparse_data_buffer *)((u8 *)io +
604 					     le32_to_cpu(io->OutputOffset));
605 	return parse_reparse_point(buf, plen, cifs_sb, true, data);
606 }
607 
608 static void wsl_to_fattr(struct cifs_open_info_data *data,
609 			 struct cifs_sb_info *cifs_sb,
610 			 u32 tag, struct cifs_fattr *fattr)
611 {
612 	struct smb2_file_full_ea_info *ea;
613 	u32 next = 0;
614 
615 	switch (tag) {
616 	case IO_REPARSE_TAG_LX_SYMLINK:
617 		fattr->cf_mode |= S_IFLNK;
618 		break;
619 	case IO_REPARSE_TAG_LX_FIFO:
620 		fattr->cf_mode |= S_IFIFO;
621 		break;
622 	case IO_REPARSE_TAG_AF_UNIX:
623 		fattr->cf_mode |= S_IFSOCK;
624 		break;
625 	case IO_REPARSE_TAG_LX_CHR:
626 		fattr->cf_mode |= S_IFCHR;
627 		break;
628 	case IO_REPARSE_TAG_LX_BLK:
629 		fattr->cf_mode |= S_IFBLK;
630 		break;
631 	}
632 
633 	if (!data->wsl.eas_len)
634 		goto out;
635 
636 	ea = (struct smb2_file_full_ea_info *)data->wsl.eas;
637 	do {
638 		const char *name;
639 		void *v;
640 		u8 nlen;
641 
642 		ea = (void *)((u8 *)ea + next);
643 		next = le32_to_cpu(ea->next_entry_offset);
644 		if (!le16_to_cpu(ea->ea_value_length))
645 			continue;
646 
647 		name = ea->ea_data;
648 		nlen = ea->ea_name_length;
649 		v = (void *)((u8 *)ea->ea_data + ea->ea_name_length + 1);
650 
651 		if (!strncmp(name, SMB2_WSL_XATTR_UID, nlen))
652 			fattr->cf_uid = wsl_make_kuid(cifs_sb, v);
653 		else if (!strncmp(name, SMB2_WSL_XATTR_GID, nlen))
654 			fattr->cf_gid = wsl_make_kgid(cifs_sb, v);
655 		else if (!strncmp(name, SMB2_WSL_XATTR_MODE, nlen))
656 			fattr->cf_mode = (umode_t)le32_to_cpu(*(__le32 *)v);
657 		else if (!strncmp(name, SMB2_WSL_XATTR_DEV, nlen))
658 			fattr->cf_rdev = reparse_mkdev(v);
659 	} while (next);
660 out:
661 	fattr->cf_dtype = S_DT(fattr->cf_mode);
662 }
663 
664 bool cifs_reparse_point_to_fattr(struct cifs_sb_info *cifs_sb,
665 				 struct cifs_fattr *fattr,
666 				 struct cifs_open_info_data *data)
667 {
668 	struct reparse_posix_data *buf = data->reparse.posix;
669 	u32 tag = data->reparse.tag;
670 
671 	if (tag == IO_REPARSE_TAG_NFS && buf) {
672 		if (le16_to_cpu(buf->ReparseDataLength) < sizeof(buf->InodeType))
673 			return false;
674 		switch (le64_to_cpu(buf->InodeType)) {
675 		case NFS_SPECFILE_CHR:
676 			if (le16_to_cpu(buf->ReparseDataLength) != sizeof(buf->InodeType) + 8)
677 				return false;
678 			fattr->cf_mode |= S_IFCHR;
679 			fattr->cf_rdev = reparse_mkdev(buf->DataBuffer);
680 			break;
681 		case NFS_SPECFILE_BLK:
682 			if (le16_to_cpu(buf->ReparseDataLength) != sizeof(buf->InodeType) + 8)
683 				return false;
684 			fattr->cf_mode |= S_IFBLK;
685 			fattr->cf_rdev = reparse_mkdev(buf->DataBuffer);
686 			break;
687 		case NFS_SPECFILE_FIFO:
688 			fattr->cf_mode |= S_IFIFO;
689 			break;
690 		case NFS_SPECFILE_SOCK:
691 			fattr->cf_mode |= S_IFSOCK;
692 			break;
693 		case NFS_SPECFILE_LNK:
694 			fattr->cf_mode |= S_IFLNK;
695 			break;
696 		default:
697 			WARN_ON_ONCE(1);
698 			return false;
699 		}
700 		goto out;
701 	}
702 
703 	switch (tag) {
704 	case IO_REPARSE_TAG_INTERNAL:
705 		if (!(fattr->cf_cifsattrs & ATTR_DIRECTORY))
706 			return false;
707 		fallthrough;
708 	case IO_REPARSE_TAG_DFS:
709 	case IO_REPARSE_TAG_DFSR:
710 	case IO_REPARSE_TAG_MOUNT_POINT:
711 		/* See cifs_create_junction_fattr() */
712 		fattr->cf_mode = S_IFDIR | 0711;
713 		break;
714 	case IO_REPARSE_TAG_LX_SYMLINK:
715 	case IO_REPARSE_TAG_LX_FIFO:
716 	case IO_REPARSE_TAG_AF_UNIX:
717 	case IO_REPARSE_TAG_LX_CHR:
718 	case IO_REPARSE_TAG_LX_BLK:
719 		wsl_to_fattr(data, cifs_sb, tag, fattr);
720 		break;
721 	case 0: /* SMB1 symlink */
722 	case IO_REPARSE_TAG_SYMLINK:
723 	case IO_REPARSE_TAG_NFS:
724 		fattr->cf_mode |= S_IFLNK;
725 		break;
726 	default:
727 		return false;
728 	}
729 out:
730 	fattr->cf_dtype = S_DT(fattr->cf_mode);
731 	return true;
732 }
733