1 // SPDX-License-Identifier: LGPL-2.1
2 /*
3 *
4 * Copyright (C) International Business Machines Corp., 2002, 2011
5 * Author(s): Steve French (sfrench@us.ibm.com),
6 * Pavel Shilovsky ((pshilovsky@samba.org) 2012
7 *
8 */
9 #include <linux/fs.h>
10 #include <linux/filelock.h>
11 #include <linux/stat.h>
12 #include <linux/slab.h>
13 #include <linux/pagemap.h>
14 #include <asm/div64.h>
15 #include "cifsfs.h"
16 #include "cifspdu.h"
17 #include "cifsglob.h"
18 #include "cifsproto.h"
19 #include "cifs_debug.h"
20 #include "cifs_fs_sb.h"
21 #include "cifs_unicode.h"
22 #include "fscache.h"
23 #include "smb2proto.h"
24 #include "../common/smb2status.h"
25
symlink_data(const struct kvec * iov)26 static struct smb2_symlink_err_rsp *symlink_data(const struct kvec *iov)
27 {
28 struct smb2_err_rsp *err = iov->iov_base;
29 struct smb2_symlink_err_rsp *sym = ERR_PTR(-EINVAL);
30 u32 len;
31
32 if (err->ErrorContextCount) {
33 struct smb2_error_context_rsp *p, *end;
34
35 len = (u32)err->ErrorContextCount * (offsetof(struct smb2_error_context_rsp,
36 ErrorContextData) +
37 sizeof(struct smb2_symlink_err_rsp));
38 if (le32_to_cpu(err->ByteCount) < len || iov->iov_len < len + sizeof(*err) + 1)
39 return ERR_PTR(-EINVAL);
40
41 p = (struct smb2_error_context_rsp *)err->ErrorData;
42 end = (struct smb2_error_context_rsp *)((u8 *)err + iov->iov_len);
43 do {
44 if (le32_to_cpu(p->ErrorId) == SMB2_ERROR_ID_DEFAULT) {
45 sym = (struct smb2_symlink_err_rsp *)p->ErrorContextData;
46 break;
47 }
48 cifs_dbg(FYI, "%s: skipping unhandled error context: 0x%x\n",
49 __func__, le32_to_cpu(p->ErrorId));
50
51 len = ALIGN(le32_to_cpu(p->ErrorDataLength), 8);
52 p = (struct smb2_error_context_rsp *)(p->ErrorContextData + len);
53 } while (p < end);
54 } else if (le32_to_cpu(err->ByteCount) >= sizeof(*sym) &&
55 iov->iov_len >= SMB2_SYMLINK_STRUCT_SIZE) {
56 sym = (struct smb2_symlink_err_rsp *)err->ErrorData;
57 }
58
59 if (!IS_ERR(sym) && (le32_to_cpu(sym->SymLinkErrorTag) != SYMLINK_ERROR_TAG ||
60 le32_to_cpu(sym->ReparseTag) != IO_REPARSE_TAG_SYMLINK))
61 sym = ERR_PTR(-EINVAL);
62
63 return sym;
64 }
65
smb2_fix_symlink_target_type(char ** target,bool directory,struct cifs_sb_info * cifs_sb)66 int smb2_fix_symlink_target_type(char **target, bool directory, struct cifs_sb_info *cifs_sb)
67 {
68 char *buf;
69 int len;
70
71 /*
72 * POSIX server does not distinguish between symlinks to file and
73 * symlink directory. So nothing is needed to fix on the client side.
74 */
75 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)
76 return 0;
77
78 if (!*target)
79 return -EIO;
80
81 len = strlen(*target);
82 if (!len)
83 return -EIO;
84
85 /*
86 * If this is directory symlink and it does not have trailing slash then
87 * append it. Trailing slash simulates Windows/SMB behavior which do not
88 * allow resolving directory symlink to file.
89 */
90 if (directory && (*target)[len-1] != '/') {
91 buf = krealloc(*target, len+2, GFP_KERNEL);
92 if (!buf)
93 return -ENOMEM;
94 buf[len] = '/';
95 buf[len+1] = '\0';
96 *target = buf;
97 len++;
98 }
99
100 /*
101 * If this is a file (non-directory) symlink and it points to path name
102 * with trailing slash then this is an invalid symlink because file name
103 * cannot contain slash character. File name with slash is invalid on
104 * both Windows and Linux systems. So return an error for such symlink.
105 */
106 if (!directory && (*target)[len-1] == '/')
107 return -EIO;
108
109 return 0;
110 }
111
smb2_parse_symlink_response(struct cifs_sb_info * cifs_sb,const struct kvec * iov,const char * full_path,char ** path)112 int smb2_parse_symlink_response(struct cifs_sb_info *cifs_sb, const struct kvec *iov,
113 const char *full_path, char **path)
114 {
115 struct smb2_symlink_err_rsp *sym;
116 unsigned int sub_offs, sub_len;
117 unsigned int print_offs, print_len;
118
119 if (!cifs_sb || !iov || !iov->iov_base || !iov->iov_len || !path)
120 return -EINVAL;
121
122 sym = symlink_data(iov);
123 if (IS_ERR(sym))
124 return PTR_ERR(sym);
125
126 sub_len = le16_to_cpu(sym->SubstituteNameLength);
127 sub_offs = le16_to_cpu(sym->SubstituteNameOffset);
128 print_len = le16_to_cpu(sym->PrintNameLength);
129 print_offs = le16_to_cpu(sym->PrintNameOffset);
130
131 if (iov->iov_len < SMB2_SYMLINK_STRUCT_SIZE + sub_offs + sub_len ||
132 iov->iov_len < SMB2_SYMLINK_STRUCT_SIZE + print_offs + print_len)
133 return -EINVAL;
134
135 return smb2_parse_native_symlink(path,
136 (char *)sym->PathBuffer + sub_offs,
137 sub_len,
138 le32_to_cpu(sym->Flags) & SYMLINK_FLAG_RELATIVE,
139 full_path,
140 cifs_sb);
141 }
142
smb2_open_file(const unsigned int xid,struct cifs_open_parms * oparms,__u32 * oplock,void * buf)143 int smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms, __u32 *oplock, void *buf)
144 {
145 int rc;
146 __le16 *smb2_path;
147 __u8 smb2_oplock;
148 struct cifs_open_info_data *data = buf;
149 struct smb2_file_all_info file_info = {};
150 struct smb2_file_all_info *smb2_data = data ? &file_info : NULL;
151 struct kvec err_iov = {};
152 int err_buftype = CIFS_NO_BUFFER;
153 struct cifs_fid *fid = oparms->fid;
154 struct network_resiliency_req nr_ioctl_req;
155 bool retry_without_read_attributes = false;
156
157 smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb);
158 if (smb2_path == NULL)
159 return -ENOMEM;
160
161 /*
162 * GENERIC_READ, GENERIC_EXECUTE, GENERIC_ALL and MAXIMUM_ALLOWED
163 * contains also FILE_READ_ATTRIBUTES access right. So do not append
164 * FILE_READ_ATTRIBUTES when not needed and prevent calling code path
165 * for retry_without_read_attributes.
166 */
167 if (!(oparms->desired_access & FILE_READ_ATTRIBUTES) &&
168 !(oparms->desired_access & GENERIC_READ) &&
169 !(oparms->desired_access & GENERIC_EXECUTE) &&
170 !(oparms->desired_access & GENERIC_ALL) &&
171 !(oparms->desired_access & MAXIMUM_ALLOWED)) {
172 oparms->desired_access |= FILE_READ_ATTRIBUTES;
173 retry_without_read_attributes = true;
174 }
175 smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
176
177 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov,
178 &err_buftype);
179 if (rc == -EACCES && retry_without_read_attributes) {
180 oparms->desired_access &= ~FILE_READ_ATTRIBUTES;
181 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov,
182 &err_buftype);
183 }
184 if (rc && data) {
185 struct smb2_hdr *hdr = err_iov.iov_base;
186
187 if (unlikely(!err_iov.iov_base || err_buftype == CIFS_NO_BUFFER))
188 goto out;
189 if (hdr->Status == STATUS_STOPPED_ON_SYMLINK) {
190 rc = smb2_parse_symlink_response(oparms->cifs_sb, &err_iov,
191 oparms->path,
192 &data->symlink_target);
193 if (!rc) {
194 memset(smb2_data, 0, sizeof(*smb2_data));
195 oparms->create_options |= OPEN_REPARSE_POINT;
196 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data,
197 NULL, NULL, NULL);
198 oparms->create_options &= ~OPEN_REPARSE_POINT;
199 }
200 if (!rc) {
201 bool directory = le32_to_cpu(data->fi.Attributes) & ATTR_DIRECTORY;
202 rc = smb2_fix_symlink_target_type(&data->symlink_target,
203 directory, oparms->cifs_sb);
204 }
205 }
206 }
207
208 if (rc)
209 goto out;
210
211 if (oparms->tcon->use_resilient) {
212 /* default timeout is 0, servers pick default (120 seconds) */
213 nr_ioctl_req.Timeout =
214 cpu_to_le32(oparms->tcon->handle_timeout);
215 nr_ioctl_req.Reserved = 0;
216 rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid,
217 fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY,
218 (char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
219 CIFSMaxBufSize, NULL, NULL /* no return info */);
220 if (rc == -EOPNOTSUPP) {
221 cifs_dbg(VFS,
222 "resiliency not supported by server, disabling\n");
223 oparms->tcon->use_resilient = false;
224 } else if (rc)
225 cifs_dbg(FYI, "error %d setting resiliency\n", rc);
226
227 rc = 0;
228 }
229
230 if (smb2_data) {
231 /* if open response does not have IndexNumber field - get it */
232 if (smb2_data->IndexNumber == 0) {
233 rc = SMB2_get_srv_num(xid, oparms->tcon,
234 fid->persistent_fid,
235 fid->volatile_fid,
236 &smb2_data->IndexNumber);
237 if (rc) {
238 /*
239 * let get_inode_info disable server inode
240 * numbers
241 */
242 smb2_data->IndexNumber = 0;
243 rc = 0;
244 }
245 }
246 memcpy(&data->fi, smb2_data, sizeof(data->fi));
247 }
248
249 *oplock = smb2_oplock;
250 out:
251 free_rsp_buf(err_buftype, err_iov.iov_base);
252 kfree(smb2_path);
253 return rc;
254 }
255
256 int
smb2_unlock_range(struct cifsFileInfo * cfile,struct file_lock * flock,const unsigned int xid)257 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
258 const unsigned int xid)
259 {
260 int rc = 0, stored_rc;
261 unsigned int max_num, num = 0, max_buf;
262 struct smb2_lock_element *buf, *cur;
263 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
264 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
265 struct cifsLockInfo *li, *tmp;
266 __u64 length = 1 + flock->fl_end - flock->fl_start;
267 LIST_HEAD(tmp_llist);
268
269 /*
270 * Accessing maxBuf is racy with cifs_reconnect - need to store value
271 * and check it before using.
272 */
273 max_buf = tcon->ses->server->maxBuf;
274 if (max_buf < sizeof(struct smb2_lock_element))
275 return -EINVAL;
276
277 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
278 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
279 max_num = max_buf / sizeof(struct smb2_lock_element);
280 buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
281 if (!buf)
282 return -ENOMEM;
283
284 cur = buf;
285
286 cifs_down_write(&cinode->lock_sem);
287 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
288 if (flock->fl_start > li->offset ||
289 (flock->fl_start + length) <
290 (li->offset + li->length))
291 continue;
292 if (current->tgid != li->pid)
293 /*
294 * flock and OFD lock are associated with an open
295 * file description, not the process.
296 */
297 if (!(flock->c.flc_flags & (FL_FLOCK | FL_OFDLCK)))
298 continue;
299 if (cinode->can_cache_brlcks) {
300 /*
301 * We can cache brlock requests - simply remove a lock
302 * from the file's list.
303 */
304 list_del(&li->llist);
305 cifs_del_lock_waiters(li);
306 kfree(li);
307 continue;
308 }
309 cur->Length = cpu_to_le64(li->length);
310 cur->Offset = cpu_to_le64(li->offset);
311 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
312 /*
313 * We need to save a lock here to let us add it again to the
314 * file's list if the unlock range request fails on the server.
315 */
316 list_move(&li->llist, &tmp_llist);
317 if (++num == max_num) {
318 stored_rc = smb2_lockv(xid, tcon,
319 cfile->fid.persistent_fid,
320 cfile->fid.volatile_fid,
321 current->tgid, num, buf);
322 if (stored_rc) {
323 /*
324 * We failed on the unlock range request - add
325 * all locks from the tmp list to the head of
326 * the file's list.
327 */
328 cifs_move_llist(&tmp_llist,
329 &cfile->llist->locks);
330 rc = stored_rc;
331 } else
332 /*
333 * The unlock range request succeed - free the
334 * tmp list.
335 */
336 cifs_free_llist(&tmp_llist);
337 cur = buf;
338 num = 0;
339 } else
340 cur++;
341 }
342 if (num) {
343 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
344 cfile->fid.volatile_fid, current->tgid,
345 num, buf);
346 if (stored_rc) {
347 cifs_move_llist(&tmp_llist, &cfile->llist->locks);
348 rc = stored_rc;
349 } else
350 cifs_free_llist(&tmp_llist);
351 }
352 up_write(&cinode->lock_sem);
353
354 kfree(buf);
355 return rc;
356 }
357
358 static int
smb2_push_mand_fdlocks(struct cifs_fid_locks * fdlocks,const unsigned int xid,struct smb2_lock_element * buf,unsigned int max_num)359 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
360 struct smb2_lock_element *buf, unsigned int max_num)
361 {
362 int rc = 0, stored_rc;
363 struct cifsFileInfo *cfile = fdlocks->cfile;
364 struct cifsLockInfo *li;
365 unsigned int num = 0;
366 struct smb2_lock_element *cur = buf;
367 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
368
369 list_for_each_entry(li, &fdlocks->locks, llist) {
370 cur->Length = cpu_to_le64(li->length);
371 cur->Offset = cpu_to_le64(li->offset);
372 cur->Flags = cpu_to_le32(li->type |
373 SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
374 if (++num == max_num) {
375 stored_rc = smb2_lockv(xid, tcon,
376 cfile->fid.persistent_fid,
377 cfile->fid.volatile_fid,
378 current->tgid, num, buf);
379 if (stored_rc)
380 rc = stored_rc;
381 cur = buf;
382 num = 0;
383 } else
384 cur++;
385 }
386 if (num) {
387 stored_rc = smb2_lockv(xid, tcon,
388 cfile->fid.persistent_fid,
389 cfile->fid.volatile_fid,
390 current->tgid, num, buf);
391 if (stored_rc)
392 rc = stored_rc;
393 }
394
395 return rc;
396 }
397
398 int
smb2_push_mandatory_locks(struct cifsFileInfo * cfile)399 smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
400 {
401 int rc = 0, stored_rc;
402 unsigned int xid;
403 unsigned int max_num, max_buf;
404 struct smb2_lock_element *buf;
405 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
406 struct cifs_fid_locks *fdlocks;
407
408 xid = get_xid();
409
410 /*
411 * Accessing maxBuf is racy with cifs_reconnect - need to store value
412 * and check it for zero before using.
413 */
414 max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
415 if (max_buf < sizeof(struct smb2_lock_element)) {
416 free_xid(xid);
417 return -EINVAL;
418 }
419
420 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
421 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
422 max_num = max_buf / sizeof(struct smb2_lock_element);
423 buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
424 if (!buf) {
425 free_xid(xid);
426 return -ENOMEM;
427 }
428
429 list_for_each_entry(fdlocks, &cinode->llist, llist) {
430 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
431 if (stored_rc)
432 rc = stored_rc;
433 }
434
435 kfree(buf);
436 free_xid(xid);
437 return rc;
438 }
439