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 "cifsglob.h"
17 #include "cifsproto.h"
18 #include "cifs_debug.h"
19 #include "cifs_fs_sb.h"
20 #include "cifs_unicode.h"
21 #include "fscache.h"
22 #include "smb2proto.h"
23 #include "../common/smb2status.h"
24 #include "../common/smbfsctl.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 smb_EIO(smb_eio_trace_null_pointers);
80
81 len = strlen(*target);
82 if (!len)
83 return smb_EIO1(smb_eio_trace_sym_target_len, len);
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 smb_EIO(smb_eio_trace_sym_slash);
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,
144 __u32 *oplock, void *buf)
145 {
146 int rc;
147 __le16 *smb2_path;
148 __u8 smb2_oplock;
149 struct cifs_open_info_data *data = buf;
150 struct smb2_file_all_info file_info = {};
151 struct smb2_file_all_info *smb2_data = data ? &file_info : NULL;
152 struct kvec err_iov = {};
153 int err_buftype = CIFS_NO_BUFFER;
154 struct cifs_fid *fid = oparms->fid;
155 struct network_resiliency_req nr_ioctl_req;
156 bool retry_without_read_attributes = false;
157
158 smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb);
159 if (smb2_path == NULL)
160 return -ENOMEM;
161
162 /*
163 * GENERIC_READ, GENERIC_EXECUTE, GENERIC_ALL and MAXIMUM_ALLOWED
164 * contains also FILE_READ_ATTRIBUTES access right. So do not append
165 * FILE_READ_ATTRIBUTES when not needed and prevent calling code path
166 * for retry_without_read_attributes.
167 */
168 if (!(oparms->desired_access & FILE_READ_ATTRIBUTES) &&
169 !(oparms->desired_access & GENERIC_READ) &&
170 !(oparms->desired_access & GENERIC_EXECUTE) &&
171 !(oparms->desired_access & GENERIC_ALL) &&
172 !(oparms->desired_access & MAXIMUM_ALLOWED)) {
173 oparms->desired_access |= FILE_READ_ATTRIBUTES;
174 retry_without_read_attributes = true;
175 }
176 smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
177
178 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov,
179 &err_buftype);
180 if (rc == -EACCES && retry_without_read_attributes) {
181 free_rsp_buf(err_buftype, err_iov.iov_base);
182 memset(&err_iov, 0, sizeof(err_iov));
183 err_buftype = CIFS_NO_BUFFER;
184 oparms->desired_access &= ~FILE_READ_ATTRIBUTES;
185 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov,
186 &err_buftype);
187 }
188 if (rc && data) {
189 struct smb2_hdr *hdr = err_iov.iov_base;
190
191 if (unlikely(!err_iov.iov_base || err_buftype == CIFS_NO_BUFFER))
192 goto out;
193 if (hdr->Status == STATUS_STOPPED_ON_SYMLINK) {
194 rc = smb2_parse_symlink_response(oparms->cifs_sb, &err_iov,
195 oparms->path,
196 &data->symlink_target);
197 if (!rc) {
198 memset(smb2_data, 0, sizeof(*smb2_data));
199 oparms->create_options |= OPEN_REPARSE_POINT;
200 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data,
201 NULL, NULL, NULL);
202 oparms->create_options &= ~OPEN_REPARSE_POINT;
203 }
204 if (!rc) {
205 bool directory = le32_to_cpu(data->fi.Attributes) & ATTR_DIRECTORY;
206 rc = smb2_fix_symlink_target_type(&data->symlink_target,
207 directory, oparms->cifs_sb);
208 }
209 }
210 }
211
212 if (rc)
213 goto out;
214
215 if (oparms->tcon->use_resilient) {
216 /* default timeout is 0, servers pick default (120 seconds) */
217 nr_ioctl_req.Timeout =
218 cpu_to_le32(oparms->tcon->handle_timeout);
219 nr_ioctl_req.Reserved = 0;
220 rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid,
221 fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY,
222 (char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
223 CIFSMaxBufSize, NULL, NULL /* no return info */);
224 if (rc == -EOPNOTSUPP) {
225 cifs_dbg(VFS,
226 "resiliency not supported by server, disabling\n");
227 oparms->tcon->use_resilient = false;
228 } else if (rc)
229 cifs_dbg(FYI, "error %d setting resiliency\n", rc);
230
231 rc = 0;
232 }
233
234 if (smb2_data) {
235 /* if open response does not have IndexNumber field - get it */
236 if (smb2_data->IndexNumber == 0) {
237 rc = SMB2_get_srv_num(xid, oparms->tcon,
238 fid->persistent_fid,
239 fid->volatile_fid,
240 &smb2_data->IndexNumber);
241 if (rc) {
242 /*
243 * let get_inode_info disable server inode
244 * numbers
245 */
246 smb2_data->IndexNumber = 0;
247 rc = 0;
248 }
249 }
250 memcpy(&data->fi, smb2_data, sizeof(data->fi));
251 }
252
253 *oplock = smb2_oplock;
254 out:
255 free_rsp_buf(err_buftype, err_iov.iov_base);
256 kfree(smb2_path);
257 return rc;
258 }
259
260 int
smb2_unlock_range(struct cifsFileInfo * cfile,struct file_lock * flock,const unsigned int xid)261 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
262 const unsigned int xid)
263 {
264 int rc = 0, stored_rc;
265 unsigned int max_num, num = 0, max_buf;
266 struct smb2_lock_element *buf, *cur;
267 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
268 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
269 struct cifsLockInfo *li, *tmp;
270 __u64 length = 1 + flock->fl_end - flock->fl_start;
271 LIST_HEAD(tmp_llist);
272
273 /*
274 * Accessing maxBuf is racy with cifs_reconnect - need to store value
275 * and check it before using.
276 */
277 max_buf = tcon->ses->server->maxBuf;
278 if (max_buf < sizeof(struct smb2_lock_element))
279 return -EINVAL;
280
281 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
282 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
283 max_num = max_buf / sizeof(struct smb2_lock_element);
284 buf = kzalloc_objs(struct smb2_lock_element, max_num);
285 if (!buf)
286 return -ENOMEM;
287
288 cur = buf;
289
290 cifs_down_write(&cinode->lock_sem);
291 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
292 if (flock->fl_start > li->offset ||
293 (flock->fl_start + length) <
294 (li->offset + li->length))
295 continue;
296 if (current->tgid != li->pid)
297 /*
298 * flock and OFD lock are associated with an open
299 * file description, not the process.
300 */
301 if (!(flock->c.flc_flags & (FL_FLOCK | FL_OFDLCK)))
302 continue;
303 if (cinode->can_cache_brlcks) {
304 /*
305 * We can cache brlock requests - simply remove a lock
306 * from the file's list.
307 */
308 list_del(&li->llist);
309 cifs_del_lock_waiters(li);
310 kfree(li);
311 continue;
312 }
313 cur->Length = cpu_to_le64(li->length);
314 cur->Offset = cpu_to_le64(li->offset);
315 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
316 /*
317 * We need to save a lock here to let us add it again to the
318 * file's list if the unlock range request fails on the server.
319 */
320 list_move(&li->llist, &tmp_llist);
321 if (++num == max_num) {
322 stored_rc = smb2_lockv(xid, tcon,
323 cfile->fid.persistent_fid,
324 cfile->fid.volatile_fid,
325 current->tgid, num, buf);
326 if (stored_rc) {
327 /*
328 * We failed on the unlock range request - add
329 * all locks from the tmp list to the head of
330 * the file's list.
331 */
332 cifs_move_llist(&tmp_llist,
333 &cfile->llist->locks);
334 rc = stored_rc;
335 } else
336 /*
337 * The unlock range request succeed - free the
338 * tmp list.
339 */
340 cifs_free_llist(&tmp_llist);
341 cur = buf;
342 num = 0;
343 } else
344 cur++;
345 }
346 if (num) {
347 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
348 cfile->fid.volatile_fid, current->tgid,
349 num, buf);
350 if (stored_rc) {
351 cifs_move_llist(&tmp_llist, &cfile->llist->locks);
352 rc = stored_rc;
353 } else
354 cifs_free_llist(&tmp_llist);
355 }
356 up_write(&cinode->lock_sem);
357
358 kfree(buf);
359 return rc;
360 }
361
362 static int
smb2_push_mand_fdlocks(struct cifs_fid_locks * fdlocks,const unsigned int xid,struct smb2_lock_element * buf,unsigned int max_num)363 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
364 struct smb2_lock_element *buf, unsigned int max_num)
365 {
366 int rc = 0, stored_rc;
367 struct cifsFileInfo *cfile = fdlocks->cfile;
368 struct cifsLockInfo *li;
369 unsigned int num = 0;
370 struct smb2_lock_element *cur = buf;
371 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
372
373 list_for_each_entry(li, &fdlocks->locks, llist) {
374 cur->Length = cpu_to_le64(li->length);
375 cur->Offset = cpu_to_le64(li->offset);
376 cur->Flags = cpu_to_le32(li->type |
377 SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
378 if (++num == max_num) {
379 stored_rc = smb2_lockv(xid, tcon,
380 cfile->fid.persistent_fid,
381 cfile->fid.volatile_fid,
382 current->tgid, num, buf);
383 if (stored_rc)
384 rc = stored_rc;
385 cur = buf;
386 num = 0;
387 } else
388 cur++;
389 }
390 if (num) {
391 stored_rc = smb2_lockv(xid, tcon,
392 cfile->fid.persistent_fid,
393 cfile->fid.volatile_fid,
394 current->tgid, num, buf);
395 if (stored_rc)
396 rc = stored_rc;
397 }
398
399 return rc;
400 }
401
402 int
smb2_push_mandatory_locks(struct cifsFileInfo * cfile)403 smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
404 {
405 int rc = 0, stored_rc;
406 unsigned int xid;
407 unsigned int max_num, max_buf;
408 struct smb2_lock_element *buf;
409 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
410 struct cifs_fid_locks *fdlocks;
411
412 xid = get_xid();
413
414 /*
415 * Accessing maxBuf is racy with cifs_reconnect - need to store value
416 * and check it for zero before using.
417 */
418 max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
419 if (max_buf < sizeof(struct smb2_lock_element)) {
420 free_xid(xid);
421 return -EINVAL;
422 }
423
424 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
425 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
426 max_num = max_buf / sizeof(struct smb2_lock_element);
427 buf = kzalloc_objs(struct smb2_lock_element, max_num);
428 if (!buf) {
429 free_xid(xid);
430 return -ENOMEM;
431 }
432
433 list_for_each_entry(fdlocks, &cinode->llist, llist) {
434 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
435 if (stored_rc)
436 rc = stored_rc;
437 }
438
439 kfree(buf);
440 free_xid(xid);
441 return rc;
442 }
443