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