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 "smb2status.h"
25
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 *)((u8 *)&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
66 int smb2_parse_symlink_response(struct cifs_sb_info *cifs_sb, const struct kvec *iov, char **path)
67 {
68 struct smb2_symlink_err_rsp *sym;
69 unsigned int sub_offs, sub_len;
70 unsigned int print_offs, print_len;
71 char *s;
72
73 if (!cifs_sb || !iov || !iov->iov_base || !iov->iov_len || !path)
74 return -EINVAL;
75
76 sym = symlink_data(iov);
77 if (IS_ERR(sym))
78 return PTR_ERR(sym);
79
80 sub_len = le16_to_cpu(sym->SubstituteNameLength);
81 sub_offs = le16_to_cpu(sym->SubstituteNameOffset);
82 print_len = le16_to_cpu(sym->PrintNameLength);
83 print_offs = le16_to_cpu(sym->PrintNameOffset);
84
85 if (iov->iov_len < SMB2_SYMLINK_STRUCT_SIZE + sub_offs + sub_len ||
86 iov->iov_len < SMB2_SYMLINK_STRUCT_SIZE + print_offs + print_len)
87 return -EINVAL;
88
89 s = cifs_strndup_from_utf16((char *)sym->PathBuffer + sub_offs, sub_len, true,
90 cifs_sb->local_nls);
91 if (!s)
92 return -ENOMEM;
93 convert_delimiter(s, '/');
94 cifs_dbg(FYI, "%s: symlink target: %s\n", __func__, s);
95
96 *path = s;
97 return 0;
98 }
99
100 int smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms, __u32 *oplock, void *buf)
101 {
102 int rc;
103 __le16 *smb2_path;
104 __u8 smb2_oplock;
105 struct cifs_open_info_data *data = buf;
106 struct smb2_file_all_info file_info = {};
107 struct smb2_file_all_info *smb2_data = data ? &file_info : NULL;
108 struct kvec err_iov = {};
109 int err_buftype = CIFS_NO_BUFFER;
110 struct cifs_fid *fid = oparms->fid;
111 struct network_resiliency_req nr_ioctl_req;
112
113 smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb);
114 if (smb2_path == NULL)
115 return -ENOMEM;
116
117 oparms->desired_access |= FILE_READ_ATTRIBUTES;
118 smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
119
120 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov,
121 &err_buftype);
122 if (rc && data) {
123 struct smb2_hdr *hdr = err_iov.iov_base;
124
125 if (unlikely(!err_iov.iov_base || err_buftype == CIFS_NO_BUFFER))
126 goto out;
127 if (hdr->Status == STATUS_STOPPED_ON_SYMLINK) {
128 rc = smb2_parse_symlink_response(oparms->cifs_sb, &err_iov,
129 &data->symlink_target);
130 if (!rc) {
131 memset(smb2_data, 0, sizeof(*smb2_data));
132 oparms->create_options |= OPEN_REPARSE_POINT;
133 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data,
134 NULL, NULL, NULL);
135 oparms->create_options &= ~OPEN_REPARSE_POINT;
136 }
137 }
138 }
139
140 if (rc)
141 goto out;
142
143 if (oparms->tcon->use_resilient) {
144 /* default timeout is 0, servers pick default (120 seconds) */
145 nr_ioctl_req.Timeout =
146 cpu_to_le32(oparms->tcon->handle_timeout);
147 nr_ioctl_req.Reserved = 0;
148 rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid,
149 fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY,
150 (char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
151 CIFSMaxBufSize, NULL, NULL /* no return info */);
152 if (rc == -EOPNOTSUPP) {
153 cifs_dbg(VFS,
154 "resiliency not supported by server, disabling\n");
155 oparms->tcon->use_resilient = false;
156 } else if (rc)
157 cifs_dbg(FYI, "error %d setting resiliency\n", rc);
158
159 rc = 0;
160 }
161
162 if (smb2_data) {
163 /* if open response does not have IndexNumber field - get it */
164 if (smb2_data->IndexNumber == 0) {
165 rc = SMB2_get_srv_num(xid, oparms->tcon,
166 fid->persistent_fid,
167 fid->volatile_fid,
168 &smb2_data->IndexNumber);
169 if (rc) {
170 /*
171 * let get_inode_info disable server inode
172 * numbers
173 */
174 smb2_data->IndexNumber = 0;
175 rc = 0;
176 }
177 }
178 memcpy(&data->fi, smb2_data, sizeof(data->fi));
179 }
180
181 *oplock = smb2_oplock;
182 out:
183 free_rsp_buf(err_buftype, err_iov.iov_base);
184 kfree(smb2_path);
185 return rc;
186 }
187
188 int
189 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
190 const unsigned int xid)
191 {
192 int rc = 0, stored_rc;
193 unsigned int max_num, num = 0, max_buf;
194 struct smb2_lock_element *buf, *cur;
195 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
196 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
197 struct cifsLockInfo *li, *tmp;
198 __u64 length = 1 + flock->fl_end - flock->fl_start;
199 struct list_head tmp_llist;
200
201 INIT_LIST_HEAD(&tmp_llist);
202
203 /*
204 * Accessing maxBuf is racy with cifs_reconnect - need to store value
205 * and check it before using.
206 */
207 max_buf = tcon->ses->server->maxBuf;
208 if (max_buf < sizeof(struct smb2_lock_element))
209 return -EINVAL;
210
211 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
212 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
213 max_num = max_buf / sizeof(struct smb2_lock_element);
214 buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
215 if (!buf)
216 return -ENOMEM;
217
218 cur = buf;
219
220 cifs_down_write(&cinode->lock_sem);
221 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
222 if (flock->fl_start > li->offset ||
223 (flock->fl_start + length) <
224 (li->offset + li->length))
225 continue;
226 if (current->tgid != li->pid)
227 /*
228 * flock and OFD lock are associated with an open
229 * file description, not the process.
230 */
231 if (!(flock->c.flc_flags & (FL_FLOCK | FL_OFDLCK)))
232 continue;
233 if (cinode->can_cache_brlcks) {
234 /*
235 * We can cache brlock requests - simply remove a lock
236 * from the file's list.
237 */
238 list_del(&li->llist);
239 cifs_del_lock_waiters(li);
240 kfree(li);
241 continue;
242 }
243 cur->Length = cpu_to_le64(li->length);
244 cur->Offset = cpu_to_le64(li->offset);
245 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
246 /*
247 * We need to save a lock here to let us add it again to the
248 * file's list if the unlock range request fails on the server.
249 */
250 list_move(&li->llist, &tmp_llist);
251 if (++num == max_num) {
252 stored_rc = smb2_lockv(xid, tcon,
253 cfile->fid.persistent_fid,
254 cfile->fid.volatile_fid,
255 current->tgid, num, buf);
256 if (stored_rc) {
257 /*
258 * We failed on the unlock range request - add
259 * all locks from the tmp list to the head of
260 * the file's list.
261 */
262 cifs_move_llist(&tmp_llist,
263 &cfile->llist->locks);
264 rc = stored_rc;
265 } else
266 /*
267 * The unlock range request succeed - free the
268 * tmp list.
269 */
270 cifs_free_llist(&tmp_llist);
271 cur = buf;
272 num = 0;
273 } else
274 cur++;
275 }
276 if (num) {
277 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
278 cfile->fid.volatile_fid, current->tgid,
279 num, buf);
280 if (stored_rc) {
281 cifs_move_llist(&tmp_llist, &cfile->llist->locks);
282 rc = stored_rc;
283 } else
284 cifs_free_llist(&tmp_llist);
285 }
286 up_write(&cinode->lock_sem);
287
288 kfree(buf);
289 return rc;
290 }
291
292 static int
293 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
294 struct smb2_lock_element *buf, unsigned int max_num)
295 {
296 int rc = 0, stored_rc;
297 struct cifsFileInfo *cfile = fdlocks->cfile;
298 struct cifsLockInfo *li;
299 unsigned int num = 0;
300 struct smb2_lock_element *cur = buf;
301 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
302
303 list_for_each_entry(li, &fdlocks->locks, llist) {
304 cur->Length = cpu_to_le64(li->length);
305 cur->Offset = cpu_to_le64(li->offset);
306 cur->Flags = cpu_to_le32(li->type |
307 SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
308 if (++num == max_num) {
309 stored_rc = smb2_lockv(xid, tcon,
310 cfile->fid.persistent_fid,
311 cfile->fid.volatile_fid,
312 current->tgid, num, buf);
313 if (stored_rc)
314 rc = stored_rc;
315 cur = buf;
316 num = 0;
317 } else
318 cur++;
319 }
320 if (num) {
321 stored_rc = smb2_lockv(xid, tcon,
322 cfile->fid.persistent_fid,
323 cfile->fid.volatile_fid,
324 current->tgid, num, buf);
325 if (stored_rc)
326 rc = stored_rc;
327 }
328
329 return rc;
330 }
331
332 int
333 smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
334 {
335 int rc = 0, stored_rc;
336 unsigned int xid;
337 unsigned int max_num, max_buf;
338 struct smb2_lock_element *buf;
339 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
340 struct cifs_fid_locks *fdlocks;
341
342 xid = get_xid();
343
344 /*
345 * Accessing maxBuf is racy with cifs_reconnect - need to store value
346 * and check it for zero before using.
347 */
348 max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
349 if (max_buf < sizeof(struct smb2_lock_element)) {
350 free_xid(xid);
351 return -EINVAL;
352 }
353
354 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
355 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
356 max_num = max_buf / sizeof(struct smb2_lock_element);
357 buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
358 if (!buf) {
359 free_xid(xid);
360 return -ENOMEM;
361 }
362
363 list_for_each_entry(fdlocks, &cinode->llist, llist) {
364 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
365 if (stored_rc)
366 rc = stored_rc;
367 }
368
369 kfree(buf);
370 free_xid(xid);
371 return rc;
372 }
373
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