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
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 *)((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
smb2_parse_symlink_response(struct cifs_sb_info * cifs_sb,const struct kvec * iov,const char * full_path,char ** path)66 int smb2_parse_symlink_response(struct cifs_sb_info *cifs_sb, const struct kvec *iov,
67 const char *full_path, char **path)
68 {
69 struct smb2_symlink_err_rsp *sym;
70 unsigned int sub_offs, sub_len;
71 unsigned int print_offs, print_len;
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 return smb2_parse_native_symlink(path,
90 (char *)sym->PathBuffer + sub_offs,
91 sub_len,
92 true,
93 le32_to_cpu(sym->Flags) & SYMLINK_FLAG_RELATIVE,
94 full_path,
95 cifs_sb);
96 }
97
smb2_open_file(const unsigned int xid,struct cifs_open_parms * oparms,__u32 * oplock,void * buf)98 int smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms, __u32 *oplock, void *buf)
99 {
100 int rc;
101 __le16 *smb2_path;
102 __u8 smb2_oplock;
103 struct cifs_open_info_data *data = buf;
104 struct smb2_file_all_info file_info = {};
105 struct smb2_file_all_info *smb2_data = data ? &file_info : NULL;
106 struct kvec err_iov = {};
107 int err_buftype = CIFS_NO_BUFFER;
108 struct cifs_fid *fid = oparms->fid;
109 struct network_resiliency_req nr_ioctl_req;
110 bool retry_without_read_attributes = false;
111
112 smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb);
113 if (smb2_path == NULL)
114 return -ENOMEM;
115
116 if (!(oparms->desired_access & FILE_READ_ATTRIBUTES)) {
117 oparms->desired_access |= FILE_READ_ATTRIBUTES;
118 retry_without_read_attributes = true;
119 }
120 smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
121
122 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov,
123 &err_buftype);
124 if (rc == -EACCES && retry_without_read_attributes) {
125 oparms->desired_access &= ~FILE_READ_ATTRIBUTES;
126 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov,
127 &err_buftype);
128 }
129 if (rc && data) {
130 struct smb2_hdr *hdr = err_iov.iov_base;
131
132 if (unlikely(!err_iov.iov_base || err_buftype == CIFS_NO_BUFFER))
133 goto out;
134 if (hdr->Status == STATUS_STOPPED_ON_SYMLINK) {
135 rc = smb2_parse_symlink_response(oparms->cifs_sb, &err_iov,
136 oparms->path,
137 &data->symlink_target);
138 if (!rc) {
139 memset(smb2_data, 0, sizeof(*smb2_data));
140 oparms->create_options |= OPEN_REPARSE_POINT;
141 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data,
142 NULL, NULL, NULL);
143 oparms->create_options &= ~OPEN_REPARSE_POINT;
144 }
145 }
146 }
147
148 if (rc)
149 goto out;
150
151 if (oparms->tcon->use_resilient) {
152 /* default timeout is 0, servers pick default (120 seconds) */
153 nr_ioctl_req.Timeout =
154 cpu_to_le32(oparms->tcon->handle_timeout);
155 nr_ioctl_req.Reserved = 0;
156 rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid,
157 fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY,
158 (char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
159 CIFSMaxBufSize, NULL, NULL /* no return info */);
160 if (rc == -EOPNOTSUPP) {
161 cifs_dbg(VFS,
162 "resiliency not supported by server, disabling\n");
163 oparms->tcon->use_resilient = false;
164 } else if (rc)
165 cifs_dbg(FYI, "error %d setting resiliency\n", rc);
166
167 rc = 0;
168 }
169
170 if (smb2_data) {
171 /* if open response does not have IndexNumber field - get it */
172 if (smb2_data->IndexNumber == 0) {
173 rc = SMB2_get_srv_num(xid, oparms->tcon,
174 fid->persistent_fid,
175 fid->volatile_fid,
176 &smb2_data->IndexNumber);
177 if (rc) {
178 /*
179 * let get_inode_info disable server inode
180 * numbers
181 */
182 smb2_data->IndexNumber = 0;
183 rc = 0;
184 }
185 }
186 memcpy(&data->fi, smb2_data, sizeof(data->fi));
187 }
188
189 *oplock = smb2_oplock;
190 out:
191 free_rsp_buf(err_buftype, err_iov.iov_base);
192 kfree(smb2_path);
193 return rc;
194 }
195
196 int
smb2_unlock_range(struct cifsFileInfo * cfile,struct file_lock * flock,const unsigned int xid)197 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
198 const unsigned int xid)
199 {
200 int rc = 0, stored_rc;
201 unsigned int max_num, num = 0, max_buf;
202 struct smb2_lock_element *buf, *cur;
203 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
204 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
205 struct cifsLockInfo *li, *tmp;
206 __u64 length = 1 + flock->fl_end - flock->fl_start;
207 struct list_head tmp_llist;
208
209 INIT_LIST_HEAD(&tmp_llist);
210
211 /*
212 * Accessing maxBuf is racy with cifs_reconnect - need to store value
213 * and check it before using.
214 */
215 max_buf = tcon->ses->server->maxBuf;
216 if (max_buf < sizeof(struct smb2_lock_element))
217 return -EINVAL;
218
219 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
220 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
221 max_num = max_buf / sizeof(struct smb2_lock_element);
222 buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
223 if (!buf)
224 return -ENOMEM;
225
226 cur = buf;
227
228 cifs_down_write(&cinode->lock_sem);
229 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
230 if (flock->fl_start > li->offset ||
231 (flock->fl_start + length) <
232 (li->offset + li->length))
233 continue;
234 if (current->tgid != li->pid)
235 /*
236 * flock and OFD lock are associated with an open
237 * file description, not the process.
238 */
239 if (!(flock->fl_flags & (FL_FLOCK | FL_OFDLCK)))
240 continue;
241 if (cinode->can_cache_brlcks) {
242 /*
243 * We can cache brlock requests - simply remove a lock
244 * from the file's list.
245 */
246 list_del(&li->llist);
247 cifs_del_lock_waiters(li);
248 kfree(li);
249 continue;
250 }
251 cur->Length = cpu_to_le64(li->length);
252 cur->Offset = cpu_to_le64(li->offset);
253 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
254 /*
255 * We need to save a lock here to let us add it again to the
256 * file's list if the unlock range request fails on the server.
257 */
258 list_move(&li->llist, &tmp_llist);
259 if (++num == max_num) {
260 stored_rc = smb2_lockv(xid, tcon,
261 cfile->fid.persistent_fid,
262 cfile->fid.volatile_fid,
263 current->tgid, num, buf);
264 if (stored_rc) {
265 /*
266 * We failed on the unlock range request - add
267 * all locks from the tmp list to the head of
268 * the file's list.
269 */
270 cifs_move_llist(&tmp_llist,
271 &cfile->llist->locks);
272 rc = stored_rc;
273 } else
274 /*
275 * The unlock range request succeed - free the
276 * tmp list.
277 */
278 cifs_free_llist(&tmp_llist);
279 cur = buf;
280 num = 0;
281 } else
282 cur++;
283 }
284 if (num) {
285 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
286 cfile->fid.volatile_fid, current->tgid,
287 num, buf);
288 if (stored_rc) {
289 cifs_move_llist(&tmp_llist, &cfile->llist->locks);
290 rc = stored_rc;
291 } else
292 cifs_free_llist(&tmp_llist);
293 }
294 up_write(&cinode->lock_sem);
295
296 kfree(buf);
297 return rc;
298 }
299
300 static int
smb2_push_mand_fdlocks(struct cifs_fid_locks * fdlocks,const unsigned int xid,struct smb2_lock_element * buf,unsigned int max_num)301 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
302 struct smb2_lock_element *buf, unsigned int max_num)
303 {
304 int rc = 0, stored_rc;
305 struct cifsFileInfo *cfile = fdlocks->cfile;
306 struct cifsLockInfo *li;
307 unsigned int num = 0;
308 struct smb2_lock_element *cur = buf;
309 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
310
311 list_for_each_entry(li, &fdlocks->locks, llist) {
312 cur->Length = cpu_to_le64(li->length);
313 cur->Offset = cpu_to_le64(li->offset);
314 cur->Flags = cpu_to_le32(li->type |
315 SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
316 if (++num == max_num) {
317 stored_rc = smb2_lockv(xid, tcon,
318 cfile->fid.persistent_fid,
319 cfile->fid.volatile_fid,
320 current->tgid, num, buf);
321 if (stored_rc)
322 rc = stored_rc;
323 cur = buf;
324 num = 0;
325 } else
326 cur++;
327 }
328 if (num) {
329 stored_rc = smb2_lockv(xid, tcon,
330 cfile->fid.persistent_fid,
331 cfile->fid.volatile_fid,
332 current->tgid, num, buf);
333 if (stored_rc)
334 rc = stored_rc;
335 }
336
337 return rc;
338 }
339
340 int
smb2_push_mandatory_locks(struct cifsFileInfo * cfile)341 smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
342 {
343 int rc = 0, stored_rc;
344 unsigned int xid;
345 unsigned int max_num, max_buf;
346 struct smb2_lock_element *buf;
347 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
348 struct cifs_fid_locks *fdlocks;
349
350 xid = get_xid();
351
352 /*
353 * Accessing maxBuf is racy with cifs_reconnect - need to store value
354 * and check it for zero before using.
355 */
356 max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
357 if (max_buf < sizeof(struct smb2_lock_element)) {
358 free_xid(xid);
359 return -EINVAL;
360 }
361
362 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
363 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
364 max_num = max_buf / sizeof(struct smb2_lock_element);
365 buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
366 if (!buf) {
367 free_xid(xid);
368 return -ENOMEM;
369 }
370
371 list_for_each_entry(fdlocks, &cinode->llist, llist) {
372 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
373 if (stored_rc)
374 rc = stored_rc;
375 }
376
377 kfree(buf);
378 free_xid(xid);
379 return rc;
380 }
381