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 *)((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,char ** path)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
smb2_open_file(const unsigned int xid,struct cifs_open_parms * oparms,__u32 * oplock,void * buf)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
smb2_unlock_range(struct cifsFileInfo * cfile,struct file_lock * flock,const unsigned int xid)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 LIST_HEAD(tmp_llist);
200
201 /*
202 * Accessing maxBuf is racy with cifs_reconnect - need to store value
203 * and check it before using.
204 */
205 max_buf = tcon->ses->server->maxBuf;
206 if (max_buf < sizeof(struct smb2_lock_element))
207 return -EINVAL;
208
209 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
210 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
211 max_num = max_buf / sizeof(struct smb2_lock_element);
212 buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
213 if (!buf)
214 return -ENOMEM;
215
216 cur = buf;
217
218 cifs_down_write(&cinode->lock_sem);
219 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
220 if (flock->fl_start > li->offset ||
221 (flock->fl_start + length) <
222 (li->offset + li->length))
223 continue;
224 if (current->tgid != li->pid)
225 /*
226 * flock and OFD lock are associated with an open
227 * file description, not the process.
228 */
229 if (!(flock->c.flc_flags & (FL_FLOCK | FL_OFDLCK)))
230 continue;
231 if (cinode->can_cache_brlcks) {
232 /*
233 * We can cache brlock requests - simply remove a lock
234 * from the file's list.
235 */
236 list_del(&li->llist);
237 cifs_del_lock_waiters(li);
238 kfree(li);
239 continue;
240 }
241 cur->Length = cpu_to_le64(li->length);
242 cur->Offset = cpu_to_le64(li->offset);
243 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
244 /*
245 * We need to save a lock here to let us add it again to the
246 * file's list if the unlock range request fails on the server.
247 */
248 list_move(&li->llist, &tmp_llist);
249 if (++num == max_num) {
250 stored_rc = smb2_lockv(xid, tcon,
251 cfile->fid.persistent_fid,
252 cfile->fid.volatile_fid,
253 current->tgid, num, buf);
254 if (stored_rc) {
255 /*
256 * We failed on the unlock range request - add
257 * all locks from the tmp list to the head of
258 * the file's list.
259 */
260 cifs_move_llist(&tmp_llist,
261 &cfile->llist->locks);
262 rc = stored_rc;
263 } else
264 /*
265 * The unlock range request succeed - free the
266 * tmp list.
267 */
268 cifs_free_llist(&tmp_llist);
269 cur = buf;
270 num = 0;
271 } else
272 cur++;
273 }
274 if (num) {
275 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
276 cfile->fid.volatile_fid, current->tgid,
277 num, buf);
278 if (stored_rc) {
279 cifs_move_llist(&tmp_llist, &cfile->llist->locks);
280 rc = stored_rc;
281 } else
282 cifs_free_llist(&tmp_llist);
283 }
284 up_write(&cinode->lock_sem);
285
286 kfree(buf);
287 return rc;
288 }
289
290 static int
smb2_push_mand_fdlocks(struct cifs_fid_locks * fdlocks,const unsigned int xid,struct smb2_lock_element * buf,unsigned int max_num)291 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
292 struct smb2_lock_element *buf, unsigned int max_num)
293 {
294 int rc = 0, stored_rc;
295 struct cifsFileInfo *cfile = fdlocks->cfile;
296 struct cifsLockInfo *li;
297 unsigned int num = 0;
298 struct smb2_lock_element *cur = buf;
299 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
300
301 list_for_each_entry(li, &fdlocks->locks, llist) {
302 cur->Length = cpu_to_le64(li->length);
303 cur->Offset = cpu_to_le64(li->offset);
304 cur->Flags = cpu_to_le32(li->type |
305 SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
306 if (++num == max_num) {
307 stored_rc = smb2_lockv(xid, tcon,
308 cfile->fid.persistent_fid,
309 cfile->fid.volatile_fid,
310 current->tgid, num, buf);
311 if (stored_rc)
312 rc = stored_rc;
313 cur = buf;
314 num = 0;
315 } else
316 cur++;
317 }
318 if (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 rc = stored_rc;
325 }
326
327 return rc;
328 }
329
330 int
smb2_push_mandatory_locks(struct cifsFileInfo * cfile)331 smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
332 {
333 int rc = 0, stored_rc;
334 unsigned int xid;
335 unsigned int max_num, max_buf;
336 struct smb2_lock_element *buf;
337 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
338 struct cifs_fid_locks *fdlocks;
339
340 xid = get_xid();
341
342 /*
343 * Accessing maxBuf is racy with cifs_reconnect - need to store value
344 * and check it for zero before using.
345 */
346 max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
347 if (max_buf < sizeof(struct smb2_lock_element)) {
348 free_xid(xid);
349 return -EINVAL;
350 }
351
352 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
353 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
354 max_num = max_buf / sizeof(struct smb2_lock_element);
355 buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
356 if (!buf) {
357 free_xid(xid);
358 return -ENOMEM;
359 }
360
361 list_for_each_entry(fdlocks, &cinode->llist, llist) {
362 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
363 if (stored_rc)
364 rc = stored_rc;
365 }
366
367 kfree(buf);
368 free_xid(xid);
369 return rc;
370 }
371