1 // SPDX-License-Identifier: LGPL-2.1
4 * Copyright (C) International Business Machines Corp., 2002,2008
9 #include <linux/stat.h>
10 #include <linux/slab.h>
11 #include <linux/namei.h>
15 #include "cifsproto.h"
16 #include "cifs_debug.h"
17 #include "cifs_fs_sb.h"
18 #include "cifs_unicode.h"
19 #include "smb2proto.h"
20 #include "cifs_ioctl.h"
23 * M-F Symlink Functions - Begin
26 #define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
27 #define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
28 #define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
29 #define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
30 #define CIFS_MF_SYMLINK_FILE_SIZE \
31 (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
33 #define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
34 #define CIFS_MF_SYMLINK_MD5_FORMAT "%16phN\n"
35 #define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) md5_hash
38 symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
41 struct shash_desc *md5 = NULL;
43 rc = cifs_alloc_hash("md5", &md5);
47 rc = crypto_shash_digest(md5, link_str, link_len, md5_hash);
49 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
55 parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
59 unsigned int link_len;
65 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
68 md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
69 link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
71 rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
75 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
78 rc = symlink_hash(link_len, link_str, md5_hash);
80 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
84 scnprintf(md5_str2, sizeof(md5_str2),
85 CIFS_MF_SYMLINK_MD5_FORMAT,
86 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
88 if (strncmp(md5_str1, md5_str2, 17) != 0)
92 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
97 *_link_len = link_len;
102 format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
105 unsigned int link_len;
109 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
112 link_len = strlen(link_str);
114 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
115 return -ENAMETOOLONG;
117 rc = symlink_hash(link_len, link_str, md5_hash);
119 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
123 scnprintf(buf, buf_len,
124 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
126 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
128 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
129 memcpy(buf + ofs, link_str, link_len);
132 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
137 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
146 couldbe_mf_symlink(const struct cifs_fattr *fattr)
148 if (!S_ISREG(fattr->cf_mode))
149 /* it's not a symlink */
152 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
153 /* it's not a symlink */
160 create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
161 struct cifs_sb_info *cifs_sb, const char *fromName,
166 unsigned int bytes_written = 0;
168 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
172 rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
176 if (tcon->ses->server->ops->create_mf_symlink)
177 rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
178 cifs_sb, fromName, buf, &bytes_written);
185 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
193 check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
194 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
195 const unsigned char *path)
199 unsigned int link_len = 0;
200 unsigned int bytes_read = 0;
201 char *symlink = NULL;
203 if (!couldbe_mf_symlink(fattr))
204 /* it's not a symlink */
207 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
211 if (tcon->ses->server->ops->query_mf_symlink)
212 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
213 cifs_sb, path, buf, &bytes_read);
220 if (bytes_read == 0) /* not a symlink */
223 rc = parse_mf_symlink(buf, bytes_read, &link_len, &symlink);
225 /* it's not a symlink */
233 /* it is a symlink */
234 fattr->cf_eof = link_len;
235 fattr->cf_mode &= ~S_IFMT;
236 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
237 fattr->cf_dtype = DT_LNK;
238 fattr->cf_symlink_target = symlink;
244 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
246 * SMB 1.0 Protocol specific functions
250 cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
251 struct cifs_sb_info *cifs_sb, const unsigned char *path,
252 char *pbuf, unsigned int *pbytes_read)
257 struct cifs_open_parms oparms;
258 struct cifs_io_parms io_parms = {0};
259 int buf_type = CIFS_NO_BUFFER;
260 FILE_ALL_INFO file_info;
262 oparms = (struct cifs_open_parms) {
265 .desired_access = GENERIC_READ,
266 .create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
267 .disposition = FILE_OPEN,
272 rc = CIFS_open(xid, &oparms, &oplock, &file_info);
276 if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
278 /* it's not a symlink */
282 io_parms.netfid = fid.netfid;
283 io_parms.pid = current->tgid;
284 io_parms.tcon = tcon;
286 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
288 rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
290 CIFSSMBClose(xid, tcon, fid.netfid);
295 cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
296 struct cifs_sb_info *cifs_sb, const unsigned char *path,
297 char *pbuf, unsigned int *pbytes_written)
302 struct cifs_open_parms oparms;
303 struct cifs_io_parms io_parms = {0};
305 oparms = (struct cifs_open_parms) {
308 .desired_access = GENERIC_WRITE,
309 .create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
310 .disposition = FILE_CREATE,
315 rc = CIFS_open(xid, &oparms, &oplock, NULL);
319 io_parms.netfid = fid.netfid;
320 io_parms.pid = current->tgid;
321 io_parms.tcon = tcon;
323 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
325 rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
326 CIFSSMBClose(xid, tcon, fid.netfid);
329 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
332 * SMB 2.1/SMB3 Protocol specific functions
335 smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
336 struct cifs_sb_info *cifs_sb, const unsigned char *path,
337 char *pbuf, unsigned int *pbytes_read)
341 struct cifs_open_parms oparms;
342 struct cifs_io_parms io_parms = {0};
343 int buf_type = CIFS_NO_BUFFER;
345 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
346 struct smb2_file_all_info *pfile_info = NULL;
348 oparms = (struct cifs_open_parms) {
352 .desired_access = GENERIC_READ,
353 .create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
354 .disposition = FILE_OPEN,
358 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
359 if (utf16_path == NULL)
362 pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
365 if (pfile_info == NULL) {
370 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
373 goto qmf_out_open_fail;
375 if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
376 /* it's not a symlink */
377 rc = -ENOENT; /* Is there a better rc to return? */
381 io_parms.netfid = fid.netfid;
382 io_parms.pid = current->tgid;
383 io_parms.tcon = tcon;
385 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
386 io_parms.persistent_fid = fid.persistent_fid;
387 io_parms.volatile_fid = fid.volatile_fid;
388 rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
390 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
398 smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
399 struct cifs_sb_info *cifs_sb, const unsigned char *path,
400 char *pbuf, unsigned int *pbytes_written)
404 struct cifs_open_parms oparms;
405 struct cifs_io_parms io_parms = {0};
407 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
410 cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
412 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
416 oparms = (struct cifs_open_parms) {
420 .desired_access = GENERIC_WRITE,
421 .create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
422 .disposition = FILE_CREATE,
427 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
434 io_parms.netfid = fid.netfid;
435 io_parms.pid = current->tgid;
436 io_parms.tcon = tcon;
438 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
439 io_parms.persistent_fid = fid.persistent_fid;
440 io_parms.volatile_fid = fid.volatile_fid;
442 /* iov[0] is reserved for smb header */
443 iov[1].iov_base = pbuf;
444 iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
446 rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
448 /* Make sure we wrote all of the symlink data */
449 if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
452 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
459 * M-F Symlink Functions - End
463 cifs_hardlink(struct dentry *old_file, struct inode *inode,
464 struct dentry *direntry)
468 const char *from_name, *to_name;
470 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
471 struct tcon_link *tlink;
472 struct cifs_tcon *tcon;
473 struct TCP_Server_Info *server;
474 struct cifsInodeInfo *cifsInode;
476 if (unlikely(cifs_forced_shutdown(cifs_sb)))
479 tlink = cifs_sb_tlink(cifs_sb);
481 return PTR_ERR(tlink);
482 tcon = tlink_tcon(tlink);
485 page1 = alloc_dentry_path();
486 page2 = alloc_dentry_path();
488 from_name = build_path_from_dentry(old_file, page1);
489 if (IS_ERR(from_name)) {
490 rc = PTR_ERR(from_name);
493 to_name = build_path_from_dentry(direntry, page2);
494 if (IS_ERR(to_name)) {
495 rc = PTR_ERR(to_name);
499 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
501 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
503 cifs_remap(cifs_sb));
507 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
508 server = tcon->ses->server;
509 if (!server->ops->create_hardlink) {
513 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
515 if ((rc == -EIO) || (rc == -EINVAL))
519 d_drop(direntry); /* force new lookup from server of target */
522 * if source file is cached (oplocked) revalidate will not go to server
523 * until the file is closed or oplock broken so update nlinks locally
525 if (d_really_is_positive(old_file)) {
526 cifsInode = CIFS_I(d_inode(old_file));
528 spin_lock(&d_inode(old_file)->i_lock);
529 inc_nlink(d_inode(old_file));
530 spin_unlock(&d_inode(old_file)->i_lock);
533 * parent dir timestamps will update from srv within a
534 * second, would it really be worth it to set the parent
535 * dir cifs inode time to zero to force revalidate
536 * (faster) for it too?
540 * if not oplocked will force revalidate to get info on source
541 * file from srv. Note Samba server prior to 4.2 has bug -
542 * not updating src file ctime on hardlinks but Windows servers
548 * Will update parent dir timestamps from srv within a second.
549 * Would it really be worth it to set the parent dir (cifs
550 * inode) time field to zero to force revalidate on parent
551 * directory faster ie
553 * CIFS_I(inode)->time = 0;
558 free_dentry_path(page1);
559 free_dentry_path(page2);
561 cifs_put_tlink(tlink);
566 cifs_symlink(struct mnt_idmap *idmap, struct inode *inode,
567 struct dentry *direntry, const char *symname)
569 int rc = -EOPNOTSUPP;
571 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
572 struct tcon_link *tlink;
573 struct cifs_tcon *pTcon;
574 const char *full_path;
576 struct inode *newinode = NULL;
578 if (unlikely(cifs_forced_shutdown(cifs_sb)))
581 page = alloc_dentry_path();
587 tlink = cifs_sb_tlink(cifs_sb);
592 pTcon = tlink_tcon(tlink);
594 full_path = build_path_from_dentry(direntry, page);
595 if (IS_ERR(full_path)) {
596 rc = PTR_ERR(full_path);
600 cifs_dbg(FYI, "Full path: %s\n", full_path);
601 cifs_dbg(FYI, "symname is %s\n", symname);
603 /* BB what if DFS and this volume is on different share? BB */
604 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
605 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
606 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
607 else if (pTcon->unix_ext)
608 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
610 cifs_remap(cifs_sb));
611 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
613 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
614 cifs_sb_target->local_nls); */
617 if (pTcon->posix_extensions)
618 rc = smb311_posix_get_inode_info(&newinode, full_path, inode->i_sb, xid);
619 else if (pTcon->unix_ext)
620 rc = cifs_get_inode_info_unix(&newinode, full_path,
623 rc = cifs_get_inode_info(&newinode, full_path, NULL,
624 inode->i_sb, xid, NULL);
627 cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
630 d_instantiate(direntry, newinode);
634 free_dentry_path(page);
635 cifs_put_tlink(tlink);