4 * Copyright (C) International Business Machines Corp., 2002,2008
5 * Author(s): Steve French (sfrench@us.ibm.com)
7 * This library is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU Lesser General Public License as published
9 * by the Free Software Foundation; either version 2.1 of the License, or
10 * (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
15 * the GNU Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this library; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #include <linux/stat.h>
23 #include <linux/slab.h>
24 #include <linux/namei.h>
28 #include "cifsproto.h"
29 #include "cifs_debug.h"
30 #include "cifs_fs_sb.h"
32 #define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
33 #define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
34 #define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
35 #define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
36 #define CIFS_MF_SYMLINK_FILE_SIZE \
37 (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
39 #define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
40 #define CIFS_MF_SYMLINK_MD5_FORMAT \
41 "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n"
42 #define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) \
43 md5_hash[0], md5_hash[1], md5_hash[2], md5_hash[3], \
44 md5_hash[4], md5_hash[5], md5_hash[6], md5_hash[7], \
45 md5_hash[8], md5_hash[9], md5_hash[10], md5_hash[11],\
46 md5_hash[12], md5_hash[13], md5_hash[14], md5_hash[15]
49 symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
53 struct crypto_shash *md5;
54 struct sdesc *sdescmd5;
56 md5 = crypto_alloc_shash("md5", 0, 0);
59 cERROR(1, "%s: Crypto md5 allocation error %d", __func__, rc);
62 size = sizeof(struct shash_desc) + crypto_shash_descsize(md5);
63 sdescmd5 = kmalloc(size, GFP_KERNEL);
66 cERROR(1, "%s: Memory allocation failure", __func__);
67 goto symlink_hash_err;
69 sdescmd5->shash.tfm = md5;
70 sdescmd5->shash.flags = 0x0;
72 rc = crypto_shash_init(&sdescmd5->shash);
74 cERROR(1, "%s: Could not init md5 shash", __func__);
75 goto symlink_hash_err;
77 rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
79 cERROR(1, "%s: Could not update iwth link_str", __func__);
80 goto symlink_hash_err;
82 rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
84 cERROR(1, "%s: Could not generate md5 hash", __func__);
87 crypto_free_shash(md5);
94 CIFSParseMFSymlink(const u8 *buf,
96 unsigned int *_link_len,
100 unsigned int link_len;
101 const char *md5_str1;
102 const char *link_str;
106 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
109 md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
110 link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
112 rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
116 rc = symlink_hash(link_len, link_str, md5_hash);
118 cFYI(1, "%s: MD5 hash failure: %d", __func__, rc);
122 snprintf(md5_str2, sizeof(md5_str2),
123 CIFS_MF_SYMLINK_MD5_FORMAT,
124 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
126 if (strncmp(md5_str1, md5_str2, 17) != 0)
130 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
135 *_link_len = link_len;
140 CIFSFormatMFSymlink(u8 *buf, unsigned int buf_len, const char *link_str)
143 unsigned int link_len;
147 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
150 link_len = strlen(link_str);
152 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
153 return -ENAMETOOLONG;
155 rc = symlink_hash(link_len, link_str, md5_hash);
157 cFYI(1, "%s: MD5 hash failure: %d", __func__, rc);
161 snprintf(buf, buf_len,
162 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
164 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
166 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
167 memcpy(buf + ofs, link_str, link_len);
170 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
175 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
184 CIFSCreateMFSymLink(const unsigned int xid, struct cifs_tcon *tcon,
185 const char *fromName, const char *toName,
186 struct cifs_sb_info *cifs_sb)
191 int create_options = CREATE_NOT_DIR;
194 unsigned int bytes_written = 0;
195 struct cifs_io_parms io_parms;
196 struct nls_table *nls_codepage;
198 nls_codepage = cifs_sb->local_nls;
199 remap = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR;
201 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
205 rc = CIFSFormatMFSymlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
211 if (backup_cred(cifs_sb))
212 create_options |= CREATE_OPEN_BACKUP_INTENT;
214 rc = CIFSSMBOpen(xid, tcon, fromName, FILE_CREATE, GENERIC_WRITE,
215 create_options, &netfid, &oplock, NULL,
216 nls_codepage, remap);
222 io_parms.netfid = netfid;
223 io_parms.pid = current->tgid;
224 io_parms.tcon = tcon;
226 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
228 rc = CIFSSMBWrite(xid, &io_parms, &bytes_written, buf, NULL, 0);
229 CIFSSMBClose(xid, tcon, netfid);
234 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
241 CIFSQueryMFSymLink(const unsigned int xid, struct cifs_tcon *tcon,
242 const unsigned char *searchName, char **symlinkinfo,
243 const struct nls_table *nls_codepage, int remap)
250 unsigned int bytes_read = 0;
251 int buf_type = CIFS_NO_BUFFER;
252 unsigned int link_len = 0;
253 struct cifs_io_parms io_parms;
254 FILE_ALL_INFO file_info;
256 rc = CIFSSMBOpen(xid, tcon, searchName, FILE_OPEN, GENERIC_READ,
257 CREATE_NOT_DIR, &netfid, &oplock, &file_info,
258 nls_codepage, remap);
262 if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
263 CIFSSMBClose(xid, tcon, netfid);
264 /* it's not a symlink */
268 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
272 io_parms.netfid = netfid;
273 io_parms.pid = current->tgid;
274 io_parms.tcon = tcon;
276 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
278 rc = CIFSSMBRead(xid, &io_parms, &bytes_read, &pbuf, &buf_type);
279 CIFSSMBClose(xid, tcon, netfid);
285 rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, symlinkinfo);
294 CIFSCouldBeMFSymlink(const struct cifs_fattr *fattr)
296 if (!(fattr->cf_mode & S_IFREG))
297 /* it's not a symlink */
300 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
301 /* it's not a symlink */
308 CIFSCheckMFSymlink(struct cifs_fattr *fattr,
309 const unsigned char *path,
310 struct cifs_sb_info *cifs_sb, unsigned int xid)
315 struct tcon_link *tlink;
316 struct cifs_tcon *pTcon;
317 struct cifs_io_parms io_parms;
320 unsigned int bytes_read = 0;
321 int buf_type = CIFS_NO_BUFFER;
322 unsigned int link_len = 0;
323 FILE_ALL_INFO file_info;
325 if (!CIFSCouldBeMFSymlink(fattr))
326 /* it's not a symlink */
329 tlink = cifs_sb_tlink(cifs_sb);
331 return PTR_ERR(tlink);
332 pTcon = tlink_tcon(tlink);
334 rc = CIFSSMBOpen(xid, pTcon, path, FILE_OPEN, GENERIC_READ,
335 CREATE_NOT_DIR, &netfid, &oplock, &file_info,
337 cifs_sb->mnt_cifs_flags &
338 CIFS_MOUNT_MAP_SPECIAL_CHR);
342 if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
343 CIFSSMBClose(xid, pTcon, netfid);
344 /* it's not a symlink */
348 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
354 io_parms.netfid = netfid;
355 io_parms.pid = current->tgid;
356 io_parms.tcon = pTcon;
358 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
360 rc = CIFSSMBRead(xid, &io_parms, &bytes_read, &pbuf, &buf_type);
361 CIFSSMBClose(xid, pTcon, netfid);
367 rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, NULL);
370 /* it's not a symlink */
378 /* it is a symlink */
379 fattr->cf_eof = link_len;
380 fattr->cf_mode &= ~S_IFMT;
381 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
382 fattr->cf_dtype = DT_LNK;
384 cifs_put_tlink(tlink);
389 cifs_hardlink(struct dentry *old_file, struct inode *inode,
390 struct dentry *direntry)
394 char *fromName = NULL;
396 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
397 struct tcon_link *tlink;
398 struct cifs_tcon *pTcon;
399 struct cifsInodeInfo *cifsInode;
401 tlink = cifs_sb_tlink(cifs_sb);
403 return PTR_ERR(tlink);
404 pTcon = tlink_tcon(tlink);
408 fromName = build_path_from_dentry(old_file);
409 toName = build_path_from_dentry(direntry);
410 if ((fromName == NULL) || (toName == NULL)) {
416 rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName,
418 cifs_sb->mnt_cifs_flags &
419 CIFS_MOUNT_MAP_SPECIAL_CHR);
421 rc = CIFSCreateHardLink(xid, pTcon, fromName, toName,
423 cifs_sb->mnt_cifs_flags &
424 CIFS_MOUNT_MAP_SPECIAL_CHR);
425 if ((rc == -EIO) || (rc == -EINVAL))
429 d_drop(direntry); /* force new lookup from server of target */
431 /* if source file is cached (oplocked) revalidate will not go to server
432 until the file is closed or oplock broken so update nlinks locally */
433 if (old_file->d_inode) {
434 cifsInode = CIFS_I(old_file->d_inode);
436 spin_lock(&old_file->d_inode->i_lock);
437 inc_nlink(old_file->d_inode);
438 spin_unlock(&old_file->d_inode->i_lock);
439 /* BB should we make this contingent on superblock flag NOATIME? */
440 /* old_file->d_inode->i_ctime = CURRENT_TIME;*/
441 /* parent dir timestamps will update from srv
442 within a second, would it really be worth it
443 to set the parent dir cifs inode time to zero
444 to force revalidate (faster) for it too? */
446 /* if not oplocked will force revalidate to get info
447 on source file from srv */
450 /* Will update parent dir timestamps from srv within a second.
451 Would it really be worth it to set the parent dir (cifs
452 inode) time field to zero to force revalidate on parent
454 CIFS_I(inode)->time = 0; */
461 cifs_put_tlink(tlink);
466 cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
468 struct inode *inode = direntry->d_inode;
471 char *full_path = NULL;
472 char *target_path = NULL;
473 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
474 struct tcon_link *tlink = NULL;
475 struct cifs_tcon *tcon;
479 tlink = cifs_sb_tlink(cifs_sb);
485 tcon = tlink_tcon(tlink);
488 * For now, we just handle symlinks with unix extensions enabled.
489 * Eventually we should handle NTFS reparse points, and MacOS
490 * symlink support. For instance...
492 * rc = CIFSSMBQueryReparseLinkInfo(...)
494 * For now, just return -EACCES when the server doesn't support posix
495 * extensions. Note that we still allow querying symlinks when posix
496 * extensions are manually disabled. We could disable these as well
497 * but there doesn't seem to be any harm in allowing the client to
500 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
501 !cap_unix(tcon->ses)) {
506 full_path = build_path_from_dentry(direntry);
510 cFYI(1, "Full path: %s inode = 0x%p", full_path, inode);
514 * First try Minshall+French Symlinks, if configured
515 * and fallback to UNIX Extensions Symlinks.
517 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
518 rc = CIFSQueryMFSymLink(xid, tcon, full_path, &target_path,
520 cifs_sb->mnt_cifs_flags &
521 CIFS_MOUNT_MAP_SPECIAL_CHR);
523 if ((rc != 0) && cap_unix(tcon->ses))
524 rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, &target_path,
531 target_path = ERR_PTR(rc);
536 cifs_put_tlink(tlink);
537 nd_set_link(nd, target_path);
542 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
544 int rc = -EOPNOTSUPP;
546 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
547 struct tcon_link *tlink;
548 struct cifs_tcon *pTcon;
549 char *full_path = NULL;
550 struct inode *newinode = NULL;
554 tlink = cifs_sb_tlink(cifs_sb);
559 pTcon = tlink_tcon(tlink);
561 full_path = build_path_from_dentry(direntry);
562 if (full_path == NULL) {
567 cFYI(1, "Full path: %s", full_path);
568 cFYI(1, "symname is %s", symname);
570 /* BB what if DFS and this volume is on different share? BB */
571 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
572 rc = CIFSCreateMFSymLink(xid, pTcon, full_path, symname,
574 else if (pTcon->unix_ext)
575 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
578 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
579 cifs_sb_target->local_nls); */
583 rc = cifs_get_inode_info_unix(&newinode, full_path,
586 rc = cifs_get_inode_info(&newinode, full_path, NULL,
587 inode->i_sb, xid, NULL);
590 cFYI(1, "Create symlink ok, getinodeinfo fail rc = %d",
593 d_instantiate(direntry, newinode);
598 cifs_put_tlink(tlink);
603 void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
605 char *p = nd_get_link(nd);