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\n", __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\n", __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\n", __func__);
75 goto symlink_hash_err;
77 crypto_shash_update(&sdescmd5->shash, link_str, link_len);
78 rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
81 crypto_free_shash(md5);
88 CIFSParseMFSymlink(const u8 *buf,
90 unsigned int *_link_len,
94 unsigned int link_len;
100 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
103 md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
104 link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
106 rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
110 rc = symlink_hash(link_len, link_str, md5_hash);
112 cFYI(1, "%s: MD5 hash failure: %d\n", __func__, rc);
116 snprintf(md5_str2, sizeof(md5_str2),
117 CIFS_MF_SYMLINK_MD5_FORMAT,
118 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
120 if (strncmp(md5_str1, md5_str2, 17) != 0)
124 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
129 *_link_len = link_len;
134 CIFSFormatMFSymlink(u8 *buf, unsigned int buf_len, const char *link_str)
137 unsigned int link_len;
141 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
144 link_len = strlen(link_str);
146 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
147 return -ENAMETOOLONG;
149 rc = symlink_hash(link_len, link_str, md5_hash);
151 cFYI(1, "%s: MD5 hash failure: %d\n", __func__, rc);
155 snprintf(buf, buf_len,
156 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
158 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
160 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
161 memcpy(buf + ofs, link_str, link_len);
164 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
169 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
178 CIFSCreateMFSymLink(const int xid, struct cifsTconInfo *tcon,
179 const char *fromName, const char *toName,
180 const struct nls_table *nls_codepage, int remap)
186 unsigned int bytes_written = 0;
188 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
192 rc = CIFSFormatMFSymlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
198 rc = CIFSSMBOpen(xid, tcon, fromName, FILE_CREATE, GENERIC_WRITE,
199 CREATE_NOT_DIR, &netfid, &oplock, NULL,
200 nls_codepage, remap);
206 rc = CIFSSMBWrite(xid, tcon, netfid,
207 CIFS_MF_SYMLINK_FILE_SIZE /* length */,
209 &bytes_written, buf, NULL, 0);
210 CIFSSMBClose(xid, tcon, netfid);
215 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
222 CIFSQueryMFSymLink(const int xid, struct cifsTconInfo *tcon,
223 const unsigned char *searchName, char **symlinkinfo,
224 const struct nls_table *nls_codepage, int remap)
231 unsigned int bytes_read = 0;
232 int buf_type = CIFS_NO_BUFFER;
233 unsigned int link_len = 0;
234 FILE_ALL_INFO file_info;
236 rc = CIFSSMBOpen(xid, tcon, searchName, FILE_OPEN, GENERIC_READ,
237 CREATE_NOT_DIR, &netfid, &oplock, &file_info,
238 nls_codepage, remap);
242 if (file_info.EndOfFile != CIFS_MF_SYMLINK_FILE_SIZE) {
243 CIFSSMBClose(xid, tcon, netfid);
244 /* it's not a symlink */
248 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
253 rc = CIFSSMBRead(xid, tcon, netfid,
254 CIFS_MF_SYMLINK_FILE_SIZE /* length */,
256 &bytes_read, &pbuf, &buf_type);
257 CIFSSMBClose(xid, tcon, netfid);
263 rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, symlinkinfo);
272 CIFSCouldBeMFSymlink(const struct cifs_fattr *fattr)
274 if (!(fattr->cf_mode & S_IFREG))
275 /* it's not a symlink */
278 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
279 /* it's not a symlink */
286 CIFSCheckMFSymlink(struct cifs_fattr *fattr,
287 const unsigned char *path,
288 struct cifs_sb_info *cifs_sb, int xid)
293 struct tcon_link *tlink;
294 struct cifsTconInfo *pTcon;
297 unsigned int bytes_read = 0;
298 int buf_type = CIFS_NO_BUFFER;
299 unsigned int link_len = 0;
300 FILE_ALL_INFO file_info;
302 if (!CIFSCouldBeMFSymlink(fattr))
303 /* it's not a symlink */
306 tlink = cifs_sb_tlink(cifs_sb);
308 return PTR_ERR(tlink);
309 pTcon = tlink_tcon(tlink);
311 rc = CIFSSMBOpen(xid, pTcon, path, FILE_OPEN, GENERIC_READ,
312 CREATE_NOT_DIR, &netfid, &oplock, &file_info,
314 cifs_sb->mnt_cifs_flags &
315 CIFS_MOUNT_MAP_SPECIAL_CHR);
319 if (file_info.EndOfFile != CIFS_MF_SYMLINK_FILE_SIZE) {
320 CIFSSMBClose(xid, pTcon, netfid);
321 /* it's not a symlink */
325 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
332 rc = CIFSSMBRead(xid, pTcon, netfid,
333 CIFS_MF_SYMLINK_FILE_SIZE /* length */,
335 &bytes_read, &pbuf, &buf_type);
336 CIFSSMBClose(xid, pTcon, netfid);
342 rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, NULL);
345 /* it's not a symlink */
353 /* it is a symlink */
354 fattr->cf_eof = link_len;
355 fattr->cf_mode &= ~S_IFMT;
356 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
357 fattr->cf_dtype = DT_LNK;
359 cifs_put_tlink(tlink);
364 cifs_hardlink(struct dentry *old_file, struct inode *inode,
365 struct dentry *direntry)
369 char *fromName = NULL;
371 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
372 struct tcon_link *tlink;
373 struct cifsTconInfo *pTcon;
374 struct cifsInodeInfo *cifsInode;
376 tlink = cifs_sb_tlink(cifs_sb);
378 return PTR_ERR(tlink);
379 pTcon = tlink_tcon(tlink);
383 fromName = build_path_from_dentry(old_file);
384 toName = build_path_from_dentry(direntry);
385 if ((fromName == NULL) || (toName == NULL)) {
391 rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName,
393 cifs_sb->mnt_cifs_flags &
394 CIFS_MOUNT_MAP_SPECIAL_CHR);
396 rc = CIFSCreateHardLink(xid, pTcon, fromName, toName,
398 cifs_sb->mnt_cifs_flags &
399 CIFS_MOUNT_MAP_SPECIAL_CHR);
400 if ((rc == -EIO) || (rc == -EINVAL))
404 d_drop(direntry); /* force new lookup from server of target */
406 /* if source file is cached (oplocked) revalidate will not go to server
407 until the file is closed or oplock broken so update nlinks locally */
408 if (old_file->d_inode) {
409 cifsInode = CIFS_I(old_file->d_inode);
411 old_file->d_inode->i_nlink++;
412 /* BB should we make this contingent on superblock flag NOATIME? */
413 /* old_file->d_inode->i_ctime = CURRENT_TIME;*/
414 /* parent dir timestamps will update from srv
415 within a second, would it really be worth it
416 to set the parent dir cifs inode time to zero
417 to force revalidate (faster) for it too? */
419 /* if not oplocked will force revalidate to get info
420 on source file from srv */
423 /* Will update parent dir timestamps from srv within a second.
424 Would it really be worth it to set the parent dir (cifs
425 inode) time field to zero to force revalidate on parent
427 CIFS_I(inode)->time = 0; */
434 cifs_put_tlink(tlink);
439 cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
441 struct inode *inode = direntry->d_inode;
444 char *full_path = NULL;
445 char *target_path = NULL;
446 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
447 struct tcon_link *tlink = NULL;
448 struct cifsTconInfo *tcon;
452 tlink = cifs_sb_tlink(cifs_sb);
458 tcon = tlink_tcon(tlink);
461 * For now, we just handle symlinks with unix extensions enabled.
462 * Eventually we should handle NTFS reparse points, and MacOS
463 * symlink support. For instance...
465 * rc = CIFSSMBQueryReparseLinkInfo(...)
467 * For now, just return -EACCES when the server doesn't support posix
468 * extensions. Note that we still allow querying symlinks when posix
469 * extensions are manually disabled. We could disable these as well
470 * but there doesn't seem to be any harm in allowing the client to
473 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
474 && !(tcon->ses->capabilities & CAP_UNIX)) {
479 full_path = build_path_from_dentry(direntry);
483 cFYI(1, "Full path: %s inode = 0x%p", full_path, inode);
487 * First try Minshall+French Symlinks, if configured
488 * and fallback to UNIX Extensions Symlinks.
490 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
491 rc = CIFSQueryMFSymLink(xid, tcon, full_path, &target_path,
493 cifs_sb->mnt_cifs_flags &
494 CIFS_MOUNT_MAP_SPECIAL_CHR);
496 if ((rc != 0) && (tcon->ses->capabilities & CAP_UNIX))
497 rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, &target_path,
504 target_path = ERR_PTR(rc);
509 cifs_put_tlink(tlink);
510 nd_set_link(nd, target_path);
515 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
517 int rc = -EOPNOTSUPP;
519 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
520 struct tcon_link *tlink;
521 struct cifsTconInfo *pTcon;
522 char *full_path = NULL;
523 struct inode *newinode = NULL;
527 tlink = cifs_sb_tlink(cifs_sb);
532 pTcon = tlink_tcon(tlink);
534 full_path = build_path_from_dentry(direntry);
535 if (full_path == NULL) {
540 cFYI(1, "Full path: %s", full_path);
541 cFYI(1, "symname is %s", symname);
543 /* BB what if DFS and this volume is on different share? BB */
544 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
545 rc = CIFSCreateMFSymLink(xid, pTcon, full_path, symname,
547 cifs_sb->mnt_cifs_flags &
548 CIFS_MOUNT_MAP_SPECIAL_CHR);
549 else if (pTcon->unix_ext)
550 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
553 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
554 cifs_sb_target->local_nls); */
558 rc = cifs_get_inode_info_unix(&newinode, full_path,
561 rc = cifs_get_inode_info(&newinode, full_path, NULL,
562 inode->i_sb, xid, NULL);
565 cFYI(1, "Create symlink ok, getinodeinfo fail rc = %d",
568 d_instantiate(direntry, newinode);
573 cifs_put_tlink(tlink);
578 void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
580 char *p = nd_get_link(nd);