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"
33 #define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
34 #define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
35 #define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
36 #define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
37 #define CIFS_MF_SYMLINK_FILE_SIZE \
38 (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
40 #define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
41 #define CIFS_MF_SYMLINK_MD5_FORMAT \
42 "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n"
43 #define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) \
44 md5_hash[0], md5_hash[1], md5_hash[2], md5_hash[3], \
45 md5_hash[4], md5_hash[5], md5_hash[6], md5_hash[7], \
46 md5_hash[8], md5_hash[9], md5_hash[10], md5_hash[11],\
47 md5_hash[12], md5_hash[13], md5_hash[14], md5_hash[15]
50 CIFSParseMFSymlink(const u8 *buf,
52 unsigned int *_link_len,
56 unsigned int link_len;
59 struct MD5Context md5_ctx;
63 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
66 md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
67 link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
69 rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
73 cifs_MD5_init(&md5_ctx);
74 cifs_MD5_update(&md5_ctx, (const u8 *)link_str, link_len);
75 cifs_MD5_final(md5_hash, &md5_ctx);
77 snprintf(md5_str2, sizeof(md5_str2),
78 CIFS_MF_SYMLINK_MD5_FORMAT,
79 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
81 if (strncmp(md5_str1, md5_str2, 17) != 0)
85 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
90 *_link_len = link_len;
95 CIFSFormatMFSymlink(u8 *buf, unsigned int buf_len, const char *link_str)
97 unsigned int link_len;
99 struct MD5Context md5_ctx;
102 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
105 link_len = strlen(link_str);
107 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
108 return -ENAMETOOLONG;
110 cifs_MD5_init(&md5_ctx);
111 cifs_MD5_update(&md5_ctx, (const u8 *)link_str, link_len);
112 cifs_MD5_final(md5_hash, &md5_ctx);
114 snprintf(buf, buf_len,
115 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
117 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
119 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
120 memcpy(buf + ofs, link_str, link_len);
123 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
128 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
136 CIFSQueryMFSymLink(const int xid, struct cifsTconInfo *tcon,
137 const unsigned char *searchName, char **symlinkinfo,
138 const struct nls_table *nls_codepage, int remap)
145 unsigned int bytes_read = 0;
146 int buf_type = CIFS_NO_BUFFER;
147 unsigned int link_len = 0;
148 FILE_ALL_INFO file_info;
150 rc = CIFSSMBOpen(xid, tcon, searchName, FILE_OPEN, GENERIC_READ,
151 CREATE_NOT_DIR, &netfid, &oplock, &file_info,
152 nls_codepage, remap);
156 if (file_info.EndOfFile != CIFS_MF_SYMLINK_FILE_SIZE) {
157 CIFSSMBClose(xid, tcon, netfid);
158 /* it's not a symlink */
162 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
167 rc = CIFSSMBRead(xid, tcon, netfid,
168 CIFS_MF_SYMLINK_FILE_SIZE /* length */,
170 &bytes_read, &pbuf, &buf_type);
171 CIFSSMBClose(xid, tcon, netfid);
177 rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, symlinkinfo);
186 CIFSCouldBeMFSymlink(const struct cifs_fattr *fattr)
188 if (!(fattr->cf_mode & S_IFREG))
189 /* it's not a symlink */
192 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
193 /* it's not a symlink */
200 CIFSCheckMFSymlink(struct cifs_fattr *fattr,
201 const unsigned char *path,
202 struct cifs_sb_info *cifs_sb, int xid)
207 struct cifsTconInfo *pTcon = cifs_sb->tcon;
210 unsigned int bytes_read = 0;
211 int buf_type = CIFS_NO_BUFFER;
212 unsigned int link_len = 0;
213 FILE_ALL_INFO file_info;
215 if (!CIFSCouldBeMFSymlink(fattr))
216 /* it's not a symlink */
219 rc = CIFSSMBOpen(xid, pTcon, path, FILE_OPEN, GENERIC_READ,
220 CREATE_NOT_DIR, &netfid, &oplock, &file_info,
222 cifs_sb->mnt_cifs_flags &
223 CIFS_MOUNT_MAP_SPECIAL_CHR);
227 if (file_info.EndOfFile != CIFS_MF_SYMLINK_FILE_SIZE) {
228 CIFSSMBClose(xid, pTcon, netfid);
229 /* it's not a symlink */
233 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
238 rc = CIFSSMBRead(xid, pTcon, netfid,
239 CIFS_MF_SYMLINK_FILE_SIZE /* length */,
241 &bytes_read, &pbuf, &buf_type);
242 CIFSSMBClose(xid, pTcon, netfid);
248 rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, NULL);
251 /* it's not a symlink */
256 /* it is a symlink */
257 fattr->cf_eof = link_len;
258 fattr->cf_mode &= ~S_IFMT;
259 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
260 fattr->cf_dtype = DT_LNK;
265 cifs_hardlink(struct dentry *old_file, struct inode *inode,
266 struct dentry *direntry)
270 char *fromName = NULL;
272 struct cifs_sb_info *cifs_sb_target;
273 struct cifsTconInfo *pTcon;
274 struct cifsInodeInfo *cifsInode;
278 cifs_sb_target = CIFS_SB(inode->i_sb);
279 pTcon = cifs_sb_target->tcon;
281 /* No need to check for cross device links since server will do that
282 BB note DFS case in future though (when we may have to check) */
284 fromName = build_path_from_dentry(old_file);
285 toName = build_path_from_dentry(direntry);
286 if ((fromName == NULL) || (toName == NULL)) {
291 /* if (cifs_sb_target->tcon->ses->capabilities & CAP_UNIX)*/
293 rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName,
294 cifs_sb_target->local_nls,
295 cifs_sb_target->mnt_cifs_flags &
296 CIFS_MOUNT_MAP_SPECIAL_CHR);
298 rc = CIFSCreateHardLink(xid, pTcon, fromName, toName,
299 cifs_sb_target->local_nls,
300 cifs_sb_target->mnt_cifs_flags &
301 CIFS_MOUNT_MAP_SPECIAL_CHR);
302 if ((rc == -EIO) || (rc == -EINVAL))
306 d_drop(direntry); /* force new lookup from server of target */
308 /* if source file is cached (oplocked) revalidate will not go to server
309 until the file is closed or oplock broken so update nlinks locally */
310 if (old_file->d_inode) {
311 cifsInode = CIFS_I(old_file->d_inode);
313 old_file->d_inode->i_nlink++;
314 /* BB should we make this contingent on superblock flag NOATIME? */
315 /* old_file->d_inode->i_ctime = CURRENT_TIME;*/
316 /* parent dir timestamps will update from srv
317 within a second, would it really be worth it
318 to set the parent dir cifs inode time to zero
319 to force revalidate (faster) for it too? */
321 /* if not oplocked will force revalidate to get info
322 on source file from srv */
325 /* Will update parent dir timestamps from srv within a second.
326 Would it really be worth it to set the parent dir (cifs
327 inode) time field to zero to force revalidate on parent
329 CIFS_I(inode)->time = 0; */
340 cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
342 struct inode *inode = direntry->d_inode;
345 char *full_path = NULL;
346 char *target_path = NULL;
347 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
348 struct cifsTconInfo *tcon = cifs_sb->tcon;
353 * For now, we just handle symlinks with unix extensions enabled.
354 * Eventually we should handle NTFS reparse points, and MacOS
355 * symlink support. For instance...
357 * rc = CIFSSMBQueryReparseLinkInfo(...)
359 * For now, just return -EACCES when the server doesn't support posix
360 * extensions. Note that we still allow querying symlinks when posix
361 * extensions are manually disabled. We could disable these as well
362 * but there doesn't seem to be any harm in allowing the client to
365 if (!(tcon->ses->capabilities & CAP_UNIX)) {
370 full_path = build_path_from_dentry(direntry);
374 cFYI(1, "Full path: %s inode = 0x%p", full_path, inode);
376 rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, &target_path,
382 target_path = ERR_PTR(rc);
386 nd_set_link(nd, target_path);
391 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
393 int rc = -EOPNOTSUPP;
395 struct cifs_sb_info *cifs_sb;
396 struct cifsTconInfo *pTcon;
397 char *full_path = NULL;
398 struct inode *newinode = NULL;
402 cifs_sb = CIFS_SB(inode->i_sb);
403 pTcon = cifs_sb->tcon;
405 full_path = build_path_from_dentry(direntry);
407 if (full_path == NULL) {
413 cFYI(1, "Full path: %s", full_path);
414 cFYI(1, "symname is %s", symname);
416 /* BB what if DFS and this volume is on different share? BB */
418 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
421 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
422 cifs_sb_target->local_nls); */
426 rc = cifs_get_inode_info_unix(&newinode, full_path,
429 rc = cifs_get_inode_info(&newinode, full_path, NULL,
430 inode->i_sb, xid, NULL);
433 cFYI(1, "Create symlink ok, getinodeinfo fail rc = %d",
437 direntry->d_op = &cifs_ci_dentry_ops;
439 direntry->d_op = &cifs_dentry_ops;
440 d_instantiate(direntry, newinode);
449 void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
451 char *p = nd_get_link(nd);