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) {
137 CIFSCreateMFSymLink(const int xid, struct cifsTconInfo *tcon,
138 const char *fromName, const char *toName,
139 const struct nls_table *nls_codepage, int remap)
145 unsigned int bytes_written = 0;
147 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
151 rc = CIFSFormatMFSymlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
157 rc = CIFSSMBOpen(xid, tcon, fromName, FILE_CREATE, GENERIC_WRITE,
158 CREATE_NOT_DIR, &netfid, &oplock, NULL,
159 nls_codepage, remap);
165 rc = CIFSSMBWrite(xid, tcon, netfid,
166 CIFS_MF_SYMLINK_FILE_SIZE /* length */,
168 &bytes_written, buf, NULL, 0);
169 CIFSSMBClose(xid, tcon, netfid);
174 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
181 CIFSQueryMFSymLink(const int xid, struct cifsTconInfo *tcon,
182 const unsigned char *searchName, char **symlinkinfo,
183 const struct nls_table *nls_codepage, int remap)
190 unsigned int bytes_read = 0;
191 int buf_type = CIFS_NO_BUFFER;
192 unsigned int link_len = 0;
193 FILE_ALL_INFO file_info;
195 rc = CIFSSMBOpen(xid, tcon, searchName, FILE_OPEN, GENERIC_READ,
196 CREATE_NOT_DIR, &netfid, &oplock, &file_info,
197 nls_codepage, remap);
201 if (file_info.EndOfFile != CIFS_MF_SYMLINK_FILE_SIZE) {
202 CIFSSMBClose(xid, tcon, netfid);
203 /* it's not a symlink */
207 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
212 rc = CIFSSMBRead(xid, tcon, netfid,
213 CIFS_MF_SYMLINK_FILE_SIZE /* length */,
215 &bytes_read, &pbuf, &buf_type);
216 CIFSSMBClose(xid, tcon, netfid);
222 rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, symlinkinfo);
231 CIFSCouldBeMFSymlink(const struct cifs_fattr *fattr)
233 if (!(fattr->cf_mode & S_IFREG))
234 /* it's not a symlink */
237 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
238 /* it's not a symlink */
245 CIFSCheckMFSymlink(struct cifs_fattr *fattr,
246 const unsigned char *path,
247 struct cifs_sb_info *cifs_sb, int xid)
252 struct cifsTconInfo *pTcon = cifs_sb->tcon;
255 unsigned int bytes_read = 0;
256 int buf_type = CIFS_NO_BUFFER;
257 unsigned int link_len = 0;
258 FILE_ALL_INFO file_info;
260 if (!CIFSCouldBeMFSymlink(fattr))
261 /* it's not a symlink */
264 rc = CIFSSMBOpen(xid, pTcon, path, FILE_OPEN, GENERIC_READ,
265 CREATE_NOT_DIR, &netfid, &oplock, &file_info,
267 cifs_sb->mnt_cifs_flags &
268 CIFS_MOUNT_MAP_SPECIAL_CHR);
272 if (file_info.EndOfFile != CIFS_MF_SYMLINK_FILE_SIZE) {
273 CIFSSMBClose(xid, pTcon, netfid);
274 /* it's not a symlink */
278 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
283 rc = CIFSSMBRead(xid, pTcon, netfid,
284 CIFS_MF_SYMLINK_FILE_SIZE /* length */,
286 &bytes_read, &pbuf, &buf_type);
287 CIFSSMBClose(xid, pTcon, netfid);
293 rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, NULL);
296 /* it's not a symlink */
301 /* it is a symlink */
302 fattr->cf_eof = link_len;
303 fattr->cf_mode &= ~S_IFMT;
304 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
305 fattr->cf_dtype = DT_LNK;
310 cifs_hardlink(struct dentry *old_file, struct inode *inode,
311 struct dentry *direntry)
315 char *fromName = NULL;
317 struct cifs_sb_info *cifs_sb_target;
318 struct cifsTconInfo *pTcon;
319 struct cifsInodeInfo *cifsInode;
323 cifs_sb_target = CIFS_SB(inode->i_sb);
324 pTcon = cifs_sb_target->tcon;
326 /* No need to check for cross device links since server will do that
327 BB note DFS case in future though (when we may have to check) */
329 fromName = build_path_from_dentry(old_file);
330 toName = build_path_from_dentry(direntry);
331 if ((fromName == NULL) || (toName == NULL)) {
336 /* if (cifs_sb_target->tcon->ses->capabilities & CAP_UNIX)*/
338 rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName,
339 cifs_sb_target->local_nls,
340 cifs_sb_target->mnt_cifs_flags &
341 CIFS_MOUNT_MAP_SPECIAL_CHR);
343 rc = CIFSCreateHardLink(xid, pTcon, fromName, toName,
344 cifs_sb_target->local_nls,
345 cifs_sb_target->mnt_cifs_flags &
346 CIFS_MOUNT_MAP_SPECIAL_CHR);
347 if ((rc == -EIO) || (rc == -EINVAL))
351 d_drop(direntry); /* force new lookup from server of target */
353 /* if source file is cached (oplocked) revalidate will not go to server
354 until the file is closed or oplock broken so update nlinks locally */
355 if (old_file->d_inode) {
356 cifsInode = CIFS_I(old_file->d_inode);
358 old_file->d_inode->i_nlink++;
359 /* BB should we make this contingent on superblock flag NOATIME? */
360 /* old_file->d_inode->i_ctime = CURRENT_TIME;*/
361 /* parent dir timestamps will update from srv
362 within a second, would it really be worth it
363 to set the parent dir cifs inode time to zero
364 to force revalidate (faster) for it too? */
366 /* if not oplocked will force revalidate to get info
367 on source file from srv */
370 /* Will update parent dir timestamps from srv within a second.
371 Would it really be worth it to set the parent dir (cifs
372 inode) time field to zero to force revalidate on parent
374 CIFS_I(inode)->time = 0; */
385 cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
387 struct inode *inode = direntry->d_inode;
390 char *full_path = NULL;
391 char *target_path = NULL;
392 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
393 struct cifsTconInfo *tcon = cifs_sb->tcon;
398 * For now, we just handle symlinks with unix extensions enabled.
399 * Eventually we should handle NTFS reparse points, and MacOS
400 * symlink support. For instance...
402 * rc = CIFSSMBQueryReparseLinkInfo(...)
404 * For now, just return -EACCES when the server doesn't support posix
405 * extensions. Note that we still allow querying symlinks when posix
406 * extensions are manually disabled. We could disable these as well
407 * but there doesn't seem to be any harm in allowing the client to
410 if (!(tcon->ses->capabilities & CAP_UNIX)) {
415 full_path = build_path_from_dentry(direntry);
419 cFYI(1, "Full path: %s inode = 0x%p", full_path, inode);
421 rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, &target_path,
427 target_path = ERR_PTR(rc);
431 nd_set_link(nd, target_path);
436 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
438 int rc = -EOPNOTSUPP;
440 struct cifs_sb_info *cifs_sb;
441 struct cifsTconInfo *pTcon;
442 char *full_path = NULL;
443 struct inode *newinode = NULL;
447 cifs_sb = CIFS_SB(inode->i_sb);
448 pTcon = cifs_sb->tcon;
450 full_path = build_path_from_dentry(direntry);
452 if (full_path == NULL) {
458 cFYI(1, "Full path: %s", full_path);
459 cFYI(1, "symname is %s", symname);
461 /* BB what if DFS and this volume is on different share? BB */
463 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
466 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
467 cifs_sb_target->local_nls); */
471 rc = cifs_get_inode_info_unix(&newinode, full_path,
474 rc = cifs_get_inode_info(&newinode, full_path, NULL,
475 inode->i_sb, xid, NULL);
478 cFYI(1, "Create symlink ok, getinodeinfo fail rc = %d",
482 direntry->d_op = &cifs_ci_dentry_ops;
484 direntry->d_op = &cifs_dentry_ops;
485 d_instantiate(direntry, newinode);
494 void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
496 char *p = nd_get_link(nd);