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v6.2
  1// SPDX-License-Identifier: LGPL-2.1
  2/*
 
  3 *
  4 *   Copyright (C) International Business Machines  Corp., 2002,2008
  5 *   Author(s): Steve French (sfrench@us.ibm.com)
  6 *
 
 
 
 
 
 
 
 
 
 
 
 
 
  7 */
  8#include <linux/fs.h>
  9#include <linux/stat.h>
 10#include <linux/slab.h>
 11#include <linux/namei.h>
 12#include "cifsfs.h"
 13#include "cifspdu.h"
 14#include "cifsglob.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"
 21
 22/*
 23 * M-F Symlink Functions - Begin
 24 */
 25
 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)
 32
 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
 36
 37static int
 38symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
 39{
 40	int rc;
 41	struct shash_desc *md5 = NULL;
 
 42
 43	rc = cifs_alloc_hash("md5", &md5);
 44	if (rc)
 45		goto symlink_hash_err;
 46
 47	rc = crypto_shash_init(md5);
 48	if (rc) {
 49		cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
 50		goto symlink_hash_err;
 51	}
 52	rc = crypto_shash_update(md5, link_str, link_len);
 53	if (rc) {
 54		cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
 55		goto symlink_hash_err;
 56	}
 57	rc = crypto_shash_final(md5, md5_hash);
 58	if (rc)
 59		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
 60
 61symlink_hash_err:
 62	cifs_free_hash(&md5);
 63	return rc;
 64}
 65
 66static int
 67parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
 68		 char **_link_str)
 69{
 70	int rc;
 71	unsigned int link_len;
 72	const char *md5_str1;
 73	const char *link_str;
 74	u8 md5_hash[16];
 75	char md5_str2[34];
 76
 77	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
 78		return -EINVAL;
 79
 80	md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
 81	link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
 82
 83	rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
 84	if (rc != 1)
 85		return -EINVAL;
 86
 87	if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
 88		return -EINVAL;
 89
 90	rc = symlink_hash(link_len, link_str, md5_hash);
 91	if (rc) {
 92		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
 93		return rc;
 94	}
 95
 96	scnprintf(md5_str2, sizeof(md5_str2),
 97		  CIFS_MF_SYMLINK_MD5_FORMAT,
 98		  CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
 99
100	if (strncmp(md5_str1, md5_str2, 17) != 0)
101		return -EINVAL;
102
103	if (_link_str) {
104		*_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
105		if (!*_link_str)
106			return -ENOMEM;
107	}
108
109	*_link_len = link_len;
110	return 0;
111}
112
113static int
114format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
115{
116	int rc;
117	unsigned int link_len;
118	unsigned int ofs;
119	u8 md5_hash[16];
120
121	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
122		return -EINVAL;
123
124	link_len = strlen(link_str);
125
126	if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
127		return -ENAMETOOLONG;
128
129	rc = symlink_hash(link_len, link_str, md5_hash);
130	if (rc) {
131		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
132		return rc;
133	}
134
135	scnprintf(buf, buf_len,
136		  CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
137		  link_len,
138		  CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
139
140	ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
141	memcpy(buf + ofs, link_str, link_len);
142
143	ofs += link_len;
144	if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
145		buf[ofs] = '\n';
146		ofs++;
147	}
148
149	while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
150		buf[ofs] = ' ';
151		ofs++;
152	}
153
154	return 0;
155}
156
157bool
158couldbe_mf_symlink(const struct cifs_fattr *fattr)
159{
160	if (!S_ISREG(fattr->cf_mode))
161		/* it's not a symlink */
162		return false;
163
164	if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
165		/* it's not a symlink */
166		return false;
167
168	return true;
169}
170
171static int
172create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
173		  struct cifs_sb_info *cifs_sb, const char *fromName,
174		  const char *toName)
175{
176	int rc;
177	u8 *buf;
178	unsigned int bytes_written = 0;
179
180	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
181	if (!buf)
182		return -ENOMEM;
183
184	rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
185	if (rc)
186		goto out;
187
188	if (tcon->ses->server->ops->create_mf_symlink)
189		rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
190					cifs_sb, fromName, buf, &bytes_written);
191	else
192		rc = -EOPNOTSUPP;
193
194	if (rc)
195		goto out;
196
197	if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
198		rc = -EIO;
199out:
200	kfree(buf);
201	return rc;
202}
203
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
204int
205check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
206		 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
207		 const unsigned char *path)
208{
209	int rc;
210	u8 *buf = NULL;
211	unsigned int link_len = 0;
212	unsigned int bytes_read = 0;
213	char *symlink = NULL;
214
215	if (!couldbe_mf_symlink(fattr))
216		/* it's not a symlink */
217		return 0;
218
219	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
220	if (!buf)
221		return -ENOMEM;
222
223	if (tcon->ses->server->ops->query_mf_symlink)
224		rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
225					      cifs_sb, path, buf, &bytes_read);
226	else
227		rc = -ENOSYS;
228
229	if (rc)
230		goto out;
231
232	if (bytes_read == 0) /* not a symlink */
233		goto out;
234
235	rc = parse_mf_symlink(buf, bytes_read, &link_len, &symlink);
236	if (rc == -EINVAL) {
237		/* it's not a symlink */
238		rc = 0;
239		goto out;
240	}
241
242	if (rc != 0)
243		goto out;
244
245	/* it is a symlink */
246	fattr->cf_eof = link_len;
247	fattr->cf_mode &= ~S_IFMT;
248	fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
249	fattr->cf_dtype = DT_LNK;
250	fattr->cf_symlink_target = symlink;
251out:
252	kfree(buf);
253	return rc;
254}
255
256#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
257/*
258 * SMB 1.0 Protocol specific functions
259 */
260
261int
262cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
263		      struct cifs_sb_info *cifs_sb, const unsigned char *path,
264		      char *pbuf, unsigned int *pbytes_read)
265{
266	int rc;
267	int oplock = 0;
268	struct cifs_fid fid;
269	struct cifs_open_parms oparms;
270	struct cifs_io_parms io_parms = {0};
271	int buf_type = CIFS_NO_BUFFER;
272	FILE_ALL_INFO file_info;
273
274	oparms.tcon = tcon;
275	oparms.cifs_sb = cifs_sb;
276	oparms.desired_access = GENERIC_READ;
277	oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
278	oparms.disposition = FILE_OPEN;
279	oparms.path = path;
280	oparms.fid = &fid;
281	oparms.reconnect = false;
282
283	rc = CIFS_open(xid, &oparms, &oplock, &file_info);
284	if (rc)
285		return rc;
286
287	if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
288		rc = -ENOENT;
289		/* it's not a symlink */
290		goto out;
291	}
292
293	io_parms.netfid = fid.netfid;
294	io_parms.pid = current->tgid;
295	io_parms.tcon = tcon;
296	io_parms.offset = 0;
297	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
298
299	rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
300out:
301	CIFSSMBClose(xid, tcon, fid.netfid);
302	return rc;
303}
304
305int
306cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
307		       struct cifs_sb_info *cifs_sb, const unsigned char *path,
308		       char *pbuf, unsigned int *pbytes_written)
309{
310	int rc;
311	int oplock = 0;
312	struct cifs_fid fid;
313	struct cifs_open_parms oparms;
314	struct cifs_io_parms io_parms = {0};
 
 
 
 
315
316	oparms.tcon = tcon;
317	oparms.cifs_sb = cifs_sb;
318	oparms.desired_access = GENERIC_WRITE;
319	oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
320	oparms.disposition = FILE_CREATE;
321	oparms.path = path;
322	oparms.fid = &fid;
323	oparms.reconnect = false;
324
325	rc = CIFS_open(xid, &oparms, &oplock, NULL);
326	if (rc)
327		return rc;
328
329	io_parms.netfid = fid.netfid;
330	io_parms.pid = current->tgid;
331	io_parms.tcon = tcon;
332	io_parms.offset = 0;
333	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
334
335	rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
336	CIFSSMBClose(xid, tcon, fid.netfid);
337	return rc;
338}
339#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
340
341/*
342 * SMB 2.1/SMB3 Protocol specific functions
343 */
344int
345smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
346		      struct cifs_sb_info *cifs_sb, const unsigned char *path,
347		      char *pbuf, unsigned int *pbytes_read)
348{
349	int rc;
350	struct cifs_fid fid;
351	struct cifs_open_parms oparms;
352	struct cifs_io_parms io_parms = {0};
353	int buf_type = CIFS_NO_BUFFER;
354	__le16 *utf16_path;
355	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
356	struct smb2_file_all_info *pfile_info = NULL;
357
358	oparms.tcon = tcon;
359	oparms.cifs_sb = cifs_sb;
360	oparms.desired_access = GENERIC_READ;
361	oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
 
 
362	oparms.disposition = FILE_OPEN;
363	oparms.fid = &fid;
364	oparms.reconnect = false;
365
366	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
367	if (utf16_path == NULL)
368		return -ENOMEM;
369
370	pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
371			     GFP_KERNEL);
372
373	if (pfile_info == NULL) {
374		kfree(utf16_path);
375		return  -ENOMEM;
376	}
377
378	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
379		       NULL, NULL);
380	if (rc)
381		goto qmf_out_open_fail;
382
383	if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
384		/* it's not a symlink */
385		rc = -ENOENT; /* Is there a better rc to return? */
386		goto qmf_out;
387	}
388
389	io_parms.netfid = fid.netfid;
390	io_parms.pid = current->tgid;
391	io_parms.tcon = tcon;
392	io_parms.offset = 0;
393	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
394	io_parms.persistent_fid = fid.persistent_fid;
395	io_parms.volatile_fid = fid.volatile_fid;
396	rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
397qmf_out:
398	SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
399qmf_out_open_fail:
400	kfree(utf16_path);
401	kfree(pfile_info);
402	return rc;
403}
404
405int
406smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
407		       struct cifs_sb_info *cifs_sb, const unsigned char *path,
408		       char *pbuf, unsigned int *pbytes_written)
409{
410	int rc;
411	struct cifs_fid fid;
412	struct cifs_open_parms oparms;
413	struct cifs_io_parms io_parms = {0};
 
414	__le16 *utf16_path;
415	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
416	struct kvec iov[2];
417
 
 
 
418	cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
419
420	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
421	if (!utf16_path)
422		return -ENOMEM;
423
424	oparms.tcon = tcon;
425	oparms.cifs_sb = cifs_sb;
426	oparms.desired_access = GENERIC_WRITE;
427	oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
428	oparms.disposition = FILE_CREATE;
429	oparms.fid = &fid;
430	oparms.reconnect = false;
431	oparms.mode = 0644;
432
433	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
434		       NULL, NULL);
435	if (rc) {
436		kfree(utf16_path);
437		return rc;
438	}
439
440	io_parms.netfid = fid.netfid;
441	io_parms.pid = current->tgid;
442	io_parms.tcon = tcon;
443	io_parms.offset = 0;
444	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
445	io_parms.persistent_fid = fid.persistent_fid;
446	io_parms.volatile_fid = fid.volatile_fid;
447
448	/* iov[0] is reserved for smb header */
449	iov[1].iov_base = pbuf;
450	iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
451
452	rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
453
454	/* Make sure we wrote all of the symlink data */
455	if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
456		rc = -EIO;
457
458	SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
459
460	kfree(utf16_path);
461	return rc;
462}
463
464/*
465 * M-F Symlink Functions - End
466 */
467
468int
469cifs_hardlink(struct dentry *old_file, struct inode *inode,
470	      struct dentry *direntry)
471{
472	int rc = -EACCES;
473	unsigned int xid;
474	const char *from_name, *to_name;
475	void *page1, *page2;
476	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
477	struct tcon_link *tlink;
478	struct cifs_tcon *tcon;
479	struct TCP_Server_Info *server;
480	struct cifsInodeInfo *cifsInode;
481
482	if (unlikely(cifs_forced_shutdown(cifs_sb)))
483		return -EIO;
484
485	tlink = cifs_sb_tlink(cifs_sb);
486	if (IS_ERR(tlink))
487		return PTR_ERR(tlink);
488	tcon = tlink_tcon(tlink);
489
490	xid = get_xid();
491	page1 = alloc_dentry_path();
492	page2 = alloc_dentry_path();
493
494	from_name = build_path_from_dentry(old_file, page1);
495	if (IS_ERR(from_name)) {
496		rc = PTR_ERR(from_name);
497		goto cifs_hl_exit;
498	}
499	to_name = build_path_from_dentry(direntry, page2);
500	if (IS_ERR(to_name)) {
501		rc = PTR_ERR(to_name);
502		goto cifs_hl_exit;
503	}
504
505#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
506	if (tcon->unix_ext)
507		rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
508					    cifs_sb->local_nls,
509					    cifs_remap(cifs_sb));
510	else {
511#else
512	{
513#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
514		server = tcon->ses->server;
515		if (!server->ops->create_hardlink) {
516			rc = -ENOSYS;
517			goto cifs_hl_exit;
518		}
519		rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
520						  cifs_sb);
521		if ((rc == -EIO) || (rc == -EINVAL))
522			rc = -EOPNOTSUPP;
523	}
524
525	d_drop(direntry);	/* force new lookup from server of target */
526
527	/*
528	 * if source file is cached (oplocked) revalidate will not go to server
529	 * until the file is closed or oplock broken so update nlinks locally
530	 */
531	if (d_really_is_positive(old_file)) {
532		cifsInode = CIFS_I(d_inode(old_file));
533		if (rc == 0) {
534			spin_lock(&d_inode(old_file)->i_lock);
535			inc_nlink(d_inode(old_file));
536			spin_unlock(&d_inode(old_file)->i_lock);
537
538			/*
539			 * parent dir timestamps will update from srv within a
540			 * second, would it really be worth it to set the parent
541			 * dir cifs inode time to zero to force revalidate
542			 * (faster) for it too?
543			 */
544		}
545		/*
546		 * if not oplocked will force revalidate to get info on source
547		 * file from srv.  Note Samba server prior to 4.2 has bug -
548		 * not updating src file ctime on hardlinks but Windows servers
549		 * handle it properly
550		 */
551		cifsInode->time = 0;
552
553		/*
554		 * Will update parent dir timestamps from srv within a second.
555		 * Would it really be worth it to set the parent dir (cifs
556		 * inode) time field to zero to force revalidate on parent
557		 * directory faster ie
558		 *
559		 * CIFS_I(inode)->time = 0;
560		 */
561	}
562
563cifs_hl_exit:
564	free_dentry_path(page1);
565	free_dentry_path(page2);
566	free_xid(xid);
567	cifs_put_tlink(tlink);
568	return rc;
569}
570
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
571int
572cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
573	     struct dentry *direntry, const char *symname)
574{
575	int rc = -EOPNOTSUPP;
576	unsigned int xid;
577	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
578	struct tcon_link *tlink;
579	struct cifs_tcon *pTcon;
580	const char *full_path;
581	void *page;
582	struct inode *newinode = NULL;
583
584	if (unlikely(cifs_forced_shutdown(cifs_sb)))
585		return -EIO;
586
587	page = alloc_dentry_path();
588	if (!page)
589		return -ENOMEM;
590
591	xid = get_xid();
592
593	tlink = cifs_sb_tlink(cifs_sb);
594	if (IS_ERR(tlink)) {
595		rc = PTR_ERR(tlink);
596		goto symlink_exit;
597	}
598	pTcon = tlink_tcon(tlink);
599
600	full_path = build_path_from_dentry(direntry, page);
601	if (IS_ERR(full_path)) {
602		rc = PTR_ERR(full_path);
603		goto symlink_exit;
604	}
605
606	cifs_dbg(FYI, "Full path: %s\n", full_path);
607	cifs_dbg(FYI, "symname is %s\n", symname);
608
609	/* BB what if DFS and this volume is on different share? BB */
610	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
611		rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
612#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
613	else if (pTcon->unix_ext)
614		rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
615					   cifs_sb->local_nls,
616					   cifs_remap(cifs_sb));
617#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
618	/* else
619	   rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
620					cifs_sb_target->local_nls); */
621
622	if (rc == 0) {
623		if (pTcon->posix_extensions)
624			rc = smb311_posix_get_inode_info(&newinode, full_path, inode->i_sb, xid);
625		else if (pTcon->unix_ext)
626			rc = cifs_get_inode_info_unix(&newinode, full_path,
627						      inode->i_sb, xid);
628		else
629			rc = cifs_get_inode_info(&newinode, full_path, NULL,
630						 inode->i_sb, xid, NULL);
631
632		if (rc != 0) {
633			cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
634				 rc);
635		} else {
636			d_instantiate(direntry, newinode);
637		}
638	}
639symlink_exit:
640	free_dentry_path(page);
641	cifs_put_tlink(tlink);
642	free_xid(xid);
643	return rc;
644}
v5.4
 
  1/*
  2 *   fs/cifs/link.c
  3 *
  4 *   Copyright (C) International Business Machines  Corp., 2002,2008
  5 *   Author(s): Steve French (sfrench@us.ibm.com)
  6 *
  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.
 11 *
 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.
 16 *
 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
 20 */
 21#include <linux/fs.h>
 22#include <linux/stat.h>
 23#include <linux/slab.h>
 24#include <linux/namei.h>
 25#include "cifsfs.h"
 26#include "cifspdu.h"
 27#include "cifsglob.h"
 28#include "cifsproto.h"
 29#include "cifs_debug.h"
 30#include "cifs_fs_sb.h"
 31#include "cifs_unicode.h"
 32#include "smb2proto.h"
 
 33
 34/*
 35 * M-F Symlink Functions - Begin
 36 */
 37
 38#define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
 39#define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
 40#define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
 41#define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
 42#define CIFS_MF_SYMLINK_FILE_SIZE \
 43	(CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
 44
 45#define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
 46#define CIFS_MF_SYMLINK_MD5_FORMAT "%16phN\n"
 47#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) md5_hash
 48
 49static int
 50symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
 51{
 52	int rc;
 53	struct crypto_shash *md5 = NULL;
 54	struct sdesc *sdescmd5 = NULL;
 55
 56	rc = cifs_alloc_hash("md5", &md5, &sdescmd5);
 57	if (rc)
 58		goto symlink_hash_err;
 59
 60	rc = crypto_shash_init(&sdescmd5->shash);
 61	if (rc) {
 62		cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
 63		goto symlink_hash_err;
 64	}
 65	rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
 66	if (rc) {
 67		cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
 68		goto symlink_hash_err;
 69	}
 70	rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
 71	if (rc)
 72		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
 73
 74symlink_hash_err:
 75	cifs_free_hash(&md5, &sdescmd5);
 76	return rc;
 77}
 78
 79static int
 80parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
 81		 char **_link_str)
 82{
 83	int rc;
 84	unsigned int link_len;
 85	const char *md5_str1;
 86	const char *link_str;
 87	u8 md5_hash[16];
 88	char md5_str2[34];
 89
 90	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
 91		return -EINVAL;
 92
 93	md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
 94	link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
 95
 96	rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
 97	if (rc != 1)
 98		return -EINVAL;
 99
 
 
 
100	rc = symlink_hash(link_len, link_str, md5_hash);
101	if (rc) {
102		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
103		return rc;
104	}
105
106	scnprintf(md5_str2, sizeof(md5_str2),
107		  CIFS_MF_SYMLINK_MD5_FORMAT,
108		  CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
109
110	if (strncmp(md5_str1, md5_str2, 17) != 0)
111		return -EINVAL;
112
113	if (_link_str) {
114		*_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
115		if (!*_link_str)
116			return -ENOMEM;
117	}
118
119	*_link_len = link_len;
120	return 0;
121}
122
123static int
124format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
125{
126	int rc;
127	unsigned int link_len;
128	unsigned int ofs;
129	u8 md5_hash[16];
130
131	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
132		return -EINVAL;
133
134	link_len = strlen(link_str);
135
136	if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
137		return -ENAMETOOLONG;
138
139	rc = symlink_hash(link_len, link_str, md5_hash);
140	if (rc) {
141		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
142		return rc;
143	}
144
145	scnprintf(buf, buf_len,
146		  CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
147		  link_len,
148		  CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
149
150	ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
151	memcpy(buf + ofs, link_str, link_len);
152
153	ofs += link_len;
154	if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
155		buf[ofs] = '\n';
156		ofs++;
157	}
158
159	while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
160		buf[ofs] = ' ';
161		ofs++;
162	}
163
164	return 0;
165}
166
167bool
168couldbe_mf_symlink(const struct cifs_fattr *fattr)
169{
170	if (!S_ISREG(fattr->cf_mode))
171		/* it's not a symlink */
172		return false;
173
174	if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
175		/* it's not a symlink */
176		return false;
177
178	return true;
179}
180
181static int
182create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
183		  struct cifs_sb_info *cifs_sb, const char *fromName,
184		  const char *toName)
185{
186	int rc;
187	u8 *buf;
188	unsigned int bytes_written = 0;
189
190	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
191	if (!buf)
192		return -ENOMEM;
193
194	rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
195	if (rc)
196		goto out;
197
198	if (tcon->ses->server->ops->create_mf_symlink)
199		rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
200					cifs_sb, fromName, buf, &bytes_written);
201	else
202		rc = -EOPNOTSUPP;
203
204	if (rc)
205		goto out;
206
207	if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
208		rc = -EIO;
209out:
210	kfree(buf);
211	return rc;
212}
213
214static int
215query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
216		 struct cifs_sb_info *cifs_sb, const unsigned char *path,
217		 char **symlinkinfo)
218{
219	int rc;
220	u8 *buf = NULL;
221	unsigned int link_len = 0;
222	unsigned int bytes_read = 0;
223
224	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
225	if (!buf)
226		return -ENOMEM;
227
228	if (tcon->ses->server->ops->query_mf_symlink)
229		rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
230					      cifs_sb, path, buf, &bytes_read);
231	else
232		rc = -ENOSYS;
233
234	if (rc)
235		goto out;
236
237	if (bytes_read == 0) { /* not a symlink */
238		rc = -EINVAL;
239		goto out;
240	}
241
242	rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
243out:
244	kfree(buf);
245	return rc;
246}
247
248int
249check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
250		 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
251		 const unsigned char *path)
252{
253	int rc;
254	u8 *buf = NULL;
255	unsigned int link_len = 0;
256	unsigned int bytes_read = 0;
 
257
258	if (!couldbe_mf_symlink(fattr))
259		/* it's not a symlink */
260		return 0;
261
262	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
263	if (!buf)
264		return -ENOMEM;
265
266	if (tcon->ses->server->ops->query_mf_symlink)
267		rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
268					      cifs_sb, path, buf, &bytes_read);
269	else
270		rc = -ENOSYS;
271
272	if (rc)
273		goto out;
274
275	if (bytes_read == 0) /* not a symlink */
276		goto out;
277
278	rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
279	if (rc == -EINVAL) {
280		/* it's not a symlink */
281		rc = 0;
282		goto out;
283	}
284
285	if (rc != 0)
286		goto out;
287
288	/* it is a symlink */
289	fattr->cf_eof = link_len;
290	fattr->cf_mode &= ~S_IFMT;
291	fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
292	fattr->cf_dtype = DT_LNK;
 
293out:
294	kfree(buf);
295	return rc;
296}
297
 
298/*
299 * SMB 1.0 Protocol specific functions
300 */
301
302int
303cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
304		      struct cifs_sb_info *cifs_sb, const unsigned char *path,
305		      char *pbuf, unsigned int *pbytes_read)
306{
307	int rc;
308	int oplock = 0;
309	struct cifs_fid fid;
310	struct cifs_open_parms oparms;
311	struct cifs_io_parms io_parms;
312	int buf_type = CIFS_NO_BUFFER;
313	FILE_ALL_INFO file_info;
314
315	oparms.tcon = tcon;
316	oparms.cifs_sb = cifs_sb;
317	oparms.desired_access = GENERIC_READ;
318	oparms.create_options = CREATE_NOT_DIR;
319	oparms.disposition = FILE_OPEN;
320	oparms.path = path;
321	oparms.fid = &fid;
322	oparms.reconnect = false;
323
324	rc = CIFS_open(xid, &oparms, &oplock, &file_info);
325	if (rc)
326		return rc;
327
328	if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
329		rc = -ENOENT;
330		/* it's not a symlink */
331		goto out;
332	}
333
334	io_parms.netfid = fid.netfid;
335	io_parms.pid = current->tgid;
336	io_parms.tcon = tcon;
337	io_parms.offset = 0;
338	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
339
340	rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
341out:
342	CIFSSMBClose(xid, tcon, fid.netfid);
343	return rc;
344}
345
346int
347cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
348		       struct cifs_sb_info *cifs_sb, const unsigned char *path,
349		       char *pbuf, unsigned int *pbytes_written)
350{
351	int rc;
352	int oplock = 0;
353	struct cifs_fid fid;
354	struct cifs_open_parms oparms;
355	struct cifs_io_parms io_parms;
356	int create_options = CREATE_NOT_DIR;
357
358	if (backup_cred(cifs_sb))
359		create_options |= CREATE_OPEN_BACKUP_INTENT;
360
361	oparms.tcon = tcon;
362	oparms.cifs_sb = cifs_sb;
363	oparms.desired_access = GENERIC_WRITE;
364	oparms.create_options = create_options;
365	oparms.disposition = FILE_CREATE;
366	oparms.path = path;
367	oparms.fid = &fid;
368	oparms.reconnect = false;
369
370	rc = CIFS_open(xid, &oparms, &oplock, NULL);
371	if (rc)
372		return rc;
373
374	io_parms.netfid = fid.netfid;
375	io_parms.pid = current->tgid;
376	io_parms.tcon = tcon;
377	io_parms.offset = 0;
378	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
379
380	rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
381	CIFSSMBClose(xid, tcon, fid.netfid);
382	return rc;
383}
 
384
385/*
386 * SMB 2.1/SMB3 Protocol specific functions
387 */
388int
389smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
390		      struct cifs_sb_info *cifs_sb, const unsigned char *path,
391		      char *pbuf, unsigned int *pbytes_read)
392{
393	int rc;
394	struct cifs_fid fid;
395	struct cifs_open_parms oparms;
396	struct cifs_io_parms io_parms;
397	int buf_type = CIFS_NO_BUFFER;
398	__le16 *utf16_path;
399	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
400	struct smb2_file_all_info *pfile_info = NULL;
401
402	oparms.tcon = tcon;
403	oparms.cifs_sb = cifs_sb;
404	oparms.desired_access = GENERIC_READ;
405	oparms.create_options = CREATE_NOT_DIR;
406	if (backup_cred(cifs_sb))
407		oparms.create_options |= CREATE_OPEN_BACKUP_INTENT;
408	oparms.disposition = FILE_OPEN;
409	oparms.fid = &fid;
410	oparms.reconnect = false;
411
412	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
413	if (utf16_path == NULL)
414		return -ENOMEM;
415
416	pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
417			     GFP_KERNEL);
418
419	if (pfile_info == NULL) {
420		kfree(utf16_path);
421		return  -ENOMEM;
422	}
423
424	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
425		       NULL);
426	if (rc)
427		goto qmf_out_open_fail;
428
429	if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
430		/* it's not a symlink */
431		rc = -ENOENT; /* Is there a better rc to return? */
432		goto qmf_out;
433	}
434
435	io_parms.netfid = fid.netfid;
436	io_parms.pid = current->tgid;
437	io_parms.tcon = tcon;
438	io_parms.offset = 0;
439	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
440	io_parms.persistent_fid = fid.persistent_fid;
441	io_parms.volatile_fid = fid.volatile_fid;
442	rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
443qmf_out:
444	SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
445qmf_out_open_fail:
446	kfree(utf16_path);
447	kfree(pfile_info);
448	return rc;
449}
450
451int
452smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
453		       struct cifs_sb_info *cifs_sb, const unsigned char *path,
454		       char *pbuf, unsigned int *pbytes_written)
455{
456	int rc;
457	struct cifs_fid fid;
458	struct cifs_open_parms oparms;
459	struct cifs_io_parms io_parms;
460	int create_options = CREATE_NOT_DIR;
461	__le16 *utf16_path;
462	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
463	struct kvec iov[2];
464
465	if (backup_cred(cifs_sb))
466		create_options |= CREATE_OPEN_BACKUP_INTENT;
467
468	cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
469
470	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
471	if (!utf16_path)
472		return -ENOMEM;
473
474	oparms.tcon = tcon;
475	oparms.cifs_sb = cifs_sb;
476	oparms.desired_access = GENERIC_WRITE;
477	oparms.create_options = create_options;
478	oparms.disposition = FILE_CREATE;
479	oparms.fid = &fid;
480	oparms.reconnect = false;
 
481
482	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
483		       NULL);
484	if (rc) {
485		kfree(utf16_path);
486		return rc;
487	}
488
489	io_parms.netfid = fid.netfid;
490	io_parms.pid = current->tgid;
491	io_parms.tcon = tcon;
492	io_parms.offset = 0;
493	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
494	io_parms.persistent_fid = fid.persistent_fid;
495	io_parms.volatile_fid = fid.volatile_fid;
496
497	/* iov[0] is reserved for smb header */
498	iov[1].iov_base = pbuf;
499	iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
500
501	rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
502
503	/* Make sure we wrote all of the symlink data */
504	if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
505		rc = -EIO;
506
507	SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
508
509	kfree(utf16_path);
510	return rc;
511}
512
513/*
514 * M-F Symlink Functions - End
515 */
516
517int
518cifs_hardlink(struct dentry *old_file, struct inode *inode,
519	      struct dentry *direntry)
520{
521	int rc = -EACCES;
522	unsigned int xid;
523	char *from_name = NULL;
524	char *to_name = NULL;
525	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
526	struct tcon_link *tlink;
527	struct cifs_tcon *tcon;
528	struct TCP_Server_Info *server;
529	struct cifsInodeInfo *cifsInode;
530
 
 
 
531	tlink = cifs_sb_tlink(cifs_sb);
532	if (IS_ERR(tlink))
533		return PTR_ERR(tlink);
534	tcon = tlink_tcon(tlink);
535
536	xid = get_xid();
 
 
537
538	from_name = build_path_from_dentry(old_file);
539	to_name = build_path_from_dentry(direntry);
540	if ((from_name == NULL) || (to_name == NULL)) {
541		rc = -ENOMEM;
 
 
 
 
542		goto cifs_hl_exit;
543	}
544
 
545	if (tcon->unix_ext)
546		rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
547					    cifs_sb->local_nls,
548					    cifs_remap(cifs_sb));
549	else {
 
 
 
550		server = tcon->ses->server;
551		if (!server->ops->create_hardlink) {
552			rc = -ENOSYS;
553			goto cifs_hl_exit;
554		}
555		rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
556						  cifs_sb);
557		if ((rc == -EIO) || (rc == -EINVAL))
558			rc = -EOPNOTSUPP;
559	}
560
561	d_drop(direntry);	/* force new lookup from server of target */
562
563	/*
564	 * if source file is cached (oplocked) revalidate will not go to server
565	 * until the file is closed or oplock broken so update nlinks locally
566	 */
567	if (d_really_is_positive(old_file)) {
568		cifsInode = CIFS_I(d_inode(old_file));
569		if (rc == 0) {
570			spin_lock(&d_inode(old_file)->i_lock);
571			inc_nlink(d_inode(old_file));
572			spin_unlock(&d_inode(old_file)->i_lock);
573
574			/*
575			 * parent dir timestamps will update from srv within a
576			 * second, would it really be worth it to set the parent
577			 * dir cifs inode time to zero to force revalidate
578			 * (faster) for it too?
579			 */
580		}
581		/*
582		 * if not oplocked will force revalidate to get info on source
583		 * file from srv.  Note Samba server prior to 4.2 has bug -
584		 * not updating src file ctime on hardlinks but Windows servers
585		 * handle it properly
586		 */
587		cifsInode->time = 0;
588
589		/*
590		 * Will update parent dir timestamps from srv within a second.
591		 * Would it really be worth it to set the parent dir (cifs
592		 * inode) time field to zero to force revalidate on parent
593		 * directory faster ie
594		 *
595		 * CIFS_I(inode)->time = 0;
596		 */
597	}
598
599cifs_hl_exit:
600	kfree(from_name);
601	kfree(to_name);
602	free_xid(xid);
603	cifs_put_tlink(tlink);
604	return rc;
605}
606
607const char *
608cifs_get_link(struct dentry *direntry, struct inode *inode,
609	      struct delayed_call *done)
610{
611	int rc = -ENOMEM;
612	unsigned int xid;
613	char *full_path = NULL;
614	char *target_path = NULL;
615	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
616	struct tcon_link *tlink = NULL;
617	struct cifs_tcon *tcon;
618	struct TCP_Server_Info *server;
619
620	if (!direntry)
621		return ERR_PTR(-ECHILD);
622
623	xid = get_xid();
624
625	tlink = cifs_sb_tlink(cifs_sb);
626	if (IS_ERR(tlink)) {
627		free_xid(xid);
628		return ERR_CAST(tlink);
629	}
630	tcon = tlink_tcon(tlink);
631	server = tcon->ses->server;
632
633	full_path = build_path_from_dentry(direntry);
634	if (!full_path) {
635		free_xid(xid);
636		cifs_put_tlink(tlink);
637		return ERR_PTR(-ENOMEM);
638	}
639
640	cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
641
642	rc = -EACCES;
643	/*
644	 * First try Minshall+French Symlinks, if configured
645	 * and fallback to UNIX Extensions Symlinks.
646	 */
647	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
648		rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
649				      &target_path);
650
651	if (rc != 0 && server->ops->query_symlink) {
652		struct cifsInodeInfo *cifsi = CIFS_I(inode);
653		bool reparse_point = false;
654
655		if (cifsi->cifsAttrs & ATTR_REPARSE)
656			reparse_point = true;
657
658		rc = server->ops->query_symlink(xid, tcon, cifs_sb, full_path,
659						&target_path, reparse_point);
660	}
661
662	kfree(full_path);
663	free_xid(xid);
664	cifs_put_tlink(tlink);
665	if (rc != 0) {
666		kfree(target_path);
667		return ERR_PTR(rc);
668	}
669	set_delayed_call(done, kfree_link, target_path);
670	return target_path;
671}
672
673int
674cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
 
675{
676	int rc = -EOPNOTSUPP;
677	unsigned int xid;
678	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
679	struct tcon_link *tlink;
680	struct cifs_tcon *pTcon;
681	char *full_path = NULL;
 
682	struct inode *newinode = NULL;
683
 
 
 
 
 
 
 
684	xid = get_xid();
685
686	tlink = cifs_sb_tlink(cifs_sb);
687	if (IS_ERR(tlink)) {
688		rc = PTR_ERR(tlink);
689		goto symlink_exit;
690	}
691	pTcon = tlink_tcon(tlink);
692
693	full_path = build_path_from_dentry(direntry);
694	if (full_path == NULL) {
695		rc = -ENOMEM;
696		goto symlink_exit;
697	}
698
699	cifs_dbg(FYI, "Full path: %s\n", full_path);
700	cifs_dbg(FYI, "symname is %s\n", symname);
701
702	/* BB what if DFS and this volume is on different share? BB */
703	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
704		rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
 
705	else if (pTcon->unix_ext)
706		rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
707					   cifs_sb->local_nls,
708					   cifs_remap(cifs_sb));
 
709	/* else
710	   rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
711					cifs_sb_target->local_nls); */
712
713	if (rc == 0) {
714		if (pTcon->unix_ext)
 
 
715			rc = cifs_get_inode_info_unix(&newinode, full_path,
716						      inode->i_sb, xid);
717		else
718			rc = cifs_get_inode_info(&newinode, full_path, NULL,
719						 inode->i_sb, xid, NULL);
720
721		if (rc != 0) {
722			cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
723				 rc);
724		} else {
725			d_instantiate(direntry, newinode);
726		}
727	}
728symlink_exit:
729	kfree(full_path);
730	cifs_put_tlink(tlink);
731	free_xid(xid);
732	return rc;
733}