[linux-2.6-block.git] / fs / cifs / link.c

/*
 *   fs/cifs/link.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2008
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/namei.h>
#include "cifsfs.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"

/*
 * M-F Symlink Functions - Begin
 */

#define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
#define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
#define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
#define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
#define CIFS_MF_SYMLINK_FILE_SIZE \
	(CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)

#define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
#define CIFS_MF_SYMLINK_MD5_FORMAT \
	"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n"
#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) \
	md5_hash[0],  md5_hash[1],  md5_hash[2],  md5_hash[3], \
	md5_hash[4],  md5_hash[5],  md5_hash[6],  md5_hash[7], \
	md5_hash[8],  md5_hash[9],  md5_hash[10], md5_hash[11],\
	md5_hash[12], md5_hash[13], md5_hash[14], md5_hash[15]

static int
symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
{
	int rc;
	unsigned int size;
	struct crypto_shash *md5;
	struct sdesc *sdescmd5;

	md5 = crypto_alloc_shash("md5", 0, 0);
	if (IS_ERR(md5)) {
		rc = PTR_ERR(md5);
		cifs_dbg(VFS, "%s: Crypto md5 allocation error %d\n",
			 __func__, rc);
		return rc;
	}
	size = sizeof(struct shash_desc) + crypto_shash_descsize(md5);
	sdescmd5 = kmalloc(size, GFP_KERNEL);
	if (!sdescmd5) {
		rc = -ENOMEM;
		goto symlink_hash_err;
	}
	sdescmd5->shash.tfm = md5;
	sdescmd5->shash.flags = 0x0;

	rc = crypto_shash_init(&sdescmd5->shash);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
		goto symlink_hash_err;
	}
	rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
		goto symlink_hash_err;
	}
	rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
	if (rc)
		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);

symlink_hash_err:
	crypto_free_shash(md5);
	kfree(sdescmd5);

	return rc;
}

static int
parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
		 char **_link_str)
{
	int rc;
	unsigned int link_len;
	const char *md5_str1;
	const char *link_str;
	u8 md5_hash[16];
	char md5_str2[34];

	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
		return -EINVAL;

	md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
	link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];

	rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
	if (rc != 1)
		return -EINVAL;

	rc = symlink_hash(link_len, link_str, md5_hash);
	if (rc) {
		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
		return rc;
	}

	snprintf(md5_str2, sizeof(md5_str2),
		 CIFS_MF_SYMLINK_MD5_FORMAT,
		 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));

	if (strncmp(md5_str1, md5_str2, 17) != 0)
		return -EINVAL;

	if (_link_str) {
		*_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
		if (!*_link_str)
			return -ENOMEM;
	}

	*_link_len = link_len;
	return 0;
}

static int
format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
{
	int rc;
	unsigned int link_len;
	unsigned int ofs;
	u8 md5_hash[16];

	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
		return -EINVAL;

	link_len = strlen(link_str);

	if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
		return -ENAMETOOLONG;

	rc = symlink_hash(link_len, link_str, md5_hash);
	if (rc) {
		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
		return rc;
	}

	snprintf(buf, buf_len,
		 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
		 link_len,
		 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));

	ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
	memcpy(buf + ofs, link_str, link_len);

	ofs += link_len;
	if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
		buf[ofs] = '\n';
		ofs++;
	}

	while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
		buf[ofs] = ' ';
		ofs++;
	}

	return 0;
}

bool
couldbe_mf_symlink(const struct cifs_fattr *fattr)
{
	if (!S_ISREG(fattr->cf_mode))
		/* it's not a symlink */
		return false;

	if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
		/* it's not a symlink */
		return false;

	return true;
}

static int
create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
		  struct cifs_sb_info *cifs_sb, const char *fromName,
		  const char *toName)
{
	int rc;
	u8 *buf;
	unsigned int bytes_written = 0;

	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
	if (rc)
		goto out;

	rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon, cifs_sb,
					fromName, buf, &bytes_written);
	if (rc)
		goto out;

	if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
		rc = -EIO;
out:
	kfree(buf);
	return rc;
}

static int
query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
		 struct cifs_sb_info *cifs_sb, const unsigned char *path,
		 char **symlinkinfo)
{
	int rc;
	u8 *buf = NULL;
	unsigned int link_len = 0;
	unsigned int bytes_read = 0;

	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	if (tcon->ses->server->ops->query_mf_symlink)
		rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
					      cifs_sb, path, buf, &bytes_read);
	else
		rc = -ENOSYS;

	if (rc)
		goto out;

	if (bytes_read == 0) { /* not a symlink */
		rc = -EINVAL;
		goto out;
	}

	rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
out:
	kfree(buf);
	return rc;
}

int
check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
		 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
		 const unsigned char *path)
{
	int rc;
	u8 *buf = NULL;
	unsigned int link_len = 0;
	unsigned int bytes_read = 0;

	if (!couldbe_mf_symlink(fattr))
		/* it's not a symlink */
		return 0;

	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	if (tcon->ses->server->ops->query_mf_symlink)
		rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
					      cifs_sb, path, buf, &bytes_read);
	else
		rc = -ENOSYS;

	if (rc)
		goto out;

	if (bytes_read == 0) /* not a symlink */
		goto out;

	rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
	if (rc == -EINVAL) {
		/* it's not a symlink */
		rc = 0;
		goto out;
	}

	if (rc != 0)
		goto out;

	/* it is a symlink */
	fattr->cf_eof = link_len;
	fattr->cf_mode &= ~S_IFMT;
	fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
	fattr->cf_dtype = DT_LNK;
out:
	kfree(buf);
	return rc;
}

/*
 * SMB 1.0 Protocol specific functions
 */

int
cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
		      struct cifs_sb_info *cifs_sb, const unsigned char *path,
		      char *pbuf, unsigned int *pbytes_read)
{
	int rc;
	int oplock = 0;
	struct cifs_fid fid;
	struct cifs_open_parms oparms;
	struct cifs_io_parms io_parms;
	int buf_type = CIFS_NO_BUFFER;
	FILE_ALL_INFO file_info;

	oparms.tcon = tcon;
	oparms.cifs_sb = cifs_sb;
	oparms.desired_access = GENERIC_READ;
	oparms.create_options = CREATE_NOT_DIR;
	oparms.disposition = FILE_OPEN;
	oparms.path = path;
	oparms.fid = &fid;
	oparms.reconnect = false;

	rc = CIFS_open(xid, &oparms, &oplock, &file_info);
	if (rc)
		return rc;

	if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE))
		/* it's not a symlink */
		goto out;

	io_parms.netfid = fid.netfid;
	io_parms.pid = current->tgid;
	io_parms.tcon = tcon;
	io_parms.offset = 0;
	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;

	rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
out:
	CIFSSMBClose(xid, tcon, fid.netfid);
	return rc;
}

int
cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
		       struct cifs_sb_info *cifs_sb, const unsigned char *path,
		       char *pbuf, unsigned int *pbytes_written)
{
	int rc;
	int oplock = 0;
	struct cifs_fid fid;
	struct cifs_open_parms oparms;
	struct cifs_io_parms io_parms;
	int create_options = CREATE_NOT_DIR;

	if (backup_cred(cifs_sb))
		create_options |= CREATE_OPEN_BACKUP_INTENT;

	oparms.tcon = tcon;
	oparms.cifs_sb = cifs_sb;
	oparms.desired_access = GENERIC_WRITE;
	oparms.create_options = create_options;
	oparms.disposition = FILE_CREATE;
	oparms.path = path;
	oparms.fid = &fid;
	oparms.reconnect = false;

	rc = CIFS_open(xid, &oparms, &oplock, NULL);
	if (rc)
		return rc;

	io_parms.netfid = fid.netfid;
	io_parms.pid = current->tgid;
	io_parms.tcon = tcon;
	io_parms.offset = 0;
	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;

	rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf, NULL, 0);
	CIFSSMBClose(xid, tcon, fid.netfid);
	return rc;
}

/*
 * M-F Symlink Functions - End
 */

int
cifs_hardlink(struct dentry *old_file, struct inode *inode,
	      struct dentry *direntry)
{
	int rc = -EACCES;
	unsigned int xid;
	char *from_name = NULL;
	char *to_name = NULL;
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct tcon_link *tlink;
	struct cifs_tcon *tcon;
	struct TCP_Server_Info *server;
	struct cifsInodeInfo *cifsInode;

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);
	tcon = tlink_tcon(tlink);

	xid = get_xid();

	from_name = build_path_from_dentry(old_file);
	to_name = build_path_from_dentry(direntry);
	if ((from_name == NULL) || (to_name == NULL)) {
		rc = -ENOMEM;
		goto cifs_hl_exit;
	}

	if (tcon->unix_ext)
		rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
					    cifs_sb->local_nls,
					    cifs_sb->mnt_cifs_flags &
						CIFS_MOUNT_MAP_SPECIAL_CHR);
	else {
		server = tcon->ses->server;
		if (!server->ops->create_hardlink) {
			rc = -ENOSYS;
			goto cifs_hl_exit;
		}
		rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
						  cifs_sb);
		if ((rc == -EIO) || (rc == -EINVAL))
			rc = -EOPNOTSUPP;
	}

	d_drop(direntry);	/* force new lookup from server of target */

	/*
	 * if source file is cached (oplocked) revalidate will not go to server
	 * until the file is closed or oplock broken so update nlinks locally
	 */
	if (old_file->d_inode) {
		cifsInode = CIFS_I(old_file->d_inode);
		if (rc == 0) {
			spin_lock(&old_file->d_inode->i_lock);
			inc_nlink(old_file->d_inode);
			spin_unlock(&old_file->d_inode->i_lock);
			/*
			 * BB should we make this contingent on superblock flag
			 * NOATIME?
			 */
			/* old_file->d_inode->i_ctime = CURRENT_TIME; */
			/*
			 * parent dir timestamps will update from srv within a
			 * second, would it really be worth it to set the parent
			 * dir cifs inode time to zero to force revalidate
			 * (faster) for it too?
			 */
		}
		/*
		 * if not oplocked will force revalidate to get info on source
		 * file from srv
		 */
		cifsInode->time = 0;

		/*
		 * Will update parent dir timestamps from srv within a second.
		 * Would it really be worth it to set the parent dir (cifs
		 * inode) time field to zero to force revalidate on parent
		 * directory faster ie
		 *
		 * CIFS_I(inode)->time = 0;
		 */
	}

cifs_hl_exit:
	kfree(from_name);
	kfree(to_name);
	free_xid(xid);
	cifs_put_tlink(tlink);
	return rc;
}

void *
cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
{
	struct inode *inode = direntry->d_inode;
	int rc = -ENOMEM;
	unsigned int xid;
	char *full_path = NULL;
	char *target_path = NULL;
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct tcon_link *tlink = NULL;
	struct cifs_tcon *tcon;
	struct TCP_Server_Info *server;

	xid = get_xid();

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink)) {
		rc = PTR_ERR(tlink);
		tlink = NULL;
		goto out;
	}
	tcon = tlink_tcon(tlink);
	server = tcon->ses->server;

	full_path = build_path_from_dentry(direntry);
	if (!full_path)
		goto out;

	cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);

	rc = -EACCES;
	/*
	 * First try Minshall+French Symlinks, if configured
	 * and fallback to UNIX Extensions Symlinks.
	 */
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
		rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
				      &target_path);

	if (rc != 0 && server->ops->query_symlink)
		rc = server->ops->query_symlink(xid, tcon, full_path,
						&target_path, cifs_sb);

	kfree(full_path);
out:
	if (rc != 0) {
		kfree(target_path);
		target_path = ERR_PTR(rc);
	}

	free_xid(xid);
	if (tlink)
		cifs_put_tlink(tlink);
	nd_set_link(nd, target_path);
	return NULL;
}

int
cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
{
	int rc = -EOPNOTSUPP;
	unsigned int xid;
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct tcon_link *tlink;
	struct cifs_tcon *pTcon;
	char *full_path = NULL;
	struct inode *newinode = NULL;

	xid = get_xid();

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink)) {
		rc = PTR_ERR(tlink);
		goto symlink_exit;
	}
	pTcon = tlink_tcon(tlink);

	full_path = build_path_from_dentry(direntry);
	if (full_path == NULL) {
		rc = -ENOMEM;
		goto symlink_exit;
	}

	cifs_dbg(FYI, "Full path: %s\n", full_path);
	cifs_dbg(FYI, "symname is %s\n", symname);

	/* BB what if DFS and this volume is on different share? BB */
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
		rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
	else if (pTcon->unix_ext)
		rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
					   cifs_sb->local_nls);
	/* else
	   rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
					cifs_sb_target->local_nls); */

	if (rc == 0) {
		if (pTcon->unix_ext)
			rc = cifs_get_inode_info_unix(&newinode, full_path,
						      inode->i_sb, xid);
		else
			rc = cifs_get_inode_info(&newinode, full_path, NULL,
						 inode->i_sb, xid, NULL);

		if (rc != 0) {
			cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
				 rc);
		} else {
			d_instantiate(direntry, newinode);
		}
	}
symlink_exit:
	kfree(full_path);
	cifs_put_tlink(tlink);
	free_xid(xid);
	return rc;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* fs/cifs/link.c
	3	*
366781c1	4	* Copyright (C) International Business Machines Corp., 2002,2008
1da177e4 LT	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>
5a0e3ad6	23	#include <linux/slab.h>
1da177e4 LT	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"
c69c1b6e	31
0f8dce1c SP	32	/*
	33	* M-F Symlink Functions - Begin
	34	*/
	35
c69c1b6e SM	36	#define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
	37	#define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
	38	#define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
	39	#define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
	40	#define CIFS_MF_SYMLINK_FILE_SIZE \
	41	(CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
	42
	43	#define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
	44	#define CIFS_MF_SYMLINK_MD5_FORMAT \
	45	"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n"
	46	#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) \
	47	md5_hash[0], md5_hash[1], md5_hash[2], md5_hash[3], \
	48	md5_hash[4], md5_hash[5], md5_hash[6], md5_hash[7], \
	49	md5_hash[8], md5_hash[9], md5_hash[10], md5_hash[11],\
	50	md5_hash[12], md5_hash[13], md5_hash[14], md5_hash[15]
	51
93c100c0 SF	52	static int
	53	symlink_hash(unsigned int link_len, const char link_str, u8 md5_hash)
	54	{
	55	int rc;
	56	unsigned int size;
	57	struct crypto_shash *md5;
	58	struct sdesc *sdescmd5;
	59
	60	md5 = crypto_alloc_shash("md5", 0, 0);
ee2c9258	61	if (IS_ERR(md5)) {
ffeb414a	62	rc = PTR_ERR(md5);
f96637be JP	63	cifs_dbg(VFS, "%s: Crypto md5 allocation error %d\n",
f96637be JP	64	__func__, rc);
ffeb414a	65	return rc;
93c100c0 SF	66	}
	67	size = sizeof(struct shash_desc) + crypto_shash_descsize(md5);
	68	sdescmd5 = kmalloc(size, GFP_KERNEL);
	69	if (!sdescmd5) {
	70	rc = -ENOMEM;
93c100c0 SF	71	goto symlink_hash_err;
	72	}
	73	sdescmd5->shash.tfm = md5;
	74	sdescmd5->shash.flags = 0x0;
	75
	76	rc = crypto_shash_init(&sdescmd5->shash);
	77	if (rc) {
f96637be	78	cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
93c100c0 SF	79	goto symlink_hash_err;
93c100c0 SF	80	}
14cae324 SP	81	rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
14cae324 SP	82	if (rc) {
f96637be	83	cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
14cae324 SP	84	goto symlink_hash_err;
14cae324 SP	85	}
93c100c0	86	rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
14cae324	87	if (rc)
f96637be	88	cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
93c100c0 SF	89
	90	symlink_hash_err:
	91	crypto_free_shash(md5);
	92	kfree(sdescmd5);
	93
	94	return rc;
	95	}
	96
c69c1b6e	97	static int
cb084b1a SP	98	parse_mf_symlink(const u8 buf, unsigned int buf_len, unsigned int _link_len,
cb084b1a SP	99	char **_link_str)
c69c1b6e SM	100	{
	101	int rc;
	102	unsigned int link_len;
	103	const char *md5_str1;
	104	const char *link_str;
c69c1b6e SM	105	u8 md5_hash[16];
	106	char md5_str2[34];
	107
	108	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
	109	return -EINVAL;
	110
	111	md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
	112	link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
	113
	114	rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
	115	if (rc != 1)
	116	return -EINVAL;
	117
93c100c0 SF	118	rc = symlink_hash(link_len, link_str, md5_hash);
93c100c0 SF	119	if (rc) {
f96637be	120	cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
93c100c0 SF	121	return rc;
93c100c0 SF	122	}
c69c1b6e SM	123
	124	snprintf(md5_str2, sizeof(md5_str2),
	125	CIFS_MF_SYMLINK_MD5_FORMAT,
	126	CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
	127
	128	if (strncmp(md5_str1, md5_str2, 17) != 0)
	129	return -EINVAL;
	130
	131	if (_link_str) {
	132	*_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
	133	if (!*_link_str)
	134	return -ENOMEM;
	135	}
	136
	137	*_link_len = link_len;
	138	return 0;
	139	}
1da177e4	140
0fd43ae4	141	static int
cb084b1a	142	format_mf_symlink(u8 buf, unsigned int buf_len, const char link_str)
18bddd10	143	{
93c100c0	144	int rc;
18bddd10 SM	145	unsigned int link_len;
18bddd10 SM	146	unsigned int ofs;
18bddd10 SM	147	u8 md5_hash[16];
	148
	149	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
	150	return -EINVAL;
	151
	152	link_len = strlen(link_str);
	153
	154	if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
	155	return -ENAMETOOLONG;
	156
93c100c0 SF	157	rc = symlink_hash(link_len, link_str, md5_hash);
93c100c0 SF	158	if (rc) {
f96637be	159	cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
93c100c0 SF	160	return rc;
93c100c0 SF	161	}
18bddd10 SM	162
	163	snprintf(buf, buf_len,
	164	CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
	165	link_len,
	166	CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
	167
	168	ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
	169	memcpy(buf + ofs, link_str, link_len);
	170
	171	ofs += link_len;
	172	if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
	173	buf[ofs] = '\n';
	174	ofs++;
	175	}
	176
	177	while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
	178	buf[ofs] = ' ';
	179	ofs++;
	180	}
	181
	182	return 0;
	183	}
	184
0f8dce1c SP	185	bool
	186	couldbe_mf_symlink(const struct cifs_fattr *fattr)
	187	{
a9a315d4	188	if (!S_ISREG(fattr->cf_mode))
0f8dce1c SP	189	/* it's not a symlink */
	190	return false;
	191
	192	if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
	193	/* it's not a symlink */
	194	return false;
	195
	196	return true;
	197	}
	198
8713d01d	199	static int
cb084b1a	200	create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
cbb0aba6 SP	201	struct cifs_sb_info cifs_sb, const char fromName,
cbb0aba6 SP	202	const char *toName)
8713d01d SM	203	{
8713d01d SM	204	int rc;
8713d01d SM	205	u8 *buf;
	206	unsigned int bytes_written = 0;
	207
	208	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
	209	if (!buf)
	210	return -ENOMEM;
	211
cb084b1a	212	rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
cbb0aba6 SP	213	if (rc)
cbb0aba6 SP	214	goto out;
fa2989f4	215
cbb0aba6 SP	216	rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon, cifs_sb,
	217	fromName, buf, &bytes_written);
	218	if (rc)
	219	goto out;
8713d01d SM	220
8713d01d SM	221	if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
cbb0aba6 SP	222	rc = -EIO;
	223	out:
	224	kfree(buf);
	225	return rc;
8713d01d SM	226	}
	227
	228	static int
cb084b1a	229	query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
8205d1bb SP	230	struct cifs_sb_info cifs_sb, const unsigned char path,
8205d1bb SP	231	char **symlinkinfo)
0fd43ae4 SM	232	{
0fd43ae4 SM	233	int rc;
8205d1bb	234	u8 *buf = NULL;
0fd43ae4	235	unsigned int link_len = 0;
8205d1bb	236	unsigned int bytes_read = 0;
0fd43ae4 SM	237
	238	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
	239	if (!buf)
	240	return -ENOMEM;
0fd43ae4	241
8205d1bb SP	242	if (tcon->ses->server->ops->query_mf_symlink)
	243	rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
	244	cifs_sb, path, buf, &bytes_read);
	245	else
	246	rc = -ENOSYS;
	247
	248	if (rc)
	249	goto out;
	250
	251	if (bytes_read == 0) { /* not a symlink */
	252	rc = -EINVAL;
	253	goto out;
0fd43ae4 SM	254	}
0fd43ae4 SM	255
cb084b1a	256	rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
8205d1bb	257	out:
0fd43ae4	258	kfree(buf);
8205d1bb	259	return rc;
0fd43ae4 SM	260	}
0fd43ae4 SM	261
0f8dce1c SP	262	int
	263	check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
	264	struct cifs_sb_info cifs_sb, struct cifs_fattr fattr,
	265	const unsigned char *path)
8bfb50a8	266	{
0f8dce1c SP	267	int rc;
	268	u8 *buf = NULL;
	269	unsigned int link_len = 0;
	270	unsigned int bytes_read = 0;
	271
	272	if (!couldbe_mf_symlink(fattr))
8bfb50a8	273	/* it's not a symlink */
0f8dce1c	274	return 0;
8bfb50a8	275
0f8dce1c SP	276	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
	277	if (!buf)
	278	return -ENOMEM;
	279
	280	if (tcon->ses->server->ops->query_mf_symlink)
	281	rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
	282	cifs_sb, path, buf, &bytes_read);
	283	else
	284	rc = -ENOSYS;
	285
	286	if (rc)
	287	goto out;
	288
	289	if (bytes_read == 0) /* not a symlink */
	290	goto out;
	291
	292	rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
	293	if (rc == -EINVAL) {
8bfb50a8	294	/* it's not a symlink */
0f8dce1c SP	295	rc = 0;
	296	goto out;
	297	}
8bfb50a8	298
0f8dce1c SP	299	if (rc != 0)
	300	goto out;
	301
	302	/* it is a symlink */
	303	fattr->cf_eof = link_len;
	304	fattr->cf_mode &= ~S_IFMT;
	305	fattr->cf_mode \|= S_IFLNK \| S_IRWXU \| S_IRWXG \| S_IRWXO;
	306	fattr->cf_dtype = DT_LNK;
	307	out:
	308	kfree(buf);
	309	return rc;
8bfb50a8 SM	310	}
8bfb50a8 SM	311
0f8dce1c SP	312	/*
	313	* SMB 1.0 Protocol specific functions
	314	*/
	315
8bfb50a8	316	int
b5be1a1c SP	317	cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
	318	struct cifs_sb_info cifs_sb, const unsigned char path,
	319	char pbuf, unsigned int pbytes_read)
8bfb50a8 SM	320	{
	321	int rc;
	322	int oplock = 0;
d81b8a40 PS	323	struct cifs_fid fid;
d81b8a40 PS	324	struct cifs_open_parms oparms;
d4ffff1f	325	struct cifs_io_parms io_parms;
8bfb50a8	326	int buf_type = CIFS_NO_BUFFER;
8bfb50a8 SM	327	FILE_ALL_INFO file_info;
8bfb50a8 SM	328
d81b8a40 PS	329	oparms.tcon = tcon;
	330	oparms.cifs_sb = cifs_sb;
	331	oparms.desired_access = GENERIC_READ;
	332	oparms.create_options = CREATE_NOT_DIR;
	333	oparms.disposition = FILE_OPEN;
	334	oparms.path = path;
	335	oparms.fid = &fid;
	336	oparms.reconnect = false;
	337
	338	rc = CIFS_open(xid, &oparms, &oplock, &file_info);
b5be1a1c	339	if (rc)
1b244081	340	return rc;
8bfb50a8	341
b5be1a1c	342	if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE))
8bfb50a8	343	/* it's not a symlink */
b5be1a1c	344	goto out;
8bfb50a8	345
d81b8a40	346	io_parms.netfid = fid.netfid;
d4ffff1f	347	io_parms.pid = current->tgid;
b5be1a1c	348	io_parms.tcon = tcon;
d4ffff1f PS	349	io_parms.offset = 0;
d4ffff1f PS	350	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
8bfb50a8	351
1b244081	352	rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
b5be1a1c	353	out:
d81b8a40	354	CIFSSMBClose(xid, tcon, fid.netfid);
1b244081 SF	355	return rc;
	356	}
	357
cbb0aba6 SP	358	int
	359	cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
	360	struct cifs_sb_info cifs_sb, const unsigned char path,
	361	char pbuf, unsigned int pbytes_written)
	362	{
	363	int rc;
	364	int oplock = 0;
d81b8a40 PS	365	struct cifs_fid fid;
d81b8a40 PS	366	struct cifs_open_parms oparms;
cbb0aba6 SP	367	struct cifs_io_parms io_parms;
	368	int create_options = CREATE_NOT_DIR;
	369
	370	if (backup_cred(cifs_sb))
	371	create_options \|= CREATE_OPEN_BACKUP_INTENT;
	372
d81b8a40 PS	373	oparms.tcon = tcon;
	374	oparms.cifs_sb = cifs_sb;
	375	oparms.desired_access = GENERIC_WRITE;
	376	oparms.create_options = create_options;
a1d0b84c	377	oparms.disposition = FILE_CREATE;
d81b8a40 PS	378	oparms.path = path;
	379	oparms.fid = &fid;
	380	oparms.reconnect = false;
	381
	382	rc = CIFS_open(xid, &oparms, &oplock, NULL);
cbb0aba6 SP	383	if (rc)
	384	return rc;
	385
d81b8a40	386	io_parms.netfid = fid.netfid;
cbb0aba6 SP	387	io_parms.pid = current->tgid;
	388	io_parms.tcon = tcon;
	389	io_parms.offset = 0;
	390	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
	391
	392	rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf, NULL, 0);
d81b8a40	393	CIFSSMBClose(xid, tcon, fid.netfid);
cbb0aba6 SP	394	return rc;
	395	}
	396
0f8dce1c SP	397	/*
	398	* M-F Symlink Functions - End
	399	*/
8bfb50a8	400
1da177e4 LT	401	int
	402	cifs_hardlink(struct dentry old_file, struct inode inode,
	403	struct dentry *direntry)
	404	{
	405	int rc = -EACCES;
6d5786a3	406	unsigned int xid;
d6e906f1 SF	407	char *from_name = NULL;
d6e906f1 SF	408	char *to_name = NULL;
7ffec372 JL	409	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
7ffec372 JL	410	struct tcon_link *tlink;
d6e906f1 SF	411	struct cifs_tcon *tcon;
d6e906f1 SF	412	struct TCP_Server_Info *server;
1da177e4 LT	413	struct cifsInodeInfo *cifsInode;
1da177e4 LT	414
7ffec372 JL	415	tlink = cifs_sb_tlink(cifs_sb);
	416	if (IS_ERR(tlink))
	417	return PTR_ERR(tlink);
d6e906f1	418	tcon = tlink_tcon(tlink);
1da177e4	419
6d5786a3	420	xid = get_xid();
1da177e4	421
d6e906f1 SF	422	from_name = build_path_from_dentry(old_file);
	423	to_name = build_path_from_dentry(direntry);
	424	if ((from_name == NULL) \|\| (to_name == NULL)) {
1da177e4 LT	425	rc = -ENOMEM;
	426	goto cifs_hl_exit;
	427	}
	428
d6e906f1 SF	429	if (tcon->unix_ext)
d6e906f1 SF	430	rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
7ffec372 JL	431	cifs_sb->local_nls,
7ffec372 JL	432	cifs_sb->mnt_cifs_flags &
737b758c	433	CIFS_MOUNT_MAP_SPECIAL_CHR);
1da177e4	434	else {
d6e906f1	435	server = tcon->ses->server;
abf9767c CE	436	if (!server->ops->create_hardlink) {
	437	rc = -ENOSYS;
	438	goto cifs_hl_exit;
	439	}
d6e906f1 SF	440	rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
d6e906f1 SF	441	cifs_sb);
fb8c4b14 SF	442	if ((rc == -EIO) \|\| (rc == -EINVAL))
fb8c4b14 SF	443	rc = -EOPNOTSUPP;
1da177e4 LT	444	}
1da177e4 LT	445
31ec35d6 SF	446	d_drop(direntry); /* force new lookup from server of target */
31ec35d6 SF	447
d6e906f1 SF	448	/*
	449	* if source file is cached (oplocked) revalidate will not go to server
	450	* until the file is closed or oplock broken so update nlinks locally
	451	*/
fb8c4b14	452	if (old_file->d_inode) {
31ec35d6	453	cifsInode = CIFS_I(old_file->d_inode);
fb8c4b14	454	if (rc == 0) {
b7ca6928	455	spin_lock(&old_file->d_inode->i_lock);
6d6b77f1	456	inc_nlink(old_file->d_inode);
b7ca6928	457	spin_unlock(&old_file->d_inode->i_lock);
d6e906f1 SF	458	/*
	459	* BB should we make this contingent on superblock flag
	460	* NOATIME?
	461	*/
	462	/* old_file->d_inode->i_ctime = CURRENT_TIME; */
	463	/*
	464	* parent dir timestamps will update from srv within a
	465	* second, would it really be worth it to set the parent
	466	* dir cifs inode time to zero to force revalidate
	467	* (faster) for it too?
	468	*/
31ec35d6	469	}
d6e906f1 SF	470	/*
	471	* if not oplocked will force revalidate to get info on source
	472	* file from srv
	473	*/
31ec35d6 SF	474	cifsInode->time = 0;
31ec35d6 SF	475
d6e906f1 SF	476	/*
	477	* Will update parent dir timestamps from srv within a second.
	478	* Would it really be worth it to set the parent dir (cifs
	479	* inode) time field to zero to force revalidate on parent
	480	* directory faster ie
	481	*
	482	* CIFS_I(inode)->time = 0;
	483	*/
1da177e4	484	}
1da177e4 LT	485
1da177e4 LT	486	cifs_hl_exit:
d6e906f1 SF	487	kfree(from_name);
d6e906f1 SF	488	kfree(to_name);
6d5786a3	489	free_xid(xid);
7ffec372	490	cifs_put_tlink(tlink);
1da177e4 LT	491	return rc;
	492	}
	493
cc314eef	494	void *
1da177e4 LT	495	cifs_follow_link(struct dentry direntry, struct nameidata nd)
	496	{
	497	struct inode *inode = direntry->d_inode;
8b6427a2	498	int rc = -ENOMEM;
6d5786a3	499	unsigned int xid;
1da177e4	500	char *full_path = NULL;
8b6427a2 JL	501	char *target_path = NULL;
8b6427a2 JL	502	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
7ffec372	503	struct tcon_link *tlink = NULL;
96daf2b0	504	struct cifs_tcon *tcon;
b42bf888	505	struct TCP_Server_Info *server;
1da177e4	506
6d5786a3	507	xid = get_xid();
1da177e4	508
7ffec372 JL	509	tlink = cifs_sb_tlink(cifs_sb);
	510	if (IS_ERR(tlink)) {
	511	rc = PTR_ERR(tlink);
	512	tlink = NULL;
	513	goto out;
	514	}
	515	tcon = tlink_tcon(tlink);
b42bf888	516	server = tcon->ses->server;
1da177e4	517
8b6427a2	518	full_path = build_path_from_dentry(direntry);
1da177e4	519	if (!full_path)
460b9696	520	goto out;
1da177e4	521
f96637be	522	cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
1da177e4	523
1b12b9c1 SM	524	rc = -EACCES;
	525	/*
	526	* First try Minshall+French Symlinks, if configured
	527	* and fallback to UNIX Extensions Symlinks.
	528	*/
	529	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
8205d1bb SP	530	rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
8205d1bb SP	531	&target_path);
1b12b9c1	532
0ecdb4f5	533	if (rc != 0 && server->ops->query_symlink)
b42bf888 PS	534	rc = server->ops->query_symlink(xid, tcon, full_path,
b42bf888 PS	535	&target_path, cifs_sb);
1b12b9c1	536
8b6427a2 JL	537	kfree(full_path);
8b6427a2 JL	538	out:
460b9696	539	if (rc != 0) {
1da177e4 LT	540	kfree(target_path);
	541	target_path = ERR_PTR(rc);
	542	}
	543
6d5786a3	544	free_xid(xid);
7ffec372 JL	545	if (tlink)
7ffec372 JL	546	cifs_put_tlink(tlink);
1da177e4	547	nd_set_link(nd, target_path);
460b9696	548	return NULL;
1da177e4 LT	549	}
	550
	551	int
	552	cifs_symlink(struct inode inode, struct dentry direntry, const char *symname)
	553	{
	554	int rc = -EOPNOTSUPP;
6d5786a3	555	unsigned int xid;
7ffec372 JL	556	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
7ffec372 JL	557	struct tcon_link *tlink;
96daf2b0	558	struct cifs_tcon *pTcon;
1da177e4 LT	559	char *full_path = NULL;
	560	struct inode *newinode = NULL;
	561
6d5786a3	562	xid = get_xid();
1da177e4	563
7ffec372 JL	564	tlink = cifs_sb_tlink(cifs_sb);
	565	if (IS_ERR(tlink)) {
	566	rc = PTR_ERR(tlink);
	567	goto symlink_exit;
	568	}
	569	pTcon = tlink_tcon(tlink);
1da177e4	570
7f57356b	571	full_path = build_path_from_dentry(direntry);
fb8c4b14	572	if (full_path == NULL) {
0f3bc09e	573	rc = -ENOMEM;
7ffec372	574	goto symlink_exit;
1da177e4 LT	575	}
1da177e4 LT	576
f96637be JP	577	cifs_dbg(FYI, "Full path: %s\n", full_path);
f96637be JP	578	cifs_dbg(FYI, "symname is %s\n", symname);
1da177e4 LT	579
1da177e4 LT	580	/* BB what if DFS and this volume is on different share? BB */
1b12b9c1	581	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
cbb0aba6	582	rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
1b12b9c1	583	else if (pTcon->unix_ext)
1da177e4 LT	584	rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
	585	cifs_sb->local_nls);
	586	/* else
fb8c4b14 SF	587	rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
fb8c4b14 SF	588	cifs_sb_target->local_nls); */
1da177e4 LT	589
1da177e4 LT	590	if (rc == 0) {
c18c842b	591	if (pTcon->unix_ext)
1da177e4	592	rc = cifs_get_inode_info_unix(&newinode, full_path,
fb8c4b14	593	inode->i_sb, xid);
1da177e4 LT	594	else
1da177e4 LT	595	rc = cifs_get_inode_info(&newinode, full_path, NULL,
8b1327f6	596	inode->i_sb, xid, NULL);
1da177e4 LT	597
1da177e4 LT	598	if (rc != 0) {
f96637be JP	599	cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
f96637be JP	600	rc);
1da177e4	601	} else {
1da177e4 LT	602	d_instantiate(direntry, newinode);
	603	}
	604	}
7ffec372	605	symlink_exit:
f99d49ad	606	kfree(full_path);
7ffec372	607	cifs_put_tlink(tlink);
6d5786a3	608	free_xid(xid);
1da177e4 LT	609	return rc;
1da177e4 LT	610	}