[mirror_ubuntu-bionic-kernel.git] / fs / cifs / smb2misc.c

/*
 *   fs/cifs/smb2misc.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2011
 *                 Etersoft, 2012
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *              Pavel Shilovsky (pshilovsky@samba.org) 2012
 *
 *   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/ctype.h>
#include "smb2pdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "smb2proto.h"
#include "cifs_debug.h"
#include "cifs_unicode.h"
#include "smb2status.h"

static int
check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
{
	/*
	 * Make sure that this really is an SMB, that it is a response,
	 * and that the message ids match.
	 */
	if ((*(__le32 *)hdr->ProtocolId == SMB2_PROTO_NUMBER) &&
	    (mid == hdr->MessageId)) {
		if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
			return 0;
		else {
			/* only one valid case where server sends us request */
			if (hdr->Command == SMB2_OPLOCK_BREAK)
				return 0;
			else
				cifs_dbg(VFS, "Received Request not response\n");
		}
	} else { /* bad signature or mid */
		if (*(__le32 *)hdr->ProtocolId != SMB2_PROTO_NUMBER)
			cifs_dbg(VFS, "Bad protocol string signature header %x\n",
				 *(unsigned int *) hdr->ProtocolId);
		if (mid != hdr->MessageId)
			cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
				 mid, hdr->MessageId);
	}
	cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", hdr->MessageId);
	return 1;
}

/*
 *  The following table defines the expected "StructureSize" of SMB2 responses
 *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS responses.
 *
 *  Note that commands are defined in smb2pdu.h in le16 but the array below is
 *  indexed by command in host byte order
 */
static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
	/* SMB2_NEGOTIATE */ __constant_cpu_to_le16(65),
	/* SMB2_SESSION_SETUP */ __constant_cpu_to_le16(9),
	/* SMB2_LOGOFF */ __constant_cpu_to_le16(4),
	/* SMB2_TREE_CONNECT */ __constant_cpu_to_le16(16),
	/* SMB2_TREE_DISCONNECT */ __constant_cpu_to_le16(4),
	/* SMB2_CREATE */ __constant_cpu_to_le16(89),
	/* SMB2_CLOSE */ __constant_cpu_to_le16(60),
	/* SMB2_FLUSH */ __constant_cpu_to_le16(4),
	/* SMB2_READ */ __constant_cpu_to_le16(17),
	/* SMB2_WRITE */ __constant_cpu_to_le16(17),
	/* SMB2_LOCK */ __constant_cpu_to_le16(4),
	/* SMB2_IOCTL */ __constant_cpu_to_le16(49),
	/* BB CHECK this ... not listed in documentation */
	/* SMB2_CANCEL */ __constant_cpu_to_le16(0),
	/* SMB2_ECHO */ __constant_cpu_to_le16(4),
	/* SMB2_QUERY_DIRECTORY */ __constant_cpu_to_le16(9),
	/* SMB2_CHANGE_NOTIFY */ __constant_cpu_to_le16(9),
	/* SMB2_QUERY_INFO */ __constant_cpu_to_le16(9),
	/* SMB2_SET_INFO */ __constant_cpu_to_le16(2),
	/* BB FIXME can also be 44 for lease break */
	/* SMB2_OPLOCK_BREAK */ __constant_cpu_to_le16(24)
};

int
smb2_check_message(char *buf, unsigned int length)
{
	struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
	struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
	__u64 mid = hdr->MessageId;
	__u32 len = get_rfc1002_length(buf);
	__u32 clc_len;  /* calculated length */
	int command;

	/* BB disable following printk later */
	cifs_dbg(FYI, "%s length: 0x%x, smb_buf_length: 0x%x\n",
		 __func__, length, len);

	/*
	 * Add function to do table lookup of StructureSize by command
	 * ie Validate the wct via smb2_struct_sizes table above
	 */

	if (length < sizeof(struct smb2_pdu)) {
		if ((length >= sizeof(struct smb2_hdr)) && (hdr->Status != 0)) {
			pdu->StructureSize2 = 0;
			/*
			 * As with SMB/CIFS, on some error cases servers may
			 * not return wct properly
			 */
			return 0;
		} else {
			cifs_dbg(VFS, "Length less than SMB header size\n");
		}
		return 1;
	}
	if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE - 4) {
		cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
			 mid);
		return 1;
	}

	if (check_smb2_hdr(hdr, mid))
		return 1;

	if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
		cifs_dbg(VFS, "Illegal structure size %u\n",
			 le16_to_cpu(hdr->StructureSize));
		return 1;
	}

	command = le16_to_cpu(hdr->Command);
	if (command >= NUMBER_OF_SMB2_COMMANDS) {
		cifs_dbg(VFS, "Illegal SMB2 command %d\n", command);
		return 1;
	}

	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
		if (command != SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0 ||
		    pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2)) {
			/* error packets have 9 byte structure size */
			cifs_dbg(VFS, "Illegal response size %u for command %d\n",
				 le16_to_cpu(pdu->StructureSize2), command);
			return 1;
		} else if (command == SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0)
			   && (le16_to_cpu(pdu->StructureSize2) != 44)
			   && (le16_to_cpu(pdu->StructureSize2) != 36)) {
			/* special case for SMB2.1 lease break message */
			cifs_dbg(VFS, "Illegal response size %d for oplock break\n",
				 le16_to_cpu(pdu->StructureSize2));
			return 1;
		}
	}

	if (4 + len != length) {
		cifs_dbg(VFS, "Total length %u RFC1002 length %u mismatch mid %llu\n",
			 length, 4 + len, mid);
		return 1;
	}

	clc_len = smb2_calc_size(hdr);

	if (4 + len != clc_len) {
		cifs_dbg(FYI, "Calculated size %u length %u mismatch mid %llu\n",
			 clc_len, 4 + len, mid);
		/* create failed on symlink */
		if (command == SMB2_CREATE_HE &&
		    hdr->Status == STATUS_STOPPED_ON_SYMLINK)
			return 0;
		/* Windows 7 server returns 24 bytes more */
		if (clc_len + 20 == len && command == SMB2_OPLOCK_BREAK_HE)
			return 0;
		/* server can return one byte more */
		if (clc_len == 4 + len + 1)
			return 0;
		return 1;
	}
	return 0;
}

/*
 * The size of the variable area depends on the offset and length fields
 * located in different fields for various SMB2 responses. SMB2 responses
 * with no variable length info, show an offset of zero for the offset field.
 */
static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
	/* SMB2_NEGOTIATE */ true,
	/* SMB2_SESSION_SETUP */ true,
	/* SMB2_LOGOFF */ false,
	/* SMB2_TREE_CONNECT */	false,
	/* SMB2_TREE_DISCONNECT */ false,
	/* SMB2_CREATE */ true,
	/* SMB2_CLOSE */ false,
	/* SMB2_FLUSH */ false,
	/* SMB2_READ */	true,
	/* SMB2_WRITE */ false,
	/* SMB2_LOCK */	false,
	/* SMB2_IOCTL */ true,
	/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
	/* SMB2_ECHO */ false,
	/* SMB2_QUERY_DIRECTORY */ true,
	/* SMB2_CHANGE_NOTIFY */ true,
	/* SMB2_QUERY_INFO */ true,
	/* SMB2_SET_INFO */ false,
	/* SMB2_OPLOCK_BREAK */ false
};

/*
 * Returns the pointer to the beginning of the data area. Length of the data
 * area and the offset to it (from the beginning of the smb are also returned.
 */
char *
smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *hdr)
{
	*off = 0;
	*len = 0;

	/* error responses do not have data area */
	if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
	    (((struct smb2_err_rsp *)hdr)->StructureSize) ==
						SMB2_ERROR_STRUCTURE_SIZE2)
		return NULL;

	/*
	 * Following commands have data areas so we have to get the location
	 * of the data buffer offset and data buffer length for the particular
	 * command.
	 */
	switch (hdr->Command) {
	case SMB2_NEGOTIATE:
		*off = le16_to_cpu(
		    ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferOffset);
		*len = le16_to_cpu(
		    ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferLength);
		break;
	case SMB2_SESSION_SETUP:
		*off = le16_to_cpu(
		    ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferOffset);
		*len = le16_to_cpu(
		    ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferLength);
		break;
	case SMB2_CREATE:
		*off = le32_to_cpu(
		    ((struct smb2_create_rsp *)hdr)->CreateContextsOffset);
		*len = le32_to_cpu(
		    ((struct smb2_create_rsp *)hdr)->CreateContextsLength);
		break;
	case SMB2_QUERY_INFO:
		*off = le16_to_cpu(
		    ((struct smb2_query_info_rsp *)hdr)->OutputBufferOffset);
		*len = le32_to_cpu(
		    ((struct smb2_query_info_rsp *)hdr)->OutputBufferLength);
		break;
	case SMB2_READ:
		*off = ((struct smb2_read_rsp *)hdr)->DataOffset;
		*len = le32_to_cpu(((struct smb2_read_rsp *)hdr)->DataLength);
		break;
	case SMB2_QUERY_DIRECTORY:
		*off = le16_to_cpu(
		  ((struct smb2_query_directory_rsp *)hdr)->OutputBufferOffset);
		*len = le32_to_cpu(
		  ((struct smb2_query_directory_rsp *)hdr)->OutputBufferLength);
		break;
	case SMB2_IOCTL:
		*off = le32_to_cpu(
		  ((struct smb2_ioctl_rsp *)hdr)->OutputOffset);
		*len = le32_to_cpu(((struct smb2_ioctl_rsp *)hdr)->OutputCount);
		break;
	case SMB2_CHANGE_NOTIFY:
	default:
		/* BB FIXME for unimplemented cases above */
		cifs_dbg(VFS, "no length check for command\n");
		break;
	}

	/*
	 * Invalid length or offset probably means data area is invalid, but
	 * we have little choice but to ignore the data area in this case.
	 */
	if (*off > 4096) {
		cifs_dbg(VFS, "offset %d too large, data area ignored\n", *off);
		*len = 0;
		*off = 0;
	} else if (*off < 0) {
		cifs_dbg(VFS, "negative offset %d to data invalid ignore data area\n",
			 *off);
		*off = 0;
		*len = 0;
	} else if (*len < 0) {
		cifs_dbg(VFS, "negative data length %d invalid, data area ignored\n",
			 *len);
		*len = 0;
	} else if (*len > 128 * 1024) {
		cifs_dbg(VFS, "data area larger than 128K: %d\n", *len);
		*len = 0;
	}

	/* return pointer to beginning of data area, ie offset from SMB start */
	if ((*off != 0) && (*len != 0))
		return hdr->ProtocolId + *off;
	else
		return NULL;
}

/*
 * Calculate the size of the SMB message based on the fixed header
 * portion, the number of word parameters and the data portion of the message.
 */
unsigned int
smb2_calc_size(void *buf)
{
	struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
	struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
	int offset; /* the offset from the beginning of SMB to data area */
	int data_length; /* the length of the variable length data area */
	/* Structure Size has already been checked to make sure it is 64 */
	int len = 4 + le16_to_cpu(pdu->hdr.StructureSize);

	/*
	 * StructureSize2, ie length of fixed parameter area has already
	 * been checked to make sure it is the correct length.
	 */
	len += le16_to_cpu(pdu->StructureSize2);

	if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false)
		goto calc_size_exit;

	smb2_get_data_area_len(&offset, &data_length, hdr);
	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);

	if (data_length > 0) {
		/*
		 * Check to make sure that data area begins after fixed area,
		 * Note that last byte of the fixed area is part of data area
		 * for some commands, typically those with odd StructureSize,
		 * so we must add one to the calculation (and 4 to account for
		 * the size of the RFC1001 hdr.
		 */
		if (offset + 4 + 1 < len) {
			cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
				 offset + 4 + 1, len);
			data_length = 0;
		} else {
			len = 4 + offset + data_length;
		}
	}
calc_size_exit:
	cifs_dbg(FYI, "SMB2 len %d\n", len);
	return len;
}

/* Note: caller must free return buffer */
__le16 *
cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
{
	int len;
	const char *start_of_path;
	__le16 *to;

	/* Windows doesn't allow paths beginning with \ */
	if (from[0] == '\\')
		start_of_path = from + 1;
	else
		start_of_path = from;
	to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
				   cifs_sb->local_nls,
				   cifs_sb->mnt_cifs_flags &
					CIFS_MOUNT_MAP_SPECIAL_CHR);
	return to;
}

__le32
smb2_get_lease_state(struct cifsInodeInfo *cinode)
{
	if (cinode->clientCanCacheAll)
		return SMB2_LEASE_WRITE_CACHING | SMB2_LEASE_READ_CACHING;
	else if (cinode->clientCanCacheRead)
		return SMB2_LEASE_READ_CACHING;
	return 0;
}

__u8 smb2_map_lease_to_oplock(__le32 lease_state)
{
	if (lease_state & SMB2_LEASE_WRITE_CACHING) {
		if (lease_state & SMB2_LEASE_HANDLE_CACHING)
			return SMB2_OPLOCK_LEVEL_BATCH;
		else
			return SMB2_OPLOCK_LEVEL_EXCLUSIVE;
	} else if (lease_state & SMB2_LEASE_READ_CACHING)
		return SMB2_OPLOCK_LEVEL_II;
	return 0;
}

struct smb2_lease_break_work {
	struct work_struct lease_break;
	struct tcon_link *tlink;
	__u8 lease_key[16];
	__le32 lease_state;
};

static void
cifs_ses_oplock_break(struct work_struct *work)
{
	struct smb2_lease_break_work *lw = container_of(work,
				struct smb2_lease_break_work, lease_break);
	int rc;

	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
			      lw->lease_state);
	cifs_dbg(FYI, "Lease release rc %d\n", rc);
	cifs_put_tlink(lw->tlink);
	kfree(lw);
}

static bool
smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
{
	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
	struct list_head *tmp, *tmp1, *tmp2;
	struct cifs_ses *ses;
	struct cifs_tcon *tcon;
	struct cifsInodeInfo *cinode;
	struct cifsFileInfo *cfile;
	struct cifs_pending_open *open;
	struct smb2_lease_break_work *lw;
	bool found;
	int ack_req = le32_to_cpu(rsp->Flags &
				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);

	lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
	if (!lw)
		return false;

	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
	lw->lease_state = rsp->NewLeaseState;

	cifs_dbg(FYI, "Checking for lease break\n");

	/* look up tcon based on tid & uid */
	spin_lock(&cifs_tcp_ses_lock);
	list_for_each(tmp, &server->smb_ses_list) {
		ses = list_entry(tmp, struct cifs_ses, smb_ses_list);

		spin_lock(&cifs_file_list_lock);
		list_for_each(tmp1, &ses->tcon_list) {
			tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);

			cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
			list_for_each(tmp2, &tcon->openFileList) {
				cfile = list_entry(tmp2, struct cifsFileInfo,
						   tlist);
				cinode = CIFS_I(cfile->dentry->d_inode);

				if (memcmp(cinode->lease_key, rsp->LeaseKey,
					   SMB2_LEASE_KEY_SIZE))
					continue;

				cifs_dbg(FYI, "found in the open list\n");
				cifs_dbg(FYI, "lease key match, lease break 0x%d\n",
					 le32_to_cpu(rsp->NewLeaseState));

				smb2_set_oplock_level(cinode,
				  smb2_map_lease_to_oplock(rsp->NewLeaseState));

				if (ack_req)
					cfile->oplock_break_cancelled = false;
				else
					cfile->oplock_break_cancelled = true;

				queue_work(cifsiod_wq, &cfile->oplock_break);

				kfree(lw);
				spin_unlock(&cifs_file_list_lock);
				spin_unlock(&cifs_tcp_ses_lock);
				return true;
			}

			found = false;
			list_for_each_entry(open, &tcon->pending_opens, olist) {
				if (memcmp(open->lease_key, rsp->LeaseKey,
					   SMB2_LEASE_KEY_SIZE))
					continue;

				if (!found && ack_req) {
					found = true;
					memcpy(lw->lease_key, open->lease_key,
					       SMB2_LEASE_KEY_SIZE);
					lw->tlink = cifs_get_tlink(open->tlink);
					queue_work(cifsiod_wq,
						   &lw->lease_break);
				}

				cifs_dbg(FYI, "found in the pending open list\n");
				cifs_dbg(FYI, "lease key match, lease break 0x%d\n",
					 le32_to_cpu(rsp->NewLeaseState));

				open->oplock =
				  smb2_map_lease_to_oplock(rsp->NewLeaseState);
			}
			if (found) {
				spin_unlock(&cifs_file_list_lock);
				spin_unlock(&cifs_tcp_ses_lock);
				return true;
			}
		}
		spin_unlock(&cifs_file_list_lock);
	}
	spin_unlock(&cifs_tcp_ses_lock);
	kfree(lw);
	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
	return false;
}

bool
smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
{
	struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
	struct list_head *tmp, *tmp1, *tmp2;
	struct cifs_ses *ses;
	struct cifs_tcon *tcon;
	struct cifsInodeInfo *cinode;
	struct cifsFileInfo *cfile;

	cifs_dbg(FYI, "Checking for oplock break\n");

	if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
		return false;

	if (rsp->StructureSize !=
				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
		if (le16_to_cpu(rsp->StructureSize) == 44)
			return smb2_is_valid_lease_break(buffer, server);
		else
			return false;
	}

	cifs_dbg(FYI, "oplock level 0x%d\n", rsp->OplockLevel);

	/* look up tcon based on tid & uid */
	spin_lock(&cifs_tcp_ses_lock);
	list_for_each(tmp, &server->smb_ses_list) {
		ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
		list_for_each(tmp1, &ses->tcon_list) {
			tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);

			cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
			spin_lock(&cifs_file_list_lock);
			list_for_each(tmp2, &tcon->openFileList) {
				cfile = list_entry(tmp2, struct cifsFileInfo,
						     tlist);
				if (rsp->PersistentFid !=
				    cfile->fid.persistent_fid ||
				    rsp->VolatileFid !=
				    cfile->fid.volatile_fid)
					continue;

				cifs_dbg(FYI, "file id match, oplock break\n");
				cinode = CIFS_I(cfile->dentry->d_inode);

				if (!cinode->clientCanCacheAll &&
				    rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
					cfile->oplock_break_cancelled = true;
				else
					cfile->oplock_break_cancelled = false;

				smb2_set_oplock_level(cinode,
				  rsp->OplockLevel ? SMB2_OPLOCK_LEVEL_II : 0);

				queue_work(cifsiod_wq, &cfile->oplock_break);

				spin_unlock(&cifs_file_list_lock);
				spin_unlock(&cifs_tcp_ses_lock);
				return true;
			}
			spin_unlock(&cifs_file_list_lock);
			spin_unlock(&cifs_tcp_ses_lock);
			cifs_dbg(FYI, "No matching file for oplock break\n");
			return true;
		}
	}
	spin_unlock(&cifs_tcp_ses_lock);
	cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
	return false;
}
Commit	Line	Data
093b2bda PS	1	/*
	2	* fs/cifs/smb2misc.c
	3	*
	4	* Copyright (C) International Business Machines Corp., 2002,2011
	5	* Etersoft, 2012
	6	* Author(s): Steve French (sfrench@us.ibm.com)
	7	* Pavel Shilovsky (pshilovsky@samba.org) 2012
	8	*
	9	* This library is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU Lesser General Public License as published
	11	* by the Free Software Foundation; either version 2.1 of the License, or
	12	* (at your option) any later version.
	13	*
	14	* This library is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
	17	* the GNU Lesser General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU Lesser General Public License
	20	* along with this library; if not, write to the Free Software
	21	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	22	*/
	23	#include <linux/ctype.h>
	24	#include "smb2pdu.h"
	25	#include "cifsglob.h"
	26	#include "cifsproto.h"
	27	#include "smb2proto.h"
	28	#include "cifs_debug.h"
	29	#include "cifs_unicode.h"
	30	#include "smb2status.h"
	31
	32	static int
	33	check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
	34	{
	35	/*
	36	* Make sure that this really is an SMB, that it is a response,
	37	* and that the message ids match.
	38	*/
	39	if (((__le32 )hdr->ProtocolId == SMB2_PROTO_NUMBER) &&
	40	(mid == hdr->MessageId)) {
	41	if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
	42	return 0;
	43	else {
	44	/* only one valid case where server sends us request */
	45	if (hdr->Command == SMB2_OPLOCK_BREAK)
	46	return 0;
	47	else
f96637be	48	cifs_dbg(VFS, "Received Request not response\n");
093b2bda PS	49	}
	50	} else { /* bad signature or mid */
	51	if ((__le32 )hdr->ProtocolId != SMB2_PROTO_NUMBER)
f96637be JP	52	cifs_dbg(VFS, "Bad protocol string signature header %x\n",
f96637be JP	53	(unsigned int ) hdr->ProtocolId);
093b2bda	54	if (mid != hdr->MessageId)
f96637be JP	55	cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
f96637be JP	56	mid, hdr->MessageId);
093b2bda	57	}
f96637be	58	cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", hdr->MessageId);
093b2bda PS	59	return 1;
	60	}
	61
	62	/*
	63	* The following table defines the expected "StructureSize" of SMB2 responses
	64	* in order by SMB2 command. This is similar to "wct" in SMB/CIFS responses.
	65	*
	66	* Note that commands are defined in smb2pdu.h in le16 but the array below is
	67	* indexed by command in host byte order
	68	*/
	69	static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
	70	/* SMB2_NEGOTIATE */ __constant_cpu_to_le16(65),
	71	/* SMB2_SESSION_SETUP */ __constant_cpu_to_le16(9),
	72	/* SMB2_LOGOFF */ __constant_cpu_to_le16(4),
	73	/* SMB2_TREE_CONNECT */ __constant_cpu_to_le16(16),
	74	/* SMB2_TREE_DISCONNECT */ __constant_cpu_to_le16(4),
	75	/* SMB2_CREATE */ __constant_cpu_to_le16(89),
	76	/* SMB2_CLOSE */ __constant_cpu_to_le16(60),
	77	/* SMB2_FLUSH */ __constant_cpu_to_le16(4),
	78	/* SMB2_READ */ __constant_cpu_to_le16(17),
	79	/* SMB2_WRITE */ __constant_cpu_to_le16(17),
	80	/* SMB2_LOCK */ __constant_cpu_to_le16(4),
	81	/* SMB2_IOCTL */ __constant_cpu_to_le16(49),
	82	/* BB CHECK this ... not listed in documentation */
	83	/* SMB2_CANCEL */ __constant_cpu_to_le16(0),
	84	/* SMB2_ECHO */ __constant_cpu_to_le16(4),
	85	/* SMB2_QUERY_DIRECTORY */ __constant_cpu_to_le16(9),
	86	/* SMB2_CHANGE_NOTIFY */ __constant_cpu_to_le16(9),
	87	/* SMB2_QUERY_INFO */ __constant_cpu_to_le16(9),
	88	/* SMB2_SET_INFO */ __constant_cpu_to_le16(2),
	89	/* BB FIXME can also be 44 for lease break */
	90	/* SMB2_OPLOCK_BREAK */ __constant_cpu_to_le16(24)
	91	};
	92
	93	int
	94	smb2_check_message(char *buf, unsigned int length)
	95	{
	96	struct smb2_hdr hdr = (struct smb2_hdr )buf;
	97	struct smb2_pdu pdu = (struct smb2_pdu )hdr;
	98	__u64 mid = hdr->MessageId;
	99	__u32 len = get_rfc1002_length(buf);
	100	__u32 clc_len; /* calculated length */
	101	int command;
	102
	103	/* BB disable following printk later */
f96637be JP	104	cifs_dbg(FYI, "%s length: 0x%x, smb_buf_length: 0x%x\n",
f96637be JP	105	__func__, length, len);
093b2bda PS	106
	107	/*
	108	* Add function to do table lookup of StructureSize by command
	109	* ie Validate the wct via smb2_struct_sizes table above
	110	*/
	111
74112860	112	if (length < sizeof(struct smb2_pdu)) {
093b2bda PS	113	if ((length >= sizeof(struct smb2_hdr)) && (hdr->Status != 0)) {
	114	pdu->StructureSize2 = 0;
	115	/*
	116	* As with SMB/CIFS, on some error cases servers may
	117	* not return wct properly
	118	*/
	119	return 0;
	120	} else {
f96637be	121	cifs_dbg(VFS, "Length less than SMB header size\n");
093b2bda PS	122	}
	123	return 1;
	124	}
	125	if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE - 4) {
f96637be JP	126	cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
f96637be JP	127	mid);
093b2bda PS	128	return 1;
	129	}
	130
	131	if (check_smb2_hdr(hdr, mid))
	132	return 1;
	133
74112860	134	if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
f96637be JP	135	cifs_dbg(VFS, "Illegal structure size %u\n",
f96637be JP	136	le16_to_cpu(hdr->StructureSize));
093b2bda PS	137	return 1;
	138	}
	139
	140	command = le16_to_cpu(hdr->Command);
	141	if (command >= NUMBER_OF_SMB2_COMMANDS) {
f96637be	142	cifs_dbg(VFS, "Illegal SMB2 command %d\n", command);
093b2bda PS	143	return 1;
	144	}
	145
	146	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
983c88a4 PS	147	if (command != SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0 \|\|
983c88a4 PS	148	pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2)) {
093b2bda	149	/* error packets have 9 byte structure size */
f96637be JP	150	cifs_dbg(VFS, "Illegal response size %u for command %d\n",
f96637be JP	151	le16_to_cpu(pdu->StructureSize2), command);
093b2bda	152	return 1;
0822f514 PS	153	} else if (command == SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0)
	154	&& (le16_to_cpu(pdu->StructureSize2) != 44)
	155	&& (le16_to_cpu(pdu->StructureSize2) != 36)) {
	156	/* special case for SMB2.1 lease break message */
f96637be JP	157	cifs_dbg(VFS, "Illegal response size %d for oplock break\n",
f96637be JP	158	le16_to_cpu(pdu->StructureSize2));
0822f514	159	return 1;
093b2bda PS	160	}
	161	}
	162
	163	if (4 + len != length) {
f96637be JP	164	cifs_dbg(VFS, "Total length %u RFC1002 length %u mismatch mid %llu\n",
f96637be JP	165	length, 4 + len, mid);
093b2bda PS	166	return 1;
	167	}
	168
	169	clc_len = smb2_calc_size(hdr);
	170
	171	if (4 + len != clc_len) {
f96637be JP	172	cifs_dbg(FYI, "Calculated size %u length %u mismatch mid %llu\n",
f96637be JP	173	clc_len, 4 + len, mid);
b42bf888 PS	174	/* create failed on symlink */
	175	if (command == SMB2_CREATE_HE &&
	176	hdr->Status == STATUS_STOPPED_ON_SYMLINK)
	177	return 0;
983c88a4 PS	178	/* Windows 7 server returns 24 bytes more */
	179	if (clc_len + 20 == len && command == SMB2_OPLOCK_BREAK_HE)
	180	return 0;
74112860 PS	181	/* server can return one byte more */
	182	if (clc_len == 4 + len + 1)
	183	return 0;
093b2bda PS	184	return 1;
	185	}
	186	return 0;
	187	}
	188
	189	/*
	190	* The size of the variable area depends on the offset and length fields
	191	* located in different fields for various SMB2 responses. SMB2 responses
	192	* with no variable length info, show an offset of zero for the offset field.
	193	*/
	194	static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
	195	/* SMB2_NEGOTIATE */ true,
	196	/* SMB2_SESSION_SETUP */ true,
	197	/* SMB2_LOGOFF */ false,
	198	/* SMB2_TREE_CONNECT */ false,
	199	/* SMB2_TREE_DISCONNECT */ false,
	200	/* SMB2_CREATE */ true,
	201	/* SMB2_CLOSE */ false,
	202	/* SMB2_FLUSH */ false,
	203	/* SMB2_READ */ true,
	204	/* SMB2_WRITE */ false,
	205	/* SMB2_LOCK */ false,
	206	/* SMB2_IOCTL */ true,
	207	/* SMB2_CANCEL / false, / BB CHECK this not listed in documentation */
	208	/* SMB2_ECHO */ false,
	209	/* SMB2_QUERY_DIRECTORY */ true,
	210	/* SMB2_CHANGE_NOTIFY */ true,
	211	/* SMB2_QUERY_INFO */ true,
	212	/* SMB2_SET_INFO */ false,
	213	/* SMB2_OPLOCK_BREAK */ false
	214	};
	215
	216	/*
	217	* Returns the pointer to the beginning of the data area. Length of the data
	218	* area and the offset to it (from the beginning of the smb are also returned.
	219	*/
ec2e4523	220	char *
093b2bda PS	221	smb2_get_data_area_len(int off, int len, struct smb2_hdr *hdr)
	222	{
	223	*off = 0;
	224	*len = 0;
	225
	226	/* error responses do not have data area */
	227	if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
	228	(((struct smb2_err_rsp *)hdr)->StructureSize) ==
	229	SMB2_ERROR_STRUCTURE_SIZE2)
	230	return NULL;
	231
	232	/*
	233	* Following commands have data areas so we have to get the location
	234	* of the data buffer offset and data buffer length for the particular
	235	* command.
	236	*/
	237	switch (hdr->Command) {
	238	case SMB2_NEGOTIATE:
ec2e4523 PS	239	*off = le16_to_cpu(
	240	((struct smb2_negotiate_rsp *)hdr)->SecurityBufferOffset);
	241	*len = le16_to_cpu(
	242	((struct smb2_negotiate_rsp *)hdr)->SecurityBufferLength);
	243	break;
093b2bda	244	case SMB2_SESSION_SETUP:
5478f9ba PS	245	*off = le16_to_cpu(
	246	((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferOffset);
	247	*len = le16_to_cpu(
	248	((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferLength);
	249	break;
093b2bda	250	case SMB2_CREATE:
2503a0db PS	251	*off = le32_to_cpu(
	252	((struct smb2_create_rsp *)hdr)->CreateContextsOffset);
	253	*len = le32_to_cpu(
	254	((struct smb2_create_rsp *)hdr)->CreateContextsLength);
	255	break;
093b2bda	256	case SMB2_QUERY_INFO:
be4cb9e3 PS	257	*off = le16_to_cpu(
	258	((struct smb2_query_info_rsp *)hdr)->OutputBufferOffset);
	259	*len = le32_to_cpu(
	260	((struct smb2_query_info_rsp *)hdr)->OutputBufferLength);
	261	break;
	262	case SMB2_READ:
09a4707e PS	263	off = ((struct smb2_read_rsp )hdr)->DataOffset;
	264	len = le32_to_cpu(((struct smb2_read_rsp )hdr)->DataLength);
	265	break;
093b2bda	266	case SMB2_QUERY_DIRECTORY:
d324f08d PS	267	*off = le16_to_cpu(
	268	((struct smb2_query_directory_rsp *)hdr)->OutputBufferOffset);
	269	*len = le32_to_cpu(
	270	((struct smb2_query_directory_rsp *)hdr)->OutputBufferLength);
	271	break;
093b2bda	272	case SMB2_IOCTL:
4a72dafa SF	273	*off = le32_to_cpu(
	274	((struct smb2_ioctl_rsp *)hdr)->OutputOffset);
	275	len = le32_to_cpu(((struct smb2_ioctl_rsp )hdr)->OutputCount);
	276	break;
093b2bda PS	277	case SMB2_CHANGE_NOTIFY:
	278	default:
	279	/* BB FIXME for unimplemented cases above */
f96637be	280	cifs_dbg(VFS, "no length check for command\n");
093b2bda PS	281	break;
	282	}
	283
	284	/*
	285	* Invalid length or offset probably means data area is invalid, but
	286	* we have little choice but to ignore the data area in this case.
	287	*/
	288	if (*off > 4096) {
f96637be	289	cifs_dbg(VFS, "offset %d too large, data area ignored\n", *off);
093b2bda PS	290	*len = 0;
	291	*off = 0;
	292	} else if (*off < 0) {
f96637be JP	293	cifs_dbg(VFS, "negative offset %d to data invalid ignore data area\n",
f96637be JP	294	*off);
093b2bda PS	295	*off = 0;
	296	*len = 0;
	297	} else if (*len < 0) {
f96637be JP	298	cifs_dbg(VFS, "negative data length %d invalid, data area ignored\n",
f96637be JP	299	*len);
093b2bda PS	300	*len = 0;
093b2bda PS	301	} else if (len > 128 1024) {
f96637be	302	cifs_dbg(VFS, "data area larger than 128K: %d\n", *len);
093b2bda PS	303	*len = 0;
	304	}
	305
	306	/* return pointer to beginning of data area, ie offset from SMB start */
	307	if ((off != 0) && (len != 0))
	308	return hdr->ProtocolId + *off;
	309	else
	310	return NULL;
	311	}
	312
	313	/*
	314	* Calculate the size of the SMB message based on the fixed header
	315	* portion, the number of word parameters and the data portion of the message.
	316	*/
	317	unsigned int
d324f08d	318	smb2_calc_size(void *buf)
093b2bda	319	{
d324f08d	320	struct smb2_hdr hdr = (struct smb2_hdr )buf;
093b2bda PS	321	struct smb2_pdu pdu = (struct smb2_pdu )hdr;
	322	int offset; /* the offset from the beginning of SMB to data area */
	323	int data_length; /* the length of the variable length data area */
	324	/* Structure Size has already been checked to make sure it is 64 */
	325	int len = 4 + le16_to_cpu(pdu->hdr.StructureSize);
	326
	327	/*
	328	* StructureSize2, ie length of fixed parameter area has already
	329	* been checked to make sure it is the correct length.
	330	*/
	331	len += le16_to_cpu(pdu->StructureSize2);
	332
	333	if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false)
	334	goto calc_size_exit;
	335
	336	smb2_get_data_area_len(&offset, &data_length, hdr);
f96637be	337	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
093b2bda PS	338
	339	if (data_length > 0) {
	340	/*
	341	* Check to make sure that data area begins after fixed area,
	342	* Note that last byte of the fixed area is part of data area
	343	* for some commands, typically those with odd StructureSize,
	344	* so we must add one to the calculation (and 4 to account for
	345	* the size of the RFC1001 hdr.
	346	*/
	347	if (offset + 4 + 1 < len) {
f96637be JP	348	cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
f96637be JP	349	offset + 4 + 1, len);
093b2bda PS	350	data_length = 0;
	351	} else {
	352	len = 4 + offset + data_length;
	353	}
	354	}
	355	calc_size_exit:
f96637be	356	cifs_dbg(FYI, "SMB2 len %d\n", len);
093b2bda PS	357	return len;
093b2bda PS	358	}
2503a0db PS	359
	360	/* Note: caller must free return buffer */
	361	__le16 *
	362	cifs_convert_path_to_utf16(const char from, struct cifs_sb_info cifs_sb)
	363	{
	364	int len;
	365	const char *start_of_path;
	366	__le16 *to;
	367
	368	/* Windows doesn't allow paths beginning with \ */
	369	if (from[0] == '\\')
	370	start_of_path = from + 1;
	371	else
	372	start_of_path = from;
	373	to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
	374	cifs_sb->local_nls,
	375	cifs_sb->mnt_cifs_flags &
	376	CIFS_MOUNT_MAP_SPECIAL_CHR);
	377	return to;
	378	}
983c88a4	379
0822f514 PS	380	__le32
	381	smb2_get_lease_state(struct cifsInodeInfo *cinode)
	382	{
	383	if (cinode->clientCanCacheAll)
	384	return SMB2_LEASE_WRITE_CACHING \| SMB2_LEASE_READ_CACHING;
	385	else if (cinode->clientCanCacheRead)
	386	return SMB2_LEASE_READ_CACHING;
	387	return 0;
	388	}
	389
	390	__u8 smb2_map_lease_to_oplock(__le32 lease_state)
	391	{
	392	if (lease_state & SMB2_LEASE_WRITE_CACHING) {
	393	if (lease_state & SMB2_LEASE_HANDLE_CACHING)
	394	return SMB2_OPLOCK_LEVEL_BATCH;
	395	else
	396	return SMB2_OPLOCK_LEVEL_EXCLUSIVE;
	397	} else if (lease_state & SMB2_LEASE_READ_CACHING)
	398	return SMB2_OPLOCK_LEVEL_II;
	399	return 0;
	400	}
	401
233839b1 PS	402	struct smb2_lease_break_work {
	403	struct work_struct lease_break;
	404	struct tcon_link *tlink;
	405	__u8 lease_key[16];
	406	__le32 lease_state;
	407	};
	408
	409	static void
	410	cifs_ses_oplock_break(struct work_struct *work)
	411	{
	412	struct smb2_lease_break_work *lw = container_of(work,
	413	struct smb2_lease_break_work, lease_break);
	414	int rc;
	415
	416	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
	417	lw->lease_state);
f96637be	418	cifs_dbg(FYI, "Lease release rc %d\n", rc);
233839b1 PS	419	cifs_put_tlink(lw->tlink);
	420	kfree(lw);
	421	}
	422
0822f514 PS	423	static bool
	424	smb2_is_valid_lease_break(char buffer, struct TCP_Server_Info server)
	425	{
	426	struct smb2_lease_break rsp = (struct smb2_lease_break )buffer;
	427	struct list_head tmp, tmp1, *tmp2;
	428	struct cifs_ses *ses;
	429	struct cifs_tcon *tcon;
	430	struct cifsInodeInfo *cinode;
	431	struct cifsFileInfo *cfile;
233839b1 PS	432	struct cifs_pending_open *open;
	433	struct smb2_lease_break_work *lw;
	434	bool found;
12e8a208 SF	435	int ack_req = le32_to_cpu(rsp->Flags &
12e8a208 SF	436	SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
233839b1 PS	437
233839b1 PS	438	lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
f96637be	439	if (!lw)
233839b1	440	return false;
233839b1 PS	441
	442	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
	443	lw->lease_state = rsp->NewLeaseState;
0822f514	444
f96637be	445	cifs_dbg(FYI, "Checking for lease break\n");
0822f514 PS	446
	447	/* look up tcon based on tid & uid */
	448	spin_lock(&cifs_tcp_ses_lock);
	449	list_for_each(tmp, &server->smb_ses_list) {
	450	ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
233839b1 PS	451
233839b1 PS	452	spin_lock(&cifs_file_list_lock);
0822f514 PS	453	list_for_each(tmp1, &ses->tcon_list) {
	454	tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
	455
	456	cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
0822f514 PS	457	list_for_each(tmp2, &tcon->openFileList) {
0822f514 PS	458	cfile = list_entry(tmp2, struct cifsFileInfo,
233839b1	459	tlist);
0822f514 PS	460	cinode = CIFS_I(cfile->dentry->d_inode);
	461
	462	if (memcmp(cinode->lease_key, rsp->LeaseKey,
	463	SMB2_LEASE_KEY_SIZE))
	464	continue;
	465
f96637be JP	466	cifs_dbg(FYI, "found in the open list\n");
	467	cifs_dbg(FYI, "lease key match, lease break 0x%d\n",
	468	le32_to_cpu(rsp->NewLeaseState));
0822f514 PS	469
	470	smb2_set_oplock_level(cinode,
	471	smb2_map_lease_to_oplock(rsp->NewLeaseState));
	472
233839b1	473	if (ack_req)
0822f514 PS	474	cfile->oplock_break_cancelled = false;
	475	else
	476	cfile->oplock_break_cancelled = true;
	477
	478	queue_work(cifsiod_wq, &cfile->oplock_break);
	479
1a05096d	480	kfree(lw);
0822f514 PS	481	spin_unlock(&cifs_file_list_lock);
	482	spin_unlock(&cifs_tcp_ses_lock);
	483	return true;
	484	}
233839b1 PS	485
	486	found = false;
	487	list_for_each_entry(open, &tcon->pending_opens, olist) {
	488	if (memcmp(open->lease_key, rsp->LeaseKey,
	489	SMB2_LEASE_KEY_SIZE))
	490	continue;
	491
	492	if (!found && ack_req) {
	493	found = true;
	494	memcpy(lw->lease_key, open->lease_key,
	495	SMB2_LEASE_KEY_SIZE);
	496	lw->tlink = cifs_get_tlink(open->tlink);
	497	queue_work(cifsiod_wq,
	498	&lw->lease_break);
	499	}
	500
f96637be JP	501	cifs_dbg(FYI, "found in the pending open list\n");
	502	cifs_dbg(FYI, "lease key match, lease break 0x%d\n",
	503	le32_to_cpu(rsp->NewLeaseState));
233839b1 PS	504
	505	open->oplock =
	506	smb2_map_lease_to_oplock(rsp->NewLeaseState);
	507	}
	508	if (found) {
	509	spin_unlock(&cifs_file_list_lock);
	510	spin_unlock(&cifs_tcp_ses_lock);
	511	return true;
	512	}
0822f514	513	}
233839b1	514	spin_unlock(&cifs_file_list_lock);
0822f514 PS	515	}
0822f514 PS	516	spin_unlock(&cifs_tcp_ses_lock);
233839b1	517	kfree(lw);
f96637be	518	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
0822f514 PS	519	return false;
	520	}
	521
983c88a4 PS	522	bool
	523	smb2_is_valid_oplock_break(char buffer, struct TCP_Server_Info server)
	524	{
	525	struct smb2_oplock_break rsp = (struct smb2_oplock_break )buffer;
	526	struct list_head tmp, tmp1, *tmp2;
	527	struct cifs_ses *ses;
	528	struct cifs_tcon *tcon;
	529	struct cifsInodeInfo *cinode;
	530	struct cifsFileInfo *cfile;
	531
f96637be	532	cifs_dbg(FYI, "Checking for oplock break\n");
983c88a4 PS	533
	534	if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
	535	return false;
	536
12e8a208	537	if (rsp->StructureSize !=
983c88a4	538	smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
0822f514 PS	539	if (le16_to_cpu(rsp->StructureSize) == 44)
	540	return smb2_is_valid_lease_break(buffer, server);
	541	else
	542	return false;
983c88a4 PS	543	}
983c88a4 PS	544
f96637be	545	cifs_dbg(FYI, "oplock level 0x%d\n", rsp->OplockLevel);
983c88a4 PS	546
	547	/* look up tcon based on tid & uid */
	548	spin_lock(&cifs_tcp_ses_lock);
	549	list_for_each(tmp, &server->smb_ses_list) {
	550	ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
	551	list_for_each(tmp1, &ses->tcon_list) {
	552	tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
	553
	554	cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
	555	spin_lock(&cifs_file_list_lock);
	556	list_for_each(tmp2, &tcon->openFileList) {
	557	cfile = list_entry(tmp2, struct cifsFileInfo,
	558	tlist);
	559	if (rsp->PersistentFid !=
	560	cfile->fid.persistent_fid \|\|
	561	rsp->VolatileFid !=
	562	cfile->fid.volatile_fid)
	563	continue;
	564
f96637be	565	cifs_dbg(FYI, "file id match, oplock break\n");
983c88a4 PS	566	cinode = CIFS_I(cfile->dentry->d_inode);
	567
	568	if (!cinode->clientCanCacheAll &&
	569	rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
	570	cfile->oplock_break_cancelled = true;
	571	else
	572	cfile->oplock_break_cancelled = false;
	573
	574	smb2_set_oplock_level(cinode,
	575	rsp->OplockLevel ? SMB2_OPLOCK_LEVEL_II : 0);
	576
	577	queue_work(cifsiod_wq, &cfile->oplock_break);
	578
	579	spin_unlock(&cifs_file_list_lock);
	580	spin_unlock(&cifs_tcp_ses_lock);
	581	return true;
	582	}
	583	spin_unlock(&cifs_file_list_lock);
	584	spin_unlock(&cifs_tcp_ses_lock);
f96637be	585	cifs_dbg(FYI, "No matching file for oplock break\n");
983c88a4 PS	586	return true;
	587	}
	588	}
	589	spin_unlock(&cifs_tcp_ses_lock);
f96637be	590	cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
983c88a4 PS	591	return false;
983c88a4 PS	592	}