path: root/fs/cifs/smb2pdu.c

/*
 *   fs/cifs/smb2pdu.c
 *
 *   Copyright (C) International Business Machines  Corp., 2009, 2011
 *                 Etersoft, 2012
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *              Pavel Shilovsky (pshilovsky@samba.org) 2012
 *
 *   Contains the routines for constructing the SMB2 PDUs themselves
 *
 *   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
 */

 /* SMB2 PDU handling routines here - except for leftovers (eg session setup) */
 /* Note that there are handle based routines which must be		      */
 /* treated slightly differently for reconnection purposes since we never     */
 /* want to reuse a stale file handle and only the caller knows the file info */

#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/vfs.h>
#include <linux/uaccess.h>
#include <linux/xattr.h>
#include "smb2pdu.h"
#include "cifsglob.h"
#include "cifsacl.h"
#include "cifsproto.h"
#include "smb2proto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "ntlmssp.h"
#include "smb2status.h"

/*
 *  The following table defines the expected "StructureSize" of SMB2 requests
 *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS requests.
 *
 *  Note that commands are defined in smb2pdu.h in le16 but the array below is
 *  indexed by command in host byte order.
 */
static const int smb2_req_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
	/* SMB2_NEGOTIATE */ 36,
	/* SMB2_SESSION_SETUP */ 25,
	/* SMB2_LOGOFF */ 4,
	/* SMB2_TREE_CONNECT */	9,
	/* SMB2_TREE_DISCONNECT */ 4,
	/* SMB2_CREATE */ 57,
	/* SMB2_CLOSE */ 24,
	/* SMB2_FLUSH */ 24,
	/* SMB2_READ */	49,
	/* SMB2_WRITE */ 49,
	/* SMB2_LOCK */	48,
	/* SMB2_IOCTL */ 57,
	/* SMB2_CANCEL */ 4,
	/* SMB2_ECHO */ 4,
	/* SMB2_QUERY_DIRECTORY */ 33,
	/* SMB2_CHANGE_NOTIFY */ 32,
	/* SMB2_QUERY_INFO */ 41,
	/* SMB2_SET_INFO */ 33,
	/* SMB2_OPLOCK_BREAK */ 24 /* BB this is 36 for LEASE_BREAK variant */
};


static void
smb2_hdr_assemble(struct smb2_hdr *hdr, __le16 smb2_cmd /* command */ ,
		  const struct cifs_tcon *tcon)
{
	struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
	char *temp = (char *)hdr;
	/* lookup word count ie StructureSize from table */
	__u16 parmsize = smb2_req_struct_sizes[le16_to_cpu(smb2_cmd)];

	/*
	 * smaller than SMALL_BUFFER_SIZE but bigger than fixed area of
	 * largest operations (Create)
	 */
	memset(temp, 0, 256);

	/* Note this is only network field converted to big endian */
	hdr->smb2_buf_length = cpu_to_be32(parmsize + sizeof(struct smb2_hdr)
			- 4 /*  RFC 1001 length field itself not counted */);

	hdr->ProtocolId[0] = 0xFE;
	hdr->ProtocolId[1] = 'S';
	hdr->ProtocolId[2] = 'M';
	hdr->ProtocolId[3] = 'B';
	hdr->StructureSize = cpu_to_le16(64);
	hdr->Command = smb2_cmd;
	hdr->CreditRequest = cpu_to_le16(2); /* BB make this dynamic */
	hdr->ProcessId = cpu_to_le32((__u16)current->tgid);

	if (!tcon)
		goto out;

	hdr->TreeId = tcon->tid;
	/* Uid is not converted */
	if (tcon->ses)
		hdr->SessionId = tcon->ses->Suid;
	/* BB check following DFS flags BB */
	/* BB do we have to add check for SHI1005_FLAGS_DFS_ROOT too? */
	if (tcon->share_flags & SHI1005_FLAGS_DFS)
		hdr->Flags |= SMB2_FLAGS_DFS_OPERATIONS;
	/* BB how does SMB2 do case sensitive? */
	/* if (tcon->nocase)
		hdr->Flags |= SMBFLG_CASELESS; */
	/* if (tcon->ses && tcon->ses->server &&
	    (tcon->ses->server->sec_mode & SECMODE_SIGN_REQUIRED))
		hdr->Flags |= SMB2_FLAGS_SIGNED; */
out:
	pdu->StructureSize2 = cpu_to_le16(parmsize);
	return;
}

static int
smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
{
	int rc = 0;
	struct nls_table *nls_codepage;
	struct cifs_ses *ses;
	struct TCP_Server_Info *server;

	/*
	 * SMB2s NegProt, SessSetup, Logoff do not have tcon yet so
	 * check for tcp and smb session status done differently
	 * for those three - in the calling routine.
	 */
	if (tcon == NULL)
		return rc;

	if (smb2_command == SMB2_TREE_CONNECT)
		return rc;

	if (tcon->tidStatus == CifsExiting) {
		/*
		 * only tree disconnect, open, and write,
		 * (and ulogoff which does not have tcon)
		 * are allowed as we start