/*
   *   fs/cifs/sess.c
   *
   *   SMB/CIFS session setup handling routines
   *

   *   Copyright (c) International Business Machines  Corp., 2006, 2009

   *   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 "cifspdu.h"
  #include "cifsglob.h"
  #include "cifsproto.h"
  #include "cifs_unicode.h"
  #include "cifs_debug.h"
  #include "ntlmssp.h"
  #include "nterr.h"

  #include <linux/utsname.h>

  #include <linux/slab.h>

  #include "cifs_spnego.h"

  static __u32 cifs_ssetup_hdr(struct cifs_ses *ses, SESSION_SETUP_ANDX *pSMB)

  {
  	__u32 capabilities = 0;
  
  	/* init fields common to all four types of SessSetup */

  	/* Note that offsets for first seven fields in req struct are same  */
  	/*	in CIFS Specs so does not matter which of 3 forms of struct */
  	/*	that we use in next few lines                               */
  	/* Note that header is initialized to zero in header_assemble */

  	pSMB->req.AndXCommand = 0xFF;

  	pSMB->req.MaxBufferSize = cpu_to_le16(min_t(u32,
  					CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4,
  					USHRT_MAX));

  	pSMB->req.MaxMpxCount = cpu_to_le16(ses->server->maxReq);

  	pSMB->req.VcNumber = cpu_to_le16(1);

  
  	/* Now no need to set SMBFLG_CASELESS or obsolete CANONICAL PATH */

  	/* BB verify whether signing required on neg or just on auth frame

  	   (and NTLM case) */
  
  	capabilities = CAP_LARGE_FILES | CAP_NT_SMBS | CAP_LEVEL_II_OPLOCKS |
  			CAP_LARGE_WRITE_X | CAP_LARGE_READ_X;

  	if (ses->server->sign)

  		pSMB->req.hdr.Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
  
  	if (ses->capabilities & CAP_UNICODE) {
  		pSMB->req.hdr.Flags2 |= SMBFLG2_UNICODE;
  		capabilities |= CAP_UNICODE;
  	}
  	if (ses->capabilities & CAP_STATUS32) {
  		pSMB->req.hdr.Flags2 |= SMBFLG2_ERR_STATUS;
  		capabilities |= CAP_STATUS32;
  	}
  	if (ses->capabilities & CAP_DFS) {
  		pSMB->req.hdr.Flags2 |= SMBFLG2_DFS;
  		capabilities |= CAP_DFS;
  	}

  	if (ses->capabilities & CAP_UNIX)

  		capabilities |= CAP_UNIX;

  	return capabilities;
  }

  static void
  unicode_oslm_strings(char **pbcc_area, const struct nls_table *nls_cp)
  {
  	char *bcc_ptr = *pbcc_area;
  	int bytes_ret = 0;
  
  	/* Copy OS version */

  	bytes_ret = cifs_strtoUTF16((__le16 *)bcc_ptr, "Linux version ", 32,
  				    nls_cp);

  	bcc_ptr += 2 * bytes_ret;

  	bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, init_utsname()->release,
  				    32, nls_cp);

  	bcc_ptr += 2 * bytes_ret;
  	bcc_ptr += 2; /* trailing null */

  	bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, CIFS_NETWORK_OPSYS,
  				    32, nls_cp);

  	bcc_ptr += 2 * bytes_ret;
  	bcc_ptr += 2; /* trailing null */
  
  	*pbcc_area = bcc_ptr;
  }

  static void unicode_domain_string(char **pbcc_area, struct cifs_ses *ses,

  				   const struct nls_table *nls_cp)
  {
  	char *bcc_ptr = *pbcc_area;
  	int bytes_ret = 0;
  
  	/* copy domain */
  	if (ses->domainName == NULL) {
  		/* Sending null domain better than using a bogus domain name (as
  		we did briefly in 2.6.18) since server will use its default */
  		*bcc_ptr = 0;
  		*(bcc_ptr+1) = 0;
  		bytes_ret = 0;
  	} else

  		bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->domainName,

  					    CIFS_MAX_DOMAINNAME_LEN, nls_cp);

  	bcc_ptr += 2 * bytes_ret;
  	bcc_ptr += 2;  /* account for null terminator */
  
  	*pbcc_area = bcc_ptr;
  }

  static void unicode_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,

  				   const struct nls_table *nls_cp)

  {

  	char *bcc_ptr = *pbcc_area;

  	int bytes_ret = 0;
  
  	/* BB FIXME add check that strings total less
  	than 335 or will need to send them as arrays */

  	/* unicode strings, must be word aligned before the call */
  /*	if ((long) bcc_ptr % 2)	{

  		*bcc_ptr = 0;
  		bcc_ptr++;

  	} */

  	/* copy user */

  	if (ses->user_name == NULL) {

  		/* null user mount */
  		*bcc_ptr = 0;
  		*(bcc_ptr+1) = 0;

  	} else {

  		bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->user_name,

  					    CIFS_MAX_USERNAME_LEN, nls_cp);

  	}
  	bcc_ptr += 2 * bytes_ret;
  	bcc_ptr += 2; /* account for null termination */

  	unicode_domain_string(&bcc_ptr, ses, nls_cp);
  	unicode_oslm_strings(&bcc_ptr, nls_cp);

  
  	*pbcc_area = bcc_ptr;
  }

  static void ascii_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,

  				 const struct nls_table *nls_cp)

  {

  	char *bcc_ptr = *pbcc_area;

  
  	/* copy user */
  	/* BB what about null user mounts - check that we do this BB */

  	/* copy user */

  	if (ses->user_name != NULL) {

  		strncpy(bcc_ptr, ses->user_name, CIFS_MAX_USERNAME_LEN);
  		bcc_ptr += strnlen(ses->user_name, CIFS_MAX_USERNAME_LEN);

  	}

  	/* else null user mount */

  	*bcc_ptr = 0;

  	bcc_ptr++; /* account for null termination */

  	/* copy domain */

  	if (ses->domainName != NULL) {

  		strncpy(bcc_ptr, ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
  		bcc_ptr += strnlen(ses->domainName, CIFS_MAX_DOMAINNAME_LEN);

  	} /* else we will send a null domain name

  	     so the server will default to its own domain */

  	*bcc_ptr = 0;
  	bcc_ptr++;
  
  	/* BB check for overflow here */
  
  	strcpy(bcc_ptr, "Linux version ");
  	bcc_ptr += strlen("Linux version ");

  	strcpy(bcc_ptr, init_utsname()->release);
  	bcc_ptr += strlen(init_utsname()->release) + 1;

  
  	strcpy(bcc_ptr, CIFS_NETWORK_OPSYS);
  	bcc_ptr += strlen(CIFS_NETWORK_OPSYS) + 1;

  	*pbcc_area = bcc_ptr;

  }

  static void

  decode_unicode_ssetup(char **pbcc_area, int bleft, struct cifs_ses *ses,

  		      const struct nls_table *nls_cp)

  {

  	int len;

  	char *data = *pbcc_area;

  	cifs_dbg(FYI, "bleft %d
  ", bleft);

  	kfree(ses->serverOS);

  	ses->serverOS = cifs_strndup_from_utf16(data, bleft, true, nls_cp);

  	cifs_dbg(FYI, "serverOS=%s
  ", ses->serverOS);

  	len = (UniStrnlen((wchar_t *) data, bleft / 2) * 2) + 2;
  	data += len;
  	bleft -= len;
  	if (bleft <= 0)
  		return;

  	kfree(ses->serverNOS);

  	ses->serverNOS = cifs_strndup_from_utf16(data, bleft, true, nls_cp);

  	cifs_dbg(FYI, "serverNOS=%s
  ", ses->serverNOS);

  	len = (UniStrnlen((wchar_t *) data, bleft / 2) * 2) + 2;
  	data += len;
  	bleft -= len;
  	if (bleft <= 0)
  		return;

  	kfree(ses->serverDomain);

  	ses->serverDomain = cifs_strndup_from_utf16(data, bleft, true, nls_cp);

  	cifs_dbg(FYI, "serverDomain=%s
  ", ses->serverDomain);

  	return;

  }

  static void decode_ascii_ssetup(char **pbcc_area, __u16 bleft,
  				struct cifs_ses *ses,
  				const struct nls_table *nls_cp)

  {

  	int len;

  	char *bcc_ptr = *pbcc_area;

  	cifs_dbg(FYI, "decode sessetup ascii. bleft %d
  ", bleft);

  	len = strnlen(bcc_ptr, bleft);

  	if (len >= bleft)

  		return;

  	kfree(ses->serverOS);

  
  	ses->serverOS = kzalloc(len + 1, GFP_KERNEL);

  	if (ses->serverOS) {

  		strncpy(ses->serverOS, bcc_ptr, len);

  		if (strncmp(ses->serverOS, "OS/2", 4) == 0)
  			cifs_dbg(FYI, "OS/2 server
  ");
  	}

  
  	bcc_ptr += len + 1;
  	bleft -= len + 1;
  
  	len = strnlen(bcc_ptr, bleft);

  	if (len >= bleft)

  		return;

  	kfree(ses->serverNOS);

  
  	ses->serverNOS = kzalloc(len + 1, GFP_KERNEL);

  	if (ses->serverNOS)

  		strncpy(ses->serverNOS, bcc_ptr, len);
  
  	bcc_ptr += len + 1;
  	bleft -= len + 1;

  	len = strnlen(bcc_ptr, bleft);
  	if (len > bleft)

  		return;

  	/* No domain field in LANMAN case. Domain is
  	   returned by old servers in the SMB negprot response */
  	/* BB For newer servers which do not support Unicode,
  	   but thus do return domain here we could add parsing
  	   for it later, but it is not very important */

  	cifs_dbg(FYI, "ascii: bytes left %d
  ", bleft);

  }

  int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,

  				    struct cifs_ses *ses)

  {

  	unsigned int tioffset; /* challenge message target info area */
  	unsigned int tilen; /* challenge message target info area length  */

  	CHALLENGE_MESSAGE *pblob = (CHALLENGE_MESSAGE *)bcc_ptr;
  
  	if (blob_len < sizeof(CHALLENGE_MESSAGE)) {

  		cifs_dbg(VFS, "challenge blob len %d too small
  ", blob_len);

  		return -EINVAL;
  	}
  
  	if (memcmp(pblob->Signature, "NTLMSSP", 8)) {

  		cifs_dbg(VFS, "blob signature incorrect %s
  ",
  			 pblob->Signature);

  		return -EINVAL;
  	}
  	if (pblob->MessageType != NtLmChallenge) {

  		cifs_dbg(VFS, "Incorrect message type %d
  ",
  			 pblob->MessageType);

  		return -EINVAL;
  	}

  	memcpy(ses->ntlmssp->cryptkey, pblob->Challenge, CIFS_CRYPTO_KEY_SIZE);

  	/* BB we could decode pblob->NegotiateFlags; some may be useful */
  	/* In particular we can examine sign flags */
  	/* BB spec says that if AvId field of MsvAvTimestamp is populated then
  		we must set the MIC field of the AUTHENTICATE_MESSAGE */

  	ses->ntlmssp->server_flags = le32_to_cpu(pblob->NegotiateFlags);

  	tioffset = le32_to_cpu(pblob->TargetInfoArray.BufferOffset);
  	tilen = le16_to_cpu(pblob->TargetInfoArray.Length);

  	if (tioffset > blob_len || tioffset + tilen > blob_len) {

  		cifs_dbg(VFS, "tioffset + tilen too high %u + %u",
  			tioffset, tilen);

  		return -EINVAL;
  	}

  	if (tilen) {

  		ses->auth_key.response = kmemdup(bcc_ptr + tioffset, tilen,
  						 GFP_KERNEL);

  		if (!ses->auth_key.response) {

  			cifs_dbg(VFS, "Challenge target info alloc failure");

  			return -ENOMEM;
  		}

  		ses->auth_key.len = tilen;

  	}

  	return 0;
  }

  /* BB Move to ntlmssp.c eventually */
  
  /* We do not malloc the blob, it is passed in pbuffer, because
     it is fixed size, and small, making this approach cleaner */

  void build_ntlmssp_negotiate_blob(unsigned char *pbuffer,

  					 struct cifs_ses *ses)

  {
  	NEGOTIATE_MESSAGE *sec_blob = (NEGOTIATE_MESSAGE *)pbuffer;
  	__u32 flags;

  	memset(pbuffer, 0, sizeof(NEGOTIATE_MESSAGE));

  	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
  	sec_blob->MessageType = NtLmNegotiate;
  
  	/* BB is NTLMV2 session security format easier to use here? */
  	flags = NTLMSSP_NEGOTIATE_56 |	NTLMSSP_REQUEST_TARGET |
  		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |

  		NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC;

  	if (ses->server->sign) {

  		flags |= NTLMSSP_NEGOTIATE_SIGN;

  		if (!ses->server->session_estab ||
  				ses->ntlmssp->sesskey_per_smbsess)

  			flags |= NTLMSSP_NEGOTIATE_KEY_XCH;

  	}

  	sec_blob->NegotiateFlags = cpu_to_le32(flags);

  
  	sec_blob->WorkstationName.BufferOffset = 0;
  	sec_blob->WorkstationName.Length = 0;
  	sec_blob->WorkstationName.MaximumLength = 0;
  
  	/* Domain name is sent on the Challenge not Negotiate NTLMSSP request */
  	sec_blob->DomainName.BufferOffset = 0;
  	sec_blob->DomainName.Length = 0;
  	sec_blob->DomainName.MaximumLength = 0;
  }

  static int size_of_ntlmssp_blob(struct cifs_ses *ses)
  {
  	int sz = sizeof(AUTHENTICATE_MESSAGE) + ses->auth_key.len
  		- CIFS_SESS_KEY_SIZE + CIFS_CPHTXT_SIZE + 2;
  
  	if (ses->domainName)
  		sz += 2 * strnlen(ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
  	else
  		sz += 2;
  
  	if (ses->user_name)
  		sz += 2 * strnlen(ses->user_name, CIFS_MAX_USERNAME_LEN);
  	else
  		sz += 2;
  
  	return sz;
  }
  
  int build_ntlmssp_auth_blob(unsigned char **pbuffer,

  					u16 *buflen,

  				   struct cifs_ses *ses,

  				   const struct nls_table *nls_cp)

  {

  	int rc;

  	AUTHENTICATE_MESSAGE *sec_blob;

  	__u32 flags;
  	unsigned char *tmp;

  	rc = setup_ntlmv2_rsp(ses, nls_cp);
  	if (rc) {
  		cifs_dbg(VFS, "Error %d during NTLMSSP authentication
  ", rc);
  		*buflen = 0;
  		goto setup_ntlmv2_ret;
  	}
  	*pbuffer = kmalloc(size_of_ntlmssp_blob(ses), GFP_KERNEL);
  	sec_blob = (AUTHENTICATE_MESSAGE *)*pbuffer;

  	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
  	sec_blob->MessageType = NtLmAuthenticate;
  
  	flags = NTLMSSP_NEGOTIATE_56 |
  		NTLMSSP_REQUEST_TARGET | NTLMSSP_NEGOTIATE_TARGET_INFO |
  		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |

  		NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC;

  	if (ses->server->sign) {

  		flags |= NTLMSSP_NEGOTIATE_SIGN;

  		if (!ses->server->session_estab ||
  				ses->ntlmssp->sesskey_per_smbsess)

  			flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
  	}

  	tmp = *pbuffer + sizeof(AUTHENTICATE_MESSAGE);

  	sec_blob->NegotiateFlags = cpu_to_le32(flags);

  
  	sec_blob->LmChallengeResponse.BufferOffset =
  				cpu_to_le32(sizeof(AUTHENTICATE_MESSAGE));
  	sec_blob->LmChallengeResponse.Length = 0;
  	sec_blob->LmChallengeResponse.MaximumLength = 0;

  	sec_blob->NtChallengeResponse.BufferOffset =
  				cpu_to_le32(tmp - *pbuffer);

  	if (ses->user_name != NULL) {

  		memcpy(tmp, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
  				ses->auth_key.len - CIFS_SESS_KEY_SIZE);
  		tmp += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
  
  		sec_blob->NtChallengeResponse.Length =
  				cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
  		sec_blob->NtChallengeResponse.MaximumLength =
  				cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
  	} else {
  		/*
  		 * don't send an NT Response for anonymous access
  		 */
  		sec_blob->NtChallengeResponse.Length = 0;
  		sec_blob->NtChallengeResponse.MaximumLength = 0;

  	}

  
  	if (ses->domainName == NULL) {

  		sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - *pbuffer);

  		sec_blob->DomainName.Length = 0;
  		sec_blob->DomainName.MaximumLength = 0;
  		tmp += 2;
  	} else {
  		int len;

  		len = cifs_strtoUTF16((__le16 *)tmp, ses->domainName,

  				      CIFS_MAX_DOMAINNAME_LEN, nls_cp);

  		len *= 2; /* unicode is 2 bytes each */

  		sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - *pbuffer);

  		sec_blob->DomainName.Length = cpu_to_le16(len);
  		sec_blob->DomainName.MaximumLength = cpu_to_le16(len);
  		tmp += len;
  	}

  	if (ses->user_name == NULL) {

  		sec_blob->UserName.BufferOffset = cpu_to_le32(tmp - *pbuffer);

  		sec_blob->UserName.Length = 0;
  		sec_blob->UserName.MaximumLength = 0;
  		tmp += 2;
  	} else {
  		int len;

  		len = cifs_strtoUTF16((__le16 *)tmp, ses->user_name,

  				      CIFS_MAX_USERNAME_LEN, nls_cp);

  		len *= 2; /* unicode is 2 bytes each */

  		sec_blob->UserName.BufferOffset = cpu_to_le32(tmp - *pbuffer);

  		sec_blob->UserName.Length = cpu_to_le16(len);
  		sec_blob->UserName.MaximumLength = cpu_to_le16(len);
  		tmp += len;
  	}

  	sec_blob->WorkstationName.BufferOffset = cpu_to_le32(tmp - *pbuffer);

  	sec_blob->WorkstationName.Length = 0;
  	sec_blob->WorkstationName.MaximumLength = 0;
  	tmp += 2;

  	if (((ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) ||
  		(ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_EXTENDED_SEC))
  			&& !calc_seckey(ses)) {

  		memcpy(tmp, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);

  		sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);

  		sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE);
  		sec_blob->SessionKey.MaximumLength =
  				cpu_to_le16(CIFS_CPHTXT_SIZE);
  		tmp += CIFS_CPHTXT_SIZE;
  	} else {

  		sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);

  		sec_blob->SessionKey.Length = 0;
  		sec_blob->SessionKey.MaximumLength = 0;
  	}

  	*buflen = tmp - *pbuffer;

  setup_ntlmv2_ret:

  	return rc;

  }

  enum securityEnum
  select_sectype(struct TCP_Server_Info *server, enum securityEnum requested)
  {
  	switch (server->negflavor) {
  	case CIFS_NEGFLAVOR_EXTENDED:
  		switch (requested) {
  		case Kerberos:
  		case RawNTLMSSP:
  			return requested;
  		case Unspecified:
  			if (server->sec_ntlmssp &&
  			    (global_secflags & CIFSSEC_MAY_NTLMSSP))
  				return RawNTLMSSP;
  			if ((server->sec_kerberos || server->sec_mskerberos) &&
  			    (global_secflags & CIFSSEC_MAY_KRB5))
  				return Kerberos;
  			/* Fallthrough */
  		default:
  			return Unspecified;
  		}
  	case CIFS_NEGFLAVOR_UNENCAP:
  		switch (requested) {
  		case NTLM:
  		case NTLMv2:
  			return requested;
  		case Unspecified:
  			if (global_secflags & CIFSSEC_MAY_NTLMV2)
  				return NTLMv2;
  			if (global_secflags & CIFSSEC_MAY_NTLM)
  				return NTLM;

  		default:

  			/* Fallthrough to attempt LANMAN authentication next */
  			break;

  		}
  	case CIFS_NEGFLAVOR_LANMAN:
  		switch (requested) {
  		case LANMAN:
  			return requested;
  		case Unspecified:
  			if (global_secflags & CIFSSEC_MAY_LANMAN)
  				return LANMAN;
  			/* Fallthrough */
  		default:
  			return Unspecified;
  		}
  	default:
  		return Unspecified;
  	}
  }

  struct sess_data {
  	unsigned int xid;
  	struct cifs_ses *ses;
  	struct nls_table *nls_cp;
  	void (*func)(struct sess_data *);
  	int result;
  
  	/* we will send the SMB in three pieces:
  	 * a fixed length beginning part, an optional
  	 * SPNEGO blob (which can be zero length), and a
  	 * last part which will include the strings
  	 * and rest of bcc area. This allows us to avoid
  	 * a large buffer 17K allocation
  	 */
  	int buf0_type;
  	struct kvec iov[3];
  };
  
  static int
  sess_alloc_buffer(struct sess_data *sess_data, int wct)
  {
  	int rc;
  	struct cifs_ses *ses = sess_data->ses;
  	struct smb_hdr *smb_buf;
  
  	rc = small_smb_init_no_tc(SMB_COM_SESSION_SETUP_ANDX, wct, ses,
  				  (void **)&smb_buf);
  
  	if (rc)
  		return rc;
  
  	sess_data->iov[0].iov_base = (char *)smb_buf;
  	sess_data->iov[0].iov_len = be32_to_cpu(smb_buf->smb_buf_length) + 4;
  	/*
  	 * This variable will be used to clear the buffer
  	 * allocated above in case of any error in the calling function.
  	 */
  	sess_data->buf0_type = CIFS_SMALL_BUFFER;
  
  	/* 2000 big enough to fit max user, domain, NOS name etc. */
  	sess_data->iov[2].iov_base = kmalloc(2000, GFP_KERNEL);
  	if (!sess_data->iov[2].iov_base) {
  		rc = -ENOMEM;
  		goto out_free_smb_buf;
  	}
  
  	return 0;
  
  out_free_smb_buf:
  	kfree(smb_buf);
  	sess_data->iov[0].iov_base = NULL;
  	sess_data->iov[0].iov_len = 0;
  	sess_data->buf0_type = CIFS_NO_BUFFER;
  	return rc;
  }
  
  static void
  sess_free_buffer(struct sess_data *sess_data)
  {
  
  	free_rsp_buf(sess_data->buf0_type, sess_data->iov[0].iov_base);
  	sess_data->buf0_type = CIFS_NO_BUFFER;
  	kfree(sess_data->iov[2].iov_base);
  }
  
  static int
  sess_establish_session(struct sess_data *sess_data)
  {
  	struct cifs_ses *ses = sess_data->ses;
  
  	mutex_lock(&ses->server->srv_mutex);
  	if (!ses->server->session_estab) {
  		if (ses->server->sign) {
  			ses->server->session_key.response =
  				kmemdup(ses->auth_key.response,
  				ses->auth_key.len, GFP_KERNEL);
  			if (!ses->server->session_key.response) {
  				mutex_unlock(&ses->server->srv_mutex);
  				return -ENOMEM;
  			}
  			ses->server->session_key.len =
  						ses->auth_key.len;
  		}
  		ses->server->sequence_number = 0x2;
  		ses->server->session_estab = true;
  	}
  	mutex_unlock(&ses->server->srv_mutex);
  
  	cifs_dbg(FYI, "CIFS session established successfully
  ");
  	spin_lock(&GlobalMid_Lock);
  	ses->status = CifsGood;
  	ses->need_reconnect = false;
  	spin_unlock(&GlobalMid_Lock);
  
  	return 0;
  }
  
  static int
  sess_sendreceive(struct sess_data *sess_data)
  {
  	int rc;
  	struct smb_hdr *smb_buf = (struct smb_hdr *) sess_data->iov[0].iov_base;
  	__u16 count;
  
  	count = sess_data->iov[1].iov_len + sess_data->iov[2].iov_len;
  	smb_buf->smb_buf_length =
  		cpu_to_be32(be32_to_cpu(smb_buf->smb_buf_length) + count);
  	put_bcc(count, smb_buf);
  
  	rc = SendReceive2(sess_data->xid, sess_data->ses,
  			  sess_data->iov, 3 /* num_iovecs */,
  			  &sess_data->buf0_type,
  			  CIFS_LOG_ERROR);
  
  	return rc;
  }
  
  /*
   * LANMAN and plaintext are less secure and off by default.
   * So we make this explicitly be turned on in kconfig (in the
   * build) and turned on at runtime (changed from the default)
   * in proc/fs/cifs or via mount parm.  Unfortunately this is
   * needed for old Win (e.g. Win95), some obscure NAS and OS/2
   */
  #ifdef CONFIG_CIFS_WEAK_PW_HASH
  static void
  sess_auth_lanman(struct sess_data *sess_data)
  {
  	int rc = 0;
  	struct smb_hdr *smb_buf;
  	SESSION_SETUP_ANDX *pSMB;
  	char *bcc_ptr;
  	struct cifs_ses *ses = sess_data->ses;
  	char lnm_session_key[CIFS_AUTH_RESP_SIZE];
  	__u32 capabilities;
  	__u16 bytes_remaining;
  
  	/* lanman 2 style sessionsetup */
  	/* wct = 10 */
  	rc = sess_alloc_buffer(sess_data, 10);
  	if (rc)
  		goto out;
  
  	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
  	bcc_ptr = sess_data->iov[2].iov_base;
  	capabilities = cifs_ssetup_hdr(ses, pSMB);
  
  	pSMB->req.hdr.Flags2 &= ~SMBFLG2_UNICODE;

  	if (ses->user_name != NULL) {
  		/* no capabilities flags in old lanman negotiation */
  		pSMB->old_req.PasswordLength = cpu_to_le16(CIFS_AUTH_RESP_SIZE);

  		/* Calculate hash with password and copy into bcc_ptr.
  		 * Encryption Key (stored as in cryptkey) gets used if the
  		 * security mode bit in Negottiate Protocol response states
  		 * to use challenge/response method (i.e. Password bit is 1).
  		 */
  		rc = calc_lanman_hash(ses->password, ses->server->cryptkey,
  				      ses->server->sec_mode & SECMODE_PW_ENCRYPT ?
  				      true : false, lnm_session_key);

  		if (rc)
  			goto out;

  		memcpy(bcc_ptr, (char *)lnm_session_key, CIFS_AUTH_RESP_SIZE);
  		bcc_ptr += CIFS_AUTH_RESP_SIZE;
  	} else {
  		pSMB->old_req.PasswordLength = 0;
  	}

  
  	/*
  	 * can not sign if LANMAN negotiated so no need
  	 * to calculate signing key? but what if server
  	 * changed to do higher than lanman dialect and
  	 * we reconnected would we ever calc signing_key?
  	 */
  
  	cifs_dbg(FYI, "Negotiating LANMAN setting up strings
  ");
  	/* Unicode not allowed for LANMAN dialects */
  	ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
  
  	sess_data->iov[2].iov_len = (long) bcc_ptr -
  			(long) sess_data->iov[2].iov_base;
  
  	rc = sess_sendreceive(sess_data);
  	if (rc)
  		goto out;
  
  	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
  	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
  
  	/* lanman response has a word count of 3 */
  	if (smb_buf->WordCount != 3) {
  		rc = -EIO;
  		cifs_dbg(VFS, "bad word count %d
  ", smb_buf->WordCount);
  		goto out;
  	}
  
  	if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
  		cifs_dbg(FYI, "Guest login
  "); /* BB mark SesInfo struct? */
  
  	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
  	cifs_dbg(FYI, "UID = %llu
  ", ses->Suid);
  
  	bytes_remaining = get_bcc(smb_buf);
  	bcc_ptr = pByteArea(smb_buf);
  
  	/* BB check if Unicode and decode strings */
  	if (bytes_remaining == 0) {
  		/* no string area to decode, do nothing */
  	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
  		/* unicode string area must be word-aligned */
  		if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
  			++bcc_ptr;
  			--bytes_remaining;
  		}
  		decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
  				      sess_data->nls_cp);
  	} else {
  		decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
  				    sess_data->nls_cp);
  	}
  
  	rc = sess_establish_session(sess_data);
  out:
  	sess_data->result = rc;
  	sess_data->func = NULL;
  	sess_free_buffer(sess_data);
  }

  #endif

  static void
  sess_auth_ntlm(struct sess_data *sess_data)
  {
  	int rc = 0;
  	struct smb_hdr *smb_buf;
  	SESSION_SETUP_ANDX *pSMB;
  	char *bcc_ptr;
  	struct cifs_ses *ses = sess_data->ses;
  	__u32 capabilities;
  	__u16 bytes_remaining;
  
  	/* old style NTLM sessionsetup */
  	/* wct = 13 */
  	rc = sess_alloc_buffer(sess_data, 13);
  	if (rc)
  		goto out;
  
  	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
  	bcc_ptr = sess_data->iov[2].iov_base;
  	capabilities = cifs_ssetup_hdr(ses, pSMB);
  
  	pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);

  	if (ses->user_name != NULL) {
  		pSMB->req_no_secext.CaseInsensitivePasswordLength =
  				cpu_to_le16(CIFS_AUTH_RESP_SIZE);
  		pSMB->req_no_secext.CaseSensitivePasswordLength =
  				cpu_to_le16(CIFS_AUTH_RESP_SIZE);
  
  		/* calculate ntlm response and session key */
  		rc = setup_ntlm_response(ses, sess_data->nls_cp);
  		if (rc) {
  			cifs_dbg(VFS, "Error %d during NTLM authentication
  ",
  					 rc);
  			goto out;
  		}

  		/* copy ntlm response */
  		memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
  				CIFS_AUTH_RESP_SIZE);
  		bcc_ptr += CIFS_AUTH_RESP_SIZE;
  		memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
  				CIFS_AUTH_RESP_SIZE);
  		bcc_ptr += CIFS_AUTH_RESP_SIZE;
  	} else {
  		pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;
  		pSMB->req_no_secext.CaseSensitivePasswordLength = 0;
  	}

  
  	if (ses->capabilities & CAP_UNICODE) {
  		/* unicode strings must be word aligned */
  		if (sess_data->iov[0].iov_len % 2) {
  			*bcc_ptr = 0;
  			bcc_ptr++;
  		}
  		unicode_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
  	} else {
  		ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
  	}
  
  
  	sess_data->iov[2].iov_len = (long) bcc_ptr -
  			(long) sess_data->iov[2].iov_base;
  
  	rc = sess_sendreceive(sess_data);
  	if (rc)
  		goto out;
  
  	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
  	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
  
  	if (smb_buf->WordCount != 3) {
  		rc = -EIO;
  		cifs_dbg(VFS, "bad word count %d
  ", smb_buf->WordCount);
  		goto out;
  	}
  
  	if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
  		cifs_dbg(FYI, "Guest login
  "); /* BB mark SesInfo struct? */
  
  	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
  	cifs_dbg(FYI, "UID = %llu
  ", ses->Suid);
  
  	bytes_remaining = get_bcc(smb_buf);
  	bcc_ptr = pByteArea(smb_buf);
  
  	/* BB check if Unicode and decode strings */
  	if (bytes_remaining == 0) {
  		/* no string area to decode, do nothing */
  	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
  		/* unicode string area must be word-aligned */
  		if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
  			++bcc_ptr;
  			--bytes_remaining;
  		}
  		decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
  				      sess_data->nls_cp);
  	} else {
  		decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
  				    sess_data->nls_cp);
  	}
  
  	rc = sess_establish_session(sess_data);
  out:
  	sess_data->result = rc;
  	sess_data->func = NULL;
  	sess_free_buffer(sess_data);
  	kfree(ses->auth_key.response);
  	ses->auth_key.response = NULL;
  }
  
  static void
  sess_auth_ntlmv2(struct sess_data *sess_data)
  {
  	int rc = 0;
  	struct smb_hdr *smb_buf;
  	SESSION_SETUP_ANDX *pSMB;
  	char *bcc_ptr;
  	struct cifs_ses *ses = sess_data->ses;
  	__u32 capabilities;
  	__u16 bytes_remaining;
  
  	/* old style NTLM sessionsetup */
  	/* wct = 13 */
  	rc = sess_alloc_buffer(sess_data, 13);
  	if (rc)
  		goto out;
  
  	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
  	bcc_ptr = sess_data->iov[2].iov_base;
  	capabilities = cifs_ssetup_hdr(ses, pSMB);
  
  	pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
  
  	/* LM2 password would be here if we supported it */
  	pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;

  	if (ses->user_name != NULL) {
  		/* calculate nlmv2 response and session key */
  		rc = setup_ntlmv2_rsp(ses, sess_data->nls_cp);
  		if (rc) {
  			cifs_dbg(VFS, "Error %d during NTLMv2 authentication
  ", rc);
  			goto out;
  		}

  		memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
  				ses->auth_key.len - CIFS_SESS_KEY_SIZE);
  		bcc_ptr += ses->auth_key.len - CIFS_SESS_KEY_SIZE;

  		/* set case sensitive password length after tilen may get
  		 * assigned, tilen is 0 otherwise.
  		 */
  		pSMB->req_no_secext.CaseSensitivePasswordLength =
  			cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
  	} else {
  		pSMB->req_no_secext.CaseSensitivePasswordLength = 0;
  	}

  
  	if (ses->capabilities & CAP_UNICODE) {
  		if (sess_data->iov[0].iov_len % 2) {
  			*bcc_ptr = 0;
  			bcc_ptr++;
  		}
  		unicode_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
  	} else {
  		ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
  	}
  
  
  	sess_data->iov[2].iov_len = (long) bcc_ptr -
  			(long) sess_data->iov[2].iov_base;
  
  	rc = sess_sendreceive(sess_data);
  	if (rc)
  		goto out;
  
  	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
  	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
  
  	if (smb_buf->WordCount != 3) {
  		rc = -EIO;
  		cifs_dbg(VFS, "bad word count %d
  ", smb_buf->WordCount);
  		goto out;
  	}
  
  	if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
  		cifs_dbg(FYI, "Guest login
  "); /* BB mark SesInfo struct? */
  
  	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
  	cifs_dbg(FYI, "UID = %llu
  ", ses->Suid);
  
  	bytes_remaining = get_bcc(smb_buf);
  	bcc_ptr = pByteArea(smb_buf);
  
  	/* BB check if Unicode and decode strings */
  	if (bytes_remaining == 0) {
  		/* no string area to decode, do nothing */
  	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
  		/* unicode string area must be word-aligned */
  		if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
  			++bcc_ptr;
  			--bytes_remaining;
  		}
  		decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
  				      sess_data->nls_cp);
  	} else {
  		decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
  				    sess_data->nls_cp);
  	}
  
  	rc = sess_establish_session(sess_data);
  out:
  	sess_data->result = rc;
  	sess_data->func = NULL;
  	sess_free_buffer(sess_data);
  	kfree(ses->auth_key.response);
  	ses->auth_key.response = NULL;
  }

  #ifdef CONFIG_CIFS_UPCALL
  static void
  sess_auth_kerberos(struct sess_data *sess_data)
  {
  	int rc = 0;
  	struct smb_hdr *smb_buf;
  	SESSION_SETUP_ANDX *pSMB;
  	char *bcc_ptr;
  	struct cifs_ses *ses = sess_data->ses;
  	__u32 capabilities;
  	__u16 bytes_remaining;
  	struct key *spnego_key = NULL;
  	struct cifs_spnego_msg *msg;
  	u16 blob_len;
  
  	/* extended security */
  	/* wct = 12 */
  	rc = sess_alloc_buffer(sess_data, 12);
  	if (rc)
  		goto out;
  
  	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
  	bcc_ptr = sess_data->iov[2].iov_base;
  	capabilities = cifs_ssetup_hdr(ses, pSMB);
  
  	spnego_key = cifs_get_spnego_key(ses);
  	if (IS_ERR(spnego_key)) {
  		rc = PTR_ERR(spnego_key);
  		spnego_key = NULL;
  		goto out;
  	}

  	msg = spnego_key->payload.data[0];

  	/*
  	 * check version field to make sure that cifs.upcall is
  	 * sending us a response in an expected form
  	 */
  	if (msg->version != CIFS_SPNEGO_UPCALL_VERSION) {
  		cifs_dbg(VFS,
  		  "incorrect version of cifs.upcall (expected %d but got %d)",
  			      CIFS_SPNEGO_UPCALL_VERSION, msg->version);
  		rc = -EKEYREJECTED;
  		goto out_put_spnego_key;
  	}
  
  	ses->auth_key.response = kmemdup(msg->data, msg->sesskey_len,
  					 GFP_KERNEL);
  	if (!ses->auth_key.response) {
  		cifs_dbg(VFS, "Kerberos can't allocate (%u bytes) memory",
  				msg->sesskey_len);
  		rc = -ENOMEM;
  		goto out_put_spnego_key;
  	}
  	ses->auth_key.len = msg->sesskey_len;
  
  	pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
  	capabilities |= CAP_EXTENDED_SECURITY;
  	pSMB->req.Capabilities = cpu_to_le32(capabilities);
  	sess_data->iov[1].iov_base = msg->data + msg->sesskey_len;
  	sess_data->iov[1].iov_len = msg->secblob_len;
  	pSMB->req.SecurityBlobLength = cpu_to_le16(sess_data->iov[1].iov_len);
  
  	if (ses->capabilities & CAP_UNICODE) {
  		/* unicode strings must be word aligned */
  		if ((sess_data->iov[0].iov_len
  			+ sess_data->iov[1].iov_len) % 2) {
  			*bcc_ptr = 0;
  			bcc_ptr++;
  		}
  		unicode_oslm_strings(&bcc_ptr, sess_data->nls_cp);
  		unicode_domain_string(&bcc_ptr, ses, sess_data->nls_cp);
  	} else {
  		/* BB: is this right? */
  		ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
  	}
  
  	sess_data->iov[2].iov_len = (long) bcc_ptr -
  			(long) sess_data->iov[2].iov_base;
  
  	rc = sess_sendreceive(sess_data);
  	if (rc)
  		goto out_put_spnego_key;
  
  	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
  	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
  
  	if (smb_buf->WordCount != 4) {
  		rc = -EIO;
  		cifs_dbg(VFS, "bad word count %d
  ", smb_buf->WordCount);
  		goto out_put_spnego_key;
  	}
  
  	if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
  		cifs_dbg(FYI, "Guest login
  "); /* BB mark SesInfo struct? */
  
  	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
  	cifs_dbg(FYI, "UID = %llu
  ", ses->Suid);
  
  	bytes_remaining = get_bcc(smb_buf);
  	bcc_ptr = pByteArea(smb_buf);
  
  	blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
  	if (blob_len > bytes_remaining) {
  		cifs_dbg(VFS, "bad security blob length %d
  ",
  				blob_len);
  		rc = -EINVAL;
  		goto out_put_spnego_key;
  	}
  	bcc_ptr += blob_len;
  	bytes_remaining -= blob_len;
  
  	/* BB check if Unicode and decode strings */
  	if (bytes_remaining == 0) {
  		/* no string area to decode, do nothing */
  	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
  		/* unicode string area must be word-aligned */
  		if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
  			++bcc_ptr;
  			--bytes_remaining;
  		}
  		decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
  				      sess_data->nls_cp);
  	} else {
  		decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
  				    sess_data->nls_cp);
  	}
  
  	rc = sess_establish_session(sess_data);
  out_put_spnego_key:
  	key_invalidate(spnego_key);
  	key_put(spnego_key);
  out:
  	sess_data->result = rc;
  	sess_data->func = NULL;
  	sess_free_buffer(sess_data);
  	kfree(ses->auth_key.response);
  	ses->auth_key.response = NULL;
  }

  #endif /* ! CONFIG_CIFS_UPCALL */

  /*
   * The required kvec buffers have to be allocated before calling this
   * function.
   */
  static int
  _sess_auth_rawntlmssp_assemble_req(struct sess_data *sess_data)

  {

  	struct smb_hdr *smb_buf;

  	SESSION_SETUP_ANDX *pSMB;

  	struct cifs_ses *ses = sess_data->ses;

  	__u32 capabilities;

  	char *bcc_ptr;

  	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
  	smb_buf = (struct smb_hdr *)pSMB;
  
  	capabilities = cifs_ssetup_hdr(ses, pSMB);
  	if ((pSMB->req.hdr.Flags2 & SMBFLG2_UNICODE) == 0) {
  		cifs_dbg(VFS, "NTLMSSP requires Unicode support
  ");
  		return -ENOSYS;

  	}

  	pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
  	capabilities |= CAP_EXTENDED_SECURITY;
  	pSMB->req.Capabilities |= cpu_to_le32(capabilities);

  	bcc_ptr = sess_data->iov[2].iov_base;
  	/* unicode strings must be word aligned */
  	if ((sess_data->iov[0].iov_len + sess_data->iov[1].iov_len) % 2) {
  		*bcc_ptr = 0;
  		bcc_ptr++;

  	}

  	unicode_oslm_strings(&bcc_ptr, sess_data->nls_cp);

  	sess_data->iov[2].iov_len = (long) bcc_ptr -
  					(long) sess_data->iov[2].iov_base;

  	return 0;
  }
  
  static void
  sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data);
  
  static void
  sess_auth_rawntlmssp_negotiate(struct sess_data *sess_data)
  {
  	int rc;
  	struct smb_hdr *smb_buf;
  	SESSION_SETUP_ANDX *pSMB;
  	struct cifs_ses *ses = sess_data->ses;
  	__u16 bytes_remaining;
  	char *bcc_ptr;
  	u16 blob_len;
  
  	cifs_dbg(FYI, "rawntlmssp session setup negotiate phase
  ");

  	/*
  	 * if memory allocation is successful, caller of this function
  	 * frees it.
  	 */
  	ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
  	if (!ses->ntlmssp) {
  		rc = -ENOMEM;
  		goto out;

  	}

  	ses->ntlmssp->sesskey_per_smbsess = false;

  	/* wct = 12 */
  	rc = sess_alloc_buffer(sess_data, 12);
  	if (rc)
  		goto out;

  	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;

  	/* Build security blob before we assemble the request */
  	build_ntlmssp_negotiate_blob(pSMB->req.SecurityBlob, ses);
  	sess_data->iov[1].iov_len = sizeof(NEGOTIATE_MESSAGE);
  	sess_data->iov[1].iov_base = pSMB->req.SecurityBlob;
  	pSMB->req.SecurityBlobLength = cpu_to_le16(sizeof(NEGOTIATE_MESSAGE));
  
  	rc = _sess_auth_rawntlmssp_assemble_req(sess_data);

  	if (rc)

  		goto out;

  	rc = sess_sendreceive(sess_data);

  	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
  	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;

  	/* If true, rc here is expected and not an error */
  	if (sess_data->buf0_type != CIFS_NO_BUFFER &&
  	    smb_buf->Status.CifsError ==
  			cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))
  		rc = 0;

  	if (rc)
  		goto out;
  
  	cifs_dbg(FYI, "rawntlmssp session setup challenge phase
  ");
  
  	if (smb_buf->WordCount != 4) {
  		rc = -EIO;
  		cifs_dbg(VFS, "bad word count %d
  ", smb_buf->WordCount);
  		goto out;

  	}

  	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
  	cifs_dbg(FYI, "UID = %llu
  ", ses->Suid);

  	bytes_remaining = get_bcc(smb_buf);
  	bcc_ptr = pByteArea(smb_buf);

  	blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
  	if (blob_len > bytes_remaining) {
  		cifs_dbg(VFS, "bad security blob length %d
  ",
  				blob_len);
  		rc = -EINVAL;
  		goto out;
  	}

  	rc = decode_ntlmssp_challenge(bcc_ptr, blob_len, ses);
  out:
  	sess_free_buffer(sess_data);
  
  	if (!rc) {
  		sess_data->func = sess_auth_rawntlmssp_authenticate;
  		return;

  	}

  	/* Else error. Cleanup */
  	kfree(ses->auth_key.response);
  	ses->auth_key.response = NULL;
  	kfree(ses->ntlmssp);
  	ses->ntlmssp = NULL;

  	sess_data->func = NULL;
  	sess_data->result = rc;
  }

  static void
  sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data)
  {
  	int rc;
  	struct smb_hdr *smb_buf;
  	SESSION_SETUP_ANDX *pSMB;
  	struct cifs_ses *ses = sess_data->ses;
  	__u16 bytes_remaining;
  	char *bcc_ptr;

  	unsigned char *ntlmsspblob = NULL;

  	u16 blob_len;

  	cifs_dbg(FYI, "rawntlmssp session setup authenticate phase
  ");

  	/* wct = 12 */
  	rc = sess_alloc_buffer(sess_data, 12);
  	if (rc)
  		goto out;

  	/* Build security blob before we assemble the request */
  	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
  	smb_buf = (struct smb_hdr *)pSMB;

  	rc = build_ntlmssp_auth_blob(&ntlmsspblob,

  					&blob_len, ses, sess_data->nls_cp);
  	if (rc)
  		goto out_free_ntlmsspblob;
  	sess_data->iov[1].iov_len = blob_len;
  	sess_data->iov[1].iov_base = ntlmsspblob;
  	pSMB->req.SecurityBlobLength = cpu_to_le16(blob_len);
  	/*
  	 * Make sure that we tell the server that we are using
  	 * the uid that it just gave us back on the response
  	 * (challenge)
  	 */
  	smb_buf->Uid = ses->Suid;
  
  	rc = _sess_auth_rawntlmssp_assemble_req(sess_data);

  	if (rc)

  		goto out_free_ntlmsspblob;

  	rc = sess_sendreceive(sess_data);
  	if (rc)
  		goto out_free_ntlmsspblob;
  
  	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
  	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;

  	if (smb_buf->WordCount != 4) {

  		rc = -EIO;

  		cifs_dbg(VFS, "bad word count %d
  ", smb_buf->WordCount);

  		goto out_free_ntlmsspblob;

  	}

  
  	if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)

  		cifs_dbg(FYI, "Guest login
  "); /* BB mark SesInfo struct? */

  	if (ses->Suid != smb_buf->Uid) {
  		ses->Suid = smb_buf->Uid;
  		cifs_dbg(FYI, "UID changed! new UID = %llu
  ", ses->Suid);
  	}

  	bytes_remaining = get_bcc(smb_buf);

  	bcc_ptr = pByteArea(smb_buf);

  	blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
  	if (blob_len > bytes_remaining) {
  		cifs_dbg(VFS, "bad security blob length %d
  ",

  				blob_len);

  		rc = -EINVAL;

  		goto out_free_ntlmsspblob;

  	}

  	bcc_ptr += blob_len;
  	bytes_remaining -= blob_len;

  	/* BB check if Unicode and decode strings */

  	if (bytes_remaining == 0) {
  		/* no string area to decode, do nothing */
  	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {

  		/* unicode string area must be word-aligned */
  		if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
  			++bcc_ptr;
  			--bytes_remaining;
  		}

  		decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
  				      sess_data->nls_cp);

  	} else {

  		decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
  				    sess_data->nls_cp);

  	}

  out_free_ntlmsspblob:

  	kfree(ntlmsspblob);

  out:
  	sess_free_buffer(sess_data);

  	 if (!rc)
  		rc = sess_establish_session(sess_data);

  	/* Cleanup */

  	kfree(ses->auth_key.response);
  	ses->auth_key.response = NULL;
  	kfree(ses->ntlmssp);

  	ses->ntlmssp = NULL;

  	sess_data->func = NULL;
  	sess_data->result = rc;
  }

  static int select_sec(struct cifs_ses *ses, struct sess_data *sess_data)

  {
  	int type;
  
  	type = select_sectype(ses->server, ses->sectype);
  	cifs_dbg(FYI, "sess setup type %d
  ", type);
  	if (type == Unspecified) {
  		cifs_dbg(VFS,
  			"Unable to select appropriate authentication method!");
  		return -EINVAL;
  	}
  
  	switch (type) {
  	case LANMAN:
  		/* LANMAN and plaintext are less secure and off by default.
  		 * So we make this explicitly be turned on in kconfig (in the
  		 * build) and turned on at runtime (changed from the default)
  		 * in proc/fs/cifs or via mount parm.  Unfortunately this is
  		 * needed for old Win (e.g. Win95), some obscure NAS and OS/2 */
  #ifdef CONFIG_CIFS_WEAK_PW_HASH
  		sess_data->func = sess_auth_lanman;
  		break;
  #else
  		return -EOPNOTSUPP;
  #endif
  	case NTLM:
  		sess_data->func = sess_auth_ntlm;
  		break;
  	case NTLMv2:
  		sess_data->func = sess_auth_ntlmv2;
  		break;
  	case Kerberos:
  #ifdef CONFIG_CIFS_UPCALL
  		sess_data->func = sess_auth_kerberos;
  		break;
  #else
  		cifs_dbg(VFS, "Kerberos negotiated but upcall support disabled!
  ");
  		return -ENOSYS;
  		break;
  #endif /* CONFIG_CIFS_UPCALL */
  	case RawNTLMSSP:
  		sess_data->func = sess_auth_rawntlmssp_negotiate;
  		break;
  	default:
  		cifs_dbg(VFS, "secType %d not supported!
  ", type);
  		return -ENOSYS;
  	}
  
  	return 0;
  }
  
  int CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses,
  		    const struct nls_table *nls_cp)
  {
  	int rc = 0;
  	struct sess_data *sess_data;
  
  	if (ses == NULL) {
  		WARN(1, "%s: ses == NULL!", __func__);
  		return -EINVAL;
  	}
  
  	sess_data = kzalloc(sizeof(struct sess_data), GFP_KERNEL);
  	if (!sess_data)
  		return -ENOMEM;
  
  	rc = select_sec(ses, sess_data);
  	if (rc)
  		goto out;
  
  	sess_data->xid = xid;
  	sess_data->ses = ses;
  	sess_data->buf0_type = CIFS_NO_BUFFER;
  	sess_data->nls_cp = (struct nls_table *) nls_cp;
  
  	while (sess_data->func)
  		sess_data->func(sess_data);
  
  	/* Store result before we free sess_data */

  	rc = sess_data->result;

  
  out:

  	kfree(sess_data);
  	return rc;

  }