cifssmb.c

Linux内核自带的cifs模块

	OPEN_RSP *pSMBr = NULL;
	int bytes_returned;
	int name_len;
	__u16 count;

openRetry:
	rc = smb_init(SMB_COM_NT_CREATE_ANDX, 24, tcon, (void **) &pSMB,
		      (void **) &pSMBr);
	if (rc)
		return rc;

	pSMB->AndXCommand = 0xFF;	/* none */

	if (pSMB->hdr.Flags2 & SMBFLG2_UNICODE) {
		count = 1;	/* account for one byte pad to word boundary */
		name_len =
		    cifsConvertToUCS((__le16 *) (pSMB->fileName + 1),
				     fileName, PATH_MAX, nls_codepage, remap);
		name_len++;	/* trailing null */
		name_len *= 2;
		pSMB->NameLength = cpu_to_le16(name_len);
	} else {		/* BB improve check for buffer overruns BB */
		count = 0;	/* no pad */
		name_len = strnlen(fileName, PATH_MAX);
		name_len++;	/* trailing null */
		pSMB->NameLength = cpu_to_le16(name_len);
		strncpy(pSMB->fileName, fileName, name_len);
	}
	if (*pOplock & REQ_OPLOCK)
		pSMB->OpenFlags = cpu_to_le32(REQ_OPLOCK);
	else if (*pOplock & REQ_BATCHOPLOCK)
		pSMB->OpenFlags = cpu_to_le32(REQ_BATCHOPLOCK);
	pSMB->DesiredAccess = cpu_to_le32(access_flags);
	pSMB->AllocationSize = 0;
	/* set file as system file if special file such
	   as fifo and server expecting SFU style and
	   no Unix extensions */
	if (create_options & CREATE_OPTION_SPECIAL)
		pSMB->FileAttributes = cpu_to_le32(ATTR_SYSTEM);
	else
		pSMB->FileAttributes = cpu_to_le32(ATTR_NORMAL);
	/* XP does not handle ATTR_POSIX_SEMANTICS */
	/* but it helps speed up case sensitive checks for other
	servers such as Samba */
	if (tcon->ses->capabilities & CAP_UNIX)
		pSMB->FileAttributes |= cpu_to_le32(ATTR_POSIX_SEMANTICS);

	/* if ((omode & S_IWUGO) == 0)
		pSMB->FileAttributes |= cpu_to_le32(ATTR_READONLY);*/
	/*  Above line causes problems due to vfs splitting create into two
		pieces - need to set mode after file created not while it is
		being created */
	pSMB->ShareAccess = cpu_to_le32(FILE_SHARE_ALL);
	pSMB->CreateDisposition = cpu_to_le32(openDisposition);
	pSMB->CreateOptions = cpu_to_le32(create_options & CREATE_OPTIONS_MASK);
	/* BB Expirement with various impersonation levels and verify */
	pSMB->ImpersonationLevel = cpu_to_le32(SECURITY_IMPERSONATION);
	pSMB->SecurityFlags =
	    SECURITY_CONTEXT_TRACKING | SECURITY_EFFECTIVE_ONLY;

	count += name_len;
	pSMB->hdr.smb_buf_length += count;

	pSMB->ByteCount = cpu_to_le16(count);
	/* long_op set to 1 to allow for oplock break timeouts */
	rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
			 (struct smb_hdr *) pSMBr, &bytes_returned, 1);
	cifs_stats_inc(&tcon->num_opens);
	if (rc) {
		cFYI(1, ("Error in Open = %d", rc));
	} else {
		*pOplock = pSMBr->OplockLevel; /* 1 byte no need to le_to_cpu */
		*netfid = pSMBr->Fid;	/* cifs fid stays in le */
		/* Let caller know file was created so we can set the mode. */
		/* Do we care about the CreateAction in any other cases? */
		if (cpu_to_le32(FILE_CREATE) == pSMBr->CreateAction)
			*pOplock |= CIFS_CREATE_ACTION;
		if (pfile_info) {
		    memcpy((char *)pfile_info, (char *)&pSMBr->CreationTime,
			36 /* CreationTime to Attributes */);
		    /* the file_info buf is endian converted by caller */
		    pfile_info->AllocationSize = pSMBr->AllocationSize;
		    pfile_info->EndOfFile = pSMBr->EndOfFile;
		    pfile_info->NumberOfLinks = cpu_to_le32(1);
		}
	}

	cifs_buf_release(pSMB);
	if (rc == -EAGAIN)
		goto openRetry;
	return rc;
}

int
CIFSSMBRead(const int xid, struct cifsTconInfo *tcon, const int netfid,
	    const unsigned int count, const __u64 lseek, unsigned int *nbytes,
	    char **buf, int *pbuf_type)
{
	int rc = -EACCES;
	READ_REQ *pSMB = NULL;
	READ_RSP *pSMBr = NULL;
	char *pReadData = NULL;
	int wct;
	int resp_buf_type = 0;
	struct kvec iov[1];

	cFYI(1, ("Reading %d bytes on fid %d", count, netfid));
	if (tcon->ses->capabilities & CAP_LARGE_FILES)
		wct = 12;
	else
		wct = 10; /* old style read */

	*nbytes = 0;
	rc = small_smb_init(SMB_COM_READ_ANDX, wct, tcon, (void **) &pSMB);
	if (rc)
		return rc;

	/* tcon and ses pointer are checked in smb_init */
	if (tcon->ses->server == NULL)
		return -ECONNABORTED;

	pSMB->AndXCommand = 0xFF;       /* none */
	pSMB->Fid = netfid;
	pSMB->OffsetLow = cpu_to_le32(lseek & 0xFFFFFFFF);
	if (wct == 12)
		pSMB->OffsetHigh = cpu_to_le32(lseek >> 32);
	else if ((lseek >> 32) > 0) /* can not handle this big offset for old */
		return -EIO;

	pSMB->Remaining = 0;
	pSMB->MaxCount = cpu_to_le16(count & 0xFFFF);
	pSMB->MaxCountHigh = cpu_to_le32(count >> 16);
	if (wct == 12)
		pSMB->ByteCount = 0;  /* no need to do le conversion since 0 */
	else {
		/* old style read */
		struct smb_com_readx_req *pSMBW =
			(struct smb_com_readx_req *)pSMB;
		pSMBW->ByteCount = 0;
	}

	iov[0].iov_base = (char *)pSMB;
	iov[0].iov_len = pSMB->hdr.smb_buf_length + 4;
	rc = SendReceive2(xid, tcon->ses, iov,
			  1 /* num iovecs */,
			  &resp_buf_type, 0);
	cifs_stats_inc(&tcon->num_reads);
	pSMBr = (READ_RSP *)iov[0].iov_base;
	if (rc) {
		cERROR(1, ("Send error in read = %d", rc));
	} else {
		int data_length = le16_to_cpu(pSMBr->DataLengthHigh);
		data_length = data_length << 16;
		data_length += le16_to_cpu(pSMBr->DataLength);
		*nbytes = data_length;

		/*check that DataLength would not go beyond end of SMB */
		if ((data_length > CIFSMaxBufSize)
				|| (data_length > count)) {
			cFYI(1, ("bad length %d for count %d",
				 data_length, count));
			rc = -EIO;
			*nbytes = 0;
		} else {
			pReadData = (char *) (&pSMBr->hdr.Protocol) +
					le16_to_cpu(pSMBr->DataOffset);
/*			if (rc = copy_to_user(buf, pReadData, data_length)) {
				cERROR(1,("Faulting on read rc = %d",rc));
				rc = -EFAULT;
			}*/ /* can not use copy_to_user when using page cache*/
			if (*buf)
				memcpy(*buf, pReadData, data_length);
		}
	}

/*	cifs_small_buf_release(pSMB); */ /* Freed earlier now in SendReceive2 */
	if (*buf) {
		if (resp_buf_type == CIFS_SMALL_BUFFER)
			cifs_small_buf_release(iov[0].iov_base);
		else if (resp_buf_type == CIFS_LARGE_BUFFER)
			cifs_buf_release(iov[0].iov_base);
	} else if (resp_buf_type != CIFS_NO_BUFFER) {
		/* return buffer to caller to free */
		*buf = iov[0].iov_base;
		if (resp_buf_type == CIFS_SMALL_BUFFER)
			*pbuf_type = CIFS_SMALL_BUFFER;
		else if (resp_buf_type == CIFS_LARGE_BUFFER)
			*pbuf_type = CIFS_LARGE_BUFFER;
	} /* else no valid buffer on return - leave as null */

	/* Note: On -EAGAIN error only caller can retry on handle based calls
		since file handle passed in no longer valid */
	return rc;
}


int
CIFSSMBWrite(const int xid, struct cifsTconInfo *tcon,
	     const int netfid, const unsigned int count,
	     const __u64 offset, unsigned int *nbytes, const char *buf,
	     const char __user *ubuf, const int long_op)
{
	int rc = -EACCES;
	WRITE_REQ *pSMB = NULL;
	WRITE_RSP *pSMBr = NULL;
	int bytes_returned, wct;
	__u32 bytes_sent;
	__u16 byte_count;

	/* cFYI(1,("write at %lld %d bytes",offset,count));*/
	if (tcon->ses == NULL)
		return -ECONNABORTED;

	if (tcon->ses->capabilities & CAP_LARGE_FILES)
		wct = 14;
	else
		wct = 12;

	rc = smb_init(SMB_COM_WRITE_ANDX, wct, tcon, (void **) &pSMB,
		      (void **) &pSMBr);
	if (rc)
		return rc;
	/* tcon and ses pointer are checked in smb_init */
	if (tcon->ses->server == NULL)
		return -ECONNABORTED;

	pSMB->AndXCommand = 0xFF;	/* none */
	pSMB->Fid = netfid;
	pSMB->OffsetLow = cpu_to_le32(offset & 0xFFFFFFFF);
	if (wct == 14)
		pSMB->OffsetHigh = cpu_to_le32(offset >> 32);
	else if ((offset >> 32) > 0) /* can not handle big offset for old srv */
		return -EIO;

	pSMB->Reserved = 0xFFFFFFFF;
	pSMB->WriteMode = 0;
	pSMB->Remaining = 0;

	/* Can increase buffer size if buffer is big enough in some cases ie we
	can send more if LARGE_WRITE_X capability returned by the server and if
	our buffer is big enough or if we convert to iovecs on socket writes
	and eliminate the copy to the CIFS buffer */
	if (tcon->ses->capabilities & CAP_LARGE_WRITE_X) {
		bytes_sent = min_t(const unsigned int, CIFSMaxBufSize, count);
	} else {
		bytes_sent = (tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE)
			 & ~0xFF;
	}

	if (bytes_sent > count)
		bytes_sent = count;
	pSMB->DataOffset =
		cpu_to_le16(offsetof(struct smb_com_write_req, Data) - 4);
	if (buf)
	    memcpy(pSMB->Data, buf, bytes_sent);
	else if (ubuf) {
		if (copy_from_user(pSMB->Data, ubuf, bytes_sent)) {
			cifs_buf_release(pSMB);
			return -EFAULT;
		}
	} else if (count != 0) {
		/* No buffer */
		cifs_buf_release(pSMB);
		return -EINVAL;
	} /* else setting file size with write of zero bytes */
	if (wct == 14)
		byte_count = bytes_sent + 1; /* pad */
	else /* wct == 12 */ {
		byte_count = bytes_sent + 5; /* bigger pad, smaller smb hdr */
	}
	pSMB->DataLengthLow = cpu_to_le16(bytes_sent & 0xFFFF);
	pSMB->DataLengthHigh = cpu_to_le16(bytes_sent >> 16);
	pSMB->hdr.smb_buf_length += byte_count;

	if (wct == 14)
		pSMB->ByteCount = cpu_to_le16(byte_count);
	else { /* old style write has byte count 4 bytes earlier
		  so 4 bytes pad  */
		struct smb_com_writex_req *pSMBW =
			(struct smb_com_writex_req *)pSMB;
		pSMBW->ByteCount = cpu_to_le16(byte_count);
	}

	rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
			 (struct smb_hdr *) pSMBr, &bytes_returned, long_op);
	cifs_stats_inc(&tcon->num_writes);
	if (rc) {
		cFYI(1, ("Send error in write = %d", rc));
		*nbytes = 0;
	} else {
		*nbytes = le16_to_cpu(pSMBr->CountHigh);
		*nbytes = (*nbytes) << 16;
		*nbytes += le16_to_cpu(pSMBr->Count);
	}

	cifs_buf_release(pSMB);

	/* Note: On -EAGAIN error only caller can retry on handle based calls
		since file handle passed in no longer valid */

	return rc;
}

int
CIFSSMBWrite2(const int xid, struct cifsTconInfo *tcon,
	     const int netfid, const unsigned int count,
	     const __u64 offset, unsigned int *nbytes, struct kvec *iov,
	     int n_vec, const int long_op)
{
	int rc = -EACCES;
	WRITE_REQ *pSMB = NULL;
	int wct;
	int smb_hdr_len;
	int resp_buf_type = 0;

	cFYI(1, ("write2 at %lld %d bytes", (long long)offset, count));

	if (tcon->ses->capabilities & CAP_LARGE_FILES)
		wct = 14;
	else
		wct = 12;
	rc = small_smb_init(SMB_COM_WRITE_ANDX, wct, tcon, (void **) &pSMB);
	if (rc)
		return rc;
	/* tcon and ses pointer are checked in smb_init */
	if (tcon->ses->server == NULL)
		return -ECONNABORTED;

	pSMB->AndXCommand = 0xFF;	/* none */
	pSMB->Fid = netfid;
	pSMB->OffsetLow = cpu_to_le32(offset & 0xFFFFFFFF);
	if (wct == 14)
		pSMB->OffsetHigh = cpu_to_le32(offset >> 32);
	else if ((offset >> 32) > 0) /* can not handle big offset for old srv */
		return -EIO;
	pSMB->Reserved = 0xFFFFFFFF;
	pSMB->WriteMode = 0;
	pSMB->Remaining = 0;

	pSMB->DataOffset =
	    cpu_to_le16(offsetof(struct smb_com_write_req, Data) - 4);

	pSMB->DataLengthLow = cpu_to_le16(count & 0xFFFF);
	pSMB->DataLengthHigh = cpu_to_le16(count >> 16);
	smb_hdr_len = pSMB->hdr.smb_buf_length + 1; /* hdr + 1 byte pad */
	if (wct == 14)
		pSMB->hdr.smb_buf_length += count+1;
	else /* wct == 12 */
		pSMB->hdr.smb_buf_length += count+5; /* smb data starts later */
	if (wct == 14)
		pSMB->ByteCount = cpu_to_le16(count + 1);
	else /* wct == 12 */ /* bigger pad, smaller smb hdr, keep offset ok */ {
		struct smb_com_writex_req *pSMBW =
				(struct smb_com_writex_req *)pSMB;
		pSMBW->ByteCount = cpu_to_le16(count + 5);
	}
	iov[0].iov_base = pSMB;
	if (wct == 14)
		iov[0].iov_len = smb_hdr_len + 4;
	else /* wct == 12 pad bigger by four bytes */
		iov[0].iov_len = smb_hdr_len + 8;


	rc = SendReceive2(xid, tcon->ses, iov, n_vec + 1, &resp_buf_type,
			  long_op);
	cifs_stats_inc(&tcon->num_writes);
	if (rc) {
		cFYI(1, ("Send error Write2 = %d", rc));
		*nbytes = 0;
	} else if (resp_buf_type == 0) {
		/* presumably this can not happen, but best to be safe */
		rc = -EIO;
		*nbytes = 0;
	} else {
		WRITE_RSP * pSMBr = (WRITE_RSP *)iov[0].iov_base;
		*nbytes = le16_to_cpu(pSMBr->CountHigh);
		*nbytes = (*nbytes) << 16;
		*nbytes += le16_to_cpu(pSMBr->Count);
	}

/*	cifs_small_buf_release(pSMB); */ /* Freed earlier now in SendReceive2 */
	if (resp_buf_type == CIFS_SMALL_BUFFER)
		cifs_small_buf_release(iov[0].iov_base);
	else if (resp_buf_type == CIFS_LARGE_BUFFER)
		cifs_buf_release(iov[0].iov_base);

	/* Note: On -EAGAIN error only caller can retry on handle based calls
		since file handle passed in no longer valid */

	return rc;
}


int
CIFSSMBLock(const int xid, struct cifsTconInfo *tcon,
	    const __u16 smb_file_id, const __u64 len,
	    const __u64 offset, const __u32 numUnlock,
	    const __u32 numLock, const __u8 lockType, const int waitFlag)
{
	int rc = 0;
	LOCK_REQ *pSMB = NULL;
	LOCK_RSP *pSMBr = NULL;
	int bytes_returned;
	int timeout = 0;
	__u16 count;

	cFYI(1, ("In CIFSSMBLock - timeout %d numLock %d", waitFlag, numLock));
	rc = small_smb_init(SMB_COM_LOCKING_ANDX, 8, tcon, (void **) &pSMB);

	if (rc)
		return rc;

	pSMBr = (LOCK_RSP *)pSMB; /* BB removeme BB */

	if (lockType == LOCKING_ANDX_OPLOCK_RELEASE) {
		timeout = -1; /* no response expected */
		pSMB->Timeout = 0;
	} else if (waitFlag == TRUE) {
		timeout = 3;  /* blocking operation, no timeout */
		pSMB->Timeout = cpu_to_le32(-1);/* blocking - do not time out */
	} else {
		pSMB->Timeout = 0;
	}

	pSMB->NumberOfLocks = cpu_to_le16(numLock);
	pSMB->NumberOfUnlocks = cpu_to_le16(numUnlock);
	pSMB->LockType = lockType;
	pSMB->AndXCommand = 0xFF;	/* none */
	pSMB->Fid = smb_file_id; /* netfid stays le */

	if ((numLock != 0) || (numUnlock != 0)) {
		pSMB->Locks[0].Pid = cpu_to_le16(current->tgid);
		/* BB where to store pid high? */