一个问题，困扰多时

我定义了一个结构
typedef struct _WRITE_CMD
{
unsigned long cmd_id;
unsigned long start_lba;
unsigned long write_len;
unsigned char sector[1];

} WRITE_CMD, *PWRITE_CMD;

通过如下方式分配空间
unsigned char sector[1]这个变量的空间不定。

ULONG dBufferSize;
dBufferSize = sizeof(unsigned long) * 2+ left＋1;

write_cmd = (PWRITE_CMD)ExAllocatePool (
NonPagedPool,
dBufferSize);

write_cmd->cmd_id = 0x2a

write_cmd->start_lba = htonl(StartLBA);
write_cmd->write_len = htonl(left);

RtlCopyMemory((void*)write_cmd->sector, (UCHAR *)(pSrb->DataBuffer), left);

len = sizeof(dBufferSize);
dStatus = TdiSendDatagram ( // send datagram
pTdiTransportObject, // to transport
MY_PORT, // port
dTdiRemoteAddress, // address
&write_cmd, // data
len ); // size
if ( !NT_SUCCESS ( dStatus ) )
DbgPrint ( \"ERROR: writing sending %X\\n\", dStatus );
else
DbgPrint ( \"writing send success\\n\" );
发到Server端以后
通过
iRtn = recvfrom( s, (char *)buf, sizeof(buf), 0, (struct sockaddr *)&from, &len);接收数据
后，发现buf[0]不是0x2a，同时通过
WRITE_CMD *p_write_cmd = (WRITE_CMD *)buf;
  int len = ntohl(p_write_cmd->write_len);
这样的得到的len 不正确。