我目前正在使用网络的项目。我必须发送一个结构通过C++中的套接字的数据
struct Header
{
uint32_t magic;
uint32_t checksum;
uint32_t timestamp;
uint16_t commandId;
uint16_t dataSize;
};
struct Packet
{
struct Header header;
char data[128];
};
我试图从一个套接字发送结构数据包到另一个使用TCP。我试图把我的结构一样,
send(socket, &my_struct, sizeof(my_struct), 0);
但它不工作,所以我已经试过*
unsigned char *Serialization::serialize_uint32(unsigned char *buffer, uint32_t arg)
{
buffer[3] = (arg >> 24);
buffer[2] = (arg >> 16);
buffer[1] = (arg >> 8);
buffer[0] = (arg);
return (buffer + sizeof(uint32_t));
}
unsigned char *Serialization::serialize_uint16(unsigned char *buffer, uint16_t arg)
{
buffer[1] = (arg >> 8);
buffer[0] = (arg);
return (buffer + sizeof(uint16_t));
}
unsigned char *Serialization::deserialize_uint32(unsigned char *buffer, uint32_t *arg)
{
memcpy((char*)arg, buffer, sizeof(uint32_t));
return (buffer + sizeof(uint32_t));
}
unsigned char *Serialization::deserialize_uint16(unsigned char *buffer, uint16_t *arg)
{
memcpy((char*)arg, buffer, sizeof(uint16_t));
return (buffer + sizeof(uint16_t));
}
即使在客户端symply发送结构序列化我的结构到一个char当我读取服务器端时,标头数据已损坏 为什么数据损坏?
客户端发送环路
TcpSocket tcp;
Packet p;
std::stringstream ss;
int cpt = 0;
int ret = 0;
char *serialized;
tcp.connectSocket("127.0.0.1", 4242);
while (getchar())
{
ss.str("");
ss.clear();
ss << cpt++;
p.header.magic = 0;
p.header.checksum = 1;
p.header.timestamp = 2;
p.header.commandId = 3;
p.header.dataSize = ss.str().length();
memset(p.data, 0, 128);
memcpy(p.data, ss.str().c_str(), ss.str().length());
serialized = new char[sizeof(Header) + ss.str().length()];
bzero(serialized, sizeof(Header) + ss.str().length());
Serialization::serialize_packet(serialized, p);
hexDump("serialized", serialized+1, sizeof(Header) + ss.str().length());
ret = tcp.write(serialized+1, sizeof(Header) + ss.str().length());
}
服务器的recv循环:
buff = new char[bav];
socket->read(buff, bav);
hexdump("buff", buff, bav);
(通过select()调用fonction)插座 - >阅读():
int TcpSocket::read(char *buff, int len)
{
int ret;
ret = recv(this->_socket, buff, len, 0);
return (ret);
}
当我运行那些方案:
./server
[Server] new connexion :: [5]
recv returns : 17
buff serialized:
0000 00 00 00 00 14 00 00 00 1c 00 00 00 1a 00 00 00 ................
0010 1b
./client
serialized data:
0000 00 00 00 00 00 00 01 00 00 00 02 00 03 00 01 30 ...............0
0010 00
send returns : 17
我们是否假定客户端是用适当的反向算法解压缩的(注意你应该使用'unsigned char'作为你的包缓冲区)。另外,第一种情况下的结构打包以及机器端格式*将起作用。 – WhozCraig
对于uint16和uint32,您可以使用ntohl,ntohs,htonl和htons。简短的答案是这样的:您必须在字节级精确定义数据格式,并且在发送和接收时正确地将数据格式转换为“有线格式”或从该格式转换而来。 –
@DavidSchwartz我同意,但是当我在几天前提出这个问题的时候,由于它不在“标准”中,所以我总结了一个问题。仍然从那一个刺痛(我仍然会用POSIX函数来做,无论顺便说一句,就像你可能会那样)。 – WhozCraig