Windows SIO_RCVALL 完整代码示例

Windows SIO_RCVALL 是用于接收网络包的一个特殊的套接字选项，它允许应用程序一次性接收所有的可用数据，包括分片的数据报。这是一个高级功能，通常在需要处理大型数据传输或者需要完整数据流的情况下使用。以下是一个简单的代码示例，展示如何设置和使用这个选项：

#include <winsock2.h>
#include <ws2tcpip.h>
#include <windows.h>

#pragma comment(lib, "Ws2_32.lib")

int main() {
    WSADATA wsaData;
    int iResult;

    // 初始化 Winsock
    iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
    if (iResult != 0) {
        printf("WSAStartup failed: %d\n", iResult);
        return 1;
    }

    SOCKET ListenSocket = socket(AF_INET, SOCK_RAW, IPPROTO_IP); // 创建原始套接字
    if (ListenSocket == INVALID_SOCKET) {
        printf("socket failed with error: %ld\n", WSAGetLastError());
        WSACleanup();
        return 1;
    }

    sockaddr_in addr;
    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = htonl(INADDR_ANY);
    addr.sin_port = htons(RAW_IPPORT_ANY);

    // 设置SO_RCVALL选项
    u_long level = IPPROTO_IP;
    int on = 1; // ON for receiving all packets
    iResult = setsockopt(ListenSocket, level, SO_RCVALL, (char*)&on, sizeof(on));
    if (iResult == SOCKET_ERROR) {
        printf("setsockopt(SO_RCVALL) failed: %d\n", WSAGetLastError());
        closesocket(ListenSocket);
        WSACleanup();
        return 1;
    }

    // 现在可以开始监听和接收数据
    char buffer[4096];
    DWORD dwBytesReceived = 0;
    while (true) {
        iResult = recvfrom(ListenSocket, buffer, sizeof(buffer), 0, (sockaddr*)&addr, &dwBytesReceived);
        if (iResult > 0) {
            printf("Received %d bytes from %s\n", iResult, inet_ntoa(addr.sin_addr));
        } else {
            printf("recvfrom failed with error: %d\n", WSAGetLastError());
            break;
        }
    }

    // 关闭套接字和清理
    closesocket(ListenSocket);
    WSACleanup();

    return 0;
}