在winpcap中创建udp完整报文包含以太网帧头,并且发送数据,使用c++编写有个示例

在WinPcap库中，你需要先安装它并在C++项目中链接，以便能够处理网络包。创建UDP完整报文并附带以太网帧头涉及到底层网络编程，这里提供一个简化版的C++示例，展示了如何完成这个任务：

#include <pcap.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// Ethernet header structure
struct EthHeader {
    uint8_t dest[6];   // Destination MAC address
    uint8_t src[6];     // Source MAC address
    uint16_t type;      // EtherType (usually UDP)
};

// IP header structure
struct IpHeader {
    uint8_t ver_ihl;   // Version and Internet Header Length
    uint16_t tos;       // Type of Service
    uint16_t total_len; // Total length in bytes
    uint16_t id;        // Identification number
    uint16_t frag_off;  // Fragment offset
    uint8_t ttl;        // Time to live
    uint8_t proto;      // Protocol (17 for UDP)
    uint16_t check;     // Checksum
    struct In_addr saddr; // Source IP address
    struct In_addr daddr; // Destination IP address
};

// UDP header structure
struct UdpHeader {
    uint16_t source_port;   // Source port number
    uint16_t destination_port;   // Destination port number
    uint16_t len;            // Data length in bytes
    uint16_t checksum;       // UDP checksum
};

int main() {
    char errbuf[PCAP_ERRBUF_SIZE];
    pcap_if_t* devices;
    pcap_t* handle;
    bpf_u_int32 filter = 0;
    struct EthHeader eth;
    struct IpHeader ip;
    struct UdpHeader udp;

    // Get the list of network interfaces
    if ((devices = pcap_findalldevs(&errbuf)) == NULL) {
        printf("Error opening device: %s\n", errbuf);
        return -1;
    }

    // Select a network interface for capture
    char nic_name[PCAP_IF_MAXNAMELEN];
    pcap_if_t* selected_device = devices;
    while (selected_device != NULL) {
        strncpy(nic_name, selected_device->name, PCAP_IF_MAXNAMELEN - 1);
        nic_name[PCAP_IF_MAXNAMELEN - 1] = '\0';
        if (nic_name[0] != '\0') { // Replace with your desired interface name
            break;
        }
        selected_device = selected_device->next;
    }

    if (selected_device == NULL) {
        printf("No network interface found.\n");
        free(devices);
        return -1;
    }

    // Open a handle to the device
    if ((handle = pcap_open_live(nic_name, BUFSIZ, 1, 1000, errbuf)) == NULL) {
        printf("Error opening device: %s\n", errbuf);
        free(devices);
        return -1;
    }

    // Set up Ethernet frame
    memset(&eth, 0, sizeof(eth));
    memcpy(eth.dest, "YourDestinationMAC", 6); // Replace with destination MAC
    memcpy(eth.src, "YourSourceMAC", 6); // Replace with source MAC

    // Set up IP packet
    memset(&ip, 0, sizeof(ip));
    ip.ver_ihl = 4 << 4 | 5; // IPv4, no fragmentation
    ip.total_len = htons(sizeof(struct EthHeader) + sizeof(struct IpHeader) + sizeof(struct UdpHeader) + /*YourDataLength*/);
    ip.tos = 0; // Set as needed
    ip.id = htons(time(NULL)); // Random identifier
    ip.proto = IPPROTO_UDP; // UDP protocol
    ip.check = 0; // Calculate and set later when we have the full packet

    // Set up UDP packet
    memset(&udp, 0, sizeof(udp));
    udp.source_port = htons(/*YourSourcePort*/);
    udp.destination_port = htons(/*YourDestinationPort*/);
    udp.len = htons(sizeof(struct EthHeader) + sizeof(struct IpHeader) + sizeof(struct UdpHeader));

    // Create a packet payload (replace this with your actual data)
    char data[] = "YourData"; // Replace with your string or binary data

    // Build the complete packet by concatenating headers and data
    unsigned char packet[ETH_HEADER_LEN + IP_HEADER_LEN + UDP_HEADER_LEN + strlen(data)];
    memcpy(packet, &eth, ETH_HEADER_LEN);
    memcpy(packet + ETH_HEADER_LEN, &ip, IP_HEADER_LEN);
    memcpy(packet + ETH_HEADER_LEN + IP_HEADER_LEN, &udp, UDP_HEADER_LEN);
    memcpy(packet + ETH_HEADER_LEN + IP_HEADER_LEN + UDP_HEADER_LEN, data, strlen(data));

    // Calculate IP checksum if not already done
    ip.check = in_cksum((uint16_t*)&ip, sizeof(ip));

    // Send the packet
    if (pcap_sendpacket(handle, packet, ETH_HEADER_LEN + IP_HEADER_LEN + UDP_HEADER_LEN + strlen(data)) < 0) {
        printf("Error sending packet: %s\n", pcap_geterr(handle));
    }

    // Close the handle
    pcap_close(handle);

    free(devices);
    return 0;
}

请注意，这只是一个基本示例，并未涵盖错误处理和完整的IP/UDP checksum计算。实际应用中需要考虑更多的边界条件和错误处理。此外，这个例子假设你的目标设备在同一局域网内，如果跨路由器传输，还需要设置相应的路由规则。