How does C++ function implement network sniffing in network programming?

Network sniffing in C can be achieved through the pcap library. Use pcap_lookupdev(NULL) to find the network adapter, pcap_open_live() to open the sniffing interface, pcap_loop() to listen for packets, and use a callback function (such as packet_handler) to handle the captured packets. This technology can be used for penetration testing, security monitoring, and network troubleshooting.

Network sniffing using C functions

Network sniffing allows developers to capture and analyze network traffic, which is useful for penetration testing , security monitoring and network troubleshooting are critical. In C, network sniffing can be performed using a library called "pcap".

Code example:

#include <pcap.h>
#include <iostream>

int main() {
  // 打开用于嗅探的网卡
  char *dev = pcap_lookupdev(NULL);
  pcap_t *handle = pcap_open_live(dev, BUFSIZ, 1, 1000, NULL);

  // 定义回调函数以处理捕获的数据包
  void packet_handler(u_char *args, const struct pcap_pkthdr *header, const u_char *packet) {
    std::cout << "捕获到数据包：" << std::endl;
    std::cout << "包大小：" << header->len << std::endl;
  }

  // 将回调函数附加到捕获的句柄
  pcap_loop(handle, -1, packet_handler, NULL);

  // 关闭嗅探句柄
  pcap_close(handle);
  
  return 0;
}

Practical case:

This code can be used to capture and analyze the network during penetration testing traffic to identify potential vulnerabilities or network attacks. Additionally, it can be used to monitor network activity, detect security incidents, or troubleshoot network issues.

Other notes:

• pcap_lookupdev(NULL) Used to find the default network adapter.
• pcap_open_live() Function opens the adapter interface for sniffing.
• pcap_loop() The function starts listening for data packets and executes the callback function.
• The callback function can be modified as needed to perform other operations, such as writing to a file or performing deeper analysis.

The above is the detailed content of How does C++ function implement network sniffing in network programming?. For more information, please follow other related articles on the PHP Chinese website!