C++ packet sniffing

[nucleo_type98]

how do you actually sniff/capture a packets in c++? is it even possible?

 

[Takis99]

There is always an answer on google my friend.

 

[nucleo_type98]

There is always an answer on google my friend.

but then what's the goal of having forums?

 

[FResher]

see by "winpcap" lib.

It's a capture lib used by "wireshark/etherreal" tool.
those tools are design to make network capture for lot of protocols ( Eth / Wifi ... )

it could help you a lot.
If I remenber it's an open project at starting, perfect for your needs.

 

[nucleo_type98]

see by "winpcap" lib.

It's a capture lib used by "wireshark/etherreal" tool.
those tools are design to make network capture for lot of protocols ( Eth / Wifi ... )

it could help you a lot.
If I remenber it's an open project at starting, perfect for your needs.

thanks dude, does it work on both linux/windows if i may ask?

 

[Infinityhost]

winsocket is cool thing

You pockets are here xD

 

[alexcray]

how do you actually sniff/capture a packets in c++? is it even possible?

Yes, it's possible to sniff or capture packets in C++. However, it typically involves using platform-specific libraries or APIs to interact with the network interface and handle packet capture.

One of the most commonly used libraries for packet sniffing in C++ is libpcap, which is a portable C/C++ library for network traffic capture. It provides functions and data structures for capturing packets from a network interface, filtering packets based on various criteria, and processing captured packets.

Here's a basic outline of how you can capture packets using libpcap in C++:

1. Include libpcap Header: Include the libpcap header file in your C++ source code:
   cpp
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   #include <pcap.h>
2. Open a Network Interface: Open a network interface for packet capture using the pcap_open_live() function:
   cpp
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   pcap_t* handle;
   char errbuf[PCAP_ERRBUF_SIZE];
   handle = pcap_open_live("eth0", BUFSIZ, 1, 1000, errbuf);
   if (handle == NULL) {
   fprintf(stderr, "Error opening interface: %s\n", errbuf);
   return -1;
   }
   Replace "eth0" with the name of the network interface you want to capture packets from.
3. Set Packet Capture Filter (Optional): Optionally, you can set a packet capture filter using the pcap_compile() and pcap_setfilter() functions to specify which packets you want to capture:
   cpp
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   struct bpf_program fp;
   char filter_exp[] = "tcp port 80";
   if (pcap_compile(handle, &fp, filter_exp, 0, PCAP_NETMASK_UNKNOWN) == -1) {
   fprintf(stderr, "Error compiling filter\n");
   return -1;
   }
   if (pcap_setfilter(handle, &fp) == -1) {
   fprintf(stderr, "Error setting filter\n");
   return -1;
   }
   This example filter captures only TCP packets with destination port 80 (HTTP).
4. Capture Packets: Use the pcap_loop() function to capture packets in a loop:
   cpp
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   void packet_handler(u_char* user_data, const struct pcap_pkthdr* pkthdr, const u_char* packet) {
   // Packet processing code goes here
   }
   
   pcap_loop(handle, -1, packet_handler, NULL);
   The packet_handler function is called for each captured packet, and you can process the packet data within this function.
5. Close the Capture Handle: Close the capture handle when done:
   cpp
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   pcap_close(handle);

This is a simplified overview of packet capture using libpcap in C++. Depending on your specific requirements and use case, you may need to handle packet processing, filtering, and other tasks more elaborately within your code. Additionally, be aware of potential security and legal considerations when capturing network traffic.