Pinging from a C/C++ program
Have a blast at The Ping Page, which has a link to full source on the original Unix ping(8).
network-programming
AlamoFire Download in Background Session
Update Based on this amazing tutorial, I have put together an example project available on GitHub. It has an example for background session management. According to Apple’s URL Loading System Programming Guide: In both iOS and OS X, when the user relaunches your app, your app should immediately create background configuration objects with the same … Read more
What is “backlog” in TCP connections?
NOTE : Answers are framed without having any background in Python, but, the questions are irrelevant to language, to be answered. What are these queued connections? In simple words, the backlog parameter specifies the number of pending connections the queue will hold. When multiple clients connect to the server, the server then holds the incoming … Read more
Sending and receiving files on socket
You need to: Send the length of the file ahead of the file. You can use DataOutputStream.writeLong() for that, and DataInputStream.readLong() at the receiver. Read exactly that many bytes from the stream at the receiver: while (total < length && (count = in.read(buffer, 0, length-total > buffer.length ? buffer.length : (int)(length-total))) > 0) { out.write(buffer, … Read more
How to exit a blocking recv() call? [duplicate]
You can shutdown() the socket for input. The recv() will unblock and return zero and everybody will be happy.
Get the Default Gateway
It will probably be the first valid and enabled gateway address of the first enabled network interface: public static IPAddress GetDefaultGateway() { return NetworkInterface .GetAllNetworkInterfaces() .Where(n => n.OperationalStatus == OperationalStatus.Up) .Where(n => n.NetworkInterfaceType != NetworkInterfaceType.Loopback) .SelectMany(n => n.GetIPProperties()?.GatewayAddresses) .Select(g => g?.Address) .Where(a => a != null) // .Where(a => a.AddressFamily == AddressFamily.InterNetwork) // .Where(a => … Read more
How send raw ethernet packet with C#? [closed]
Based on suggestion by Saint_pl: I found probably better solution – similar to SharpPcap. It’s Pcap.Net – .NET wrapper for WinPcap. Now I can modify my packets whatever I want. I have some resources for you that maybe helpful. I don’t try that solutions in Windows 7 but maybe it contains some good info to … Read more
How do you determine if an IP address is private, in Python?
Since Python 3.3 there is an ipaddress module in the stdlib that you can use. >>> import ipaddress >>> ipaddress.ip_address(‘192.168.0.1’).is_private True If using Python 2.6 or higher I would strongly recommend to use a backport of this module.
how to bind raw socket to specific interface
const char *opt; opt = “eth0”; const len = strnlen(opt, IFNAMSIZ); if (len == IFNAMSIZ) { fprintf(stderr, “Too long iface name”); return 1; } setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, opt, len); First line: set up your variable Second line: tell the program which interface to bind to Lines 3-5: get length of interface name and check if … Read more
Application control of TCP retransmission on Linux
Looks like this was added in Kernel 2.6.37. Commit diff from kernel Git and Excerpt from change log below; commit dca43c75e7e545694a9dd6288553f55c53e2a3a3 Author: Jerry Chu Date: Fri Aug 27 19:13:28 2010 +0000 tcp: Add TCP_USER_TIMEOUT socket option. This patch provides a “user timeout” support as described in RFC793. The socket option is also needed for the … Read more