Thread: Socket Programming in C

Trying to program a stop and wait network protocol in C which will send a packet in the form of a struct

Code:

struct MyHdr{
	unsigned char seq;  //sequence number
	unsigned char wndwsize;  //size of the send window
	unsigned char pcktsize;   //packet size
	data char[sizeof pcktsize];    //data array size of packetsize (-overhead)
};

I have been reading up on the send() and recv() classes but still don't have enough knowledge to know how to send a "packet" over. Can someone clarify how to do this with me?

Here's what I have been playing with

Code:

	

while(fread(buffer,1,64,in) !=0){
		struct MyHdr packet;
		
		resent =0;
		count++;
		
		packet.pcktsize = buffer;//copy buffer into our packet 64bytes
		packet.seq = count;
		packet.wndwsize = count;
		
		do
		{
		//something with a CRC
		//
		}

		send(sockfd,packet);

	}

Can I just send with the given socket and the packet? Also how would I receive it?

can someone move this to the C programming forum?

You do not need to worry about the header portion of the packet; this will be done for you. All you need to worry about is the packet payload (the data you are sending and receiving).

In other words, something like this is perfectly valid:

Code:

send(fd, "here is some data", 18, 0);

From your code, it's clear that you need to read the documentation on the send() function. You do not need to worry about CRCs, sequence numbers, or window sizes.

Hi all,

Can anybody give me a guideline for writing a DHCP client using socket programming on Linux platform?

Any kind of help, suggestion of good books and links will be highly appreciated ...

Thanks and regards,
Dash

what are netlink sockets. When and why they are used.