Re^2: Need help with (un)pack templates

Replies are listed 'Best First'.
Re^3: Need help with (un)pack templates by gmargo (Hermit) on Dec 20, 2009 at 14:08 UTC
I typed it in from the front inside cover of my Stevens book (TCP/IP Illustrated Volume 1). Wikipedia has it too: http://en.wikipedia.org/wiki/IPv4, but the real gospel is RFC791: http://www.ietf.org/rfc/rfc791.txt. Update: Other protocol standards you might like: RFC 768 User Datagram Protocol RFC 792 Internet Control Message Protocol RFC 793 Transmission Control Protocol	[reply]
Re^4: Need help with (un)pack templates by Subop (Acolyte) on Dec 20, 2009 at 14:23 UTC
I have that same book and just see the IP header format. How do you know what letters to use in the (un)pack template just by looking at the header format?	[reply]
Re^5: Need help with (un)pack templates by gmargo (Hermit) on Dec 20, 2009 at 14:39 UTC
It's pretty well spelled out in the pack documentation. C for unsigned char (byte), n for unsigned 16-bit short in network order, N for 32-bit long in network order, a for "arbitrary binary data". Don't be confused by the 32-bit CCCC's, since an IP address is 4 8-bit numbers, not a 32-bit number.	[reply]
Re^6: Need help with (un)pack templates by ikegami (Patriarch) on Dec 20, 2009 at 17:25 UTC
Re^6: Need help with (un)pack templates by keszler (Priest) on Dec 20, 2009 at 15:06 UTC
Re^7: Need help with (un)pack templates by gmargo (Hermit) on Dec 20, 2009 at 17:08 UTC
Re^6: Need help with (un)pack templates by Subop (Acolyte) on Dec 20, 2009 at 15:47 UTC