fragmentation in linux for IXP2350 proc

subraybhat · 11-28-2007, 04:28 AM

I need to fragment the IPv4 packets which are longer than MTU and DF bit is not set,by sending it to OS.
Is there any inbuilt function in linux kernel to fragment the packet according to the size MTU of next span of the network?
How do I send the packet to linux kernel and how do i recieve the fragmented packets from linux kernel?
plz suggest me some packet handling mechanism in such case.
Mainly i need to do this operation in IXP2350 processor.

Mara · 11-29-2007, 05:03 PM

Moved: This thread is more suitable in Linux-Kernel and has been moved accordingly to help your thread/question get the exposure it deserves.

The functions are in ip_fragment.c (in net/ipv4/ directory of the kernel sources). All that functionality is used by the input and output functions for IP.

If you plan to use that functionality without touching the code, you can setup normal routing and set MTU at the link out of the Linux machine to the desired value. Before being sent to the interface, the packets will get fragmented and you'll get what you want.

subraybhat · 11-30-2007, 01:06 AM

i am using reassembly of packet functionality.The reassembled packets are clloected back from kernel by an open socket. So if i go for another open socket to collect fragmented packet will there be any conflict of these two open sockets?