Subject: Re: [net-next fragmentation icmp v4 3/4] bridge_netfilter: No ICMP packet on IPv4 defragmentation timeout

From: Florian Westphal <[email-masked]>
Date: Thu, 14 May 2015 10:59:40 +0200

Andy Zhou <[email-masked]> wrote:
> Currently, on defragmentation timeout error, ICMP error message
> will be generated. This is fine when they are used in a routing context,
> but does not make sense in the context of bridging netfilter.
> 
> This patch adds a bit (IPSKB_NO_FRAG_ICMP) in IPCB to control
> whether ICMP error message should be generated. br_netfiler sets
> this bit.

Could you please explain why we need this patch?
After the previous change (patch 2 in your series), we will already
bail out before hitting

/* Send an ICMP "Fragment Reassembly Timeout" message. */
icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);

in ip_expire() based on qp->user value test?