Re: CVS commit: src/sys

[Joerg Sonnenberger <joerg%bec.de@localhost>]

On Wed, Feb 03, 2021 at 11:03:25AM +0100, Kamil Rytarowski wrote:
> On 03.02.2021 06:51, Roy Marples wrote:
> > Module Name:	src
> > Committed By:	roy
> > Date:		Wed Feb  3 05:51:40 UTC 2021
> > 
> > Modified Files:
> > 	src/sys/net: if_arp.h if_ether.h if_gre.h
> > 	src/sys/netinet: if_ether.h igmp.h in.h ip.h ip6.h ip_carp.h ip_icmp.h
> > 	    ip_mroute.h ip_var.h tcp.h tcp_debug.h tcp_var.h udp.h udp_var.h
> > 
> > Log Message:
> > Remove __packed from various network structures
> > 
> > They are already network aligned and adding the __packed attribute
> > just causes needless compiler warnings about accssing members of packed
> > objects.
> > 
> 
> This changes the ABI for userland programs. With __packed, these
> structures, whenever contain at least 2-byte data, can be placed in a
> different location inside another structure now.

It doesn't break any of *our* ABI contracts. I also refuse us to be taken
hostage here for any (hypothetical) user program exposing internals of
the network stack on ABI boundaries. There is a very real price for the
__packed and *any* fix for the misuse has the same ABI impacts.

Joerg