[CFT/Review] net byte order for AF_INET

[Maxim Dounin]

Hello!

On Thu, Oct 11, 2012 at 03:34:04AM +0400, Gleb Smirnoff wrote:

[...]

> This is de facto standard for raw sockets in most OS-es. Byte order
> in raw socket is host. And this is the same behavior we had before
> the patch. So no reason for extra comments.

As I already pointed out (in an off-list message), many consider 
this as a "known bug" in many OSes instead.

E.g. here is a quote from /usr/ports/net/openospfd/files/patch-ospfd_packet.c
patch:

@@ -70,7 +70,12 @@
        ip_hdr.ip_v = IPVERSION;
        ip_hdr.ip_hl = sizeof(ip_hdr) >> 2;
        ip_hdr.ip_tos = IPTOS_PREC_INTERNETCONTROL;
+#if defined(__FreeBSD__) || defined(__NetBSD__)
+       /* FreeBSD/NetBSD wants the length in the native host byte order. */
+       ip_hdr.ip_len = len + sizeof(ip_hdr);
+#else
        ip_hdr.ip_len = htons(len + sizeof(ip_hdr));
+#endif

I would suggests it at least deserves a comment, and probably API 
change/fix too.

[...]

> --- sys/netinet/raw_ip.c	(revision 241405)
> +++ sys/netinet/raw_ip.c	(working copy)
> @@ -292,7 +292,7 @@
>  	 * not modify the packet except for some
>  	 * byte order swaps.
>  	 */
> -	ip->ip_len += off;
> +	ip->ip_len = ntohs(ip->ip_len) + off;

So, you've moved a switch to host byteorder into rip_input().  
What about ip->ip_off then?

Note that this may also need some adjustments for protocols which use
rip_output() but not rip_input() (or vice versa).

[...]

-- 
Maxim Dounin