From: Stephen Hemminger <shemminger@vyatta•com>
To: Andreas Jaggi <aj@open•ch>
Cc: netdev@vger•kernel.org, davem@davemloft•net,
kuznet@ms2•inr.ac.ru, kaber@trash•net
Subject: Re: [PATCH] gre: copy ToS/DiffServ bits to outer IP header
Date: Mon, 13 Jul 2009 08:33:03 -0700 [thread overview]
Message-ID: <20090713083303.61a59b63@nehalam> (raw)
In-Reply-To: <20090713133225.GA20946@urbino.open.ch>
On Mon, 13 Jul 2009 15:32:25 +0200
Andreas Jaggi <aj@open•ch> wrote:
> When tunneling IP traffic with GRE this patch makes it possible to export the
> ToS/DiffServ information to the outer IP header. This is particularly useful in
> a scenario with ESP/AH where the inner IP header is encrypted but the packet
> priority/DiffServ information should still be respected by the transporting
> routers (for example in an MPLS backbone network).
>
> The feature is disabled by default and can be enabled on per-interface basis.
> The flag is stored in an unused bit of ip_tunnel_parm.o_flags, and can be
> modified through the rntl_link interface.
Why make it an option? Sounds like it should always be on.
> Also does this bring Linux back in the game, as JunOS/IOS provide this for
> quite some time:
> http://www.cisco.com/en/US/docs/ios/11_3/feature/guide/greqos.html
> http://www.juniper.net/techpubs/software/junos/junos94/swconfig-services/configuring-a-gre-tunnel-to-copy-tos-bits-to-the-outer-ip-header.html
>
> Signed-off-by: Andreas Jaggi <aj@open•ch>
>
> diff -urN vanilla-linux-2.6.29.4/include/linux/if_tunnel.h dev-gre/include/linux/if_tunnel.h
> --- vanilla-linux-2.6.29.4/include/linux/if_tunnel.h 2009-05-19 01:52:34.000000000 +0200
> +++ dev-gre/include/linux/if_tunnel.h 2009-07-13 15:15:26.000000000 +0200
> @@ -24,6 +24,7 @@
> #define GRE_REC __constant_htons(0x0700)
> #define GRE_FLAGS __constant_htons(0x00F8)
> #define GRE_VERSION __constant_htons(0x0007)
> +#define GRE_COPY_TOS __constant_htons(0x0008)
>
> struct ip_tunnel_parm
> {
> diff -urN vanilla-linux-2.6.29.4/net/ipv4/ip_gre.c dev-gre/net/ipv4/ip_gre.c
> --- vanilla-linux-2.6.29.4/net/ipv4/ip_gre.c 2009-05-19 01:52:34.000000000 +0200
> +++ dev-gre/net/ipv4/ip_gre.c 2009-07-01 15:30:44.000000000 +0200
> @@ -677,7 +677,7 @@
> }
>
> tos = tiph->tos;
> - if (tos&1) {
> + if (tunnel->parms.o_flags&GRE_COPY_TOS || tos&1) {
This needs whitespace and parenthesis, to be safe and conform to
kernel coding style.
> if (skb->protocol == htons(ETH_P_IP))
> tos = old_iph->tos;
> tos &= ~1;
> @@ -804,7 +804,7 @@
> iph->ttl = dst_metric(&rt->u.dst, RTAX_HOPLIMIT);
> }
>
> - ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
> + ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags&~GRE_FLAGS;
more white space
> ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
> htons(ETH_P_TEB) : skb->protocol;
>
> @@ -1080,7 +1080,7 @@
> __be16 *p = (__be16*)(iph+1);
>
> memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
> - p[0] = t->parms.o_flags;
> + p[0] = t->parms.o_flags&~GRE_FLAGS;
> p[1] = htons(type);
>
> /*
> @@ -1503,6 +1503,7 @@
> t->parms.iph.ttl = p.iph.ttl;
> t->parms.iph.tos = p.iph.tos;
> t->parms.iph.frag_off = p.iph.frag_off;
> + t->parms.o_flags |= p.o_flags&GRE_COPY_TOS;
>
> if (t->parms.link != p.link) {
> t->parms.link = p.link;
> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
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> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
next prev parent reply other threads:[~2009-07-13 15:33 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-13 13:32 [PATCH] gre: copy ToS/DiffServ bits to outer IP header Andreas Jaggi
2009-07-13 15:33 ` Stephen Hemminger [this message]
2009-07-13 16:01 ` Andreas Jaggi
2009-07-13 16:07 ` Stephen Hemminger
2009-07-13 16:27 ` David Miller
2009-07-13 17:44 ` David Miller
2009-07-14 7:14 ` Andreas Jaggi
2009-07-14 16:35 ` David Miller
2009-07-14 14:21 ` Andreas Jaggi
-- strict thread matches above, loose matches on Subject: below --
2009-06-29 13:07 Andreas Jaggi
2009-06-29 13:48 ` Patrick McHardy
2009-06-30 9:05 ` Andreas Jaggi
2009-07-01 10:28 ` Patrick McHardy
2009-06-30 9:06 ` Andreas Jaggi
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