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| author | David Ward <david.ward@ll.mit.edu> | 2013-01-27 13:04:58 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-01-29 14:05:28 -0500 |
| commit | 040468a0a7b3f9c7966126d98151bc64f1423657 (patch) | |
| tree | 454a47cf1a533492017579efe7658fc3b8496922 /net/ipv4 | |
| parent | 5c766d642bcaffd0c2a5b354db2068515b3846cf (diff) | |
| download | linux-040468a0a7b3f9c7966126d98151bc64f1423657.tar.bz2 | |
ip_gre: When TOS is inherited, use configured TOS value for non-IP packets
A GRE tunnel can be configured so that outgoing tunnel packets inherit
the value of the TOS field from the inner IP header. In doing so, when
a non-IP packet is transmitted through the tunnel, the TOS field will
always be set to 0.
Instead, the user should be able to configure a different TOS value as
the fallback to use for non-IP packets. This is helpful when the non-IP
packets are all control packets and should be handled by routers outside
the tunnel as having Internet Control precedence. One example of this is
the NHRP packets that control a DMVPN-compatible mGRE tunnel; they are
encapsulated directly by GRE and do not contain an inner IP header.
Under the existing behavior, the IFLA_GRE_TOS parameter must be set to
'1' for the TOS value to be inherited. Now, only the least significant
bit of this parameter must be set to '1', and when a non-IP packet is
sent through the tunnel, the upper 6 bits of this same parameter will be
copied into the TOS field. (The ECN bits get masked off as before.)
This behavior is backwards-compatible with existing configurations and
iproute2 versions.
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/ip_gre.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index af6be70821c4..801e02355ec4 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -820,8 +820,8 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev ttl = tiph->ttl; tos = tiph->tos; - if (tos == 1) { - tos = 0; + if (tos & 0x1) { + tos &= ~0x1; if (skb->protocol == htons(ETH_P_IP)) tos = old_iph->tos; else if (skb->protocol == htons(ETH_P_IPV6)) |