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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2008-10-09 11:58:54 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-10-09 11:58:54 -0700 |
| commit | c95b819ad75b13102139aad0e7062d927be23cc6 (patch) | |
| tree | 22b21d4c56f24ae1a33617099e2708a9d8f012ef /net/ipv4 | |
| parent | ec2a5652ea53c102306f08cdf516f98e32bd4b61 (diff) | |
| download | linux-c95b819ad75b13102139aad0e7062d927be23cc6.tar.bz2 | |
gre: Use needed_headroom
Now that we have dev->needed_headroom, we can use it instead of
having a bogus dev->hard_header_len. This also allows us to
include dev->hard_header_len in the MTU computation so that when
we do have a meaningful hard_harder_len in future it is included
automatically in figuring out the MTU.
Incidentally, this fixes a bug where we ignored the needed_headroom
field of the underlying device in calculating our own hard_header_len.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/ip_gre.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index 2a61158ea722..fd192d676955 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -637,7 +637,7 @@ static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) df = tiph->frag_off; if (df) - mtu = dst_mtu(&rt->u.dst) - tunnel->hlen; + mtu = dst_mtu(&rt->u.dst) - dev->hard_header_len - tunnel->hlen; else mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; @@ -785,7 +785,7 @@ static void ipgre_tunnel_bind_dev(struct net_device *dev) tunnel = netdev_priv(dev); iph = &tunnel->parms.iph; - /* Guess output device to choose reasonable mtu and hard_header_len */ + /* Guess output device to choose reasonable mtu and needed_headroom */ if (iph->daddr) { struct flowi fl = { .oif = tunnel->parms.link, @@ -806,7 +806,7 @@ static void ipgre_tunnel_bind_dev(struct net_device *dev) tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); if (tdev) { - hlen = tdev->hard_header_len; + hlen = tdev->hard_header_len + tdev->needed_headroom; mtu = tdev->mtu; } dev->iflink = tunnel->parms.link; @@ -820,8 +820,8 @@ static void ipgre_tunnel_bind_dev(struct net_device *dev) if (tunnel->parms.o_flags&GRE_SEQ) addend += 4; } - dev->hard_header_len = hlen + addend; - dev->mtu = mtu - addend; + dev->needed_headroom = addend + hlen; + dev->mtu = mtu - dev->hard_header_len - addend; tunnel->hlen = addend; } @@ -959,7 +959,8 @@ done: static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu) { struct ip_tunnel *tunnel = netdev_priv(dev); - if (new_mtu < 68 || new_mtu > 0xFFF8 - tunnel->hlen) + if (new_mtu < 68 || + new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen) return -EINVAL; dev->mtu = new_mtu; return 0; @@ -1085,7 +1086,7 @@ static void ipgre_tunnel_setup(struct net_device *dev) dev->change_mtu = ipgre_tunnel_change_mtu; dev->type = ARPHRD_IPGRE; - dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr) + 4; + dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4; dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4; dev->flags = IFF_NOARP; dev->iflink = 0; |