When GRE tunnel is in NBMA mode, this patch allows an application to use
a PF_PACKET socket to:
- send a packet to specific NBMA address with sendto()
- use recvfrom() to receive packet and check which NBMA address it came from
Signed-off-by: Timo Teras <[email protected]>
---
This is useful for implementing NHRP over NBMA GRE tunnels.
Sent earlier to netdev list only. Resending to wider audience with
a style issue fixed.
net/ipv4/ip_gre.c | 12 +++++++++++-
1 files changed, 11 insertions(+), 1 deletions(-)
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index f151900..b1e3816 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1033,7 +1033,6 @@ static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
return 0;
}
-#ifdef CONFIG_NET_IPGRE_BROADCAST
/* Nice toy. Unfortunately, useless in real life :-)
It allows to construct virtual multiprotocol broadcast "LAN"
over the Internet, provided multicast routing is tuned.
@@ -1092,10 +1091,19 @@ static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
return -t->hlen;
}
+static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
+{
+ struct iphdr *iph = (struct iphdr *) skb_mac_header(skb);
+ memcpy(haddr, &iph->saddr, 4);
+ return 4;
+}
+
static const struct header_ops ipgre_header_ops = {
.create = ipgre_header,
+ .parse = ipgre_header_parse,
};
+#ifdef CONFIG_NET_IPGRE_BROADCAST
static int ipgre_open(struct net_device *dev)
{
struct ip_tunnel *t = netdev_priv(dev);
@@ -1197,6 +1205,8 @@ static int ipgre_tunnel_init(struct net_device *dev)
dev->stop = ipgre_close;
}
#endif
+ } else {
+ dev->header_ops = &ipgre_header_ops;
}
if (!tdev && tunnel->parms.link)