On Wed, Aug 16, 2017 at 11:38:06PM +0300, Nikolay Aleksandrov wrote:
> On 16/08/17 20:01, David Lamparter wrote:
> > This implements holding dst metadata information in the bridge layer,
> > but only for unicast entries in the MAC table. Multicast is still left
> > to design and implement.
> >
> > Signed-off-by: David Lamparter <equinox@xxxxxxxxxx>
> > ---
>
> Hi David,
> Sorry but I do not agree with this change, adding a special case for VPLS
To prove that this is not a special case for VPLS, I have attached a
patch for GRETAP multicast+unicast learning below.
It's just 24(!) lines added to get functionality similar to "basic
VXLAN" (i.e. multicast with dataplane learning.)
-David
---
From: David Lamparter <equinox@xxxxxxxxxx>
Date: Thu, 17 Aug 2017 18:11:16 +0200
Subject: [PATCH] gretap: support multicast + unicast learning
This enables using an IPv4 multicast destination for gretap and enables
learning unicast destinations through the bridge fdb.
Signed-off-by: David Lamparter <equinox@xxxxxxxxxx>
---
net/ipv4/ip_gre.c | 27 +++++++++++++++++++++++----
net/ipv4/ip_tunnel.c | 1 +
2 files changed, 24 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 7a7829e839c2..e58f8ccb2c87 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -266,7 +266,8 @@ static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
skb_pop_mac_header(skb);
else
skb_reset_mac_header(skb);
- if (tunnel->collect_md) {
+ if (tunnel->collect_md
+ || ipv4_is_multicast(tunnel->parms.iph.daddr)) {
__be16 flags;
__be64 tun_id;
@@ -379,7 +380,7 @@ static struct rtable *gre_get_rt(struct sk_buff *skb,
static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
__be16 proto)
{
- struct ip_tunnel_info *tun_info;
+ struct ip_tunnel_info *tun_info, flipped;
const struct ip_tunnel_key *key;
struct rtable *rt = NULL;
struct flowi4 fl;
@@ -390,10 +391,22 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
int err;
tun_info = skb_tunnel_info(skb);
- if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
+ if (unlikely(!tun_info ||
ip_tunnel_info_af(tun_info) != AF_INET))
goto err_free_skb;
+ if (!(tun_info->mode & IP_TUNNEL_INFO_TX)) {
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+
+ flipped = *tun_info;
+ flipped.mode |= IP_TUNNEL_INFO_TX;
+ flipped.key.u.ipv4.dst = tun_info->key.u.ipv4.src;
+ flipped.key.u.ipv4.src = tunnel->parms.iph.saddr;
+ flipped.key.tp_src = tun_info->key.tp_dst;
+ flipped.key.tp_dst = tun_info->key.tp_src;
+ tun_info = &flipped;
+ }
+
key = &tun_info->key;
use_cache = ip_tunnel_dst_cache_usable(skb, tun_info);
if (use_cache)
@@ -507,8 +520,9 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
+ struct ip_tunnel_info *tun_info = skb_tunnel_info(skb);
- if (tunnel->collect_md) {
+ if (tunnel->collect_md || tun_info) {
gre_fb_xmit(skb, dev, htons(ETH_P_TEB));
return NETDEV_TX_OK;
}
@@ -933,6 +947,7 @@ static int gre_tap_init(struct net_device *dev)
{
__gre_tunnel_init(dev);
dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+ netif_keep_dst(dev);
return ip_tunnel_init(dev);
}
@@ -940,6 +955,10 @@ static int gre_tap_init(struct net_device *dev)
static const struct net_device_ops gre_tap_netdev_ops = {
.ndo_init = gre_tap_init,
.ndo_uninit = ip_tunnel_uninit,
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+ .ndo_open = ipgre_open,
+ .ndo_stop = ipgre_close,
+#endif
.ndo_start_xmit = gre_tap_xmit,
.ndo_set_mac_address = eth_mac_addr,
.ndo_validate_addr = eth_validate_addr,
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 129d1a3616f8..451c11fc9ae5 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -140,6 +140,7 @@ struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
hlist_for_each_entry_rcu(t, head, hash_node) {
if ((local != t->parms.iph.saddr || t->parms.iph.daddr != 0) &&
+ (local != t->parms.iph.saddr || !ipv4_is_multicast(t->parms.iph.daddr)) &&
(local != t->parms.iph.daddr || !ipv4_is_multicast(local)))
continue;
--
2.13.0
