gre: Add Transparent Ethernet Bridging
This patch adds support for Ethernet over GRE encapsulation.
This is exposed to user-space with a new link type of "gretap"
instead of "gre". It will create an ARPHRD_ETHER device in
lieu of the usual ARPHRD_IPGRE.
Note that to preserver backwards compatibility all Transparent
Ethernet Bridging packets are passed to an ARPHRD_IPGRE tunnel
if its key matches and there is no ARPHRD_ETHER device whose
key matches more closely.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 25d2c77..44ed948 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -27,6 +27,7 @@
#include <linux/inetdevice.h>
#include <linux/igmp.h>
#include <linux/netfilter_ipv4.h>
+#include <linux/etherdevice.h>
#include <linux/if_ether.h>
#include <net/sock.h>
@@ -166,38 +167,64 @@
/* Given src, dst and key, find appropriate for input tunnel. */
static struct ip_tunnel * ipgre_tunnel_lookup(struct net *net,
- __be32 remote, __be32 local, __be32 key)
+ __be32 remote, __be32 local,
+ __be32 key, __be16 gre_proto)
{
unsigned h0 = HASH(remote);
unsigned h1 = HASH(key);
struct ip_tunnel *t;
+ struct ip_tunnel *t2 = NULL;
struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+ int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
+ ARPHRD_ETHER : ARPHRD_IPGRE;
for (t = ign->tunnels_r_l[h0^h1]; t; t = t->next) {
if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) {
- if (t->parms.i_key == key && (t->dev->flags&IFF_UP))
- return t;
+ if (t->parms.i_key == key && t->dev->flags & IFF_UP) {
+ if (t->dev->type == dev_type)
+ return t;
+ if (t->dev->type == ARPHRD_IPGRE && !t2)
+ t2 = t;
+ }
}
}
+
for (t = ign->tunnels_r[h0^h1]; t; t = t->next) {
if (remote == t->parms.iph.daddr) {
- if (t->parms.i_key == key && (t->dev->flags&IFF_UP))
- return t;
+ if (t->parms.i_key == key && t->dev->flags & IFF_UP) {
+ if (t->dev->type == dev_type)
+ return t;
+ if (t->dev->type == ARPHRD_IPGRE && !t2)
+ t2 = t;
+ }
}
}
+
for (t = ign->tunnels_l[h1]; t; t = t->next) {
if (local == t->parms.iph.saddr ||
(local == t->parms.iph.daddr &&
ipv4_is_multicast(local))) {
- if (t->parms.i_key == key && (t->dev->flags&IFF_UP))
- return t;
+ if (t->parms.i_key == key && t->dev->flags & IFF_UP) {
+ if (t->dev->type == dev_type)
+ return t;
+ if (t->dev->type == ARPHRD_IPGRE && !t2)
+ t2 = t;
+ }
}
}
+
for (t = ign->tunnels_wc[h1]; t; t = t->next) {
- if (t->parms.i_key == key && (t->dev->flags&IFF_UP))
- return t;
+ if (t->parms.i_key == key && t->dev->flags & IFF_UP) {
+ if (t->dev->type == dev_type)
+ return t;
+ if (t->dev->type == ARPHRD_IPGRE && !t2)
+ t2 = t;
+ }
}
+ if (t2)
+ return t2;
+
if (ign->fb_tunnel_dev->flags&IFF_UP)
return netdev_priv(ign->fb_tunnel_dev);
return NULL;
@@ -252,25 +279,37 @@
}
}
-static struct ip_tunnel * ipgre_tunnel_locate(struct net *net,
- struct ip_tunnel_parm *parms, int create)
+static struct ip_tunnel *ipgre_tunnel_find(struct net *net,
+ struct ip_tunnel_parm *parms,
+ int type)
{
__be32 remote = parms->iph.daddr;
__be32 local = parms->iph.saddr;
__be32 key = parms->i_key;
- struct ip_tunnel *t, **tp, *nt;
+ struct ip_tunnel *t, **tp;
+ struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+
+ for (tp = __ipgre_bucket(ign, parms); (t = *tp) != NULL; tp = &t->next)
+ if (local == t->parms.iph.saddr &&
+ remote == t->parms.iph.daddr &&
+ key == t->parms.i_key &&
+ type == t->dev->type)
+ break;
+
+ return t;
+}
+
+static struct ip_tunnel * ipgre_tunnel_locate(struct net *net,
+ struct ip_tunnel_parm *parms, int create)
+{
+ struct ip_tunnel *t, *nt;
struct net_device *dev;
char name[IFNAMSIZ];
struct ipgre_net *ign = net_generic(net, ipgre_net_id);
- for (tp = __ipgre_bucket(ign, parms); (t = *tp) != NULL; tp = &t->next) {
- if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) {
- if (key == t->parms.i_key)
- return t;
- }
- }
- if (!create)
- return NULL;
+ t = ipgre_tunnel_find(net, parms, ARPHRD_IPGRE);
+ if (t || !create)
+ return t;
if (parms->name[0])
strlcpy(name, parms->name, IFNAMSIZ);
@@ -385,8 +424,9 @@
read_lock(&ipgre_lock);
t = ipgre_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr,
- (flags&GRE_KEY) ?
- *(((__be32*)p) + (grehlen>>2) - 1) : 0);
+ flags & GRE_KEY ?
+ *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
+ p[1]);
if (t == NULL || t->parms.iph.daddr == 0 ||
ipv4_is_multicast(t->parms.iph.daddr))
goto out;
@@ -436,6 +476,7 @@
u32 seqno = 0;
struct ip_tunnel *tunnel;
int offset = 4;
+ __be16 gre_proto;
if (!pskb_may_pull(skb, 16))
goto drop_nolock;
@@ -475,20 +516,22 @@
}
}
+ gre_proto = *(__be16 *)(h + 2);
+
read_lock(&ipgre_lock);
if ((tunnel = ipgre_tunnel_lookup(dev_net(skb->dev),
- iph->saddr, iph->daddr, key)) != NULL) {
+ iph->saddr, iph->daddr, key,
+ gre_proto))) {
struct net_device_stats *stats = &tunnel->dev->stats;
secpath_reset(skb);
- skb->protocol = *(__be16*)(h + 2);
+ skb->protocol = gre_proto;
/* WCCP version 1 and 2 protocol decoding.
* - Change protocol to IP
* - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
*/
- if (flags == 0 &&
- skb->protocol == htons(ETH_P_WCCP)) {
+ if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
skb->protocol = htons(ETH_P_IP);
if ((*(h + offset) & 0xF0) != 0x40)
offset += 4;
@@ -496,7 +539,6 @@
skb->mac_header = skb->network_header;
__pskb_pull(skb, offset);
- skb_reset_network_header(skb);
skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
skb->pkt_type = PACKET_HOST;
#ifdef CONFIG_NET_IPGRE_BROADCAST
@@ -524,13 +566,30 @@
}
tunnel->i_seqno = seqno + 1;
}
+
+ /* Warning: All skb pointers will be invalidated! */
+ if (tunnel->dev->type == ARPHRD_ETHER) {
+ if (!pskb_may_pull(skb, ETH_HLEN)) {
+ stats->rx_length_errors++;
+ stats->rx_errors++;
+ goto drop;
+ }
+
+ iph = ip_hdr(skb);
+ skb->protocol = eth_type_trans(skb, tunnel->dev);
+ skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
+ }
+
stats->rx_packets++;
stats->rx_bytes += skb->len;
skb->dev = tunnel->dev;
dst_release(skb->dst);
skb->dst = NULL;
nf_reset(skb);
+
+ skb_reset_network_header(skb);
ipgre_ecn_decapsulate(iph, skb);
+
netif_rx(skb);
read_unlock(&ipgre_lock);
return(0);
@@ -565,7 +624,10 @@
goto tx_error;
}
- if (dev->header_ops) {
+ if (dev->type == ARPHRD_ETHER)
+ IPCB(skb)->flags = 0;
+
+ if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
gre_hlen = 0;
tiph = (struct iphdr*)skb->data;
} else {
@@ -741,8 +803,9 @@
iph->ttl = dst_metric(&rt->u.dst, RTAX_HOPLIMIT);
}
- ((__be16*)(iph+1))[0] = tunnel->parms.o_flags;
- ((__be16*)(iph+1))[1] = skb->protocol;
+ ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
+ ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
+ htons(ETH_P_TEB) : skb->protocol;
if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
__be32 *ptr = (__be32*)(((u8*)iph) + tunnel->hlen - 4);
@@ -804,7 +867,9 @@
tdev = rt->u.dst.dev;
ip_rt_put(rt);
}
- dev->flags |= IFF_POINTOPOINT;
+
+ if (dev->type != ARPHRD_ETHER)
+ dev->flags |= IFF_POINTOPOINT;
}
if (!tdev && tunnel->parms.link)
@@ -1250,6 +1315,30 @@
return 0;
}
+static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+ __be32 daddr;
+
+ if (tb[IFLA_ADDRESS]) {
+ if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
+ return -EINVAL;
+ if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
+ return -EADDRNOTAVAIL;
+ }
+
+ if (!data)
+ goto out;
+
+ if (data[IFLA_GRE_REMOTE]) {
+ memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
+ if (!daddr)
+ return -EINVAL;
+ }
+
+out:
+ return ipgre_tunnel_validate(tb, data);
+}
+
static void ipgre_netlink_parms(struct nlattr *data[],
struct ip_tunnel_parm *parms)
{
@@ -1291,6 +1380,35 @@
parms->iph.frag_off = htons(IP_DF);
}
+static int ipgre_tap_init(struct net_device *dev)
+{
+ struct ip_tunnel *tunnel;
+
+ tunnel = netdev_priv(dev);
+
+ tunnel->dev = dev;
+ strcpy(tunnel->parms.name, dev->name);
+
+ ipgre_tunnel_bind_dev(dev);
+
+ return 0;
+}
+
+static void ipgre_tap_setup(struct net_device *dev)
+{
+
+ ether_setup(dev);
+
+ dev->init = ipgre_tap_init;
+ dev->uninit = ipgre_tunnel_uninit;
+ dev->destructor = free_netdev;
+ dev->hard_start_xmit = ipgre_tunnel_xmit;
+ dev->change_mtu = ipgre_tunnel_change_mtu;
+
+ dev->iflink = 0;
+ dev->features |= NETIF_F_NETNS_LOCAL;
+}
+
static int ipgre_newlink(struct net_device *dev, struct nlattr *tb[],
struct nlattr *data[])
{
@@ -1303,9 +1421,12 @@
nt = netdev_priv(dev);
ipgre_netlink_parms(data, &nt->parms);
- if (ipgre_tunnel_locate(net, &nt->parms, 0))
+ if (ipgre_tunnel_find(net, &nt->parms, dev->type))
return -EEXIST;
+ if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
+ random_ether_addr(dev->dev_addr);
+
mtu = ipgre_tunnel_bind_dev(dev);
if (!tb[IFLA_MTU])
dev->mtu = mtu;
@@ -1455,6 +1576,19 @@
.fill_info = ipgre_fill_info,
};
+static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
+ .kind = "gretap",
+ .maxtype = IFLA_GRE_MAX,
+ .policy = ipgre_policy,
+ .priv_size = sizeof(struct ip_tunnel),
+ .setup = ipgre_tap_setup,
+ .validate = ipgre_tap_validate,
+ .newlink = ipgre_newlink,
+ .changelink = ipgre_changelink,
+ .get_size = ipgre_get_size,
+ .fill_info = ipgre_fill_info,
+};
+
/*
* And now the modules code and kernel interface.
*/
@@ -1478,9 +1612,15 @@
if (err < 0)
goto rtnl_link_failed;
+ err = rtnl_link_register(&ipgre_tap_ops);
+ if (err < 0)
+ goto tap_ops_failed;
+
out:
return err;
+tap_ops_failed:
+ rtnl_link_unregister(&ipgre_link_ops);
rtnl_link_failed:
unregister_pernet_gen_device(ipgre_net_id, &ipgre_net_ops);
gen_device_failed:
@@ -1490,6 +1630,7 @@
static void __exit ipgre_fini(void)
{
+ rtnl_link_unregister(&ipgre_tap_ops);
rtnl_link_unregister(&ipgre_link_ops);
unregister_pernet_gen_device(ipgre_net_id, &ipgre_net_ops);
if (inet_del_protocol(&ipgre_protocol, IPPROTO_GRE) < 0)
@@ -1500,3 +1641,4 @@
module_exit(ipgre_fini);
MODULE_LICENSE("GPL");
MODULE_ALIAS("rtnl-link-gre");
+MODULE_ALIAS("rtnl-link-gretap");