This commit introduces the MPLSoGRE support (RFC 4023), using ip tunnel
API.
Encap:
- Add a new iptunnel type mpls.
- Share tx path: gre type mpls loaded from skb->protocol.
Decap:
- pull gre hdr and call mpls_forward().
Signed-off-by: Amine Kherbouche <amine.kherbou...@6wind.com>
---
include/linux/mpls.h | 2 ++
include/uapi/linux/if_tunnel.h | 1 +
net/ipv4/ip_gre.c | 11 +++++++++
net/ipv6/ip6_gre.c | 11 +++++++++
net/mpls/af_mpls.c | 52 ++++++++++++++++++++++++++++++++++++++++++
5 files changed, 77 insertions(+)
diff --git a/include/linux/mpls.h b/include/linux/mpls.h
index 384fb22..57203c1 100644
--- a/include/linux/mpls.h
+++ b/include/linux/mpls.h
@@ -8,4 +8,6 @@
#define MPLS_TC_MASK (MPLS_LS_TC_MASK >> MPLS_LS_TC_SHIFT)
#define MPLS_LABEL_MASK (MPLS_LS_LABEL_MASK >>
MPLS_LS_LABEL_SHIFT)
+int mpls_gre_rcv(struct sk_buff *skb, int gre_hdr_len);
+
#endif /* _LINUX_MPLS_H */
diff --git a/include/uapi/linux/if_tunnel.h b/include/uapi/linux/if_tunnel.h
index 2e52088..a2f48c0 100644
--- a/include/uapi/linux/if_tunnel.h
+++ b/include/uapi/linux/if_tunnel.h
@@ -84,6 +84,7 @@ enum tunnel_encap_types {
TUNNEL_ENCAP_NONE,
TUNNEL_ENCAP_FOU,
TUNNEL_ENCAP_GUE,
+ TUNNEL_ENCAP_MPLS,
};
#define TUNNEL_ENCAP_FLAG_CSUM (1<<0)
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 9cee986..0a898f4 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -32,6 +32,9 @@
#include <linux/netfilter_ipv4.h>
#include <linux/etherdevice.h>
#include <linux/if_ether.h>
+#if IS_ENABLED(CONFIG_MPLS)
+#include <linux/mpls.h>
+#endif
#include <net/sock.h>
#include <net/ip.h>
@@ -412,6 +415,14 @@ static int gre_rcv(struct sk_buff *skb)
return 0;
}
+ if (unlikely(tpi.proto == htons(ETH_P_MPLS_UC))) {
+#if IS_ENABLED(CONFIG_MPLS)
+ return mpls_gre_rcv(skb, hdr_len);
+#else
+ goto drop;
+#endif
+ }
+
if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
return 0;
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index c82d41e..5a0f5e1 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -34,6 +34,9 @@
#include <linux/hash.h>
#include <linux/if_tunnel.h>
#include <linux/ip6_tunnel.h>
+#if IS_ENABLED(CONFIG_MPLS)
+#include <linux/mpls.h>
+#endif
#include <net/sock.h>
#include <net/ip.h>
@@ -476,6 +479,14 @@ static int gre_rcv(struct sk_buff *skb)
if (hdr_len < 0)
goto drop;
+ if (unlikely(tpi.proto == htons(ETH_P_MPLS_UC))) {
+#if IS_ENABLED(CONFIG_MPLS)
+ return mpls_gre_rcv(skb, hdr_len);
+#else
+ goto drop;
+#endif
+ }
+
if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
goto drop;
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index c5b9ce4..53ec7c0 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -16,6 +16,7 @@
#include <net/arp.h>
#include <net/ip_fib.h>
#include <net/netevent.h>
+#include <net/ip_tunnels.h>
#include <net/netns/generic.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
@@ -39,6 +40,36 @@ static int one = 1;
static int label_limit = (1 << 20) - 1;
static int ttl_max = 255;
+#if IS_ENABLED(CONFIG_NET_IP_TUNNEL)
+size_t ipgre_mpls_encap_hlen(struct ip_tunnel_encap *e)
+{
+ return sizeof(struct mpls_shim_hdr);
+}
+
+static const struct ip_tunnel_encap_ops mpls_iptun_ops = {
+ .encap_hlen = ipgre_mpls_encap_hlen,
+};
+
+static int ipgre_tunnel_encap_add_mpls_ops(void)
+{
+ return ip_tunnel_encap_add_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
+}
+
+static void ipgre_tunnel_encap_del_mpls_ops(void)
+{
+ ip_tunnel_encap_del_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
+}
+#else
+static int ipgre_tunnel_encap_add_mpls_ops(void)
+{
+ return 0;
+}
+
+static void ipgre_tunnel_encap_del_mpls_ops(void)
+{
+}
+#endif
+
static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
struct nlmsghdr *nlh, struct net *net, u32 portid,
unsigned int nlm_flags);
@@ -443,6 +474,22 @@ static int mpls_forward(struct sk_buff *skb, struct
net_device *dev,
return NET_RX_DROP;
}
+int mpls_gre_rcv(struct sk_buff *skb, int gre_hdr_len)
+{
+ if (unlikely(!pskb_may_pull(skb, gre_hdr_len)))
+ goto drop;
+
+ /* Pop GRE hdr and reset the skb */
+ skb_pull(skb, gre_hdr_len);
+ skb_reset_network_header(skb);
+
+ return mpls_forward(skb, skb->dev, NULL, NULL);
+drop:
+ kfree_skb(skb);
+ return NET_RX_DROP;
+}
+EXPORT_SYMBOL(mpls_gre_rcv);
+
static struct packet_type mpls_packet_type __read_mostly = {
.type = cpu_to_be16(ETH_P_MPLS_UC),
.func = mpls_forward,
@@ -2485,6 +2532,10 @@ static int __init mpls_init(void)
0);
rtnl_register(PF_MPLS, RTM_GETNETCONF, mpls_netconf_get_devconf,
mpls_netconf_dump_devconf, 0);
+ err = ipgre_tunnel_encap_add_mpls_ops();
+ if (err)
+ pr_err("Can't add mpls over gre tunnel ops\n");
+
err = 0;
out:
return err;
@@ -2502,6 +2553,7 @@ static void __exit mpls_exit(void)
dev_remove_pack(&mpls_packet_type);
unregister_netdevice_notifier(&mpls_dev_notifier);
unregister_pernet_subsys(&mpls_net_ops);
+ ipgre_tunnel_encap_del_mpls_ops();
}
module_exit(mpls_exit);
--
2.1.4
