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/net/gre.h | 3 +++
include/uapi/linux/if_tunnel.h | 1 +
net/ipv4/gre_demux.c | 22 ++++++++++++++++++++++
net/ipv4/ip_gre.c | 9 +++++++++
net/ipv6/ip6_gre.c | 7 +++++++
net/mpls/af_mpls.c | 40 ++++++++++++++++++++++++++++++++++++++++
6 files changed, 82 insertions(+)
diff --git a/include/net/gre.h b/include/net/gre.h
index d25d836..88a8343 100644
--- a/include/net/gre.h
+++ b/include/net/gre.h
@@ -35,6 +35,9 @@ struct net_device *gretap_fb_dev_create(struct net *net,
const char *name,
u8 name_assign_type);
int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
bool *csum_err, __be16 proto, int nhs);
+#if IS_ENABLED(CONFIG_MPLS)
+int mpls_gre_rcv(struct sk_buff *skb, int gre_hdr_len);
+#endif
static inline int gre_calc_hlen(__be16 o_flags)
{
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/gre_demux.c b/net/ipv4/gre_demux.c
index b798862..a6a937e 100644
--- a/net/ipv4/gre_demux.c
+++ b/net/ipv4/gre_demux.c
@@ -23,6 +23,9 @@
#include <linux/netdevice.h>
#include <linux/if_tunnel.h>
#include <linux/spinlock.h>
+#if IS_ENABLED(CONFIG_MPLS)
+#include <linux/mpls.h>
+#endif
#include <net/protocol.h>
#include <net/gre.h>
@@ -122,6 +125,25 @@ int gre_parse_header(struct sk_buff *skb, struct
tnl_ptk_info *tpi,
}
EXPORT_SYMBOL(gre_parse_header);
+#if IS_ENABLED(CONFIG_MPLS)
+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);
+
+ mpls_forward(skb, skb->dev, NULL, NULL);
+
+ return 0;
+drop:
+ return NET_RX_DROP;
+}
+EXPORT_SYMBOL(mpls_gre_rcv);
+#endif
+
static int gre_rcv(struct sk_buff *skb)
{
const struct gre_protocol *proto;
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 9cee986..dd4431c 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -412,10 +412,19 @@ static int gre_rcv(struct sk_buff *skb)
return 0;
}
+#if IS_ENABLED(CONFIG_MPLS)
+ if (unlikely(tpi.proto == htons(ETH_P_MPLS_UC))) {
+ if (mpls_gre_rcv(skb, hdr_len))
+ goto drop;
+ return 0;
+ }
+#endif
+
if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
return 0;
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+
drop:
kfree_skb(skb);
return 0;
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index c82d41e..e52396d 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -476,6 +476,13 @@ static int gre_rcv(struct sk_buff *skb)
if (hdr_len < 0)
goto drop;
+#if IS_ENABLED(CONFIG_MPLS)
+ if (unlikely(tpi.proto == htons(ETH_P_MPLS_UC))) {
+ if (mpls_gre_rcv(skb, hdr_len))
+ goto drop;
+ return 0;
+ }
+#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 36ea2ad..5505074 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 +40,40 @@ static int one = 1;
static int label_limit = (1 << 20) - 1;
static int ttl_max = 255;
+size_t ipgre_mpls_encap_hlen(struct ip_tunnel_encap *e)
+{
+ return sizeof(struct mpls_shim_hdr);
+}
+
+int ipgre_mpls_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
+ u8 *protocol, struct flowi4 *fl4)
+{
+ return 0;
+}
+
+static const struct ip_tunnel_encap_ops mpls_iptun_ops = {
+ .encap_hlen = ipgre_mpls_encap_hlen,
+ .build_header = ipgre_mpls_build_header,
+};
+
+static int ipgre_tunnel_encap_add_mpls_ops(void)
+{
+ int ret = -1;
+
+#if IS_ENABLED(CONFIG_NET_IP_TUNNEL)
+ ret = ip_tunnel_encap_add_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
+#endif
+
+ return ret;
+}
+
+static void ipgre_tunnel_encap_del_mpls_ops(void)
+{
+#if IS_ENABLED(CONFIG_NET_IP_TUNNEL)
+ ip_tunnel_encap_del_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
+#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);
@@ -2486,6 +2521,10 @@ 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;
@@ -2503,6 +2542,7 @@ 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
