On Thu, Sep 21, 2017 at 2:25 AM, Amine Kherbouche
<amine.kherbou...@6wind.com> wrote:
> This commit introduces the MPLSoGRE support (RFC 4023), using ip tunnel
> API.
>
> Encap:
> - Add a new iptunnel type mpls.
>
> 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 | 37 +++++++++++++++++++++++++++++++++++++
> 6 files changed, 79 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..060ed07 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;
> +}
any reason you are supporting only rx ?
> +
> +static const struct ip_tunnel_encap_ops mpls_iptun_ops = {
> + .encap_hlen = ipgre_mpls_encap_hlen,
> + .build_header = ipgre_mpls_build_header,
> +};
> +
> +int ipgre_tunnel_encap_add_mpls_ops(void)
> +{
> + int ret;
> +
> + ret = ip_tunnel_encap_add_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
> + if (ret < 0) {
> + pr_err("can't add mplsgre ops\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static void ipgre_tunnel_encap_del_mpls_ops(void)
> +{
> + ip_tunnel_encap_del_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
> +}
> +
> 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 +2521,7 @@ static int __init mpls_init(void)
> 0);
> rtnl_register(PF_MPLS, RTM_GETNETCONF, mpls_netconf_get_devconf,
> mpls_netconf_dump_devconf, 0);
> + ipgre_tunnel_encap_add_mpls_ops();
> err = 0;
> out:
> return err;
> @@ -2503,6 +2539,7 @@ 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
>
