forked from mirrors/linux
mpls: ip tunnel support
This implementation uses lwtunnel infrastructure to register hooks for mpls tunnel encaps. It picks cues from iptunnel_encaps infrastructure and previous mpls iptunnel RFC patches from Eric W. Biederman and Robert Shearman Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Roopa Prabhu
David S. Miller
parent
face0188e3
commit
e3e4712ec0
6 changed files with 304 additions and 1 deletions
6
include/linux/mpls_iptunnel.h
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6
include/linux/mpls_iptunnel.h
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@ -0,0 +1,6 @@
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#ifndef _LINUX_MPLS_IPTUNNEL_H
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#define _LINUX_MPLS_IPTUNNEL_H
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#include <uapi/linux/mpls_iptunnel.h>
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#endif /* _LINUX_MPLS_IPTUNNEL_H */
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29
include/net/mpls_iptunnel.h
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include/net/mpls_iptunnel.h
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/*
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* Copyright (c) 2015 Cumulus Networks, Inc.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#ifndef _NET_MPLS_IPTUNNEL_H
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#define _NET_MPLS_IPTUNNEL_H 1
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#define MAX_NEW_LABELS 2
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struct mpls_iptunnel_encap {
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u32 label[MAX_NEW_LABELS];
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u32 labels;
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};
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static inline struct mpls_iptunnel_encap *mpls_lwtunnel_encap(struct lwtunnel_state *lwtstate)
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{
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return (struct mpls_iptunnel_encap *)lwtstate->data;
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}
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#endif
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28
include/uapi/linux/mpls_iptunnel.h
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28
include/uapi/linux/mpls_iptunnel.h
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@ -0,0 +1,28 @@
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/*
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* mpls tunnel api
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*
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* Authors:
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* Roopa Prabhu <roopa@cumulusnetworks.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _UAPI_LINUX_MPLS_IPTUNNEL_H
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#define _UAPI_LINUX_MPLS_IPTUNNEL_H
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/* MPLS tunnel attributes
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* [RTA_ENCAP] = {
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* [MPLS_IPTUNNEL_DST]
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* }
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*/
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enum {
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MPLS_IPTUNNEL_UNSPEC,
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MPLS_IPTUNNEL_DST,
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__MPLS_IPTUNNEL_MAX,
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};
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#define MPLS_IPTUNNEL_MAX (__MPLS_IPTUNNEL_MAX - 1)
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#endif /* _UAPI_LINUX_MPLS_IPTUNNEL_H */
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@ -24,7 +24,13 @@ config NET_MPLS_GSO
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config MPLS_ROUTING
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tristate "MPLS: routing support"
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help
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---help---
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Add support for forwarding of mpls packets.
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config MPLS_IPTUNNEL
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tristate "MPLS: IP over MPLS tunnel support"
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depends on LWTUNNEL && MPLS_ROUTING
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---help---
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mpls ip tunnel support.
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endif # MPLS
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@ -3,5 +3,6 @@
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#
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obj-$(CONFIG_NET_MPLS_GSO) += mpls_gso.o
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obj-$(CONFIG_MPLS_ROUTING) += mpls_router.o
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obj-$(CONFIG_MPLS_IPTUNNEL) += mpls_iptunnel.o
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mpls_router-y := af_mpls.o
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233
net/mpls/mpls_iptunnel.c
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233
net/mpls/mpls_iptunnel.c
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/*
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* mpls tunnels An implementation mpls tunnels using the light weight tunnel
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* infrastructure
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*
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* Authors: Roopa Prabhu, <roopa@cumulusnetworks.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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*/
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#include <linux/types.h>
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#include <linux/skbuff.h>
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#include <linux/net.h>
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#include <linux/module.h>
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#include <linux/mpls.h>
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#include <linux/vmalloc.h>
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#include <net/ip.h>
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#include <net/dst.h>
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#include <net/lwtunnel.h>
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#include <net/netevent.h>
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#include <net/netns/generic.h>
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#include <net/ip6_fib.h>
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#include <net/route.h>
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#include <net/mpls_iptunnel.h>
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#include <linux/mpls_iptunnel.h>
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#include "internal.h"
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static const struct nla_policy mpls_iptunnel_policy[MPLS_IPTUNNEL_MAX + 1] = {
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[MPLS_IPTUNNEL_DST] = { .type = NLA_U32 },
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};
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static unsigned int mpls_encap_size(struct mpls_iptunnel_encap *en)
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{
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/* The size of the layer 2.5 labels to be added for this route */
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return en->labels * sizeof(struct mpls_shim_hdr);
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}
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int mpls_output(struct sock *sk, struct sk_buff *skb)
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{
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struct mpls_iptunnel_encap *tun_encap_info;
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struct mpls_shim_hdr *hdr;
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struct net_device *out_dev;
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unsigned int hh_len;
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unsigned int new_header_size;
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unsigned int mtu;
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struct dst_entry *dst = skb_dst(skb);
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struct rtable *rt = NULL;
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struct rt6_info *rt6 = NULL;
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struct lwtunnel_state *lwtstate = NULL;
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int err = 0;
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bool bos;
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int i;
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unsigned int ttl;
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/* Obtain the ttl */
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if (skb->protocol == htons(ETH_P_IP)) {
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ttl = ip_hdr(skb)->ttl;
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rt = (struct rtable *)dst;
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lwtstate = rt->rt_lwtstate;
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} else if (skb->protocol == htons(ETH_P_IPV6)) {
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ttl = ipv6_hdr(skb)->hop_limit;
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rt6 = (struct rt6_info *)dst;
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lwtstate = rt6->rt6i_lwtstate;
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} else {
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goto drop;
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}
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skb_orphan(skb);
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/* Find the output device */
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out_dev = rcu_dereference(dst->dev);
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if (!mpls_output_possible(out_dev) ||
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!lwtstate || skb_warn_if_lro(skb))
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goto drop;
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skb_forward_csum(skb);
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tun_encap_info = mpls_lwtunnel_encap(lwtstate);
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/* Verify the destination can hold the packet */
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new_header_size = mpls_encap_size(tun_encap_info);
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mtu = mpls_dev_mtu(out_dev);
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if (mpls_pkt_too_big(skb, mtu - new_header_size))
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goto drop;
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hh_len = LL_RESERVED_SPACE(out_dev);
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if (!out_dev->header_ops)
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hh_len = 0;
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/* Ensure there is enough space for the headers in the skb */
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if (skb_cow(skb, hh_len + new_header_size))
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goto drop;
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skb_push(skb, new_header_size);
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skb_reset_network_header(skb);
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skb->dev = out_dev;
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skb->protocol = htons(ETH_P_MPLS_UC);
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/* Push the new labels */
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hdr = mpls_hdr(skb);
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bos = true;
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for (i = tun_encap_info->labels - 1; i >= 0; i--) {
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hdr[i] = mpls_entry_encode(tun_encap_info->label[i],
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ttl, 0, bos);
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bos = false;
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}
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if (rt)
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err = neigh_xmit(NEIGH_ARP_TABLE, out_dev, &rt->rt_gateway,
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skb);
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else if (rt6)
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err = neigh_xmit(NEIGH_ND_TABLE, out_dev, &rt6->rt6i_gateway,
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skb);
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if (err)
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net_dbg_ratelimited("%s: packet transmission failed: %d\n",
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__func__, err);
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return 0;
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drop:
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kfree_skb(skb);
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return -EINVAL;
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}
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static int mpls_build_state(struct net_device *dev, struct nlattr *nla,
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struct lwtunnel_state **ts)
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{
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struct mpls_iptunnel_encap *tun_encap_info;
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struct nlattr *tb[MPLS_IPTUNNEL_MAX + 1];
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struct lwtunnel_state *newts;
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int tun_encap_info_len;
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int ret;
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ret = nla_parse_nested(tb, MPLS_IPTUNNEL_MAX, nla,
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mpls_iptunnel_policy);
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if (ret < 0)
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return ret;
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if (!tb[MPLS_IPTUNNEL_DST])
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return -EINVAL;
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tun_encap_info_len = sizeof(*tun_encap_info);
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newts = lwtunnel_state_alloc(tun_encap_info_len);
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if (!newts)
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return -ENOMEM;
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newts->len = tun_encap_info_len;
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tun_encap_info = mpls_lwtunnel_encap(newts);
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ret = nla_get_labels(tb[MPLS_IPTUNNEL_DST], MAX_NEW_LABELS,
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&tun_encap_info->labels, tun_encap_info->label);
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if (ret)
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goto errout;
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newts->type = LWTUNNEL_ENCAP_MPLS;
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newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT;
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*ts = newts;
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return 0;
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errout:
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kfree(newts);
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*ts = NULL;
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return ret;
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}
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static int mpls_fill_encap_info(struct sk_buff *skb,
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struct lwtunnel_state *lwtstate)
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{
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struct mpls_iptunnel_encap *tun_encap_info;
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tun_encap_info = mpls_lwtunnel_encap(lwtstate);
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if (nla_put_labels(skb, MPLS_IPTUNNEL_DST, tun_encap_info->labels,
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tun_encap_info->label))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -EMSGSIZE;
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}
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static int mpls_encap_nlsize(struct lwtunnel_state *lwtstate)
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{
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struct mpls_iptunnel_encap *tun_encap_info;
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tun_encap_info = mpls_lwtunnel_encap(lwtstate);
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return nla_total_size(tun_encap_info->labels * 4);
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}
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static int mpls_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
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{
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struct mpls_iptunnel_encap *a_hdr = mpls_lwtunnel_encap(a);
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struct mpls_iptunnel_encap *b_hdr = mpls_lwtunnel_encap(b);
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int l;
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if (a_hdr->labels != b_hdr->labels)
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return 1;
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for (l = 0; l < MAX_NEW_LABELS; l++)
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if (a_hdr->label[l] != b_hdr->label[l])
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return 1;
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return 0;
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}
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static const struct lwtunnel_encap_ops mpls_iptun_ops = {
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.build_state = mpls_build_state,
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.output = mpls_output,
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.fill_encap = mpls_fill_encap_info,
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.get_encap_size = mpls_encap_nlsize,
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.cmp_encap = mpls_encap_cmp,
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};
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static int __init mpls_iptunnel_init(void)
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{
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return lwtunnel_encap_add_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS);
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}
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module_init(mpls_iptunnel_init);
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static void __exit mpls_iptunnel_exit(void)
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{
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lwtunnel_encap_del_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS);
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}
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module_exit(mpls_iptunnel_exit);
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MODULE_DESCRIPTION("MultiProtocol Label Switching IP Tunnels");
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MODULE_LICENSE("GPL v2");
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