2 * mpls tunnels An implementation mpls tunnels using the light weight tunnel
5 * Authors: Roopa Prabhu, <roopa@cumulusnetworks.com>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
13 #include <linux/types.h>
14 #include <linux/skbuff.h>
15 #include <linux/net.h>
16 #include <linux/module.h>
17 #include <linux/mpls.h>
18 #include <linux/vmalloc.h>
21 #include <net/lwtunnel.h>
22 #include <net/netevent.h>
23 #include <net/netns/generic.h>
24 #include <net/ip6_fib.h>
25 #include <net/route.h>
26 #include <net/mpls_iptunnel.h>
27 #include <linux/mpls_iptunnel.h>
30 static const struct nla_policy mpls_iptunnel_policy[MPLS_IPTUNNEL_MAX + 1] = {
31 [MPLS_IPTUNNEL_DST] = { .type = NLA_U32 },
34 static unsigned int mpls_encap_size(struct mpls_iptunnel_encap *en)
36 /* The size of the layer 2.5 labels to be added for this route */
37 return en->labels * sizeof(struct mpls_shim_hdr);
40 int mpls_output(struct sock *sk, struct sk_buff *skb)
42 struct mpls_iptunnel_encap *tun_encap_info;
43 struct mpls_shim_hdr *hdr;
44 struct net_device *out_dev;
46 unsigned int new_header_size;
48 struct dst_entry *dst = skb_dst(skb);
49 struct rtable *rt = NULL;
50 struct rt6_info *rt6 = NULL;
57 if (skb->protocol == htons(ETH_P_IP)) {
58 ttl = ip_hdr(skb)->ttl;
59 rt = (struct rtable *)dst;
60 } else if (skb->protocol == htons(ETH_P_IPV6)) {
61 ttl = ipv6_hdr(skb)->hop_limit;
62 rt6 = (struct rt6_info *)dst;
69 /* Find the output device */
71 if (!mpls_output_possible(out_dev) ||
72 !dst->lwtstate || skb_warn_if_lro(skb))
75 skb_forward_csum(skb);
77 tun_encap_info = mpls_lwtunnel_encap(dst->lwtstate);
79 /* Verify the destination can hold the packet */
80 new_header_size = mpls_encap_size(tun_encap_info);
81 mtu = mpls_dev_mtu(out_dev);
82 if (mpls_pkt_too_big(skb, mtu - new_header_size))
85 hh_len = LL_RESERVED_SPACE(out_dev);
86 if (!out_dev->header_ops)
89 /* Ensure there is enough space for the headers in the skb */
90 if (skb_cow(skb, hh_len + new_header_size))
93 skb_push(skb, new_header_size);
94 skb_reset_network_header(skb);
97 skb->protocol = htons(ETH_P_MPLS_UC);
99 /* Push the new labels */
102 for (i = tun_encap_info->labels - 1; i >= 0; i--) {
103 hdr[i] = mpls_entry_encode(tun_encap_info->label[i],
109 err = neigh_xmit(NEIGH_ARP_TABLE, out_dev, &rt->rt_gateway,
112 err = neigh_xmit(NEIGH_ND_TABLE, out_dev, &rt6->rt6i_gateway,
115 net_dbg_ratelimited("%s: packet transmission failed: %d\n",
125 static int mpls_build_state(struct net_device *dev, struct nlattr *nla,
126 struct lwtunnel_state **ts)
128 struct mpls_iptunnel_encap *tun_encap_info;
129 struct nlattr *tb[MPLS_IPTUNNEL_MAX + 1];
130 struct lwtunnel_state *newts;
131 int tun_encap_info_len;
134 ret = nla_parse_nested(tb, MPLS_IPTUNNEL_MAX, nla,
135 mpls_iptunnel_policy);
139 if (!tb[MPLS_IPTUNNEL_DST])
142 tun_encap_info_len = sizeof(*tun_encap_info);
144 newts = lwtunnel_state_alloc(tun_encap_info_len);
148 newts->len = tun_encap_info_len;
149 tun_encap_info = mpls_lwtunnel_encap(newts);
150 ret = nla_get_labels(tb[MPLS_IPTUNNEL_DST], MAX_NEW_LABELS,
151 &tun_encap_info->labels, tun_encap_info->label);
154 newts->type = LWTUNNEL_ENCAP_MPLS;
155 newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT;
168 static int mpls_fill_encap_info(struct sk_buff *skb,
169 struct lwtunnel_state *lwtstate)
171 struct mpls_iptunnel_encap *tun_encap_info;
173 tun_encap_info = mpls_lwtunnel_encap(lwtstate);
175 if (nla_put_labels(skb, MPLS_IPTUNNEL_DST, tun_encap_info->labels,
176 tun_encap_info->label))
177 goto nla_put_failure;
185 static int mpls_encap_nlsize(struct lwtunnel_state *lwtstate)
187 struct mpls_iptunnel_encap *tun_encap_info;
189 tun_encap_info = mpls_lwtunnel_encap(lwtstate);
191 return nla_total_size(tun_encap_info->labels * 4);
194 static int mpls_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
196 struct mpls_iptunnel_encap *a_hdr = mpls_lwtunnel_encap(a);
197 struct mpls_iptunnel_encap *b_hdr = mpls_lwtunnel_encap(b);
200 if (a_hdr->labels != b_hdr->labels)
203 for (l = 0; l < MAX_NEW_LABELS; l++)
204 if (a_hdr->label[l] != b_hdr->label[l])
209 static const struct lwtunnel_encap_ops mpls_iptun_ops = {
210 .build_state = mpls_build_state,
211 .output = mpls_output,
212 .fill_encap = mpls_fill_encap_info,
213 .get_encap_size = mpls_encap_nlsize,
214 .cmp_encap = mpls_encap_cmp,
217 static int __init mpls_iptunnel_init(void)
219 return lwtunnel_encap_add_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS);
221 module_init(mpls_iptunnel_init);
223 static void __exit mpls_iptunnel_exit(void)
225 lwtunnel_encap_del_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS);
227 module_exit(mpls_iptunnel_exit);
229 MODULE_DESCRIPTION("MultiProtocol Label Switching IP Tunnels");
230 MODULE_LICENSE("GPL v2");