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![Alexander Aring](/assets/img/avatar_default.png)
The build_state callback of lwtunnel doesn't contain the net namespace structure yet. This patch will add it so we can check on specific address configuration at creation time of rpl source routes. Signed-off-by: Alexander Aring <alex.aring@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
304 lines
7.7 KiB
C
304 lines
7.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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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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#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] = { .len = sizeof(u32) },
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[MPLS_IPTUNNEL_TTL] = { .type = NLA_U8 },
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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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static int mpls_xmit(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 mpls_dev *out_mdev;
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struct net *net;
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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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/* Find the output device */
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out_dev = dst->dev;
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net = dev_net(out_dev);
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skb_orphan(skb);
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if (!mpls_output_possible(out_dev) ||
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!dst->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(dst->lwtstate);
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/* Obtain the ttl using the following set of rules.
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*
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* LWT ttl propagation setting:
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* - disabled => use default TTL value from LWT
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* - enabled => use TTL value from IPv4/IPv6 header
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* - default =>
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* Global ttl propagation setting:
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* - disabled => use default TTL value from global setting
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* - enabled => use TTL value from IPv4/IPv6 header
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*/
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if (dst->ops->family == AF_INET) {
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if (tun_encap_info->ttl_propagate == MPLS_TTL_PROP_DISABLED)
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ttl = tun_encap_info->default_ttl;
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else if (tun_encap_info->ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
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!net->mpls.ip_ttl_propagate)
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ttl = net->mpls.default_ttl;
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else
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ttl = ip_hdr(skb)->ttl;
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rt = (struct rtable *)dst;
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} else if (dst->ops->family == AF_INET6) {
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if (tun_encap_info->ttl_propagate == MPLS_TTL_PROP_DISABLED)
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ttl = tun_encap_info->default_ttl;
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else if (tun_encap_info->ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
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!net->mpls.ip_ttl_propagate)
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ttl = net->mpls.default_ttl;
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else
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ttl = ipv6_hdr(skb)->hop_limit;
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rt6 = (struct rt6_info *)dst;
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} else {
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goto drop;
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}
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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_set_inner_protocol(skb, skb->protocol);
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skb_reset_inner_network_header(skb);
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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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mpls_stats_inc_outucastpkts(out_dev, skb);
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if (rt) {
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if (rt->rt_gw_family == AF_INET6)
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err = neigh_xmit(NEIGH_ND_TABLE, out_dev, &rt->rt_gw6,
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skb);
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else
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err = neigh_xmit(NEIGH_ARP_TABLE, out_dev, &rt->rt_gw4,
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skb);
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} else if (rt6) {
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if (ipv6_addr_v4mapped(&rt6->rt6i_gateway)) {
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/* 6PE (RFC 4798) */
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err = neigh_xmit(NEIGH_ARP_TABLE, out_dev, &rt6->rt6i_gateway.s6_addr32[3],
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skb);
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} else
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err = neigh_xmit(NEIGH_ND_TABLE, out_dev, &rt6->rt6i_gateway,
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skb);
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}
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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 LWTUNNEL_XMIT_DONE;
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drop:
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out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL;
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if (out_mdev)
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MPLS_INC_STATS(out_mdev, tx_errors);
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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 *net, struct nlattr *nla,
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unsigned int family, const void *cfg,
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struct lwtunnel_state **ts,
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struct netlink_ext_ack *extack)
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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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u8 n_labels;
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int ret;
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ret = nla_parse_nested_deprecated(tb, MPLS_IPTUNNEL_MAX, nla,
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mpls_iptunnel_policy, extack);
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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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NL_SET_ERR_MSG(extack, "MPLS_IPTUNNEL_DST attribute is missing");
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return -EINVAL;
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}
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/* determine number of labels */
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if (nla_get_labels(tb[MPLS_IPTUNNEL_DST], MAX_NEW_LABELS,
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&n_labels, NULL, extack))
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return -EINVAL;
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newts = lwtunnel_state_alloc(struct_size(tun_encap_info, label,
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n_labels));
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if (!newts)
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return -ENOMEM;
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tun_encap_info = mpls_lwtunnel_encap(newts);
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ret = nla_get_labels(tb[MPLS_IPTUNNEL_DST], n_labels,
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&tun_encap_info->labels, tun_encap_info->label,
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extack);
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if (ret)
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goto errout;
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tun_encap_info->ttl_propagate = MPLS_TTL_PROP_DEFAULT;
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if (tb[MPLS_IPTUNNEL_TTL]) {
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tun_encap_info->default_ttl = nla_get_u8(tb[MPLS_IPTUNNEL_TTL]);
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/* TTL 0 implies propagate from IP header */
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tun_encap_info->ttl_propagate = tun_encap_info->default_ttl ?
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MPLS_TTL_PROP_DISABLED :
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MPLS_TTL_PROP_ENABLED;
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}
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newts->type = LWTUNNEL_ENCAP_MPLS;
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newts->flags |= LWTUNNEL_STATE_XMIT_REDIRECT;
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newts->headroom = mpls_encap_size(tun_encap_info);
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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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if (tun_encap_info->ttl_propagate != MPLS_TTL_PROP_DEFAULT &&
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nla_put_u8(skb, MPLS_IPTUNNEL_TTL, tun_encap_info->default_ttl))
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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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int nlsize;
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tun_encap_info = mpls_lwtunnel_encap(lwtstate);
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nlsize = nla_total_size(tun_encap_info->labels * 4);
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if (tun_encap_info->ttl_propagate != MPLS_TTL_PROP_DEFAULT)
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nlsize += nla_total_size(1);
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return nlsize;
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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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a_hdr->ttl_propagate != b_hdr->ttl_propagate ||
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a_hdr->default_ttl != b_hdr->default_ttl)
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return 1;
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for (l = 0; l < a_hdr->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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.xmit = mpls_xmit,
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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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.owner = THIS_MODULE,
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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_ALIAS_RTNL_LWT(MPLS);
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MODULE_DESCRIPTION("MultiProtocol Label Switching IP Tunnels");
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MODULE_LICENSE("GPL v2");
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