![Nicolas Dichtel](/assets/img/avatar_default.png)
This patch allows to switch the netns when packet is encapsulated or decapsulated. In other word, the encapsulated packet is received in a netns, where the lookup is done to find the tunnel. Once the tunnel is found, the packet is decapsulated and injecting into the corresponding interface which stands to another netns. When one of the two netns is removed, the tunnel is destroyed. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
473 lines
11 KiB
C
473 lines
11 KiB
C
/*
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* Linux NET3: IP/IP protocol decoder modified to support
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* virtual tunnel interface
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*
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* Authors:
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* Saurabh Mohan (saurabh.mohan@vyatta.com) 05/07/2012
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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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/*
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This version of net/ipv4/ip_vti.c is cloned of net/ipv4/ipip.c
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For comments look at net/ipv4/ip_gre.c --ANK
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*/
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#include <linux/capability.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/uaccess.h>
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#include <linux/skbuff.h>
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#include <linux/netdevice.h>
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#include <linux/in.h>
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#include <linux/tcp.h>
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#include <linux/udp.h>
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#include <linux/if_arp.h>
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#include <linux/mroute.h>
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#include <linux/init.h>
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#include <linux/netfilter_ipv4.h>
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#include <linux/if_ether.h>
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#include <net/sock.h>
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#include <net/ip.h>
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#include <net/icmp.h>
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#include <net/ip_tunnels.h>
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#include <net/inet_ecn.h>
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#include <net/xfrm.h>
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#include <net/net_namespace.h>
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#include <net/netns/generic.h>
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static struct rtnl_link_ops vti_link_ops __read_mostly;
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static int vti_net_id __read_mostly;
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static int vti_tunnel_init(struct net_device *dev);
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static int vti_err(struct sk_buff *skb, u32 info)
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{
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/* All the routers (except for Linux) return only
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* 8 bytes of packet payload. It means, that precise relaying of
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* ICMP in the real Internet is absolutely infeasible.
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*/
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struct net *net = dev_net(skb->dev);
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struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
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struct iphdr *iph = (struct iphdr *)skb->data;
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const int type = icmp_hdr(skb)->type;
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const int code = icmp_hdr(skb)->code;
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struct ip_tunnel *t;
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int err;
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switch (type) {
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default:
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case ICMP_PARAMETERPROB:
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return 0;
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case ICMP_DEST_UNREACH:
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switch (code) {
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case ICMP_SR_FAILED:
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case ICMP_PORT_UNREACH:
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/* Impossible event. */
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return 0;
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default:
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/* All others are translated to HOST_UNREACH. */
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break;
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}
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break;
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case ICMP_TIME_EXCEEDED:
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if (code != ICMP_EXC_TTL)
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return 0;
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break;
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}
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err = -ENOENT;
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t = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
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iph->daddr, iph->saddr, 0);
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if (t == NULL)
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goto out;
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if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
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ipv4_update_pmtu(skb, dev_net(skb->dev), info,
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t->parms.link, 0, IPPROTO_IPIP, 0);
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err = 0;
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goto out;
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}
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err = 0;
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if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
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goto out;
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if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
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t->err_count++;
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else
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t->err_count = 1;
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t->err_time = jiffies;
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out:
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return err;
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}
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/* We dont digest the packet therefore let the packet pass */
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static int vti_rcv(struct sk_buff *skb)
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{
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struct ip_tunnel *tunnel;
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const struct iphdr *iph = ip_hdr(skb);
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struct net *net = dev_net(skb->dev);
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struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
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tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
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iph->saddr, iph->daddr, 0);
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if (tunnel != NULL) {
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struct pcpu_tstats *tstats;
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if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
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return -1;
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tstats = this_cpu_ptr(tunnel->dev->tstats);
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u64_stats_update_begin(&tstats->syncp);
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tstats->rx_packets++;
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tstats->rx_bytes += skb->len;
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u64_stats_update_end(&tstats->syncp);
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skb->mark = 0;
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secpath_reset(skb);
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skb->dev = tunnel->dev;
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return 1;
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}
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return -1;
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}
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/* This function assumes it is being called from dev_queue_xmit()
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* and that skb is filled properly by that function.
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*/
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static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
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{
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struct ip_tunnel *tunnel = netdev_priv(dev);
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struct iphdr *tiph = &tunnel->parms.iph;
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u8 tos;
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struct rtable *rt; /* Route to the other host */
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struct net_device *tdev; /* Device to other host */
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struct iphdr *old_iph = ip_hdr(skb);
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__be32 dst = tiph->daddr;
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struct flowi4 fl4;
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int err;
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if (skb->protocol != htons(ETH_P_IP))
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goto tx_error;
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tos = old_iph->tos;
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memset(&fl4, 0, sizeof(fl4));
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flowi4_init_output(&fl4, tunnel->parms.link,
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be32_to_cpu(tunnel->parms.i_key), RT_TOS(tos),
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RT_SCOPE_UNIVERSE,
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IPPROTO_IPIP, 0,
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dst, tiph->saddr, 0, 0);
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rt = ip_route_output_key(dev_net(dev), &fl4);
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if (IS_ERR(rt)) {
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dev->stats.tx_carrier_errors++;
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goto tx_error_icmp;
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}
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/* if there is no transform then this tunnel is not functional.
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* Or if the xfrm is not mode tunnel.
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*/
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if (!rt->dst.xfrm ||
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rt->dst.xfrm->props.mode != XFRM_MODE_TUNNEL) {
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dev->stats.tx_carrier_errors++;
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goto tx_error_icmp;
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}
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tdev = rt->dst.dev;
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if (tdev == dev) {
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ip_rt_put(rt);
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dev->stats.collisions++;
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goto tx_error;
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}
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if (tunnel->err_count > 0) {
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if (time_before(jiffies,
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tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
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tunnel->err_count--;
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dst_link_failure(skb);
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} else
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tunnel->err_count = 0;
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}
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memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
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skb_dst_drop(skb);
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skb_dst_set(skb, &rt->dst);
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nf_reset(skb);
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skb->dev = skb_dst(skb)->dev;
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err = dst_output(skb);
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if (net_xmit_eval(err) == 0)
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err = skb->len;
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iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
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return NETDEV_TX_OK;
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tx_error_icmp:
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dst_link_failure(skb);
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tx_error:
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dev->stats.tx_errors++;
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dev_kfree_skb(skb);
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return NETDEV_TX_OK;
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}
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static int
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vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
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{
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int err = 0;
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struct ip_tunnel_parm p;
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if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
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return -EFAULT;
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if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
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if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
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p.iph.ihl != 5)
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return -EINVAL;
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}
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err = ip_tunnel_ioctl(dev, &p, cmd);
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if (err)
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return err;
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if (cmd != SIOCDELTUNNEL) {
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p.i_flags |= GRE_KEY | VTI_ISVTI;
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p.o_flags |= GRE_KEY;
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}
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if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
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return -EFAULT;
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return 0;
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}
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static const struct net_device_ops vti_netdev_ops = {
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.ndo_init = vti_tunnel_init,
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.ndo_uninit = ip_tunnel_uninit,
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.ndo_start_xmit = vti_tunnel_xmit,
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.ndo_do_ioctl = vti_tunnel_ioctl,
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.ndo_change_mtu = ip_tunnel_change_mtu,
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.ndo_get_stats64 = ip_tunnel_get_stats64,
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};
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static void vti_tunnel_setup(struct net_device *dev)
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{
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dev->netdev_ops = &vti_netdev_ops;
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ip_tunnel_setup(dev, vti_net_id);
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}
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static int vti_tunnel_init(struct net_device *dev)
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{
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struct ip_tunnel *tunnel = netdev_priv(dev);
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struct iphdr *iph = &tunnel->parms.iph;
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memcpy(dev->dev_addr, &iph->saddr, 4);
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memcpy(dev->broadcast, &iph->daddr, 4);
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dev->type = ARPHRD_TUNNEL;
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dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
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dev->mtu = ETH_DATA_LEN;
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dev->flags = IFF_NOARP;
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dev->iflink = 0;
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dev->addr_len = 4;
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dev->features |= NETIF_F_NETNS_LOCAL;
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dev->features |= NETIF_F_LLTX;
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dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
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return ip_tunnel_init(dev);
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}
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static void __net_init vti_fb_tunnel_init(struct net_device *dev)
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{
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struct ip_tunnel *tunnel = netdev_priv(dev);
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struct iphdr *iph = &tunnel->parms.iph;
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iph->version = 4;
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iph->protocol = IPPROTO_IPIP;
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iph->ihl = 5;
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}
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static struct xfrm_tunnel vti_handler __read_mostly = {
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.handler = vti_rcv,
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.err_handler = vti_err,
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.priority = 1,
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};
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static int __net_init vti_init_net(struct net *net)
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{
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int err;
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struct ip_tunnel_net *itn;
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err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0");
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if (err)
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return err;
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itn = net_generic(net, vti_net_id);
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vti_fb_tunnel_init(itn->fb_tunnel_dev);
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return 0;
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}
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static void __net_exit vti_exit_net(struct net *net)
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{
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struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
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ip_tunnel_delete_net(itn, &vti_link_ops);
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}
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static struct pernet_operations vti_net_ops = {
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.init = vti_init_net,
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.exit = vti_exit_net,
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.id = &vti_net_id,
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.size = sizeof(struct ip_tunnel_net),
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};
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static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
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{
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return 0;
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}
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static void vti_netlink_parms(struct nlattr *data[],
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struct ip_tunnel_parm *parms)
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{
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memset(parms, 0, sizeof(*parms));
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parms->iph.protocol = IPPROTO_IPIP;
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if (!data)
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return;
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if (data[IFLA_VTI_LINK])
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parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
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if (data[IFLA_VTI_IKEY])
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parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
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if (data[IFLA_VTI_OKEY])
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parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
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if (data[IFLA_VTI_LOCAL])
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parms->iph.saddr = nla_get_be32(data[IFLA_VTI_LOCAL]);
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if (data[IFLA_VTI_REMOTE])
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parms->iph.daddr = nla_get_be32(data[IFLA_VTI_REMOTE]);
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}
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static int vti_newlink(struct net *src_net, struct net_device *dev,
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struct nlattr *tb[], struct nlattr *data[])
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{
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struct ip_tunnel_parm parms;
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vti_netlink_parms(data, &parms);
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return ip_tunnel_newlink(dev, tb, &parms);
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}
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static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
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struct nlattr *data[])
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{
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struct ip_tunnel_parm p;
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vti_netlink_parms(data, &p);
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return ip_tunnel_changelink(dev, tb, &p);
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}
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static size_t vti_get_size(const struct net_device *dev)
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{
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return
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/* IFLA_VTI_LINK */
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nla_total_size(4) +
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/* IFLA_VTI_IKEY */
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nla_total_size(4) +
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/* IFLA_VTI_OKEY */
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nla_total_size(4) +
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/* IFLA_VTI_LOCAL */
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nla_total_size(4) +
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/* IFLA_VTI_REMOTE */
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nla_total_size(4) +
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0;
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}
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static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
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{
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struct ip_tunnel *t = netdev_priv(dev);
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struct ip_tunnel_parm *p = &t->parms;
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nla_put_u32(skb, IFLA_VTI_LINK, p->link);
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nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key);
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nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key);
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nla_put_be32(skb, IFLA_VTI_LOCAL, p->iph.saddr);
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nla_put_be32(skb, IFLA_VTI_REMOTE, p->iph.daddr);
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return 0;
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}
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static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
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[IFLA_VTI_LINK] = { .type = NLA_U32 },
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[IFLA_VTI_IKEY] = { .type = NLA_U32 },
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[IFLA_VTI_OKEY] = { .type = NLA_U32 },
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[IFLA_VTI_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
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[IFLA_VTI_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
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};
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static struct rtnl_link_ops vti_link_ops __read_mostly = {
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.kind = "vti",
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.maxtype = IFLA_VTI_MAX,
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.policy = vti_policy,
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.priv_size = sizeof(struct ip_tunnel),
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.setup = vti_tunnel_setup,
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.validate = vti_tunnel_validate,
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.newlink = vti_newlink,
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.changelink = vti_changelink,
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.get_size = vti_get_size,
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.fill_info = vti_fill_info,
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};
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static int __init vti_init(void)
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{
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int err;
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pr_info("IPv4 over IPSec tunneling driver\n");
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err = register_pernet_device(&vti_net_ops);
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if (err < 0)
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return err;
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err = xfrm4_mode_tunnel_input_register(&vti_handler);
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if (err < 0) {
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unregister_pernet_device(&vti_net_ops);
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pr_info("vti init: can't register tunnel\n");
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}
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err = rtnl_link_register(&vti_link_ops);
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if (err < 0)
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goto rtnl_link_failed;
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return err;
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rtnl_link_failed:
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xfrm4_mode_tunnel_input_deregister(&vti_handler);
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unregister_pernet_device(&vti_net_ops);
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return err;
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}
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static void __exit vti_fini(void)
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{
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rtnl_link_unregister(&vti_link_ops);
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if (xfrm4_mode_tunnel_input_deregister(&vti_handler))
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pr_info("vti close: can't deregister tunnel\n");
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unregister_pernet_device(&vti_net_ops);
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}
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module_init(vti_init);
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module_exit(vti_fini);
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_RTNL_LINK("vti");
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MODULE_ALIAS_NETDEV("ip_vti0");
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