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* Copyright (c) 2011 Nicira, Inc.
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* Copyright (c) 2013 Cisco Systems, Inc.
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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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* 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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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/version.h>
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#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
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#include <linux/net.h>
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#include <linux/rculist.h>
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#include <linux/udp.h>
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* LISP encapsulation header:
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* |N|L|E|V|I|flags| Nonce/Map-Version |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Instance ID/Locator Status Bits |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* struct lisphdr - LISP header
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* @nonce_present: Flag indicating the presence of a 24 bit nonce value.
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* @locator_status_bits_present: Flag indicating the presence of Locator Status
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* @solicit_echo_nonce: Flag indicating the use of the echo noncing mechanism.
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* @map_version_present: Flag indicating the use of mapping versioning.
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* @instance_id_present: Flag indicating the presence of a 24 bit Instance ID.
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* @reserved_flags: 3 bits reserved for future flags.
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* @nonce: 24 bit nonce value.
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* @map_version: 24 bit mapping version.
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* @locator_status_bits: Locator Status Bits: 32 bits when instance_id_present
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* is not set, 8 bits when it is.
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* @instance_id: 24 bit Instance ID
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#ifdef __LITTLE_ENDIAN_BITFIELD
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__u8 reserved_flags:3;
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__u8 instance_id_present:1;
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__u8 map_version_present:1;
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__u8 solicit_echo_nonce:1;
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__u8 locator_status_bits_present:1;
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__u8 locator_status_bits_present:1;
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__u8 solicit_echo_nonce:1;
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__u8 map_version_present:1;
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__u8 instance_id_present:1;
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__u8 reserved_flags:3;
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__be32 locator_status_bits;
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__u8 locator_status_bits;
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#define LISP_HLEN (sizeof(struct udphdr) + sizeof(struct lisphdr))
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* struct lisp_port - Keeps track of open UDP ports
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* @dst_port: lisp UDP port no.
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* @list: list element in @lisp_ports.
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* @lisp_rcv_socket: The socket created for this port number.
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struct list_head list;
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struct socket *lisp_rcv_socket;
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static LIST_HEAD(lisp_ports);
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static inline struct lisp_port *lisp_vport(const struct vport *vport)
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return vport_priv(vport);
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static struct lisp_port *lisp_find_port(struct net *net, __be16 port)
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struct lisp_port *lisp_port;
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list_for_each_entry_rcu(lisp_port, &lisp_ports, list) {
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if (lisp_port->dst_port == port &&
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net_eq(sock_net(lisp_port->lisp_rcv_socket->sk), net))
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static inline struct lisphdr *lisp_hdr(const struct sk_buff *skb)
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return (struct lisphdr *)(udp_hdr(skb) + 1);
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/* Convert 64 bit tunnel ID to 24 bit Instance ID. */
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static void tunnel_id_to_instance_id(__be64 tun_id, __u8 *iid)
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iid[0] = (__force __u8)(tun_id >> 16);
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iid[1] = (__force __u8)(tun_id >> 8);
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iid[2] = (__force __u8)tun_id;
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iid[0] = (__force __u8)((__force u64)tun_id >> 40);
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iid[1] = (__force __u8)((__force u64)tun_id >> 48);
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iid[2] = (__force __u8)((__force u64)tun_id >> 56);
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/* Convert 24 bit Instance ID to 64 bit tunnel ID. */
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static __be64 instance_id_to_tunnel_id(__u8 *iid)
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return (iid[0] << 16) | (iid[1] << 8) | iid[2];
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return (__force __be64)(((__force u64)iid[0] << 40) |
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((__force u64)iid[1] << 48) |
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((__force u64)iid[2] << 56));
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static void lisp_build_header(const struct vport *vport,
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struct lisp_port *lisp_port = lisp_vport(vport);
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struct udphdr *udph = udp_hdr(skb);
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struct lisphdr *lisph = (struct lisphdr *)(udph + 1);
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const struct ovs_key_ipv4_tunnel *tun_key = OVS_CB(skb)->tun_key;
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udph->dest = lisp_port->dst_port;
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udph->source = htons(ovs_tnl_get_src_port(skb));
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udph->len = htons(skb->len - skb_transport_offset(skb));
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lisph->nonce_present = 0; /* We don't support echo nonce algorithm */
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lisph->locator_status_bits_present = 1; /* Set LSB */
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lisph->solicit_echo_nonce = 0; /* No echo noncing */
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lisph->map_version_present = 0; /* No mapping versioning, nonce instead */
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lisph->instance_id_present = 1; /* Store the tun_id as Instance ID */
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lisph->reserved_flags = 0; /* Reserved flags, set to 0 */
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lisph->u1.nonce[0] = 0;
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lisph->u1.nonce[1] = 0;
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lisph->u1.nonce[2] = 0;
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tunnel_id_to_instance_id(tun_key->tun_id, &lisph->u2.word2.instance_id[0]);
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lisph->u2.word2.locator_status_bits = 1;
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/* Called with rcu_read_lock and BH disabled. */
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static int lisp_rcv(struct sock *sk, struct sk_buff *skb)
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struct lisp_port *lisp_port;
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struct lisphdr *lisph;
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struct iphdr *iph, *inner_iph;
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struct ovs_key_ipv4_tunnel tun_key;
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lisp_port = lisp_find_port(dev_net(skb->dev), udp_hdr(skb)->dest);
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if (unlikely(!lisp_port))
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if (unlikely(!pskb_may_pull(skb, LISP_HLEN)))
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lisph = lisp_hdr(skb);
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skb_pull_rcsum(skb, LISP_HLEN);
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if (lisph->instance_id_present != 1)
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key = instance_id_to_tunnel_id(&lisph->u2.word2.instance_id[0]);
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/* Save outer tunnel values */
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tnl_tun_key_init(&tun_key, iph, key, TUNNEL_KEY);
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/* Drop non-IP inner packets */
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inner_iph = (struct iphdr *)(lisph + 1);
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switch (inner_iph->version) {
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protocol = htons(ETH_P_IP);
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protocol = htons(ETH_P_IPV6);
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/* Add Ethernet header */
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ethh = (struct ethhdr *)skb_push(skb, ETH_HLEN);
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memset(ethh, 0, ETH_HLEN);
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ethh->h_dest[0] = 0x02;
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ethh->h_source[0] = 0x02;
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ethh->h_proto = protocol;
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ovs_skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
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ovs_tnl_rcv(vport_from_priv(lisp_port), skb, &tun_key);
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/* Arbitrary value. Irrelevant as long as it's not 0 since we set the handler. */
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#define UDP_ENCAP_LISP 1
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static int lisp_socket_init(struct lisp_port *lisp_port, struct net *net)
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struct sockaddr_in sin;
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err = sock_create_kern(AF_INET, SOCK_DGRAM, 0,
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&lisp_port->lisp_rcv_socket);
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/* release net ref. */
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sk_change_net(lisp_port->lisp_rcv_socket->sk, net);
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sin.sin_family = AF_INET;
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sin.sin_addr.s_addr = htonl(INADDR_ANY);
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sin.sin_port = lisp_port->dst_port;
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err = kernel_bind(lisp_port->lisp_rcv_socket, (struct sockaddr *)&sin,
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sizeof(struct sockaddr_in));
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udp_sk(lisp_port->lisp_rcv_socket->sk)->encap_type = UDP_ENCAP_LISP;
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udp_sk(lisp_port->lisp_rcv_socket->sk)->encap_rcv = lisp_rcv;
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sk_release_kernel(lisp_port->lisp_rcv_socket->sk);
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pr_warn("cannot register lisp protocol handler: %d\n", err);
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static int lisp_get_options(const struct vport *vport, struct sk_buff *skb)
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struct lisp_port *lisp_port = lisp_vport(vport);
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if (nla_put_u16(skb, OVS_TUNNEL_ATTR_DST_PORT, ntohs(lisp_port->dst_port)))
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static void lisp_tnl_destroy(struct vport *vport)
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struct lisp_port *lisp_port = lisp_vport(vport);
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list_del_rcu(&lisp_port->list);
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sk_release_kernel(lisp_port->lisp_rcv_socket->sk);
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ovs_vport_deferred_free(vport);
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static struct vport *lisp_tnl_create(const struct vport_parms *parms)
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struct net *net = ovs_dp_get_net(parms->dp);
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struct nlattr *options = parms->options;
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struct lisp_port *lisp_port;
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a = nla_find_nested(options, OVS_TUNNEL_ATTR_DST_PORT);
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if (a && nla_len(a) == sizeof(u16)) {
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dst_port = nla_get_u16(a);
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/* Require destination port from userspace. */
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/* Verify if we already have a socket created for this port */
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if (lisp_find_port(net, htons(dst_port))) {
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vport = ovs_vport_alloc(sizeof(struct lisp_port),
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&ovs_lisp_vport_ops, parms);
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lisp_port = lisp_vport(vport);
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lisp_port->dst_port = htons(dst_port);
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strncpy(lisp_port->name, parms->name, IFNAMSIZ);
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err = lisp_socket_init(lisp_port, net);
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list_add_tail_rcu(&lisp_port->list, &lisp_ports);
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ovs_vport_free(vport);
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static int lisp_tnl_send(struct vport *vport, struct sk_buff *skb)
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int network_offset = skb_network_offset(skb);
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if (unlikely(!OVS_CB(skb)->tun_key))
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/* We only encapsulate IPv4 and IPv6 packets */
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switch (skb->protocol) {
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case htons(ETH_P_IP):
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case htons(ETH_P_IPV6):
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/* Pop off "inner" Ethernet header */
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skb_pull(skb, network_offset);
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tnl_len = ovs_tnl_send(vport, skb, IPPROTO_UDP,
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LISP_HLEN, lisp_build_header);
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return tnl_len > 0 ? tnl_len + network_offset : tnl_len;
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static const char *lisp_get_name(const struct vport *vport)
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struct lisp_port *lisp_port = lisp_vport(vport);
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return lisp_port->name;
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const struct vport_ops ovs_lisp_vport_ops = {
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.type = OVS_VPORT_TYPE_LISP,
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.create = lisp_tnl_create,
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.destroy = lisp_tnl_destroy,
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.get_name = lisp_get_name,
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.get_options = lisp_get_options,
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.send = lisp_tnl_send,
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#warning LISP tunneling will not be available on kernels before 2.6.26
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#endif /* Linux kernel < 2.6.26 */