+/*
+ * Copyright (c) 2011 Nicira, Inc.
+ * Copyright (c) 2012 Cisco Systems, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/version.h>
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
+
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/list.h>
+#include <linux/net.h>
+#include <linux/udp.h>
+
+#include <net/icmp.h>
+#include <net/ip.h>
+#include <net/udp.h>
+
+#include "datapath.h"
+#include "tunnel.h"
+#include "vport.h"
+#include "vport-generic.h"
+
+#define VXLAN_FLAGS 0x08000000 /* struct vxlanhdr.vx_flags required value. */
+
+/**
+ * struct vxlanhdr - VXLAN header
+ * @vx_flags: Must have the exact value %VXLAN_FLAGS.
+ * @vx_vni: VXLAN Network Identifier (VNI) in top 24 bits, low 8 bits zeroed.
+ */
+struct vxlanhdr {
+ __be32 vx_flags;
+ __be32 vx_vni;
+};
+
+#define VXLAN_HLEN (sizeof(struct udphdr) + sizeof(struct vxlanhdr))
+
+static inline int vxlan_hdr_len(const struct tnl_mutable_config *mutable,
+ const struct ovs_key_ipv4_tunnel *tun_key)
+{
+ return VXLAN_HLEN;
+}
+
+/**
+ * struct vxlan_port - Keeps track of open UDP ports
+ * @list: list element.
+ * @port: The UDP port number in network byte order.
+ * @socket: The socket created for this port number.
+ * @count: How many ports are using this socket/port.
+ */
+struct vxlan_port {
+ struct list_head list;
+ __be16 port;
+ struct socket *vxlan_rcv_socket;
+ int count;
+};
+
+static LIST_HEAD(vxlan_ports);
+
+static struct vxlan_port *vxlan_port_exists(struct net *net, __be16 port)
+{
+ struct vxlan_port *vxlan_port;
+
+ list_for_each_entry(vxlan_port, &vxlan_ports, list) {
+ if (vxlan_port->port == port &&
+ net_eq(sock_net(vxlan_port->vxlan_rcv_socket->sk), net))
+ return vxlan_port;
+ }
+
+ return NULL;
+}
+
+static inline struct vxlanhdr *vxlan_hdr(const struct sk_buff *skb)
+{
+ return (struct vxlanhdr *)(udp_hdr(skb) + 1);
+}
+
+/* Compute source port for outgoing packet.
+ * Currently we use the flow hash.
+ */
+static u16 get_src_port(struct sk_buff *skb)
+{
+ int low;
+ int high;
+ unsigned int range;
+ u32 hash = OVS_CB(skb)->flow->hash;
+
+ inet_get_local_port_range(&low, &high);
+ range = (high - low) + 1;
+ return (((u64) hash * range) >> 32) + low;
+}
+
+static struct sk_buff *vxlan_build_header(const struct vport *vport,
+ const struct tnl_mutable_config *mutable,
+ struct dst_entry *dst,
+ struct sk_buff *skb,
+ int tunnel_hlen)
+{
+ struct udphdr *udph = udp_hdr(skb);
+ struct vxlanhdr *vxh = (struct vxlanhdr *)(udph + 1);
+ const struct ovs_key_ipv4_tunnel *tun_key = OVS_CB(skb)->tun_key;
+ __be64 out_key;
+ u32 flags;
+
+ tnl_get_param(mutable, tun_key, &flags, &out_key);
+
+ udph->dest = mutable->dst_port;
+ udph->source = htons(get_src_port(skb));
+ udph->check = 0;
+ udph->len = htons(skb->len - skb_transport_offset(skb));
+
+ vxh->vx_flags = htonl(VXLAN_FLAGS);
+ vxh->vx_vni = htonl(be64_to_cpu(out_key) << 8);
+
+ /*
+ * Allow our local IP stack to fragment the outer packet even if the
+ * DF bit is set as a last resort. We also need to force selection of
+ * an IP ID here because Linux will otherwise leave it at 0 if the
+ * packet originally had DF set.
+ */
+ skb->local_df = 1;
+ __ip_select_ident(ip_hdr(skb), dst, 0);
+
+ return skb;
+}
+
+/* Called with rcu_read_lock and BH disabled. */
+static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
+{
+ struct vport *vport;
+ struct vxlanhdr *vxh;
+ const struct tnl_mutable_config *mutable;
+ struct iphdr *iph;
+ struct ovs_key_ipv4_tunnel tun_key;
+ __be64 key;
+ u32 tunnel_flags = 0;
+
+ if (unlikely(!pskb_may_pull(skb, VXLAN_HLEN + ETH_HLEN)))
+ goto error;
+
+ vxh = vxlan_hdr(skb);
+ if (unlikely(vxh->vx_flags != htonl(VXLAN_FLAGS) ||
+ vxh->vx_vni & htonl(0xff)))
+ goto error;
+
+ __skb_pull(skb, VXLAN_HLEN);
+ skb_postpull_rcsum(skb, skb_transport_header(skb), VXLAN_HLEN + ETH_HLEN);
+
+ key = cpu_to_be64(ntohl(vxh->vx_vni) >> 8);
+
+ iph = ip_hdr(skb);
+ vport = ovs_tnl_find_port(dev_net(skb->dev), iph->daddr, iph->saddr,
+ key, TNL_T_PROTO_VXLAN, &mutable);
+ if (unlikely(!vport)) {
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+ goto error;
+ }
+
+ if (mutable->flags & TNL_F_IN_KEY_MATCH || !mutable->key.daddr)
+ tunnel_flags = OVS_TNL_F_KEY;
+ else
+ key = 0;
+
+ /* Save outer tunnel values */
+ tnl_tun_key_init(&tun_key, iph, key, tunnel_flags);
+ OVS_CB(skb)->tun_key = &tun_key;
+
+ ovs_tnl_rcv(vport, skb);
+ goto out;
+
+error:
+ kfree_skb(skb);
+out:
+ return 0;
+}
+
+/* Random value. Irrelevant as long as it's not 0 since we set the handler. */
+#define UDP_ENCAP_VXLAN 1
+static int vxlan_socket_init(struct vxlan_port *vxlan_port, struct net *net)
+{
+ int err;
+ struct sockaddr_in sin;
+
+ err = sock_create_kern(AF_INET, SOCK_DGRAM, 0,
+ &vxlan_port->vxlan_rcv_socket);
+ if (err)
+ goto error;
+
+ /* release net ref. */
+ sk_change_net(vxlan_port->vxlan_rcv_socket->sk, net);
+
+ sin.sin_family = AF_INET;
+ sin.sin_addr.s_addr = htonl(INADDR_ANY);
+ sin.sin_port = vxlan_port->port;
+
+ err = kernel_bind(vxlan_port->vxlan_rcv_socket, (struct sockaddr *)&sin,
+ sizeof(struct sockaddr_in));
+ if (err)
+ goto error_sock;
+
+ udp_sk(vxlan_port->vxlan_rcv_socket->sk)->encap_type = UDP_ENCAP_VXLAN;
+ udp_sk(vxlan_port->vxlan_rcv_socket->sk)->encap_rcv = vxlan_rcv;
+
+ udp_encap_enable();
+
+ return 0;
+
+error_sock:
+ sock_release(vxlan_port->vxlan_rcv_socket);
+error:
+ pr_warn("cannot register vxlan protocol handler\n");
+ return err;
+}
+
+static void vxlan_tunnel_release(struct vxlan_port *vxlan_port)
+{
+ vxlan_port->count--;
+
+ if (vxlan_port->count == 0) {
+ /* Release old socket */
+ sock_release(vxlan_port->vxlan_rcv_socket);
+ list_del(&vxlan_port->list);
+ kfree(vxlan_port);
+ }
+}
+static int vxlan_tunnel_setup(struct net *net, struct nlattr *options,
+ struct vxlan_port **vxport)
+{
+ struct nlattr *a;
+ int err;
+ u16 dst_port;
+ struct vxlan_port *vxlan_port = NULL;
+
+ *vxport = NULL;
+
+ if (!options) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ a = nla_find_nested(options, OVS_TUNNEL_ATTR_DST_PORT);
+ if (a && nla_len(a) == sizeof(u16)) {
+ dst_port = nla_get_u16(a);
+ } else {
+ /* Require destination port from userspace. */
+ err = -EINVAL;
+ goto out;
+ }
+
+ /* Verify if we already have a socket created for this port */
+ vxlan_port = vxlan_port_exists(net, htons(dst_port));
+ if (vxlan_port) {
+ vxlan_port->count++;
+ err = 0;
+ goto out;
+ }
+
+ /* Add a new socket for this port */
+ vxlan_port = kzalloc(sizeof(struct vxlan_port), GFP_KERNEL);
+ if (!vxlan_port) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ vxlan_port->port = htons(dst_port);
+ vxlan_port->count = 1;
+ list_add_tail(&vxlan_port->list, &vxlan_ports);
+
+ err = vxlan_socket_init(vxlan_port, net);
+ if (err)
+ goto error;
+
+ *vxport = vxlan_port;
+ goto out;
+
+error:
+ list_del(&vxlan_port->list);
+ kfree(vxlan_port);
+out:
+ return err;
+}
+
+static int vxlan_set_options(struct vport *vport, struct nlattr *options)
+{
+ int err;
+ struct net *net = ovs_dp_get_net(vport->dp);
+ struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
+ struct tnl_mutable_config *config;
+ struct vxlan_port *old_port = NULL;
+ struct vxlan_port *vxlan_port = NULL;
+
+ config = rtnl_dereference(tnl_vport->mutable);
+
+ old_port = vxlan_port_exists(net, config->dst_port);
+
+ err = vxlan_tunnel_setup(net, options, &vxlan_port);
+ if (err)
+ goto out;
+
+ err = ovs_tnl_set_options(vport, options);
+
+ if (err)
+ vxlan_tunnel_release(vxlan_port);
+ else {
+ /* Release old socket */
+ vxlan_tunnel_release(old_port);
+ }
+out:
+ return err;
+}
+
+static const struct tnl_ops ovs_vxlan_tnl_ops = {
+ .tunnel_type = TNL_T_PROTO_VXLAN,
+ .ipproto = IPPROTO_UDP,
+ .hdr_len = vxlan_hdr_len,
+ .build_header = vxlan_build_header,
+};
+
+static void vxlan_tnl_destroy(struct vport *vport)
+{
+ struct vxlan_port *vxlan_port;
+ struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
+ struct tnl_mutable_config *config;
+
+ config = rtnl_dereference(tnl_vport->mutable);
+
+ vxlan_port = vxlan_port_exists(ovs_dp_get_net(vport->dp),
+ config->dst_port);
+
+ vxlan_tunnel_release(vxlan_port);
+
+ ovs_tnl_destroy(vport);
+}
+
+static struct vport *vxlan_tnl_create(const struct vport_parms *parms)
+{
+ int err;
+ struct vport *vport;
+ struct vxlan_port *vxlan_port = NULL;
+
+ err = vxlan_tunnel_setup(ovs_dp_get_net(parms->dp), parms->options,
+ &vxlan_port);
+ if (err)
+ return ERR_PTR(err);
+
+ vport = ovs_tnl_create(parms, &ovs_vxlan_vport_ops, &ovs_vxlan_tnl_ops);
+
+ if (IS_ERR(vport))
+ vxlan_tunnel_release(vxlan_port);
+
+ return vport;
+}
+
+const struct vport_ops ovs_vxlan_vport_ops = {
+ .type = OVS_VPORT_TYPE_VXLAN,
+ .flags = VPORT_F_TUN_ID,
+ .create = vxlan_tnl_create,
+ .destroy = vxlan_tnl_destroy,
+ .set_addr = ovs_tnl_set_addr,
+ .get_name = ovs_tnl_get_name,
+ .get_addr = ovs_tnl_get_addr,
+ .get_options = ovs_tnl_get_options,
+ .set_options = vxlan_set_options,
+ .get_dev_flags = ovs_vport_gen_get_dev_flags,
+ .is_running = ovs_vport_gen_is_running,
+ .get_operstate = ovs_vport_gen_get_operstate,
+ .send = ovs_tnl_send,
+};
+#else
+#warning VXLAN tunneling will not be available on kernels before 2.6.26
+#endif /* Linux kernel < 2.6.26 */