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Message-ID: <20120924130239.18767146@nehalam.linuxnetplumber.net>
Date: Mon, 24 Sep 2012 13:02:39 -0700
From: Stephen Hemminger <shemminger@...tta.com>
To: Eric Dumazet <eric.dumazet@...il.com>
Cc: David Miller <davem@...emloft.net>,
Chris Wright <chrisw@...hat.com>, netdev@...r.kernel.org
Subject: [PATCHv3 net-next 3/3] vxlan: virtual extensible lan
This is an implementation of Virtual eXtensible Local Area Network
as described in draft RFC:
http://tools.ietf.org/html/draft-mahalingam-dutt-dcops-vxlan-02
The driver integrates a Virtual Tunnel Endpoint (VTEP) functionality
that learns MAC to IP address mapping.
This implementation has not been tested for Interoperation with
other equipment.
Signed-off-by: Stephen Hemminger <shemminger@...tta.com>
---
v3 - fix ordering of change versus migration message
v2 - fix use of ip header after pskb_may_pull
Documentation/networking/vxlan.txt | 36 +
drivers/net/Kconfig | 13
drivers/net/Makefile | 1
drivers/net/vxlan.c | 1180 +++++++++++++++++++++++++++++++++++++
include/linux/if_link.h | 14
5 files changed, 1244 insertions(+)
--- a/drivers/net/Kconfig 2012-09-24 10:56:57.080291529 -0700
+++ b/drivers/net/Kconfig 2012-09-24 12:43:25.298239026 -0700
@@ -149,6 +149,19 @@ config MACVTAP
To compile this driver as a module, choose M here: the module
will be called macvtap.
+config VXLAN
+ tristate "Virtual eXtensible Local Area Network (VXLAN)"
+ depends on EXPERIMENTAL
+ ---help---
+ This allows one to create vxlan virtual interfaces that provide
+ Layer 2 Networks over Layer 3 Networks. VXLAN is often used
+ to tunnel virtual network infrastructure in virtualized environments.
+ For more information see:
+ http://tools.ietf.org/html/draft-mahalingam-dutt-dcops-vxlan-02
+
+ To compile this driver as a module, choose M here: the module
+ will be called vxlan.
+
config NETCONSOLE
tristate "Network console logging support"
---help---
--- a/drivers/net/Makefile 2012-09-24 10:56:57.080291529 -0700
+++ b/drivers/net/Makefile 2012-09-24 11:08:02.865416523 -0700
@@ -21,6 +21,7 @@ obj-$(CONFIG_NET_TEAM) += team/
obj-$(CONFIG_TUN) += tun.o
obj-$(CONFIG_VETH) += veth.o
obj-$(CONFIG_VIRTIO_NET) += virtio_net.o
+obj-$(CONFIG_VXLAN) += vxlan.o
#
# Networking Drivers
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ b/drivers/net/vxlan.c 2012-09-24 12:58:01.809401221 -0700
@@ -0,0 +1,1171 @@
+/*
+ * VXLAN: Virtual eXtensiable Local Area Network
+ *
+ * Copyright (c) 2012 Vyatta Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * TODO
+ * - use IANA UDP port number (when defined)
+ * - IPv6 (not in RFC)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/skbuff.h>
+#include <linux/rculist.h>
+#include <linux/netdevice.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/udp.h>
+#include <linux/igmp.h>
+#include <linux/etherdevice.h>
+#include <linux/if_ether.h>
+#include <linux/version.h>
+#include <linux/hash.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/udp.h>
+#include <net/rtnetlink.h>
+#include <net/route.h>
+#include <net/dsfield.h>
+#include <net/inet_ecn.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+
+#define VXLAN_VERSION "0.0"
+
+#define VNI_HASH_BITS 10
+#define VNI_HASH_SIZE (1<<VNI_HASH_BITS)
+#define FDB_HASH_BITS 8
+#define FDB_HASH_SIZE (1<<FDB_HASH_BITS)
+
+#define VXLAN_N_VID (1u << 24)
+#define VXLAN_VID_MASK (VXLAN_N_VID - 1)
+
+#define FDB_AGE_INTERVAL (10 * HZ) /* rescan interval */
+#define FDB_AGE_TIME (300 * HZ) /* drop if not used in 5 min */
+
+#define VXLAN_FLAGS 0x08000000 /* struct vxlanhdr.vx_flags required value. */
+
+/* VXLAN protocol header */
+struct vxlanhdr {
+ __be32 vx_flags;
+ __be32 vx_vni;
+};
+
+#define VXLAN_HEADROOM (sizeof(struct iphdr) \
+ + sizeof(struct udphdr) \
+ + sizeof(struct vxlanhdr))
+
+/* UDP port for VXLAN traffic. */
+static unsigned int vxlan_port __read_mostly = 8472;
+module_param_named(port, vxlan_port, uint, 0);
+MODULE_PARM_DESC(vxlan_port, "Destination UDP port");
+
+/* per-net private data for this module */
+static unsigned int vxlan_net_id;
+struct vxlan_net {
+ struct socket *sock; /* UDP encap socket */
+ struct hlist_head vni_list[VNI_HASH_SIZE];
+};
+
+/* Forwarding table entry */
+struct vxlan_fdb {
+ struct hlist_node hlist; /* linked list of entries */
+ struct rcu_head rcu;
+ unsigned long updated; /* jiffies */
+ unsigned long used;
+#define VXLAN_FDB_PERM 0x1
+ u32 flags;
+ __be32 remote_ip;
+ u8 eth_addr[ETH_ALEN];
+};
+
+/* Per-cpu network traffic stats */
+struct vxlan_stats {
+ u64 rx_packets;
+ u64 rx_bytes;
+ u64 tx_packets;
+ u64 tx_bytes;
+ struct u64_stats_sync syncp;
+};
+
+/* Pseudo network device */
+struct vxlan_dev {
+ struct hlist_node hlist;
+ struct net_device *dev;
+ struct vxlan_stats __percpu *stats;
+ __u32 vni; /* virtual network id */
+ __be32 gaddr; /* multicast group */
+ __be32 saddr; /* source address */
+ unsigned int link; /* link to multicast over */
+ __u8 tos; /* TOS override */
+ __u8 ttl;
+ bool learn;
+
+ struct timer_list age_timer;
+ spinlock_t hash_lock;
+ struct hlist_head fdb_head[FDB_HASH_SIZE];
+};
+
+/* salt for hash table */
+static u32 vxlan_salt __read_mostly;
+
+static inline struct hlist_head *vni_head(struct net *net, u32 id)
+{
+ struct vxlan_net *vn = net_generic(net, vxlan_net_id);
+
+ return &vn->vni_list[hash_32(id, VNI_HASH_BITS)];
+}
+
+/* Look up VNI in a per net namespace table */
+static struct vxlan_dev *vxlan_find_vni(struct net *net, u32 id)
+{
+ struct vxlan_dev *vxlan;
+ struct hlist_node *node;
+
+ hlist_for_each_entry_rcu(vxlan, node, vni_head(net, id), hlist) {
+ if (vxlan->vni == id)
+ return vxlan;
+ }
+
+ return NULL;
+}
+
+/* Fill in neighbour message in skbuff. */
+static int vxlan_fdb_info(struct sk_buff *skb, struct vxlan_dev *vxlan,
+ const struct vxlan_fdb *fdb,
+ u32 portid, u32 seq, int type, unsigned int flags)
+{
+ unsigned long now = jiffies;
+ struct nda_cacheinfo ci;
+ struct nlmsghdr *nlh;
+ struct ndmsg *ndm;
+
+ nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
+ if (nlh == NULL)
+ return -EMSGSIZE;
+
+ ndm = nlmsg_data(nlh);
+ memset(ndm, 0, sizeof(*ndm));
+ ndm->ndm_family = AF_BRIDGE;
+
+ if (fdb->flags & VXLAN_FDB_PERM)
+ ndm->ndm_state = NUD_PERMANENT;
+ else if (time_before_eq(fdb->used + FDB_AGE_TIME, now))
+ ndm->ndm_state = NUD_STALE;
+ else
+ ndm->ndm_state = NUD_REACHABLE;
+
+ if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->eth_addr))
+ goto nla_put_failure;
+
+ if (nla_put_be32(skb, NDA_DST, fdb->remote_ip))
+ goto nla_put_failure;
+
+ ci.ndm_used = jiffies_to_clock_t(now - fdb->used);
+ ci.ndm_confirmed = 0;
+ ci.ndm_updated = jiffies_to_clock_t(now - fdb->updated);
+ ci.ndm_refcnt = 0;
+
+ if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
+ goto nla_put_failure;
+
+ return nlmsg_end(skb, nlh);
+
+nla_put_failure:
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
+}
+
+static inline size_t vxlan_nlmsg_size(void)
+{
+ return NLMSG_ALIGN(sizeof(struct ndmsg))
+ + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
+ + nla_total_size(sizeof(__be32)) /* NDA_DST */
+ + nla_total_size(sizeof(struct nda_cacheinfo));
+}
+
+static void vxlan_fdb_notify(struct vxlan_dev *vxlan,
+ const struct vxlan_fdb *fdb, int type)
+{
+ struct net *net = dev_net(vxlan->dev);
+ struct sk_buff *skb;
+ int err = -ENOBUFS;
+
+ skb = nlmsg_new(vxlan_nlmsg_size(), GFP_ATOMIC);
+ if (skb == NULL)
+ goto errout;
+
+ err = vxlan_fdb_info(skb, vxlan, fdb, 0, 0, type, 0);
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in vxlan_nlmsg_size() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
+
+ rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
+ return;
+errout:
+ if (err < 0)
+ rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
+}
+
+/* Hash Ethernet address */
+static u32 eth_hash(const unsigned char *addr)
+{
+ /* could be optimized for unaligned access */
+ u32 a = addr[5] << 8 | addr[4];
+ u32 b = addr[3] << 24 | addr[2] << 16 | addr[1] << 8 | addr[0];
+
+ return jhash_2words(a, b, vxlan_salt);
+}
+
+/* Hash chain to use given mac address */
+static inline struct hlist_head *vxlan_fdb_head(struct vxlan_dev *vxlan,
+ const u8 *mac)
+{
+ return &vxlan->fdb_head[hash_32(eth_hash(mac), FDB_HASH_BITS)];
+}
+
+/* Look up Ethernet address in forwarding table */
+static struct vxlan_fdb *vxlan_find_mac(struct vxlan_dev *vxlan,
+ const u8 *mac)
+
+{
+ struct hlist_head *head = vxlan_fdb_head(vxlan, mac);
+ struct vxlan_fdb *f;
+ struct hlist_node *node;
+
+ hlist_for_each_entry_rcu(f, node, head, hlist) {
+ if (compare_ether_addr(mac, f->eth_addr) == 0)
+ return f;
+ }
+
+ return NULL;
+}
+
+/* Add new entry to forwarding table -- assumes lock held */
+static int vxlan_fdb_create(struct vxlan_dev *vxlan,
+ const u8 *mac, __be32 ip,
+ u32 flags)
+{
+ struct vxlan_fdb *f;
+
+ if (unlikely(vxlan_find_mac(vxlan, mac))) {
+ netdev_dbg(vxlan->dev,
+ "lost race to create %pM\n", mac);
+ return -EEXIST;
+ }
+
+ netdev_dbg(vxlan->dev, "add %pM -> %pI4\n", mac, &ip);
+
+ f = kmalloc(sizeof(*f), GFP_ATOMIC);
+ if (!f)
+ return -ENOMEM;
+
+ f->remote_ip = ip;
+ memcpy(f->eth_addr, mac, ETH_ALEN);
+ hlist_add_head_rcu(&f->hlist,
+ vxlan_fdb_head(vxlan, mac));
+ f->updated = f->used = jiffies;
+ f->flags = flags;
+
+ vxlan_fdb_notify(vxlan, f, RTM_NEWNEIGH);
+
+ return 0;
+}
+
+static void vxlan_fdb_destroy(struct vxlan_dev *vxlan, struct vxlan_fdb *f)
+{
+ netdev_dbg(vxlan->dev,
+ "delete %pM\n", f->eth_addr);
+
+ vxlan_fdb_notify(vxlan, f, RTM_DELNEIGH);
+
+ hlist_del_rcu(&f->hlist);
+ kfree_rcu(f, rcu);
+}
+
+/* Add static entry (via netlink) */
+static int vxlan_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
+ struct net_device *dev,
+ const unsigned char *addr, u16 flags)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+ __be32 ip;
+ int err;
+
+ if (tb[NDA_DST] == NULL)
+ return -EINVAL;
+
+ if (nla_len(tb[NDA_DST]) != sizeof(__be32))
+ return -EAFNOSUPPORT;
+
+ ip = nla_get_be32(tb[NDA_DST]);
+
+ spin_lock_bh(&vxlan->hash_lock);
+ err = vxlan_fdb_create(vxlan, addr, ip, VXLAN_FDB_PERM);
+ spin_unlock_bh(&vxlan->hash_lock);
+
+ return err;
+}
+
+/* Delete entry (via netlink) */
+static int vxlan_fdb_delete(struct ndmsg *ndm, struct net_device *dev,
+ const unsigned char *addr)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+ struct vxlan_fdb *f;
+ int err = -ENOENT;
+
+ spin_lock_bh(&vxlan->hash_lock);
+ f = vxlan_find_mac(vxlan, addr);
+ if (f) {
+ vxlan_fdb_destroy(vxlan, f);
+ err = 0;
+ }
+ spin_unlock_bh(&vxlan->hash_lock);
+
+ return err;
+}
+
+/* Dump forwarding table */
+static int vxlan_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb,
+ struct net_device *dev, int idx)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+ unsigned int h;
+
+ for (h = 0; h < FDB_HASH_SIZE; ++h) {
+ struct vxlan_fdb *f;
+ struct hlist_node *n;
+
+ hlist_for_each_entry_rcu(f, n, &vxlan->fdb_head[h], hlist) {
+ if (idx < cb->args[0])
+ goto skip;
+
+ if (vxlan_fdb_info(skb, vxlan, f,
+ NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq,
+ RTM_NEWNEIGH,
+ NLM_F_MULTI) < 0)
+ break;
+skip:
+ ++idx;
+ }
+ }
+
+ return idx;
+}
+
+/* Watch incoming packets to learn mapping between Ethernet address
+ * and Tunnel endpoint.
+ */
+static void vxlan_snoop(struct net_device *dev,
+ __be32 src_ip, const u8 *src_mac)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+ struct vxlan_fdb *f;
+ int err;
+
+ f = vxlan_find_mac(vxlan, src_mac);
+ if (likely(f)) {
+ f->used = jiffies;
+ if (likely(f->remote_ip == src_ip))
+ return;
+
+ if (net_ratelimit())
+ netdev_info(dev,
+ "%pM migrated from %pI4 to %pI4\n",
+ src_mac, &f->remote_ip, &src_ip);
+
+ f->remote_ip = src_ip;
+ f->updated = jiffies;
+ } else {
+ /* learned new entry */
+ spin_lock(&vxlan->hash_lock);
+ err = vxlan_fdb_create(vxlan, src_mac, src_ip, 0);
+ spin_unlock(&vxlan->hash_lock);
+ }
+}
+
+
+/* See if multicast group is already in use by other ID */
+static bool vxlan_group_used(struct vxlan_net *vn,
+ const struct vxlan_dev *this)
+{
+ const struct vxlan_dev *vxlan;
+ struct hlist_node *node;
+ unsigned h;
+
+ for (h = 0; h < VNI_HASH_SIZE; ++h)
+ hlist_for_each_entry(vxlan, node, &vn->vni_list[h], hlist) {
+ if (vxlan == this)
+ continue;
+
+ if (!netif_running(vxlan->dev))
+ continue;
+
+ if (vxlan->gaddr == this->gaddr)
+ return true;
+ }
+
+ return false;
+}
+
+/* kernel equivalent to IP_ADD_MEMBERSHIP */
+static int vxlan_join_group(struct net_device *dev)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+ struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id);
+ struct sock *sk = vn->sock->sk;
+ struct ip_mreqn mreq = {
+ .imr_multiaddr.s_addr = vxlan->gaddr,
+ };
+ int err;
+
+ if (vxlan_group_used(vn, vxlan))
+ return 0;
+
+ /* Need to drop RTNL to call multicast join */
+ rtnl_unlock();
+ lock_sock(sk);
+ err = ip_mc_join_group(sk, &mreq);
+ release_sock(sk);
+ rtnl_lock();
+
+ return err;
+}
+
+
+/* kernel equivalent to IP_DROP_MEMBERSHIP */
+static int vxlan_leave_group(struct net_device *dev)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+ struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id);
+ int err = 0;
+ struct sock *sk = vn->sock->sk;
+ struct ip_mreqn mreq = {
+ .imr_multiaddr.s_addr = vxlan->gaddr,
+ };
+
+ if (vxlan_group_used(vn, vxlan))
+ return 0;
+
+ /* Need to drop RTNL to call multicast leave */
+ rtnl_unlock();
+ lock_sock(sk);
+ err = ip_mc_leave_group(sk, &mreq);
+ release_sock(sk);
+ rtnl_lock();
+
+ return err;
+}
+
+/* Propogate ECN from outer IP header to tunneled packet */
+static inline void vxlan_ecn_decap(const struct iphdr *iph, struct sk_buff *skb)
+{
+ if (INET_ECN_is_ce(iph->tos)) {
+ if (skb->protocol == htons(ETH_P_IP))
+ IP_ECN_set_ce(ip_hdr(skb));
+ else if (skb->protocol == htons(ETH_P_IPV6))
+ IP6_ECN_set_ce(ipv6_hdr(skb));
+ }
+}
+
+/* Callback from net/ipv4/udp.c to receive packets */
+static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
+{
+ struct iphdr *oip;
+ struct vxlanhdr *vxh;
+ struct vxlan_dev *vxlan;
+ struct vxlan_stats *stats;
+ __u32 vni;
+
+ /* pop off outer UDP header */
+ __skb_pull(skb, sizeof(struct udphdr));
+
+ /* Need Vxlan and inner Ethernet header to be present */
+ if (!pskb_may_pull(skb,
+ sizeof(struct vxlanhdr) + sizeof(struct ethhdr)))
+ goto error;
+
+ oip = ip_hdr(skb);
+
+ /* Drop packets with reserved bits set */
+ vxh = (struct vxlanhdr *) skb->data;
+ if (vxh->vx_flags != htonl(VXLAN_FLAGS) ||
+ (vxh->vx_vni & htonl(0xff)))
+ goto error;
+
+ __skb_pull(skb, sizeof(struct vxlanhdr));
+
+ /* Is this VNI defined? */
+ vni = ntohl(vxh->vx_vni) >> 8;
+ vxlan = vxlan_find_vni(sock_net(sk), vni);
+ if (!vxlan)
+ goto drop;
+
+ /* Ignore packets if device is not up */
+ if (!netif_running(vxlan->dev))
+ goto drop;
+
+ /* Re-examine inner Ethernet packet */
+ skb->protocol = eth_type_trans(skb, vxlan->dev);
+ skb->ip_summed = CHECKSUM_NONE;
+
+ /* Ignore packet loops (and multicast echo) */
+ if (compare_ether_addr(eth_hdr(skb)->h_source,
+ vxlan->dev->dev_addr) == 0)
+ goto drop;
+
+ /* Check for multicast group configuration errors */
+ if (IN_MULTICAST(ntohl(oip->daddr)) &&
+ oip->daddr != vxlan->gaddr) {
+ if (net_ratelimit())
+ netdev_notice(vxlan->dev,
+ "group address %pI4 does not match\n",
+ &oip->daddr);
+ goto drop;
+ }
+
+ if (vxlan->learn)
+ vxlan_snoop(skb->dev, oip->saddr, eth_hdr(skb)->h_source);
+
+ stats = this_cpu_ptr(vxlan->stats);
+ u64_stats_update_begin(&stats->syncp);
+ stats->rx_packets++;
+ stats->rx_bytes += skb->len;
+ u64_stats_update_end(&stats->syncp);
+
+ __skb_tunnel_rx(skb, vxlan->dev);
+ skb_reset_network_header(skb);
+ vxlan_ecn_decap(oip, skb);
+
+ netif_rx(skb);
+
+ return 0;
+error:
+ /* Put UDP header back */
+ __skb_push(skb, sizeof(struct udphdr));
+
+ return 1;
+drop:
+ /* Consume bad packet */
+ kfree_skb(skb);
+ return 0;
+}
+
+/* Extract dsfield from inner protocol */
+static inline u8 vxlan_get_dsfield(const struct iphdr *iph,
+ const struct sk_buff *skb)
+{
+ if (skb->protocol == htons(ETH_P_IP))
+ return iph->tos;
+ else if (skb->protocol == htons(ETH_P_IPV6))
+ return ipv6_get_dsfield((const struct ipv6hdr *)iph);
+ else
+ return 0;
+}
+
+/* Propogate ECN bits out */
+static inline u8 vxlan_ecn_encap(u8 tos,
+ const struct iphdr *iph,
+ const struct sk_buff *skb)
+{
+ u8 inner = vxlan_get_dsfield(iph, skb);
+
+ return INET_ECN_encapsulate(tos, inner);
+}
+
+/* Transmit local packets over Vxlan
+ *
+ * Outer IP header inherits ECN and DF from inner header.
+ * Outer UDP destination is the VXLAN assigned port.
+ * source port is based on hash of flow if available
+ * otherwise use a random value
+ */
+static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+ struct rtable *rt;
+ const struct ethhdr *eth;
+ const struct iphdr *old_iph;
+ struct iphdr *iph;
+ struct vxlanhdr *vxh;
+ struct udphdr *uh;
+ struct flowi4 fl4;
+ struct vxlan_fdb *f;
+ unsigned int pkt_len = skb->len;
+ unsigned int mtu;
+ u32 hash;
+ __be32 dst;
+ __be16 df = 0;
+ __u8 tos, ttl;
+ int err;
+
+ /* Need space for new headers (invalidates iph ptr) */
+ if (skb_cow_head(skb, VXLAN_HEADROOM))
+ goto drop;
+
+ eth = (void *)skb->data;
+ old_iph = ip_hdr(skb);
+
+ if (!is_multicast_ether_addr(eth->h_dest) &&
+ (f = vxlan_find_mac(vxlan, eth->h_dest)))
+ dst = f->remote_ip;
+ else if (vxlan->gaddr) {
+ dst = vxlan->gaddr;
+ } else
+ goto drop;
+
+ ttl = vxlan->ttl;
+ if (!ttl && IN_MULTICAST(ntohl(dst)))
+ ttl = 1;
+
+ tos = vxlan->tos;
+ if (tos == 1)
+ tos = vxlan_get_dsfield(old_iph, skb);
+
+ hash = skb_get_rxhash(skb);
+
+ rt = ip_route_output_gre(dev_net(dev), &fl4, dst,
+ vxlan->saddr, vxlan->vni,
+ RT_TOS(tos), vxlan->link);
+ if (IS_ERR(rt)) {
+ netdev_dbg(dev, "no route to %pI4\n", &dst);
+ dev->stats.tx_carrier_errors++;
+ goto tx_error;
+ }
+
+ if (rt->dst.dev == dev) {
+ netdev_dbg(dev, "circular route to %pI4\n", &dst);
+ ip_rt_put(rt);
+ dev->stats.collisions++;
+ goto tx_error;
+ }
+
+ mtu = dst_mtu(&rt->dst) - VXLAN_HEADROOM;
+ /* Do PMTU */
+ if (skb->protocol == htons(ETH_P_IP)) {
+ df |= old_iph->frag_off & htons(IP_DF);
+ if (df && mtu < pkt_len) {
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
+ htonl(mtu));
+ ip_rt_put(rt);
+ goto tx_error;
+ }
+ }
+#if IS_ENABLED(CONFIG_IPV6)
+ else if (skb->protocol == htons(ETH_P_IPV6)) {
+ if (mtu >= IPV6_MIN_MTU && mtu < pkt_len) {
+ icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+ ip_rt_put(rt);
+ goto tx_error;
+ }
+ }
+#endif
+
+ memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+ IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
+ IPSKB_REROUTED);
+ skb_dst_drop(skb);
+ skb_dst_set(skb, &rt->dst);
+
+ vxh = (struct vxlanhdr *) __skb_push(skb, sizeof(*vxh));
+ vxh->vx_flags = htonl(VXLAN_FLAGS);
+ vxh->vx_vni = htonl(vxlan->vni << 8);
+
+ __skb_push(skb, sizeof(*uh));
+ skb_reset_transport_header(skb);
+ uh = udp_hdr(skb);
+
+ uh->dest = htons(vxlan_port);
+ uh->source = hash ? :random32();
+
+ uh->len = htons(skb->len);
+ uh->check = 0;
+
+ __skb_push(skb, sizeof(*iph));
+ skb_reset_network_header(skb);
+ iph = ip_hdr(skb);
+ iph->version = 4;
+ iph->ihl = sizeof(struct iphdr) >> 2;
+ iph->frag_off = df;
+ iph->protocol = IPPROTO_UDP;
+ iph->tos = tos;
+ iph->daddr = fl4.daddr;
+ iph->saddr = fl4.saddr;
+ iph->ttl = ttl ? : ip4_dst_hoplimit(&rt->dst);
+
+ /* See __IPTUNNEL_XMIT */
+ skb->ip_summed = CHECKSUM_NONE;
+ ip_select_ident(iph, &rt->dst, NULL);
+
+ err = ip_local_out(skb);
+ if (likely(net_xmit_eval(err) == 0)) {
+ struct vxlan_stats *stats = this_cpu_ptr(vxlan->stats);
+
+ u64_stats_update_begin(&stats->syncp);
+ stats->tx_packets++;
+ stats->tx_bytes += pkt_len;
+ u64_stats_update_end(&stats->syncp);
+ } else {
+ dev->stats.tx_errors++;
+ dev->stats.tx_aborted_errors++;
+ }
+ return NETDEV_TX_OK;
+
+drop:
+ dev->stats.tx_dropped++;
+ goto tx_free;
+
+tx_error:
+ dev->stats.tx_errors++;
+tx_free:
+ dev_kfree_skb(skb);
+ return NETDEV_TX_OK;
+}
+
+/* Walk the forwarding table and purge stale entries */
+static void vxlan_cleanup(unsigned long arg)
+{
+ struct vxlan_dev *vxlan = (struct vxlan_dev *) arg;
+ unsigned long next_timer = jiffies + FDB_AGE_INTERVAL;
+ unsigned int h;
+
+ if (!netif_running(vxlan->dev))
+ return;
+
+ spin_lock_bh(&vxlan->hash_lock);
+ for (h = 0; h < FDB_HASH_SIZE; ++h) {
+ struct hlist_node *p, *n;
+ hlist_for_each_safe(p, n, &vxlan->fdb_head[h]) {
+ struct vxlan_fdb *f
+ = container_of(p, struct vxlan_fdb, hlist);
+ unsigned long timeout = f->used + FDB_AGE_TIME;
+
+ if (f->flags & VXLAN_FDB_PERM)
+ continue;
+
+ if (time_before_eq(timeout, jiffies)) {
+ netdev_dbg(vxlan->dev,
+ "garbage collect %pM\n",
+ f->eth_addr);
+ vxlan_fdb_destroy(vxlan, f);
+ } else if (time_before(timeout, next_timer))
+ next_timer = timeout;
+ }
+ }
+ spin_unlock_bh(&vxlan->hash_lock);
+
+ mod_timer(&vxlan->age_timer, next_timer);
+}
+
+/* Setup stats when device is created */
+static int vxlan_init(struct net_device *dev)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+
+ vxlan->stats = alloc_percpu(struct vxlan_stats);
+ if (!vxlan->stats)
+ return -ENOMEM;
+
+ return 0;
+}
+
+/* Start ageing timer and join group when device is brought up */
+static int vxlan_open(struct net_device *dev)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+ int err;
+
+ if (vxlan->gaddr) {
+ err = vxlan_join_group(dev);
+ if (err)
+ return err;
+ }
+
+ mod_timer(&vxlan->age_timer, jiffies + FDB_AGE_INTERVAL);
+ return 0;
+}
+
+/* Purge the forwarding table */
+static void vxlan_flush(struct vxlan_dev *vxlan)
+{
+ unsigned h;
+
+ spin_lock_bh(&vxlan->hash_lock);
+ for (h = 0; h < FDB_HASH_SIZE; ++h) {
+ struct hlist_node *p, *n;
+ hlist_for_each_safe(p, n, &vxlan->fdb_head[h]) {
+ struct vxlan_fdb *f
+ = container_of(p, struct vxlan_fdb, hlist);
+ vxlan_fdb_destroy(vxlan, f);
+ }
+ }
+ spin_unlock_bh(&vxlan->hash_lock);
+}
+
+/* Cleanup timer and forwarding table on shutdown */
+static int vxlan_stop(struct net_device *dev)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+
+ if (vxlan->gaddr)
+ vxlan_leave_group(dev);
+
+ del_timer_sync(&vxlan->age_timer);
+
+ vxlan_flush(vxlan);
+
+ return 0;
+}
+
+/* Merge per-cpu statistics */
+static struct rtnl_link_stats64 *vxlan_stats64(struct net_device *dev,
+ struct rtnl_link_stats64 *stats)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+ struct vxlan_stats tmp, sum = { 0 };
+ unsigned int cpu;
+
+ for_each_possible_cpu(cpu) {
+ unsigned int start;
+ const struct vxlan_stats *stats
+ = per_cpu_ptr(vxlan->stats, cpu);
+
+ do {
+ start = u64_stats_fetch_begin_bh(&stats->syncp);
+ memcpy(&tmp, stats, sizeof(tmp));
+ } while (u64_stats_fetch_retry_bh(&stats->syncp, start));
+
+ sum.tx_bytes += tmp.tx_bytes;
+ sum.tx_packets += tmp.tx_packets;
+ sum.rx_bytes += tmp.rx_bytes;
+ sum.rx_packets += tmp.rx_packets;
+ }
+
+ stats->tx_bytes = sum.tx_bytes;
+ stats->tx_packets = sum.tx_packets;
+ stats->rx_bytes = sum.rx_bytes;
+ stats->rx_packets = sum.rx_packets;
+
+ stats->tx_dropped = dev->stats.tx_dropped;
+ stats->tx_errors = dev->stats.tx_errors;
+ stats->tx_carrier_errors = dev->stats.tx_carrier_errors;
+ stats->collisions = dev->stats.collisions;
+
+ return stats;
+}
+
+/* Stub, nothing needs to be done. */
+static void vxlan_set_multicast_list(struct net_device *dev)
+{
+}
+
+static const struct net_device_ops vxlan_netdev_ops = {
+ .ndo_init = vxlan_init,
+ .ndo_open = vxlan_open,
+ .ndo_stop = vxlan_stop,
+ .ndo_start_xmit = vxlan_xmit,
+ .ndo_get_stats64 = vxlan_stats64,
+ .ndo_set_rx_mode = vxlan_set_multicast_list,
+ .ndo_change_mtu = eth_change_mtu,
+ .ndo_validate_addr = eth_validate_addr,
+ .ndo_set_mac_address = eth_mac_addr,
+ .ndo_fdb_add = vxlan_fdb_add,
+ .ndo_fdb_del = vxlan_fdb_delete,
+ .ndo_fdb_dump = vxlan_fdb_dump,
+};
+
+/* Info for udev, that this is a virtual tunnel endpoint */
+static struct device_type vxlan_type = {
+ .name = "vxlan",
+};
+
+static void vxlan_free(struct net_device *dev)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+
+ free_percpu(vxlan->stats);
+ free_netdev(dev);
+}
+
+/* Initialize the device structure. */
+static void vxlan_setup(struct net_device *dev)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+ unsigned h;
+
+ eth_hw_addr_random(dev);
+ ether_setup(dev);
+
+ dev->netdev_ops = &vxlan_netdev_ops;
+ dev->destructor = vxlan_free;
+ SET_NETDEV_DEVTYPE(dev, &vxlan_type);
+
+ dev->tx_queue_len = 0;
+ dev->features |= NETIF_F_LLTX;
+ dev->features |= NETIF_F_NETNS_LOCAL;
+ dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
+
+ spin_lock_init(&vxlan->hash_lock);
+
+ init_timer_deferrable(&vxlan->age_timer);
+ vxlan->age_timer.function = vxlan_cleanup;
+ vxlan->age_timer.data = (unsigned long) vxlan;
+
+ vxlan->dev = dev;
+
+ for (h = 0; h < FDB_HASH_SIZE; ++h)
+ INIT_HLIST_HEAD(&vxlan->fdb_head[h]);
+}
+
+static const struct nla_policy vxlan_policy[IFLA_VXLAN_MAX + 1] = {
+ [IFLA_VXLAN_ID] = { .type = NLA_U32 },
+ [IFLA_VXLAN_GROUP] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
+ [IFLA_VXLAN_LINK] = { .type = NLA_U32 },
+ [IFLA_VXLAN_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
+ [IFLA_VXLAN_TOS] = { .type = NLA_U8 },
+ [IFLA_VXLAN_LEARNING] = { .type = NLA_U8 },
+};
+
+static int vxlan_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+ if (tb[IFLA_ADDRESS]) {
+ if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
+ pr_debug("invalid link address (not ethernet)\n");
+ return -EINVAL;
+ }
+
+ if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
+ pr_debug("invalid all zero ethernet address\n");
+ return -EADDRNOTAVAIL;
+ }
+ }
+
+ if (!data)
+ return -EINVAL;
+
+ if (data[IFLA_VXLAN_ID]) {
+ __u32 id = nla_get_u32(data[IFLA_VXLAN_ID]);
+ if (id >= VXLAN_VID_MASK)
+ return -ERANGE;
+ }
+
+ if (data[IFLA_VXLAN_GROUP]) {
+ __be32 gaddr = nla_get_be32(data[IFLA_VXLAN_GROUP]);
+ if (!IN_MULTICAST(ntohl(gaddr))) {
+ pr_debug("group address is not IPv4 multicast\n");
+ return -EADDRNOTAVAIL;
+ }
+ }
+
+ return 0;
+}
+
+static int vxlan_newlink(struct net *net, struct net_device *dev,
+ struct nlattr *tb[], struct nlattr *data[])
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+ __u32 vni;
+ int err;
+
+ if (!data[IFLA_VXLAN_ID])
+ return -EINVAL;
+
+ vni = nla_get_u32(data[IFLA_VXLAN_ID]);
+ if (vxlan_find_vni(net, vni)) {
+ pr_info("duplicate VNI %u\n", vni);
+ return -EEXIST;
+ }
+ vxlan->vni = vni;
+
+ if (data[IFLA_VXLAN_GROUP])
+ vxlan->gaddr = nla_get_be32(data[IFLA_VXLAN_GROUP]);
+
+ if (data[IFLA_VXLAN_LOCAL])
+ vxlan->saddr = nla_get_be32(data[IFLA_VXLAN_LOCAL]);
+
+ if (data[IFLA_VXLAN_LINK])
+ vxlan->link = nla_get_u32(data[IFLA_VXLAN_LINK]);
+
+ if (data[IFLA_VXLAN_TOS])
+ vxlan->tos = nla_get_u8(data[IFLA_VXLAN_TOS]);
+
+ if (!data[IFLA_VXLAN_LEARNING] || nla_get_u8(data[IFLA_VXLAN_LEARNING]))
+ vxlan->learn = true;
+
+ err = register_netdevice(dev);
+ if (!err)
+ hlist_add_head_rcu(&vxlan->hlist, vni_head(net, vxlan->vni));
+
+ return err;
+}
+
+static void vxlan_dellink(struct net_device *dev, struct list_head *head)
+{
+ struct vxlan_dev *vxlan = netdev_priv(dev);
+
+ hlist_del_rcu(&vxlan->hlist);
+
+ unregister_netdevice_queue(dev, head);
+}
+
+static size_t vxlan_get_size(const struct net_device *dev)
+{
+
+ return nla_total_size(sizeof(__u32)) + /* IFLA_VXLAN_ID */
+ nla_total_size(sizeof(__be32)) +/* IFLA_VXLAN_GROUP */
+ nla_total_size(sizeof(__u32)) + /* IFLA_VXLAN_LINK */
+ nla_total_size(sizeof(__be32))+ /* IFLA_VXLAN_LOCAL */
+ nla_total_size(sizeof(__u8)) + /* IFLA_VXLAN_TTL */
+ nla_total_size(sizeof(__u8)) + /* IFLA_VXLAN_TOS */
+ nla_total_size(sizeof(__u8)) + /* IFLA_VXLAN_LEARNING */
+ 0;
+}
+
+static int vxlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+ const struct vxlan_dev *vxlan = netdev_priv(dev);
+
+ if (nla_put_u32(skb, IFLA_VXLAN_ID, vxlan->vni))
+ goto nla_put_failure;
+
+ if (vxlan->gaddr && nla_put_u32(skb, IFLA_VXLAN_GROUP, vxlan->gaddr))
+ goto nla_put_failure;
+
+ if (vxlan->link && nla_put_u32(skb, IFLA_VXLAN_LINK, vxlan->link))
+ goto nla_put_failure;
+
+ if (vxlan->saddr && nla_put_u32(skb, IFLA_VXLAN_LOCAL, vxlan->saddr))
+ goto nla_put_failure;
+
+ if (nla_put_u8(skb, IFLA_VXLAN_TTL, vxlan->ttl) ||
+ nla_put_u8(skb, IFLA_VXLAN_TOS, vxlan->tos) ||
+ nla_put_u8(skb, IFLA_VXLAN_LEARNING, vxlan->learn))
+ goto nla_put_failure;
+
+ return 0;
+
+nla_put_failure:
+ return -EMSGSIZE;
+}
+
+static struct rtnl_link_ops vxlan_link_ops __read_mostly = {
+ .kind = "vxlan",
+ .maxtype = IFLA_VXLAN_MAX,
+ .policy = vxlan_policy,
+ .priv_size = sizeof(struct vxlan_dev),
+ .setup = vxlan_setup,
+ .validate = vxlan_validate,
+ .newlink = vxlan_newlink,
+ .dellink = vxlan_dellink,
+ .get_size = vxlan_get_size,
+ .fill_info = vxlan_fill_info,
+};
+
+static __net_init int vxlan_init_net(struct net *net)
+{
+ struct vxlan_net *vn = net_generic(net, vxlan_net_id);
+ struct sock *sk;
+ struct sockaddr_in addr;
+ int rc;
+ unsigned h;
+
+ /* Create UDP socket for encapsulation receive. */
+ rc = sock_create_kern(AF_INET, SOCK_DGRAM, IPPROTO_UDP, &vn->sock);
+ if (rc < 0) {
+ pr_debug("UDP socket create failed\n");
+ return rc;
+ }
+
+ addr.sin_family = AF_INET;
+ addr.sin_addr.s_addr = INADDR_ANY;
+ addr.sin_port = htons(vxlan_port);
+
+ rc = kernel_bind(vn->sock, (struct sockaddr *) &addr, sizeof(addr));
+ if (rc < 0) {
+ pr_debug("bind for port %u failed %d\n", vxlan_port, rc);
+ sock_release(vn->sock);
+ vn->sock = NULL;
+ return rc;
+ }
+
+ /* Disable multicast loopback */
+ sk = vn->sock->sk;
+ inet_sk(sk)->mc_loop = 0;
+
+ /* Mark socket as an encapsulation socket. */
+ udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP;
+ udp_sk(sk)->encap_rcv = vxlan_udp_encap_recv;
+ udp_encap_enable();
+
+ for (h = 0; h < VNI_HASH_SIZE; ++h)
+ INIT_HLIST_HEAD(&vn->vni_list[h]);
+
+ return 0;
+}
+
+static __net_exit void vxlan_exit_net(struct net *net)
+{
+ struct vxlan_net *vn = net_generic(net, vxlan_net_id);
+
+ if (vn->sock) {
+ sock_release(vn->sock);
+ vn->sock = NULL;
+ }
+}
+
+static struct pernet_operations vxlan_net_ops = {
+ .init = vxlan_init_net,
+ .exit = vxlan_exit_net,
+ .id = &vxlan_net_id,
+ .size = sizeof(struct vxlan_net),
+};
+
+static int __init vxlan_init_module(void)
+{
+ int rc;
+
+ get_random_bytes(&vxlan_salt, sizeof(vxlan_salt));
+
+ rc = register_pernet_device(&vxlan_net_ops);
+ if (rc)
+ goto out1;
+
+ rc = rtnl_link_register(&vxlan_link_ops);
+ if (rc)
+ goto out2;
+
+ return 0;
+
+out2:
+ unregister_pernet_device(&vxlan_net_ops);
+out1:
+ return rc;
+}
+module_init(vxlan_init_module);
+
+static void __exit vxlan_cleanup_module(void)
+{
+ rtnl_link_unregister(&vxlan_link_ops);
+ unregister_pernet_device(&vxlan_net_ops);
+}
+module_exit(vxlan_cleanup_module);
+
+MODULE_LICENSE("GPL");
+MODULE_VERSION(VXLAN_VERSION);
+MODULE_AUTHOR("Stephen Hemminger <shemminger@...tta.com>");
+MODULE_ALIAS_RTNL_LINK("vxlan");
--- a/include/linux/if_link.h 2012-09-24 10:56:57.080291529 -0700
+++ b/include/linux/if_link.h 2012-09-24 11:08:02.869416484 -0700
@@ -272,6 +272,20 @@ enum macvlan_mode {
#define MACVLAN_FLAG_NOPROMISC 1
+/* VXLAN section */
+enum {
+ IFLA_VXLAN_UNSPEC,
+ IFLA_VXLAN_ID,
+ IFLA_VXLAN_GROUP,
+ IFLA_VXLAN_LINK,
+ IFLA_VXLAN_LOCAL,
+ IFLA_VXLAN_TTL,
+ IFLA_VXLAN_TOS,
+ IFLA_VXLAN_LEARNING,
+ __IFLA_VXLAN_MAX
+};
+#define IFLA_VXLAN_MAX (__IFLA_VXLAN_MAX - 1)
+
/* SR-IOV virtual function management section */
enum {
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ b/Documentation/networking/vxlan.txt 2012-09-24 11:08:02.869416484 -0700
@@ -0,0 +1,36 @@
+Virtual eXtensible Local Area Networking documentation
+======================================================
+
+The VXLAN protocol is a tunnelling protocol that is designed to
+solve the problem of limited number of available VLAN's (4096).
+With VXLAN identifier is expanded to 24 bits.
+
+It is a draft RFC standard, that is implemented by Cisco Nexus,
+Vmware and Brocade. The protocol runs over UDP using a single
+destination port (still not standardized by IANA).
+This document describes the Linux kernel tunnel device,
+there is also an implantation of VXLAN for Openvswitch.
+
+Unlike most tunnels, a VXLAN is a 1 to N network, not just point
+to point. A VXLAN device can either dynamically learn the IP address
+of the other end, in a manner similar to a learning bridge, or the
+forwarding entries can be configured statically.
+
+The management of vxlan is done in a similar fashion to it's
+too closest neighbors GRE and VLAN. Configuring VXLAN requires
+the version of iproute2 that matches the kernel release
+where VXLAN was first merged upstream.
+
+1. Create vxlan device
+ # ip li add vxlan0 type vxlan id 42 group 239.1.1.1 dev eth1
+
+This creates a new device (vxlan0). The device uses the
+the multicast group 239.1.1.1 over eth1 to handle packets where
+no entry is in the forwarding table.
+
+2. Delete vxlan device
+ # ip link delete vxlan0
+
+3. Show vxlan info
+ # ip -d show vxlan0
+
--
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