net: Add Geneve tunneling protocol driver

This adds a device level support for Geneve -- Generic Network
Virtualization Encapsulation. The protocol is documented at
http://tools.ietf.org/html/draft-gross-geneve-01

Only protocol layer Geneve support is provided by this driver.
Openvswitch can be used for configuring, set up and tear down
functional Geneve tunnels.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Andy Zhou 2014-10-03 15:35:28 -07:00 committed by David S. Miller
parent c259c132ad
commit 0b5e8b8eea
5 changed files with 481 additions and 0 deletions

91
include/net/geneve.h Normal file
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@ -0,0 +1,91 @@
#ifndef __NET_GENEVE_H
#define __NET_GENEVE_H 1
#include <net/udp_tunnel.h>
struct geneve_sock;
typedef void (geneve_rcv_t)(struct geneve_sock *gs, struct sk_buff *skb);
struct geneve_sock {
struct hlist_node hlist;
geneve_rcv_t *rcv;
void *rcv_data;
struct work_struct del_work;
struct socket *sock;
struct rcu_head rcu;
atomic_t refcnt;
struct udp_offload udp_offloads;
};
/* Geneve Header:
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |Ver| Opt Len |O|C| Rsvd. | Protocol Type |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Virtual Network Identifier (VNI) | Reserved |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Variable Length Options |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Option Header:
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Option Class | Type |R|R|R| Length |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Variable Option Data |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
struct geneve_opt {
__be16 opt_class;
u8 type;
#ifdef __LITTLE_ENDIAN_BITFIELD
u8 length:5;
u8 r3:1;
u8 r2:1;
u8 r1:1;
#else
u8 r1:1;
u8 r2:1;
u8 r3:1;
u8 length:5;
#endif
u8 opt_data[];
};
#define GENEVE_CRIT_OPT_TYPE (1 << 7)
struct genevehdr {
#ifdef __LITTLE_ENDIAN_BITFIELD
u8 opt_len:6;
u8 ver:2;
u8 rsvd1:6;
u8 critical:1;
u8 oam:1;
#else
u8 ver:2;
u8 opt_len:6;
u8 oam:1;
u8 critical:1;
u8 rsvd1:6;
#endif
__be16 proto_type;
u8 vni[3];
u8 rsvd2;
struct geneve_opt options[];
};
#define GENEVE_VER 0
#define GENEVE_BASE_HLEN (sizeof(struct udphdr) + sizeof(struct genevehdr))
struct geneve_sock *geneve_sock_add(struct net *net, __be16 port,
geneve_rcv_t *rcv, void *data,
bool no_share, bool ipv6);
void geneve_sock_release(struct geneve_sock *vs);
int geneve_xmit_skb(struct geneve_sock *gs, struct rtable *rt,
struct sk_buff *skb, __be32 src, __be32 dst, __u8 tos,
__u8 ttl, __be16 df, __be16 src_port, __be16 dst_port,
__be16 tun_flags, u8 vni[3], u8 opt_len, u8 *opt,
bool xnet);
#endif

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@ -95,6 +95,8 @@ struct ip_tunnel {
#define TUNNEL_VERSION __cpu_to_be16(0x40)
#define TUNNEL_NO_KEY __cpu_to_be16(0x80)
#define TUNNEL_DONT_FRAGMENT __cpu_to_be16(0x0100)
#define TUNNEL_OAM __cpu_to_be16(0x0200)
#define TUNNEL_CRIT_OPT __cpu_to_be16(0x0400)
struct tnl_ptk_info {
__be16 flags;

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@ -453,6 +453,20 @@ config TCP_CONG_BIC
increase provides TCP friendliness.
See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
config GENEVE
tristate "Generic Network Virtualization Encapsulation (Geneve)"
depends on INET
select NET_IP_TUNNEL
select NET_UDP_TUNNEL
---help---
This allows one to create Geneve virtual interfaces that provide
Layer 2 Networks over Layer 3 Networks. Geneve is often used
to tunnel virtual network infrastructure in virtualized environments.
For more information see:
http://tools.ietf.org/html/draft-gross-geneve-01
To compile this driver as a module, choose M here: the module
config TCP_CONG_CUBIC
tristate "CUBIC TCP"
default y

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@ -56,6 +56,7 @@ obj-$(CONFIG_TCP_CONG_YEAH) += tcp_yeah.o
obj-$(CONFIG_TCP_CONG_ILLINOIS) += tcp_illinois.o
obj-$(CONFIG_MEMCG_KMEM) += tcp_memcontrol.o
obj-$(CONFIG_NETLABEL) += cipso_ipv4.o
obj-$(CONFIG_GENEVE) += geneve.o
obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \
xfrm4_output.o xfrm4_protocol.o

373
net/ipv4/geneve.c Normal file
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@ -0,0 +1,373 @@
/*
* Geneve: Generic Network Virtualization Encapsulation
*
* Copyright (c) 2014 Nicira, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#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/if_vlan.h>
#include <linux/hash.h>
#include <linux/ethtool.h>
#include <net/arp.h>
#include <net/ndisc.h>
#include <net/ip.h>
#include <net/ip_tunnels.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>
#include <net/geneve.h>
#include <net/protocol.h>
#include <net/udp_tunnel.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
#include <net/addrconf.h>
#include <net/ip6_tunnel.h>
#include <net/ip6_checksum.h>
#endif
#define PORT_HASH_BITS 8
#define PORT_HASH_SIZE (1<<PORT_HASH_BITS)
/* per-network namespace private data for this module */
struct geneve_net {
struct hlist_head sock_list[PORT_HASH_SIZE];
spinlock_t sock_lock; /* Protects sock_list */
};
static int geneve_net_id;
static struct workqueue_struct *geneve_wq;
static inline struct genevehdr *geneve_hdr(const struct sk_buff *skb)
{
return (struct genevehdr *)(udp_hdr(skb) + 1);
}
static struct hlist_head *gs_head(struct net *net, __be16 port)
{
struct geneve_net *gn = net_generic(net, geneve_net_id);
return &gn->sock_list[hash_32(ntohs(port), PORT_HASH_BITS)];
}
/* Find geneve socket based on network namespace and UDP port */
static struct geneve_sock *geneve_find_sock(struct net *net, __be16 port)
{
struct geneve_sock *gs;
hlist_for_each_entry_rcu(gs, gs_head(net, port), hlist) {
if (inet_sk(gs->sock->sk)->inet_sport == port)
return gs;
}
return NULL;
}
static void geneve_build_header(struct genevehdr *geneveh,
__be16 tun_flags, u8 vni[3],
u8 options_len, u8 *options)
{
geneveh->ver = GENEVE_VER;
geneveh->opt_len = options_len / 4;
geneveh->oam = !!(tun_flags & TUNNEL_OAM);
geneveh->critical = !!(tun_flags & TUNNEL_CRIT_OPT);
geneveh->rsvd1 = 0;
memcpy(geneveh->vni, vni, 3);
geneveh->proto_type = htons(ETH_P_TEB);
geneveh->rsvd2 = 0;
memcpy(geneveh->options, options, options_len);
}
/* Transmit a fully formated Geneve frame.
*
* When calling this function. The skb->data should point
* to the geneve header which is fully formed.
*
* This function will add other UDP tunnel headers.
*/
int geneve_xmit_skb(struct geneve_sock *gs, struct rtable *rt,
struct sk_buff *skb, __be32 src, __be32 dst, __u8 tos,
__u8 ttl, __be16 df, __be16 src_port, __be16 dst_port,
__be16 tun_flags, u8 vni[3], u8 opt_len, u8 *opt,
bool xnet)
{
struct genevehdr *gnvh;
int min_headroom;
int err;
skb = udp_tunnel_handle_offloads(skb, !gs->sock->sk->sk_no_check_tx);
min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
+ GENEVE_BASE_HLEN + opt_len + sizeof(struct iphdr)
+ (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0);
err = skb_cow_head(skb, min_headroom);
if (unlikely(err))
return err;
if (vlan_tx_tag_present(skb)) {
if (unlikely(!__vlan_put_tag(skb,
skb->vlan_proto,
vlan_tx_tag_get(skb)))) {
err = -ENOMEM;
return err;
}
skb->vlan_tci = 0;
}
gnvh = (struct genevehdr *)__skb_push(skb, sizeof(*gnvh) + opt_len);
geneve_build_header(gnvh, tun_flags, vni, opt_len, opt);
return udp_tunnel_xmit_skb(gs->sock, rt, skb, src, dst,
tos, ttl, df, src_port, dst_port, xnet);
}
EXPORT_SYMBOL_GPL(geneve_xmit_skb);
static void geneve_notify_add_rx_port(struct geneve_sock *gs)
{
struct sock *sk = gs->sock->sk;
sa_family_t sa_family = sk->sk_family;
int err;
if (sa_family == AF_INET) {
err = udp_add_offload(&gs->udp_offloads);
if (err)
pr_warn("geneve: udp_add_offload failed with status %d\n",
err);
}
}
/* Callback from net/ipv4/udp.c to receive packets */
static int geneve_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
{
struct genevehdr *geneveh;
struct geneve_sock *gs;
int opts_len;
/* Need Geneve and inner Ethernet header to be present */
if (unlikely(!pskb_may_pull(skb, GENEVE_BASE_HLEN)))
goto error;
/* Return packets with reserved bits set */
geneveh = geneve_hdr(skb);
if (unlikely(geneveh->ver != GENEVE_VER))
goto error;
if (unlikely(geneveh->proto_type != htons(ETH_P_TEB)))
goto error;
opts_len = geneveh->opt_len * 4;
if (iptunnel_pull_header(skb, GENEVE_BASE_HLEN + opts_len,
htons(ETH_P_TEB)))
goto drop;
gs = rcu_dereference_sk_user_data(sk);
if (!gs)
goto drop;
gs->rcv(gs, skb);
return 0;
drop:
/* Consume bad packet */
kfree_skb(skb);
return 0;
error:
/* Let the UDP layer deal with the skb */
return 1;
}
static void geneve_del_work(struct work_struct *work)
{
struct geneve_sock *gs = container_of(work, struct geneve_sock,
del_work);
udp_tunnel_sock_release(gs->sock);
kfree_rcu(gs, rcu);
}
static struct socket *geneve_create_sock(struct net *net, bool ipv6,
__be16 port)
{
struct socket *sock;
struct udp_port_cfg udp_conf;
int err;
memset(&udp_conf, 0, sizeof(udp_conf));
if (ipv6) {
udp_conf.family = AF_INET6;
} else {
udp_conf.family = AF_INET;
udp_conf.local_ip.s_addr = INADDR_ANY;
}
udp_conf.local_udp_port = port;
/* Open UDP socket */
err = udp_sock_create(net, &udp_conf, &sock);
if (err < 0)
return ERR_PTR(err);
return sock;
}
/* Create new listen socket if needed */
static struct geneve_sock *geneve_socket_create(struct net *net, __be16 port,
geneve_rcv_t *rcv, void *data,
bool ipv6)
{
struct geneve_net *gn = net_generic(net, geneve_net_id);
struct geneve_sock *gs;
struct socket *sock;
struct udp_tunnel_sock_cfg tunnel_cfg;
gs = kzalloc(sizeof(*gs), GFP_KERNEL);
if (!gs)
return ERR_PTR(-ENOMEM);
INIT_WORK(&gs->del_work, geneve_del_work);
sock = geneve_create_sock(net, ipv6, port);
if (IS_ERR(sock)) {
kfree(gs);
return ERR_CAST(sock);
}
gs->sock = sock;
atomic_set(&gs->refcnt, 1);
gs->rcv = rcv;
gs->rcv_data = data;
/* Initialize the geneve udp offloads structure */
gs->udp_offloads.port = port;
gs->udp_offloads.callbacks.gro_receive = NULL;
gs->udp_offloads.callbacks.gro_complete = NULL;
spin_lock(&gn->sock_lock);
hlist_add_head_rcu(&gs->hlist, gs_head(net, port));
geneve_notify_add_rx_port(gs);
spin_unlock(&gn->sock_lock);
/* Mark socket as an encapsulation socket */
tunnel_cfg.sk_user_data = gs;
tunnel_cfg.encap_type = 1;
tunnel_cfg.encap_rcv = geneve_udp_encap_recv;
tunnel_cfg.encap_destroy = NULL;
setup_udp_tunnel_sock(net, sock, &tunnel_cfg);
return gs;
}
struct geneve_sock *geneve_sock_add(struct net *net, __be16 port,
geneve_rcv_t *rcv, void *data,
bool no_share, bool ipv6)
{
struct geneve_sock *gs;
gs = geneve_socket_create(net, port, rcv, data, ipv6);
if (!IS_ERR(gs))
return gs;
if (no_share) /* Return error if sharing is not allowed. */
return ERR_PTR(-EINVAL);
gs = geneve_find_sock(net, port);
if (gs) {
if (gs->rcv == rcv)
atomic_inc(&gs->refcnt);
else
gs = ERR_PTR(-EBUSY);
} else {
gs = ERR_PTR(-EINVAL);
}
return gs;
}
EXPORT_SYMBOL_GPL(geneve_sock_add);
void geneve_sock_release(struct geneve_sock *gs)
{
if (!atomic_dec_and_test(&gs->refcnt))
return;
queue_work(geneve_wq, &gs->del_work);
}
EXPORT_SYMBOL_GPL(geneve_sock_release);
static __net_init int geneve_init_net(struct net *net)
{
struct geneve_net *gn = net_generic(net, geneve_net_id);
unsigned int h;
spin_lock_init(&gn->sock_lock);
for (h = 0; h < PORT_HASH_SIZE; ++h)
INIT_HLIST_HEAD(&gn->sock_list[h]);
return 0;
}
static struct pernet_operations geneve_net_ops = {
.init = geneve_init_net,
.exit = NULL,
.id = &geneve_net_id,
.size = sizeof(struct geneve_net),
};
static int __init geneve_init_module(void)
{
int rc;
geneve_wq = alloc_workqueue("geneve", 0, 0);
if (!geneve_wq)
return -ENOMEM;
rc = register_pernet_subsys(&geneve_net_ops);
if (rc)
return rc;
pr_info("Geneve driver\n");
return 0;
}
late_initcall(geneve_init_module);
static void __exit geneve_cleanup_module(void)
{
destroy_workqueue(geneve_wq);
}
module_exit(geneve_cleanup_module);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jesse Gross <jesse@nicira.com>");
MODULE_DESCRIPTION("Driver for GENEVE encapsulated traffic");
MODULE_ALIAS_RTNL_LINK("geneve");