linux/net/ipv4/geneve.c

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/*
* 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 formatted 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);
if (IS_ERR(skb))
return PTR_ERR(skb);
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)) {
kfree_skb(skb);
return err;
}
skb = vlan_hwaccel_push_inside(skb);
if (unlikely(!skb))
return -ENOMEM;
gnvh = (struct genevehdr *)__skb_push(skb, sizeof(*gnvh) + opt_len);
geneve_build_header(gnvh, tun_flags, vni, opt_len, opt);
skb_set_inner_protocol(skb, htons(ETH_P_TEB));
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);
}
}
static void geneve_notify_del_rx_port(struct geneve_sock *gs)
{
struct sock *sk = gs->sock->sk;
sa_family_t sa_family = sk->sk_family;
if (sa_family == AF_INET)
udp_del_offload(&gs->udp_offloads);
}
/* 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 = htonl(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_net *gn = net_generic(net, geneve_net_id);
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);
spin_lock(&gn->sock_lock);
gs = geneve_find_sock(net, port);
if (gs && ((gs->rcv != rcv) ||
!atomic_add_unless(&gs->refcnt, 1, 0)))
gs = ERR_PTR(-EBUSY);
spin_unlock(&gn->sock_lock);
if (!gs)
gs = ERR_PTR(-EINVAL);
return gs;
}
EXPORT_SYMBOL_GPL(geneve_sock_add);
void geneve_sock_release(struct geneve_sock *gs)
{
struct net *net = sock_net(gs->sock->sk);
struct geneve_net *gn = net_generic(net, geneve_net_id);
if (!atomic_dec_and_test(&gs->refcnt))
return;
spin_lock(&gn->sock_lock);
hlist_del_rcu(&gs->hlist);
geneve_notify_del_rx_port(gs);
spin_unlock(&gn->sock_lock);
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);
unregister_pernet_subsys(&geneve_net_ops);
}
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");