path: root/drivers/net/geneve.c

/*
 * GENEVE: Generic Network Virtualization Encapsulation
 *
 * Copyright (c) 2015 Red Hat, 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/etherdevice.h>
#include <linux/hash.h>
#include <net/dst_metadata.h>
#include <net/gro_cells.h>
#include <net/rtnetlink.h>
#include <net/geneve.h>
#include <net/protocol.h>

#define GENEVE_NETDEV_VER	"0.6"

#define GENEVE_UDP_PORT		6081

#define GENEVE_N_VID		(1u << 24)
#define GENEVE_VID_MASK		(GENEVE_N_VID - 1)

#define VNI_HASH_BITS		10
#define VNI_HASH_SIZE		(1<<VNI_HASH_BITS)

static bool log_ecn_error = true;
module_param(log_ecn_error, bool, 0644);
MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");

#define GENEVE_VER 0
#define GENEVE_BASE_HLEN (sizeof(struct udphdr) + sizeof(struct genevehdr))

/* per-network namespace private data for this module */
struct geneve_net {
	struct list_head	geneve_list;
	struct list_head	sock_list;
};

static int geneve_net_id;

union geneve_addr {
	struct sockaddr_in sin;
	struct sockaddr_in6 sin6;
	struct sockaddr sa;
};

static union geneve_addr geneve_remote_unspec = { .sa.sa_family = AF_UNSPEC, };

/* Pseudo network device */
struct geneve_dev {
	struct hlist_node  hlist;	/* vni hash table */
	struct net	   *net;	/* netns for packet i/o */
	struct net_device  *dev;	/* netdev for geneve tunnel */
	struct geneve_sock *sock4;	/* IPv4 socket used for geneve tunnel */
#if IS_ENABLED(CONFIG_IPV6)
	struct geneve_sock *sock6;	/* IPv6 socket used for geneve tunnel */
#endif
	u8                 vni[3];	/* virtual network ID for tunnel */
	u8                 ttl;		/* TTL override */
	u8                 tos;		/* TOS override */
	union geneve_addr  remote;	/* IP address for link partner */
	struct list_head   next;	/* geneve's per namespace list */
	__be32		   label;	/* IPv6 flowlabel override */
	__be16		   dst_port;
	bool		   collect_md;
	struct gro_cells   gro_cells;
	u32		   flags;
	struct dst_cache   dst_cache;
};

/* Geneve device flags */
#define GENEVE_F_UDP_ZERO_CSUM_TX	BIT(0)
#define GENEVE_F_UDP_ZERO_CSUM6_TX	BIT(1)
#define GENEVE_F_UDP_ZERO_CSUM6_RX	BIT(2)

struct geneve_sock {
	bool			collect_md;
	struct list_head	list;
	struct socket		*sock;
	struct rcu_head		rcu;
	int			refcnt;
	struct hlist_head	vni_list[VNI_HASH_SIZE];
	u32			flags;
};

static inline __u32 geneve_net_vni_hash(u8 vni[3])
{
	__u32 vnid;

	vnid = (vni[0] << 16) | (vni[1] << 8) | vni[2];
	return hash_32(vnid, VNI_HASH_BITS);
}

static __be64 vni_to_tunnel_id(const __u8 *vni)
{
#ifdef __BIG_ENDIAN
	return (vni[0] << 16) | (vni[1] << 8) | vni[2];
#else
	return (__force __be64)(((__force u64)vni[0] << 40) |
				((__force u64)vni[1] << 48) |
				((__force u64)vni[2] << 56));
#endif
}

static sa_family_t geneve_get_sk_family(struct geneve_sock *gs)
{
	return gs->sock->sk->sk_family;
}

static struct geneve_dev *geneve_lookup(struct geneve_sock *gs,
					__be32 addr, u8 vni[])
{
	struct hlist_head *vni_list_head;
	struct geneve_dev *geneve;
	__u32 hash;

	/* Find the device for this VNI */
	hash = geneve_net_vni_hash(vni);
	vni_list_head = &gs->vni_list[hash];
	hlist_for_each_entry_rcu(geneve, vni_list_head, hlist) {
		if (!memcmp(vni, geneve->vni, sizeof(geneve->vni)) &&
		    addr == geneve->remote.sin.sin_addr.s_addr)
			return geneve;
	}
	return NULL;
}

#if IS_ENABLED(CONFIG_IPV6)
static struct geneve_dev *geneve6_lookup(struct geneve_sock *gs,
					 struct in6_addr addr6, u8 vni[])
{
	struct hlist_head *vni_list_head;
	struct geneve_dev *geneve;
	__u32 hash;

	/* Find the device for this VNI */
	hash = geneve_net_vni_hash(vni);
	vni_list_head = &gs->vni_list[hash];
	hlist_for_each_entry_rcu(geneve, vni_list_head, hlist) {
		if (!memcmp(vni, geneve->vni, sizeof(geneve->vni)) &&
		    ipv6_addr_equal(&addr6, &geneve->remote.sin6.sin6_addr))
			return geneve;
	}
	return NULL;
}
#endif

static inline struct genevehdr *geneve_hdr(const struct sk_buff *skb)
{
	return (struct genevehdr *)(udp_hdr(skb) + 1);
}

static struct geneve_dev *geneve_lookup_skb(struct geneve_sock *gs,
					    struct sk_buff *skb)
{
	u8 *vni;
	__be32 addr;
	static u8 zero_vni[3];
#if IS_ENABLED(CONFIG_IPV6)
	static struct in6_addr zero_addr6;
#endif

	if (geneve_get_sk_family(gs) == AF_INET) {
		struct iphdr *iph;

		iph = ip_hdr(skb); /* outer IP header... */

		if (gs->collect_md) {
			vni = zero_vni;
			addr = 0;
		} else {
			vni = geneve_hdr(skb)->vni;
			addr = iph->saddr;