// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C)2003,2004 USAGI/WIDE Project
*
* Authors Mitsuru KANDA <[email protected]>
* YOSHIFUJI Hideaki <[email protected]>
*
* Based on net/ipv4/xfrm4_tunnel.c
*/
#include <linux/module.h>
#include <linux/xfrm.h>
#include <linux/slab.h>
#include <linux/rculist.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/ipv6.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/mutex.h>
#include <net/netns/generic.h>
#define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256
#define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256
#define XFRM6_TUNNEL_SPI_MIN 1
#define XFRM6_TUNNEL_SPI_MAX 0xffffffff
struct xfrm6_tunnel_net {
struct hlist_head spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE];
struct hlist_head spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE];
u32 spi;
};
static unsigned int xfrm6_tunnel_net_id __read_mostly;
static inline struct xfrm6_tunnel_net *xfrm6_tunnel_pernet(struct net *net)
{
return net_generic(net, xfrm6_tunnel_net_id);
}
/*
* xfrm_tunnel_spi things are for allocating unique id ("spi")
* per xfrm_address_t.
*/
struct xfrm6_tunnel_spi {
struct hlist_node list_byaddr;
struct hlist_node list_byspi;
xfrm_address_t addr;
u32 spi;
refcount_t refcnt;
struct rcu_head rcu_head;
};
static DEFINE_SPINLOCK(xfrm6_tunnel_spi_lock);
static struct kmem_cache *xfrm6_tunnel_spi_kmem __read_mostly;
static inline unsigned int xfrm6_tunnel_spi_hash_byaddr(const xfrm_address_t *addr)
{
unsigned int h;
h = ipv6_addr_hash((const struct in6_addr *)addr);
h ^= h >> 16;
h ^= h >> 8;
h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1;
return h;
}
static inline unsigned int xfrm6_tunnel_spi_hash_byspi(u32 spi)
{
return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE;
}
static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr)
{
struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
struct xfrm6_tunnel_spi *x6spi;
hlist_for_each_entry_rcu(x6spi,
&xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
list_byaddr, lockdep_is_held(&xfrm6_tunnel_spi_lock)) {
if (xfrm6_addr_equal(&x6spi->addr, saddr))
return x6spi;
}
return NULL;
}
__be32 xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr)
{
struct xfrm6_tunnel_spi *x6spi;
u32 spi;
rcu_read_lock_bh();
x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
spi = x6spi ? x6spi->spi : 0;
rcu_read_unlock_bh();
return htonl(spi);
}
EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup);
static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi)
{
struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
struct xfrm6_tunnel_spi *x6spi;
int index = xfrm6_tunnel_spi_hash_byspi(spi);
hlist_for_each_entry(x6spi,
&xfrm6_tn->spi_byspi[index],
list_byspi) {
if (x6spi->spi == spi)
return -1;
}
return index;
}
static u32 __xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr)
{
struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
u32 spi;
struct xfrm6_tunnel_spi *x6spi;
int index;
if (xfrm6_tn->spi < XFRM6_TUNNEL_SPI_MIN ||
xfrm6_tn->spi >= XFRM6_TUNNEL_SPI_MAX)
xfrm6_tn->spi = XFRM6_TUNNEL_SPI_MIN;
else
xfrm6_tn->spi++;
for (spi = xfrm6_tn->spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) {
index = __xfrm6_tunnel_spi_check(net, spi);
if (index >= 0)
goto alloc_spi;
if (spi == XFRM6_TUNNEL_SPI_MAX)
break;
}
for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) {
index = __xfrm6_tunnel_spi_check(net, spi);
if (index >= 0)
goto alloc_spi;
}
spi = 0;
goto out;
alloc_spi:
xfrm6_tn->spi = spi;
x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC);
if (!x6spi)
goto out;
memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
x6spi->spi = spi;
refcount_set(&x6spi->refcnt, 1);
hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]);
index = xfrm6_tunnel_spi_hash_byaddr(saddr);
hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tn->spi_byaddr[index]);
out:
return spi;
}
__be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr)
{
struct xfrm6_tunnel_spi *x6spi;
u32 spi;
spin_lock_bh(&xfrm6_tunnel_spi_lock);
x6spi = __xfrm6_tunnel_spi_lookup(net, saddr);
if (x6spi) {
refcount_inc(&x6spi->refcnt);
spi = x6spi->spi;
} else
spi = __xfrm6_tunnel_alloc_spi(net, saddr);
spin_unlock_bh(&xfrm6_tunnel_spi_lock);
return htonl(spi);
}
EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi);
static void x6spi_destroy_rcu(struct rcu_head *head)
{
kmem_cache_free(xfrm6_tunnel_spi_kmem,
container_of(head, struct xfrm6_tunnel_spi, rcu_head));
}
static void xfrm6_tunnel_free_spi(struct net *net, xfrm_address_t *saddr)
{
struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
struct xfrm6_tunnel_spi *x6spi;
struct hlist_node *n;
spin_lock_bh(&xfrm6_tunnel_spi_lock);
hlist_for_each_entry_safe(x6spi, n,
&xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
list_byaddr)
{
if (xfrm6_addr_equal(&x6spi->addr, saddr)) {
if (refcount_dec_and_test(&x6spi->refcnt)) {
hlist_del_rcu(&x6spi->list_byaddr);
hlist_del_rcu(&x6spi->list_byspi);
call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu);
break;
}
}
}
spin_unlock_bh(&xfrm6_tunnel_spi_lock);
}
static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
skb_push(skb, -skb_network_offset(skb));
return 0;
}
static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
{
return skb_network_header(skb)[IP6CB(skb)->nhoff];
}
static int xfrm6_tunnel_rcv(struct sk_buff *skb)
{
struct net *net = dev_net(skb->dev);
const struct ipv6hdr *iph = ipv6_hdr(skb);
__be32 spi;
spi = xfrm6_tunnel_spi_lookup(net, (const xfrm_address_t *)&iph->saddr);
return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi, NULL);
}
static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
/* xfrm6_tunnel native err handling */
switch (type) {
case ICMPV6_DEST_UNREACH:
switch (code) {
case ICMPV6_NOROUTE:
case ICMPV6_ADM_PROHIBITED:
case ICMPV6_NOT_NEIGHBOUR:
case ICMPV6_ADDR_UNREACH:
case ICMPV6_PORT_UNREACH:
default:
break;
}
break;
case ICMPV6_PKT_TOOBIG:
break;
case ICMPV6_TIME_EXCEED:
switch (code) {
case ICMPV6_EXC_HOPLIMIT:
break;
case ICMPV6_EXC_FRAGTIME:
default:
break;
}
break;
case ICMPV6_PARAMPROB:
switch (code) {
case ICMPV6_HDR_FIELD: break;
case ICMPV6_UNK_NEXTHDR: break;
case ICMPV6_UNK_OPTION: break;
}
break;
default:
break;
}
return 0;
}
static int xfrm6_tunnel_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack)
{
if (x->props.mode != XFRM_MODE_TUNNEL) {
NL_SET_ERR_MSG(extack, "IPv6 tunnel can only be used with tunnel mode");
return -EINVAL;
}
if (x->encap) {
NL_SET_ERR_MSG(extack, "IPv6 tunnel is not compatible with encapsulation");
return -EINVAL;
}
x->props.header_len = sizeof(struct ipv6hdr);
return 0;
}
static void xfrm6_tunnel_destroy(struct xfrm_state *x)
{
struct net *net = xs_net(x);
xfrm6_tunnel_free_spi(net, (xfrm_address_t *)&x->props.saddr);
}
static const struct xfrm_type xfrm6_tunnel_type = {
.owner = THIS_MODULE,
.proto = IPPROTO_IPV6,
.init_state = xfrm6_tunnel_init_state,
.destructor = xfrm6_tunnel_destroy,
.input = xfrm6_tunnel_input,
.output = xfrm6_tunnel_output,
};
static struct xfrm6_tunnel xfrm6_tunnel_handler __read_mostly = {
.handler = xfrm6_tunnel_rcv,
.err_handler = xfrm6_tunnel_err,
.priority = 3,
};
static struct xfrm6_tunnel xfrm46_tunnel_handler __read_mostly = {
.handler = xfrm6_tunnel_rcv,
.err_handler = xfrm6_tunnel_err,
.priority = 3,
};
static int __net_init xfrm6_tunnel_net_init(struct net *net)
{
struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
unsigned int i;
for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
INIT_HLIST_HEAD(&xfrm6_tn->spi_byaddr[i]);
for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
INIT_HLIST_HEAD(&xfrm6_tn->spi_byspi[i]);
xfrm6_tn->spi = 0;
return 0;
}
static void __net_exit xfrm6_tunnel_net_exit(struct net *net)
{
struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
unsigned int i;
xfrm_flush_gc();
xfrm_state_flush(net, 0, false, true);
for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
WARN_ON_ONCE(!hlist_empty(&xfrm6_tn->spi_byaddr[i]));
for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
WARN_ON_ONCE(!hlist_empty(&xfrm6_tn->spi_byspi[i]));
}
static struct pernet_operations xfrm6_tunnel_net_ops = {
.init = xfrm6_tunnel_net_init,
.exit = xfrm6_tunnel_net_exit,
.id = &xfrm6_tunnel_net_id,
.size = sizeof(struct xfrm6_tunnel_net),
};
static int __init xfrm6_tunnel_init(void)
{
int rv;
xfrm6_tunnel_spi_kmem = KMEM_CACHE(xfrm6_tunnel_spi, SLAB_HWCACHE_ALIGN);
if (!xfrm6_tunnel_spi_kmem)
return -ENOMEM;
rv = register_pernet_subsys(&xfrm6_tunnel_net_ops);
if (rv < 0)
goto out_pernet;
rv = xfrm_register_type(&xfrm6_tunnel_type, AF_INET6);
if (rv < 0)
goto out_type;
rv = xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6);
if (rv < 0)
goto out_xfrm6;
rv = xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET);
if (rv < 0)
goto out_xfrm46;
return 0;
out_xfrm46:
xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
out_xfrm6:
xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
out_type:
unregister_pernet_subsys(&xfrm6_tunnel_net_ops);
out_pernet:
kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
return rv;
}
static void __exit xfrm6_tunnel_fini(void)
{
xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET);
xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6);
xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
unregister_pernet_subsys(&xfrm6_tunnel_net_ops);
/* Someone maybe has gotten the xfrm6_tunnel_spi.
* So need to wait it.
*/
rcu_barrier();
kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
}
module_init(xfrm6_tunnel_init);
module_exit(xfrm6_tunnel_fini);
MODULE_DESCRIPTION("IPv6 XFRM tunnel driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6);
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