blob: 3a4c1f93023a8088649471a1dabdad432f312b1d [file] [log] [blame]
/*
* xfrm4_policy.c
*
* Changes:
* Kazunori MIYAZAWA @USAGI
* YOSHIFUJI Hideaki @USAGI
* Split up af-specific portion
*
*/
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/inetdevice.h>
#include <linux/if_tunnel.h>
#include <net/dst.h>
#include <net/xfrm.h>
#include <net/ip.h>
static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
static struct dst_entry *__xfrm4_dst_lookup(struct net *net, struct flowi4 *fl4,
int tos,
const xfrm_address_t *saddr,
const xfrm_address_t *daddr)
{
struct rtable *rt;
memset(fl4, 0, sizeof(*fl4));
fl4->daddr = daddr->a4;
fl4->flowi4_tos = tos;
if (saddr)
fl4->saddr = saddr->a4;
rt = __ip_route_output_key(net, fl4);
if (!IS_ERR(rt))
return &rt->dst;
return ERR_CAST(rt);
}
static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos,
const xfrm_address_t *saddr,
const xfrm_address_t *daddr)
{
struct flowi4 fl4;
return __xfrm4_dst_lookup(net, &fl4, tos, saddr, daddr);
}
static int xfrm4_get_saddr(struct net *net,
xfrm_address_t *saddr, xfrm_address_t *daddr)
{
struct dst_entry *dst;
struct flowi4 fl4;
dst = __xfrm4_dst_lookup(net, &fl4, 0, NULL, daddr);
if (IS_ERR(dst))
return -EHOSTUNREACH;
saddr->a4 = fl4.saddr;
dst_release(dst);
return 0;
}
static int xfrm4_get_tos(const struct flowi *fl)
{
return IPTOS_RT_MASK & fl->u.ip4.flowi4_tos; /* Strip ECN bits */
}
static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst,
int nfheader_len)
{
return 0;
}
static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
const struct flowi *fl)
{
struct rtable *rt = (struct rtable *)xdst->route;
const struct flowi4 *fl4 = &fl->u.ip4;
xdst->u.rt.rt_iif = fl4->flowi4_iif;
xdst->u.dst.dev = dev;
dev_hold(dev);
/* Sheit... I remember I did this right. Apparently,
* it was magically lost, so this code needs audit */
xdst->u.rt.rt_is_input = rt->rt_is_input;
xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST |
RTCF_LOCAL);
xdst->u.rt.rt_type = rt->rt_type;
xdst->u.rt.rt_gateway = rt->rt_gateway;
xdst->u.rt.rt_uses_gateway = rt->rt_uses_gateway;
xdst->u.rt.rt_pmtu = rt->rt_pmtu;
xdst->u.rt.rt_mtu_locked = rt->rt_mtu_locked;
INIT_LIST_HEAD(&xdst->u.rt.rt_uncached);
return 0;
}
static void
_decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse)
{
const struct iphdr *iph = ip_hdr(skb);
u8 *xprth = skb_network_header(skb) + iph->ihl * 4;
struct flowi4 *fl4 = &fl->u.ip4;
int oif = 0;
if (skb_dst(skb))
oif = skb_dst(skb)->dev->ifindex;
memset(fl4, 0, sizeof(struct flowi4));
fl4->flowi4_mark = skb->mark;
fl4->flowi4_oif = reverse ? skb->skb_iif : oif;
if (!ip_is_fragment(iph)) {
switch (iph->protocol) {
case IPPROTO_UDP:
case IPPROTO_UDPLITE:
case IPPROTO_TCP:
case IPPROTO_SCTP:
case IPPROTO_DCCP:
if (xprth + 4 < skb->data ||
pskb_may_pull(skb, xprth + 4 - skb->data)) {
__be16 *ports = (__be16 *)xprth;
fl4->fl4_sport = ports[!!reverse];
fl4->fl4_dport = ports[!reverse];
}
break;
case IPPROTO_ICMP:
if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
u8 *icmp = xprth;
fl4->fl4_icmp_type = icmp[0];
fl4->fl4_icmp_code = icmp[1];
}
break;
case IPPROTO_ESP:
if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
__be32 *ehdr = (__be32 *)xprth;
fl4->fl4_ipsec_spi = ehdr[0];
}
break;
case IPPROTO_AH:
if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
__be32 *ah_hdr = (__be32 *)xprth;
fl4->fl4_ipsec_spi = ah_hdr[1];
}
break;
case IPPROTO_COMP:
if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
__be16 *ipcomp_hdr = (__be16 *)xprth;
fl4->fl4_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
}
break;
case IPPROTO_GRE:
if (pskb_may_pull(skb, xprth + 12 - skb->data)) {
__be16 *greflags = (__be16 *)xprth;
__be32 *gre_hdr = (__be32 *)xprth;
if (greflags[0] & GRE_KEY) {
if (greflags[0] & GRE_CSUM)
gre_hdr++;
fl4->fl4_gre_key = gre_hdr[1];
}
}
break;
default:
fl4->fl4_ipsec_spi = 0;
break;
}
}
fl4->flowi4_proto = iph->protocol;
fl4->daddr = reverse ? iph->saddr : iph->daddr;
fl4->saddr = reverse ? iph->daddr : iph->saddr;
fl4->flowi4_tos = iph->tos;
}
static inline int xfrm4_garbage_collect(struct dst_ops *ops)
{
struct net *net = container_of(ops, struct net, xfrm.xfrm4_dst_ops);
xfrm4_policy_afinfo.garbage_collect(net);
return (dst_entries_get_slow(ops) > ops->gc_thresh * 2);
}
static void xfrm4_update_pmtu(struct dst_entry *dst, struct sock *sk,
struct sk_buff *skb, u32 mtu)
{
struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
struct dst_entry *path = xdst->route;
path->ops->update_pmtu(path, sk, skb, mtu);
}
static void xfrm4_redirect(struct dst_entry *dst, struct sock *sk,
struct sk_buff *skb)
{
struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
struct dst_entry *path = xdst->route;
path->ops->redirect(path, sk, skb);
}
static void xfrm4_dst_destroy(struct dst_entry *dst)
{
struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
dst_destroy_metrics_generic(dst);
xfrm_dst_destroy(xdst);
}
static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
int unregister)
{
if (!unregister)
return;
xfrm_dst_ifdown(dst, dev);
}
static struct dst_ops xfrm4_dst_ops_template = {
.family = AF_INET,
.protocol = cpu_to_be16(ETH_P_IP),
.gc = xfrm4_garbage_collect,
.update_pmtu = xfrm4_update_pmtu,
.redirect = xfrm4_redirect,
.cow_metrics = dst_cow_metrics_generic,
.destroy = xfrm4_dst_destroy,
.ifdown = xfrm4_dst_ifdown,
.local_out = __ip_local_out,
.gc_thresh = 32768,
};
static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
.family = AF_INET,
.dst_ops = &xfrm4_dst_ops_template,
.dst_lookup = xfrm4_dst_lookup,
.get_saddr = xfrm4_get_saddr,
.decode_session = _decode_session4,
.get_tos = xfrm4_get_tos,
.init_path = xfrm4_init_path,
.fill_dst = xfrm4_fill_dst,
.blackhole_route = ipv4_blackhole_route,
};
#ifdef CONFIG_SYSCTL
static struct ctl_table xfrm4_policy_table[] = {
{
.procname = "xfrm4_gc_thresh",
.data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{ }
};
static int __net_init xfrm4_net_sysctl_init(struct net *net)
{
struct ctl_table *table;
struct ctl_table_header *hdr;
table = xfrm4_policy_table;
if (!net_eq(net, &init_net)) {
table = kmemdup(table, sizeof(xfrm4_policy_table), GFP_KERNEL);
if (!table)
goto err_alloc;
table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh;
}
hdr = register_net_sysctl(net, "net/ipv4", table);
if (!hdr)
goto err_reg;
net->ipv4.xfrm4_hdr = hdr;
return 0;
err_reg:
if (!net_eq(net, &init_net))
kfree(table);
err_alloc:
return -ENOMEM;
}
static void __net_exit xfrm4_net_sysctl_exit(struct net *net)
{
struct ctl_table *table;
if (net->ipv4.xfrm4_hdr == NULL)
return;
table = net->ipv4.xfrm4_hdr->ctl_table_arg;
unregister_net_sysctl_table(net->ipv4.xfrm4_hdr);
if (!net_eq(net, &init_net))
kfree(table);
}
#else /* CONFIG_SYSCTL */
static int inline xfrm4_net_sysctl_init(struct net *net)
{
return 0;
}
static void inline xfrm4_net_sysctl_exit(struct net *net)
{
}
#endif
static int __net_init xfrm4_net_init(struct net *net)
{
int ret;
memcpy(&net->xfrm.xfrm4_dst_ops, &xfrm4_dst_ops_template,
sizeof(xfrm4_dst_ops_template));
ret = dst_entries_init(&net->xfrm.xfrm4_dst_ops);
if (ret)
return ret;
ret = xfrm4_net_sysctl_init(net);
if (ret)
dst_entries_destroy(&net->xfrm.xfrm4_dst_ops);
return ret;
}
static void __net_exit xfrm4_net_exit(struct net *net)
{
xfrm4_net_sysctl_exit(net);
dst_entries_destroy(&net->xfrm.xfrm4_dst_ops);
}
static struct pernet_operations __net_initdata xfrm4_net_ops = {
.init = xfrm4_net_init,
.exit = xfrm4_net_exit,
};
static void __init xfrm4_policy_init(void)
{
xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
}
void __init xfrm4_init(void)
{
xfrm4_state_init();
xfrm4_policy_init();
xfrm4_protocol_init();
register_pernet_subsys(&xfrm4_net_ops);
}