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// SPDX-License-Identifier: GPL-2.0
/*
* xfrm6_policy.c: based on xfrm4_policy.c
*
* Authors:
* Mitsuru KANDA @USAGI
* Kazunori MIYAZAWA @USAGI
* Kunihiro Ishiguro <kunihiro@ipinfusion.com>
* IPv6 support
* YOSHIFUJI Hideaki
* Split up af-specific portion
*
*/
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <net/addrconf.h>
#include <net/dst.h>
#include <net/xfrm.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/ip6_route.h>
#include <net/l3mdev.h>
#if IS_ENABLED(CONFIG_IPV6_MIP6)
#include <net/mip6.h>
#endif
static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, int oif,
const xfrm_address_t *saddr,
const xfrm_address_t *daddr,
u32 mark)
{
struct flowi6 fl6;
struct dst_entry *dst;
int err;
memset(&fl6, 0, sizeof(fl6));
fl6.flowi6_oif = l3mdev_master_ifindex_by_index(net, oif);
fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF;
fl6.flowi6_mark = mark;
memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr));
if (saddr)
memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr));
dst = ip6_route_output(net, NULL, &fl6);
err = dst->error;
if (dst->error) {
dst_release(dst);
dst = ERR_PTR(err);
}
return dst;
}
static int xfrm6_get_saddr(struct net *net, int oif,
xfrm_address_t *saddr, xfrm_address_t *daddr,
u32 mark)
{
struct dst_entry *dst;
struct net_device *dev;
dst = xfrm6_dst_lookup(net, 0, oif, NULL, daddr, mark);
if (IS_ERR(dst))
return -EHOSTUNREACH;
dev = ip6_dst_idev(dst)->dev;
ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6);
dst_release(dst);
return 0;
}
static int xfrm6_get_tos(const struct flowi *fl)
{
return 0;
}
static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst,
int nfheader_len)
{
if (dst->ops->family == AF_INET6) {
struct rt6_info *rt = (struct rt6_info *)dst;
path->path_cookie = rt6_get_cookie(rt);
}
path->u.rt6.rt6i_nfheader_len = nfheader_len;
return 0;
}
static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
const struct flowi *fl)
{
struct rt6_info *rt = (struct rt6_info *)xdst->route;
xdst->u.dst.dev = dev;
dev_hold(dev);
xdst->u.rt6.rt6i_idev = in6_dev_get(dev);
if (!xdst->u.rt6.rt6i_idev) {
dev_put(dev);
return -ENODEV;
}
/* Sheit... I remember I did this right. Apparently,
* it was magically lost, so this code needs audit */
xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST |
RTF_LOCAL);
xdst->u.rt6.rt6i_metric = rt->rt6i_metric;
xdst->u.rt6.rt6i_node = rt->rt6i_node;
xdst->route_cookie = rt6_get_cookie(rt);
xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway;
xdst->u.rt6.rt6i_dst = rt->rt6i_dst;
xdst->u.rt6.rt6i_src = rt->rt6i_src;
return 0;
}
static inline void
_decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
{
struct flowi6 *fl6 = &fl->u.ip6;
int onlyproto = 0;
const struct ipv6hdr *hdr = ipv6_hdr(skb);
u32 offset = sizeof(*hdr);
struct ipv6_opt_hdr *exthdr;
const unsigned char *nh = skb_network_header(skb);
u16 nhoff = IP6CB(skb)->nhoff;
int oif = 0;
u8 nexthdr;
if (!nhoff)
nhoff = offsetof(struct ipv6hdr, nexthdr);
nexthdr = nh[nhoff];
if (skb_dst(skb))
oif = skb_dst(skb)->dev->ifindex;
memset(fl6, 0, sizeof(struct flowi6));
fl6->flowi6_mark = skb->mark;
fl6->flowi6_oif = reverse ? skb->skb_iif : oif;
fl6->daddr = reverse ? hdr->saddr : hdr->daddr;
fl6->saddr = reverse ? hdr->daddr : hdr->saddr;
while (nh + offset + 1 < skb->data ||
pskb_may_pull(skb, nh + offset + 1 - skb->data)) {
nh = skb_network_header(skb);
exthdr = (struct ipv6_opt_hdr *)(nh + offset);
switch (nexthdr) {
case NEXTHDR_FRAGMENT:
onlyproto = 1;
case NEXTHDR_ROUTING:
case NEXTHDR_HOP:
case NEXTHDR_DEST:
offset += ipv6_optlen(exthdr);
nexthdr = exthdr->nexthdr;
exthdr = (struct ipv6_opt_hdr *)(nh + offset);
break;
case IPPROTO_UDP:
case IPPROTO_UDPLITE:
case IPPROTO_TCP:
case IPPROTO_SCTP:
case IPPROTO_DCCP:
if (!onlyproto && (nh + offset + 4 < skb->data ||
pskb_may_pull(skb, nh + offset + 4 - skb->data))) {
__be16 *ports;
nh = skb_network_header(skb);
ports = (__be16 *)(nh + offset);
fl6->fl6_sport = ports[!!reverse];
fl6->fl6_dport = ports[!reverse];
}
fl6->flowi6_proto = nexthdr;
return;
case IPPROTO_ICMPV6:
if (!onlyproto && (nh + offset + 2 < skb->data ||
pskb_may_pull(skb, nh + offset + 2 - skb->data))) {
u8 *icmp;
nh = skb_network_header(skb);
icmp = (u8 *)(nh + offset);
fl6->fl6_icmp_type = icmp[0];
fl6->fl6_icmp_code = icmp[1];
}
fl6->flowi6_proto = nexthdr;
return;
#if IS_ENABLED(CONFIG_IPV6_MIP6)
case IPPROTO_MH:
offset += ipv6_optlen(exthdr);
if (!onlyproto && (nh + offset + 3 < skb->data ||
pskb_may_pull(skb, nh + offset + 3 - skb->data))) {
struct ip6_mh *mh;
nh = skb_network_header(skb);
mh = (struct ip6_mh *)(nh + offset);
fl6->fl6_mh_type = mh->ip6mh_type;
}
fl6->flowi6_proto = nexthdr;
return;
#endif
/* XXX Why are there these headers? */
case IPPROTO_AH:
case IPPROTO_ESP:
case IPPROTO_COMP:
default:
fl6->fl6_ipsec_spi = 0;
fl6->flowi6_proto = nexthdr;
return;
}
}
}
static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk,
struct sk_buff *skb, u32 mtu,
bool confirm_neigh)
{
struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
struct dst_entry *path = xdst->route;
path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh);
}
static void xfrm6_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 xfrm6_dst_destroy(struct dst_entry *dst)
{
struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
if (likely(xdst->u.rt6.rt6i_idev))
in6_dev_put(xdst->u.rt6.rt6i_idev);
dst_destroy_metrics_generic(dst);
xfrm_dst_destroy(xdst);
}
static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
int unregister)
{
struct xfrm_dst *xdst;
if (!unregister)
return;
xdst = (struct xfrm_dst *)dst;
if (xdst->u.rt6.rt6i_idev->dev == dev) {
struct inet6_dev *loopback_idev =
in6_dev_get(dev_net(dev)->loopback_dev);
BUG_ON(!loopback_idev);
do {
in6_dev_put(xdst->u.rt6.rt6i_idev);
xdst->u.rt6.rt6i_idev = loopback_idev;
in6_dev_hold(loopback_idev);
xdst = (struct xfrm_dst *)xdst->u.dst.child;
} while (xdst->u.dst.xfrm);
__in6_dev_put(loopback_idev);
}
xfrm_dst_ifdown(dst, dev);
}
static struct dst_ops xfrm6_dst_ops_template = {
.family = AF_INET6,
.update_pmtu = xfrm6_update_pmtu,
.redirect = xfrm6_redirect,
.cow_metrics = dst_cow_metrics_generic,
.destroy = xfrm6_dst_destroy,
.ifdown = xfrm6_dst_ifdown,
.local_out = __ip6_local_out,
.gc_thresh = 32768,
};
static const struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
.dst_ops = &xfrm6_dst_ops_template,
.dst_lookup = xfrm6_dst_lookup,
.get_saddr = xfrm6_get_saddr,
.decode_session = _decode_session6,
.get_tos = xfrm6_get_tos,
.init_path = xfrm6_init_path,
.fill_dst = xfrm6_fill_dst,
.blackhole_route = ip6_blackhole_route,
};
static int __init xfrm6_policy_init(void)
{
return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo, AF_INET6);
}
static void xfrm6_policy_fini(void)
{
xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
}
#ifdef CONFIG_SYSCTL
static struct ctl_table xfrm6_policy_table[] = {
{
.procname = "xfrm6_gc_thresh",
.data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{ }
};
static int __net_init xfrm6_net_sysctl_init(struct net *net)
{
struct ctl_table *table;
struct ctl_table_header *hdr;
table = xfrm6_policy_table;
if (!net_eq(net, &init_net)) {
table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL);
if (!table)
goto err_alloc;
table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh;
}
hdr = register_net_sysctl(net, "net/ipv6", table);
if (!hdr)
goto err_reg;
net->ipv6.sysctl.xfrm6_hdr = hdr;
return 0;
err_reg:
if (!net_eq(net, &init_net))
kfree(table);
err_alloc:
return -ENOMEM;
}
static void __net_exit xfrm6_net_sysctl_exit(struct net *net)
{
struct ctl_table *table;
if (!net->ipv6.sysctl.xfrm6_hdr)
return;
table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg;
unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr);
if (!net_eq(net, &init_net))
kfree(table);
}
#else /* CONFIG_SYSCTL */
static inline int xfrm6_net_sysctl_init(struct net *net)
{
return 0;
}
static inline void xfrm6_net_sysctl_exit(struct net *net)
{
}
#endif
static int __net_init xfrm6_net_init(struct net *net)
{
int ret;
memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template,
sizeof(xfrm6_dst_ops_template));
ret = dst_entries_init(&net->xfrm.xfrm6_dst_ops);
if (ret)
return ret;
ret = xfrm6_net_sysctl_init(net);
if (ret)
dst_entries_destroy(&net->xfrm.xfrm6_dst_ops);
return ret;
}
static void __net_exit xfrm6_net_exit(struct net *net)
{
xfrm6_net_sysctl_exit(net);
dst_entries_destroy(&net->xfrm.xfrm6_dst_ops);
}
static struct pernet_operations xfrm6_net_ops = {
.init = xfrm6_net_init,
.exit = xfrm6_net_exit,
};
int __init xfrm6_init(void)
{
int ret;
ret = xfrm6_policy_init();
if (ret)
goto out;
ret = xfrm6_state_init();
if (ret)
goto out_policy;
ret = xfrm6_protocol_init();
if (ret)
goto out_state;
register_pernet_subsys(&xfrm6_net_ops);
out:
return ret;
out_state:
xfrm6_state_fini();
out_policy:
xfrm6_policy_fini();
goto out;
}
void xfrm6_fini(void)
{
unregister_pernet_subsys(&xfrm6_net_ops);
xfrm6_protocol_fini();
xfrm6_policy_fini();
xfrm6_state_fini();
}