1 files changed, 435 insertions, 0 deletions

diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
new file mode 100644
index 000000000..30232591c
--- /dev/null
+++ b/net/ipv6/xfrm6_policy.c
@@ -0,0 +1,435 @@
+// 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->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;
+	INIT_LIST_HEAD(&xdst->u.rt6.rt6i_uncached);
+	rt6_uncached_list_add(&xdst->u.rt6);
+	atomic_inc(&dev_net(dev)->ipv6.rt6_stats->fib_rt_uncache);
+
+	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 + sizeof(*exthdr) < skb->data ||
+	       pskb_may_pull(skb, nh + offset + sizeof(*exthdr) - skb->data)) {
+		nh = skb_network_header(skb);
+		exthdr = (struct ipv6_opt_hdr *)(nh + offset);
+
+		switch (nexthdr) {
+		case NEXTHDR_FRAGMENT:
+			onlyproto = 1;
+			/* fall through */
+		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);
+	if (xdst->u.rt6.rt6i_uncached_list)
+		rt6_uncached_list_del(&xdst->u.rt6);
+	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 *)xfrm_dst_child(&xdst->u.dst);
+		} 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();
+}