1 files changed, 281 insertions, 0 deletions
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
new file mode 100644
index 000000000000..7fe2afd2e669
--- /dev/null
+++ b/net/ipv4/xfrm4_policy.c
@@ -0,0 +1,281 @@
+/* 
+ * xfrm4_policy.c
+ *
+ * Changes:
+ *	Kazunori MIYAZAWA @USAGI
+ * 	YOSHIFUJI Hideaki @USAGI
+ *		Split up af-specific portion
+ * 	
+ */
+
+#include <linux/config.h>
+#include <net/xfrm.h>
+#include <net/ip.h>
+
+static struct dst_ops xfrm4_dst_ops;
+static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
+
+static struct xfrm_type_map xfrm4_type_map = { .lock = RW_LOCK_UNLOCKED };
+
+static int xfrm4_dst_lookup(struct xfrm_dst **dst, struct flowi *fl)
+{
+	return __ip_route_output_key((struct rtable**)dst, fl);
+}
+
+static struct dst_entry *
+__xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
+{
+	struct dst_entry *dst;
+
+	read_lock_bh(&policy->lock);
+	for (dst = policy->bundles; dst; dst = dst->next) {
+		struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
+		if (xdst->u.rt.fl.oif == fl->oif &&	/*XXX*/
+		    xdst->u.rt.fl.fl4_dst == fl->fl4_dst &&
+	    	    xdst->u.rt.fl.fl4_src == fl->fl4_src &&
+		    xfrm_bundle_ok(xdst, fl, AF_INET)) {
+			dst_clone(dst);
+			break;
+		}
+	}
+	read_unlock_bh(&policy->lock);
+	return dst;
+}
+
+/* Allocate chain of dst_entry's, attach known xfrm's, calculate
+ * all the metrics... Shortly, bundle a bundle.
+ */
+
+static int
+__xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
+		      struct flowi *fl, struct dst_entry **dst_p)
+{
+	struct dst_entry *dst, *dst_prev;
+	struct rtable *rt0 = (struct rtable*)(*dst_p);
+	struct rtable *rt = rt0;
+	u32 remote = fl->fl4_dst;
+	u32 local  = fl->fl4_src;
+	struct flowi fl_tunnel = {
+		.nl_u = {
+			.ip4_u = {
+				.saddr = local,
+				.daddr = remote
+			}
+		}
+	};
+	int i;
+	int err;
+	int header_len = 0;
+	int trailer_len = 0;
+
+	dst = dst_prev = NULL;
+	dst_hold(&rt->u.dst);
+
+	for (i = 0; i < nx; i++) {
+		struct dst_entry *dst1 = dst_alloc(&xfrm4_dst_ops);
+		struct xfrm_dst *xdst;
+		int tunnel = 0;
+
+		if (unlikely(dst1 == NULL)) {
+			err = -ENOBUFS;
+			dst_release(&rt->u.dst);
+			goto error;
+		}
+
+		if (!dst)
+			dst = dst1;
+		else {
+			dst_prev->child = dst1;
+			dst1->flags |= DST_NOHASH;
+			dst_clone(dst1);
+		}
+
+		xdst = (struct xfrm_dst *)dst1;
+		xdst->route = &rt->u.dst;
+
+		dst1->next = dst_prev;
+		dst_prev = dst1;
+		if (xfrm[i]->props.mode) {
+			remote = xfrm[i]->id.daddr.a4;
+			local  = xfrm[i]->props.saddr.a4;
+			tunnel = 1;
+		}
+		header_len += xfrm[i]->props.header_len;
+		trailer_len += xfrm[i]->props.trailer_len;
+
+		if (tunnel) {
+			fl_tunnel.fl4_src = local;
+			fl_tunnel.fl4_dst = remote;
+			err = xfrm_dst_lookup((struct xfrm_dst **)&rt,
+					      &fl_tunnel, AF_INET);
+			if (err)
+				goto error;
+		} else
+			dst_hold(&rt->u.dst);
+	}
+
+	dst_prev->child = &rt->u.dst;
+	dst->path = &rt->u.dst;
+
+	*dst_p = dst;
+	dst = dst_prev;
+
+	dst_prev = *dst_p;
+	i = 0;
+	for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) {
+		struct xfrm_dst *x = (struct xfrm_dst*)dst_prev;
+		x->u.rt.fl = *fl;
+
+		dst_prev->xfrm = xfrm[i++];
+		dst_prev->dev = rt->u.dst.dev;
+		if (rt->u.dst.dev)
+			dev_hold(rt->u.dst.dev);
+		dst_prev->obsolete	= -1;
+		dst_prev->flags	       |= DST_HOST;
+		dst_prev->lastuse	= jiffies;
+		dst_prev->header_len	= header_len;
+		dst_prev->trailer_len	= trailer_len;
+		memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics));
+
+		/* Copy neighbout for reachability confirmation */
+		dst_prev->neighbour	= neigh_clone(rt->u.dst.neighbour);
+		dst_prev->input		= rt->u.dst.input;
+		dst_prev->output	= xfrm4_output;
+		if (rt->peer)
+			atomic_inc(&rt->peer->refcnt);
+		x->u.rt.peer = rt->peer;
+		/* Sheit... I remember I did this right. Apparently,
+		 * it was magically lost, so this code needs audit */
+		x->u.rt.rt_flags = rt0->rt_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL);
+		x->u.rt.rt_type = rt->rt_type;
+		x->u.rt.rt_src = rt0->rt_src;
+		x->u.rt.rt_dst = rt0->rt_dst;
+		x->u.rt.rt_gateway = rt->rt_gateway;
+		x->u.rt.rt_spec_dst = rt0->rt_spec_dst;
+		header_len -= x->u.dst.xfrm->props.header_len;
+		trailer_len -= x->u.dst.xfrm->props.trailer_len;
+	}
+
+	xfrm_init_pmtu(dst);
+	return 0;
+
+error:
+	if (dst)
+		dst_free(dst);
+	return err;
+}
+
+static void
+_decode_session4(struct sk_buff *skb, struct flowi *fl)
+{
+	struct iphdr *iph = skb->nh.iph;
+	u8 *xprth = skb->nh.raw + iph->ihl*4;
+
+	memset(fl, 0, sizeof(struct flowi));
+	if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) {
+		switch (iph->protocol) {
+		case IPPROTO_UDP:
+		case IPPROTO_TCP:
+		case IPPROTO_SCTP:
+			if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
+				u16 *ports = (u16 *)xprth;
+
+				fl->fl_ip_sport = ports[0];
+				fl->fl_ip_dport = ports[1];
+			}
+			break;
+
+		case IPPROTO_ICMP:
+			if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
+				u8 *icmp = xprth;
+
+				fl->fl_icmp_type = icmp[0];
+				fl->fl_icmp_code = icmp[1];
+			}
+			break;
+
+		case IPPROTO_ESP:
+			if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
+				u32 *ehdr = (u32 *)xprth;
+
+				fl->fl_ipsec_spi = ehdr[0];
+			}
+			break;
+
+		case IPPROTO_AH:
+			if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
+				u32 *ah_hdr = (u32*)xprth;
+
+				fl->fl_ipsec_spi = ah_hdr[1];
+			}
+			break;
+
+		case IPPROTO_COMP:
+			if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
+				u16 *ipcomp_hdr = (u16 *)xprth;
+
+				fl->fl_ipsec_spi = ntohl(ntohs(ipcomp_hdr[1]));
+			}
+			break;
+		default:
+			fl->fl_ipsec_spi = 0;
+			break;
+		};
+	}
+	fl->proto = iph->protocol;
+	fl->fl4_dst = iph->daddr;
+	fl->fl4_src = iph->saddr;
+}
+
+static inline int xfrm4_garbage_collect(void)
+{
+	read_lock(&xfrm4_policy_afinfo.lock);
+	xfrm4_policy_afinfo.garbage_collect();
+	read_unlock(&xfrm4_policy_afinfo.lock);
+	return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2);
+}
+
+static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
+{
+	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
+	struct dst_entry *path = xdst->route;
+
+	path->ops->update_pmtu(path, mtu);
+}
+
+static struct dst_ops xfrm4_dst_ops = {
+	.family =		AF_INET,
+	.protocol =		__constant_htons(ETH_P_IP),
+	.gc =			xfrm4_garbage_collect,
+	.update_pmtu =		xfrm4_update_pmtu,
+	.gc_thresh =		1024,
+	.entry_size =		sizeof(struct xfrm_dst),
+};
+
+static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
+	.family = 		AF_INET,
+	.lock = 		RW_LOCK_UNLOCKED,
+	.type_map = 		&xfrm4_type_map,
+	.dst_ops =		&xfrm4_dst_ops,
+	.dst_lookup =		xfrm4_dst_lookup,
+	.find_bundle = 		__xfrm4_find_bundle,
+	.bundle_create =	__xfrm4_bundle_create,
+	.decode_session =	_decode_session4,
+};
+
+static void __init xfrm4_policy_init(void)
+{
+	xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
+}
+
+static void __exit xfrm4_policy_fini(void)
+{
+	xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
+}
+
+void __init xfrm4_init(void)
+{
+	xfrm4_state_init();
+	xfrm4_policy_init();
+}
+