1 files changed, 363 insertions, 0 deletions

diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
new file mode 100644
index 000000000..f2e464eba
--- /dev/null
+++ b/net/ipv6/ip6_input.c
@@ -0,0 +1,363 @@
+/*
+ *	IPv6 input
+ *	Linux INET6 implementation
+ *
+ *	Authors:
+ *	Pedro Roque		<roque@di.fc.ul.pt>
+ *	Ian P. Morris		<I.P.Morris@soton.ac.uk>
+ *
+ *	Based in linux/net/ipv4/ip_input.c
+ *
+ *	This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+/* Changes
+ *
+ *	Mitsuru KANDA @USAGI and
+ *	YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs().
+ */
+
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/in6.h>
+#include <linux/icmpv6.h>
+#include <linux/mroute6.h>
+#include <linux/slab.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv6.h>
+
+#include <net/sock.h>
+#include <net/snmp.h>
+
+#include <net/ipv6.h>
+#include <net/protocol.h>
+#include <net/transp_v6.h>
+#include <net/rawv6.h>
+#include <net/ndisc.h>
+#include <net/ip6_route.h>
+#include <net/addrconf.h>
+#include <net/xfrm.h>
+#include <net/inet_ecn.h>
+
+int ip6_rcv_finish(struct sock *sk, struct sk_buff *skb)
+{
+	if (sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) {
+		const struct inet6_protocol *ipprot;
+
+		ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
+		if (ipprot && ipprot->early_demux)
+			ipprot->early_demux(skb);
+	}
+	if (!skb_dst(skb))
+		ip6_route_input(skb);
+
+	return dst_input(skb);
+}
+
+int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
+{
+	const struct ipv6hdr *hdr;
+	u32 pkt_len;
+	struct inet6_dev *idev;
+	struct net *net = dev_net(skb->dev);
+
+	if (skb->pkt_type == PACKET_OTHERHOST) {
+		kfree_skb(skb);
+		return NET_RX_DROP;
+	}
+
+	rcu_read_lock();
+
+	idev = __in6_dev_get(skb->dev);
+
+	IP6_UPD_PO_STATS_BH(net, idev, IPSTATS_MIB_IN, skb->len);
+
+	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
+	    !idev || unlikely(idev->cnf.disable_ipv6)) {
+		IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
+		goto drop;
+	}
+
+	memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
+
+	/*
+	 * Store incoming device index. When the packet will
+	 * be queued, we cannot refer to skb->dev anymore.
+	 *
+	 * BTW, when we send a packet for our own local address on a
+	 * non-loopback interface (e.g. ethX), it is being delivered
+	 * via the loopback interface (lo) here; skb->dev = loopback_dev.
+	 * It, however, should be considered as if it is being
+	 * arrived via the sending interface (ethX), because of the
+	 * nature of scoping architecture. --yoshfuji
+	 */
+	IP6CB(skb)->iif = skb_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;
+
+	if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
+		goto err;
+
+	hdr = ipv6_hdr(skb);
+
+	if (hdr->version != 6)
+		goto err;
+
+	IP6_ADD_STATS_BH(dev_net(dev), idev,
+			 IPSTATS_MIB_NOECTPKTS +
+				(ipv6_get_dsfield(hdr) & INET_ECN_MASK),
+			 max_t(unsigned short, 1, skb_shinfo(skb)->gso_segs));
+	/*
+	 * RFC4291 2.5.3
+	 * A packet received on an interface with a destination address
+	 * of loopback must be dropped.
+	 */
+	if (!(dev->flags & IFF_LOOPBACK) &&
+	    ipv6_addr_loopback(&hdr->daddr))
+		goto err;
+
+	/* RFC4291 Errata ID: 3480
+	 * Interface-Local scope spans only a single interface on a
+	 * node and is useful only for loopback transmission of
+	 * multicast.  Packets with interface-local scope received
+	 * from another node must be discarded.
+	 */
+	if (!(skb->pkt_type == PACKET_LOOPBACK ||
+	      dev->flags & IFF_LOOPBACK) &&
+	    ipv6_addr_is_multicast(&hdr->daddr) &&
+	    IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 1)
+		goto err;
+
+	/* RFC4291 2.7
+	 * Nodes must not originate a packet to a multicast address whose scope
+	 * field contains the reserved value 0; if such a packet is received, it
+	 * must be silently dropped.
+	 */
+	if (ipv6_addr_is_multicast(&hdr->daddr) &&
+	    IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0)
+		goto err;
+
+	/*
+	 * RFC4291 2.7
+	 * Multicast addresses must not be used as source addresses in IPv6
+	 * packets or appear in any Routing header.
+	 */
+	if (ipv6_addr_is_multicast(&hdr->saddr))
+		goto err;
+
+	skb->transport_header = skb->network_header + sizeof(*hdr);
+	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
+
+	pkt_len = ntohs(hdr->payload_len);
+
+	/* pkt_len may be zero if Jumbo payload option is present */
+	if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
+		if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
+			IP6_INC_STATS_BH(net,
+					 idev, IPSTATS_MIB_INTRUNCATEDPKTS);
+			goto drop;
+		}
+		if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
+			IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
+			goto drop;
+		}
+		hdr = ipv6_hdr(skb);
+	}
+
+	if (hdr->nexthdr == NEXTHDR_HOP) {
+		if (ipv6_parse_hopopts(skb) < 0) {
+			IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
+			rcu_read_unlock();
+			return NET_RX_DROP;
+		}
+	}
+
+	rcu_read_unlock();
+
+	/* Must drop socket now because of tproxy. */
+	skb_orphan(skb);
+
+	return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, NULL, skb,
+		       dev, NULL,
+		       ip6_rcv_finish);
+err:
+	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
+drop:
+	rcu_read_unlock();
+	kfree_skb(skb);
+	return NET_RX_DROP;
+}
+
+/*
+ *	Deliver the packet to the host
+ */
+
+
+static int ip6_input_finish(struct sock *sk, struct sk_buff *skb)
+{
+	struct net *net = dev_net(skb_dst(skb)->dev);
+	const struct inet6_protocol *ipprot;
+	struct inet6_dev *idev;
+	unsigned int nhoff;
+	int nexthdr;
+	bool raw;
+
+	/*
+	 *	Parse extension headers
+	 */
+
+	rcu_read_lock();
+resubmit:
+	idev = ip6_dst_idev(skb_dst(skb));
+	if (!pskb_pull(skb, skb_transport_offset(skb)))
+		goto discard;
+	nhoff = IP6CB(skb)->nhoff;
+	nexthdr = skb_network_header(skb)[nhoff];
+
+	raw = raw6_local_deliver(skb, nexthdr);
+	ipprot = rcu_dereference(inet6_protos[nexthdr]);
+	if (ipprot) {
+		int ret;
+
+		if (ipprot->flags & INET6_PROTO_FINAL) {
+			const struct ipv6hdr *hdr;
+
+			/* Free reference early: we don't need it any more,
+			   and it may hold ip_conntrack module loaded
+			   indefinitely. */
+			nf_reset(skb);
+
+			skb_postpull_rcsum(skb, skb_network_header(skb),
+					   skb_network_header_len(skb));
+			hdr = ipv6_hdr(skb);
+			if (ipv6_addr_is_multicast(&hdr->daddr) &&
+			    !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
+			    &hdr->saddr) &&
+			    !ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb)))
+				goto discard;
+		}
+		if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
+		    !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
+			goto discard;
+
+		ret = ipprot->handler(skb);
+		if (ret > 0)
+			goto resubmit;
+		else if (ret == 0)
+			IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
+	} else {
+		if (!raw) {
+			if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+				IP6_INC_STATS_BH(net, idev,
+						 IPSTATS_MIB_INUNKNOWNPROTOS);
+				icmpv6_send(skb, ICMPV6_PARAMPROB,
+					    ICMPV6_UNK_NEXTHDR, nhoff);
+			}
+			kfree_skb(skb);
+		} else {
+			IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
+			consume_skb(skb);
+		}
+	}
+	rcu_read_unlock();
+	return 0;
+
+discard:
+	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
+	rcu_read_unlock();
+	kfree_skb(skb);
+	return 0;
+}
+
+
+int ip6_input(struct sk_buff *skb)
+{
+	return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, NULL, skb,
+		       skb->dev, NULL,
+		       ip6_input_finish);
+}
+
+int ip6_mc_input(struct sk_buff *skb)
+{
+	const struct ipv6hdr *hdr;
+	bool deliver;
+
+	IP6_UPD_PO_STATS_BH(dev_net(skb_dst(skb)->dev),
+			 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
+			 skb->len);
+
+	hdr = ipv6_hdr(skb);
+	deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
+
+#ifdef CONFIG_IPV6_MROUTE
+	/*
+	 *      IPv6 multicast router mode is now supported ;)
+	 */
+	if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
+	    !(ipv6_addr_type(&hdr->daddr) &
+	      (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) &&
+	    likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
+		/*
+		 * Okay, we try to forward - split and duplicate
+		 * packets.
+		 */
+		struct sk_buff *skb2;
+		struct inet6_skb_parm *opt = IP6CB(skb);
+
+		/* Check for MLD */
+		if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
+			/* Check if this is a mld message */
+			u8 nexthdr = hdr->nexthdr;
+			__be16 frag_off;
+			int offset;
+
+			/* Check if the value of Router Alert
+			 * is for MLD (0x0000).
+			 */
+			if (opt->ra == htons(IPV6_OPT_ROUTERALERT_MLD)) {
+				deliver = false;
+
+				if (!ipv6_ext_hdr(nexthdr)) {
+					/* BUG */
+					goto out;
+				}
+				offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
+							  &nexthdr, &frag_off);
+				if (offset < 0)
+					goto out;
+
+				if (!ipv6_is_mld(skb, nexthdr, offset))
+					goto out;
+
+				deliver = true;
+			}
+			/* unknown RA - process it normally */
+		}
+
+		if (deliver)
+			skb2 = skb_clone(skb, GFP_ATOMIC);
+		else {
+			skb2 = skb;
+			skb = NULL;
+		}
+
+		if (skb2) {
+			ip6_mr_input(skb2);
+		}
+	}
+out:
+#endif
+	if (likely(deliver))
+		ip6_input(skb);
+	else {
+		/* discard */
+		kfree_skb(skb);
+	}
+
+	return 0;
+}