/* *	IPv6 input *	Linux INET6 implementation * *	Authors: *	Pedro Roque		<roque@di.fc.ul.pt> *	Ian P. Morris		<I.P.Morris@soton.ac.uk> * *	$Id: ip6_input.c,v 1.19 2000/12/13 18:31:50 davem Exp $ * *	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/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>   inline int ip6_rcv_finish( struct sk_buff *skb){	if (skb->dst == NULL)		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){	struct ipv6hdr *hdr;	u32 		pkt_len;	struct inet6_dev *idev; 	if (skb->pkt_type == PACKET_OTHERHOST) {		kfree_skb(skb);		return 0;	} 	rcu_read_lock(); 	idev = __in6_dev_get(skb->dev); 	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INRECEIVES); 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {		IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);		rcu_read_unlock();		goto out;	} 	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 ? ip6_dst_idev(skb->dst)->dev->ifindex : dev->ifindex; 	if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))		goto err; 	hdr = skb->nh.ipv6h; 	if (hdr->version != 6)		goto err; 	skb->h.raw = (u8 *)(hdr + 1);	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(idev, IPSTATS_MIB_INTRUNCATEDPKTS);			goto drop;		}		if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {			IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);			goto drop;		}		hdr = skb->nh.ipv6h;	} 	if (hdr->nexthdr == NEXTHDR_HOP) {		if (ipv6_parse_hopopts(&skb) < 0) {			IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);			rcu_read_unlock();			return 0;		}	} 	rcu_read_unlock(); 	return NF_HOOK(PF_INET6,NF_IP6_PRE_ROUTING, skb, dev, NULL, ip6_rcv_finish);err:	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);drop:	rcu_read_unlock();	kfree_skb(skb);out:	return 0;} /* *	Deliver the packet to the host */  static inline int ip6_input_finish(struct sk_buff *skb){	struct inet6_protocol *ipprot;	struct sock *raw_sk;	unsigned int nhoff;	int nexthdr;	u8 hash;	struct inet6_dev *idev; 	/*	 *	Parse extension headers	 */ 	rcu_read_lock();resubmit:	idev = ip6_dst_idev(skb->dst);	if (!pskb_pull(skb, skb->h.raw - skb->data))		goto discard;	nhoff = IP6CB(skb)->nhoff;	nexthdr = skb->nh.raw[nhoff]; 	raw_sk = sk_head(&raw_v6_htable[nexthdr & (MAX_INET_PROTOS - 1)]);	if (raw_sk && !ipv6_raw_deliver(skb, nexthdr))		raw_sk = NULL; 	hash = nexthdr & (MAX_INET_PROTOS - 1);	if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {		int ret; 		if (ipprot->flags & INET6_PROTO_FINAL) {			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->nh.raw,					   skb->h.raw - skb->nh.raw);			hdr = skb->nh.ipv6h;			if (ipv6_addr_is_multicast(&hdr->daddr) &&			    !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,			    &hdr->saddr) &&			    !ipv6_is_mld(skb, nexthdr))				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(idev, IPSTATS_MIB_INDELIVERS);	} else {		if (!raw_sk) {			if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {				IP6_INC_STATS_BH(idev, IPSTATS_MIB_INUNKNOWNPROTOS);				icmpv6_send(skb, ICMPV6_PARAMPROB,					    ICMPV6_UNK_NEXTHDR, nhoff,					    skb->dev);			}		} else			IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS);		kfree_skb(skb);	}	rcu_read_unlock();	return 0; discard:	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);	rcu_read_unlock();	kfree_skb(skb);	return 0;}  int ip6_input(struct sk_buff *skb){	return NF_HOOK(PF_INET6,NF_IP6_LOCAL_IN, skb, skb->dev, NULL, ip6_input_finish);} int ip6_mc_input(struct sk_buff *skb){	struct ipv6hdr *hdr;	int deliver; 	IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INMCASTPKTS); 	hdr = skb->nh.ipv6h;	deliver = likely(!(skb->dev->flags & (IFF_PROMISC|IFF_ALLMULTI))) ||	    ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL); 	/*	 *	IPv6 multicast router mode isnt currently supported.	 */#if 0	if (ipv6_config.multicast_route) {		int addr_type; 		addr_type = ipv6_addr_type(&hdr->daddr); 		if (!(addr_type & (IPV6_ADDR_LOOPBACK | IPV6_ADDR_LINKLOCAL))) {			struct sk_buff *skb2;			struct dst_entry *dst; 			dst = skb->dst; 			if (deliver) {				skb2 = skb_clone(skb, GFP_ATOMIC);				dst_output(skb2);			} else {				dst_output(skb);				return 0;			}		}	}#endif 	if (likely(deliver)) {		ip6_input(skb);		return 0;	}	/* discard */	kfree_skb(skb); 	return 0;}