334 строки
7.5 KiB
C
334 строки
7.5 KiB
C
/*
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* IPv6 input
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* Linux INET6 implementation
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*
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* Authors:
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* Pedro Roque <roque@di.fc.ul.pt>
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* Ian P. Morris <I.P.Morris@soton.ac.uk>
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*
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* Based in linux/net/ipv4/ip_input.c
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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/* Changes
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*
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* Mitsuru KANDA @USAGI and
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* YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs().
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*/
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/socket.h>
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#include <linux/sockios.h>
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#include <linux/net.h>
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#include <linux/netdevice.h>
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#include <linux/in6.h>
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#include <linux/icmpv6.h>
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#include <linux/mroute6.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter_ipv6.h>
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#include <net/sock.h>
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#include <net/snmp.h>
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#include <net/ipv6.h>
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#include <net/protocol.h>
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#include <net/transp_v6.h>
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#include <net/rawv6.h>
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#include <net/ndisc.h>
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#include <net/ip6_route.h>
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#include <net/addrconf.h>
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#include <net/xfrm.h>
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inline int ip6_rcv_finish( struct sk_buff *skb)
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{
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if (skb->dst == NULL)
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ip6_route_input(skb);
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return dst_input(skb);
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}
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int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
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{
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struct ipv6hdr *hdr;
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u32 pkt_len;
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struct inet6_dev *idev;
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struct net *net = dev_net(skb->dev);
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if (skb->pkt_type == PACKET_OTHERHOST) {
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kfree_skb(skb);
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return 0;
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}
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rcu_read_lock();
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idev = __in6_dev_get(skb->dev);
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IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INRECEIVES);
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if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
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!idev || unlikely(idev->cnf.disable_ipv6)) {
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IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
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rcu_read_unlock();
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goto out;
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}
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memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
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/*
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* Store incoming device index. When the packet will
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* be queued, we cannot refer to skb->dev anymore.
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*
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* BTW, when we send a packet for our own local address on a
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* non-loopback interface (e.g. ethX), it is being delivered
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* via the loopback interface (lo) here; skb->dev = loopback_dev.
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* It, however, should be considered as if it is being
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* arrived via the sending interface (ethX), because of the
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* nature of scoping architecture. --yoshfuji
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*/
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IP6CB(skb)->iif = skb->dst ? ip6_dst_idev(skb->dst)->dev->ifindex : dev->ifindex;
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if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
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goto err;
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hdr = ipv6_hdr(skb);
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if (hdr->version != 6)
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goto err;
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/*
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* RFC4291 2.5.3
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* A packet received on an interface with a destination address
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* of loopback must be dropped.
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*/
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if (!(dev->flags & IFF_LOOPBACK) &&
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ipv6_addr_loopback(&hdr->daddr))
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goto err;
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skb->transport_header = skb->network_header + sizeof(*hdr);
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IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
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pkt_len = ntohs(hdr->payload_len);
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/* pkt_len may be zero if Jumbo payload option is present */
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if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
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if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
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IP6_INC_STATS_BH(net,
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idev, IPSTATS_MIB_INTRUNCATEDPKTS);
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goto drop;
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}
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if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
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IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
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goto drop;
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}
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hdr = ipv6_hdr(skb);
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}
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if (hdr->nexthdr == NEXTHDR_HOP) {
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if (ipv6_parse_hopopts(skb) < 0) {
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IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
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rcu_read_unlock();
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return 0;
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}
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}
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rcu_read_unlock();
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return NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, dev, NULL,
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ip6_rcv_finish);
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err:
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IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
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drop:
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rcu_read_unlock();
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kfree_skb(skb);
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out:
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return 0;
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}
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/*
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* Deliver the packet to the host
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*/
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static int ip6_input_finish(struct sk_buff *skb)
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{
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struct inet6_protocol *ipprot;
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unsigned int nhoff;
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int nexthdr, raw;
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u8 hash;
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struct inet6_dev *idev;
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struct net *net = dev_net(skb->dst->dev);
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/*
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* Parse extension headers
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*/
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rcu_read_lock();
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resubmit:
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idev = ip6_dst_idev(skb->dst);
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if (!pskb_pull(skb, skb_transport_offset(skb)))
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goto discard;
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nhoff = IP6CB(skb)->nhoff;
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nexthdr = skb_network_header(skb)[nhoff];
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raw = raw6_local_deliver(skb, nexthdr);
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hash = nexthdr & (MAX_INET_PROTOS - 1);
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if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
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int ret;
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if (ipprot->flags & INET6_PROTO_FINAL) {
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struct ipv6hdr *hdr;
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/* Free reference early: we don't need it any more,
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and it may hold ip_conntrack module loaded
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indefinitely. */
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nf_reset(skb);
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skb_postpull_rcsum(skb, skb_network_header(skb),
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skb_network_header_len(skb));
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hdr = ipv6_hdr(skb);
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if (ipv6_addr_is_multicast(&hdr->daddr) &&
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!ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
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&hdr->saddr) &&
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!ipv6_is_mld(skb, nexthdr))
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goto discard;
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}
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if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
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!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
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goto discard;
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ret = ipprot->handler(skb);
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if (ret > 0)
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goto resubmit;
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else if (ret == 0)
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IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
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} else {
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if (!raw) {
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if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
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IP6_INC_STATS_BH(net, idev,
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IPSTATS_MIB_INUNKNOWNPROTOS);
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icmpv6_send(skb, ICMPV6_PARAMPROB,
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ICMPV6_UNK_NEXTHDR, nhoff,
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skb->dev);
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}
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} else
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IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
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kfree_skb(skb);
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}
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rcu_read_unlock();
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return 0;
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discard:
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IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
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rcu_read_unlock();
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kfree_skb(skb);
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return 0;
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}
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int ip6_input(struct sk_buff *skb)
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{
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return NF_HOOK(PF_INET6, NF_INET_LOCAL_IN, skb, skb->dev, NULL,
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ip6_input_finish);
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}
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int ip6_mc_input(struct sk_buff *skb)
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{
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struct ipv6hdr *hdr;
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int deliver;
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IP6_INC_STATS_BH(dev_net(skb->dst->dev),
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ip6_dst_idev(skb->dst), IPSTATS_MIB_INMCASTPKTS);
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hdr = ipv6_hdr(skb);
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deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
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#ifdef CONFIG_IPV6_MROUTE
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/*
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* IPv6 multicast router mode is now supported ;)
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*/
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if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
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!(ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) &&
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likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
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/*
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* Okay, we try to forward - split and duplicate
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* packets.
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*/
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struct sk_buff *skb2;
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struct inet6_skb_parm *opt = IP6CB(skb);
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/* Check for MLD */
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if (unlikely(opt->ra)) {
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/* Check if this is a mld message */
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u8 *ptr = skb_network_header(skb) + opt->ra;
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struct icmp6hdr *icmp6;
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u8 nexthdr = hdr->nexthdr;
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int offset;
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/* Check if the value of Router Alert
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* is for MLD (0x0000).
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*/
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if ((ptr[2] | ptr[3]) == 0) {
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deliver = 0;
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if (!ipv6_ext_hdr(nexthdr)) {
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/* BUG */
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goto out;
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}
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offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
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&nexthdr);
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if (offset < 0)
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goto out;
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if (nexthdr != IPPROTO_ICMPV6)
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goto out;
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if (!pskb_may_pull(skb, (skb_network_header(skb) +
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offset + 1 - skb->data)))
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goto out;
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icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
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switch (icmp6->icmp6_type) {
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case ICMPV6_MGM_QUERY:
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case ICMPV6_MGM_REPORT:
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case ICMPV6_MGM_REDUCTION:
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case ICMPV6_MLD2_REPORT:
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deliver = 1;
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break;
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}
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goto out;
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}
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/* unknown RA - process it normally */
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}
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if (deliver)
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skb2 = skb_clone(skb, GFP_ATOMIC);
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else {
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skb2 = skb;
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skb = NULL;
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}
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if (skb2) {
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ip6_mr_input(skb2);
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}
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}
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out:
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#endif
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if (likely(deliver))
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ip6_input(skb);
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else {
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/* discard */
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kfree_skb(skb);
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}
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return 0;
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}
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