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/*
* 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/sched.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>
static 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;
if (skb->pkt_type == PACKET_OTHERHOST)
goto drop;
IP6_INC_STATS_BH(IPSTATS_MIB_INRECEIVES);
if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
IP6_INC_STATS_BH(IPSTATS_MIB_INDISCARDS);
goto out;
}
/*
* 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 ? ((struct rt6_info *)skb->dst)->rt6i_idev->dev->ifindex : dev->ifindex;
if (skb->len < sizeof(struct ipv6hdr))
goto err;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) {
IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
goto drop;
}
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)
goto truncated;
if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
goto drop;
}
hdr = skb->nh.ipv6h;
}
if (hdr->nexthdr == NEXTHDR_HOP) {
if (ipv6_parse_hopopts(skb, IP6CB(skb)->nhoff) < 0) {
IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
return 0;
}
hdr = skb->nh.ipv6h;
}
return NF_HOOK(PF_INET6,NF_IP6_PRE_ROUTING, skb, dev, NULL, ip6_rcv_finish);
truncated:
IP6_INC_STATS_BH(IPSTATS_MIB_INTRUNCATEDPKTS);
err:
IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
drop:
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;
/*
* Parse extension headers
*/
rcu_read_lock();
resubmit:
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(IPSTATS_MIB_INDELIVERS);
} else {
if (!raw_sk) {
if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
IP6_INC_STATS_BH(IPSTATS_MIB_INUNKNOWNPROTOS);
icmpv6_send(skb, ICMPV6_PARAMPROB,
ICMPV6_UNK_NEXTHDR, nhoff,
skb->dev);
}
} else
IP6_INC_STATS_BH(IPSTATS_MIB_INDELIVERS);
kfree_skb(skb);
}
rcu_read_unlock();
return 0;
discard:
IP6_INC_STATS_BH(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(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;
}
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