linux/net/ipv6/ip6_input.c

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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;
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) {
skb->h.raw = (u8*)(hdr+1);
if (ipv6_parse_hopopts(skb, offsetof(struct ipv6hdr, nexthdr)) < 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;
skb->h.raw = skb->nh.raw + sizeof(struct ipv6hdr);
/*
* Parse extension headers
*/
nexthdr = skb->nh.ipv6h->nexthdr;
nhoff = offsetof(struct ipv6hdr, nexthdr);
/* Skip hop-by-hop options, they are already parsed. */
if (nexthdr == NEXTHDR_HOP) {
nhoff = sizeof(struct ipv6hdr);
nexthdr = skb->h.raw[0];
skb->h.raw += (skb->h.raw[1]+1)<<3;
}
rcu_read_lock();
resubmit:
if (!pskb_pull(skb, skb->h.raw - skb->data))
goto discard;
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;
[NETFILTER]: Add nf_conntrack subsystem. The existing connection tracking subsystem in netfilter can only handle ipv4. There were basically two choices present to add connection tracking support for ipv6. We could either duplicate all of the ipv4 connection tracking code into an ipv6 counterpart, or (the choice taken by these patches) we could design a generic layer that could handle both ipv4 and ipv6 and thus requiring only one sub-protocol (TCP, UDP, etc.) connection tracking helper module to be written. In fact nf_conntrack is capable of working with any layer 3 protocol. The existing ipv4 specific conntrack code could also not deal with the pecularities of doing connection tracking on ipv6, which is also cured here. For example, these issues include: 1) ICMPv6 handling, which is used for neighbour discovery in ipv6 thus some messages such as these should not participate in connection tracking since effectively they are like ARP messages 2) fragmentation must be handled differently in ipv6, because the simplistic "defrag, connection track and NAT, refrag" (which the existing ipv4 connection tracking does) approach simply isn't feasible in ipv6 3) ipv6 extension header parsing must occur at the correct spots before and after connection tracking decisions, and there were no provisions for this in the existing connection tracking design 4) ipv6 has no need for stateful NAT The ipv4 specific conntrack layer is kept around, until all of the ipv4 specific conntrack helpers are ported over to nf_conntrack and it is feature complete. Once that occurs, the old conntrack stuff will get placed into the feature-removal-schedule and we will fully kill it off 6 months later. Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp> Signed-off-by: Harald Welte <laforge@netfilter.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-11-10 00:38:16 +00:00
/* 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, &nhoff);
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;
}