Viewing file:  ip6_input.c (5.38 KB) -rw-r--r--
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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.
*/
#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>
static inline int ip6_rcv_finish( struct sk_buff *skb)
{
if (skb->dst == NULL)
ip6_route_input(skb);
return skb->dst->input(skb);
}
int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
{
struct ipv6hdr *hdr;
u32 pkt_len;
if (skb->pkt_type == PACKET_OTHERHOST)
goto drop;
IP6_INC_STATS_BH(Ip6InReceives);
if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
goto out;
/* Store incoming device index. When the packet will
be queued, we cannot refer to skb->dev anymore.
*/
((struct inet6_skb_parm *)skb->cb)->iif = dev->ifindex;
if (skb->len < sizeof(struct ipv6hdr))
goto err;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
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 (pkt_len + sizeof(struct ipv6hdr) < skb->len) {
if (__pskb_trim(skb, pkt_len + sizeof(struct ipv6hdr)))
goto drop;
hdr = skb->nh.ipv6h;
if (skb->ip_summed == CHECKSUM_HW)
skb->ip_summed = CHECKSUM_NONE;
}
}
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(Ip6InHdrErrors);
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(Ip6InTruncatedPkts);
err:
IP6_INC_STATS_BH(Ip6InHdrErrors);
drop:
kfree_skb(skb);
out:
return 0;
}
/*
* Deliver the packet to the host
*/
static inline int ip6_input_finish(struct sk_buff *skb)
{
struct ipv6hdr *hdr = skb->nh.ipv6h;
struct inet6_protocol *ipprot;
struct sock *raw_sk;
int nhoff;
int nexthdr;
int found = 0;
u8 hash;
skb->h.raw = skb->nh.raw + sizeof(struct ipv6hdr);
/*
* Parse extension headers
*/
nexthdr = hdr->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;
}
/* This check is sort of optimization.
It would be stupid to detect for optional headers,
which are missing with probability of 200%
*/
if (nexthdr != IPPROTO_TCP && nexthdr != IPPROTO_UDP) {
nhoff = ipv6_parse_exthdrs(&skb, nhoff);
if (nhoff < 0)
return 0;
nexthdr = skb->nh.raw[nhoff];
hdr = skb->nh.ipv6h;
}
if (!pskb_pull(skb, skb->h.raw - skb->data))
goto discard;
if (skb->ip_summed == CHECKSUM_HW)
skb->csum = csum_sub(skb->csum,
csum_partial(skb->nh.raw, skb->h.raw-skb->nh.raw, 0));
raw_sk = raw_v6_htable[nexthdr&(MAX_INET_PROTOS-1)];
if (raw_sk)
raw_sk = ipv6_raw_deliver(skb, nexthdr);
hash = nexthdr & (MAX_INET_PROTOS - 1);
for (ipprot = (struct inet6_protocol *) inet6_protos[hash];
ipprot != NULL;
ipprot = (struct inet6_protocol *) ipprot->next) {
struct sk_buff *buff = skb;
if (ipprot->protocol != nexthdr)
continue;
if (ipprot->copy || raw_sk)
buff = skb_clone(skb, GFP_ATOMIC);
if (buff)
ipprot->handler(buff);
found = 1;
}
if (raw_sk) {
rawv6_rcv(raw_sk, skb);
sock_put(raw_sk);
found = 1;
}
/*
* not found: send ICMP parameter problem back
*/
if (!found) {
IP6_INC_STATS_BH(Ip6InUnknownProtos);
icmpv6_param_prob(skb, ICMPV6_UNK_NEXTHDR, nhoff);
}
return 0;
discard:
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 = 0;
int discard = 1;
IP6_INC_STATS_BH(Ip6InMcastPkts);
hdr = skb->nh.ipv6h;
if (ipv6_chk_mcast_addr(skb->dev, &hdr->daddr))
deliver = 1;
/*
* 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);
} else {
discard = 0;
skb2 = skb;
}
dst->output(skb2);
}
}
#endif
if (deliver) {
discard = 0;
ip6_input(skb);
}
if (discard)
kfree_skb(skb);
return 0;
}
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