557 lines
14 KiB
C
557 lines
14 KiB
C
/*
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* Copyright (C)2004 USAGI/WIDE Project
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Author:
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* Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
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*
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* 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
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* - support Layer 3 protocol independent connection tracking.
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* Based on the original ip_conntrack code which had the following
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* copyright information:
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* (C) 1999-2001 Paul `Rusty' Russell
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* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
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*
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* 23 Mar 2004: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
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* - add get_features() to support various size of conntrack
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* structures.
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*/
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#include <linux/config.h>
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#include <linux/types.h>
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#include <linux/ipv6.h>
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#include <linux/in6.h>
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#include <linux/netfilter.h>
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/icmp.h>
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#include <linux/sysctl.h>
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#include <net/ipv6.h>
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#include <linux/netfilter_ipv6.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_helper.h>
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#include <net/netfilter/nf_conntrack_protocol.h>
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#include <net/netfilter/nf_conntrack_l3proto.h>
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#include <net/netfilter/nf_conntrack_core.h>
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#if 0
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#define DEBUGP printk
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#else
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#define DEBUGP(format, args...)
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#endif
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DECLARE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat);
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static int ipv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
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struct nf_conntrack_tuple *tuple)
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{
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u_int32_t _addrs[8], *ap;
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ap = skb_header_pointer(skb, nhoff + offsetof(struct ipv6hdr, saddr),
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sizeof(_addrs), _addrs);
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if (ap == NULL)
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return 0;
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memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6));
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memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6));
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return 1;
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}
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static int ipv6_invert_tuple(struct nf_conntrack_tuple *tuple,
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const struct nf_conntrack_tuple *orig)
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{
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memcpy(tuple->src.u3.ip6, orig->dst.u3.ip6, sizeof(tuple->src.u3.ip6));
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memcpy(tuple->dst.u3.ip6, orig->src.u3.ip6, sizeof(tuple->dst.u3.ip6));
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return 1;
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}
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static int ipv6_print_tuple(struct seq_file *s,
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const struct nf_conntrack_tuple *tuple)
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{
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return seq_printf(s, "src=%x:%x:%x:%x:%x:%x:%x:%x dst=%x:%x:%x:%x:%x:%x:%x:%x ",
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NIP6(*((struct in6_addr *)tuple->src.u3.ip6)),
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NIP6(*((struct in6_addr *)tuple->dst.u3.ip6)));
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}
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static int ipv6_print_conntrack(struct seq_file *s,
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const struct nf_conn *conntrack)
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{
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return 0;
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}
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/*
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* Based on ipv6_skip_exthdr() in net/ipv6/exthdr.c
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*
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* This function parses (probably truncated) exthdr set "hdr"
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* of length "len". "nexthdrp" initially points to some place,
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* where type of the first header can be found.
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*
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* It skips all well-known exthdrs, and returns pointer to the start
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* of unparsable area i.e. the first header with unknown type.
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* if success, *nexthdr is updated by type/protocol of this header.
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*
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* NOTES: - it may return pointer pointing beyond end of packet,
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* if the last recognized header is truncated in the middle.
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* - if packet is truncated, so that all parsed headers are skipped,
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* it returns -1.
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* - if packet is fragmented, return pointer of the fragment header.
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* - ESP is unparsable for now and considered like
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* normal payload protocol.
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* - Note also special handling of AUTH header. Thanks to IPsec wizards.
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*/
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int nf_ct_ipv6_skip_exthdr(struct sk_buff *skb, int start, u8 *nexthdrp,
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int len)
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{
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u8 nexthdr = *nexthdrp;
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while (ipv6_ext_hdr(nexthdr)) {
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struct ipv6_opt_hdr hdr;
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int hdrlen;
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if (len < (int)sizeof(struct ipv6_opt_hdr))
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return -1;
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if (nexthdr == NEXTHDR_NONE)
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break;
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if (nexthdr == NEXTHDR_FRAGMENT)
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break;
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if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
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BUG();
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if (nexthdr == NEXTHDR_AUTH)
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hdrlen = (hdr.hdrlen+2)<<2;
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else
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hdrlen = ipv6_optlen(&hdr);
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nexthdr = hdr.nexthdr;
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len -= hdrlen;
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start += hdrlen;
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}
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*nexthdrp = nexthdr;
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return start;
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}
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static int
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ipv6_prepare(struct sk_buff **pskb, unsigned int hooknum, unsigned int *dataoff,
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u_int8_t *protonum)
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{
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unsigned int extoff;
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unsigned char pnum;
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int protoff;
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extoff = (u8*)((*pskb)->nh.ipv6h + 1) - (*pskb)->data;
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pnum = (*pskb)->nh.ipv6h->nexthdr;
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protoff = nf_ct_ipv6_skip_exthdr(*pskb, extoff, &pnum,
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(*pskb)->len - extoff);
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/*
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* (protoff == (*pskb)->len) mean that the packet doesn't have no data
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* except of IPv6 & ext headers. but it's tracked anyway. - YK
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*/
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if ((protoff < 0) || (protoff > (*pskb)->len)) {
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DEBUGP("ip6_conntrack_core: can't find proto in pkt\n");
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NF_CT_STAT_INC(error);
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NF_CT_STAT_INC(invalid);
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return -NF_ACCEPT;
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}
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*dataoff = protoff;
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*protonum = pnum;
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return NF_ACCEPT;
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}
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static u_int32_t ipv6_get_features(const struct nf_conntrack_tuple *tuple)
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{
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return NF_CT_F_BASIC;
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}
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static unsigned int ipv6_confirm(unsigned int hooknum,
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struct sk_buff **pskb,
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const struct net_device *in,
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const struct net_device *out,
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int (*okfn)(struct sk_buff *))
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{
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struct nf_conn *ct;
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enum ip_conntrack_info ctinfo;
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/* This is where we call the helper: as the packet goes out. */
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ct = nf_ct_get(*pskb, &ctinfo);
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if (ct && ct->helper) {
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unsigned int ret, protoff;
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unsigned int extoff = (u8*)((*pskb)->nh.ipv6h + 1)
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- (*pskb)->data;
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unsigned char pnum = (*pskb)->nh.ipv6h->nexthdr;
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protoff = nf_ct_ipv6_skip_exthdr(*pskb, extoff, &pnum,
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(*pskb)->len - extoff);
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if (protoff < 0 || protoff > (*pskb)->len ||
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pnum == NEXTHDR_FRAGMENT) {
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DEBUGP("proto header not found\n");
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return NF_ACCEPT;
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}
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ret = ct->helper->help(pskb, protoff, ct, ctinfo);
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if (ret != NF_ACCEPT)
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return ret;
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}
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/* We've seen it coming out the other side: confirm it */
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return nf_conntrack_confirm(pskb);
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}
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extern struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb);
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extern void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb,
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struct net_device *in,
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struct net_device *out,
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int (*okfn)(struct sk_buff *));
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static unsigned int ipv6_defrag(unsigned int hooknum,
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struct sk_buff **pskb,
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const struct net_device *in,
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const struct net_device *out,
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int (*okfn)(struct sk_buff *))
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{
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struct sk_buff *reasm;
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/* Previously seen (loopback)? */
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if ((*pskb)->nfct)
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return NF_ACCEPT;
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reasm = nf_ct_frag6_gather(*pskb);
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/* queued */
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if (reasm == NULL)
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return NF_STOLEN;
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/* error occured or not fragmented */
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if (reasm == *pskb)
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return NF_ACCEPT;
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nf_ct_frag6_output(hooknum, reasm, (struct net_device *)in,
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(struct net_device *)out, okfn);
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return NF_STOLEN;
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}
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static unsigned int ipv6_conntrack_in(unsigned int hooknum,
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struct sk_buff **pskb,
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const struct net_device *in,
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const struct net_device *out,
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int (*okfn)(struct sk_buff *))
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{
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struct sk_buff *reasm = (*pskb)->nfct_reasm;
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/* This packet is fragmented and has reassembled packet. */
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if (reasm) {
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/* Reassembled packet isn't parsed yet ? */
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if (!reasm->nfct) {
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unsigned int ret;
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ret = nf_conntrack_in(PF_INET6, hooknum, &reasm);
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if (ret != NF_ACCEPT)
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return ret;
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}
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nf_conntrack_get(reasm->nfct);
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(*pskb)->nfct = reasm->nfct;
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return NF_ACCEPT;
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}
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return nf_conntrack_in(PF_INET6, hooknum, pskb);
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}
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static unsigned int ipv6_conntrack_local(unsigned int hooknum,
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struct sk_buff **pskb,
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const struct net_device *in,
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const struct net_device *out,
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int (*okfn)(struct sk_buff *))
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{
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/* root is playing with raw sockets. */
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if ((*pskb)->len < sizeof(struct ipv6hdr)) {
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if (net_ratelimit())
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printk("ipv6_conntrack_local: packet too short\n");
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return NF_ACCEPT;
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}
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return ipv6_conntrack_in(hooknum, pskb, in, out, okfn);
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}
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/* Connection tracking may drop packets, but never alters them, so
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make it the first hook. */
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static struct nf_hook_ops ipv6_conntrack_defrag_ops = {
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.hook = ipv6_defrag,
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.owner = THIS_MODULE,
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.pf = PF_INET6,
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.hooknum = NF_IP6_PRE_ROUTING,
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.priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
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};
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static struct nf_hook_ops ipv6_conntrack_in_ops = {
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.hook = ipv6_conntrack_in,
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.owner = THIS_MODULE,
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.pf = PF_INET6,
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.hooknum = NF_IP6_PRE_ROUTING,
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.priority = NF_IP6_PRI_CONNTRACK,
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};
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static struct nf_hook_ops ipv6_conntrack_local_out_ops = {
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.hook = ipv6_conntrack_local,
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.owner = THIS_MODULE,
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.pf = PF_INET6,
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.hooknum = NF_IP6_LOCAL_OUT,
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.priority = NF_IP6_PRI_CONNTRACK,
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};
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static struct nf_hook_ops ipv6_conntrack_defrag_local_out_ops = {
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.hook = ipv6_defrag,
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.owner = THIS_MODULE,
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.pf = PF_INET6,
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.hooknum = NF_IP6_LOCAL_OUT,
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.priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
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};
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/* Refragmenter; last chance. */
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static struct nf_hook_ops ipv6_conntrack_out_ops = {
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.hook = ipv6_confirm,
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.owner = THIS_MODULE,
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.pf = PF_INET6,
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.hooknum = NF_IP6_POST_ROUTING,
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.priority = NF_IP6_PRI_LAST,
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};
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static struct nf_hook_ops ipv6_conntrack_local_in_ops = {
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.hook = ipv6_confirm,
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.owner = THIS_MODULE,
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.pf = PF_INET6,
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.hooknum = NF_IP6_LOCAL_IN,
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.priority = NF_IP6_PRI_LAST-1,
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};
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#ifdef CONFIG_SYSCTL
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/* From nf_conntrack_proto_icmpv6.c */
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extern unsigned long nf_ct_icmpv6_timeout;
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/* From nf_conntrack_frag6.c */
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extern unsigned long nf_ct_frag6_timeout;
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extern unsigned long nf_ct_frag6_low_thresh;
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extern unsigned long nf_ct_frag6_high_thresh;
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static struct ctl_table_header *nf_ct_ipv6_sysctl_header;
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static ctl_table nf_ct_sysctl_table[] = {
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{
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.ctl_name = NET_NF_CONNTRACK_ICMPV6_TIMEOUT,
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.procname = "nf_conntrack_icmpv6_timeout",
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.data = &nf_ct_icmpv6_timeout,
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.maxlen = sizeof(unsigned int),
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.mode = 0644,
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.proc_handler = &proc_dointvec_jiffies,
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},
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{
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.ctl_name = NET_NF_CONNTRACK_FRAG6_TIMEOUT,
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.procname = "nf_conntrack_frag6_timeout",
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.data = &nf_ct_frag6_timeout,
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.maxlen = sizeof(unsigned int),
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.mode = 0644,
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.proc_handler = &proc_dointvec_jiffies,
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},
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{
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.ctl_name = NET_NF_CONNTRACK_FRAG6_LOW_THRESH,
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.procname = "nf_conntrack_frag6_low_thresh",
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.data = &nf_ct_frag6_low_thresh,
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.maxlen = sizeof(unsigned int),
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.mode = 0644,
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.proc_handler = &proc_dointvec_jiffies,
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},
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{
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.ctl_name = NET_NF_CONNTRACK_FRAG6_HIGH_THRESH,
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.procname = "nf_conntrack_frag6_high_thresh",
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.data = &nf_ct_frag6_high_thresh,
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.maxlen = sizeof(unsigned int),
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.mode = 0644,
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.proc_handler = &proc_dointvec_jiffies,
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},
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{ .ctl_name = 0 }
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};
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static ctl_table nf_ct_netfilter_table[] = {
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{
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.ctl_name = NET_NETFILTER,
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.procname = "netfilter",
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.mode = 0555,
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.child = nf_ct_sysctl_table,
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},
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{ .ctl_name = 0 }
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};
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static ctl_table nf_ct_net_table[] = {
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{
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.ctl_name = CTL_NET,
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.procname = "net",
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.mode = 0555,
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.child = nf_ct_netfilter_table,
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},
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{ .ctl_name = 0 }
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};
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#endif
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struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 = {
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.l3proto = PF_INET6,
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.name = "ipv6",
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.pkt_to_tuple = ipv6_pkt_to_tuple,
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.invert_tuple = ipv6_invert_tuple,
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.print_tuple = ipv6_print_tuple,
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.print_conntrack = ipv6_print_conntrack,
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.prepare = ipv6_prepare,
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.get_features = ipv6_get_features,
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.me = THIS_MODULE,
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};
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extern struct nf_conntrack_protocol nf_conntrack_protocol_tcp6;
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extern struct nf_conntrack_protocol nf_conntrack_protocol_udp6;
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extern struct nf_conntrack_protocol nf_conntrack_protocol_icmpv6;
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extern int nf_ct_frag6_init(void);
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extern void nf_ct_frag6_cleanup(void);
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static int init_or_cleanup(int init)
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{
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int ret = 0;
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if (!init) goto cleanup;
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ret = nf_ct_frag6_init();
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if (ret < 0) {
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printk("nf_conntrack_ipv6: can't initialize frag6.\n");
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goto cleanup_nothing;
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}
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ret = nf_conntrack_protocol_register(&nf_conntrack_protocol_tcp6);
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if (ret < 0) {
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printk("nf_conntrack_ipv6: can't register tcp.\n");
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goto cleanup_frag6;
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}
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ret = nf_conntrack_protocol_register(&nf_conntrack_protocol_udp6);
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if (ret < 0) {
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printk("nf_conntrack_ipv6: can't register udp.\n");
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goto cleanup_tcp;
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}
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ret = nf_conntrack_protocol_register(&nf_conntrack_protocol_icmpv6);
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if (ret < 0) {
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printk("nf_conntrack_ipv6: can't register icmpv6.\n");
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goto cleanup_udp;
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}
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ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv6);
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if (ret < 0) {
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printk("nf_conntrack_ipv6: can't register ipv6\n");
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goto cleanup_icmpv6;
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}
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ret = nf_register_hook(&ipv6_conntrack_defrag_ops);
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if (ret < 0) {
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printk("nf_conntrack_ipv6: can't register pre-routing defrag "
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"hook.\n");
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goto cleanup_ipv6;
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}
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ret = nf_register_hook(&ipv6_conntrack_defrag_local_out_ops);
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if (ret < 0) {
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printk("nf_conntrack_ipv6: can't register local_out defrag "
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"hook.\n");
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goto cleanup_defragops;
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}
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ret = nf_register_hook(&ipv6_conntrack_in_ops);
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if (ret < 0) {
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printk("nf_conntrack_ipv6: can't register pre-routing hook.\n");
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goto cleanup_defraglocalops;
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}
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ret = nf_register_hook(&ipv6_conntrack_local_out_ops);
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if (ret < 0) {
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printk("nf_conntrack_ipv6: can't register local out hook.\n");
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goto cleanup_inops;
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|
}
|
|
|
|
ret = nf_register_hook(&ipv6_conntrack_out_ops);
|
|
if (ret < 0) {
|
|
printk("nf_conntrack_ipv6: can't register post-routing hook.\n");
|
|
goto cleanup_inandlocalops;
|
|
}
|
|
|
|
ret = nf_register_hook(&ipv6_conntrack_local_in_ops);
|
|
if (ret < 0) {
|
|
printk("nf_conntrack_ipv6: can't register local in hook.\n");
|
|
goto cleanup_inoutandlocalops;
|
|
}
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
nf_ct_ipv6_sysctl_header = register_sysctl_table(nf_ct_net_table, 0);
|
|
if (nf_ct_ipv6_sysctl_header == NULL) {
|
|
printk("nf_conntrack: can't register to sysctl.\n");
|
|
ret = -ENOMEM;
|
|
goto cleanup_localinops;
|
|
}
|
|
#endif
|
|
return ret;
|
|
|
|
cleanup:
|
|
synchronize_net();
|
|
#ifdef CONFIG_SYSCTL
|
|
unregister_sysctl_table(nf_ct_ipv6_sysctl_header);
|
|
cleanup_localinops:
|
|
#endif
|
|
nf_unregister_hook(&ipv6_conntrack_local_in_ops);
|
|
cleanup_inoutandlocalops:
|
|
nf_unregister_hook(&ipv6_conntrack_out_ops);
|
|
cleanup_inandlocalops:
|
|
nf_unregister_hook(&ipv6_conntrack_local_out_ops);
|
|
cleanup_inops:
|
|
nf_unregister_hook(&ipv6_conntrack_in_ops);
|
|
cleanup_defraglocalops:
|
|
nf_unregister_hook(&ipv6_conntrack_defrag_local_out_ops);
|
|
cleanup_defragops:
|
|
nf_unregister_hook(&ipv6_conntrack_defrag_ops);
|
|
cleanup_ipv6:
|
|
nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6);
|
|
cleanup_icmpv6:
|
|
nf_conntrack_protocol_unregister(&nf_conntrack_protocol_icmpv6);
|
|
cleanup_udp:
|
|
nf_conntrack_protocol_unregister(&nf_conntrack_protocol_udp6);
|
|
cleanup_tcp:
|
|
nf_conntrack_protocol_unregister(&nf_conntrack_protocol_tcp6);
|
|
cleanup_frag6:
|
|
nf_ct_frag6_cleanup();
|
|
cleanup_nothing:
|
|
return ret;
|
|
}
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>");
|
|
|
|
static int __init init(void)
|
|
{
|
|
need_nf_conntrack();
|
|
return init_or_cleanup(1);
|
|
}
|
|
|
|
static void __exit fini(void)
|
|
{
|
|
init_or_cleanup(0);
|
|
}
|
|
|
|
module_init(init);
|
|
module_exit(fini);
|
|
|
|
void need_ip6_conntrack(void)
|
|
{
|
|
}
|
|
|
|
EXPORT_SYMBOL(need_ip6_conntrack);
|