linux/net/ipv6/netfilter/nf_conntrack_reasm.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * IPv6 fragment reassembly for connection tracking
 *
 * Copyright (C)2004 USAGI/WIDE Project
 *
 * Author:
 *	Yasuyuki Kozakai @USAGI <[email protected]>
 *
 * Based on: net/ipv6/reassembly.c
 */

#define pr_fmt(fmt) …

#include <linux/errno.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/ipv6.h>
#include <linux/slab.h>

#include <net/ipv6_frag.h>

#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
#include <linux/sysctl.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
#include <net/netns/generic.h>

static const char nf_frags_cache_name[] = …;

static unsigned int nf_frag_pernet_id __read_mostly;
static struct inet_frags nf_frags;

static struct nft_ct_frag6_pernet *nf_frag_pernet(struct net *net)
{ … }

#ifdef CONFIG_SYSCTL

static struct ctl_table nf_ct_frag6_sysctl_table[] = …;

static int nf_ct_frag6_sysctl_register(struct net *net)
{ … }

static void __net_exit nf_ct_frags6_sysctl_unregister(struct net *net)
{ … }

#else
static int nf_ct_frag6_sysctl_register(struct net *net)
{
	return 0;
}
static void __net_exit nf_ct_frags6_sysctl_unregister(struct net *net)
{
}
#endif

static int nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *skb,
			     struct sk_buff *prev_tail, struct net_device *dev);

static inline u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h)
{ … }

static void nf_ct_frag6_expire(struct timer_list *t)
{ … }

/* Creation primitives. */
static struct frag_queue *fq_find(struct net *net, __be32 id, u32 user,
				  const struct ipv6hdr *hdr, int iif)
{ … }


static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb,
			     const struct frag_hdr *fhdr, int nhoff)
{ … }

/*
 *	Check if this packet is complete.
 *
 *	It is called with locked fq, and caller must check that
 *	queue is eligible for reassembly i.e. it is not COMPLETE,
 *	the last and the first frames arrived and all the bits are here.
 */
static int nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *skb,
			     struct sk_buff *prev_tail, struct net_device *dev)
{ … }

/*
 * find the header just before Fragment Header.
 *
 * if success return 0 and set ...
 * (*prevhdrp): the value of "Next Header Field" in the header
 *		just before Fragment Header.
 * (*prevhoff): the offset of "Next Header Field" in the header
 *		just before Fragment Header.
 * (*fhoff)   : the offset of Fragment Header.
 *
 * Based on ipv6_skip_hdr() in net/ipv6/exthdr.c
 *
 */
static int
find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int *prevhoff, int *fhoff)
{ … }

int nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 user)
{ … }
EXPORT_SYMBOL_GPL(…);

static int nf_ct_net_init(struct net *net)
{ … }

static void nf_ct_net_pre_exit(struct net *net)
{ … }

static void nf_ct_net_exit(struct net *net)
{ … }

static struct pernet_operations nf_ct_net_ops = …;

static const struct rhashtable_params nfct_rhash_params = …;

int nf_ct_frag6_init(void)
{ … }

void nf_ct_frag6_cleanup(void)
{ … }