Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
882 lines
21 KiB
C
882 lines
21 KiB
C
/*
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* IPv6 fragment reassembly for connection tracking
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*
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* Copyright (C)2004 USAGI/WIDE Project
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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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* Based on: net/ipv6/reassembly.c
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/string.h>
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#include <linux/socket.h>
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#include <linux/sockios.h>
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#include <linux/jiffies.h>
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#include <linux/net.h>
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#include <linux/list.h>
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#include <linux/netdevice.h>
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#include <linux/in6.h>
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#include <linux/ipv6.h>
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#include <linux/icmpv6.h>
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#include <linux/random.h>
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#include <linux/jhash.h>
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#include <net/sock.h>
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#include <net/snmp.h>
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#include <net/ipv6.h>
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#include <net/protocol.h>
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#include <net/transp_v6.h>
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#include <net/rawv6.h>
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#include <net/ndisc.h>
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#include <net/addrconf.h>
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#include <linux/sysctl.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter_ipv6.h>
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#include <linux/kernel.h>
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#include <linux/module.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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#define NF_CT_FRAG6_HIGH_THRESH 262144 /* == 256*1024 */
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#define NF_CT_FRAG6_LOW_THRESH 196608 /* == 192*1024 */
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#define NF_CT_FRAG6_TIMEOUT IPV6_FRAG_TIMEOUT
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unsigned int nf_ct_frag6_high_thresh __read_mostly = 256*1024;
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unsigned int nf_ct_frag6_low_thresh __read_mostly = 192*1024;
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unsigned long nf_ct_frag6_timeout __read_mostly = IPV6_FRAG_TIMEOUT;
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struct nf_ct_frag6_skb_cb
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{
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struct inet6_skb_parm h;
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int offset;
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struct sk_buff *orig;
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};
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#define NFCT_FRAG6_CB(skb) ((struct nf_ct_frag6_skb_cb*)((skb)->cb))
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struct nf_ct_frag6_queue
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{
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struct hlist_node list;
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struct list_head lru_list; /* lru list member */
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__be32 id; /* fragment id */
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struct in6_addr saddr;
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struct in6_addr daddr;
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spinlock_t lock;
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atomic_t refcnt;
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struct timer_list timer; /* expire timer */
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struct sk_buff *fragments;
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int len;
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int meat;
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struct timeval stamp;
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unsigned int csum;
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__u8 last_in; /* has first/last segment arrived? */
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#define COMPLETE 4
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#define FIRST_IN 2
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#define LAST_IN 1
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__u16 nhoffset;
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};
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/* Hash table. */
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#define FRAG6Q_HASHSZ 64
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static struct hlist_head nf_ct_frag6_hash[FRAG6Q_HASHSZ];
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static DEFINE_RWLOCK(nf_ct_frag6_lock);
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static u32 nf_ct_frag6_hash_rnd;
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static LIST_HEAD(nf_ct_frag6_lru_list);
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int nf_ct_frag6_nqueues = 0;
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static __inline__ void __fq_unlink(struct nf_ct_frag6_queue *fq)
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{
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hlist_del(&fq->list);
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list_del(&fq->lru_list);
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nf_ct_frag6_nqueues--;
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}
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static __inline__ void fq_unlink(struct nf_ct_frag6_queue *fq)
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{
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write_lock(&nf_ct_frag6_lock);
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__fq_unlink(fq);
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write_unlock(&nf_ct_frag6_lock);
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}
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static unsigned int ip6qhashfn(__be32 id, struct in6_addr *saddr,
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struct in6_addr *daddr)
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{
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u32 a, b, c;
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a = (__force u32)saddr->s6_addr32[0];
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b = (__force u32)saddr->s6_addr32[1];
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c = (__force u32)saddr->s6_addr32[2];
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a += JHASH_GOLDEN_RATIO;
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b += JHASH_GOLDEN_RATIO;
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c += nf_ct_frag6_hash_rnd;
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__jhash_mix(a, b, c);
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a += (__force u32)saddr->s6_addr32[3];
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b += (__force u32)daddr->s6_addr32[0];
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c += (__force u32)daddr->s6_addr32[1];
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__jhash_mix(a, b, c);
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a += (__force u32)daddr->s6_addr32[2];
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b += (__force u32)daddr->s6_addr32[3];
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c += (__force u32)id;
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__jhash_mix(a, b, c);
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return c & (FRAG6Q_HASHSZ - 1);
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}
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static struct timer_list nf_ct_frag6_secret_timer;
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int nf_ct_frag6_secret_interval = 10 * 60 * HZ;
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static void nf_ct_frag6_secret_rebuild(unsigned long dummy)
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{
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unsigned long now = jiffies;
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int i;
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write_lock(&nf_ct_frag6_lock);
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get_random_bytes(&nf_ct_frag6_hash_rnd, sizeof(u32));
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for (i = 0; i < FRAG6Q_HASHSZ; i++) {
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struct nf_ct_frag6_queue *q;
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struct hlist_node *p, *n;
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hlist_for_each_entry_safe(q, p, n, &nf_ct_frag6_hash[i], list) {
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unsigned int hval = ip6qhashfn(q->id,
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&q->saddr,
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&q->daddr);
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if (hval != i) {
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hlist_del(&q->list);
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/* Relink to new hash chain. */
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hlist_add_head(&q->list,
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&nf_ct_frag6_hash[hval]);
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}
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}
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}
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write_unlock(&nf_ct_frag6_lock);
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mod_timer(&nf_ct_frag6_secret_timer, now + nf_ct_frag6_secret_interval);
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}
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atomic_t nf_ct_frag6_mem = ATOMIC_INIT(0);
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/* Memory Tracking Functions. */
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static inline void frag_kfree_skb(struct sk_buff *skb, unsigned int *work)
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{
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if (work)
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*work -= skb->truesize;
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atomic_sub(skb->truesize, &nf_ct_frag6_mem);
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if (NFCT_FRAG6_CB(skb)->orig)
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kfree_skb(NFCT_FRAG6_CB(skb)->orig);
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kfree_skb(skb);
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}
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static inline void frag_free_queue(struct nf_ct_frag6_queue *fq,
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unsigned int *work)
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{
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if (work)
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*work -= sizeof(struct nf_ct_frag6_queue);
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atomic_sub(sizeof(struct nf_ct_frag6_queue), &nf_ct_frag6_mem);
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kfree(fq);
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}
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static inline struct nf_ct_frag6_queue *frag_alloc_queue(void)
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{
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struct nf_ct_frag6_queue *fq = kmalloc(sizeof(struct nf_ct_frag6_queue), GFP_ATOMIC);
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if (!fq)
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return NULL;
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atomic_add(sizeof(struct nf_ct_frag6_queue), &nf_ct_frag6_mem);
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return fq;
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}
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/* Destruction primitives. */
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/* Complete destruction of fq. */
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static void nf_ct_frag6_destroy(struct nf_ct_frag6_queue *fq,
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unsigned int *work)
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{
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struct sk_buff *fp;
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BUG_TRAP(fq->last_in&COMPLETE);
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BUG_TRAP(del_timer(&fq->timer) == 0);
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/* Release all fragment data. */
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fp = fq->fragments;
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while (fp) {
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struct sk_buff *xp = fp->next;
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frag_kfree_skb(fp, work);
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fp = xp;
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}
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frag_free_queue(fq, work);
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}
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static __inline__ void fq_put(struct nf_ct_frag6_queue *fq, unsigned int *work)
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{
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if (atomic_dec_and_test(&fq->refcnt))
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nf_ct_frag6_destroy(fq, work);
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}
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/* Kill fq entry. It is not destroyed immediately,
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* because caller (and someone more) holds reference count.
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*/
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static __inline__ void fq_kill(struct nf_ct_frag6_queue *fq)
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{
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if (del_timer(&fq->timer))
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atomic_dec(&fq->refcnt);
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if (!(fq->last_in & COMPLETE)) {
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fq_unlink(fq);
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atomic_dec(&fq->refcnt);
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fq->last_in |= COMPLETE;
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}
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}
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static void nf_ct_frag6_evictor(void)
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{
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struct nf_ct_frag6_queue *fq;
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struct list_head *tmp;
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unsigned int work;
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work = atomic_read(&nf_ct_frag6_mem);
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if (work <= nf_ct_frag6_low_thresh)
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return;
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work -= nf_ct_frag6_low_thresh;
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while (work > 0) {
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read_lock(&nf_ct_frag6_lock);
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if (list_empty(&nf_ct_frag6_lru_list)) {
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read_unlock(&nf_ct_frag6_lock);
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return;
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}
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tmp = nf_ct_frag6_lru_list.next;
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BUG_ON(tmp == NULL);
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fq = list_entry(tmp, struct nf_ct_frag6_queue, lru_list);
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atomic_inc(&fq->refcnt);
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read_unlock(&nf_ct_frag6_lock);
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spin_lock(&fq->lock);
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if (!(fq->last_in&COMPLETE))
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fq_kill(fq);
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spin_unlock(&fq->lock);
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fq_put(fq, &work);
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}
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}
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static void nf_ct_frag6_expire(unsigned long data)
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{
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struct nf_ct_frag6_queue *fq = (struct nf_ct_frag6_queue *) data;
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spin_lock(&fq->lock);
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if (fq->last_in & COMPLETE)
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goto out;
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fq_kill(fq);
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out:
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spin_unlock(&fq->lock);
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fq_put(fq, NULL);
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}
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/* Creation primitives. */
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static struct nf_ct_frag6_queue *nf_ct_frag6_intern(unsigned int hash,
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struct nf_ct_frag6_queue *fq_in)
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{
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struct nf_ct_frag6_queue *fq;
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#ifdef CONFIG_SMP
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struct hlist_node *n;
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#endif
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write_lock(&nf_ct_frag6_lock);
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#ifdef CONFIG_SMP
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hlist_for_each_entry(fq, n, &nf_ct_frag6_hash[hash], list) {
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if (fq->id == fq_in->id &&
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ipv6_addr_equal(&fq_in->saddr, &fq->saddr) &&
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ipv6_addr_equal(&fq_in->daddr, &fq->daddr)) {
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atomic_inc(&fq->refcnt);
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write_unlock(&nf_ct_frag6_lock);
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fq_in->last_in |= COMPLETE;
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fq_put(fq_in, NULL);
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return fq;
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}
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}
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#endif
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fq = fq_in;
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if (!mod_timer(&fq->timer, jiffies + nf_ct_frag6_timeout))
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atomic_inc(&fq->refcnt);
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atomic_inc(&fq->refcnt);
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hlist_add_head(&fq->list, &nf_ct_frag6_hash[hash]);
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INIT_LIST_HEAD(&fq->lru_list);
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list_add_tail(&fq->lru_list, &nf_ct_frag6_lru_list);
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nf_ct_frag6_nqueues++;
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write_unlock(&nf_ct_frag6_lock);
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return fq;
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}
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static struct nf_ct_frag6_queue *
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nf_ct_frag6_create(unsigned int hash, __be32 id, struct in6_addr *src, struct in6_addr *dst)
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{
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struct nf_ct_frag6_queue *fq;
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if ((fq = frag_alloc_queue()) == NULL) {
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DEBUGP("Can't alloc new queue\n");
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goto oom;
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}
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memset(fq, 0, sizeof(struct nf_ct_frag6_queue));
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fq->id = id;
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ipv6_addr_copy(&fq->saddr, src);
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ipv6_addr_copy(&fq->daddr, dst);
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init_timer(&fq->timer);
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fq->timer.function = nf_ct_frag6_expire;
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fq->timer.data = (long) fq;
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spin_lock_init(&fq->lock);
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atomic_set(&fq->refcnt, 1);
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return nf_ct_frag6_intern(hash, fq);
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oom:
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return NULL;
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}
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static __inline__ struct nf_ct_frag6_queue *
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fq_find(__be32 id, struct in6_addr *src, struct in6_addr *dst)
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{
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struct nf_ct_frag6_queue *fq;
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struct hlist_node *n;
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unsigned int hash = ip6qhashfn(id, src, dst);
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read_lock(&nf_ct_frag6_lock);
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hlist_for_each_entry(fq, n, &nf_ct_frag6_hash[hash], list) {
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if (fq->id == id &&
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ipv6_addr_equal(src, &fq->saddr) &&
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ipv6_addr_equal(dst, &fq->daddr)) {
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atomic_inc(&fq->refcnt);
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read_unlock(&nf_ct_frag6_lock);
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return fq;
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}
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}
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read_unlock(&nf_ct_frag6_lock);
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return nf_ct_frag6_create(hash, id, src, dst);
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}
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static int nf_ct_frag6_queue(struct nf_ct_frag6_queue *fq, struct sk_buff *skb,
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struct frag_hdr *fhdr, int nhoff)
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{
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struct sk_buff *prev, *next;
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int offset, end;
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if (fq->last_in & COMPLETE) {
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DEBUGP("Allready completed\n");
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goto err;
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}
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offset = ntohs(fhdr->frag_off) & ~0x7;
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end = offset + (ntohs(skb->nh.ipv6h->payload_len) -
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((u8 *) (fhdr + 1) - (u8 *) (skb->nh.ipv6h + 1)));
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if ((unsigned int)end > IPV6_MAXPLEN) {
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DEBUGP("offset is too large.\n");
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return -1;
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}
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if (skb->ip_summed == CHECKSUM_COMPLETE)
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skb->csum = csum_sub(skb->csum,
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csum_partial(skb->nh.raw,
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(u8*)(fhdr + 1) - skb->nh.raw,
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0));
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/* Is this the final fragment? */
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if (!(fhdr->frag_off & htons(IP6_MF))) {
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/* If we already have some bits beyond end
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* or have different end, the segment is corrupted.
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*/
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if (end < fq->len ||
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((fq->last_in & LAST_IN) && end != fq->len)) {
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DEBUGP("already received last fragment\n");
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goto err;
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}
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fq->last_in |= LAST_IN;
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fq->len = end;
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} else {
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/* Check if the fragment is rounded to 8 bytes.
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* Required by the RFC.
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*/
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if (end & 0x7) {
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/* RFC2460 says always send parameter problem in
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* this case. -DaveM
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*/
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DEBUGP("the end of this fragment is not rounded to 8 bytes.\n");
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return -1;
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}
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if (end > fq->len) {
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/* Some bits beyond end -> corruption. */
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if (fq->last_in & LAST_IN) {
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DEBUGP("last packet already reached.\n");
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goto err;
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}
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fq->len = end;
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}
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}
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if (end == offset)
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goto err;
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/* Point into the IP datagram 'data' part. */
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if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) {
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DEBUGP("queue: message is too short.\n");
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goto err;
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}
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if (pskb_trim_rcsum(skb, end - offset)) {
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DEBUGP("Can't trim\n");
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goto err;
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}
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/* Find out which fragments are in front and at the back of us
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* in the chain of fragments so far. We must know where to put
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* this fragment, right?
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*/
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prev = NULL;
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for (next = fq->fragments; next != NULL; next = next->next) {
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if (NFCT_FRAG6_CB(next)->offset >= offset)
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break; /* bingo! */
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prev = next;
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}
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/* We found where to put this one. Check for overlap with
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* preceding fragment, and, if needed, align things so that
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* any overlaps are eliminated.
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*/
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if (prev) {
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int i = (NFCT_FRAG6_CB(prev)->offset + prev->len) - offset;
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if (i > 0) {
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offset += i;
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if (end <= offset) {
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DEBUGP("overlap\n");
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goto err;
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}
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if (!pskb_pull(skb, i)) {
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DEBUGP("Can't pull\n");
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goto err;
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}
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if (skb->ip_summed != CHECKSUM_UNNECESSARY)
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skb->ip_summed = CHECKSUM_NONE;
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}
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}
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/* Look for overlap with succeeding segments.
|
|
* If we can merge fragments, do it.
|
|
*/
|
|
while (next && NFCT_FRAG6_CB(next)->offset < end) {
|
|
/* overlap is 'i' bytes */
|
|
int i = end - NFCT_FRAG6_CB(next)->offset;
|
|
|
|
if (i < next->len) {
|
|
/* Eat head of the next overlapped fragment
|
|
* and leave the loop. The next ones cannot overlap.
|
|
*/
|
|
DEBUGP("Eat head of the overlapped parts.: %d", i);
|
|
if (!pskb_pull(next, i))
|
|
goto err;
|
|
|
|
/* next fragment */
|
|
NFCT_FRAG6_CB(next)->offset += i;
|
|
fq->meat -= i;
|
|
if (next->ip_summed != CHECKSUM_UNNECESSARY)
|
|
next->ip_summed = CHECKSUM_NONE;
|
|
break;
|
|
} else {
|
|
struct sk_buff *free_it = next;
|
|
|
|
/* Old fragmnet is completely overridden with
|
|
* new one drop it.
|
|
*/
|
|
next = next->next;
|
|
|
|
if (prev)
|
|
prev->next = next;
|
|
else
|
|
fq->fragments = next;
|
|
|
|
fq->meat -= free_it->len;
|
|
frag_kfree_skb(free_it, NULL);
|
|
}
|
|
}
|
|
|
|
NFCT_FRAG6_CB(skb)->offset = offset;
|
|
|
|
/* Insert this fragment in the chain of fragments. */
|
|
skb->next = next;
|
|
if (prev)
|
|
prev->next = skb;
|
|
else
|
|
fq->fragments = skb;
|
|
|
|
skb->dev = NULL;
|
|
skb_get_timestamp(skb, &fq->stamp);
|
|
fq->meat += skb->len;
|
|
atomic_add(skb->truesize, &nf_ct_frag6_mem);
|
|
|
|
/* The first fragment.
|
|
* nhoffset is obtained from the first fragment, of course.
|
|
*/
|
|
if (offset == 0) {
|
|
fq->nhoffset = nhoff;
|
|
fq->last_in |= FIRST_IN;
|
|
}
|
|
write_lock(&nf_ct_frag6_lock);
|
|
list_move_tail(&fq->lru_list, &nf_ct_frag6_lru_list);
|
|
write_unlock(&nf_ct_frag6_lock);
|
|
return 0;
|
|
|
|
err:
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Check if this packet is complete.
|
|
* Returns NULL on failure by any reason, and pointer
|
|
* to current nexthdr field in reassembled frame.
|
|
*
|
|
* 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 struct sk_buff *
|
|
nf_ct_frag6_reasm(struct nf_ct_frag6_queue *fq, struct net_device *dev)
|
|
{
|
|
struct sk_buff *fp, *op, *head = fq->fragments;
|
|
int payload_len;
|
|
|
|
fq_kill(fq);
|
|
|
|
BUG_TRAP(head != NULL);
|
|
BUG_TRAP(NFCT_FRAG6_CB(head)->offset == 0);
|
|
|
|
/* Unfragmented part is taken from the first segment. */
|
|
payload_len = (head->data - head->nh.raw) - sizeof(struct ipv6hdr) + fq->len - sizeof(struct frag_hdr);
|
|
if (payload_len > IPV6_MAXPLEN) {
|
|
DEBUGP("payload len is too large.\n");
|
|
goto out_oversize;
|
|
}
|
|
|
|
/* Head of list must not be cloned. */
|
|
if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) {
|
|
DEBUGP("skb is cloned but can't expand head");
|
|
goto out_oom;
|
|
}
|
|
|
|
/* If the first fragment is fragmented itself, we split
|
|
* it to two chunks: the first with data and paged part
|
|
* and the second, holding only fragments. */
|
|
if (skb_shinfo(head)->frag_list) {
|
|
struct sk_buff *clone;
|
|
int i, plen = 0;
|
|
|
|
if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) {
|
|
DEBUGP("Can't alloc skb\n");
|
|
goto out_oom;
|
|
}
|
|
clone->next = head->next;
|
|
head->next = clone;
|
|
skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
|
|
skb_shinfo(head)->frag_list = NULL;
|
|
for (i=0; i<skb_shinfo(head)->nr_frags; i++)
|
|
plen += skb_shinfo(head)->frags[i].size;
|
|
clone->len = clone->data_len = head->data_len - plen;
|
|
head->data_len -= clone->len;
|
|
head->len -= clone->len;
|
|
clone->csum = 0;
|
|
clone->ip_summed = head->ip_summed;
|
|
|
|
NFCT_FRAG6_CB(clone)->orig = NULL;
|
|
atomic_add(clone->truesize, &nf_ct_frag6_mem);
|
|
}
|
|
|
|
/* We have to remove fragment header from datagram and to relocate
|
|
* header in order to calculate ICV correctly. */
|
|
head->nh.raw[fq->nhoffset] = head->h.raw[0];
|
|
memmove(head->head + sizeof(struct frag_hdr), head->head,
|
|
(head->data - head->head) - sizeof(struct frag_hdr));
|
|
head->mac.raw += sizeof(struct frag_hdr);
|
|
head->nh.raw += sizeof(struct frag_hdr);
|
|
|
|
skb_shinfo(head)->frag_list = head->next;
|
|
head->h.raw = head->data;
|
|
skb_push(head, head->data - head->nh.raw);
|
|
atomic_sub(head->truesize, &nf_ct_frag6_mem);
|
|
|
|
for (fp=head->next; fp; fp = fp->next) {
|
|
head->data_len += fp->len;
|
|
head->len += fp->len;
|
|
if (head->ip_summed != fp->ip_summed)
|
|
head->ip_summed = CHECKSUM_NONE;
|
|
else if (head->ip_summed == CHECKSUM_COMPLETE)
|
|
head->csum = csum_add(head->csum, fp->csum);
|
|
head->truesize += fp->truesize;
|
|
atomic_sub(fp->truesize, &nf_ct_frag6_mem);
|
|
}
|
|
|
|
head->next = NULL;
|
|
head->dev = dev;
|
|
skb_set_timestamp(head, &fq->stamp);
|
|
head->nh.ipv6h->payload_len = htons(payload_len);
|
|
|
|
/* Yes, and fold redundant checksum back. 8) */
|
|
if (head->ip_summed == CHECKSUM_COMPLETE)
|
|
head->csum = csum_partial(head->nh.raw, head->h.raw-head->nh.raw, head->csum);
|
|
|
|
fq->fragments = NULL;
|
|
|
|
/* all original skbs are linked into the NFCT_FRAG6_CB(head).orig */
|
|
fp = skb_shinfo(head)->frag_list;
|
|
if (NFCT_FRAG6_CB(fp)->orig == NULL)
|
|
/* at above code, head skb is divided into two skbs. */
|
|
fp = fp->next;
|
|
|
|
op = NFCT_FRAG6_CB(head)->orig;
|
|
for (; fp; fp = fp->next) {
|
|
struct sk_buff *orig = NFCT_FRAG6_CB(fp)->orig;
|
|
|
|
op->next = orig;
|
|
op = orig;
|
|
NFCT_FRAG6_CB(fp)->orig = NULL;
|
|
}
|
|
|
|
return head;
|
|
|
|
out_oversize:
|
|
if (net_ratelimit())
|
|
printk(KERN_DEBUG "nf_ct_frag6_reasm: payload len = %d\n", payload_len);
|
|
goto out_fail;
|
|
out_oom:
|
|
if (net_ratelimit())
|
|
printk(KERN_DEBUG "nf_ct_frag6_reasm: no memory for reassembly\n");
|
|
out_fail:
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
u8 nexthdr = skb->nh.ipv6h->nexthdr;
|
|
u8 prev_nhoff = (u8 *)&skb->nh.ipv6h->nexthdr - skb->data;
|
|
int start = (u8 *)(skb->nh.ipv6h+1) - skb->data;
|
|
int len = skb->len - start;
|
|
u8 prevhdr = NEXTHDR_IPV6;
|
|
|
|
while (nexthdr != NEXTHDR_FRAGMENT) {
|
|
struct ipv6_opt_hdr hdr;
|
|
int hdrlen;
|
|
|
|
if (!ipv6_ext_hdr(nexthdr)) {
|
|
return -1;
|
|
}
|
|
if (len < (int)sizeof(struct ipv6_opt_hdr)) {
|
|
DEBUGP("too short\n");
|
|
return -1;
|
|
}
|
|
if (nexthdr == NEXTHDR_NONE) {
|
|
DEBUGP("next header is none\n");
|
|
return -1;
|
|
}
|
|
if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
|
|
BUG();
|
|
if (nexthdr == NEXTHDR_AUTH)
|
|
hdrlen = (hdr.hdrlen+2)<<2;
|
|
else
|
|
hdrlen = ipv6_optlen(&hdr);
|
|
|
|
prevhdr = nexthdr;
|
|
prev_nhoff = start;
|
|
|
|
nexthdr = hdr.nexthdr;
|
|
len -= hdrlen;
|
|
start += hdrlen;
|
|
}
|
|
|
|
if (len < 0)
|
|
return -1;
|
|
|
|
*prevhdrp = prevhdr;
|
|
*prevhoff = prev_nhoff;
|
|
*fhoff = start;
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb)
|
|
{
|
|
struct sk_buff *clone;
|
|
struct net_device *dev = skb->dev;
|
|
struct frag_hdr *fhdr;
|
|
struct nf_ct_frag6_queue *fq;
|
|
struct ipv6hdr *hdr;
|
|
int fhoff, nhoff;
|
|
u8 prevhdr;
|
|
struct sk_buff *ret_skb = NULL;
|
|
|
|
/* Jumbo payload inhibits frag. header */
|
|
if (skb->nh.ipv6h->payload_len == 0) {
|
|
DEBUGP("payload len = 0\n");
|
|
return skb;
|
|
}
|
|
|
|
if (find_prev_fhdr(skb, &prevhdr, &nhoff, &fhoff) < 0)
|
|
return skb;
|
|
|
|
clone = skb_clone(skb, GFP_ATOMIC);
|
|
if (clone == NULL) {
|
|
DEBUGP("Can't clone skb\n");
|
|
return skb;
|
|
}
|
|
|
|
NFCT_FRAG6_CB(clone)->orig = skb;
|
|
|
|
if (!pskb_may_pull(clone, fhoff + sizeof(*fhdr))) {
|
|
DEBUGP("message is too short.\n");
|
|
goto ret_orig;
|
|
}
|
|
|
|
clone->h.raw = clone->data + fhoff;
|
|
hdr = clone->nh.ipv6h;
|
|
fhdr = (struct frag_hdr *)clone->h.raw;
|
|
|
|
if (!(fhdr->frag_off & htons(0xFFF9))) {
|
|
DEBUGP("Invalid fragment offset\n");
|
|
/* It is not a fragmented frame */
|
|
goto ret_orig;
|
|
}
|
|
|
|
if (atomic_read(&nf_ct_frag6_mem) > nf_ct_frag6_high_thresh)
|
|
nf_ct_frag6_evictor();
|
|
|
|
fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr);
|
|
if (fq == NULL) {
|
|
DEBUGP("Can't find and can't create new queue\n");
|
|
goto ret_orig;
|
|
}
|
|
|
|
spin_lock(&fq->lock);
|
|
|
|
if (nf_ct_frag6_queue(fq, clone, fhdr, nhoff) < 0) {
|
|
spin_unlock(&fq->lock);
|
|
DEBUGP("Can't insert skb to queue\n");
|
|
fq_put(fq, NULL);
|
|
goto ret_orig;
|
|
}
|
|
|
|
if (fq->last_in == (FIRST_IN|LAST_IN) && fq->meat == fq->len) {
|
|
ret_skb = nf_ct_frag6_reasm(fq, dev);
|
|
if (ret_skb == NULL)
|
|
DEBUGP("Can't reassemble fragmented packets\n");
|
|
}
|
|
spin_unlock(&fq->lock);
|
|
|
|
fq_put(fq, NULL);
|
|
return ret_skb;
|
|
|
|
ret_orig:
|
|
kfree_skb(clone);
|
|
return skb;
|
|
}
|
|
|
|
void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb,
|
|
struct net_device *in, struct net_device *out,
|
|
int (*okfn)(struct sk_buff *))
|
|
{
|
|
struct sk_buff *s, *s2;
|
|
|
|
for (s = NFCT_FRAG6_CB(skb)->orig; s;) {
|
|
nf_conntrack_put_reasm(s->nfct_reasm);
|
|
nf_conntrack_get_reasm(skb);
|
|
s->nfct_reasm = skb;
|
|
|
|
s2 = s->next;
|
|
s->next = NULL;
|
|
|
|
NF_HOOK_THRESH(PF_INET6, hooknum, s, in, out, okfn,
|
|
NF_IP6_PRI_CONNTRACK_DEFRAG + 1);
|
|
s = s2;
|
|
}
|
|
nf_conntrack_put_reasm(skb);
|
|
}
|
|
|
|
int nf_ct_frag6_kfree_frags(struct sk_buff *skb)
|
|
{
|
|
struct sk_buff *s, *s2;
|
|
|
|
for (s = NFCT_FRAG6_CB(skb)->orig; s; s = s2) {
|
|
|
|
s2 = s->next;
|
|
kfree_skb(s);
|
|
}
|
|
|
|
kfree_skb(skb);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int nf_ct_frag6_init(void)
|
|
{
|
|
nf_ct_frag6_hash_rnd = (u32) ((num_physpages ^ (num_physpages>>7)) ^
|
|
(jiffies ^ (jiffies >> 6)));
|
|
|
|
init_timer(&nf_ct_frag6_secret_timer);
|
|
nf_ct_frag6_secret_timer.function = nf_ct_frag6_secret_rebuild;
|
|
nf_ct_frag6_secret_timer.expires = jiffies
|
|
+ nf_ct_frag6_secret_interval;
|
|
add_timer(&nf_ct_frag6_secret_timer);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void nf_ct_frag6_cleanup(void)
|
|
{
|
|
del_timer(&nf_ct_frag6_secret_timer);
|
|
nf_ct_frag6_low_thresh = 0;
|
|
nf_ct_frag6_evictor();
|
|
}
|