146 строки
3.4 KiB
C
146 строки
3.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _IPV6_FRAG_H
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#define _IPV6_FRAG_H
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#include <linux/icmpv6.h>
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#include <linux/kernel.h>
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#include <net/addrconf.h>
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#include <net/ipv6.h>
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#include <net/inet_frag.h>
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enum ip6_defrag_users {
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IP6_DEFRAG_LOCAL_DELIVER,
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IP6_DEFRAG_CONNTRACK_IN,
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__IP6_DEFRAG_CONNTRACK_IN = IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
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IP6_DEFRAG_CONNTRACK_OUT,
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__IP6_DEFRAG_CONNTRACK_OUT = IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
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IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
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__IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
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};
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/*
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* Equivalent of ipv4 struct ip
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*/
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struct frag_queue {
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struct inet_frag_queue q;
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int iif;
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__u16 nhoffset;
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u8 ecn;
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};
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#if IS_ENABLED(CONFIG_IPV6)
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static inline void ip6frag_init(struct inet_frag_queue *q, const void *a)
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{
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struct frag_queue *fq = container_of(q, struct frag_queue, q);
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const struct frag_v6_compare_key *key = a;
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q->key.v6 = *key;
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fq->ecn = 0;
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}
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static inline u32 ip6frag_key_hashfn(const void *data, u32 len, u32 seed)
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{
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return jhash2(data,
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sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
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}
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static inline u32 ip6frag_obj_hashfn(const void *data, u32 len, u32 seed)
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{
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const struct inet_frag_queue *fq = data;
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return jhash2((const u32 *)&fq->key.v6,
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sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
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}
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static inline int
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ip6frag_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
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{
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const struct frag_v6_compare_key *key = arg->key;
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const struct inet_frag_queue *fq = ptr;
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return !!memcmp(&fq->key, key, sizeof(*key));
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}
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static inline void
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ip6frag_expire_frag_queue(struct net *net, struct frag_queue *fq)
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{
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struct net_device *dev = NULL;
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struct sk_buff *head;
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rcu_read_lock();
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/* Paired with the WRITE_ONCE() in fqdir_pre_exit(). */
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if (READ_ONCE(fq->q.fqdir->dead))
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goto out_rcu_unlock;
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spin_lock(&fq->q.lock);
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if (fq->q.flags & INET_FRAG_COMPLETE)
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goto out;
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fq->q.flags |= INET_FRAG_DROP;
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inet_frag_kill(&fq->q);
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dev = dev_get_by_index_rcu(net, fq->iif);
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if (!dev)
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goto out;
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__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
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__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
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/* Don't send error if the first segment did not arrive. */
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if (!(fq->q.flags & INET_FRAG_FIRST_IN))
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goto out;
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/* sk_buff::dev and sk_buff::rbnode are unionized. So we
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* pull the head out of the tree in order to be able to
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* deal with head->dev.
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*/
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head = inet_frag_pull_head(&fq->q);
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if (!head)
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goto out;
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head->dev = dev;
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spin_unlock(&fq->q.lock);
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icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
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kfree_skb_reason(head, SKB_DROP_REASON_FRAG_REASM_TIMEOUT);
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goto out_rcu_unlock;
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out:
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spin_unlock(&fq->q.lock);
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out_rcu_unlock:
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rcu_read_unlock();
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inet_frag_put(&fq->q);
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}
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/* Check if the upper layer header is truncated in the first fragment. */
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static inline bool
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ipv6frag_thdr_truncated(struct sk_buff *skb, int start, u8 *nexthdrp)
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{
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u8 nexthdr = *nexthdrp;
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__be16 frag_off;
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int offset;
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offset = ipv6_skip_exthdr(skb, start, &nexthdr, &frag_off);
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if (offset < 0 || (frag_off & htons(IP6_OFFSET)))
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return false;
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switch (nexthdr) {
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case NEXTHDR_TCP:
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offset += sizeof(struct tcphdr);
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break;
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case NEXTHDR_UDP:
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offset += sizeof(struct udphdr);
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break;
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case NEXTHDR_ICMP:
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offset += sizeof(struct icmp6hdr);
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break;
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default:
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offset += 1;
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}
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if (offset > skb->len)
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return true;
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return false;
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}
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#endif
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#endif
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