LXR linux/include/net/ipv6

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _IPV6_FRAG_H
   3#define _IPV6_FRAG_H
   4#include <linux/kernel.h>
   5#include <net/addrconf.h>
   6#include <net/ipv6.h>
   7#include <net/inet_frag.h>
   8
   9enum ip6_defrag_users {
  10        IP6_DEFRAG_LOCAL_DELIVER,
  11        IP6_DEFRAG_CONNTRACK_IN,
  12        __IP6_DEFRAG_CONNTRACK_IN       = IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
  13        IP6_DEFRAG_CONNTRACK_OUT,
  14        __IP6_DEFRAG_CONNTRACK_OUT      = IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
  15        IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
  16        __IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
  17};
  18
  19/*
  20 *      Equivalent of ipv4 struct ip
  21 */
  22struct frag_queue {
  23        struct inet_frag_queue  q;
  24
  25        int                     iif;
  26        __u16                   nhoffset;
  27        u8                      ecn;
  28};
  29
  30#if IS_ENABLED(CONFIG_IPV6)
  31static inline void ip6frag_init(struct inet_frag_queue *q, const void *a)
  32{
  33        struct frag_queue *fq = container_of(q, struct frag_queue, q);
  34        const struct frag_v6_compare_key *key = a;
  35
  36        q->key.v6 = *key;
  37        fq->ecn = 0;
  38}
  39
  40static inline u32 ip6frag_key_hashfn(const void *data, u32 len, u32 seed)
  41{
  42        return jhash2(data,
  43                      sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
  44}
  45
  46static inline u32 ip6frag_obj_hashfn(const void *data, u32 len, u32 seed)
  47{
  48        const struct inet_frag_queue *fq = data;
  49
  50        return jhash2((const u32 *)&fq->key.v6,
  51                      sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
  52}
  53
  54static inline int
  55ip6frag_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
  56{
  57        const struct frag_v6_compare_key *key = arg->key;
  58        const struct inet_frag_queue *fq = ptr;
  59
  60        return !!memcmp(&fq->key, key, sizeof(*key));
  61}
  62
  63static inline void
  64ip6frag_expire_frag_queue(struct net *net, struct frag_queue *fq)
  65{
  66        struct net_device *dev = NULL;
  67        struct sk_buff *head;
  68
  69        rcu_read_lock();
  70        if (fq->q.fqdir->dead)
  71                goto out_rcu_unlock;
  72        spin_lock(&fq->q.lock);
  73
  74        if (fq->q.flags & INET_FRAG_COMPLETE)
  75                goto out;
  76
  77        inet_frag_kill(&fq->q);
  78
  79        dev = dev_get_by_index_rcu(net, fq->iif);
  80        if (!dev)
  81                goto out;
  82
  83        __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
  84        __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
  85
  86        /* Don't send error if the first segment did not arrive. */
  87        if (!(fq->q.flags & INET_FRAG_FIRST_IN))
  88                goto out;
  89
  90        /* sk_buff::dev and sk_buff::rbnode are unionized. So we
  91         * pull the head out of the tree in order to be able to
  92         * deal with head->dev.
  93         */
  94        head = inet_frag_pull_head(&fq->q);
  95        if (!head)
  96                goto out;
  97
  98        head->dev = dev;
  99        spin_unlock(&fq->q.lock);
 100
 101        icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
 102        kfree_skb(head);
 103        goto out_rcu_unlock;
 104
 105out:
 106        spin_unlock(&fq->q.lock);
 107out_rcu_unlock:
 108        rcu_read_unlock();
 109        inet_frag_put(&fq->q);
 110}
 111
 112/* Check if the upper layer header is truncated in the first fragment. */
 113static inline bool
 114ipv6frag_thdr_truncated(struct sk_buff *skb, int start, u8 *nexthdrp)
 115{
 116        u8 nexthdr = *nexthdrp;
 117        __be16 frag_off;
 118        int offset;
 119
 120        offset = ipv6_skip_exthdr(skb, start, &nexthdr, &frag_off);
 121        if (offset < 0 || (frag_off & htons(IP6_OFFSET)))
 122                return false;
 123        switch (nexthdr) {
 124        case NEXTHDR_TCP:
 125                offset += sizeof(struct tcphdr);
 126                break;
 127        case NEXTHDR_UDP:
 128                offset += sizeof(struct udphdr);
 129                break;
 130        case NEXTHDR_ICMP:
 131                offset += sizeof(struct icmp6hdr);
 132                break;
 133        default:
 134                offset += 1;
 135        }
 136        if (offset > skb->len)
 137                return true;
 138        return false;
 139}
 140
 141#endif
 142#endif
 143