include/net/ipv6_frag.h

   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
   9 enum 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  */
  22 struct 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)
  31 static 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
  40 static 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
  46 static 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
  54 static inline int
  55 ip6frag_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
  63 static inline void
  64 ip6frag_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         spin_lock(&fq->q.lock);
  71
  72         if (fq->q.flags & INET_FRAG_COMPLETE)
  73                 goto out;
  74
  75         inet_frag_kill(&fq->q);
  76
  77         dev = dev_get_by_index_rcu(net, fq->iif);
  78         if (!dev)
  79                 goto out;
  80
  81         __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
  82         __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
  83
  84         /* Don't send error if the first segment did not arrive. */
  85         if (!(fq->q.flags & INET_FRAG_FIRST_IN))
  86                 goto out;
  87
  88         /* sk_buff::dev and sk_buff::rbnode are unionized. So we
  89          * pull the head out of the tree in order to be able to
  90          * deal with head->dev.
  91          */
  92         head = inet_frag_pull_head(&fq->q);
  93         if (!head)
  94                 goto out;
  95
  96         head->dev = dev;
  97         skb_get(head);
  98         spin_unlock(&fq->q.lock);
  99
 100         icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
 101         kfree_skb(head);
 102         goto out_rcu_unlock;
 103
 104 out:
 105         spin_unlock(&fq->q.lock);
 106 out_rcu_unlock:
 107         rcu_read_unlock();
 108         inet_frag_put(&fq->q);
 109 }
 110 #endif
 111 #endif