include/net/inet_frag.h

   1 #ifndef __NET_FRAG_H__
   2 #define __NET_FRAG_H__
   3
   4 struct netns_frags {
   5         int                     nqueues;
   6         atomic_t                mem;
   7         struct list_head        lru_list;
   8
   9         /* sysctls */
  10         int                     timeout;
  11         int                     high_thresh;
  12         int                     low_thresh;
  13 };
  14
  15 struct inet_frag_queue {
  16         struct hlist_node       list;
  17         struct netns_frags      *net;
  18         struct list_head        lru_list;   /* lru list member */
  19         spinlock_t              lock;
  20         atomic_t                refcnt;
  21         struct timer_list       timer;      /* when will this queue expire? */
  22         struct sk_buff          *fragments; /* list of received fragments */
  23         struct sk_buff          *fragments_tail;
  24         ktime_t                 stamp;
  25         int                     len;        /* total length of orig datagram */
  26         int                     meat;
  27         __u8                    last_in;    /* first/last segment arrived? */
  28
  29 #define INET_FRAG_COMPLETE      4
  30 #define INET_FRAG_FIRST_IN      2
  31 #define INET_FRAG_LAST_IN       1
  32 };
  33
  34 #define INETFRAGS_HASHSZ                64
  35
  36 /* averaged:
  37  * max_depth = default ipfrag_high_thresh / INETFRAGS_HASHSZ /
  38  *             rounded up (SKB_TRUELEN(0) + sizeof(struct ipq or
  39  *             struct frag_queue))
  40  */
  41 #define INETFRAGS_MAXDEPTH              128
  42
  43 struct inet_frags {
  44         struct hlist_head       hash[INETFRAGS_HASHSZ];
  45         rwlock_t                lock;
  46         u32                     rnd;
  47         int                     qsize;
  48         int                     secret_interval;
  49         struct timer_list       secret_timer;
  50
  51         unsigned int            (*hashfn)(struct inet_frag_queue *);
  52         void                    (*constructor)(struct inet_frag_queue *q,
  53                                                 void *arg);
  54         void                    (*destructor)(struct inet_frag_queue *);
  55         void                    (*skb_free)(struct sk_buff *);
  56         int                     (*match)(struct inet_frag_queue *q,
  57                                                 void *arg);
  58         void                    (*frag_expire)(unsigned long data);
  59 };
  60
  61 void inet_frags_init(struct inet_frags *);
  62 void inet_frags_fini(struct inet_frags *);
  63
  64 void inet_frags_init_net(struct netns_frags *nf);
  65 void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f);
  66
  67 void inet_frag_kill(struct inet_frag_queue *q, struct inet_frags *f);
  68 void inet_frag_destroy(struct inet_frag_queue *q,
  69                                 struct inet_frags *f, int *work);
  70 int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f);
  71 struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
  72                 struct inet_frags *f, void *key, unsigned int hash)
  73         __releases(&f->lock);
  74 void inet_frag_maybe_warn_overflow(struct inet_frag_queue *q,
  75                                    const char *prefix);
  76
  77 static inline void inet_frag_put(struct inet_frag_queue *q, struct inet_frags *f)
  78 {
  79         if (atomic_dec_and_test(&q->refcnt))
  80                 inet_frag_destroy(q, f, NULL);
  81 }
  82
  83 #endif