include/net/inet_frag.h

   1 #ifndef __NET_FRAG_H__
   2 #define __NET_FRAG_H__
   3
   4 #include <linux/percpu_counter.h>
   5
   6 struct netns_frags {
   7         int                     nqueues;
   8         struct list_head        lru_list;
   9         spinlock_t              lru_lock;
  10
  11         /* The percpu_counter "mem" need to be cacheline aligned.
  12          *  mem.count must not share cacheline with other writers
  13          */
  14         struct percpu_counter   mem ____cacheline_aligned_in_smp;
  15
  16         /* sysctls */
  17         int                     timeout;
  18         int                     high_thresh;
  19         int                     low_thresh;
  20 };
  21
  22 struct inet_frag_queue {
  23         spinlock_t              lock;
  24         struct timer_list       timer;      /* when will this queue expire? */
  25         struct list_head        lru_list;   /* lru list member */
  26         struct hlist_node       list;
  27         atomic_t                refcnt;
  28         struct sk_buff          *fragments; /* list of received fragments */
  29         struct sk_buff          *fragments_tail;
  30         ktime_t                 stamp;
  31         int                     len;        /* total length of orig datagram */
  32         int                     meat;
  33         __u8                    last_in;    /* first/last segment arrived? */
  34
  35 #define INET_FRAG_COMPLETE      4
  36 #define INET_FRAG_FIRST_IN      2
  37 #define INET_FRAG_LAST_IN       1
  38
  39         u16                     max_size;
  40
  41         struct netns_frags      *net;
  42 };
  43
  44 #define INETFRAGS_HASHSZ                64
  45
  46 struct inet_frags {
  47         struct hlist_head       hash[INETFRAGS_HASHSZ];
  48         /* This rwlock is a global lock (seperate per IPv4, IPv6 and
  49          * netfilter). Important to keep this on a seperate cacheline.
  50          */
  51         rwlock_t                lock ____cacheline_aligned_in_smp;
  52         int                     secret_interval;
  53         struct timer_list       secret_timer;
  54         u32                     rnd;
  55         int                     qsize;
  56
  57         unsigned int            (*hashfn)(struct inet_frag_queue *);
  58         bool                    (*match)(struct inet_frag_queue *q, void *arg);
  59         void                    (*constructor)(struct inet_frag_queue *q,
  60                                                 void *arg);
  61         void                    (*destructor)(struct inet_frag_queue *);
  62         void                    (*skb_free)(struct sk_buff *);
  63         void                    (*frag_expire)(unsigned long data);
  64 };
  65
  66 void inet_frags_init(struct inet_frags *);
  67 void inet_frags_fini(struct inet_frags *);
  68
  69 void inet_frags_init_net(struct netns_frags *nf);
  70 void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f);
  71
  72 void inet_frag_kill(struct inet_frag_queue *q, struct inet_frags *f);
  73 void inet_frag_destroy(struct inet_frag_queue *q,
  74                                 struct inet_frags *f, int *work);
  75 int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f, bool force);
  76 struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
  77                 struct inet_frags *f, void *key, unsigned int hash)
  78         __releases(&f->lock);
  79
  80 static inline void inet_frag_put(struct inet_frag_queue *q, struct inet_frags *f)
  81 {
  82         if (atomic_dec_and_test(&q->refcnt))
  83                 inet_frag_destroy(q, f, NULL);
  84 }
  85
  86 /* Memory Tracking Functions. */
  87
  88 /* The default percpu_counter batch size is not big enough to scale to
  89  * fragmentation mem acct sizes.
  90  * The mem size of a 64K fragment is approx:
  91  *  (44 fragments * 2944 truesize) + frag_queue struct(200) = 129736 bytes
  92  */
  93 static unsigned int frag_percpu_counter_batch = 130000;
  94
  95 static inline int frag_mem_limit(struct netns_frags *nf)
  96 {
  97         return percpu_counter_read(&nf->mem);
  98 }
  99
 100 static inline void sub_frag_mem_limit(struct inet_frag_queue *q, int i)
 101 {
 102         __percpu_counter_add(&q->net->mem, -i, frag_percpu_counter_batch);
 103 }
 104
 105 static inline void add_frag_mem_limit(struct inet_frag_queue *q, int i)
 106 {
 107         __percpu_counter_add(&q->net->mem, i, frag_percpu_counter_batch);
 108 }
 109
 110 static inline void init_frag_mem_limit(struct netns_frags *nf)
 111 {
 112         percpu_counter_init(&nf->mem, 0);
 113 }
 114
 115 static inline int sum_frag_mem_limit(struct netns_frags *nf)
 116 {
 117         int res;
 118
 119         local_bh_disable();
 120         res = percpu_counter_sum_positive(&nf->mem);
 121         local_bh_enable();
 122
 123         return res;
 124 }
 125
 126 static inline void inet_frag_lru_move(struct inet_frag_queue *q)
 127 {
 128         spin_lock(&q->net->lru_lock);
 129         list_move_tail(&q->lru_list, &q->net->lru_list);
 130         spin_unlock(&q->net->lru_lock);
 131 }
 132
 133 static inline void inet_frag_lru_del(struct inet_frag_queue *q)
 134 {
 135         spin_lock(&q->net->lru_lock);
 136         list_del(&q->lru_list);
 137         spin_unlock(&q->net->lru_lock);
 138 }
 139
 140 static inline void inet_frag_lru_add(struct netns_frags *nf,
 141                                      struct inet_frag_queue *q)
 142 {
 143         spin_lock(&nf->lru_lock);
 144         list_add_tail(&q->lru_list, &nf->lru_list);
 145         spin_unlock(&nf->lru_lock);
 146 }
 147 #endif