4 #include <linux/percpu_counter.h>
7 /* The percpu_counter "mem" need to be cacheline aligned.
8 * mem.count must not share cacheline with other writers
10 struct percpu_counter mem ____cacheline_aligned_in_smp;
18 struct inet_frag_queue {
20 struct timer_list timer; /* when will this queue expire? */
21 struct hlist_node list;
23 struct sk_buff *fragments; /* list of received fragments */
24 struct sk_buff *fragments_tail;
26 int len; /* total length of orig datagram */
28 __u8 last_in; /* first/last segment arrived? */
30 #define INET_FRAG_EVICTED 8
31 #define INET_FRAG_COMPLETE 4
32 #define INET_FRAG_FIRST_IN 2
33 #define INET_FRAG_LAST_IN 1
37 struct netns_frags *net;
40 #define INETFRAGS_HASHSZ 1024
43 * max_depth = default ipfrag_high_thresh / INETFRAGS_HASHSZ /
44 * rounded up (SKB_TRUELEN(0) + sizeof(struct ipq or
47 #define INETFRAGS_MAXDEPTH 128
49 struct inet_frag_bucket {
50 struct hlist_head chain;
51 spinlock_t chain_lock;
55 struct inet_frag_bucket hash[INETFRAGS_HASHSZ];
57 struct work_struct frags_work;
58 unsigned int next_bucket;
59 unsigned long last_rebuild_jiffies;
62 /* The first call to hashfn is responsible to initialize
63 * rnd. This is best done with net_get_random_once.
65 * rnd_seqlock is used to let hash insertion detect
66 * when it needs to re-lookup the hash chain to use.
69 seqlock_t rnd_seqlock;
72 unsigned int (*hashfn)(const struct inet_frag_queue *);
73 bool (*match)(const struct inet_frag_queue *q,
75 void (*constructor)(struct inet_frag_queue *q,
77 void (*destructor)(struct inet_frag_queue *);
78 void (*skb_free)(struct sk_buff *);
79 void (*frag_expire)(unsigned long data);
82 void inet_frags_init(struct inet_frags *);
83 void inet_frags_fini(struct inet_frags *);
85 void inet_frags_init_net(struct netns_frags *nf);
86 void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f);
88 void inet_frag_kill(struct inet_frag_queue *q, struct inet_frags *f);
89 void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f);
90 struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
91 struct inet_frags *f, void *key, unsigned int hash);
93 void inet_frag_maybe_warn_overflow(struct inet_frag_queue *q,
96 static inline void inet_frag_put(struct inet_frag_queue *q, struct inet_frags *f)
98 if (atomic_dec_and_test(&q->refcnt))
99 inet_frag_destroy(q, f);
102 /* Memory Tracking Functions. */
104 /* The default percpu_counter batch size is not big enough to scale to
105 * fragmentation mem acct sizes.
106 * The mem size of a 64K fragment is approx:
107 * (44 fragments * 2944 truesize) + frag_queue struct(200) = 129736 bytes
109 static unsigned int frag_percpu_counter_batch = 130000;
111 static inline int frag_mem_limit(struct netns_frags *nf)
113 return percpu_counter_read(&nf->mem);
116 static inline void sub_frag_mem_limit(struct inet_frag_queue *q, int i)
118 __percpu_counter_add(&q->net->mem, -i, frag_percpu_counter_batch);
121 static inline void add_frag_mem_limit(struct inet_frag_queue *q, int i)
123 __percpu_counter_add(&q->net->mem, i, frag_percpu_counter_batch);
126 static inline void init_frag_mem_limit(struct netns_frags *nf)
128 percpu_counter_init(&nf->mem, 0);
131 static inline unsigned int sum_frag_mem_limit(struct netns_frags *nf)
136 res = percpu_counter_sum_positive(&nf->mem);
142 /* RFC 3168 support :
143 * We want to check ECN values of all fragments, do detect invalid combinations.
144 * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
146 #define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */
147 #define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */
148 #define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */
149 #define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */
151 extern const u8 ip_frag_ecn_table[16];