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];
56 /* This rwlock is a global lock (seperate per IPv4, IPv6 and
57 * netfilter). Important to keep this on a seperate cacheline.
58 * Its primarily a rebuild protection rwlock.
60 rwlock_t lock ____cacheline_aligned_in_smp;
62 struct timer_list secret_timer;
64 struct work_struct frags_work;
65 unsigned int next_bucket;
67 /* The first call to hashfn is responsible to initialize
68 * rnd. This is best done with net_get_random_once.
73 unsigned int (*hashfn)(const struct inet_frag_queue *);
74 bool (*match)(const struct inet_frag_queue *q,
76 void (*constructor)(struct inet_frag_queue *q,
78 void (*destructor)(struct inet_frag_queue *);
79 void (*skb_free)(struct sk_buff *);
80 void (*frag_expire)(unsigned long data);
83 void inet_frags_init(struct inet_frags *);
84 void inet_frags_fini(struct inet_frags *);
86 void inet_frags_init_net(struct netns_frags *nf);
87 void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f);
89 void inet_frag_kill(struct inet_frag_queue *q, struct inet_frags *f);
90 void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f);
91 struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
92 struct inet_frags *f, void *key, unsigned int hash)
94 void inet_frag_maybe_warn_overflow(struct inet_frag_queue *q,
97 static inline void inet_frag_put(struct inet_frag_queue *q, struct inet_frags *f)
99 if (atomic_dec_and_test(&q->refcnt))
100 inet_frag_destroy(q, f);
103 /* Memory Tracking Functions. */
105 /* The default percpu_counter batch size is not big enough to scale to
106 * fragmentation mem acct sizes.
107 * The mem size of a 64K fragment is approx:
108 * (44 fragments * 2944 truesize) + frag_queue struct(200) = 129736 bytes
110 static unsigned int frag_percpu_counter_batch = 130000;
112 static inline int frag_mem_limit(struct netns_frags *nf)
114 return percpu_counter_read(&nf->mem);
117 static inline void sub_frag_mem_limit(struct inet_frag_queue *q, int i)
119 __percpu_counter_add(&q->net->mem, -i, frag_percpu_counter_batch);
122 static inline void add_frag_mem_limit(struct inet_frag_queue *q, int i)
124 __percpu_counter_add(&q->net->mem, i, frag_percpu_counter_batch);
127 static inline void init_frag_mem_limit(struct netns_frags *nf)
129 percpu_counter_init(&nf->mem, 0);
132 static inline unsigned int sum_frag_mem_limit(struct netns_frags *nf)
137 res = percpu_counter_sum_positive(&nf->mem);
143 /* RFC 3168 support :
144 * We want to check ECN values of all fragments, do detect invalid combinations.
145 * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
147 #define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */
148 #define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */
149 #define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */
150 #define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */
152 extern const u8 ip_frag_ecn_table[16];