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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1#ifndef __NET_FRAG_H__
2#define __NET_FRAG_H__
3
4#include <linux/percpu_counter.h>
5
6struct 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
22struct 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
46struct 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
66void inet_frags_init(struct inet_frags *);
67void inet_frags_fini(struct inet_frags *);
68
69void inet_frags_init_net(struct netns_frags *nf);
70void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f);
71
72void inet_frag_kill(struct inet_frag_queue *q, struct inet_frags *f);
73void inet_frag_destroy(struct inet_frag_queue *q,
74 struct inet_frags *f, int *work);
75int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f, bool force);
76struct 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
80static 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 */
93static unsigned int frag_percpu_counter_batch = 130000;
94
95static inline int frag_mem_limit(struct netns_frags *nf)
96{
97 return percpu_counter_read(&nf->mem);
98}
99
100static 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
105static 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
110static inline void init_frag_mem_limit(struct netns_frags *nf)
111{
112 percpu_counter_init(&nf->mem, 0);
113}
114
115static 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
126static 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
133static 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
140static 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