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[mirror_ubuntu-bionic-kernel.git] / 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 1024
45
46 /* averaged:
47 * max_depth = default ipfrag_high_thresh / INETFRAGS_HASHSZ /
48 * rounded up (SKB_TRUELEN(0) + sizeof(struct ipq or
49 * struct frag_queue))
50 */
51 #define INETFRAGS_MAXDEPTH 128
52
53 struct inet_frag_bucket {
54 struct hlist_head chain;
55 spinlock_t chain_lock;
56 };
57
58 struct inet_frags {
59 struct inet_frag_bucket hash[INETFRAGS_HASHSZ];
60 /* This rwlock is a global lock (seperate per IPv4, IPv6 and
61 * netfilter). Important to keep this on a seperate cacheline.
62 * Its primarily a rebuild protection rwlock.
63 */
64 rwlock_t lock ____cacheline_aligned_in_smp;
65 int secret_interval;
66 struct timer_list secret_timer;
67 u32 rnd;
68 int qsize;
69
70 unsigned int (*hashfn)(struct inet_frag_queue *);
71 bool (*match)(struct inet_frag_queue *q, void *arg);
72 void (*constructor)(struct inet_frag_queue *q,
73 void *arg);
74 void (*destructor)(struct inet_frag_queue *);
75 void (*skb_free)(struct sk_buff *);
76 void (*frag_expire)(unsigned long data);
77 };
78
79 void inet_frags_init(struct inet_frags *);
80 void inet_frags_fini(struct inet_frags *);
81
82 void inet_frags_init_net(struct netns_frags *nf);
83 void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f);
84
85 void inet_frag_kill(struct inet_frag_queue *q, struct inet_frags *f);
86 void inet_frag_destroy(struct inet_frag_queue *q,
87 struct inet_frags *f, int *work);
88 int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f, bool force);
89 struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
90 struct inet_frags *f, void *key, unsigned int hash)
91 __releases(&f->lock);
92 void inet_frag_maybe_warn_overflow(struct inet_frag_queue *q,
93 const char *prefix);
94
95 static inline void inet_frag_put(struct inet_frag_queue *q, struct inet_frags *f)
96 {
97 if (atomic_dec_and_test(&q->refcnt))
98 inet_frag_destroy(q, f, NULL);
99 }
100
101 /* Memory Tracking Functions. */
102
103 /* The default percpu_counter batch size is not big enough to scale to
104 * fragmentation mem acct sizes.
105 * The mem size of a 64K fragment is approx:
106 * (44 fragments * 2944 truesize) + frag_queue struct(200) = 129736 bytes
107 */
108 static unsigned int frag_percpu_counter_batch = 130000;
109
110 static inline int frag_mem_limit(struct netns_frags *nf)
111 {
112 return percpu_counter_read(&nf->mem);
113 }
114
115 static inline void sub_frag_mem_limit(struct inet_frag_queue *q, int i)
116 {
117 __percpu_counter_add(&q->net->mem, -i, frag_percpu_counter_batch);
118 }
119
120 static inline void add_frag_mem_limit(struct inet_frag_queue *q, int i)
121 {
122 __percpu_counter_add(&q->net->mem, i, frag_percpu_counter_batch);
123 }
124
125 static inline void init_frag_mem_limit(struct netns_frags *nf)
126 {
127 percpu_counter_init(&nf->mem, 0);
128 }
129
130 static inline int sum_frag_mem_limit(struct netns_frags *nf)
131 {
132 int res;
133
134 local_bh_disable();
135 res = percpu_counter_sum_positive(&nf->mem);
136 local_bh_enable();
137
138 return res;
139 }
140
141 static inline void inet_frag_lru_move(struct inet_frag_queue *q)
142 {
143 spin_lock(&q->net->lru_lock);
144 if (!list_empty(&q->lru_list))
145 list_move_tail(&q->lru_list, &q->net->lru_list);
146 spin_unlock(&q->net->lru_lock);
147 }
148
149 static inline void inet_frag_lru_del(struct inet_frag_queue *q)
150 {
151 spin_lock(&q->net->lru_lock);
152 list_del_init(&q->lru_list);
153 q->net->nqueues--;
154 spin_unlock(&q->net->lru_lock);
155 }
156
157 static inline void inet_frag_lru_add(struct netns_frags *nf,
158 struct inet_frag_queue *q)
159 {
160 spin_lock(&nf->lru_lock);
161 list_add_tail(&q->lru_list, &nf->lru_list);
162 q->net->nqueues++;
163 spin_unlock(&nf->lru_lock);
164 }
165
166 /* RFC 3168 support :
167 * We want to check ECN values of all fragments, do detect invalid combinations.
168 * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
169 */
170 #define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */
171 #define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */
172 #define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */
173 #define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */
174
175 extern const u8 ip_frag_ecn_table[16];
176
177 #endif