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15#ifndef _REQUEST_SOCK_H
16#define _REQUEST_SOCK_H
17
18#include <linux/slab.h>
19#include <linux/spinlock.h>
20#include <linux/types.h>
21#include <linux/bug.h>
22
23#include <net/sock.h>
24
25struct request_sock;
26struct sk_buff;
27struct dst_entry;
28struct proto;
29
30struct request_sock_ops {
31 int family;
32 int obj_size;
33 struct kmem_cache *slab;
34 char *slab_name;
35 int (*rtx_syn_ack)(struct sock *sk,
36 struct request_sock *req);
37 void (*send_ack)(struct sock *sk, struct sk_buff *skb,
38 struct request_sock *req);
39 void (*send_reset)(struct sock *sk,
40 struct sk_buff *skb);
41 void (*destructor)(struct request_sock *req);
42 void (*syn_ack_timeout)(const struct request_sock *req);
43};
44
45int inet_rtx_syn_ack(struct sock *parent, struct request_sock *req);
46
47
48
49struct request_sock {
50 struct sock_common __req_common;
51#define rsk_refcnt __req_common.skc_refcnt
52#define rsk_hash __req_common.skc_hash
53
54 struct request_sock *dl_next;
55 struct sock *rsk_listener;
56 u16 mss;
57 u8 num_retrans;
58 u8 cookie_ts:1;
59 u8 num_timeout:7;
60
61 u32 window_clamp;
62 u32 rcv_wnd;
63 u32 ts_recent;
64 struct timer_list rsk_timer;
65 const struct request_sock_ops *rsk_ops;
66 struct sock *sk;
67 u32 *saved_syn;
68 u32 secid;
69 u32 peer_secid;
70};
71
72static inline struct request_sock *
73reqsk_alloc(const struct request_sock_ops *ops, struct sock *sk_listener)
74{
75 struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC);
76
77 if (req) {
78 req->rsk_ops = ops;
79 sock_hold(sk_listener);
80 req->rsk_listener = sk_listener;
81 req->saved_syn = NULL;
82
83
84
85 atomic_set(&req->rsk_refcnt, 0);
86 }
87 return req;
88}
89
90static inline struct request_sock *inet_reqsk(struct sock *sk)
91{
92 return (struct request_sock *)sk;
93}
94
95static inline struct sock *req_to_sk(struct request_sock *req)
96{
97 return (struct sock *)req;
98}
99
100static inline void reqsk_free(struct request_sock *req)
101{
102
103 WARN_ON_ONCE(atomic_read(&req->rsk_refcnt) != 0);
104
105 req->rsk_ops->destructor(req);
106 if (req->rsk_listener)
107 sock_put(req->rsk_listener);
108 kfree(req->saved_syn);
109 kmem_cache_free(req->rsk_ops->slab, req);
110}
111
112static inline void reqsk_put(struct request_sock *req)
113{
114 if (atomic_dec_and_test(&req->rsk_refcnt))
115 reqsk_free(req);
116}
117
118extern int sysctl_max_syn_backlog;
119
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123
124struct listen_sock {
125 int qlen_inc;
126 int young_inc;
127
128
129 atomic_t qlen_dec;
130 atomic_t young_dec;
131
132 u8 max_qlen_log ____cacheline_aligned_in_smp;
133 u8 synflood_warned;
134
135 u32 hash_rnd;
136 u32 nr_table_entries;
137 struct request_sock *syn_table[0];
138};
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156
157struct fastopen_queue {
158 struct request_sock *rskq_rst_head;
159 struct request_sock *rskq_rst_tail;
160
161
162
163 spinlock_t lock;
164 int qlen;
165 int max_qlen;
166};
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178
179struct request_sock_queue {
180 struct request_sock *rskq_accept_head;
181 struct request_sock *rskq_accept_tail;
182 u8 rskq_defer_accept;
183 struct listen_sock *listen_opt;
184 struct fastopen_queue *fastopenq;
185
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191
192 spinlock_t syn_wait_lock ____cacheline_aligned_in_smp;
193};
194
195int reqsk_queue_alloc(struct request_sock_queue *queue,
196 unsigned int nr_table_entries);
197
198void __reqsk_queue_destroy(struct request_sock_queue *queue);
199void reqsk_queue_destroy(struct request_sock_queue *queue);
200void reqsk_fastopen_remove(struct sock *sk, struct request_sock *req,
201 bool reset);
202
203static inline struct request_sock *
204 reqsk_queue_yank_acceptq(struct request_sock_queue *queue)
205{
206 struct request_sock *req = queue->rskq_accept_head;
207
208 queue->rskq_accept_head = NULL;
209 return req;
210}
211
212static inline int reqsk_queue_empty(struct request_sock_queue *queue)
213{
214 return queue->rskq_accept_head == NULL;
215}
216
217static inline void reqsk_queue_add(struct request_sock_queue *queue,
218 struct request_sock *req,
219 struct sock *parent,
220 struct sock *child)
221{
222 req->sk = child;
223 sk_acceptq_added(parent);
224
225 if (queue->rskq_accept_head == NULL)
226 queue->rskq_accept_head = req;
227 else
228 queue->rskq_accept_tail->dl_next = req;
229
230 queue->rskq_accept_tail = req;
231 req->dl_next = NULL;
232}
233
234static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue)
235{
236 struct request_sock *req = queue->rskq_accept_head;
237
238 WARN_ON(req == NULL);
239
240 queue->rskq_accept_head = req->dl_next;
241 if (queue->rskq_accept_head == NULL)
242 queue->rskq_accept_tail = NULL;
243
244 return req;
245}
246
247static inline void reqsk_queue_removed(struct request_sock_queue *queue,
248 const struct request_sock *req)
249{
250 struct listen_sock *lopt = queue->listen_opt;
251
252 if (req->num_timeout == 0)
253 atomic_inc(&lopt->young_dec);
254 atomic_inc(&lopt->qlen_dec);
255}
256
257static inline void reqsk_queue_added(struct request_sock_queue *queue)
258{
259 struct listen_sock *lopt = queue->listen_opt;
260
261 lopt->young_inc++;
262 lopt->qlen_inc++;
263}
264
265static inline int listen_sock_qlen(const struct listen_sock *lopt)
266{
267 return lopt->qlen_inc - atomic_read(&lopt->qlen_dec);
268}
269
270static inline int listen_sock_young(const struct listen_sock *lopt)
271{
272 return lopt->young_inc - atomic_read(&lopt->young_dec);
273}
274
275static inline int reqsk_queue_len(const struct request_sock_queue *queue)
276{
277 const struct listen_sock *lopt = queue->listen_opt;
278
279 return lopt ? listen_sock_qlen(lopt) : 0;
280}
281
282static inline int reqsk_queue_len_young(const struct request_sock_queue *queue)
283{
284 return listen_sock_young(queue->listen_opt);
285}
286
287static inline int reqsk_queue_is_full(const struct request_sock_queue *queue)
288{
289 return reqsk_queue_len(queue) >> queue->listen_opt->max_qlen_log;
290}
291
292void reqsk_queue_hash_req(struct request_sock_queue *queue,
293 u32 hash, struct request_sock *req,
294 unsigned long timeout);
295
296#endif
297