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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)(struct sock *sk,
43 struct request_sock *req);
44};
45
46extern int inet_rtx_syn_ack(struct sock *parent, struct request_sock *req);
47
48
49
50struct request_sock {
51 struct request_sock *dl_next;
52 u16 mss;
53 u8 num_retrans;
54 u8 cookie_ts:1;
55 u8 num_timeout:7;
56
57 u32 window_clamp;
58 u32 rcv_wnd;
59 u32 ts_recent;
60 unsigned long expires;
61 const struct request_sock_ops *rsk_ops;
62 struct sock *sk;
63 u32 secid;
64 u32 peer_secid;
65};
66
67static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops)
68{
69 struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC);
70
71 if (req != NULL)
72 req->rsk_ops = ops;
73
74 return req;
75}
76
77static inline void __reqsk_free(struct request_sock *req)
78{
79 kmem_cache_free(req->rsk_ops->slab, req);
80}
81
82static inline void reqsk_free(struct request_sock *req)
83{
84 req->rsk_ops->destructor(req);
85 __reqsk_free(req);
86}
87
88extern int sysctl_max_syn_backlog;
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93
94struct listen_sock {
95 u8 max_qlen_log;
96 u8 synflood_warned;
97
98 int qlen;
99 int qlen_young;
100 int clock_hand;
101 u32 hash_rnd;
102 u32 nr_table_entries;
103 struct request_sock *syn_table[0];
104};
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123struct fastopen_queue {
124 struct request_sock *rskq_rst_head;
125 struct request_sock *rskq_rst_tail;
126
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129 spinlock_t lock;
130 int qlen;
131 int max_qlen;
132};
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149
150struct request_sock_queue {
151 struct request_sock *rskq_accept_head;
152 struct request_sock *rskq_accept_tail;
153 rwlock_t syn_wait_lock;
154 u8 rskq_defer_accept;
155
156 struct listen_sock *listen_opt;
157 struct fastopen_queue *fastopenq;
158
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162
163};
164
165extern int reqsk_queue_alloc(struct request_sock_queue *queue,
166 unsigned int nr_table_entries);
167
168extern void __reqsk_queue_destroy(struct request_sock_queue *queue);
169extern void reqsk_queue_destroy(struct request_sock_queue *queue);
170extern void reqsk_fastopen_remove(struct sock *sk,
171 struct request_sock *req, bool reset);
172
173static inline struct request_sock *
174 reqsk_queue_yank_acceptq(struct request_sock_queue *queue)
175{
176 struct request_sock *req = queue->rskq_accept_head;
177
178 queue->rskq_accept_head = NULL;
179 return req;
180}
181
182static inline int reqsk_queue_empty(struct request_sock_queue *queue)
183{
184 return queue->rskq_accept_head == NULL;
185}
186
187static inline void reqsk_queue_unlink(struct request_sock_queue *queue,
188 struct request_sock *req,
189 struct request_sock **prev_req)
190{
191 write_lock(&queue->syn_wait_lock);
192 *prev_req = req->dl_next;
193 write_unlock(&queue->syn_wait_lock);
194}
195
196static inline void reqsk_queue_add(struct request_sock_queue *queue,
197 struct request_sock *req,
198 struct sock *parent,
199 struct sock *child)
200{
201 req->sk = child;
202 sk_acceptq_added(parent);
203
204 if (queue->rskq_accept_head == NULL)
205 queue->rskq_accept_head = req;
206 else
207 queue->rskq_accept_tail->dl_next = req;
208
209 queue->rskq_accept_tail = req;
210 req->dl_next = NULL;
211}
212
213static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue)
214{
215 struct request_sock *req = queue->rskq_accept_head;
216
217 WARN_ON(req == NULL);
218
219 queue->rskq_accept_head = req->dl_next;
220 if (queue->rskq_accept_head == NULL)
221 queue->rskq_accept_tail = NULL;
222
223 return req;
224}
225
226static inline int reqsk_queue_removed(struct request_sock_queue *queue,
227 struct request_sock *req)
228{
229 struct listen_sock *lopt = queue->listen_opt;
230
231 if (req->num_timeout == 0)
232 --lopt->qlen_young;
233
234 return --lopt->qlen;
235}
236
237static inline int reqsk_queue_added(struct request_sock_queue *queue)
238{
239 struct listen_sock *lopt = queue->listen_opt;
240 const int prev_qlen = lopt->qlen;
241
242 lopt->qlen_young++;
243 lopt->qlen++;
244 return prev_qlen;
245}
246
247static inline int reqsk_queue_len(const struct request_sock_queue *queue)
248{
249 return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0;
250}
251
252static inline int reqsk_queue_len_young(const struct request_sock_queue *queue)
253{
254 return queue->listen_opt->qlen_young;
255}
256
257static inline int reqsk_queue_is_full(const struct request_sock_queue *queue)
258{
259 return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log;
260}
261
262static inline void reqsk_queue_hash_req(struct request_sock_queue *queue,
263 u32 hash, struct request_sock *req,
264 unsigned long timeout)
265{
266 struct listen_sock *lopt = queue->listen_opt;
267
268 req->expires = jiffies + timeout;
269 req->num_retrans = 0;
270 req->num_timeout = 0;
271 req->sk = NULL;
272 req->dl_next = lopt->syn_table[hash];
273
274 write_lock(&queue->syn_wait_lock);
275 lopt->syn_table[hash] = req;
276 write_unlock(&queue->syn_wait_lock);
277}
278
279#endif
280