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-rw-r--r--include/net/request_sock.h255
1 files changed, 255 insertions, 0 deletions
diff --git a/include/net/request_sock.h b/include/net/request_sock.h
new file mode 100644
index 000000000000..72fd6f5e86b1
--- /dev/null
+++ b/include/net/request_sock.h
@@ -0,0 +1,255 @@
1/*
2 * NET Generic infrastructure for Network protocols.
3 *
4 * Definitions for request_sock
5 *
6 * Authors: Arnaldo Carvalho de Melo <acme@conectiva.com.br>
7 *
8 * From code originally in include/net/tcp.h
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 */
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
22#include <net/sock.h>
23
24struct request_sock;
25struct sk_buff;
26struct dst_entry;
27struct proto;
28
29struct request_sock_ops {
30 int family;
31 kmem_cache_t *slab;
32 int obj_size;
33 int (*rtx_syn_ack)(struct sock *sk,
34 struct request_sock *req,
35 struct dst_entry *dst);
36 void (*send_ack)(struct sk_buff *skb,
37 struct request_sock *req);
38 void (*send_reset)(struct sk_buff *skb);
39 void (*destructor)(struct request_sock *req);
40};
41
42/* struct request_sock - mini sock to represent a connection request
43 */
44struct request_sock {
45 struct request_sock *dl_next; /* Must be first member! */
46 u16 mss;
47 u8 retrans;
48 u8 __pad;
49 /* The following two fields can be easily recomputed I think -AK */
50 u32 window_clamp; /* window clamp at creation time */
51 u32 rcv_wnd; /* rcv_wnd offered first time */
52 u32 ts_recent;
53 unsigned long expires;
54 struct request_sock_ops *rsk_ops;
55 struct sock *sk;
56};
57
58static inline struct request_sock *reqsk_alloc(struct request_sock_ops *ops)
59{
60 struct request_sock *req = kmem_cache_alloc(ops->slab, SLAB_ATOMIC);
61
62 if (req != NULL)
63 req->rsk_ops = ops;
64
65 return req;
66}
67
68static inline void __reqsk_free(struct request_sock *req)
69{
70 kmem_cache_free(req->rsk_ops->slab, req);
71}
72
73static inline void reqsk_free(struct request_sock *req)
74{
75 req->rsk_ops->destructor(req);
76 __reqsk_free(req);
77}
78
79extern int sysctl_max_syn_backlog;
80
81/** struct listen_sock - listen state
82 *
83 * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs
84 */
85struct listen_sock {
86 u8 max_qlen_log;
87 /* 3 bytes hole, try to use */
88 int qlen;
89 int qlen_young;
90 int clock_hand;
91 u32 hash_rnd;
92 struct request_sock *syn_table[0];
93};
94
95/** struct request_sock_queue - queue of request_socks
96 *
97 * @rskq_accept_head - FIFO head of established children
98 * @rskq_accept_tail - FIFO tail of established children
99 * @syn_wait_lock - serializer
100 *
101 * %syn_wait_lock is necessary only to avoid proc interface having to grab the main
102 * lock sock while browsing the listening hash (otherwise it's deadlock prone).
103 *
104 * This lock is acquired in read mode only from listening_get_next() seq_file
105 * op and it's acquired in write mode _only_ from code that is actively
106 * changing rskq_accept_head. All readers that are holding the master sock lock
107 * don't need to grab this lock in read mode too as rskq_accept_head. writes
108 * are always protected from the main sock lock.
109 */
110struct request_sock_queue {
111 struct request_sock *rskq_accept_head;
112 struct request_sock *rskq_accept_tail;
113 rwlock_t syn_wait_lock;
114 struct listen_sock *listen_opt;
115};
116
117extern int reqsk_queue_alloc(struct request_sock_queue *queue,
118 const int nr_table_entries);
119
120static inline struct listen_sock *reqsk_queue_yank_listen_sk(struct request_sock_queue *queue)
121{
122 struct listen_sock *lopt;
123
124 write_lock_bh(&queue->syn_wait_lock);
125 lopt = queue->listen_opt;
126 queue->listen_opt = NULL;
127 write_unlock_bh(&queue->syn_wait_lock);
128
129 return lopt;
130}
131
132static inline void reqsk_queue_destroy(struct request_sock_queue *queue)
133{
134 kfree(reqsk_queue_yank_listen_sk(queue));
135}
136
137static inline struct request_sock *
138 reqsk_queue_yank_acceptq(struct request_sock_queue *queue)
139{
140 struct request_sock *req = queue->rskq_accept_head;
141
142 queue->rskq_accept_head = queue->rskq_accept_head = NULL;
143 return req;
144}
145
146static inline int reqsk_queue_empty(struct request_sock_queue *queue)
147{
148 return queue->rskq_accept_head == NULL;
149}
150
151static inline void reqsk_queue_unlink(struct request_sock_queue *queue,
152 struct request_sock *req,
153 struct request_sock **prev_req)
154{
155 write_lock(&queue->syn_wait_lock);
156 *prev_req = req->dl_next;
157 write_unlock(&queue->syn_wait_lock);
158}
159
160static inline void reqsk_queue_add(struct request_sock_queue *queue,
161 struct request_sock *req,
162 struct sock *parent,
163 struct sock *child)
164{
165 req->sk = child;
166 sk_acceptq_added(parent);
167
168 if (queue->rskq_accept_head == NULL)
169 queue->rskq_accept_head = req;
170 else
171 queue->rskq_accept_tail->dl_next = req;
172
173 queue->rskq_accept_tail = req;
174 req->dl_next = NULL;
175}
176
177static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue)
178{
179 struct request_sock *req = queue->rskq_accept_head;
180
181 BUG_TRAP(req != NULL);
182
183 queue->rskq_accept_head = req->dl_next;
184 if (queue->rskq_accept_head == NULL)
185 queue->rskq_accept_tail = NULL;
186
187 return req;
188}
189
190static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue,
191 struct sock *parent)
192{
193 struct request_sock *req = reqsk_queue_remove(queue);
194 struct sock *child = req->sk;
195
196 BUG_TRAP(child != NULL);
197
198 sk_acceptq_removed(parent);
199 __reqsk_free(req);
200 return child;
201}
202
203static inline int reqsk_queue_removed(struct request_sock_queue *queue,
204 struct request_sock *req)
205{
206 struct listen_sock *lopt = queue->listen_opt;
207
208 if (req->retrans == 0)
209 --lopt->qlen_young;
210
211 return --lopt->qlen;
212}
213
214static inline int reqsk_queue_added(struct request_sock_queue *queue)
215{
216 struct listen_sock *lopt = queue->listen_opt;
217 const int prev_qlen = lopt->qlen;
218
219 lopt->qlen_young++;
220 lopt->qlen++;
221 return prev_qlen;
222}
223
224static inline int reqsk_queue_len(struct request_sock_queue *queue)
225{
226 return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0;
227}
228
229static inline int reqsk_queue_len_young(struct request_sock_queue *queue)
230{
231 return queue->listen_opt->qlen_young;
232}
233
234static inline int reqsk_queue_is_full(struct request_sock_queue *queue)
235{
236 return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log;
237}
238
239static inline void reqsk_queue_hash_req(struct request_sock_queue *queue,
240 u32 hash, struct request_sock *req,
241 unsigned timeout)
242{
243 struct listen_sock *lopt = queue->listen_opt;
244
245 req->expires = jiffies + timeout;
246 req->retrans = 0;
247 req->sk = NULL;
248 req->dl_next = lopt->syn_table[hash];
249
250 write_lock(&queue->syn_wait_lock);
251 lopt->syn_table[hash] = req;
252 write_unlock(&queue->syn_wait_lock);
253}
254
255#endif /* _REQUEST_SOCK_H */
generated by cgit v1.2.2 (git 2.25.0) at 2025-12-28 03:05:30 -0500