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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#include <linux/bug.h>
22
23#include <net/sock.h>
24
25struct request_sock;
26struct sk_buff;
27struct dst_entry;
28struct proto;
29
30/* empty to "strongly type" an otherwise void parameter.
31 */
32struct request_values {
33};
34
35struct request_sock_ops {
36 int family;
37 int obj_size;
38 struct kmem_cache *slab;
39 char *slab_name;
40 int (*rtx_syn_ack)(struct sock *sk,
41 struct request_sock *req,
42 struct request_values *rvp);
43 void (*send_ack)(struct sock *sk, struct sk_buff *skb,
44 struct request_sock *req);
45 void (*send_reset)(struct sock *sk,
46 struct sk_buff *skb);
47 void (*destructor)(struct request_sock *req);
48 void (*syn_ack_timeout)(struct sock *sk,
49 struct request_sock *req);
50};
51
52/* struct request_sock - mini sock to represent a connection request
53 */
54struct request_sock {
55 struct request_sock *dl_next; /* Must be first member! */
56 u16 mss;
57 u8 retrans;
58 u8 cookie_ts; /* syncookie: encode tcpopts in timestamp */
59 /* The following two fields can be easily recomputed I think -AK */
60 u32 window_clamp; /* window clamp at creation time */
61 u32 rcv_wnd; /* rcv_wnd offered first time */
62 u32 ts_recent;
63 unsigned long expires;
64 const struct request_sock_ops *rsk_ops;
65 struct sock *sk;
66 u32 secid;
67 u32 peer_secid;
68};
69
70static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops)
71{
72 struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC);
73
74 if (req != NULL)
75 req->rsk_ops = ops;
76
77 return req;
78}
79
80static inline void __reqsk_free(struct request_sock *req)
81{
82 kmem_cache_free(req->rsk_ops->slab, req);
83}
84
85static inline void reqsk_free(struct request_sock *req)
86{
87 req->rsk_ops->destructor(req);
88 __reqsk_free(req);
89}
90
91extern int sysctl_max_syn_backlog;
92
93/** struct listen_sock - listen state
94 *
95 * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs
96 */
97struct listen_sock {
98 u8 max_qlen_log;
99 u8 synflood_warned;
100 /* 2 bytes hole, try to use */
101 int qlen;
102 int qlen_young;
103 int clock_hand;
104 u32 hash_rnd;
105 u32 nr_table_entries;
106 struct request_sock *syn_table[0];
107};
108
109/** struct request_sock_queue - queue of request_socks
110 *
111 * @rskq_accept_head - FIFO head of established children
112 * @rskq_accept_tail - FIFO tail of established children
113 * @rskq_defer_accept - User waits for some data after accept()
114 * @syn_wait_lock - serializer
115 *
116 * %syn_wait_lock is necessary only to avoid proc interface having to grab the main
117 * lock sock while browsing the listening hash (otherwise it's deadlock prone).
118 *
119 * This lock is acquired in read mode only from listening_get_next() seq_file
120 * op and it's acquired in write mode _only_ from code that is actively
121 * changing rskq_accept_head. All readers that are holding the master sock lock
122 * don't need to grab this lock in read mode too as rskq_accept_head. writes
123 * are always protected from the main sock lock.
124 */
125struct request_sock_queue {
126 struct request_sock *rskq_accept_head;
127 struct request_sock *rskq_accept_tail;
128 rwlock_t syn_wait_lock;
129 u8 rskq_defer_accept;
130 /* 3 bytes hole, try to pack */
131 struct listen_sock *listen_opt;
132};
133
134extern int reqsk_queue_alloc(struct request_sock_queue *queue,
135 unsigned int nr_table_entries);
136
137extern void __reqsk_queue_destroy(struct request_sock_queue *queue);
138extern void reqsk_queue_destroy(struct request_sock_queue *queue);
139
140static inline struct request_sock *
141 reqsk_queue_yank_acceptq(struct request_sock_queue *queue)
142{
143 struct request_sock *req = queue->rskq_accept_head;
144
145 queue->rskq_accept_head = NULL;
146 return req;
147}
148
149static inline int reqsk_queue_empty(struct request_sock_queue *queue)
150{
151 return queue->rskq_accept_head == NULL;
152}
153
154static inline void reqsk_queue_unlink(struct request_sock_queue *queue,
155 struct request_sock *req,
156 struct request_sock **prev_req)
157{
158 write_lock(&queue->syn_wait_lock);
159 *prev_req = req->dl_next;
160 write_unlock(&queue->syn_wait_lock);
161}
162
163static inline void reqsk_queue_add(struct request_sock_queue *queue,
164 struct request_sock *req,
165 struct sock *parent,
166 struct sock *child)
167{
168 req->sk = child;
169 sk_acceptq_added(parent);
170
171 if (queue->rskq_accept_head == NULL)
172 queue->rskq_accept_head = req;
173 else
174 queue->rskq_accept_tail->dl_next = req;
175
176 queue->rskq_accept_tail = req;
177 req->dl_next = NULL;
178}
179
180static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue)
181{
182 struct request_sock *req = queue->rskq_accept_head;
183
184 WARN_ON(req == NULL);
185
186 queue->rskq_accept_head = req->dl_next;
187 if (queue->rskq_accept_head == NULL)
188 queue->rskq_accept_tail = NULL;
189
190 return req;
191}
192
193static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue,
194 struct sock *parent)
195{
196 struct request_sock *req = reqsk_queue_remove(queue);
197 struct sock *child = req->sk;
198
199 WARN_ON(child == NULL);
200
201 sk_acceptq_removed(parent);
202 __reqsk_free(req);
203 return child;
204}
205
206static inline int reqsk_queue_removed(struct request_sock_queue *queue,
207 struct request_sock *req)
208{
209 struct listen_sock *lopt = queue->listen_opt;
210
211 if (req->retrans == 0)
212 --lopt->qlen_young;
213
214 return --lopt->qlen;
215}
216
217static inline int reqsk_queue_added(struct request_sock_queue *queue)
218{
219 struct listen_sock *lopt = queue->listen_opt;
220 const int prev_qlen = lopt->qlen;
221
222 lopt->qlen_young++;
223 lopt->qlen++;
224 return prev_qlen;
225}
226
227static inline int reqsk_queue_len(const struct request_sock_queue *queue)
228{
229 return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0;
230}
231
232static inline int reqsk_queue_len_young(const struct request_sock_queue *queue)
233{
234 return queue->listen_opt->qlen_young;
235}
236
237static inline int reqsk_queue_is_full(const struct request_sock_queue *queue)
238{
239 return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log;
240}
241
242static inline void reqsk_queue_hash_req(struct request_sock_queue *queue,
243 u32 hash, struct request_sock *req,
244 unsigned long timeout)
245{
246 struct listen_sock *lopt = queue->listen_opt;
247
248 req->expires = jiffies + timeout;
249 req->retrans = 0;
250 req->sk = NULL;
251 req->dl_next = lopt->syn_table[hash];
252
253 write_lock(&queue->syn_wait_lock);
254 lopt->syn_table[hash] = req;
255 write_unlock(&queue->syn_wait_lock);
256}
257
258#endif /* _REQUEST_SOCK_H */
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#include <linux/bug.h>
22
23#include <net/sock.h>
24
25struct request_sock;
26struct sk_buff;
27struct dst_entry;
28struct proto;
29
30/* empty to "strongly type" an otherwise void parameter.
31 */
32struct request_values {
33};
34
35struct request_sock_ops {
36 int family;
37 int obj_size;
38 struct kmem_cache *slab;
39 char *slab_name;
40 int (*rtx_syn_ack)(struct sock *sk,
41 struct request_sock *req,
42 struct request_values *rvp);
43 void (*send_ack)(struct sock *sk, struct sk_buff *skb,
44 struct request_sock *req);
45 void (*send_reset)(struct sock *sk,
46 struct sk_buff *skb);
47 void (*destructor)(struct request_sock *req);
48 void (*syn_ack_timeout)(struct sock *sk,
49 struct request_sock *req);
50};
51
52/* struct request_sock - mini sock to represent a connection request
53 */
54struct request_sock {
55 struct request_sock *dl_next; /* Must be first member! */
56 u16 mss;
57 u8 retrans;
58 u8 cookie_ts; /* syncookie: encode tcpopts in timestamp */
59 /* The following two fields can be easily recomputed I think -AK */
60 u32 window_clamp; /* window clamp at creation time */
61 u32 rcv_wnd; /* rcv_wnd offered first time */
62 u32 ts_recent;
63 unsigned long expires;
64 const struct request_sock_ops *rsk_ops;
65 struct sock *sk;
66 u32 secid;
67 u32 peer_secid;
68};
69
70static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops)
71{
72 struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC);
73
74 if (req != NULL)
75 req->rsk_ops = ops;
76
77 return req;
78}
79
80static inline void __reqsk_free(struct request_sock *req)
81{
82 kmem_cache_free(req->rsk_ops->slab, req);
83}
84
85static inline void reqsk_free(struct request_sock *req)
86{
87 req->rsk_ops->destructor(req);
88 __reqsk_free(req);
89}
90
91extern int sysctl_max_syn_backlog;
92
93/** struct listen_sock - listen state
94 *
95 * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs
96 */
97struct listen_sock {
98 u8 max_qlen_log;
99 u8 synflood_warned;
100 /* 2 bytes hole, try to use */
101 int qlen;
102 int qlen_young;
103 int clock_hand;
104 u32 hash_rnd;
105 u32 nr_table_entries;
106 struct request_sock *syn_table[0];
107};
108
109/** struct request_sock_queue - queue of request_socks
110 *
111 * @rskq_accept_head - FIFO head of established children
112 * @rskq_accept_tail - FIFO tail of established children
113 * @rskq_defer_accept - User waits for some data after accept()
114 * @syn_wait_lock - serializer
115 *
116 * %syn_wait_lock is necessary only to avoid proc interface having to grab the main
117 * lock sock while browsing the listening hash (otherwise it's deadlock prone).
118 *
119 * This lock is acquired in read mode only from listening_get_next() seq_file
120 * op and it's acquired in write mode _only_ from code that is actively
121 * changing rskq_accept_head. All readers that are holding the master sock lock
122 * don't need to grab this lock in read mode too as rskq_accept_head. writes
123 * are always protected from the main sock lock.
124 */
125struct request_sock_queue {
126 struct request_sock *rskq_accept_head;
127 struct request_sock *rskq_accept_tail;
128 rwlock_t syn_wait_lock;
129 u8 rskq_defer_accept;
130 /* 3 bytes hole, try to pack */
131 struct listen_sock *listen_opt;
132};
133
134extern int reqsk_queue_alloc(struct request_sock_queue *queue,
135 unsigned int nr_table_entries);
136
137extern void __reqsk_queue_destroy(struct request_sock_queue *queue);
138extern void reqsk_queue_destroy(struct request_sock_queue *queue);
139
140static inline struct request_sock *
141 reqsk_queue_yank_acceptq(struct request_sock_queue *queue)
142{
143 struct request_sock *req = queue->rskq_accept_head;
144
145 queue->rskq_accept_head = NULL;
146 return req;
147}
148
149static inline int reqsk_queue_empty(struct request_sock_queue *queue)
150{
151 return queue->rskq_accept_head == NULL;
152}
153
154static inline void reqsk_queue_unlink(struct request_sock_queue *queue,
155 struct request_sock *req,
156 struct request_sock **prev_req)
157{
158 write_lock(&queue->syn_wait_lock);
159 *prev_req = req->dl_next;
160 write_unlock(&queue->syn_wait_lock);
161}
162
163static inline void reqsk_queue_add(struct request_sock_queue *queue,
164 struct request_sock *req,
165 struct sock *parent,
166 struct sock *child)
167{
168 req->sk = child;
169 sk_acceptq_added(parent);
170
171 if (queue->rskq_accept_head == NULL)
172 queue->rskq_accept_head = req;
173 else
174 queue->rskq_accept_tail->dl_next = req;
175
176 queue->rskq_accept_tail = req;
177 req->dl_next = NULL;
178}
179
180static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue)
181{
182 struct request_sock *req = queue->rskq_accept_head;
183
184 WARN_ON(req == NULL);
185
186 queue->rskq_accept_head = req->dl_next;
187 if (queue->rskq_accept_head == NULL)
188 queue->rskq_accept_tail = NULL;
189
190 return req;
191}
192
193static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue,
194 struct sock *parent)
195{
196 struct request_sock *req = reqsk_queue_remove(queue);
197 struct sock *child = req->sk;
198
199 WARN_ON(child == NULL);
200
201 sk_acceptq_removed(parent);
202 __reqsk_free(req);
203 return child;
204}
205
206static inline int reqsk_queue_removed(struct request_sock_queue *queue,
207 struct request_sock *req)
208{
209 struct listen_sock *lopt = queue->listen_opt;
210
211 if (req->retrans == 0)
212 --lopt->qlen_young;
213
214 return --lopt->qlen;
215}
216
217static inline int reqsk_queue_added(struct request_sock_queue *queue)
218{
219 struct listen_sock *lopt = queue->listen_opt;
220 const int prev_qlen = lopt->qlen;
221
222 lopt->qlen_young++;
223 lopt->qlen++;
224 return prev_qlen;
225}
226
227static inline int reqsk_queue_len(const struct request_sock_queue *queue)
228{
229 return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0;
230}
231
232static inline int reqsk_queue_len_young(const struct request_sock_queue *queue)
233{
234 return queue->listen_opt->qlen_young;
235}
236
237static inline int reqsk_queue_is_full(const struct request_sock_queue *queue)
238{
239 return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log;
240}
241
242static inline void reqsk_queue_hash_req(struct request_sock_queue *queue,
243 u32 hash, struct request_sock *req,
244 unsigned long timeout)
245{
246 struct listen_sock *lopt = queue->listen_opt;
247
248 req->expires = jiffies + timeout;
249 req->retrans = 0;
250 req->sk = NULL;
251 req->dl_next = lopt->syn_table[hash];
252
253 write_lock(&queue->syn_wait_lock);
254 lopt->syn_table[hash] = req;
255 write_unlock(&queue->syn_wait_lock);
256}
257
258#endif /* _REQUEST_SOCK_H */