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2e6599cb ACM |
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> | |
0e87506f | 19 | #include <linux/spinlock.h> |
2e6599cb | 20 | #include <linux/types.h> |
547b792c | 21 | #include <linux/bug.h> |
0e87506f | 22 | |
2e6599cb ACM |
23 | #include <net/sock.h> |
24 | ||
60236fdd | 25 | struct request_sock; |
2e6599cb ACM |
26 | struct sk_buff; |
27 | struct dst_entry; | |
28 | struct proto; | |
29 | ||
e6b4d113 WAS |
30 | /* empty to "strongly type" an otherwise void parameter. |
31 | */ | |
32 | struct request_values { | |
33 | }; | |
34 | ||
60236fdd | 35 | struct request_sock_ops { |
2e6599cb | 36 | int family; |
2e6599cb | 37 | int obj_size; |
e18b890b | 38 | struct kmem_cache *slab; |
7e56b5d6 | 39 | char *slab_name; |
2e6599cb | 40 | int (*rtx_syn_ack)(struct sock *sk, |
e6b4d113 WAS |
41 | struct request_sock *req, |
42 | struct request_values *rvp); | |
6edafaaf | 43 | void (*send_ack)(struct sock *sk, struct sk_buff *skb, |
60236fdd | 44 | struct request_sock *req); |
cfb6eeb4 YH |
45 | void (*send_reset)(struct sock *sk, |
46 | struct sk_buff *skb); | |
60236fdd | 47 | void (*destructor)(struct request_sock *req); |
72659ecc OP |
48 | void (*syn_ack_timeout)(struct sock *sk, |
49 | struct request_sock *req); | |
2e6599cb ACM |
50 | }; |
51 | ||
60236fdd | 52 | /* struct request_sock - mini sock to represent a connection request |
2e6599cb | 53 | */ |
60236fdd ACM |
54 | struct request_sock { |
55 | struct request_sock *dl_next; /* Must be first member! */ | |
2e6599cb ACM |
56 | u16 mss; |
57 | u8 retrans; | |
4dfc2817 | 58 | u8 cookie_ts; /* syncookie: encode tcpopts in timestamp */ |
2e6599cb ACM |
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; | |
72a3effa | 64 | const struct request_sock_ops *rsk_ops; |
2e6599cb | 65 | struct sock *sk; |
4237c75c | 66 | u32 secid; |
6b877699 | 67 | u32 peer_secid; |
2e6599cb ACM |
68 | }; |
69 | ||
72a3effa | 70 | static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops) |
2e6599cb | 71 | { |
54e6ecb2 | 72 | struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC); |
2e6599cb ACM |
73 | |
74 | if (req != NULL) | |
60236fdd | 75 | req->rsk_ops = ops; |
2e6599cb ACM |
76 | |
77 | return req; | |
78 | } | |
79 | ||
60236fdd | 80 | static inline void __reqsk_free(struct request_sock *req) |
2e6599cb | 81 | { |
60236fdd | 82 | kmem_cache_free(req->rsk_ops->slab, req); |
2e6599cb ACM |
83 | } |
84 | ||
60236fdd | 85 | static inline void reqsk_free(struct request_sock *req) |
2e6599cb | 86 | { |
60236fdd ACM |
87 | req->rsk_ops->destructor(req); |
88 | __reqsk_free(req); | |
2e6599cb ACM |
89 | } |
90 | ||
0e87506f ACM |
91 | extern int sysctl_max_syn_backlog; |
92 | ||
2ad69c55 | 93 | /** struct listen_sock - listen state |
0e87506f ACM |
94 | * |
95 | * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs | |
96 | */ | |
2ad69c55 | 97 | struct listen_sock { |
0e87506f ACM |
98 | u8 max_qlen_log; |
99 | /* 3 bytes hole, try to use */ | |
100 | int qlen; | |
101 | int qlen_young; | |
102 | int clock_hand; | |
103 | u32 hash_rnd; | |
83e3609e | 104 | u32 nr_table_entries; |
0e87506f ACM |
105 | struct request_sock *syn_table[0]; |
106 | }; | |
107 | ||
108 | /** struct request_sock_queue - queue of request_socks | |
109 | * | |
110 | * @rskq_accept_head - FIFO head of established children | |
111 | * @rskq_accept_tail - FIFO tail of established children | |
295f7324 | 112 | * @rskq_defer_accept - User waits for some data after accept() |
0e87506f ACM |
113 | * @syn_wait_lock - serializer |
114 | * | |
115 | * %syn_wait_lock is necessary only to avoid proc interface having to grab the main | |
116 | * lock sock while browsing the listening hash (otherwise it's deadlock prone). | |
117 | * | |
118 | * This lock is acquired in read mode only from listening_get_next() seq_file | |
119 | * op and it's acquired in write mode _only_ from code that is actively | |
120 | * changing rskq_accept_head. All readers that are holding the master sock lock | |
121 | * don't need to grab this lock in read mode too as rskq_accept_head. writes | |
122 | * are always protected from the main sock lock. | |
123 | */ | |
124 | struct request_sock_queue { | |
125 | struct request_sock *rskq_accept_head; | |
126 | struct request_sock *rskq_accept_tail; | |
127 | rwlock_t syn_wait_lock; | |
ec0a1966 DM |
128 | u8 rskq_defer_accept; |
129 | /* 3 bytes hole, try to pack */ | |
2ad69c55 | 130 | struct listen_sock *listen_opt; |
0e87506f ACM |
131 | }; |
132 | ||
133 | extern int reqsk_queue_alloc(struct request_sock_queue *queue, | |
72a3effa | 134 | unsigned int nr_table_entries); |
0e87506f | 135 | |
dab6ba36 | 136 | extern void __reqsk_queue_destroy(struct request_sock_queue *queue); |
83e3609e ACM |
137 | extern void reqsk_queue_destroy(struct request_sock_queue *queue); |
138 | ||
0e87506f ACM |
139 | static inline struct request_sock * |
140 | reqsk_queue_yank_acceptq(struct request_sock_queue *queue) | |
141 | { | |
142 | struct request_sock *req = queue->rskq_accept_head; | |
143 | ||
3eb4801d | 144 | queue->rskq_accept_head = NULL; |
0e87506f ACM |
145 | return req; |
146 | } | |
147 | ||
148 | static inline int reqsk_queue_empty(struct request_sock_queue *queue) | |
149 | { | |
150 | return queue->rskq_accept_head == NULL; | |
151 | } | |
152 | ||
153 | static inline void reqsk_queue_unlink(struct request_sock_queue *queue, | |
154 | struct request_sock *req, | |
155 | struct request_sock **prev_req) | |
156 | { | |
157 | write_lock(&queue->syn_wait_lock); | |
158 | *prev_req = req->dl_next; | |
159 | write_unlock(&queue->syn_wait_lock); | |
160 | } | |
161 | ||
162 | static inline void reqsk_queue_add(struct request_sock_queue *queue, | |
163 | struct request_sock *req, | |
164 | struct sock *parent, | |
165 | struct sock *child) | |
166 | { | |
167 | req->sk = child; | |
168 | sk_acceptq_added(parent); | |
169 | ||
170 | if (queue->rskq_accept_head == NULL) | |
171 | queue->rskq_accept_head = req; | |
172 | else | |
173 | queue->rskq_accept_tail->dl_next = req; | |
174 | ||
175 | queue->rskq_accept_tail = req; | |
176 | req->dl_next = NULL; | |
177 | } | |
178 | ||
179 | static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue) | |
180 | { | |
181 | struct request_sock *req = queue->rskq_accept_head; | |
182 | ||
547b792c | 183 | WARN_ON(req == NULL); |
0e87506f ACM |
184 | |
185 | queue->rskq_accept_head = req->dl_next; | |
186 | if (queue->rskq_accept_head == NULL) | |
187 | queue->rskq_accept_tail = NULL; | |
188 | ||
189 | return req; | |
190 | } | |
191 | ||
192 | static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue, | |
193 | struct sock *parent) | |
194 | { | |
195 | struct request_sock *req = reqsk_queue_remove(queue); | |
196 | struct sock *child = req->sk; | |
197 | ||
547b792c | 198 | WARN_ON(child == NULL); |
0e87506f ACM |
199 | |
200 | sk_acceptq_removed(parent); | |
201 | __reqsk_free(req); | |
202 | return child; | |
203 | } | |
204 | ||
205 | static inline int reqsk_queue_removed(struct request_sock_queue *queue, | |
206 | struct request_sock *req) | |
207 | { | |
2ad69c55 | 208 | struct listen_sock *lopt = queue->listen_opt; |
0e87506f ACM |
209 | |
210 | if (req->retrans == 0) | |
211 | --lopt->qlen_young; | |
212 | ||
213 | return --lopt->qlen; | |
214 | } | |
215 | ||
216 | static inline int reqsk_queue_added(struct request_sock_queue *queue) | |
217 | { | |
2ad69c55 | 218 | struct listen_sock *lopt = queue->listen_opt; |
0e87506f ACM |
219 | const int prev_qlen = lopt->qlen; |
220 | ||
221 | lopt->qlen_young++; | |
222 | lopt->qlen++; | |
223 | return prev_qlen; | |
224 | } | |
225 | ||
463c84b9 | 226 | static inline int reqsk_queue_len(const struct request_sock_queue *queue) |
0e87506f ACM |
227 | { |
228 | return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0; | |
229 | } | |
230 | ||
463c84b9 | 231 | static inline int reqsk_queue_len_young(const struct request_sock_queue *queue) |
0e87506f ACM |
232 | { |
233 | return queue->listen_opt->qlen_young; | |
234 | } | |
235 | ||
463c84b9 | 236 | static inline int reqsk_queue_is_full(const struct request_sock_queue *queue) |
0e87506f ACM |
237 | { |
238 | return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log; | |
239 | } | |
240 | ||
241 | static inline void reqsk_queue_hash_req(struct request_sock_queue *queue, | |
242 | u32 hash, struct request_sock *req, | |
8129765a | 243 | unsigned long timeout) |
0e87506f | 244 | { |
2ad69c55 | 245 | struct listen_sock *lopt = queue->listen_opt; |
0e87506f ACM |
246 | |
247 | req->expires = jiffies + timeout; | |
248 | req->retrans = 0; | |
249 | req->sk = NULL; | |
250 | req->dl_next = lopt->syn_table[hash]; | |
251 | ||
252 | write_lock(&queue->syn_wait_lock); | |
253 | lopt->syn_table[hash] = req; | |
254 | write_unlock(&queue->syn_wait_lock); | |
255 | } | |
256 | ||
2e6599cb | 257 | #endif /* _REQUEST_SOCK_H */ |