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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> |
0e87506f | 21 | |
2e6599cb ACM |
22 | #include <net/sock.h> |
23 | ||
60236fdd | 24 | struct request_sock; |
2e6599cb ACM |
25 | struct sk_buff; |
26 | struct dst_entry; | |
27 | struct proto; | |
28 | ||
60236fdd | 29 | struct request_sock_ops { |
2e6599cb | 30 | int family; |
2e6599cb | 31 | int obj_size; |
e18b890b | 32 | struct kmem_cache *slab; |
2e6599cb | 33 | int (*rtx_syn_ack)(struct sock *sk, |
60236fdd | 34 | struct request_sock *req, |
2e6599cb ACM |
35 | struct dst_entry *dst); |
36 | void (*send_ack)(struct sk_buff *skb, | |
60236fdd | 37 | struct request_sock *req); |
cfb6eeb4 YH |
38 | void (*send_reset)(struct sock *sk, |
39 | struct sk_buff *skb); | |
60236fdd | 40 | void (*destructor)(struct request_sock *req); |
2e6599cb ACM |
41 | }; |
42 | ||
60236fdd | 43 | /* struct request_sock - mini sock to represent a connection request |
2e6599cb | 44 | */ |
60236fdd ACM |
45 | struct request_sock { |
46 | struct request_sock *dl_next; /* Must be first member! */ | |
2e6599cb ACM |
47 | u16 mss; |
48 | u8 retrans; | |
49 | u8 __pad; | |
50 | /* The following two fields can be easily recomputed I think -AK */ | |
51 | u32 window_clamp; /* window clamp at creation time */ | |
52 | u32 rcv_wnd; /* rcv_wnd offered first time */ | |
53 | u32 ts_recent; | |
54 | unsigned long expires; | |
72a3effa | 55 | const struct request_sock_ops *rsk_ops; |
2e6599cb | 56 | struct sock *sk; |
4237c75c | 57 | u32 secid; |
6b877699 | 58 | u32 peer_secid; |
2e6599cb ACM |
59 | }; |
60 | ||
72a3effa | 61 | static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops) |
2e6599cb | 62 | { |
54e6ecb2 | 63 | struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC); |
2e6599cb ACM |
64 | |
65 | if (req != NULL) | |
60236fdd | 66 | req->rsk_ops = ops; |
2e6599cb ACM |
67 | |
68 | return req; | |
69 | } | |
70 | ||
60236fdd | 71 | static inline void __reqsk_free(struct request_sock *req) |
2e6599cb | 72 | { |
60236fdd | 73 | kmem_cache_free(req->rsk_ops->slab, req); |
2e6599cb ACM |
74 | } |
75 | ||
60236fdd | 76 | static inline void reqsk_free(struct request_sock *req) |
2e6599cb | 77 | { |
60236fdd ACM |
78 | req->rsk_ops->destructor(req); |
79 | __reqsk_free(req); | |
2e6599cb ACM |
80 | } |
81 | ||
0e87506f ACM |
82 | extern int sysctl_max_syn_backlog; |
83 | ||
2ad69c55 | 84 | /** struct listen_sock - listen state |
0e87506f ACM |
85 | * |
86 | * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs | |
87 | */ | |
2ad69c55 | 88 | struct listen_sock { |
0e87506f ACM |
89 | u8 max_qlen_log; |
90 | /* 3 bytes hole, try to use */ | |
91 | int qlen; | |
92 | int qlen_young; | |
93 | int clock_hand; | |
94 | u32 hash_rnd; | |
83e3609e | 95 | u32 nr_table_entries; |
0e87506f ACM |
96 | struct request_sock *syn_table[0]; |
97 | }; | |
98 | ||
99 | /** struct request_sock_queue - queue of request_socks | |
100 | * | |
101 | * @rskq_accept_head - FIFO head of established children | |
102 | * @rskq_accept_tail - FIFO tail of established children | |
295f7324 | 103 | * @rskq_defer_accept - User waits for some data after accept() |
0e87506f ACM |
104 | * @syn_wait_lock - serializer |
105 | * | |
106 | * %syn_wait_lock is necessary only to avoid proc interface having to grab the main | |
107 | * lock sock while browsing the listening hash (otherwise it's deadlock prone). | |
108 | * | |
109 | * This lock is acquired in read mode only from listening_get_next() seq_file | |
110 | * op and it's acquired in write mode _only_ from code that is actively | |
111 | * changing rskq_accept_head. All readers that are holding the master sock lock | |
112 | * don't need to grab this lock in read mode too as rskq_accept_head. writes | |
113 | * are always protected from the main sock lock. | |
114 | */ | |
115 | struct request_sock_queue { | |
116 | struct request_sock *rskq_accept_head; | |
117 | struct request_sock *rskq_accept_tail; | |
118 | rwlock_t syn_wait_lock; | |
295f7324 ACM |
119 | u8 rskq_defer_accept; |
120 | /* 3 bytes hole, try to pack */ | |
2ad69c55 | 121 | struct listen_sock *listen_opt; |
0e87506f ACM |
122 | }; |
123 | ||
124 | extern int reqsk_queue_alloc(struct request_sock_queue *queue, | |
72a3effa | 125 | unsigned int nr_table_entries); |
0e87506f | 126 | |
2ad69c55 | 127 | static inline struct listen_sock *reqsk_queue_yank_listen_sk(struct request_sock_queue *queue) |
0e87506f | 128 | { |
2ad69c55 | 129 | struct listen_sock *lopt; |
0e87506f ACM |
130 | |
131 | write_lock_bh(&queue->syn_wait_lock); | |
132 | lopt = queue->listen_opt; | |
133 | queue->listen_opt = NULL; | |
134 | write_unlock_bh(&queue->syn_wait_lock); | |
135 | ||
136 | return lopt; | |
137 | } | |
138 | ||
83e3609e | 139 | static inline void __reqsk_queue_destroy(struct request_sock_queue *queue) |
0e87506f ACM |
140 | { |
141 | kfree(reqsk_queue_yank_listen_sk(queue)); | |
142 | } | |
143 | ||
83e3609e ACM |
144 | extern void reqsk_queue_destroy(struct request_sock_queue *queue); |
145 | ||
0e87506f ACM |
146 | static inline struct request_sock * |
147 | reqsk_queue_yank_acceptq(struct request_sock_queue *queue) | |
148 | { | |
149 | struct request_sock *req = queue->rskq_accept_head; | |
150 | ||
3eb4801d | 151 | queue->rskq_accept_head = NULL; |
0e87506f ACM |
152 | return req; |
153 | } | |
154 | ||
155 | static inline int reqsk_queue_empty(struct request_sock_queue *queue) | |
156 | { | |
157 | return queue->rskq_accept_head == NULL; | |
158 | } | |
159 | ||
160 | static inline void reqsk_queue_unlink(struct request_sock_queue *queue, | |
161 | struct request_sock *req, | |
162 | struct request_sock **prev_req) | |
163 | { | |
164 | write_lock(&queue->syn_wait_lock); | |
165 | *prev_req = req->dl_next; | |
166 | write_unlock(&queue->syn_wait_lock); | |
167 | } | |
168 | ||
169 | static inline void reqsk_queue_add(struct request_sock_queue *queue, | |
170 | struct request_sock *req, | |
171 | struct sock *parent, | |
172 | struct sock *child) | |
173 | { | |
174 | req->sk = child; | |
175 | sk_acceptq_added(parent); | |
176 | ||
177 | if (queue->rskq_accept_head == NULL) | |
178 | queue->rskq_accept_head = req; | |
179 | else | |
180 | queue->rskq_accept_tail->dl_next = req; | |
181 | ||
182 | queue->rskq_accept_tail = req; | |
183 | req->dl_next = NULL; | |
184 | } | |
185 | ||
186 | static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue) | |
187 | { | |
188 | struct request_sock *req = queue->rskq_accept_head; | |
189 | ||
190 | BUG_TRAP(req != NULL); | |
191 | ||
192 | queue->rskq_accept_head = req->dl_next; | |
193 | if (queue->rskq_accept_head == NULL) | |
194 | queue->rskq_accept_tail = NULL; | |
195 | ||
196 | return req; | |
197 | } | |
198 | ||
199 | static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue, | |
200 | struct sock *parent) | |
201 | { | |
202 | struct request_sock *req = reqsk_queue_remove(queue); | |
203 | struct sock *child = req->sk; | |
204 | ||
205 | BUG_TRAP(child != NULL); | |
206 | ||
207 | sk_acceptq_removed(parent); | |
208 | __reqsk_free(req); | |
209 | return child; | |
210 | } | |
211 | ||
212 | static inline int reqsk_queue_removed(struct request_sock_queue *queue, | |
213 | struct request_sock *req) | |
214 | { | |
2ad69c55 | 215 | struct listen_sock *lopt = queue->listen_opt; |
0e87506f ACM |
216 | |
217 | if (req->retrans == 0) | |
218 | --lopt->qlen_young; | |
219 | ||
220 | return --lopt->qlen; | |
221 | } | |
222 | ||
223 | static inline int reqsk_queue_added(struct request_sock_queue *queue) | |
224 | { | |
2ad69c55 | 225 | struct listen_sock *lopt = queue->listen_opt; |
0e87506f ACM |
226 | const int prev_qlen = lopt->qlen; |
227 | ||
228 | lopt->qlen_young++; | |
229 | lopt->qlen++; | |
230 | return prev_qlen; | |
231 | } | |
232 | ||
463c84b9 | 233 | static inline int reqsk_queue_len(const struct request_sock_queue *queue) |
0e87506f ACM |
234 | { |
235 | return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0; | |
236 | } | |
237 | ||
463c84b9 | 238 | static inline int reqsk_queue_len_young(const struct request_sock_queue *queue) |
0e87506f ACM |
239 | { |
240 | return queue->listen_opt->qlen_young; | |
241 | } | |
242 | ||
463c84b9 | 243 | static inline int reqsk_queue_is_full(const struct request_sock_queue *queue) |
0e87506f ACM |
244 | { |
245 | return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log; | |
246 | } | |
247 | ||
248 | static inline void reqsk_queue_hash_req(struct request_sock_queue *queue, | |
249 | u32 hash, struct request_sock *req, | |
8129765a | 250 | unsigned long timeout) |
0e87506f | 251 | { |
2ad69c55 | 252 | struct listen_sock *lopt = queue->listen_opt; |
0e87506f ACM |
253 | |
254 | req->expires = jiffies + timeout; | |
255 | req->retrans = 0; | |
256 | req->sk = NULL; | |
257 | req->dl_next = lopt->syn_table[hash]; | |
258 | ||
259 | write_lock(&queue->syn_wait_lock); | |
260 | lopt->syn_table[hash] = req; | |
261 | write_unlock(&queue->syn_wait_lock); | |
262 | } | |
263 | ||
2e6599cb | 264 | #endif /* _REQUEST_SOCK_H */ |