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Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001/*
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>
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -070019#include <linux/spinlock.h>
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070020#include <linux/types.h>
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -070021
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070022#include <net/sock.h>
23
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070024struct request_sock;
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070025struct sk_buff;
26struct dst_entry;
27struct proto;
28
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070029struct request_sock_ops {
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070030 int family;
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070031 int obj_size;
Christoph Lametere18b8902006-12-06 20:33:20 -080032 struct kmem_cache *slab;
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070033 int (*rtx_syn_ack)(struct sock *sk,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070034 struct request_sock *req,
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070035 struct dst_entry *dst);
36 void (*send_ack)(struct sk_buff *skb,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070037 struct request_sock *req);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -080038 void (*send_reset)(struct sock *sk,
39 struct sk_buff *skb);
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070040 void (*destructor)(struct request_sock *req);
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070041};
42
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070043/* struct request_sock - mini sock to represent a connection request
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070044 */
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070045struct request_sock {
46 struct request_sock *dl_next; /* Must be first member! */
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070047 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;
Eric Dumazet72a3eff2006-11-16 02:30:37 -080055 const struct request_sock_ops *rsk_ops;
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070056 struct sock *sk;
Venkat Yekkirala4237c752006-07-24 23:32:50 -070057 u32 secid;
Venkat Yekkirala6b877692006-11-08 17:04:09 -060058 u32 peer_secid;
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070059};
60
Eric Dumazet72a3eff2006-11-16 02:30:37 -080061static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops)
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070062{
Christoph Lameter54e6ecb2006-12-06 20:33:16 -080063 struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC);
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070064
65 if (req != NULL)
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070066 req->rsk_ops = ops;
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070067
68 return req;
69}
70
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070071static inline void __reqsk_free(struct request_sock *req)
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070072{
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070073 kmem_cache_free(req->rsk_ops->slab, req);
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070074}
75
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070076static inline void reqsk_free(struct request_sock *req)
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070077{
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070078 req->rsk_ops->destructor(req);
79 __reqsk_free(req);
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070080}
81
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -070082extern int sysctl_max_syn_backlog;
83
Arnaldo Carvalho de Melo2ad69c52005-06-18 22:48:55 -070084/** struct listen_sock - listen state
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -070085 *
86 * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs
87 */
Arnaldo Carvalho de Melo2ad69c52005-06-18 22:48:55 -070088struct listen_sock {
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -070089 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;
Arnaldo Carvalho de Melo83e36092005-08-09 19:33:31 -070095 u32 nr_table_entries;
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -070096 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
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -0700103 * @rskq_defer_accept - User waits for some data after accept()
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700104 * @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 */
115struct request_sock_queue {
116 struct request_sock *rskq_accept_head;
117 struct request_sock *rskq_accept_tail;
118 rwlock_t syn_wait_lock;
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -0700119 u8 rskq_defer_accept;
120 /* 3 bytes hole, try to pack */
Arnaldo Carvalho de Melo2ad69c52005-06-18 22:48:55 -0700121 struct listen_sock *listen_opt;
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700122};
123
124extern int reqsk_queue_alloc(struct request_sock_queue *queue,
Eric Dumazet72a3eff2006-11-16 02:30:37 -0800125 unsigned int nr_table_entries);
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700126
Pavel Emelyanovdab6ba32007-11-15 02:57:06 -0800127extern void __reqsk_queue_destroy(struct request_sock_queue *queue);
Arnaldo Carvalho de Melo83e36092005-08-09 19:33:31 -0700128extern void reqsk_queue_destroy(struct request_sock_queue *queue);
129
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700130static inline struct request_sock *
131 reqsk_queue_yank_acceptq(struct request_sock_queue *queue)
132{
133 struct request_sock *req = queue->rskq_accept_head;
134
Norbert Kiesel3eb48012006-03-26 17:39:55 -0800135 queue->rskq_accept_head = NULL;
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700136 return req;
137}
138
139static inline int reqsk_queue_empty(struct request_sock_queue *queue)
140{
141 return queue->rskq_accept_head == NULL;
142}
143
144static inline void reqsk_queue_unlink(struct request_sock_queue *queue,
145 struct request_sock *req,
146 struct request_sock **prev_req)
147{
148 write_lock(&queue->syn_wait_lock);
149 *prev_req = req->dl_next;
150 write_unlock(&queue->syn_wait_lock);
151}
152
153static inline void reqsk_queue_add(struct request_sock_queue *queue,
154 struct request_sock *req,
155 struct sock *parent,
156 struct sock *child)
157{
158 req->sk = child;
159 sk_acceptq_added(parent);
160
161 if (queue->rskq_accept_head == NULL)
162 queue->rskq_accept_head = req;
163 else
164 queue->rskq_accept_tail->dl_next = req;
165
166 queue->rskq_accept_tail = req;
167 req->dl_next = NULL;
168}
169
170static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue)
171{
172 struct request_sock *req = queue->rskq_accept_head;
173
174 BUG_TRAP(req != NULL);
175
176 queue->rskq_accept_head = req->dl_next;
177 if (queue->rskq_accept_head == NULL)
178 queue->rskq_accept_tail = NULL;
179
180 return req;
181}
182
183static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue,
184 struct sock *parent)
185{
186 struct request_sock *req = reqsk_queue_remove(queue);
187 struct sock *child = req->sk;
188
189 BUG_TRAP(child != NULL);
190
191 sk_acceptq_removed(parent);
192 __reqsk_free(req);
193 return child;
194}
195
196static inline int reqsk_queue_removed(struct request_sock_queue *queue,
197 struct request_sock *req)
198{
Arnaldo Carvalho de Melo2ad69c52005-06-18 22:48:55 -0700199 struct listen_sock *lopt = queue->listen_opt;
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700200
201 if (req->retrans == 0)
202 --lopt->qlen_young;
203
204 return --lopt->qlen;
205}
206
207static inline int reqsk_queue_added(struct request_sock_queue *queue)
208{
Arnaldo Carvalho de Melo2ad69c52005-06-18 22:48:55 -0700209 struct listen_sock *lopt = queue->listen_opt;
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700210 const int prev_qlen = lopt->qlen;
211
212 lopt->qlen_young++;
213 lopt->qlen++;
214 return prev_qlen;
215}
216
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700217static inline int reqsk_queue_len(const struct request_sock_queue *queue)
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700218{
219 return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0;
220}
221
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700222static inline int reqsk_queue_len_young(const struct request_sock_queue *queue)
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700223{
224 return queue->listen_opt->qlen_young;
225}
226
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700227static inline int reqsk_queue_is_full(const struct request_sock_queue *queue)
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700228{
229 return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log;
230}
231
232static inline void reqsk_queue_hash_req(struct request_sock_queue *queue,
233 u32 hash, struct request_sock *req,
Arnaldo Carvalho de Melo81297652005-12-13 23:15:24 -0800234 unsigned long timeout)
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700235{
Arnaldo Carvalho de Melo2ad69c52005-06-18 22:48:55 -0700236 struct listen_sock *lopt = queue->listen_opt;
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700237
238 req->expires = jiffies + timeout;
239 req->retrans = 0;
240 req->sk = NULL;
241 req->dl_next = lopt->syn_table[hash];
242
243 write_lock(&queue->syn_wait_lock);
244 lopt->syn_table[hash] = req;
245 write_unlock(&queue->syn_wait_lock);
246}
247
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700248#endif /* _REQUEST_SOCK_H */