blob: 0c96e7bed5db39e7eff4718353697ce52e06df96 [file] [log] [blame]
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,
Denis V. Lunevfd80eb92008-02-29 11:43:03 -080034 struct request_sock *req);
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070035 void (*send_ack)(struct sk_buff *skb,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070036 struct request_sock *req);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -080037 void (*send_reset)(struct sock *sk,
38 struct sk_buff *skb);
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070039 void (*destructor)(struct request_sock *req);
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070040};
41
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070042/* struct request_sock - mini sock to represent a connection request
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070043 */
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070044struct request_sock {
45 struct request_sock *dl_next; /* Must be first member! */
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070046 u16 mss;
47 u8 retrans;
Florian Westphal4dfc2812008-04-10 03:12:40 -070048 u8 cookie_ts; /* syncookie: encode tcpopts in timestamp */
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070049 /* 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;
Eric Dumazet72a3eff2006-11-16 02:30:37 -080054 const struct request_sock_ops *rsk_ops;
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070055 struct sock *sk;
Venkat Yekkirala4237c752006-07-24 23:32:50 -070056 u32 secid;
Venkat Yekkirala6b877692006-11-08 17:04:09 -060057 u32 peer_secid;
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070058};
59
Eric Dumazet72a3eff2006-11-16 02:30:37 -080060static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops)
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070061{
Christoph Lameter54e6ecb2006-12-06 20:33:16 -080062 struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC);
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070063
64 if (req != NULL)
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070065 req->rsk_ops = ops;
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070066
67 return req;
68}
69
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070070static inline void __reqsk_free(struct request_sock *req)
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070071{
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070072 kmem_cache_free(req->rsk_ops->slab, req);
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070073}
74
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070075static inline void reqsk_free(struct request_sock *req)
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070076{
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070077 req->rsk_ops->destructor(req);
78 __reqsk_free(req);
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070079}
80
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -070081extern int sysctl_max_syn_backlog;
82
Arnaldo Carvalho de Melo2ad69c52005-06-18 22:48:55 -070083/** struct listen_sock - listen state
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -070084 *
85 * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs
86 */
Arnaldo Carvalho de Melo2ad69c52005-06-18 22:48:55 -070087struct listen_sock {
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -070088 u8 max_qlen_log;
89 /* 3 bytes hole, try to use */
90 int qlen;
91 int qlen_young;
92 int clock_hand;
93 u32 hash_rnd;
Arnaldo Carvalho de Melo83e36092005-08-09 19:33:31 -070094 u32 nr_table_entries;
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -070095 struct request_sock *syn_table[0];
96};
97
98/** struct request_sock_queue - queue of request_socks
99 *
100 * @rskq_accept_head - FIFO head of established children
101 * @rskq_accept_tail - FIFO tail of established children
Arnaldo Carvalho de Melo295f7322005-08-09 20:11:56 -0700102 * @rskq_defer_accept - User waits for some data after accept()
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700103 * @syn_wait_lock - serializer
104 *
105 * %syn_wait_lock is necessary only to avoid proc interface having to grab the main
106 * lock sock while browsing the listening hash (otherwise it's deadlock prone).
107 *
108 * This lock is acquired in read mode only from listening_get_next() seq_file
109 * op and it's acquired in write mode _only_ from code that is actively
110 * changing rskq_accept_head. All readers that are holding the master sock lock
111 * don't need to grab this lock in read mode too as rskq_accept_head. writes
112 * are always protected from the main sock lock.
113 */
114struct request_sock_queue {
115 struct request_sock *rskq_accept_head;
116 struct request_sock *rskq_accept_tail;
117 rwlock_t syn_wait_lock;
David S. Millerec0a1962008-06-12 16:31:35 -0700118 u8 rskq_defer_accept;
119 /* 3 bytes hole, try to pack */
Arnaldo Carvalho de Melo2ad69c52005-06-18 22:48:55 -0700120 struct listen_sock *listen_opt;
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700121};
122
123extern int reqsk_queue_alloc(struct request_sock_queue *queue,
Eric Dumazet72a3eff2006-11-16 02:30:37 -0800124 unsigned int nr_table_entries);
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700125
Pavel Emelyanovdab6ba32007-11-15 02:57:06 -0800126extern void __reqsk_queue_destroy(struct request_sock_queue *queue);
Arnaldo Carvalho de Melo83e36092005-08-09 19:33:31 -0700127extern void reqsk_queue_destroy(struct request_sock_queue *queue);
128
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700129static inline struct request_sock *
130 reqsk_queue_yank_acceptq(struct request_sock_queue *queue)
131{
132 struct request_sock *req = queue->rskq_accept_head;
133
Norbert Kiesel3eb48012006-03-26 17:39:55 -0800134 queue->rskq_accept_head = NULL;
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700135 return req;
136}
137
138static inline int reqsk_queue_empty(struct request_sock_queue *queue)
139{
140 return queue->rskq_accept_head == NULL;
141}
142
143static inline void reqsk_queue_unlink(struct request_sock_queue *queue,
144 struct request_sock *req,
145 struct request_sock **prev_req)
146{
147 write_lock(&queue->syn_wait_lock);
148 *prev_req = req->dl_next;
149 write_unlock(&queue->syn_wait_lock);
150}
151
152static inline void reqsk_queue_add(struct request_sock_queue *queue,
153 struct request_sock *req,
154 struct sock *parent,
155 struct sock *child)
156{
157 req->sk = child;
158 sk_acceptq_added(parent);
159
160 if (queue->rskq_accept_head == NULL)
161 queue->rskq_accept_head = req;
162 else
163 queue->rskq_accept_tail->dl_next = req;
164
165 queue->rskq_accept_tail = req;
166 req->dl_next = NULL;
167}
168
169static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue)
170{
171 struct request_sock *req = queue->rskq_accept_head;
172
173 BUG_TRAP(req != NULL);
174
175 queue->rskq_accept_head = req->dl_next;
176 if (queue->rskq_accept_head == NULL)
177 queue->rskq_accept_tail = NULL;
178
179 return req;
180}
181
182static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue,
183 struct sock *parent)
184{
185 struct request_sock *req = reqsk_queue_remove(queue);
186 struct sock *child = req->sk;
187
188 BUG_TRAP(child != NULL);
189
190 sk_acceptq_removed(parent);
191 __reqsk_free(req);
192 return child;
193}
194
195static inline int reqsk_queue_removed(struct request_sock_queue *queue,
196 struct request_sock *req)
197{
Arnaldo Carvalho de Melo2ad69c52005-06-18 22:48:55 -0700198 struct listen_sock *lopt = queue->listen_opt;
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700199
200 if (req->retrans == 0)
201 --lopt->qlen_young;
202
203 return --lopt->qlen;
204}
205
206static inline int reqsk_queue_added(struct request_sock_queue *queue)
207{
Arnaldo Carvalho de Melo2ad69c52005-06-18 22:48:55 -0700208 struct listen_sock *lopt = queue->listen_opt;
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700209 const int prev_qlen = lopt->qlen;
210
211 lopt->qlen_young++;
212 lopt->qlen++;
213 return prev_qlen;
214}
215
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700216static inline int reqsk_queue_len(const struct request_sock_queue *queue)
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700217{
218 return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0;
219}
220
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700221static inline int reqsk_queue_len_young(const struct request_sock_queue *queue)
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700222{
223 return queue->listen_opt->qlen_young;
224}
225
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700226static inline int reqsk_queue_is_full(const struct request_sock_queue *queue)
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700227{
228 return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log;
229}
230
231static inline void reqsk_queue_hash_req(struct request_sock_queue *queue,
232 u32 hash, struct request_sock *req,
Arnaldo Carvalho de Melo81297652005-12-13 23:15:24 -0800233 unsigned long timeout)
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700234{
Arnaldo Carvalho de Melo2ad69c52005-06-18 22:48:55 -0700235 struct listen_sock *lopt = queue->listen_opt;
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700236
237 req->expires = jiffies + timeout;
238 req->retrans = 0;
239 req->sk = NULL;
240 req->dl_next = lopt->syn_table[hash];
241
242 write_lock(&queue->syn_wait_lock);
243 lopt->syn_table[hash] = req;
244 write_unlock(&queue->syn_wait_lock);
245}
246
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700247#endif /* _REQUEST_SOCK_H */