[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / net / request_sock.h

/*
 * NET		Generic infrastructure for Network protocols.
 *
 *		Definitions for request_sock 
 *
 * Authors:	Arnaldo Carvalho de Melo <acme@conectiva.com.br>
 *
 * 		From code originally in include/net/tcp.h
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 */
#ifndef _REQUEST_SOCK_H
#define _REQUEST_SOCK_H

#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/types.h>

#include <net/sock.h>

struct request_sock;
struct sk_buff;
struct dst_entry;
struct proto;

struct request_sock_ops {
	int		family;
	int		obj_size;
	kmem_cache_t	*slab;
	int		(*rtx_syn_ack)(struct sock *sk,
				       struct request_sock *req,
				       struct dst_entry *dst);
	void		(*send_ack)(struct sk_buff *skb,
				    struct request_sock *req);
	void		(*send_reset)(struct sock *sk,
				      struct sk_buff *skb);
	void		(*destructor)(struct request_sock *req);
};

/* struct request_sock - mini sock to represent a connection request
 */
struct request_sock {
	struct request_sock		*dl_next; /* Must be first member! */
	u16				mss;
	u8				retrans;
	u8				__pad;
	/* The following two fields can be easily recomputed I think -AK */
	u32				window_clamp; /* window clamp at creation time */
	u32				rcv_wnd;	  /* rcv_wnd offered first time */
	u32				ts_recent;
	unsigned long			expires;
	const struct request_sock_ops	*rsk_ops;
	struct sock			*sk;
	u32				secid;
	u32				peer_secid;
};

static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops)
{
	struct request_sock *req = kmem_cache_alloc(ops->slab, SLAB_ATOMIC);

	if (req != NULL)
		req->rsk_ops = ops;

	return req;
}

static inline void __reqsk_free(struct request_sock *req)
{
	kmem_cache_free(req->rsk_ops->slab, req);
}

static inline void reqsk_free(struct request_sock *req)
{
	req->rsk_ops->destructor(req);
	__reqsk_free(req);
}

extern int sysctl_max_syn_backlog;

/** struct listen_sock - listen state
 *
 * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs
 */
struct listen_sock {
	u8			max_qlen_log;
	/* 3 bytes hole, try to use */
	int			qlen;
	int			qlen_young;
	int			clock_hand;
	u32			hash_rnd;
	u32			nr_table_entries;
	struct request_sock	*syn_table[0];
};

/** struct request_sock_queue - queue of request_socks
 *
 * @rskq_accept_head - FIFO head of established children
 * @rskq_accept_tail - FIFO tail of established children
 * @rskq_defer_accept - User waits for some data after accept()
 * @syn_wait_lock - serializer
 *
 * %syn_wait_lock is necessary only to avoid proc interface having to grab the main
 * lock sock while browsing the listening hash (otherwise it's deadlock prone).
 *
 * This lock is acquired in read mode only from listening_get_next() seq_file
 * op and it's acquired in write mode _only_ from code that is actively
 * changing rskq_accept_head. All readers that are holding the master sock lock
 * don't need to grab this lock in read mode too as rskq_accept_head. writes
 * are always protected from the main sock lock.
 */
struct request_sock_queue {
	struct request_sock	*rskq_accept_head;
	struct request_sock	*rskq_accept_tail;
	rwlock_t		syn_wait_lock;
	u8			rskq_defer_accept;
	/* 3 bytes hole, try to pack */
	struct listen_sock	*listen_opt;
};

extern int reqsk_queue_alloc(struct request_sock_queue *queue,
			     unsigned int nr_table_entries);

static inline struct listen_sock *reqsk_queue_yank_listen_sk(struct request_sock_queue *queue)
{
	struct listen_sock *lopt;

	write_lock_bh(&queue->syn_wait_lock);
	lopt = queue->listen_opt;
	queue->listen_opt = NULL;
	write_unlock_bh(&queue->syn_wait_lock);

	return lopt;
}

static inline void __reqsk_queue_destroy(struct request_sock_queue *queue)
{
	kfree(reqsk_queue_yank_listen_sk(queue));
}

extern void reqsk_queue_destroy(struct request_sock_queue *queue);

static inline struct request_sock *
	reqsk_queue_yank_acceptq(struct request_sock_queue *queue)
{
	struct request_sock *req = queue->rskq_accept_head;

	queue->rskq_accept_head = NULL;
	return req;
}

static inline int reqsk_queue_empty(struct request_sock_queue *queue)
{
	return queue->rskq_accept_head == NULL;
}

static inline void reqsk_queue_unlink(struct request_sock_queue *queue,
				      struct request_sock *req,
				      struct request_sock **prev_req)
{
	write_lock(&queue->syn_wait_lock);
	*prev_req = req->dl_next;
	write_unlock(&queue->syn_wait_lock);
}

static inline void reqsk_queue_add(struct request_sock_queue *queue,
				   struct request_sock *req,
				   struct sock *parent,
				   struct sock *child)
{
	req->sk = child;
	sk_acceptq_added(parent);

	if (queue->rskq_accept_head == NULL)
		queue->rskq_accept_head = req;
	else
		queue->rskq_accept_tail->dl_next = req;

	queue->rskq_accept_tail = req;
	req->dl_next = NULL;
}

static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue)
{
	struct request_sock *req = queue->rskq_accept_head;

	BUG_TRAP(req != NULL);

	queue->rskq_accept_head = req->dl_next;
	if (queue->rskq_accept_head == NULL)
		queue->rskq_accept_tail = NULL;

	return req;
}

static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue,
						 struct sock *parent)
{
	struct request_sock *req = reqsk_queue_remove(queue);
	struct sock *child = req->sk;

	BUG_TRAP(child != NULL);

	sk_acceptq_removed(parent);
	__reqsk_free(req);
	return child;
}

static inline int reqsk_queue_removed(struct request_sock_queue *queue,
				      struct request_sock *req)
{
	struct listen_sock *lopt = queue->listen_opt;

	if (req->retrans == 0)
		--lopt->qlen_young;

	return --lopt->qlen;
}

static inline int reqsk_queue_added(struct request_sock_queue *queue)
{
	struct listen_sock *lopt = queue->listen_opt;
	const int prev_qlen = lopt->qlen;

	lopt->qlen_young++;
	lopt->qlen++;
	return prev_qlen;
}

static inline int reqsk_queue_len(const struct request_sock_queue *queue)
{
	return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0;
}

static inline int reqsk_queue_len_young(const struct request_sock_queue *queue)
{
	return queue->listen_opt->qlen_young;
}

static inline int reqsk_queue_is_full(const struct request_sock_queue *queue)
{
	return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log;
}

static inline void reqsk_queue_hash_req(struct request_sock_queue *queue,
					u32 hash, struct request_sock *req,
					unsigned long timeout)
{
	struct listen_sock *lopt = queue->listen_opt;

	req->expires = jiffies + timeout;
	req->retrans = 0;
	req->sk = NULL;
	req->dl_next = lopt->syn_table[hash];

	write_lock(&queue->syn_wait_lock);
	lopt->syn_table[hash] = req;
	write_unlock(&queue->syn_wait_lock);
}

#endif /* _REQUEST_SOCK_H */
Commit	Line	Data
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>
2e6599cb ACM	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;
72a3effa	32	kmem_cache_t *slab;
2e6599cb	33	int (rtx_syn_ack)(struct sock sk,
60236fdd	34	struct request_sock *req,
2e6599cb ACM	35	struct dst_entry *dst);
2e6599cb ACM	36	void (send_ack)(struct sk_buff skb,
60236fdd	37	struct request_sock *req);
cfb6eeb4 YH	38	void (send_reset)(struct sock sk,
cfb6eeb4 YH	39	struct sk_buff *skb);
60236fdd	40	void (destructor)(struct request_sock req);
2e6599cb ACM	41	};
2e6599cb ACM	42
60236fdd	43	/* struct request_sock - mini sock to represent a connection request
2e6599cb	44	*/
60236fdd ACM	45	struct request_sock {
60236fdd ACM	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	};
2e6599cb ACM	60
72a3effa	61	static inline struct request_sock reqsk_alloc(const struct request_sock_ops ops)
2e6599cb	62	{
60236fdd	63	struct request_sock *req = kmem_cache_alloc(ops->slab, SLAB_ATOMIC);
2e6599cb ACM	64
2e6599cb ACM	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	}
2e6599cb ACM	75
60236fdd	76	static inline void reqsk_free(struct request_sock *req)
2e6599cb	77	{
60236fdd ACM	78	req->rsk_ops->destructor(req);
60236fdd ACM	79	__reqsk_free(req);
2e6599cb ACM	80	}
2e6599cb ACM	81
0e87506f ACM	82	extern int sysctl_max_syn_backlog;
0e87506f ACM	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;
295f7324 ACM	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);
83e3609e ACM	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 */