[net-next-2.6.git] / net / dccp / feat.h

#ifndef _DCCP_FEAT_H
#define _DCCP_FEAT_H
/*
 *  net/dccp/feat.h
 *
 *  An implementation of the DCCP protocol
 *  Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk>
 *
 *	This program is free software; you can redistribute it and/or modify it
 *	under the terms of the GNU General Public License version 2 as
 *	published by the Free Software Foundation.
 */

#include <linux/types.h>
#include "dccp.h"

/*
 * Known limit values
 */
/* Ack Ratio takes 2-byte integer values (11.3) */
#define DCCPF_ACK_RATIO_MAX	0xFFFF
/* Wmin=32 and Wmax=2^46-1 from 7.5.2 */
#define DCCPF_SEQ_WMIN		32
#define DCCPF_SEQ_WMAX		0x3FFFFFFFFFFFull

enum dccp_feat_type {
	FEAT_AT_RX   = 1,	/* located at RX side of half-connection  */
	FEAT_AT_TX   = 2,	/* located at TX side of half-connection  */
	FEAT_SP      = 4,	/* server-priority reconciliation (6.3.1) */
	FEAT_NN	     = 8,	/* non-negotiable reconciliation (6.3.2)  */
	FEAT_UNKNOWN = 0xFF	/* not understood or invalid feature	  */
};

enum dccp_feat_state {
	FEAT_DEFAULT = 0,	/* using default values from 6.4 */
	FEAT_INITIALISING,	/* feature is being initialised  */
	FEAT_CHANGING,		/* Change sent but not confirmed yet */
	FEAT_UNSTABLE,		/* local modification in state CHANGING */
	FEAT_STABLE		/* both ends (think they) agree */
};

/**
 * dccp_feat_val  -  Container for SP or NN feature values
 * @nn:     single NN value
 * @sp.vec: single SP value plus optional preference list
 * @sp.len: length of @sp.vec in bytes
 */
typedef union {
	u64 nn;
	struct {
		u8	*vec;
		u8	len;
	}   sp;
} dccp_feat_val;

/**
 * struct feat_entry  -  Data structure to perform feature negotiation
 * @val: feature's current value (SP features may have preference list)
 * @state: feature's current state
 * @feat_num: one of %dccp_feature_numbers
 * @needs_mandatory: whether Mandatory options should be sent
 * @needs_confirm: whether to send a Confirm instead of a Change
 * @empty_confirm: whether to send an empty Confirm (depends on @needs_confirm)
 * @is_local: feature location (1) or feature-remote (0)
 * @node: list pointers, entries arranged in FIFO order
 */
struct dccp_feat_entry {
	dccp_feat_val           val;
	enum dccp_feat_state    state:8;
	u8                      feat_num;

	bool			needs_mandatory,
				needs_confirm,
				empty_confirm,
				is_local;

	struct list_head	node;
};

static inline u8 dccp_feat_genopt(struct dccp_feat_entry *entry)
{
	if (entry->needs_confirm)
		return entry->is_local ? DCCPO_CONFIRM_L : DCCPO_CONFIRM_R;
	return entry->is_local ? DCCPO_CHANGE_L : DCCPO_CHANGE_R;
}

/**
 * struct ccid_dependency  -  Track changes resulting from choosing a CCID
 * @dependent_feat: one of %dccp_feature_numbers
 * @is_local: local (1) or remote (0) @dependent_feat
 * @is_mandatory: whether presence of @dependent_feat is mission-critical or not
 * @val: corresponding default value for @dependent_feat (u8 is sufficient here)
 */
struct ccid_dependency {
	u8	dependent_feat;
	bool	is_local:1,
		is_mandatory:1;
	u8	val;
};

#ifdef CONFIG_IP_DCCP_DEBUG
extern const char *dccp_feat_typename(const u8 type);
extern const char *dccp_feat_name(const u8 feat);

static inline void dccp_feat_debug(const u8 type, const u8 feat, const u8 val)
{
	dccp_pr_debug("%s(%s (%d), %d)\n", dccp_feat_typename(type),
					   dccp_feat_name(feat), feat, val);
}
#else
#define dccp_feat_debug(type, feat, val)
#endif /* CONFIG_IP_DCCP_DEBUG */

extern int  dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local,
				  u8 const *list, u8 len);
extern int  dccp_feat_register_nn(struct sock *sk, u8 feat, u64 val);
extern int  dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature,
				  u8 *val, u8 len);
extern int  dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
				   u8 *val, u8 len);
extern void dccp_feat_clean(struct dccp_minisock *dmsk);
extern int  dccp_feat_clone(struct sock *oldsk, struct sock *newsk);
extern int  dccp_feat_clone_list(struct list_head const *, struct list_head *);
extern int  dccp_feat_init(struct sock *sk);

#endif /* _DCCP_FEAT_H */
Commit	Line	Data
afe00251 AB	1	#ifndef _DCCP_FEAT_H
	2	#define _DCCP_FEAT_H
	3	/*
	4	* net/dccp/feat.h
	5	*
	6	* An implementation of the DCCP protocol
	7	* Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk>
	8	*
	9	* This program is free software; you can redistribute it and/or modify it
	10	* under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*/
	13
	14	#include <linux/types.h>
c02fdc0e	15	#include "dccp.h"
afe00251	16
e8ef967a GR	17	/*
	18	* Known limit values
	19	*/
	20	/* Ack Ratio takes 2-byte integer values (11.3) */
	21	#define DCCPF_ACK_RATIO_MAX 0xFFFF
	22	/* Wmin=32 and Wmax=2^46-1 from 7.5.2 */
	23	#define DCCPF_SEQ_WMIN 32
	24	#define DCCPF_SEQ_WMAX 0x3FFFFFFFFFFFull
	25
bd012f2e GR	26	enum dccp_feat_type {
	27	FEAT_AT_RX = 1, /* located at RX side of half-connection */
	28	FEAT_AT_TX = 2, /* located at TX side of half-connection */
	29	FEAT_SP = 4, /* server-priority reconciliation (6.3.1) */
	30	FEAT_NN = 8, /* non-negotiable reconciliation (6.3.2) */
	31	FEAT_UNKNOWN = 0xFF /* not understood or invalid feature */
	32	};
	33
	34	enum dccp_feat_state {
	35	FEAT_DEFAULT = 0, /* using default values from 6.4 */
	36	FEAT_INITIALISING, /* feature is being initialised */
	37	FEAT_CHANGING, /* Change sent but not confirmed yet */
	38	FEAT_UNSTABLE, /* local modification in state CHANGING */
	39	FEAT_STABLE /* both ends (think they) agree */
	40	};
	41
	42	/**
	43	* dccp_feat_val - Container for SP or NN feature values
	44	* @nn: single NN value
	45	* @sp.vec: single SP value plus optional preference list
	46	* @sp.len: length of @sp.vec in bytes
	47	*/
	48	typedef union {
	49	u64 nn;
	50	struct {
	51	u8 *vec;
	52	u8 len;
	53	} sp;
	54	} dccp_feat_val;
	55
	56	/**
	57	* struct feat_entry - Data structure to perform feature negotiation
	58	* @val: feature's current value (SP features may have preference list)
	59	* @state: feature's current state
	60	* @feat_num: one of %dccp_feature_numbers
	61	* @needs_mandatory: whether Mandatory options should be sent
	62	* @needs_confirm: whether to send a Confirm instead of a Change
	63	* @empty_confirm: whether to send an empty Confirm (depends on @needs_confirm)
	64	* @is_local: feature location (1) or feature-remote (0)
	65	* @node: list pointers, entries arranged in FIFO order
	66	*/
	67	struct dccp_feat_entry {
	68	dccp_feat_val val;
	69	enum dccp_feat_state state:8;
	70	u8 feat_num;
	71
	72	bool needs_mandatory,
	73	needs_confirm,
	74	empty_confirm,
	75	is_local;
	76
	77	struct list_head node;
	78	};
	79
	80	static inline u8 dccp_feat_genopt(struct dccp_feat_entry *entry)
	81	{
	82	if (entry->needs_confirm)
	83	return entry->is_local ? DCCPO_CONFIRM_L : DCCPO_CONFIRM_R;
	84	return entry->is_local ? DCCPO_CHANGE_L : DCCPO_CHANGE_R;
	85	}
	86
e8ef967a GR	87	/**
	88	* struct ccid_dependency - Track changes resulting from choosing a CCID
	89	* @dependent_feat: one of %dccp_feature_numbers
	90	* @is_local: local (1) or remote (0) @dependent_feat
	91	* @is_mandatory: whether presence of @dependent_feat is mission-critical or not
	92	* @val: corresponding default value for @dependent_feat (u8 is sufficient here)
	93	*/
	94	struct ccid_dependency {
	95	u8 dependent_feat;
	96	bool is_local:1,
	97	is_mandatory:1;
	98	u8 val;
	99	};
	100
c02fdc0e GR	101	#ifdef CONFIG_IP_DCCP_DEBUG
	102	extern const char *dccp_feat_typename(const u8 type);
	103	extern const char *dccp_feat_name(const u8 feat);
	104
	105	static inline void dccp_feat_debug(const u8 type, const u8 feat, const u8 val)
	106	{
	107	dccp_pr_debug("%s(%s (%d), %d)\n", dccp_feat_typename(type),
	108	dccp_feat_name(feat), feat, val);
	109	}
	110	#else
	111	#define dccp_feat_debug(type, feat, val)
	112	#endif /* CONFIG_IP_DCCP_DEBUG */
afe00251	113
49aebc66 GR	114	extern int dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local,
	115	u8 const *list, u8 len);
	116	extern int dccp_feat_register_nn(struct sock *sk, u8 feat, u64 val);
afe00251 AB	117	extern int dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature,
	118	u8 *val, u8 len);
	119	extern int dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
	120	u8 *val, u8 len);
8ca0d17b	121	extern void dccp_feat_clean(struct dccp_minisock *dmsk);
afe00251	122	extern int dccp_feat_clone(struct sock oldsk, struct sock newsk);
ac75773c	123	extern int dccp_feat_clone_list(struct list_head const , struct list_head );
e8ef967a	124	extern int dccp_feat_init(struct sock *sk);
afe00251 AB	125
afe00251 AB	126	#endif /* _DCCP_FEAT_H */