[mirror_ubuntu-bionic-kernel.git] / net / dccp / dccp.h

#ifndef _DCCP_H
#define _DCCP_H
/*
 *  net/dccp/dccp.h
 *
 *  An implementation of the DCCP protocol
 *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
 *
 *	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/dccp.h>
#include <net/snmp.h>
#include <net/sock.h>
#include <net/tcp.h>

#define DCCP_DEBUG

#ifdef DCCP_DEBUG
extern int dccp_debug;

#define dccp_pr_debug(format, a...) \
	do { if (dccp_debug) \
		printk(KERN_DEBUG "%s: " format, __FUNCTION__ , ##a); \
	} while (0)
#define dccp_pr_debug_cat(format, a...) do { if (dccp_debug) \
					     printk(format, ##a); } while (0)
#else
#define dccp_pr_debug(format, a...)
#define dccp_pr_debug_cat(format, a...)
#endif

extern struct inet_hashinfo dccp_hashinfo;

extern atomic_t dccp_orphan_count;
extern int dccp_tw_count;
extern void dccp_tw_deschedule(struct inet_timewait_sock *tw);

extern void dccp_time_wait(struct sock *sk, int state, int timeo);

/* FIXME: Right size this */
#define DCCP_MAX_OPT_LEN 128

#define DCCP_MAX_PACKET_HDR 32

#define MAX_DCCP_HEADER  (DCCP_MAX_PACKET_HDR + DCCP_MAX_OPT_LEN + MAX_HEADER)

#define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
				     * state, about 60 seconds */

/* draft-ietf-dccp-spec-11.txt initial RTO value */
#define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))

/* Maximal interval between probes for local resources.  */
#define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))

#define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */

extern struct proto dccp_v4_prot;

/* is seq1 < seq2 ? */
static inline const  int before48(const u64 seq1, const u64 seq2)
{
	return (const s64)((seq1 << 16) - (seq2 << 16)) < 0;
}

/* is seq1 > seq2 ? */
static inline const  int after48(const u64 seq1, const u64 seq2)
{
	return (const s64)((seq2 << 16) - (seq1 << 16)) < 0;
}

/* is seq2 <= seq1 <= seq3 ? */
static inline const int between48(const u64 seq1, const u64 seq2,
				  const u64 seq3)
{
	return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
}

static inline u64 max48(const u64 seq1, const u64 seq2)
{
	return after48(seq1, seq2) ? seq1 : seq2;
}

enum {
	DCCP_MIB_NUM = 0,
	DCCP_MIB_ACTIVEOPENS,			/* ActiveOpens */
	DCCP_MIB_ESTABRESETS,			/* EstabResets */
	DCCP_MIB_CURRESTAB,			/* CurrEstab */
	DCCP_MIB_OUTSEGS,			/* OutSegs */ 
	DCCP_MIB_OUTRSTS,
	DCCP_MIB_ABORTONTIMEOUT,
	DCCP_MIB_TIMEOUTS,
	DCCP_MIB_ABORTFAILED,
	DCCP_MIB_PASSIVEOPENS,
	DCCP_MIB_ATTEMPTFAILS,
	DCCP_MIB_OUTDATAGRAMS,
	DCCP_MIB_INERRS,
	DCCP_MIB_OPTMANDATORYERROR,
	DCCP_MIB_INVALIDOPT,
	__DCCP_MIB_MAX
};

#define DCCP_MIB_MAX	__DCCP_MIB_MAX
struct dccp_mib {
	unsigned long	mibs[DCCP_MIB_MAX];
} __SNMP_MIB_ALIGN__;

DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
#define DCCP_INC_STATS(field)	    SNMP_INC_STATS(dccp_statistics, field)
#define DCCP_INC_STATS_BH(field)    SNMP_INC_STATS_BH(dccp_statistics, field)
#define DCCP_INC_STATS_USER(field)  SNMP_INC_STATS_USER(dccp_statistics, field)
#define DCCP_DEC_STATS(field)	    SNMP_DEC_STATS(dccp_statistics, field)
#define DCCP_ADD_STATS_BH(field, val) \
			SNMP_ADD_STATS_BH(dccp_statistics, field, val)
#define DCCP_ADD_STATS_USER(field, val)	\
			SNMP_ADD_STATS_USER(dccp_statistics, field, val)

extern int  dccp_transmit_skb(struct sock *sk, struct sk_buff *skb);
extern int  dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);

extern int dccp_send_response(struct sock *sk);
extern void dccp_send_ack(struct sock *sk);
extern void dccp_send_delayed_ack(struct sock *sk);
extern void dccp_send_sync(struct sock *sk, u64 seq);

extern int dccp_write_xmit(struct sock *sk, struct sk_buff *skb,
			   const int len);

extern void dccp_init_xmit_timers(struct sock *sk);
static inline void dccp_clear_xmit_timers(struct sock *sk)
{
	inet_csk_clear_xmit_timers(sk);
}

extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);

extern const char *dccp_packet_name(const int type);
extern const char *dccp_state_name(const int state);

static inline void dccp_set_state(struct sock *sk, const int state)
{
	const int oldstate = sk->sk_state;

	dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
		      dccp_role(sk), sk,
		      dccp_state_name(oldstate), dccp_state_name(state));
	WARN_ON(state == oldstate);

	switch (state) {
	case DCCP_OPEN:
		if (oldstate != DCCP_OPEN)
			DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
		break;

	case DCCP_CLOSED:
		if (oldstate == DCCP_CLOSING || oldstate == DCCP_OPEN)
			DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);

		sk->sk_prot->unhash(sk);
		if (inet_csk(sk)->icsk_bind_hash != NULL &&
		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
			inet_put_port(&dccp_hashinfo, sk);
		/* fall through */
	default:
		if (oldstate == DCCP_OPEN)
			DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
	}

	/* Change state AFTER socket is unhashed to avoid closed
	 * socket sitting in hash tables.
	 */
	sk->sk_state = state;
}

static inline void dccp_done(struct sock *sk)
{
	dccp_set_state(sk, DCCP_CLOSED);
	dccp_clear_xmit_timers(sk);

	sk->sk_shutdown = SHUTDOWN_MASK;

	if (!sock_flag(sk, SOCK_DEAD))
		sk->sk_state_change(sk);
	else
		inet_csk_destroy_sock(sk);
}

static inline void dccp_openreq_init(struct request_sock *req,
				     struct dccp_sock *dp,
				     struct sk_buff *skb)
{
	/*
	 * FIXME: fill in the other req fields from the DCCP options
	 * received
	 */
	inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
	inet_rsk(req)->acked	= 0;
	req->rcv_wnd = 0;
}

extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);

extern struct sock *dccp_create_openreq_child(struct sock *sk,
					      const struct request_sock *req,
					      const struct sk_buff *skb);

extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);

extern void dccp_v4_err(struct sk_buff *skb, u32);

extern int dccp_v4_rcv(struct sk_buff *skb);

extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
					      struct sk_buff *skb,
					      struct request_sock *req,
					      struct dst_entry *dst);
extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
				   struct request_sock *req,
				   struct request_sock **prev);

extern int dccp_child_process(struct sock *parent, struct sock *child,
			      struct sk_buff *skb);
extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
				  struct dccp_hdr *dh, unsigned len);
extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
				const struct dccp_hdr *dh, const unsigned len);

extern void		dccp_close(struct sock *sk, long timeout);
extern struct sk_buff	*dccp_make_response(struct sock *sk,
					    struct dst_entry *dst,
					    struct request_sock *req);

extern int	   dccp_connect(struct sock *sk);
extern int	   dccp_disconnect(struct sock *sk, int flags);
extern int	   dccp_getsockopt(struct sock *sk, int level, int optname,
				   char *optval, int *optlen);
extern int	   dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
extern int	   dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
				struct msghdr *msg, size_t size);
extern int	   dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
				struct msghdr *msg, size_t len, int nonblock,
				int flags, int *addr_len);
extern int	   dccp_setsockopt(struct sock *sk, int level, int optname,
				   char *optval, int optlen);
extern void	   dccp_shutdown(struct sock *sk, int how);

extern int	   dccp_v4_checksum(const struct sk_buff *skb,
				    const u32 saddr, const u32 daddr);

extern int	   dccp_v4_send_reset(struct sock *sk,
				      enum dccp_reset_codes code);
extern void	   dccp_send_close(struct sock *sk);

struct dccp_skb_cb {
	__u8 dccpd_type;
	__u8 dccpd_reset_code;
	__u8 dccpd_service;
	__u8 dccpd_ccval;
	__u64 dccpd_seq;
	__u64 dccpd_ack_seq;
	int  dccpd_opt_len;
};

#define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))

static inline int dccp_non_data_packet(const struct sk_buff *skb)
{
	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;

	return type == DCCP_PKT_ACK	 ||
	       type == DCCP_PKT_CLOSE	 ||
	       type == DCCP_PKT_CLOSEREQ ||
	       type == DCCP_PKT_RESET	 ||
	       type == DCCP_PKT_SYNC	 ||
	       type == DCCP_PKT_SYNCACK;
}

static inline int dccp_packet_without_ack(const struct sk_buff *skb)
{
	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;

	return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
}

#define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
#define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)

static inline void dccp_set_seqno(u64 *seqno, u64 value)
{
	if (value > DCCP_MAX_SEQNO)
		value -= DCCP_MAX_SEQNO + 1;
	*seqno = value;
}

static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
{
	return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
}

static inline void dccp_inc_seqno(u64 *seqno)
{
	if (++*seqno > DCCP_MAX_SEQNO)
		*seqno = 0;
}

static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
{
	struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
							   sizeof(*dh));

#if defined(__LITTLE_ENDIAN_BITFIELD)
	dh->dccph_seq	   = htonl((gss >> 32)) >> 8;
#elif defined(__BIG_ENDIAN_BITFIELD)
	dh->dccph_seq	   = htonl((gss >> 32));
#else
#error  "Adjust your <asm/byteorder.h> defines"
#endif
	dhx->dccph_seq_low = htonl(gss & 0xffffffff);
}

static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
				    const u64 gsr)
{
#if defined(__LITTLE_ENDIAN_BITFIELD)
	dhack->dccph_ack_nr_high = htonl((gsr >> 32)) >> 8;
#elif defined(__BIG_ENDIAN_BITFIELD)
	dhack->dccph_ack_nr_high = htonl((gsr >> 32));
#else
#error  "Adjust your <asm/byteorder.h> defines"
#endif
	dhack->dccph_ack_nr_low  = htonl(gsr & 0xffffffff);
}

static inline void dccp_update_gsr(struct sock *sk, u64 seq)
{
	struct dccp_sock *dp = dccp_sk(sk);
	u64 tmp_gsr;

	dccp_set_seqno(&tmp_gsr,
		       (dp->dccps_gsr + 1 -
		        (dp->dccps_options.dccpo_sequence_window / 4)));
	dp->dccps_gsr = seq;
	dccp_set_seqno(&dp->dccps_swl, max48(tmp_gsr, dp->dccps_isr));
	dccp_set_seqno(&dp->dccps_swh,
		       (dp->dccps_gsr +
			(3 * dp->dccps_options.dccpo_sequence_window) / 4));
}

static inline void dccp_update_gss(struct sock *sk, u64 seq)
{
	struct dccp_sock *dp = dccp_sk(sk);
	u64 tmp_gss;

	dccp_set_seqno(&tmp_gss,
		       (dp->dccps_gss -
			dp->dccps_options.dccpo_sequence_window + 1));
	dp->dccps_awl = max48(tmp_gss, dp->dccps_iss);
	dp->dccps_awh = dp->dccps_gss = seq;
}

extern void dccp_insert_options(struct sock *sk, struct sk_buff *skb);
extern void dccp_insert_option_elapsed_time(struct sock *sk,
					    struct sk_buff *skb,
					    u32 elapsed_time);
extern void dccp_insert_option(struct sock *sk, struct sk_buff *skb,
			       unsigned char option,
			       const void *value, unsigned char len);

extern struct socket *dccp_ctl_socket;

#define DCCP_ACKPKTS_STATE_RECEIVED	0
#define DCCP_ACKPKTS_STATE_ECN_MARKED	(1 << 6)
#define DCCP_ACKPKTS_STATE_NOT_RECEIVED	(3 << 6)

#define DCCP_ACKPKTS_STATE_MASK		0xC0 /* 11000000 */
#define DCCP_ACKPKTS_LEN_MASK		0x3F /* 00111111 */

/** struct dccp_ackpkts - acknowledgeable packets
 *
 * This data structure is the one defined in the DCCP draft
 * Appendix A.
 *
 * @dccpap_buf_head - circular buffer head
 * @dccpap_buf_tail - circular buffer tail
 * @dccpap_buf_ackno - ack # of the most recent packet acknowledgeable in the
 * 		       buffer (i.e. %dccpap_buf_head)
 * @dccpap_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
 * 		       by the buffer with State 0
 *
 * Additionally, the HC-Receiver must keep some information about the
 * Ack Vectors it has recently sent. For each packet sent carrying an
 * Ack Vector, it remembers four variables:
 *
 * @dccpap_ack_seqno - the Sequence Number used for the packet
 * 		       (HC-Receiver seqno)
 * @dccpap_ack_ptr - the value of buf_head at the time of acknowledgement.
 * @dccpap_ack_ackno - the Acknowledgement Number used for the packet
 * 		       (HC-Sender seqno)
 * @dccpap_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
 *
 * @dccpap_buf_len - circular buffer length
 * @dccpap_buf - circular buffer of acknowledgeable packets
 */
struct dccp_ackpkts {
	unsigned int		dccpap_buf_head;
	unsigned int		dccpap_buf_tail;
	u64			dccpap_buf_ackno;
	u64			dccpap_ack_seqno;
	u64			dccpap_ack_ackno;
	unsigned int		dccpap_ack_ptr;
	unsigned int		dccpap_buf_vector_len;
	unsigned int		dccpap_ack_vector_len;
	unsigned int		dccpap_buf_len;
	unsigned long           dccpap_time;
	u8			dccpap_buf_nonce;
	u8			dccpap_ack_nonce;
	u8			dccpap_buf[0];
};

extern struct dccp_ackpkts *dccp_ackpkts_alloc(unsigned int len, int priority);
extern void dccp_ackpkts_free(struct dccp_ackpkts *ap);
extern int dccp_ackpkts_add(struct dccp_ackpkts *ap, u64 ackno, u8 state);
extern void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap,
					 struct sock *sk, u64 ackno);

#ifdef DCCP_DEBUG
extern void dccp_ackvector_print(const u64 ackno,
				 const unsigned char *vector, int len);
extern void dccp_ackpkts_print(const struct dccp_ackpkts *ap);
#else
static inline void dccp_ackvector_print(const u64 ackno,
					const unsigned char *vector,
					int len) { }
static inline void dccp_ackpkts_print(const struct dccp_ackpkts *ap) { }
#endif

#endif /* _DCCP_H */
Commit	Line	Data
7c657876 ACM	1	#ifndef _DCCP_H
	2	#define _DCCP_H
	3	/*
	4	* net/dccp/dccp.h
	5	*
	6	* An implementation of the DCCP protocol
	7	* Arnaldo Carvalho de Melo <acme@conectiva.com.br>
	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/dccp.h>
	15	#include <net/snmp.h>
	16	#include <net/sock.h>
	17	#include <net/tcp.h>
	18
	19	#define DCCP_DEBUG
	20
	21	#ifdef DCCP_DEBUG
	22	extern int dccp_debug;
	23
	24	#define dccp_pr_debug(format, a...) \
	25	do { if (dccp_debug) \
	26	printk(KERN_DEBUG "%s: " format, __FUNCTION__ , ##a); \
	27	} while (0)
7690af3f ACM	28	#define dccp_pr_debug_cat(format, a...) do { if (dccp_debug) \
7690af3f ACM	29	printk(format, ##a); } while (0)
7c657876 ACM	30	#else
	31	#define dccp_pr_debug(format, a...)
	32	#define dccp_pr_debug_cat(format, a...)
	33	#endif
	34
	35	extern struct inet_hashinfo dccp_hashinfo;
	36
	37	extern atomic_t dccp_orphan_count;
	38	extern int dccp_tw_count;
	39	extern void dccp_tw_deschedule(struct inet_timewait_sock *tw);
	40
	41	extern void dccp_time_wait(struct sock *sk, int state, int timeo);
	42
	43	/* FIXME: Right size this */
	44	#define DCCP_MAX_OPT_LEN 128
	45
	46	#define DCCP_MAX_PACKET_HDR 32
	47
	48	#define MAX_DCCP_HEADER (DCCP_MAX_PACKET_HDR + DCCP_MAX_OPT_LEN + MAX_HEADER)
	49
	50	#define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
	51	* state, about 60 seconds */
	52
	53	/* draft-ietf-dccp-spec-11.txt initial RTO value */
	54	#define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
	55
	56	/* Maximal interval between probes for local resources. */
	57	#define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
	58
	59	#define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */
	60
	61	extern struct proto dccp_v4_prot;
	62
	63	/* is seq1 < seq2 ? */
	64	static inline const int before48(const u64 seq1, const u64 seq2)
	65	{
	66	return (const s64)((seq1 << 16) - (seq2 << 16)) < 0;
	67	}
	68
	69	/* is seq1 > seq2 ? */
	70	static inline const int after48(const u64 seq1, const u64 seq2)
	71	{
	72	return (const s64)((seq2 << 16) - (seq1 << 16)) < 0;
	73	}
	74
	75	/* is seq2 <= seq1 <= seq3 ? */
7690af3f ACM	76	static inline const int between48(const u64 seq1, const u64 seq2,
7690af3f ACM	77	const u64 seq3)
7c657876 ACM	78	{
	79	return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
	80	}
	81
	82	static inline u64 max48(const u64 seq1, const u64 seq2)
	83	{
	84	return after48(seq1, seq2) ? seq1 : seq2;
	85	}
	86
	87	enum {
	88	DCCP_MIB_NUM = 0,
	89	DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
	90	DCCP_MIB_ESTABRESETS, /* EstabResets */
	91	DCCP_MIB_CURRESTAB, /* CurrEstab */
	92	DCCP_MIB_OUTSEGS, /* OutSegs */
	93	DCCP_MIB_OUTRSTS,
	94	DCCP_MIB_ABORTONTIMEOUT,
	95	DCCP_MIB_TIMEOUTS,
	96	DCCP_MIB_ABORTFAILED,
	97	DCCP_MIB_PASSIVEOPENS,
	98	DCCP_MIB_ATTEMPTFAILS,
	99	DCCP_MIB_OUTDATAGRAMS,
	100	DCCP_MIB_INERRS,
	101	DCCP_MIB_OPTMANDATORYERROR,
	102	DCCP_MIB_INVALIDOPT,
	103	__DCCP_MIB_MAX
	104	};
	105
	106	#define DCCP_MIB_MAX __DCCP_MIB_MAX
	107	struct dccp_mib {
	108	unsigned long mibs[DCCP_MIB_MAX];
	109	} __SNMP_MIB_ALIGN__;
	110
	111	DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
7690af3f ACM	112	#define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
	113	#define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
	114	#define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
	115	#define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
	116	#define DCCP_ADD_STATS_BH(field, val) \
	117	SNMP_ADD_STATS_BH(dccp_statistics, field, val)
	118	#define DCCP_ADD_STATS_USER(field, val) \
	119	SNMP_ADD_STATS_USER(dccp_statistics, field, val)
7c657876 ACM	120
	121	extern int dccp_transmit_skb(struct sock sk, struct sk_buff skb);
	122	extern int dccp_retransmit_skb(struct sock sk, struct sk_buff skb);
	123
	124	extern int dccp_send_response(struct sock *sk);
	125	extern void dccp_send_ack(struct sock *sk);
	126	extern void dccp_send_delayed_ack(struct sock *sk);
	127	extern void dccp_send_sync(struct sock *sk, u64 seq);
	128
27258ee5 ACM	129	extern int dccp_write_xmit(struct sock sk, struct sk_buff skb,
	130	const int len);
	131
7c657876 ACM	132	extern void dccp_init_xmit_timers(struct sock *sk);
	133	static inline void dccp_clear_xmit_timers(struct sock *sk)
	134	{
	135	inet_csk_clear_xmit_timers(sk);
	136	}
	137
	138	extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
	139
	140	extern const char *dccp_packet_name(const int type);
	141	extern const char *dccp_state_name(const int state);
	142
	143	static inline void dccp_set_state(struct sock *sk, const int state)
	144	{
	145	const int oldstate = sk->sk_state;
	146
	147	dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
	148	dccp_role(sk), sk,
	149	dccp_state_name(oldstate), dccp_state_name(state));
	150	WARN_ON(state == oldstate);
	151
	152	switch (state) {
	153	case DCCP_OPEN:
	154	if (oldstate != DCCP_OPEN)
	155	DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
	156	break;
	157
	158	case DCCP_CLOSED:
	159	if (oldstate == DCCP_CLOSING \|\| oldstate == DCCP_OPEN)
	160	DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
	161
	162	sk->sk_prot->unhash(sk);
	163	if (inet_csk(sk)->icsk_bind_hash != NULL &&
	164	!(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
	165	inet_put_port(&dccp_hashinfo, sk);
	166	/* fall through */
	167	default:
	168	if (oldstate == DCCP_OPEN)
	169	DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
	170	}
	171
	172	/* Change state AFTER socket is unhashed to avoid closed
	173	* socket sitting in hash tables.
	174	*/
	175	sk->sk_state = state;
	176	}
	177
	178	static inline void dccp_done(struct sock *sk)
	179	{
	180	dccp_set_state(sk, DCCP_CLOSED);
	181	dccp_clear_xmit_timers(sk);
	182
	183	sk->sk_shutdown = SHUTDOWN_MASK;
	184
	185	if (!sock_flag(sk, SOCK_DEAD))
	186	sk->sk_state_change(sk);
	187	else
	188	inet_csk_destroy_sock(sk);
	189	}
	190
	191	static inline void dccp_openreq_init(struct request_sock *req,
	192	struct dccp_sock *dp,
	193	struct sk_buff *skb)
	194	{
	195	/*
196	* FIXME: fill in the other req fields from the DCCP options
197	* received
198	*/
199	inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
200	inet_rsk(req)->acked = 0;
201	req->rcv_wnd = 0;
202	}
203
7c657876 ACM	204	extern int dccp_v4_conn_request(struct sock sk, struct sk_buff skb);
	205
	206	extern struct sock dccp_create_openreq_child(struct sock sk,
	207	const struct request_sock *req,
	208	const struct sk_buff *skb);
	209
	210	extern int dccp_v4_do_rcv(struct sock sk, struct sk_buff skb);
	211
	212	extern void dccp_v4_err(struct sk_buff *skb, u32);
	213
	214	extern int dccp_v4_rcv(struct sk_buff *skb);
	215
	216	extern struct sock dccp_v4_request_recv_sock(struct sock sk,
	217	struct sk_buff *skb,
	218	struct request_sock *req,
	219	struct dst_entry *dst);
	220	extern struct sock dccp_check_req(struct sock sk, struct sk_buff *skb,
	221	struct request_sock *req,
	222	struct request_sock **prev);
	223
	224	extern int dccp_child_process(struct sock parent, struct sock child,
	225	struct sk_buff *skb);
	226	extern int dccp_rcv_state_process(struct sock sk, struct sk_buff skb,
	227	struct dccp_hdr *dh, unsigned len);
	228	extern int dccp_rcv_established(struct sock sk, struct sk_buff skb,
	229	const struct dccp_hdr *dh, const unsigned len);
	230
	231	extern void dccp_close(struct sock *sk, long timeout);
	232	extern struct sk_buff dccp_make_response(struct sock sk,
	233	struct dst_entry *dst,
	234	struct request_sock *req);
	235
	236	extern int dccp_connect(struct sock *sk);
	237	extern int dccp_disconnect(struct sock *sk, int flags);
	238	extern int dccp_getsockopt(struct sock *sk, int level, int optname,
	239	char optval, int optlen);
	240	extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
7690af3f ACM	241	extern int dccp_sendmsg(struct kiocb iocb, struct sock sk,
7690af3f ACM	242	struct msghdr *msg, size_t size);
7c657876 ACM	243	extern int dccp_recvmsg(struct kiocb iocb, struct sock sk,
	244	struct msghdr *msg, size_t len, int nonblock,
	245	int flags, int *addr_len);
	246	extern int dccp_setsockopt(struct sock *sk, int level, int optname,
	247	char *optval, int optlen);
	248	extern void dccp_shutdown(struct sock *sk, int how);
	249
95b81ef7 YN	250	extern int dccp_v4_checksum(const struct sk_buff *skb,
95b81ef7 YN	251	const u32 saddr, const u32 daddr);
7c657876	252
7690af3f ACM	253	extern int dccp_v4_send_reset(struct sock *sk,
7690af3f ACM	254	enum dccp_reset_codes code);
7c657876 ACM	255	extern void dccp_send_close(struct sock *sk);
	256
	257	struct dccp_skb_cb {
	258	__u8 dccpd_type;
	259	__u8 dccpd_reset_code;
	260	__u8 dccpd_service;
	261	__u8 dccpd_ccval;
	262	__u64 dccpd_seq;
	263	__u64 dccpd_ack_seq;
	264	int dccpd_opt_len;
	265	};
	266
	267	#define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
	268
	269	static inline int dccp_non_data_packet(const struct sk_buff *skb)
	270	{
	271	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
	272
	273	return type == DCCP_PKT_ACK \|\|
	274	type == DCCP_PKT_CLOSE \|\|
	275	type == DCCP_PKT_CLOSEREQ \|\|
	276	type == DCCP_PKT_RESET \|\|
	277	type == DCCP_PKT_SYNC \|\|
	278	type == DCCP_PKT_SYNCACK;
	279	}
	280
	281	static inline int dccp_packet_without_ack(const struct sk_buff *skb)
	282	{
	283	const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
	284
	285	return type == DCCP_PKT_DATA \|\| type == DCCP_PKT_REQUEST;
	286	}
	287
	288	#define DCCP_MAX_SEQNO ((((u64)1) << 48) - 1)
	289	#define DCCP_PKT_WITHOUT_ACK_SEQ (DCCP_MAX_SEQNO << 2)
	290
	291	static inline void dccp_set_seqno(u64 *seqno, u64 value)
	292	{
	293	if (value > DCCP_MAX_SEQNO)
	294	value -= DCCP_MAX_SEQNO + 1;
	295	*seqno = value;
	296	}
	297
	298	static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
	299	{
	300	return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
	301	}
	302
	303	static inline void dccp_inc_seqno(u64 *seqno)
	304	{
	305	if (++*seqno > DCCP_MAX_SEQNO)
	306	*seqno = 0;
	307	}
	308
	309	static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
	310	{
7690af3f ACM	311	struct dccp_hdr_ext dhx = (struct dccp_hdr_ext )((void *)dh +
7690af3f ACM	312	sizeof(*dh));
7c657876 ACM	313
	314	#if defined(__LITTLE_ENDIAN_BITFIELD)
	315	dh->dccph_seq = htonl((gss >> 32)) >> 8;
	316	#elif defined(__BIG_ENDIAN_BITFIELD)
	317	dh->dccph_seq = htonl((gss >> 32));
	318	#else
	319	#error "Adjust your <asm/byteorder.h> defines"
	320	#endif
	321	dhx->dccph_seq_low = htonl(gss & 0xffffffff);
	322	}
	323
7690af3f ACM	324	static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
7690af3f ACM	325	const u64 gsr)
7c657876 ACM	326	{
	327	#if defined(__LITTLE_ENDIAN_BITFIELD)
	328	dhack->dccph_ack_nr_high = htonl((gsr >> 32)) >> 8;
	329	#elif defined(__BIG_ENDIAN_BITFIELD)
	330	dhack->dccph_ack_nr_high = htonl((gsr >> 32));
	331	#else
	332	#error "Adjust your <asm/byteorder.h> defines"
	333	#endif
	334	dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
	335	}
	336
	337	static inline void dccp_update_gsr(struct sock *sk, u64 seq)
	338	{
	339	struct dccp_sock *dp = dccp_sk(sk);
	340	u64 tmp_gsr;
	341
7690af3f ACM	342	dccp_set_seqno(&tmp_gsr,
	343	(dp->dccps_gsr + 1 -
	344	(dp->dccps_options.dccpo_sequence_window / 4)));
7c657876 ACM	345	dp->dccps_gsr = seq;
	346	dccp_set_seqno(&dp->dccps_swl, max48(tmp_gsr, dp->dccps_isr));
	347	dccp_set_seqno(&dp->dccps_swh,
7690af3f ACM	348	(dp->dccps_gsr +
7690af3f ACM	349	(3 * dp->dccps_options.dccpo_sequence_window) / 4));
7c657876 ACM	350	}
	351
	352	static inline void dccp_update_gss(struct sock *sk, u64 seq)
	353	{
	354	struct dccp_sock *dp = dccp_sk(sk);
	355	u64 tmp_gss;
	356
7690af3f ACM	357	dccp_set_seqno(&tmp_gss,
	358	(dp->dccps_gss -
	359	dp->dccps_options.dccpo_sequence_window + 1));
7c657876 ACM	360	dp->dccps_awl = max48(tmp_gss, dp->dccps_iss);
	361	dp->dccps_awh = dp->dccps_gss = seq;
	362	}
	363
	364	extern void dccp_insert_options(struct sock sk, struct sk_buff skb);
	365	extern void dccp_insert_option_elapsed_time(struct sock *sk,
	366	struct sk_buff *skb,
	367	u32 elapsed_time);
	368	extern void dccp_insert_option(struct sock sk, struct sk_buff skb,
	369	unsigned char option,
	370	const void *value, unsigned char len);
	371
	372	extern struct socket *dccp_ctl_socket;
	373
	374	#define DCCP_ACKPKTS_STATE_RECEIVED 0
	375	#define DCCP_ACKPKTS_STATE_ECN_MARKED (1 << 6)
	376	#define DCCP_ACKPKTS_STATE_NOT_RECEIVED (3 << 6)
	377
	378	#define DCCP_ACKPKTS_STATE_MASK 0xC0 /* 11000000 */
	379	#define DCCP_ACKPKTS_LEN_MASK 0x3F /* 00111111 */
	380
	381	/** struct dccp_ackpkts - acknowledgeable packets
	382	*
	383	* This data structure is the one defined in the DCCP draft
	384	* Appendix A.
	385	*
	386	* @dccpap_buf_head - circular buffer head
	387	* @dccpap_buf_tail - circular buffer tail
7690af3f ACM	388	* @dccpap_buf_ackno - ack # of the most recent packet acknowledgeable in the
	389	* buffer (i.e. %dccpap_buf_head)
	390	* @dccpap_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked
	391	* by the buffer with State 0
7c657876 ACM	392	*
	393	* Additionally, the HC-Receiver must keep some information about the
	394	* Ack Vectors it has recently sent. For each packet sent carrying an
	395	* Ack Vector, it remembers four variables:
	396	*
7690af3f ACM	397	* @dccpap_ack_seqno - the Sequence Number used for the packet
7690af3f ACM	398	* (HC-Receiver seqno)
7c657876	399	* @dccpap_ack_ptr - the value of buf_head at the time of acknowledgement.
7690af3f ACM	400	* @dccpap_ack_ackno - the Acknowledgement Number used for the packet
7690af3f ACM	401	* (HC-Sender seqno)
7c657876 ACM	402	* @dccpap_ack_nonce - the one-bit sum of the ECN Nonces for all State 0.
	403	*
	404	* @dccpap_buf_len - circular buffer length
	405	* @dccpap_buf - circular buffer of acknowledgeable packets
	406	*/
	407	struct dccp_ackpkts {
	408	unsigned int dccpap_buf_head;
	409	unsigned int dccpap_buf_tail;
	410	u64 dccpap_buf_ackno;
	411	u64 dccpap_ack_seqno;
	412	u64 dccpap_ack_ackno;
	413	unsigned int dccpap_ack_ptr;
	414	unsigned int dccpap_buf_vector_len;
	415	unsigned int dccpap_ack_vector_len;
	416	unsigned int dccpap_buf_len;
	417	unsigned long dccpap_time;
	418	u8 dccpap_buf_nonce;
	419	u8 dccpap_ack_nonce;
	420	u8 dccpap_buf[0];
	421	};
	422
	423	extern struct dccp_ackpkts *dccp_ackpkts_alloc(unsigned int len, int priority);
	424	extern void dccp_ackpkts_free(struct dccp_ackpkts *ap);
	425	extern int dccp_ackpkts_add(struct dccp_ackpkts *ap, u64 ackno, u8 state);
	426	extern void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap,
	427	struct sock *sk, u64 ackno);
	428
	429	#ifdef DCCP_DEBUG
	430	extern void dccp_ackvector_print(const u64 ackno,
	431	const unsigned char *vector, int len);
	432	extern void dccp_ackpkts_print(const struct dccp_ackpkts *ap);
	433	#else
	434	static inline void dccp_ackvector_print(const u64 ackno,
	435	const unsigned char *vector,
	436	int len) { }
	437	static inline void dccp_ackpkts_print(const struct dccp_ackpkts *ap) { }
	438	#endif
	439
	440	#endif /* _DCCP_H */