xref: /illumos-gate/usr/src/uts/common/inet/sctp/sctp_impl.h (revision 1a5e258f)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
 */

#ifndef	_INET_SCTP_SCTP_IMPL_H
#define	_INET_SCTP_SCTP_IMPL_H

#include <sys/inttypes.h>
#include <sys/taskq.h>
#include <sys/list.h>
#include <sys/strsun.h>
#include <sys/zone.h>
#include <sys/cpuvar.h>
#include <sys/clock_impl.h>

#include <netinet/ip6.h>
#include <inet/optcom.h>
#include <inet/tunables.h>
#include <netinet/sctp.h>
#include <inet/sctp_itf.h>
#include "sctp_stack.h"

#ifdef	__cplusplus
extern "C" {
#endif

/* Streams device identifying info and version */
#define	SCTP_DEV_IDINFO	"SCTP Streams device 1.0"

#define	SSN_GT(a, b)	((int16_t)((a)-(b)) > 0)
#define	SSN_GE(a, b)	((int16_t)((a)-(b)) >= 0)

/* Default buffer size and flow control wake up threshold. */
#define	SCTP_XMIT_LOWATER	8192
#define	SCTP_XMIT_HIWATER	102400
#define	SCTP_RECV_LOWATER	8192
#define	SCTP_RECV_HIWATER	102400

/* SCTP Timer control structure */
typedef struct sctpt_s {
	pfv_t	sctpt_pfv;	/* The routine we are to call */
	struct sctp_s *sctpt_sctp;	/* The parameter we are to pass in */
	struct sctp_faddr_s *sctpt_faddr;
} sctpt_t;

/*
 * Maximum number of duplicate TSNs we can report. This is currently
 * static, and governs the size of the mblk used to hold the duplicate
 * reports. The use of duplcate TSN reports is currently experimental,
 * so for now a static limit should suffice.
 */
#define	SCTP_DUP_MBLK_SZ	64

#define	SCTP_IS_ADDR_UNSPEC(isv4, addr)		\
	((isv4) ? IN6_IS_ADDR_V4MAPPED_ANY(&(addr)) :	\
	IN6_IS_ADDR_UNSPECIFIED(&(addr)))

/*
 * SCTP properties/tunables
 */
#define	sctps_max_init_retr		sctps_propinfo_tbl[0].prop_cur_uval
#define	sctps_max_init_retr_high	sctps_propinfo_tbl[0].prop_max_uval
#define	sctps_max_init_retr_low		sctps_propinfo_tbl[0].prop_min_uval
#define	sctps_pa_max_retr		sctps_propinfo_tbl[1].prop_cur_uval
#define	sctps_pa_max_retr_high		sctps_propinfo_tbl[1].prop_max_uval
#define	sctps_pa_max_retr_low		sctps_propinfo_tbl[1].prop_min_uval
#define	sctps_pp_max_retr		sctps_propinfo_tbl[2].prop_cur_uval
#define	sctps_pp_max_retr_high		sctps_propinfo_tbl[2].prop_max_uval
#define	sctps_pp_max_retr_low		sctps_propinfo_tbl[2].prop_min_uval
#define	sctps_cwnd_max_			sctps_propinfo_tbl[3].prop_cur_uval
#define	sctps_smallest_nonpriv_port	sctps_propinfo_tbl[4].prop_cur_uval
#define	sctps_ipv4_ttl			sctps_propinfo_tbl[5].prop_cur_uval
#define	sctps_heartbeat_interval	sctps_propinfo_tbl[6].prop_cur_uval
#define	sctps_heartbeat_interval_high	sctps_propinfo_tbl[6].prop_max_uval
#define	sctps_heartbeat_interval_low	sctps_propinfo_tbl[6].prop_min_uval
#define	sctps_initial_mtu		sctps_propinfo_tbl[7].prop_cur_uval
#define	sctps_mtu_probe_interval	sctps_propinfo_tbl[8].prop_cur_uval
#define	sctps_new_secret_interval	sctps_propinfo_tbl[9].prop_cur_uval
#define	sctps_deferred_ack_interval	sctps_propinfo_tbl[10].prop_cur_uval
#define	sctps_snd_lowat_fraction	sctps_propinfo_tbl[11].prop_cur_uval
#define	sctps_ignore_path_mtu		sctps_propinfo_tbl[12].prop_cur_bval
#define	sctps_initial_ssthresh		sctps_propinfo_tbl[13].prop_cur_uval
#define	sctps_smallest_anon_port	sctps_propinfo_tbl[14].prop_cur_uval
#define	sctps_largest_anon_port		sctps_propinfo_tbl[15].prop_cur_uval
#define	sctps_xmit_hiwat		sctps_propinfo_tbl[16].prop_cur_uval
#define	sctps_xmit_lowat		sctps_propinfo_tbl[17].prop_cur_uval
#define	sctps_recv_hiwat		sctps_propinfo_tbl[18].prop_cur_uval
#define	sctps_max_buf			sctps_propinfo_tbl[19].prop_cur_uval
#define	sctps_rtt_updates		sctps_propinfo_tbl[20].prop_cur_uval
#define	sctps_ipv6_hoplimit		sctps_propinfo_tbl[21].prop_cur_uval
#define	sctps_rto_ming			sctps_propinfo_tbl[22].prop_cur_uval
#define	sctps_rto_ming_high		sctps_propinfo_tbl[22].prop_max_uval
#define	sctps_rto_ming_low		sctps_propinfo_tbl[22].prop_min_uval
#define	sctps_rto_maxg			sctps_propinfo_tbl[23].prop_cur_uval
#define	sctps_rto_maxg_high		sctps_propinfo_tbl[23].prop_max_uval
#define	sctps_rto_maxg_low		sctps_propinfo_tbl[23].prop_min_uval
#define	sctps_rto_initialg		sctps_propinfo_tbl[24].prop_cur_uval
#define	sctps_rto_initialg_high		sctps_propinfo_tbl[24].prop_max_uval
#define	sctps_rto_initialg_low		sctps_propinfo_tbl[24].prop_min_uval
#define	sctps_cookie_life		sctps_propinfo_tbl[25].prop_cur_uval
#define	sctps_cookie_life_high		sctps_propinfo_tbl[25].prop_max_uval
#define	sctps_cookie_life_low		sctps_propinfo_tbl[25].prop_min_uval
#define	sctps_max_in_streams		sctps_propinfo_tbl[26].prop_cur_uval
#define	sctps_max_in_streams_high	sctps_propinfo_tbl[26].prop_max_uval
#define	sctps_max_in_streams_low	sctps_propinfo_tbl[26].prop_min_uval
#define	sctps_initial_out_streams	sctps_propinfo_tbl[27].prop_cur_uval
#define	sctps_initial_out_streams_high	sctps_propinfo_tbl[27].prop_max_uval
#define	sctps_initial_out_streams_low	sctps_propinfo_tbl[27].prop_min_uval
#define	sctps_shutack_wait_bound	sctps_propinfo_tbl[28].prop_cur_uval
#define	sctps_maxburst			sctps_propinfo_tbl[29].prop_cur_uval
#define	sctps_addip_enabled		sctps_propinfo_tbl[30].prop_cur_bval
#define	sctps_recv_hiwat_minmss		sctps_propinfo_tbl[31].prop_cur_uval
#define	sctps_slow_start_initial	sctps_propinfo_tbl[32].prop_cur_uval
#define	sctps_slow_start_after_idle	sctps_propinfo_tbl[33].prop_cur_uval
#define	sctps_prsctp_enabled		sctps_propinfo_tbl[34].prop_cur_bval
#define	sctps_fast_rxt_thresh		sctps_propinfo_tbl[35].prop_cur_uval
#define	sctps_deferred_acks_max		sctps_propinfo_tbl[36].prop_cur_uval
#define	sctps_wroff_xtra		sctps_propinfo_tbl[37].prop_cur_uval

/*
 * Retransmission timer start and stop macro for a given faddr.
 */
#define	SCTP_FADDR_TIMER_RESTART(sctp, fp, intvl)			\
{									\
	dprint(3, ("faddr_timer_restart: fp=%p %x:%x:%x:%x %d\n",	\
	    (void *)(fp), SCTP_PRINTADDR((fp)->sf_faddr), (int)(intvl))); \
	sctp_timer((sctp), (fp)->sf_timer_mp, (intvl));			\
	(fp)->sf_timer_running = 1;					\
}

#define	SCTP_FADDR_TIMER_STOP(fp)			\
	ASSERT((fp)->sf_timer_mp != NULL);		\
	if ((fp)->sf_timer_running) {			\
		sctp_timer_stop((fp)->sf_timer_mp);	\
		(fp)->sf_timer_running = 0;		\
	}

/* For per endpoint association statistics */
#define	SCTP_MAX_RTO(sctp, fp) {			\
	/*						\
	 * Record the maximum observed RTO,		\
	 * sctp_maxrto is zeroed elsewhere		\
	 * at the end of each stats request.		\
	 */						\
	(sctp)->sctp_maxrto =				\
	    MAX((sctp)->sctp_maxrto, (fp)->sf_rto);	\
	DTRACE_PROBE2(sctp__maxrto, sctp_t *,		\
	    sctp, struct sctp_faddr_s, fp);		\
}

#define	SCTP_CALC_RXT(sctp, fp, max)	\
{					\
	if (((fp)->sf_rto <<= 1) > (max))	\
		(fp)->sf_rto = (max);	\
	SCTP_MAX_RTO(sctp, fp);		\
}


#define	SCTP_MAX_COMBINED_HEADER_LENGTH	(60 + 12) /* Maxed out ip + sctp */
#define	SCTP_MAX_IP_OPTIONS_LENGTH	(60 - IP_SIMPLE_HDR_LENGTH)
#define	SCTP_MAX_HDR_LENGTH		60

#define	SCTP_SECRET_LEN	16

#define	SCTP_REFHOLD(sctp) {				\
	mutex_enter(&(sctp)->sctp_reflock);		\
	(sctp)->sctp_refcnt++;				\
	DTRACE_PROBE1(sctp_refhold, sctp_t, sctp);	\
	ASSERT((sctp)->sctp_refcnt != 0);		\
	mutex_exit(&(sctp)->sctp_reflock);		\
}

#define	SCTP_REFRELE(sctp) {					\
	mutex_enter(&(sctp)->sctp_reflock);			\
	ASSERT((sctp)->sctp_refcnt != 0);			\
	if (--(sctp)->sctp_refcnt == 0) {			\
		DTRACE_PROBE1(sctp_refrele, sctp_t, sctp);	\
		mutex_exit(&(sctp)->sctp_reflock);		\
		CONN_DEC_REF((sctp)->sctp_connp);		\
	} else {						\
		DTRACE_PROBE1(sctp_refrele, sctp_t, sctp);	\
		mutex_exit(&(sctp)->sctp_reflock);		\
	}							\
}

#define	SCTP_PRINTADDR(a)	(a).s6_addr32[0], (a).s6_addr32[1],\
				(a).s6_addr32[2], (a).s6_addr32[3]

#define	CONN2SCTP(conn)	((sctp_t *)(&((conn_t *)conn)[1]))

/*
 * Outbound data, flags and macros for per-message, per-chunk info
 */
typedef struct {
	int64_t		smh_ttl;		/* Time to Live */
	int64_t		smh_tob;		/* Time of Birth */
	uint32_t	smh_context;
	uint16_t	smh_sid;
	uint16_t	smh_ssn;
	uint32_t	smh_ppid;
	uint16_t	smh_flags;
	uint32_t	smh_msglen;
} sctp_msg_hdr_t;

#define	SCTP_CHUNK_FLAG_SENT		0x01
#define	SCTP_CHUNK_FLAG_REXMIT		0x02
#define	SCTP_CHUNK_FLAG_ACKED		0x04
#define	SCTP_MSG_FLAG_CHUNKED		0x08
#define	SCTP_MSG_FLAG_ABANDONED		0x10
#define	SCTP_CHUNK_FLAG_ABANDONED	0x20

#define	SCTP_CHUNK_CLEAR_FLAGS(mp) ((mp)->b_flag = 0)
/*
 * If we are transmitting the chunk for the first time we assign the TSN and
 * SSN here. The reason we assign the SSN here (as opposed to doing it in
 * sctp_chunkify()) is that the chunk may expire, if PRSCTP is enabled, before
 * we get a chance to send it out. If we assign the SSN in sctp_chunkify()
 * and this happens, then we need to send a Forward TSN to the peer, which
 * will be expecting this SSN, assuming ordered. If we assign it here we
 * can just take out the chunk from the transmit list without having to
 * send a Forward TSN chunk. While assigning the SSN we use (meta)->b_cont
 * to determine if it needs a new SSN (i.e. the next SSN for the stream),
 * since (meta)->b_cont signifies the first chunk of a message (if the message
 * is unordered, then the SSN is 0).
 *
 */
#define	SCTP_CHUNK_SENT(sctp, mp, sdc, fp, chunkdata, meta) {		\
	if (!SCTP_CHUNK_ISSENT(mp)) {					\
		sctp_msg_hdr_t	*mhdr = (sctp_msg_hdr_t *)(meta)->b_rptr; \
		ASSERT(!SCTP_CHUNK_ABANDONED(mp));			\
		(mp)->b_flag = SCTP_CHUNK_FLAG_SENT;			\
		(sdc)->sdh_tsn = htonl((sctp)->sctp_ltsn++);		\
		if ((mhdr)->smh_flags & MSG_UNORDERED) {		\
			(sdc)->sdh_ssn = 0;				\
			SCTP_DATA_SET_UBIT(sdc);			\
			BUMP_LOCAL((sctp)->sctp_oudchunks);		\
		} else {						\
			BUMP_LOCAL((sctp)->sctp_odchunks);		\
			if ((mp) == (meta)->b_cont) {			\
				mhdr->smh_ssn = htons(			\
				    (sctp)->sctp_ostrcntrs[mhdr->smh_sid]++); \
			}						\
			(sdc)->sdh_ssn = mhdr->smh_ssn;			\
		}							\
		DTRACE_PROBE3(sctp__chunk__sent1, sctp_t *, sctp,	\
		    mblk_t *, mp, mblk_t *, meta);			\
		(sctp)->sctp_unacked += (chunkdata);			\
		(sctp)->sctp_unsent -= (chunkdata);			\
		(sctp)->sctp_frwnd -= (chunkdata);			\
	} else {							\
		if (SCTP_CHUNK_ISACKED(mp)) {				\
			(sctp)->sctp_unacked += (chunkdata);		\
		} else {						\
			ASSERT(SCTP_CHUNK_DEST(mp)->sf_suna >= ((chunkdata) + \
							sizeof (*sdc))); \
			SCTP_CHUNK_DEST(mp)->sf_suna -= ((chunkdata) + 	\
					sizeof (*sdc));			\
		}							\
		DTRACE_PROBE3(sctp__chunk__sent2, sctp_t *, sctp,	\
		    mblk_t *, mp, mblk_t *, meta);			\
		(mp)->b_flag &= ~(SCTP_CHUNK_FLAG_REXMIT |		\
			SCTP_CHUNK_FLAG_ACKED);				\
		SCTP_CHUNK_SET_SACKCNT(mp, 0);				\
		BUMP_LOCAL(sctp->sctp_rxtchunks);			\
		BUMP_LOCAL((sctp)->sctp_T3expire);			\
		BUMP_LOCAL((fp)->sf_T3expire);				\
	}								\
	SCTP_SET_CHUNK_DEST(mp, fp);					\
	(fp)->sf_suna += ((chunkdata) + sizeof (*sdc));			\
}

#define	SCTP_CHUNK_ISSENT(mp)	((mp)->b_flag & SCTP_CHUNK_FLAG_SENT)
#define	SCTP_CHUNK_CANSEND(mp)	\
	(!(SCTP_CHUNK_ABANDONED(mp)) &&	\
	(((mp)->b_flag & (SCTP_CHUNK_FLAG_REXMIT|SCTP_CHUNK_FLAG_SENT)) != \
	SCTP_CHUNK_FLAG_SENT))

#define	SCTP_CHUNK_DEST(mp)		((sctp_faddr_t *)(mp)->b_queue)
#define	SCTP_SET_CHUNK_DEST(mp, fp)	((mp)->b_queue = (queue_t *)fp)

#define	SCTP_CHUNK_REXMIT(sctp, mp) {					\
	DTRACE_PROBE2(sctp__chunk__rexmit, sctp_t *, sctp, mblk_t *,	\
	    mp);							\
	(mp)->b_flag |= SCTP_CHUNK_FLAG_REXMIT; 			\
}
#define	SCTP_CHUNK_CLEAR_REXMIT(mp) ((mp)->b_flag &= ~SCTP_CHUNK_FLAG_REXMIT)
#define	SCTP_CHUNK_WANT_REXMIT(mp) ((mp)->b_flag & SCTP_CHUNK_FLAG_REXMIT)

#define	SCTP_CHUNK_ACKED(mp) \
	((mp)->b_flag = (SCTP_CHUNK_FLAG_SENT|SCTP_CHUNK_FLAG_ACKED))
#define	SCTP_CHUNK_ISACKED(mp)	((mp)->b_flag & SCTP_CHUNK_FLAG_ACKED)
#define	SCTP_CHUNK_CLEAR_ACKED(sctp, mp) {				\
	DTRACE_PROBE2(sctp__chunk__clracked, sctp_t *, sctp, mblk_t *,	\
	    mp);							\
	(mp)->b_flag &= ~SCTP_CHUNK_FLAG_ACKED;				\
}

#define	SCTP_CHUNK_SACKCNT(mp)	((intptr_t)((mp)->b_prev))
#define	SCTP_CHUNK_SET_SACKCNT(mp, val) ((mp)->b_prev = \
					(mblk_t *)(uintptr_t)(val))

#define	SCTP_MSG_SET_CHUNKED(mp)	((mp)->b_flag |= SCTP_MSG_FLAG_CHUNKED)
#define	SCTP_MSG_CLEAR_CHUNKED(mp)((mp)->b_flag &= ~SCTP_MSG_FLAG_CHUNKED)
#define	SCTP_IS_MSG_CHUNKED(mp)	((mp)->b_flag & SCTP_MSG_FLAG_CHUNKED)

/* For PR-SCTP */
#define	SCTP_ABANDON_CHUNK(mp)	((mp)->b_flag |= SCTP_CHUNK_FLAG_ABANDONED)
#define	SCTP_CHUNK_ABANDONED(mp) \
	((mp)->b_flag & SCTP_CHUNK_FLAG_ABANDONED)

#define	SCTP_MSG_SET_ABANDONED(mp)	\
	((mp)->b_flag |= SCTP_MSG_FLAG_ABANDONED)
#define	SCTP_MSG_CLEAR_ABANDONED(mp)((mp)->b_flag &= ~SCTP_MSG_FLAG_ABANDONED)
#define	SCTP_IS_MSG_ABANDONED(mp)	((mp)->b_flag & SCTP_MSG_FLAG_ABANDONED)

/*
 * Check if a message has expired.  A message is expired if
 *	1. It has a non-zero time to live value and has not been sent before
 *	that time expires.
 *	2. It is sent using PRSCTP and it has not been SACK'ed before
 *	its lifetime expires.
 */
#define	SCTP_MSG_TO_BE_ABANDONED(meta, mhdr, sctp)			     \
	(((!SCTP_CHUNK_ISSENT((meta)->b_cont) && (mhdr)->smh_ttl > 0) ||     \
	((sctp)->sctp_prsctp_aware && ((mhdr)->smh_flags & MSG_PR_SCTP))) && \
	((ddi_get_lbolt64() - (mhdr)->smh_tob) > (mhdr)->smh_ttl))

/* SCTP association hash function. */
#define	SCTP_CONN_HASH(sctps, ports)			\
	((((ports) ^ ((ports) >> 16)) * 31) & 		\
	    ((sctps)->sctps_conn_hash_size - 1))

/*
 * Linked list struct to store SCTP listener association limit configuration
 * per IP stack.  The list is stored at sctps_listener_conf in sctp_stack_t.
 *
 * sl_port: the listener port of this limit configuration
 * sl_ratio: the maximum amount of memory consumed by all concurrent SCTP
 *           connections created by a listener does not exceed 1/tl_ratio
 *           of the total system memory.  Note that this is only an
 *           approximation.
 * sl_link: linked list struct
 */
typedef struct sctp_listener_s {
	in_port_t	sl_port;
	uint32_t	sl_ratio;
	list_node_t	sl_link;
} sctp_listener_t;

/*
 * If there is a limit set on the number of association allowed per each
 * listener, the following struct is used to store that counter.  It keeps
 * the number of SCTP association created by a listener.  Note that this needs
 * to be separated from the listener since the listener can go away before
 * all the associations are gone.
 *
 * When the struct is allocated, slc_cnt is set to 1.  When a new association
 * is created by the listener, slc_cnt is incremented by 1.  When an
 * association created by the listener goes away, slc_count is decremented by
 * 1.  When the listener itself goes away, slc_cnt is decremented  by one.
 * The last association (or the listener) which decrements slc_cnt to zero
 * frees the struct.
 *
 * slc_max is the maximum number of concurrent associations created from a
 * listener.  It is calculated when the sctp_listen_cnt_t is allocated.
 *
 * slc_report_time stores the time when cmn_err() is called to report that the
 * max has been exceeeded.  Report is done at most once every
 * SCTP_SLC_REPORT_INTERVAL mins for a listener.
 *
 * slc_drop stores the number of connection attempt dropped because the
 * limit has reached.
 */
typedef struct sctp_listen_cnt_s {
	uint32_t	slc_max;
	uint32_t	slc_cnt;
	int64_t		slc_report_time;
	uint32_t	slc_drop;
} sctp_listen_cnt_t;

#define	SCTP_SLC_REPORT_INTERVAL	(30 * MINUTES)

#define	SCTP_DECR_LISTEN_CNT(sctp)					\
{									\
	ASSERT((sctp)->sctp_listen_cnt->slc_cnt > 0);			\
	if (atomic_dec_32_nv(&(sctp)->sctp_listen_cnt->slc_cnt) == 0) \
		kmem_free((sctp)->sctp_listen_cnt, sizeof (sctp_listen_cnt_t));\
	(sctp)->sctp_listen_cnt = NULL;					\
}

/* Increment and decrement the number of associations in sctp_stack_t. */
#define	SCTPS_ASSOC_INC(sctps)						\
	atomic_inc_64(							\
	    (uint64_t *)&(sctps)->sctps_sc[CPU->cpu_seqid]->sctp_sc_assoc_cnt)

#define	SCTPS_ASSOC_DEC(sctps)						\
	atomic_dec_64(							\
	    (uint64_t *)&(sctps)->sctps_sc[CPU->cpu_seqid]->sctp_sc_assoc_cnt)

#define	SCTP_ASSOC_EST(sctps, sctp)					\
{									\
	(sctp)->sctp_state = SCTPS_ESTABLISHED;				\
	(sctp)->sctp_assoc_start_time = (uint32_t)LBOLT_FASTPATH64;	\
	SCTPS_ASSOC_INC(sctps);						\
}

/*
 * Bind hash array size and hash function.  The size must be a power
 * of 2 and lport must be in host byte order.
 */
#define	SCTP_BIND_FANOUT_SIZE	2048
#define	SCTP_BIND_HASH(lport)	(((lport) * 31) & (SCTP_BIND_FANOUT_SIZE - 1))

/* options that SCTP negotiates during association establishment */
#define	SCTP_PRSCTP_OPTION	0x01

/*
 * Listener hash array size and hash function.  The size must be a power
 * of 2 and lport must be in host byte order.
 */
#define	SCTP_LISTEN_FANOUT_SIZE	512
#define	SCTP_LISTEN_HASH(lport) (((lport) * 31) & (SCTP_LISTEN_FANOUT_SIZE - 1))

typedef struct sctp_tf_s {
	struct sctp_s	*tf_sctp;
	kmutex_t	tf_lock;
} sctp_tf_t;

/* Round up the value to the nearest mss. */
#define	MSS_ROUNDUP(value, mss)		((((value) - 1) / (mss) + 1) * (mss))

extern sin_t	sctp_sin_null;	/* Zero address for quick clears */
extern sin6_t	sctp_sin6_null;	/* Zero address for quick clears */

#define	SCTP_IS_DETACHED(sctp)		((sctp)->sctp_detached)

/* Data structure used to track received TSNs */
typedef struct sctp_set_s {
	struct sctp_set_s *next;
	struct sctp_set_s *prev;
	uint32_t begin;
	uint32_t end;
} sctp_set_t;

/* Data structure used to track TSNs for PR-SCTP */
typedef struct sctp_ftsn_set_s {
	struct sctp_ftsn_set_s *next;
	ftsn_entry_t	ftsn_entries;
} sctp_ftsn_set_t;

/* Data structure used to track incoming SCTP streams */
typedef struct sctp_instr_s {
	mblk_t		*istr_msgs;
	int		istr_nmsgs;
	uint16_t	nextseq;
	struct sctp_s	*sctp;
	mblk_t		*istr_reass;
} sctp_instr_t;

/* Reassembly data structure (per-stream) */
typedef struct sctp_reass_s {
	uint16_t	sr_ssn;
	uint16_t	sr_needed;
	uint16_t	sr_got;
	uint16_t	sr_msglen;	/* len of consecutive fragments */
					/* from the begining (B-bit) */
	mblk_t		*sr_tail;
	boolean_t	sr_hasBchunk;	/* If the fragment list begins with */
					/* a B-bit set chunk */
	uint32_t	sr_nexttsn;	/* TSN of the next fragment we */
					/* are expecting */
	boolean_t	sr_partial_delivered;
} sctp_reass_t;

/* debugging */
#undef	dprint
#ifdef DEBUG
extern int sctpdebug;
#define	dprint(level, args)	{ if (sctpdebug > (level)) printf args; }
#else
#define	dprint(level, args) {}
#endif


/* Peer address tracking */

/*
 * States for peer addresses
 *
 * SCTP_FADDRS_UNCONFIRMED: we have not communicated with this peer address
 *     before, mark it as unconfirmed so that we will not send data to it.
 *     All addresses initially are in unconfirmed state and required
 *     validation.  SCTP sends a heartbeat to each of them and when it gets
 *     back a heartbeat ACK, the address will be marked as alive.  This
 *     validation fixes a security issue with multihoming.  If an attacker
 *     establishes an association with us and tells us that it has addresses
 *     belonging to another host A, this will prevent A from communicating
 *     with us.  This is fixed by peer address validation.  In the above case,
 *     A will respond with an abort.
 *
 * SCTP_FADDRS_ALIVE: this peer address is alive and we can communicate with
 *     it with no problem.
 *
 * SCTP_FADDRS_DOWN: we have exceeded the retransmission limit to this
 *     peer address.  Once an address is marked down, we will only send
 *     a heartbeat to it every hb_interval in case it becomes alive now.
 *
 * SCTP_FADDRS_UNREACH: there is no suitable source address to send to
 *     this peer address.  For example, the peer address is v6 but we only
 *     have v4 addresses.  It is marked unreachable until there is an
 *     address configuration change.  At that time, mark these addresses
 *     as unconfirmed and try again to see if those unreachable addresses
 *     are OK as we may have more source addresses.
 */
typedef enum {
	SCTP_FADDRS_UNREACH,
	SCTP_FADDRS_DOWN,
	SCTP_FADDRS_ALIVE,
	SCTP_FADDRS_UNCONFIRMED
} faddr_state_t;

typedef struct sctp_faddr_s {
	struct sctp_faddr_s *sf_next;
	faddr_state_t	sf_state;

	in6_addr_t	sf_faddr;
	in6_addr_t	sf_saddr;

	int64_t		sf_hb_expiry;	/* time to retransmit heartbeat */
	uint32_t	sf_hb_interval;	/* the heartbeat interval */

	int		sf_rto;		/* RTO in tick */
	int		sf_srtt;	/* Smoothed RTT in tick */
	int		sf_rttvar;	/* RTT variance in tick */
	uint32_t	sf_rtt_updates;
	int		sf_strikes;
	int		sf_max_retr;
	uint32_t	sf_pmss;
	uint32_t	sf_cwnd;
	uint32_t	sf_ssthresh;
	uint32_t	sf_suna;	/* sent - unack'ed */
	uint32_t	sf_pba;		/* partial bytes acked */
	uint32_t	sf_acked;
	int64_t		sf_lastactive;
	mblk_t		*sf_timer_mp;	/* retransmission timer control */
	uint32_t
			sf_hb_pending : 1,
			sf_timer_running : 1,
			sf_df : 1,
			sf_pmtu_discovered : 1,

			sf_rc_timer_running : 1,
			sf_isv4 : 1,
			sf_hb_enabled : 1;

	mblk_t		*sf_rc_timer_mp; /* reliable control chunk timer */
	ip_xmit_attr_t	*sf_ixa;	/* Transmit attributes */
	uint32_t	sf_T3expire;	/* # of times T3 timer expired */

	uint64_t	sf_hb_secret;	/* per addr "secret" in heartbeat */
	uint32_t	sf_rxt_unacked;	/* # unack'ed retransmitted bytes */
} sctp_faddr_t;

/* Flags to indicate supported address type in the PARM_SUP_ADDRS. */
#define	PARM_SUPP_V6	0x1
#define	PARM_SUPP_V4	0x2

/*
 * Set heartbeat interval plus jitter.  The jitter is supposed to be random,
 * up to +/- 50% of the RTO.  We use gethrtime() here for  performance reason
 * as the jitter does not really need to be "very" random.
 */
#define	SET_HB_INTVL(fp)					\
	((fp)->sf_hb_interval + (fp)->sf_rto + ((fp)->sf_rto >> 1) -	\
	(uint_t)gethrtime() % (fp)->sf_rto)

#define	SCTP_IPIF_HASH	16

typedef	struct	sctp_ipif_hash_s {
	list_t		sctp_ipif_list;
	int		ipif_count;
	krwlock_t	ipif_hash_lock;
} sctp_ipif_hash_t;


/*
 * Initialize cwnd according to RFC 3390.  def_max_init_cwnd is
 * either sctp_slow_start_initial or sctp_slow_start_after idle
 * depending on the caller.
 */
#define	SET_CWND(fp, mss, def_max_init_cwnd)				\
{									\
	(fp)->sf_cwnd = MIN(def_max_init_cwnd * (mss),			\
	    MIN(4 * (mss), MAX(2 * (mss), 4380 / (mss) * (mss))));	\
}


struct sctp_s;

/*
 * Control structure for each open SCTP stream,
 * defined only within the kernel or for a kmem user.
 * NOTE: sctp_reinit_values MUST have a line for each field in this structure!
 */
#if (defined(_KERNEL) || defined(_KMEMUSER))

typedef struct sctp_s {

	/*
	 * The following is shared with (and duplicated) in IP, so if you
	 * make changes, make sure you also change things in ip_sctp.c.
	 */
	struct sctp_s	*sctp_conn_hash_next;
	struct sctp_s	*sctp_conn_hash_prev;

	struct sctp_s	*sctp_listen_hash_next;
	struct sctp_s	*sctp_listen_hash_prev;

	sctp_tf_t	*sctp_listen_tfp;	/* Ptr to tf */
	sctp_tf_t	*sctp_conn_tfp;		/* Ptr to tf */

	/* Global list of sctp */
	list_node_t	sctp_list;

	sctp_faddr_t		*sctp_faddrs;
	int			sctp_nfaddrs;
	sctp_ipif_hash_t	sctp_saddrs[SCTP_IPIF_HASH];
	int			sctp_nsaddrs;

	kmutex_t	sctp_lock;
	kcondvar_t	sctp_cv;
	boolean_t	sctp_running;

#define	sctp_ulpd	sctp_connp->conn_upper_handle
#define	sctp_upcalls	sctp_connp->conn_upcalls

#define	sctp_ulp_newconn	sctp_upcalls->su_newconn
#define	sctp_ulp_connected	sctp_upcalls->su_connected
#define	sctp_ulp_disconnected	sctp_upcalls->su_disconnected
#define	sctp_ulp_opctl		sctp_upcalls->su_opctl
#define	sctp_ulp_recv		sctp_upcalls->su_recv
#define	sctp_ulp_txq_full	sctp_upcalls->su_txq_full
#define	sctp_ulp_prop		sctp_upcalls->su_set_proto_props

	int32_t		sctp_state;

	conn_t		*sctp_connp;		/* conn_t stuff */
	sctp_stack_t	*sctp_sctps;

	/* Peer address tracking */
	sctp_faddr_t	*sctp_lastfaddr;	/* last faddr in list */
	sctp_faddr_t	*sctp_primary;		/* primary faddr */
	sctp_faddr_t	*sctp_current;		/* current faddr */
	sctp_faddr_t	*sctp_lastdata;		/* last data seen from this */

	/* Outbound data tracking */
	mblk_t		*sctp_xmit_head;
	mblk_t		*sctp_xmit_tail;
	mblk_t		*sctp_xmit_unsent;
	mblk_t		*sctp_xmit_unsent_tail;
	mblk_t		*sctp_xmit_unacked;

	int32_t		sctp_unacked;		/* # of unacked bytes */
	int32_t		sctp_unsent;		/* # of unsent bytes in hand */

	uint32_t	sctp_ltsn;		/* Local instance TSN */
	uint32_t	sctp_lastack_rxd;	/* Last rx'd cumtsn */
	uint32_t	sctp_recovery_tsn;	/* Exit from fast recovery */
	uint32_t	sctp_adv_pap;		/* Adv. Peer Ack Point */

	uint16_t	sctp_num_ostr;
	uint16_t	*sctp_ostrcntrs;

	mblk_t		*sctp_pad_mp;		/* pad unaligned data chunks */

	/* sendmsg() default parameters */
	uint16_t	sctp_def_stream;	/* default stream id */
	uint16_t	sctp_def_flags;		/* default xmit flags */
	uint32_t	sctp_def_ppid;		/* default payload id */
	uint32_t	sctp_def_context;	/* default context */
	uint32_t	sctp_def_timetolive;	/* default msg TTL */

	/* Inbound data tracking */
	sctp_set_t	*sctp_sack_info;	/* Sack tracking */
	mblk_t		*sctp_ack_mp;		/* Delayed ACK timer block */
	sctp_instr_t	*sctp_instr;		/* Instream trackers */
	mblk_t		*sctp_uo_frags;		/* Un-ordered msg. fragments */
	uint32_t	sctp_ftsn;		/* Peer's TSN */
	uint32_t	sctp_lastacked;		/* last cumtsn SACKd */
	uint16_t	sctp_num_istr;		/* No. of instreams */
	int32_t		sctp_istr_nmsgs;	/* No. of chunks in instreams */
	int32_t		sctp_sack_gaps;		/* No. of received gaps */
	int32_t		sctp_sack_toggle;	/* SACK every other pkt */

	/* RTT calculation */
	uint32_t	sctp_rtt_tsn;
	int64_t		sctp_out_time;

	/* Stats can be reset by snmp users kstat, netstat and snmp agents */
	uint64_t	sctp_opkts;		/* sent pkts */
	uint64_t	sctp_obchunks;		/* sent control chunks */
	uint64_t	sctp_odchunks;		/* sent ordered data chunks */
	uint64_t	sctp_oudchunks;		/* sent unord data chunks */
	uint64_t	sctp_rxtchunks;		/* retransmitted chunks */
	uint64_t	sctp_ipkts;		/* recv pkts */
	uint64_t	sctp_ibchunks;		/* recv control chunks */
	uint64_t	sctp_idchunks;		/* recv ordered data chunks */
	uint64_t	sctp_iudchunks;		/* recv unord data chunks */
	uint64_t	sctp_fragdmsgs;
	uint64_t	sctp_reassmsgs;
	uint32_t	sctp_T1expire;		/* # of times T1timer expired */
	uint32_t	sctp_T2expire;		/* # of times T2timer expired */
	uint32_t	sctp_T3expire;		/* # of times T3timer expired */
	uint32_t	sctp_assoc_start_time;	/* time when assoc was est. */

	uint32_t	sctp_frwnd;		/* Peer RWND */
	uint32_t	sctp_cwnd_max;

	/* Inbound flow control */
	int32_t		sctp_rwnd;		/* Current receive window */
	int32_t		sctp_arwnd;		/* Last advertised window */
	int32_t		sctp_rxqueued;		/* No. of bytes in RX q's */
	int32_t		sctp_ulp_rxqueued;	/* Data in ULP */

	/* Pre-initialized composite headers */
	uchar_t		*sctp_iphc;	/* v4 sctp/ip hdr template buffer */
	uchar_t		*sctp_iphc6;	/* v6 sctp/ip hdr template buffer */

	int32_t		sctp_iphc_len;	/* actual allocated v4 buffer size */
	int32_t		sctp_iphc6_len;	/* actual allocated v6 buffer size */

	int32_t		sctp_hdr_len;	/* len of combined SCTP/IP v4 hdr */
	int32_t		sctp_hdr6_len;	/* len of combined SCTP/IP v6 hdr */

	ipha_t		*sctp_ipha;	/* IPv4 header in the buffer */
	ip6_t		*sctp_ip6h;	/* IPv6 header in the buffer */

	int32_t		sctp_ip_hdr_len; /* Byte len of our current v4 hdr */
	int32_t		sctp_ip_hdr6_len; /* Byte len of our current v6 hdr */

	sctp_hdr_t	*sctp_sctph;	/* sctp header in combined v4 hdr */
	sctp_hdr_t	*sctp_sctph6;	/* sctp header in combined v6 hdr */

	uint32_t	sctp_lvtag;	/* local SCTP instance verf tag */
	uint32_t	sctp_fvtag;	/* Peer's SCTP verf tag */

	/* Path MTU Discovery */
	int64_t		sctp_last_mtu_probe;
	clock_t		sctp_mtu_probe_intvl;
	uint32_t	sctp_mss;	/* Max send size (not TCP MSS!) */

	/* structs sctp_bits, sctp_events are for clearing all bits at once */
	struct {
		uint32_t

		sctp_understands_asconf : 1, /* Peer handles ASCONF chunks */
		sctp_cchunk_pend : 1,	/* Control chunk in flight. */
		sctp_lingering : 1,	/* Lingering in close */
		sctp_loopback: 1,	/* src and dst are the same machine */

		sctp_force_sack : 1,
		sctp_ack_timer_running: 1,	/* Delayed ACK timer running */
		sctp_hwcksum : 1,	/* The NIC is capable of hwcksum */
		sctp_understands_addip : 1,

		sctp_bound_to_all : 1,
		sctp_cansleep : 1,	/* itf routines can sleep */
		sctp_detached : 1,	/* If we're detached from a stream */
		sctp_send_adaptation : 1,	/* send adaptation layer ind */

		sctp_recv_adaptation : 1,	/* recv adaptation layer ind */
		sctp_ndelay : 1,	/* turn off Nagle */
		sctp_condemned : 1,	/* this sctp is about to disappear */
		sctp_chk_fast_rexmit : 1, /* check for fast rexmit message */

		sctp_prsctp_aware : 1,	/* is peer PR-SCTP aware? */
		sctp_linklocal : 1,	/* is linklocal assoc. */
		sctp_rexmitting : 1,	/* SCTP is retransmitting */
		sctp_zero_win_probe : 1,	/* doing zero win probe */

		sctp_txq_full : 1,	/* the tx queue is full */
		sctp_ulp_discon_done : 1,	/* ulp_disconnecting done */
		sctp_flowctrld : 1,	/* upper layer flow controlled */
		sctp_dummy : 5;
	} sctp_bits;
	struct {
		uint32_t

		sctp_recvsndrcvinfo : 1,
		sctp_recvassocevnt : 1,
		sctp_recvpathevnt : 1,
		sctp_recvsendfailevnt : 1,

		sctp_recvpeererr : 1,
		sctp_recvshutdownevnt : 1,
		sctp_recvpdevnt : 1,
		sctp_recvalevnt : 1;
	} sctp_events;
#define	sctp_priv_stream sctp_bits.sctp_priv_stream
#define	sctp_understands_asconf sctp_bits.sctp_understands_asconf
#define	sctp_cchunk_pend sctp_bits.sctp_cchunk_pend
#define	sctp_lingering sctp_bits.sctp_lingering
#define	sctp_loopback sctp_bits.sctp_loopback
#define	sctp_force_sack sctp_bits.sctp_force_sack
#define	sctp_ack_timer_running sctp_bits.sctp_ack_timer_running
#define	sctp_hwcksum sctp_bits.sctp_hwcksum
#define	sctp_understands_addip sctp_bits.sctp_understands_addip
#define	sctp_bound_to_all sctp_bits.sctp_bound_to_all
#define	sctp_cansleep sctp_bits.sctp_cansleep
#define	sctp_detached sctp_bits.sctp_detached
#define	sctp_send_adaptation sctp_bits.sctp_send_adaptation
#define	sctp_recv_adaptation sctp_bits.sctp_recv_adaptation
#define	sctp_ndelay sctp_bits.sctp_ndelay
#define	sctp_condemned sctp_bits.sctp_condemned
#define	sctp_chk_fast_rexmit sctp_bits.sctp_chk_fast_rexmit
#define	sctp_prsctp_aware sctp_bits.