diff --git a/usrsctplib/netinet/sctp_pcb.h b/usrsctplib/netinet/sctp_pcb.h
new file mode 100755
index 0000000..72309db
--- /dev/null
+++ b/usrsctplib/netinet/sctp_pcb.h
@@ -0,0 +1,910 @@
+/*-
+ * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
+ * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
+ * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * a) Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * b) Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the distribution.
+ *
+ * c) Neither the name of Cisco Systems, Inc. nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef __FreeBSD__
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD: head/sys/netinet/sctp_pcb.h 310590 2016-12-26 11:06:41Z tuexen $");
+#endif
+
+#ifndef _NETINET_SCTP_PCB_H_
+#define _NETINET_SCTP_PCB_H_
+
+#include <netinet/sctp_os.h>
+#include <netinet/sctp.h>
+#include <netinet/sctp_constants.h>
+#include <netinet/sctp_sysctl.h>
+
+LIST_HEAD(sctppcbhead, sctp_inpcb);
+LIST_HEAD(sctpasochead, sctp_tcb);
+LIST_HEAD(sctpladdr, sctp_laddr);
+LIST_HEAD(sctpvtaghead, sctp_tagblock);
+LIST_HEAD(sctp_vrflist, sctp_vrf);
+LIST_HEAD(sctp_ifnlist, sctp_ifn);
+LIST_HEAD(sctp_ifalist, sctp_ifa);
+TAILQ_HEAD(sctp_readhead, sctp_queued_to_read);
+TAILQ_HEAD(sctp_streamhead, sctp_stream_queue_pending);
+
+#include <netinet/sctp_structs.h>
+#include <netinet/sctp_auth.h>
+
+#define SCTP_PCBHASH_ALLADDR(port, mask) (port & mask)
+#define SCTP_PCBHASH_ASOC(tag, mask) (tag & mask)
+#define MAXLEN_MBUF_CHAIN 32
+
+struct sctp_vrf {
+	LIST_ENTRY (sctp_vrf) next_vrf;
+	struct sctp_ifalist *vrf_addr_hash;
+	struct sctp_ifnlist ifnlist;
+	uint32_t vrf_id;
+	uint32_t tbl_id_v4;		/* default v4 table id */
+	uint32_t tbl_id_v6;		/* default v6 table id */
+	uint32_t total_ifa_count;
+	u_long   vrf_addr_hashmark;
+	uint32_t refcount;
+};
+
+struct sctp_ifn {
+	struct sctp_ifalist ifalist;
+	struct sctp_vrf *vrf;
+	LIST_ENTRY(sctp_ifn) next_ifn;
+	LIST_ENTRY(sctp_ifn) next_bucket;
+	void     *ifn_p;	/* never access without appropriate lock */
+	uint32_t ifn_mtu;
+	uint32_t ifn_type;
+	uint32_t ifn_index;	/* shorthand way to look at ifn for reference */
+	uint32_t refcount;	/* number of reference held should be >= ifa_count */
+	uint32_t ifa_count;	/* IFA's we hold (in our list - ifalist)*/
+	uint32_t num_v6;	/* number of v6 addresses */
+	uint32_t num_v4;	/* number of v4 addresses */
+	uint32_t registered_af;	/* registered address family for i/f events */
+	char     ifn_name[SCTP_IFNAMSIZ];
+};
+
+/* SCTP local IFA flags */
+#define SCTP_ADDR_VALID         0x00000001	/* its up and active */
+#define SCTP_BEING_DELETED      0x00000002	/* being deleted,
+						 * when refcount = 0. Note
+						 * that it is pulled from the ifn list
+						 * and ifa_p is nulled right away but
+						 * it cannot be freed until the last *net
+						 * pointing to it is deleted.
+						 */
+#define SCTP_ADDR_DEFER_USE     0x00000004	/* Hold off using this one */
+#define SCTP_ADDR_IFA_UNUSEABLE 0x00000008
+
+struct sctp_ifa {
+	LIST_ENTRY(sctp_ifa) next_ifa;
+	LIST_ENTRY(sctp_ifa) next_bucket;
+	struct sctp_ifn *ifn_p;	/* back pointer to parent ifn */
+	void    *ifa;		/* pointer to ifa, needed for flag
+				 * update for that we MUST lock
+				 * appropriate locks. This is for V6.
+				 */
+	union sctp_sockstore address;
+	uint32_t refcount;	/* number of folks referring to this */
+	uint32_t flags;
+	uint32_t localifa_flags;
+	uint32_t vrf_id;	/* vrf_id of this addr (for deleting) */
+	uint8_t src_is_loop;
+	uint8_t src_is_priv;
+	uint8_t src_is_glob;
+	uint8_t resv;
+};
+
+struct sctp_laddr {
+	LIST_ENTRY(sctp_laddr) sctp_nxt_addr;	/* next in list */
+	struct sctp_ifa *ifa;
+	uint32_t action;		/* Used during asconf and adding
+					 * if no-zero src-addr selection will
+					 * not consider this address.
+					 */
+	struct timeval start_time;      /* time when this address was created */
+};
+
+struct sctp_block_entry {
+	int error;
+};
+
+struct sctp_timewait {
+	uint32_t tv_sec_at_expire;	/* the seconds from boot to expire */
+        uint32_t v_tag;		        /* the vtag that can not be reused */
+        uint16_t lport;                 /* the local port used in vtag */
+        uint16_t rport;                 /* the remote port used in vtag */
+};
+
+struct sctp_tagblock {
+	LIST_ENTRY(sctp_tagblock) sctp_nxt_tagblock;
+	struct sctp_timewait vtag_block[SCTP_NUMBER_IN_VTAG_BLOCK];
+};
+
+
+struct sctp_epinfo {
+#if defined(__FreeBSD__)
+#ifdef INET
+	struct socket *udp4_tun_socket;
+#endif
+#ifdef INET6
+	struct socket *udp6_tun_socket;
+#endif
+#endif
+	struct sctpasochead *sctp_asochash;
+	u_long hashasocmark;
+
+	struct sctppcbhead *sctp_ephash;
+	u_long hashmark;
+
+	/*-
+	 * The TCP model represents a substantial overhead in that we get an
+	 * additional hash table to keep explicit connections in. The
+	 * listening TCP endpoint will exist in the usual ephash above and
+	 * accept only INIT's. It will be incapable of sending off an INIT.
+	 * When a dg arrives we must look in the normal ephash. If we find a
+	 * TCP endpoint that will tell us to go to the specific endpoint
+	 * hash and re-hash to find the right assoc/socket. If we find a UDP
+	 * model socket we then must complete the lookup. If this fails,
+	 * i.e. no association can be found then we must continue to see if
+	 * a sctp_peeloff()'d socket is in the tcpephash (a spun off socket
+	 * acts like a TCP model connected socket).
+	 */
+	struct sctppcbhead *sctp_tcpephash;
+	u_long hashtcpmark;
+	uint32_t hashtblsize;
+
+	struct sctp_vrflist *sctp_vrfhash;
+	u_long hashvrfmark;
+
+	struct sctp_ifnlist *vrf_ifn_hash;
+	u_long   vrf_ifn_hashmark;
+
+	struct sctppcbhead listhead;
+	struct sctpladdr addr_wq;
+
+#if defined(__APPLE__)
+	struct inpcbhead inplisthead;
+	struct inpcbinfo sctbinfo;
+#endif
+	/* ep zone info */
+	sctp_zone_t ipi_zone_ep;
+	sctp_zone_t ipi_zone_asoc;
+	sctp_zone_t ipi_zone_laddr;
+	sctp_zone_t ipi_zone_net;
+	sctp_zone_t ipi_zone_chunk;
+	sctp_zone_t ipi_zone_readq;
+	sctp_zone_t ipi_zone_strmoq;
+	sctp_zone_t ipi_zone_asconf;
+	sctp_zone_t ipi_zone_asconf_ack;
+
+#if defined(__FreeBSD__) && __FreeBSD_version >= 503000
+#if __FreeBSD_version <= 602000
+	struct mtx ipi_ep_mtx;
+#else
+	struct rwlock ipi_ep_mtx;
+#endif
+	struct mtx ipi_iterator_wq_mtx;
+#if __FreeBSD_version <= 602000
+	struct mtx ipi_addr_mtx;
+#else
+	struct rwlock ipi_addr_mtx;
+#endif
+	struct mtx ipi_pktlog_mtx;
+	struct mtx wq_addr_mtx;
+#elif defined(SCTP_PROCESS_LEVEL_LOCKS)
+	userland_mutex_t ipi_ep_mtx;
+	userland_mutex_t ipi_addr_mtx;
+	userland_mutex_t ipi_count_mtx;
+	userland_mutex_t ipi_pktlog_mtx;
+	userland_mutex_t wq_addr_mtx;
+#elif defined(__APPLE__)
+#ifdef _KERN_LOCKS_H_
+	lck_mtx_t *ipi_addr_mtx;
+	lck_mtx_t *ipi_count_mtx;
+	lck_mtx_t *ipi_pktlog_mtx;
+	lck_mtx_t *logging_mtx;
+	lck_mtx_t *wq_addr_mtx;
+#else
+	void *ipi_count_mtx;
+	void *logging_mtx;
+#endif /* _KERN_LOCKS_H_ */
+#elif defined(__Windows__)
+	struct rwlock ipi_ep_lock;
+	struct rwlock ipi_addr_lock;
+	struct spinlock ipi_pktlog_mtx;
+	struct rwlock wq_addr_mtx;
+#elif defined(__Userspace__)
+    /* TODO decide on __Userspace__ locks */
+#endif
+	uint32_t ipi_count_ep;
+
+	/* assoc/tcb zone info */
+	uint32_t ipi_count_asoc;
+
+	/* local addrlist zone info */
+	uint32_t ipi_count_laddr;
+
+	/* remote addrlist zone info */
+	uint32_t ipi_count_raddr;
+
+	/* chunk structure list for output */
+	uint32_t ipi_count_chunk;
+
+	/* socket queue zone info */
+	uint32_t ipi_count_readq;
+
+	/* socket queue zone info */
+	uint32_t ipi_count_strmoq;
+
+	/* Number of vrfs */
+	uint32_t ipi_count_vrfs;
+
+        /* Number of ifns */
+	uint32_t ipi_count_ifns;
+
+        /* Number of ifas */
+	uint32_t ipi_count_ifas;
+
+	/* system wide number of free chunks hanging around */
+	uint32_t ipi_free_chunks;
+	uint32_t ipi_free_strmoq;
+
+	struct sctpvtaghead vtag_timewait[SCTP_STACK_VTAG_HASH_SIZE];
+
+	/* address work queue handling */
+	struct sctp_timer addr_wq_timer;
+
+#if defined(_SCTP_NEEDS_CALLOUT_) || defined(_USER_SCTP_NEEDS_CALLOUT_)
+	struct calloutlist callqueue;
+#endif
+};
+
+
+struct sctp_base_info {
+	/* All static structures that
+	 * anchor the system must be here.
+	 */
+	struct sctp_epinfo sctppcbinfo;
+#if defined(__FreeBSD__) && defined(SMP) && defined(SCTP_USE_PERCPU_STAT)
+	struct sctpstat    *sctpstat;
+#else
+	struct sctpstat    sctpstat;
+#endif
+	struct sctp_sysctl sctpsysctl;
+	uint8_t first_time;
+	char sctp_pcb_initialized;
+#if defined(SCTP_PACKET_LOGGING)
+	int packet_log_writers;
+	int packet_log_end;
+	uint8_t packet_log_buffer[SCTP_PACKET_LOG_SIZE];
+#endif
+#if defined(__APPLE__)
+	int sctp_main_timer_ticks;
+#endif
+#if defined(__Userspace__)
+	userland_mutex_t timer_mtx;
+	userland_thread_t timer_thread;
+	uint8_t timer_thread_should_exit;
+#if !defined(__Userspace_os_Windows)
+	pthread_mutexattr_t mtx_attr;
+#if defined(INET) || defined(INET6)
+	int userspace_route;
+	userland_thread_t recvthreadroute;
+#endif
+#endif
+#ifdef INET
+#if defined(__Userspace_os_Windows)
+	SOCKET userspace_rawsctp;
+	SOCKET userspace_udpsctp;
+#else
+	int userspace_rawsctp;
+	int userspace_udpsctp;
+#endif
+	userland_thread_t recvthreadraw;
+	userland_thread_t recvthreadudp;
+#if !defined(THREAD_SUPPORT)
+	struct mbuf **recvmbuf4;
+	int to_fill4;
+	struct mbuf **recvmbuf6;
+	int to_fill6;
+	struct mbuf **udp_recvmbuf4;
+	int udp_to_fill4;
+	struct mbuf **udp_recvmbuf6;
+	int udp_to_fill6;
+#if !defined(__Userspace_os_Windows)
+	struct iovec recv_iovec4[MAXLEN_MBUF_CHAIN];
+	struct iovec recv_iovec6[MAXLEN_MBUF_CHAIN];
+	struct iovec udp_recv_iovec4[MAXLEN_MBUF_CHAIN];
+	struct iovec udp_recv_iovec6[MAXLEN_MBUF_CHAIN];
+#else
+    WSABUF *rcv_iovec4;
+    WSABUF *rcv_iovec6;
+    WSABUF *udp_rcv_iovec4;
+    WSABUF *udp_rcv_iovec6;
+#endif
+#endif
+#endif
+#ifdef INET6
+#if defined(__Userspace_os_Windows)
+	SOCKET userspace_rawsctp6;
+	SOCKET userspace_udpsctp6;
+#else
+	int userspace_rawsctp6;
+	int userspace_udpsctp6;
+#endif
+	userland_thread_t recvthreadraw6;
+	userland_thread_t recvthreadudp6;
+#endif
+	int (*conn_output)(void *addr, void *buffer, size_t length, uint8_t tos, uint8_t set_df);
+	void (*debug_printf)(const char *format, ...);
+	int crc32c_offloaded;
+#endif
+};
+
+/*-
+ * Here we have all the relevant information for each SCTP entity created. We
+ * will need to modify this as approprate. We also need to figure out how to
+ * access /dev/random.
+ */
+struct sctp_pcb {
+	unsigned int time_of_secret_change;	/* number of seconds from
+						 * timeval.tv_sec */
+	uint32_t secret_key[SCTP_HOW_MANY_SECRETS][SCTP_NUMBER_OF_SECRETS];
+	unsigned int size_of_a_cookie;
+
+	unsigned int sctp_timeoutticks[SCTP_NUM_TMRS];
+	unsigned int sctp_minrto;
+	unsigned int sctp_maxrto;
+	unsigned int initial_rto;
+	int initial_init_rto_max;
+
+	unsigned int sctp_sack_freq;
+	uint32_t sctp_sws_sender;
+	uint32_t sctp_sws_receiver;
+
+	uint32_t sctp_default_cc_module;
+	uint32_t sctp_default_ss_module;
+	/* authentication related fields */
+	struct sctp_keyhead shared_keys;
+	sctp_auth_chklist_t *local_auth_chunks;
+	sctp_hmaclist_t *local_hmacs;
+	uint16_t default_keyid;
+
+	/* various thresholds */
+	/* Max times I will init at a guy */
+	uint16_t max_init_times;
+
+	/* Max times I will send before we consider someone dead */
+	uint16_t max_send_times;
+
+	uint16_t def_net_failure;
+
+	uint16_t def_net_pf_threshold;
+
+	/* number of streams to pre-open on a association */
+	uint16_t pre_open_stream_count;
+	uint16_t max_open_streams_intome;
+
+	/* random number generator */
+	uint32_t random_counter;
+	uint8_t random_numbers[SCTP_SIGNATURE_ALOC_SIZE];
+	uint8_t random_store[SCTP_SIGNATURE_ALOC_SIZE];
+
+	/*
+	 * This timer is kept running per endpoint.  When it fires it will
+	 * change the secret key.  The default is once a hour
+	 */
+	struct sctp_timer signature_change;
+
+	/* Zero copy full buffer timer */
+	struct sctp_timer zero_copy_timer;
+        /* Zero copy app to transport (sendq) read repulse timer */
+	struct sctp_timer zero_copy_sendq_timer;
+	uint32_t def_cookie_life;
+	/* defaults to 0 */
+	int auto_close_time;
+	uint32_t initial_sequence_debug;
+	uint32_t adaptation_layer_indicator;
+	uint8_t adaptation_layer_indicator_provided;
+	uint32_t store_at;
+	uint32_t max_burst;
+	uint32_t fr_max_burst;
+#ifdef INET6
+	uint32_t default_flowlabel;
+#endif
+	uint8_t default_dscp;
+	char current_secret_number;
+	char last_secret_number;
+	uint16_t port; /* remote UDP encapsulation port */
+};
+
+#ifndef SCTP_ALIGNMENT
+#define SCTP_ALIGNMENT 32
+#endif
+
+#ifndef SCTP_ALIGNM1
+#define SCTP_ALIGNM1 (SCTP_ALIGNMENT-1)
+#endif
+
+#define sctp_lport ip_inp.inp.inp_lport
+
+struct sctp_pcbtsn_rlog {
+	uint32_t vtag;
+	uint16_t strm;
+	uint16_t seq;
+	uint16_t sz;
+	uint16_t flgs;
+};
+#define SCTP_READ_LOG_SIZE 135	/* we choose the number to make a pcb a page */
+
+
+struct sctp_inpcb {
+	/*-
+	 * put an inpcb in front of it all, kind of a waste but we need to
+	 * for compatibility with all the other stuff.
+	 */
+	union {
+		struct inpcb inp;
+		char align[(sizeof(struct in6pcb) + SCTP_ALIGNM1) &
+		        ~SCTP_ALIGNM1];
+	}     ip_inp;
+
+#if defined(__APPLE__)
+	/* leave some space in case i386 inpcb is bigger than ppc */
+	uint8_t		padding[128];
+#endif
+
+	/* Socket buffer lock protects read_queue and of course sb_cc */
+	struct sctp_readhead read_queue;
+
+	LIST_ENTRY(sctp_inpcb) sctp_list;	/* lists all endpoints */
+        /* hash of all endpoints for model */
+	LIST_ENTRY(sctp_inpcb) sctp_hash;
+	/* count of local addresses bound, 0 if bound all */
+	int laddr_count;
+
+	/* list of addrs in use by the EP, NULL if bound-all */
+	struct sctpladdr sctp_addr_list;
+	/* used for source address selection rotation when we are subset bound */
+	struct sctp_laddr *next_addr_touse;
+
+	/* back pointer to our socket */
+	struct socket *sctp_socket;
+	uint64_t sctp_features;	/* Feature flags */
+	uint32_t sctp_flags;	/* INP state flag set */
+	uint32_t sctp_mobility_features; /* Mobility  Feature flags */
+	struct sctp_pcb sctp_ep;/* SCTP ep data */
+	/* head of the hash of all associations */
+	struct sctpasochead *sctp_tcbhash;
+	u_long sctp_hashmark;
+	/* head of the list of all associations */
+	struct sctpasochead sctp_asoc_list;
+#ifdef SCTP_TRACK_FREED_ASOCS
+	struct sctpasochead sctp_asoc_free_list;
+#endif
+	struct sctp_iterator *inp_starting_point_for_iterator;
+	uint32_t sctp_frag_point;
+	uint32_t partial_delivery_point;
+	uint32_t sctp_context;
+	uint32_t max_cwnd;
+	uint8_t local_strreset_support;
+	uint32_t sctp_cmt_on_off;
+	uint8_t ecn_supported;
+	uint8_t prsctp_supported;
+	uint8_t auth_supported;
+	uint8_t idata_supported;
+	uint8_t asconf_supported;
+	uint8_t reconfig_supported;
+	uint8_t nrsack_supported;
+	uint8_t pktdrop_supported;
+	struct sctp_nonpad_sndrcvinfo def_send;
+	/*-
+	 * These three are here for the sosend_dgram
+	 * (pkt, pkt_last and control).
+	 * routine. However, I don't think anyone in
+	 * the current FreeBSD kernel calls this. So
+	 * they are candidates with sctp_sendm for
+	 * de-supporting.
+	 */
+#ifdef __Panda__
+	pakhandle_type pak_to_read;
+	pakhandle_type pak_to_read_sendq;
+#endif
+	struct mbuf *pkt, *pkt_last;
+	struct mbuf *control;
+#if !(defined(__FreeBSD__) || defined(__APPLE__) || defined(__Windows__) || defined(__Userspace__))
+#ifndef INP_IPV6
+#define INP_IPV6	0x1
+#endif
+#ifndef INP_IPV4
+#define INP_IPV4	0x2
+#endif
+	uint8_t inp_vflag;
+                               /* TODO __Userspace__ where is our inp_vlag going to be? */
+	uint8_t inp_ip_ttl;
+        uint8_t inp_ip_tos;    /* defined as macro in user_inpcb.h */
+	uint8_t inp_ip_resv;
+#endif
+#if defined(__FreeBSD__) && __FreeBSD_version >= 503000
+	struct mtx inp_mtx;
+	struct mtx inp_create_mtx;
+	struct mtx inp_rdata_mtx;
+	int32_t refcount;
+#elif defined(SCTP_PROCESS_LEVEL_LOCKS)
+	userland_mutex_t inp_mtx;
+	userland_mutex_t inp_create_mtx;
+	userland_mutex_t inp_rdata_mtx;
+	int32_t refcount;
+#elif defined(__APPLE__)
+#if defined(SCTP_APPLE_RWLOCK)
+	lck_rw_t *inp_mtx;
+#else
+	lck_mtx_t *inp_mtx;
+#endif
+	lck_mtx_t *inp_create_mtx;
+	lck_mtx_t *inp_rdata_mtx;
+#elif defined(__Windows__)
+	struct rwlock inp_lock;
+	struct spinlock inp_create_lock;
+	struct spinlock inp_rdata_lock;
+	int32_t refcount;
+#elif defined(__Userspace__)
+    /* TODO decide on __Userspace__ locks */
+	int32_t refcount;
+#endif
+#if defined(__APPLE__)
+	int32_t refcount;
+
+	uint32_t lock_caller1;
+	uint32_t lock_caller2;
+	uint32_t lock_caller3;
+	uint32_t unlock_caller1;
+	uint32_t unlock_caller2;
+	uint32_t unlock_caller3;
+	uint32_t getlock_caller1;
+	uint32_t getlock_caller2;
+	uint32_t getlock_caller3;
+	uint32_t gen_count;
+	uint32_t lock_gen_count;
+	uint32_t unlock_gen_count;
+	uint32_t getlock_gen_count;
+
+	uint32_t i_am_here_file;
+	uint32_t i_am_here_line;
+#endif
+	uint32_t def_vrf_id;
+	uint16_t fibnum;
+#ifdef SCTP_MVRF
+	uint32_t *m_vrf_ids;
+	uint32_t num_vrfs;
+	uint32_t vrf_size;
+#endif
+	uint32_t total_sends;
+	uint32_t total_recvs;
+	uint32_t last_abort_code;
+	uint32_t total_nospaces;
+	struct sctpasochead *sctp_asocidhash;
+	u_long hashasocidmark;
+        uint32_t sctp_associd_counter;
+
+#ifdef SCTP_ASOCLOG_OF_TSNS
+	struct sctp_pcbtsn_rlog readlog[SCTP_READ_LOG_SIZE];
+	uint32_t readlog_index;
+#endif
+#if defined(__Userspace__)
+	void *ulp_info;
+	int (*recv_callback)(struct socket *, union sctp_sockstore, void *, size_t,
+                             struct sctp_rcvinfo, int, void *);
+	uint32_t send_sb_threshold;
+	int (*send_callback)(struct socket *, uint32_t);
+#endif
+};
+
+#if defined(__Userspace__)
+int register_recv_cb (struct socket *,
+                      int (*)(struct socket *, union sctp_sockstore, void *, size_t,
+                              struct sctp_rcvinfo, int, void *));
+int register_send_cb (struct socket *, uint32_t, int (*)(struct socket *, uint32_t));
+int register_ulp_info (struct socket *, void *);
+
+#endif
+struct sctp_tcb {
+	struct socket *sctp_socket;	/* back pointer to socket */
+	struct sctp_inpcb *sctp_ep;	/* back pointer to ep */
+	LIST_ENTRY(sctp_tcb) sctp_tcbhash;	/* next link in hash
+						 * table */
+        LIST_ENTRY(sctp_tcb) sctp_tcblist;	/* list of all of the
+						 * TCB's */
+        LIST_ENTRY(sctp_tcb) sctp_tcbasocidhash;	/* next link in asocid
+							 * hash table
+							 */
+        LIST_ENTRY(sctp_tcb) sctp_asocs;	/* vtag hash list */
+	struct sctp_block_entry *block_entry;	/* pointer locked by  socket
+						 * send buffer */
+	struct sctp_association asoc;
+	/*-
+	 * freed_by_sorcv_sincelast is protected by the sockbuf_lock NOT the
+	 * tcb_lock. Its special in this way to help avoid extra mutex calls
+	 * in the reading of data.
+	 */
+	uint32_t freed_by_sorcv_sincelast;
+	uint32_t total_sends;
+	uint32_t total_recvs;
+	int freed_from_where;
+	uint16_t rport;		/* remote port in network format */
+	uint16_t resv;
+#if defined(__FreeBSD__) && __FreeBSD_version >= 503000
+	struct mtx tcb_mtx;
+	struct mtx tcb_send_mtx;
+#elif defined(SCTP_PROCESS_LEVEL_LOCKS)
+	userland_mutex_t tcb_mtx;
+	userland_mutex_t tcb_send_mtx;
+#elif defined(__APPLE__)
+	lck_mtx_t* tcb_mtx;
+	lck_mtx_t* tcb_send_mtx;
+#elif defined(__Windows__)
+	struct spinlock tcb_lock;
+	struct spinlock tcb_send_lock;
+#elif defined(__Userspace__)
+    /* TODO decide on __Userspace__ locks */
+#endif
+#if defined(__APPLE__)
+	uint32_t caller1;
+	uint32_t caller2;
+	uint32_t caller3;
+#endif
+};
+
+
+#if defined(__FreeBSD__) && __FreeBSD_version >= 503000
+
+#include <netinet/sctp_lock_bsd.h>
+
+#elif defined(__APPLE__)
+/*
+ * Apple MacOS X 10.4 "Tiger"
+ */
+
+#include <netinet/sctp_lock_apple_fg.h>
+
+#elif defined(SCTP_PROCESS_LEVEL_LOCKS)
+
+#include <netinet/sctp_process_lock.h>
+
+#elif defined(__Windows__)
+
+#include <netinet/sctp_lock_windows.h>
+
+#elif defined(__Userspace__)
+
+#include <netinet/sctp_lock_userspace.h>
+
+#else
+/*
+ * Pre-5.x FreeBSD, and others.
+ */
+#include <netinet/sctp_lock_empty.h>
+#endif
+
+/* TODO where to put non-_KERNEL things for __Userspace__? */
+#if defined(_KERNEL) || defined(__Userspace__)
+
+/* Attention Julian, this is the extern that
+ * goes with the base info. sctp_pcb.c has
+ * the real definition.
+ */
+#if defined(__FreeBSD__) && __FreeBSD_version >= 801000
+VNET_DECLARE(struct sctp_base_info, system_base_info) ;
+#else
+extern struct sctp_base_info system_base_info;
+#endif
+
+#ifdef INET6
+int SCTP6_ARE_ADDR_EQUAL(struct sockaddr_in6 *a, struct sockaddr_in6 *b);
+#endif
+
+void sctp_fill_pcbinfo(struct sctp_pcbinfo *);
+
+struct sctp_ifn *
+sctp_find_ifn(void *ifn, uint32_t ifn_index);
+
+struct sctp_vrf *sctp_allocate_vrf(int vrfid);
+struct sctp_vrf *sctp_find_vrf(uint32_t vrfid);
+void sctp_free_vrf(struct sctp_vrf *vrf);
+
+/*-
+ * Change address state, can be used if
+ * O/S supports telling transports about
+ * changes to IFA/IFN's (link layer triggers).
+ * If a ifn goes down, we will do src-addr-selection
+ * and NOT use that, as a source address. This does
+ * not stop the routing system from routing out
+ * that interface, but we won't put it as a source.
+ */
+void sctp_mark_ifa_addr_down(uint32_t vrf_id, struct sockaddr *addr, const char *if_name, uint32_t ifn_index);
+void sctp_mark_ifa_addr_up(uint32_t vrf_id, struct sockaddr *addr, const char *if_name, uint32_t ifn_index);
+
+struct sctp_ifa *
+sctp_add_addr_to_vrf(uint32_t vrfid,
+		     void *ifn, uint32_t ifn_index, uint32_t ifn_type,
+		     const char *if_name,
+		     void *ifa, struct sockaddr *addr, uint32_t ifa_flags,
+		     int dynamic_add);
+
+void sctp_update_ifn_mtu(uint32_t ifn_index, uint32_t mtu);
+
+void sctp_free_ifn(struct sctp_ifn *sctp_ifnp);
+void sctp_free_ifa(struct sctp_ifa *sctp_ifap);
+
+
+void sctp_del_addr_from_vrf(uint32_t vrfid, struct sockaddr *addr,
+			    uint32_t ifn_index, const char *if_name);
+
+
+
+struct sctp_nets *sctp_findnet(struct sctp_tcb *, struct sockaddr *);
+
+struct sctp_inpcb *sctp_pcb_findep(struct sockaddr *, int, int, uint32_t);
+
+#if defined(__FreeBSD__) && __FreeBSD_version >= 500000
+int sctp_inpcb_bind(struct socket *, struct sockaddr *,
+		    struct sctp_ifa *,struct thread *);
+#elif defined(__Windows__)
+int sctp_inpcb_bind(struct socket *, struct sockaddr *,
+		    struct sctp_ifa *,PKTHREAD);
+#else
+/* struct proc is a dummy for __Userspace__ */
+int sctp_inpcb_bind(struct socket *, struct sockaddr *,
+		    struct sctp_ifa *, struct proc *);
+#endif
+
+struct sctp_tcb *
+sctp_findassociation_addr(struct mbuf *, int,
+    struct sockaddr *, struct sockaddr *,
+    struct sctphdr *, struct sctp_chunkhdr *, struct sctp_inpcb **,
+    struct sctp_nets **, uint32_t vrf_id);
+
+struct sctp_tcb *
+sctp_findassociation_addr_sa(struct sockaddr *,
+    struct sockaddr *, struct sctp_inpcb **, struct sctp_nets **, int, uint32_t);
+
+void
+sctp_move_pcb_and_assoc(struct sctp_inpcb *, struct sctp_inpcb *,
+    struct sctp_tcb *);
+
+/*-
+ * For this call ep_addr, the to is the destination endpoint address of the
+ * peer (relative to outbound). The from field is only used if the TCP model
+ * is enabled and helps distingush amongst the subset bound (non-boundall).
+ * The TCP model MAY change the actual ep field, this is why it is passed.
+ */
+struct sctp_tcb *
+sctp_findassociation_ep_addr(struct sctp_inpcb **,
+    struct sockaddr *, struct sctp_nets **, struct sockaddr *,
+    struct sctp_tcb *);
+
+struct sctp_tcb *
+sctp_findasoc_ep_asocid_locked(struct sctp_inpcb *inp, sctp_assoc_t asoc_id, int want_lock);
+
+struct sctp_tcb *
+sctp_findassociation_ep_asocid(struct sctp_inpcb *,
+    sctp_assoc_t, int);
+
+struct sctp_tcb *
+sctp_findassociation_ep_asconf(struct mbuf *, int, struct sockaddr *,
+			       struct sctphdr *, struct sctp_inpcb **, struct sctp_nets **, uint32_t vrf_id);
+
+int sctp_inpcb_alloc(struct socket *so, uint32_t vrf_id);
+
+int sctp_is_address_on_local_host(struct sockaddr *addr, uint32_t vrf_id);
+
+void sctp_inpcb_free(struct sctp_inpcb *, int, int);
+
+#if defined(__FreeBSD__) && __FreeBSD_version >= 500000
+struct sctp_tcb *
+sctp_aloc_assoc(struct sctp_inpcb *, struct sockaddr *,
+                int *, uint32_t, uint32_t, uint16_t, uint16_t, struct thread *);
+#elif defined(__Windows__)
+struct sctp_tcb *
+sctp_aloc_assoc(struct sctp_inpcb *, struct sockaddr *,
+                int *, uint32_t, uint32_t, uint16_t, uint16_t, PKTHREAD);
+#else
+/* proc will be NULL for __Userspace__ */
+struct sctp_tcb *
+sctp_aloc_assoc(struct sctp_inpcb *, struct sockaddr *,
+                int *, uint32_t, uint32_t, uint16_t, uint16_t, struct proc *);
+#endif
+
+int sctp_free_assoc(struct sctp_inpcb *, struct sctp_tcb *, int, int);
+
+
+void sctp_delete_from_timewait(uint32_t, uint16_t, uint16_t);
+
+int sctp_is_in_timewait(uint32_t tag, uint16_t lport, uint16_t rport);
+
+void
+sctp_add_vtag_to_timewait(uint32_t tag, uint32_t time, uint16_t lport, uint16_t rport);
+
+void sctp_add_local_addr_ep(struct sctp_inpcb *, struct sctp_ifa *, uint32_t);
+
+void sctp_del_local_addr_ep(struct sctp_inpcb *, struct sctp_ifa *);
+
+int sctp_add_remote_addr(struct sctp_tcb *, struct sockaddr *, struct sctp_nets **, uint16_t, int, int);
+
+void sctp_remove_net(struct sctp_tcb *, struct sctp_nets *);
+
+int sctp_del_remote_addr(struct sctp_tcb *, struct sockaddr *);
+
+void sctp_pcb_init(void);
+
+void sctp_pcb_finish(void);
+
+void sctp_add_local_addr_restricted(struct sctp_tcb *, struct sctp_ifa *);
+void sctp_del_local_addr_restricted(struct sctp_tcb *, struct sctp_ifa *);
+
+int
+sctp_load_addresses_from_init(struct sctp_tcb *, struct mbuf *, int, int,
+    struct sockaddr *, struct sockaddr *, struct sockaddr *, uint16_t);
+
+int
+sctp_set_primary_addr(struct sctp_tcb *, struct sockaddr *,
+    struct sctp_nets *);
+
+int sctp_is_vtag_good(uint32_t, uint16_t lport, uint16_t rport, struct timeval *);
+
+/* void sctp_drain(void); */
+
+int sctp_destination_is_reachable(struct sctp_tcb *, struct sockaddr *);
+
+int sctp_swap_inpcb_for_listen(struct sctp_inpcb *inp);
+
+void sctp_clean_up_stream(struct sctp_tcb *stcb, struct sctp_readhead *rh);
+
+/*-
+ * Null in last arg inpcb indicate run on ALL ep's. Specific inp in last arg
+ * indicates run on ONLY assoc's of the specified endpoint.
+ */
+int
+sctp_initiate_iterator(inp_func inpf,
+		       asoc_func af,
+		       inp_func inpe,
+		       uint32_t, uint32_t,
+		       uint32_t, void *,
+		       uint32_t,
+		       end_func ef,
+		       struct sctp_inpcb *,
+		       uint8_t co_off);
+#if defined(__FreeBSD__) && defined(SCTP_MCORE_INPUT) && defined(SMP)
+void
+sctp_queue_to_mcore(struct mbuf *m, int off, int cpu_to_use);
+
+#endif
+
+#endif				/* _KERNEL */
+#endif				/* !__sctp_pcb_h__ */