This is xnu-8019. See this file in:
/*
 * Copyright (c) 2008-2020 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1982, 1986, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 *
 *	@(#)unpcb.h	8.1 (Berkeley) 6/2/93
 */

#ifndef _SYS_UNPCB_H_
#define _SYS_UNPCB_H_

#include <sys/appleapiopts.h>
#include <sys/queue.h>
#include <sys/un.h>
#include <sys/ucred.h>
#include <sys/socketvar.h>
#if !KERNEL && PRIVATE
#include <TargetConditionals.h>
#endif

/*
 * Protocol control block for an active
 * instance of a UNIX internal protocol.
 *
 * A socket may be associated with an vnode in the
 * file system.  If so, the unp_vnode pointer holds
 * a reference count to this vnode, which should be irele'd
 * when the socket goes away.
 *
 * A socket may be connected to another socket, in which
 * case the control block of the socket to which it is connected
 * is given by unp_conn.
 *
 * A socket may be referenced by a number of sockets (e.g. several
 * sockets may be connected to a datagram socket.)  These sockets
 * are in a linked list starting with unp_refs, linked through
 * unp_nextref and null-terminated.  Note that a socket may be referenced
 * by a number of other sockets and may also reference a socket (not
 * necessarily one which is referencing it).  This generates
 * the need for unp_refs and unp_nextref to be separate fields.
 *
 * Stream sockets keep copies of receive sockbuf sb_cc and sb_mbcnt
 * so that changes in the sockbuf may be computed to modify
 * back pressure on the sender accordingly.
 */

typedef u_quad_t        unp_gen_t;

#if defined(__LP64__)
struct _unpcb_list_entry {
	u_int32_t   le_next;
	u_int32_t   le_prev;
};
#define _UCPCB_LIST_HEAD(name, type)    \
struct name {                           \
	u_int32_t	lh_first;       \
};
#define _UNPCB_LIST_ENTRY(x)            struct _unpcb_list_entry
#define _UNPCB_PTR(x)                   u_int32_t
#else
#define _UCPCB_LIST_HEAD(name, type)    LIST_HEAD(name, type)
#define _UNPCB_LIST_ENTRY(x)            LIST_ENTRY(x)
#define _UNPCB_PTR(x)                   x
#endif

#ifdef PRIVATE
#ifndef KERNEL
_UCPCB_LIST_HEAD(unp_head, unpcb);
#else
LIST_HEAD(unp_head, unpcb);
#define sotounpcb(so)   ((struct unpcb *)((so)->so_pcb))

struct  unpcb {
	LIST_ENTRY(unpcb) unp_link;     /* glue on list of all PCBs */
	struct socket   *unp_socket;    /* pointer back to socket */
	struct vnode    *unp_vnode;     /* if associated with file */
	ino_t                   unp_ino;        /* fake inode number */
	struct unpcb    *unp_conn;      /* control block of connected socket */
	struct unp_head unp_refs;       /* referencing socket linked list */
	LIST_ENTRY(unpcb) unp_reflink;  /* link in unp_refs list */
	struct sockaddr_un *unp_addr;   /* bound address of socket */
	int             unp_cc;         /* copy of rcv.sb_cc */
	int             unp_mbcnt;      /* copy of rcv.sb_mbcnt */
	unp_gen_t       unp_gencnt;     /* generation count of this instance */
	int             unp_flags;      /* flags */
	struct xucred   unp_peercred;   /* peer credentials, if applicable */
	decl_lck_mtx_data(, unp_mtx);   /* per unpcb lock */
	int             rw_thrcount;    /* disconnect should wait for this count to become zero */
};
#endif /* KERNEL */

/*
 * Flags in unp_flags.
 *
 * UNP_HAVEPC - indicates that the unp_peercred member is filled in
 * and is really the credentials of the connected peer.  This is used
 * to determine whether the contents should be sent to the user or
 * not.
 *
 * UNP_HAVEPCCACHED - indicates that the unp_peercred member is filled
 * in, but does *not* contain the credentials of the connected peer
 * (there may not even be a peer).  This is set in unp_listen() when
 * it fills in unp_peercred for later consumption by unp_connect().
 */
#define UNP_HAVEPC                      0x0001
#define UNP_HAVEPCCACHED                0x0002
#define UNP_DONTDISCONNECT              0x0004
#define UNP_TRACE_MDNS                  0x1000

#ifdef KERNEL
struct  unpcb_compat {
#else /* KERNEL */
#define unpcb_compat unpcb
struct  unpcb {
#endif /* KERNEL */
	_UNPCB_LIST_ENTRY(unpcb_compat) unp_link;       /* glue on list of all PCBs */
	_UNPCB_PTR(struct socket *)     unp_socket;     /* pointer back to socket */
	_UNPCB_PTR(struct vnode *)      unp_vnode;      /* if associated with file */
	u_int32_t                       unp_ino;        /* fake inode number */
	_UNPCB_PTR(struct unpcb_compat *) unp_conn;     /* control block of connected socket */
#if defined(KERNEL)
	u_int32_t                       unp_refs;
#else
	struct unp_head                 unp_refs;       /* referencing socket linked list */
#endif
	_UNPCB_LIST_ENTRY(unpcb_compat) unp_reflink;    /* link in unp_refs list */
	_UNPCB_PTR(struct sockaddr_un *) unp_addr;      /* bound address of socket */
	int                             unp_cc;         /* copy of rcv.sb_cc */
	int                             unp_mbcnt;      /* copy of rcv.sb_mbcnt */
	unp_gen_t                       unp_gencnt;     /* generation count of this instance */
};

/* Hack alert -- this structure depends on <sys/socketvar.h>. */
#ifdef  _SYS_SOCKETVAR_H_

#pragma pack(4)

struct  xunpcb {
	u_int32_t                       xu_len;         /* length of this structure */
	_UNPCB_PTR(struct unpcb_compat *) xu_unpp;      /* to help netstat, fstat */
	struct unpcb_compat             xu_unp;         /* our information */
	union {
		struct sockaddr_un      xuu_addr;       /* our bound address */
		char                    xu_dummy1[256];
	} xu_au;
#define xu_addr xu_au.xuu_addr
	union {
		struct sockaddr_un      xuu_caddr;      /* their bound address */
		char                    xu_dummy2[256];
	} xu_cau;
#define xu_caddr xu_cau.xuu_caddr
	struct xsocket                  xu_socket;
	u_quad_t                        xu_alignment_hack;
};

#if XNU_TARGET_OS_OSX || KERNEL || !(TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR)

struct xunpcb64_list_entry {
	u_int64_t   le_next;
	u_int64_t   le_prev;
};

struct xunpcb64 {
	u_int32_t                       xu_len;         /* length of this structure */
	u_int64_t                       xu_unpp;        /* to help netstat, fstat */
	struct xunpcb64_list_entry      xunp_link;      /* glue on list of all PCBs */
	u_int64_t                       xunp_socket;    /* pointer back to socket */
	u_int64_t                       xunp_vnode;     /* if associated with file */
	u_int64_t                       xunp_ino;       /* fake inode number */
	u_int64_t                       xunp_conn;      /* control block of connected socket */
	u_int64_t                       xunp_refs;      /* referencing socket linked list */
	struct xunpcb64_list_entry      xunp_reflink;   /* link in unp_refs list */
	int                             xunp_cc;                /* copy of rcv.sb_cc */
	int                             xunp_mbcnt;     /* copy of rcv.sb_mbcnt */
	unp_gen_t                       xunp_gencnt;    /* generation count of this instance */
	int                             xunp_flags;     /* flags */
	union {
		struct sockaddr_un              xuu_addr;
		char                            xu_dummy1[256];
	}                               xu_au;          /* our bound address */
#define xunp_addr xu_au.xuu_addr
	union {
		struct sockaddr_un              xuu_caddr;
		char                            xu_dummy2[256];
	}                               xu_cau;         /* their bound address */
#define xunp_caddr xu_cau.xuu_caddr
	struct xsocket64        xu_socket;
};

#endif /* XNU_TARGET_OS_OSX || KERNEL || !(TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR) */

#pragma pack()

#endif /* _SYS_SOCKETVAR_H_ */

#endif /* PRIVATE */

struct  xunpgen {
	u_int32_t       xug_len;
	u_int           xug_count;
	unp_gen_t       xug_gen;
	so_gen_t        xug_sogen;
};

#endif /* _SYS_UNPCB_H_ */