This is xnu-8019. See this file in:
/*
 * Copyright (c) 2010 Apple Computer, 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) 2009 Bruce Simpson.
 *
 * 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. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 *
 * $FreeBSD$
 */

#ifndef _NETINET6_MLD6_H_
#define _NETINET6_MLD6_H_

/*
 * Multicast Listener Discovery (MLD) definitions.
 */

/* Minimum length of any MLD protocol message. */
#define MLD_MINLEN      sizeof(struct icmp6_hdr)

/*
 * MLD v2 query format.
 * See <netinet/icmp6.h> for struct mld_hdr
 * (MLDv1 query and host report format).
 */
struct mldv2_query {
	struct icmp6_hdr        mld_icmp6_hdr;  /* ICMPv6 header */
	struct in6_addr         mld_addr;       /* address being queried */
	uint8_t         mld_misc;       /* reserved/suppress/robustness   */
	uint8_t         mld_qqi;        /* querier's query interval       */
	uint16_t        mld_numsrc;     /* number of sources              */
	/* followed by 1..numsrc source addresses */
} __attribute__((__packed__));
#define MLD_V2_QUERY_MINLEN             sizeof(struct mldv2_query)
#define MLD_MRC_EXP(x)                  ((ntohs((x)) >> 12) & 0x0007)
#define MLD_MRC_MANT(x)                 (ntohs((x)) & 0x0fff)
#define MLD_QQIC_EXP(x)                 (((x) >> 4) & 0x07)
#define MLD_QQIC_MANT(x)                ((x) & 0x0f)
#define MLD_QRESV(x)                    (((x) >> 4) & 0x0f)
#define MLD_SFLAG(x)                    (((x) >> 3) & 0x01)
#define MLD_QRV(x)                      ((x) & 0x07)

/*
 * MLDv2 host membership report header.
 * mld_type: MLDV2_LISTENER_REPORT
 */
struct mldv2_report {
	struct icmp6_hdr        mld_icmp6_hdr;
	/* followed by 1..numgrps records */
} __attribute__((__packed__));
/* overlaid on struct icmp6_hdr. */
#define mld_numrecs     mld_icmp6_hdr.icmp6_data16[1]

struct mldv2_record {
	uint8_t                 mr_type;        /* record type */
	uint8_t                 mr_datalen;     /* length of auxiliary data */
	uint16_t                mr_numsrc;      /* number of sources */
	struct in6_addr         mr_addr;        /* address being reported */
	/* followed by 1..numsrc source addresses */
} __attribute__((__packed__));
#define MLD_V2_REPORT_MAXRECS           65535

/*
 * MLDv2 report modes.
 */
#define MLD_DO_NOTHING                  0       /* don't send a record */
#define MLD_MODE_IS_INCLUDE             1       /* MODE_IN */
#define MLD_MODE_IS_EXCLUDE             2       /* MODE_EX */
#define MLD_CHANGE_TO_INCLUDE_MODE      3       /* TO_IN */
#define MLD_CHANGE_TO_EXCLUDE_MODE      4       /* TO_EX */
#define MLD_ALLOW_NEW_SOURCES           5       /* ALLOW_NEW */
#define MLD_BLOCK_OLD_SOURCES           6       /* BLOCK_OLD */

/*
 * MLDv2 query types.
 */
#define MLD_V2_GENERAL_QUERY            1
#define MLD_V2_GROUP_QUERY              2
#define MLD_V2_GROUP_SOURCE_QUERY       3

/*
 * Maximum report interval for MLDv1 host membership reports.
 */
#define MLD_V1_MAX_RI                   10

/*
 * MLD_TIMER_SCALE denotes that the MLD code field specifies
 * time in milliseconds.
 */
#define MLD_TIMER_SCALE                 1000

#endif /* _NETINET6_MLD6_H_ */