#ifndef LINUX_MLD_H
  #define LINUX_MLD_H
  
  #include <linux/in6.h>
  #include <linux/icmpv6.h>
  
  /* MLDv1 Query/Report/Done */
  struct mld_msg {
  	struct icmp6hdr		mld_hdr;
  	struct in6_addr		mld_mca;
  };
  
  #define mld_type		mld_hdr.icmp6_type
  #define mld_code		mld_hdr.icmp6_code
  #define mld_cksum		mld_hdr.icmp6_cksum
  #define mld_maxdelay		mld_hdr.icmp6_maxdelay
  #define mld_reserved		mld_hdr.icmp6_dataun.un_data16[1]
  
  /* Multicast Listener Discovery version 2 headers */
  /* MLDv2 Report */
  struct mld2_grec {
  	__u8		grec_type;
  	__u8		grec_auxwords;
  	__be16		grec_nsrcs;
  	struct in6_addr	grec_mca;
  	struct in6_addr	grec_src[0];
  };
  
  struct mld2_report {
  	struct icmp6hdr		mld2r_hdr;
  	struct mld2_grec	mld2r_grec[0];
  };
  
  #define mld2r_type		mld2r_hdr.icmp6_type
  #define mld2r_resv1		mld2r_hdr.icmp6_code
  #define mld2r_cksum		mld2r_hdr.icmp6_cksum
  #define mld2r_resv2		mld2r_hdr.icmp6_dataun.un_data16[0]
  #define mld2r_ngrec		mld2r_hdr.icmp6_dataun.un_data16[1]
  
  /* MLDv2 Query */
  struct mld2_query {
  	struct icmp6hdr		mld2q_hdr;
  	struct in6_addr		mld2q_mca;
  #if defined(__LITTLE_ENDIAN_BITFIELD)
  	__u8			mld2q_qrv:3,
  				mld2q_suppress:1,
  				mld2q_resv2:4;
  #elif defined(__BIG_ENDIAN_BITFIELD)
  	__u8			mld2q_resv2:4,
  				mld2q_suppress:1,
  				mld2q_qrv:3;
  #else
  #error "Please fix <asm/byteorder.h>"
  #endif
  	__u8			mld2q_qqic;
  	__be16			mld2q_nsrcs;
  	struct in6_addr		mld2q_srcs[0];
  };
  
  #define mld2q_type		mld2q_hdr.icmp6_type
  #define mld2q_code		mld2q_hdr.icmp6_code
  #define mld2q_cksum		mld2q_hdr.icmp6_cksum
  #define mld2q_mrc		mld2q_hdr.icmp6_maxdelay
  #define mld2q_resv1		mld2q_hdr.icmp6_dataun.un_data16[1]

  /* RFC3810, 5.1.3. Maximum Response Code:
   *
   * If Maximum Response Code >= 32768, Maximum Response Code represents a
   * floating-point value as follows:
   *
   *  0 1 2 3 4 5 6 7 8 9 A B C D E F
   * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   * |1| exp |          mant         |
   * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   */
  #define MLDV2_MRC_EXP(value)	(((value) >> 12) & 0x0007)
  #define MLDV2_MRC_MAN(value)	((value) & 0x0fff)
  
  /* RFC3810, 5.1.9. QQIC (Querier's Query Interval Code):
   *
   * If QQIC >= 128, QQIC represents a floating-point value as follows:
   *
   *  0 1 2 3 4 5 6 7
   * +-+-+-+-+-+-+-+-+
   * |1| exp | mant  |
   * +-+-+-+-+-+-+-+-+
   */
  #define MLDV2_QQIC_EXP(value)	(((value) >> 4) & 0x07)
  #define MLDV2_QQIC_MAN(value)	((value) & 0x0f)

  #define MLD_EXP_MIN_LIMIT	32768UL
  #define MLDV1_MRD_MAX_COMPAT	(MLD_EXP_MIN_LIMIT - 1)

  static inline unsigned long mldv2_mrc(const struct mld2_query *mlh2)
  {
  	/* RFC3810, 5.1.3. Maximum Response Code */
  	unsigned long ret, mc_mrc = ntohs(mlh2->mld2q_mrc);

  	if (mc_mrc < MLD_EXP_MIN_LIMIT) {

  		ret = mc_mrc;
  	} else {
  		unsigned long mc_man, mc_exp;
  
  		mc_exp = MLDV2_MRC_EXP(mc_mrc);
  		mc_man = MLDV2_MRC_MAN(mc_mrc);
  
  		ret = (mc_man | 0x1000) << (mc_exp + 3);
  	}
  
  	return ret;
  }

  #endif