LXR linux/include/net/mld.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef LINUX_MLD_H
   3#define LINUX_MLD_H
   4
   5#include <linux/in6.h>
   6#include <linux/icmpv6.h>
   7
   8/* MLDv1 Query/Report/Done */
   9struct mld_msg {
  10        struct icmp6hdr         mld_hdr;
  11        struct in6_addr         mld_mca;
  12};
  13
  14#define mld_type                mld_hdr.icmp6_type
  15#define mld_code                mld_hdr.icmp6_code
  16#define mld_cksum               mld_hdr.icmp6_cksum
  17#define mld_maxdelay            mld_hdr.icmp6_maxdelay
  18#define mld_reserved            mld_hdr.icmp6_dataun.un_data16[1]
  19
  20/* Multicast Listener Discovery version 2 headers */
  21/* MLDv2 Report */
  22struct mld2_grec {
  23        __u8            grec_type;
  24        __u8            grec_auxwords;
  25        __be16          grec_nsrcs;
  26        struct in6_addr grec_mca;
  27        struct in6_addr grec_src[0];
  28};
  29
  30struct mld2_report {
  31        struct icmp6hdr         mld2r_hdr;
  32        struct mld2_grec        mld2r_grec[0];
  33};
  34
  35#define mld2r_type              mld2r_hdr.icmp6_type
  36#define mld2r_resv1             mld2r_hdr.icmp6_code
  37#define mld2r_cksum             mld2r_hdr.icmp6_cksum
  38#define mld2r_resv2             mld2r_hdr.icmp6_dataun.un_data16[0]
  39#define mld2r_ngrec             mld2r_hdr.icmp6_dataun.un_data16[1]
  40
  41/* MLDv2 Query */
  42struct mld2_query {
  43        struct icmp6hdr         mld2q_hdr;
  44        struct in6_addr         mld2q_mca;
  45#if defined(__LITTLE_ENDIAN_BITFIELD)
  46        __u8                    mld2q_qrv:3,
  47                                mld2q_suppress:1,
  48                                mld2q_resv2:4;
  49#elif defined(__BIG_ENDIAN_BITFIELD)
  50        __u8                    mld2q_resv2:4,
  51                                mld2q_suppress:1,
  52                                mld2q_qrv:3;
  53#else
  54#error "Please fix <asm/byteorder.h>"
  55#endif
  56        __u8                    mld2q_qqic;
  57        __be16                  mld2q_nsrcs;
  58        struct in6_addr         mld2q_srcs[0];
  59};
  60
  61#define mld2q_type              mld2q_hdr.icmp6_type
  62#define mld2q_code              mld2q_hdr.icmp6_code
  63#define mld2q_cksum             mld2q_hdr.icmp6_cksum
  64#define mld2q_mrc               mld2q_hdr.icmp6_maxdelay
  65#define mld2q_resv1             mld2q_hdr.icmp6_dataun.un_data16[1]
  66
  67/* RFC3810, 5.1.3. Maximum Response Code:
  68 *
  69 * If Maximum Response Code >= 32768, Maximum Response Code represents a
  70 * floating-point value as follows:
  71 *
  72 *  0 1 2 3 4 5 6 7 8 9 A B C D E F
  73 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  74 * |1| exp |          mant         |
  75 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  76 */
  77#define MLDV2_MRC_EXP(value)    (((value) >> 12) & 0x0007)
  78#define MLDV2_MRC_MAN(value)    ((value) & 0x0fff)
  79
  80/* RFC3810, 5.1.9. QQIC (Querier's Query Interval Code):
  81 *
  82 * If QQIC >= 128, QQIC represents a floating-point value as follows:
  83 *
  84 *  0 1 2 3 4 5 6 7
  85 * +-+-+-+-+-+-+-+-+
  86 * |1| exp | mant  |
  87 * +-+-+-+-+-+-+-+-+
  88 */
  89#define MLDV2_QQIC_EXP(value)   (((value) >> 4) & 0x07)
  90#define MLDV2_QQIC_MAN(value)   ((value) & 0x0f)
  91
  92#define MLD_EXP_MIN_LIMIT       32768UL
  93#define MLDV1_MRD_MAX_COMPAT    (MLD_EXP_MIN_LIMIT - 1)
  94
  95static inline unsigned long mldv2_mrc(const struct mld2_query *mlh2)
  96{
  97        /* RFC3810, 5.1.3. Maximum Response Code */
  98        unsigned long ret, mc_mrc = ntohs(mlh2->mld2q_mrc);
  99
 100        if (mc_mrc < MLD_EXP_MIN_LIMIT) {
 101                ret = mc_mrc;
 102        } else {
 103                unsigned long mc_man, mc_exp;
 104
 105                mc_exp = MLDV2_MRC_EXP(mc_mrc);
 106                mc_man = MLDV2_MRC_MAN(mc_mrc);
 107
 108                ret = (mc_man | 0x1000) << (mc_exp + 3);
 109        }
 110
 111        return ret;
 112}
 113
 114#endif
 115