include/net/mld.h

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