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 */ 9 struct 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 */ 22 struct 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[]; 28 }; 29 30 struct mld2_report { 31 struct icmp6hdr mld2r_hdr; 32 struct mld2_grec mld2r_grec[]; 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 */ 42 struct 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[]; 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 95 static 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