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