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[0];
28 };
29
30 struct 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 */
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[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
mldv2_mrc(const struct mld2_query * mlh2)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