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[];
28};
29
30struct 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 */
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[];
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#define MLD_MAX_QUEUE		8
96#define MLD_MAX_SKBS		32
97
98static inline unsigned long mldv2_mrc(const struct mld2_query *mlh2)
99{
100	/* RFC3810, 5.1.3. Maximum Response Code */
101	unsigned long ret, mc_mrc = ntohs(mlh2->mld2q_mrc);
102
103	if (mc_mrc < MLD_EXP_MIN_LIMIT) {
104		ret = mc_mrc;
105	} else {
106		unsigned long mc_man, mc_exp;
107
108		mc_exp = MLDV2_MRC_EXP(mc_mrc);
109		mc_man = MLDV2_MRC_MAN(mc_mrc);
110
111		ret = (mc_man | 0x1000) << (mc_exp + 3);
112	}
113
114	return ret;
115}
116
117#endif
118