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 */
8struct 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 */
21struct 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
29struct 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 */
41struct 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
94static 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
114