xref: /openbmc/linux/include/net/mld.h (revision f185de28)
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 #define MLD_MAX_QUEUE		8
96 #define MLD_MAX_SKBS		32
97 
mldv2_mrc(const struct mld2_query * mlh2)98 static 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