xref: /linux-6.15/include/linux/igmp.h (revision f60d24d2)
1 /*
2  *	Linux NET3:	Internet Group Management Protocol  [IGMP]
3  *
4  *	Authors:
5  *		Alan Cox <[email protected]>
6  *
7  *	Extended to talk the BSD extended IGMP protocol of mrouted 3.6
8  *
9  *
10  *	This program is free software; you can redistribute it and/or
11  *	modify it under the terms of the GNU General Public License
12  *	as published by the Free Software Foundation; either version
13  *	2 of the License, or (at your option) any later version.
14  */
15 
16 #ifndef _LINUX_IGMP_H
17 #define _LINUX_IGMP_H
18 
19 #include <linux/types.h>
20 #include <asm/byteorder.h>
21 
22 /*
23  *	IGMP protocol structures
24  */
25 
26 /*
27  *	Header in on cable format
28  */
29 
30 struct igmphdr
31 {
32 	__u8 type;
33 	__u8 code;		/* For newer IGMP */
34 	__sum16 csum;
35 	__be32 group;
36 };
37 
38 /* V3 group record types [grec_type] */
39 #define IGMPV3_MODE_IS_INCLUDE		1
40 #define IGMPV3_MODE_IS_EXCLUDE		2
41 #define IGMPV3_CHANGE_TO_INCLUDE	3
42 #define IGMPV3_CHANGE_TO_EXCLUDE	4
43 #define IGMPV3_ALLOW_NEW_SOURCES	5
44 #define IGMPV3_BLOCK_OLD_SOURCES	6
45 
46 struct igmpv3_grec {
47 	__u8	grec_type;
48 	__u8	grec_auxwords;
49 	__be16	grec_nsrcs;
50 	__be32	grec_mca;
51 	__be32	grec_src[0];
52 };
53 
54 struct igmpv3_report {
55 	__u8 type;
56 	__u8 resv1;
57 	__be16 csum;
58 	__be16 resv2;
59 	__be16 ngrec;
60 	struct igmpv3_grec grec[0];
61 };
62 
63 struct igmpv3_query {
64 	__u8 type;
65 	__u8 code;
66 	__be16 csum;
67 	__be32 group;
68 #if defined(__LITTLE_ENDIAN_BITFIELD)
69 	__u8 qrv:3,
70 	     suppress:1,
71 	     resv:4;
72 #elif defined(__BIG_ENDIAN_BITFIELD)
73 	__u8 resv:4,
74 	     suppress:1,
75 	     qrv:3;
76 #else
77 #error "Please fix <asm/byteorder.h>"
78 #endif
79 	__u8 qqic;
80 	__be16 nsrcs;
81 	__be32 srcs[0];
82 };
83 
84 #define IGMP_HOST_MEMBERSHIP_QUERY	0x11	/* From RFC1112 */
85 #define IGMP_HOST_MEMBERSHIP_REPORT	0x12	/* Ditto */
86 #define IGMP_DVMRP			0x13	/* DVMRP routing */
87 #define IGMP_PIM			0x14	/* PIM routing */
88 #define IGMP_TRACE			0x15
89 #define IGMPV2_HOST_MEMBERSHIP_REPORT	0x16	/* V2 version of 0x11 */
90 #define IGMP_HOST_LEAVE_MESSAGE 	0x17
91 #define IGMPV3_HOST_MEMBERSHIP_REPORT	0x22	/* V3 version of 0x11 */
92 
93 #define IGMP_MTRACE_RESP		0x1e
94 #define IGMP_MTRACE			0x1f
95 
96 
97 /*
98  *	Use the BSD names for these for compatibility
99  */
100 
101 #define IGMP_DELAYING_MEMBER		0x01
102 #define IGMP_IDLE_MEMBER		0x02
103 #define IGMP_LAZY_MEMBER		0x03
104 #define IGMP_SLEEPING_MEMBER		0x04
105 #define IGMP_AWAKENING_MEMBER		0x05
106 
107 #define IGMP_MINLEN			8
108 
109 #define IGMP_MAX_HOST_REPORT_DELAY	10	/* max delay for response to */
110 						/* query (in seconds)	*/
111 
112 #define IGMP_TIMER_SCALE		10	/* denotes that the igmphdr->timer field */
113 						/* specifies time in 10th of seconds	 */
114 
115 #define IGMP_AGE_THRESHOLD		400	/* If this host don't hear any IGMP V1	*/
116 						/* message in this period of time,	*/
117 						/* revert to IGMP v2 router.		*/
118 
119 #define IGMP_ALL_HOSTS		htonl(0xE0000001L)
120 #define IGMP_ALL_ROUTER 	htonl(0xE0000002L)
121 #define IGMPV3_ALL_MCR	 	htonl(0xE0000016L)
122 #define IGMP_LOCAL_GROUP	htonl(0xE0000000L)
123 #define IGMP_LOCAL_GROUP_MASK	htonl(0xFFFFFF00L)
124 
125 /*
126  * struct for keeping the multicast list in
127  */
128 
129 #ifdef __KERNEL__
130 #include <linux/skbuff.h>
131 #include <linux/timer.h>
132 #include <linux/in.h>
133 
134 static inline struct igmphdr *igmp_hdr(const struct sk_buff *skb)
135 {
136 	return (struct igmphdr *)skb_transport_header(skb);
137 }
138 
139 static inline struct igmpv3_report *
140 			igmpv3_report_hdr(const struct sk_buff *skb)
141 {
142 	return (struct igmpv3_report *)skb_transport_header(skb);
143 }
144 
145 static inline struct igmpv3_query *
146 			igmpv3_query_hdr(const struct sk_buff *skb)
147 {
148 	return (struct igmpv3_query *)skb_transport_header(skb);
149 }
150 
151 extern int sysctl_igmp_max_memberships;
152 extern int sysctl_igmp_max_msf;
153 
154 struct ip_sf_socklist
155 {
156 	unsigned int		sl_max;
157 	unsigned int		sl_count;
158 	__be32			sl_addr[0];
159 };
160 
161 #define IP_SFLSIZE(count)	(sizeof(struct ip_sf_socklist) + \
162 	(count) * sizeof(__be32))
163 
164 #define IP_SFBLOCK	10	/* allocate this many at once */
165 
166 /* ip_mc_socklist is real list now. Speed is not argument;
167    this list never used in fast path code
168  */
169 
170 struct ip_mc_socklist
171 {
172 	struct ip_mc_socklist	*next;
173 	struct ip_mreqn		multi;
174 	unsigned int		sfmode;		/* MCAST_{INCLUDE,EXCLUDE} */
175 	struct ip_sf_socklist	*sflist;
176 };
177 
178 struct ip_sf_list
179 {
180 	struct ip_sf_list	*sf_next;
181 	__be32			sf_inaddr;
182 	unsigned long		sf_count[2];	/* include/exclude counts */
183 	unsigned char		sf_gsresp;	/* include in g & s response? */
184 	unsigned char		sf_oldin;	/* change state */
185 	unsigned char		sf_crcount;	/* retrans. left to send */
186 };
187 
188 struct ip_mc_list
189 {
190 	struct in_device	*interface;
191 	__be32			multiaddr;
192 	struct ip_sf_list	*sources;
193 	struct ip_sf_list	*tomb;
194 	unsigned int		sfmode;
195 	unsigned long		sfcount[2];
196 	struct ip_mc_list	*next;
197 	struct timer_list	timer;
198 	int			users;
199 	atomic_t		refcnt;
200 	spinlock_t		lock;
201 	char			tm_running;
202 	char			reporter;
203 	char			unsolicit_count;
204 	char			loaded;
205 	unsigned char		gsquery;	/* check source marks? */
206 	unsigned char		crcount;
207 };
208 
209 /* V3 exponential field decoding */
210 #define IGMPV3_MASK(value, nb) ((nb)>=32 ? (value) : ((1<<(nb))-1) & (value))
211 #define IGMPV3_EXP(thresh, nbmant, nbexp, value) \
212 	((value) < (thresh) ? (value) : \
213         ((IGMPV3_MASK(value, nbmant) | (1<<(nbmant))) << \
214          (IGMPV3_MASK((value) >> (nbmant), nbexp) + (nbexp))))
215 
216 #define IGMPV3_QQIC(value) IGMPV3_EXP(0x80, 4, 3, value)
217 #define IGMPV3_MRC(value) IGMPV3_EXP(0x80, 4, 3, value)
218 
219 extern int ip_check_mc(struct in_device *dev, __be32 mc_addr, __be32 src_addr, u16 proto);
220 extern int igmp_rcv(struct sk_buff *);
221 extern int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr);
222 extern int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr);
223 extern void ip_mc_drop_socket(struct sock *sk);
224 extern int ip_mc_source(int add, int omode, struct sock *sk,
225 		struct ip_mreq_source *mreqs, int ifindex);
226 extern int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf,int ifindex);
227 extern int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
228 		struct ip_msfilter __user *optval, int __user *optlen);
229 extern int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
230 		struct group_filter __user *optval, int __user *optlen);
231 extern int ip_mc_sf_allow(struct sock *sk, __be32 local, __be32 rmt, int dif);
232 extern void ip_mc_init_dev(struct in_device *);
233 extern void ip_mc_destroy_dev(struct in_device *);
234 extern void ip_mc_up(struct in_device *);
235 extern void ip_mc_down(struct in_device *);
236 extern void ip_mc_unmap(struct in_device *);
237 extern void ip_mc_remap(struct in_device *);
238 extern void ip_mc_dec_group(struct in_device *in_dev, __be32 addr);
239 extern void ip_mc_inc_group(struct in_device *in_dev, __be32 addr);
240 extern void ip_mc_rejoin_group(struct ip_mc_list *im);
241 
242 #endif
243 #endif
244