xref: /linux-6.15/include/linux/igmp.h (revision eb2bce7f)
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 <asm/byteorder.h>
20 
21 /*
22  *	IGMP protocol structures
23  */
24 
25 /*
26  *	Header in on cable format
27  */
28 
29 struct igmphdr
30 {
31 	__u8 type;
32 	__u8 code;		/* For newer IGMP */
33 	__sum16 csum;
34 	__be32 group;
35 };
36 
37 /* V3 group record types [grec_type] */
38 #define IGMPV3_MODE_IS_INCLUDE		1
39 #define IGMPV3_MODE_IS_EXCLUDE		2
40 #define IGMPV3_CHANGE_TO_INCLUDE	3
41 #define IGMPV3_CHANGE_TO_EXCLUDE	4
42 #define IGMPV3_ALLOW_NEW_SOURCES	5
43 #define IGMPV3_BLOCK_OLD_SOURCES	6
44 
45 struct igmpv3_grec {
46 	__u8	grec_type;
47 	__u8	grec_auxwords;
48 	__be16	grec_nsrcs;
49 	__be32	grec_mca;
50 	__be32	grec_src[0];
51 };
52 
53 struct igmpv3_report {
54 	__u8 type;
55 	__u8 resv1;
56 	__be16 csum;
57 	__be16 resv2;
58 	__be16 ngrec;
59 	struct igmpv3_grec grec[0];
60 };
61 
62 struct igmpv3_query {
63 	__u8 type;
64 	__u8 code;
65 	__be16 csum;
66 	__be32 group;
67 #if defined(__LITTLE_ENDIAN_BITFIELD)
68 	__u8 qrv:3,
69 	     suppress:1,
70 	     resv:4;
71 #elif defined(__BIG_ENDIAN_BITFIELD)
72 	__u8 resv:4,
73 	     suppress:1,
74 	     qrv:3;
75 #else
76 #error "Please fix <asm/byteorder.h>"
77 #endif
78 	__u8 qqic;
79 	__be16 nsrcs;
80 	__be32 srcs[0];
81 };
82 
83 #ifdef __KERNEL__
84 #include <linux/skbuff.h>
85 
86 static inline struct igmphdr *igmp_hdr(const struct sk_buff *skb)
87 {
88 	return (struct igmphdr *)skb_transport_header(skb);
89 }
90 
91 static inline struct igmpv3_report *
92 			igmpv3_report_hdr(const struct sk_buff *skb)
93 {
94 	return (struct igmpv3_report *)skb_transport_header(skb);
95 }
96 
97 static inline struct igmpv3_query *
98 			igmpv3_query_hdr(const struct sk_buff *skb)
99 {
100 	return (struct igmpv3_query *)skb_transport_header(skb);
101 }
102 #endif
103 
104 #define IGMP_HOST_MEMBERSHIP_QUERY	0x11	/* From RFC1112 */
105 #define IGMP_HOST_MEMBERSHIP_REPORT	0x12	/* Ditto */
106 #define IGMP_DVMRP			0x13	/* DVMRP routing */
107 #define IGMP_PIM			0x14	/* PIM routing */
108 #define IGMP_TRACE			0x15
109 #define IGMPV2_HOST_MEMBERSHIP_REPORT	0x16	/* V2 version of 0x11 */
110 #define IGMP_HOST_LEAVE_MESSAGE 	0x17
111 #define IGMPV3_HOST_MEMBERSHIP_REPORT	0x22	/* V3 version of 0x11 */
112 
113 #define IGMP_MTRACE_RESP		0x1e
114 #define IGMP_MTRACE			0x1f
115 
116 
117 /*
118  *	Use the BSD names for these for compatibility
119  */
120 
121 #define IGMP_DELAYING_MEMBER		0x01
122 #define IGMP_IDLE_MEMBER		0x02
123 #define IGMP_LAZY_MEMBER		0x03
124 #define IGMP_SLEEPING_MEMBER		0x04
125 #define IGMP_AWAKENING_MEMBER		0x05
126 
127 #define IGMP_MINLEN			8
128 
129 #define IGMP_MAX_HOST_REPORT_DELAY	10	/* max delay for response to */
130 						/* query (in seconds)	*/
131 
132 #define IGMP_TIMER_SCALE		10	/* denotes that the igmphdr->timer field */
133 						/* specifies time in 10th of seconds	 */
134 
135 #define IGMP_AGE_THRESHOLD		400	/* If this host don't hear any IGMP V1	*/
136 						/* message in this period of time,	*/
137 						/* revert to IGMP v2 router.		*/
138 
139 #define IGMP_ALL_HOSTS		htonl(0xE0000001L)
140 #define IGMP_ALL_ROUTER 	htonl(0xE0000002L)
141 #define IGMPV3_ALL_MCR	 	htonl(0xE0000016L)
142 #define IGMP_LOCAL_GROUP	htonl(0xE0000000L)
143 #define IGMP_LOCAL_GROUP_MASK	htonl(0xFFFFFF00L)
144 
145 /*
146  * struct for keeping the multicast list in
147  */
148 
149 #ifdef __KERNEL__
150 #include <linux/skbuff.h>
151 #include <linux/timer.h>
152 #include <linux/in.h>
153 
154 extern int sysctl_igmp_max_memberships;
155 extern int sysctl_igmp_max_msf;
156 
157 struct ip_sf_socklist
158 {
159 	unsigned int		sl_max;
160 	unsigned int		sl_count;
161 	__be32			sl_addr[0];
162 };
163 
164 #define IP_SFLSIZE(count)	(sizeof(struct ip_sf_socklist) + \
165 	(count) * sizeof(__be32))
166 
167 #define IP_SFBLOCK	10	/* allocate this many at once */
168 
169 /* ip_mc_socklist is real list now. Speed is not argument;
170    this list never used in fast path code
171  */
172 
173 struct ip_mc_socklist
174 {
175 	struct ip_mc_socklist	*next;
176 	struct ip_mreqn		multi;
177 	unsigned int		sfmode;		/* MCAST_{INCLUDE,EXCLUDE} */
178 	struct ip_sf_socklist	*sflist;
179 };
180 
181 struct ip_sf_list
182 {
183 	struct ip_sf_list	*sf_next;
184 	__be32			sf_inaddr;
185 	unsigned long		sf_count[2];	/* include/exclude counts */
186 	unsigned char		sf_gsresp;	/* include in g & s response? */
187 	unsigned char		sf_oldin;	/* change state */
188 	unsigned char		sf_crcount;	/* retrans. left to send */
189 };
190 
191 struct ip_mc_list
192 {
193 	struct in_device	*interface;
194 	__be32			multiaddr;
195 	struct ip_sf_list	*sources;
196 	struct ip_sf_list	*tomb;
197 	unsigned int		sfmode;
198 	unsigned long		sfcount[2];
199 	struct ip_mc_list	*next;
200 	struct timer_list	timer;
201 	int			users;
202 	atomic_t		refcnt;
203 	spinlock_t		lock;
204 	char			tm_running;
205 	char			reporter;
206 	char			unsolicit_count;
207 	char			loaded;
208 	unsigned char		gsquery;	/* check source marks? */
209 	unsigned char		crcount;
210 };
211 
212 /* V3 exponential field decoding */
213 #define IGMPV3_MASK(value, nb) ((nb)>=32 ? (value) : ((1<<(nb))-1) & (value))
214 #define IGMPV3_EXP(thresh, nbmant, nbexp, value) \
215 	((value) < (thresh) ? (value) : \
216         ((IGMPV3_MASK(value, nbmant) | (1<<(nbmant))) << \
217          (IGMPV3_MASK((value) >> (nbmant), nbexp) + (nbexp))))
218 
219 #define IGMPV3_QQIC(value) IGMPV3_EXP(0x80, 4, 3, value)
220 #define IGMPV3_MRC(value) IGMPV3_EXP(0x80, 4, 3, value)
221 
222 extern int ip_check_mc(struct in_device *dev, __be32 mc_addr, __be32 src_addr, u16 proto);
223 extern int igmp_rcv(struct sk_buff *);
224 extern int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr);
225 extern int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr);
226 extern void ip_mc_drop_socket(struct sock *sk);
227 extern int ip_mc_source(int add, int omode, struct sock *sk,
228 		struct ip_mreq_source *mreqs, int ifindex);
229 extern int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf,int ifindex);
230 extern int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
231 		struct ip_msfilter __user *optval, int __user *optlen);
232 extern int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
233 		struct group_filter __user *optval, int __user *optlen);
234 extern int ip_mc_sf_allow(struct sock *sk, __be32 local, __be32 rmt, int dif);
235 extern void ip_mr_init(void);
236 extern void ip_mc_init_dev(struct in_device *);
237 extern void ip_mc_destroy_dev(struct in_device *);
238 extern void ip_mc_up(struct in_device *);
239 extern void ip_mc_down(struct in_device *);
240 extern void ip_mc_dec_group(struct in_device *in_dev, __be32 addr);
241 extern void ip_mc_inc_group(struct in_device *in_dev, __be32 addr);
242 extern void ip_mc_rejoin_group(struct ip_mc_list *im);
243 
244 #endif
245 #endif
246