1 /*
2  *	Linux NET3:	Internet Group Management Protocol  [IGMP]
3  *
4  *	Authors:
5  *		Alan Cox <alan@lxorguk.ukuu.org.uk>
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 	__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 #define IGMP_HOST_MEMBERSHIP_QUERY	0x11	/* From RFC1112 */
84 #define IGMP_HOST_MEMBERSHIP_REPORT	0x12	/* Ditto */
85 #define IGMP_DVMRP			0x13	/* DVMRP routing */
86 #define IGMP_PIM			0x14	/* PIM routing */
87 #define IGMP_TRACE			0x15
88 #define IGMPV2_HOST_MEMBERSHIP_REPORT	0x16	/* V2 version of 0x12 */
89 #define IGMP_HOST_LEAVE_MESSAGE 	0x17
90 #define IGMPV3_HOST_MEMBERSHIP_REPORT	0x22	/* V3 version of 0x12 */
91 
92 #define IGMP_MTRACE_RESP		0x1e
93 #define IGMP_MTRACE			0x1f
94 
95 
96 /*
97  *	Use the BSD names for these for compatibility
98  */
99 
100 #define IGMP_DELAYING_MEMBER		0x01
101 #define IGMP_IDLE_MEMBER		0x02
102 #define IGMP_LAZY_MEMBER		0x03
103 #define IGMP_SLEEPING_MEMBER		0x04
104 #define IGMP_AWAKENING_MEMBER		0x05
105 
106 #define IGMP_MINLEN			8
107 
108 #define IGMP_MAX_HOST_REPORT_DELAY	10	/* max delay for response to */
109 						/* query (in seconds)	*/
110 
111 #define IGMP_TIMER_SCALE		10	/* denotes that the igmphdr->timer field */
112 						/* specifies time in 10th of seconds	 */
113 
114 #define IGMP_AGE_THRESHOLD		400	/* If this host don't hear any IGMP V1	*/
115 						/* message in this period of time,	*/
116 						/* revert to IGMP v2 router.		*/
117 
118 #define IGMP_ALL_HOSTS		htonl(0xE0000001L)
119 #define IGMP_ALL_ROUTER 	htonl(0xE0000002L)
120 #define IGMPV3_ALL_MCR	 	htonl(0xE0000016L)
121 #define IGMP_LOCAL_GROUP	htonl(0xE0000000L)
122 #define IGMP_LOCAL_GROUP_MASK	htonl(0xFFFFFF00L)
123 
124 /*
125  * struct for keeping the multicast list in
126  */
127 
128 #ifdef __KERNEL__
129 #include <linux/skbuff.h>
130 #include <linux/timer.h>
131 #include <linux/in.h>
132 
igmp_hdr(const struct sk_buff * skb)133 static inline struct igmphdr *igmp_hdr(const struct sk_buff *skb)
134 {
135 	return (struct igmphdr *)skb_transport_header(skb);
136 }
137 
138 static inline struct igmpv3_report *
igmpv3_report_hdr(const struct sk_buff * skb)139 			igmpv3_report_hdr(const struct sk_buff *skb)
140 {
141 	return (struct igmpv3_report *)skb_transport_header(skb);
142 }
143 
144 static inline struct igmpv3_query *
igmpv3_query_hdr(const struct sk_buff * skb)145 			igmpv3_query_hdr(const struct sk_buff *skb)
146 {
147 	return (struct igmpv3_query *)skb_transport_header(skb);
148 }
149 
150 extern int sysctl_igmp_max_memberships;
151 extern int sysctl_igmp_max_msf;
152 
153 struct ip_sf_socklist {
154 	unsigned int		sl_max;
155 	unsigned int		sl_count;
156 	struct rcu_head		rcu;
157 	__be32			sl_addr[0];
158 };
159 
160 #define IP_SFLSIZE(count)	(sizeof(struct ip_sf_socklist) + \
161 	(count) * sizeof(__be32))
162 
163 #define IP_SFBLOCK	10	/* allocate this many at once */
164 
165 /* ip_mc_socklist is real list now. Speed is not argument;
166    this list never used in fast path code
167  */
168 
169 struct ip_mc_socklist {
170 	struct ip_mc_socklist __rcu *next_rcu;
171 	struct ip_mreqn		multi;
172 	unsigned int		sfmode;		/* MCAST_{INCLUDE,EXCLUDE} */
173 	struct ip_sf_socklist __rcu	*sflist;
174 	struct rcu_head		rcu;
175 };
176 
177 struct ip_sf_list {
178 	struct ip_sf_list	*sf_next;
179 	__be32			sf_inaddr;
180 	unsigned long		sf_count[2];	/* include/exclude counts */
181 	unsigned char		sf_gsresp;	/* include in g & s response? */
182 	unsigned char		sf_oldin;	/* change state */
183 	unsigned char		sf_crcount;	/* retrans. left to send */
184 };
185 
186 struct ip_mc_list {
187 	struct in_device	*interface;
188 	__be32			multiaddr;
189 	unsigned int		sfmode;
190 	struct ip_sf_list	*sources;
191 	struct ip_sf_list	*tomb;
192 	unsigned long		sfcount[2];
193 	union {
194 		struct ip_mc_list *next;
195 		struct ip_mc_list __rcu *next_rcu;
196 	};
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 	struct rcu_head		rcu;
208 };
209 
210 /* V3 exponential field decoding */
211 #define IGMPV3_MASK(value, nb) ((nb)>=32 ? (value) : ((1<<(nb))-1) & (value))
212 #define IGMPV3_EXP(thresh, nbmant, nbexp, value) \
213 	((value) < (thresh) ? (value) : \
214         ((IGMPV3_MASK(value, nbmant) | (1<<(nbmant))) << \
215          (IGMPV3_MASK((value) >> (nbmant), nbexp) + (nbexp))))
216 
217 #define IGMPV3_QQIC(value) IGMPV3_EXP(0x80, 4, 3, value)
218 #define IGMPV3_MRC(value) IGMPV3_EXP(0x80, 4, 3, value)
219 
220 extern int ip_check_mc_rcu(struct in_device *dev, __be32 mc_addr, __be32 src_addr, u16 proto);
221 extern int igmp_rcv(struct sk_buff *);
222 extern int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr);
223 extern int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr);
224 extern void ip_mc_drop_socket(struct sock *sk);
225 extern int ip_mc_source(int add, int omode, struct sock *sk,
226 		struct ip_mreq_source *mreqs, int ifindex);
227 extern int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf,int ifindex);
228 extern int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
229 		struct ip_msfilter __user *optval, int __user *optlen);
230 extern int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
231 		struct group_filter __user *optval, int __user *optlen);
232 extern int ip_mc_sf_allow(struct sock *sk, __be32 local, __be32 rmt, int dif);
233 extern void ip_mc_init_dev(struct in_device *);
234 extern void ip_mc_destroy_dev(struct in_device *);
235 extern void ip_mc_up(struct in_device *);
236 extern void ip_mc_down(struct in_device *);
237 extern void ip_mc_unmap(struct in_device *);
238 extern void ip_mc_remap(struct in_device *);
239 extern void ip_mc_dec_group(struct in_device *in_dev, __be32 addr);
240 extern void ip_mc_inc_group(struct in_device *in_dev, __be32 addr);
241 extern void ip_mc_rejoin_groups(struct in_device *in_dev);
242 
243 #endif
244 #endif
245