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 #ifndef _LINUX_IGMP_H
16 #define _LINUX_IGMP_H
17 
18 #include <linux/skbuff.h>
19 #include <linux/timer.h>
20 #include <linux/in.h>
21 #include <linux/refcount.h>
22 #include <uapi/linux/igmp.h>
23 
igmp_hdr(const struct sk_buff * skb)24 static inline struct igmphdr *igmp_hdr(const struct sk_buff *skb)
25 {
26 	return (struct igmphdr *)skb_transport_header(skb);
27 }
28 
29 static inline struct igmpv3_report *
igmpv3_report_hdr(const struct sk_buff * skb)30 			igmpv3_report_hdr(const struct sk_buff *skb)
31 {
32 	return (struct igmpv3_report *)skb_transport_header(skb);
33 }
34 
35 static inline struct igmpv3_query *
igmpv3_query_hdr(const struct sk_buff * skb)36 			igmpv3_query_hdr(const struct sk_buff *skb)
37 {
38 	return (struct igmpv3_query *)skb_transport_header(skb);
39 }
40 
41 struct ip_sf_socklist {
42 	unsigned int		sl_max;
43 	unsigned int		sl_count;
44 	struct rcu_head		rcu;
45 	__be32			sl_addr[0];
46 };
47 
48 #define IP_SFLSIZE(count)	(sizeof(struct ip_sf_socklist) + \
49 	(count) * sizeof(__be32))
50 
51 #define IP_SFBLOCK	10	/* allocate this many at once */
52 
53 /* ip_mc_socklist is real list now. Speed is not argument;
54    this list never used in fast path code
55  */
56 
57 struct ip_mc_socklist {
58 	struct ip_mc_socklist __rcu *next_rcu;
59 	struct ip_mreqn		multi;
60 	unsigned int		sfmode;		/* MCAST_{INCLUDE,EXCLUDE} */
61 	struct ip_sf_socklist __rcu	*sflist;
62 	struct rcu_head		rcu;
63 };
64 
65 struct ip_sf_list {
66 	struct ip_sf_list	*sf_next;
67 	__be32			sf_inaddr;
68 	unsigned long		sf_count[2];	/* include/exclude counts */
69 	unsigned char		sf_gsresp;	/* include in g & s response? */
70 	unsigned char		sf_oldin;	/* change state */
71 	unsigned char		sf_crcount;	/* retrans. left to send */
72 };
73 
74 struct ip_mc_list {
75 	struct in_device	*interface;
76 	__be32			multiaddr;
77 	unsigned int		sfmode;
78 	struct ip_sf_list	*sources;
79 	struct ip_sf_list	*tomb;
80 	unsigned long		sfcount[2];
81 	union {
82 		struct ip_mc_list *next;
83 		struct ip_mc_list __rcu *next_rcu;
84 	};
85 	struct ip_mc_list __rcu *next_hash;
86 	struct timer_list	timer;
87 	int			users;
88 	refcount_t		refcnt;
89 	spinlock_t		lock;
90 	char			tm_running;
91 	char			reporter;
92 	char			unsolicit_count;
93 	char			loaded;
94 	unsigned char		gsquery;	/* check source marks? */
95 	unsigned char		crcount;
96 	struct rcu_head		rcu;
97 };
98 
99 /* V3 exponential field decoding */
100 #define IGMPV3_MASK(value, nb) ((nb)>=32 ? (value) : ((1<<(nb))-1) & (value))
101 #define IGMPV3_EXP(thresh, nbmant, nbexp, value) \
102 	((value) < (thresh) ? (value) : \
103         ((IGMPV3_MASK(value, nbmant) | (1<<(nbmant))) << \
104          (IGMPV3_MASK((value) >> (nbmant), nbexp) + (nbexp))))
105 
106 #define IGMPV3_QQIC(value) IGMPV3_EXP(0x80, 4, 3, value)
107 #define IGMPV3_MRC(value) IGMPV3_EXP(0x80, 4, 3, value)
108 
109 extern int ip_check_mc_rcu(struct in_device *dev, __be32 mc_addr, __be32 src_addr, u8 proto);
110 extern int igmp_rcv(struct sk_buff *);
111 extern int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr);
112 extern int ip_mc_join_group_ssm(struct sock *sk, struct ip_mreqn *imr,
113 				unsigned int mode);
114 extern int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr);
115 extern void ip_mc_drop_socket(struct sock *sk);
116 extern int ip_mc_source(int add, int omode, struct sock *sk,
117 		struct ip_mreq_source *mreqs, int ifindex);
118 extern int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf,int ifindex);
119 extern int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
120 		struct ip_msfilter __user *optval, int __user *optlen);
121 extern int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
122 		struct group_filter __user *optval, int __user *optlen);
123 extern int ip_mc_sf_allow(struct sock *sk, __be32 local, __be32 rmt,
124 			  int dif, int sdif);
125 extern void ip_mc_init_dev(struct in_device *);
126 extern void ip_mc_destroy_dev(struct in_device *);
127 extern void ip_mc_up(struct in_device *);
128 extern void ip_mc_down(struct in_device *);
129 extern void ip_mc_unmap(struct in_device *);
130 extern void ip_mc_remap(struct in_device *);
131 extern void ip_mc_dec_group(struct in_device *in_dev, __be32 addr);
132 extern void ip_mc_inc_group(struct in_device *in_dev, __be32 addr);
133 int ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed);
134 
135 #endif
136