1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  *	Linux NET3:	Internet Group Management Protocol  [IGMP]
4  *
5  *	Authors:
6  *		Alan Cox <alan@lxorguk.ukuu.org.uk>
7  *
8  *	Extended to talk the BSD extended IGMP protocol of mrouted 3.6
9  */
10 #ifndef _LINUX_IGMP_H
11 #define _LINUX_IGMP_H
12 
13 #include <linux/skbuff.h>
14 #include <linux/timer.h>
15 #include <linux/in.h>
16 #include <linux/ip.h>
17 #include <linux/refcount.h>
18 #include <uapi/linux/igmp.h>
19 
igmp_hdr(const struct sk_buff * skb)20 static inline struct igmphdr *igmp_hdr(const struct sk_buff *skb)
21 {
22 	return (struct igmphdr *)skb_transport_header(skb);
23 }
24 
25 static inline struct igmpv3_report *
igmpv3_report_hdr(const struct sk_buff * skb)26 			igmpv3_report_hdr(const struct sk_buff *skb)
27 {
28 	return (struct igmpv3_report *)skb_transport_header(skb);
29 }
30 
31 static inline struct igmpv3_query *
igmpv3_query_hdr(const struct sk_buff * skb)32 			igmpv3_query_hdr(const struct sk_buff *skb)
33 {
34 	return (struct igmpv3_query *)skb_transport_header(skb);
35 }
36 
37 struct ip_sf_socklist {
38 	unsigned int		sl_max;
39 	unsigned int		sl_count;
40 	struct rcu_head		rcu;
41 	__be32			sl_addr[];
42 };
43 
44 #define IP_SFBLOCK	10	/* allocate this many at once */
45 
46 /* ip_mc_socklist is real list now. Speed is not argument;
47    this list never used in fast path code
48  */
49 
50 struct ip_mc_socklist {
51 	struct ip_mc_socklist __rcu *next_rcu;
52 	struct ip_mreqn		multi;
53 	unsigned int		sfmode;		/* MCAST_{INCLUDE,EXCLUDE} */
54 	struct ip_sf_socklist __rcu	*sflist;
55 	struct rcu_head		rcu;
56 };
57 
58 struct ip_sf_list {
59 	struct ip_sf_list	*sf_next;
60 	unsigned long		sf_count[2];	/* include/exclude counts */
61 	__be32			sf_inaddr;
62 	unsigned char		sf_gsresp;	/* include in g & s response? */
63 	unsigned char		sf_oldin;	/* change state */
64 	unsigned char		sf_crcount;	/* retrans. left to send */
65 };
66 
67 struct ip_mc_list {
68 	struct in_device	*interface;
69 	__be32			multiaddr;
70 	unsigned int		sfmode;
71 	struct ip_sf_list	*sources;
72 	struct ip_sf_list	*tomb;
73 	unsigned long		sfcount[2];
74 	union {
75 		struct ip_mc_list *next;
76 		struct ip_mc_list __rcu *next_rcu;
77 	};
78 	struct ip_mc_list __rcu *next_hash;
79 	struct timer_list	timer;
80 	int			users;
81 	refcount_t		refcnt;
82 	spinlock_t		lock;
83 	char			tm_running;
84 	char			reporter;
85 	char			unsolicit_count;
86 	char			loaded;
87 	unsigned char		gsquery;	/* check source marks? */
88 	unsigned char		crcount;
89 	struct rcu_head		rcu;
90 };
91 
92 /* V3 exponential field decoding */
93 #define IGMPV3_MASK(value, nb) ((nb)>=32 ? (value) : ((1<<(nb))-1) & (value))
94 #define IGMPV3_EXP(thresh, nbmant, nbexp, value) \
95 	((value) < (thresh) ? (value) : \
96         ((IGMPV3_MASK(value, nbmant) | (1<<(nbmant))) << \
97          (IGMPV3_MASK((value) >> (nbmant), nbexp) + (nbexp))))
98 
99 #define IGMPV3_QQIC(value) IGMPV3_EXP(0x80, 4, 3, value)
100 #define IGMPV3_MRC(value) IGMPV3_EXP(0x80, 4, 3, value)
101 
ip_mc_may_pull(struct sk_buff * skb,unsigned int len)102 static inline int ip_mc_may_pull(struct sk_buff *skb, unsigned int len)
103 {
104 	if (skb_transport_offset(skb) + ip_transport_len(skb) < len)
105 		return 0;
106 
107 	return pskb_may_pull(skb, len);
108 }
109 
110 extern int ip_check_mc_rcu(struct in_device *dev, __be32 mc_addr, __be32 src_addr, u8 proto);
111 extern int igmp_rcv(struct sk_buff *);
112 extern int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr);
113 extern int ip_mc_join_group_ssm(struct sock *sk, struct ip_mreqn *imr,
114 				unsigned int mode);
115 extern int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr);
116 extern void ip_mc_drop_socket(struct sock *sk);
117 extern int ip_mc_source(int add, int omode, struct sock *sk,
118 		struct ip_mreq_source *mreqs, int ifindex);
119 extern int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf,int ifindex);
120 extern int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
121 			sockptr_t optval, sockptr_t optlen);
122 extern int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
123 			sockptr_t optval, size_t offset);
124 extern int ip_mc_sf_allow(struct sock *sk, __be32 local, __be32 rmt,
125 			  int dif, int sdif);
126 extern void ip_mc_init_dev(struct in_device *);
127 extern void ip_mc_destroy_dev(struct in_device *);
128 extern void ip_mc_up(struct in_device *);
129 extern void ip_mc_down(struct in_device *);
130 extern void ip_mc_unmap(struct in_device *);
131 extern void ip_mc_remap(struct in_device *);
132 extern void __ip_mc_dec_group(struct in_device *in_dev, __be32 addr, gfp_t gfp);
ip_mc_dec_group(struct in_device * in_dev,__be32 addr)133 static inline void ip_mc_dec_group(struct in_device *in_dev, __be32 addr)
134 {
135 	return __ip_mc_dec_group(in_dev, addr, GFP_KERNEL);
136 }
137 extern void __ip_mc_inc_group(struct in_device *in_dev, __be32 addr,
138 			      gfp_t gfp);
139 extern void ip_mc_inc_group(struct in_device *in_dev, __be32 addr);
140 int ip_mc_check_igmp(struct sk_buff *skb);
141 
142 #endif
143