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_SFLSIZE(count)	(sizeof(struct ip_sf_socklist) + \
45 	(count) * sizeof(__be32))
46 
47 #define IP_SFBLOCK	10	/* allocate this many at once */
48 
49 /* ip_mc_socklist is real list now. Speed is not argument;
50    this list never used in fast path code
51  */
52 
53 struct ip_mc_socklist {
54 	struct ip_mc_socklist __rcu *next_rcu;
55 	struct ip_mreqn		multi;
56 	unsigned int		sfmode;		/* MCAST_{INCLUDE,EXCLUDE} */
57 	struct ip_sf_socklist __rcu	*sflist;
58 	struct rcu_head		rcu;
59 };
60 
61 struct ip_sf_list {
62 	struct ip_sf_list	*sf_next;
63 	unsigned long		sf_count[2];	/* include/exclude counts */
64 	__be32			sf_inaddr;
65 	unsigned char		sf_gsresp;	/* include in g & s response? */
66 	unsigned char		sf_oldin;	/* change state */
67 	unsigned char		sf_crcount;	/* retrans. left to send */
68 };
69 
70 struct ip_mc_list {
71 	struct in_device	*interface;
72 	__be32			multiaddr;
73 	unsigned int		sfmode;
74 	struct ip_sf_list	*sources;
75 	struct ip_sf_list	*tomb;
76 	unsigned long		sfcount[2];
77 	union {
78 		struct ip_mc_list *next;
79 		struct ip_mc_list __rcu *next_rcu;
80 	};
81 	struct ip_mc_list __rcu *next_hash;
82 	struct timer_list	timer;
83 	int			users;
84 	refcount_t		refcnt;
85 	spinlock_t		lock;
86 	char			tm_running;
87 	char			reporter;
88 	char			unsolicit_count;
89 	char			loaded;
90 	unsigned char		gsquery;	/* check source marks? */
91 	unsigned char		crcount;
92 	struct rcu_head		rcu;
93 };
94 
95 /* V3 exponential field decoding */
96 #define IGMPV3_MASK(value, nb) ((nb)>=32 ? (value) : ((1<<(nb))-1) & (value))
97 #define IGMPV3_EXP(thresh, nbmant, nbexp, value) \
98 	((value) < (thresh) ? (value) : \
99         ((IGMPV3_MASK(value, nbmant) | (1<<(nbmant))) << \
100          (IGMPV3_MASK((value) >> (nbmant), nbexp) + (nbexp))))
101 
102 #define IGMPV3_QQIC(value) IGMPV3_EXP(0x80, 4, 3, value)
103 #define IGMPV3_MRC(value) IGMPV3_EXP(0x80, 4, 3, value)
104 
ip_mc_may_pull(struct sk_buff * skb,unsigned int len)105 static inline int ip_mc_may_pull(struct sk_buff *skb, unsigned int len)
106 {
107 	if (skb_transport_offset(skb) + ip_transport_len(skb) < len)
108 		return 0;
109 
110 	return pskb_may_pull(skb, len);
111 }
112 
113 extern int ip_check_mc_rcu(struct in_device *dev, __be32 mc_addr, __be32 src_addr, u8 proto);
114 extern int igmp_rcv(struct sk_buff *);
115 extern int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr);
116 extern int ip_mc_join_group_ssm(struct sock *sk, struct ip_mreqn *imr,
117 				unsigned int mode);
118 extern int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr);
119 extern void ip_mc_drop_socket(struct sock *sk);
120 extern int ip_mc_source(int add, int omode, struct sock *sk,
121 		struct ip_mreq_source *mreqs, int ifindex);
122 extern int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf,int ifindex);
123 extern int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
124 		struct ip_msfilter __user *optval, int __user *optlen);
125 extern int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
126 			struct sockaddr_storage __user *p);
127 extern int ip_mc_sf_allow(struct sock *sk, __be32 local, __be32 rmt,
128 			  int dif, int sdif);
129 extern void ip_mc_init_dev(struct in_device *);
130 extern void ip_mc_destroy_dev(struct in_device *);
131 extern void ip_mc_up(struct in_device *);
132 extern void ip_mc_down(struct in_device *);
133 extern void ip_mc_unmap(struct in_device *);
134 extern void ip_mc_remap(struct in_device *);
135 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)136 static inline void ip_mc_dec_group(struct in_device *in_dev, __be32 addr)
137 {
138 	return __ip_mc_dec_group(in_dev, addr, GFP_KERNEL);
139 }
140 extern void __ip_mc_inc_group(struct in_device *in_dev, __be32 addr,
141 			      gfp_t gfp);
142 extern void ip_mc_inc_group(struct in_device *in_dev, __be32 addr);
143 int ip_mc_check_igmp(struct sk_buff *skb);
144 
145 #endif
146