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 <linux/sockptr.h>
19 #include <uapi/linux/igmp.h>
20
21 static inline struct igmphdr *igmp_hdr(const struct sk_buff *skb)
22 {
23 return (struct igmphdr *)skb_transport_header(skb);
24 }
25
26 static inline struct igmpv3_report *
27 igmpv3_report_hdr(const struct sk_buff *skb)
28 {
29 return (struct igmpv3_report *)skb_transport_header(skb);
30 }
31
32 static inline struct igmpv3_query *
33 igmpv3_query_hdr(const struct sk_buff *skb)
34 {
35 return (struct igmpv3_query *)skb_transport_header(skb);
36 }
37
38 struct ip_sf_socklist {
39 unsigned int sl_max;
40 unsigned int sl_count;
41 struct rcu_head rcu;
42 __be32 sl_addr[] __counted_by(sl_max);
43 };
44
45 #define IP_SFBLOCK 10 /* allocate this many at once */
46
47 /* ip_mc_socklist is real list now. Speed is not argument;
48 this list never used in fast path code
49 */
50
51 struct ip_mc_socklist {
52 struct ip_mc_socklist __rcu *next_rcu;
53 struct ip_mreqn multi;
54 unsigned int sfmode; /* MCAST_{INCLUDE,EXCLUDE} */
55 struct ip_sf_socklist __rcu *sflist;
56 struct rcu_head rcu;
57 };
58
59 struct ip_sf_list {
60 struct ip_sf_list *sf_next;
61 unsigned long sf_count[2]; /* include/exclude counts */
62 __be32 sf_inaddr;
63 unsigned char sf_gsresp; /* include in g & s response? */
64 unsigned char sf_oldin; /* change state */
65 unsigned char sf_crcount; /* retrans. left to send */
66 };
67
68 struct ip_mc_list {
69 struct in_device *interface;
70 __be32 multiaddr;
71 unsigned int sfmode;
72 struct ip_sf_list *sources;
73 struct ip_sf_list *tomb;
74 unsigned long sfcount[2];
75 union {
76 struct ip_mc_list *next;
77 struct ip_mc_list __rcu *next_rcu;
78 };
79 struct ip_mc_list __rcu *next_hash;
80 struct timer_list timer;
81 int users;
82 refcount_t refcnt;
83 spinlock_t lock;
84 char tm_running;
85 char reporter;
86 char unsolicit_count;
87 char loaded;
88 unsigned char gsquery; /* check source marks? */
89 unsigned char crcount;
90 struct rcu_head rcu;
91 };
92
93 /* V3 exponential field decoding */
94 #define IGMPV3_MASK(value, nb) ((nb)>=32 ? (value) : ((1<<(nb))-1) & (value))
95 #define IGMPV3_EXP(thresh, nbmant, nbexp, value) \
96 ((value) < (thresh) ? (value) : \
97 ((IGMPV3_MASK(value, nbmant) | (1<<(nbmant))) << \
98 (IGMPV3_MASK((value) >> (nbmant), nbexp) + (nbexp))))
99
100 #define IGMPV3_QQIC(value) IGMPV3_EXP(0x80, 4, 3, value)
101 #define IGMPV3_MRC(value) IGMPV3_EXP(0x80, 4, 3, value)
102
103 static inline int ip_mc_may_pull(struct sk_buff *skb, unsigned int len)
104 {
105 if (skb_transport_offset(skb) + ip_transport_len(skb) < len)
106 return 0;
107
108 return pskb_may_pull(skb, len);
109 }
110
111 extern int ip_check_mc_rcu(struct in_device *dev, __be32 mc_addr, __be32 src_addr, u8 proto);
112 extern int igmp_rcv(struct sk_buff *);
113 extern int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr);
114 extern int ip_mc_join_group_ssm(struct sock *sk, struct ip_mreqn *imr,
115 unsigned int mode);
116 extern int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr);
117 extern void ip_mc_drop_socket(struct sock *sk);
118 extern int ip_mc_source(int add, int omode, struct sock *sk,
119 struct ip_mreq_source *mreqs, int ifindex);
120 extern int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf,int ifindex);
121 extern int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
122 sockptr_t optval, sockptr_t optlen);
123 extern int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
124 sockptr_t optval, size_t offset);
125 extern int ip_mc_sf_allow(const struct sock *sk, __be32 local, __be32 rmt,
126 int dif, int sdif);
127 extern void ip_mc_init_dev(struct in_device *);
128 extern void ip_mc_destroy_dev(struct in_device *);
129 extern void ip_mc_up(struct in_device *);
130 extern void ip_mc_down(struct in_device *);
131 extern void ip_mc_unmap(struct in_device *);
132 extern void ip_mc_remap(struct in_device *);
133 extern void __ip_mc_dec_group(struct in_device *in_dev, __be32 addr, gfp_t gfp);
134 static inline void ip_mc_dec_group(struct in_device *in_dev, __be32 addr)
135 {
136 return __ip_mc_dec_group(in_dev, addr, GFP_KERNEL);
137 }
138 extern void __ip_mc_inc_group(struct in_device *in_dev, __be32 addr,
139 gfp_t gfp);
140 extern void ip_mc_inc_group(struct in_device *in_dev, __be32 addr);
141 int ip_mc_check_igmp(struct sk_buff *skb);
142
143 #endif
144
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