igmp.h

  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
 21static inline struct igmphdr *igmp_hdr(const struct sk_buff *skb)
 22{
 23	return (struct igmphdr *)skb_transport_header(skb);
 24}
 25
 26static 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
 32static 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
 38struct 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
 51struct 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
 59struct 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
 68struct 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	unsigned long		mca_cstamp;
 91	unsigned long		mca_tstamp;
 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
105static 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
113extern int ip_check_mc_rcu(struct in_device *dev, __be32 mc_addr, __be32 src_addr, u8 proto);
114extern int igmp_rcv(struct sk_buff *);
115extern int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr);
116extern int ip_mc_join_group_ssm(struct sock *sk, struct ip_mreqn *imr,
117				unsigned int mode);
118extern int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr);
119extern void ip_mc_drop_socket(struct sock *sk);
120extern int ip_mc_source(int add, int omode, struct sock *sk,
121		struct ip_mreq_source *mreqs, int ifindex);
122extern int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf,int ifindex);
123extern int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
124			sockptr_t optval, sockptr_t optlen);
125extern int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
126			sockptr_t optval, size_t offset);
127extern int ip_mc_sf_allow(const struct sock *sk, __be32 local, __be32 rmt,
128			  int dif, int sdif);
129extern void ip_mc_init_dev(struct in_device *);
130extern void ip_mc_destroy_dev(struct in_device *);
131extern void ip_mc_up(struct in_device *);
132extern void ip_mc_down(struct in_device *);
133extern void ip_mc_unmap(struct in_device *);
134extern void ip_mc_remap(struct in_device *);
135extern void __ip_mc_dec_group(struct in_device *in_dev, __be32 addr, gfp_t gfp);
136static 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}
140extern void __ip_mc_inc_group(struct in_device *in_dev, __be32 addr,
141			      gfp_t gfp);
142extern void ip_mc_inc_group(struct in_device *in_dev, __be32 addr);
143int ip_mc_check_igmp(struct sk_buff *skb);
144
145#endif