include/linux/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 <uapi/linux/igmp.h>
  19
  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 *
  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 *
  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
 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);
 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