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 <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