Line data    Source code

       1             : /* $Id: igmp_proto.h 346474 2009-11-14 10:18:58Z ssiano $
       2             :  *
       3             :  * igmp_proto.h - IGMP protocol message definitions
       4             :  *
       5             :  * Dave Katz, March 2008
       6             :  *
       7             :  * Copyright (c) 2008, Juniper Networks, Inc.
       8             :  * All rights reserved.
       9             :  */
      10             : 
      11             : #ifndef __IGMP_PROTO_H__
      12             : #define __IGMP_PROTO_H__
      13             : 
      14             : /*
      15             :  * This module defines the message formats for IGMP, as well as some
      16             :  * helper routines.
      17             :  */
      18             : 
      19             : 
      20             : /*
      21             :  * IGMP packet header format
      22             :  *
      23             :  * The IGMP header qualifies the contents of the rest of the packet.
      24             :  */
      25             : typedef struct igmp_hdr_ {
      26             :     uint8_t igmp_hdr_type;        /* packet type */
      27             :     uint8_t igmp_hdr_maxresp;        /* Max resp code or reserved */
      28             :     uint16_t igmp_hdr_cksum;        /* Checksum */
      29             : } igmp_hdr;
      30             : 
      31             : #define IGMP_TYPE_QUERY        0x11    /* Query (all versions) */
      32             : #define IGMP_TYPE_V1_REPORT    0x12    /* Version 1 Report */
      33             : #define IGMP_TYPE_V2_REPORT    0x16    /* Version 2 Report */
      34             : #define IGMP_TYPE_V2_LEAVE    0x17    /* Version 2 Leave */
      35             : #define IGMP_TYPE_V3_REPORT    0x22    /* Version 3 Report */
      36             : 
      37             : /*
      38             :  * Version 1 and version 2 packets
      39             :  *
      40             :  * All IGMP v1 and v2 packets have the same format.
      41             :  */
      42             : typedef struct igmp_v1v2_pkt_ {
      43             :     igmp_hdr igmp_v1v2_pkt_hdr;        /* Packet header */
      44             :     uint8_t igmp_v1v2_pkt_group[IPV4_ADDR_LEN]; /* Group address */
      45             : } igmp_v1v2_pkt;
      46             : 
      47             : 
      48             : /*
      49             :  * Version 3 Query packet
      50             :  */
      51             : typedef struct igmp_v3_query_ {
      52             :     igmp_hdr igmp_v3_query_hdr;        /* Packet header */
      53             :     uint8_t igmp_v3_query_group[IPV4_ADDR_LEN]; /* Group address */
      54             :     uint8_t igmp_v3_query_s_qrv;    /* S/QRV fields */
      55             :     uint8_t igmp_v3_query_qqic;    /* QQIC */
      56             :     uint16_t igmp_v3_query_num_srcs;    /* Number of sources */
      57             :     uint8_t igmp_v3_query_source[0];    /* Array of sources */
      58             : } igmp_v3_query;
      59             : 
      60             : #define IGMP_SUPP_RTR_PROC_MASK 0x8    /* "S" bit in s_qrv field */
      61             : #define IGMP_QRV_MASK 0x7        /* QRV value in s_qrv field */
      62             : 
      63             : 
      64             : /*
      65             :  * Version 3 Report packet
      66             :  *
      67             :  * Version 3 reports have one or more group records.
      68             :  */
      69             : typedef struct igmp_v3_rpt_rcrd_ {
      70             :     uint8_t igmp_v3_rpt_rec_type;    /* Record type */
      71             :     uint8_t igmp_v3_rpt_aux_len;    /* Auxiliary data length */
      72             :     uint16_t igmp_v3_rpt_num_srcs;    /* Number of sources */
      73             :     uint8_t igmp_v3_rpt_group[IPV4_ADDR_LEN]; /* Group address */
      74             : } igmp_v3_rpt_rcrd;
      75             : 
      76             : /* Array of sources */
      77          59 : static inline uint8_t* get_igmp_v3_rpt_source(igmp_v3_rpt_rcrd *ptr) {
      78          59 :     return (uint8_t*)(ptr + 1);
      79             : }
      80             : 
      81             : typedef struct igmp_v3_report_ {
      82             :     igmp_hdr igmp_v3_report_hdr;    /* Packet header */
      83             :     uint16_t igmp_v3_report_rsvd;    /* Reserved */
      84             :     uint16_t igmp_v3_report_num_rcrds;    /* Number of records */
      85             :     igmp_v3_rpt_rcrd igmp_v3_report_rcrd[0]; /* Set records */
      86             : } igmp_v3_report;
      87             : 
      88             : 
      89             : /*
      90             :  * Naked header
      91             :  *
      92             :  * This is a hack to access the header to determine the packet type.
      93             :  */
      94             : typedef struct igmp_naked_header_ {
      95             :     igmp_hdr igmp_naked_header_hdr;    /* Packet header */
      96             : } igmp_naked_header;
      97             : 
      98             : 
      99             : /*
     100             :  * IGMP Packet
     101             :  *
     102             :  * This is a union of all types to aid in type coercion.
     103             :  */
     104             : typedef union igmp_packet_ {
     105             :     igmp_naked_header igmp_pkt_naked;    /* Naked header */
     106             :     igmp_v1v2_pkt igmp_pkt_v1v2;    /* V1/V2 packet */
     107             :     igmp_v3_query igmp_pkt_v3_query;    /* V3 query */
     108             :     igmp_v3_report igmp_pkt_v3_rpt;    /* V3 report */
     109             : } igmp_packet;
     110             : 
     111             : 
     112             : /*
     113             :  * Max Resp and QQIC fields
     114             :  *
     115             :  * The Max Resp and QQIC fields in version 3 can be fixed or floating point.
     116             :  */
     117             : #define IGMP_FIXFLOAT_FLAG 0x80        /* Set if floating point */
     118             : #define IGMP_FLOAT_EXP_MASK 0x70    /* Floating point exponent mask */
     119             : #define IGMP_FLOAT_EXP_SHIFT 4        /* Shift count for exponent */
     120             : #define IGMP_FLOAT_MANT_MASK 0x0F    /* Floating point mantissa mask */
     121             : #define IGMP_FLOAT_MANT_HIGHBIT 0x10    /* High bit of mantissa */
     122             : #define IGMP_FLOAT_MAX_MANT 0x1F    /* Max mantissa portion */
     123             : #define IGMP_FLOAT_MANT_SHIFT 0        /* Shift count for mantissa */
     124             : #define IGMP_FLOAT_EXP_OFFSET 3        /* Offset bits to add */
     125             : #define IGMP_FLOAT_MAX_EXP 0x07        /* Maximum exponent value */
     126             : #define IGMP_MAX_FLOAT_ENCODABLE \
     127             :     ((IGMP_FLOAT_MANT_MASK | IGMP_FLOAT_MANT_HIGHBIT) << \
     128             :      (IGMP_FLOAT_MAX_EXP + IGMP_FLOAT_EXP_OFFSET))
     129             :                     /* Maximum encodable value */
     130             : 
     131             : 
     132             : #define IGMP_MAX_RESP_MSEC 100        /* Max Resp is in units of 100 msec */
     133             : #define IGMP_MAX_RESP_DEFAULT 100    /* Default Max Resp val (* 100 msec) */
     134             : #define IGMP_V2_MAX_MAX_RESP 0xFF    /* Maximum Max Resp value for V2 */
     135             : 
     136             : 
     137             : /*
     138             :  * igmp_addr_is_mcast
     139             :  *
     140             :  * Returns TRUE if the address is multicast, or FALSE if not.
     141             :  */
     142             : static inline boolean
     143         140 : igmp_addr_is_mcast (const uint8_t *addr)
     144             : {
     145         140 :     return ((*addr & 0xf0) == 0xe0);
     146             : }
     147             : 
     148             : #endif /* __IGMP_PROTO_H__ */