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