mDNSMacOSX/BonjourTop/source/Frame.cpp

   1 //
   2 //  Frame.cpp
   3 //  TestTB
   4 //
   5 //  Created by Terrin Eager on 1/19/13.
   6 //
   7 //
   8
   9 #include "Frame.h"
  10
  11 #define EthernetHeaderStart 14
  12
  13 void Frame::Set(BJ_UINT8* data,BJ_UINT32 len,BJ_UINT64 t)
  14 {
  15     frameData = data;
  16     length = len;
  17     frameTime = t;
  18 }
  19
  20 BJ_UINT8* Frame::GetEthernetStart()
  21 {
  22     //todo Support other media types
  23     return frameData;
  24 }
  25 BJ_UINT8* Frame::GetIPStart()
  26 {
  27     BJ_UINT8* ether = GetEthernetStart();
  28
  29     return ether + 14;
  30
  31 }
  32 BJ_UINT8* Frame::GetUDPStart()
  33 {
  34     BJ_UINT8* ip = GetIPStart();
  35
  36     BJ_UINT16 nSize = *((__uint16_t*) (ip));
  37     BJ_UINT16 nVerison = (nSize&0xf0) >> 4;
  38     if (nVerison == 0x4)
  39     {
  40         m_bCurrentFrameIPversion = 4;
  41
  42         nSize &= 0x0f;
  43         nSize *= 4;
  44
  45
  46         BJ_UINT8 nProtocol = *(ip+9);
  47
  48         if (nProtocol != 17) // Not UDP
  49             return NULL;
  50     }
  51     else if (nVerison == 0x6)
  52     {
  53         m_bCurrentFrameIPversion = 6;
  54         BJ_UINT8 nProtocol = *(ip+6);
  55
  56         if (nProtocol != 17) // Not UDP
  57             return NULL;
  58         nSize = 40;
  59
  60     }
  61
  62     return ip+nSize;
  63 }
  64
  65 BJ_UINT8* Frame::GetBonjourStart()
  66 {
  67     BJ_UINT8* udp = GetUDPStart();
  68
  69
  70     if (udp == NULL)
  71         return NULL;
  72
  73     BJ_UINT16 nSourcePort = *((__uint16_t*)(udp));
  74     BJ_UINT16 nDestPort = *((__uint16_t*)(udp+2));
  75     BJ_UINT16 nBonjourPort  = htons(5353);
  76
  77     if (nSourcePort == nBonjourPort && nDestPort == nBonjourPort)
  78         return (udp+8);
  79     else
  80         return NULL;
  81
  82 }
  83
  84
  85
  86 BJIPAddr* Frame::GetSrcIPAddr()
  87 {
  88     BJ_UINT8* ip = GetIPStart();
  89
  90     BJ_UINT16 nSize = (__uint16_t) (*ip);
  91     BJ_UINT16 nVerison = (nSize&0xf0) >> 4;
  92     if (nVerison == 0x4)
  93     {
  94         m_bCurrentFrameIPversion = 4;
  95
  96         struct in_addr* ipi_addr;
  97
  98         ipi_addr = (in_addr*)(ip+12);
  99
 100         sourceIPAddr.Set(ipi_addr);
 101
 102     }
 103     else if (nVerison == 0x6)
 104     {
 105         m_bCurrentFrameIPversion = 6;
 106         BJ_UINT8* ipi_addr;
 107
 108         ipi_addr = (ip+8);
 109
 110         sourceIPAddr.Setv6Raw(ipi_addr);
 111
 112     }
 113
 114     return &sourceIPAddr;
 115 }
 116
 117 BJIPAddr* Frame::GetDestIPAddr()
 118 {
 119     BJ_UINT8* ip = GetIPStart();
 120
 121     BJ_UINT16 nSize = *((__uint16_t*) (ip));
 122     BJ_UINT16 nVerison = (nSize&0xf0) >> 4;
 123     if (nVerison == 0x4)
 124     {
 125         m_bCurrentFrameIPversion = 4;
 126
 127         struct in_addr* ipi_addr;
 128
 129         ipi_addr = (in_addr*)(ip+16);
 130
 131         destIPAddr.Set(ipi_addr);
 132
 133     }
 134     else if (nVerison == 0x6)
 135     {
 136         m_bCurrentFrameIPversion = 6;
 137         struct in6_addr* ipi_addr;
 138
 139         ipi_addr = (in6_addr*)(ip+24);
 140
 141         destIPAddr.Set(ipi_addr);
 142
 143     }
 144     return &destIPAddr;
 145 }
 146
 147 BJMACAddr* Frame::GetSrcMACAddr()
 148 {
 149     sourceMACAddr.Set(GetEthernetStart()+6);
 150
 151     return &sourceMACAddr;
 152 }
 153
 154 BJMACAddr* Frame::GetDestMACAddr()
 155 {
 156     destMACAddr.Set(GetEthernetStart());
 157
 158     return &destMACAddr;
 159 }
 160
 161 void Frame::SetDatalinkType(BJ_DATALINKTYPE datalinkType)
 162 {
 163     m_datalinkType = datalinkType;
 164 }
 165
 166 BJ_UINT32 Frame::GetLinklayerHeaderLength()
 167 {
 168     switch (m_datalinkType)
 169     {
 170         case (BJ_DLT_EN10MB):
 171             return EthernetHeaderStart;
 172         case (BJ_DLT_IEEE802_11):
 173             return Get80211HeaderLength();
 174         default:
 175             // Default to Ethernet
 176             return EthernetHeaderStart;
 177     }
 178 }
 179
 180 BJ_UINT32 Frame::Get80211HeaderLength()
 181 {
 182     // XXX: 802.11 header is tricky since it has no "length" field.
 183     // We should look at "FrameControl" and derive the length manually for each frame.
 184     BJ_UINT16 * frameControl = (BJ_UINT16*)GetEthernetStart();
 185
 186     // [SubType] [Type - Ver]
 187
 188     bool isFrameData = (0x0C & *frameControl) == 0x08;
 189     bool isQosData   = ((0xF0 & *frameControl) == 0x80) && isFrameData;
 190
 191     if (isQosData)
 192     {
 193         //Standard (24) + QoS (2) + LLC (3) + SNAP (5)
 194         return 24 + 2 + 3 + 5;
 195     }
 196     else
 197     {
 198         //Standard (24) + LLC (3) + SNAP (5)
 199         return 24 + 3 + 5;
 200     }
 201 }