private static void ParseHTCapabilities(InformationElement ie, TypeNSettings settings)
{
settings.Is40Mhz = ((ie.ItsData[0] & 0x02) == 0x02);
settings.ShortGi20MHz = (ie.ItsData[0] & 0x20) == 0x20;
settings.ShortGi40MHz = (ie.ItsData[0] & 0x40) == 0x40;
//Get supported MCS indexes
//1 bit per index
byte[] bits = new byte[4];
//Array.ConstrainedCopy(ies, index + 5, bits, 0, 4);
Array.Copy(ie.ItsData, 4, bits, 0, 4);
BitArray b = new BitArray(bits);
//settings.Rates = new List<double>();
//The MCS indexes are in little endian,
//so this loop will start at the lowest rates
for (int i = 0; i < b.Length; i++)
{
//If the MCS index bit is 0, skip it
if (b[i] == false)
{
continue;
}
//Add the rate
settings.Rates.Add(McsSet.GetSpeed((uint)i, settings.ShortGi20MHz, settings.ShortGi40MHz,
settings.Is40Mhz));
}
}
public TypeNSettings(TypeNSettings settings)
{
Is40Mhz = settings.Is40Mhz;
ShortGi20MHz = settings.ShortGi20MHz;
ShortGi40MHz = settings.ShortGi40MHz;
PrimaryChannel = settings.PrimaryChannel;
SecondaryChannelLower = settings.SecondaryChannelLower;
//MaxMcs = settings.MaxMcs;
Rates = settings.Rates;
}
public override bool Equals(object obj)
{
if (obj is TypeNSettings)
{
TypeNSettings set = (TypeNSettings)obj;
bool yes = set.Is40Mhz == Is40Mhz;
yes &= set.ShortGi20MHz == ShortGi20MHz;
yes &= set.ShortGi40MHz == ShortGi40MHz;
yes &= set.PrimaryChannel == PrimaryChannel;
yes &= set.SecondaryChannelLower == SecondaryChannelLower;
//Don't compare rates
return(yes);
}
return(false);
}
private static void ParseHTOperation(InformationElement ie, TypeNSettings settings)
{
const int channel = 0;
const int subset1 = 1;
//Primary channel
settings.PrimaryChannel = ie.ItsData[0];
//Secondary channel location
settings.SecondaryChannelLower = (ie.ItsData[channel] & 0x03) == 0x03;
//Check if there is no secondary channel and set 40MHz to false
if (settings.Is40Mhz)
{
settings.Is40Mhz = (ie.ItsData[subset1] & 0x03) == 0x03 || (ie.ItsData[subset1] & 0x01) == 0x01;
}
}
public static TypeNSettings Parse(byte[] ies)
{
var informationElements = BuildInformationElements(ies);
var settings = new TypeNSettings();
bool returnNull = true;
foreach (var informationElement in informationElements)
{
switch (informationElement.ItsNumber)
{
case 45: //HT Capabilities
ParseHTCapabilities(informationElement, settings);
returnNull = false;
break;
case 61: //HT Information
ParseHTOperation(informationElement, settings);
returnNull = false;
break;
}
}
return returnNull ? null : settings;
}
public static TypeNSettings Parse(byte[] ies)
{
var informationElements = BuildInformationElements(ies);
var settings = new TypeNSettings();
bool returnNull = true;
foreach (var informationElement in informationElements)
{
switch (informationElement.ItsNumber)
{
case 45: //HT Capabilities
ParseHTCapabilities(informationElement, settings);
returnNull = false;
break;
case 61: //HT Information
ParseHTOperation(informationElement, settings);
returnNull = false;
break;
}
}
return(returnNull ? null : settings);
}
public TypeNSettings(TypeNSettings settings)
{
Is40Mhz = settings.Is40Mhz;
ShortGi20MHz = settings.ShortGi20MHz;
ShortGi40MHz = settings.ShortGi40MHz;
PrimaryChannel = settings.PrimaryChannel;
SecondaryChannelLower = settings.SecondaryChannelLower;
//MaxMcs = settings.MaxMcs;
Rates = settings.Rates;
}
private static void ParseHTCapabilities(InformationElement ie, TypeNSettings settings)
{
settings.Is40Mhz = ((ie.ItsData[0] & 0x02) == 0x02);
settings.ShortGi20MHz = (ie.ItsData[0] & 0x20) == 0x20;
settings.ShortGi40MHz = (ie.ItsData[0] & 0x40) == 0x40;
//Get supported MCS indexes
//1 bit per index
byte[] bits = new byte[4];
//Array.ConstrainedCopy(ies, index + 5, bits, 0, 4);
Array.Copy(ie.ItsData, 4, bits, 0, 4);
BitArray b = new BitArray(bits);
//settings.Rates = new List<double>();
//The MCS indexes are in little endian,
//so this loop will start at the lowest rates
for (int i = 0; i < b.Length; i++)
{
//If the MCS index bit is 0, skip it
if (b[i] == false) continue;
//Add the rate
settings.Rates.Add(McsSet.GetSpeed((uint) i, settings.ShortGi20MHz, settings.ShortGi40MHz,
settings.Is40Mhz));
}
}
private static void ParseHTOperation(InformationElement ie, TypeNSettings settings)
{
const int channel = 0;
const int subset1 = 1;
//Primary channel
settings.PrimaryChannel = ie.ItsData[0];
//Secondary channel location
settings.SecondaryChannelLower = (ie.ItsData[channel] & 0x03) == 0x03;
//Check if there is no secondary channel and set 40MHz to false
if (settings.Is40Mhz)
settings.Is40Mhz = (ie.ItsData[subset1] & 0x03) == 0x03 || (ie.ItsData[subset1] & 0x01) == 0x01;
}
/*public static TypeNSettings Parse(byte[] ies)
{
try
{
int index = -1;
//for (int i = 0; i < ies.Length; i++)
for (int i = 0; i < ies.Length - 31; i++)
{
//loop until we find the HT IE field 41 with length of 26 and the extended info futher down
//HT IE 1's signature is 2D 1A
//HT IE 2's signature is 3D 16
if ((ies[i] == 0x2D && ies[i + 1] == 0x1A) && (ies[i + 28] == 0x3D && ies[i + 29] == 0x16))
{
index = i;
break;
}
}
if (index == -1) return null;
// We know that ies.Length > index + 31 so all of the following array indexes should be in bounds
TypeNSettings settings = new TypeNSettings
{
Is40MHz = ((ies[index + 2] & 0x02) == 0x02),
ShortGi20MHz = (ies[index + 2] & 0x20) == 0x20,
ShortGi40MHz = (ies[index + 2] & 0x40) == 0x40
};
//Supported MCS indexes
//1 bit per index
byte[] bits = new byte[4];
Array.ConstrainedCopy(ies, index + 5, bits, 0, 4);
BitArray b = new BitArray(bits);
settings.Rates = new List<double>();
int maxIndex = -1;
for (int i = 0; i < b.Length; i++)
{
if (b[i] == false) continue;
//Update the highest MCS index
if (b[i]) maxIndex = i;
//Add the rate
settings.Rates.Add(McsSet.GetSpeed((uint)i, settings.ShortGi20MHz, settings.ShortGi40MHz,
settings.Is40MHz));
}
if (maxIndex == -1) return null; // there has been an error
//settings.MaxMcs = (uint)maxIndex;
//Extended info
//Primary channel
settings.PrimaryChannel = ies[index + 30];
//Secondary channel location
settings.SecondaryChannelLower = (ies[index + 31] & 0x03) == 0x03;
//Check if there is no secondary channel and set 40MHz to false
if (settings.Is40MHz)
settings.Is40MHz = (ies[index + 31] & 0x03) == 0x03 || (ies[index + 31] & 0x01) == 0x01;
return settings;
}
catch (IndexOutOfRangeException)
{
//We can't get the 802.11n IEs. Just return null
return null;
}
}*/
public static TypeNSettings Parse(byte[] ies)
{
//The indexes for both elements
int HtCapIndex = -1;
int HtInfoIndex = -1;
bool returnNull = true;
//Look for the HT Capabilities element
for (int i = 0; i < ies.Length - 31; i++)
{
//HT Capabilities's signature is 2D 1A
if ((ies[i] == 0x2D && ies[i + 1] == 0x1A) && (ies.Length >= i + 27))
{
//Found it
HtCapIndex = i;
}
//HT Information's signature is 3D 16
if ((ies[i] == 0x3D && ies[i + 1] == 0x16) && (ies.Length >= i + 24))
{
//Found it
HtInfoIndex = i;
}
}
TypeNSettings settings = new TypeNSettings();
//Parse the info blocks if we found them
if (HtCapIndex > -1)
{
settings.Is40MHz = ((ies[HtCapIndex + 2] & 0x02) == 0x02);
settings.ShortGi20MHz = (ies[HtCapIndex + 2] & 0x20) == 0x20;
settings.ShortGi40MHz = (ies[HtCapIndex + 2] & 0x40) == 0x40;
//Get supported MCS indexes
//1 bit per index
byte[] bits = new byte[4];
//Array.ConstrainedCopy(ies, index + 5, bits, 0, 4);
Array.Copy(ies, HtCapIndex + 5, bits, 0, 4);
BitArray b = new BitArray(bits);
//settings.Rates = new List<double>();
//The MCS indexes are in little endian,
//so this loop will start at the lowest rates
for (int i = 0; i < b.Length; i++)
{
//If the MCS index bit is 0, skip it
if (b[i] == false) continue;
//Add the rate
settings.Rates.Add(McsSet.GetSpeed((uint)i, settings.ShortGi20MHz, settings.ShortGi40MHz,
settings.Is40MHz));
}
returnNull = false;
}
if (HtInfoIndex > -1)
{
//Primary channel
settings.PrimaryChannel = ies[HtInfoIndex + 2];
//Secondary channel location
settings.SecondaryChannelLower = (ies[HtInfoIndex + 3] & 0x03) == 0x03;
//Check if there is no secondary channel and set 40MHz to false
if (settings.Is40MHz)
settings.Is40MHz = (ies[HtInfoIndex + 3] & 0x03) == 0x03 || (ies[HtInfoIndex + 3] & 0x01) == 0x01;
returnNull = false;
}
return returnNull ? null : settings;
}
public static TypeNSettings Parse(byte[] ies)
{
try
{
int index = -1;
//for (int i = 0; i < ies.Length; i++)
for (int i = 0; i < ies.Length - 31; i++)
{
//loop until we find the HT IE field 41 with length of 26 and the extended info futher down
//HT IE 1's signature is 2D 1A
//HT IE 2's signature is 3D 16
if ((ies[i] == 0x2D && ies[i + 1] == 0x1A) && (ies[i + 28] == 0x3D && ies[i + 29] == 0x16))
{
index = i;
break;
}
}
if (index == -1) return null;
// We know that ies.Length > index + 31 so all of the following array indexes should be in bounds
TypeNSettings settings = new TypeNSettings
{
Is40MHz = ((ies[index + 2] & 0x02) == 0x02),
ShortGi20MHz = (ies[index + 2] & 0x20) == 0x20,
ShortGi40MHz = (ies[index + 2] & 0x40) == 0x40
};
//Supported MCS indexes
//1 bit per index
byte[] bits = new byte[4];
Array.ConstrainedCopy(ies, index + 5, bits, 0, 4);
BitArray b = new BitArray(bits);
settings.Rates = new List<double>();
int maxIndex = -1;
for (int i = 0; i < b.Length; i++)
{
if (b[i] == false) continue;
//Update the highest MCS index
if (b[i]) maxIndex = i;
//Add the rate
settings.Rates.Add(McsSet.GetSpeed((uint) i, settings.ShortGi20MHz, settings.ShortGi40MHz,
settings.Is40MHz));
}
if (maxIndex == -1) return null; // there has been an error
settings.MaxMcs = (uint) maxIndex;
//Extended info
//Primary channel
settings.PrimaryChannel = ies[index + 30];
//Secondary channel location
settings.SecondaryChannelLower = (ies[index + 31] & 0x03) == 0x03;
//Check if there is no secondary channel and set 40MHz to false
if (settings.Is40MHz)
settings.Is40MHz = (ies[index + 31] & 0x03) == 0x03 || (ies[index + 31] & 0x01) == 0x01;
return settings;
}
catch(IndexOutOfRangeException)
{
//We can't get the 802.11n IEs. Just return null
return null;
}
}