/// <summary>
/// This method replaces IP addresses based on some identifier
/// </summary>
/// <param name="payload">Payload to be translated</param>
/// <param name="old_ss_ip">Old source IP address</param>
/// <param name="old_sd_ip">Old destination IP</param>
/// <param name="new_ss_ip">New source IP address</param>
/// <param name="new_sd_ip">New destination IP address</param>
/// <param name="packet_id">A packet identifier</param>
/// <returns>A MemBlock of the translated payload</returns>
public static MemBlock TextTranslate(MemBlock payload, string old_ss_ip,
string old_sd_ip, string new_ss_ip,
string new_sd_ip, string packet_id)
{
string sdata = payload.GetString(System.Text.Encoding.UTF8);
if(sdata.Contains(packet_id)) {
sdata = sdata.Replace(old_ss_ip, new_ss_ip);
sdata = sdata.Replace(old_sd_ip, new_sd_ip);
payload = MemBlock.Reference(System.Text.Encoding.UTF8.GetBytes(sdata));
}
return payload;
}
public static string ReadString(MemBlock b, int offset, out int bytelength)
{
int null_idx = b.IndexOf(0, offset);
int raw_length = null_idx - offset;
bytelength = raw_length + 1; //One for the null
Encoding e;
/*
* Benchmarks of mono show this to be about twice as fast as just
* using UTF8. That really means UTF8 could be optimized in mono
*/
if( b.IsAscii(offset, raw_length) ) {
e = Encoding.ASCII;
} else {
e = Encoding.UTF8;
}
return b.GetString(e, offset, raw_length);
}