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dsd-fme/src/nxdn_element.c
lwvmobile d1efa05164 NXDN Permissed Data Conditional Check;
2022-11-11 22:45:33 -05:00

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/*
============================================================================
Name : nxdn_element.c (formerly nxdn_lib)
Author :
Version : 1.0
Date : 2018 December 26
Copyright : No copyright
Description : NXDN decoding source lib - modified from nxdn_lib
Origin : Originally found at - https://github.com/LouisErigHerve/dsd
============================================================================
*/
#include "dsd.h"
#define NXDN_VCALL 0b000001 /* VCALL = VCALL_REQ = VCALL_RESP */
#define NXDN_VCALL_IV 0b000011
#define NXDN_DCALL_HDR 0b001001 /* Header Format - NXDN_DCALL_HDR = NXDN_DCALL_REQ = NXDN_DCALL_RESP */
#define NXDN_DCALL_USR 0b001011 /* User Data Format */
#define NXDN_DCALL_ACK 0b001100
#define NXDN_REL_EX 0b000111
#define NXDN_HEAD_DLY 0b001111
#define NXDN_SDCALL_REQ_HDR 0b111000 /* Header Format */
#define NXDN_SDCALL_REQ_USR 0b111001 /* User Data Format */
#define NXDN_SDCALL_RESP 0b111011
#define NXDN_SDCALL_IV 0b111010
#define NXDN_STAT_INQ_REQ 0b110000
#define NXDN_STAT_INQ_RESP 0b110001
#define NXDN_STAT_REQ 0b110010
#define NXDN_STAT_RESP 0b110011
#define NXDN_REM_CON_REQ 0b110100
#define NXDN_REM_CON_RESP 0b110101
#define NXDN_REM_CON_E_REQ 0b110110
#define NXDN_REM_CON_E_RESP 0b110111
//NXDN_VCALL_REQ = 0b000001, /* VCALL = VCALL_REQ = VCALL_RESP */
//NXDN_VCALL_RESP = 0b000001, /* VCALL = VCALL_REQ = VCALL_RESP */
#define NXDN_VCALL_REC_REQ = 0b000010 /* NXDN_VCALL_REC_REQ = NXDN_VCALL_REC_RESP */
//NXDN_VCALL_REC_RESP = 0b000010,
#define NXDN_VCALL_CONN_REQ = 0b000011 /* NXDN_VCALL_CONN_REQ = NXDN_VCALL_CONN_RESP */
//NXDN_VCALL_CONN_RESP = 0b000011, /* NXDN_VCALL_CONN_REQ = NXDN_VCALL_CONN_RESP */
#define NXDN_VCALL_ASSGN_DUP = 0b000101
//NXDN_DCALL_REQ = 0b001001, /* NXDN_DCALL_HDR = NXDN_DCALL_REQ = NXDN_DCALL_RESP */
//NXDN_DCALL_RESP = 0b001001, /* NXDN_DCALL_HDR = NXDN_DCALL_REQ = NXDN_DCALL_RESP */
#define NXDN_DCALL_REC_REQ = 0b001010 /* NXDN_DCALL_REC_REQ = NXDN_DCALL_REC_RESP */
//NXDN_DCALL_REC_RESP = 0b001010, /* NXDN_DCALL_REC_REQ = NXDN_DCALL_REC_RESP */
#define NXDN_DCALL_ASSGN = 0b001110
#define NXDN_DCALL_ASSGN_DUP = 0b001101
#define NXDN_IDLE 0b010000
#define NXDN_DISC_REQ = 0b010001 /* NXDN_DISC_REQ = NXDN_DISC */
#define NXDN_DISC = 0b010001 /* NXDN_DISC_REQ = NXDN_DISC */
/*
* @brief : This function decodes the full SACCH (when 4 voice frame parts
* have been successfully received)
*
* @param opts : Option structure parameters pointer
*
* @param state : State structure parameters pointer
*
* @return None
*
*/
void NXDN_SACCH_Full_decode(dsd_opts * opts, dsd_state * state)
{
uint8_t SACCH[72];
uint32_t i;
uint8_t CrcCorrect = 1;
/* Consider all SACCH CRC parts as corrects */
CrcCorrect = 1;
/* Reconstitute the full 72 bits SACCH */
for(i = 0; i < 4; i++)
{
memcpy(&SACCH[i * 18], state->nxdn_sacch_frame_segment[i], 18);
/* Check CRC */
if (state->nxdn_sacch_frame_segcrc[i] != 0) CrcCorrect = 0;
}
/* Decodes the element content */
//run it under crccorrect, or under payload (if incorrect, hide bad data unless payload enabled)
if (CrcCorrect == 1 || opts->payload == 1) NXDN_Elements_Content_decode(opts, state, CrcCorrect, SACCH);
} /* End NXDN_SACCH_Full_decode() */
void NXDN_Elements_Content_decode(dsd_opts * opts, dsd_state * state,
uint8_t CrcCorrect, uint8_t * ElementsContent)
{
uint32_t i;
uint8_t MessageType;
uint64_t CurrentIV = 0;
unsigned long long int FullMessage = 0;
/* Get the "Message Type" field */
MessageType = (ElementsContent[2] & 1) << 5;
MessageType |= (ElementsContent[3] & 1) << 4;
MessageType |= (ElementsContent[4] & 1) << 3;
MessageType |= (ElementsContent[5] & 1) << 2;
MessageType |= (ElementsContent[6] & 1) << 1;
MessageType |= (ElementsContent[7] & 1) << 0;
//only run message type if good CRC?
if (CrcCorrect == 1) nxdn_message_type (opts, state, MessageType);
/* Save the "F1" and "F2" flags */
state->NxdnElementsContent.F1 = ElementsContent[0];
state->NxdnElementsContent.F2 = ElementsContent[1];
/* Save the "Message Type" field */
state->NxdnElementsContent.MessageType = MessageType;
/* Decode the right "Message Type" */
switch(MessageType)
{
//Alias 0x3F
case 0x3F:
{
NXDN_decode_Alias(opts, state, ElementsContent);
}
break;
//Idle
case NXDN_IDLE:
{
//sprintf (state->nxdn_call_type, "NXDN IDLE ");
break;
}
/* VCALL */
case NXDN_VCALL:
{
/* Set the CRC state */
state->NxdnElementsContent.VCallCrcIsGood = CrcCorrect;
/* Decode the "VCALL" message */
NXDN_decode_VCALL(opts, state, ElementsContent);
/* Check the "Cipher Type" and the "Key ID" validity */
if(CrcCorrect)
{
state->NxdnElementsContent.CipherParameterValidity = 1;
}
else state->NxdnElementsContent.CipherParameterValidity = 0;
break;
} /* End case NXDN_VCALL: */
/* VCALL_IV */
case NXDN_VCALL_IV:
{
/* Set the CRC state */
state->NxdnElementsContent.VCallIvCrcIsGood = CrcCorrect;
/* Decode the "VCALL_IV" message */
NXDN_decode_VCALL_IV(opts, state, ElementsContent);
if(CrcCorrect)
{
/* CRC is correct, copy the next theorical IV to use directly from the
* received VCALL_IV */
memcpy(state->NxdnElementsContent.NextIVComputed, state->NxdnElementsContent.IV, 8);
}
else
{
/* CRC is incorrect, compute the next IV to use */
CurrentIV = 0;
/* Convert the 8 bytes buffer into a 64 bits integer */
for(i = 0; i < 8; i++)
{
CurrentIV |= state->NxdnElementsContent.NextIVComputed[i];
CurrentIV = CurrentIV << 8;
}
}
break;
} /* End case NXDN_VCALL_IV: */
/* Unknown Message Type */
default:
{
//fprintf(stderr, "Unknown Message type ");
break;
}
} /* End switch(MessageType) */
} /* End NXDN_Elements_Content_decode() */
void NXDN_decode_Alias(dsd_opts * opts, dsd_state * state, uint8_t * Message)
{
uint8_t Alias1 = 0x0; //value of an ascii 'NULL' character
uint8_t Alias2 = 0x0;
uint8_t Alias3 = 0x0;
uint8_t Alias4 = 0x0;
uint8_t blocknumber = 0;
uint8_t CrcCorrect = 1;
state->NxdnElementsContent.VCallCrcIsGood = CrcCorrect;
//FACCH Payload [3F][68][82][04][2 <- block number4] "[69][6F][6E][20]" <- 4 alias octets [00][7F][1C]
blocknumber = (uint8_t)ConvertBitIntoBytes(&Message[32], 4) & 0x7; // & 0x7, might just be three bits, unsure
Alias1 = (uint8_t)ConvertBitIntoBytes(&Message[40], 8);
Alias2 = (uint8_t)ConvertBitIntoBytes(&Message[48], 8);
Alias3 = (uint8_t)ConvertBitIntoBytes(&Message[56], 8);
Alias4 = (uint8_t)ConvertBitIntoBytes(&Message[64], 8);
//sanity check to prevent OOB array assignment
if (blocknumber > 0 && blocknumber < 5)
{
//assign to index -1, since block number conveyed here is 1,2,3,4, and index values are 0,1,2,3
//only assign if within valid range of ascii characters (not including diacritical extended alphabet)
//else assign "null" ascii character
//since we are zeroing out the blocks on tx_rel and other conditions, better to just set nothing to bad Alias bytes
//tends to zero out otherwise already good blocks set in a previous repitition.
if (Alias1 > 0x19 && Alias1 < 0x7F) sprintf (state->nxdn_alias_block_segment[blocknumber-1][0], "%c", Alias1);
else ;// sprintf (state->nxdn_alias_block_segment[blocknumber-1][0], "%c", 0);
if (Alias2 > 0x19 && Alias2 < 0x7F) sprintf (state->nxdn_alias_block_segment[blocknumber-1][1], "%c", Alias2);
else ; //sprintf (state->nxdn_alias_block_segment[blocknumber-1][1], "%c", 0);
if (Alias3 > 0x19 && Alias3 < 0x7F) sprintf (state->nxdn_alias_block_segment[blocknumber-1][2], "%c", Alias3);
else ; //sprintf (state->nxdn_alias_block_segment[blocknumber-1][2], "%c", 0);
if (Alias4 > 0x19 && Alias4 < 0x7F) sprintf (state->nxdn_alias_block_segment[blocknumber-1][3], "%c", Alias4);
else ; //sprintf (state->nxdn_alias_block_segment[blocknumber-1][3], "%c", 0);
}
if (CrcCorrect) //was by blocknumber being 4, but wasn't as frequent as I would like in the console
{
fprintf (stderr, " "); //probably just want a space instead
for (int i = 0; i < 4; i++)
{
for (int j = 0; j < 4; j++)
{
fprintf (stderr, "%s", state->nxdn_alias_block_segment[i][j]);
}
}
fprintf (stderr, " ");
}
else fprintf (stderr, " CRC ERR "); //redundant print? or okay?
}
void NXDN_decode_cch_info(dsd_opts * opts, dsd_state * state, uint8_t * Message)
{
uint8_t location_id = 0;
uint8_t channel_ifno = 0;
}
/*
* @brief : This function decodes the VCALL message
*
* @param opts : Option structure parameters pointer
*
* @param state : State structure parameters pointer
*
* @param Message : A 64 bit buffer containing the VCALL message to decode
*
* @return None
*
*/
void NXDN_decode_VCALL(dsd_opts * opts, dsd_state * state, uint8_t * Message)
{
//uint32_t i;
uint8_t CCOption = 0;
uint8_t CallType = 0;
uint8_t VoiceCallOption = 0;
uint16_t SourceUnitID = 0;
uint16_t DestinationID = 0;
uint8_t CipherType = 0;
uint8_t KeyID = 0;
uint8_t DuplexMode[32] = {0};
uint8_t TransmissionMode[32] = {0};
unsigned long long int FullMessage = 0;
/* Message[0..7] contains :
* - The "F1" and "F2" flags
* - The "Message Type" (already decoded before calling this function)
*
* So no need to decode it a second time
*/
/* Decode "CC Option" */
CCOption = (uint8_t)ConvertBitIntoBytes(&Message[8], 8);
state->NxdnElementsContent.CCOption = CCOption;
/* Decode "Call Type" */
CallType = (uint8_t)ConvertBitIntoBytes(&Message[16], 3);
state->NxdnElementsContent.CallType = CallType;
/* Decode "Voice Call Option" */
VoiceCallOption = (uint8_t)ConvertBitIntoBytes(&Message[19], 5);
state->NxdnElementsContent.VoiceCallOption = VoiceCallOption;
/* Decode "Source Unit ID" */
SourceUnitID = (uint16_t)ConvertBitIntoBytes(&Message[24], 16);
state->NxdnElementsContent.SourceUnitID = SourceUnitID;
/* Decode "Destination ID" */
DestinationID = (uint16_t)ConvertBitIntoBytes(&Message[40], 16);
state->NxdnElementsContent.DestinationID = DestinationID;
/* Decode the "Cipher Type" */
CipherType = (uint8_t)ConvertBitIntoBytes(&Message[56], 2);
state->NxdnElementsContent.CipherType = CipherType;
/* Decode the "Key ID" */
KeyID = (uint8_t)ConvertBitIntoBytes(&Message[58], 6);
state->NxdnElementsContent.KeyID = KeyID;
/* Print the "CC Option" */
if(CCOption & 0x80) fprintf(stderr, "Emergency ");
if(CCOption & 0x40) fprintf(stderr, "Visitor ");
if(CCOption & 0x20) fprintf(stderr, "Priority Paging ");
if((CipherType == 2) || (CipherType == 3))
{
state->NxdnElementsContent.PartOfCurrentEncryptedFrame = 1;
state->NxdnElementsContent.PartOfNextEncryptedFrame = 2;
}
else
{
state->NxdnElementsContent.PartOfCurrentEncryptedFrame = 1;
state->NxdnElementsContent.PartOfNextEncryptedFrame = 1;
}
/* Print the "Call Type" */
fprintf (stderr, "%s", KGRN);
fprintf(stderr, "\n %s - ", NXDN_Call_Type_To_Str(CallType));
sprintf (state->nxdn_call_type, "%s", NXDN_Call_Type_To_Str(CallType));
/* Print the "Voice Call Option" */
NXDN_Voice_Call_Option_To_Str(VoiceCallOption, DuplexMode, TransmissionMode);
fprintf(stderr, "%s %s - ", DuplexMode, TransmissionMode);
/* Print Source ID and Destination ID (Talk Group or Unit ID) */
//fprintf (stderr, "%s", KGRN);
fprintf(stderr, "Src=%u - Dst/TG=%u ", SourceUnitID & 0xFFFF, DestinationID & 0xFFFF);
fprintf (stderr, "%s", KNRM);
/* Print the "Cipher Type" */
if(CipherType != 0)
{
fprintf (stderr, "\n %s", KYEL);
fprintf(stderr, "%s - ", NXDN_Cipher_Type_To_Str(CipherType));
//state->nxdn_cipher_type = CipherType;
}
/* Print the Key ID */
if(CipherType != 0)
{
fprintf(stderr, "Key ID %u - ", KeyID & 0xFF);
fprintf (stderr, "%s", KNRM);
//state->nxdn_key = (KeyID & 0xFF);
}
if (state->nxdn_cipher_type == 0x01 && state->R > 0) //scrambler key value
{
fprintf (stderr, "%s", KYEL);
fprintf(stderr, "Value: %05lld", state->R);
fprintf (stderr, "%s", KNRM);
}
if(state->NxdnElementsContent.VCallCrcIsGood)
{
if ( (SourceUnitID & 0xFFFF) > 0 )
{
state->nxdn_last_rid = SourceUnitID & 0xFFFF; //only grab if CRC is okay
state->nxdn_last_tg = (DestinationID & 0xFFFF);
state->nxdn_key = (KeyID & 0xFF);
state->nxdn_cipher_type = CipherType; //will this set to zero if no enc?
}
}
else
{
fprintf (stderr, "%s", KRED);
fprintf(stderr, "(CRC ERR) ");
fprintf (stderr, "%s", KNRM);
}
//set enc bit here so we can tell playSynthesizedVoice whether or not to play enc traffic
if (state->nxdn_cipher_type != 0)
{
state->dmr_encL = 1;
}
if (state->nxdn_cipher_type == 0 || state->R != 0)
{
state->dmr_encL = 0;
}
} /* End NXDN_decode_VCALL() */
/*
* @brief : This function decodes the VCALL_IV message
*
* @param opts : Option structure parameters pointer
*
* @param state : State structure parameters pointer
*
* @param Message : A 72 bit buffer containing the VCALL_IV message to decode
*
* @return None
*
*/
void NXDN_decode_VCALL_IV(dsd_opts * opts, dsd_state * state, uint8_t * Message)
{
uint32_t i;
/* Message[0..7] contains :
* - The "F1" and "F2" flags
* - The "Message Type" (already decoded before calling this function)
*
* So no need to decode it a second time
*
* Message[8..71] contains : The 64 bits IV
*/
state->payload_miN = 0; //zero out
/* Extract the IV from the VCALL_IV message */
for(i = 0; i < 8; i++)
{
state->NxdnElementsContent.IV[i] = (uint8_t)ConvertBitIntoBytes(&Message[(i + 1) * 8], 8);
state->payload_miN = state->payload_miN << 8 | state->NxdnElementsContent.IV[i];
}
state->NxdnElementsContent.PartOfCurrentEncryptedFrame = 2;
state->NxdnElementsContent.PartOfNextEncryptedFrame = 1;
} /* End NXDN_decode_VCALL_IV() */
/*
* @brief : This function decodes the "Call Type" and return the
* ASCII string corresponding to it.
*
* @param CallType : The call type parameter to decode
*
* @return An ASCII string of the "Call Type"
*
*/
char * NXDN_Call_Type_To_Str(uint8_t CallType)
{
char * Ptr = NULL;
switch(CallType)
{
case 0: Ptr = "Broadcast Call"; break;
case 1: Ptr = "Group Call"; break;
case 2: Ptr = "Unspecified Call"; break;
case 3: Ptr = "Reserved"; break;
case 4: Ptr = "Individual Call"; break;
case 5: Ptr = "Reserved"; break;
case 6: Ptr = "Interconnect Call"; break;
case 7: Ptr = "Speed Dial Call"; break;
default: Ptr = "Unknown Call Type"; break;
}
return Ptr;
} /* End NXDN_Call_Type_To_Str() */
/*
* @brief : This function decodes the "Voice Call Option" and return the
* ASCII string corresponding to it.
*
* @param VoiceCallOption : The call type parameter to decode
*
* @param Duplex : A 32 bytes ASCII buffer pointer where store
* the Duplex/Half duplex mode
*
* @param TransmissionMode : A 32 bytes ASCII buffer pointer where store
* the transmission mode (bit rate)
*
* @return An ASCII string of the "Voice Call Option"
*
*/
void NXDN_Voice_Call_Option_To_Str(uint8_t VoiceCallOption, uint8_t * Duplex, uint8_t * TransmissionMode)
{
char * Ptr = NULL;
Duplex[0] = 0;
TransmissionMode[0] = 0;
if(VoiceCallOption & 0x10) strcpy((char *)Duplex, "Duplex");
else strcpy((char *)Duplex, "Half Duplex");
switch(VoiceCallOption & 0x17)
{
case 0: Ptr = "4800bps/EHR"; break;
case 2: Ptr = "9600bps/EHR"; break;
case 3: Ptr = "9600bps/EFR"; break;
default: Ptr = "Reserved Voice Call Option"; break;
}
strcpy((char *)TransmissionMode, Ptr);
} /* End NXDN_Voice_Call_Option_To_Str() */
/*
* @brief : This function decodes the "Cipher Type" and return the
* ASCII string corresponding to it.
*
* @param CipherType : The cipher type parameter to decode
*
* @return An ASCII string of the "Cipher Type"
*
*/
char * NXDN_Cipher_Type_To_Str(uint8_t CipherType)
{
char * Ptr = NULL;
switch(CipherType)
{
case 0: Ptr = ""; break; /* Non-ciphered mode / clear call */
case 1: Ptr = "Scrambler"; break;
case 2: Ptr = "DES"; break;
case 3: Ptr = "AES"; break;
default: Ptr = "Unknown Cipher Type"; break;
}
return Ptr;
} /* End NXDN_Cipher_Type_To_Str() */
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