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DMR: Add Support for the MNIS Header; #283

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lwvmobile
2025-03-05 02:35:42 -05:00
parent 6c277da869
commit 6fb464f57d
2 changed files with 39 additions and 16 deletions
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47
src/dmr_block.c
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@@ -212,7 +212,7 @@ void dmr_dheader (dsd_opts * opts, dsd_state * state, uint8_t dheader[], uint8_t
else if (sap == 9) sprintf (sap_string, "%s", "EXTD HDR"); //Extended Header (Proprietary)
else if (sap == 10) sprintf (sap_string, "%s", "Short DT"); //Short Data
else if (sap == 1 && p_mfid == 0x10)
sprintf (sap_string, "%s", "Moto EXT"); //motorola extended format
sprintf (sap_string, "%s", "Moto NET"); //motorola network interface service
else sprintf (sap_string, "%s", "Reserved"); //reserved, or err/unk
//mfid string handling
@@ -375,10 +375,10 @@ void dmr_dheader (dsd_opts * opts, dsd_state * state, uint8_t dheader[], uint8_t
state->data_p_head[slot] = 1;
//my observation on chained p_head is that the enc header will come first, and then
//a second extended header, and the keystream on that starts after the sap/dpf and mfid value
//this is the only time starting the keystream at an offset value will be required
//a second extended header, and the keystream on that starts after the sap/dpf, mfid, and 3rd octet (opcode?)
//this is the only time starting the keystream at an offset value will be required (after 0x1F1002)
//set ks start value to 3 (confirmed on several samples of various enc ciphers)
//set ks start value to 3 (confirmed on several samples rc4 and bp)
state->data_ks_start[slot] = 3;
}
@@ -438,8 +438,18 @@ void dmr_dheader (dsd_opts * opts, dsd_state * state, uint8_t dheader[], uint8_t
}
else if (p_sap == 1 && p_mfid == 0x10)
{
//This can be an LRRP packet first block (but slightly different configuration)
fprintf (stderr, "\n Motorola Extended Header; ");
//This can contain various things also found in IP (UDP) protocol data
//LRRP and ARS observed in the Remus samples when sent in this format, and then
//returned in the uncompressed IPv4 / UDP Format attached to an ICMP PDU
fprintf (stderr, "\n Motorola Network Interface Service Header (MNIS); ");
//see: https://cwh050.blogspot.com/2019/08/what-does-mnis-do.html
//see: https://github.com/DSheirer/sdrtrunk/blob/8718d04ef534553e6165b158ebd4d10efc1178cd/src/main/java/io/github/dsheirer/module/decode/dmr/message/type/ApplicationType.java
//one issue is that this portion of the header is encrypted, if encryption is used
//so that can only be checked after the completed PDU assembly if decryptd properly
}
else //if (p_mfid == 0x10)
{
@@ -1025,7 +1035,7 @@ void dmr_block_assembler (dsd_opts * opts, dsd_state * state, uint8_t block_byte
uint16_t len = ((blocks+1)*block_len)-4; //total number of bytes in PDU minus 4 CRC32 bytes
dmr_udp_comp_pdu (opts, state, len, state->dmr_pdu_sf[slot]);
}
else if (state->data_header_sap[slot] == 1 && state->dmr_pdu_sf[slot][1] == 0x10) //test SAP 1 MFID 10 (with -F) as a potential LRRP message (header inclusive)
else if (state->data_header_sap[slot] == 1 && state->dmr_pdu_sf[slot][1] == 0x10) //MNIS Proprietary Header
{
//len calc
uint16_t ctr = state->data_byte_ctr[slot];
@@ -1036,15 +1046,28 @@ void dmr_block_assembler (dsd_opts * opts, dsd_state * state, uint8_t block_byte
if (len > 150)
len = 150;
//this may be some form of compressed header, but contents are thus unknown (aside from sap/dpf and mfid)
//set src and dst from the original data header
uint32_t msrc = state->dmr_lrrp_source[slot];
uint32_t mdst = state->dmr_lrrp_target[slot];
fprintf (stderr, "\n SRC(Header): %08d; ", msrc);
fprintf (stderr, "\n DST(Header): %08d; ", mdst);
fprintf (stderr, "\n SRC(MNIS): %08d; ", msrc);
fprintf (stderr, "\n DST(MNIS): %08d; ", mdst);
//+7 offset
dmr_lrrp (opts, state, len, msrc, mdst, state->dmr_pdu_sf[slot]+7);
//TODO: Look for samples with various types in them
uint8_t mnis_type = state->dmr_pdu_sf[slot][4];
if (mnis_type == 0x01) fprintf (stderr, "MNIS LOCN; ");
else if (mnis_type == 0x11) fprintf (stderr, "MNIS LRRP; ");
else if (mnis_type == 0x33) fprintf (stderr, "MNIS ARS; ");
else if (mnis_type == 0x88) fprintf (stderr, "MNIS XCMP; ");
else fprintf (stderr, "Unknown MNIS Type: %02X; ", mnis_type);
//unknown value after type field and before start of data field (at least on LRRP)
uint16_t mnis_unk = (state->dmr_pdu_sf[slot][5] << 8) | state->dmr_pdu_sf[slot][6];
fprintf (stderr, " ???: %04X", mnis_unk);
if (mnis_type == 0x11) //+7 offset
dmr_lrrp (opts, state, len, msrc, mdst, state->dmr_pdu_sf[slot]+7);
}
}

8
src/dmr_pdu.c
View File

@@ -296,16 +296,16 @@ void dmr_ip_pdu (dsd_opts * opts, dsd_state * state, uint16_t len, uint8_t * DMR
{
fprintf (stderr, "Job Ticket Server;");
}
//ETSI specific
//ETSI specific -- unknown entry value, assuming +28
else if (port1 == 5016 && port2 == 5016)
{
fprintf (stderr, "TMS;");
utf16_to_text(len, DMR_PDU+35);
utf16_to_text(len, DMR_PDU+28);
}
else if (port1 == 5017 && port2 == 5017)
{
uint8_t DMR_PDU_bits[127*8]; memset(DMR_PDU_bits, 0, sizeof(DMR_PDU_bits));
unpack_byte_array_into_bit_array(DMR_PDU+35, DMR_PDU_bits, (len-4-35)*sizeof(uint8_t));
uint8_t DMR_PDU_bits[127*12*8]; memset(DMR_PDU_bits, 0, sizeof(DMR_PDU_bits));
unpack_byte_array_into_bit_array(DMR_PDU+28, DMR_PDU_bits, (len-4-28)*sizeof(uint8_t));
lip_protocol_decoder(opts, state, DMR_PDU_bits);
}
else fprintf (stderr, "Unknown UDP Contents;");