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Line 1: − This service was added with [[2.0.0-2]]. It employs a custom packet format with obfuscation and error detection.+ − − = Command set = − When sending data, SendIrnop is used when the size is <=0xFC, otherwise SendIrnopLarge is used. − − {| class="wikitable" border="1" − |- − ! Command Header − ! Available since system version − ! Description − |- − | 0x00010182 − | [[2.0.0-2]] − | InitializeIrnop − |- − | 0x00020000 − | [[2.0.0-2]] − | FinalizeIrnop − |- − | 0x00030000 − | [[2.0.0-2]] − | ClearReceiveBuffer − |- − | 0x00040000 − | [[2.0.0-2]] − | ClearSendBuffer − |- − | 0x0005.... − | [[2.0.0-2]] − | WaitConnection − |- − | 0x00060040 − | [[2.0.0-2]] − | RequireConnection (u8 input) − |- − | 0x0007.... − | [[2.0.0-2]] − | AutoConnection − |- − | 0x0008.... − | [[2.0.0-2]] − | AnyConnection − |- − | 0x00090000 − | [[2.0.0-2]] − | Disconnect − |- − | 0x000A0000 − | [[2.0.0-2]] − | GetReceiveEvent (writes event handle to cmdreply[3]) − |- − | 0x000B0000 − | [[2.0.0-2]] − | GetSendEvent (writes event handle to cmdreply[3]) − |- − | 0x000C0000 − | [[2.0.0-2]] − | GetConnectionStatusEvent (writes event handle to cmdreply[3]) − |- − | 0x000D0042 − | [[2.0.0-2]] − | SendIrnop (u32 size, ((Size<<14) <nowiki>|</nowiki> 2), inbufptr) − |- − | 0x000E0042 − | [[2.0.0-2]] − | SendIrnopLarge (u32 size, ((Size<<8) <nowiki>|</nowiki> 10), inbufptr) − |- − | 0x000F.... − | [[2.0.0-2]] − | ReceiveIrnop − |- − | 0x0010.... − | [[2.0.0-2]] − | ReceiveIrnopLarge − |- − | 0x0011.... − | [[2.0.0-2]] − | GetLatestReceiveErrorResult − |- − | 0x0012.... − | [[2.0.0-2]] − | GetLatestSendErrorResult − |- − | 0x0013.... − | [[2.0.0-2]] − | GetConnectionStatus − |- − | 0x0014.... − | [[2.0.0-2]] − | GetTryingToConnectStatus − |- − | 0x0015.... − | [[2.0.0-2]] − | GetReceiveSizeFreeAndUsed − |- − | 0x0016.... − | [[2.0.0-2]] − | GetSendSizeFreeAndUsed − |- − | 0x0017.... − | [[2.2.0-X]] − | GetConnectionRole − |- − | 0x00180182 − | [[2.2.0-X]] − | InitializeIrnopShared (u32, u32, u32, u32, u32, u8, 0, handle) − |- − | 0x00190040 − | [[2.2.0-X]] − | ReleaseReceivedData (32bit_value input) − |- − | 0x001A0040 − | [[2.2.0-X]] − | SetOwnMachineId (u8 input) − |} − − = Protocol description = − Packets are sent using IrDA-SIR, with a 8N1 encoding (eight data bits, one stop bit, without parity). Each one is formed by a 2-byte header, a varint with the payload size, an obfuscated payload, and trailing error detection byte. − − == Packet header == − The packet header is fixed and consists in a synchronization byte (0xA5), followed by a unused (possibly RFU) zero byte. After these two hardcoded bytes, there's a varint representing the payload size, which may use one byte or two, depending on the how big the payload is. − − * For payloads with less than 64 bytes, the third byte represents the payload size. − * For packets with up to 16383 bytes, the size is split in two bytes, with the third byte being the upper 6 bits of the payload size, OR'd with 0x40, and the fourth being the lower eight bits of the payload size − − For packets with less than 64 bytes: − {| class="wikitable" border="1" − ! Sync − ! RFU − ! Size − |- − | 0xA5 − | 0x00 − | size − |} − − For packets with up to 16383 bytes: − {| class="wikitable" border="1" − ! Sync − ! RFU − ! Size (1) − ! Size (2) − |- − | 0xA5 − | 0x00 − | (size >> 8) <nowiki>|</nowiki> 0x40 − | size & 0xFF − |} − − In C: − <nowiki>uint8_t * setPacketHeader(uint8_t * buffer, size_t payloadSize) { − assert(payloadSize < 16384); − − buffer[0] = 0xA5; − buffer[1] = 0x00; − − if (payloadSize < 64) { − buffer[2] = payloadSize; − buffer += 3; − } else { − buffer[2] = 0x40 | (payloadSize >> 8); − buffer[3] = payloadSize; − buffer += 4; − } − − return buffer; − }</nowiki> − − == Payload == − The payload is obfuscated using a XOR-based encryption. In C: − <nowiki>void payloadObfuscate(const void * voidplain, void * voidcipher, size_t size) { − uint16_t * plain = (uint16_t *) voidplain; − uint16_t * cipher = (uint16_t *) voidcipher; − size_t halfCount = size / sizeof(uint16_t); − − uint16_t xorval = htobe16(0xE963); − size_t i; − − for (i = 0; i < halfCount; i++) { − xorval ^= plain[i]; − cipher[i] = xorval; − } − } − − void payloadDeobfuscate(const void * voidcipher, void * voidplain, size_t size) { − uint16_t * cipher = (uint16_t *) voidcipher; − uint16_t * plain = (uint16_t *) voidplain; − size_t halfCount = size / sizeof(uint16_t); − − if (halfCount) { − size_t i; − for (i = halfCount - 1; i > 0; i--) { − plain[i] = cipher[i] ^ cipher[i - 1]; − } − − plain[0] = cipher[0] ^ htobe16(0xE963); − } − }</nowiki> − − == Error detection == − The trailing error detection byte is calculated using [[CRC-8-CCITT]] <b>over the whole packet</b> (both the header and the payload)
Undo revision 12391 by Socram8888 (talk)
#REDIRECT [[IR Services#IR Service "ir:USER"]]