unleashed-firmware/lib/subghz/protocols/megacode.c
Max Lapan 3360f818a1
Subghz: Adding checks for get_upload functions (#1704)
* Adding checks for get_upload functions
  Almost in every protocol, function which generates upload might fail and return false.
  But we don't check this result, which might end up sending random memory contents to the air.
* Format sources and fix crash on ivalid bit count in chamberlain

Co-authored-by: あく <alleteam@gmail.com>
2022-09-20 14:29:10 +09:00

429 lines
15 KiB
C

#include "megacode.h"
#include "../blocks/const.h"
#include "../blocks/decoder.h"
#include "../blocks/encoder.h"
#include "../blocks/generic.h"
#include "../blocks/math.h"
/*
* Help
* https://wiki.cuvoodoo.info/doku.php?id=megacode
* https://wiki.cuvoodoo.info/lib/exe/fetch.php?media=megacode:megacode_1.pdf
* https://fccid.io/EF4ACP00872/Test-Report/Megacode-2-112615.pdf
* https://github.com/aaronsp777/megadecoder
* https://github.com/rjmendez/Linear_keyfob
* https://github.com/j07rdi/Linear_MegaCode_Garage_Remote
*
*/
#define TAG "SubGhzProtocolMegaCode"
static const SubGhzBlockConst subghz_protocol_megacode_const = {
.te_short = 1000,
.te_long = 1000,
.te_delta = 200,
.min_count_bit_for_found = 24,
};
struct SubGhzProtocolDecoderMegaCode {
SubGhzProtocolDecoderBase base;
SubGhzBlockDecoder decoder;
SubGhzBlockGeneric generic;
uint8_t last_bit;
};
struct SubGhzProtocolEncoderMegaCode {
SubGhzProtocolEncoderBase base;
SubGhzProtocolBlockEncoder encoder;
SubGhzBlockGeneric generic;
};
typedef enum {
MegaCodeDecoderStepReset = 0,
MegaCodeDecoderStepFoundStartBit,
MegaCodeDecoderStepSaveDuration,
MegaCodeDecoderStepCheckDuration,
} MegaCodeDecoderStep;
const SubGhzProtocolDecoder subghz_protocol_megacode_decoder = {
.alloc = subghz_protocol_decoder_megacode_alloc,
.free = subghz_protocol_decoder_megacode_free,
.feed = subghz_protocol_decoder_megacode_feed,
.reset = subghz_protocol_decoder_megacode_reset,
.get_hash_data = subghz_protocol_decoder_megacode_get_hash_data,
.serialize = subghz_protocol_decoder_megacode_serialize,
.deserialize = subghz_protocol_decoder_megacode_deserialize,
.get_string = subghz_protocol_decoder_megacode_get_string,
};
const SubGhzProtocolEncoder subghz_protocol_megacode_encoder = {
.alloc = subghz_protocol_encoder_megacode_alloc,
.free = subghz_protocol_encoder_megacode_free,
.deserialize = subghz_protocol_encoder_megacode_deserialize,
.stop = subghz_protocol_encoder_megacode_stop,
.yield = subghz_protocol_encoder_megacode_yield,
};
const SubGhzProtocol subghz_protocol_megacode = {
.name = SUBGHZ_PROTOCOL_MEGACODE_NAME,
.type = SubGhzProtocolTypeStatic,
.flag = SubGhzProtocolFlag_315 | SubGhzProtocolFlag_AM | SubGhzProtocolFlag_Decodable |
SubGhzProtocolFlag_Load | SubGhzProtocolFlag_Save | SubGhzProtocolFlag_Send,
.decoder = &subghz_protocol_megacode_decoder,
.encoder = &subghz_protocol_megacode_encoder,
};
void* subghz_protocol_encoder_megacode_alloc(SubGhzEnvironment* environment) {
UNUSED(environment);
SubGhzProtocolEncoderMegaCode* instance = malloc(sizeof(SubGhzProtocolEncoderMegaCode));
instance->base.protocol = &subghz_protocol_megacode;
instance->generic.protocol_name = instance->base.protocol->name;
instance->encoder.repeat = 10;
instance->encoder.size_upload = 52;
instance->encoder.upload = malloc(instance->encoder.size_upload * sizeof(LevelDuration));
instance->encoder.is_running = false;
return instance;
}
void subghz_protocol_encoder_megacode_free(void* context) {
furi_assert(context);
SubGhzProtocolEncoderMegaCode* instance = context;
free(instance->encoder.upload);
free(instance);
}
/**
* Generating an upload from data.
* @param instance Pointer to a SubGhzProtocolEncoderMegaCode instance
* @return true On success
*/
static bool subghz_protocol_encoder_megacode_get_upload(SubGhzProtocolEncoderMegaCode* instance) {
furi_assert(instance);
uint8_t last_bit = 0;
size_t size_upload = (instance->generic.data_count_bit * 2);
if(size_upload > instance->encoder.size_upload) {
FURI_LOG_E(TAG, "Size upload exceeds allocated encoder buffer.");
return false;
} else {
instance->encoder.size_upload = size_upload;
}
/*
* Due to the nature of the protocol
*
* 00000 1
* _____|-| = 1 becomes
*
* 00 1 000
* __|-|___ = 0 becomes
*
* it's easier for us to generate an upload backwards
*/
size_t index = size_upload - 1;
// Send end level
instance->encoder.upload[index--] =
level_duration_make(true, (uint32_t)subghz_protocol_megacode_const.te_short);
if(bit_read(instance->generic.data, 0)) {
last_bit = 1;
} else {
last_bit = 0;
}
//Send key data
for(uint8_t i = 1; i < instance->generic.data_count_bit; i++) {
if(bit_read(instance->generic.data, i)) {
//if bit 1
instance->encoder.upload[index--] = level_duration_make(
false,
last_bit ? (uint32_t)subghz_protocol_megacode_const.te_short * 5 :
(uint32_t)subghz_protocol_megacode_const.te_short * 2);
last_bit = 1;
} else {
//if bit 0
instance->encoder.upload[index--] = level_duration_make(
false,
last_bit ? (uint32_t)subghz_protocol_megacode_const.te_short * 8 :
(uint32_t)subghz_protocol_megacode_const.te_short * 5);
last_bit = 0;
}
instance->encoder.upload[index--] =
level_duration_make(true, (uint32_t)subghz_protocol_megacode_const.te_short);
}
//Send PT_GUARD
if(bit_read(instance->generic.data, 0)) {
//if end bit 1
instance->encoder.upload[index] =
level_duration_make(false, (uint32_t)subghz_protocol_megacode_const.te_short * 11);
} else {
//if end bit 1
instance->encoder.upload[index] =
level_duration_make(false, (uint32_t)subghz_protocol_megacode_const.te_short * 14);
}
return true;
}
bool subghz_protocol_encoder_megacode_deserialize(void* context, FlipperFormat* flipper_format) {
furi_assert(context);
SubGhzProtocolEncoderMegaCode* instance = context;
bool res = false;
do {
if(!subghz_block_generic_deserialize(&instance->generic, flipper_format)) {
FURI_LOG_E(TAG, "Deserialize error");
break;
}
if(instance->generic.data_count_bit !=
subghz_protocol_megacode_const.min_count_bit_for_found) {
FURI_LOG_E(TAG, "Wrong number of bits in key");
break;
}
//optional parameter parameter
flipper_format_read_uint32(
flipper_format, "Repeat", (uint32_t*)&instance->encoder.repeat, 1);
if(!subghz_protocol_encoder_megacode_get_upload(instance)) break;
instance->encoder.is_running = true;
res = true;
} while(false);
return res;
}
void subghz_protocol_encoder_megacode_stop(void* context) {
SubGhzProtocolEncoderMegaCode* instance = context;
instance->encoder.is_running = false;
}
LevelDuration subghz_protocol_encoder_megacode_yield(void* context) {
SubGhzProtocolEncoderMegaCode* instance = context;
if(instance->encoder.repeat == 0 || !instance->encoder.is_running) {
instance->encoder.is_running = false;
return level_duration_reset();
}
LevelDuration ret = instance->encoder.upload[instance->encoder.front];
if(++instance->encoder.front == instance->encoder.size_upload) {
instance->encoder.repeat--;
instance->encoder.front = 0;
}
return ret;
}
void* subghz_protocol_decoder_megacode_alloc(SubGhzEnvironment* environment) {
UNUSED(environment);
SubGhzProtocolDecoderMegaCode* instance = malloc(sizeof(SubGhzProtocolDecoderMegaCode));
instance->base.protocol = &subghz_protocol_megacode;
instance->generic.protocol_name = instance->base.protocol->name;
return instance;
}
void subghz_protocol_decoder_megacode_free(void* context) {
furi_assert(context);
SubGhzProtocolDecoderMegaCode* instance = context;
free(instance);
}
void subghz_protocol_decoder_megacode_reset(void* context) {
furi_assert(context);
SubGhzProtocolDecoderMegaCode* instance = context;
instance->decoder.parser_step = MegaCodeDecoderStepReset;
}
void subghz_protocol_decoder_megacode_feed(void* context, bool level, uint32_t duration) {
furi_assert(context);
SubGhzProtocolDecoderMegaCode* instance = context;
switch(instance->decoder.parser_step) {
case MegaCodeDecoderStepReset:
if((!level) && (DURATION_DIFF(duration, subghz_protocol_megacode_const.te_short * 13) <
subghz_protocol_megacode_const.te_delta * 17)) { //10..16ms
//Found header MegaCode
instance->decoder.parser_step = MegaCodeDecoderStepFoundStartBit;
}
break;
case MegaCodeDecoderStepFoundStartBit:
if(level && (DURATION_DIFF(duration, subghz_protocol_megacode_const.te_short) <
subghz_protocol_megacode_const.te_delta)) {
//Found start bit MegaCode
instance->decoder.parser_step = MegaCodeDecoderStepSaveDuration;
instance->decoder.decode_data = 0;
instance->decoder.decode_count_bit = 0;
subghz_protocol_blocks_add_bit(&instance->decoder, 1);
instance->last_bit = 1;
} else {
instance->decoder.parser_step = MegaCodeDecoderStepReset;
}
break;
case MegaCodeDecoderStepSaveDuration:
if(!level) { //save interval
if(duration >= (subghz_protocol_megacode_const.te_short * 10)) {
instance->decoder.parser_step = MegaCodeDecoderStepReset;
if(instance->decoder.decode_count_bit ==
subghz_protocol_megacode_const.min_count_bit_for_found) {
instance->generic.data = instance->decoder.decode_data;
instance->generic.data_count_bit = instance->decoder.decode_count_bit;
if(instance->base.callback)
instance->base.callback(&instance->base, instance->base.context);
}
break;
}
if(!instance->last_bit) {
instance->decoder.te_last = duration - subghz_protocol_megacode_const.te_short * 3;
} else {
instance->decoder.te_last = duration;
}
instance->decoder.parser_step = MegaCodeDecoderStepCheckDuration;
} else {
instance->decoder.parser_step = MegaCodeDecoderStepReset;
}
break;
case MegaCodeDecoderStepCheckDuration:
if(level) {
if((DURATION_DIFF(
instance->decoder.te_last, subghz_protocol_megacode_const.te_short * 5) <
subghz_protocol_megacode_const.te_delta * 5) &&
(DURATION_DIFF(duration, subghz_protocol_megacode_const.te_short) <
subghz_protocol_megacode_const.te_delta)) {
subghz_protocol_blocks_add_bit(&instance->decoder, 1);
instance->last_bit = 1;
instance->decoder.parser_step = MegaCodeDecoderStepSaveDuration;
} else if(
(DURATION_DIFF(
instance->decoder.te_last, subghz_protocol_megacode_const.te_short * 2) <
subghz_protocol_megacode_const.te_delta * 2) &&
(DURATION_DIFF(duration, subghz_protocol_megacode_const.te_short) <
subghz_protocol_megacode_const.te_delta)) {
subghz_protocol_blocks_add_bit(&instance->decoder, 0);
instance->last_bit = 0;
instance->decoder.parser_step = MegaCodeDecoderStepSaveDuration;
} else
instance->decoder.parser_step = MegaCodeDecoderStepReset;
} else {
instance->decoder.parser_step = MegaCodeDecoderStepReset;
}
break;
}
}
/**
* Analysis of received data
* @param instance Pointer to a SubGhzBlockGeneric* instance
*/
static void subghz_protocol_megacode_check_remote_controller(SubGhzBlockGeneric* instance) {
/*
* Short: 1000 µs
* Long: 1000 µs
* Gap: 11000 .. 14000 µs
* A Linear Megacode transmission consists of 24 bit frames starting with
* the most significant bit and ending with the least. Each of the 24 bit
* frames is 6 milliseconds wide and always contains a single 1 millisecond
* pulse. A frame with more than 1 pulse or a frame with no pulse is invalid
* and a receiver should reset and begin watching for another start bit.
* Start bit is always 1.
*
*
* Example (I created with my own remote):
* Remote “A” has the code “17316”, a Facility Code of “3”, and a single button.
* Start bit (S) = 1
* Facility Code 3 (F) = 0011
* Remote Code (Key) 17316 = 43A4 = 0100001110100100
* Button (Btn) 1 = 001
* S F Key Btn
* Result = 1|0011|0100001110100100|001
*
* 00000 1
* _____|-| = 1 becomes
*
* 00 1 000
* __|-|___ = 0 becomes
*
* The device needs to transmit with a 9000 µs gap between retransmissions:
* 000001 001000 001000 000001 000001 001000 000001 001000 001000 001000 001000 000001
* 000001 000001 001000 000001 001000 001000 000001 001000 001000 001000 001000 000001
* wait 9000 µs
* 000001 001000 001000 000001 000001 001000 000001 001000 001000 001000 001000 000001
* 000001 000001 001000 000001 001000 001000 000001 001000 001000 001000 001000 000001
*
*/
if((instance->data >> 23) == 1) {
instance->serial = (instance->data >> 3) & 0xFFFF;
instance->btn = instance->data & 0b111;
instance->cnt = (instance->data >> 19) & 0b1111;
} else {
instance->serial = 0;
instance->btn = 0;
instance->cnt = 0;
}
}
uint8_t subghz_protocol_decoder_megacode_get_hash_data(void* context) {
furi_assert(context);
SubGhzProtocolDecoderMegaCode* instance = context;
return subghz_protocol_blocks_get_hash_data(
&instance->decoder, (instance->decoder.decode_count_bit / 8) + 1);
}
bool subghz_protocol_decoder_megacode_serialize(
void* context,
FlipperFormat* flipper_format,
SubGhzPresetDefinition* preset) {
furi_assert(context);
SubGhzProtocolDecoderMegaCode* instance = context;
return subghz_block_generic_serialize(&instance->generic, flipper_format, preset);
}
bool subghz_protocol_decoder_megacode_deserialize(void* context, FlipperFormat* flipper_format) {
furi_assert(context);
SubGhzProtocolDecoderMegaCode* instance = context;
bool ret = false;
do {
if(!subghz_block_generic_deserialize(&instance->generic, flipper_format)) {
break;
}
if(instance->generic.data_count_bit !=
subghz_protocol_megacode_const.min_count_bit_for_found) {
FURI_LOG_E(TAG, "Wrong number of bits in key");
break;
}
ret = true;
} while(false);
return ret;
}
void subghz_protocol_decoder_megacode_get_string(void* context, string_t output) {
furi_assert(context);
SubGhzProtocolDecoderMegaCode* instance = context;
subghz_protocol_megacode_check_remote_controller(&instance->generic);
string_cat_printf(
output,
"%s %dbit\r\n"
"Key:0x%06lX\r\n"
"Sn:0x%04lX - %d\r\n"
"Facility:%X Btn:%X\r\n",
instance->generic.protocol_name,
instance->generic.data_count_bit,
(uint32_t)instance->generic.data,
instance->generic.serial,
instance->generic.serial,
instance->generic.cnt,
instance->generic.btn);
}