Commit ddb6ce05 authored by Manolis Surligas's avatar Manolis Surligas

Merge branch 'next' of https://github.com/satnogs/gr-satnogs into next

# Conflicts:
#	lib/upsat_fsk_frame_encoder_impl.cc
parents 92843c43 a22d37e9
This diff is collapsed.
......@@ -22,6 +22,7 @@
#define INCLUDED_SATNOGS_WHITENING_H
#include <satnogs/api.h>
#include <gnuradio/digital/lfsr.h>
namespace gr
{
......@@ -36,7 +37,6 @@ namespace gr
{
public:
whitening (uint32_t mask, uint32_t seed, uint32_t order);
~whitening ();
void
reset();
......@@ -44,10 +44,15 @@ namespace gr
void scramble(uint8_t *out, const uint8_t *in, size_t len);
void descramble(uint8_t *out, const uint8_t *in, size_t len);
void
scramble_one_bit_per_byte (uint8_t *out, const uint8_t *in,
size_t bits_num);
void
descramble_one_bit_per_byte (uint8_t *out, const uint8_t *in,
size_t bits_num);
private:
const size_t d_lut_len;
size_t d_lut_idx;
uint8_t *d_lut;
digital::lfsr d_lfsr;
};
} // namespace satnogs
......
......@@ -77,7 +77,7 @@ namespace gr
d_decoded_bytes (0),
d_decoded_bits (0),
d_frame_len (0),
d_descrambler(0x21, 0x1FF, 9)
d_descrambler(0x1001, 0x1FF, 17)
{
size_t i;
message_port_register_out (pmt::mp ("pdu"));
......@@ -183,6 +183,7 @@ namespace gr
{
size_t i;
uint8_t *in = d_pdu + 1;
for(i = 0; i < len_bytes; i++){
d_ax25_tmp_buf[8*i] = (in[i] >> 7) & 0x1;
d_ax25_tmp_buf[8*i + 1] = (in[i] >> 6) & 0x1;
......@@ -193,6 +194,13 @@ namespace gr
d_ax25_tmp_buf[8*i + 6] = (in[i] >> 1) & 0x1;
d_ax25_tmp_buf[8*i + 7] = in[i] & 0x1;
}
/* De-white the data if necessary */
if (d_whitening) {
d_descrambler.descramble_one_bit_per_byte (d_ax25_tmp_buf,
d_ax25_tmp_buf,
len_bytes * 8);
}
}
int
......@@ -298,6 +306,7 @@ namespace gr
if (d_decoded_bytes == d_frame_len) {
if(d_is_ax25) {
unpack_ax25_bytes(d_frame_len - 1);
status = ax25_decode(d_ax25_buf, &ax25_frame_len,
d_ax25_tmp_buf, (d_frame_len - 1)*8);
......
......@@ -86,7 +86,7 @@ namespace gr
d_settling_samples(settling_samples),
d_encoded(0),
d_pdu_len(0),
d_scrambler(0x21, 0x1FF, 9)
d_scrambler(0x1001, 0x1FF, 17)
{
/* Simplify the logic of the output samples handling */
set_output_multiple(8);
......@@ -294,6 +294,7 @@ namespace gr
ax25_encode_status_t status;
size_t extra_bits;
size_t i;
uint8_t len_field;
/*
* If the whole previous frame has been successfully sent, block waiting
......@@ -314,6 +315,7 @@ namespace gr
len = ax25_prepare_frame(d_ax25_tmp_buf, (uint8_t *) pmt::blob_data (pdu),
d_pdu_len, AX25_UI_FRAME, d_ax25_addr,
d_ax25_addr_len, 0x03, 1, 1, 1);
status = ax25_bit_stuffing(d_ax25_pdu, &encoded_len,
d_ax25_tmp_buf, len, 1, 1);
if(status != AX25_ENC_OK) {
......@@ -335,22 +337,23 @@ namespace gr
* the address field (if exists) and the payload. Length and CRC fields
* are NOT included.
*/
d_pdu[d_preamble_len + d_sync_word_len] = (uint8_t) (encoded_len/8);
len_field = (uint8_t) (encoded_len/8);
/* Apply whitening */
if (d_whitening) {
d_scrambler.reset ();
d_scrambler.scramble(&len_field, &len_field, 1);
d_scrambler.scramble_one_bit_per_byte (d_ax25_pdu, d_ax25_pdu,
encoded_len);
}
d_pdu[d_preamble_len + d_sync_word_len] = len_field;
/* If it is necessary calculate and append the CRC */
if (d_append_crc) {
LOG_WARN("AX.25 has its own CRC-16 field. Skipping...");
}
/*
* Whitening can not be applied in the AX.25 because it will alter
* the SYNC flag of the stack
*/
if (d_whitening) {
LOG_WARN("AX.25 and whitening are not compatible."
" No whitening will be performed");
}
d_pdu_len = d_preamble_len + d_sync_word_len + 1 + encoded_len/8;
/* NRZ encoding the FSK preamble with the standard method */
......
......@@ -37,33 +37,11 @@ namespace gr {
* number of memory stages.
*/
whitening::whitening (uint32_t mask, uint32_t seed, uint32_t order) :
d_lut_len (std::pow (2, order)),
d_lut_idx (0)
d_lfsr(mask, seed, order)
{
size_t i;
size_t j;
uint32_t cnt;
uint32_t shift_reg = seed;
if (order > 32) {
throw std::invalid_argument ("The maximum allowed order is 32");
}
d_lut = new uint8_t[d_lut_len];
for (i = 0; i < d_lut_len; i++) {
d_lut[i] = shift_reg & 0xFF;
for (j = 0; j < 8; j++) {
cnt = bit_count (shift_reg & mask) % 2;
shift_reg = shift_reg >> 1;
shift_reg |= cnt << (order - 1);
}
}
}
whitening::~whitening()
{
delete [] d_lut;
}
/**
......@@ -73,7 +51,7 @@ namespace gr {
void
whitening::reset ()
{
d_lut_idx = 0;
d_lfsr.reset();
}
/**
......@@ -86,10 +64,18 @@ namespace gr {
whitening::scramble (uint8_t* out, const uint8_t* in, size_t len)
{
size_t i;
uint8_t b;
for(i = 0; i < len; i++){
out[i] = in[i] ^ d_lut[ (d_lut_idx + i ) % d_lut_len];
b = d_lfsr.next_bit();
b |= d_lfsr.next_bit() << 1;
b |= d_lfsr.next_bit() << 2;
b |= d_lfsr.next_bit() << 3;
b |= d_lfsr.next_bit() << 4;
b |= d_lfsr.next_bit() << 5;
b |= d_lfsr.next_bit() << 6;
b |= d_lfsr.next_bit() << 7;
out[i] = in[i] ^ b;
}
d_lut_idx = (d_lut_idx + len ) % d_lut_len;
}
/**
......@@ -104,6 +90,36 @@ namespace gr {
scramble(out, in, len);
}
/**
* Performs data scrambling. The input and output buffer
* contain one bit per byte
* @param out the output buffer
* @param in the input buffer
* @param bits_num the number of bits to be scrambled
*/
void
whitening::scramble_one_bit_per_byte (uint8_t* out, const uint8_t* in,
size_t bits_num)
{
size_t i;
for(i = 0; i < bits_num; i++){
out[i] = in[i] ^ d_lfsr.next_bit();
}
}
/**
* Performs data descrambling. The input and output buffer
* contain one bit per byte
* @param out the output buffer
* @param in the input buffer
* @param bits_num the number of bits to be descrambled
*/
void
whitening::descramble_one_bit_per_byte (uint8_t* out, const uint8_t* in,
size_t bits_num)
{
scramble_one_bit_per_byte(out, in, bits_num);
}
} /* namespace satnogs */
} /* namespace gr */
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