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M17: MPKT Buffer Size Fix; CRC Fix;

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lwvmobile
2024-04-10 09:17:44 -04:00
parent 2160b369bb
commit 6bfbdbd9df
2 changed files with 24 additions and 9 deletions
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2
src/dsd_rigctl.c
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@@ -331,7 +331,7 @@ int m17_socket_receiver(dsd_opts * opts, void * data)
socklen_t len = sizeof(cliaddr);
//receive data from socket
err = recvfrom(opts->udp_sockfd, data, MSG_WAITALL, 0, (struct sockaddr * ) & address, &len);
err = recvfrom(opts->udp_sockfd, data, 1000, 0, (struct sockaddr * ) & address, &len); //was MSG_WAITALL, but that seems to be = 256
return err;
}

31
src/m17.c
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@@ -2906,6 +2906,11 @@ void encodeM17PKT(dsd_opts * opts, dsd_state * state)
else use_ip = 1;
}
//NOTE: IP Framing is not standard on M17 for PKT mode, but
//I don't see any reason why we can't send them anyways, just
//need to use a new magic for it: MPKT. The receiver here is capable
//of decoding them
//Standard IP Framing
uint8_t mpkt[4] = {0x4D, 0x50, 0x4B, 0x54};
uint8_t ackn[4] = {0x41, 0x43, 0x4B, 0x4E}; UNUSED(ackn);
@@ -2964,32 +2969,33 @@ void encodeM17PKT(dsd_opts * opts, dsd_state * state)
for (i = 0; i < 34; i++)
m17_ip_packed[i] = (uint8_t)ConvertBitIntoBytes(&m17_ip_frame[i*8], 8);
//pack the entire PKT payload (plus Terminator, sans CRC)
//pack the entire PKT payload (plus terminator, sans CRC)
for (i = 0; i < x+1; i++)
m17_ip_packed[i+34] = (uint8_t)ConvertBitIntoBytes(&m17_p1_full[i*8], 8);
//Calculate CRC over everthing packed
//Calculate CRC over everthing packed (including the terminator)
ip_crc = crc16m17(m17_ip_packed, 34+1+x);
//add CRC value to the ip frame
uint8_t crc_bits[16]; memset (crc_bits, 0, sizeof(crc_bits));
for (i = 0; i < 16; i++)
crc_bits[i++] = (ip_crc >> 15-i)&1;
crc_bits[i] = (ip_crc >> 15-i)&1;
//pack CRC into the byte array as well
for (i = x+34+1, j = 0; i < (x+34+3); i++, j++) //double check this
m17_ip_packed[i] = (uint8_t)ConvertBitIntoBytes(&crc_bits[j*8], 8);
//NOTE: There seems to be a limitation of receiving only 256 octets on
//the receiving end, will need to investigate that. Appears to be UDP Buffer Limitation?
//NOTE: Fixed recvfrom limitation, MSG_WAITALL seems to be 256
//manually inserted 1000 into recvfrom instead, max MPKT size should be 809.
//Send MPKT to reflector
if (use_ip == 1)
udp_return = m17_socket_blaster (opts, state, x+34+3, m17_ip_packed);
//debug
fprintf (stderr, " UDP RETURN: %d: X: %d; SENT: %d; \n", udp_return, x, x+34+3);
if (use_ip == 1)
fprintf (stderr, " UDP IP Frame CRC: %04X; UDP RETURN: %d: X: %d; SENT: %d;", ip_crc, udp_return, x, x+34+3);
//SEND EOTX to reflector
if (use_ip == 1)
@@ -3567,6 +3573,13 @@ void processM17IPF(dsd_opts * opts, dsd_state * state)
else if (memcmp(ip_frame, mpkt, 4) == 0)
{
//copy received CRC
uint16_t crc_ext = (ip_frame[err-2] << 8) + ip_frame[err-1];
//calculate CRC on received packet
uint16_t crc_cmp = crc16m17(ip_frame, err-2);
fprintf (stderr, "\n M17 IP MPKT: ");
if (opts->payload == 1)
{
@@ -3576,11 +3589,13 @@ void processM17IPF(dsd_opts * opts, dsd_state * state)
fprintf (stderr, "\n ");
fprintf (stderr, "%02X ", ip_frame[i]);
}
fprintf (stderr, "\n M17 IP MPKT: %d", err);
fprintf (stderr, " E-%04X; C-%04X (CRC CHK)", crc_ext, crc_cmp);
fprintf (stderr, "\n M17 IP RECD: %d", err);
}
//TODO: CRC Check, figure out why return is only 256 on long PKT
// if (crc_ext == crc_cmp) //just run it anyways, should always be good
decodeM17PKT (opts, state, ip_frame+34, err-34-3);
if (crc_ext != crc_cmp) fprintf (stderr, " IP CRC ERR");
}