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direwolf/kiss_frame.c

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//
// This file is part of Dire Wolf, an amateur radio packet TNC.
//
// Copyright (C) 2013, 2014, 2017 John Langner, WB2OSZ
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
/*------------------------------------------------------------------
*
* Module: kiss_frame.c
*
* Purpose: Common code used by Serial port and network versions of KISS protocol.
*
* Description: The KISS TNC protocol is described in http://www.ka9q.net/papers/kiss.html
*
* ( An extended form, to handle multiple TNCs on a single serial port.
* Not applicable for our situation. http://he.fi/pub/oh7lzb/bpq/multi-kiss.pdf )
*
* Briefly, a frame is composed of
*
* * FEND (0xC0)
* * Contents - with special escape sequences so a 0xc0
* byte in the data is not taken as end of frame.
* as part of the data.
* * FEND
*
* The first byte of the frame contains:
*
* * port number (radio channel) in upper nybble.
* * command in lower nybble.
*
*
* Commands from application tp TNC:
*
* _0 Data Frame AX.25 frame in raw format.
*
* _1 TXDELAY See explanation in xmit.c.
*
* _2 Persistence " "
*
* _3 SlotTime " "
*
* _4 TXtail " "
* Spec says it is obsolete but Xastir
* sends it and we respect it.
*
* _5 FullDuplex Full Duplex. Transmit immediately without
* waiting for channel to be clear.
*
* _6 SetHardware TNC specific.
*
* _C XKISS extension - not supported.
* _E XKISS extention - not supported.
*
* FF Return Exit KISS mode. Ignored.
*
*
* Messages sent to client application:
*
* _0 Data Frame Received AX.25 frame in raw format.
*
* _6 SetHardware TNC specific.
* Usually a response to a query.
*
*---------------------------------------------------------------*/
#include "direwolf.h"
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <ctype.h>
#include <assert.h>
#include <string.h>
#include "ax25_pad.h"
#include "textcolor.h"
#include "kiss_frame.h"
#include "tq.h"
#include "xmit.h"
#include "version.h"
#include "kissnet.h"
/* In server.c. Should probably move to some misc. function file. */
void hex_dump (unsigned char *p, int len);
#ifdef KISSUTIL
void hex_dump (unsigned char *p, int len)
{
int n, i, offset;
offset = 0;
while (len > 0) {
n = len < 16 ? len : 16;
printf (" %03x: ", offset);
for (i=0; i<n; i++) {
printf (" %02x", p[i]);
}
for (i=n; i<16; i++) {
printf (" ");
}
printf (" ");
for (i=0; i<n; i++) {
printf ("%c", isprint(p[i]) ? p[i] : '.');
}
printf ("\n");
p += 16;
offset += 16;
len -= 16;
}
}
#endif
#if KISSTEST
#define dw_printf printf
void text_color_set (dw_color_t c)
{
return;
}
#else
#ifndef DECAMAIN
#ifndef KISSUTIL
static void kiss_set_hardware (int chan, char *command, int debug, int client, void (*sendfun)(int,int,unsigned char*,int,int));
#endif
#endif
#endif
//#if KISSUTIL
//#define text_color_set(x) ;
//#define dw_printf printf
//#endif
/*-------------------------------------------------------------------
*
* Name: kiss_frame_init
*
* Purpose: Save information about valid channels for later error checking.
*
* Inputs: pa - Address of structure of type audio_s.
*
*-----------------------------------------------------------------*/
static struct audio_s *save_audio_config_p;
void kiss_frame_init (struct audio_s *pa)
{
save_audio_config_p = pa;
}
/*-------------------------------------------------------------------
*
* Name: kiss_encapsulate
*
* Purpose: Ecapsulate a frame into KISS format.
*
* Inputs: in - Address of input block.
* First byte is the "type indicator" with type and
* channel but we don't care about that here.
* If it happens to be FEND or FESC, it is escaped, like any other byte.
*
* This seems cumbersome and confusing to have this
* one byte offset when encapsulating an AX.25 frame.
* Maybe the type/channel byte should be passed in
* as a separate argument.
*
* Note that this is "binary" data and can contain
* nul (0x00) values. Don't treat it like a text string!
*
* ilen - Number of bytes in input block.
*
* Outputs: out - Address where to place the KISS encoded representation.
* The sequence is:
* FEND - Magic frame separator.
* data - with certain byte values replaced so
* FEND will never occur here.
* FEND - Magic frame separator.
*
* Returns: Number of bytes in the output.
* Absolute max length (extremely unlikely) will be twice input plus 2.
*
*-----------------------------------------------------------------*/
int kiss_encapsulate (unsigned char *in, int ilen, unsigned char *out)
{
int olen;
int j;
olen = 0;
out[olen++] = FEND;
for (j=0; j<ilen; j++) {
if (in[j] == FEND) {
out[olen++] = FESC;
out[olen++] = TFEND;
}
else if (in[j] == FESC) {
out[olen++] = FESC;
out[olen++] = TFESC;
}
else {
out[olen++] = in[j];
}
}
out[olen++] = FEND;
return (olen);
} /* end kiss_encapsulate */
#ifndef WALK96
/*-------------------------------------------------------------------
*
* Name: kiss_unwrap
*
* Purpose: Extract original data from a KISS frame.
*
* Inputs: in - Address of the received the KISS encoded representation.
* The sequence is:
* FEND - Magic frame separator, optional.
* data - with certain byte values replaced so
* FEND will never occur here.
* FEND - Magic frame separator.
* ilen - Number of bytes in input block.
*
* Inputs: out - Where to put the resulting frame without
* the escapes or FEND.
* First byte is the "type indicator" with type and
* channel but we don't care about that here.
* We treat it like any other byte with special handling
* if it happens to be FESC.
* Note that this is "binary" data and can contain
* nul (0x00) values. Don't treat it like a text string!
*
* Returns: Number of bytes in the output.
*
*-----------------------------------------------------------------*/
int kiss_unwrap (unsigned char *in, int ilen, unsigned char *out)
{
int olen;
int j;
int escaped_mode;
olen = 0;
escaped_mode = 0;
if (ilen < 2) {
/* Need at least the "type indicator" byte and FEND. */
/* Probably more. */
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS message less than minimum length.\n");
return (0);
}
if (in[ilen-1] == FEND) {
ilen--; /* Don't try to process below. */
}
else {
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS frame should end with FEND.\n");
}
if (in[0] == FEND) {
j = 1; /* skip over optional leading FEND. */
}
else {
j = 0;
}
for ( ; j<ilen; j++) {
if (in[j] == FEND) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS frame should not have FEND in the middle.\n");
}
if (escaped_mode) {
if (in[j] == TFESC) {
out[olen++] = FESC;
}
else if (in[j] == TFEND) {
out[olen++] = FEND;
}
else {
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS protocol error. Found 0x%02x after FESC.\n", in[j]);
}
escaped_mode = 0;
}
else if (in[j] == FESC) {
escaped_mode = 1;
}
else {
out[olen++] = in[j];
}
}
return (olen);
} /* end kiss_unwrap */
#ifndef DECAMAIN
#ifndef KISSTEST
/*-------------------------------------------------------------------
*
* Name: kiss_rec_byte
*
* Purpose: Process one byte from a KISS client app.
*
* Inputs: kf - Current state of building a frame.
* ch - A byte from the input stream.
* debug - Activates debug output.
* client - Client app number for TCP KISS.
* Ignored for pseudo termal and serial port.
* sendfun - Function to send something to the client application.
*
* Outputs: kf - Current state is updated.
*
* Returns: none.
*
*-----------------------------------------------------------------*/
/*
* Application might send some commands to put TNC into KISS mode.
* For example, APRSIS32 sends something like:
*
* <0x0d>
* <0x0d>
* XFLOW OFF<0x0d>
* FULLDUP OFF<0x0d>
* KISS ON<0x0d>
* RESTART<0x0d>
* <0x03><0x03><0x03>
* TC 1<0x0d>
* TN 2,0<0x0d><0x0d><0x0d>
* XFLOW OFF<0x0d>
* FULLDUP OFF<0x0d>
* KISS ON<0x0d>
* RESTART<0x0d>
*
* This keeps repeating over and over and over and over again if
* it doesn't get any sort of response.
*
* Let's try to keep it happy by sending back a command prompt.
*/
void kiss_rec_byte (kiss_frame_t *kf, unsigned char ch, int debug, int client, void (*sendfun)(int,int,unsigned char*,int,int))
{
//dw_printf ("kiss_frame ( %c %02x ) \n", ch, ch);
switch (kf->state) {
case KS_SEARCHING: /* Searching for starting FEND. */
default:
if (ch == FEND) {
/* Start of frame. But first print any collected noise for debugging. */
if (kf->noise_len > 0) {
if (debug) {
kiss_debug_print (FROM_CLIENT, "Rejected Noise", kf->noise, kf->noise_len);
}
kf->noise_len = 0;
}
kf->kiss_len = 0;
kf->kiss_msg[kf->kiss_len++] = ch;
kf->state = KS_COLLECTING;
return;
}
/* Noise to be rejected. */
if (kf->noise_len < MAX_NOISE_LEN) {
kf->noise[kf->noise_len++] = ch;
}
if (ch == '\r') {
if (debug) {
kiss_debug_print (FROM_CLIENT, "Rejected Noise", kf->noise, kf->noise_len);
kf->noise[kf->noise_len] = '\0';
}
#ifndef KISSUTIL
/* Try to appease client app by sending something back. */
if (strcasecmp("restart\r", (char*)(kf->noise)) == 0 ||
strcasecmp("reset\r", (char*)(kf->noise)) == 0) {
// first 2 parameters don't matter when length is -1 indicating text.
(*sendfun) (0, 0, (unsigned char *)"\xc0\xc0", -1, client);
}
else {
(*sendfun) (0, 0, (unsigned char *)"\r\ncmd:", -1, client);
}
#endif
kf->noise_len = 0;
}
return;
break;
case KS_COLLECTING: /* Frame collection in progress. */
if (ch == FEND) {
unsigned char unwrapped[AX25_MAX_PACKET_LEN];
int ulen;
/* End of frame. */
if (kf->kiss_len == 0) {
/* Empty frame. Starting a new one. */
kf->kiss_msg[kf->kiss_len++] = ch;
return;
}
if (kf->kiss_len == 1 && kf->kiss_msg[0] == FEND) {
/* Empty frame. Just go on collecting. */
return;
}
kf->kiss_msg[kf->kiss_len++] = ch;
if (debug) {
/* As received over the wire from client app. */
kiss_debug_print (FROM_CLIENT, NULL, kf->kiss_msg, kf->kiss_len);
}
ulen = kiss_unwrap (kf->kiss_msg, kf->kiss_len, unwrapped);
if (debug >= 2) {
/* Append CRC to this and it goes out over the radio. */
text_color_set(DW_COLOR_DEBUG);
dw_printf ("\n");
dw_printf ("Packet content after removing KISS framing and any escapes:\n");
/* Don't include the "type" indicator. */
/* It contains the radio channel and type should always be 0 here. */
hex_dump (unwrapped+1, ulen-1);
}
kiss_process_msg (unwrapped, ulen, debug, client, sendfun);
kf->state = KS_SEARCHING;
return;
}
if (kf->kiss_len < MAX_KISS_LEN) {
kf->kiss_msg[kf->kiss_len++] = ch;
}
else {
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS message exceeded maximum length.\n");
}
return;
break;
}
return; /* unreachable but suppress compiler warning. */
} /* end kiss_rec_byte */
/*-------------------------------------------------------------------
*
* Name: kiss_process_msg
*
* Purpose: Process a message from the KISS client.
*
* Inputs: kiss_msg - Kiss frame with FEND and escapes removed.
* The first byte contains channel and command.
*
* kiss_len - Number of bytes including the command.
*
* debug - Debug option is selected.
*
* client - Client app number for TCP KISS.
* Should be -1 for pseudo termal and serial port.
*
* sendfun - Function to send something to the client application.
* "Set Hardware" can send a response.
*
*-----------------------------------------------------------------*/
#ifndef KISSUTIL // All these ifdefs in here are a sign that this should be refactored.
// Should split this into multiple files.
// Some functions are only for the TNC end.
// Other functions are suitble for both TNC and client app.
// This is used only by the TNC sided.
void kiss_process_msg (unsigned char *kiss_msg, int kiss_len, int debug, int client, void (*sendfun)(int,int,unsigned char*,int,int))
{
int port; // Should rename to chan because that's what we use everywhere else.
int cmd;
packet_t pp;
alevel_t alevel;
port = (kiss_msg[0] >> 4) & 0xf;
cmd = kiss_msg[0] & 0xf;
switch (cmd)
{
case KISS_CMD_DATA_FRAME: /* 0 = Data Frame */
if (client >= 0) {
kissnet_copy (kiss_msg, kiss_len, port, cmd, client);
}
/* Note July 2017: There is a variant of of KISS, called SMACK, that assumes */
/* a TNC can never have more than 8 ports. http://symek.de/g/smack.html */
/* It uses the MSB to indicate that a checksum is added. I wonder if this */
/* is why we sometimes hear about a request to transmit on channel 8. */
/* Should we have a message that asks the user if SMACK is being used, */
/* and if so, turn it off in the application configuration? */
/* Our current default is a maximum of 6 channels but it is easily */
/* increased by changing one number and recompiling. */
// Additional information, from Mike Playle, December 2018, for Issue #42
//
// I came across this the other day with Xastir, and took a quick look.
// The problem is fixable without the kiss_frame.c hack, which doesn't help with Xastir anyway.
//
// Workaround
//
// After the kissattach command, put the interface into CRC mode "none" with a command like this:
//
// # kissparms -c 1 -p radio
//
// Analysis
//
// The source of this behaviour is the kernel's KISS implementation:
//
// https://elixir.bootlin.com/linux/v4.9/source/drivers/net/hamradio/mkiss.c#L489
//
// It defaults to starting in state CRC_MODE_SMACK_TEST and ending up in mode CRC_NONE
// after the first two packets, which have their framing byte modified by this code in the process.
// It looks to me like deliberate behaviour on the kernel's part.
//
// Setting the CRC mode explicitly before sending any packets stops this state machine from running.
//
// Is this a bug? I don't know - that's up to you! Maybe it would make sense for Direwolf to set
// the CRC mode itself, or to expect this behaviour and ignore these flags on the first packets
// received from the Linux pty.
//
// This workaround seems sound to me, though, so perhaps this is just a documentation issue.
// Would it make sense to implement SMACK? I don't think so.
// Adding a checksum to the KISS data offers no benefit because it is very reliable.
// It violates the original protocol specification which states that 16 ports (radio channels) are possible.
// SMACK imposes a limit of 8. That limit might have been OK back in 1991 but not now.
// There are people using more than 8 radio channels (using SDR not traditional radios) with direwolf.
/* Verify that the port (channel) number is valid. */
/* Any sort of medium should be OK here. */
if (port < 0 || port >= MAX_CHANS || save_audio_config_p->achan[port].medium == MEDIUM_NONE) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Invalid transmit channel %d from KISS client app.\n", port);
dw_printf ("\n");
dw_printf ("Are you using AX.25 for Linux? It might be trying to use a modified\n");
dw_printf ("version of KISS which uses the port field differently than the\n");
dw_printf ("original KISS protocol specification. The solution might be to use\n");
dw_printf ("a command like \"kissparms -c 1 -p radio\" to set CRC none mode.\n");
dw_printf ("\n");
text_color_set(DW_COLOR_DEBUG);
kiss_debug_print (FROM_CLIENT, NULL, kiss_msg, kiss_len);
return;
}
memset (&alevel, 0xff, sizeof(alevel));
pp = ax25_from_frame (kiss_msg+1, kiss_len-1, alevel);
if (pp == NULL) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("ERROR - Invalid KISS data frame from client app.\n");
}
else {
/* How can we determine if it is an original or repeated message? */
/* If there is at least one digipeater in the frame, AND */
/* that digipeater has been used, it should go out quickly thru */
/* the high priority queue. */
/* Otherwise, it is an original for the low priority queue. */
if (ax25_get_num_repeaters(pp) >= 1 &&
ax25_get_h(pp,AX25_REPEATER_1)) {
tq_append (port, TQ_PRIO_0_HI, pp);
}
else {
tq_append (port, TQ_PRIO_1_LO, pp);
}
}
break;
case KISS_CMD_TXDELAY: /* 1 = TXDELAY */
if (kiss_len < 2) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS ERROR: Missing value for TXDELAY command.\n");
return;
}
text_color_set(DW_COLOR_INFO);
dw_printf ("KISS protocol set TXDELAY = %d (*10mS units = %d mS), port %d\n", kiss_msg[1], kiss_msg[1] * 10, port);
if (kiss_msg[1] < 4 || kiss_msg[1] > 100) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Are you sure you want such an extreme value for TXDELAY?\n");
dw_printf ("See \"Radio Channel - Transmit Timing\" section of User Guide for explanation.\n");
}
xmit_set_txdelay (port, kiss_msg[1]);
break;
case KISS_CMD_PERSISTENCE: /* 2 = Persistence */
if (kiss_len < 2) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS ERROR: Missing value for PERSISTENCE command.\n");
return;
}
text_color_set(DW_COLOR_INFO);
dw_printf ("KISS protocol set Persistence = %d, port %d\n", kiss_msg[1], port);
if (kiss_msg[1] < 5 || kiss_msg[1] > 250) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Are you sure you want such an extreme value for PERSIST?\n");
dw_printf ("See \"Radio Channel - Transmit Timing\" section of User Guide for explanation.\n");
}
xmit_set_persist (port, kiss_msg[1]);
break;
case KISS_CMD_SLOTTIME: /* 3 = SlotTime */
if (kiss_len < 2) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS ERROR: Missing value for SLOTTIME command.\n");
return;
}
text_color_set(DW_COLOR_INFO);
dw_printf ("KISS protocol set SlotTime = %d (*10mS units = %d mS), port %d\n", kiss_msg[1], kiss_msg[1] * 10, port);
if (kiss_msg[1] < 2 || kiss_msg[1] > 50) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Are you sure you want such an extreme value for SLOTTIME?\n");
dw_printf ("See \"Radio Channel - Transmit Timing\" section of User Guide for explanation.\n");
}
xmit_set_slottime (port, kiss_msg[1]);
break;
case KISS_CMD_TXTAIL: /* 4 = TXtail */
if (kiss_len < 2) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS ERROR: Missing value for TXTAIL command.\n");
return;
}
text_color_set(DW_COLOR_INFO);
dw_printf ("KISS protocol set TXtail = %d (*10mS units = %d mS), port %d\n", kiss_msg[1], kiss_msg[1] * 10, port);
if (kiss_msg[1] < 2) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Setting TXTAIL so low is asking for trouble. You probably don't want to do this.\n");
dw_printf ("See \"Radio Channel - Transmit Timing\" section of User Guide for explanation.\n");
}
xmit_set_txtail (port, kiss_msg[1]);
break;
case KISS_CMD_FULLDUPLEX: /* 5 = FullDuplex */
if (kiss_len < 2) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS ERROR: Missing value for FULLDUPLEX command.\n");
return;
}
text_color_set(DW_COLOR_INFO);
dw_printf ("KISS protocol set FullDuplex = %d, port %d\n", kiss_msg[1], port);
xmit_set_fulldup (port, kiss_msg[1]);
break;
case KISS_CMD_SET_HARDWARE: /* 6 = TNC specific */
if (kiss_len < 2) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS ERROR: Missing value for SET HARDWARE command.\n");
return;
}
kiss_msg[kiss_len] = '\0';
text_color_set(DW_COLOR_INFO);
dw_printf ("KISS protocol set hardware \"%s\", port %d\n", (char*)(kiss_msg+1), port);
kiss_set_hardware (port, (char*)(kiss_msg+1), debug, client, sendfun);
break;
case KISS_CMD_END_KISS: /* 15 = End KISS mode, port should be 15. */
/* Ignore it. */
text_color_set(DW_COLOR_INFO);
dw_printf ("KISS protocol end KISS mode - Ignored.\n");
break;
default:
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS Invalid command %d\n", cmd);
kiss_debug_print (FROM_CLIENT, NULL, kiss_msg, kiss_len);
text_color_set(DW_COLOR_INFO);
dw_printf ("Troubleshooting tip:\n");
dw_printf ("Use \"-d kn\" option on direwolf command line to observe\n");
dw_printf ("all communication with the client application.\n");
if (cmd == XKISS_CMD_DATA || cmd == XKISS_CMD_POLL) {
dw_printf ("\n");
dw_printf ("It looks like you are trying to use the \"XKISS\" protocol which is not supported.\n");
dw_printf ("Change your application settings to use standard \"KISS\" rather than some other variant.\n");
dw_printf ("If you are using Winlink Express, configure like this:\n");
dw_printf (" Packet TNC Type: KISS\n");
dw_printf (" Packet TNC Model: NORMAL -- Using ACKMODE will cause this error.\n");
dw_printf ("\n");
}
break;
}
} /* end kiss_process_msg */
#endif // ifndef KISSUTIL
/*-------------------------------------------------------------------
*
* Name: kiss_set_hardware
*
* Purpose: Process the "set hardware" command.
*
* Inputs: chan - channel, 0 - 15.
*
* command - All but the first byte. e.g. "TXBUF:99"
* Case sensitive.
* Will be modified so be sure caller doesn't care.
*
* debug - debug level.
*
* client - Client app number for TCP KISS.
* Needed so we can send any response to the right client app.
* Ignored for pseudo terminal and serial port.
*
* sendfun - Function to send something to the client application.
*
* This is the tricky part. We can have any combination of
* serial port, pseudo terminal, and multiple TCP clients.
* We need to send the response to same place where query came
* from. The function is different for each class of device
* and we need a client number for the TCP case because we
* can have multiple TCP KISS clients at the same time.
*
*
* Description: This is new in version 1.5. "Set hardware" was previously ignored.
*
* There are times when the client app might want to send configuration
* commands, such as modem speed, to the KISS TNC or inquire about its
* current state.
*
* The immediate motivation for adding this is that one application wants
* to know how many frames are currently in the transmit queue. This can
* be used for throttling of large transmissions and performing some action
* after the last frame has been sent.
*
* The original KISS protocol spec offers no guidance on what "Set Hardware" might look
* like. I'm aware of only two, drastically different, implementations:
*
* fldigi - http://www.w1hkj.com/FldigiHelp-3.22/kiss_command_page.html
*
* Everything is in human readable in both directions:
*
* COMMAND: [ parameter [ , parameter ... ] ]
*
* Lack of a parameter, in the client to TNC direction, is a query
* which should generate a response in the same format.
*
* Used by applications, http://www.w1hkj.com/FldigiHelp/kiss_host_prgs_page.html
* - BPQ32
* - UIChar
* - YAAC
*
* mobilinkd - https://raw.githubusercontent.com/mobilinkd/tnc1/tnc2/bertos/net/kiss.c
*
* Single byte with the command / response code, followed by
* zero or more value bytes.
*
* Used by applications:
* - APRSdroid
*
* It would be beneficial to adopt one of them rather than doing something
* completely different. It might even be possible to recognize both.
* This might allow leveraging of other existing applications.
*
* Let's start with the easy to understand human readable format.
*
* Commands: (Client to TNC, with parameter(s) to set something.)
*
* none yet
*
* Queries: (Client to TNC, no parameters, generate a response.)
*
* Query Response Comment
* ----- -------- -------
*
* TNC: TNC:DIREWOLF 9.9 9.9 represents current version.
*
* TXBUF: TXBUF:999 Number of bytes (not frames) in transmit queue.
*
*--------------------------------------------------------------------*/
#ifndef KISSUTIL
static void kiss_set_hardware (int chan, char *command, int debug, int client, void (*sendfun)(int,int,unsigned char*,int,int))
{
char *param;
char response[100];
param = strchr (command, ':');
if (param != NULL) {
*param = '\0';
param++;
if (strcmp(command, "TNC") == 0) { /* TNC - Identify software version. */
if (strlen(param) > 0) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS Set Hardware TNC: Did not expect a parameter.\n");
}
snprintf (response, sizeof(response), "DIREWOLF %d.%d", MAJOR_VERSION, MINOR_VERSION);
(*sendfun) (chan, KISS_CMD_SET_HARDWARE, (unsigned char *)response, strlen(response), client);
}
else if (strcmp(command, "TXBUF") == 0) { /* TXBUF - Number of bytes in transmit queue. */
if (strlen(param) > 0) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS Set Hardware TXBUF: Did not expect a parameter.\n");
}
int n = tq_count (chan, -1, "", "", 1);
snprintf (response, sizeof(response), "TXBUF:%d", n);
(*sendfun) (chan, KISS_CMD_SET_HARDWARE, (unsigned char *)response, strlen(response), client);
}
else {
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS Set Hardware unrecognized command: %s.\n", command);
}
}
else {
text_color_set(DW_COLOR_ERROR);
dw_printf ("KISS Set Hardware \"%s\" expected the form COMMAND:[parameter[,parameter...]]\n", command);
}
return;
} /* end kiss_set_hardware */
#endif // ifndef KISSUTIL
/*-------------------------------------------------------------------
*
* Name: kiss_debug_print
*
* Purpose: Print message to/from client for debugging.
*
* Inputs: fromto - Direction of message.
* special - Comment if not a KISS frame.
* pmsg - Address of the message block.
* msg_len - Length of the message.
*
*--------------------------------------------------------------------*/
void kiss_debug_print (fromto_t fromto, char *special, unsigned char *pmsg, int msg_len)
{
#ifndef KISSUTIL
const char *direction [2] = { "from", "to" };
const char *prefix [2] = { "<<<", ">>>" };
const char *function[16] = {
"Data frame", "TXDELAY", "P", "SlotTime",
"TXtail", "FullDuplex", "SetHardware", "Invalid 7",
"Invalid 8", "Invalid 9", "Invalid 10", "Invalid 11",
"Invalid 12", "Invalid 13", "Invalid 14", "Return" };
#endif
text_color_set(DW_COLOR_DEBUG);
#ifdef KISSUTIL
dw_printf ("From KISS TNC:\n");
#else
dw_printf ("\n");
if (special == NULL) {
unsigned char *p; /* to skip over FEND if present. */
p = pmsg;
if (*p == FEND) p++;
dw_printf ("%s %s %s KISS client application, port %d, total length = %d\n",
prefix[(int)fromto], function[p[0] & 0xf], direction[(int)fromto],
(p[0] >> 4) & 0xf, msg_len);
}
else {
dw_printf ("%s %s %s KISS client application, total length = %d\n",
prefix[(int)fromto], special, direction[(int)fromto],
msg_len);
}
#endif
hex_dump (pmsg, msg_len);
} /* end kiss_debug_print */
#endif
#endif /* DECAMAIN */
/* Quick unit test for encapsulate & unwrap */
// $ gcc -DKISSTEST kiss_frame.c ; ./a
// Quick KISS test passed OK.
#if KISSTEST
int main ()
{
unsigned char din[512];
unsigned char kissed[520];
unsigned char dout[520];
int klen;
int dlen;
int k;
for (k = 0; k < 512; k++) {
if (k < 256) {
din[k] = k;
}
else {
din[k] = 511 - k;
}
}
klen = kiss_encapsulate (din, 512, kissed);
assert (klen == 512 + 6);
dlen = kiss_unwrap (kissed, klen, dout);
assert (dlen == 512);
assert (memcmp(din, dout, 512) == 0);
dlen = kiss_unwrap (kissed+1, klen-1, dout);
assert (dlen == 512);
assert (memcmp(din, dout, 512) == 0);
dw_printf ("Quick KISS test passed OK.\n");
exit (EXIT_SUCCESS);
}
#endif /* KISSTEST */
#endif /* WALK96 */
/* end kiss_frame.c */
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