//
// This file is part of Dire Wolf, an amateur radio packet TNC.
//
// Copyright (C) 2011, 2013, 2014, 2015 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 .
//
/*------------------------------------------------------------------
*
* Name: digipeater.c
*
* Purpose: Act as an APRS digital repeater.
*
*
* Description: Decide whether the specified packet should
* be digipeated and make necessary modifications.
*
*
* References: APRS Protocol Reference, document version 1.0.1
*
* http://www.aprs.org/doc/APRS101.PDF
*
* APRS SPEC Addendum 1.1
*
* http://www.aprs.org/aprs11.html
*
* APRS SPEC Addendum 1.2
*
* http://www.aprs.org/aprs12.html
*
* "The New n-N Paradigm"
*
* http://www.aprs.org/fix14439.html
*
* Preemptive Digipeating (new in version 0.8)
*
* http://www.aprs.org/aprs12/preemptive-digipeating.txt
*
*------------------------------------------------------------------*/
#define DIGIPEATER_C
#include "direwolf.h"
#include
#include
#include
#include
#include /* for isdigit, isupper */
#include "regex.h"
#include
#include "ax25_pad.h"
#include "digipeater.h"
#include "textcolor.h"
#include "dedupe.h"
#include "tq.h"
#include "pfilter.h"
static packet_t digipeat_match (int from_chan, packet_t pp, char *mycall_rec, char *mycall_xmit,
regex_t *uidigi, regex_t *uitrace, int to_chan, enum preempt_e preempt, char *type_filter);
/*
* Keep pointer to configuration options.
* Set by digipeater_init and used later.
*/
static struct audio_s *save_audio_config_p;
static struct digi_config_s *save_digi_config_p;
/*
* Maintain count of packets digipeated for each combination of from/to channel.
*/
static int digi_count[MAX_CHANS][MAX_CHANS];
int digipeater_get_count (int from_chan, int to_chan) {
return (digi_count[from_chan][to_chan]);
}
/*------------------------------------------------------------------------------
*
* Name: digipeater_init
*
* Purpose: Initialize with stuff from configuration file.
*
* Inputs: p_audio_config - Configuration for audio channels.
*
* p_digi_config - Digipeater configuration details.
*
* Outputs: Save pointers to configuration for later use.
*
* Description: Called once at application startup time.
*
*------------------------------------------------------------------------------*/
void digipeater_init (struct audio_s *p_audio_config, struct digi_config_s *p_digi_config)
{
save_audio_config_p = p_audio_config;
save_digi_config_p = p_digi_config;
dedupe_init (p_digi_config->dedupe_time);
}
/*------------------------------------------------------------------------------
*
* Name: digipeater
*
* Purpose: Re-transmit packet if it matches the rules.
*
* Inputs: chan - Radio channel where it was received.
*
* pp - Packet object.
*
* Returns: None.
*
*
*------------------------------------------------------------------------------*/
void digipeater (int from_chan, packet_t pp)
{
int to_chan;
// dw_printf ("digipeater()\n");
assert (from_chan >= 0 && from_chan < MAX_CHANS);
if ( ! save_audio_config_p->achan[from_chan].valid) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("digipeater: Did not expect to receive on invalid channel %d.\n", from_chan);
}
/*
* First pass: Look at packets being digipeated to same channel.
*
* We want these to get out quickly.
*/
for (to_chan=0; to_chanenabled[from_chan][to_chan]) {
if (to_chan == from_chan) {
packet_t result;
result = digipeat_match (from_chan, pp, save_audio_config_p->achan[from_chan].mycall,
save_audio_config_p->achan[to_chan].mycall,
&save_digi_config_p->alias[from_chan][to_chan], &save_digi_config_p->wide[from_chan][to_chan],
to_chan, save_digi_config_p->preempt[from_chan][to_chan],
save_digi_config_p->filter_str[from_chan][to_chan]);
if (result != NULL) {
dedupe_remember (pp, to_chan);
tq_append (to_chan, TQ_PRIO_0_HI, result);
digi_count[from_chan][to_chan]++;
}
}
}
}
/*
* Second pass: Look at packets being digipeated to different channel.
*
* These are lower priority
*/
for (to_chan=0; to_chanenabled[from_chan][to_chan]) {
if (to_chan != from_chan) {
packet_t result;
result = digipeat_match (from_chan, pp, save_audio_config_p->achan[from_chan].mycall,
save_audio_config_p->achan[to_chan].mycall,
&save_digi_config_p->alias[from_chan][to_chan], &save_digi_config_p->wide[from_chan][to_chan],
to_chan, save_digi_config_p->preempt[from_chan][to_chan],
save_digi_config_p->filter_str[from_chan][to_chan]);
if (result != NULL) {
dedupe_remember (pp, to_chan);
tq_append (to_chan, TQ_PRIO_1_LO, result);
digi_count[from_chan][to_chan]++;
}
}
}
}
} /* end digipeater */
/*------------------------------------------------------------------------------
*
* Name: digipeat_match
*
* Purpose: A simple digipeater for APRS.
*
* Input: pp - Pointer to a packet object.
*
* mycall_rec - Call of my station, with optional SSID,
* associated with the radio channel where the
* packet was received.
*
* mycall_xmit - Call of my station, with optional SSID,
* associated with the radio channel where the
* packet is to be transmitted. Could be the same as
* mycall_rec or different.
*
* alias - Compiled pattern for my station aliases or
* "trapping" (repeating only once).
*
* wide - Compiled pattern for normal WIDEn-n digipeating.
*
* to_chan - Channel number that we are transmitting to.
* This is needed to maintain a history for
* removing duplicates during specified time period.
*
* preempt - Option for "preemptive" digipeating.
*
* filter_str - Filter expression string or NULL.
*
* Returns: Packet object for transmission or NULL.
* The original packet is not modified. (with one exception, probably obsolete)
* We make a copy and return that modified copy!
* This is very important because we could digipeat from one channel to many.
*
* Description: The packet will be digipeated if the next unused digipeater
* field matches one of the following:
*
* - mycall_rec
* - udigi list (only once)
* - wide list (usual wideN-N rules)
*
*------------------------------------------------------------------------------*/
static char *dest_ssid_path[16] = {
"", /* Use VIA path */
"WIDE1-1",
"WIDE2-2",
"WIDE3-3",
"WIDE4-4",
"WIDE5-5",
"WIDE6-6",
"WIDE7-7",
"WIDE1-1", /* North */
"WIDE1-1", /* South */
"WIDE1-1", /* East */
"WIDE1-1", /* West */
"WIDE2-2", /* North */
"WIDE2-2", /* South */
"WIDE2-2", /* East */
"WIDE2-2" }; /* West */
static packet_t digipeat_match (int from_chan, packet_t pp, char *mycall_rec, char *mycall_xmit,
regex_t *alias, regex_t *wide, int to_chan, enum preempt_e preempt, char *filter_str)
{
int ssid;
int r;
char repeater[AX25_MAX_ADDR_LEN];
int err;
char err_msg[100];
/*
* First check if filtering has been configured.
*/
if (filter_str != NULL) {
if (pfilter(from_chan, to_chan, filter_str, pp) != 1) {
// TODO1.2: take out debug message
// Actually it turns out to be useful.
// Maybe add a quiet option to suppress it although no one has complained about it yet.
//#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("Packet was rejected for digipeating from channel %d to %d by filter: %s\n", from_chan, to_chan, filter_str);
//#endif
return(NULL);
}
}
/*
* The spec says:
*
* The SSID in the Destination Address field of all packets is coded to specify
* the APRS digipeater path.
* If the Destination Address SSID is -0, the packet follows the standard AX.25
* digipeater ("VIA") path contained in the Digipeater Addresses field of the
* AX.25 frame.
* If the Destination Address SSID is non-zero, the packet follows one of 15
* generic APRS digipeater paths.
*
*
* What if this is non-zero but there is also a digipeater path?
* I will ignore this if there is an explicit path.
*
* Note that this modifies the input. But only once!
* Otherwise we don't want to modify the input because this could be called multiple times.
*/
if (ax25_get_num_repeaters(pp) == 0 && (ssid = ax25_get_ssid(pp, AX25_DESTINATION)) > 0) {
ax25_set_addr(pp, AX25_REPEATER_1, dest_ssid_path[ssid]);
ax25_set_ssid(pp, AX25_DESTINATION, 0);
/* Continue with general case, below. */
}
/*
* Find the first repeater station which doesn't have "has been repeated" set.
*
* r = index of the address position in the frame.
*/
r = ax25_get_first_not_repeated(pp);
if (r < AX25_REPEATER_1) {
return (NULL);
}
ax25_get_addr_with_ssid(pp, r, repeater);
ssid = ax25_get_ssid(pp, r);
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("First unused digipeater is %s, ssid=%d\n", repeater, ssid);
#endif
/*
* First check for explicit use of my call.
* In this case, we don't check the history so it would be possible
* to have a loop (of limited size) if someone constructed the digipeater paths
* correctly.
*/
if (strcmp(repeater, mycall_rec) == 0) {
packet_t result;
result = ax25_dup (pp);
assert (result != NULL);
/* If using multiple radio channels, they */
/* could have different calls. */
ax25_set_addr (result, r, mycall_xmit);
ax25_set_h (result, r);
return (result);
}
/*
* Next try to avoid retransmitting redundant information.
* Duplicates are detected by comparing only:
* - source
* - destination
* - info part
* - but none of the digipeaters
* A history is kept for some amount of time, typically 30 seconds.
* For efficiency, only a checksum, rather than the complete fields
* might be kept but the result is the same.
* Packets transmitted recently will not be transmitted again during
* the specified time period.
*
*/
if (dedupe_check(pp, to_chan)) {
//#if DEBUG
/* Might be useful if people are wondering why */
/* some are not repeated. Might also cause confusion. */
text_color_set(DW_COLOR_INFO);
dw_printf ("Digipeater: Drop redundant packet to channel %d.\n", to_chan);
//#endif
return NULL;
}
/*
* For the alias pattern, we unconditionally digipeat it once.
* i.e. Just replace it with MYCALL don't even look at the ssid.
*/
err = regexec(alias,repeater,0,NULL,0);
if (err == 0) {
packet_t result;
result = ax25_dup (pp);
assert (result != NULL);
ax25_set_addr (result, r, mycall_xmit);
ax25_set_h (result, r);
return (result);
}
else if (err != REG_NOMATCH) {
regerror(err, alias, err_msg, sizeof(err_msg));
text_color_set (DW_COLOR_ERROR);
dw_printf ("%s\n", err_msg);
}
/*
* If preemptive digipeating is enabled, try matching my call
* and aliases against all remaining unused digipeaters.
*/
if (preempt != PREEMPT_OFF) {
int r2;
for (r2 = r+1; r2 < ax25_get_num_addr(pp); r2++) {
char repeater2[AX25_MAX_ADDR_LEN];
ax25_get_addr_with_ssid(pp, r2, repeater2);
//text_color_set (DW_COLOR_DEBUG);
//dw_printf ("test match %d %s\n", r2, repeater2);
if (strcmp(repeater2, mycall_rec) == 0 ||
regexec(alias,repeater2,0,NULL,0) == 0) {
packet_t result;
result = ax25_dup (pp);
assert (result != NULL);
ax25_set_addr (result, r2, mycall_xmit);
ax25_set_h (result, r2);
switch (preempt) {
case PREEMPT_DROP: /* remove all prior */
while (r2 > AX25_REPEATER_1) {
ax25_remove_addr (result, r2-1);
r2--;
}
break;
case PREEMPT_MARK:
r2--;
while (r2 >= AX25_REPEATER_1 && ax25_get_h(result,r2) == 0) {
ax25_set_h (result, r2);
r2--;
}
break;
case PREEMPT_TRACE: /* remove prior unused */
default:
while (r2 > AX25_REPEATER_1 && ax25_get_h(result,r2-1) == 0) {
ax25_remove_addr (result, r2-1);
r2--;
}
break;
}
return (result);
}
}
}
/*
* For the wide pattern, we check the ssid and decrement it.
*/
err = regexec(wide,repeater,0,NULL,0);
if (err == 0) {
/*
* If ssid == 1, we simply replace the repeater with my call and
* mark it as being used.
*
* Otherwise, if ssid in range of 2 to 7,
* Decrement y and don't mark repeater as being used.
* Insert own call ahead of this one for tracing if we don't already have the
* maximum number of repeaters.
*/
if (ssid == 1) {
packet_t result;
result = ax25_dup (pp);
assert (result != NULL);
ax25_set_addr (result, r, mycall_xmit);
ax25_set_h (result, r);
return (result);
}
if (ssid >= 2 && ssid <= 7) {
packet_t result;
result = ax25_dup (pp);
assert (result != NULL);
ax25_set_ssid(result, r, ssid-1); // should be at least 1
if (ax25_get_num_repeaters(pp) < AX25_MAX_REPEATERS) {
ax25_insert_addr (result, r, mycall_xmit);
ax25_set_h (result, r);
}
return (result);
}
}
else if (err != REG_NOMATCH) {
regerror(err, wide, err_msg, sizeof(err_msg));
text_color_set (DW_COLOR_ERROR);
dw_printf ("%s\n", err_msg);
}
/*
* Don't repeat it if we get here.
*/
return (NULL);
}
/*------------------------------------------------------------------------------
*
* Name: digi_regen
*
* Purpose: Send regenerated copy of what we received.
*
* Inputs: chan - Radio channel where it was received.
*
* pp - Packet object.
*
* Returns: None.
*
* Description: TODO...
*
* Initial reports were favorable.
* Should document what this is all about if there is still interest...
*
*------------------------------------------------------------------------------*/
void digi_regen (int from_chan, packet_t pp)
{
int to_chan;
packet_t result;
// dw_printf ("digi_regen()\n");
assert (from_chan >= 0 && from_chan < MAX_CHANS);
for (to_chan=0; to_chanregen[from_chan][to_chan]) {
result = ax25_dup (pp);
if (result != NULL) {
// TODO: if AX.25 and has been digipeated, put in HI queue?
tq_append (to_chan, TQ_PRIO_1_LO, result);
}
}
}
} /* end dig_regen */
/*-------------------------------------------------------------------------
*
* Name: main
*
* Purpose: Standalone test case for this funtionality.
*
* Usage: make -f Makefile. dtest
* ./dtest
*
*------------------------------------------------------------------------*/
#if DIGITEST
static char mycall[] = "WB2OSZ-9";
static regex_t alias_re;
static regex_t wide_re;
static int failed;
static enum preempt_e preempt = PREEMPT_OFF;
static void test (char *in, char *out)
{
packet_t pp, result;
char rec[256];
char xmit[256];
unsigned char *pinfo;
int info_len;
unsigned char frame[AX25_MAX_PACKET_LEN];
int frame_len;
alevel_t alevel;
dw_printf ("\n");
/*
* As an extra test, change text to internal format back to
* text again to make sure it comes out the same.
*/
pp = ax25_from_text (in, 1);
assert (pp != NULL);
ax25_format_addrs (pp, rec);
info_len = ax25_get_info (pp, &pinfo);
(void)info_len;
strlcat (rec, (char*)pinfo, sizeof(rec));
if (strcmp(in, rec) != 0) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Text/internal/text error-1 %s -> %s\n", in, rec);
}
/*
* Just for more fun, write as the frame format, read it back
* again, and make sure it is still the same.
*/
frame_len = ax25_pack (pp, frame);
ax25_delete (pp);
alevel.rec = 50;
alevel.mark = 50;
alevel.space = 50;
pp = ax25_from_frame (frame, frame_len, alevel);
assert (pp != NULL);
ax25_format_addrs (pp, rec);
info_len = ax25_get_info (pp, &pinfo);
strlcat (rec, (char*)pinfo, sizeof(rec));
if (strcmp(in, rec) != 0) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("internal/frame/internal/text error-2 %s -> %s\n", in, rec);
}
/*
* On with the digipeater test.
*/
text_color_set(DW_COLOR_REC);
dw_printf ("Rec\t%s\n", rec);
//TODO: Add filtering to test.
// V
result = digipeat_match (0, pp, mycall, mycall, &alias_re, &wide_re, 0, preempt, NULL);
if (result != NULL) {
dedupe_remember (result, 0);
ax25_format_addrs (result, xmit);
info_len = ax25_get_info (result, &pinfo);
strlcat (xmit, (char*)pinfo, sizeof(xmit));
ax25_delete (result);
}
else {
strlcpy (xmit, "", sizeof(xmit));
}
text_color_set(DW_COLOR_XMIT);
dw_printf ("Xmit\t%s\n", xmit);
if (strcmp(xmit, out) == 0) {
text_color_set(DW_COLOR_INFO);
dw_printf ("OK\n");
}
else {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Expect\t%s\n", out);
failed++;
}
dw_printf ("\n");
}
int main (int argc, char *argv[])
{
int e;
failed = 0;
char message[256];
dedupe_init (4);
/*
* Compile the patterns.
*/
e = regcomp (&alias_re, "^WIDE[4-7]-[1-7]|CITYD$", REG_EXTENDED|REG_NOSUB);
if (e != 0) {
regerror (e, &alias_re, message, sizeof(message));
text_color_set(DW_COLOR_ERROR);
dw_printf ("\n%s\n\n", message);
exit (1);
}
e = regcomp (&wide_re, "^WIDE[1-7]-[1-7]$|^TRACE[1-7]-[1-7]$|^MA[1-7]-[1-7]$", REG_EXTENDED|REG_NOSUB);
if (e != 0) {
regerror (e, &wide_re, message, sizeof(message));
text_color_set(DW_COLOR_ERROR);
dw_printf ("\n%s\n\n", message);
exit (1);
}
/*
* Let's start with the most basic cases.
*/
test ( "W1ABC>TEST01,TRACE3-3:",
"W1ABC>TEST01,WB2OSZ-9*,TRACE3-2:");
test ( "W1ABC>TEST02,WIDE3-3:",
"W1ABC>TEST02,WB2OSZ-9*,WIDE3-2:");
test ( "W1ABC>TEST03,WIDE3-2:",
"W1ABC>TEST03,WB2OSZ-9*,WIDE3-1:");
test ( "W1ABC>TEST04,WIDE3-1:",
"W1ABC>TEST04,WB2OSZ-9*:");
/*
* Look at edge case of maximum number of digipeaters.
*/
test ( "W1ABC>TEST11,R1,R2,R3,R4,R5,R6*,WIDE3-3:",
"W1ABC>TEST11,R1,R2,R3,R4,R5,R6,WB2OSZ-9*,WIDE3-2:");
test ( "W1ABC>TEST12,R1,R2,R3,R4,R5,R6,R7*,WIDE3-3:",
"W1ABC>TEST12,R1,R2,R3,R4,R5,R6,R7*,WIDE3-2:");
test ( "W1ABC>TEST13,R1,R2,R3,R4,R5,R6,R7*,WIDE3-1:",
"W1ABC>TEST13,R1,R2,R3,R4,R5,R6,R7,WB2OSZ-9*:");
/*
* "Trap" large values of "N" by repeating only once.
*/
test ( "W1ABC>TEST21,WIDE4-4:",
"W1ABC>TEST21,WB2OSZ-9*:");
test ( "W1ABC>TEST22,WIDE7-7:",
"W1ABC>TEST22,WB2OSZ-9*:");
/*
* Only values in range of 1 thru 7 are valid.
*/
test ( "W1ABC>TEST31,WIDE0-4:",
"");
test ( "W1ABC>TEST32,WIDE8-4:",
"");
test ( "W1ABC>TEST33,WIDE2:",
"");
/*
* and a few cases actually heard.
*/
test ( "WA1ENO>FN42ND,W1MV-1*,WIDE3-2:",
"WA1ENO>FN42ND,W1MV-1,WB2OSZ-9*,WIDE3-1:");
test ( "W1ON-3>BEACON:",
"");
test ( "W1CMD-9>TQ3Y8P,N1RCW-2,W1CLA-1,N8VIM,WIDE2*:",
"");
test ( "W1CLA-1>APX192,W1GLO-1,WIDE2*:",
"");
test ( "AC1U-9>T2TX4S,AC1U,WIDE1,N8VIM*,WIDE2-1:",
"AC1U-9>T2TX4S,AC1U,WIDE1,N8VIM,WB2OSZ-9*:");
/*
* Someone is still using the old style and will probably be disappointed.
*/
test ( "K1CPD-1>T2SR5R,RELAY*,WIDE,WIDE,SGATE,WIDE:",
"");
/*
* Change destination SSID to normal digipeater if none specified.
*/
test ( "W1ABC>TEST-3:",
"W1ABC>TEST,WB2OSZ-9*,WIDE3-2:");
test ( "W1DEF>TEST-3,WIDE2-2:",
"W1DEF>TEST-3,WB2OSZ-9*,WIDE2-1:");
/*
* Drop duplicates within specified time interval.
* Only the first 1 of 3 should be retransmitted.
*/
test ( "W1XYZ>TEST,R1*,WIDE3-2:info1",
"W1XYZ>TEST,R1,WB2OSZ-9*,WIDE3-1:info1");
test ( "W1XYZ>TEST,R2*,WIDE3-2:info1",
"");
test ( "W1XYZ>TEST,R3*,WIDE3-2:info1",
"");
/*
* Allow same thing after adequate time.
*/
SLEEP_SEC (5);
test ( "W1XYZ>TEST,R3*,WIDE3-2:info1",
"W1XYZ>TEST,R3,WB2OSZ-9*,WIDE3-1:info1");
/*
* Although source and destination match, the info field is different.
*/
test ( "W1XYZ>TEST,R1*,WIDE3-2:info4",
"W1XYZ>TEST,R1,WB2OSZ-9*,WIDE3-1:info4");
test ( "W1XYZ>TEST,R1*,WIDE3-2:info5",
"W1XYZ>TEST,R1,WB2OSZ-9*,WIDE3-1:info5");
test ( "W1XYZ>TEST,R1*,WIDE3-2:info6",
"W1XYZ>TEST,R1,WB2OSZ-9*,WIDE3-1:info6");
/*
* New in version 0.8.
* "Preemptive" digipeating looks ahead beyond the first unused digipeater.
*/
test ( "W1ABC>TEST11,CITYA*,CITYB,CITYC,CITYD,CITYE:off",
"");
preempt = PREEMPT_DROP;
test ( "W1ABC>TEST11,CITYA*,CITYB,CITYC,CITYD,CITYE:drop",
"W1ABC>TEST11,WB2OSZ-9*,CITYE:drop");
preempt = PREEMPT_MARK;
test ( "W1ABC>TEST11,CITYA*,CITYB,CITYC,CITYD,CITYE:mark1",
"W1ABC>TEST11,CITYA,CITYB,CITYC,WB2OSZ-9*,CITYE:mark1");
test ( "W1ABC>TEST11,CITYA*,CITYB,CITYC,WB2OSZ-9,CITYE:mark2",
"W1ABC>TEST11,CITYA,CITYB,CITYC,WB2OSZ-9*,CITYE:mark2");
preempt = PREEMPT_TRACE;
test ( "W1ABC>TEST11,CITYA*,CITYB,CITYC,CITYD,CITYE:trace1",
"W1ABC>TEST11,CITYA,WB2OSZ-9*,CITYE:trace1");
test ( "W1ABC>TEST11,CITYA*,CITYB,CITYC,CITYD:trace2",
"W1ABC>TEST11,CITYA,WB2OSZ-9*:trace2");
test ( "W1ABC>TEST11,CITYB,CITYC,CITYD:trace3",
"W1ABC>TEST11,WB2OSZ-9*:trace3");
test ( "W1ABC>TEST11,CITYA*,CITYW,CITYX,CITYY,CITYZ:nomatch",
"");
/*
* Did I miss any cases?
*/
if (failed == 0) {
dw_printf ("SUCCESS -- All digipeater tests passed.\n");
}
else {
text_color_set(DW_COLOR_ERROR);
dw_printf ("ERROR - %d digipeater tests failed.\n", failed);
}
return ( failed != 0 );
} /* end main */
#endif /* if DIGITEST */
/* end digipeater.c */