//
// This file is part of Dire Wolf, an amateur radio packet TNC.
//
// Copyright (C) 2016 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/>.
//
/*------------------------------------------------------------------
*
* File: mheard.c
*
* Purpose: Maintain a list of all stations heard.
*
* Description: This was added for IGate statistics and checking if a user is local
* but would also be useful for the AGW network protocol 'H' request.
*
* This application has no GUI and is not interactive so
* I'm not sure what else we might do with the information.
*
* Why mheard instead of just heard? The KPC-3+ has an MHEARD command
* to list stations heard. I guess that stuck in my mind.
* It should be noted that here "heard" refers to the AX.25 source station.
* Before printing the received packet, the "heard" line refers to who
* we heard over the radio. This would be the digipeater with "*" after
* its name.
*
* Future Ideas: Someone suggested using SQLite to store the information
* so other applications could access it.
*
*------------------------------------------------------------------*/
#include "direwolf.h"
#include <stdio.h>
#include <time.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "textcolor.h"
#include "decode_aprs.h"
#include "ax25_pad.h"
#include "hdlc_rec2.h" // for retry_t
#include "mheard.h"
#include "latlong.h"
// This is getting updated from two different threads so we need a critical region
// for adding new nodes.
static dw_mutex_t mheard_mutex;
// I think we can get away without a critical region for reading if we follow these
// rules:
//
// (1) When adding a new node, make sure it is complete, including next ptr,
// before adding it to the list.
// (2) Update the start of list pointer last.
// (2) Nothing gets deleted.
// If we ever decide to start cleaning out very old data, all access would then
// need to use the mutex.
/*
* Information for each station heard over the radio or from Internet Server.
*/
typedef struct mheard_s {
struct mheard_s *pnext; // Pointer to next in list.
char callsign[AX25_MAX_ADDR_LEN]; // Callsign from the AX.25 source field.
int count; // Number of times heard.
// We don't use this for anything.
// Just something potentially interesting when looking at data dump.
int chan; // Most recent channel where heard.
int num_digi_hops; // Number of digipeater hops before we heard it.
// over radio. Zero when heard directly.
time_t last_heard_rf; // Timestamp when last heard over the radio.
time_t last_heard_is; // Timestamp when last heard from Internet Server.
double dlat, dlon; // Last position. G_UNKNOWN for unknown.
int msp; // Allow message sender positon report.
// When non zero, an IS>RF position report is allowed.
// Then decremented.
// What else would be useful?
// The AGW protocol is by channel and returns
// first heard in addition to last heard.
} mheard_t;
/*
* The list could be quite long and we hit this a lot so use a hash table.
*/
#define MHEARD_HASH_SIZE 73 // Best if prime number.
static mheard_t *mheard_hash[MHEARD_HASH_SIZE];
static inline int hash_index(char *callsign) {
int n = 0;
char *p = callsign;
while (*p != '\0') {
n += *p++;
}
return (n % MHEARD_HASH_SIZE);
}
static mheard_t *mheard_ptr(char *callsign) {
int n = hash_index(callsign);
mheard_t *p = mheard_hash[n];
while (p != NULL) {
if (strcmp(callsign,p->callsign) == 0) return (p);
p = p->pnext;
}
return (NULL);
}
static int mheard_debug = 0;
/*------------------------------------------------------------------
*
* Function: mheard_init
*
* Purpose: Initialization at start of application.
*
* Inputs: debug - Debug level.
*
* Description: Clear pointer table.
* Save debug level for later use.
*
*------------------------------------------------------------------*/
void mheard_init (int debug)
{
int i;
mheard_debug = debug;
for (i = 0; i < MHEARD_HASH_SIZE; i++) {
mheard_hash[i] = NULL;
}
/*
* Mutex to coordinate adding new nodes.
*/
dw_mutex_init(&mheard_mutex);
} /* end mheard_init */
/*------------------------------------------------------------------
*
* Function: mheard_dump
*
* Purpose: Print list of stations heard for debugging.
*
*------------------------------------------------------------------*/
/* convert some time in past to hours:minutes text format. */
static void age(char *result, time_t now, time_t t)
{
int s, h, m;
if (t == 0) {
strcpy (result, "- ");
return;
}
s = (int)(now - t);
m = s / 60;
h = m / 60;
m -= h * 60;
sprintf (result, "%4d:%02d", h, m);
}
/* Convert latitude, longitude to text or - if not defined. */
static void latlon (char * result, double dlat, double dlon)
{
if (dlat != G_UNKNOWN && dlon != G_UNKNOWN) {
sprintf (result, "%6.2f %7.2f", dlat, dlon);
}
else {
strcpy (result, " - - ");
}
}
/* Compare last heard time for use with qsort. */
#define MAXX(x,y) (((x)>(y))?(x):(y))
static int compar(const void *a, const void *b)
{
mheard_t *ma = *((mheard_t **)a);
mheard_t *mb = *((mheard_t **)b);
time_t ta = MAXX(ma->last_heard_rf, ma->last_heard_is);
time_t tb = MAXX(mb->last_heard_rf, mb->last_heard_is);
return (tb - ta);
}
#define MAXDUMP 1000
static void mheard_dump (void)
{
int i;
mheard_t *mptr;
time_t now = time(NULL);
char stuff[80];
char rf[16]; // hours:minutes
char is[16];
char position[40];
mheard_t *station[MAXDUMP];
int num_stations = 0;
/* Get linear array of node pointers so they can be sorted easily. */
num_stations = 0;
for (i = 0; i < MHEARD_HASH_SIZE; i++) {
for (mptr = mheard_hash[i]; mptr != NULL; mptr = mptr->pnext) {
if (num_stations < MAXDUMP) {
station[num_stations] = mptr;
num_stations++;
}
else {
text_color_set(DW_COLOR_ERROR);
dw_printf ("mheard_dump - max number of stations exceeded.\n");
}
}
}
/* Sort most recently heard to the top then print. */
qsort (station, num_stations, sizeof(mheard_t *), compar);
text_color_set(DW_COLOR_DEBUG);
dw_printf ("callsign cnt chan hops RF IS lat long msp\n");
for (i = 0; i < num_stations; i++) {
mptr = station[i];
age (rf, now, mptr->last_heard_rf);
age (is, now, mptr->last_heard_is);
latlon (position, mptr->dlat, mptr->dlon);
snprintf (stuff, sizeof(stuff), "%-9s %3d %d %d %7s %7s %s %d\n",
mptr->callsign, mptr->count, mptr->chan, mptr->num_digi_hops, rf, is, position, mptr->msp);
dw_printf ("%s", stuff);
}
} /* end mheard_dump */
/*------------------------------------------------------------------
*
* Function: mheard_save_rf
*
* Purpose: Save information about station heard over the radio.
*
* Inputs: chan - Radio channel where heard.
*
* A - Exploded information from APRS packet.
*
* pp - Received packet object.
*
* alevel - audio level.
*
* retries - Amount of effort to get a good CRC.
*
* Description: Calling sequence was copied from "log_write."
* It has a lot more than what we currently keep but the
* hooks are there so it will be easy to capture additional
* information when the need arises.
*
*------------------------------------------------------------------*/
void mheard_save_rf (int chan, decode_aprs_t *A, packet_t pp, alevel_t alevel, retry_t retries)
{
time_t now = time(NULL);
char source[AX25_MAX_ADDR_LEN];
int hops;
mheard_t *mptr;
ax25_get_addr_with_ssid (pp, AX25_SOURCE, source);
/*
* How many digipeaters has it gone thru before we hear it?
* We can count the number of digi addresses that are marked as "has been used."
* This is not always accurate because there is inconsistency in digipeater behavior.
* The base AX.25 spec seems clear in this regard. The used digipeaters should
* should accurately reflict the path taken by the packet. Sometimes we see excess
* stuff in there. Even when you understand what is going on, it is still an ambiguous
* situation. Look for my rant in the User Guide.
*/
hops = ax25_get_heard(pp) - AX25_SOURCE;
mptr = mheard_ptr(source);
if (mptr == NULL) {
int i;
/*
* Not heard before. Add it.
*/
if (mheard_debug) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("mheard_save_rf: %s %d - added new\n", source, hops);
}
mptr = calloc(sizeof(mheard_t),1);
strlcpy (mptr->callsign, source, sizeof(mptr->callsign));
mptr->count = 1;
mptr->chan = chan;
mptr->num_digi_hops = hops;
mptr->last_heard_rf = now;
mptr->dlat = G_UNKNOWN;
mptr->dlon = G_UNKNOWN;
i = hash_index(source);
dw_mutex_lock (&mheard_mutex);
mptr->pnext = mheard_hash[i]; // before inserting into list.
mheard_hash[i] = mptr;
dw_mutex_unlock (&mheard_mutex);
}
else {
/*
* Update existing entry.
* The only tricky part here is that we might hear the same transmission
* several times. First direct, then thru various digipeater paths.
* We are interested in the shortest path if heard very recently.
*/
if (hops > mptr->num_digi_hops && (int)(now - mptr->last_heard_rf) < 15) {
if (mheard_debug) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("mheard_save_rf: %s %d - skip because hops was %d %d seconds ago.\n", source, hops, mptr->num_digi_hops, (int)(now - mptr->last_heard_rf) );
}
}
else {
if (mheard_debug) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("mheard_save_rf: %s %d - update time, was %d hops %d seconds ago.\n", source, hops, mptr->num_digi_hops, (int)(now - mptr->last_heard_rf));
}
mptr->count++;
mptr->chan = chan;
mptr->num_digi_hops = hops;
mptr->last_heard_rf = now;
}
}
if (A->g_lat != G_UNKNOWN && A->g_lon != G_UNKNOWN) {
mptr->dlat = A->g_lat;
mptr->dlon = A->g_lon;
}
if (mheard_debug >= 2) {
int limit = 10; // normally 30 or 60. more frequent when debugging.
text_color_set(DW_COLOR_DEBUG);
dw_printf ("mheard debug, %d min, DIR_CNT=%d,LOC_CNT=%d,RF_CNT=%d\n", limit, mheard_count(0,limit), mheard_count(2,limit), mheard_count(8,limit));
}
if (mheard_debug) {
mheard_dump ();
}
} /* end mheard_save_rf */
/*------------------------------------------------------------------
*
* Function: mheard_save_is
*
* Purpose: Save information about station heard via Internet Server.
*
* Inputs: ptext - Packet in monitoring text form as sent by the Internet server.
*
* Any trailing CRLF should have been removed.
* Typical examples:
*
* KA1BTK-5>APDR13,TCPIP*,qAC,T2IRELAND:=4237.62N/07040.68W$/A=-00054 http://aprsdroid.org/
* N1HKO-10>APJI40,TCPIP*,qAC,N1HKO-JS:<IGATE,MSG_CNT=0,LOC_CNT=0
* K1RI-2>APWW10,WIDE1-1,WIDE2-1,qAS,K1RI:/221700h/9AmA<Ct3_ sT010/002g005t045r000p023P020h97b10148
* KC1BOS-2>T3PQ3S,WIDE1-1,WIDE2-1,qAR,W1TG-1:`c)@qh\>/"50}TinyTrak4 Mobile
*
* Notice how the final address in the header might not
* be a valid AX.25 address. We see a 9 character address
* (with no ssid) and an ssid of two letters.
*
* The "q construct" ( http://www.aprs-is.net/q.aspx ) provides
* a clue about the journey taken but I don't think we care here.
*
* All we should care about here is the the source address.
*
* Description:
*
*------------------------------------------------------------------*/
void mheard_save_is (char *ptext)
{
packet_t pp;
time_t now = time(NULL);
char source[AX25_MAX_ADDR_LEN];
mheard_t *mptr;
/*
* Try to parse it into a packet object.
* This will contain "q constructs" and we might see an address
* with two alphnumeric characters in the SSID so we must use
* the non-strict parsing.
*
* Bug: Up to 8 digipeaters are allowed in radio format.
* There is a potential of finding a larger number here.
*/
pp = ax25_from_text(ptext, 0);
if (pp == NULL) {
if (mheard_debug) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("mheard_save_is: Could not parse message from server.\n");
dw_printf ("%s\n", ptext);
}
return;
}
ax25_get_addr_with_ssid (pp, AX25_SOURCE, source);
mptr = mheard_ptr(source);
if (mptr == NULL) {
int i;
/*
* Not heard before. Add it.
*/
if (mheard_debug) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("mheard_save_is: %s - added new\n", source);
}
mptr = calloc(sizeof(mheard_t),1);
strlcpy (mptr->callsign, source, sizeof(mptr->callsign));
mptr->count = 1;
mptr->last_heard_is = now;
mptr->dlat = G_UNKNOWN;
mptr->dlon = G_UNKNOWN;
i = hash_index(source);
dw_mutex_lock (&mheard_mutex);
mptr->pnext = mheard_hash[i]; // before inserting into list.
mheard_hash[i] = mptr;
dw_mutex_unlock (&mheard_mutex);
}
else {
/* Already there. UPdate last heard from IS time. */
if (mheard_debug) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("mheard_save_is: %s - update time, was %d seconds ago.\n", source, (int)(now - mptr->last_heard_rf));
}
mptr->count++;
mptr->last_heard_is = now;
}
// Is is desirable to save any location in this case?
// I don't think it would help.
// The whole purpose of keeping the location is for message sending filter.
// We wouldn't want to try sending a message to the station if we didn't hear it over the radio.
// On the other hand, I don't think it would hurt.
// The filter always includes a time since last heard over the radi.
if (mheard_debug >= 2) {
int limit = 10; // normally 30 or 60
text_color_set(DW_COLOR_DEBUG);
dw_printf ("mheard debug, %d min, DIR_CNT=%d,LOC_CNT=%d,RF_CNT=%d\n", limit, mheard_count(0,limit), mheard_count(2,limit), mheard_count(8,limit));
}
if (mheard_debug) {
mheard_dump ();
}
ax25_delete (pp);
} /* end mheard_save_is */
/*------------------------------------------------------------------
*
* Function: mheard_count
*
* Purpose: Count local stations for IGate statistics report like this:
*
* <IGATE,MSG_CNT=1,LOC_CNT=25
*
* Inputs: max_hops - Include only stations heard with this number of
* digipeater hops or less. For reporting, we might use:
*
* 0 for DIR_CNT (heard directly)
* IGate transmit path for LOC_CNT.
* e.g. 3 for WIDE1-1,WIDE2-2
* 8 for RF_CNT.
*
* time_limit - Include only stations heard within this many minutes.
* Typically 30 or 60.
*
* Returns: Number to be used in the statistics report.
*
* Description: Look for discussion here: http://www.tapr.org/pipermail/aprssig/2016-June/045837.html
*
* Lynn KJ4ERJ:
*
* For APRSISCE/32, "Local" is defined as those stations to which messages
* would be gated if any are received from the APRS-IS. This currently
* means unique stations heard within the past 30 minutes with at most two
* used path hops.
*
* I added DIR_CNT and RF_CNT with comma delimiters to APRSISCE/32's IGate
* status. DIR_CNT is the count of unique stations received on RF in the
* past 30 minutes with no used hops. RF_CNT is the total count of unique
* stations received on RF in the past 30 minutes.
*
* Steve K4HG:
*
* The number of hops defining local should match the number of hops of the
* outgoing packets from the IGate. So if the path is only WIDE, then local
* should only be stations heard direct or through one hop. From the beginning
* I was very much against on a standardization of the outgoing IGate path,
* hams should be free to manage their local RF network in a way that works
* for them. Busy areas one hop may be best, I lived in an area where three was
* a much better choice. I avoided as much as possible prescribing anything
* that might change between locations.
*
* The intent was how many stations are there for which messages could be IGated.
* IGate software keeps an internal list of the 'local' stations so it knows
* when to IGate a message, and this number should be the length of that list.
* Some IGates have a parameter for local timeout, 1 hour was the original default,
* so if in an hour the IGate has not heard another local packet the station is
* dropped from the local list. Messages will no longer be IGated to that station
* and the station count would drop by one. The number should not just continue to rise.
*
*
*------------------------------------------------------------------*/
int mheard_count (int max_hops, int time_limit)
{
time_t since = time(NULL) - time_limit * 60;
int count = 0;
int i;
mheard_t *p;
for (i = 0; i < MHEARD_HASH_SIZE; i++) {
for (p = mheard_hash[i]; p != NULL; p = p->pnext) {
if (p->last_heard_rf >= since && p->num_digi_hops <= max_hops) {
count++;
}
}
}
if (mheard_debug == 1) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("mheard_count(<= %d digi hops, last %d minutes) returns %d\n", max_hops, time_limit, count);
}
return (count);
} /* end mheard_count */
/*------------------------------------------------------------------
*
* Function: mheard_was_recently_nearby
*
* Purpose: Determine whether given station was heard recently on the radio.
*
* Inputs: role - "addressee" or "source" if debug out is desired.
* Otherwise empty string.
*
* callsign - Callsign for station.
*
* time_limit - Include only stations heard within this many minutes.
* Typically 30 or 60.
*
* max_hops - Include only stations heard with this number of
* digipeater hops or less. For reporting, we might use:
*
* dlat, dlon, km - Include only stations within distance of location.
* Not used if G_UNKNOWN is supplied.
*
* Returns: 1 for true, 0 for false.
*
*------------------------------------------------------------------*/
int mheard_was_recently_nearby (char *role, char *callsign, int time_limit, int max_hops, double dlat, double dlon, double km)
{
mheard_t *mptr;
time_t now;
int heard_ago;
if (role != NULL && strlen(role) > 0) {
text_color_set(DW_COLOR_INFO);
if (dlat != G_UNKNOWN && dlon != G_UNKNOWN && km != G_UNKNOWN) {
dw_printf ("Was message %s %s heard in the past %d minutes, with %d or fewer digipeater hops, and within %.1f km of %.2f %.2f?\n", role, callsign, time_limit, max_hops, km, dlat, dlon);
}
else {
dw_printf ("Was message %s %s heard in the past %d minutes, with %d or fewer digipeater hops?\n", role, callsign, time_limit, max_hops);
}
}
mptr = mheard_ptr(callsign);
if (mptr == NULL || mptr->last_heard_rf == 0) {
if (role != NULL && strlen(role) > 0) {
text_color_set(DW_COLOR_INFO);
dw_printf ("No, we have not heard %s over the radio.\n", callsign);
}
return (0);
}
now = time(NULL);
heard_ago = (int)(now - mptr->last_heard_rf) / 60;
if (heard_ago > time_limit) {
if (role != NULL && strlen(role) > 0) {
text_color_set(DW_COLOR_INFO);
dw_printf ("No, %s was last heard over the radio %d minutes ago with %d digipeater hops.\n", callsign, heard_ago, mptr->num_digi_hops);
}
return (0);
}
if (mptr->num_digi_hops > max_hops) {
if (role != NULL && strlen(role) > 0) {
text_color_set(DW_COLOR_INFO);
dw_printf ("No, %s was last heard over the radio with %d digipeater hops %d minutes ago.\n", callsign, mptr->num_digi_hops, heard_ago);
}
return (0);
}
// Apply physical distance check?
if (dlat != G_UNKNOWN && dlon != G_UNKNOWN && km != G_UNKNOWN && mptr->dlat != G_UNKNOWN && mptr->dlon != G_UNKNOWN) {
double dist = ll_distance_km (mptr->dlat, mptr->dlon, dlat, dlon);
if (dist > km) {
if (role != NULL && strlen(role) > 0) {
text_color_set(DW_COLOR_INFO);
dw_printf ("No, %s was %.1f km away although it was %d digipeater hops %d minutes ago.\n", callsign, dist, mptr->num_digi_hops, heard_ago);
}
return (0);
}
else {
if (role != NULL && strlen(role) > 0) {
text_color_set(DW_COLOR_INFO);
dw_printf ("Yes, %s last heard over radio %d minutes ago, %d digipeater hops. Last location %.1f km away.\n", callsign, heard_ago, mptr->num_digi_hops, dist);
}
return (1);
}
}
// Passed all the tests.
if (role != NULL && strlen(role) > 0) {
text_color_set(DW_COLOR_INFO);
dw_printf ("Yes, %s last heard over radio %d minutes ago, %d digipeater hops.\n", callsign, heard_ago, mptr->num_digi_hops);
}
return (1);
} /* end mheard_was_recently_nearby */
/*------------------------------------------------------------------
*
* Function: mheard_set_msp
*
* Purpose: Set the "message sender position" count for specified station.
*
* Inputs: callsign - Callsign for station which sent the "message."
*
* num - Number of position reports to allow. Typically 1.
*
*------------------------------------------------------------------*/
void mheard_set_msp (char *callsign, int num)
{
mheard_t *mptr;
mptr = mheard_ptr(callsign);
if (mptr != NULL) {
mptr->msp = num;
if (mheard_debug) {
text_color_set(DW_COLOR_INFO);
dw_printf ("MSP for %s set to %d\n", callsign, num);
}
}
else {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error: Can't find %s to set MSP.\n", callsign);
}
} /* end mheard_set_msp */
/*------------------------------------------------------------------
*
* Function: mheard_get_msp
*
* Purpose: Get the "message sender position" count for specified station.
*
* Inputs: callsign - Callsign for station which sent the "message."
*
* Returns: The cound for the specified station.
* 0 if not found.
*
*------------------------------------------------------------------*/
int mheard_get_msp (char *callsign)
{
mheard_t *mptr;
mptr = mheard_ptr(callsign);
if (mptr != NULL) {
if (mheard_debug) {
text_color_set(DW_COLOR_INFO);
dw_printf ("MSP for %s is %d\n", callsign, mptr->msp);
}
return (mptr->msp); // Should we have a time limit?
}
return (0);
} /* end mheard_get_msp */
/* end mheard.c */