//
// This file is part of Dire Wolf, an amateur radio packet TNC.
//
// Copyright (C) 2013, 2014, 2015, 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/>.
//
/*------------------------------------------------------------------
*
* Module: igate.c
*
* Purpose: IGate client.
*
* Description: Establish connection with a tier 2 IGate server
* and relay packets between RF and Internet.
*
* References: APRS-IS (Automatic Packet Reporting System-Internet Service)
* http://www.aprs-is.net/Default.aspx
*
* APRS iGate properties
* http://wiki.ham.fi/APRS_iGate_properties
*
* Notes to iGate developers
* https://github.com/hessu/aprsc/blob/master/doc/IGATE-HINTS.md#igates-dropping-duplicate-packets-unnecessarily
*
* SATgate mode.
* http://www.tapr.org/pipermail/aprssig/2016-January/045283.html
*
*---------------------------------------------------------------*/
/*------------------------------------------------------------------
*
* From http://windows.microsoft.com/en-us/windows7/ipv6-frequently-asked-questions
*
* How can I enable IPv6?
* Follow these steps:
*
* Open Network Connections by clicking the Start button, and then clicking
* Control Panel. In the search box, type adapter, and then, under Network
* and Sharing Center, click View network connections.
*
* Right-click your network connection, and then click Properties.
* If you're prompted for an administrator password or confirmation, type
* the password or provide confirmation.
*
* Select the check box next to Internet Protocol Version 6 (TCP/IPv6).
*
*---------------------------------------------------------------*/
/*
* Native Windows: Use the Winsock interface.
* Linux: Use the BSD socket interface.
* Cygwin: Can use either one.
*/
#include "direwolf.h" // Sets _WIN32_WINNT for XP API level needed by ws2tcpip.h
#if __WIN32__
/* The goal is to support Windows XP and later. */
#include <winsock2.h>
#include <ws2tcpip.h> // _WIN32_WINNT must be set to 0x0501 before including this
#else
#include <stdlib.h>
#include <netdb.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#endif
#include <unistd.h>
#include <stdio.h>
#include <assert.h>
#include <string.h>
#include <time.h>
#include "direwolf.h"
#include "ax25_pad.h"
#include "textcolor.h"
#include "version.h"
#include "digipeater.h"
#include "tq.h"
#include "igate.h"
#include "latlong.h"
#include "pfilter.h"
#include "dtime_now.h"
#include "mheard.h"
#if __WIN32__
static unsigned __stdcall connnect_thread (void *arg);
static unsigned __stdcall igate_recv_thread (void *arg);
static unsigned __stdcall satgate_delay_thread (void *arg);
#else
static void * connnect_thread (void *arg);
static void * igate_recv_thread (void *arg);
static void * satgate_delay_thread (void *arg);
#endif
static dw_mutex_t dp_mutex; /* Critical section for delayed packet queue. */
static packet_t dp_queue_head;
static void satgate_delay_packet (packet_t pp, int chan);
static void send_packet_to_server (packet_t pp, int chan);
static void send_msg_to_server (const char *msg, int msg_len);
static void maybe_xmit_packet_from_igate (char *message, int chan);
static void rx_to_ig_init (void);
static void rx_to_ig_remember (packet_t pp);
static int rx_to_ig_allow (packet_t pp);
static void ig_to_tx_init (void);
static int ig_to_tx_allow (packet_t pp, int chan);
/*
* File descriptor for socket to IGate server.
* Set to -1 if not connected.
* (Don't use SOCKET type because it is unsigned.)
*/
static volatile int igate_sock = -1;
/*
* After connecting to server, we want to make sure
* that the login sequence is sent first.
* This is set to true after the login is complete.
*/
static volatile int ok_to_send = 0;
/*
* Convert Internet address to text.
* Can't use InetNtop because it is supported only on Windows Vista and later.
*/
static char * ia_to_text (int Family, void * pAddr, char * pStringBuf, size_t StringBufSize)
{
struct sockaddr_in *sa4;
struct sockaddr_in6 *sa6;
switch (Family) {
case AF_INET:
sa4 = (struct sockaddr_in *)pAddr;
#if __WIN32__
snprintf (pStringBuf, StringBufSize, "%d.%d.%d.%d", sa4->sin_addr.S_un.S_un_b.s_b1,
sa4->sin_addr.S_un.S_un_b.s_b2,
sa4->sin_addr.S_un.S_un_b.s_b3,
sa4->sin_addr.S_un.S_un_b.s_b4);
#else
inet_ntop (AF_INET, &(sa4->sin_addr), pStringBuf, StringBufSize);
#endif
break;
case AF_INET6:
sa6 = (struct sockaddr_in6 *)pAddr;
#if __WIN32__
snprintf (pStringBuf, StringBufSize, "%x:%x:%x:%x:%x:%x:%x:%x",
ntohs(((unsigned short *)(&(sa6->sin6_addr)))[0]),
ntohs(((unsigned short *)(&(sa6->sin6_addr)))[1]),
ntohs(((unsigned short *)(&(sa6->sin6_addr)))[2]),
ntohs(((unsigned short *)(&(sa6->sin6_addr)))[3]),
ntohs(((unsigned short *)(&(sa6->sin6_addr)))[4]),
ntohs(((unsigned short *)(&(sa6->sin6_addr)))[5]),
ntohs(((unsigned short *)(&(sa6->sin6_addr)))[6]),
ntohs(((unsigned short *)(&(sa6->sin6_addr)))[7]));
#else
inet_ntop (AF_INET6, &(sa6->sin6_addr), pStringBuf, StringBufSize);
#endif
break;
default:
snprintf (pStringBuf, StringBufSize, "Invalid address family!");
}
//assert (strlen(pStringBuf) < StringBufSize);
return pStringBuf;
}
#if ITEST
/* For unit testing. */
int main (int argc, char *argv[])
{
struct audio_s audio_config;
struct igate_config_s igate_config;
struct digi_config_s digi_config;
packet_t pp;
memset (&audio_config, 0, sizeof(audio_config));
audio_config.adev[0].num_chans = 2;
strlcpy (audio_config.achan[0].mycall, "WB2OSZ-1", sizeof(audio_config.achan[0].mycall));
strlcpy (audio_config.achan[1].mycall, "WB2OSZ-2", sizeof(audio_config.achan[0].mycall));
memset (&igate_config, 0, sizeof(igate_config));
strlcpy (igate_config.t2_server_name, "localhost", sizeof(igate_config.t2_server_name));
igate_config.t2_server_port = 14580;
strlcpy (igate_config.t2_login, "WB2OSZ-JL", sizeof(igate_config.t2_login));
strlcpy (igate_config.t2_passcode, "-1", sizeof(igate_config.t2_passcode));
igate_config.t2_filter = strdup ("r/1/2/3");
igate_config.tx_chan = 0;
strlcpy (igate_config.tx_via, ",WIDE2-1", sizeof(igate_config.tx_via));
igate_config.tx_limit_1 = 3;
igate_config.tx_limit_5 = 5;
memset (&digi_config, 0, sizeof(digi_config));
igate_init(&igate_config, &digi_config);
while (igate_sock == -1) {
SLEEP_SEC(1);
}
SLEEP_SEC (2);
pp = ax25_from_text ("A>B,C,D:Ztest message 1", 0);
igate_send_rec_packet (0, pp);
ax25_delete (pp);
SLEEP_SEC (2);
pp = ax25_from_text ("A>B,C,D:Ztest message 2", 0);
igate_send_rec_packet (0, pp);
ax25_delete (pp);
SLEEP_SEC (2);
pp = ax25_from_text ("A>B,C,D:Ztest message 2", 0); /* Should suppress duplicate. */
igate_send_rec_packet (0, pp);
ax25_delete (pp);
SLEEP_SEC (2);
pp = ax25_from_text ("A>B,TCPIP,D:ZShould drop this due to path", 0);
igate_send_rec_packet (0, pp);
ax25_delete (pp);
SLEEP_SEC (2);
pp = ax25_from_text ("A>B,C,D:?Should drop query", 0);
igate_send_rec_packet (0, pp);
ax25_delete (pp);
SLEEP_SEC (5);
pp = ax25_from_text ("A>B,C,D:}E>F,G*,H:Zthird party stuff", 0);
igate_send_rec_packet (0, pp);
ax25_delete (pp);
#if 1
while (1) {
SLEEP_SEC (20);
text_color_set(DW_COLOR_INFO);
dw_printf ("Send received packet\n");
send_msg_to_server ("W1ABC>APRS:?", strlen("W1ABC>APRS:?");
}
#endif
return 0;
}
#endif
/*
* Global stuff (to this file)
*
* These are set by init function and need to
* be kept around in case connection is lost and
* we need to reestablish the connection later.
*/
static struct audio_s *save_audio_config_p;
static struct igate_config_s *save_igate_config_p;
static struct digi_config_s *save_digi_config_p;
static int s_debug;
/*
* Statistics for IGate function.
* Note that the RF related counters are just a subset of what is happening on radio channels.
*
* TODO: should have debug option to print these occasionally.
*/
static int stats_failed_connect; /* Number of times we tried to connect to */
/* a server and failed. A small number is not */
/* a bad thing. Each name should have a bunch */
/* of addresses for load balancing and */
/* redundancy. */
static int stats_connects; /* Number of successful connects to a server. */
/* Normally you'd expect this to be 1. */
/* Could be larger if one disappears and we */
/* try again to find a different one. */
static time_t stats_connect_at; /* Most recent time connection was established. */
/* can be used to determine elapsed connect time. */
static int stats_rf_recv_packets; /* Number of candidate packets from the radio. */
/* This is not the total number of AX.25 frames received */
/* over the radio; only APRS packets get this far. */
static int stats_uplink_packets; /* Number of packets passed along to the IGate */
/* server after filtering. */
static int stats_uplink_bytes; /* Total number of bytes sent to IGate server */
/* including login, packets, and hearbeats. */
static int stats_downlink_bytes; /* Total number of bytes from IGate server including */
/* packets, heartbeats, other messages. */
static int stats_downlink_packets; /* Number of packets from IGate server for possible transmission. */
/* Fewer might be transmitted due to filtering or rate limiting. */
static int stats_rf_xmit_packets; /* Number of packets passed along to radio, for the IGate function, */
/* after filtering, rate limiting, or other restrictions. */
/* Number of packets transmitted for beacons, digipeating, */
/* or client applications are not included here. */
static int stats_msg_cnt; /* Number of "messages" transmitted. Subset of above. */
/* A "message" has the data type indicator of ":" and it is */
/* not the special case of telemetry metadata. */
/*
* Make some of these available for IGate statistics beacon like
*
* WB2OSZ>APDW14,WIDE1-1:<IGATE,MSG_CNT=2,PKT_CNT=0,DIR_CNT=10,LOC_CNT=35,RF_CNT=45
*
* MSG_CNT is only "messages." From original spec.
* PKT_CNT is other (non-message) packets. Followed precedent of APRSISCE32.
*/
int igate_get_msg_cnt (void) {
return (stats_msg_cnt);
}
int igate_get_pkt_cnt (void) {
return (stats_rf_xmit_packets - stats_msg_cnt);
}
int igate_get_upl_cnt (void) {
return (stats_uplink_packets);
}
int igate_get_dnl_cnt (void) {
return (stats_downlink_packets);
}
/*-------------------------------------------------------------------
*
* Name: igate_init
*
* Purpose: One time initialization when main application starts up.
*
* Inputs: p_audio_config - Audio channel configuration. All we care about is:
* - Number of radio channels.
* - Radio call and SSID for each channel.
*
* p_igate_config - IGate configuration.
*
* p_digi_config - Digipeater configuration.
* All we care about here is the packet filtering options.
*
* debug_level - 0 print packets FROM APRS-IS,
* establishing connection with sergver, and
* and anything rejected by client side filtering.
* 1 plus packets sent TO server or why not.
* 2 plus duplicate detection overview.
* 3 plus duplicate detection details.
*
* Description: This starts two threads:
*
* * to establish and maintain a connection to the server.
* * to listen for packets from the server.
*
*--------------------------------------------------------------------*/
void igate_init (struct audio_s *p_audio_config, struct igate_config_s *p_igate_config, struct digi_config_s *p_digi_config, int debug_level)
{
#if __WIN32__
HANDLE connnect_th;
HANDLE cmd_recv_th;
HANDLE satgate_delay_th;
#else
pthread_t connect_listen_tid;
pthread_t cmd_listen_tid;
pthread_t satgate_delay_tid;
int e;
#endif
s_debug = debug_level;
dp_queue_head = NULL;
#if DEBUGx
text_color_set(DW_COLOR_DEBUG);
dw_printf ("igate_init ( %s, %d, %s, %s, %s )\n",
p_igate_config->t2_server_name,
p_igate_config->t2_server_port,
p_igate_config->t2_login,
p_igate_config->t2_passcode,
p_igate_config->t2_filter);
#endif
/*
* Save the arguments for later use.
*/
save_audio_config_p = p_audio_config;
save_igate_config_p = p_igate_config;
save_digi_config_p = p_digi_config;
stats_failed_connect = 0;
stats_connects = 0;
stats_connect_at = 0;
stats_rf_recv_packets = 0;
stats_uplink_packets = 0;
stats_uplink_bytes = 0;
stats_downlink_bytes = 0;
stats_downlink_packets = 0;
stats_rf_xmit_packets = 0;
stats_msg_cnt = 0;
rx_to_ig_init ();
ig_to_tx_init ();
/*
* Continue only if we have server name, login, and passcode.
*/
if (strlen(p_igate_config->t2_server_name) == 0 ||
strlen(p_igate_config->t2_login) == 0 ||
strlen(p_igate_config->t2_passcode) == 0) {
return;
}
/*
* This connects to the server and sets igate_sock.
* It also sends periodic messages to say I'm still alive.
*/
#if __WIN32__
connnect_th = (HANDLE)_beginthreadex (NULL, 0, connnect_thread, (void *)NULL, 0, NULL);
if (connnect_th == NULL) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error: Could not create IGate connection thread\n");
return;
}
#else
e = pthread_create (&connect_listen_tid, NULL, connnect_thread, (void *)NULL);
if (e != 0) {
text_color_set(DW_COLOR_ERROR);
perror("Internal error: Could not create IGate connection thread");
return;
}
#endif
/*
* This reads messages from client when igate_sock is valid.
*/
#if __WIN32__
cmd_recv_th = (HANDLE)_beginthreadex (NULL, 0, igate_recv_thread, NULL, 0, NULL);
if (cmd_recv_th == NULL) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error: Could not create IGate reading thread\n");
return;
}
#else
e = pthread_create (&cmd_listen_tid, NULL, igate_recv_thread, NULL);
if (e != 0) {
text_color_set(DW_COLOR_ERROR);
perror("Internal error: Could not create IGate reading thread");
return;
}
#endif
/*
* This lets delayed packets continue after specified amount of time.
*/
if (p_igate_config->satgate_delay > 0) {
#if __WIN32__
satgate_delay_th = (HANDLE)_beginthreadex (NULL, 0, satgate_delay_thread, NULL, 0, NULL);
if (satgate_delay_th == NULL) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error: Could not create SATgate delay thread\n");
return;
}
#else
e = pthread_create (&satgate_delay_tid, NULL, satgate_delay_thread, NULL);
if (e != 0) {
text_color_set(DW_COLOR_ERROR);
perror("Internal error: Could not create SATgate delay thread");
return;
}
#endif
dw_mutex_init(&dp_mutex);
}
} /* end igate_init */
/*-------------------------------------------------------------------
*
* Name: connnect_thread
*
* Purpose: Establish connection with IGate server.
* Send periodic heartbeat to keep keep connection active.
* Reconnect if something goes wrong and we got disconnected.
*
* Inputs: arg - Not used.
*
* Outputs: igate_sock - File descriptor for communicating with client app.
* Will be -1 if not connected.
*
* References: TCP client example.
* http://msdn.microsoft.com/en-us/library/windows/desktop/ms737591(v=vs.85).aspx
*
* Linux IPv6 HOWTO
* http://www.tldp.org/HOWTO/Linux+IPv6-HOWTO/
*
*--------------------------------------------------------------------*/
/*
* Addresses don't get mixed up very well.
* IPv6 always shows up last so we'd probably never
* end up using any of them. Use our own shuffle.
*/
static void shuffle (struct addrinfo *host[], int nhosts)
{
int j, k;
assert (RAND_MAX >= nhosts); /* for % to work right */
if (nhosts < 2) return;
srand (time(NULL));
for (j=0; j<nhosts; j++) {
k = rand() % nhosts;
assert (k >=0 && k<nhosts);
if (j != k) {
struct addrinfo *temp;
temp = host[j]; host[j] = host[k]; host[k] = temp;
}
}
}
#define MAX_HOSTS 50
#if __WIN32__
static unsigned __stdcall connnect_thread (void *arg)
#else
static void * connnect_thread (void *arg)
#endif
{
struct addrinfo hints;
struct addrinfo *ai_head = NULL;
struct addrinfo *ai;
struct addrinfo *hosts[MAX_HOSTS];
int num_hosts, n;
int err;
char server_port_str[12]; /* text form of port number */
char ipaddr_str[46]; /* text form of IP address */
#if __WIN32__
WSADATA wsadata;
#endif
snprintf (server_port_str, sizeof(server_port_str), "%d", save_igate_config_p->t2_server_port);
#if DEBUGx
text_color_set(DW_COLOR_DEBUG);
dw_printf ("DEBUG: igate connect_thread start, port = %d = '%s'\n", save_igate_config_p->t2_server_port, server_port_str);
#endif
#if __WIN32__
err = WSAStartup (MAKEWORD(2,2), &wsadata);
if (err != 0) {
text_color_set(DW_COLOR_ERROR);
dw_printf("WSAStartup failed: %d\n", err);
return (0);
}
if (LOBYTE(wsadata.wVersion) != 2 || HIBYTE(wsadata.wVersion) != 2) {
text_color_set(DW_COLOR_ERROR);
dw_printf("Could not find a usable version of Winsock.dll\n");
WSACleanup();
//sleep (1);
return (0);
}
#endif
memset (&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC; /* Allow either IPv4 or IPv6. */
// IPv6 is half baked on Windows XP.
// We might need to leave out IPv6 support for Windows version.
// hints.ai_family = AF_INET; /* IPv4 only. */
#if IPV6_ONLY
/* IPv6 addresses always show up at end of list. */
/* Force use of them for testing. */
hints.ai_family = AF_INET6; /* IPv6 only */
#endif
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
/*
* Repeat forever.
*/
while (1) {
/*
* Connect to IGate server if not currently connected.
*/
if (igate_sock == -1) {
SLEEP_SEC (5);
ai_head = NULL;
err = getaddrinfo(save_igate_config_p->t2_server_name, server_port_str, &hints, &ai_head);
if (err != 0) {
text_color_set(DW_COLOR_ERROR);
#if __WIN32__
dw_printf ("Can't get address for IGate server %s, err=%d\n",
save_igate_config_p->t2_server_name, WSAGetLastError());
#else
dw_printf ("Can't get address for IGate server %s, %s\n",
save_igate_config_p->t2_server_name, gai_strerror(err));
#endif
freeaddrinfo(ai_head);
continue;
}
#if DEBUG_DNS
text_color_set(DW_COLOR_DEBUG);
dw_printf ("getaddrinfo returns:\n");
#endif
num_hosts = 0;
for (ai = ai_head; ai != NULL; ai = ai->ai_next) {
#if DEBUG_DNS
text_color_set(DW_COLOR_DEBUG);
ia_to_text (ai->ai_family, ai->ai_addr, ipaddr_str, sizeof(ipaddr_str));
dw_printf (" %s\n", ipaddr_str);
#endif
hosts[num_hosts] = ai;
if (num_hosts < MAX_HOSTS) num_hosts++;
}
// We can get multiple addresses back for the host name.
// These should be somewhat randomized for load balancing.
// It turns out the IPv6 addresses are always at the
// end for both Windows and Linux. We do our own shuffling
// to mix them up better and give IPv6 a chance.
shuffle (hosts, num_hosts);
#if DEBUG_DNS
text_color_set(DW_COLOR_DEBUG);
dw_printf ("after shuffling:\n");
for (n=0; n<num_hosts; n++) {
ia_to_text (hosts[n]->ai_family, hosts[n]->ai_addr, ipaddr_str, sizeof(ipaddr_str));
dw_printf (" %s\n", ipaddr_str);
}
#endif
// Try each address until we find one that is successful.
for (n=0; n<num_hosts; n++) {
#if __WIN32__
SOCKET is;
#else
int is;
#endif
ai = hosts[n];
ia_to_text (ai->ai_family, ai->ai_addr, ipaddr_str, sizeof(ipaddr_str));
is = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
#if __WIN32__
if (is == INVALID_SOCKET) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("IGate: Socket creation failed, err=%d", WSAGetLastError());
WSACleanup();
is = -1;
stats_failed_connect++;
continue;
}
#else
if (err != 0) {
text_color_set(DW_COLOR_INFO);
dw_printf("Connect to IGate server %s (%s) failed.\n\n",
save_igate_config_p->t2_server_name, ipaddr_str);
(void) close (is);
is = -1;
stats_failed_connect++;
continue;
}
#endif
#ifndef DEBUG_DNS
err = connect(is, ai->ai_addr, (int)ai->ai_addrlen);
#if __WIN32__
if (err == SOCKET_ERROR) {
text_color_set(DW_COLOR_INFO);
dw_printf("Connect to IGate server %s (%s) failed.\n\n",
save_igate_config_p->t2_server_name, ipaddr_str);
closesocket (is);
is = -1;
stats_failed_connect++;
continue;
}
// TODO: set TCP_NODELAY?
#else
if (err != 0) {
text_color_set(DW_COLOR_INFO);
dw_printf("Connect to IGate server %s (%s) failed.\n\n",
save_igate_config_p->t2_server_name, ipaddr_str);
(void) close (is);
is = -1;
stats_failed_connect++;
continue;
}
/* IGate documentation says to use it. */
/* Does it really make a difference for this application? */
int flag = 1;
err = setsockopt (is, IPPROTO_TCP, TCP_NODELAY, (void*)(long)(&flag), sizeof(flag));
if (err < 0) {
text_color_set(DW_COLOR_INFO);
dw_printf("setsockopt TCP_NODELAY failed.\n");
}
#endif
stats_connects++;
stats_connect_at = time(NULL);
/* Success. */
text_color_set(DW_COLOR_INFO);
dw_printf("\nNow connected to IGate server %s (%s)\n", save_igate_config_p->t2_server_name, ipaddr_str );
if (strchr(ipaddr_str, ':') != NULL) {
dw_printf("Check server status here http://[%s]:14501\n\n", ipaddr_str);
}
else {
dw_printf("Check server status here http://%s:14501\n\n", ipaddr_str);
}
/*
* Set igate_sock so everyone else can start using it.
* But make the Rx -> Internet messages wait until after login.
*/
ok_to_send = 0;
igate_sock = is;
#endif
break;
}
freeaddrinfo(ai_head);
if (igate_sock != -1) {
char stemp[256];
/*
* Send login message.
* Software name and version must not contain spaces.
*/
SLEEP_SEC(3);
snprintf (stemp, sizeof(stemp), "user %s pass %s vers Dire-Wolf %d.%d",
save_igate_config_p->t2_login, save_igate_config_p->t2_passcode,
MAJOR_VERSION, MINOR_VERSION);
if (save_igate_config_p->t2_filter != NULL) {
strlcat (stemp, " filter ", sizeof(stemp));
strlcat (stemp, save_igate_config_p->t2_filter, sizeof(stemp));
}
send_msg_to_server (stemp, strlen(stemp));
/* Delay until it is ok to start sending packets. */
SLEEP_SEC(7);
ok_to_send = 1;
}
}
/*
* If connected to IGate server, send heartbeat periodically to keep connection active.
*/
if (igate_sock != -1) {
SLEEP_SEC(10);
}
if (igate_sock != -1) {
SLEEP_SEC(10);
}
if (igate_sock != -1) {
SLEEP_SEC(10);
}
if (igate_sock != -1) {
char heartbeat[10];
strlcpy (heartbeat, "#", sizeof(heartbeat));
/* This will close the socket if any error. */
send_msg_to_server (heartbeat, strlen(heartbeat));
}
}
exit(0); // Unreachable but stops compiler from complaining
// about function not returning a value.
} /* end connnect_thread */
/*-------------------------------------------------------------------
*
* Name: igate_send_rec_packet
*
* Purpose: Send a packet to the IGate server
*
* Inputs: chan - Radio channel it was received on.
*
* recv_pp - Pointer to packet object.
* *** CALLER IS RESPONSIBLE FOR DELETING IT! **
*
*
* Description: Send message to IGate Server if connected.
*
* Assumptions: (1) Caller has already verified it is an APRS packet.
* i.e. control = 3 for UI frame, protocol id = 0xf0 for no layer 3
*
* (2) This is being called only for packets received with
* a correct CRC. We don't want to propagate corrupted data.
*
*--------------------------------------------------------------------*/
#define IGATE_MAX_MSG 512 /* "All 'packets' sent to APRS-IS must be in the TNC2 format terminated */
/* by a carriage return, line feed sequence. No line may exceed 512 bytes */
/* including the CR/LF sequence." */
void igate_send_rec_packet (int chan, packet_t recv_pp)
{
packet_t pp;
int n;
unsigned char *pinfo;
int info_len;
if (igate_sock == -1) {
return; /* Silently discard if not connected. */
}
if ( ! ok_to_send) {
return; /* Login not complete. */
}
/* Gather statistics. */
stats_rf_recv_packets++;
/*
* Check for filtering from specified channel to the IGate server.
*
* Should we do this after unwrapping the payload from a third party packet?
* In my experience, third party packets have only been seen coming from IGates.
* In that case, the payload will have TCPIP in the path and it will be dropped.
*/
if (save_digi_config_p->filter_str[chan][MAX_CHANS] != NULL) {
if (pfilter(chan, MAX_CHANS, save_digi_config_p->filter_str[chan][MAX_CHANS], recv_pp, 1) != 1) {
// Is this useful troubleshooting information or just distracting noise?
// Originally this was always printed but there was a request to add a "quiet" option to suppress this.
// version 1.4: Instead, make the default off and activate it only with the debug igate option.
if (s_debug >= 1) {
text_color_set(DW_COLOR_INFO);
dw_printf ("Packet from channel %d to IGate was rejected by filter: %s\n", chan, save_digi_config_p->filter_str[chan][MAX_CHANS]);
}
return;
}
}
/*
* First make a copy of it because it might be modified in place.
*/
pp = ax25_dup (recv_pp);
assert (pp != NULL);
/*
* Third party frames require special handling to unwrap payload.
*/
while (ax25_get_dti(pp) == '}') {
packet_t inner_pp;
for (n = 0; n < ax25_get_num_repeaters(pp); n++) {
char via[AX25_MAX_ADDR_LEN]; /* includes ssid. Do we want to ignore it? */
ax25_get_addr_with_ssid (pp, n + AX25_REPEATER_1, via);
if (strcmp(via, "TCPIP") == 0 ||
strcmp(via, "TCPXX") == 0 ||
strcmp(via, "RFONLY") == 0 ||
strcmp(via, "NOGATE") == 0) {
if (s_debug >= 1) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("Rx IGate: Do not relay with %s in path.\n", via);
}
ax25_delete (pp);
return;
}
}
if (s_debug >= 1) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("Rx IGate: Unwrap third party message.\n");
}
inner_pp = ax25_unwrap_third_party(pp);
if (inner_pp == NULL) {
ax25_delete (pp);
return;
}
ax25_delete (pp);
pp = inner_pp;
}
/*
* Do not relay packets with TCPIP, TCPXX, RFONLY, or NOGATE in the via path.
*/
for (n = 0; n < ax25_get_num_repeaters(pp); n++) {
char via[AX25_MAX_ADDR_LEN]; /* includes ssid. Do we want to ignore it? */
ax25_get_addr_with_ssid (pp, n + AX25_REPEATER_1, via);
if (strcmp(via, "TCPIP") == 0 ||
strcmp(via, "TCPXX") == 0 ||
strcmp(via, "RFONLY") == 0 ||
strcmp(via, "NOGATE") == 0) {
if (s_debug >= 1) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("Rx IGate: Do not relay with %s in path.\n", via);
}
ax25_delete (pp);
return;
}
}
/*
* Do not relay generic query.
*/
if (ax25_get_dti(pp) == '?') {
if (s_debug >= 1) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("Rx IGate: Do not relay generic query.\n");
}
ax25_delete (pp);
return;
}
/*
* Cut the information part at the first CR or LF.
* This is required because CR/LF is used as record separator when sending to server.
* Do NOT trim trailing spaces.
* Starting in 1.4 we preserve any nul characters in the information part.
*/
if (ax25_cut_at_crlf (pp) > 0) {
if (s_debug >= 1) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("Rx IGate: Truncated information part at CR.\n");
}
}
info_len = ax25_get_info (pp, &pinfo);
/*
* Someone around here occasionally sends a packet with no information part.
*/
if (info_len == 0) {
if (s_debug >= 1) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("Rx IGate: Information part length is zero.\n");
}
ax25_delete (pp);
return;
}
// TODO: Should we drop raw touch tone data object type generated here?
/*
* If the SATgate mode is enabled, see if it should be delayed.
* The rule is if we hear it directly and it has at least one
* digipeater so there is potential of being re-transmitted.
* (Digis are all unused if we are hearing it directly from source.)
*/
if (save_igate_config_p->satgate_delay > 0 &&
ax25_get_heard(pp) == AX25_SOURCE &&
ax25_get_num_repeaters(pp) > 0) {
satgate_delay_packet (pp, chan);
}
else {
send_packet_to_server (pp, chan);
}
} /* end igate_send_rec_packet */
/*-------------------------------------------------------------------
*
* Name: send_packet_to_server
*
* Purpose: Convert to text and send to the IGate server.
*
* Inputs: pp - Packet object.
*
* chan - Radio channel where it was received.
*
* Description: Duplicate detection is handled here.
* Suppress if same was sent recently.
*
*--------------------------------------------------------------------*/
static void send_packet_to_server (packet_t pp, int chan)
{
unsigned char *pinfo;
int info_len;
char msg[IGATE_MAX_MSG];
info_len = ax25_get_info (pp, &pinfo);
/*
* We will often see the same packet multiple times close together due to digipeating.
* The consensus seems to be that we should just send the first and drop the later duplicates.
* There is some dissent on this issue. http://www.tapr.org/pipermail/aprssig/2016-July/045907.html
* There could be some value to sending them all to provide information about digipeater paths.
* However, the servers should drop all duplicates so we wasting everyone's time but sending duplicates.
* If you feel strongly about this issue, you could remove the following section.
* Currently rx_to_ig_allow only checks for recent duplicates.
*/
if ( ! rx_to_ig_allow(pp)) {
if (s_debug >= 1) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("Rx IGate: Drop duplicate of same packet seen recently.\n");
}
ax25_delete (pp);
return;
}
/*
* Finally, append ",qAR," and my call to the path.
*/
/*
* It seems that the specification has changed recently.
* http://www.tapr.org/pipermail/aprssig/2016-December/046456.html
*
* We can see the history at the Internet Archive Wayback Machine.
*
* http://www.aprs-is.net/Connecting.aspx
* captured Oct 19, 2016:
* ... Only the qAR construct may be generated by a client (IGate) on APRS-IS.
* Captured Dec 1, 2016:
* ... Only the qAR and qAO constructs may be generated by a client (IGate) on APRS-IS.
*
* http://www.aprs-is.net/q.aspx
* Captured April 23, 2016:
* (no mention of client generating qAO.)
* Captured July 19, 2016:
* qAO - (letter O) Packet is placed on APRS-IS by a receive-only IGate from RF.
* The callSSID following the qAO is the callSSID of the IGate. Note that receive-only
* IGates are discouraged on standard APRS frequencies. Please consider a bidirectional
* IGate that only gates to RF messages for stations heard directly.
*/
ax25_format_addrs (pp, msg);
msg[strlen(msg)-1] = '\0'; /* Remove trailing ":" */
if (save_igate_config_p->tx_chan >= 0) {
strlcat (msg, ",qAR,", sizeof(msg));
}
else {
strlcat (msg, ",qAO,", sizeof(msg)); // new for version 1.4.
}
strlcat (msg, save_audio_config_p->achan[chan].mycall, sizeof(msg));
strlcat (msg, ":", sizeof(msg));
// It was reported that APRS packets, containing a nul byte in the information part,
// are being truncated. https://github.com/wb2osz/direwolf/issues/84
//
// One might argue that the packets are invalid and the proper behavior would be
// to simply discard them, the same way we do if the CRC is bad. One might argue
// that we should simply pass along whatever we receive even if we don't like it.
// We really shouldn't modify it and make the situation even worse.
//
// Chapter 5 of the APRS spec ( http://www.aprs.org/doc/APRS101.PDF ) says:
//
// "The comment may contain any printable ASCII characters (except | and ~,
// which are reserved for TNC channel switching)."
//
// "Printable" would exclude character values less than space (00100000), e.g.
// tab, carriage return, line feed, nul. Sometimes we see carriage return
// (00001010) at the end of APRS packets. This would be in violation of the
// specification.
//
// The MIC-E position format can have non printable characters (0x1c ... 0x1f, 0x7f)
// in the information part. An unfortunate decision, but it is not in the comment part.
//
// The base 91 telemetry format (http://he.fi/doc/aprs-base91-comment-telemetry.txt ),
// which is not part of the APRS spec, uses the | character in the comment to delimit encoded
// telemetry data. This would be in violation of the original spec. No one cares.
//
// The APRS Spec Addendum 1.2 Proposals ( http://www.aprs.org/aprs12/datum.txt)
// adds use of UTF-8 (https://en.wikipedia.org/wiki/UTF-8 )for the free form text in
// messages and comments. It can't be used in the fixed width fields.
//
// Non-ASCII characters are represented by multi-byte sequences. All bytes in these
// multi-byte sequences have the most significant bit set to 1. Using UTF-8 would not
// add any nul (00000000) bytes to the stream.
//
// Based on all of that, we would not expect to see a nul character in the information part.
//
// There are two known cases where we can have a nul character value.
//
// * The Kenwood TM-D710A sometimes sends packets like this:
//
// VA3AJ-9>T2QU6X,VE3WRC,WIDE1,K8UNS,WIDE2*:4P<0x00><0x0f>4T<0x00><0x0f>4X<0x00><0x0f>4\<0x00>`nW<0x1f>oS8>/]"6M}driving fast=
// K4JH-9>S5UQ6X,WR4AGC-3*,WIDE1*:4P<0x00><0x0f>4T<0x00><0x0f>4X<0x00><0x0f>4\<0x00>`jP}l"&>/]"47}QRV from the EV =
//
// Notice that the data type indicator of "4" is not valid. If we remove
// 4P<0x00><0x0f>4T<0x00><0x0f>4X<0x00><0x0f>4\<0x00> we are left with a good MIC-E format.
// This same thing has been observed from others and is intermittent.
//
// * AGW Tracker can send UTF-16 if an option is selected. This can introduce nul bytes.
// This is wrong, it should be using UTF-8.
//
// Rather than using strlcat here, we need to use memcpy and maintain our
// own lengths, being careful to avoid buffer overflow.
int msg_len = strlen(msg); // What we have so far before info part.
if (info_len > IGATE_MAX_MSG - msg_len - 2) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Rx IGate: Too long. Truncating.\n");
info_len = IGATE_MAX_MSG - msg_len - 2;
}
if (info_len > 0) {
memcpy (msg + msg_len, pinfo, info_len);
msg_len += info_len;
}
send_msg_to_server (msg, msg_len);
stats_uplink_packets++;
/*
* Remember what was sent to avoid duplicates in near future.
*/
rx_to_ig_remember (pp);
ax25_delete (pp);
} /* end send_packet_to_server */
/*-------------------------------------------------------------------
*
* Name: send_msg_to_server
*
* Purpose: Send something to the IGate server.
* This one function should be used for login, hearbeats,
* and packets.
*
* Inputs: imsg - Message. We will add CR/LF here.
*
* imsg_len - Length of imsg in bytes.
* It could contain nul characters so we can't
* use the normal C string functions.
*
* Description: Send message to IGate Server if connected.
* Disconnect from server, and notify user, if any error.
* Should use a word other than message because that has
* a specific meaning for APRS.
*
*--------------------------------------------------------------------*/
static void send_msg_to_server (const char *imsg, int imsg_len)
{
int err;
char stemp[IGATE_MAX_MSG+1];
int stemp_len;
if (igate_sock == -1) {
return; /* Silently discard if not connected. */
}
stemp_len = imsg_len;
if (stemp_len + 2 > IGATE_MAX_MSG) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Rx IGate: Too long. Truncating.\n");
stemp_len = IGATE_MAX_MSG - 2;
}
memcpy (stemp, imsg, stemp_len);
if (s_debug >= 1) {
text_color_set(DW_COLOR_XMIT);
dw_printf ("[rx>ig] ");
ax25_safe_print (stemp, stemp_len, 0);
dw_printf ("\n");
}
stemp[stemp_len++] = '\r';
stemp[stemp_len++] = '\n';
stemp[stemp_len] = '\0';
stats_uplink_bytes += stemp_len;
#if __WIN32__
err = SOCK_SEND (igate_sock, stemp, stemp_len);
if (err == SOCKET_ERROR)
{
text_color_set(DW_COLOR_ERROR);
dw_printf ("\nError %d sending to IGate server. Closing connection.\n\n", WSAGetLastError());
//dw_printf ("DEBUG: igate_sock=%d, line=%d\n", igate_sock, __LINE__);
closesocket (igate_sock);
igate_sock = -1;
WSACleanup();
}
#else
err = SOCK_SEND (igate_sock, stemp, stemp_len);
if (err <= 0)
{
text_color_set(DW_COLOR_ERROR);
dw_printf ("\nError sending to IGate server. Closing connection.\n\n");
close (igate_sock);
igate_sock = -1;
}
#endif
} /* end send_msg_to_server */
/*-------------------------------------------------------------------
*
* Name: get1ch
*
* Purpose: Read one byte from socket.
*
* Inputs: igate_sock - file handle for socket.
*
* Returns: One byte from stream.
* Waits and tries again later if any error.
*
*
*--------------------------------------------------------------------*/
static int get1ch (void)
{
unsigned char ch;
int n;
while (1) {
while (igate_sock == -1) {
SLEEP_SEC(5); /* Not connected. Try again later. */
}
/* Just get one byte at a time. */
// TODO: might read complete packets and unpack from own buffer
// rather than using a system call for each byte.
n = SOCK_RECV (igate_sock, (char*)(&ch), 1);
if (n == 1) {
#if DEBUG9
dw_printf (log_fp, "%02x %c %c", ch,
isprint(ch) ? ch : '.' ,
(isupper(ch>>1) || isdigit(ch>>1) || (ch>>1) == ' ') ? (ch>>1) : '.');
if (ch == '\r') fprintf (log_fp, " CR");
if (ch == '\n') fprintf (log_fp, " LF");
fprintf (log_fp, "\n");
#endif
return(ch);
}
text_color_set(DW_COLOR_ERROR);
dw_printf ("\nError reading from IGate server. Closing connection.\n\n");
#if __WIN32__
closesocket (igate_sock);
#else
close (igate_sock);
#endif
igate_sock = -1;
}
} /* end get1ch */
/*-------------------------------------------------------------------
*
* Name: igate_recv_thread
*
* Purpose: Wait for messages from IGate Server.
*
* Inputs: arg - Not used.
*
* Outputs: igate_sock - File descriptor for communicating with client app.
*
* Description: Process messages from the IGate server.
*
*--------------------------------------------------------------------*/
#if __WIN32__
static unsigned __stdcall igate_recv_thread (void *arg)
#else
static void * igate_recv_thread (void *arg)
#endif
{
unsigned char ch;
unsigned char message[1000]; // Spec says max 512.
int len;
#if DEBUGx
text_color_set(DW_COLOR_DEBUG);
dw_printf ("igate_recv_thread ( socket = %d )\n", igate_sock);
#endif
while (1) {
len = 0;
do
{
ch = get1ch();
stats_downlink_bytes++;
// I never expected to see a nul character but it can happen.
// If found, change it to <0x00> and ax25_from_text will change it back to a single byte.
// Along the way we can use the normal C string handling.
if (ch == 0 && len < (int)(sizeof(message)) - 5) {
message[len++] = '<';
message[len++] = '0';
message[len++] = 'x';
message[len++] = '0';
message[len++] = '0';
message[len++] = '>';
}
else if (len < (int)(sizeof(message)))
{
message[len++] = ch;
}
} while (ch != '\n');
message[sizeof(message)-1] = '\0';
/*
* We have a complete message terminated by LF.
*
* Remove CR LF from end.
* This is a record separator for the protocol, not part of the data.
* Should probably have an error if we don't have this.
*/
if (len >=2 && message[len-1] == '\n') { message[len-1] = '\0'; len--; }
if (len >=1 && message[len-1] == '\r') { message[len-1] = '\0'; len--; }
/*
* I've seen a case where the original RF packet had a trailing CR but
* after someone else sent it to the server and it came back to me, that
* CR was now a trailing space.
*
* At first I was tempted to trim a trailing space as well.
* By fixing this one case it might corrupt the data in other cases.
* We compensate for this by ignoring trailing spaces when performing
* the duplicate detection and removal.
*
* We need to transmit exactly as we get it.
*/
/*
* I've also seen a multiple trailing spaces like this.
* Notice how safe_print shows a trailing space in hexadecimal to make it obvious.
*
* W1CLA-1>APVR30,TCPIP*,qAC,T2TOKYO3:;IRLP-4942*141503z4218.46NI07108.24W0446325-146IDLE <0x20>
*/
if (len == 0)
{
/*
* Discard if zero length.
*/
}
else if (message[0] == '#') {
/*
* Heartbeat or other control message.
*
* Print only if within seconds of logging in.
* That way we can see login confirmation but not
* be bothered by the heart beat messages.
*/
if ( ! ok_to_send) {
text_color_set(DW_COLOR_REC);
dw_printf ("[ig] ");
ax25_safe_print ((char *)message, len, 0);
dw_printf ("\n");
}
}
else
{
/*
* Convert to third party packet and transmit.
*
* Future: might have ability to configure multiple transmit
* channels, each with own client side filtering and via path.
* Loop here over all configured channels.
*/
text_color_set(DW_COLOR_REC);
dw_printf ("\n[ig>tx] "); // formerly just [ig]
ax25_safe_print ((char *)message, len, 0);
dw_printf ("\n");
if ((int)strlen((char*)message) != len) {
// Invalid. Either drop it or pass it along as-is. Don't change.
text_color_set(DW_COLOR_ERROR);
dw_printf("'nul' character found in packet from IS. This should never happen.\n");
dw_printf("The source station is probably transmitting with defective software.\n");
//if (strcmp((char*)pinfo, "4P") == 0) {
// dw_printf("The TM-D710 will do this intermittently. A firmware upgrade is needed to fix it.\n");
//}
}
/*
* Record that we heard from the source address.
*/
mheard_save_is ((char *)message);
stats_downlink_packets++;
/*
* Possibly transmit if so configured.
*/
int to_chan = save_igate_config_p->tx_chan;
if (to_chan >= 0) {
maybe_xmit_packet_from_igate ((char*)message, to_chan);
}
}
} /* while (1) */
return (0);
} /* end igate_recv_thread */
/*-------------------------------------------------------------------
*
* Name: satgate_delay_packet
*
* Purpose: Put packet into holding area for a while rather than
* sending it immediately to the IS server.
*
* Inputs: pp - Packet object.
*
* chan - Radio channel where received.
*
* Outputs: Appended to queue.
*
* Description: If we hear a packet directly and the same one digipeated,
* we only send the first to the APRS IS due to duplicate removal.
* It may be desirable to favor the digipeated packet over the
* original. For this situation, we have an option which delays
* a packet if we hear it directly and the via path is not empty.
* We know we heard it directly if none of the digipeater
* addresses have been used.
* This way the digipeated packet will go first.
* The original is sent about 10 seconds later.
* Duplicate removal will drop the original if there is no
* corresponding digipeated version.
*
*--------------------------------------------------------------------*/
static void satgate_delay_packet (packet_t pp, int chan)
{
packet_t pnext, plast;
//if (s_debug >= 1) {
text_color_set(DW_COLOR_INFO);
dw_printf ("Rx IGate: SATgate mode, delay packet heard directly.\n");
//}
ax25_set_release_time (pp, dtime_now() + save_igate_config_p->satgate_delay);
//TODO: save channel too.
dw_mutex_lock (&dp_mutex);
if (dp_queue_head == NULL) {
dp_queue_head = pp;
}
else {
plast = dp_queue_head;
while ((pnext = ax25_get_nextp(plast)) != NULL) {
plast = pnext;
}
ax25_set_nextp (plast, pp);
}
dw_mutex_unlock (&dp_mutex);
} /* end satgate_delay_packet */
/*-------------------------------------------------------------------
*
* Name: satgate_delay_thread
*
* Purpose: Release packet when specified release time has arrived.
*
* Inputs: dp_queue_head - Queue of packets.
*
* Outputs: Sent to APRS IS.
*
* Description: For simplicity we'll just poll each second.
* Release the packet when its time has arrived.
*
*--------------------------------------------------------------------*/
#if __WIN32__
static unsigned __stdcall satgate_delay_thread (void *arg)
#else
static void * satgate_delay_thread (void *arg)
#endif
{
double release_time;
int chan = 0; // TODO: get receive channel somehow.
// only matters if multi channel with different names.
while (1) {
SLEEP_SEC (1);
/* Don't need critical region just to peek */
if (dp_queue_head != NULL) {
double now = dtime_now();
release_time = ax25_get_release_time (dp_queue_head);
#if 0
text_color_set(DW_COLOR_DEBUG);
dw_printf ("SATgate: %.1f sec remaining\n", release_time - now);
#endif
if (now > release_time) {
packet_t pp;
dw_mutex_lock (&dp_mutex);
pp = dp_queue_head;
dp_queue_head = ax25_get_nextp(pp);
dw_mutex_unlock (&dp_mutex);
ax25_set_nextp (pp, NULL);
send_packet_to_server (pp, chan);
}
} /* if something in queue */
} /* while (1) */
return (0);
} /* end satgate_delay_thread */
/*-------------------------------------------------------------------
*
* Name: maybe_xmit_packet_from_igate
*
* Purpose: Convert text string, from IGate server, to third party
* packet and send to transmit queue if appropriate.
*
* Inputs: message - As sent by the 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.
* We don't care because we end up discarding them before
* repackaging to go over the radio.
*
* The "q construct" ( http://www.aprs-is.net/q.aspx ) provides
* a clue about the journey taken. "qAX" means that the station sending
* the packet to the server did not login properly as a ham radio
* operator so we don't want to put this on to RF.
*
* to_chan - Radio channel for transmitting.
*
*--------------------------------------------------------------------*/
static void maybe_xmit_packet_from_igate (char *message, int to_chan)
{
packet_t pp3;
char payload[AX25_MAX_PACKET_LEN]; /* what is max len? */
char src[AX25_MAX_ADDR_LEN]; /* Source address. */
char *pinfo = NULL;
int info_len;
int n;
assert (to_chan >= 0 && to_chan < MAX_CHANS);
/*
* 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.
*/
pp3 = ax25_from_text(message, 0);
if (pp3 == NULL) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Tx IGate: Could not parse message from server.\n");
dw_printf ("%s\n", message);
return;
}
ax25_get_addr_with_ssid (pp3, AX25_SOURCE, src);
/*
* Drop if path contains:
* NOGATE or RFONLY - means IGate should not pass them.
* TCPXX or qAX - means it came from somewhere that did not identify itself correctly.
*/
for (n = 0; n < ax25_get_num_repeaters(pp3); n++) {
char via[AX25_MAX_ADDR_LEN]; /* includes ssid. Do we want to ignore it? */
ax25_get_addr_with_ssid (pp3, n + AX25_REPEATER_1, via);
if (strcmp(via, "qAX") == 0 ||
strcmp(via, "TCPXX") == 0 ||
strcmp(via, "RFONLY") == 0 ||
strcmp(via, "NOGATE") == 0) {
if (s_debug >= 1) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("Tx IGate: Do not transmit with %s in path.\n", via);
}
ax25_delete (pp3);
return;
}
}
/*
* Apply our own packet filtering if configured.
* Do we want to do this before or after removing the VIA path?
* I suppose by doing it first, we have the possibility of
* filtering by stations along the way or the q construct.
*/
assert (to_chan >= 0 && to_chan < MAX_CHANS);
/*
* We have a rather strange special case here.
* If we recently transmitted a 'message' from some station,
* send the position of the message sender when it comes along later.
*
* If we have a position report, look up the sender and see if we should
* bypass the normal filtering.
*/
// TODO: Not quite this simple. Should have a function to check for position.
// $ raw gps could be a position. @ could be weather data depending on symbol.
info_len = ax25_get_info (pp3, (unsigned char **)(&pinfo));
int msp_special_case = 0;
if (info_len >= 1 && strchr("!=/@'`", *pinfo) != NULL) {
int n = mheard_get_msp(src);
if (n > 0) {
msp_special_case = 1;
if (s_debug >= 1) {
text_color_set(DW_COLOR_INFO);
dw_printf ("Special case, allow position from message sender %s, %d remaining.\n", src, n - 1);
}
mheard_set_msp (src, n - 1);
}
}
if ( ! msp_special_case) {
if (save_digi_config_p->filter_str[MAX_CHANS][to_chan] != NULL) {
if (pfilter(MAX_CHANS, to_chan, save_digi_config_p->filter_str[MAX_CHANS][to_chan], pp3, 1) != 1) {
// Previously there was a debug message here about the packet being dropped by filtering.
// This is now handled better by the "-df" command line option for filtering details.
// TODO: clean up - remove these lines.
//if (s_debug >= 1) {
// text_color_set(DW_COLOR_INFO);
// dw_printf ("Packet from IGate to channel %d was rejected by filter: %s\n", to_chan, save_digi_config_p->filter_str[MAX_CHANS][to_chan]);
//}
ax25_delete (pp3);
return;
}
}
}
/*
* Remove the VIA path.
*
* For example, we might get something like this from the server.
* K1USN-1>APWW10,TCPIP*,qAC,N5JXS-F1:T#479,100,048,002,500,000,10000000<0x0d><0x0a>
*
* We want to reduce it to this before wrapping it as third party traffic.
* K1USN-1>APWW10:T#479,100,048,002,500,000,10000000<0x0d><0x0a>
*/
/*
* These are typical examples where we see TCPIP*,qAC,<server>
*
* N3LLO-4>APRX28,TCPIP*,qAC,T2NUENGLD:T#474,21.4,0.3,114.0,4.0,0.0,00000000
* N1WJO>APWW10,TCPIP*,qAC,T2MAINE:)147.120!4412.27N/07033.27WrW1OCA repeater136.5 Tone Norway Me
* AB1OC-10>APWW10,TCPIP*,qAC,T2IAD2:=4242.70N/07135.41W#(Time 0:00:00)!INSERVICE!!W60!
*
* But sometimes we get a different form:
*
* N1YG-1>T1SY9P,WIDE1-1,WIDE2-2,qAR,W2DAN-15:'c&<0x7f>l <0x1c>-/>
* W1HS-8>TSSP9T,WIDE1-1,WIDE2-1,qAR,N3LLO-2:`d^Vl"W>/'"85}|*&%_'[|!wLK!|3
* N1RCW-1>APU25N,MA2-2,qAR,KA1VCQ-1:=4140.41N/07030.21W-Home Station/Fill-in Digi {UIV32N}
* N1IEJ>T4PY3U,W1EMA-1,WIDE1*,WIDE2-2,qAR,KD1KE:`a5"l!<0x7f>-/]"4f}Retired & Busy=
*
* Oh! They have qAR rather than qAC. What does that mean?
* From http://www.aprs-is.net/q.aspx
*
* qAC - Packet was received from the client directly via a verified connection (FROMCALL=login).
* The callSSID following the qAC is the server's callsign-SSID.
*
* qAR - Packet was received directly (via a verified connection) from an IGate using the ,I construct.
* The callSSID following the qAR it the callSSID of the IGate.
*
* What is the ",I" construct?
* Do we care here?
* Is is something new and improved that we should be using in the other direction?
*/
while (ax25_get_num_repeaters(pp3) > 0) {
ax25_remove_addr (pp3, AX25_REPEATER_1);
}
/*
* Replace the VIA path with TCPIP and my call.
* Mark my call as having been used.
*/
ax25_set_addr (pp3, AX25_REPEATER_1, "TCPIP");
ax25_set_h (pp3, AX25_REPEATER_1);
ax25_set_addr (pp3, AX25_REPEATER_2, save_audio_config_p->achan[to_chan].mycall);
ax25_set_h (pp3, AX25_REPEATER_2);
/*
* Convert to text representation.
*/
memset (payload, 0, sizeof(payload));
ax25_format_addrs (pp3, payload);
info_len = ax25_get_info (pp3, (unsigned char **)(&pinfo));
(void)(info_len);
strlcat (payload, pinfo, sizeof(payload));
#if DEBUGx
text_color_set(DW_COLOR_DEBUG);
dw_printf ("Tx IGate: payload=%s\n", payload);
#endif
/*
* Encapsulate for sending over radio if no reason to drop it.
*/
/*
* We don't want to suppress duplicate "messages" within a short time period.
* Suppose we transmitted a "message" for some station and it did not respond with an ack.
* 25 seconds later the sender retries. Wouldn't we want to pass along that retry?
*
* "Messages" get preferential treatment because they are high value and very rare.
* -> Bypass the duplicate suppression.
* -> Raise the rate limiting value.
*/
if (ig_to_tx_allow (pp3, to_chan)) {
char radio [500];
packet_t pradio;
snprintf (radio, sizeof(radio), "%s>%s%d%d%s:}%s",
save_audio_config_p->achan[to_chan].mycall,
APP_TOCALL, MAJOR_VERSION, MINOR_VERSION,
save_igate_config_p->tx_via,
payload);
pradio = ax25_from_text (radio, 1);
/* Oops. Didn't have a check for NULL here. */
/* Could this be the cause of rare and elusive crashes in 1.2? */
if (pradio != NULL) {
#if ITEST
text_color_set(DW_COLOR_XMIT);
dw_printf ("Xmit: %s\n", radio);
ax25_delete (pradio);
#else
/* This consumes packet so don't reference it again! */
tq_append (to_chan, TQ_PRIO_1_LO, pradio);
#endif
stats_rf_xmit_packets++; // Any type of packet.
// TEMP TEST: metadata temporarily allowed during testing.
if (*pinfo == ':' && ! is_telem_metadata(pinfo)) {
// temp test // if (*pinfo == ':') {
// We transmitted a "message." Telemetry metadata is excluded.
// Remember to pass along address of the sender later.
stats_msg_cnt++; // Update statistics.
mheard_set_msp (src, save_igate_config_p->igmsp);
}
ig_to_tx_remember (pp3, save_igate_config_p->tx_chan, 0); // correct. version before encapsulating it.
}
else {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Received invalid packet from IGate.\n");
dw_printf ("%s\n", payload);
dw_printf ("Will not attempt to transmit third party packet.\n");
dw_printf ("%s\n", radio);
}
}
ax25_delete (pp3);
} /* end maybe_xmit_packet_from_igate */
/*-------------------------------------------------------------------
*
* Name: rx_to_ig_remember
*
* Purpose: Keep a record of packets sent to the IGate server
* so we don't send duplicates within some set amount of time.
*
* Inputs: pp - Pointer to a packet object.
*
*-------------------------------------------------------------------
*
* Name: rx_to_ig_allow
*
* Purpose: Check whether this is a duplicate of another
* recently received from RF and sent to the Server
*
* Input: pp - Pointer to packet object.
*
* Returns: True if it is OK to send.
*
*-------------------------------------------------------------------
*
* Description: These two functions perform the final stage of filtering
* before sending a received (from radio) packet to the IGate server.
*
* rx_to_ig_remember must be called for every packet sent to the server.
*
* rx_to_ig_allow decides whether this should be allowed thru
* based on recent activity. We will drop the packet if it is a
* duplicate of another sent recently.
*
* Rather than storing the entire packet, we just keep a CRC to
* reduce memory and processing requirements. We do the same in
* the digipeater function to suppress duplicates.
*
* There is a 1 / 65536 chance of getting a false positive match
* which is good enough for this application.
*
*
* Original thinking:
*
* Occasionally someone will get on one of the discussion groups and say:
* I don't think my IGate is working. I look at packets, from local stations,
* on aprs.fi or findu.com, and they are always through some other IGate station,
* never mine.
* Then someone has to explain, this is not a valid strategy for analyzing
* everything going thru the network. The APRS-IS servers drop duplicate
* packets (ignoring the via path) within a 30 second period. If some
* other IGate gets the same thing there a millisecond faster than you,
* the one you send is discarded.
* In this scenario, it would make sense to perform additional duplicate
* suppression before forwarding RF packets to the Server.
* I don't recall if I saw some specific recommendation to do this or if
* it just seemed like the obvious thing to do to avoid sending useless
* stuff that would just be discarded anyhow. It seems others came to the
* same conclusion. http://www.tapr.org/pipermail/aprssig/2016-July/045907.html
*
* Version 1.5: Rethink strategy.
*
* Issue 85, https://github.com/wb2osz/direwolf/issues/85 ,
* got me thinking about this some more. Sending more information will
* allow the APRS-IS servers to perform future additional network analysis.
* To make a long story short, the RF>IS direction duplicate checking
* is now disabled. The code is still there in case I change my mind
* and want to add a configuration option to allow it. The dedupe
* time is set to 0 which means don't do the checking.
*
*--------------------------------------------------------------------*/
#define RX2IG_HISTORY_MAX 30 /* Remember the last 30 sent to IGate server. */
static int rx2ig_insert_next;
static time_t rx2ig_time_stamp[RX2IG_HISTORY_MAX];
static unsigned short rx2ig_checksum[RX2IG_HISTORY_MAX];
static void rx_to_ig_init (void)
{
int n;
for (n=0; n<RX2IG_HISTORY_MAX; n++) {
rx2ig_time_stamp[n] = 0;
rx2ig_checksum[n] = 0;
}
rx2ig_insert_next = 0;
}
static void rx_to_ig_remember (packet_t pp)
{
// No need to save the information if we are not doing duplicate checking.
if (save_igate_config_p->rx2ig_dedupe_time == 0) {
return;
}
rx2ig_time_stamp[rx2ig_insert_next] = time(NULL);
rx2ig_checksum[rx2ig_insert_next] = ax25_dedupe_crc(pp);
if (s_debug >= 3) {
char src[AX25_MAX_ADDR_LEN];
char dest[AX25_MAX_ADDR_LEN];
unsigned char *pinfo;
int info_len;
ax25_get_addr_with_ssid(pp, AX25_SOURCE, src);
ax25_get_addr_with_ssid(pp, AX25_DESTINATION, dest);
info_len = ax25_get_info (pp, &pinfo);
(void)info_len;
text_color_set(DW_COLOR_DEBUG);
dw_printf ("rx_to_ig_remember [%d] = %d %d \"%s>%s:%s\"\n",
rx2ig_insert_next,
(int)(rx2ig_time_stamp[rx2ig_insert_next]),
rx2ig_checksum[rx2ig_insert_next],
src, dest, pinfo);
}
rx2ig_insert_next++;
if (rx2ig_insert_next >= RX2IG_HISTORY_MAX) {
rx2ig_insert_next = 0;
}
}
static int rx_to_ig_allow (packet_t pp)
{
unsigned short crc = ax25_dedupe_crc(pp);
time_t now = time(NULL);
int j;
if (s_debug >= 2) {
char src[AX25_MAX_ADDR_LEN];
char dest[AX25_MAX_ADDR_LEN];
unsigned char *pinfo;
int info_len;
ax25_get_addr_with_ssid(pp, AX25_SOURCE, src);
ax25_get_addr_with_ssid(pp, AX25_DESTINATION, dest);
info_len = ax25_get_info (pp, &pinfo);
(void)info_len;
text_color_set(DW_COLOR_DEBUG);
dw_printf ("rx_to_ig_allow? %d \"%s>%s:%s\"\n", crc, src, dest, pinfo);
}
// Do we have duplicate checking at all in the RF>IS direction?
if (save_igate_config_p->rx2ig_dedupe_time == 0) {
if (s_debug >= 2) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("rx_to_ig_allow? YES, no dedupe checking\n");
}
return 1;
}
// Yes, check for duplicates within certain time.
for (j=0; j<RX2IG_HISTORY_MAX; j++) {
if (rx2ig_checksum[j] == crc && rx2ig_time_stamp[j] >= now - save_igate_config_p->rx2ig_dedupe_time) {
if (s_debug >= 2) {
text_color_set(DW_COLOR_DEBUG);
// could be multiple entries and this might not be the most recent.
dw_printf ("rx_to_ig_allow? NO. Seen %d seconds ago.\n", (int)(now - rx2ig_time_stamp[j]));
}
return 0;
}
}
if (s_debug >= 2) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("rx_to_ig_allow? YES\n");
}
return 1;
} /* end rx_to_ig_allow */
/*-------------------------------------------------------------------
*
* Name: ig_to_tx_remember
*
* Purpose: Keep a record of packets sent from IGate server to radio transmitter
* so we don't send duplicates within some set amount of time.
*
* Inputs: pp - Pointer to a packet object.
*
* chan - Channel number where it is being transmitted.
* Duplicate detection needs to be separate for each radio channel.
*
* bydigi - True if transmitted by digipeater function. False for IGate.
* Why do we care about digpeating here? See discussion below.
*
*------------------------------------------------------------------------------
*
* Name: ig_to_tx_allow
*
* Purpose: Check whether this is a duplicate of another sent recently
* or if we exceed the transmit rate limits.
*
* Input: pp - Pointer to packet object.
*
* chan - Radio channel number where we want to transmit.
*
* Returns: True if it is OK to send.
*
*------------------------------------------------------------------------------
*
* Description: These two functions perform the final stage of filtering
* before sending a packet from the IGate server to the radio.
*
* ig_to_tx_remember must be called for every packet, from the IGate
* server, sent to the radio transmitter.
*
* ig_to_tx_allow decides whether this should be allowed thru
* based on recent activity. We will drop the packet if it is a
* duplicate of another sent recently.
*
* This is the essentially the same as the pair of functions
* above, for RF to IS, with one additional restriction.
*
* The typical residential Internet connection is around 10,000
* to 50,000 times faster than the radio links we are using. It would
* be easy to completely saturate the radio channel if we are
* not careful.
*
* Besides looking for duplicates, this will also tabulate the
* number of packets sent during the past minute and past 5
* minutes and stop sending if a limit is reached.
*
* More Discussion:
*
* Consider the following example.
* I hear a packet from W1TG-1 three times over the radio then get the
* (almost) same thing twice from APRS-IS.
*
*
* Digipeater N3LEE-10 audio level = 23(10/6) [NONE] __|||||||
* [0.5] W1TG-1>APU25N,N3LEE-10*,WIDE2-1:<IGATE,MSG_CNT=30,LOC_CNT=61<0x0d>
* Station Capabilities, Ambulance, UIview 32 bit apps
* IGATE,MSG_CNT=30,LOC_CNT=61
*
* [0H] W1TG-1>APU25N,N3LEE-10,WB2OSZ-14*:<IGATE,MSG_CNT=30,LOC_CNT=61<0x0d>
*
* Digipeater WIDE2 (probably N3LEE-4) audio level = 22(10/6) [NONE] __|||||||
* [0.5] W1TG-1>APU25N,N3LEE-10,N3LEE-4,WIDE2*:<IGATE,MSG_CNT=30,LOC_CNT=61<0x0d>
* Station Capabilities, Ambulance, UIview 32 bit apps
* IGATE,MSG_CNT=30,LOC_CNT=61
*
* Digipeater WIDE2 (probably AB1OC-10) audio level = 31(14/11) [SINGLE] ____:____
* [0.4] W1TG-1>APU25N,N3LEE-10,AB1OC-10,WIDE2*:<IGATE,MSG_CNT=30,LOC_CNT=61<0x0d>
* Station Capabilities, Ambulance, UIview 32 bit apps
* IGATE,MSG_CNT=30,LOC_CNT=61
*
* [ig] W1TG-1>APU25N,WIDE2-2,qAR,W1GLO-11:<IGATE,MSG_CNT=30,LOC_CNT=61
* [0L] WB2OSZ-14>APDW13,WIDE1-1:}W1TG-1>APU25N,TCPIP,WB2OSZ-14*:<IGATE,MSG_CNT=30,LOC_CNT=61
*
* [ig] W1TG-1>APU25N,K1FFK,WIDE2*,qAR,WB2ZII-15:<IGATE,MSG_CNT=30,LOC_CNT=61<0x20>
* [0L] WB2OSZ-14>APDW13,WIDE1-1:}W1TG-1>APU25N,TCPIP,WB2OSZ-14*:<IGATE,MSG_CNT=30,LOC_CNT=61<0x20>
*
*
* The first one gets retransmitted by digipeating.
*
* Why are we getting the same thing twice from APRS-IS? Shouldn't remove duplicates?
* Look closely. The original packet, on RF, had a CR character at the end.
* At first I thought duplicate removal was broken but it turns out they
* are not exactly the same.
*
* >>> The receive IGate spec says a packet should be cut at a CR. <<<
*
* In one case it is removed as expected In another case, it is replaced by a trailing
* space character. Maybe someone thought non printable characters should be
* replaced by spaces??? (I have since been told someone thought it would be a good
* idea to replace unprintable characters with spaces. How's that working out for MIC-E position???)
*
* At first I was tempted to remove any trailing spaces to make up for the other
* IGate adding it. Two wrongs don't make a right. Trailing spaces are not that
* rare and removing them would corrupt the data. My new strategy is for
* the duplicate detection compare to ignore trailing space, CR, and LF.
*
* We already transmitted the same thing by the digipeater function so this should
* also go into memory for avoiding duplicates out of the transmit IGate.
*
* Future:
* Should the digipeater function avoid transmitting something if it
* was recently transmitted by the IGate funtion?
* This code is pretty much the same as dedupe.c. Maybe it could all
* be combined into one. Need to ponder this some more.
*
*--------------------------------------------------------------------*/
/*
Here is another complete example, with the "-diii" debugging option to show details.
We receive the signal directly from the source: (zzz.log 1011)
N1ZKO-7 audio level = 33(16/10) [NONE] ___||||||
[0.5] N1ZKO-7>T2TS7X,WIDE1-1,WIDE2-1:`c6wl!i[/>"4]}[scanning]=<0x0d>
MIC-E, Human, Kenwood TH-D72, In Service
N 42 43.7800, W 071 26.9100, 0 MPH, course 177, alt 230 ft
[scanning]
We did not send it to the IS server recently.
Rx IGate: Truncated information part at CR.
rx_to_ig_allow? 57185 "N1ZKO-7>T2TS7X:`c6wl!i[/>"4]}[scanning]="
rx_to_ig_allow? YES
Send it now and remember that fact.
[rx>ig] N1ZKO-7>T2TS7X,WIDE1-1,WIDE2-1,qAR,WB2OSZ-14:`c6wl!i[/>"4]}[scanning]=
rx_to_ig_remember [21] = 1447683040 57185 "N1ZKO-7>T2TS7X:`c6wl!i[/>"4]}[scanning]="
Digipeat it. Notice how it has a trailing CR.
TODO: Why is the CRC different? Content looks the same.
ig_to_tx_remember [38] = ch0 d1 1447683040 27598 "N1ZKO-7>T2TS7X:`c6wl!i[/>"4]}[scanning]=
"
[0H] N1ZKO-7>T2TS7X,WB2OSZ-14*,WIDE2-1:`c6wl!i[/>"4]}[scanning]=<0x0d>
Now we hear it again, thru a digipeater.
Not sure who. Was it UNCAN or was it someone else who doesn't use tracing?
See my rant in the User Guide about this.
Digipeater WIDE2 (probably UNCAN) audio level = 30(15/10) [NONE] __|||::__
[0.4] N1ZKO-7>T2TS7X,KB1POR-2,UNCAN,WIDE2*:`c6wl!i[/>"4]}[scanning]=<0x0d>
MIC-E, Human, Kenwood TH-D72, In Service
N 42 43.7800, W 071 26.9100, 0 MPH, course 177, alt 230 ft
[scanning]
Was sent to server recently so don't do it again.
Rx IGate: Truncated information part at CR.
rx_to_ig_allow? 57185 "N1ZKO-7>T2TS7X:`c6wl!i[/>"4]}[scanning]="
rx_to_ig_allow? NO. Seen 1 seconds ago.
Rx IGate: Drop duplicate of same packet seen recently.
We hear it a third time, by a different digipeater.
Digipeater WIDE1 (probably N3LEE-10) audio level = 23(12/6) [NONE] __|||||||
[0.5] N1ZKO-7>T2TS7X,N3LEE-10,WIDE1*,WIDE2-1:`c6wl!i[/>"4]}[scanning]=<0x0d>
MIC-E, Human, Kenwood TH-D72, In Service
N 42 43.7800, W 071 26.9100, 0 MPH, course 177, alt 230 ft
[scanning]
It's a duplicate, so don't send to server.
Rx IGate: Truncated information part at CR.
rx_to_ig_allow? 57185 "N1ZKO-7>T2TS7X:`c6wl!i[/>"4]}[scanning]="
rx_to_ig_allow? NO. Seen 2 seconds ago.
Rx IGate: Drop duplicate of same packet seen recently.
Digipeater: Drop redundant packet to channel 0.
The server sends it to us.
NOTICE: The CR at the end has been replaced by a space.
[ig>tx] N1ZKO-7>T2TS7X,K1FFK,WA2MJM-15*,qAR,WB2ZII-15:`c6wl!i[/>"4]}[scanning]=<0x20>
Should we transmit it?
No, we sent it recently by the digipeating function (note "bydigi=1").
DEBUG: ax25_dedupe_crc ignoring trailing space.
ig_to_tx_allow? ch0 27598 "N1ZKO-7>T2TS7X:`c6wl!i[/>"4]}[scanning]= "
ig_to_tx_allow? NO. Sent 4 seconds ago. bydigi=1
Tx IGate: Drop duplicate packet transmitted recently.
[0L] WB2OSZ-14>APDW13,WIDE1-1:}W1AST>TRPR4T,TCPIP,WB2OSZ-14*:`d=Ml!3>/"4N}
[rx>ig] #
*/
#define IG2TX_DEDUPE_TIME 60 /* Do not send duplicate within 60 seconds. */
#define IG2TX_HISTORY_MAX 50 /* Remember the last 50 sent from server to radio. */
/* Ideally this should be a critical region because */
/* it is being written by two threads but I'm not that concerned. */
static int ig2tx_insert_next;
static time_t ig2tx_time_stamp[IG2TX_HISTORY_MAX];
static unsigned short ig2tx_checksum[IG2TX_HISTORY_MAX];
static unsigned char ig2tx_chan[IG2TX_HISTORY_MAX];
static unsigned short ig2tx_bydigi[IG2TX_HISTORY_MAX];
static void ig_to_tx_init (void)
{
int n;
for (n=0; n<IG2TX_HISTORY_MAX; n++) {
ig2tx_time_stamp[n] = 0;
ig2tx_checksum[n] = 0;
ig2tx_chan[n] = 0xff;
ig2tx_bydigi[n] = 0;
}
ig2tx_insert_next = 0;
}
void ig_to_tx_remember (packet_t pp, int chan, int bydigi)
{
time_t now = time(NULL);
unsigned short crc = ax25_dedupe_crc(pp);
if (s_debug >= 3) {
char src[AX25_MAX_ADDR_LEN];
char dest[AX25_MAX_ADDR_LEN];
unsigned char *pinfo;
int info_len;
ax25_get_addr_with_ssid(pp, AX25_SOURCE, src);
ax25_get_addr_with_ssid(pp, AX25_DESTINATION, dest);
info_len = ax25_get_info (pp, &pinfo);
(void)info_len;
text_color_set(DW_COLOR_DEBUG);
dw_printf ("ig_to_tx_remember [%d] = ch%d d%d %d %d \"%s>%s:%s\"\n",
ig2tx_insert_next,
chan, bydigi,
(int)(now), crc,
src, dest, pinfo);
}
ig2tx_time_stamp[ig2tx_insert_next] = now;
ig2tx_checksum[ig2tx_insert_next] = crc;
ig2tx_chan[ig2tx_insert_next] = chan;
ig2tx_bydigi[ig2tx_insert_next] = bydigi;
ig2tx_insert_next++;
if (ig2tx_insert_next >= IG2TX_HISTORY_MAX) {
ig2tx_insert_next = 0;
}
}
static int ig_to_tx_allow (packet_t pp, int chan)
{
unsigned short crc = ax25_dedupe_crc(pp);
time_t now = time(NULL);
int j;
int count_1, count_5;
int increase_limit;
unsigned char *pinfo;
int info_len;
info_len = ax25_get_info (pp, &pinfo);
(void)info_len;
if (s_debug >= 2) {
char src[AX25_MAX_ADDR_LEN];
char dest[AX25_MAX_ADDR_LEN];
ax25_get_addr_with_ssid(pp, AX25_SOURCE, src);
ax25_get_addr_with_ssid(pp, AX25_DESTINATION, dest);
text_color_set(DW_COLOR_DEBUG);
dw_printf ("ig_to_tx_allow? ch%d %d \"%s>%s:%s\"\n", chan, crc, src, dest, pinfo);
}
/* Consider transmissions on this channel only by either digi or IGate. */
for (j=0; j<IG2TX_HISTORY_MAX; j++) {
if (ig2tx_checksum[j] == crc && ig2tx_chan[j] == chan && ig2tx_time_stamp[j] >= now - IG2TX_DEDUPE_TIME) {
/* We have a duplicate within some time period. */
if (*pinfo == ':' && ! is_telem_metadata((char*)pinfo)) {
/* I think I want to avoid the duplicate suppression for "messages." */
/* Suppose we transmit a message from station X and it doesn't get an ack back. */
/* Station X then sends exactly the same thing 20 seconds later. */
/* We don't want to suppress the retry. */
if (s_debug >= 2) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("ig_to_tx_allow? Yes for duplicate message sent %d seconds ago. bydigi=%d\n", (int)(now - ig2tx_time_stamp[j]), ig2tx_bydigi[j]);
}
}
else {
/* Normal (non-message) case. */
if (s_debug >= 2) {
text_color_set(DW_COLOR_DEBUG);
// could be multiple entries and this might not be the most recent.
dw_printf ("ig_to_tx_allow? NO. Duplicate sent %d seconds ago. bydigi=%d\n", (int)(now - ig2tx_time_stamp[j]), ig2tx_bydigi[j]);
}
text_color_set(DW_COLOR_INFO);
dw_printf ("Tx IGate: Drop duplicate packet transmitted recently.\n");
return 0;
}
}
}
/* IGate transmit counts must not include digipeater transmissions. */
count_1 = 0;
count_5 = 0;
for (j=0; j<IG2TX_HISTORY_MAX; j++) {
if (ig2tx_chan[j] == chan && ig2tx_bydigi[j] == 0) {
if (ig2tx_time_stamp[j] >= now - 60) count_1++;
if (ig2tx_time_stamp[j] >= now - 300) count_5++;
}
}
/* "Messages" (special APRS data type ":") are intentional and more */
/* important than all of the other mostly repetitive useless junk */
/* flowing thru here. */
/* It would be unfortunate to discard a message because we already */
/* hit our limit. I don't want to completely eliminate limiting for */
/* messages, in case something goes terribly wrong, but we can triple */
/* the normal limit for them. */
increase_limit = 1;
if (*pinfo == ':' && ! is_telem_metadata((char*)pinfo)) {
increase_limit = 3;
}
if (count_1 >= save_igate_config_p->tx_limit_1 * increase_limit) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Tx IGate: Already transmitted maximum of %d packets in 1 minute.\n", save_igate_config_p->tx_limit_1);
return 0;
}
if (count_5 >= save_igate_config_p->tx_limit_5 * increase_limit) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Tx IGate: Already transmitted maximum of %d packets in 5 minutes.\n", save_igate_config_p->tx_limit_5);
return 0;
}
if (s_debug >= 2) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("ig_to_tx_allow? YES\n");
}
return 1;
} /* end ig_to_tx_allow */
/* end igate.c */