// // 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. * Similar cdigipeater.c is for connected mode. * * * 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) * *------------------------------------------------------------------------------*/ #define OBSOLETE14 1 #ifndef OBSOLETE14 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 */ #endif 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) != 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. */ #ifndef OBSOLETE14 // Took it out in 1.4 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. */ } #endif /* * 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. (Obsolete, removed.) */ test ( "W1ABC>TEST-3:", #ifndef OBSOLETE14 "W1ABC>TEST,WB2OSZ-9*,WIDE3-2:"); #else ""); #endif 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 */