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ax25_pad.c
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//
// 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 <http://www.gnu.org/licenses/>.
//
/*------------------------------------------------------------------
*
* Name: ax25_pad
*
* Purpose: Packet assembler and disasembler.
*
* This was written when I was only concerned about APRS which
* uses only UI frames. ax25_pad2.c, added years later, has
* functions for dealing with other types of frames.
*
* We can obtain AX.25 packets from different sources:
*
* (a) from an HDLC frame.
* (b) from text representation.
* (c) built up piece by piece.
*
* We also want to use a packet in different ways:
*
* (a) transmit as an HDLC frame.
* (b) print in human-readable text.
* (c) take it apart piece by piece.
*
* Looking at the more general case, we also want to modify
* an existing packet. For instance an APRS repeater might
* want to change "WIDE2-2" to "WIDE2-1" and retransmit it.
*
*
* Description:
*
*
* APRS uses only UI frames.
* Each starts with 2-10 addressses (14-70 octets):
*
* * Destination Address (note: opposite order in printed format)
*
* * Source Address
*
* * 0-8 Digipeater Addresses (Could there ever be more as a result of
* digipeaters inserting their own call for
* the tracing feature?
* NO. The limit is 8 when transmitting AX.25 over the
* radio.
* Communication with an IGate server could
* have a longer VIA path but that is only in text form,
* not as an AX.25 frame.)
*
* Each address is composed of:
*
* * 6 upper case letters or digits, blank padded.
* These are shifted left one bit, leaving the LSB always 0.
*
* * a 7th octet containing the SSID and flags.
* The LSB is always 0 except for the last octet of the address field.
*
* The final octet of the Destination has the form:
*
* C R R SSID 0, where,
*
* C = command/response = 1
* R R = Reserved = 1 1
* SSID = substation ID
* 0 = zero
*
* The AX.25 spec states that the RR bits should be 11 if not used.
* There are a couple documents talking about possible uses for APRS.
* I'm ignoring them for now.
* http://www.aprs.org/aprs12/preemptive-digipeating.txt
* http://www.aprs.org/aprs12/RR-bits.txt
*
* I don't recall why I originally intended to set the source/destination C bits both to 1.
* Reviewing this 5 years later, after spending more time delving into the
* AX.25 spec, I think it should be 1 for destination and 0 for source.
* In practice you see all four combinations being used by APRS stations
* and no one really cares about these two bits.
*
* The final octet of the Source has the form:
*
* C R R SSID 0, where,
*
* C = command/response = 1 (originally, now I think it should be 0 for source.)
* (Haven't gone back to check to see what code actually does.)
* R R = Reserved = 1 1
* SSID = substation ID
* 0 = zero (or 1 if no repeaters)
*
* The final octet of each repeater has the form:
*
* H R R SSID 0, where,
*
* H = has-been-repeated = 0 initially.
* Set to 1 after this address has been used.
* R R = Reserved = 1 1
* SSID = substation ID
* 0 = zero (or 1 if last repeater in list)
*
* A digipeater would repeat this frame if it finds its address
* with the "H" bit set to 0 and all earlier repeater addresses
* have the "H" bit set to 1.
* The "H" bit would be set to 1 in the repeated frame.
*
* In standard monitoring format, an asterisk is displayed after the last
* digipeater with the "H" bit set. That indicates who you are hearing
* over the radio.
* (That is if digipeaters update the via path properly. Some don't so
* we don't know who we are hearing. This is discussed in the User Guide.)
* No asterisk means the source is being heard directly.
*
* Example, if we can hear all stations involved,
*
* SRC>DST,RPT1,RPT2,RPT3: -- we heard SRC
* SRC>DST,RPT1*,RPT2,RPT3: -- we heard RPT1
* SRC>DST,RPT1,RPT2*,RPT3: -- we heard RPT2
* SRC>DST,RPT1,RPT2,RPT3*: -- we heard RPT3
*
*
* Next we have:
*
* * One byte Control Field - APRS uses 3 for UI frame
* The more general AX.25 frame can have two.
*
* * One byte Protocol ID - APRS uses 0xf0 for no layer 3
*
* Finally the Information Field of 1-256 bytes.
*
* And, of course, the 2 byte CRC.
*
* The descriptions above, for the C, H, and RR bits, are for APRS usage.
* When operating as a KISS TNC we just pass everything along and don't
* interpret or change them.
*
*
* Constructors: ax25_init - Clear everything.
* ax25_from_text - Tear apart a text string
* ax25_from_frame - Tear apart an AX.25 frame.
* Must be called before any other function.
*
* Get methods: .... - Extract destination, source, or digipeater
* address from frame.
*
* Assumptions: CRC has already been verified to be correct.
*
*------------------------------------------------------------------*/
#define AX25_PAD_C /* this will affect behavior of ax25_pad.h */
#include "direwolf.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <stdio.h>
#include <ctype.h>
#include "regex.h"
#if __WIN32__
char *strtok_r(char *str, const char *delim, char **saveptr);
#endif
#include "textcolor.h"
#include "ax25_pad.h"
#include "fcs_calc.h"
/*
* Accumulate statistics.
* If new_count gets much larger than delete_count plus the size of
* the transmit queue we have a memory leak.
*/
static volatile int new_count = 0;
static volatile int delete_count = 0;
static volatile int last_seq_num = 0;
#if AX25MEMDEBUG
int ax25memdebug = 0;
void ax25memdebug_set(void)
{
ax25memdebug = 1;
}
int ax25memdebug_get (void)
{
return (ax25memdebug);
}
int ax25memdebug_seq (packet_t this_p)
{
return (this_p->seq);
}
#endif
#define CLEAR_LAST_ADDR_FLAG this_p->frame_data[this_p->num_addr*7-1] &= ~ SSID_LAST_MASK
#define SET_LAST_ADDR_FLAG this_p->frame_data[this_p->num_addr*7-1] |= SSID_LAST_MASK
/*------------------------------------------------------------------------------
*
* Name: ax25_new
*
* Purpose: Allocate memory for a new packet object.
*
* Returns: Identifier for a new packet object.
* In the current implementation this happens to be a pointer.
*
*------------------------------------------------------------------------------*/
packet_t ax25_new (void)
{
struct packet_s *this_p;
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("ax25_new(): before alloc, new=%d, delete=%d\n", new_count, delete_count);
#endif
last_seq_num++;
new_count++;
/*
* check for memory leak.
*/
// version 1.4 push up the threshold. We could have considerably more with connected mode.
//if (new_count > delete_count + 100) {
if (new_count > delete_count + 256) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Report to WB2OSZ - Memory leak for packet objects. new=%d, delete=%d\n", new_count, delete_count);
#if AX25MEMDEBUG
// Force on debug option to gather evidence.
ax25memdebug_set();
#endif
}
this_p = calloc(sizeof (struct packet_s), (size_t)1);
if (this_p == NULL) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("ERROR - can't allocate memory in ax25_new.\n");
}
assert (this_p != NULL);
this_p->magic1 = MAGIC;
this_p->seq = last_seq_num;
this_p->magic2 = MAGIC;
this_p->num_addr = (-1);
return (this_p);
}
/*------------------------------------------------------------------------------
*
* Name: ax25_delete
*
* Purpose: Destroy a packet object, freeing up memory it was using.
*
*------------------------------------------------------------------------------*/
#if AX25MEMDEBUG
void ax25_delete_debug (packet_t this_p, char *src_file, int src_line)
#else
void ax25_delete (packet_t this_p)
#endif
{
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("ax25_delete(): before free, new=%d, delete=%d\n", new_count, delete_count);
#endif
if (this_p == NULL) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("ERROR - NULL pointer passed to ax25_delete.\n");
return;
}
delete_count++;
#if AX25MEMDEBUG
if (ax25memdebug) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("ax25_delete, seq=%d, called from %s %d, new_count=%d, delete_count=%d\n", this_p->seq, src_file, src_line, new_count, delete_count);
}
#endif
assert (this_p->magic1 == MAGIC);
assert (this_p->magic2 == MAGIC);
this_p->magic1 = 0;
this_p->magic1 = 0;
//memset (this_p, 0, sizeof (struct packet_s));
free (this_p);
}
/*------------------------------------------------------------------------------
*
* Name: ax25_from_text
*
* Purpose: Parse a frame in human-readable monitoring format and change
* to internal representation.
*
* Input: monitor - "TNC-2" monitor format for packet. i.e.
* source>dest[,repeater1,repeater2,...]:information
*
* The information part can have non-printable characters
* in the form of <0xff>. This will be converted to single
* bytes. e.g. <0x0d> is carriage return.
* In version 1.4H we will allow nul characters which means
* we have to maintain a length rather than using strlen().
* I maintain that it violates the spec but want to handle it
* because it does happen and we want to preserve it when
* acting as an IGate rather than corrupting it.
*
* strict - True to enforce rules for packets sent over the air.
* False to be more lenient for packets from IGate server.
*
* Messages from an IGate server can have longer
* addresses after qAC. Up to 9 observed so far.
*
* We can just truncate the name because we will only
* end up discarding it. TODO: check on this.
*
* Returns: Pointer to new packet object in the current implementation.
*
* Outputs: Use the "get" functions to retrieve information in different ways.
*
*------------------------------------------------------------------------------*/
#if AX25MEMDEBUG
packet_t ax25_from_text_debug (char *monitor, int strict, char *src_file, int src_line)
#else
packet_t ax25_from_text (char *monitor, int strict)
#endif
{
/*
* Tearing it apart is destructive so make our own copy first.
*/
char stuff[512];
char *pinfo;
char *pa;
char *saveptr; /* Used with strtok_r because strtok is not thread safe. */
int ssid_temp, heard_temp;
char atemp[AX25_MAX_ADDR_LEN];
char info_part[AX25_MAX_INFO_LEN+1];
int info_len;
packet_t this_p = ax25_new ();
#if AX25MEMDEBUG
if (ax25memdebug) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("ax25_from_text, seq=%d, called from %s %d\n", this_p->seq, src_file, src_line);
}
#endif
/* Is it possible to have a nul character (zero byte) in the */
/* information field of an AX.25 frame? */
/* At this point, we have a normal C string. */
/* It is possible that will convert <0x00> to a nul character later. */
/* There we need to maintain a separate length and not use normal C string functions. */
strlcpy (stuff, monitor, sizeof(stuff));
/*
* Initialize the packet structure with two addresses and control/pid
* for APRS.
*/
memset (this_p->frame_data + AX25_DESTINATION*7, ' ' << 1, 6);
this_p->frame_data[AX25_DESTINATION*7+6] = SSID_H_MASK | SSID_RR_MASK;
memset (this_p->frame_data + AX25_SOURCE*7, ' ' << 1, 6);
this_p->frame_data[AX25_SOURCE*7+6] = SSID_H_MASK | SSID_RR_MASK | SSID_LAST_MASK;
this_p->frame_data[14] = AX25_UI_FRAME;
this_p->frame_data[15] = AX25_PID_NO_LAYER_3;
this_p->frame_len = 7 + 7 + 1 + 1;
this_p->num_addr = (-1);
assert (ax25_get_num_addr(this_p) == 2);
/*
* Separate the addresses from the rest.
*/
pinfo = strchr (stuff, ':');
if (pinfo == NULL) {
ax25_delete (this_p);
return (NULL);
}
*pinfo = '\0';
pinfo++;
/*
* Separate the addresses.
* Note that source and destination order is swappped.
*/
/*
* Source address.
* Don't use traditional strtok because it is not thread safe.
*/
pa = strtok_r (stuff, ">", &saveptr);
if (pa == NULL) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Failed to create packet from text. No source address\n");
ax25_delete (this_p);
return (NULL);
}
if ( ! ax25_parse_addr (AX25_SOURCE, pa, strict, atemp, &ssid_temp, &heard_temp)) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Failed to create packet from text. Bad source address\n");
ax25_delete (this_p);
return (NULL);
}
ax25_set_addr (this_p, AX25_SOURCE, atemp);
ax25_set_h (this_p, AX25_SOURCE); // c/r in this position
ax25_set_ssid (this_p, AX25_SOURCE, ssid_temp);
/*
* Destination address.
*/
pa = strtok_r (NULL, ",", &saveptr);
if (pa == NULL) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Failed to create packet from text. No destination address\n");
ax25_delete (this_p);
return (NULL);
}
if ( ! ax25_parse_addr (AX25_DESTINATION, pa, strict, atemp, &ssid_temp, &heard_temp)) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Failed to create packet from text. Bad destination address\n");
ax25_delete (this_p);
return (NULL);
}
ax25_set_addr (this_p, AX25_DESTINATION, atemp);
ax25_set_h (this_p, AX25_DESTINATION); // c/r in this position
ax25_set_ssid (this_p, AX25_DESTINATION, ssid_temp);
/*
* VIA path.
*/
while (( pa = strtok_r (NULL, ",", &saveptr)) != NULL && this_p->num_addr < AX25_MAX_ADDRS ) {
int k;
k = this_p->num_addr;
if ( ! ax25_parse_addr (k, pa, strict, atemp, &ssid_temp, &heard_temp)) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Failed to create packet from text. Bad digipeater address\n");
ax25_delete (this_p);
return (NULL);
}
ax25_set_addr (this_p, k, atemp);
ax25_set_ssid (this_p, k, ssid_temp);
// Does it have an "*" at the end?
// TODO: Complain if more than one "*".
// Could also check for all has been repeated bits are adjacent.
if (heard_temp) {
for ( ; k >= AX25_REPEATER_1; k--) {
ax25_set_h (this_p, k);
}
}
}
/*
* Finally, process the information part.
*
* Translate hexadecimal values like <0xff> to single bytes.
* MIC-E format uses 5 different non-printing characters.
* We might want to manually generate UTF-8 characters such as degree.
*/
//#define DEBUG14H 1
#if DEBUG14H
text_color_set(DW_COLOR_DEBUG);
dw_printf ("BEFORE: %s\nSAFE: ", pinfo);
ax25_safe_print (pinfo, -1, 0);
dw_printf ("\n");
#endif
info_len = 0;
while (*pinfo != '\0' && info_len < AX25_MAX_INFO_LEN) {
if (strlen(pinfo) >= 6 &&
pinfo[0] == '<' &&
pinfo[1] == '0' &&
pinfo[2] == 'x' &&
isxdigit(pinfo[3]) &&
isxdigit(pinfo[4]) &&
pinfo[5] == '>') {
char *p;
info_part[info_len] = strtol (pinfo + 3, &p, 16);
info_len++;
pinfo += 6;
}
else {
info_part[info_len] = *pinfo;
info_len++;
pinfo++;
}
}
info_part[info_len] = '\0';
#if DEBUG14H
text_color_set(DW_COLOR_DEBUG);
dw_printf ("AFTER: %s\nSAFE: ", info_part);
ax25_safe_print (info_part, info_len, 0);
dw_printf ("\n");
#endif
/*
* Append the info part.
*/
memcpy ((char*)(this_p->frame_data+this_p->frame_len), info_part, info_len);
this_p->frame_len += info_len;
return (this_p);
}
/*------------------------------------------------------------------------------
*
* Name: ax25_from_frame
*
* Purpose: Split apart an HDLC frame to components.
*
* Inputs: fbuf - Pointer to beginning of frame.
*
* flen - Length excluding the two FCS bytes.
*
* alevel - Audio level of received signal.
* Maximum range 0 - 100.
* -1 might be used when not applicable.
*
* Returns: Pointer to new packet object or NULL if error.
*
* Outputs: Use the "get" functions to retrieve information in different ways.
*
*------------------------------------------------------------------------------*/
#if AX25MEMDEBUG
packet_t ax25_from_frame_debug (unsigned char *fbuf, int flen, alevel_t alevel, char *src_file, int src_line)
#else
packet_t ax25_from_frame (unsigned char *fbuf, int flen, alevel_t alevel)
#endif
{
packet_t this_p;
/*
* First make sure we have an acceptable length:
*
* We are not concerned with the FCS (CRC) because someone else checked it.
*
* Is is possible to have zero length for info?
*
* In the original version, assuming APRS, the answer was no.
* We always had at least 3 octets after the address part:
* control, protocol, and first byte of info part for data type.
*
* In later versions, this restriction was relaxed so other
* variations of AX.25 could be used. Now the minimum length
* is 7+7 for addresses plus 1 for control.
*
*/
if (flen < AX25_MIN_PACKET_LEN || flen > AX25_MAX_PACKET_LEN)
{
text_color_set(DW_COLOR_ERROR);
dw_printf ("Frame length %d not in allowable range of %d to %d.\n", flen, AX25_MIN_PACKET_LEN, AX25_MAX_PACKET_LEN);
return (NULL);
}
this_p = ax25_new ();
#if AX25MEMDEBUG
if (ax25memdebug) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("ax25_from_frame, seq=%d, called from %s %d\n", this_p->seq, src_file, src_line);
}
#endif
/* Copy the whole thing intact. */
memcpy (this_p->frame_data, fbuf, flen);
this_p->frame_data[flen] = 0;
this_p->frame_len = flen;
/* Find number of addresses. */
this_p->num_addr = (-1);
(void) ax25_get_num_addr (this_p);
return (this_p);
}
/*------------------------------------------------------------------------------
*
* Name: ax25_dup
*
* Purpose: Make a copy of given packet object.
*
* Inputs: copy_from - Existing packet object.
*
* Returns: Pointer to new packet object or NULL if error.
*
*
*------------------------------------------------------------------------------*/
#if AX25MEMDEBUG
packet_t ax25_dup_debug (packet_t copy_from, char *src_file, int src_line)
#else
packet_t ax25_dup (packet_t copy_from)
#endif
{
int save_seq;
packet_t this_p;
this_p = ax25_new ();
assert (this_p != NULL);
save_seq = this_p->seq;
memcpy (this_p, copy_from, sizeof (struct packet_s));
this_p->seq = save_seq;
#if AX25MEMDEBUG
if (ax25memdebug) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("ax25_dup, seq=%d, called from %s %d, clone of seq %d\n", this_p->seq, src_file, src_line, copy_from->seq);
}
#endif
return (this_p);
}
/*------------------------------------------------------------------------------
*
* Name: ax25_parse_addr
*
* Purpose: Parse address with optional ssid.
*
* Inputs: position - AX25_DESTINATION, AX25_SOURCE, AX25_REPEATER_1...
* Used for more specific error message. -1 if not used.
*
* in_addr - Input such as "WB2OSZ-15*"
*
* strict - 1 (true) for strict checking (6 characters, no lower case,
* SSID must be in range of 0 to 15).
* Strict is appropriate for packets sent
* over the radio. Communication with IGate
* allows lower case (e.g. "qAR") and two
* alphanumeric characters for the SSID.
* We also get messages like this from a server.
* KB1POR>APU25N,TCPIP*,qAC,T2NUENGLD:...
*
* 2 (extra true) will complain if * is found at end.
*
* Outputs: out_addr - Address without any SSID.
* Must be at least AX25_MAX_ADDR_LEN bytes.
*
* out_ssid - Numeric value of SSID.
*
* out_heard - True if "*" found.
*
* Returns: True (1) if OK, false (0) if any error.
* When 0, out_addr, out_ssid, and out_heard are unpredictable.
*
*
*------------------------------------------------------------------------------*/
static const char *position_name[1 + AX25_MAX_ADDRS] = {
"", "Destination ", "Source ",
"Digi1 ", "Digi2 ", "Digi3 ", "Digi4 ",
"Digi5 ", "Digi6 ", "Digi7 ", "Digi8 " };
int ax25_parse_addr (int position, char *in_addr, int strict, char *out_addr, int *out_ssid, int *out_heard)
{
char *p;
char sstr[8]; /* Should be 1 or 2 digits for SSID. */
int i, j, k;
int maxlen;
*out_addr = '\0';
*out_ssid = 0;
*out_heard = 0;
if (position < -1) position = -1;
if (position > AX25_REPEATER_8) position = AX25_REPEATER_8;
position++; /* Adjust for position_name above. */
if (strict && strlen(in_addr) >= 2 && strncmp(in_addr, "qA", 2) == 0) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("%sAddress \"%s\" is a \"q-construct\" used for communicating with\n", position_name[position], in_addr);
dw_printf ("APRS Internet Servers. It should never appear when going over the radio.\n");
}
//dw_printf ("ax25_parse_addr in: %s\n", in_addr);
maxlen = strict ? 6 : (AX25_MAX_ADDR_LEN-1);
p = in_addr;
i = 0;
for (p = in_addr; *p != '\0' && *p != '-' && *p != '*'; p++) {
if (i >= maxlen) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("%sAddress is too long. \"%s\" has more than %d characters.\n", position_name[position], in_addr, maxlen);
return 0;
}
if ( ! isalnum(*p)) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("%sAddress, \"%s\" contains character other than letter or digit in character position %d.\n", position_name[position], in_addr, (int)(long)(p-in_addr)+1);
return 0;
}
out_addr[i++] = *p;
out_addr[i] = '\0';
#if DECAMAIN // Hack when running in decode_aprs utility.
// Exempt the "qA..." case because it was already mentioned.
if (strict && islower(*p) && strncmp(in_addr, "qA", 2) != 0) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("%sAddress has lower case letters. \"%s\" must be all upper case.\n", position_name[position], in_addr);
}
#else
if (strict && islower(*p)) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("%sAddress has lower case letters. \"%s\" must be all upper case.\n", position_name[position], in_addr);
return 0;
}
#endif
}
j = 0;
sstr[j] = '\0';
if (*p == '-') {
for (p++; isalnum(*p); p++) {
if (j >= 2) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("%sSSID is too long. SSID part of \"%s\" has more than 2 characters.\n", position_name[position], in_addr);
return 0;
}
sstr[j++] = *p;
sstr[j] = '\0';
if (strict && ! isdigit(*p)) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("%sSSID must be digits. \"%s\" has letters in SSID.\n", position_name[position], in_addr);
return 0;
}
}
k = atoi(sstr);
if (k < 0 || k > 15) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("%sSSID out of range. SSID of \"%s\" not in range of 0 to 15.\n", position_name[position], in_addr);
return 0;
}
*out_ssid = k;
}
if (*p == '*') {
*out_heard = 1;
p++;
if (strict == 2) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("\"*\" is not allowed at end of address \"%s\" here.\n", in_addr);
return 0;
}
}
if (*p != '\0') {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Invalid character \"%c\" found in %saddress \"%s\".\n", *p, position_name[position], in_addr);
return 0;
}
//dw_printf ("ax25_parse_addr out: %s %d %d\n", out_addr, *out_ssid, *out_heard);
return (1);
} /* end ax25_parse_addr */
/*-------------------------------------------------------------------
*
* Name: ax25_check_addresses
*
* Purpose: Check addresses of given packet and print message if any issues.
* We call this when receiving and transmitting.
*
* Inputs: pp - packet object pointer.
*
* Errors: Print error message.
*
* Returns: 1 for all valid. 0 if not.
*
* Examples: I was surprised to get this from an APRS-IS server with
* a lower case source address.
*
* n1otx>APRS,TCPIP*,qAC,THIRD:@141335z4227.48N/07111.73W_348/005g014t044r000p000h60b10075.wview_5_20_2
*
* I haven't gotten to the bottom of this yet but it sounds
* like "q constructs" are somehow getting on to the air when
* they should only appear in conversations with IGate servers.
*
* https://groups.yahoo.com/neo/groups/direwolf_packet/conversations/topics/678
*
* WB0VGI-7>APDW12,W0YC-5*,qAR,AE0RF-10:}N0DZQ-10>APWW10,TCPIP,WB0VGI-7*:;145.230MN*080306z4607.62N/09230.58WrKE0ACL/R 145.230- T146.2 (Pine County ARES)
*
* Typical result:
*
* Digipeater WIDE2 (probably N3LEE-4) audio level = 28(10/6) [NONE] __|||||||
* [0.5] VE2DJE-9>P_0_P?,VE2PCQ-3,K1DF-7,N3LEE-4,WIDE2*:'{S+l <0x1c>>/
* Invalid character "_" in MIC-E destination/latitude.
* Invalid character "_" in MIC-E destination/latitude.
* Invalid character "?" in MIC-E destination/latitude.
* Invalid MIC-E N/S encoding in 4th character of destination.
* Invalid MIC-E E/W encoding in 6th character of destination.
* MIC-E, normal car (side view), Unknown manufacturer, Returning
* N 00 00.0000, E 005 55.1500, 0 MPH
* Invalid character "_" found in Destination address "P_0_P?".
*
* *** The origin and journey of this packet should receive some scrutiny. ***
*
*--------------------------------------------------------------------*/
int ax25_check_addresses (packet_t pp)
{
int n;
char addr[AX25_MAX_ADDR_LEN];
char ignore1[AX25_MAX_ADDR_LEN];
int ignore2, ignore3;
int all_ok = 1;
for (n = 0; n < ax25_get_num_addr(pp); n++) {
ax25_get_addr_with_ssid (pp, n, addr);
all_ok &= ax25_parse_addr (n, addr, 1, ignore1, &ignore2, &ignore3);
}
if (! all_ok) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("\n");
dw_printf ("*** The origin and journey of this packet should receive some scrutiny. ***\n");
dw_printf ("\n");
}
return (all_ok);
} /* end ax25_check_addresses */
/*------------------------------------------------------------------------------
*
* Name: ax25_unwrap_third_party
*
* Purpose: Unwrap a third party messge from the header.
*
* Inputs: copy_from - Existing packet object.
*
* Returns: Pointer to new packet object or NULL if error.
*
* Example: Input: A>B,C:}D>E,F:info
* Output: D>E,F:info
*
*------------------------------------------------------------------------------*/
packet_t ax25_unwrap_third_party (packet_t from_pp)
{
unsigned char *info_p;
packet_t result_pp;
if (ax25_get_dti(from_pp) != '}') {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error: ax25_unwrap_third_party: wrong data type.\n");
return (NULL);
}
(void) ax25_get_info (from_pp, &info_p);
// Want strict because addresses should conform to AX.25 here.
// That's not the case for something from an Internet Server.
result_pp = ax25_from_text((char *)info_p + 1, 1);
return (result_pp);
}
/*------------------------------------------------------------------------------
*
* Name: ax25_set_addr
*
* Purpose: Add or change an address.
*
* Inputs: n - Index of address. Use the symbols
* AX25_DESTINATION, AX25_SOURCE, AX25_REPEATER1, etc.
*
* Must be either an existing address or one greater
* than the final which causes a new one to be added.
*
* ad - Address with optional dash and substation id.
*
* Assumption: ax25_from_text or ax25_from_frame was called first.
*
* TODO: ax25_from_text could use this.
*
* Returns: None.
*
*------------------------------------------------------------------------------*/
void ax25_set_addr (packet_t this_p, int n, char *ad)
{
int ssid_temp, heard_temp;
char atemp[AX25_MAX_ADDR_LEN];
int i;
assert (this_p->magic1 == MAGIC);
assert (this_p->magic2 == MAGIC);
assert (n >= 0 && n < AX25_MAX_ADDRS);
//dw_printf ("ax25_set_addr (%d, %s) num_addr=%d\n", n, ad, this_p->num_addr);
if (n >= 0 && n < this_p->num_addr) {
//dw_printf ("ax25_set_addr , existing case\n");
/*
* Set existing address position.
*/
// Why aren't we setting 'strict' here?
// Messages from IGate have q-constructs.
// We use this to parse it and later remove unwanted parts.
ax25_parse_addr (n, ad, 0, atemp, &ssid_temp, &heard_temp);
memset (this_p->frame_data + n*7, ' ' << 1, 6);