//
// This file is part of Dire Wolf, an amateur radio packet TNC.
//
// Copyright (C) 2016 John Langner, WB2OSZ
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
/*------------------------------------------------------------------
*
* Name: ax25_pad2.c
*
* Purpose: Packet assembler and disasembler, part 2.
*
* Description:
*
* The original ax25_pad.c was written with APRS in mind.
* It handles UI frames and transparency for a KISS TNC.
* Here we add new functions that can handle the
* more general cases of AX.25 frames.
*
*
* * Destination Address (note: opposite order in printed format)
*
* * Source Address
*
* * 0-8 Digipeater Addresses
* (The AX.25 v2.2 spec reduced this number to
* a maximum of 2 but I allow the original 8.)
*
* 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. Set to 1 for command.
* R R = Reserved = 1 1 (See RR note, below)
* SSID = substation ID
* 0 = zero
*
* The final octet of the Source has the form:
*
* C R R SSID 0, where,
*
* C = command/response. Must be inverse of destination C bit.
* R R = Reserved = 1 1 (See RR note, below)
* 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.
*
*
* Next we have:
*
* * One or two byte Control Field - A U frame always has one control byte.
* When using modulo 128 sequence numbers, the
* I and S frames can have a second byte allowing
* 7 bit fields instead of 3 bit fields.
* Unfortunately, we can't tell which we have by looking
* at a frame out of context. :-(
* If we are one end of the link, we would know this
* from SABM/SABME and possible later negotiation
* with XID. But if we start monitoring two other
* stations that are already conversing, we don't know.
*
* RR note: It seems that some implementations put a hint
* in the "RR" reserved bits.
* http://www.tapr.org/pipermail/ax25-layer2/2005-October/000297.html
* The RR bits can also be used for "DAMA" which is
* some sort of channel access coordination scheme.
* http://internet.freepage.de/cgi-bin/feets/freepage_ext/41030x030A/rewrite/hennig/afu/afudoc/afudama.html
* Neither is part of the official protocol spec.
*
* * One byte Protocol ID - Only for I and UI frames.
* Normally we would use 0xf0 for no layer 3.
*
* Finally the Information Field. The initial max size is 256 but it
* can be negotiated higher if both ends agree.
*
* Only these types of frames can have an information part:
* - I
* - UI
* - XID
* - TEST
* - FRMR
*
* The 2 byte CRC is not stored here.
*
*
* Constructors:
* ax25_u_frame - Construct a U frame.
* ax25_s_frame - Construct a S frame.
* ax25_i_frame - Construct a I frame.
*
* Get methods: .... ???
*
*------------------------------------------------------------------*/
#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 "textcolor.h"
#include "ax25_pad.h"
#include "ax25_pad2.h"
extern int ax25memdebug;
static int set_addrs (packet_t pp, char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_addr, cmdres_t cr);
//#if AX25MEMDEBUG
//#undef AX25MEMDEBUG
//#endif
/*------------------------------------------------------------------------------
*
* Name: ax25_u_frame
*
* Purpose: Construct a U frame.
*
* Input: addrs - Array of addresses.
*
* num_addr - Number of addresses, range 2 .. 10.
*
* cr - cr_cmd command frame, cr_res for a response frame.
*
* ftype - One of:
* frame_type_U_SABME // Set Async Balanced Mode, Extended
* frame_type_U_SABM // Set Async Balanced Mode
* frame_type_U_DISC // Disconnect
* frame_type_U_DM // Disconnect Mode
* frame_type_U_UA // Unnumbered Acknowledge
* frame_type_U_FRMR // Frame Reject
* frame_type_U_UI // Unnumbered Information
* frame_type_U_XID // Exchange Identification
* frame_type_U_TEST // Test
*
* pf - Poll/Final flag.
*
* pid - Protocol ID. >>> Used ONLY for the UI type. <<<
* Normally 0xf0 meaning no level 3.
* Could be other values for NET/ROM, etc.
*
* pinfo - Pointer to data for Info field. Allowed only for UI, XID, TEST, FRMR.
*
* info_len - Length for Info field.
*
*
* Returns: Pointer to new packet object.
*
*------------------------------------------------------------------------------*/
#if AX25MEMDEBUG
packet_t ax25_u_frame_debug (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_addr, cmdres_t cr, ax25_frame_type_t ftype, int pf, int pid, unsigned char *pinfo, int info_len, char *src_file, int src_line)
#else
packet_t ax25_u_frame (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_addr, cmdres_t cr, ax25_frame_type_t ftype, int pf, int pid, unsigned char *pinfo, int info_len)
#endif
{
packet_t this_p;
unsigned char *p;
int ctrl = 0;
unsigned int t = 999; // 1 = must be cmd, 0 = must be response, 2 = can be either.
int i = 0; // Is Info part allowed?
this_p = ax25_new ();
#if AX25MEMDEBUG
if (ax25memdebug) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("ax25_u_frame, seq=%d, called from %s %d\n", this_p->seq, src_file, src_line);
}
#endif
if (this_p == NULL) return (NULL);
this_p->modulo = 0;
if ( ! set_addrs (this_p, addrs, num_addr, cr)) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: Could not set addresses for U frame.\n", __func__);
ax25_delete (this_p);
return (NULL);
}
switch (ftype) {
// 1 = cmd only, 0 = res only, 2 = either
case frame_type_U_SABME: ctrl = 0x6f; t = 1; break;
case frame_type_U_SABM: ctrl = 0x2f; t = 1; break;
case frame_type_U_DISC: ctrl = 0x43; t = 1; break;
case frame_type_U_DM: ctrl = 0x0f; t = 0; break;
case frame_type_U_UA: ctrl = 0x63; t = 0; break;
case frame_type_U_FRMR: ctrl = 0x87; t = 0; i = 1; break;
case frame_type_U_UI: ctrl = 0x03; t = 2; i = 1; break;
case frame_type_U_XID: ctrl = 0xaf; t = 2; i = 1; break;
case frame_type_U_TEST: ctrl = 0xe3; t = 2; i = 1; break;
default:
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: Invalid ftype %d for U frame.\n", __func__, ftype);
ax25_delete (this_p);
return (NULL);
break;
}
if (pf) ctrl |= 0x10;
if (t != 2) {
if (cr != t) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: U frame, cr is %d but must be %d. ftype=%d\n", __func__, cr, t, ftype);
}
}
p = this_p->frame_data + this_p->frame_len;
*p++ = ctrl;
this_p->frame_len++;
if (ftype == frame_type_U_UI) {
// Definitely don't want pid value of 0 (not in valid list)
// or 0xff (which means more bytes follow).
if (pid < 0 || pid == 0 || pid == 0xff) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: U frame, Invalid pid value 0x%02x.\n", __func__, pid);
pid = AX25_PID_NO_LAYER_3;
}
*p++ = pid;
this_p->frame_len++;
}
if (i) {
if (pinfo != NULL && info_len > 0) {
if (info_len > AX25_MAX_INFO_LEN) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: U frame, Invalid information field length %d.\n", __func__, info_len);
info_len = AX25_MAX_INFO_LEN;
}
memcpy (p, pinfo, info_len);
p += info_len;
this_p->frame_len += info_len;
}
}
else {
if (pinfo != NULL && info_len > 0) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: Info part not allowed for U frame type.\n", __func__);
}
}
*p = '\0';
assert (p == this_p->frame_data + this_p->frame_len);
assert (this_p->magic1 == MAGIC);
assert (this_p->magic2 == MAGIC);
#if PAD2TEST
ax25_frame_type_t check_ftype;
cmdres_t check_cr;
char check_desc[80];
int check_pf;
int check_nr;
int check_ns;
check_ftype = ax25_frame_type (this_p, &check_cr, check_desc, &check_pf, &check_nr, &check_ns);
text_color_set(DW_COLOR_DEBUG);
dw_printf ("check: ftype=%d, desc=\"%s\", pf=%d\n", check_ftype, check_desc, check_pf);
assert (check_cr == cr);
assert (check_ftype == ftype);
assert (check_pf == pf);
assert (check_nr == -1);
assert (check_ns == -1);
#endif
return (this_p);
} /* end ax25_u_frame */
/*------------------------------------------------------------------------------
*
* Name: ax25_s_frame
*
* Purpose: Construct an S frame.
*
* Input: addrs - Array of addresses.
*
* num_addr - Number of addresses, range 2 .. 10.
*
* cr - cr_cmd command frame, cr_res for a response frame.
*
* ftype - One of:
* frame_type_S_RR, // Receive Ready - System Ready To Receive
* frame_type_S_RNR, // Receive Not Ready - TNC Buffer Full
* frame_type_S_REJ, // Reject Frame - Out of Sequence or Duplicate
* frame_type_S_SREJ, // Selective Reject - Request single frame repeat
*
* modulo - 8 or 128. Determines if we have 1 or 2 control bytes.
*
* nr - N(R) field --- describe.
*
* pf - Poll/Final flag.
*
* pinfo - Pointer to data for Info field. Allowed only for SREJ.
*
* info_len - Length for Info field.
*
*
* Returns: Pointer to new packet object.
*
*------------------------------------------------------------------------------*/
#if AX25MEMDEBUG
packet_t ax25_s_frame_debug (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_addr, cmdres_t cr, ax25_frame_type_t ftype, int modulo, int nr, int pf, unsigned char *pinfo, int info_len, char *src_file, int src_line)
#else
packet_t ax25_s_frame (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_addr, cmdres_t cr, ax25_frame_type_t ftype, int modulo, int nr, int pf, unsigned char *pinfo, int info_len)
#endif
{
packet_t this_p;
unsigned char *p;
int ctrl = 0;
this_p = ax25_new ();
#if AX25MEMDEBUG
if (ax25memdebug) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("ax25_s_frame, seq=%d, called from %s %d\n", this_p->seq, src_file, src_line);
}
#endif
if (this_p == NULL) return (NULL);
if ( ! set_addrs (this_p, addrs, num_addr, cr)) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: Could not set addresses for S frame.\n", __func__);
ax25_delete (this_p);
return (NULL);
}
if (modulo != 8 && modulo != 128) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: Invalid modulo %d for S frame.\n", __func__, modulo);
modulo = 8;
}
this_p->modulo = modulo;
if (nr < 0 || nr >= modulo) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: Invalid N(R) %d for S frame.\n", __func__, nr);
nr &= (modulo - 1);
}
// Erratum: The AX.25 spec is not clear about whether SREJ should be command, response, or both.
// The underlying X.25 spec clearly says it is reponse only. Let's go with that.
if (ftype == frame_type_S_SREJ && cr != cr_res) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: SREJ must be response.\n", __func__);
}
switch (ftype) {
case frame_type_S_RR: ctrl = 0x01; break;
case frame_type_S_RNR: ctrl = 0x05; break;
case frame_type_S_REJ: ctrl = 0x09; break;
case frame_type_S_SREJ: ctrl = 0x0d; break;
default:
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: Invalid ftype %d for S frame.\n", __func__, ftype);
ax25_delete (this_p);
return (NULL);
break;
}
p = this_p->frame_data + this_p->frame_len;
if (modulo == 8) {
if (pf) ctrl |= 0x10;
ctrl |= nr << 5;
*p++ = ctrl;
this_p->frame_len++;
}
else {
*p++ = ctrl;
this_p->frame_len++;
ctrl = pf & 1;
ctrl |= nr << 1;
*p++ = ctrl;
this_p->frame_len++;
}
if (ftype == frame_type_S_SREJ) {
if (pinfo != NULL && info_len > 0) {
if (info_len > AX25_MAX_INFO_LEN) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: SREJ frame, Invalid information field length %d.\n", __func__, info_len);
info_len = AX25_MAX_INFO_LEN;
}
memcpy (p, pinfo, info_len);
p += info_len;
this_p->frame_len += info_len;
}
}
else {
if (pinfo != NULL || info_len != 0) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: Info part not allowed for RR, RNR, REJ frame.\n", __func__);
}
}
*p = '\0';
assert (p == this_p->frame_data + this_p->frame_len);
assert (this_p->magic1 == MAGIC);
assert (this_p->magic2 == MAGIC);
#if PAD2TEST
ax25_frame_type_t check_ftype;
cmdres_t check_cr;
char check_desc[80];
int check_pf;
int check_nr;
int check_ns;
// todo modulo must be input.
check_ftype = ax25_frame_type (this_p, &check_cr, check_desc, &check_pf, &check_nr, &check_ns);
text_color_set(DW_COLOR_DEBUG);
dw_printf ("check: ftype=%d, desc=\"%s\", pf=%d, nr=%d\n", check_ftype, check_desc, check_pf, check_nr);
assert (check_cr == cr);
assert (check_ftype == ftype);
assert (check_pf == pf);
assert (check_nr == nr);
assert (check_ns == -1);
#endif
return (this_p);
} /* end ax25_s_frame */
/*------------------------------------------------------------------------------
*
* Name: ax25_i_frame
*
* Purpose: Construct an I frame.
*
* Input: addrs - Array of addresses.
*
* num_addr - Number of addresses, range 2 .. 10.
*
* cr - cr_cmd command frame, cr_res for a response frame.
*
* modulo - 8 or 128.
*
* nr - N(R) field --- describe.
*
* ns - N(S) field --- describe.
*
* pf - Poll/Final flag.
*
* pid - Protocol ID.
* Normally 0xf0 meaning no level 3.
* Could be other values for NET/ROM, etc.
*
* pinfo - Pointer to data for Info field.
*
* info_len - Length for Info field.
*
*
* Returns: Pointer to new packet object.
*
*------------------------------------------------------------------------------*/
#if AX25MEMDEBUG
packet_t ax25_i_frame_debug (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_addr, cmdres_t cr, int modulo, int nr, int ns, int pf, int pid, unsigned char *pinfo, int info_len, char *src_file, int src_line)
#else
packet_t ax25_i_frame (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_addr, cmdres_t cr, int modulo, int nr, int ns, int pf, int pid, unsigned char *pinfo, int info_len)
#endif
{
packet_t this_p;
unsigned char *p;
int ctrl = 0;
this_p = ax25_new ();
#if AX25MEMDEBUG
if (ax25memdebug) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("ax25_i_frame, seq=%d, called from %s %d\n", this_p->seq, src_file, src_line);
}
#endif
if (this_p == NULL) return (NULL);
if ( ! set_addrs (this_p, addrs, num_addr, cr)) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: Could not set addresses for I frame.\n", __func__);
ax25_delete (this_p);
return (NULL);
}
if (modulo != 8 && modulo != 128) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: Invalid modulo %d for I frame.\n", __func__, modulo);
modulo = 8;
}
this_p->modulo = modulo;
if (nr < 0 || nr >= modulo) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: Invalid N(R) %d for I frame.\n", __func__, nr);
nr &= (modulo - 1);
}
if (ns < 0 || ns >= modulo) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: Invalid N(S) %d for I frame.\n", __func__, ns);
ns &= (modulo - 1);
}
p = this_p->frame_data + this_p->frame_len;
if (modulo == 8) {
ctrl = (nr << 5) | (ns << 1);
if (pf) ctrl |= 0x10;
*p++ = ctrl;
this_p->frame_len++;
}
else {
ctrl = ns << 1;
*p++ = ctrl;
this_p->frame_len++;
ctrl = nr << 1;
if (pf) ctrl |= 0x01;
*p++ = ctrl;
this_p->frame_len++;
}
// Definitely don't want pid value of 0 (not in valid list)
// or 0xff (which means more bytes follow).
if (pid < 0 || pid == 0 || pid == 0xff) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("Warning: Client application provided invalid PID value, 0x%02x, for I frame.\n", pid);
pid = AX25_PID_NO_LAYER_3;
}
*p++ = pid;
this_p->frame_len++;
if (pinfo != NULL && info_len > 0) {
if (info_len > AX25_MAX_INFO_LEN) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("Internal error in %s: I frame, Invalid information field length %d.\n", __func__, info_len);
info_len = AX25_MAX_INFO_LEN;
}
memcpy (p, pinfo, info_len);
p += info_len;
this_p->frame_len += info_len;
}
*p = '\0';
assert (p == this_p->frame_data + this_p->frame_len);
assert (this_p->magic1 == MAGIC);
assert (this_p->magic2 == MAGIC);
#if PAD2TEST
ax25_frame_type_t check_ftype;
cmdres_t check_cr;
char check_desc[80];
int check_pf;
int check_nr;
int check_ns;
unsigned char *check_pinfo;
int check_info_len;
check_ftype = ax25_frame_type (this_p, &check_cr, check_desc, &check_pf, &check_nr, &check_ns);
text_color_set(DW_COLOR_DEBUG);
dw_printf ("check: ftype=%d, desc=\"%s\", pf=%d, nr=%d, ns=%d\n", check_ftype, check_desc, check_pf, check_nr, check_ns);
check_info_len = ax25_get_info (this_p, &check_pinfo);
assert (check_cr == cr);
assert (check_ftype == frame_type_I);
assert (check_pf == pf);
assert (check_nr == nr);
assert (check_ns == ns);
assert (check_info_len == info_len);
assert (strcmp((char*)check_pinfo,(char*)pinfo) == 0);
#endif
return (this_p);
} /* end ax25_i_frame */
/*------------------------------------------------------------------------------
*
* Name: set_addrs
*
* Purpose: Set address fields
*
* Input: pp - Packet object.
*
* addrs - Array of addresses. Same order as in frame.
*
* num_addr - Number of addresses, range 2 .. 10.
*
* cr - cr_cmd command frame, cr_res for a response frame.
*
* Output: pp->frame_data - 7 bytes for each address.
*
* pp->frame_len - num_addr * 7
*
* p->num_addr - num_addr
*
* Returns: 1 for success. 0 for failure.
*
*------------------------------------------------------------------------------*/
static int set_addrs (packet_t pp, char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_addr, cmdres_t cr)
{
int n;
assert (pp->frame_len == 0);
assert (cr == cr_cmd || cr == cr_res);
if (num_addr < AX25_MIN_ADDRS || num_addr > AX25_MAX_ADDRS) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("INTERNAL ERROR: %s %s %d, num_addr = %d\n", __FILE__, __func__, __LINE__, num_addr);
return (0);
}
for (n = 0; n < num_addr; n++) {
unsigned char *pa = pp->frame_data + n * 7;
int ok;
int strict = 1;
char oaddr[AX25_MAX_ADDR_LEN];
int ssid;
int heard;
int j;
ok = ax25_parse_addr (n, addrs[n], strict, oaddr, &ssid, &heard);
if (! ok) return (0);
// Fill in address.
memset (pa, ' ' << 1, 6);
for (j = 0; oaddr[j]; j++) {
pa[j] = oaddr[j] << 1;
}
pa += 6;
// Fill in SSID.
*pa = 0x60 | ((ssid & 0xf) << 1);
// Command / response flag.
switch (n) {
case AX25_DESTINATION:
if (cr == cr_cmd) *pa |= 0x80;
break;
case AX25_SOURCE:
if (cr == cr_res) *pa |= 0x80;
break;
default:
break;
}
// Is this the end of address field?
if (n == num_addr - 1) {
*pa |= 1;
}
pp->frame_len += 7;
}
pp->num_addr = num_addr;
return (1);
} /* end set_addrs */
/*------------------------------------------------------------------------------
*
* Name: main
*
* Purpose: Quick unit test for this file.
*
* Description: Generate a variety of frames.
* Each function calls ax25_frame_type to verify results.
*
* $ gcc -DPAD2TEST -DUSE_REGEX_STATIC -Iregex ax25_pad.c ax25_pad2.c fcs_calc.o textcolor.o regex.a misc.a
*
*------------------------------------------------------------------------------*/
#if PAD2TEST
int main ()
{
char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN];
int num_addr = 2;
cmdres_t cr;
ax25_frame_type_t ftype;
int pf = 0;
int pid = 0xf0;
int modulo;
int nr, ns;
unsigned char *pinfo = NULL;
int info_len = 0;
packet_t pp;
strcpy (addrs[0], "W2UB");
strcpy (addrs[1], "WB2OSZ-15");
num_addr = 2;
/* U frame */
for (ftype = frame_type_U_SABME; ftype <= frame_type_U_TEST; ftype++) {
for (pf = 0; pf <= 1; pf++) {
int cmin, cmax;
switch (ftype) {
// 0 = response, 1 = command
case frame_type_U_SABME: cmin = 1; cmax = 1; break;
case frame_type_U_SABM: cmin = 1; cmax = 1; break;
case frame_type_U_DISC: cmin = 1; cmax = 1; break;
case frame_type_U_DM: cmin = 0; cmax = 0; break;
case frame_type_U_UA: cmin = 0; cmax = 0; break;
case frame_type_U_FRMR: cmin = 0; cmax = 0; break;
case frame_type_U_UI: cmin = 0; cmax = 1; break;
case frame_type_U_XID: cmin = 0; cmax = 1; break;
case frame_type_U_TEST: cmin = 0; cmax = 1; break;
default: break; // avoid compiler warning.
}
for (cr = cmin; cr <= cmax; cr++) {
text_color_set(DW_COLOR_INFO);
dw_printf ("\nConstruct U frame, cr=%d, ftype=%d, pid=0x%02x\n", cr, ftype, pid);
pp = ax25_u_frame (addrs, num_addr, cr, ftype, pf, pid, pinfo, info_len);
ax25_hex_dump (pp);
ax25_delete (pp);
}
}
}
dw_printf ("\n----------\n\n");
/* S frame */
strcpy (addrs[2], "DIGI1-1");
num_addr = 3;
for (ftype = frame_type_S_RR; ftype <= frame_type_S_SREJ; ftype++) {
for (pf = 0; pf <= 1; pf++) {
modulo = 8;
nr = modulo / 2 + 1;
for (cr = 0; cr <= 1; cr++) {
text_color_set(DW_COLOR_INFO);
dw_printf ("\nConstruct S frame, cmd=%d, ftype=%d, pid=0x%02x\n", cr, ftype, pid);
pp = ax25_s_frame (addrs, num_addr, cr, ftype, modulo, nr, pf, NULL, 0);
ax25_hex_dump (pp);
ax25_delete (pp);
}
modulo = 128;
nr = modulo / 2 + 1;
for (cr = 0; cr <= 1; cr++) {
text_color_set(DW_COLOR_INFO);
dw_printf ("\nConstruct S frame, cmd=%d, ftype=%d, pid=0x%02x\n", cr, ftype, pid);
pp = ax25_s_frame (addrs, num_addr, cr, ftype, modulo, nr, pf, NULL, 0);
ax25_hex_dump (pp);
ax25_delete (pp);
}
}
}
/* SREJ is only S frame which can have information part. */
static char srej_info[] = { 1<<1, 2<<1, 3<<1, 4<<1 };
ftype = frame_type_S_SREJ;
for (pf = 0; pf <= 1; pf++) {
modulo = 128;
nr = 127;
cr = cr_res;
text_color_set(DW_COLOR_INFO);
dw_printf ("\nConstruct Multi-SREJ S frame, cmd=%d, ftype=%d, pid=0x%02x\n", cr, ftype, pid);
pp = ax25_s_frame (addrs, num_addr, cr, ftype, modulo, nr, pf, srej_info, (int)(sizeof(srej_info)));
ax25_hex_dump (pp);
ax25_delete (pp);
}
dw_printf ("\n----------\n\n");
/* I frame */
pinfo = (unsigned char*)"The rain in Spain stays mainly on the plain.";
info_len = strlen((char*)pinfo);
for (pf = 0; pf <= 1; pf++) {
modulo = 8;
nr = 0x55 & (modulo - 1);
ns = 0xaa & (modulo - 1);
for (cr = 0; cr <= 1; cr++) {
text_color_set(DW_COLOR_INFO);
dw_printf ("\nConstruct I frame, cmd=%d, ftype=%d, pid=0x%02x\n", cr, ftype, pid);
pp = ax25_i_frame (addrs, num_addr, cr, modulo, nr, ns, pf, pid, pinfo, info_len);
ax25_hex_dump (pp);
ax25_delete (pp);
}
modulo = 128;
nr = 0x55 & (modulo - 1);
ns = 0xaa & (modulo - 1);
for (cr = 0; cr <= 1; cr++) {
text_color_set(DW_COLOR_INFO);
dw_printf ("\nConstruct I frame, cmd=%d, ftype=%d, pid=0x%02x\n", cr, ftype, pid);
pp = ax25_i_frame (addrs, num_addr, cr, modulo, nr, ns, pf, pid, pinfo, info_len);
ax25_hex_dump (pp);
ax25_delete (pp);
}
}
text_color_set(DW_COLOR_REC);
dw_printf ("\n----------\n\n");
dw_printf ("\nSUCCESS!\n");
exit (EXIT_SUCCESS);
} /* end main */
#endif
/* end ax25_pad2.c */