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D-Modem/slmodemd/modem_ec.c

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initial commit
2021-10-30 02:41:03 +08:00
/*
*
* Copyright (c) 2002, Smart Link Ltd.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* 3. Neither the name of the Smart Link Ltd. nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
/*
*
* modem_ec.c -- modem error corrector (lapm like) implementation.
*
* Author: Sasha K (sashak@smlink.com)
*
*
*/
#include <modem.h>
#include <modem_debug.h>
//#define EC_DEBUG 1
/* LAPM default parameters */
#define LAPM_DFLT_WIN_SIZE 15 /* default win size */
#define LAPM_DFLT_INFO_SIZE 128 /* default info size */
#define LAPM_MAX_RTX 5 /* max num of retransmissions (N400) */
/* timeouts */
// fixme: speed is parameter
#define _TMP_SPEED 28800
// fixme: what is timeout vals should be (2sec?)???
#define T401_TIMEOUT _TMP_SPEED*2 /* noacks timeout (in ???) */
#define T403_TIMEOUT _TMP_SPEED*2 /* no frames timeout */
/* LAPM definitions */
/* frame types */
#define FRAME_I 0x00
#define FRAME_S 0x01
#define FRAME_U 0x03
/* supervisory headers */
#define FRAME_S_RR 0x01 /* cr */
#define FRAME_S_RNR 0x05 /* cr */
#define FRAME_S_REJ 0x09 /* cr */
#define FRAME_S_SREJ 0x0d /* cr */
/* unnumbered headers */
#define FRAME_U_SABME 0x6f /* c */
#define FRAME_U_DM 0x0f /* r */
#define FRAME_U_UI 0x03 /* cr */
#define FRAME_U_DISC 0x43 /* c */
#define FRAME_U_UA 0x63 /* r */
#define FRAME_U_FRMR 0x87 /* r */
#define FRAME_U_XID 0xaf /* cr */
#define FRAME_U_TEST 0xe3 /* c */
/* useful macros */
#define FRAME_ADDR(f) ((f)->buf[0])
#define FRAME_CTRL(f) ((f)->buf[1])
#define FRAME_TYPE(f) ((f)->buf[1]&0x1 ? ((f)->buf[1]&0x3) : FRAME_I)
#define RX_IS_COMMAND(f) ((f)->buf[0] == l->rsp_addr)
#define TX_IS_COMMAND(f) ((f)->buf[0] == l->cmd_addr)
#define FRAME_I_PF(f) ((f)->buf[2]&0x1)
#define FRAME_S_PF(f) ((f)->buf[2]&0x1)
#define FRAME_U_PF(f) ((f)->buf[1]&0x10)
#define FRAME_NS(f) ((f)->buf[1]>>1)
#define FRAME_NR(f) ((f)->buf[2]>>1)
/* tx unnumbered */
#define TX_SABME(l) tx_unnum(l,l->cmd_addr,FRAME_U_SABME|0x10,0,0)
#define TX_DISC(l) tx_unnum(l,l->cmd_addr,FRAME_U_DISC|0x10,0,0)
#define TX_UA(l,pf_mask) tx_unnum(l,l->rsp_addr,FRAME_U_UA|pf_mask,0,0)
#define TX_DM(l,pf_mask) tx_unnum(l,l->rsp_addr,FRAME_U_DM|pf_mask,0,0)
/* tx supervisory */
#define TX_RR(l,addr,pf_mask) tx_super(l,addr,FRAME_S_RR,pf_mask)
#define TX_RNR(l,addr,pf_mask) tx_super(l,addr,FRAME_S_RNR,pf_mask)
#define TX_REJ(l,addr,pf_mask) tx_super(l,addr,FRAME_S_REJ,pf_mask)
/* timers */
#define T401_START(l) { EC_DBG("T401 start.\n");\
(l)->rtx_count = 0; \
(l)->modem->bit_timer = T401_TIMEOUT; \
(l)->modem->bit_timer_func = t401_timeout; }
#define T401_STOP(l) { EC_DBG("T401 stop.\n"); \
(l)->modem->bit_timer = 0; (l)->rtx_count = 0; }
#if T403_IMPLEMENTED
#define TIMER_START(l) { EC_DBG("T403 stop, T401 start.\n"); \
(l)->rtx_count = 0; \
(l)->modem->bit_timer = T401_TIMEOUT; \
(l)->modem->bit_timer_func = t401_timeout; }
#define TIMER_STOP(l) { EC_DBG("T401 stop, T403 start.\n"); \
(l)->rtx_count = 0; \
(l)->modem->bit_timer = T403_TIMEOUT; \
(l)->modem->bit_timer_func = t403_timeout; }
#else /* !T403 */
#define TIMER_START(l) T401_START(l)
#define TIMER_STOP(l) T401_STOP(l)
#endif /* !T403 */
/* xid sub-fields definitions */
#define FI_GENERAL 0x82
#define GI_PARAM_NEGOTIATION 0x80
#define GI_PRIVATE_NEGOTIATION 0xf0
#define GI_USER_DATA 0xff
/* param negotiation */
#define PI_HDLC_OPTFUNCS 0x03
#define PI_TX_INFO_MAXSIZE 0x05
#define PI_RX_INFO_MAXSIZE 0x06
#define PI_TX_WINDOW_SIZE 0x07
#define PI_RX_WINDOW_SIZE 0x08
/* private param negotiation */
#define PI_PARAMETER_SET_ID 0x00
#define PI_V42BIS_REQUEST 0x01
#define PI_V42BIS_CW_NUMBER 0x02
#define PI_V42BIS_MAX_STRING 0x03
/* user data */
/* fixme: ??? */
/* type definitions */
enum LAPM_STATES { LAPM_IDLE, LAPM_ESTAB, LAPM_DATA, LAPM_DISC };
/* prototypes */
static int lapm_connect(struct lapm_state *l);
static int lapm_disconnect(struct lapm_state *l);
static void reset(struct lapm_state *l);
/*
* service functions
*
*/
/* le/be value parsing */
extern inline u32 lapm_get_le_val(u8 *buf, int len)
{
u32 val = 0;
while(len--) {
val <<= 8;
val |= buf[len];
}
return val;
}
extern inline u32 lapm_get_be_val(u8 *buf, int len)
{
u32 val = 0;
while(len--) {
val <<= 8;
val |= *buf++;
}
return val;
}
/* debug stuffs */
#define EC_ERR(fmt,arg...) eprintf("%s ec err: " fmt , \
l->modem->name , ##arg)
#ifdef EC_DEBUG
#define EC_DBG(fmt,arg...) dprintf("%s ec: " fmt , \
l->modem->name , ##arg)
#define EC_DBG1(fmt...) // EC_DBG(fmt)
static char print_buf[(LAPM_MAX_INFO_SIZE+3)*2];
/* frame debug prints */
static const char *get_frame_name(frame_t *f)
{
if (!(f->buf[1]&0x1))
return "INFO";
switch(f->buf[1]&0xef) {
case FRAME_S_RR: return "RR";
case FRAME_S_RNR: return "RNR";
case FRAME_S_REJ: return "REJ";
case FRAME_S_SREJ: return "SREJ";
case FRAME_U_SABME: return "SABME";
case FRAME_U_DM: return "DM";
case FRAME_U_UI: return "UI";
case FRAME_U_DISC: return "DISC";
case FRAME_U_UA: return "UA";
case FRAME_U_FRMR: return "FRMR";
case FRAME_U_XID: return "XID";
case FRAME_U_TEST: return "TEST";
default:
break;
}
return "invalid frame";
}
static void print_frame(struct lapm_state *l, char *title, int cmd, frame_t *f)
{
int i;
i = sprintf(print_buf,"(va/vs/vr %d/%d/%d) %s: %s %s",
l->va,l->vs,l->vr,
title,get_frame_name(f),cmd?"cmd":"rsp");
switch (FRAME_TYPE(f)) {
case FRAME_I:
EC_DBG("%s[%d] cnt=%d, (ns/nr %d/%d)...\n",print_buf,
FRAME_I_PF(f),f->count-3,FRAME_NS(f),FRAME_NR(f));
break;
case FRAME_S:
EC_DBG("%s[%d], (nr %d)...\n",print_buf,
FRAME_S_PF(f), FRAME_NR(f));
break;
case FRAME_U:
EC_DBG("%s[%d]...\n",print_buf, FRAME_U_PF(f));
break;
default:
EC_DBG("%s: unknown frame.\n", print_buf);
break;
}
}
#define LAPM_PRINT_FRAME(str,cmd,f) print_frame(l,str,cmd,f)
/* XID debug prints */
static int print_xid_params(char *str_buf, u8 *buf, int len)
{
u8 pid, plen;
u32 pval;
int i = 0;
while (len > 0) {
pid = buf[0];
plen = buf[1];
buf += 2;
len -= 2 + plen;
if (len < 0)
break;
switch (pid) {
case PI_HDLC_OPTFUNCS:
i += sprintf(str_buf + i,"HDLC_OPTFUNC = 0x%x, ",
lapm_get_le_val(buf,plen));
break;
case PI_TX_INFO_MAXSIZE:
pval = lapm_get_be_val(buf,plen);
i += sprintf(str_buf + i,"TX_INFOSIZE = %u, ",pval>>3);
break;
case PI_RX_INFO_MAXSIZE:
pval = lapm_get_be_val(buf,plen);
i += sprintf(str_buf + i,"RX_INFOSIZE = %u, ",pval>>3);
break;
case PI_TX_WINDOW_SIZE:
i += sprintf(str_buf + i,"TX_WINSIZE = %u, ",
lapm_get_be_val(buf,plen));
break;
case PI_RX_WINDOW_SIZE:
i += sprintf(str_buf + i,"RX_WINSIZE = %u, ",
lapm_get_be_val(buf,plen));
break;
default:
i += sprintf(str_buf + i,"??, ");
break;
}
buf += plen;
}
i += sprintf(str_buf+i,"\n");
return i;
}
static int print_xid_private_params(char *str_buf, u8 *buf, int len)
{
u8 pid, plen;
int i = 0;
while (len > 0) {
pid = buf[0];
plen = buf[1];
buf += 2;
len -= 2 + plen;
if (len < 0)
break;
switch (pid) {
case PI_PARAMETER_SET_ID:
i += sprintf(str_buf + i,"PARAM_SETID = 0x%x, ",
lapm_get_be_val(buf,plen));
break;
case PI_V42BIS_REQUEST:
i += sprintf(str_buf + i,"V42BIS_REQUEST = 0x%x, ",
lapm_get_be_val(buf,plen));
break;
case PI_V42BIS_CW_NUMBER:
i += sprintf(str_buf + i,"V42BIS_CWNUM = %d, ",
lapm_get_be_val(buf,plen));
break;
case PI_V42BIS_MAX_STRING:
i += sprintf(str_buf + i,"V42BIS_MAXSTR = %d, ",
lapm_get_be_val(buf,plen));
break;
default:
i += sprintf(str_buf + i,"??, ");
break;
}
buf += plen;
}
i += sprintf(str_buf+i,"\n");
return i;
}
static int print_xid(struct lapm_state *l,char *str,frame_t *f, int len)
{
u8 *buf = f->buf + 2;
int i = 0;
i = sprintf(print_buf,"XID: FID %02x;\n",*buf);
buf++; len--;
while(len > 0) {
u8 gid = buf[0];
u16 glen = buf[1];
glen = glen << 8 | buf[2];
buf += 3;
len -= 3 + glen;
if (len < 0)
break;
switch (gid) {
case GI_PARAM_NEGOTIATION:
i += sprintf(print_buf+i,"GI_PARAMS(%d): ",glen);
i += print_xid_params(print_buf+i,buf,glen);
break;
case GI_PRIVATE_NEGOTIATION:
i += sprintf(print_buf+i,"GI_PRIVATE_PARAMS(%d): ",glen);
i += print_xid_private_params(print_buf+i,buf,glen);
break;
default:
i += sprintf(print_buf+i,"unknown GI = 0x%x (%d) ??\n",
gid,glen);
break;
}
buf += glen;
}
EC_DBG("%s : %s\n", str, print_buf);
return 0;
}
#define LAPM_PRINT_XID(str,f,len) print_xid(l,str,f,len);
#else /* !LAPM_DEBUG */
#define EC_DBG(fmt...)
#define EC_DBG1(fmt...)
#define LAPM_PRINT_FRAME(str,cmd,f)
#define LAPM_PRINT_XID(str,f,len)
#endif /* !LAPM_DEBUG */
/*
* service functions
*
*/
/* get frame from ctrl list */
static inline frame_t *get_ctrl_frame(struct lapm_state *l)
{
frame_t *f;
if ( l->ctrl_list->next == l->tx_ctrl ) {
return 0;
}
f = l->ctrl_list;
l->ctrl_list = l->ctrl_list->next;
l->ctrl_count--; // debug only
return f;
}
/* U transmission */
static int tx_unnum(struct lapm_state *l, u8 addr, u8 ctrl, u8 *info, int len)
{
frame_t *f = get_ctrl_frame(l);
if (!f) {
EC_ERR("tx_unnum: cannot alloc frame.\n");
return -1;
}
f->buf[0] = addr;
f->buf[1] = ctrl;
if (info && len)
memcpy(f->buf+2,info,len);
f->size = 2 + len;
return 0;
}
/* S transmission */
static int tx_super(struct lapm_state *l, u8 addr, u8 ctrl, u8 pf_mask)
{
frame_t *f = get_ctrl_frame(l);
if (!f) {
EC_ERR("tx_super: cannot alloc frame.\n");
return -1;
}
f->buf[0] = addr;
f->buf[1] = ctrl;
f->buf[2] = (l->vr << 1)|pf_mask;
f->size = 3;
return 0;
}
/* parse xid */
#define SET_PARAM(param,value,default) { \
if (((value)<(default) && (param)>=(default)) || \
((value)>=(default) && (param)<(default))) \
(param) = (default); \
else if (((value)<(default) && (param)<(value)) || \
((value)>=(default) && (param)>(value))) \
(param) = (value); }
static int parse_xid_params(struct lapm_state *l, u8 *buf, int len)
{
u32 pval;
u8 pid, plen;
while (len > 0) {
pid = buf[0];
plen = buf[1];
buf += 2;
len -= 2 + plen;
if (len < 0)
break;
switch (pid) {
case PI_HDLC_OPTFUNCS:
pval = lapm_get_le_val(buf,plen);
break;
case PI_TX_INFO_MAXSIZE:
pval = lapm_get_be_val(buf,plen);
pval >>= 3;
SET_PARAM(l->tx_info_size,pval,LAPM_DFLT_INFO_SIZE);
break;
case PI_RX_INFO_MAXSIZE:
pval = lapm_get_be_val(buf,plen);
pval >>= 3;
SET_PARAM(l->rx_info_size,pval,LAPM_DFLT_INFO_SIZE);
break;
case PI_TX_WINDOW_SIZE:
pval = lapm_get_be_val(buf,plen);
SET_PARAM(l->tx_win_size,pval,LAPM_DFLT_WIN_SIZE);
break;
case PI_RX_WINDOW_SIZE:
pval = lapm_get_be_val(buf,plen);
SET_PARAM(l->rx_win_size,pval,LAPM_DFLT_WIN_SIZE);
break;
default:
break;
}
buf += plen;
}
return 0;
}
static int parse_xid_private_params(struct lapm_state *l, struct modem_config *cfg, u8 *buf, int len)
{
u8 pid, plen;
while (len > 0) {
pid = buf[0];
plen = buf[1];
buf += 2;
len -= 2 + plen;
if (len < 0)
break;
switch (pid) {
case PI_PARAMETER_SET_ID:
//pval = lapm_get_be_val(buf,plen);
break;
case PI_V42BIS_REQUEST:
cfg->comp = lapm_get_le_val(buf,plen);
break;
case PI_V42BIS_CW_NUMBER:
cfg->comp_dict_size = lapm_get_be_val(buf,plen);
break;
case PI_V42BIS_MAX_STRING:
cfg->comp_max_string = lapm_get_be_val(buf,plen);
break;
default:
break;
}
buf += plen;
}
return 0;
}
#define DEFAULT_MODEM_EC_CONFIG {1,1,15,15,128,128,0,512,6}
static int rx_xid(struct lapm_state *l, frame_t *f)
{
struct modem_config cfg = DEFAULT_MODEM_EC_CONFIG;
u8 *buf = f->buf;
int len = f->count;
/* skip addr and ctrl */
buf += 2; len -= 2;
LAPM_PRINT_XID("rx_xid",f,len);
if (*buf != FI_GENERAL)
return -1;
buf++; len--;
while(len > 0) {
u8 gid = buf[0];
u16 glen = buf[1];
glen = glen << 8 | buf[2];
buf += 3;
len -= 3 + glen;
if (len < 0)
break;
switch (gid) {
case GI_PARAM_NEGOTIATION:
parse_xid_params(l,buf,glen);
break;
case GI_PRIVATE_NEGOTIATION:
parse_xid_private_params(l,&cfg,buf,glen);
break;
default:
break;
}
buf += glen;
}
cfg.ec_tx_win_size = l->tx_win_size;
cfg.ec_rx_win_size = l->rx_win_size;
cfg.ec_tx_info_size = l->tx_info_size;
cfg.ec_rx_info_size = l->rx_info_size;
modem_update_config(l->modem,&cfg);
return 0;
}
static int tx_xid(struct lapm_state *l, u8 addr)
{
u8 *buf;
int size = 2 + 1 + (3+19) + (3+15);
int len = 0;
u32 pval;
int glen;
frame_t *f = get_ctrl_frame(l);
if (!f) {
EC_ERR("tx_xid: cannot alloc frame.\n");
return -1;
}
buf = f->buf;
*buf++ = addr; /* addr */
*buf++ = FRAME_U_XID; /* ctrl */
*buf++ = FI_GENERAL; /* fid */
len += 3;
/* param negotiation group */
*buf++ = GI_PARAM_NEGOTIATION; /* group id */
glen = 19; /* group length */ // v42vmi: 19
*buf++ = (glen>>8)&0xff;
*buf++ = glen&0xff;
len += 3;
*buf++ = PI_HDLC_OPTFUNCS;
*buf++ = 3; /* p length */ // v42vmi : 3
*buf++ = 0x8a; /* p value */
*buf++ = 0x89;
*buf++ = 0x00;
//*buf++ = 0x00;
*buf++ = PI_TX_INFO_MAXSIZE;
pval = l->tx_info_size<<3;
*buf++ = 2; /* p length */
*buf++ = (pval>>8)&0xff; /* p value */
*buf++ = (pval&0xff);
*buf++ = PI_RX_INFO_MAXSIZE;
pval = l->rx_info_size<<3;
*buf++ = 2; /* p length */
*buf++ = (pval>>8)&0xff; /* p value */
*buf++ = (pval&0xff);
*buf++ = PI_TX_WINDOW_SIZE;
*buf++ = 1; /* p length */
*buf++ = l->tx_win_size; /* p value */
*buf++ = PI_RX_WINDOW_SIZE;
*buf++ = 1; /* p length */
*buf++ = l->rx_win_size; /* p value */
len += glen;
#if 1 /* v42bis-like compressor */
if(l->modem->cfg.comp) {
/* private param negotiation group */
*buf++ = GI_PRIVATE_NEGOTIATION; /* group id */
glen = 15; /* group length (msb first) */
*buf++ = (glen>>8)&0xff;
*buf++ = glen&0xff;
len += 3;
*buf++ = PI_PARAMETER_SET_ID;
*buf++ = 3; /* p length */
*buf++ = 0x56;/*old 0x26 */ /* p value */ // v42vmi: 0x56
*buf++ = 0x34;
*buf++ = 0x32;
*buf++ = PI_V42BIS_REQUEST;
*buf++ = 1; /* p length */
*buf++ = l->modem->cfg.comp; /* 3 - compression in both direction */
*buf++ = PI_V42BIS_CW_NUMBER;
*buf++ = 2; /* p length */
pval = l->modem->cfg.comp_dict_size;
*buf++ = (pval>>8)&0xff; /* p value */
*buf++ = (pval&0xff);
*buf++ = PI_V42BIS_MAX_STRING;
*buf++ = 1; /* p length */
*buf++ = l->modem->cfg.comp_max_string;
len += glen;
}
#endif
/* user data */
/* ... */
if (len > size) {
EC_ERR("tx_xid: result length(%d) > size (%d).\n", len, size);
return -1;
}
f->size = len;
LAPM_PRINT_XID("tx_xid",f,len);
return 0;
}
/* timeout procedures */
static void t401_timeout(struct modem *m)
{
struct lapm_state *l = &m->ec.lapm;
EC_DBG("t401_timeout: %d...\n",l->rtx_count);
if (l->rtx_count > LAPM_MAX_RTX ) {
EC_DBG("t401: max retransmission count was reached.\n");
l->rtx_count = 0;
// TBD
switch(l->state) {
case LAPM_ESTAB:
case LAPM_DISC:
l->state = LAPM_IDLE;
modem_update_status(l->modem,STATUS_EC_RELEASE);
break;
case LAPM_DATA:
// TBD: disconnect
EC_DBG("t401: max data rtx was reached: disconnect\n");
lapm_disconnect(l);
break;
}
return ;
}
l->rtx_count++;
if (l->config) {
tx_xid(l,l->cmd_addr);
}
else {
switch(l->state) {
case LAPM_ESTAB:
TX_SABME(l);
break;
case LAPM_DISC:
TX_DISC(l);
break;
case LAPM_DATA:
if (l->busy)
TX_RNR(l,l->cmd_addr,1);
else
TX_RR(l,l->cmd_addr,1);
break;
}
}
m->bit_timer = T401_TIMEOUT;
m->bit_timer_func = t401_timeout;
}
#if T403_IMPLEMENTED
static void t403_timeout(struct lapm_state *l)
{
EC_DBG("t403_timeout...\n");
if (l->state != LAPM_DATA) {
EC_ERR("t403: no in data state.\n");
return;
}
if (l->busy)
TX_RNR(l,l->cmd_addr,1);
else
TX_RR(l,l->cmd_addr,1);
T401_START(l);
l->rtx_count = 1;
}
#endif
/* transmit info */
static int tx_info(struct lapm_state *l)
{
frame_t *f;
int n = 0;
if (l->peer_busy ||
((l->vs - l->va)&0x7f) >= l->tx_win_size) {
return 0;
}
if (l->tx_info == l->info_list) { /* empty tx */
if (l->info_list->next == l->tx_info ||
l->info_list->next == l->sent_info) {
EC_ERR("tx_info: cannot alloc frame.\n");
return 0;
}
f = l->info_list;
if(!l->modem->get_chars)
return 0;
n = l->modem->get_chars(l->modem,(char*)(f->buf+3),l->tx_info_size);
if (n < 0) { /* error */
EC_ERR("tx_info: get chars error.\n");
modem_update_status(l->modem,STATUS_EC_ERROR);
return 0;
}
if ( n == 0) { /* no data */
return 0;
}
f->size = n + 3;
l->info_list = l->info_list->next;
l->info_count--; // debug
l->tx_count++; // debug
LAPM_PRINT_FRAME("tx_info",1,f);
}
/* start T401 */
//if (!l->timer)
// TIMER_START(l);
return 1;
}
/* reject all noacked frames (>va) */
static int reject_info(struct lapm_state *l)
{
u8 n = (l->vs-l->va)&0x7f;
if (l->state != LAPM_DATA) /* ignore retransmission */
return 0;
EC_DBG("(va/vs/vr %d/%d/%d) reject info: reject %d frames...\n",
l->va,l->vs,l->vr,n);
l->vs = l->va;
l->tx_info = l->sent_info;
l->tx_count += l->sent_count; // debug
l->sent_count = 0; // debug
return n;
}
/* ack info */
static int ack_info(struct lapm_state *l, u8 nr)
{
int n = 0;
//EC_DBG1("ack info: nr %d...\n", nr);
/* check for valid nr ( va <= nr <= vs && vs-va<= k ) */
// fixme: optimize this
if (!( ((nr-l->va)&0x7f) >= 0 &&
((l->vs-nr)&0x7f) >= 0 &&
((l->vs-l->va)&0x7f) <= l->tx_win_size) ) {
EC_ERR("nr sequince error. disconnect!\n");
// TBD notify CF
lapm_disconnect(l);
return -1;
}
while(l->va != nr) {
if (l->sent_info == l->tx_info) { /* debug only ? */
EC_ERR("ack info: VERY BAD: empty sent list: va %d, vs %d\n",
l->va,l->vs);
break;
}
l->sent_info = l->sent_info->next;
l->sent_count--; // debug
l->info_count++; // debug
l->va = (l->va+1)&0x7f;
n++;
}
/* stop T401 , start T403 */
#if 1
if(n > 0 && !l->rtx_count) {
#else
if(n > 0 && !l->rtx_count && !l->peer_busy) {
#endif
TIMER_STOP(l);
if ((l->vs-l->va)&0x7f)
TIMER_START(l); // exp.8.4.8
}
return n;
}
/* push rest data (when busy) */
static void push_rest_data(struct modem *m, int bits)
{
struct lapm_state *l = &m->ec.lapm;
if (l->state != LAPM_DATA)
return;
if (l->rx_count && l->modem->put_chars) {
int ret = l->modem->put_chars(l->modem,
(const char*)(l->rx_buf+l->rx_head),
l->rx_count);
if (ret > 0) {
l->rx_head += ret;
l->rx_count -= ret;
if (!l->rx_count) {
l->rx_head = 0;
/* reset busy state */
l->busy = 0;
TX_RR(l,l->cmd_addr,0);
l->modem->packer_process = NULL;
}
}
}
}
/* info frame process */
static int rx_info(struct lapm_state *l, frame_t *f)
{
int ret = 0, n;
//LAPM_PRINT_FRAME("rx_info",1,f);
/* ack I frames: nr -1 */
n = ack_info(l,FRAME_NR(f));
/* busy */
if (l->busy) {
if(FRAME_I_PF(f)) /* 8.4.7 */
TX_RNR(l,l->rsp_addr,1);
return 0;
}
/* NS sequence error */
if (FRAME_NS(f)!= l->vr) {
/* TBD */ /* is info may be send */
EC_DBG("seq.error: ns %d, vr %d\n",FRAME_NS(f),l->vr);
// reject should be sent
if (l->reject) /* already sent */
return -1;
EC_DBG("tx reject...\n");
TX_REJ(l,l->rsp_addr,FRAME_I_PF(f));
/* TX_REJ(l,l->cmd_addr,1); */
l->reject = 1;
// fixme: why to start timer
//if (!l->timer)
// TIMER_START(l);
return -1;
}
l->reject = 0;
/* recv data */
if(l->modem->put_chars)
ret = l->modem->put_chars(l->modem,(const char*)(f->buf+3),f->count-3);
if(ret<0) {
/* FIXME: handle error*/ ;
}
if (ret != f->count-3) {
/* save rest data, enter busy state */
l->rx_head = 0;
l->rx_count = f->count - 3 - ret;
memcpy(l->rx_buf,f->buf+3+ret,l->rx_count);
// TBD
l->busy = 1;
// try to push rest data later
l->modem->packer_process = push_rest_data;
}
/* increment vr */
l->vr = (l->vr+1)&0x7f;
/* response I,RR,RNR */
if (l->busy)
TX_RNR(l,FRAME_ADDR(f),FRAME_I_PF(f));
else if ( l->peer_busy || FRAME_I_PF(f) ||
!tx_info(l) )
TX_RR(l,FRAME_ADDR(f),FRAME_I_PF(f));
return 0;
}
/* rx supervisory frame */
static void rx_super_cmd(struct lapm_state *l, frame_t *f)
{
int n;
//LAPM_PRINT_FRAME("rx super:",1,f);
/* note 8.4.7:
if l->busy each RR,RNR,REJ with p=1 should be replied by RNR with f=1 */
switch(FRAME_CTRL(f)) {
case FRAME_S_RR:
/* clear peer_busy state */
l->peer_busy = 0;
n = ack_info(l,FRAME_NR(f));
/* p=1 may be used for status checking */
if (FRAME_S_PF(f) || !tx_info(l)) {
if (l->busy)
TX_RNR(l,FRAME_ADDR(f),FRAME_S_PF(f));
else
TX_RR(l,FRAME_ADDR(f),FRAME_S_PF(f));
}
break;
case FRAME_S_RNR:
/* going to peer_busy state */
l->peer_busy = 1;
n = ack_info(l,FRAME_NR(f));
/* if p=1 may be used for status checking ?? */
if (FRAME_S_PF(f)) {
if (l->busy)
TX_RNR(l,l->rsp_addr,FRAME_S_PF(f));
else
TX_RR(l,l->rsp_addr,FRAME_S_PF(f));
}
break;
case FRAME_S_REJ:
/* clear peer_busy state */
l->peer_busy = 0;
n = ack_info(l,FRAME_NR(f));
if (!l->rtx_count) {
TIMER_STOP(l);
reject_info(l);
}
/* p=1 may be used for status checking */
if (FRAME_S_PF(f) || !tx_info(l)) {
if (l->busy)
TX_RNR(l,FRAME_ADDR(f),FRAME_S_PF(f));
else
TX_RR(l,FRAME_ADDR(f),FRAME_S_PF(f));
}
break;
case FRAME_S_SREJ:
/* TBD, optional */
EC_ERR("unsupported SREJ command!\n");
return;
default:
EC_ERR("unknown s frame: %02x.\n",FRAME_CTRL(f));
return;
}
}
static void rx_super_rsp(struct lapm_state *l, frame_t *f)
{
int n;
//LAPM_PRINT_FRAME("rx_super",0,f);
if (!l->rtx_count && FRAME_S_PF(f)) {
EC_ERR("rx_super: unsolisited final response!\n");
return;
}
/* ack I frames <= nr -1 */
switch(FRAME_CTRL(f)) {
case FRAME_S_RR:
l->peer_busy = 0;
n = ack_info(l,FRAME_NR(f));
if (l->rtx_count && FRAME_S_PF(f)) {
reject_info(l);
TIMER_STOP(l);
}
break;
case FRAME_S_RNR:
l->peer_busy = 1;
n = ack_info(l,FRAME_NR(f));
if (l->rtx_count && FRAME_S_PF(f)) {
reject_info(l);
TIMER_STOP(l); // fixme: need stop even on RNR ??
}
if (!l->rtx_count)
TIMER_START(l);
break;
case FRAME_S_REJ:
l->peer_busy = 0;
n = ack_info(l,FRAME_NR(f));
if (!l->rtx_count || FRAME_S_PF(f)) {
reject_info(l);
TIMER_STOP(l);
}
break;
case FRAME_S_SREJ:
/* TBD, optional */
EC_ERR("unsupported SREJ response!\n");
return;
default:
EC_ERR("rx_s_rsp: unknown header %02x.\n", FRAME_CTRL(f));
return;
}
}
/* rx unnumbered frame */
static int rx_unnum_cmd(struct lapm_state *l, frame_t *f)
{
//LAPM_PRINT_FRAME("rx unnum:",1,f);
switch(FRAME_CTRL(f)&0xef) {
case FRAME_U_SABME:
EC_DBG("sabme received.\n");
/* discard unacked I frames,
reset vs,vr,va, clear exceptions */
reset(l);
/* going to connected state */
l->state = LAPM_DATA;
/* respond UA (or DM on error) */
// fixme: why may be error and TX_DM ??
TX_UA(l,FRAME_U_PF(f));
TIMER_STOP(l);
modem_update_status(l->modem,STATUS_EC_LINK);
break;
case FRAME_U_UI:
/* break signal */
/* pf = 0 */
/* TBD */
break;
case FRAME_U_DISC:
/* respond UA (or DM) */
if (l->state == LAPM_IDLE)
TX_DM(l,1);
else { /* going to disconnected state,
discard unacked I frames, reset all */
l->state = LAPM_IDLE;
reset(l);
TX_UA(l,FRAME_U_PF(f));
T401_STOP(l);
// TBD notify CF
modem_update_status(l->modem,STATUS_EC_RELEASE);
}
break;
case FRAME_U_XID:
/* exchange general id info */
rx_xid(l,f);
tx_xid(l,l->rsp_addr);
break;
case FRAME_U_TEST:
/* TBD */
/* optional */
break;
default:
EC_ERR("rx unnum cmd: unknown frame 0x%02x\n", FRAME_CTRL(f));
return -1;
}
return 0;
}
static int rx_unnum_rsp(struct lapm_state *l, frame_t *f)
{
//LAPM_PRINT_FRAME("rx unnum",0, f);
switch(FRAME_CTRL(f)&0xef) {
case FRAME_U_DM:
/* notify peer about disconnected state */
/* TBD */
switch(l->state) {
case LAPM_ESTAB:
case LAPM_DISC:
if (FRAME_U_PF(f)) {
l->state = LAPM_IDLE;
reset(l);
T401_STOP(l);
// TBD notify CF
modem_update_status(l->modem,STATUS_EC_RELEASE);
}
break;
case LAPM_DATA:
if (l->rtx_count || !FRAME_U_PF(f)) {
l->state = LAPM_IDLE;
reset(l);
// TBD: notify CF
modem_update_status(l->modem,STATUS_EC_RELEASE);
}
break;
case LAPM_IDLE:
if (!FRAME_U_PF(f)) {
// TBD: notify CF
// to establish connection
modem_update_status(l->modem,STATUS_EC_LINK);
}
break;
default:
break;
}
break;
case FRAME_U_UI:
/* break signal */
/* pf = 0 */
/* TBD */
break;
case FRAME_U_UA:
/* notify us about mode change, responds SABME,DISC */
switch(l->state) {
case LAPM_ESTAB:
l->state = LAPM_DATA;
reset(l);
TIMER_STOP(l);
modem_update_status(l->modem,STATUS_EC_LINK);
break;
case LAPM_DISC:
// TBD
l->state = LAPM_IDLE;
reset(l);
T401_STOP(l);
modem_update_status(l->modem,STATUS_EC_RELEASE);
break;
default:
// TBD
/* handle unsolicited UA */
break;
}
/* clear all exceptions, busy states (self and peer) */
/* reset vars */
break;
case FRAME_U_FRMR:
/* not recovarable error */
/* TBD */
break;
case FRAME_U_XID:
if (l->config) {
rx_xid(l,f);
l->config = 0;
T401_STOP(l);
if (l->state == LAPM_IDLE) {
lapm_connect(l);
}
else if (l->state == LAPM_DATA) {
l->busy = 0;
TX_RR(l,l->cmd_addr,0);
}
}
break;
default:
EC_ERR("rx unnum rsp: unknown frame 0x%02x\n", FRAME_CTRL(f));
break;
}
return 0;
}
/* lapm framer interface functions */
static frame_t *lapm_get_tx_frame(void *framer)
{
struct lapm_state *l = framer;
frame_t *f;
/* get ctrl frame */
if ( l->tx_ctrl != l->ctrl_list ) {
f = l->tx_ctrl;
l->tx_ctrl = l->tx_ctrl->next;
return f;
}
/* get info frame */
if ( l->peer_busy || l->config || l->state != LAPM_DATA)
return 0;
if ( l->tx_info == l->info_list && !tx_info(l) )
return 0;
f = l->tx_info;
l->tx_info = l->tx_info->next;
f->buf[0] = l->cmd_addr;
f->buf[1] = l->vs << 1;
f->buf[2] = l->vr << 1;
l->vs = (l->vs + 1)&0x7f;
if (!l->modem->bit_timer)
TIMER_START(l);
//LAPM_PRINT_FRAME("get_tx_frame",1,f);
//EC_DBG1("get_tx_frame: sent %d, tx %d, free %d...\n",
// l->sent_count,l->tx_count,l->info_count);
return f;
}
static void lapm_tx_complete(void *framer, frame_t *f)
{
struct lapm_state *l = framer;
LAPM_PRINT_FRAME("tx",TX_IS_COMMAND(f),f);
switch(FRAME_TYPE(f)) {
case FRAME_I:
l->sent_count++; // debug
l->tx_count--; // debug
//EC_DBG1("tx_info_complete: sent %d, tx %d, free %d.\n",
// l->sent_count,l->tx_count,l->info_count);
break;
case FRAME_S:
case FRAME_U:
l->ctrl_count++; // debug
break;
default:
EC_ERR("unknown frame type.\n");
break;
}
}
static int valid_data_state(struct lapm_state *l)
{
switch (l->state) {
case LAPM_ESTAB:
reset(l);
l->state = LAPM_DATA;
modem_update_status(l->modem,STATUS_EC_LINK);
case LAPM_DATA:
return 1;
case LAPM_DISC:
reset(l);
l->state = LAPM_IDLE;
modem_update_status(l->modem,STATUS_EC_RELEASE);
case LAPM_IDLE:
return 0;
default:
EC_ERR("valid_data_state: unknown state %d.\n", l->state);
return 0;
}
return 0;
}
static void lapm_rx_complete(void *framer, frame_t *f)
{
struct lapm_state *l = framer;
LAPM_PRINT_FRAME("rx",RX_IS_COMMAND(f),f);
switch(FRAME_TYPE(f)) {
case FRAME_I:
if(!valid_data_state(l))
return;
rx_info(l,f);
break;
case FRAME_S:
if(!valid_data_state(l))
return;
if (RX_IS_COMMAND(f))
rx_super_cmd(l,f);
else
rx_super_rsp(l,f);
break;
case FRAME_U:
if (RX_IS_COMMAND(f))
rx_unnum_cmd(l,f);
else
rx_unnum_rsp(l,f);
break;
default:
EC_ERR("unknown frame type.\n");
break;
}
}
/* lapm api functions */
static int lapm_connect(struct lapm_state *l)
{
if (!l->state == LAPM_IDLE)
return -1;
/* negotiate params */
//tx_xid(l,l->cmd_addr);
/* clear all */
reset(l);
/* connect */
l->state = LAPM_ESTAB;
TX_SABME(l);
/* start t401 (and not t403) */
T401_START(l);
return 0;
}
/* negotiate params */
static int lapm_config(struct lapm_state *l)
{
l->config = 1;
if (l->state == LAPM_DATA) {
l->busy = 1;
TX_RNR(l,l->cmd_addr,1);
}
tx_xid(l,l->cmd_addr);
T401_START(l);
return 0;
}
static int lapm_disconnect(struct lapm_state *l)
{
l->state = LAPM_DISC;
TX_DISC(l);
/* start T401 (and not T403) */
T401_START(l);
return 0;
}
static void reset(struct lapm_state *l)
{
l->busy = 0;
l->peer_busy = 0;
l->vs = 0;
l->va = 0;
l->vr = 0;
/* discard pended data */
// l->rx_head = l->rx_count = 0;
/* discard info frames */
l->sent_info = l->info_list;
l->tx_info = l->info_list;
l->sent_count = l->tx_count = 0;
l->info_count = LAPM_INFO_FRAMES;
/* discard ctrl frames */
// TBD ???
}
/* fixme: optimize mem usage */
static int alloc_frames(struct lapm_state *l)
{
#define arrsize(a) (sizeof(a)/sizeof((a)[0]))
frame_t *f;
int i;
EC_DBG("alloc_frames: lapm size %d (info %d, ctrl %d).\n",
sizeof(*l), sizeof(l->info_buf), sizeof(l->ctrl_buf));
/* init info list */
l->info_list = &l->info_buf[0].frame;
for (i=0;i<arrsize(l->info_buf);i++) {
f = &l->info_buf[i].frame;
f->next = &l->info_buf[i+1].frame;
f->buf = l->info_buf[i].ctrl;
f->size = sizeof(l->info_buf[0]) - sizeof(frame_t);
}
f->next = l->info_list;
l->info_count= arrsize(l->info_buf); // debug
l->tx_info = l->info_list;
l->sent_info = l->info_list;
/* init ctrl list */
l->ctrl_list = &l->ctrl_buf[0].frame;
for (i=0;i<arrsize(l->ctrl_buf);i++) {
f = &l->ctrl_buf[i].frame;
f->next = &l->ctrl_buf[i+1].frame;
f->buf = l->ctrl_buf[i].ctrl;
f->size = sizeof(l->ctrl_buf[0]) - sizeof(frame_t);
}
f->next = l->ctrl_list;
l->ctrl_count= arrsize(l->ctrl_buf); // debug
l->tx_ctrl = l->ctrl_list;
return 0;
}
static int lapm_init(struct lapm_state *l, struct modem *m)
{
memset(l,0,sizeof(*l));
l->modem = m;
l->state = LAPM_IDLE;
l->busy = 0;
l->peer_busy = 0;
/* set originator/answer addresses */
l->cmd_addr = m->caller ? 0x3 : 0x1;
l->rsp_addr = m->caller ? 0x1 : 0x3;
l->tx_win_size = m->cfg.ec_tx_win_size;
l->rx_win_size = m->cfg.ec_rx_win_size;
l->tx_info_size = m->cfg.ec_tx_info_size;
l->rx_info_size = m->cfg.ec_rx_info_size;
alloc_frames(l);
reset(l);
return 0;
}
static int lapm_exit(struct lapm_state *l)
{
reset(l);
l->info_list = 0;
l->ctrl_list = 0;
return 0;
}
/* modem ec interface func */
static void modem_ec_negotiate(struct modem *m)
{
m->packer.hdlc.tx_complete = lapm_tx_complete;
m->packer.hdlc.get_tx_frame = lapm_get_tx_frame;
lapm_config(&m->ec.lapm);
}
void modem_ec_start(struct modem *m)
{
struct hdlc_state *h = &m->packer.hdlc;
struct lapm_state *l = &m->ec.lapm;
EC_DBG("modem_ec_start...\n");
h->framer = l;
h->tx_complete = NULL;
h->rx_complete = lapm_rx_complete;
h->get_tx_frame = NULL;
if(m->caller) {
m->bit_timer = 48*8;
m->bit_timer_func = modem_ec_negotiate;
}
else {
h->tx_complete = lapm_tx_complete;
h->get_tx_frame = lapm_get_tx_frame;
}
// fixme: improve BUSY becoming, remove packer_process()
m->packer_process = NULL;
}
void modem_ec_stop(struct modem *m)
{
struct lapm_state *l = &m->ec.lapm;
EC_DBG("modem_ec_stop...\n");
m->bit_timer = 0;
m->packer_process = NULL;
lapm_disconnect(l);
}
int modem_ec_init(struct modem *m)
{
struct lapm_state *l = &m->ec.lapm;
lapm_init(l,m);
return 0;
}
void modem_ec_exit(struct modem *m)
{
struct lapm_state *l = &m->ec.lapm;
lapm_exit(l);
}
Reference in a new issue Copy permalink