isdnloop.c

linux-2.6.15.6

/* $Id: isdnloop.c,v 1.11.6.7 2001/11/11 19:54:31 kai Exp $
 *
 * ISDN low-level module implementing a dummy loop driver.
 *
 * Copyright 1997 by Fritz Elfert ([e-mail])
 *
 * This software may be used and distributed according to the terms
 * of the GNU General Public License, incorporated herein by reference.
 *
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/sched.h>
#include "isdnloop.h"

static char *revision = "$Revision: 1.11.6.7 $";
static char *isdnloop_id = "loop0";

MODULE_DESCRIPTION("ISDN4Linux: Pseudo Driver that simulates an ISDN card");
MODULE_AUTHOR("Fritz Elfert");
MODULE_LICENSE("GPL");
MODULE_PARM(isdnloop_id, "s");
MODULE_PARM_DESC(isdnloop_id, "ID-String of first card");

static int isdnloop_addcard(char *);

/*
 * Free queue completely.
 *
 * Parameter:
 *   card    = pointer to card struct
 *   channel = channel number
 */
static void
isdnloop_free_queue(isdnloop_card * card, int channel)
{
	struct sk_buff_head *queue = &card->bqueue[channel];

	skb_queue_purge(queue);
	card->sndcount[channel] = 0;
}

/*
 * Send B-Channel data to another virtual card.
 * This routine is called via timer-callback from isdnloop_pollbchan().
 *
 * Parameter:
 *   card = pointer to card struct.
 *   ch   = channel number (0-based)
 */
static void
isdnloop_bchan_send(isdnloop_card * card, int ch)
{
	isdnloop_card *rcard = card->rcard[ch];
	int rch = card->rch[ch], len, ack;
	struct sk_buff *skb;
	isdn_ctrl cmd;

	while (card->sndcount[ch]) {
		if ((skb = skb_dequeue(&card->bqueue[ch]))) {
			len = skb->len;
			card->sndcount[ch] -= len;
			ack = *(skb->head); /* used as scratch area */
			cmd.driver = card->myid;
			cmd.arg = ch;
			if (rcard){
				rcard->interface.rcvcallb_skb(rcard->myid, rch, skb);
			} else {
				printk(KERN_WARNING "isdnloop: no rcard, skb dropped\n");
				dev_kfree_skb(skb);

			};
			cmd.command = ISDN_STAT_BSENT;
			cmd.parm.length = len;
			card->interface.statcallb(&cmd);
		} else
			card->sndcount[ch] = 0;
	}
}

/*
 * Send/Receive Data to/from the B-Channel.
 * This routine is called via timer-callback.
 * It schedules itself while any B-Channel is open.
 *
 * Parameter:
 *   data = pointer to card struct, set by kernel timer.data
 */
static void
isdnloop_pollbchan(unsigned long data)
{
	isdnloop_card *card = (isdnloop_card *) data;
	unsigned long flags;

	if (card->flags & ISDNLOOP_FLAGS_B1ACTIVE)
		isdnloop_bchan_send(card, 0);
	if (card->flags & ISDNLOOP_FLAGS_B2ACTIVE)
		isdnloop_bchan_send(card, 1);
	if (card->flags & (ISDNLOOP_FLAGS_B1ACTIVE | ISDNLOOP_FLAGS_B2ACTIVE)) {
		/* schedule b-channel polling again */
		save_flags(flags);
		cli();
		card->rb_timer.expires = jiffies + ISDNLOOP_TIMER_BCREAD;
		add_timer(&card->rb_timer);
		card->flags |= ISDNLOOP_FLAGS_RBTIMER;
		restore_flags(flags);
	} else
		card->flags &= ~ISDNLOOP_FLAGS_RBTIMER;
}

/*
 * Parse ICN-type setup string and fill fields of setup-struct
 * with parsed data.
 *
 * Parameter:
 *   setup = setup string, format: [caller-id],si1,si2,[called-id]
 *   cmd   = pointer to struct to be filled.
 */
static void
isdnloop_parse_setup(char *setup, isdn_ctrl * cmd)
{
	char *t = setup;
	char *s = strchr(t, ',');

	*s++ = '\0';
	strlcpy(cmd->parm.setup.phone, t, sizeof(cmd->parm.setup.phone));
	s = strchr(t = s, ',');
	*s++ = '\0';
	if (!strlen(t))
		cmd->parm.setup.si1 = 0;
	else
		cmd->parm.setup.si1 = simple_strtoul(t, NULL, 10);
	s = strchr(t = s, ',');
	*s++ = '\0';
	if (!strlen(t))
		cmd->parm.setup.si2 = 0;
	else
		cmd->parm.setup.si2 =
		    simple_strtoul(t, NULL, 10);
	strlcpy(cmd->parm.setup.eazmsn, s, sizeof(cmd->parm.setup.eazmsn));
	cmd->parm.setup.plan = 0;
	cmd->parm.setup.screen = 0;
}

typedef struct isdnloop_stat {
	char *statstr;
	int command;
	int action;
} isdnloop_stat;
/* *INDENT-OFF* */
static isdnloop_stat isdnloop_stat_table[] =
{
	{"BCON_",          ISDN_STAT_BCONN, 1}, /* B-Channel connected        */
	{"BDIS_",          ISDN_STAT_BHUP,  2}, /* B-Channel disconnected     */
	{"DCON_",          ISDN_STAT_DCONN, 0}, /* D-Channel connected        */
	{"DDIS_",          ISDN_STAT_DHUP,  0}, /* D-Channel disconnected     */
	{"DCAL_I",         ISDN_STAT_ICALL, 3}, /* Incoming call dialup-line  */
	{"DSCA_I",         ISDN_STAT_ICALL, 3}, /* Incoming call 1TR6-SPV     */
	{"FCALL",          ISDN_STAT_ICALL, 4}, /* Leased line connection up  */
	{"CIF",            ISDN_STAT_CINF,  5}, /* Charge-info, 1TR6-type     */
	{"AOC",            ISDN_STAT_CINF,  6}, /* Charge-info, DSS1-type     */
	{"CAU",            ISDN_STAT_CAUSE, 7}, /* Cause code                 */
	{"TEI OK",         ISDN_STAT_RUN,   0}, /* Card connected to wallplug */
	{"E_L1: ACT FAIL", ISDN_STAT_BHUP,  8}, /* Layer-1 activation failed  */
	{"E_L2: DATA LIN", ISDN_STAT_BHUP,  8}, /* Layer-2 data link lost     */
	{"E_L1: ACTIVATION FAILED",
			   ISDN_STAT_BHUP,  8},         /* Layer-1 activation failed  */
	{NULL, 0, -1}
};
/* *INDENT-ON* */


/*
 * Parse Status message-strings from virtual card.
 * Depending on status, call statcallb for sending messages to upper
 * levels. Also set/reset B-Channel active-flags.
 *
 * Parameter:
 *   status  = status string to parse.
 *   channel = channel where message comes from.
 *   card    = card where message comes from.
 */
static void
isdnloop_parse_status(u_char * status, int channel, isdnloop_card * card)
{
	isdnloop_stat *s = isdnloop_stat_table;
	int action = -1;
	isdn_ctrl cmd;

	while (s->statstr) {
		if (!strncmp(status, s->statstr, strlen(s->statstr))) {
			cmd.command = s->command;
			action = s->action;
			break;
		}
		s++;
	}
	if (action == -1)
		return;
	cmd.driver = card->myid;
	cmd.arg = channel;
	switch (action) {
		case 1:
			/* BCON_x */
			card->flags |= (channel) ?
			    ISDNLOOP_FLAGS_B2ACTIVE : ISDNLOOP_FLAGS_B1ACTIVE;
			break;
		case 2:
			/* BDIS_x */
			card->flags &= ~((channel) ?
					 ISDNLOOP_FLAGS_B2ACTIVE : ISDNLOOP_FLAGS_B1ACTIVE);
			isdnloop_free_queue(card, channel);
			break;
		case 3:
			/* DCAL_I and DSCA_I */
			isdnloop_parse_setup(status + 6, &cmd);
			break;
		case 4:
			/* FCALL */
			sprintf(cmd.parm.setup.phone, "LEASED%d", card->myid);
			sprintf(cmd.parm.setup.eazmsn, "%d", channel + 1);
			cmd.parm.setup.si1 = 7;
			cmd.parm.setup.si2 = 0;
			cmd.parm.setup.plan = 0;
			cmd.parm.setup.screen = 0;
			break;
		case 5:
			/* CIF */
			strlcpy(cmd.parm.num, status + 3, sizeof(cmd.parm.num));
			break;
		case 6:
			/* AOC */
			snprintf(cmd.parm.num, sizeof(cmd.parm.num), "%d",
			     (int) simple_strtoul(status + 7, NULL, 16));
			break;
		case 7:
			/* CAU */
			status += 3;
			if (strlen(status) == 4)
				snprintf(cmd.parm.num, sizeof(cmd.parm.num), "%s%c%c",
				     status + 2, *status, *(status + 1));
			else
				strlcpy(cmd.parm.num, status + 1, sizeof(cmd.parm.num));
			break;
		case 8:
			/* Misc Errors on L1 and L2 */
			card->flags &= ~ISDNLOOP_FLAGS_B1ACTIVE;
			isdnloop_free_queue(card, 0);
			cmd.arg = 0;
			cmd.driver = card->myid;
			card->interface.statcallb(&cmd);
			cmd.command = ISDN_STAT_DHUP;
			cmd.arg = 0;
			cmd.driver = card->myid;
			card->interface.statcallb(&cmd);
			cmd.command = ISDN_STAT_BHUP;
			card->flags &= ~ISDNLOOP_FLAGS_B2ACTIVE;
			isdnloop_free_queue(card, 1);
			cmd.arg = 1;
			cmd.driver = card->myid;
			card->interface.statcallb(&cmd);
			cmd.command = ISDN_STAT_DHUP;
			cmd.arg = 1;
			cmd.driver = card->myid;
			break;
	}
	card->interface.statcallb(&cmd);
}

/*
 * Store a cwcharacter into ringbuffer for reading from /dev/isdnctrl
 *
 * Parameter:
 *   card = pointer to card struct.
 *   c    = char to store.
 */
static void
isdnloop_putmsg(isdnloop_card * card, unsigned char c)
{
	ulong flags;

	save_flags(flags);
	cli();
	*card->msg_buf_write++ = (c == 0xff) ? '\n' : c;
	if (card->msg_buf_write == card->msg_buf_read) {
		if (++card->msg_buf_read > card->msg_buf_end)
			card->msg_buf_read = card->msg_buf;
	}
	if (card->msg_buf_write > card->msg_buf_end)
		card->msg_buf_write = card->msg_buf;
	restore_flags(flags);
}

/*
 * Poll a virtual cards message queue.
 * If there are new status-replies from the card, copy them to
 * ringbuffer for reading on /dev/isdnctrl and call
 * isdnloop_parse_status() for processing them. Watch for special
 * Firmware bootmessage and parse it, to get the D-Channel protocol.
 * If there are B-Channels open, initiate a timer-callback to
 * isdnloop_pollbchan().
 * This routine is called periodically via timer interrupt.
 *
 * Parameter:
 *   data = pointer to card struct
 */
static void
isdnloop_polldchan(unsigned long data)
{
	isdnloop_card *card = (isdnloop_card *) data;
	struct sk_buff *skb;
	int avail;
	int left;
	u_char c;
	int ch;
	unsigned long flags;
	u_char *p;
	isdn_ctrl cmd;

	if ((skb = skb_dequeue(&card->dqueue)))
		avail = skb->len;
	else
		avail = 0;
	for (left = avail; left > 0; left--) {
		c = *skb->data;
		skb_pull(skb, 1);
		isdnloop_putmsg(card, c);
		card->imsg[card->iptr] = c;
		if (card->iptr < 59)
			card->iptr++;
		if (!skb->len) {
			avail++;
			isdnloop_putmsg(card, '\n');
			card->imsg[card->iptr] = 0;
			card->iptr = 0;
			if (card->imsg[0] == '0' && card->imsg[1] >= '0' &&
			  card->imsg[1] <= '2' && card->imsg[2] == ';') {
				ch = (card->imsg[1] - '0') - 1;
				p = &card->imsg[3];
				isdnloop_parse_status(p, ch, card);
			} else {
				p = card->imsg;
				if (!strncmp(p, "DRV1.", 5)) {
					printk(KERN_INFO "isdnloop: (%s) %s\n", CID, p);
					if (!strncmp(p + 7, "TC", 2)) {
						card->ptype = ISDN_PTYPE_1TR6;
						card->interface.features |= ISDN_FEATURE_P_1TR6;
						printk(KERN_INFO
						       "isdnloop: (%s) 1TR6-Protocol loaded and running\n", CID);
					}
					if (!strncmp(p + 7, "EC", 2)) {
						card->ptype = ISDN_PTYPE_EURO;
						card->interface.features |= ISDN_FEATURE_P_EURO;
						printk(KERN_INFO
						       "isdnloop: (%s) Euro-Protocol loaded and running\n", CID);
					}
					continue;

				}
			}
		}
	}
	if (avail) {
		cmd.command = ISDN_STAT_STAVAIL;
		cmd.driver = card->myid;
		cmd.arg = avail;
		card->interface.statcallb(&cmd);
	}
	if (card->flags & (ISDNLOOP_FLAGS_B1ACTIVE | ISDNLOOP_FLAGS_B2ACTIVE))
		if (!(card->flags & ISDNLOOP_FLAGS_RBTIMER)) {
			/* schedule b-channel polling */
			card->flags |= ISDNLOOP_FLAGS_RBTIMER;
			save_flags(flags);
			cli();
			del_timer(&card->rb_timer);
			card->rb_timer.function = isdnloop_pollbchan;
			card->rb_timer.data = (unsigned long) card;
			card->rb_timer.expires = jiffies + ISDNLOOP_TIMER_BCREAD;
			add_timer(&card->rb_timer);
			restore_flags(flags);
		}
	/* schedule again */
	save_flags(flags);
	cli();
	card->st_timer.expires = jiffies + ISDNLOOP_TIMER_DCREAD;
	add_timer(&card->st_timer);
	restore_flags(flags);
}

/*
 * Append a packet to the transmit buffer-queue.
 *
 * Parameter:
 *   channel = Number of B-channel
 *   skb     = packet to send.
 *   card    = pointer to card-struct
 * Return:
 *   Number of bytes transferred, -E??? on error
 */
static int
isdnloop_sendbuf(int channel, struct sk_buff *skb, isdnloop_card * card)
{
	int len = skb->len;
	unsigned long flags;
	struct sk_buff *nskb;

	if (len > 4000) {
		printk(KERN_WARNING
		       "isdnloop: Send packet too large\n");
		return -EINVAL;
	}
	if (len) {
		if (!(card->flags & (channel) ? ISDNLOOP_FLAGS_B2ACTIVE : ISDNLOOP_FLAGS_B1ACTIVE))
			return 0;
		if (card->sndcount[channel] > ISDNLOOP_MAX_SQUEUE)
			return 0;
		save_flags(flags);
		cli();
		nskb = dev_alloc_skb(skb->len);
		if (nskb) {
			memcpy(skb_put(nskb, len), skb->data, len);
			skb_queue_tail(&card->bqueue[channel], nskb);
			dev_kfree_skb(skb);
		} else
			len = 0;
		card->sndcount[channel] += len;
		restore_flags(flags);
	}
	return len;
}

/*
 * Read the messages from the card's ringbuffer
 *
 * Parameter:
 *   buf  = pointer to buffer.
 *   len  = number of bytes to read.
 *   user = flag, 1: called from userlevel 0: called from kernel.
 *   card = pointer to card struct.
 * Return:
 *   number of bytes actually transferred.
 */
static int
isdnloop_readstatus(u_char __user *buf, int len, isdnloop_card * card)
{
	int count;
	u_char __user *p;

	for (p = buf, count = 0; count < len; p++, count++) {
		if (card->msg_buf_read == card->msg_buf_write)
			return count;
		put_user(*card->msg_buf_read++, p);
		if (card->msg_buf_read > card->msg_buf_end)
			card->msg_buf_read = card->msg_buf;
	}
	return count;
}

/*
 * Simulate a card's response by appending it to the cards
 * message queue.
 *
 * Parameter:
 *   card = pointer to card struct.
 *   s    = pointer to message-string.
 *   ch   = channel: 0 = generic messages, 1 and 2 = D-channel messages.
 * Return:
 *   0 on success, 1 on memory squeeze.
 */
static int
isdnloop_fake(isdnloop_card * card, char *s, int ch)
{
	struct sk_buff *skb;
	int len = strlen(s) + ((ch >= 0) ? 3 : 0);

	if (!(skb = dev_alloc_skb(len))) {
		printk(KERN_WARNING "isdnloop: Out of memory in isdnloop_fake\n");
		return 1;
	}
	if (ch >= 0)
		sprintf(skb_put(skb, 3), "%02d;", ch);
	memcpy(skb_put(skb, strlen(s)), s, strlen(s));
	skb_queue_tail(&card->dqueue, skb);
	return 0;
}
/* *INDENT-OFF* */
static isdnloop_stat isdnloop_cmd_table[] =
{
	{"BCON_R",         0,  1},	/* B-Channel connect        */
	{"BCON_I",         0, 17},	/* B-Channel connect ind    */
	{"BDIS_R",         0,  2},	/* B-Channel disconnect     */
	{"DDIS_R",         0,  3},	/* D-Channel disconnect     */
	{"DCON_R",         0, 16},	/* D-Channel connect        */
	{"DSCA_R",         0,  4},	/* Dial 1TR6-SPV     */
	{"DCAL_R",         0,  5},	/* Dial */
	{"EAZC",           0,  6},	/* Clear EAZ listener */
	{"EAZ",            0,  7},	/* Set EAZ listener */
	{"SEEAZ",          0,  8},	/* Get EAZ listener */
	{"MSN",            0,  9},	/* Set/Clear MSN listener */
	{"MSALL",          0, 10},	/* Set multi MSN listeners */
	{"SETSIL",         0, 11},	/* Set SI list     */
	{"SEESIL",         0, 12},	/* Get SI list     */
	{"SILC",           0, 13},	/* Clear SI list     */
	{"LOCK",           0, -1},	/* LOCK channel     */
	{"UNLOCK",         0, -1},	/* UNLOCK channel     */
	{"FV2ON",          1, 14},	/* Leased mode on               */
	{"FV2OFF",         1, 15},	/* Leased mode off              */
	{NULL, 0, -1}
};
/* *INDENT-ON* */


/*
 * Simulate an error-response from a card.
 *