isdnloop.c

讲述linux的初始化过程

 *   sdefp = pointer to struct holding ioctl parameters.
 * Return:
 *   0 on success, -E??? otherwise.
 */
static int
isdnloop_start(isdnloop_card * card, isdnloop_sdef * sdefp)
{
	unsigned long flags;
	isdnloop_sdef sdef;
	int i;

	if (card->flags & ISDNLOOP_FLAGS_RUNNING)
		return -EBUSY;
	copy_from_user((char *) &sdef, (char *) sdefp, sizeof(sdef));
	save_flags(flags);
	cli();
	switch (sdef.ptype) {
		case ISDN_PTYPE_EURO:
			if (isdnloop_fake(card, "DRV1.23EC-Q.931-CAPI-CNS-BASIS-20.02.96",
					  -1)) {
				restore_flags(flags);
				return -ENOMEM;
			}
			card->sil[0] = card->sil[1] = 4;
			if (isdnloop_fake(card, "TEI OK", 0)) {
				restore_flags(flags);
				return -ENOMEM;
			}
			for (i = 0; i < 3; i++)
				strcpy(card->s0num[i], sdef.num[i]);
			break;
		case ISDN_PTYPE_1TR6:
			if (isdnloop_fake(card, "DRV1.04TC-1TR6-CAPI-CNS-BASIS-29.11.95",
					  -1)) {
				restore_flags(flags);
				return -ENOMEM;
			}
			card->sil[0] = card->sil[1] = 4;
			if (isdnloop_fake(card, "TEI OK", 0)) {
				restore_flags(flags);
				return -ENOMEM;
			}
			strcpy(card->s0num[0], sdef.num[0]);
			card->s0num[1][0] = '\0';
			card->s0num[2][0] = '\0';
			break;
		default:
			restore_flags(flags);
			printk(KERN_WARNING "isdnloop: Illegal D-channel protocol %d\n",
			       sdef.ptype);
			return -EINVAL;
	}
	init_timer(&card->st_timer);
	card->st_timer.expires = jiffies + ISDNLOOP_TIMER_DCREAD;
	card->st_timer.function = isdnloop_polldchan;
	card->st_timer.data = (unsigned long) card;
	add_timer(&card->st_timer);
	card->flags |= ISDNLOOP_FLAGS_RUNNING;
	restore_flags(flags);
	return 0;
}

/*
 * Main handler for commands sent by linklevel.
 */
static int
isdnloop_command(isdn_ctrl * c, isdnloop_card * card)
{
	ulong a;
	int i;
	char cbuf[60];
	isdn_ctrl cmd;
	isdnloop_cdef cdef;

	switch (c->command) {
		case ISDN_CMD_IOCTL:
			memcpy(&a, c->parm.num, sizeof(ulong));
			switch (c->arg) {
				case ISDNLOOP_IOCTL_DEBUGVAR:
					return (ulong) card;
				case ISDNLOOP_IOCTL_STARTUP:
					if ((i = verify_area(VERIFY_READ, (void *) a, sizeof(isdnloop_sdef))))
						return i;
					return (isdnloop_start(card, (isdnloop_sdef *) a));
					break;
				case ISDNLOOP_IOCTL_ADDCARD:
					if ((i = verify_area(VERIFY_READ, (void *) a, sizeof(isdnloop_cdef))))
						return i;
					copy_from_user((char *) &cdef, (char *) a, sizeof(cdef));
					return (isdnloop_addcard(cdef.id1));
					break;
				case ISDNLOOP_IOCTL_LEASEDCFG:
					if (a) {
						if (!card->leased) {
							card->leased = 1;
							while (card->ptype == ISDN_PTYPE_UNKNOWN) {
								schedule_timeout(10);
							}
							schedule_timeout(10);
							sprintf(cbuf, "00;FV2ON\n01;EAZ1\n02;EAZ2\n");
							i = isdnloop_writecmd(cbuf, strlen(cbuf), 0, card);
							printk(KERN_INFO
							       "isdnloop: (%s) Leased-line mode enabled\n",
							       CID);
							cmd.command = ISDN_STAT_RUN;
							cmd.driver = card->myid;
							cmd.arg = 0;
							card->interface.statcallb(&cmd);
						}
					} else {
						if (card->leased) {
							card->leased = 0;
							sprintf(cbuf, "00;FV2OFF\n");
							i = isdnloop_writecmd(cbuf, strlen(cbuf), 0, card);
							printk(KERN_INFO
							       "isdnloop: (%s) Leased-line mode disabled\n",
							       CID);
							cmd.command = ISDN_STAT_RUN;
							cmd.driver = card->myid;
							cmd.arg = 0;
							card->interface.statcallb(&cmd);
						}
					}
					return 0;
				default:
					return -EINVAL;
			}
			break;
		case ISDN_CMD_DIAL:
			if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
				return -ENODEV;
			if (card->leased)
				break;
			if ((c->arg & 255) < ISDNLOOP_BCH) {
				char *p;
				char dial[50];
				char dcode[4];

				a = c->arg;
				p = c->parm.setup.phone;
				if (*p == 's' || *p == 'S') {
					/* Dial for SPV */
					p++;
					strcpy(dcode, "SCA");
				} else
					/* Normal Dial */
					strcpy(dcode, "CAL");
				strcpy(dial, p);
				sprintf(cbuf, "%02d;D%s_R%s,%02d,%02d,%s\n", (int) (a + 1),
					dcode, dial, c->parm.setup.si1,
				c->parm.setup.si2, c->parm.setup.eazmsn);
				i = isdnloop_writecmd(cbuf, strlen(cbuf), 0, card);
			}
			break;
		case ISDN_CMD_ACCEPTD:
			if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
				return -ENODEV;
			if (c->arg < ISDNLOOP_BCH) {
				a = c->arg + 1;
				cbuf[0] = 0;
				switch (card->l2_proto[a - 1]) {
					case ISDN_PROTO_L2_X75I:
						sprintf(cbuf, "%02d;BX75\n", (int) a);
						break;
#ifdef CONFIG_ISDN_X25
					case ISDN_PROTO_L2_X25DTE:
						sprintf(cbuf, "%02d;BX2T\n", (int) a);
						break;
					case ISDN_PROTO_L2_X25DCE:
						sprintf(cbuf, "%02d;BX2C\n", (int) a);
						break;
#endif
					case ISDN_PROTO_L2_HDLC:
						sprintf(cbuf, "%02d;BTRA\n", (int) a);
						break;
				}
				if (strlen(cbuf))
					i = isdnloop_writecmd(cbuf, strlen(cbuf), 0, card);
				sprintf(cbuf, "%02d;DCON_R\n", (int) a);
				i = isdnloop_writecmd(cbuf, strlen(cbuf), 0, card);
			}
			break;
		case ISDN_CMD_ACCEPTB:
			if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
				return -ENODEV;
			if (c->arg < ISDNLOOP_BCH) {
				a = c->arg + 1;
				switch (card->l2_proto[a - 1]) {
					case ISDN_PROTO_L2_X75I:
						sprintf(cbuf, "%02d;BCON_R,BX75\n", (int) a);
						break;
#ifdef CONFIG_ISDN_X25
					case ISDN_PROTO_L2_X25DTE:
						sprintf(cbuf, "%02d;BCON_R,BX2T\n", (int) a);
						break;
					case ISDN_PROTO_L2_X25DCE:
						sprintf(cbuf, "%02d;BCON_R,BX2C\n", (int) a);
						break;
#endif
					case ISDN_PROTO_L2_HDLC:
						sprintf(cbuf, "%02d;BCON_R,BTRA\n", (int) a);
						break;
					default:
						sprintf(cbuf, "%02d;BCON_R\n", (int) a);
				}
				printk(KERN_DEBUG "isdnloop writecmd '%s'\n", cbuf);
				i = isdnloop_writecmd(cbuf, strlen(cbuf), 0, card);
				break;
		case ISDN_CMD_HANGUP:
				if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
					return -ENODEV;
				if (c->arg < ISDNLOOP_BCH) {
					a = c->arg + 1;
					sprintf(cbuf, "%02d;BDIS_R\n%02d;DDIS_R\n", (int) a, (int) a);
					i = isdnloop_writecmd(cbuf, strlen(cbuf), 0, card);
				}
				break;
		case ISDN_CMD_SETEAZ:
				if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
					return -ENODEV;
				if (card->leased)
					break;
				if (c->arg < ISDNLOOP_BCH) {
					a = c->arg + 1;
					if (card->ptype == ISDN_PTYPE_EURO) {
						sprintf(cbuf, "%02d;MS%s%s\n", (int) a,
							c->parm.num[0] ? "N" : "ALL", c->parm.num);
					} else
						sprintf(cbuf, "%02d;EAZ%s\n", (int) a,
							c->parm.num[0] ? c->parm.num : (u_char *) "0123456789");
					i = isdnloop_writecmd(cbuf, strlen(cbuf), 0, card);
				}
				break;
		case ISDN_CMD_CLREAZ:
				if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
					return -ENODEV;
				if (card->leased)
					break;
				if (c->arg < ISDNLOOP_BCH) {
					a = c->arg + 1;
					if (card->ptype == ISDN_PTYPE_EURO)
						sprintf(cbuf, "%02d;MSNC\n", (int) a);
					else
						sprintf(cbuf, "%02d;EAZC\n", (int) a);
					i = isdnloop_writecmd(cbuf, strlen(cbuf), 0, card);
				}
				break;
		case ISDN_CMD_SETL2:
				if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
					return -ENODEV;
				if ((c->arg & 255) < ISDNLOOP_BCH) {
					a = c->arg;
					switch (a >> 8) {
						case ISDN_PROTO_L2_X75I:
							sprintf(cbuf, "%02d;BX75\n", (int) (a & 255) + 1);
							break;
#ifdef CONFIG_ISDN_X25
						case ISDN_PROTO_L2_X25DTE:
							sprintf(cbuf, "%02d;BX2T\n", (int) (a & 255) + 1);
							break;
						case ISDN_PROTO_L2_X25DCE:
							sprintf(cbuf, "%02d;BX2C\n", (int) (a & 255) + 1);
							break;
#endif
						case ISDN_PROTO_L2_HDLC:
							sprintf(cbuf, "%02d;BTRA\n", (int) (a & 255) + 1);
							break;
						default:
							return -EINVAL;
					}
					i = isdnloop_writecmd(cbuf, strlen(cbuf), 0, card);
					card->l2_proto[a & 255] = (a >> 8);
				}
				break;
		case ISDN_CMD_GETL2:
				if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
					return -ENODEV;
				if ((c->arg & 255) < ISDNLOOP_BCH)
					return card->l2_proto[c->arg & 255];
				else
					return -ENODEV;
		case ISDN_CMD_SETL3:
				if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
					return -ENODEV;
				return 0;
		case ISDN_CMD_GETL3:
				if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
					return -ENODEV;
				if ((c->arg & 255) < ISDNLOOP_BCH)
					return ISDN_PROTO_L3_TRANS;
				else
					return -ENODEV;
		case ISDN_CMD_GETEAZ:
				if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
					return -ENODEV;
				break;
		case ISDN_CMD_SETSIL:
				if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
					return -ENODEV;
				break;
		case ISDN_CMD_GETSIL:
				if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
					return -ENODEV;
				break;
		case ISDN_CMD_LOCK:
				MOD_INC_USE_COUNT;
				break;
		case ISDN_CMD_UNLOCK:
				MOD_DEC_USE_COUNT;
				break;
		default:
				return -EINVAL;
			}
	}
	return 0;
}

/*
 * Find card with given driverId
 */
static inline isdnloop_card *
isdnloop_findcard(int driverid)
{
	isdnloop_card *p = cards;

	while (p) {
		if (p->myid == driverid)
			return p;
		p = p->next;
	}
	return (isdnloop_card *) 0;
}

/*
 * Wrapper functions for interface to linklevel
 */
static int
if_command(isdn_ctrl * c)
{
	isdnloop_card *card = isdnloop_findcard(c->driver);

	if (card)
		return (isdnloop_command(c, card));
	printk(KERN_ERR
	       "isdnloop: if_command called with invalid driverId!\n");
	return -ENODEV;
}

static int
if_writecmd(const u_char * buf, int len, int user, int id, int channel)
{
	isdnloop_card *card = isdnloop_findcard(id);

	if (card) {
		if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
			return -ENODEV;
		return (isdnloop_writecmd(buf, len, user, card));
	}
	printk(KERN_ERR
	       "isdnloop: if_writecmd called with invalid driverId!\n");
	return -ENODEV;
}

static int
if_readstatus(u_char * buf, int len, int user, int id, int channel)
{
	isdnloop_card *card = isdnloop_findcard(id);

	if (card) {
		if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
			return -ENODEV;
		return (isdnloop_readstatus(buf, len, user, card));
	}
	printk(KERN_ERR
	       "isdnloop: if_readstatus called with invalid driverId!\n");
	return -ENODEV;
}

static int
if_sendbuf(int id, int channel, int ack, struct sk_buff *skb)
{
	isdnloop_card *card = isdnloop_findcard(id);

	if (card) {
		if (!card->flags & ISDNLOOP_FLAGS_RUNNING)
			return -ENODEV;
		/* ack request stored in skb scratch area */
		*(skb->head) = ack;
		return (isdnloop_sendbuf(channel, skb, card));
	}
	printk(KERN_ERR
	       "isdnloop: if_sendbuf called with invalid driverId!\n");
	return -ENODEV;
}

/*
 * Allocate a new card-struct, initialize it
 * link it into cards-list and register it at linklevel.
 */
static isdnloop_card *
isdnloop_initcard(char *id)
{
	isdnloop_card *card;
	int i;

	if (!(card = (isdnloop_card *) kmalloc(sizeof(isdnloop_card), GFP_KERNEL))) {
		printk(KERN_WARNING
		 "isdnloop: (%s) Could not allocate card-struct.\n", id);
		return (isdnloop_card *) 0;
	}
	memset((char *) card, 0, sizeof(isdnloop_card));
	card->interface.channels = ISDNLOOP_BCH;
	card->interface.hl_hdrlen  = 1; /* scratch area for storing ack flag*/ 
	card->interface.maxbufsize = 4000;
	card->interface.command = if_command;
	card->interface.writebuf_skb = if_sendbuf;
	card->interface.writecmd = if_writecmd;
	card->interface.readstat = if_readstatus;
	card->interface.features = ISDN_FEATURE_L2_X75I |
#ifdef CONFIG_ISDN_X25
	    ISDN_FEATURE_L2_X25DTE |
	    ISDN_FEATURE_L2_X25DCE |
#endif
	    ISDN_FEATURE_L2_HDLC |
	    ISDN_FEATURE_L3_TRANS |
	    ISDN_FEATURE_P_UNKNOWN;
	card->ptype = ISDN_PTYPE_UNKNOWN;
	strncpy(card->interface.id, id, sizeof(card->interface.id) - 1);
	card->msg_buf_write = card->msg_buf;
	card->msg_buf_read = card->msg_buf;
	card->msg_buf_end = &card->msg_buf[sizeof(card->msg_buf) - 1];
	for (i = 0; i < ISDNLOOP_BCH; i++) {
		card->l2_proto[i] = ISDN_PROTO_L2_X75I;
		skb_queue_head_init(&card->bqueue[i]);
	}
	skb_queue_head_init(&card->dqueue);
	card->next = cards;
	cards = card;
	if (!register_isdn(&card->interface)) {
		cards = cards->next;
		printk(KERN_WARNING
		       "isdnloop: Unable to register %s\n", id);
		kfree(card);
		return (isdnloop_card *) 0;
	}
	card->myid = card->interface.channels;
	return card;
}

static int
isdnloop_addcard(char *id1)
{
	ulong flags;
	isdnloop_card *card;

	save_flags(flags);
	cli();
	if (!(card = isdnloop_initcard(id1))) {
		restore_flags(flags);
		return -EIO;
	}
	restore_flags(flags);
	printk(KERN_INFO
	       "isdnloop: (%s) virtual card added\n",
	       card->interface.id);
	return 0;
}

#ifdef MODULE
#define isdnloop_init init_module
#else
void
isdnloop_setup(char *str, int *ints)
{
	static char sid[20];

	if (strlen(str)) {
		strcpy(sid, str);
		isdnloop_id = sid;
	}
}
#endif

int
isdnloop_init(void)
{
	char *p;
	char rev[10];

	/* No symbols to export, hide all symbols */
	EXPORT_NO_SYMBOLS;

	if ((p = strchr(revision, ':'))) {
		strcpy(rev, p + 1);
		p = strchr(rev, '$');
		*p = 0;
	} else
		strcpy(rev, " ??? ");
	printk(KERN_NOTICE "isdnloop-ISDN-driver Rev%s\n", rev);
	return (isdnloop_addcard(isdnloop_id));
}

#ifdef MODULE
void
cleanup_module(void)
{
	isdn_ctrl cmd;
	isdnloop_card *card = cards;
	isdnloop_card *last;
	int i;

	isdnloop_stopallcards();
	while (card) {
		cmd.command = ISDN_STAT_UNLOAD;
		cmd.driver = card->myid;
		card->interface.statcallb(&cmd);
		for (i = 0; i < ISDNLOOP_BCH; i++)
			isdnloop_free_queue(card, i);
		card = card->next;
	}
	card = cards;
	while (card) {
		struct sk_buff *skb;

		last = card;
		while ((skb = skb_dequeue(&card->dqueue)))
			dev_kfree_skb(skb);
		card = card->next;
		kfree(last);
	}
	printk(KERN_NOTICE "isdnloop-ISDN-driver unloaded\n");
}
#endif