Esempio n. 1
0
static void fr_timer(unsigned long arg)
{
	hdlc_device *hdlc = (hdlc_device*)arg;
	int i, cnt = 0, reliable;
	u32 list;

	if (mode_is(hdlc, MODE_DCE))
		reliable = (jiffies - hdlc->lmi.last_poll < hdlc->lmi.T392*HZ);
	else {
		hdlc->lmi.last_errors <<= 1; /* Shift the list */
		if (hdlc->lmi.state & LINK_STATE_REQUEST) {
			printk(KERN_INFO "%s: No LMI status reply received\n",
			       hdlc_to_name(hdlc));
			hdlc->lmi.last_errors |= 1;
		}

		for (i = 0, list = hdlc->lmi.last_errors; i < hdlc->lmi.N393;
		     i++, list >>= 1)
			cnt += (list & 1);	/* errors count */

		reliable = (cnt < hdlc->lmi.N392);
	}

	if ((hdlc->lmi.state & LINK_STATE_RELIABLE) !=
	    (reliable ? LINK_STATE_RELIABLE : 0)) {
		pvc_device *pvc = hdlc->first_pvc;

		while (pvc) {/* Deactivate all PVCs */
			pvc->state &= ~(PVC_STATE_NEW | PVC_STATE_ACTIVE);
			pvc = pvc->next;
		}

		hdlc->lmi.state ^= LINK_STATE_RELIABLE;
		printk(KERN_INFO "%s: Link %sreliable\n", hdlc_to_name(hdlc),
		       reliable ? "" : "un");

		if (reliable) {
			hdlc->lmi.N391cnt = 0; /* Request full status */
			hdlc->lmi.state |= LINK_STATE_CHANGED;
		}
	}

	if (mode_is(hdlc, MODE_DCE))
		hdlc->timer.expires = jiffies + hdlc->lmi.T392*HZ;
	else {
		if (hdlc->lmi.N391cnt)
			hdlc->lmi.N391cnt--;

		fr_lmi_send(hdlc, hdlc->lmi.N391cnt == 0);

		hdlc->lmi.state |= LINK_STATE_REQUEST;
		hdlc->timer.expires = jiffies + hdlc->lmi.T391*HZ;
	}

	hdlc->timer.function = fr_timer;
	hdlc->timer.data = arg;
	add_timer(&hdlc->timer);
}
Esempio n. 2
0
static int hdlc_xmit(struct sk_buff *skb, struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);

#ifdef CONFIG_HDLC_X25
	if (mode_is(hdlc, MODE_X25 | MODE_SOFT)) {
		int result;


		/* X.25 to LAPB */
		switch (skb->data[0]) {
		case 0:		/* Data to be transmitted */
			skb_pull(skb, 1);
			if ((result = lapb_data_request(hdlc, skb)) != LAPB_OK)
				dev_kfree_skb(skb);
			return 0;

		case 1:
			if ((result = lapb_connect_request(hdlc))!= LAPB_OK) {
				if (result == LAPB_CONNECTED) {
				/* Send connect confirm. msg to level 3 */
					x25_connected(hdlc, 0);
				} else {
					printk(KERN_ERR "%s: LAPB connect "
					       "request failed, error code = "
					       "%i\n", hdlc_to_name(hdlc),
					       result);
				}
			}
			break;

		case 2:
			if ((result=lapb_disconnect_request(hdlc))!=LAPB_OK) {
				if (result == LAPB_NOTCONNECTED) {
				/* Send disconnect confirm. msg to level 3 */
					x25_disconnected(hdlc, 0);
				} else {
					printk(KERN_ERR "%s: LAPB disconnect "
					       "request failed, error code = "
					       "%i\n", hdlc_to_name(hdlc),
					       result);
				}
			}
			break;

		default:
			/* to be defined */
			break;
		}

		dev_kfree_skb(skb);
		return 0;
	} /* MODE_X25 */
#endif /* CONFIG_HDLC_X25 */

	return hdlc->xmit(hdlc, skb);
}
Esempio n. 3
0
static void cisco_keepalive_send(hdlc_device *hdlc, u32 type,
				 u32 par1, u32 par2)
{
	struct sk_buff *skb;
	cisco_packet *data;

	skb = dev_alloc_skb(sizeof(hdlc_header) + sizeof(cisco_packet));
	if (!skb) {
		printk(KERN_WARNING
		       "%s: Memory squeeze on cisco_keepalive_send()\n",
		       hdlc_to_name(hdlc));
		return;
	}
	skb_reserve(skb, 4);
	cisco_hard_header(skb, hdlc_to_dev(hdlc), CISCO_KEEPALIVE,
			  NULL, NULL, 0);
	data = (cisco_packet*)skb->tail;

	data->type = htonl(type);
	data->par1 = htonl(par1);
	data->par2 = htonl(par2);
	data->rel = 0xFFFF;
	/* we will need do_div here if 1000 % HZ != 0 */
	data->time = htonl(jiffies * (1000 / HZ));

	skb_put(skb, sizeof(cisco_packet));
	skb->priority = TC_PRIO_CONTROL;
	skb->dev = hdlc_to_dev(hdlc);
	skb->nh.raw = skb->data;

	dev_queue_xmit(skb);
}
Esempio n. 4
0
static void cisco_timer(unsigned long arg)
{
	hdlc_device *hdlc = (hdlc_device*)arg;

	if ((hdlc->lmi.state & LINK_STATE_RELIABLE) &&
	    (jiffies - hdlc->lmi.last_poll >= hdlc->lmi.T392 * HZ)) {
		hdlc->lmi.state &= ~LINK_STATE_RELIABLE;
		printk(KERN_INFO "%s: Link down\n", hdlc_to_name(hdlc));
	}

	cisco_keepalive_send(hdlc, CISCO_KEEPALIVE_REQ, ++hdlc->lmi.txseq,
			     hdlc->lmi.rxseq);
	hdlc->timer.expires = jiffies + hdlc->lmi.T391*HZ;

	hdlc->timer.function = cisco_timer;
	hdlc->timer.data = arg;
	add_timer(&hdlc->timer);
}
Esempio n. 5
0
static void cisco_timer(unsigned long arg)
{
	hdlc_device *hdlc = (hdlc_device*)arg;

	if (hdlc->state.cisco.up && jiffies - hdlc->state.cisco.last_poll >=
	    hdlc->state.cisco.settings.timeout * HZ) {
		hdlc->state.cisco.up = 0;
		printk(KERN_INFO "%s: Link down\n", hdlc_to_name(hdlc));
	}

	cisco_keepalive_send(hdlc, CISCO_KEEPALIVE_REQ,
			     ++hdlc->state.cisco.txseq,
			     hdlc->state.cisco.rxseq);
	hdlc->state.cisco.timer.expires = jiffies +
		hdlc->state.cisco.settings.interval * HZ;
	hdlc->state.cisco.timer.function = cisco_timer;
	hdlc->state.cisco.timer.data = arg;
	add_timer(&hdlc->state.cisco.timer);
}
Esempio n. 6
0
void x25_connect_disconnect(void *token, int reason, int code)
{
	hdlc_device *hdlc = token;
	struct sk_buff *skb;
	unsigned char *ptr;

	if ((skb = dev_alloc_skb(1)) == NULL) {
		printk(KERN_ERR "%s: out of memory\n", hdlc_to_name(hdlc));
		return;
	}

	ptr = skb_put(skb, 1);
	*ptr = code;

	skb->dev = hdlc_to_dev(hdlc);
	skb->protocol = htons(ETH_P_X25);
	skb->mac.raw = skb->data;
	skb->pkt_type = PACKET_HOST;

	netif_rx(skb);
}
Esempio n. 7
0
static void cisco_rx(struct sk_buff *skb)
{
	hdlc_device *hdlc = dev_to_hdlc(skb->dev);
	hdlc_header *data = (hdlc_header*)skb->data;
	cisco_packet *cisco_data;
	struct in_device *in_dev;
	u32 addr, mask;

	if (skb->len < sizeof(hdlc_header))
		goto rx_error;

	if (data->address != CISCO_MULTICAST &&
	    data->address != CISCO_UNICAST)
		goto rx_error;

	skb_pull(skb, sizeof(hdlc_header));

	switch(ntohs(data->protocol)) {
	case CISCO_SYS_INFO:
		/* Packet is not needed, drop it. */
		dev_kfree_skb_any(skb);
		return;

	case CISCO_KEEPALIVE:
		if (skb->len != CISCO_PACKET_LEN &&
		    skb->len != CISCO_BIG_PACKET_LEN) {
			printk(KERN_INFO "%s: Invalid length of Cisco "
			       "control packet (%d bytes)\n",
			       hdlc_to_name(hdlc), skb->len);
			goto rx_error;
		}

		cisco_data = (cisco_packet*)skb->data;

		switch(ntohl (cisco_data->type)) {
		case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */
			in_dev = hdlc_to_dev(hdlc)->ip_ptr;
			addr = 0;
			mask = ~0; /* is the mask correct? */

			if (in_dev != NULL) {
				struct in_ifaddr **ifap = &in_dev->ifa_list;

				while (*ifap != NULL) {
					if (strcmp(hdlc_to_name(hdlc),
						   (*ifap)->ifa_label) == 0) {
						addr = (*ifap)->ifa_local;
						mask = (*ifap)->ifa_mask;
						break;
					}
					ifap = &(*ifap)->ifa_next;
				}

				cisco_keepalive_send(hdlc, CISCO_ADDR_REPLY,
						     addr, mask);
			}
			dev_kfree_skb_any(skb);
			return;

		case CISCO_ADDR_REPLY:
			printk(KERN_INFO "%s: Unexpected Cisco IP address "
			       "reply\n", hdlc_to_name(hdlc));
			goto rx_error;

		case CISCO_KEEPALIVE_REQ:
			hdlc->state.cisco.rxseq = ntohl(cisco_data->par1);
			if (ntohl(cisco_data->par2)==hdlc->state.cisco.txseq) {
				hdlc->state.cisco.last_poll = jiffies;
				if (!hdlc->state.cisco.up) {
					u32 sec, min, hrs, days;
					sec = ntohl(cisco_data->time) / 1000;
					min = sec / 60; sec -= min * 60;
					hrs = min / 60; min -= hrs * 60;
					days = hrs / 24; hrs -= days * 24;
					printk(KERN_INFO "%s: Link up (peer "
					       "uptime %ud%uh%um%us)\n",
					       hdlc_to_name(hdlc), days, hrs,
					       min, sec);
				}
				hdlc->state.cisco.up = 1;
			}

			dev_kfree_skb_any(skb);
			return;
		} /* switch(keepalive type) */
	} /* switch(protocol) */

	printk(KERN_INFO "%s: Unsupported protocol %x\n", hdlc_to_name(hdlc),
	       data->protocol);
	dev_kfree_skb_any(skb);
	return;

 rx_error:
	hdlc->stats.rx_errors++; /* Mark error */
	dev_kfree_skb_any(skb);
}
Esempio n. 8
0
static void fr_netif(hdlc_device *hdlc, struct sk_buff *skb)
{
	fr_hdr *fh = (fr_hdr*)skb->data;
	u8 *data = skb->data;
	u16 dlci;
	pvc_device *pvc;

	if (skb->len<4 || fh->ea1 || data[2] != FR_UI)
		goto rx_error;

	dlci = q922_to_dlci(skb->data);

	if (dlci == LMI_DLCI) {
		if (data[3] == LMI_PROTO) {
			if (fr_lmi_recv(hdlc, skb))
				goto rx_error;
			else {
				/* No request pending */
				hdlc->lmi.state &= ~LINK_STATE_REQUEST;
				hdlc->lmi.last_poll = jiffies;
				dev_kfree_skb_any(skb);
				return;
			}
		}

		printk(KERN_INFO "%s: Received non-LMI frame with LMI DLCI\n",
		       hdlc_to_name(hdlc));
		goto rx_error;
	}

	pvc = find_pvc(hdlc, dlci);
	if (!pvc) {
#ifdef DEBUG_PKT
		printk(KERN_INFO "%s: No PVC for received frame's DLCI %d\n",
		       hdlc_to_name(hdlc), dlci);
#endif
		goto rx_error;
	}

	if ((pvc->netdev.flags & IFF_UP) == 0) {
#ifdef DEBUG_PKT
		printk(KERN_INFO "%s: PVC for received frame's DLCI %d is down\n",
		       hdlc_to_name(hdlc), dlci);
#endif
		goto rx_error;
	}

	pvc->stats.rx_packets++; /* PVC traffic */
	pvc->stats.rx_bytes += skb->len;

	if ((pvc->state & PVC_STATE_FECN) != (fh->fecn ? PVC_STATE_FECN : 0)) {
#ifdef DEBUG_FECN
		printk(KERN_DEBUG "%s: FECN O%s\n", pvc_to_name(pvc),
		       fh->fecn ? "N" : "FF");
#endif
		pvc->state ^= PVC_STATE_FECN;
	}

	if ((pvc->state & PVC_STATE_BECN) != (fh->becn ? PVC_STATE_BECN : 0)) {
#ifdef DEBUG_FECN
		printk(KERN_DEBUG "%s: BECN O%s\n", pvc_to_name(pvc),
		       fh->becn ? "N" : "FF");
#endif
		pvc->state ^= PVC_STATE_BECN;
	}

	if (pvc->state & PVC_STATE_BECN)
		pvc->stats.rx_compressed++;

	if (data[3] == NLPID_IP) {
		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
		skb->protocol = htons(ETH_P_IP);
		skb->dev = &pvc->netdev;
		netif_rx(skb);
		return;
	}


	if (data[3] == NLPID_IPV6) {
		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
		skb->protocol = htons(ETH_P_IPV6);
		skb->dev = &pvc->netdev;
		netif_rx(skb);
		return;
	}

	if (data[3] == FR_PAD && data[4] == NLPID_SNAP && data[5] == FR_PAD &&
	    data[6] == FR_PAD && data[7] == FR_PAD &&
	    ((data[8]<<8) | data[9]) == ETH_P_ARP) {
		skb_pull(skb, 10);
		skb->protocol = htons(ETH_P_ARP);
		skb->dev = &pvc->netdev;
		netif_rx(skb);
		return;
	}

	printk(KERN_INFO "%s: Unusupported protocol %x\n",
	       hdlc_to_name(hdlc), data[3]);
	dev_kfree_skb_any(skb);
	return;

 rx_error:
	hdlc->stats.rx_errors++; /* Mark error */
	dev_kfree_skb_any(skb);
}
Esempio n. 9
0
static int fr_lmi_recv(hdlc_device *hdlc, struct sk_buff *skb)
{
	int stat_len;
	pvc_device *pvc;
	int reptype = -1, error;
	u8 rxseq, txseq;
	int i;

	if (skb->len < (mode_is(hdlc, MODE_FR_ANSI) ?
			LMI_ANSI_LENGTH : LMI_LENGTH)) {
		printk(KERN_INFO "%s: Short LMI frame\n", hdlc_to_name(hdlc));
		return 1;
	}

	if (skb->data[5] != (!mode_is(hdlc, MODE_DCE) ?
			     LMI_STATUS : LMI_STATUS_ENQUIRY)) {
		printk(KERN_INFO "%s: LMI msgtype=%x, Not LMI status %s\n",
		       hdlc_to_name(hdlc), skb->data[2],
		       mode_is(hdlc, MODE_DCE) ? "enquiry" : "reply");
		return 1;
	}

	i = mode_is(hdlc, MODE_FR_ANSI) ? 7 : 6;

	if (skb->data[i] !=
	    (mode_is(hdlc, MODE_FR_CCITT) ? LMI_CCITT_REPTYPE : LMI_REPTYPE)) {
		printk(KERN_INFO "%s: Not a report type=%x\n",
		       hdlc_to_name(hdlc), skb->data[i]);
		return 1;
	}
	i++;

	i++;				/* Skip length field */

	reptype = skb->data[i++];

	if (skb->data[i]!=
	    (mode_is(hdlc, MODE_FR_CCITT) ? LMI_CCITT_ALIVE : LMI_ALIVE)) {
		printk(KERN_INFO "%s: Unsupported status element=%x\n",
		       hdlc_to_name(hdlc), skb->data[i]);
		return 1;
	}
	i++;

	i++;			/* Skip length field */

	hdlc->lmi.rxseq = skb->data[i++]; /* TX sequence from peer */
	rxseq = skb->data[i++];	/* Should confirm our sequence */

	txseq = hdlc->lmi.txseq;

	if (mode_is(hdlc, MODE_DCE)) {
		if (reptype != LMI_FULLREP && reptype != LMI_INTEGRITY) {
			printk(KERN_INFO "%s: Unsupported report type=%x\n",
			       hdlc_to_name(hdlc), reptype);
			return 1;
		}
	}

	error = 0;
	if (!(hdlc->lmi.state & LINK_STATE_RELIABLE))
		error = 1;

	if (rxseq == 0 || rxseq != txseq) {
		hdlc->lmi.N391cnt = 0; /* Ask for full report next time */
		error = 1;
	}

	if (mode_is(hdlc, MODE_DCE)) {
		if ((hdlc->lmi.state & LINK_STATE_FULLREP_SENT) && !error) {
/* Stop sending full report - the last one has been confirmed by DTE */
			hdlc->lmi.state &= ~LINK_STATE_FULLREP_SENT;
			pvc = hdlc->first_pvc;
			while (pvc) {
				if (pvc->state & PVC_STATE_NEW) {
					pvc->state &= ~PVC_STATE_NEW;
					pvc->state |= PVC_STATE_ACTIVE;
					fr_log_dlci_active(pvc);

/* Tell DTE that new PVC is now active */
					hdlc->lmi.state |= LINK_STATE_CHANGED;
				}
				pvc = pvc->next;
			}
		}

		if (hdlc->lmi.state & LINK_STATE_CHANGED) {
			reptype = LMI_FULLREP;
			hdlc->lmi.state |= LINK_STATE_FULLREP_SENT;
			hdlc->lmi.state &= ~LINK_STATE_CHANGED;
		}

		fr_lmi_send(hdlc, reptype == LMI_FULLREP ? 1 : 0);
		return 0;
	}

	/* DTE */

	if (reptype != LMI_FULLREP || error)
		return 0;

	stat_len = 3;
	pvc = hdlc->first_pvc;

	while (pvc) {
		pvc->newstate = 0;
		pvc = pvc->next;
	}

	while (skb->len >= i + 2 + stat_len) {
		u16 dlci;
		u8 state = 0;

		if (skb->data[i] != (mode_is(hdlc, MODE_FR_CCITT) ?
				     LMI_CCITT_PVCSTAT : LMI_PVCSTAT)) {
			printk(KERN_WARNING "%s: Invalid PVCSTAT ID: %x\n",
			       hdlc_to_name(hdlc), skb->data[i]);
			return 1;
		}
		i++;

		if (skb->data[i] != stat_len) {
			printk(KERN_WARNING "%s: Invalid PVCSTAT length: %x\n",
			       hdlc_to_name(hdlc), skb->data[i]);
			return 1;
		}
		i++;

		dlci = status_to_dlci(hdlc, skb->data+i, &state);
		pvc = find_pvc(hdlc, dlci);

		if (pvc)
			pvc->newstate = state;
		else if (state == PVC_STATE_NEW)
			printk(KERN_INFO "%s: new PVC available, DLCI=%u\n",
			       hdlc_to_name(hdlc), dlci);

		i += stat_len;
	}

	pvc = hdlc->first_pvc;

	while (pvc) {
		if (pvc->newstate == PVC_STATE_NEW)
			pvc->newstate = PVC_STATE_ACTIVE;

		pvc->newstate |= (pvc->state &
				  ~(PVC_STATE_NEW|PVC_STATE_ACTIVE));
		if (pvc->state != pvc->newstate) {
			pvc->state = pvc->newstate;
			fr_log_dlci_active(pvc);
		}
		pvc = pvc->next;
	}

	/* Next full report after N391 polls */
	hdlc->lmi.N391cnt = hdlc->lmi.N391;

	return 0;
}
Esempio n. 10
0
static void fr_lmi_send(hdlc_device *hdlc, int fullrep)
{
	struct sk_buff *skb;
	pvc_device *pvc = hdlc->first_pvc;
	int len = mode_is(hdlc, MODE_FR_ANSI) ? LMI_ANSI_LENGTH : LMI_LENGTH;
	int stat_len = 3;
	u8 *data;
	int i = 0;

	if (mode_is(hdlc, MODE_DCE) && fullrep) {
		len += hdlc->pvc_count * (2 + stat_len);
		if (len > HDLC_MAX_MTU) {
			printk(KERN_WARNING "%s: Too many PVCs while sending "
			       "LMI full report\n", hdlc_to_name(hdlc));
			return;
		}
	}

	skb = dev_alloc_skb(len);
	if (!skb) {
		printk(KERN_WARNING "%s: Memory squeeze on fr_lmi_send()\n",
			       hdlc_to_name(hdlc));
		return;
	}
	memset(skb->data, 0, len);
	skb_reserve(skb, 4);
	fr_hard_header(skb, hdlc_to_dev(hdlc), LMI_PROTO, NULL, NULL, 0);
	data = skb->tail;
	data[i++] = LMI_CALLREF;
	data[i++] = mode_is(hdlc, MODE_DCE) ? LMI_STATUS : LMI_STATUS_ENQUIRY;
	if (mode_is(hdlc, MODE_FR_ANSI))
		data[i++] = LMI_ANSI_LOCKSHIFT;
	data[i++] = mode_is(hdlc, MODE_FR_CCITT) ? LMI_CCITT_REPTYPE :
		LMI_REPTYPE;
	data[i++] = LMI_REPT_LEN;
	data[i++] = fullrep ? LMI_FULLREP : LMI_INTEGRITY;

	data[i++] = mode_is(hdlc, MODE_FR_CCITT) ? LMI_CCITT_ALIVE : LMI_ALIVE;
	data[i++] = LMI_INTEG_LEN;
	data[i++] = hdlc->lmi.txseq = fr_lmi_nextseq(hdlc->lmi.txseq);
	data[i++] = hdlc->lmi.rxseq;

	if (mode_is(hdlc, MODE_DCE) && fullrep) {
		while (pvc) {
			data[i++] = mode_is(hdlc, MODE_FR_CCITT) ?
				LMI_CCITT_PVCSTAT:LMI_PVCSTAT;
			data[i++] = stat_len;

			if ((hdlc->lmi.state & LINK_STATE_RELIABLE) &&
			    (pvc->netdev.flags & IFF_UP) &&
			    !(pvc->state & (PVC_STATE_ACTIVE|PVC_STATE_NEW))) {
				pvc->state |= PVC_STATE_NEW;
				fr_log_dlci_active(pvc);
			}

			dlci_to_status(hdlc, netdev_dlci(&pvc->netdev),
				       data+i, pvc->state);
			i += stat_len;
			pvc = pvc->next;
		}
	}

	skb_put(skb, i);
	skb->priority = TC_PRIO_CONTROL;
	skb->dev = hdlc_to_dev(hdlc);

	dev_queue_xmit(skb);
}
Esempio n. 11
0
static int hdlc_fr_pvc(hdlc_device *hdlc, int dlci)
{
	pvc_device **pvc_p = &hdlc->first_pvc;
	pvc_device *pvc;
	int result, create = 1;	/* Create or delete PVC */

	if(!capable(CAP_NET_ADMIN))
		return -EPERM;

	if(dlci<0) {
		dlci = -dlci;
		create = 0;
	}

	if(dlci <= 0 || dlci >= 1024)
		return -EINVAL;	/* Only 10 bits for DLCI, DLCI=0 is reserved */

	if(!mode_is(hdlc, MODE_FR))
		return -EINVAL;	/* Only meaningfull on FR */

	while(*pvc_p) {
		if (netdev_dlci(&(*pvc_p)->netdev) == dlci)
			break;
		pvc_p = &(*pvc_p)->next;
	}

	if (create) {		/* Create PVC */
		if (*pvc_p != NULL)
			return -EEXIST;

		pvc = *pvc_p = kmalloc(sizeof(pvc_device), GFP_KERNEL);
		if (!pvc) {
			printk(KERN_WARNING "%s: Memory squeeze on "
			       "hdlc_fr_pvc()\n", hdlc_to_name(hdlc));
			return -ENOBUFS;
		}
		memset(pvc, 0, sizeof(pvc_device));

		pvc->netdev.hard_start_xmit = pvc_xmit;
		pvc->netdev.get_stats = pvc_get_stats;
		pvc->netdev.open = pvc_open;
		pvc->netdev.stop = pvc_close;
		pvc->netdev.change_mtu = pvc_change_mtu;
		pvc->netdev.mtu = HDLC_MAX_MTU;

		pvc->netdev.type = ARPHRD_DLCI;
		pvc->netdev.hard_header_len = 16;
		pvc->netdev.hard_header = fr_hard_header;
		pvc->netdev.tx_queue_len = 0;
		pvc->netdev.flags = IFF_POINTOPOINT;

		pvc->master = hdlc;
		*(u16*)pvc->netdev.dev_addr = htons(dlci);
		dlci_to_q922(pvc->netdev.broadcast, dlci);
		pvc->netdev.addr_len = 2;
		pvc->netdev.irq = hdlc_to_dev(hdlc)->irq;

		result = dev_alloc_name(&pvc->netdev, "pvc%d");
		if (result < 0) {
			kfree(pvc);
			*pvc_p = NULL;
			return result;
		}

		if (register_netdevice(&pvc->netdev) != 0) {
			kfree(pvc);
			*pvc_p = NULL;
			return -EIO;
		}

		if (!mode_is(hdlc, MODE_SOFT) && hdlc->create_pvc) {
			result = hdlc->create_pvc(pvc);
			if (result) {
				unregister_netdevice(&pvc->netdev);
				kfree(pvc);
				*pvc_p = NULL;
				return result;
			}
		}

		hdlc->lmi.state |= LINK_STATE_CHANGED;
		hdlc->pvc_count++;
		return 0;
	}

	if (*pvc_p == NULL)		/* Delete PVC */
		return -ENOENT;

	pvc = *pvc_p;

	if (pvc->netdev.flags & IFF_UP)
		return -EBUSY;		/* PVC in use */

	if (!mode_is(hdlc, MODE_SOFT) && hdlc->destroy_pvc)
		hdlc->destroy_pvc(pvc);

	hdlc->lmi.state |= LINK_STATE_CHANGED;
	hdlc->pvc_count--;
	*pvc_p = pvc->next;
	unregister_netdevice(&pvc->netdev);
	kfree(pvc);
	return 0;
}