hdlc_fr.c

linux 内核源代码

			stats->tx_bytes += skb->len;
			stats->tx_packets++;
			if (pvc->state.fecn) /* TX Congestion counter */
				stats->tx_compressed++;
			skb->dev = pvc->frad;
			dev_queue_xmit(skb);
			return 0;
		}
	}

	stats->tx_dropped++;
	dev_kfree_skb(skb);
	return 0;
}



static int pvc_change_mtu(struct net_device *dev, int new_mtu)
{
	if ((new_mtu < 68) || (new_mtu > HDLC_MAX_MTU))
		return -EINVAL;
	dev->mtu = new_mtu;
	return 0;
}



static inline void fr_log_dlci_active(pvc_device *pvc)
{
	printk(KERN_INFO "%s: DLCI %d [%s%s%s]%s %s\n",
	       pvc->frad->name,
	       pvc->dlci,
	       pvc->main ? pvc->main->name : "",
	       pvc->main && pvc->ether ? " " : "",
	       pvc->ether ? pvc->ether->name : "",
	       pvc->state.new ? " new" : "",
	       !pvc->state.exist ? "deleted" :
	       pvc->state.active ? "active" : "inactive");
}



static inline u8 fr_lmi_nextseq(u8 x)
{
	x++;
	return x ? x : 1;
}


static void fr_lmi_send(struct net_device *dev, int fullrep)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	struct sk_buff *skb;
	pvc_device *pvc = state(hdlc)->first_pvc;
	int lmi = state(hdlc)->settings.lmi;
	int dce = state(hdlc)->settings.dce;
	int len = lmi == LMI_ANSI ? LMI_ANSI_LENGTH : LMI_CCITT_CISCO_LENGTH;
	int stat_len = (lmi == LMI_CISCO) ? 6 : 3;
	u8 *data;
	int i = 0;

	if (dce && fullrep) {
		len += state(hdlc)->dce_pvc_count * (2 + stat_len);
		if (len > HDLC_MAX_MRU) {
			printk(KERN_WARNING "%s: Too many PVCs while sending "
			       "LMI full report\n", dev->name);
			return;
		}
	}

	skb = dev_alloc_skb(len);
	if (!skb) {
		printk(KERN_WARNING "%s: Memory squeeze on fr_lmi_send()\n",
		       dev->name);
		return;
	}
	memset(skb->data, 0, len);
	skb_reserve(skb, 4);
	if (lmi == LMI_CISCO) {
		skb->protocol = __constant_htons(NLPID_CISCO_LMI);
		fr_hard_header(&skb, LMI_CISCO_DLCI);
	} else {
		skb->protocol = __constant_htons(NLPID_CCITT_ANSI_LMI);
		fr_hard_header(&skb, LMI_CCITT_ANSI_DLCI);
	}
	data = skb_tail_pointer(skb);
	data[i++] = LMI_CALLREF;
	data[i++] = dce ? LMI_STATUS : LMI_STATUS_ENQUIRY;
	if (lmi == LMI_ANSI)
		data[i++] = LMI_ANSI_LOCKSHIFT;
	data[i++] = lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
		LMI_ANSI_CISCO_REPTYPE;
	data[i++] = LMI_REPT_LEN;
	data[i++] = fullrep ? LMI_FULLREP : LMI_INTEGRITY;
	data[i++] = lmi == LMI_CCITT ? LMI_CCITT_ALIVE : LMI_ANSI_CISCO_ALIVE;
	data[i++] = LMI_INTEG_LEN;
	data[i++] = state(hdlc)->txseq =
		fr_lmi_nextseq(state(hdlc)->txseq);
	data[i++] = state(hdlc)->rxseq;

	if (dce && fullrep) {
		while (pvc) {
			data[i++] = lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
				LMI_ANSI_CISCO_PVCSTAT;
			data[i++] = stat_len;

			/* LMI start/restart */
			if (state(hdlc)->reliable && !pvc->state.exist) {
				pvc->state.exist = pvc->state.new = 1;
				fr_log_dlci_active(pvc);
			}

			/* ifconfig PVC up */
			if (pvc->open_count && !pvc->state.active &&
			    pvc->state.exist && !pvc->state.new) {
				pvc_carrier(1, pvc);
				pvc->state.active = 1;
				fr_log_dlci_active(pvc);
			}

			if (lmi == LMI_CISCO) {
				data[i] = pvc->dlci >> 8;
				data[i + 1] = pvc->dlci & 0xFF;
			} else {
				data[i] = (pvc->dlci >> 4) & 0x3F;
				data[i + 1] = ((pvc->dlci << 3) & 0x78) | 0x80;
				data[i + 2] = 0x80;
			}

			if (pvc->state.new)
				data[i + 2] |= 0x08;
			else if (pvc->state.active)
				data[i + 2] |= 0x02;

			i += stat_len;
			pvc = pvc->next;
		}
	}

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

	dev_queue_xmit(skb);
}



static void fr_set_link_state(int reliable, struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	pvc_device *pvc = state(hdlc)->first_pvc;

	state(hdlc)->reliable = reliable;
	if (reliable) {
		netif_dormant_off(dev);
		state(hdlc)->n391cnt = 0; /* Request full status */
		state(hdlc)->dce_changed = 1;

		if (state(hdlc)->settings.lmi == LMI_NONE) {
			while (pvc) {	/* Activate all PVCs */
				pvc_carrier(1, pvc);
				pvc->state.exist = pvc->state.active = 1;
				pvc->state.new = 0;
				pvc = pvc->next;
			}
		}
	} else {
		netif_dormant_on(dev);
		while (pvc) {		/* Deactivate all PVCs */
			pvc_carrier(0, pvc);
			pvc->state.exist = pvc->state.active = 0;
			pvc->state.new = 0;
			if (!state(hdlc)->settings.dce)
				pvc->state.bandwidth = 0;
			pvc = pvc->next;
		}
	}
}


static void fr_timer(unsigned long arg)
{
	struct net_device *dev = (struct net_device *)arg;
	hdlc_device *hdlc = dev_to_hdlc(dev);
	int i, cnt = 0, reliable;
	u32 list;

	if (state(hdlc)->settings.dce) {
		reliable = state(hdlc)->request &&
			time_before(jiffies, state(hdlc)->last_poll +
				    state(hdlc)->settings.t392 * HZ);
		state(hdlc)->request = 0;
	} else {
		state(hdlc)->last_errors <<= 1; /* Shift the list */
		if (state(hdlc)->request) {
			if (state(hdlc)->reliable)
				printk(KERN_INFO "%s: No LMI status reply "
				       "received\n", dev->name);
			state(hdlc)->last_errors |= 1;
		}

		list = state(hdlc)->last_errors;
		for (i = 0; i < state(hdlc)->settings.n393; i++, list >>= 1)
			cnt += (list & 1);	/* errors count */

		reliable = (cnt < state(hdlc)->settings.n392);
	}

	if (state(hdlc)->reliable != reliable) {
		printk(KERN_INFO "%s: Link %sreliable\n", dev->name,
		       reliable ? "" : "un");
		fr_set_link_state(reliable, dev);
	}

	if (state(hdlc)->settings.dce)
		state(hdlc)->timer.expires = jiffies +
			state(hdlc)->settings.t392 * HZ;
	else {
		if (state(hdlc)->n391cnt)
			state(hdlc)->n391cnt--;

		fr_lmi_send(dev, state(hdlc)->n391cnt == 0);

		state(hdlc)->last_poll = jiffies;
		state(hdlc)->request = 1;
		state(hdlc)->timer.expires = jiffies +
			state(hdlc)->settings.t391 * HZ;
	}

	state(hdlc)->timer.function = fr_timer;
	state(hdlc)->timer.data = arg;
	add_timer(&state(hdlc)->timer);
}


static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	pvc_device *pvc;
	u8 rxseq, txseq;
	int lmi = state(hdlc)->settings.lmi;
	int dce = state(hdlc)->settings.dce;
	int stat_len = (lmi == LMI_CISCO) ? 6 : 3, reptype, error, no_ram, i;

	if (skb->len < (lmi == LMI_ANSI ? LMI_ANSI_LENGTH :
			LMI_CCITT_CISCO_LENGTH)) {
		printk(KERN_INFO "%s: Short LMI frame\n", dev->name);
		return 1;
	}

	if (skb->data[3] != (lmi == LMI_CISCO ? NLPID_CISCO_LMI :
			     NLPID_CCITT_ANSI_LMI)) {
		printk(KERN_INFO "%s: Received non-LMI frame with LMI DLCI\n",
		       dev->name);
		return 1;
	}

	if (skb->data[4] != LMI_CALLREF) {
		printk(KERN_INFO "%s: Invalid LMI Call reference (0x%02X)\n",
		       dev->name, skb->data[4]);
		return 1;
	}

	if (skb->data[5] != (dce ? LMI_STATUS_ENQUIRY : LMI_STATUS)) {
		printk(KERN_INFO "%s: Invalid LMI Message type (0x%02X)\n",
		       dev->name, skb->data[5]);
		return 1;
	}

	if (lmi == LMI_ANSI) {
		if (skb->data[6] != LMI_ANSI_LOCKSHIFT) {
			printk(KERN_INFO "%s: Not ANSI locking shift in LMI"
			       " message (0x%02X)\n", dev->name, skb->data[6]);
			return 1;
		}
		i = 7;
	} else
		i = 6;

	if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
			     LMI_ANSI_CISCO_REPTYPE)) {
		printk(KERN_INFO "%s: Not an LMI Report type IE (0x%02X)\n",
		       dev->name, skb->data[i]);
		return 1;
	}

	if (skb->data[++i] != LMI_REPT_LEN) {
		printk(KERN_INFO "%s: Invalid LMI Report type IE length"
		       " (%u)\n", dev->name, skb->data[i]);
		return 1;
	}

	reptype = skb->data[++i];
	if (reptype != LMI_INTEGRITY && reptype != LMI_FULLREP) {
		printk(KERN_INFO "%s: Unsupported LMI Report type (0x%02X)\n",
		       dev->name, reptype);
		return 1;
	}

	if (skb->data[++i] != (lmi == LMI_CCITT ? LMI_CCITT_ALIVE :
			       LMI_ANSI_CISCO_ALIVE)) {
		printk(KERN_INFO "%s: Not an LMI Link integrity verification"
		       " IE (0x%02X)\n", dev->name, skb->data[i]);
		return 1;
	}

	if (skb->data[++i] != LMI_INTEG_LEN) {
		printk(KERN_INFO "%s: Invalid LMI Link integrity verification"
		       " IE length (%u)\n", dev->name, skb->data[i]);
		return 1;
	}
	i++;

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

	txseq = state(hdlc)->txseq;

	if (dce)
		state(hdlc)->last_poll = jiffies;

	error = 0;
	if (!state(hdlc)->reliable)
		error = 1;

	if (rxseq == 0 || rxseq != txseq) { /* Ask for full report next time */
		state(hdlc)->n391cnt = 0;
		error = 1;
	}

	if (dce) {
		if (state(hdlc)->fullrep_sent && !error) {
/* Stop sending full report - the last one has been confirmed by DTE */
			state(hdlc)->fullrep_sent = 0;
			pvc = state(hdlc)->first_pvc;
			while (pvc) {
				if (pvc->state.new) {
					pvc->state.new = 0;

/* Tell DTE that new PVC is now active */
					state(hdlc)->dce_changed = 1;
				}
				pvc = pvc->next;
			}
		}

		if (state(hdlc)->dce_changed) {
			reptype = LMI_FULLREP;
			state(hdlc)->fullrep_sent = 1;
			state(hdlc)->dce_changed = 0;
		}

		state(hdlc)->request = 1; /* got request */
		fr_lmi_send(dev, reptype == LMI_FULLREP ? 1 : 0);
		return 0;
	}

	/* DTE */

	state(hdlc)->request = 0; /* got response, no request pending */

	if (error)
		return 0;

	if (reptype != LMI_FULLREP)
		return 0;

	pvc = state(hdlc)->first_pvc;

	while (pvc) {
		pvc->state.deleted = 1;
		pvc = pvc->next;
	}

	no_ram = 0;
	while (skb->len >= i + 2 + stat_len) {
		u16 dlci;
		u32 bw;
		unsigned int active, new;

		if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
				       LMI_ANSI_CISCO_PVCSTAT)) {
			printk(KERN_INFO "%s: Not an LMI PVC status IE"
			       " (0x%02X)\n", dev->name, skb->data[i]);
			return 1;
		}

		if (skb->data[++i] != stat_len) {
			printk(KERN_INFO "%s: Invalid LMI PVC status IE length"
			       " (%u)\n", dev->name, skb->data[i]);
			return 1;
		}
		i++;

		new = !! (skb->data[i + 2] & 0x08);
		active = !! (skb->data[i + 2] & 0x02);
		if (lmi == LMI_CISCO) {
			dlci = (skb->data[i] << 8) | skb->data[i + 1];
			bw = (skb->data[i + 3] << 16) |
				(skb->data[i + 4] << 8) |
				(skb->data[i + 5]);
		} else {
			dlci = ((skb->data[i] & 0x3F) << 4) |
				((skb->data[i + 1] & 0x78) >> 3);
			bw = 0;
		}

		pvc = add_pvc(dev, dlci);

		if (!pvc && !no_ram) {
			printk(KERN_WARNING
			       "%s: Memory squeeze on fr_lmi_recv()\n",
			       dev->name);
			no_ram = 1;
		}

		if (pvc) {
			pvc->state.exist = 1;
			pvc->state.deleted = 0;
			if (active != pvc->state.active ||
			    new != pvc->state.new ||
			    bw != pvc->state.bandwidth ||
			    !pvc->state.exist) {
				pvc->state.new = new;
				pvc->state.active = active;
				pvc->state.bandwidth = bw;
				pvc_carrier(active, pvc);
				fr_log_dlci_active(pvc);
			}
		}

		i += stat_len;
	}

	pvc = state(hdlc)->first_pvc;

	while (pvc) {
		if (pvc->state.deleted && pvc->state.exist) {
			pvc_carrier(0, pvc);
			pvc->state.active = pvc->state.new = 0;
			pvc->state.exist = 0;
			pvc->state.bandwidth = 0;
			fr_log_dlci_active(pvc);
		}
		pvc = pvc->next;
	}