hdlc_fr.c

linux-2.4.29操作系统的源码

{
	int stat_len;
	pvc_device *pvc;
	int reptype = -1, error, no_ram;
	u8 rxseq, txseq;
	int i;

	if (skb->len < ((hdlc->state.fr.settings.lmi == LMI_ANSI)
			? LMI_ANSI_LENGTH : LMI_LENGTH)) {
		printk(KERN_INFO "%s: Short LMI frame\n", hdlc_to_name(hdlc));
		return 1;
	}

	if (skb->data[5] != (!hdlc->state.fr.settings.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],
		       hdlc->state.fr.settings.dce ? "enquiry" : "reply");
		return 1;
	}

	i = (hdlc->state.fr.settings.lmi == LMI_ANSI) ? 7 : 6;

	if (skb->data[i] !=
	    ((hdlc->state.fr.settings.lmi == LMI_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]!=
	    ((hdlc->state.fr.settings.lmi == LMI_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->state.fr.rxseq = skb->data[i++]; /* TX sequence from peer */
	rxseq = skb->data[i++];	/* Should confirm our sequence */

	txseq = hdlc->state.fr.txseq;

	if (hdlc->state.fr.settings.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->state.fr.reliable)
		error = 1;

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

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

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

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

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

	/* DTE */

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

	stat_len = 3;
	pvc = hdlc->state.fr.first_pvc;

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

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

		if (skb->data[i] != ((hdlc->state.fr.settings.lmi == LMI_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(skb->data + i, &active, &new);

		pvc = add_pvc(hdlc, dlci);

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

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

		i += stat_len;
	}

	pvc = hdlc->state.fr.first_pvc;

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

	/* Next full report after N391 polls */
	hdlc->state.fr.n391cnt = hdlc->state.fr.settings.n391;

	return 0;
}



static void fr_rx(struct sk_buff *skb)
{
	hdlc_device *hdlc = dev_to_hdlc(skb->dev);
	fr_hdr *fh = (fr_hdr*)skb->data;
	u8 *data = skb->data;
	u16 dlci;
	pvc_device *pvc;
	struct net_device *dev = NULL;

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

	dlci = q922_to_dlci(skb->data);

	if (dlci == LMI_DLCI) {
		if (hdlc->state.fr.settings.lmi == LMI_NONE)
			goto rx_error; /* LMI packet with no LMI? */

		if (data[3] == LMI_PROTO) {
			if (fr_lmi_recv(hdlc, skb))
				goto rx_error;
			else {
				/* No request pending */
				hdlc->state.fr.request = 0;
				hdlc->state.fr.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
		dev_kfree_skb_any(skb);
		return;
	}

	if (pvc->state.fecn != fh->fecn) {
#ifdef DEBUG_ECN
		printk(KERN_DEBUG "%s: DLCI %d FECN O%s\n", hdlc_to_name(pvc),
		       dlci, fh->fecn ? "N" : "FF");
#endif
		pvc->state.fecn ^= 1;
	}

	if (pvc->state.becn != fh->becn) {
#ifdef DEBUG_ECN
		printk(KERN_DEBUG "%s: DLCI %d BECN O%s\n", hdlc_to_name(pvc),
		       dlci, fh->becn ? "N" : "FF");
#endif
		pvc->state.becn ^= 1;
	}


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

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

	} else if (skb->len > 10 && data[3] == FR_PAD &&
		   data[4] == NLPID_SNAP && data[5] == FR_PAD) {
		u16 oui = ntohs(*(u16*)(data + 6));
		u16 pid = ntohs(*(u16*)(data + 8));
		skb_pull(skb, 10);

		switch ((((u32)oui) << 16) | pid) {
		case ETH_P_ARP: /* routed frame with SNAP */
		case ETH_P_IPX:
		case ETH_P_IP:	/* a long variant */
		case ETH_P_IPV6:
			dev = pvc->main;
			skb->protocol = htons(pid);
			break;

		case 0x80C20007: /* bridged Ethernet frame */
			if ((dev = pvc->ether) != NULL)
				skb->protocol = eth_type_trans(skb, dev);
			break;

		default:
			printk(KERN_INFO "%s: Unsupported protocol, OUI=%x "
			       "PID=%x\n", hdlc_to_name(hdlc), oui, pid);
			dev_kfree_skb_any(skb);
			return;
		}
	} else {
		printk(KERN_INFO "%s: Unsupported protocol, NLPID=%x "
		       "length = %i\n", hdlc_to_name(hdlc), data[3], skb->len);
		dev_kfree_skb_any(skb);
		return;
	}

	if (dev) {
		struct net_device_stats *stats = pvc_get_stats(dev);
		stats->rx_packets++; /* PVC traffic */
		stats->rx_bytes += skb->len;
		if (pvc->state.becn)
			stats->rx_compressed++;
		skb->dev = dev;
		netif_rx(skb);
	} else
		dev_kfree_skb_any(skb);

	return;

 rx_error:
	hdlc->stats.rx_errors++; /* Mark error */
	dev_kfree_skb_any(skb);
}



static int fr_open(hdlc_device *hdlc)
{
	if (hdlc->state.fr.settings.lmi != LMI_NONE) {
		hdlc->state.fr.last_poll = 0;
		hdlc->state.fr.reliable = 0;
		hdlc->state.fr.dce_changed = 1;
		hdlc->state.fr.request = 0;
		hdlc->state.fr.fullrep_sent = 0;
		hdlc->state.fr.last_errors = 0xFFFFFFFF;
		hdlc->state.fr.n391cnt = 0;
		hdlc->state.fr.txseq = hdlc->state.fr.rxseq = 0;

		init_timer(&hdlc->state.fr.timer);
		/* First poll after 1 s */
		hdlc->state.fr.timer.expires = jiffies + HZ;
		hdlc->state.fr.timer.function = fr_timer;
		hdlc->state.fr.timer.data = (unsigned long)hdlc;
		add_timer(&hdlc->state.fr.timer);
	} else
		hdlc->state.fr.reliable = 1;

	return 0;
}



static void fr_close(hdlc_device *hdlc)
{
	pvc_device *pvc = hdlc->state.fr.first_pvc;

	if (hdlc->state.fr.settings.lmi != LMI_NONE)
		del_timer_sync(&hdlc->state.fr.timer);

	while (pvc) {		/* Shutdown all PVCs for this FRAD */
		if (pvc->main)
			dev_close(pvc->main);
		if (pvc->ether)
			dev_close(pvc->ether);
		pvc->state.active = pvc->state.new = pvc->state.fecn =
			pvc->state.becn = 0;
		pvc->state.exist = 0;
		pvc = pvc->next;
	}
}


static int fr_add_pvc(hdlc_device *hdlc, unsigned int dlci, int type)
{
	pvc_device *pvc = NULL;
	struct net_device *dev;
	int result, used;
	char * prefix = "pvc%d";

	if (type == ARPHRD_ETHER)
		prefix = "pvceth%d";

	if ((pvc = add_pvc(hdlc, dlci)) == NULL) {
		printk(KERN_WARNING "%s: Memory squeeze on fr_add_pvc()\n",
		       hdlc_to_name(hdlc));
		return -ENOBUFS;
	}

	if (*get_dev_p(pvc, type))
		return -EEXIST;

	used = pvc_is_used(pvc);

	dev = kmalloc(sizeof(struct net_device) +
		      sizeof(struct net_device_stats), GFP_KERNEL);
	if (!dev) {
		printk(KERN_WARNING "%s: Memory squeeze on fr_pvc()\n",
		       hdlc_to_name(hdlc));
		delete_unused_pvcs(hdlc);
		return -ENOBUFS;
	}
	memset(dev, 0, sizeof(struct net_device) +
	       sizeof(struct net_device_stats));

	if (type == ARPHRD_ETHER) {
		ether_setup(dev);
		memcpy(dev->dev_addr, "\x00\x01", 2);
                get_random_bytes(dev->dev_addr + 2, ETH_ALEN - 2);
	} else {
		dev->type = ARPHRD_DLCI;
		dev->flags = IFF_POINTOPOINT;
		dev->hard_header_len = 10;
		dev->addr_len = 2;
		*(u16*)dev->dev_addr = htons(dlci);
		dlci_to_q922(dev->broadcast, dlci);
	}
	dev->hard_start_xmit = pvc_xmit;
	dev->get_stats = pvc_get_stats;
	dev->open = pvc_open;
	dev->stop = pvc_close;
	dev->do_ioctl = pvc_ioctl;
	dev->change_mtu = pvc_change_mtu;
	dev->mtu = HDLC_MAX_MTU;
	dev->tx_queue_len = 0;
	dev->priv = pvc;

	result = dev_alloc_name(dev, prefix);
	if (result < 0) {
		kfree(dev);
		delete_unused_pvcs(hdlc);
		return result;
	}

	if (register_netdevice(dev) != 0) {
		kfree(dev);
		delete_unused_pvcs(hdlc);
		return -EIO;
	}

	*get_dev_p(pvc, type) = dev;
	if (!used) {
		hdlc->state.fr.dce_changed = 1;
		hdlc->state.fr.dce_pvc_count++;
	}
	return 0;
}



static int fr_del_pvc(hdlc_device *hdlc, unsigned int dlci, int type)
{
	pvc_device *pvc;
	struct net_device *dev;

	if ((pvc = find_pvc(hdlc, dlci)) == NULL)
		return -ENOENT;

	if ((dev = *get_dev_p(pvc, type)) == NULL)
		return -ENOENT;

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

	unregister_netdevice(dev);
	kfree(dev);
	*get_dev_p(pvc, type) = NULL;

	if (!pvc_is_used(pvc)) {
		hdlc->state.fr.dce_pvc_count--;
		hdlc->state.fr.dce_changed = 1;
	}
	delete_unused_pvcs(hdlc);
	return 0;
}



static void fr_destroy(hdlc_device *hdlc)
{
	pvc_device *pvc = hdlc->state.fr.first_pvc;
	while (pvc) {
		pvc_device *next = pvc->next;
		if (pvc->main) {
			unregister_netdevice(pvc->main);
			kfree(pvc->main);
		}
		if (pvc->ether) {
			unregister_netdevice(pvc->ether);
			kfree(pvc->ether);
		}
		kfree(pvc);
		pvc = next;
	}

	hdlc->state.fr.first_pvc = NULL; /* All PVCs destroyed */
	hdlc->state.fr.dce_pvc_count = 0;
	hdlc->state.fr.dce_changed = 1;
}



int hdlc_fr_ioctl(hdlc_device *hdlc, struct ifreq *ifr)
{
	fr_proto *fr_s = ifr->ifr_settings.ifs_ifsu.fr;
	const size_t size = sizeof(fr_proto);
	fr_proto new_settings;
	struct net_device *dev = hdlc_to_dev(hdlc);
	fr_proto_pvc pvc;
	int result;

	switch (ifr->ifr_settings.type) {
	case IF_GET_PROTO:
		ifr->ifr_settings.type = IF_PROTO_FR;
		if (ifr->ifr_settings.size < size) {
			ifr->ifr_settings.size = size; /* data size wanted */
			return -ENOBUFS;
		}
		if (copy_to_user(fr_s, &hdlc->state.fr.settings, size))
			return -EFAULT;
		return 0;

	case IF_PROTO_FR:
		if(!capable(CAP_NET_ADMIN))
			return -EPERM;

		if(dev->flags & IFF_UP)
			return -EBUSY;

		if (copy_from_user(&new_settings, fr_s, size))
			return -EFAULT;

		if (new_settings.lmi == LMI_DEFAULT)
			new_settings.lmi = LMI_ANSI;

		if ((new_settings.lmi != LMI_NONE &&
		     new_settings.lmi != LMI_ANSI &&
		     new_settings.lmi != LMI_CCITT) ||
		    new_settings.t391 < 1 ||
		    new_settings.t392 < 2 ||
		    new_settings.n391 < 1 ||
		    new_settings.n392 < 1 ||
		    new_settings.n393 < new_settings.n392 ||
		    new_settings.n393 > 32 ||
		    (new_settings.dce != 0 &&
		     new_settings.dce != 1))
			return -EINVAL;

		result=hdlc->attach(hdlc, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
		if (result)
			return result;

		if (hdlc->proto != IF_PROTO_FR) {
			hdlc_proto_detach(hdlc);
			hdlc->state.fr.first_pvc = NULL;
			hdlc->state.fr.dce_pvc_count = 0;
		}
		memcpy(&hdlc->state.fr.settings, &new_settings, size);

		hdlc->open = fr_open;
		hdlc->stop = fr_close;
		hdlc->netif_rx = fr_rx;
		hdlc->type_trans = NULL;
		hdlc->proto_detach = fr_destroy;
		hdlc->proto = IF_PROTO_FR;
		dev->hard_start_xmit = hdlc->xmit;
		dev->hard_header = NULL;
		dev->type = ARPHRD_FRAD;
		dev->flags = IFF_POINTOPOINT | IFF_NOARP;
		dev->addr_len = 0;
		return 0;

	case IF_PROTO_FR_ADD_PVC:
	case IF_PROTO_FR_DEL_PVC:
	case IF_PROTO_FR_ADD_ETH_PVC:
	case IF_PROTO_FR_DEL_ETH_PVC:
		if(!capable(CAP_NET_ADMIN))
			return -EPERM;

		if (copy_from_user(&pvc, ifr->ifr_settings.ifs_ifsu.fr_pvc,
				   sizeof(fr_proto_pvc)))
			return -EFAULT;

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

		if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC ||
		    ifr->ifr_settings.type == IF_PROTO_FR_DEL_ETH_PVC)
			result = ARPHRD_ETHER; /* bridged Ethernet device */
		else
			result = ARPHRD_DLCI;

		if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_PVC ||
		    ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC)
			return fr_add_pvc(hdlc, pvc.dlci, result);
		else
			return fr_del_pvc(hdlc, pvc.dlci, result);
	}

	return -EINVAL;
}