hdlc_fr.c

linux 内核源代码

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

	return 0;
}


static int fr_rx(struct sk_buff *skb)
{
	struct net_device *frad = skb->dev;
	hdlc_device *hdlc = dev_to_hdlc(frad);
	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_CCITT_ANSI_DLCI &&
	     (state(hdlc)->settings.lmi == LMI_ANSI ||
	      state(hdlc)->settings.lmi == LMI_CCITT)) ||
	    (dlci == LMI_CISCO_DLCI &&
	     state(hdlc)->settings.lmi == LMI_CISCO)) {
		if (fr_lmi_recv(frad, skb))
			goto rx_error;
		dev_kfree_skb_any(skb);
		return NET_RX_SUCCESS;
	}

	pvc = find_pvc(hdlc, dlci);
	if (!pvc) {
#ifdef DEBUG_PKT
		printk(KERN_INFO "%s: No PVC for received frame's DLCI %d\n",
		       frad->name, dlci);
#endif
		dev_kfree_skb_any(skb);
		return NET_RX_DROP;
	}

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


	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
		dev_to_desc(frad)->stats.rx_dropped++;
		return NET_RX_DROP;
	}

	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(*(__be16*)(data + 6));
		u16 pid = ntohs(*(__be16*)(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", frad->name, oui, pid);
			dev_kfree_skb_any(skb);
			return NET_RX_DROP;
		}
	} else {
		printk(KERN_INFO "%s: Unsupported protocol, NLPID=%x "
		       "length = %i\n", frad->name, data[3], skb->len);
		dev_kfree_skb_any(skb);
		return NET_RX_DROP;
	}

	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++;
		netif_rx(skb);
		return NET_RX_SUCCESS;
	} else {
		dev_kfree_skb_any(skb);
		return NET_RX_DROP;
	}

 rx_error:
	dev_to_desc(frad)->stats.rx_errors++; /* Mark error */
	dev_kfree_skb_any(skb);
	return NET_RX_DROP;
}



static void fr_start(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
#ifdef DEBUG_LINK
	printk(KERN_DEBUG "fr_start\n");
#endif
	if (state(hdlc)->settings.lmi != LMI_NONE) {
		state(hdlc)->reliable = 0;
		state(hdlc)->dce_changed = 1;
		state(hdlc)->request = 0;
		state(hdlc)->fullrep_sent = 0;
		state(hdlc)->last_errors = 0xFFFFFFFF;
		state(hdlc)->n391cnt = 0;
		state(hdlc)->txseq = state(hdlc)->rxseq = 0;

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


static void fr_stop(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
#ifdef DEBUG_LINK
	printk(KERN_DEBUG "fr_stop\n");
#endif
	if (state(hdlc)->settings.lmi != LMI_NONE)
		del_timer_sync(&state(hdlc)->timer);
	fr_set_link_state(0, dev);
}


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

	while (pvc) {		/* Shutdown all PVCs for this FRAD */
		if (pvc->main)
			dev_close(pvc->main);
		if (pvc->ether)
			dev_close(pvc->ether);
		pvc = pvc->next;
	}
}


static void pvc_setup(struct net_device *dev)
{
	dev->type = ARPHRD_DLCI;
	dev->flags = IFF_POINTOPOINT;
	dev->hard_header_len = 10;
	dev->addr_len = 2;
}

static int fr_add_pvc(struct net_device *frad, unsigned int dlci, int type)
{
	hdlc_device *hdlc = dev_to_hdlc(frad);
	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(frad, dlci)) == NULL) {
		printk(KERN_WARNING "%s: Memory squeeze on fr_add_pvc()\n",
		       frad->name);
		return -ENOBUFS;
	}

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

	used = pvc_is_used(pvc);

	if (type == ARPHRD_ETHER)
		dev = alloc_netdev(sizeof(struct net_device_stats),
				   "pvceth%d", ether_setup);
	else
		dev = alloc_netdev(sizeof(struct net_device_stats),
				   "pvc%d", pvc_setup);

	if (!dev) {
		printk(KERN_WARNING "%s: Memory squeeze on fr_pvc()\n",
		       frad->name);
		delete_unused_pvcs(hdlc);
		return -ENOBUFS;
	}

	if (type == ARPHRD_ETHER) {
		memcpy(dev->dev_addr, "\x00\x01", 2);
                get_random_bytes(dev->dev_addr + 2, ETH_ALEN - 2);
	} else {
		*(__be16*)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, dev->name);
	if (result < 0) {
		free_netdev(dev);
		delete_unused_pvcs(hdlc);
		return result;
	}

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

	dev->destructor = free_netdev;
	*get_dev_p(pvc, type) = dev;
	if (!used) {
		state(hdlc)->dce_changed = 1;
		state(hdlc)->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); /* the destructor will free_netdev(dev) */
	*get_dev_p(pvc, type) = NULL;

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



static void fr_destroy(struct net_device *frad)
{
	hdlc_device *hdlc = dev_to_hdlc(frad);
	pvc_device *pvc = state(hdlc)->first_pvc;
	state(hdlc)->first_pvc = NULL; /* All PVCs destroyed */
	state(hdlc)->dce_pvc_count = 0;
	state(hdlc)->dce_changed = 1;

	while (pvc) {
		pvc_device *next = pvc->next;
		/* destructors will free_netdev() main and ether */
		if (pvc->main)
			unregister_netdevice(pvc->main);

		if (pvc->ether)
			unregister_netdevice(pvc->ether);

		kfree(pvc);
		pvc = next;
	}
}


static struct hdlc_proto proto = {
	.close		= fr_close,
	.start		= fr_start,
	.stop		= fr_stop,
	.detach		= fr_destroy,
	.ioctl		= fr_ioctl,
	.module		= THIS_MODULE,
};


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

	switch (ifr->ifr_settings.type) {
	case IF_GET_PROTO:
		if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
			return -EINVAL;
		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, &state(hdlc)->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.lmi != LMI_CISCO) ||
		    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(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
		if (result)
			return result;

		if (dev_to_hdlc(dev)->proto != &proto) { /* Different proto */
			result = attach_hdlc_protocol(dev, &proto, fr_rx,
						      sizeof(struct frad_state));
			if (result)
				return result;
			state(hdlc)->first_pvc = NULL;
			state(hdlc)->dce_pvc_count = 0;
		}
		memcpy(&state(hdlc)->settings, &new_settings, size);

		dev->hard_start_xmit = hdlc->xmit;
		dev->type = ARPHRD_FRAD;
		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 (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
			return -EINVAL;

		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(dev, pvc.dlci, result);
		else
			return fr_del_pvc(hdlc, pvc.dlci, result);
	}

	return -EINVAL;
}


static int __init mod_init(void)
{
	register_hdlc_protocol(&proto);
	return 0;
}


static void __exit mod_exit(void)
{
	unregister_hdlc_protocol(&proto);
}


module_init(mod_init);
module_exit(mod_exit);

MODULE_AUTHOR("Krzysztof Halasa <[e-mail]>");
MODULE_DESCRIPTION("Frame-Relay protocol support for generic HDLC");
MODULE_LICENSE("GPL v2");