/* -*- linux-c -*- * INET		802.1Q VLAN *		Ethernet-type device handling. * * Authors:	Ben Greear <greearb@candelatech.com> *              Please send support related email to: vlan@scry.wanfear.com *              VLAN Home Page: http://www.candelatech.com/~greear/vlan.html *  * Fixes:       Mar 22 2001: Martin Bokaemper <mbokaemper@unispherenetworks.com> *                - reset skb->pkt_type on incoming packets when MAC was changed *                - see that changed MAC is saddr for outgoing packets *              Oct 20, 2001:  Ard van Breeman: *                - Fix MC-list, finally. *                - Flush MC-list on VLAN destroy. *                 * *		This program is free software; you can redistribute it and/or *		modify it under the terms of the GNU General Public License *		as published by the Free Software Foundation; either version *		2 of the License, or (at your option) any later version. */#include <linux/module.h>#include <linux/mm.h>#include <linux/in.h>#include <linux/init.h>#include <asm/uaccess.h> /* for copy_from_user */#include <linux/skbuff.h>#include <linux/netdevice.h>#include <linux/etherdevice.h>#include <net/datalink.h>#include <net/p8022.h>#include <net/arp.h>#include "vlan.h"#include "vlanproc.h"#include <linux/if_vlan.h>#include <net/ip.h>/* *	Rebuild the Ethernet MAC header. This is called after an ARP *	(or in future other address resolution) has completed on this *	sk_buff. We now let ARP fill in the other fields. * *	This routine CANNOT use cached dst->neigh! *	Really, it is used only when dst->neigh is wrong. * * TODO:  This needs a checkup, I'm ignorant here. --BLG */int vlan_dev_rebuild_header(struct sk_buff *skb){	struct net_device *dev = skb->dev;	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);	switch (veth->h_vlan_encapsulated_proto) {#ifdef CONFIG_INET	case __constant_htons(ETH_P_IP):		/* TODO:  Confirm this will work with VLAN headers... */		return arp_find(veth->h_dest, skb);#endif		default:		printk(VLAN_DBG		       "%s: unable to resolve type %X addresses.\n", 		       dev->name, (int)veth->h_vlan_encapsulated_proto);	 		memcpy(veth->h_source, dev->dev_addr, ETH_ALEN);		break;	};	return 0;}static inline struct sk_buff *vlan_check_reorder_header(struct sk_buff *skb){	if (VLAN_DEV_INFO(skb->dev)->flags & 1) {		if (skb_shared(skb) || skb_cloned(skb)) {			struct sk_buff *nskb = skb_copy(skb, GFP_ATOMIC);			kfree_skb(skb);			skb = nskb;		}		if (skb) {			/* Lifted from Gleb's VLAN code... */			memmove(skb->data - ETH_HLEN,				skb->data - VLAN_ETH_HLEN, 12);			skb->mac.raw += VLAN_HLEN;		}	}	return skb;}/* *	Determine the packet's protocol ID. The rule here is that we  *	assume 802.3 if the type field is short enough to be a length. *	This is normal practice and works for any 'now in use' protocol. * *  Also, at this point we assume that we ARE dealing exclusively with *  VLAN packets, or packets that should be made into VLAN packets based *  on a default VLAN ID. * *  NOTE:  Should be similar to ethernet/eth.c. * *  SANITY NOTE:  This method is called when a packet is moving up the stack *                towards userland.  To get here, it would have already passed *                through the ethernet/eth.c eth_type_trans() method. *  SANITY NOTE 2: We are referencing to the VLAN_HDR frields, which MAY be *                 stored UNALIGNED in the memory.  RISC systems don't like *                 such cases very much... *  SANITY NOTE 2a:  According to Dave Miller & Alexey, it will always be aligned, *                 so there doesn't need to be any of the unaligned stuff.  It has *                 been commented out now...  --Ben * */int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev,                  struct packet_type* ptype, struct net_device *orig_dev){	unsigned char *rawp = NULL;	struct vlan_hdr *vhdr = (struct vlan_hdr *)(skb->data);	unsigned short vid;	struct net_device_stats *stats;	unsigned short vlan_TCI;	__be16 proto;	/* vlan_TCI = ntohs(get_unaligned(&vhdr->h_vlan_TCI)); */	vlan_TCI = ntohs(vhdr->h_vlan_TCI);	vid = (vlan_TCI & VLAN_VID_MASK);#ifdef VLAN_DEBUG	printk(VLAN_DBG "%s: skb: %p vlan_id: %hx\n",		__FUNCTION__, skb, vid);#endif	/* Ok, we will find the correct VLAN device, strip the header,	 * and then go on as usual.	 */	/* We have 12 bits of vlan ID.	 *	 * We must not drop allow preempt until we hold a	 * reference to the device (netif_rx does that) or we	 * fail.	 */	rcu_read_lock();	skb->dev = __find_vlan_dev(dev, vid);	if (!skb->dev) {		rcu_read_unlock();#ifdef VLAN_DEBUG		printk(VLAN_DBG "%s: ERROR: No net_device for VID: %i on dev: %s [%i]\n",			__FUNCTION__, (unsigned int)(vid), dev->name, dev->ifindex);#endif		kfree_skb(skb);		return -1;	}	skb->dev->last_rx = jiffies;	/* Bump the rx counters for the VLAN device. */	stats = vlan_dev_get_stats(skb->dev);	stats->rx_packets++;	stats->rx_bytes += skb->len;	/* Take off the VLAN header (4 bytes currently) */	skb_pull_rcsum(skb, VLAN_HLEN);	/* Ok, lets check to make sure the device (dev) we	 * came in on is what this VLAN is attached to.	 */	if (dev != VLAN_DEV_INFO(skb->dev)->real_dev) {		rcu_read_unlock();#ifdef VLAN_DEBUG		printk(VLAN_DBG "%s: dropping skb: %p because came in on wrong device, dev: %s  real_dev: %s, skb_dev: %s\n",			__FUNCTION__, skb, dev->name, 			VLAN_DEV_INFO(skb->dev)->real_dev->name, 			skb->dev->name);#endif		kfree_skb(skb);		stats->rx_errors++;		return -1;	}	/*	 * Deal with ingress priority mapping.	 */	skb->priority = vlan_get_ingress_priority(skb->dev, ntohs(vhdr->h_vlan_TCI));#ifdef VLAN_DEBUG	printk(VLAN_DBG "%s: priority: %lu  for TCI: %hu (hbo)\n",		__FUNCTION__, (unsigned long)(skb->priority), 		ntohs(vhdr->h_vlan_TCI));#endif	/* The ethernet driver already did the pkt_type calculations	 * for us...	 */	switch (skb->pkt_type) {	case PACKET_BROADCAST: /* Yeah, stats collect these together.. */		// stats->broadcast ++; // no such counter :-(		break;	case PACKET_MULTICAST:		stats->multicast++;		break;	case PACKET_OTHERHOST: 		/* Our lower layer thinks this is not local, let's make sure.		 * This allows the VLAN to have a different MAC than the underlying		 * device, and still route correctly.		 */		if (!compare_ether_addr(eth_hdr(skb)->h_dest, skb->dev->dev_addr)) {			/* It is for our (changed) MAC-address! */			skb->pkt_type = PACKET_HOST;		}		break;	default:		break;	};	/*  Was a VLAN packet, grab the encapsulated protocol, which the layer	 * three protocols care about.	 */	/* proto = get_unaligned(&vhdr->h_vlan_encapsulated_proto); */	proto = vhdr->h_vlan_encapsulated_proto;	skb->protocol = proto;	if (ntohs(proto) >= 1536) {		/* place it back on the queue to be handled by		 * true layer 3 protocols.		 */		/* See if we are configured to re-write the VLAN header		 * to make it look like ethernet...		 */		skb = vlan_check_reorder_header(skb);		/* Can be null if skb-clone fails when re-ordering */		if (skb) {			netif_rx(skb);		} else {			/* TODO:  Add a more specific counter here. */			stats->rx_errors++;		}		rcu_read_unlock();		return 0;	}	rawp = skb->data;	/*	 * This is a magic hack to spot IPX packets. Older Novell breaks	 * the protocol design and runs IPX over 802.3 without an 802.2 LLC	 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This	 * won't work for fault tolerant netware but does for the rest.	 */	if (*(unsigned short *)rawp == 0xFFFF) {		skb->protocol = __constant_htons(ETH_P_802_3);		/* place it back on the queue to be handled by true layer 3 protocols.		 */		/* See if we are configured to re-write the VLAN header		 * to make it look like ethernet...		 */		skb = vlan_check_reorder_header(skb);		/* Can be null if skb-clone fails when re-ordering */		if (skb) {			netif_rx(skb);		} else {			/* TODO:  Add a more specific counter here. */			stats->rx_errors++;		}		rcu_read_unlock();		return 0;	}	/*	 *	Real 802.2 LLC	 */	skb->protocol = __constant_htons(ETH_P_802_2);	/* place it back on the queue to be handled by upper layer protocols.	 */	/* See if we are configured to re-write the VLAN header	 * to make it look like ethernet...	 */	skb = vlan_check_reorder_header(skb);	/* Can be null if skb-clone fails when re-ordering */	if (skb) {		netif_rx(skb);	} else {		/* TODO:  Add a more specific counter here. */		stats->rx_errors++;	}	rcu_read_unlock();	return 0;}static inline unsigned short vlan_dev_get_egress_qos_mask(struct net_device* dev,							  struct sk_buff* skb){	struct vlan_priority_tci_mapping *mp =		VLAN_DEV_INFO(dev)->egress_priority_map[(skb->priority & 0xF)];	while (mp) {		if (mp->priority == skb->priority) {			return mp->vlan_qos; /* This should already be shifted to mask					      * correctly with the VLAN's TCI					      */		}		mp = mp->next;	}	return 0;}/* *	Create the VLAN header for an arbitrary protocol layer  * *	saddr=NULL	means use device source address *	daddr=NULL	means leave destination address (eg unresolved arp) * *  This is called when the SKB is moving down the stack towards the *  physical devices. */int vlan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,                         unsigned short type, void *daddr, void *saddr,                         unsigned len){	struct vlan_hdr *vhdr;	unsigned short veth_TCI = 0;	int rc = 0;	int build_vlan_header = 0;	struct net_device *vdev = dev; /* save this for the bottom of the method */#ifdef VLAN_DEBUG	printk(VLAN_DBG "%s: skb: %p type: %hx len: %x vlan_id: %hx, daddr: %p\n",		__FUNCTION__, skb, type, len, VLAN_DEV_INFO(dev)->vlan_id, daddr);#endif	/* build vlan header only if re_order_header flag is NOT set.  This	 * fixes some programs that get confused when they see a VLAN device	 * sending a frame that is VLAN encoded (the consensus is that the VLAN	 * device should look completely like an Ethernet device when the	 * REORDER_HEADER flag is set)	The drawback to this is some extra 	 * header shuffling in the hard_start_xmit.  Users can turn off this	 * REORDER behaviour with the vconfig tool.	 */	build_vlan_header = ((VLAN_DEV_INFO(dev)->flags & 1) == 0);	if (build_vlan_header) {		vhdr = (struct vlan_hdr *) skb_push(skb, VLAN_HLEN);		/* build the four bytes that make this a VLAN header. */		/* Now, construct the second two bytes. This field looks something		 * like:		 * usr_priority: 3 bits	 (high bits)		 * CFI		 1 bit		 * VLAN ID	 12 bits (low bits)		 *		 */		veth_TCI = VLAN_DEV_INFO(dev)->vlan_id;		veth_TCI |= vlan_dev_get_egress_qos_mask(dev, skb);		vhdr->h_vlan_TCI = htons(veth_TCI);		/*		 *  Set the protocol type.		 *  For a packet of type ETH_P_802_3 we put the length in here instead.		 *  It is up to the 802.2 layer to carry protocol information.		 */		if (type != ETH_P_802_3) {			vhdr->h_vlan_encapsulated_proto = htons(type);		} else {			vhdr->h_vlan_encapsulated_proto = htons(len);		}	}	/* Before delegating work to the lower layer, enter our MAC-address */	if (saddr == NULL)		saddr = dev->dev_addr;	dev = VLAN_DEV_INFO(dev)->real_dev;	/* MPLS can send us skbuffs w/out enough space.	 This check will grow the	 * skb if it doesn't have enough headroom.  Not a beautiful solution, so	 * I'll tick a counter so that users can know it's happening...	 If they	 * care...	 */	/* NOTE:  This may still break if the underlying device is not the final	 * device (and thus there are more headers to add...)  It should work for	 * good-ole-ethernet though.	 */	if (skb_headroom(skb) < dev->hard_header_len) {		struct sk_buff *sk_tmp = skb;		skb = skb_realloc_headroom(sk_tmp, dev->hard_header_len);		kfree_skb(sk_tmp);		if (skb == NULL) {			struct net_device_stats *stats = vlan_dev_get_stats(vdev);			stats->tx_dropped++;			return -ENOMEM;		}		VLAN_DEV_INFO(vdev)->cnt_inc_headroom_on_tx++;#ifdef VLAN_DEBUG		printk(VLAN_DBG "%s: %s: had to grow skb.\n", __FUNCTION__, vdev->name);#endif	}	if (build_vlan_header) {		/* Now make the underlying real hard header */		rc = dev->hard_header(skb, dev, ETH_P_8021Q, daddr, saddr, len + VLAN_HLEN);		if (rc > 0) {			rc += VLAN_HLEN;		} else if (rc < 0) {			rc -= VLAN_HLEN;		}	} else {		/* If here, then we'll just make a normal looking ethernet frame,		 * but, the hard_start_xmit method will insert the tag (it has to		 * be able to do this for bridged and other skbs that don't come		 * down the protocol stack in an orderly manner.		 */		rc = dev->hard_header(skb, dev, type, daddr, saddr, len);	}	return rc;}int vlan_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev){	struct net_device_stats *stats = vlan_dev_get_stats(dev);	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);	/* Handle non-VLAN frames if they are sent to us, for example by DHCP.	 *	 * NOTE: THIS ASSUMES DIX ETHERNET, SPECIFICALLY NOT SUPPORTING	 * OTHER THINGS LIKE FDDI/TokenRing/802.3 SNAPs...	 */