/* * VLAN An implementation of 802.1Q VLAN tagging. * * Authors: Ben Greear * * 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. * */ #ifndef _LINUX_IF_VLAN_H_ #define _LINUX_IF_VLAN_H_ #include #include #include #include #include #define VLAN_HLEN 4 /* The additional bytes required by VLAN * (in addition to the Ethernet header) */ #define VLAN_ETH_HLEN 18 /* Total octets in header. */ #define VLAN_ETH_ZLEN 64 /* Min. octets in frame sans FCS */ /* * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan */ #define VLAN_ETH_DATA_LEN 1500 /* Max. octets in payload */ #define VLAN_ETH_FRAME_LEN 1518 /* Max. octets in frame sans FCS */ /* * struct vlan_hdr - vlan header * @h_vlan_TCI: priority and VLAN ID * @h_vlan_encapsulated_proto: packet type ID or len */ struct vlan_hdr { __be16 h_vlan_TCI; __be16 h_vlan_encapsulated_proto; }; /** * struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr) * @h_dest: destination ethernet address * @h_source: source ethernet address * @h_vlan_proto: ethernet protocol (always 0x8100) * @h_vlan_TCI: priority and VLAN ID * @h_vlan_encapsulated_proto: packet type ID or len */ struct vlan_ethhdr { unsigned char h_dest[ETH_ALEN]; unsigned char h_source[ETH_ALEN]; __be16 h_vlan_proto; __be16 h_vlan_TCI; __be16 h_vlan_encapsulated_proto; }; #include static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb) { return (struct vlan_ethhdr *)skb_mac_header(skb); } #define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */ #define VLAN_PRIO_SHIFT 13 #define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator */ #define VLAN_TAG_PRESENT VLAN_CFI_MASK #define VLAN_VID_MASK 0x0fff /* VLAN Identifier */ #define VLAN_N_VID 4096 /* found in socket.c */ extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *)); static inline int is_vlan_dev(struct net_device *dev) { return dev->priv_flags & IFF_802_1Q_VLAN; } #define vlan_tx_tag_present(__skb) ((__skb)->vlan_tci & VLAN_TAG_PRESENT) #define vlan_tx_nonzero_tag_present(__skb) \ (vlan_tx_tag_present(__skb) && ((__skb)->vlan_tci & VLAN_VID_MASK)) #define vlan_tx_tag_get(__skb) ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT) #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev, u16 vlan_id); extern struct net_device *vlan_dev_real_dev(const struct net_device *dev); extern u16 vlan_dev_vlan_id(const struct net_device *dev); extern bool vlan_do_receive(struct sk_buff **skb); extern struct sk_buff *vlan_untag(struct sk_buff *skb); extern int vlan_vid_add(struct net_device *dev, unsigned short vid); extern void vlan_vid_del(struct net_device *dev, unsigned short vid); extern int vlan_vids_add_by_dev(struct net_device *dev, const struct net_device *by_dev); extern void vlan_vids_del_by_dev(struct net_device *dev, const struct net_device *by_dev); extern bool vlan_uses_dev(const struct net_device *dev); #else static inline struct net_device * __vlan_find_dev_deep(struct net_device *real_dev, u16 vlan_id) { return NULL; } static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev) { BUG(); return NULL; } static inline u16 vlan_dev_vlan_id(const struct net_device *dev) { BUG(); return 0; } static inline bool vlan_do_receive(struct sk_buff **skb) { return false; } static inline struct sk_buff *vlan_untag(struct sk_buff *skb) { return skb; } static inline int vlan_vid_add(struct net_device *dev, unsigned short vid) { return 0; } static inline void vlan_vid_del(struct net_device *dev, unsigned short vid) { } static inline int vlan_vids_add_by_dev(struct net_device *dev, const struct net_device *by_dev) { return 0; } static inline void vlan_vids_del_by_dev(struct net_device *dev, const struct net_device *by_dev) { } static inline bool vlan_uses_dev(const struct net_device *dev) { return false; } #endif /** * vlan_insert_tag - regular VLAN tag inserting * @skb: skbuff to tag * @vlan_tci: VLAN TCI to insert * * Inserts the VLAN tag into @skb as part of the payload * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. * * Following the skb_unshare() example, in case of error, the calling function * doesn't have to worry about freeing the original skb. * * Does not change skb->protocol so this function can be used during receive. */ static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci) { struct vlan_ethhdr *veth; if (skb_cow_head(skb, VLAN_HLEN) < 0) { kfree_skb(skb); return NULL; } veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN); /* Move the mac addresses to the beginning of the new header. */ memmove(skb->data, skb->data + VLAN_HLEN, 2 * ETH_ALEN); skb->mac_header -= VLAN_HLEN; /* first, the ethernet type */ veth->h_vlan_proto = htons(ETH_P_8021Q); /* now, the TCI */ veth->h_vlan_TCI = htons(vlan_tci); return skb; } /** * __vlan_put_tag - regular VLAN tag inserting * @skb: skbuff to tag * @vlan_tci: VLAN TCI to insert * * Inserts the VLAN tag into @skb as part of the payload * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. * * Following the skb_unshare() example, in case of error, the calling function * doesn't have to worry about freeing the original skb. */ static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci) { skb = vlan_insert_tag(skb, vlan_tci); if (skb) skb->protocol = htons(ETH_P_8021Q); return skb; } /** * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting * @skb: skbuff to tag * @vlan_tci: VLAN TCI to insert * * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest */ static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, u16 vlan_tci) { skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci; return skb; } #define HAVE_VLAN_PUT_TAG /** * vlan_put_tag - inserts VLAN tag according to device features * @skb: skbuff to tag * @vlan_tci: VLAN TCI to insert * * Assumes skb->dev is the target that will xmit this frame. * Returns a VLAN tagged skb. */ static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci) { if (skb->dev->features & NETIF_F_HW_VLAN_TX) { return __vlan_hwaccel_put_tag(skb, vlan_tci); } else { return __vlan_put_tag(skb, vlan_tci); } } /** * __vlan_get_tag - get the VLAN ID that is part of the payload * @skb: skbuff to query * @vlan_tci: buffer to store vlaue * * Returns error if the skb is not of VLAN type */ static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) { struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data; if (veth->h_vlan_proto != htons(ETH_P_8021Q)) { return -EINVAL; } *vlan_tci = ntohs(veth->h_vlan_TCI); return 0; } /** * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[] * @skb: skbuff to query * @vlan_tci: buffer to store vlaue * * Returns error if @skb->vlan_tci is not set correctly */ static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb, u16 *vlan_tci) { if (vlan_tx_tag_present(skb)) { *vlan_tci = vlan_tx_tag_get(skb); return 0; } else { *vlan_tci = 0; return -EINVAL; } } #define HAVE_VLAN_GET_TAG /** * vlan_get_tag - get the VLAN ID from the skb * @skb: skbuff to query * @vlan_tci: buffer to store vlaue * * Returns error if the skb is not VLAN tagged */ static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) { if (skb->dev->features & NETIF_F_HW_VLAN_TX) { return __vlan_hwaccel_get_tag(skb, vlan_tci); } else { return __vlan_get_tag(skb, vlan_tci); } } /** * vlan_get_protocol - get protocol EtherType. * @skb: skbuff to query * * Returns the EtherType of the packet, regardless of whether it is * vlan encapsulated (normal or hardware accelerated) or not. */ static inline __be16 vlan_get_protocol(const struct sk_buff *skb) { __be16 protocol = 0; if (vlan_tx_tag_present(skb) || skb->protocol != cpu_to_be16(ETH_P_8021Q)) protocol = skb->protocol; else { __be16 proto, *protop; protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr, h_vlan_encapsulated_proto), sizeof(proto), &proto); if (likely(protop)) protocol = *protop; } return protocol; } static inline void vlan_set_encap_proto(struct sk_buff *skb, struct vlan_hdr *vhdr) { __be16 proto; unsigned short *rawp; /* * Was a VLAN packet, grab the encapsulated protocol, which the layer * three protocols care about. */ proto = vhdr->h_vlan_encapsulated_proto; if (ntohs(proto) >= 1536) { skb->protocol = proto; return; } rawp = (unsigned short *)(vhdr + 1); if (*rawp == 0xFFFF) /* * 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. */ skb->protocol = htons(ETH_P_802_3); else /* * Real 802.2 LLC */ skb->protocol = htons(ETH_P_802_2); } #endif /* !(_LINUX_IF_VLAN_H_) */