diff options
Diffstat (limited to 'include/linux/if_vlan.h')
| -rw-r--r-- | include/linux/if_vlan.h | 816 |
1 files changed, 816 insertions, 0 deletions
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h new file mode 100644 index 000000000..3028af877 --- /dev/null +++ b/include/linux/if_vlan.h @@ -0,0 +1,816 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * VLAN An implementation of 802.1Q VLAN tagging. + * + * Authors: Ben Greear <greearb@candelatech.com> + */ +#ifndef _LINUX_IF_VLAN_H_ +#define _LINUX_IF_VLAN_H_ + +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/rtnetlink.h> +#include <linux/bug.h> +#include <uapi/linux/if_vlan.h> + +#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 */ + +#define VLAN_MAX_DEPTH 8 /* Max. number of nested VLAN tags parsed */ + +/* + * 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 + * @h_vlan_TCI: priority and VLAN ID + * @h_vlan_encapsulated_proto: packet type ID or len + */ +struct vlan_ethhdr { + struct_group(addrs, + 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 <linux/skbuff.h> + +static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb) +{ + return (struct vlan_ethhdr *)skb_mac_header(skb); +} + +/* Prefer this version in TX path, instead of + * skb_reset_mac_header() + vlan_eth_hdr() + */ +static inline struct vlan_ethhdr *skb_vlan_eth_hdr(const struct sk_buff *skb) +{ + return (struct vlan_ethhdr *)skb->data; +} + +#define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */ +#define VLAN_PRIO_SHIFT 13 +#define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator / Drop Eligible Indicator */ +#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 bool is_vlan_dev(const struct net_device *dev) +{ + return dev->priv_flags & IFF_802_1Q_VLAN; +} + +#define skb_vlan_tag_present(__skb) (!!(__skb)->vlan_all) +#define skb_vlan_tag_get(__skb) ((__skb)->vlan_tci) +#define skb_vlan_tag_get_id(__skb) ((__skb)->vlan_tci & VLAN_VID_MASK) +#define skb_vlan_tag_get_cfi(__skb) (!!((__skb)->vlan_tci & VLAN_CFI_MASK)) +#define skb_vlan_tag_get_prio(__skb) (((__skb)->vlan_tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT) + +static inline int vlan_get_rx_ctag_filter_info(struct net_device *dev) +{ + ASSERT_RTNL(); + return notifier_to_errno(call_netdevice_notifiers(NETDEV_CVLAN_FILTER_PUSH_INFO, dev)); +} + +static inline void vlan_drop_rx_ctag_filter_info(struct net_device *dev) +{ + ASSERT_RTNL(); + call_netdevice_notifiers(NETDEV_CVLAN_FILTER_DROP_INFO, dev); +} + +static inline int vlan_get_rx_stag_filter_info(struct net_device *dev) +{ + ASSERT_RTNL(); + return notifier_to_errno(call_netdevice_notifiers(NETDEV_SVLAN_FILTER_PUSH_INFO, dev)); +} + +static inline void vlan_drop_rx_stag_filter_info(struct net_device *dev) +{ + ASSERT_RTNL(); + call_netdevice_notifiers(NETDEV_SVLAN_FILTER_DROP_INFO, dev); +} + +/** + * struct vlan_pcpu_stats - VLAN percpu rx/tx stats + * @rx_packets: number of received packets + * @rx_bytes: number of received bytes + * @rx_multicast: number of received multicast packets + * @tx_packets: number of transmitted packets + * @tx_bytes: number of transmitted bytes + * @syncp: synchronization point for 64bit counters + * @rx_errors: number of rx errors + * @tx_dropped: number of tx drops + */ +struct vlan_pcpu_stats { + u64_stats_t rx_packets; + u64_stats_t rx_bytes; + u64_stats_t rx_multicast; + u64_stats_t tx_packets; + u64_stats_t tx_bytes; + struct u64_stats_sync syncp; + u32 rx_errors; + u32 tx_dropped; +}; + +#if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) + +extern struct net_device *__vlan_find_dev_deep_rcu(struct net_device *real_dev, + __be16 vlan_proto, u16 vlan_id); +extern int vlan_for_each(struct net_device *dev, + int (*action)(struct net_device *dev, int vid, + void *arg), void *arg); +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 __be16 vlan_dev_vlan_proto(const struct net_device *dev); + +/** + * struct vlan_priority_tci_mapping - vlan egress priority mappings + * @priority: skb priority + * @vlan_qos: vlan priority: (skb->priority << 13) & 0xE000 + * @next: pointer to next struct + */ +struct vlan_priority_tci_mapping { + u32 priority; + u16 vlan_qos; + struct vlan_priority_tci_mapping *next; +}; + +struct proc_dir_entry; +struct netpoll; + +/** + * struct vlan_dev_priv - VLAN private device data + * @nr_ingress_mappings: number of ingress priority mappings + * @ingress_priority_map: ingress priority mappings + * @nr_egress_mappings: number of egress priority mappings + * @egress_priority_map: hash of egress priority mappings + * @vlan_proto: VLAN encapsulation protocol + * @vlan_id: VLAN identifier + * @flags: device flags + * @real_dev: underlying netdevice + * @dev_tracker: refcount tracker for @real_dev reference + * @real_dev_addr: address of underlying netdevice + * @dent: proc dir entry + * @vlan_pcpu_stats: ptr to percpu rx stats + */ +struct vlan_dev_priv { + unsigned int nr_ingress_mappings; + u32 ingress_priority_map[8]; + unsigned int nr_egress_mappings; + struct vlan_priority_tci_mapping *egress_priority_map[16]; + + __be16 vlan_proto; + u16 vlan_id; + u16 flags; + + struct net_device *real_dev; + netdevice_tracker dev_tracker; + + unsigned char real_dev_addr[ETH_ALEN]; + + struct proc_dir_entry *dent; + struct vlan_pcpu_stats __percpu *vlan_pcpu_stats; +#ifdef CONFIG_NET_POLL_CONTROLLER + struct netpoll *netpoll; +#endif +}; + +static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev) +{ + return netdev_priv(dev); +} + +static inline u16 +vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio) +{ + struct vlan_priority_tci_mapping *mp; + + smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */ + + mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)]; + while (mp) { + if (mp->priority == skprio) { + return mp->vlan_qos; /* This should already be shifted + * to mask correctly with the + * VLAN's TCI */ + } + mp = mp->next; + } + return 0; +} + +extern bool vlan_do_receive(struct sk_buff **skb); + +extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid); +extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 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_rcu(struct net_device *real_dev, + __be16 vlan_proto, u16 vlan_id) +{ + return NULL; +} + +static inline int +vlan_for_each(struct net_device *dev, + int (*action)(struct net_device *dev, int vid, void *arg), + void *arg) +{ + return 0; +} + +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 __be16 vlan_dev_vlan_proto(const struct net_device *dev) +{ + BUG(); + return 0; +} + +static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev, + u32 skprio) +{ + return 0; +} + +static inline bool vlan_do_receive(struct sk_buff **skb) +{ + return false; +} + +static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid) +{ + return 0; +} + +static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 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 + +/** + * eth_type_vlan - check for valid vlan ether type. + * @ethertype: ether type to check + * + * Returns true if the ether type is a vlan ether type. + */ +static inline bool eth_type_vlan(__be16 ethertype) +{ + switch (ethertype) { + case htons(ETH_P_8021Q): + case htons(ETH_P_8021AD): + return true; + default: + return false; + } +} + +static inline bool vlan_hw_offload_capable(netdev_features_t features, + __be16 proto) +{ + if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX) + return true; + if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX) + return true; + return false; +} + +/** + * __vlan_insert_inner_tag - inner VLAN tag inserting + * @skb: skbuff to tag + * @vlan_proto: VLAN encapsulation protocol + * @vlan_tci: VLAN TCI to insert + * @mac_len: MAC header length including outer vlan headers + * + * Inserts the VLAN tag into @skb as part of the payload at offset mac_len + * Returns error if skb_cow_head fails. + * + * Does not change skb->protocol so this function can be used during receive. + */ +static inline int __vlan_insert_inner_tag(struct sk_buff *skb, + __be16 vlan_proto, u16 vlan_tci, + unsigned int mac_len) +{ + struct vlan_ethhdr *veth; + + if (skb_cow_head(skb, VLAN_HLEN) < 0) + return -ENOMEM; + + skb_push(skb, VLAN_HLEN); + + /* Move the mac header sans proto to the beginning of the new header. */ + if (likely(mac_len > ETH_TLEN)) + memmove(skb->data, skb->data + VLAN_HLEN, mac_len - ETH_TLEN); + if (skb_mac_header_was_set(skb)) + skb->mac_header -= VLAN_HLEN; + + veth = (struct vlan_ethhdr *)(skb->data + mac_len - ETH_HLEN); + + /* first, the ethernet type */ + if (likely(mac_len >= ETH_TLEN)) { + /* h_vlan_encapsulated_proto should already be populated, and + * skb->data has space for h_vlan_proto + */ + veth->h_vlan_proto = vlan_proto; + } else { + /* h_vlan_encapsulated_proto should not be populated, and + * skb->data has no space for h_vlan_proto + */ + veth->h_vlan_encapsulated_proto = skb->protocol; + } + + /* now, the TCI */ + veth->h_vlan_TCI = htons(vlan_tci); + + return 0; +} + +/** + * __vlan_insert_tag - regular VLAN tag inserting + * @skb: skbuff to tag + * @vlan_proto: VLAN encapsulation protocol + * @vlan_tci: VLAN TCI to insert + * + * Inserts the VLAN tag into @skb as part of the payload + * Returns error if skb_cow_head fails. + * + * Does not change skb->protocol so this function can be used during receive. + */ +static inline int __vlan_insert_tag(struct sk_buff *skb, + __be16 vlan_proto, u16 vlan_tci) +{ + return __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN); +} + +/** + * vlan_insert_inner_tag - inner VLAN tag inserting + * @skb: skbuff to tag + * @vlan_proto: VLAN encapsulation protocol + * @vlan_tci: VLAN TCI to insert + * @mac_len: MAC header length including outer vlan headers + * + * Inserts the VLAN tag into @skb as part of the payload at offset mac_len + * Returns a VLAN tagged skb. This might change skb->head. + * + * 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_inner_tag(struct sk_buff *skb, + __be16 vlan_proto, + u16 vlan_tci, + unsigned int mac_len) +{ + int err; + + err = __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, mac_len); + if (err) { + dev_kfree_skb_any(skb); + return NULL; + } + return skb; +} + +/** + * vlan_insert_tag - regular VLAN tag inserting + * @skb: skbuff to tag + * @vlan_proto: VLAN encapsulation protocol + * @vlan_tci: VLAN TCI to insert + * + * Inserts the VLAN tag into @skb as part of the payload + * Returns a VLAN tagged skb. This might change skb->head. + * + * 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, + __be16 vlan_proto, u16 vlan_tci) +{ + return vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN); +} + +/** + * vlan_insert_tag_set_proto - regular VLAN tag inserting + * @skb: skbuff to tag + * @vlan_proto: VLAN encapsulation protocol + * @vlan_tci: VLAN TCI to insert + * + * Inserts the VLAN tag into @skb as part of the payload + * Returns a VLAN tagged skb. This might change skb->head. + * + * 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_insert_tag_set_proto(struct sk_buff *skb, + __be16 vlan_proto, + u16 vlan_tci) +{ + skb = vlan_insert_tag(skb, vlan_proto, vlan_tci); + if (skb) + skb->protocol = vlan_proto; + return skb; +} + +/** + * __vlan_hwaccel_clear_tag - clear hardware accelerated VLAN info + * @skb: skbuff to clear + * + * Clears the VLAN information from @skb + */ +static inline void __vlan_hwaccel_clear_tag(struct sk_buff *skb) +{ + skb->vlan_all = 0; +} + +/** + * __vlan_hwaccel_copy_tag - copy hardware accelerated VLAN info from another skb + * @dst: skbuff to copy to + * @src: skbuff to copy from + * + * Copies VLAN information from @src to @dst (for branchless code) + */ +static inline void __vlan_hwaccel_copy_tag(struct sk_buff *dst, const struct sk_buff *src) +{ + dst->vlan_all = src->vlan_all; +} + +/* + * __vlan_hwaccel_push_inside - pushes vlan tag to the payload + * @skb: skbuff to tag + * + * Pushes the VLAN tag from @skb->vlan_tci inside to the payload. + * + * 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_hwaccel_push_inside(struct sk_buff *skb) +{ + skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto, + skb_vlan_tag_get(skb)); + if (likely(skb)) + __vlan_hwaccel_clear_tag(skb); + return skb; +} + +/** + * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting + * @skb: skbuff to tag + * @vlan_proto: VLAN encapsulation protocol + * @vlan_tci: VLAN TCI to insert + * + * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest + */ +static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb, + __be16 vlan_proto, u16 vlan_tci) +{ + skb->vlan_proto = vlan_proto; + skb->vlan_tci = vlan_tci; +} + +/** + * __vlan_get_tag - get the VLAN ID that is part of the payload + * @skb: skbuff to query + * @vlan_tci: buffer to store value + * + * 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 = skb_vlan_eth_hdr(skb); + + if (!eth_type_vlan(veth->h_vlan_proto)) + 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 value + * + * 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 (skb_vlan_tag_present(skb)) { + *vlan_tci = skb_vlan_tag_get(skb); + return 0; + } else { + *vlan_tci = 0; + return -EINVAL; + } +} + +/** + * vlan_get_tag - get the VLAN ID from the skb + * @skb: skbuff to query + * @vlan_tci: buffer to store value + * + * 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_CTAG_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 + * @type: first vlan protocol + * @depth: buffer to store length of eth and vlan tags in bytes + * + * 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 type, + int *depth) +{ + unsigned int vlan_depth = skb->mac_len, parse_depth = VLAN_MAX_DEPTH; + + /* if type is 802.1Q/AD then the header should already be + * present at mac_len - VLAN_HLEN (if mac_len > 0), or at + * ETH_HLEN otherwise + */ + if (eth_type_vlan(type)) { + if (vlan_depth) { + if (WARN_ON(vlan_depth < VLAN_HLEN)) + return 0; + vlan_depth -= VLAN_HLEN; + } else { + vlan_depth = ETH_HLEN; + } + do { + struct vlan_hdr vhdr, *vh; + + vh = skb_header_pointer(skb, vlan_depth, sizeof(vhdr), &vhdr); + if (unlikely(!vh || !--parse_depth)) + return 0; + + type = vh->h_vlan_encapsulated_proto; + vlan_depth += VLAN_HLEN; + } while (eth_type_vlan(type)); + } + + if (depth) + *depth = vlan_depth; + + return type; +} + +/** + * 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) +{ + return __vlan_get_protocol(skb, skb->protocol, NULL); +} + +/* This version of __vlan_get_protocol() also pulls mac header in skb->head */ +static inline __be16 vlan_get_protocol_and_depth(struct sk_buff *skb, + __be16 type, int *depth) +{ + int maclen; + + type = __vlan_get_protocol(skb, type, &maclen); + + if (type) { + if (!pskb_may_pull(skb, maclen)) + type = 0; + else if (depth) + *depth = maclen; + } + return type; +} + +/* A getter for the SKB protocol field which will handle VLAN tags consistently + * whether VLAN acceleration is enabled or not. + */ +static inline __be16 skb_protocol(const struct sk_buff *skb, bool skip_vlan) +{ + if (!skip_vlan) + /* VLAN acceleration strips the VLAN header from the skb and + * moves it to skb->vlan_proto + */ + return skb_vlan_tag_present(skb) ? skb->vlan_proto : skb->protocol; + + return vlan_get_protocol(skb); +} + +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 (eth_proto_is_802_3(proto)) { + 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); +} + +/** + * vlan_remove_tag - remove outer VLAN tag from payload + * @skb: skbuff to remove tag from + * @vlan_tci: buffer to store value + * + * Expects the skb to contain a VLAN tag in the payload, and to have skb->data + * pointing at the MAC header. + * + * Returns a new pointer to skb->data, or NULL on failure to pull. + */ +static inline void *vlan_remove_tag(struct sk_buff *skb, u16 *vlan_tci) +{ + struct vlan_hdr *vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN); + + *vlan_tci = ntohs(vhdr->h_vlan_TCI); + + memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN); + vlan_set_encap_proto(skb, vhdr); + return __skb_pull(skb, VLAN_HLEN); +} + +/** + * skb_vlan_tagged - check if skb is vlan tagged. + * @skb: skbuff to query + * + * Returns true if the skb is tagged, regardless of whether it is hardware + * accelerated or not. + */ +static inline bool skb_vlan_tagged(const struct sk_buff *skb) +{ + if (!skb_vlan_tag_present(skb) && + likely(!eth_type_vlan(skb->protocol))) + return false; + + return true; +} + +/** + * skb_vlan_tagged_multi - check if skb is vlan tagged with multiple headers. + * @skb: skbuff to query + * + * Returns true if the skb is tagged with multiple vlan headers, regardless + * of whether it is hardware accelerated or not. + */ +static inline bool skb_vlan_tagged_multi(struct sk_buff *skb) +{ + __be16 protocol = skb->protocol; + + if (!skb_vlan_tag_present(skb)) { + struct vlan_ethhdr *veh; + + if (likely(!eth_type_vlan(protocol))) + return false; + + if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN))) + return false; + + veh = skb_vlan_eth_hdr(skb); + protocol = veh->h_vlan_encapsulated_proto; + } + + if (!eth_type_vlan(protocol)) + return false; + + return true; +} + +/** + * vlan_features_check - drop unsafe features for skb with multiple tags. + * @skb: skbuff to query + * @features: features to be checked + * + * Returns features without unsafe ones if the skb has multiple tags. + */ +static inline netdev_features_t vlan_features_check(struct sk_buff *skb, + netdev_features_t features) +{ + if (skb_vlan_tagged_multi(skb)) { + /* In the case of multi-tagged packets, use a direct mask + * instead of using netdev_interesect_features(), to make + * sure that only devices supporting NETIF_F_HW_CSUM will + * have checksum offloading support. + */ + features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_HW_CSUM | + NETIF_F_FRAGLIST | NETIF_F_HW_VLAN_CTAG_TX | + NETIF_F_HW_VLAN_STAG_TX; + } + + return features; +} + +/** + * compare_vlan_header - Compare two vlan headers + * @h1: Pointer to vlan header + * @h2: Pointer to vlan header + * + * Compare two vlan headers, returns 0 if equal. + * + * Please note that alignment of h1 & h2 are only guaranteed to be 16 bits. + */ +static inline unsigned long compare_vlan_header(const struct vlan_hdr *h1, + const struct vlan_hdr *h2) +{ +#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) + return *(u32 *)h1 ^ *(u32 *)h2; +#else + return ((__force u32)h1->h_vlan_TCI ^ (__force u32)h2->h_vlan_TCI) | + ((__force u32)h1->h_vlan_encapsulated_proto ^ + (__force u32)h2->h_vlan_encapsulated_proto); +#endif +} +#endif /* !(_LINUX_IF_VLAN_H_) */ |