diff options
Diffstat (limited to 'include/linux/if_vlan.h')
| -rw-r--r-- | include/linux/if_vlan.h | 352 |
1 files changed, 270 insertions, 82 deletions
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index 5e6a2d4dc366..f7f34eb15e06 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -1,13 +1,8 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * VLAN An implementation of 802.1Q VLAN tagging. * * Authors: Ben Greear <greearb@candelatech.com> - * - * 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_ @@ -30,6 +25,8 @@ #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 @@ -49,8 +46,10 @@ struct vlan_hdr { * @h_vlan_encapsulated_proto: packet type ID or len */ struct vlan_ethhdr { - unsigned char h_dest[ETH_ALEN]; - unsigned char h_source[ETH_ALEN]; + 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; @@ -63,25 +62,52 @@ 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 */ -#define VLAN_TAG_PRESENT VLAN_CFI_MASK +#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) +#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) { - return dev->priv_flags & IFF_802_1Q_VLAN; + ASSERT_RTNL(); + return notifier_to_errno(call_netdevice_notifiers(NETDEV_CVLAN_FILTER_PUSH_INFO, dev)); } -#define skb_vlan_tag_present(__skb) ((__skb)->vlan_tci & VLAN_TAG_PRESENT) -#define skb_vlan_tag_get(__skb) ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT) -#define skb_vlan_tag_get_id(__skb) ((__skb)->vlan_tci & VLAN_VID_MASK) -#define skb_vlan_tag_get_prio(__skb) ((__skb)->vlan_tci & VLAN_PRIO_MASK) +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 @@ -95,20 +121,23 @@ static inline bool is_vlan_dev(const struct net_device *dev) * @tx_dropped: number of tx drops */ struct vlan_pcpu_stats { - u64 rx_packets; - u64 rx_bytes; - u64 rx_multicast; - u64 tx_packets; - u64 tx_bytes; + 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) +#if IS_ENABLED(CONFIG_VLAN_8021Q) 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); @@ -138,9 +167,11 @@ struct netpoll; * @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 + * @netpoll: netpoll instance "propagated" down to @real_dev */ struct vlan_dev_priv { unsigned int nr_ingress_mappings; @@ -153,6 +184,8 @@ struct vlan_dev_priv { u16 flags; struct net_device *real_dev; + netdevice_tracker dev_tracker; + unsigned char real_dev_addr[ETH_ALEN]; struct proc_dir_entry *dent; @@ -160,9 +193,13 @@ struct vlan_dev_priv { #ifdef CONFIG_NET_POLL_CONTROLLER struct netpoll *netpoll; #endif - unsigned int nest_level; }; +static inline bool is_vlan_dev(const struct net_device *dev) +{ + return dev->priv_flags & IFF_802_1Q_VLAN; +} + static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev) { return netdev_priv(dev); @@ -199,12 +236,12 @@ extern void vlan_vids_del_by_dev(struct net_device *dev, extern bool vlan_uses_dev(const struct net_device *dev); -static inline int vlan_get_encap_level(struct net_device *dev) +#else +static inline bool is_vlan_dev(const struct net_device *dev) { - BUG_ON(!is_vlan_dev(dev)); - return vlan_dev_priv(dev)->nest_level; + return false; } -#else + static inline struct net_device * __vlan_find_dev_deep_rcu(struct net_device *real_dev, __be16 vlan_proto, u16 vlan_id) @@ -212,21 +249,29 @@ __vlan_find_dev_deep_rcu(struct net_device *real_dev, 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(); + WARN_ON_ONCE(1); return NULL; } static inline u16 vlan_dev_vlan_id(const struct net_device *dev) { - BUG(); + WARN_ON_ONCE(1); return 0; } static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev) { - BUG(); + WARN_ON_ONCE(1); return 0; } @@ -265,18 +310,13 @@ static inline bool vlan_uses_dev(const struct net_device *dev) { return false; } -static inline int vlan_get_encap_level(struct net_device *dev) -{ - BUG(); - return 0; -} #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. + * Returns: true if the ether type is a vlan ether type. */ static inline bool eth_type_vlan(__be16 ethertype) { @@ -300,32 +340,49 @@ static inline bool vlan_hw_offload_capable(netdev_features_t features, } /** - * __vlan_insert_tag - regular VLAN tag inserting + * __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 - * Returns error if skb_cow_head failes. - * + * Inserts the VLAN tag into @skb as part of the payload at offset mac_len * Does not change skb->protocol so this function can be used during receive. + * + * Returns: error if skb_cow_head fails. */ -static inline int __vlan_insert_tag(struct sk_buff *skb, - __be16 vlan_proto, u16 vlan_tci) +static inline int __vlan_insert_inner_tag(struct sk_buff *skb, + __be16 vlan_proto, u16 vlan_tci, + unsigned int mac_len) { + const u8 meta_len = mac_len > ETH_TLEN ? skb_metadata_len(skb) : 0; struct vlan_ethhdr *veth; - if (skb_cow_head(skb, VLAN_HLEN) < 0) + if (skb_cow_head(skb, meta_len + VLAN_HLEN) < 0) return -ENOMEM; - veth = skb_push(skb, VLAN_HLEN); + skb_push(skb, VLAN_HLEN); + + /* Move the mac header sans proto to the beginning of the new header. */ + if (likely(mac_len > ETH_TLEN)) + skb_postpush_data_move(skb, VLAN_HLEN, mac_len - ETH_TLEN); + if (skb_mac_header_was_set(skb)) + skb->mac_header -= 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; + veth = (struct vlan_ethhdr *)(skb->data + mac_len - ETH_HLEN); /* first, the ethernet type */ - veth->h_vlan_proto = vlan_proto; + 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); @@ -334,25 +391,47 @@ static inline int __vlan_insert_tag(struct sk_buff *skb, } /** - * vlan_insert_tag - regular VLAN tag inserting + * __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. If a new skb is created, @skb is freed. + * Does not change skb->protocol so this function can be used during receive. + * + * Returns: error if skb_cow_head fails. + */ +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. + * + * Return: modified @skb on success, NULL on error (@skb is freed). */ -static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, - __be16 vlan_proto, u16 vlan_tci) +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_tag(skb, vlan_proto, vlan_tci); + err = __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, mac_len); if (err) { dev_kfree_skb_any(skb); return NULL; @@ -361,16 +440,40 @@ static inline struct sk_buff *vlan_insert_tag(struct sk_buff *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. + * + * Return: modified @skb on success, NULL on error (@skb is freed). + */ +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. If a new skb is created, @skb is freed. + * 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. + * + * Return: modified @skb on success, NULL on error (@skb is freed). */ static inline struct sk_buff *vlan_insert_tag_set_proto(struct sk_buff *skb, __be16 vlan_proto, @@ -382,6 +485,29 @@ static inline struct sk_buff *vlan_insert_tag_set_proto(struct sk_buff *skb, 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 @@ -396,7 +522,7 @@ 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)) - skb->vlan_tci = 0; + __vlan_hwaccel_clear_tag(skb); return skb; } @@ -412,7 +538,7 @@ 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_TAG_PRESENT | vlan_tci; + skb->vlan_tci = vlan_tci; } /** @@ -420,14 +546,14 @@ static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb, * @skb: skbuff to query * @vlan_tci: buffer to store value * - * Returns error if the skb is not of VLAN type + * 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; + struct vlan_ethhdr *veth = skb_vlan_eth_hdr(skb); if (!eth_type_vlan(veth->h_vlan_proto)) - return -EINVAL; + return -ENODATA; *vlan_tci = ntohs(veth->h_vlan_TCI); return 0; @@ -438,7 +564,7 @@ static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) * @skb: skbuff to query * @vlan_tci: buffer to store value * - * Returns error if @skb->vlan_tci is not set correctly + * 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) @@ -448,18 +574,16 @@ static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb, return 0; } else { *vlan_tci = 0; - return -EINVAL; + return -ENODATA; } } -#define HAVE_VLAN_GET_TAG - /** * 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 + * Returns: error if the skb is not VLAN tagged */ static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) { @@ -471,18 +595,21 @@ static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) } /** - * vlan_get_protocol - get protocol EtherType. + * __vlan_get_protocol_offset() - get protocol EtherType. * @skb: skbuff to query * @type: first vlan protocol + * @mac_offset: MAC offset * @depth: buffer to store length of eth and vlan tags in bytes * - * Returns the EtherType of the packet, regardless of whether it is + * 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(struct sk_buff *skb, __be16 type, - int *depth) +static inline __be16 __vlan_get_protocol_offset(const struct sk_buff *skb, + __be16 type, + int mac_offset, + int *depth) { - unsigned int vlan_depth = skb->mac_len; + 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 @@ -497,13 +624,13 @@ static inline __be16 __vlan_get_protocol(struct sk_buff *skb, __be16 type, vlan_depth = ETH_HLEN; } do { - struct vlan_hdr *vh; + struct vlan_hdr vhdr, *vh; - if (unlikely(!pskb_may_pull(skb, - vlan_depth + VLAN_HLEN))) + vh = skb_header_pointer(skb, mac_offset + vlan_depth, + sizeof(vhdr), &vhdr); + if (unlikely(!vh || !--parse_depth)) return 0; - vh = (struct vlan_hdr *)(skb->data + vlan_depth); type = vh->h_vlan_encapsulated_proto; vlan_depth += VLAN_HLEN; } while (eth_type_vlan(type)); @@ -515,18 +642,55 @@ static inline __be16 __vlan_get_protocol(struct sk_buff *skb, __be16 type, return type; } +static inline __be16 __vlan_get_protocol(const struct sk_buff *skb, __be16 type, + int *depth) +{ + return __vlan_get_protocol_offset(skb, type, 0, depth); +} + /** * vlan_get_protocol - get protocol EtherType. * @skb: skbuff to query * - * Returns the EtherType of the packet, regardless of whether it is + * 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(struct sk_buff *skb) +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) { @@ -562,10 +726,29 @@ static inline void vlan_set_encap_proto(struct sk_buff *skb, } /** + * 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. + */ +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); + + vlan_set_encap_proto(skb, vhdr); + __skb_pull(skb, VLAN_HLEN); + skb_postpull_data_move(skb, VLAN_HLEN, 2 * ETH_ALEN); +} + +/** * 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 + * 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) @@ -581,10 +764,10 @@ static inline bool skb_vlan_tagged(const struct sk_buff *skb) * 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 + * 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(const struct sk_buff *skb) +static inline bool skb_vlan_tagged_multi(struct sk_buff *skb) { __be16 protocol = skb->protocol; @@ -594,7 +777,10 @@ static inline bool skb_vlan_tagged_multi(const struct sk_buff *skb) if (likely(!eth_type_vlan(protocol))) return false; - veh = (struct vlan_ethhdr *)skb->data; + if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN))) + return false; + + veh = skb_vlan_eth_hdr(skb); protocol = veh->h_vlan_encapsulated_proto; } @@ -609,9 +795,9 @@ static inline bool skb_vlan_tagged_multi(const struct sk_buff *skb) * @skb: skbuff to query * @features: features to be checked * - * Returns features without unsafe ones if the skb has multiple tags. + * Returns: features without unsafe ones if the skb has multiple tags. */ -static inline netdev_features_t vlan_features_check(const struct sk_buff *skb, +static inline netdev_features_t vlan_features_check(struct sk_buff *skb, netdev_features_t features) { if (skb_vlan_tagged_multi(skb)) { @@ -633,9 +819,11 @@ static inline netdev_features_t vlan_features_check(const struct sk_buff *skb, * @h1: Pointer to vlan header * @h2: Pointer to vlan header * - * Compare two vlan headers, returns 0 if equal. + * Compare two vlan headers. * * Please note that alignment of h1 & h2 are only guaranteed to be 16 bits. + * + * Return: 0 if equal, arbitrary non-zero value if not equal. */ static inline unsigned long compare_vlan_header(const struct vlan_hdr *h1, const struct vlan_hdr *h2) |