[PATCH net-next 2/9] net: vlan: introduce skb_vlan_eth_hdr()

From: Vladimir Oltean
Date: Wed Mar 22 2023 - 19:38:53 EST


Similar to skb_eth_hdr() introduced in commit 96cc4b69581d ("macvlan: do
not assume mac_header is set in macvlan_broadcast()"), let's introduce a
skb_vlan_eth_hdr() helper which can be used in TX-only code paths to get
to the VLAN header based on skb->data rather than based on the
skb_mac_header(skb).

We also consolidate the drivers that dereference skb->data to go through
this helper.

Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
---
drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 3 +--
drivers/net/ethernet/emulex/benet/be_main.c | 2 +-
drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 2 +-
drivers/net/ethernet/intel/i40e/i40e_txrx.c | 2 +-
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 2 +-
drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c | 2 +-
drivers/net/ethernet/qlogic/qlcnic/qlcnic_io.c | 4 ++--
drivers/net/ethernet/sfc/tx_tso.c | 2 +-
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 7 ++-----
drivers/staging/gdm724x/gdm_lte.c | 4 ++--
include/linux/if_vlan.h | 12 ++++++++++--
net/batman-adv/soft-interface.c | 2 +-
12 files changed, 24 insertions(+), 20 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
index 16c490692f42..4950fde82d17 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -1923,8 +1923,7 @@ u16 bnx2x_select_queue(struct net_device *dev, struct sk_buff *skb,

/* Skip VLAN tag if present */
if (ether_type == ETH_P_8021Q) {
- struct vlan_ethhdr *vhdr =
- (struct vlan_ethhdr *)skb->data;
+ struct vlan_ethhdr *vhdr = skb_vlan_eth_hdr(skb);

ether_type = ntohs(vhdr->h_vlan_encapsulated_proto);
}
diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index aed1b622f51f..7e408bcc88de 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -1124,7 +1124,7 @@ static struct sk_buff *be_lancer_xmit_workarounds(struct be_adapter *adapter,
struct be_wrb_params
*wrb_params)
{
- struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
+ struct vlan_ethhdr *veh = skb_vlan_eth_hdr(skb);
unsigned int eth_hdr_len;
struct iphdr *ip;

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index 5caea154362f..7356ad965487 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -1532,7 +1532,7 @@ static int hns3_handle_vtags(struct hns3_enet_ring *tx_ring,
if (unlikely(rc < 0))
return rc;

- vhdr = (struct vlan_ethhdr *)skb->data;
+ vhdr = skb_vlan_eth_hdr(skb);
vhdr->h_vlan_TCI |= cpu_to_be16((skb->priority << VLAN_PRIO_SHIFT)
& VLAN_PRIO_MASK);

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 32cce90abbb4..81856f444d38 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -3063,7 +3063,7 @@ static inline int i40e_tx_prepare_vlan_flags(struct sk_buff *skb,
rc = skb_cow_head(skb, 0);
if (rc < 0)
return rc;
- vhdr = (struct vlan_ethhdr *)skb->data;
+ vhdr = skb_vlan_eth_hdr(skb);
vhdr->h_vlan_TCI = htons(tx_flags >>
I40E_TX_FLAGS_VLAN_SHIFT);
} else {
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 773c35fecace..eae6c89e62f4 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -8818,7 +8818,7 @@ netdev_tx_t ixgbe_xmit_frame_ring(struct sk_buff *skb,

if (skb_cow_head(skb, 0))
goto out_drop;
- vhdr = (struct vlan_ethhdr *)skb->data;
+ vhdr = skb_vlan_eth_hdr(skb);
vhdr->h_vlan_TCI = htons(tx_flags >>
IXGBE_TX_FLAGS_VLAN_SHIFT);
} else {
diff --git a/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c b/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c
index 59d0dd862fd1..1d1e183d3a8b 100644
--- a/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c
+++ b/drivers/net/ethernet/qlogic/netxen/netxen_nic_main.c
@@ -1854,7 +1854,7 @@ netxen_tso_check(struct net_device *netdev,

if (protocol == cpu_to_be16(ETH_P_8021Q)) {

- vh = (struct vlan_ethhdr *)skb->data;
+ vh = skb_vlan_eth_hdr(skb);
protocol = vh->h_vlan_encapsulated_proto;
flags = FLAGS_VLAN_TAGGED;

diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_io.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_io.c
index 92930a055cbc..41894d154013 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_io.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_io.c
@@ -318,7 +318,7 @@ static void qlcnic_send_filter(struct qlcnic_adapter *adapter,

if (adapter->flags & QLCNIC_VLAN_FILTERING) {
if (protocol == ETH_P_8021Q) {
- vh = (struct vlan_ethhdr *)skb->data;
+ vh = skb_vlan_eth_hdr(skb);
vlan_id = ntohs(vh->h_vlan_TCI);
} else if (skb_vlan_tag_present(skb)) {
vlan_id = skb_vlan_tag_get(skb);
@@ -468,7 +468,7 @@ static int qlcnic_tx_pkt(struct qlcnic_adapter *adapter,
u32 producer = tx_ring->producer;

if (protocol == ETH_P_8021Q) {
- vh = (struct vlan_ethhdr *)skb->data;
+ vh = skb_vlan_eth_hdr(skb);
flags = QLCNIC_FLAGS_VLAN_TAGGED;
vlan_tci = ntohs(vh->h_vlan_TCI);
protocol = ntohs(vh->h_vlan_encapsulated_proto);
diff --git a/drivers/net/ethernet/sfc/tx_tso.c b/drivers/net/ethernet/sfc/tx_tso.c
index 898e5c61d908..d381d8164f07 100644
--- a/drivers/net/ethernet/sfc/tx_tso.c
+++ b/drivers/net/ethernet/sfc/tx_tso.c
@@ -147,7 +147,7 @@ static __be16 efx_tso_check_protocol(struct sk_buff *skb)
EFX_WARN_ON_ONCE_PARANOID(((struct ethhdr *)skb->data)->h_proto !=
protocol);
if (protocol == htons(ETH_P_8021Q)) {
- struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
+ struct vlan_ethhdr *veh = skb_vlan_eth_hdr(skb);

protocol = veh->h_vlan_encapsulated_proto;
}
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 8f543c3ab5c5..918de65fb707 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4554,13 +4554,10 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)

static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb)
{
- struct vlan_ethhdr *veth;
- __be16 vlan_proto;
+ struct vlan_ethhdr *veth = skb_vlan_eth_hdr(skb);
+ __be16 vlan_proto = veth->h_vlan_proto;
u16 vlanid;

- veth = (struct vlan_ethhdr *)skb->data;
- vlan_proto = veth->h_vlan_proto;
-
if ((vlan_proto == htons(ETH_P_8021Q) &&
dev->features & NETIF_F_HW_VLAN_CTAG_RX) ||
(vlan_proto == htons(ETH_P_8021AD) &&
diff --git a/drivers/staging/gdm724x/gdm_lte.c b/drivers/staging/gdm724x/gdm_lte.c
index 671ee8843c88..5703a9ddb6d0 100644
--- a/drivers/staging/gdm724x/gdm_lte.c
+++ b/drivers/staging/gdm724x/gdm_lte.c
@@ -349,7 +349,7 @@ static s32 gdm_lte_tx_nic_type(struct net_device *dev, struct sk_buff *skb)
/* Get ethernet protocol */
eth = (struct ethhdr *)skb->data;
if (ntohs(eth->h_proto) == ETH_P_8021Q) {
- vlan_eth = (struct vlan_ethhdr *)skb->data;
+ vlan_eth = skb_vlan_eth_hdr(skb);
mac_proto = ntohs(vlan_eth->h_vlan_encapsulated_proto);
network_data = skb->data + VLAN_ETH_HLEN;
nic_type |= NIC_TYPE_F_VLAN;
@@ -435,7 +435,7 @@ static netdev_tx_t gdm_lte_tx(struct sk_buff *skb, struct net_device *dev)
* driver based on the NIC mac
*/
if (nic_type & NIC_TYPE_F_VLAN) {
- struct vlan_ethhdr *vlan_eth = (struct vlan_ethhdr *)skb->data;
+ struct vlan_ethhdr *vlan_eth = skb_vlan_eth_hdr(skb);

nic->vlan_id = ntohs(vlan_eth->h_vlan_TCI) & VLAN_VID_MASK;
data_buf = skb->data + (VLAN_ETH_HLEN - ETH_HLEN);
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 90b76d63c11c..3698f2b391cd 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -62,6 +62,14 @@ 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 */
@@ -529,7 +537,7 @@ static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb,
*/
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;
@@ -713,7 +721,7 @@ static inline bool skb_vlan_tagged_multi(struct sk_buff *skb)
if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
return false;

- veh = (struct vlan_ethhdr *)skb->data;
+ veh = skb_vlan_eth_hdr(skb);
protocol = veh->h_vlan_encapsulated_proto;
}

diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 125f4628687c..d3fdf82282af 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -439,7 +439,7 @@ void batadv_interface_rx(struct net_device *soft_iface,
if (!pskb_may_pull(skb, VLAN_ETH_HLEN))
goto dropped;

- vhdr = (struct vlan_ethhdr *)skb->data;
+ vhdr = skb_vlan_eth_hdr(skb);

/* drop batman-in-batman packets to prevent loops */
if (vhdr->h_vlan_encapsulated_proto != htons(ETH_P_BATMAN))
--
2.34.1