[RFC PATCH net-next 1/4] net: dsa: create a helper that strips EtherType DSA headers on RX
From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: 2021-08-09 11:57:51
Subsystem:
broadcom b53/sf2 ethernet switch driver, mediatek switch driver, networking [dsa], networking [general], qualcomm atheros qca8k dsa switch driver, the rest · Maintainers:
Florian Fainelli, Jonas Gorski, Chester A. Unal, Daniel Golle, Andrew Lunn, Vladimir Oltean, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Christian Marangi, Linus Torvalds
All header taggers open-code a memmove that is fairly not all that obvious, and we can hide the details behind a helper function, since the only thing specific to the driver is the length of the header tag. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> --- net/dsa/dsa_priv.h | 26 ++++++++++++++++++++++++++ net/dsa/tag_brcm.c | 10 ++-------- net/dsa/tag_dsa.c | 8 ++------ net/dsa/tag_lan9303.c | 5 +++-- net/dsa/tag_mtk.c | 4 +--- net/dsa/tag_qca.c | 3 +-- net/dsa/tag_rtl4_a.c | 5 +---- net/dsa/tag_sja1105.c | 4 +--- 8 files changed, 37 insertions(+), 28 deletions(-)
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 9575cabd3ec3..8a12ec1f9d21 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h@@ -452,6 +452,32 @@ static inline void dsa_default_offload_fwd_mark(struct sk_buff *skb) skb->offload_fwd_mark = !!(dp->bridge_dev); } +/* Helper for removing DSA header tags from packets in the RX path. + * Must not be called before skb_pull(len). + * skb->data + * | + * v + * | | | | | | | | | | | | | | | | | | | + * +-----------------------+-----------------------+---------------+-------+ + * | Destination MAC | Source MAC | DSA header | EType | + * +-----------------------+-----------------------+---------------+-------+ + * | | + * <----- len -----> <----- len -----> + * | + * >>>>>>> v + * >>>>>>> | | | | | | | | | | | | | | | + * >>>>>>> +-----------------------+-----------------------+-------+ + * >>>>>>> | Destination MAC | Source MAC | EType | + * +-----------------------+-----------------------+-------+ + * ^ + * | + * skb->data + */ +static inline void dsa_strip_etype_header(struct sk_buff *skb, int len) +{ + memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - len, 2 * ETH_ALEN); +} + /* switch.c */ int dsa_switch_register_notifier(struct dsa_switch *ds); void dsa_switch_unregister_notifier(struct dsa_switch *ds);
diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c
index 96e93b544a0d..2fc546b31ad8 100644
--- a/net/dsa/tag_brcm.c
+++ b/net/dsa/tag_brcm.c@@ -190,10 +190,7 @@ static struct sk_buff *brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev) if (!nskb) return nskb; - /* Move the Ethernet DA and SA */ - memmove(nskb->data - ETH_HLEN, - nskb->data - ETH_HLEN - BRCM_TAG_LEN, - 2 * ETH_ALEN); + dsa_strip_etype_header(skb, BRCM_TAG_LEN); return nskb; }
@@ -270,10 +267,7 @@ static struct sk_buff *brcm_leg_tag_rcv(struct sk_buff *skb, dsa_default_offload_fwd_mark(skb); - /* Move the Ethernet DA and SA */ - memmove(skb->data - ETH_HLEN, - skb->data - ETH_HLEN - BRCM_LEG_TAG_LEN, - 2 * ETH_ALEN); + dsa_strip_etype_header(skb, BRCM_LEG_TAG_LEN); return skb; }
diff --git a/net/dsa/tag_dsa.c b/net/dsa/tag_dsa.c
index e32f8160e895..ad9c841c998f 100644
--- a/net/dsa/tag_dsa.c
+++ b/net/dsa/tag_dsa.c@@ -312,14 +312,10 @@ static struct sk_buff *dsa_rcv_ll(struct sk_buff *skb, struct net_device *dev, memcpy(dsa_header, new_header, DSA_HLEN); if (extra) - memmove(skb->data - ETH_HLEN, - skb->data - ETH_HLEN - extra, - 2 * ETH_ALEN); + dsa_strip_etype_header(skb, extra); } else { skb_pull_rcsum(skb, DSA_HLEN); - memmove(skb->data - ETH_HLEN, - skb->data - ETH_HLEN - DSA_HLEN - extra, - 2 * ETH_ALEN); + dsa_strip_etype_header(skb, DSA_HLEN + extra); } return skb;
diff --git a/net/dsa/tag_lan9303.c b/net/dsa/tag_lan9303.c
index 58d3a0e712d2..af13c0a9cb41 100644
--- a/net/dsa/tag_lan9303.c
+++ b/net/dsa/tag_lan9303.c@@ -112,8 +112,9 @@ static struct sk_buff *lan9303_rcv(struct sk_buff *skb, struct net_device *dev) * and the current ethertype field. */ skb_pull_rcsum(skb, 2 + 2); - memmove(skb->data - ETH_HLEN, skb->data - (ETH_HLEN + LAN9303_TAG_LEN), - 2 * ETH_ALEN); + + dsa_strip_etype_header(skb, LAN9303_TAG_LEN); + if (!(lan9303_tag1 & LAN9303_TAG_RX_TRAPPED_TO_CPU)) dsa_default_offload_fwd_mark(skb);
diff --git a/net/dsa/tag_mtk.c b/net/dsa/tag_mtk.c
index bbf37c031d44..6a78e9f146e5 100644
--- a/net/dsa/tag_mtk.c
+++ b/net/dsa/tag_mtk.c@@ -80,9 +80,7 @@ static struct sk_buff *mtk_tag_rcv(struct sk_buff *skb, struct net_device *dev) /* Remove MTK tag and recalculate checksum. */ skb_pull_rcsum(skb, MTK_HDR_LEN); - memmove(skb->data - ETH_HLEN, - skb->data - ETH_HLEN - MTK_HDR_LEN, - 2 * ETH_ALEN); + dsa_strip_etype_header(skb, MTK_HDR_LEN); /* Get source port information */ port = (hdr & MTK_HDR_RECV_SOURCE_PORT_MASK);
diff --git a/net/dsa/tag_qca.c b/net/dsa/tag_qca.c
index 6e3136990491..f9fc881da591 100644
--- a/net/dsa/tag_qca.c
+++ b/net/dsa/tag_qca.c@@ -72,8 +72,7 @@ static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev) /* Remove QCA tag and recalculate checksum */ skb_pull_rcsum(skb, QCA_HDR_LEN); - memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - QCA_HDR_LEN, - ETH_HLEN - QCA_HDR_LEN); + dsa_strip_etype_header(skb, QCA_HDR_LEN); /* Get source port information */ port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK);
diff --git a/net/dsa/tag_rtl4_a.c b/net/dsa/tag_rtl4_a.c
index aaddca3c0245..ff8707ff0c5b 100644
--- a/net/dsa/tag_rtl4_a.c
+++ b/net/dsa/tag_rtl4_a.c@@ -108,10 +108,7 @@ static struct sk_buff *rtl4a_tag_rcv(struct sk_buff *skb, /* Remove RTL4 tag and recalculate checksum */ skb_pull_rcsum(skb, RTL4_A_HDR_LEN); - /* Move ethernet DA and SA in front of the data */ - memmove(skb->data - ETH_HLEN, - skb->data - ETH_HLEN - RTL4_A_HDR_LEN, - 2 * ETH_ALEN); + dsa_strip_etype_header(skb, RTL4_A_HDR_LEN); dsa_default_offload_fwd_mark(skb);
diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c
index fc4cde775e50..5e8234079d08 100644
--- a/net/dsa/tag_sja1105.c
+++ b/net/dsa/tag_sja1105.c@@ -571,9 +571,7 @@ static struct sk_buff *sja1110_rcv_inband_control_extension(struct sk_buff *skb, /* Advance skb->data past the DSA header */ skb_pull_rcsum(skb, SJA1110_HEADER_LEN); - /* Remove the DSA header */ - memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - SJA1110_HEADER_LEN, - 2 * ETH_ALEN); + dsa_strip_etype_header(skb, SJA1110_HEADER_LEN); /* With skb->data in its final place, update the MAC header * so that eth_hdr() continues to works properly.
--
2.25.1