From 6bef794da6d3bd347c18e93ad33483bd8903d9fd Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Tue, 10 Aug 2021 16:13:54 +0300 Subject: [PATCH] net: dsa: create a helper which allocates space for EtherType DSA headers Hide away the memmove used by DSA EtherType header taggers to shift the MAC SA and DA to the left to make room for the header, after they've called skb_push(). The call to skb_push() is still left explicit in drivers, to be symmetric with dsa_strip_etype_header, and because not all callers can be refactored to do it (for example, brcm_tag_xmit_ll has common code for a pre-Ethernet DSA tag and an EtherType DSA tag). Signed-off-by: Vladimir Oltean Reviewed-by: Andrew Lunn Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- net/dsa/dsa_priv.h | 29 +++++++++++++++++++++++++++++ net/dsa/tag_brcm.c | 4 ++-- net/dsa/tag_dsa.c | 4 ++-- net/dsa/tag_lan9303.c | 2 +- net/dsa/tag_mtk.c | 2 +- net/dsa/tag_qca.c | 2 +- net/dsa/tag_rtl4_a.c | 2 +- net/dsa/tag_sja1105.c | 3 +-- 8 files changed, 38 insertions(+), 10 deletions(-) diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h index 8a12ec1f9d219..28e1fbe64ee0d 100644 --- a/net/dsa/dsa_priv.h +++ b/net/dsa/dsa_priv.h @@ -478,6 +478,35 @@ 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); } +/* Helper for creating space for DSA header tags in TX path packets. + * Must not be called before skb_push(len). + * + * Before: + * + * <<<<<<< | | | | | | | | | | | | | | | + * ^ <<<<<<< +-----------------------+-----------------------+-------+ + * | <<<<<<< | Destination MAC | Source MAC | EType | + * | +-----------------------+-----------------------+-------+ + * <----- len -----> + * | + * | + * skb->data + * + * After: + * + * | | | | | | | | | | | | | | | | | | | + * +-----------------------+-----------------------+---------------+-------+ + * | Destination MAC | Source MAC | DSA header | EType | + * +-----------------------+-----------------------+---------------+-------+ + * ^ | | + * | <----- len -----> + * skb->data + */ +static inline void dsa_alloc_etype_header(struct sk_buff *skb, int len) +{ + memmove(skb->data, skb->data + 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 2fc546b31ad87..c62a89bb8de3c 100644 --- a/net/dsa/tag_brcm.c +++ b/net/dsa/tag_brcm.c @@ -99,7 +99,7 @@ static struct sk_buff *brcm_tag_xmit_ll(struct sk_buff *skb, skb_push(skb, BRCM_TAG_LEN); if (offset) - memmove(skb->data, skb->data + BRCM_TAG_LEN, offset); + dsa_alloc_etype_header(skb, BRCM_TAG_LEN); brcm_tag = skb->data + offset; @@ -228,7 +228,7 @@ static struct sk_buff *brcm_leg_tag_xmit(struct sk_buff *skb, skb_push(skb, BRCM_LEG_TAG_LEN); - memmove(skb->data, skb->data + BRCM_LEG_TAG_LEN, 2 * ETH_ALEN); + dsa_alloc_etype_header(skb, BRCM_LEG_TAG_LEN); brcm_tag = skb->data + 2 * ETH_ALEN; diff --git a/net/dsa/tag_dsa.c b/net/dsa/tag_dsa.c index ad9c841c998f5..ab2c63859d121 100644 --- a/net/dsa/tag_dsa.c +++ b/net/dsa/tag_dsa.c @@ -166,7 +166,7 @@ static struct sk_buff *dsa_xmit_ll(struct sk_buff *skb, struct net_device *dev, if (skb->protocol == htons(ETH_P_8021Q)) { if (extra) { skb_push(skb, extra); - memmove(skb->data, skb->data + extra, 2 * ETH_ALEN); + dsa_alloc_etype_header(skb, extra); } /* Construct tagged DSA tag from 802.1Q tag. */ @@ -181,7 +181,7 @@ static struct sk_buff *dsa_xmit_ll(struct sk_buff *skb, struct net_device *dev, } } else { skb_push(skb, DSA_HLEN + extra); - memmove(skb->data, skb->data + DSA_HLEN + extra, 2 * ETH_ALEN); + dsa_alloc_etype_header(skb, DSA_HLEN + extra); /* Construct untagged DSA tag. */ dsa_header = skb->data + 2 * ETH_ALEN + extra; diff --git a/net/dsa/tag_lan9303.c b/net/dsa/tag_lan9303.c index af13c0a9cb416..e8ad3727433ed 100644 --- a/net/dsa/tag_lan9303.c +++ b/net/dsa/tag_lan9303.c @@ -62,7 +62,7 @@ static struct sk_buff *lan9303_xmit(struct sk_buff *skb, struct net_device *dev) skb_push(skb, LAN9303_TAG_LEN); /* make room between MACs and Ether-Type */ - memmove(skb->data, skb->data + LAN9303_TAG_LEN, 2 * ETH_ALEN); + dsa_alloc_etype_header(skb, LAN9303_TAG_LEN); lan9303_tag = (__be16 *)(skb->data + 2 * ETH_ALEN); tag = lan9303_xmit_use_arl(dp, skb->data) ? diff --git a/net/dsa/tag_mtk.c b/net/dsa/tag_mtk.c index 6a78e9f146e57..06d1cfc6d19b4 100644 --- a/net/dsa/tag_mtk.c +++ b/net/dsa/tag_mtk.c @@ -41,7 +41,7 @@ static struct sk_buff *mtk_tag_xmit(struct sk_buff *skb, default: xmit_tpid = MTK_HDR_XMIT_UNTAGGED; skb_push(skb, MTK_HDR_LEN); - memmove(skb->data, skb->data + MTK_HDR_LEN, 2 * ETH_ALEN); + dsa_alloc_etype_header(skb, MTK_HDR_LEN); } mtk_tag = skb->data + 2 * ETH_ALEN; diff --git a/net/dsa/tag_qca.c b/net/dsa/tag_qca.c index f9fc881da591b..c68a814188e7c 100644 --- a/net/dsa/tag_qca.c +++ b/net/dsa/tag_qca.c @@ -36,7 +36,7 @@ static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev) skb_push(skb, QCA_HDR_LEN); - memmove(skb->data, skb->data + QCA_HDR_LEN, 2 * ETH_ALEN); + dsa_alloc_etype_header(skb, QCA_HDR_LEN); phdr = (__be16 *)(skb->data + 2 * ETH_ALEN); /* Set the version field, and set destination port information */ diff --git a/net/dsa/tag_rtl4_a.c b/net/dsa/tag_rtl4_a.c index ff8707ff0c5bc..06e901eda2980 100644 --- a/net/dsa/tag_rtl4_a.c +++ b/net/dsa/tag_rtl4_a.c @@ -47,7 +47,7 @@ static struct sk_buff *rtl4a_tag_xmit(struct sk_buff *skb, dp->index); skb_push(skb, RTL4_A_HDR_LEN); - memmove(skb->data, skb->data + RTL4_A_HDR_LEN, 2 * ETH_ALEN); + dsa_alloc_etype_header(skb, RTL4_A_HDR_LEN); tag = skb->data + 2 * ETH_ALEN; /* Set Ethertype */ diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c index 33fbd3d025e70..03d500236e0ed 100644 --- a/net/dsa/tag_sja1105.c +++ b/net/dsa/tag_sja1105.c @@ -206,8 +206,7 @@ static struct sk_buff *sja1110_xmit(struct sk_buff *skb, skb_push(skb, SJA1110_HEADER_LEN); - /* Move Ethernet header to the left, making space for DSA tag */ - memmove(skb->data, skb->data + SJA1110_HEADER_LEN, 2 * ETH_ALEN); + dsa_alloc_etype_header(skb, SJA1110_HEADER_LEN); trailer_pos = skb->len;