Merge branch 'eth_skb_pad'

Alexander Duyck says:

====================
net: Add helper for padding short Ethernet frames

This patch series adds a pair of helpers to pad short Ethernet frames.  The
general idea is to clean up a number of code paths that were all writing
their own versions of the same or similar function.

An added advantage is that this will help to discourage introducing new
bugs as in at least one case I found the skb->len had been updated, but the
tail pointer update was overlooked.

v2: Added skb_put_padto for cases where length is not ETH_ZLEN
    Updated intel drivers and emulex driver to use skb_put_padto
    Updated eth_skb_pad to use skb_put_padto
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

11 files changed, 32 insertions, 91 deletions

diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index e0ab7673afe7..9461ad8d837b 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -1017,9 +1017,8 @@ static struct sk_buff *be_xmit_workarounds(struct be_adapter *adapter,
 	 * to pad short packets (<= 32 bytes) to a 36-byte length.
 	 */
 	if (unlikely(!BEx_chip(adapter) && skb->len <= 32)) {
-		if (skb_padto(skb, 36))
+		if (skb_put_padto(skb, 36))
 			return NULL;
-		skb->len = 36;
 	}
 
 	if (BEx_chip(adapter) || lancer_chip(adapter)) {
diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index 24f3986cfae2..862d1989ae1c 100644
--- a/drivers/net/ethernet/intel/e1000/e1000_main.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
@@ -3136,12 +3136,8 @@ static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb,
 	 * packets may get corrupted during padding by HW.
 	 * To WA this issue, pad all small packets manually.
 	 */
-	if (skb->len < ETH_ZLEN) {
-		if (skb_pad(skb, ETH_ZLEN - skb->len))
-			return NETDEV_TX_OK;
-		skb->len = ETH_ZLEN;
-		skb_set_tail_pointer(skb, ETH_ZLEN);
-	}
+	if (eth_skb_pad(skb))
+		return NETDEV_TX_OK;
 
 	mss = skb_shinfo(skb)->gso_size;
 	/* The controller does a simple calculation to
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 370cfa275ddb..88936aa0029d 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -5554,12 +5554,8 @@ static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb,
 	/* The minimum packet size with TCTL.PSP set is 17 bytes so
 	 * pad skb in order to meet this minimum size requirement
 	 */
-	if (unlikely(skb->len < 17)) {
-		if (skb_pad(skb, 17 - skb->len))
-			return NETDEV_TX_OK;
-		skb->len = 17;
-		skb_set_tail_pointer(skb, 17);
-	}
+	if (skb_put_padto(skb, 17))
+		return NETDEV_TX_OK;
 
 	mss = skb_shinfo(skb)->gso_size;
 	if (mss) {
diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_main.c b/drivers/net/ethernet/intel/fm10k/fm10k_main.c
index 73457ede53ec..91516aed373e 100644
--- a/drivers/net/ethernet/intel/fm10k/fm10k_main.c
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_main.c
@@ -578,14 +578,9 @@ static bool fm10k_cleanup_headers(struct fm10k_ring *rx_ring,
 	if (skb_is_nonlinear(skb))
 		fm10k_pull_tail(rx_ring, rx_desc, skb);
 
-	/* if skb_pad returns an error the skb was freed */
-	if (unlikely(skb->len < 60)) {
-		int pad_len = 60 - skb->len;
-
-		if (skb_pad(skb, pad_len))
-			return true;
-		__skb_put(skb, pad_len);
-	}
+	/* if eth_skb_pad returns an error the skb was freed */
+	if (eth_skb_pad(skb))
+		return true;
 
 	return false;
 }
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 3195d82e4942..04b441460bbd 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -2399,12 +2399,8 @@ netdev_tx_t i40e_lan_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 	/* hardware can't handle really short frames, hardware padding works
 	 * beyond this point
 	 */
-	if (unlikely(skb->len < I40E_MIN_TX_LEN)) {
-		if (skb_pad(skb, I40E_MIN_TX_LEN - skb->len))
-			return NETDEV_TX_OK;
-		skb->len = I40E_MIN_TX_LEN;
-		skb_set_tail_pointer(skb, I40E_MIN_TX_LEN);
-	}
+	if (skb_put_padto(skb, I40E_MIN_TX_LEN))
+		return NETDEV_TX_OK;
 
 	return i40e_xmit_frame_ring(skb, tx_ring);
 }
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 3c0221620c9d..f04ad13f7159 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -5091,12 +5091,8 @@ static netdev_tx_t igb_xmit_frame(struct sk_buff *skb,
 	/* The minimum packet size with TCTL.PSP set is 17 so pad the skb
 	 * in order to meet this minimum size requirement.
 	 */
-	if (unlikely(skb->len < 17)) {
-		if (skb_pad(skb, 17 - skb->len))
-			return NETDEV_TX_OK;
-		skb->len = 17;
-		skb_set_tail_pointer(skb, 17);
-	}
+	if (skb_put_padto(skb, 17))
+		return NETDEV_TX_OK;
 
 	return igb_xmit_frame_ring(skb, igb_tx_queue_mapping(adapter, skb));
 }
@@ -6850,14 +6846,9 @@ static bool igb_cleanup_headers(struct igb_ring *rx_ring,
 	if (skb_is_nonlinear(skb))
 		igb_pull_tail(rx_ring, rx_desc, skb);
 
-	/* if skb_pad returns an error the skb was freed */
-	if (unlikely(skb->len < 60)) {
-		int pad_len = 60 - skb->len;
-
-		if (skb_pad(skb, pad_len))
-			return true;
-		__skb_put(skb, pad_len);
-	}
+	/* if eth_skb_pad returns an error the skb was freed */
+	if (eth_skb_pad(skb))
+		return true;
 
 	return false;
 }
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 82d418729dd4..fbd52924ee34 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -1774,14 +1774,9 @@ static bool ixgbe_cleanup_headers(struct ixgbe_ring *rx_ring,
 		return false;
 
 #endif
-	/* if skb_pad returns an error the skb was freed */
-	if (unlikely(skb->len < 60)) {
-		int pad_len = 60 - skb->len;
-
-		if (skb_pad(skb, pad_len))
-			return true;
-		__skb_put(skb, pad_len);
-	}
+	/* if eth_skb_pad returns an error the skb was freed */
+	if (eth_skb_pad(skb))
+		return true;
 
 	return false;
 }
@@ -7334,12 +7329,8 @@ static netdev_tx_t __ixgbe_xmit_frame(struct sk_buff *skb,
 	 * The minimum packet size for olinfo paylen is 17 so pad the skb
 	 * in order to meet this minimum size requirement.
 	 */
-	if (unlikely(skb->len < 17)) {
-		if (skb_pad(skb, 17 - skb->len))
-			return NETDEV_TX_OK;
-		skb->len = 17;
-		skb_set_tail_pointer(skb, 17);
-	}
+	if (skb_put_padto(skb, 17))
+		return NETDEV_TX_OK;
 
 	tx_ring = ring ? ring : adapter->tx_ring[skb->queue_mapping];
 
diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 3b0ddf757fb6..62a0d8e0f17d 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -616,14 +616,9 @@ static bool ixgbevf_cleanup_headers(struct ixgbevf_ring *rx_ring,
 	if (skb_is_nonlinear(skb))
 		ixgbevf_pull_tail(rx_ring, skb);
 
-	/* if skb_pad returns an error the skb was freed */
-	if (unlikely(skb->len < 60)) {
-		int pad_len = 60 - skb->len;
-
-		if (skb_pad(skb, pad_len))
-			return true;
-		__skb_put(skb, pad_len);
-	}
+	/* if eth_skb_pad returns an error the skb was freed */
+	if (eth_skb_pad(skb))
+		return true;
 
 	return false;
 }
diff --git a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
index 9e7e3f1dce3e..af099057f0e9 100644
--- a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
+++ b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
@@ -2913,16 +2913,11 @@ again:
 		flags |= MXGEFW_FLAGS_SMALL;
 
 		/* pad frames to at least ETH_ZLEN bytes */
-		if (unlikely(skb->len < ETH_ZLEN)) {
-			if (skb_padto(skb, ETH_ZLEN)) {
-				/* The packet is gone, so we must
-				 * return 0 */
-				ss->stats.tx_dropped += 1;
-				return NETDEV_TX_OK;
-			}
-			/* adjust the len to account for the zero pad
-			 * so that the nic can know how long it is */
-			skb->len = ETH_ZLEN;
+		if (eth_skb_pad(skb)) {
+			/* The packet is gone, so we must
+			 * return 0 */
+			ss->stats.tx_dropped += 1;
+			return NETDEV_TX_OK;
 		}
 	}
 
diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index 56280c1fc0ed..b9c2f33b463d 100644
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -6836,14 +6836,6 @@ err_out:
 	return -EIO;
 }
 
-static bool rtl_skb_pad(struct sk_buff *skb)
-{
-	if (skb_padto(skb, ETH_ZLEN))
-		return false;
-	skb_put(skb, ETH_ZLEN - skb->len);
-	return true;
-}
-
 static bool rtl_test_hw_pad_bug(struct rtl8169_private *tp, struct sk_buff *skb)
 {
 	return skb->len < ETH_ZLEN && tp->mac_version == RTL_GIGA_MAC_VER_34;
@@ -6984,7 +6976,7 @@ static bool rtl8169_tso_csum_v2(struct rtl8169_private *tp,
 		u8 ip_protocol;
 
 		if (unlikely(rtl_test_hw_pad_bug(tp, skb)))
-			return skb_checksum_help(skb) == 0 && rtl_skb_pad(skb);
+			return !(skb_checksum_help(skb) || eth_skb_pad(skb));
 
 		if (transport_offset > TCPHO_MAX) {
 			netif_warn(tp, tx_err, tp->dev,
@@ -7019,7 +7011,7 @@ static bool rtl8169_tso_csum_v2(struct rtl8169_private *tp,
 		opts[1] |= transport_offset << TCPHO_SHIFT;
 	} else {
 		if (unlikely(rtl_test_hw_pad_bug(tp, skb)))
-			return rtl_skb_pad(skb);
+			return !eth_skb_pad(skb);
 	}
 
 	return true;
diff --git a/drivers/net/ethernet/sun/niu.c b/drivers/net/ethernet/sun/niu.c
index 904fd1ab5f6e..4aaa3240453a 100644
--- a/drivers/net/ethernet/sun/niu.c
+++ b/drivers/net/ethernet/sun/niu.c
@@ -6651,13 +6651,8 @@ static netdev_tx_t niu_start_xmit(struct sk_buff *skb,
 		return NETDEV_TX_BUSY;
 	}
 
-	if (skb->len < ETH_ZLEN) {
-		unsigned int pad_bytes = ETH_ZLEN - skb->len;
-
-		if (skb_pad(skb, pad_bytes))
-			goto out;
-		skb_put(skb, pad_bytes);
-	}
+	if (eth_skb_pad(skb))
+		goto out;
 
 	len = sizeof(struct tx_pkt_hdr) + 15;
 	if (skb_headroom(skb) < len) {