lkml.org 
[lkml]   [2020]   [Oct]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH net-next] drivers/net/wan/hdlc_fr: Improvements to the code of pvc_xmit
Date
1. Keep the code for the normal (non-error) flow at the lowest
indentation level. And use "goto drop" for all error handling.

2. Replace code that pads short Ethernet frames with a "__skb_pad" call.

3. Change "dev_kfree_skb" to "kfree_skb" in error handling code.
"kfree_skb" is the correct function to call when dropping an skb due to
an error. "dev_kfree_skb", which is an alias of "consume_skb", is for
dropping skbs normally (not due to an error).

Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
---
drivers/net/wan/hdlc_fr.c | 54 +++++++++++++++++++--------------------
1 file changed, 26 insertions(+), 28 deletions(-)

diff --git a/drivers/net/wan/hdlc_fr.c b/drivers/net/wan/hdlc_fr.c
index 3a44dad87602..4dfdbca54296 100644
--- a/drivers/net/wan/hdlc_fr.c
+++ b/drivers/net/wan/hdlc_fr.c
@@ -416,38 +416,36 @@ static netdev_tx_t pvc_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct pvc_device *pvc = dev->ml_priv;

- if (pvc->state.active) {
- if (dev->type == ARPHRD_ETHER) {
- int pad = ETH_ZLEN - skb->len;
- if (pad > 0) { /* Pad the frame with zeros */
- int len = skb->len;
- if (skb_tailroom(skb) < pad)
- if (pskb_expand_head(skb, 0, pad,
- GFP_ATOMIC)) {
- dev->stats.tx_dropped++;
- dev_kfree_skb(skb);
- return NETDEV_TX_OK;
- }
- skb_put(skb, pad);
- memset(skb->data + len, 0, pad);
- }
- }
- skb->dev = dev;
- if (!fr_hard_header(&skb, pvc->dlci)) {
- dev->stats.tx_bytes += skb->len;
- dev->stats.tx_packets++;
- if (pvc->state.fecn) /* TX Congestion counter */
- dev->stats.tx_compressed++;
- skb->dev = pvc->frad;
- skb->protocol = htons(ETH_P_HDLC);
- skb_reset_network_header(skb);
- dev_queue_xmit(skb);
- return NETDEV_TX_OK;
+ if (!pvc->state.active)
+ goto drop;
+
+ if (dev->type == ARPHRD_ETHER) {
+ int pad = ETH_ZLEN - skb->len;
+
+ if (pad > 0) { /* Pad the frame with zeros */
+ if (__skb_pad(skb, pad, false))
+ goto drop;
+ skb_put(skb, pad);
}
}

+ skb->dev = dev;
+ if (fr_hard_header(&skb, pvc->dlci))
+ goto drop;
+
+ dev->stats.tx_bytes += skb->len;
+ dev->stats.tx_packets++;
+ if (pvc->state.fecn) /* TX Congestion counter */
+ dev->stats.tx_compressed++;
+ skb->dev = pvc->frad;
+ skb->protocol = htons(ETH_P_HDLC);
+ skb_reset_network_header(skb);
+ dev_queue_xmit(skb);
+ return NETDEV_TX_OK;
+
+drop:
dev->stats.tx_dropped++;
- dev_kfree_skb(skb);
+ kfree_skb(skb);
return NETDEV_TX_OK;
}

--
2.25.1
\
 
 \ /
  Last update: 2020-10-04 00:41    [W:0.034 / U:1.196 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site