@@ -880,7 +880,7 @@ static int fr_rx(struct sk_buff *skb)
u8 *data = skb->data;
u16 dlci;
struct pvc_device *pvc;
- struct net_device *dev = NULL;
+ struct net_device *dev;
if (skb->len <= 4 || fh->ea1 || data[2] != FR_UI)
goto rx_error;
@@ -930,13 +930,17 @@ static int fr_rx(struct sk_buff *skb)
}
if (data[3] == NLPID_IP) {
+ if (!pvc->main)
+ goto rx_drop;
skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
- dev = pvc->main;
+ skb->dev = pvc->main;
skb->protocol = htons(ETH_P_IP);
} else if (data[3] == NLPID_IPV6) {
+ if (!pvc->main)
+ goto rx_drop;
skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
- dev = pvc->main;
+ skb->dev = pvc->main;
skb->protocol = htons(ETH_P_IPV6);
} else if (skb->len > 10 && data[3] == FR_PAD &&
@@ -950,13 +954,16 @@ static int fr_rx(struct sk_buff *skb)
case ETH_P_IPX:
case ETH_P_IP: /* a long variant */
case ETH_P_IPV6:
- dev = pvc->main;
+ if (!pvc->main)
+ goto rx_drop;
+ skb->dev = pvc->main;
skb->protocol = htons(pid);
break;
case 0x80C20007: /* bridged Ethernet frame */
- if ((dev = pvc->ether) != NULL)
- skb->protocol = eth_type_trans(skb, dev);
+ if (!pvc->ether)
+ goto rx_drop;
+ skb->protocol = eth_type_trans(skb, pvc->ether);
break;
default:
@@ -970,17 +977,13 @@ static int fr_rx(struct sk_buff *skb)
goto rx_drop;
}
- if (dev) {
- dev->stats.rx_packets++; /* PVC traffic */
- dev->stats.rx_bytes += skb->len;
- if (pvc->state.becn)
- dev->stats.rx_compressed++;
- skb->dev = dev;
- netif_rx(skb);
- return NET_RX_SUCCESS;
- } else {
- goto rx_drop;
- }
+ dev = skb->dev;
+ dev->stats.rx_packets++; /* PVC traffic */
+ dev->stats.rx_bytes += skb->len;
+ if (pvc->state.becn)
+ dev->stats.rx_compressed++;
+ netif_rx(skb);
+ return NET_RX_SUCCESS;
rx_error:
frad->stats.rx_errors++; /* Mark error */
The eth_type_trans function is called when we receive frames carrying Ethernet frames. This function expects a non-NULL pointer as an argument, and assigns it directly to skb->dev. However, the code handling other types of frames first assigns the pointer to "dev", and then at the end checks whether the value is NULL, and if it is not NULL, assigns it to skb->dev. The two flows are different. Mixing them in this function makes the code messy. It's better that we convert the second flow to align with how eth_type_trans does things. So this patch changes the code to: first make sure the pointer is not NULL, then assign it directly to skb->dev. "dev" is no longer needed until the end where we use it to update stats. Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com> Cc: Krzysztof Halasa <khc@pm.waw.pl> Signed-off-by: Xie He <xie.he.0141@gmail.com> --- drivers/net/wan/hdlc_fr.c | 37 ++++++++++++++++++++----------------- 1 file changed, 20 insertions(+), 17 deletions(-)