Messages in this thread Patch in this message | | | From | Martin Schiller <> | Subject | [PATCH 2/2] wan/hdlc_x25: fix skb handling | Date | Mon, 13 Jan 2020 13:45:51 +0100 |
| |
o call skb_reset_network_header() before hdlc->xmit() o change skb proto to HDLC (0x0019) before hdlc->xmit() o call dev_queue_xmit_nit() before hdlc->xmit()
This changes make it possible to trace (tcpdump) outgoing layer2 (ETH_P_HDLC) packets
o use a copy of the skb for lapb_data_request() in x25_xmit()
This fixes the problem, that tracing layer3 (ETH_P_X25) packets results in a malformed first byte of the packets.
Signed-off-by: Martin Schiller <ms@dev.tdt.de> --- drivers/net/wan/hdlc_x25.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wan/hdlc_x25.c b/drivers/net/wan/hdlc_x25.c index b28051eba736..434e5263eddf 100644 --- a/drivers/net/wan/hdlc_x25.c +++ b/drivers/net/wan/hdlc_x25.c @@ -72,6 +72,7 @@ static int x25_data_indication(struct net_device *dev, struct sk_buff *skb) unsigned char *ptr; skb_push(skb, 1); + skb_reset_network_header(skb); if (skb_cow(skb, 1)) return NET_RX_DROP; @@ -88,6 +89,9 @@ static int x25_data_indication(struct net_device *dev, struct sk_buff *skb) static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb) { hdlc_device *hdlc = dev_to_hdlc(dev); + skb_reset_network_header(skb); + skb->protocol = hdlc_type_trans(skb, dev); + dev_queue_xmit_nit(skb, dev); hdlc->xmit(skb, dev); /* Ignore return value :-( */ } @@ -95,16 +99,19 @@ static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb) static netdev_tx_t x25_xmit(struct sk_buff *skb, struct net_device *dev) { + struct sk_buff *skbn; int result; /* X.25 to LAPB */ switch (skb->data[0]) { case X25_IFACE_DATA: /* Data to be transmitted */ - skb_pull(skb, 1); - if ((result = lapb_data_request(dev, skb)) != LAPB_OK) - dev_kfree_skb(skb); - return NETDEV_TX_OK; + skbn = skb_copy(skb, GFP_ATOMIC); + skb_pull(skbn, 1); + skb_reset_network_header(skbn); + if ((result = lapb_data_request(dev, skbn)) != LAPB_OK) + dev_kfree_skb(skbn); + break; case X25_IFACE_CONNECT: if ((result = lapb_connect_request(dev))!= LAPB_OK) { -- 2.20.1
| |