From 953c4a08dfc9ffe763a8340ac10f459d6c6cc4eb Mon Sep 17 00:00:00 2001 From: Martin Schiller Date: Tue, 21 Jan 2020 07:00:34 +0100 Subject: [PATCH] wan/hdlc_x25: fix skb handling 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 Additionally call skb_reset_network_header() after each skb_push() / skb_pull(). Signed-off-by: Martin Schiller Signed-off-by: David S. Miller --- drivers/net/wan/hdlc_x25.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/net/wan/hdlc_x25.c b/drivers/net/wan/hdlc_x25.c index 688233c2e1ea..63c9aeed9a34 100644 --- a/drivers/net/wan/hdlc_x25.c +++ b/drivers/net/wan/hdlc_x25.c @@ -71,11 +71,12 @@ static int x25_data_indication(struct net_device *dev, struct sk_buff *skb) { unsigned char *ptr; - skb_push(skb, 1); - if (skb_cow(skb, 1)) return NET_RX_DROP; + skb_push(skb, 1); + skb_reset_network_header(skb); + ptr = skb->data; *ptr = X25_IFACE_DATA; @@ -88,6 +89,13 @@ 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); + + if (dev_nit_active(dev)) + dev_queue_xmit_nit(skb, dev); + hdlc->xmit(skb, dev); /* Ignore return value :-( */ } @@ -102,6 +110,7 @@ static netdev_tx_t x25_xmit(struct sk_buff *skb, struct net_device *dev) switch (skb->data[0]) { case X25_IFACE_DATA: /* Data to be transmitted */ skb_pull(skb, 1); + skb_reset_network_header(skb); if ((result = lapb_data_request(dev, skb)) != LAPB_OK) dev_kfree_skb(skb); return NETDEV_TX_OK;