From 44a049c42681de71c783d75cd6e56b4e339488b0 Mon Sep 17 00:00:00 2001 From: Xie He Date: Wed, 2 Sep 2020 17:06:58 -0700 Subject: drivers/net/wan/hdlc_fr: Add needed_headroom for PVC devices PVC devices are virtual devices in this driver stacked on top of the actual HDLC device. They are the devices normal users would use. PVC devices have two types: normal PVC devices and Ethernet-emulating PVC devices. When transmitting data with PVC devices, the ndo_start_xmit function will prepend a header of 4 or 10 bytes. Currently this driver requests this headroom to be reserved for normal PVC devices by setting their hard_header_len to 10. However, this does not work when these devices are used with AF_PACKET/RAW sockets. Also, this driver does not request this headroom for Ethernet-emulating PVC devices (but deals with this problem by reallocating the skb when needed, which is not optimal). This patch replaces hard_header_len with needed_headroom, and set needed_headroom for Ethernet-emulating PVC devices, too. This makes the driver to request headroom for all PVC devices in all cases. Cc: Krzysztof Halasa Cc: Martin Schiller Signed-off-by: Xie He Signed-off-by: Jakub Kicinski --- drivers/net/wan/hdlc_fr.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/net/wan') diff --git a/drivers/net/wan/hdlc_fr.c b/drivers/net/wan/hdlc_fr.c index 9acad651ea1f..12b35404cd8e 100644 --- a/drivers/net/wan/hdlc_fr.c +++ b/drivers/net/wan/hdlc_fr.c @@ -1041,7 +1041,7 @@ static void pvc_setup(struct net_device *dev) { dev->type = ARPHRD_DLCI; dev->flags = IFF_POINTOPOINT; - dev->hard_header_len = 10; + dev->hard_header_len = 0; dev->addr_len = 2; netif_keep_dst(dev); } @@ -1093,6 +1093,7 @@ static int fr_add_pvc(struct net_device *frad, unsigned int dlci, int type) dev->mtu = HDLC_MAX_MTU; dev->min_mtu = 68; dev->max_mtu = HDLC_MAX_MTU; + dev->needed_headroom = 10; dev->priv_flags |= IFF_NO_QUEUE; dev->ml_priv = pvc; -- cgit v1.2.3