From: Xie He xie.he.0141@gmail.com
[ Upstream commit 44a049c42681de71c783d75cd6e56b4e339488b0 ]
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 khc@pm.waw.pl Cc: Martin Schiller ms@dev.tdt.de Signed-off-by: Xie He xie.he.0141@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wan/hdlc_fr.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wan/hdlc_fr.c b/drivers/net/wan/hdlc_fr.c index 78596e42a3f3f..a09af49cd08b9 100644 --- a/drivers/net/wan/hdlc_fr.c +++ b/drivers/net/wan/hdlc_fr.c @@ -1045,7 +1045,7 @@ 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); } @@ -1097,6 +1097,7 @@ 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;