[PATCH AUTOSEL 4.19 46/60] qmi_wwan: add support for QMAP padding in the RX path

Sasha Levin
2019-06-27T00:38:46Z

From: Reinhard Speyerer <rspmn@arcor.de>

[ Upstream commit 61356088ace1866a847a727d4d40da7bf00b67fc ]

The QMAP code in the qmi_wwan driver is based on the CodeAurora GobiNet
driver which does not process QMAP padding in the RX path correctly.
Add support for QMAP padding to qmimux_rx_fixup() according to the
description of the rmnet driver.

Fixes: c6adf77953bc ("net: usb: qmi_wwan: add qmap mux protocol support")
Cc: Daniele Palmas <dnlplm@gmail.com>
Signed-off-by: Reinhard Speyerer <rspmn@arcor.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/usb/qmi_wwan.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index d9a6699abe59..fd3d078a1923 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -153,7 +153,7 @@ static bool qmimux_has_slaves(struct usbnet *dev)

static int qmimux_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
{
- unsigned int len, offset = 0;
+ unsigned int len, offset = 0, pad_len, pkt_len;
struct qmimux_hdr *hdr;
struct net_device *net;
struct sk_buff *skbn;
@@ -171,10 +171,16 @@ static int qmimux_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
if (hdr->pad & 0x80)
goto skip;

+ /* extract padding length and check for valid length info */
+ pad_len = hdr->pad & 0x3f;
+ if (len == 0 || pad_len >= len)
+ goto skip;
+ pkt_len = len - pad_len;
+
net = qmimux_find_dev(dev, hdr->mux_id);
if (!net)
goto skip;
- skbn = netdev_alloc_skb(net, len);
+ skbn = netdev_alloc_skb(net, pkt_len);
if (!skbn)
return 0;
skbn->dev = net;
@@ -191,7 +197,7 @@ static int qmimux_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
goto skip;
}

- skb_put_data(skbn, skb->data + offset + qmimux_hdr_sz, len);
+ skb_put_data(skbn, skb->data + offset + qmimux_hdr_sz, pkt_len);
if (netif_rx(skbn) != NET_RX_SUCCESS)
return 0;

--
2.20.1