From 531ad4282e5105db984f1706e1a21799157655a3 Mon Sep 17 00:00:00 2001 From: Kristian Evensen Date: Fri, 2 Jan 2015 16:21:45 +0100 Subject: [PATCH] qmi_wwan: Set random MAC on devices with buggy fw Some buggy firmwares export an incorrect MAC address (00:a0:c6:00:00:00). This makes for example checking devices for random MAC addresses tricky, and you might end up with multiple network interfaces with the same address. This patch tries to fix, or at least improve, the situation by setting the MAC address of devices with this firmware bug to a random address. I tested the patch with two devices that has this firmware bug (Huawei E398 and E392), and network traffic worked fine after changing the address. Signed-off-by: Kristian Evensen Signed-off-by: David S. Miller --- drivers/net/usb/qmi_wwan.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c index b8a82b86f909..602dc6668c3a 100644 --- a/drivers/net/usb/qmi_wwan.c +++ b/drivers/net/usb/qmi_wwan.c @@ -56,6 +56,8 @@ struct qmi_wwan_state { /* default ethernet address used by the modem */ static const u8 default_modem_addr[ETH_ALEN] = {0x02, 0x50, 0xf3}; +static const u8 buggy_fw_addr[ETH_ALEN] = {0x00, 0xa0, 0xc6, 0x00, 0x00, 0x00}; + /* Make up an ethernet header if the packet doesn't have one. * * A firmware bug common among several devices cause them to send raw @@ -332,10 +334,12 @@ next_desc: usb_driver_release_interface(driver, info->data); } - /* Never use the same address on both ends of the link, even - * if the buggy firmware told us to. + /* Never use the same address on both ends of the link, even if the + * buggy firmware told us to. Or, if device is assigned the well-known + * buggy firmware MAC address, replace it with a random address, */ - if (ether_addr_equal(dev->net->dev_addr, default_modem_addr)) + if (ether_addr_equal(dev->net->dev_addr, default_modem_addr) || + ether_addr_equal(dev->net->dev_addr, buggy_fw_addr)) eth_hw_addr_random(dev->net); /* make MAC addr easily distinguishable from an IP header */ -- 2.20.1