Hi misc@,
While testing the U-blox MPCI-L210 LTE modem on OpenBSD -current
(the modem is attached as a cdce(4) device, the router mode is enabled;
other modes are also available), I noticed that the automatic configuration
via DHCP works correctly, but the MAC address assigned to the corresponding
cdce0 network interface is different from the MAC address reported by
lsusb -v. Unfortunately, due to this mismatch, incoming Ethernet frames
having the actual MAC address of the device set as the destination address
in the header are dropped by the kernel in the ether_input() function
(/src/sys/net/if_ethersubr.c).
Based on an analysis of the source code (/sys/dev/usb/if_cdce.c) and the
results of the subsequent experiments, I was able to confirm that the cdce
driver is unable to get the MAC address of the device (in particular,
the usbd_get_string_desc() function returns USBD_STALLED instead of
USBD_NORMAL_COMPLETION), and as a result, a semi-random fake Ethernet
address is set:
-----------------------------------------------------------------------------
306 if (!ethd || usbd_get_string_desc(sc->cdce_udev, ethd->iMacAddress, 0,
307 &eaddr_str, &len)) {
308 ether_fakeaddr(ifp); // <---- Set a semi-random MAC address
309 } else {
-----------------------------------------------------------------------------
As a temporary workaround, I manually set the MAC address of the cdce0
interface to the value reported by lsusb -v using ifconfig(8).
I would appreciate your comments and suggestions about how this issue
could be investigated further, and I would be happy to provide additional
information that might be helpful in the preparation of the corresponding
fix. Meanwhile, please find below the related output of the 'lsusb -v'
command.
Thank you very much for your time.
Best wishes,
Andrzej
-----------------------------------------------------------------------------
Bus 001 Device 003: ID 1546:1143 U-Blox AG
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 239 Miscellaneous Device
bDeviceSubClass 2 ?
bDeviceProtocol 1 Interface Association
bMaxPacketSize0 64
idVendor 0x1546 U-Blox AG
idProduct 0x1143
bcdDevice 1.00
iManufacturer 1 u-blox
iProduct 2 MODEM-LTE
iSerial 3 000000000100
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 278
bNumInterfaces 8
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 500mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 2 Communications
bInterfaceSubClass 6 Ethernet Networking
bInterfaceProtocol 0
iInterface 4 CDC Ethernet Control Model (ECM)
CDC Header:
bcdCDC 1.10
CDC Union:
bMasterInterface 0
bSlaveInterface 1
CDC Ethernet:
iMacAddress 6 XXXXXXXXXXXX
bmEthernetStatistics 0x00000000
wMaxSegmentSize 1514
wNumberMCFilters 0x0000
bNumberPowerFilters 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0010 1x 16 bytes
bInterval 9
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 10 CDC Data
bInterfaceSubClass 0 Unused
bInterfaceProtocol 0
iInterface 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 1
bNumEndpoints 2
bInterfaceClass 10 CDC Data
bInterfaceSubClass 0 Unused
bInterfaceProtocol 0
iInterface 5 CDC Ethernet Data
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x01 EP 1 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Interface Association:
bLength 8
bDescriptorType 11
bFirstInterface 2
bInterfaceCount 2
bFunctionClass 2 Communications
bFunctionSubClass 2 Abstract (modem)
bFunctionProtocol 0 None
iFunction 9 CDC Serial
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 2 Communications
bInterfaceSubClass 2 Abstract (modem)
bInterfaceProtocol 1 AT-commands (v.25ter)
iInterface 7 CDC Abstract Control Model (ACM)
CDC Header:
bcdCDC 1.10
CDC Call Management:
bmCapabilities 0x00
bDataInterface 3
CDC ACM:
bmCapabilities 0x02
line coding and serial state
CDC Union:
bMasterInterface 2
bSlaveInterface 3
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x84 EP 4 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x000a 1x 10 bytes
bInterval 9
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 3
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 10 CDC Data
bInterfaceSubClass 0 Unused
bInterfaceProtocol 0
iInterface 8 CDC ACM Data
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Interface Association:
bLength 8
bDescriptorType 11
bFirstInterface 4
bInterfaceCount 2
bFunctionClass 2 Communications
bFunctionSubClass 2 Abstract (modem)
bFunctionProtocol 0 None
iFunction 9 CDC Serial
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 4
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 2 Communications
bInterfaceSubClass 2 Abstract (modem)
bInterfaceProtocol 1 AT-commands (v.25ter)
iInterface 7 CDC Abstract Control Model (ACM)
CDC Header:
bcdCDC 1.10
CDC Call Management:
bmCapabilities 0x00
bDataInterface 5
CDC ACM:
bmCapabilities 0x02
line coding and serial state
CDC Union:
bMasterInterface 4
bSlaveInterface 5
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x86 EP 6 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x000a 1x 10 bytes
bInterval 9
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 5
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 10 CDC Data
bInterfaceSubClass 0 Unused
bInterfaceProtocol 0
iInterface 8 CDC ACM Data
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x85 EP 5 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x03 EP 3 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Interface Association:
bLength 8
bDescriptorType 11
bFirstInterface 6
bInterfaceCount 2
bFunctionClass 2 Communications
bFunctionSubClass 2 Abstract (modem)
bFunctionProtocol 0 None
iFunction 9 CDC Serial
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 6
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 2 Communications
bInterfaceSubClass 2 Abstract (modem)
bInterfaceProtocol 1 AT-commands (v.25ter)
iInterface 7 CDC Abstract Control Model (ACM)
CDC Header:
bcdCDC 1.10
CDC Call Management:
bmCapabilities 0x00
bDataInterface 7
CDC ACM:
bmCapabilities 0x02
line coding and serial state
CDC Union:
bMasterInterface 6
bSlaveInterface 7
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x88 EP 8 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x000a 1x 10 bytes
bInterval 9
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 7
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 10 CDC Data
bInterfaceSubClass 0 Unused
bInterfaceProtocol 0
iInterface 8 CDC ACM Data
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x87 EP 7 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x04 EP 4 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Device Qualifier (for other device speed):
bLength 10
bDescriptorType 6
bcdUSB 2.00
bDeviceClass 239 Miscellaneous Device
bDeviceSubClass 2 ?
bDeviceProtocol 1 Interface Association
bMaxPacketSize0 64
bNumConfigurations 1
Device Status: 0x0001
Self Powered
