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![Mika Westerberg](/assets/img/avatar_default.png)
Starting from Intel Falcon Ridge the internal connection manager running on the Thunderbolt host controller has been supporting 4 security levels. One reason for this is to prevent DMA attacks and only allow connecting devices the user trusts. The internal connection manager (ICM) is the preferred way of connecting Thunderbolt devices over software only implementation typically used on Macs. The driver communicates with ICM using special Thunderbolt ring 0 (control channel) messages. In order to handle these messages we add support for the ICM messages to the control channel. The security levels are as follows: none - No security, all tunnels are created automatically user - User needs to approve the device before tunnels are created secure - User need to approve the device before tunnels are created. The device is sent a challenge on future connects to be able to verify it is actually the approved device. dponly - Only Display Port and USB tunnels can be created and those are created automatically. The security levels are typically configurable from the system BIOS and by default it is set to "user" on many systems. In this patch each Thunderbolt device will have either one or two new sysfs attributes: authorized and key. The latter appears for devices that support secure connect. In order to identify the device the user can read identication information, including UUID and name of the device from sysfs and based on that make a decision to authorize the device. The device is authorized by simply writing 1 to the "authorized" sysfs attribute. This is following the USB bus device authorization mechanism. The secure connect requires an additional challenge step (writing 2 to the "authorized" attribute) in future connects when the key has already been stored to the NVM of the device. Non-ICM systems (before Alpine Ridge) continue to use the existing functionality and the security level is set to none. For systems with Alpine Ridge, even on Apple hardware, we will use ICM. This code is based on the work done by Amir Levy and Michael Jamet. Signed-off-by: Michael Jamet <michael.jamet@intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andreas Noever <andreas.noever@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 lines
170 B
Makefile
3 lines
170 B
Makefile
obj-${CONFIG_THUNDERBOLT} := thunderbolt.o
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thunderbolt-objs := nhi.o ctl.o tb.o switch.o cap.o path.o tunnel_pci.o eeprom.o
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thunderbolt-objs += domain.o dma_port.o icm.o
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