PROTOCOL INDEPENDENT WAY TO SELECTIVELY RESTRICT WRITE-ACCESS FOR REDIRECTED USB MASS STORAGE DEVICES

• US 20170063855A1
• Filed: 08/24/2015
• Published: 03/02/2017
• Est. Priority Date: 08/24/2015
• Status: Active Grant

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Vajravel, Gokul Thiruchengode
• Granted Patent: US 10,021,217 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 21/62 Protecting access to data via a platform, e.g. using keys or access control rules
• CPC Class Codes: G06F 21/79 in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

Universal serial bus (USB) mass storage devices may be redirected to a server to create USB virtual mass storage devices. For characteristics of the redirected device to be propagated to other users (accessing the redirected device via the virtual device) it is necessary to alter the Mode Sense data. In one embodiment, certain users may be given only read-only access to the redirected device. In another embodiment only some of the redirected devices are write-protected. By saving characteristics of a redirected device in the server registry or active directory, the USB virtual bus driver may impose, for example, write-protection on one or more devices connected by one or more users.

Claims

1. A method comprising:

snooping and trapping a small computer system interface (SCSI) Mode Sense response from a first redirected universal serial bus (USB) mass storage device of a first client;

determining if device protection is enable for the first (USB) mass storage device;

determining if the response includes a USB request block (URB) bulk transfer;

determining if the response includes SCSI Mode Sense data;

setting a write-protect bit of a header of the response; and

sending the response to one or more upper layers of a driver stack.

2. The method of claim 1, further comprising:

setting one or more characteristics of the redirected USB mass storage device, wherein the one or more characteristics includes a write-protect characteristics;

storing the one or more characteristics of the redirected USB mass storage device; and

retrieving the write-protect status prior to the determining device protection enabled step.

3. The method of claim 2, wherein the one or more characteristics are stored in a system registry.

4. The method of claim 2, wherein the one or more characteristics are stored in an active directory.

5. The method of claim 2, wherein the one or more characteristics include access permissions for one or more users.

6. The method of claim 2, wherein the one or more characteristics include access permissions for one or more servers to one or more redirected devices.

7. The method of claim 1, further comprising:

blocking write commands by a disk class driver for a write-protected first USB mass storage device.

8. One or more computer-readable non-transitory storage media embodying software that is operable when executed to:

snoop and trap a small computer system interface (SCSI) Mode Sense response from a first redirected universal serial bus (USB) mass storage device of a first client;

determine if device protection is enabled for the first (USB mass storage device;

determine if the response includes a USB request block (URB) bulk transfer;

determine if the response includes SCSI Mode Sense data;

set a write-protect bit of a header of the response; and

send the response to one or more upper layers of a driver stack.

9. The media of claim 8, wherein the software when executed is further operable to:

set one or more characteristics of the redirected USB mass storage device, wherein the one or more characteristics includes a write-protect characteristics;

store the one or more characteristics of the redirected USB mass storage device; and

retrieve the write-protect status prior to the determining device protection enabled step.

10. The media of claim 9, wherein the one or more characteristics are stored in a system registry.

11. The media of claim 9, wherein the one or more characteristics are stored in an active directory.

12. The media of claim 9, wherein the one or more characteristics include access permissions for one or more users.

13. The media of claim 8, wherein the software when executed is further operable to:

block write commands by a disk class driver for a write-protected first USB mass storage device.

14. A system comprising:

one or more processors; and

a memory coupled to the processors comprising instructions executable by the processors, the processors being operable when executing the instructions to;

snoop and trap a small computer system interface (SCSI) Mode Sense response from a first redirected universal serial bus (USB) mass storage device of a first client;

determine if device protection is enabled for the first (USB mass storage device;

determine if the response includes a USB request block (URB) bulk transfer;

determine if the response includes SCSI Mode Sense data;

set a write-protect bit of a header of the response; and

send the response to one or more upper layers of a driver stack.

15. The system of claim 14, wherein the processors are further operable when executing instructions to:

set one or more characteristics of the redirected USB mass storage device, wherein the one or more characteristics includes a write-protect characteristics;

store the one or more characteristics of the redirected USB mass storage device; and

retrieve the write-protect status prior to the determining device protection enabled step.

16. The system of claim 15, wherein the one or more characteristics are stored in a system registry.

17. The system of claim 15, wherein the one or more characteristics are stored in an active directory.

18. The system of claim 15, wherein the one or more characteristics include access permissions for one or more users.

19. The system of claim 15, wherein the one or more characteristics include access permissions for one or more servers to one or more redirected devices.

20. The system of claim 14, wherein the processors are further operable when executing instructions to:

block write commands by a disk class driver for a write-protected first USB mass storage device.