Hardware accelerator for a domain name server cache

• US 9,215,205 B1
• Filed: 04/20/2012
• Issued: 12/15/2015
• Est. Priority Date: 04/20/2012
• Status: Active Grant

• Current Assignee: Infoblox Incorporated
• Original Assignee: Infoblox Incorporated
• Inventors: Smith, Les
• Primary Examiner(s): Salad, Abdullahi E
• Application Number:
  US13/452,547
• Time in Patent Office: 1,334 Days
• Field of Search: 709/224, 709/225, 709/229, 709/213, 709/245, 714/47.1, 714/48
• US Class Current: 1/1
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 61/58 Caching of addresses or names
• CPC Class Codes: H04L 63/101 Access control lists [ACL]
• CPC Class Codes: H04L 63/1458 Denial of Service

Abstract

Techniques for a hardware accelerator for a domain name server (DNS) cache are disclosed. In some embodiments, a hardware accelerator for a DNS cache includes: executing a packet processing engine of a host device to identify a DNS request; and performing a DNS lookup in the DNS cache. In some embodiments, a hardware accelerator for a DNS cache includes: determining if a time to live (TTL) parameter associated with a first entry stored in the DNS cache is below a threshold value; and if the TTL parameter associated with the first entry stored in the DNS cache is below the threshold value, then performing a pre-fetch operation to update the first entry in the DNS cache, wherein the updated entry comprises an updated TTL value.

Claims

1. A system for a hardware accelerator for a domain name server (DNS) lookup, comprising:

a domain name server (DNS) cache;

a processor configured to;

store a plurality of entries in the DNS cache, comprising;

receive a DNS reply including an entry to be stored;

determine whether a time to live (TTL) parameter of the received entry is less than a second threshold value, the second threshold value being greater than 0;

in the event that the TTL parameter of the received entry is less than the second threshold value, omit storing the received entry in the DNS cache;

determine whether the time to live (TTL) parameter of the received entry is greater than a third threshold value, the third threshold value being greater than or equal to each of a first threshold value and the second threshold value; and

in the event that the TTL parameter of the received entry is greater than the third threshold value;

reduce the TTL parameter of the received entry to correspond to the third threshold value; and

store the received entry with the reduced TTL parameter;

periodically perform a pre-fetch process on the plurality of entries stored in the DNS cache, wherein the performing of the pre-fetch process comprises;

for each of the plurality of entries, determine whether a TTL parameter associated with a corresponding entry stored in the DNS cache is below the first threshold value;

in the event that the TTL parameter associated with the corresponding entry stored in the DNS cache is below the first threshold value, mark the corresponding entry; and

for each marked entry, update the each marked entry in the DNS cache, wherein the updated entry comprises an updated TTL value and an updated Internet Protocol (IP) address;

execute a packet processing engine of a host device to identify a DNS request; and

perform a DNS lookup in the DNS cache, wherein the performing of the pre-fetch process is separate from the performing of the DNS lookup; and

perform cache management on the DNS cache, comprising to;

determine whether an entry in the DNS cache satisfies a least frequently used (LFU) algorithm; and

in the event that the entry satisfies the LFU algorithm, remove the entry from the DNS cache, wherein a TTL of each entry in the DNS cache is less than or equal to the third threshold value; and

a memory coupled to the processor and configured to provide the processor with instructions.

2. The system recited in claim 1, wherein the system is implemented on a network interface card.

3. The system recited in claim 1, wherein the processor is further configured to:

apply a security filter to a DNS query.

4. The system recited in claim 1, wherein the processor is further configured to:

determine if a DNS query matches an access control list (ACL).

5. The system recited in claim 1, wherein the processor is further configured to:

determine if a DNS query matches a black list entry.

6. The system recited in claim 1, wherein the processor is further configured to:

perform cache management on the DNS cache.

7. The system recited in claim 1, wherein the processor is further configured to:

perform cache management on the DNS cache using a least recently used (replacement) algorithm.

8. A method for a hardware accelerator for a domain name server (DNS) cache, comprising:

storing a plurality of entries in the DNS cache, comprising;

receiving a DNS reply including an entry to be stored;

determining whether a time to live (TTL) parameter of the received entry is less than a second threshold value, the second threshold value being greater than 0;

in the event that the TTL parameter of the received entry is less than the second threshold value, omitting storing the received entry in the DNS cache;

determining whether the time to live (TTL) parameter of the received entry is greater than a third threshold value, the third threshold value being greater than or equal to each of a first threshold value and the second threshold value; and

in the event that the TTL parameter of the received entry is greater than the third threshold value;

reducing the TTL parameter of the received entry to correspond to the third threshold value; and

storing the received entry with the reduced TTL parameter;

periodically performing a pre-fetch process on the plurality of entries stored in the DNS cache, wherein the performing of the pre-fetch process comprises;

for each of the plurality of entries, determining whether a TTL parameter associated with a corresponding entry stored in the DNS cache is below the first threshold value;

in the event that the TTL parameter associated with the corresponding entry stored in the DNS cache is below the first threshold value, marking the corresponding entry; and

for each marked entry, updating the each marked entry in the DNS cache, wherein the updated entry comprises an updated TTL value and an updated Internet Protocol (IP) address;

executing a packet processing engine of a host device to identify a DNS request; and

performing a DNS lookup in the DNS cache, wherein the performing of the pre-fetch process is separate from the performing of the DNS lookup; and

performing cache management on the DNS cache, comprising;

determining whether an entry in the DNS cache satisfies a least frequently used (LFU) algorithm; and

in the event that the entry satisfies the LFU algorithm, removing the entry from the DNS cache, wherein a TTL of each entry in the DNS cache is less than or equal to the third threshold value.

9. The method of claim 8, wherein the DNS cache is implemented on a network interface card.

10. The method of claim 8, further comprising:

applying a security filter to a DNS query.

11. A computer program product for a hardware accelerator for a domain name server (DNS) cache, the computer program product being embodied in a tangible non-transitory computer readable storage medium and comprising computer instructions for:

storing a plurality of entries in the DNS cache, comprising;

receiving a DNS reply including an entry to be stored;

determining whether a time to live (TTL) parameter of the received entry is less than a second threshold value, the second threshold value being greater than 0;

in the event that the TTL parameter of the received entry is less than the second threshold value, omitting storing the received entry in the DNS cache;

determining whether the time to live (TTL) parameter of the received entry is greater than a third threshold value, the third threshold value being greater than or equal to each of a first threshold value and the second threshold value; and

in the event that the TTL parameter of the received entry is greater than the third threshold value;

reducing the TTL parameter of the received entry to correspond to the third threshold value; and

storing the received entry with the reduced TTL parameter;

periodically performing a pre-fetch process on the plurality of entries stored in the DNS cache, wherein the performing of the pre-fetch process comprises;

for each of the plurality of entries, determining whether a TTL parameter associated with a corresponding entry stored in the DNS cache is below the first threshold value;

in the event that the TTL parameter associated with the corresponding entry stored in the DNS cache is below the first threshold value, marking the corresponding entry; and

for each marked entry, updating the each marked entry in the DNS cache, wherein the updated entry comprises an updated TTL value and an updated Internet Protocol (IP) address;

executing a packet processing engine of a host device to identify a DNS request; and

performing a DNS lookup in the DNS cache, wherein the performing of the pre-fetch process is separate from the performing of the DNS lookup; and

performing cache management on the DNS cache, comprising;

determining whether an entry in the DNS cache satisfies a least frequently used (LFU) algorithm; and

in the event that the entry satisfies the LFU algorithm, removing the entry from the DNS cache, wherein a TTL of each entry in the DNS cache is less than or equal to the third threshold value.