STORAGE AND RETRIEVAL OF INFORMATION USING INTERNET PROTOCOL ADDRESSES
A method for storing information in a memory using an IP address having numerical fields, where penultimate and ultimate memory banks for the IP address are allocated from the memory. A penultimate pointer is stored in a location of the penultimate memory bank indexed by the value of a penultimate numerical field in the IP address. The penultimate pointer points to the ultimate memory bank. The information is stored in a location of the ultimate memory bank indexed by the value of an ultimate numerical field in the IP address.
1 . A method for storing information in a memory using an Internet Protocol (IP) address comprising a plurality of numerical fields, the method comprising:
(a) allocating, from the memory, a penultimate memory bank for the IP address;
(b) allocating, from the memory, an ultimate memory bank for the IP address;
(c) storing a penultimate pointer in a location of the penultimate memory bank indexed by the value of a penultimate numerical field in the IP address, wherein the penultimate pointer points to the ultimate memory bank; and
(d) storing the information in a location of the ultimate memory bank indexed by the value of an ultimate numerical field in the IP address.
2 . The method of claim 1 , further comprising:
(e) allocating, from the memory, an antepenultimate memory bank for the IP address; and
(f) storing an antepenultimate pointer in a location of the antepenultimate memory bank indexed by the value of an antepenultimate numerical field in the IP address, wherein the antepenultimate pointer points to the penultimate memory bank.
3 . The method of claim 1 , wherein the IP address is an IP version four (IPv4) address.
4 . The method of claim 1 , wherein step (a) comprises:
(a1) indexing into a location of an antepenultimate memory bank using the value of an antepenultimate numerical field of the IP address;
(a2) determining that an antepenultimate pointer is not stored in the location of the antepenultimate memory bank;
(a3) allocating the penultimate memory bank; and
(a4) storing, in the location of the antepenultimate memory bank, an antepenultimate pointer that points to the penultimate memory bank.
5 . The method of claim 1 , wherein step (b) comprises:
(b1) indexing into a location of the penultimate memory bank using the value of the penultimate numerical field of the IP address;
(b2) determining that a penultimate pointer is not stored in the location of the penultimate memory bank; and
(b3) allocating the ultimate memory bank.
6 . The method of claim 1 , wherein step (d) comprises:
(d1) indexing into the location of the ultimate memory bank using the value of the ultimate numerical field of the IP address; and
(d2) storing, in the location of the ultimate memory bank, the information.
7 . The method of claim 1 , wherein the information comprises one of (i) a pointer to an IPsec security association (SA) stored in memory and (ii) the IPsec SA.
8 . The method of claim 7 , wherein step (d) further comprises storing a security parameter index (SPI) in the location of the ultimate memory bank indexed by the value of the ultimate numerical field in the IP address.
9 . A security gateway comprising a memory for storing information using an Internet Protocol (IP) address comprising a plurality of numerical fields, the memory comprising:
a penultimate memory bank for the IP address; and
an ultimate memory bank for the IP address, wherein:
the penultimate memory bank stores a penultimate pointer in a location of the penultimate memory bank indexed by the value of a penultimate numerical field in the IP address, wherein the penultimate pointer points to the ultimate memory bank; and
the ultimate memory bank stores the information in a location of the ultimate memory bank indexed by the value of an ultimate numerical field in the IP address.
10 . The security gateway of claim 9 , further comprising a controller configured to:
(a) allocate the penultimate memory bank;
(b) allocate the ultimate memory bank;
(c) store the penultimate pointer in the location of the penultimate memory bank indexed by the value of the penultimate numerical field in the IP address; and
(d) store the information in the location of the ultimate memory bank indexed by the value of the ultimate numerical field in the IP address.
11 . The security gateway of claim 10 , wherein the controller is further configured to:
(e) index into the penultimate memory bank using the value of the penultimate numerical field in the IP address to obtain the penultimate pointer stored in the penultimate memory bank;
(f) follow the penultimate pointer to the ultimate memory bank;
(g) index into the ultimate memory bank using the value of the ultimate numerical field in the IP address to retrieve the information stored in the ultimate memory bank.
12 . The security gateway of claim 9 , further comprising a controller configured to:
(a) index into the penultimate memory bank using the value of the penultimate numerical field in the IP address to obtain the penultimate pointer stored in the penultimate memory bank;
(b) follow the penultimate pointer to the ultimate memory bank;
(c) index into the ultimate memory bank using the value of the ultimate numerical field in the IP address to retrieve the information stored in the ultimate memory bank.
13 . The security gateway of claim 9 , further comprising an antepenultimate memory bank that stores an antepenultimate pointer in a location of the antepenultimate memory bank indexed by the value of an antepenultimate numerical field in the IP address, wherein the antepenultimate pointer points to the penultimate memory bank.
14 . The security gateway of claim 9 , wherein the information comprises one of (i) a pointer to an IPsec security association (SA) stored in memory and (ii) the IPsec SA.
15 . The security gateway of claim 14 , wherein:
the ultimate memory bank stores a security parameter index (SPI) in the location of the ultimate memory bank indexed by the value of the ultimate numerical field in the IP address; and
the security gateway comprises a controller configured to compare the stored SPI to an SPI provided by an administrator.
16 . A method for retrieving information in a memory using an Internet Protocol (IP) address comprising a plurality of numerical fields, wherein the memory comprises a penultimate memory bank for the IP address and an ultimate memory bank for the IP address, the method comprising:
(a) indexing into the penultimate memory bank using the value of a penultimate numerical field in the IP address to obtain a penultimate pointer stored in the penultimate memory bank, wherein the penultimate pointer points to the ultimate memory bank;
(b) following the penultimate pointer to the ultimate memory bank;
(c) indexing into the ultimate memory bank using the value of an ultimate numerical field in the IP address to retrieve the information stored in the ultimate memory bank.
17 . The method of claim 16 , wherein:
the memory further comprises an antepenultimate memory bank for the IP address; and
the method comprises, before step (a):
(1) indexing into the antepenultimate memory bank using the value of an antepenultimate numerical field in the IP address to obtain an antepenultimate pointer stored in the antepenultimate memory bank, wherein the antepenultimate pointer points to the penultimate memory bank; and
(2) following the antepenultimate pointer to the penultimate memory bank.
18 . The method of claim 16 , wherein the IP address is an IP version four (IPv4) address.
19 . The method of claim 16 , wherein the information comprises one of (i) a pointer to an IPsec security association (SA) stored in memory and (ii) the IPsec SA.
20 . The method of claim 19 , wherein:
step (c) further comprises retrieving a security parameter index (SPI) stored in the ultimate memory bank; and
the method further comprises (d) comparing the stored SPI to an SPI provided by an administrator.