Network Address Functions and Operators

openGauss provides network-related functions.

is_ipv4(string)

Description: Determines whether an IPv4 address is used.

Return type: int

Example:

openGauss=# select is_ipv4('192.168.0.1');
 is_ipv4
---------
       1
(1 row)
openGauss=# select is_ipv4('192.168.0.1'::inet);
 is_ipv4
---------
       1
(1 row)

is_ipv6(string)

Description: Determines whether an IPv6 address is used.

Return type: int

Example:

openGauss=# select is_ipv6('2403:A200:A200:0:AFFF::3');
 is_ipv6
---------
       1
(1 row)
openGauss=# select is_ipv6('2403:A200:A200:0:AFFF::3'::inet);
 is_ipv6
---------
       1
(1 row)

inet_aton(text)
Description: This function takes the dotted decimal notation of an IPv4 address as a string and returns the value of the given IP address as an integer. If the input address is not a valid IPv4 address or an unrecognized expression, this function returns NULL.
Return type: int
Example:
```
openGauss=# SELECT INET_ATON('10.0.5.9');
 inet_aton
-----------
 167773449
 (1 row)
```
inet_ntoa(int)
Description: Converts an integer network host address in network byte order into a string in dotted decimal notation (for example, 127.0.0.1). If the input integer cannot be converted to a valid address, this function returns NULL.
Return type: text
Example:
```
openGauss=# SELECT INET_NTOA(167773449);
 inet_ntoa
-----------
 10.0.5.9
(1 row)
```
inet6_aton(text)
Description: This function takes the given IPv6 or IPv4 network address as a string and returns a binary string representing the numeric value of the network byte order (big-endian) address. Because an IPv6 address in numeric format requires more bytes than the maximum integer type, the value returned by this function has two lengths:
1. The length of the returned character string for an IPv6 address is 16 characters.
2. The length of the returned character string for an IPv4 address is 4 characters.
  If the parameter is not a valid address or is NULL, INET6_ATON() returns NULL.
Return type: bytea
Example:
```
openGauss=# SELECT HEX(INET6_ATON('fdfe::5a55:caff:fefa:9089'));
              hex
----------------------------------
 FDFE0000000000005A55CAFFFEFA9089
(1 row)
 openGauss=# SELECT HEX(INET6_ATON('10.0.5.9'));
   hex
----------
 0A000509
(1 row)
```
inet6_ntoa(bytea)
Description: This function in MySQL returns the given IPv6 or IPv4 network address represented as a binary string in numeric format as a delimiter-separated string. If the parameter is not a valid address or it is NULL, INET6_NTOA() returns NULL.
Return type: text
Example:
```
openGauss=# SELECT INET6_NTOA(INET6_ATON('fdfe::5a55:caff:fefa:9089'));
 inet6_ntoa
---------------------------
fdfe::5a55:caff:fefa:9089
(1 row)
openGauss=# SELECT INET6_NTOA(INET6_ATON('10.0.5.9'));
 inet6_ntoa
------------
 10.0.5.9
(1 row)
```
is_ipv4_compat(bytea)
Description: This function accepts an IPv6 address of a binary string represented as a number, as returned by INET6_ATON(). If the parameter is a valid IPv4-compatible IPv6 address, 1 is returned. Otherwise, 0 is returned. The format of an IPv4-compatible address is ::ipv4_address.
Return type: int
Example:
```
openGauss=# SELECT IS_IPV4_COMPAT(INET6_ATON('::10.0.5.9'));
 is_ipv4_compat 
----------------
              1
(1 row)
openGauss=# SELECT IS_IPV4_COMPAT(INET6_ATON('::ffff:10.0.5.9'));
 is_ipv4_compat 
----------------
              0
(1 row)
```
is_ipv4_mapped(bytea)
Description: This function accepts an IPv6 address of a binary string represented as a number, as returned by INET6_ATON(). If the parameter is a valid IPv4-mapped IPv6 address, 1 is returned. Otherwise, 0 is returned. The IPv4-mapped address format is ::ffff:ipv4_address.
Return type: int
Example:
```
openGauss=# SELECT IS_IPV4_MAPPED(INET6_ATON('::10.0.5.9'));
 is_ipv4_mapped 
----------------
              0
(1 row)

openGauss=# SELECT IS_IPV4_MAPPED(INET6_ATON('::ffff:10.0.5.9'));
 is_ipv4_mapped 
----------------
              1
(1 row)
```