On Tue, 26 Mar 2024 17:25:54 GMT, Sergey Chernyshev <[email protected]>
wrote:
> There are two distinct approaches to parsing IPv4 literal addresses. One is
> the Java baseline "strict" syntax (all-decimal d.d.d.d form family), another
> one is the "loose" syntax of RFC 6943 section 3.1.1 [1] (POSIX `inet_addr`
> allowing octal and hexadecimal forms [2]). The goal of this PR is to provide
> interface to construct InetAddress objects from literal addresses in POSIX
> form, to applications that need to mimic the behavior of `inet_addr` used by
> standard network utilities such as netcat/curl/wget and the majority of web
> browsers. At present time, there's no way to construct `InetAddress` object
> from such literal addresses because the existing APIs such as
> `InetAddress.getByName()`, `InetAddress#ofLiteral()` and
> `Inet4Address#ofLiteral()` will consume an address and successfully parse it
> as decimal, regardless of the octal prefix. Hence, the resulting object will
> point to a different IP address.
>
> Historically `InetAddress.getByName()/.getAllByName()` were the only way to
> convert a literal address into an InetAddress object. `getAllByName()` API
> relies on POSIX `getaddrinfo` / `inet_addr` which parses IP address segments
> with `strtoul` (accepts octal and hexadecimal bases).
>
> The fallback to `getaddrinfo` is undesirable as it may end up with network
> queries (blocking mode), if `inet_addr` rejects the input literal address.
> The Java standard explicitly says that
>
> "If a literal IP address is supplied, only the validity of the address format
> is checked."
>
> @AlekseiEfimov contributed JDK-8272215 [3] that adds new factory methods
> `.ofLiteral()` to `InetAddress` classes. Although the new API is not affected
> by the `getaddrinfo` fallback issue, it is not sufficient for an application
> that needs to interoperate with external tooling that follows POSIX standard.
> In the current state, `InetAddress#ofLiteral()` and
> `Inet4Address#ofLiteral()` will consume the input literal address and
> (regardless of the octal prefix) parse it as decimal numbers. Hence, it's not
> possible to reliably construct an `InetAddress` object from a literal address
> in POSIX form that would point to the desired host.
>
> It is proposed to extend the factory methods with
> `Inet4Address#ofPosixLiteral()` that allows parsing literal IP(v4) addresses
> in "loose" syntax, compatible with `inet_addr` POSIX api. The implementation
> is based on `.isBsdParsableV4()` method added along with JDK-8277608 [4]. The
> changes in the original algorithm are as follows:
>
> - `IPAddressUtil#parseBsdLiteralV4()` method is e...
src/java.base/share/classes/java/net/Inet4Address.java line 124:
> 122: * // the constructed address bytes without any rearrangement
> 123: * Inet4Address.ofPosixLiteral("017700000001"); // ==> /127.0.0.1
> 124: * }
Please move this part into the normative part of the `ofPosixLiteral` method
description
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/18493#discussion_r1557767839
