samuong
commented
4 months ago For some reason I closed this when #105 was merged, which was a mistake. That PR was about listening on a local IPv6 port, whereas this issue is about supporting IPv6-aware functions for PAC scripts to call.
As of #123, it is now possible for myIpAddress() to return an IPv6 address. If Alpaca isn't consistent about this, it might break PAC scripts that expect an IPv4 address (e.g. myIpAddress() returns an IPv6 address but the script passes the result to isInNet() rather than isInNetEx()). This should be considered before the next release.
Some references:
- Microsoft's IPv6 Extensions to Navigator Auto-Config File Format: https://learn.microsoft.com/en-us/windows/win32/winhttp/ipv6-extensions-to-navigator-auto-config-file-format
- A table from the Chromium source code showing IPv6 support in Firefox 3, Internet Explorer 8 and Chrome: https://source.chromium.org/chromium/chromium/src/+/main:services/proxy_resolver/proxy_resolver_v8.cc;l=75-86;drc=8788592a9d2efcececd4f8cfacc174671b265ad2
The PAC "standard" as defined by Netscape includes a few functions that assume IPv4, so Alpaca currently only supports IPv4.
Microsoft has a few extensions which work better for IPv6 and Google has implemented some of these functions into Chrome (although they make these functions available in the regular
FindProxyForURLfunction, rather than just scoping it toFindProxyForURLEx). These includednsResolveEx()andmyIpAddressEx(), and they both replace functions that return IPv4 addresses only with functions that could return either (or both).There are also other functions that accept IPv4 addresses, and should be extended to accept IPv6 addresses as well. These include
isResolvable()andisInNet().The only remaining function is
convert_addr(). There doesn't appear to be an IPv6 version in Mozilla, Microsoft or Google's implementations, and it doesn't make sense for Alpaca to implement its own extension to the standard, so I'll leave this as it is.