Documentation: Host sample updated for IPv4+IPv6.

[jboero]

Simple note in case anybody needs IPv6.

[cebtenzzre]

I think this addition would need to provide at least a little more context.

• 127.0.0.1 is the IPv4 localhost address, 0.0.0.0 is the IPv4 wildcard address.
• ::1 is the IPv6 localhost address.
• 'localhost' should resolve to both IPv4 and IPv6 addresses, on a properly configured system.
• :: is the IPv6 wildcard address, and its meaning depends on the OS - on Windows it binds to IPv6 only. On Linux it will also bind to IPv4 if sysctl net.ipv6.bindv6only is zero, which is usually the case. I'm not sure about macOS.

I think there would need to be a code change to reliably listen on both stacks on any OS. If configured correctly, providing the hostname of the local host instead of :: is probably sufficient - but I don't know how e.g. a Windows system will default to resolving its own hostname (e.g. it could give 127.0.0.1 instead of the local IPv4 address).

[jboero]

What change? Try it. It works on both stacks already. At least for me in Linux it works for both IPv4 and IPv6 as standard. That works for Go apps also. Oh I see what you mean now.

I agree it could use more context maybe but the functionality is there.

[cebtenzzre]

I ran into this today when trying to run the server tests (which assume the server is listening on IPv4). The root issue here is that in create_socket, httplib is calling getaddrinfo and then binding to only the first address family in the list, instead of creating a socket for each supported address family like many programs do.

[slaren]

The version of httplib that we are using is very outdated (0.12.2), there have been a lot of fixes since this version, including security issues. It should probably be updated.
https://github.com/yhirose/cpp-httplib/releases

[phymbert]

I think we should add an option to restrict the IP family in the bind socket flags in the server:

llama.cpp/examples/server/httplib.h

Lines 5901 to 5904 in ddf6568

	inline bool Server::bind_to_port(const std::string &host, int port,
	int socket_flags) {
	return bind_internal(host, port, socket_flags) >= 0;
	}

In:

https://github.com/ggerganov/llama.cpp/blob/master/examples/server/server.cpp#L2855-L2858

See:

• llama cpp server cant open to public #6268

[mofosyne]

Seems like these changes are already in the main branch. Obsolete PR?

(Btw, use https://docs.github.com/en/actions/managing-workflow-runs/skipping-workflow-runs to skip documentation only PR ci checks)