File

net/resolvers/chain.lua @ 13461:c673ff1075bd

mod_posix: Move everything to util.startup This allows greater control over the order of events. Notably, the internal ordering between daemonization, initialization of libunbound and setup of signal handling is sensitive. libunbound starts a separate thread for processing DNS requests. If this thread is started before signal handling has been set up, it will not inherit the signal handlers and instead behave as it would have before signal handlers were set up, i.e. cause the whole process to immediately exit. libunbound is usually initialized on the first DNS request, usually triggered by an outgoing s2s connection attempt. If daemonization happens before signals have been set up, signals may not be processed at all.
author Kim Alvefur <zash@zash.se>
date Sat, 23 Mar 2024 20:48:19 +0100
parent 12204:7c397a49d163
line wrap: on
line source


local methods = {};
local resolver_mt = { __index = methods };

-- Find the next target to connect to, and
-- pass it to cb()
function methods:next(cb)
	if self.resolvers then
		if not self.resolver then
			if #self.resolvers == 0 then
				cb(nil);
				return;
			end
			local next_resolver = table.remove(self.resolvers, 1);
			self.resolver = next_resolver;
		end
		self.resolver:next(function (...)
			if self.resolver then
				self.last_error = self.resolver.last_error;
			end
			if ... == nil then
				self.resolver = nil;
				self:next(cb);
			else
				cb(...);
			end
		end);
		return;
	end
end

local function new(resolvers)
	return setmetatable({ resolvers = resolvers }, resolver_mt);
end

return {
	new = new;
};