fix: enable dual-stack IPv4/IPv6 listening on Linux

[milestone-17]

Summary

Fixes #1185

Linux下绑定IPv6地址(如::)时，由于两个原因导致IPv4客户端连不上：

1. getaddrinfo解析字面量IP在不同glibc版本/容器环境下结果不稳定（AI_ADDRCONFIG标志的影响）
2. 没有显式设置IPV6_V6ONLY=false，在net.ipv6.bindv6only=1的环境下IPv6 socket拒绝IPv4连接

Changes

• 新建 include/ylt/coro_io/listen_endpoint.hpp，提取公共的地址解析和dual-stack设置逻辑
  • resolve_listen_endpoint()：字面量IP用make_address直接解析，hostname才走resolver
  • set_ipv6_only_false()：IPv6 endpoint时关闭v6_only，失败只warn不abort
• server_acceptor.hpp 和 coro_http_server.hpp 改为调用上述公共函数，消除重复代码

Testing

Windows MSVC 14.50 本地全量回归：

Test Suite	Cases	Assertions	Result
coro_io_test	40	1,171,517	PASS
coro_http_test	121	108,657	PASS
coro_rpc_test	41	200,315	PASS
easylog_test	9	28	PASS
metric_test	44	461	PASS

[CLAassistant]

All committers have signed the CLA.

[github-actions]

for detail, goto summary download Artifacts base-ylt-cov-report(base commit coverage report) and ylt-cov-report(current pull request coverage report)

[milestone-17]

Hi @qicosmos, thanks for maintaining this great project!

I've addressed the CLA issue and all CI checks are passing now. Would you have a chance to review this PR when convenient? No rush at all — just wanted to make sure it's on your radar.

Happy to make any changes if needed. Thanks!

[qicosmos]

Hi @qicosmos, thanks for maintaining this great project!

I've addressed the CLA issue and all CI checks are passing now. Would you have a chance to review this PR when convenient? No rush at all — just wanted to make sure it's on your radar.

Happy to make any changes if needed. Thanks!

Thanks for your PR, i will review it later.

[qicosmos]

建议新增文件，消除重复代码：

  // include/ylt/coro_io/listen_endpoint.hpp
  #pragma once

  #include <cstdint>
  #include <optional>
  #include <string>

  #include "asio/error_code.hpp"
  #include "asio/ip/address.hpp"
  #include "asio/ip/tcp.hpp"
  #include "asio/ip/v6_only.hpp"

  namespace coro_io::detail {

  template <typename Executor>
  inline std::optional<asio::ip::tcp::endpoint>
  resolve_listen_endpoint(
      const Executor& executor, const std::string& address, uint16_t port,
      asio::error_code& ec) {
    using asio::ip::tcp;

    auto addr = asio::ip::make_address(address, ec);
    if (!ec) {
      return tcp::endpoint(addr, port);
    }

    ec.clear();
    tcp::resolver resolver(executor);
    auto it = resolver.resolve(
        tcp::resolver::query(address, std::to_string(port)), ec);
    if (ec || it == tcp::resolver::iterator{}) {
      return std::nullopt;
    }

    return it->endpoint();
  }

  inline asio::error_code set_ipv6_only_false(
      asio::ip::tcp::acceptor& acceptor,
      const asio::ip::tcp::endpoint& endpoint) {
    asio::error_code ec;
    if (endpoint.protocol() == asio::ip::tcp::v6()) {
      acceptor.set_option(asio::ip::v6_only(false), ec);
    }
    return ec;
  }

  }  // namespace coro_io::detail

server_acceptor.hpp 里：

  #include "listen_endpoint.hpp"

  //然后 listen 里替换成：

  auto endpoint = detail::resolve_listen_endpoint(
      acceptor_->get_executor(), address_, port_, ec);
  if (!endpoint) {
    ELOG_ERROR << "resolve address " << address_
               << " error: " << ec.message();
    return listen_errc::bad_address;
  }

  acceptor_->open(endpoint->protocol(), ec);
  if (ec) {
    ELOG_ERROR << "open failed, error: " << ec.message();
    return listen_errc::open_error;
  }

  #ifdef __GNUC__
  acceptor_->set_option(tcp::acceptor::reuse_address(true), ec);
  #endif

  if (auto opt_ec =
  detail::set_ipv6_only_false(*acceptor_, *endpoint); opt_ec) {
    ELOG_WARN << "set v6_only(false) failed: " << opt_ec.message();
  }

  acceptor_->bind(*endpoint, ec);

coro_http_server.hpp 里：

  #include "ylt/coro_io/listen_endpoint.hpp"

  // 然后 listen 里替换成：

  auto endpoint =
  coro_io::detail::resolve_listen_endpoint(
      acceptor_.get_executor(), address_, port_, ec);
  if (!endpoint) {
    CINATRA_LOG_ERROR << "invalid address: " << address_
                      << " error: " << ec.message();
    if (ec) {
      return ec;
    }
    return std::make_error_code(std::errc::address_not_available);
  }

  acceptor_.open(endpoint->protocol(), ec);
  if (ec) {
    CINATRA_LOG_ERROR << "acceptor open failed"
                      << " error: " << ec.message();
    return ec;
  }

  #ifdef __GNUC__
  acceptor_.set_option(tcp::acceptor::reuse_address(true), ec);
  #endif

  if (auto opt_ec =
  coro_io::detail::set_ipv6_only_false(acceptor_, *endpoint);
      opt_ec) {
    CINATRA_LOG_WARNING << "set v6_only(false) failed:" << opt_ec.message();
  }

  acceptor_.bind(*endpoint, ec);

同时可以删掉两个原文件里直接引入的 asio/ip/ v6_only.hpp 和 asio/ip/address.hpp，因为都在listen_endpoint.hpp 了。这样解析 endpoint 和设置v6_only(false) 都集中，错误日志和返回策略仍然留在各自模块里。

[milestone-17]

OK,谢谢你的提醒,这是我的疏忽,我现在做出相应的修改

[milestone-17]

Done. I extracted resolve_listen_endpoint() and set_ipv6_only_false() into include/ylt/coro_io/listen_endpoint.hpp, and both server_acceptor.hpp and coro_http_server.hpp now call into it instead of duplicating the logic.

Tested locally on MSVC -- all existing test suites pass without regression.

[qicosmos]

LGTM

[github-actions]

for detail, goto summary download Artifacts base-ylt-cov-report(base commit coverage report) and ylt-cov-report(current pull request coverage report)

[milestone-17]

CI workflows are waiting for approval to run. Could you approve them when you get a chance? Thanks.@qicosmos

[poor-circle]

CI workflows are waiting for approval to run. Could you approve them when you get a chance? Thanks.@qicosmos

done

[github-actions]

for detail, goto summary download Artifacts base-ylt-cov-report(base commit coverage report) and ylt-cov-report(current pull request coverage report)

[github-actions]

for detail, goto summary download Artifacts base-ylt-cov-report(base commit coverage report) and ylt-cov-report(current pull request coverage report)

[milestone-17]

All checks should be green once CI is approved. Ready to merge from my side — let me know if anything else needs to be changed.