fix(proxy): added family hint for new_udp_socket

[ibigbug]

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• New feature
• Bug fix
• Performance optimization
• Enhancement feature
• Refactoring
• Code style optimization
• Test Case
• Branch merge
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🔗 Related issue link

💡 Background and solution

best effort to create proper family of socket for UDP connections

📝 Changelog

☑️ Self-Check before Merge

⚠️ Please check all items below before requesting a reviewing. ⚠️

• Doc is updated/provided or not needed
• Changelog is provided or not needed

[Copilot]

Pull Request Overview

This PR adds an optional family_hint parameter to new_udp_socket so callers can explicitly specify the socket address family, and updates all existing call sites to pass either a computed hint or None. It also refactors binding logic in TUN creation, adjusts DNS runtime UDP binding, and makes the Cargo doc package opt out of default features.

• Extend new_udp_socket signature with family_hint and incorporate it into domain selection.
• Update all proxy modules, DNS runtime, and DHCP to supply or default the new family_hint.
• Refactor TUN builder to avoid double build_async calls and tighten Cargo features in clash-doc.

Reviewed Changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
proxy/utils/socket_helpers.rs	Added family_hint to choose socket domain; switched android guard to runtime cfg!.
proxy/utils/proxy_connector.rs	Changed _destination to destination and passed its address as family_hint.
proxy/tun/inbound.rs	Cached tun_builder.build_async() into dev to prevent duplicate builds.
proxy/tuic/types.rs	Passed server.ip as family_hint for TUIC endpoints.
proxy/tuic/mod.rs	Temporarily passed None for family_hint; added TODO.
proxy/socks/outbound/mod.rs	Passed bind address as family_hint for SOCKS outbound.
proxy/socks/inbound/stream.rs	Added None placeholder for new family_hint parameter.
proxy/shadowsocks/inbound/mod.rs	Added None placeholder for new family_hint parameter.
proxy/shadowquic/mod.rs	Replaced manual bind-addr parsing with None src and Some(addr) hint.
proxy/hysteria2/mod.rs	Replaced src hint with server_socket_addr hint.
proxy/direct/mod.rs	Imported and used family_hint_for_session to compute hint.
app/dns/runtime.rs	Renamed _server_addr to server_addr and passed it as hint.
app/dns/resolver/enhanced.rs	Simplified error logging in DNS client error path.
app/dns/dhcp.rs	Added None placeholder for new family_hint in DHCP listener.
clash-doc/Cargo.toml	Disabled default features for clash-lib in the docs package.

Comments suppressed due to low confidence (3)

clash-lib/src/proxy/utils/socket_helpers.rs:94

• [nitpick] The parameter family_hint holds a full SocketAddr, which may be misleading since only the address family is used. Consider renaming it to addr_hint or socket_hint for clearer intent.

    family_hint: Option<std::net::SocketAddr>,

clash-lib/src/proxy/utils/socket_helpers.rs:91

• [nitpick] Clarify in this comment that only the IP component of the SocketAddr is used to derive the socket domain and that the port number is ignored when selecting the family.

    // Optional family hint for the socket.

clash-lib/src/proxy/utils/socket_helpers.rs:146

• Switching from a compile-time #[cfg(not(target_os = "android"))] to a runtime if !cfg!(...) means the must_bind_socket_on_interface import is omitted on Android but its calls are still compiled, causing build errors. Use a compile-time #[cfg] on the block or import the function unconditionally and keep a runtime guard inside.

    if !cfg!(target_os = "android") {

[codecov]

Codecov Report

Attention: Patch coverage is 40.69767% with 51 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
clash-lib/src/proxy/utils/socket_helpers.rs	27.45%	34 Missing and 3 partials ⚠️
clash-lib/src/proxy/tuic/types.rs	0.00%	3 Missing ⚠️
clash-lib/src/proxy/utils/platform/unix.rs	57.14%	2 Missing and 1 partial ⚠️
clash-lib/src/proxy/direct/mod.rs	0.00%	2 Missing ⚠️
clash-lib/src/proxy/tun/inbound.rs	0.00%	2 Missing ⚠️
clash-lib/src/app/dns/dhcp.rs	0.00%	1 Missing ⚠️
clash-lib/src/app/dns/resolver/enhanced.rs	0.00%	1 Missing ⚠️
clash-lib/src/proxy/shadowquic/mod.rs	87.50%	0 Missing and 1 partial ⚠️
clash-lib/src/proxy/tuic/mod.rs	50.00%	1 Missing ⚠️

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