* fix(dns): resolve CNAME chains and prevent invalid IP parsing
- Add automated in-band CNAME chain resolution to extract final A/AAAA IP addresses.
- Replace `MaxResponseAnswers` with `MaxIPs` and `MaxCNAMEs` to explicitly bound resource decoding and prevent memory exhaustion.
- Bound CNAME chain traversal to prevent infinite loops from cyclic records.
* refactor(dns): eagerly decode CNAME target into r.data, drop target field
Address review feedback on #189:
- Remove Resource.target: Resource.Decode expands CNAME RDATA in place
into r.data (uncompressed wire format) while the full message is still
available and updates header.Length, storing the name bytes exactly once.
- Add Resource.CNAMEView returning a length-bounded view of the expanded
target; Message.WriteAnswers uses it.
- Rename matchesHost to ResourceHeader.pertainsTo.
- Make ResolveConfig.MaxCNAMEs explicit: drop the silent default in
Client.StartResolve and let callers opt in (x/xnet).
- Reduce test suite to regression coverage only.
refs #189
* dns: simplify @hnw function and additional fixes
---------
Co-authored-by: Yoshio HANAWA <y@hnw.jp>
* fix(dns): decode up to four answer records
A single DNS question can return multiple answer records. Use an answer
decode limit of four in Client.StartResolve and add a regression test
covering a single-question response with multiple A records.
* fix(dns): add MaxResponseAnswers to ResolveConfig
This allows callers to explicitly declare the maximum number of answer
records to retain, removing the hardcoded limit in Client.StartResolve.
xnet.StackAsync is updated to set this limit to match the length of its
lookup-result buffer. This maintains the zero-allocation design while
fixing the issue where multiple A records were ignored.
* add ipv6 to xnet.StackAsync
* dns improvements
* improve DNS workings of StackAsync
* add tentative ICMPv6
* work on prefixes and fix some small bugs, plan UDP/TCP6
* fix bugs in StackAsync and ipv4.Prefix.Contains
* update arpsubtable
* completely remove legacy internet.StackIP for StackIPv4/v6
* ipv4/ipv6 tcp/udp
* add TCP6/UDP6 dialing APIs
* add xnet.Stack6 interface
* more ipv6 integration into StackAsync; various tweaks to lneto and documentation+TODOs
* add stack6 tests
* replace netip.Prefix with ipv4.Prefix where it makes sense
* do not rely on unspecified Go behaviour; fix TCP ring buffer bug
* even more stricter error handling on tcp connections
* stricter lock copying in tcp.Conn, even though likely not a problem
* add listener and tcp pool logging
* forgot reqAddr unused
* add logging to TCPConn and friends
Pat Whittingslow
Yoshio HANAWA
Marvin Drees