* 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>
* begin adding icmp client
* rely on anon structs
* add tests
* tests passing
* icmp fleshed out
* rework icmp to include ip addr
* rename StackAsync.Demux/Encapsulate to RecvEthernet and SendEthernet
* remove legacy unreachable TCP tests
* remove uses of deprecated internet.StackNode in preference of lneto.StackNode
* documentation
* rename methods to signal no I/O happening
* reduce heap allocations in tcp logging; omit use of AppendFloat which allocates a metric sh*tton
* debugheaplog: better heap statistic logging
* heap: use string for pcap.Frame.Protocol
* add potential to eliminate Flags.String heap alloc, remove incorrect HEAP comments
* add StackAsync.DebugErr and httpraw.SetBytes
* many heap alloc reductions and replacement of bytes.Equal with internal.BytesEqual
* pcap: reuse Frame memory
* slog: reduce heap allocations of addresses; also prevent heap alloc of dhcp options in pcap
* dns: heapless improvement; add StackAsync buffer for more heapless operation; start thinking of errors
* reuse function for reclaiming frames among all protocols for lower memory usage
* remove extraneous code
* 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
Marvin Drees