rustnet-host

Host-OS integration layer for RustNet: the metadata about a connection that only the operating system / kernel can tell us, behind one trait per concern.

Today this is per-connection process attribution — given a rustnet_core Connection, find the owning process (pid + name) — using the best strategy each platform offers, with graceful fallbacks:

• Linux — eBPF socket tracking (with the ebpf feature) and a procfs fallback.
• macOS — PKTAP packet metadata when available (no lookup needed), else lsof.
• Windows — the IP Helper API (GetExtendedTcpTable / ...UdpTable).
• FreeBSD — sockstat.

use rustnet_host::create_process_lookup;

let lookup = create_process_lookup(/* use_pktap = */ false)?;
if let Some((pid, name)) = lookup.get_process_for_connection(&conn) {
    println!("{conn:?} owned by {name} ({pid})");
}

When a platform can't use its optimal method, ProcessLookup::get_degradation_reason reports why (e.g. missing CAP_BPF, no root for PKTAP) via DegradationReason, which front-ends can surface to the user.

Scope

The crate is named rustnet-host rather than rustnet-process on purpose: it's the home for all host/kernel-derived connection metadata. Process ownership is the first inhabitant; kernel TCP/UDP counters, socket states, and cgroup/container info are natural future additions that share the same eBPF and OS-query machinery.

It depends only on rustnet-core (for Connection/Protocol); it does not depend on rustnet-capture. On macOS the application injects whether PKTAP is active rather than this crate querying capture. No UI or capture-loop dependency, so headless tools can attribute processes the same way the rustnet TUI does.

License

Apache-2.0