Module netlink 

Rust netlink helpers that replace shell-outs to ip/nsenter/sysctl for per-container overlay network setup.

This module is populated incrementally through a phased migration. Stage 1: move_link_into_netns_and_rename replaces the shell pair ip link set <name> netns <pid> + nsenter -t <pid> -n ip link set <name> name <new> with a single atomic RTNETLINK SetLink carrying both IFLA_NET_NS_FD and IFLA_IFNAME. This bypasses the /proc/<pid>/ns/net access problem caused by libcontainer setting PR_SET_DUMPABLE(false) on the container init process under SELinux enforcing. Stage 2: create_veth_pair, delete_link_by_name, and set_link_up_by_name replace the host-side veth shell commands (ip link add ... type veth peer name ..., ip link delete ..., ip link set ... up) used by overlay_manager::attach_to_interface and the orphan sweeper. These helpers talk RTNETLINK directly via the rtnetlink crate (async, tokio-backed). Stage 3: with_netns, add_address_to_link_by_name, and add_default_route_via_dev replace the remaining container-netns shell-outs in overlay_manager::attach_to_interface. with_netns runs a closure on a dedicated OS thread that has joined the target container’s network namespace via setns(2), while the two new RTNETLINK helpers operate on the current netns (so they must be invoked from inside a with_netns closure). This removes the last three nsenter -t <pid> -n ip ... shell-outs used to assign the container IP, bring eth0 / lo up, and add the default route.

Enums

NetlinkError

Errors returned by the netlink helpers in this module.

Functions

add_address_to_link_by_name

Add an IP address to the link identified by name in the current network namespace.

add_default_route_via_dev

Add a default route via the given device name in the current network namespace.

create_veth_pair

Create a veth pair with the two ends named host_name and peer_name.

delete_link_by_name

Delete the link by name. Idempotent: returns Ok(()) if the link does not exist. Any other error surfaces as NetlinkError::Netlink.

list_all_links

List all network interfaces in the current netns.

move_link_into_netns_and_rename

Move a link from the current network namespace into the target PID’s network namespace, renaming it in the same atomic operation.

move_link_into_netns_fd_and_rename

Stub for non-Linux Unix platforms (macOS/BSD) and for Linux builds without the youki-runtime feature (which provides the libcontainer-backed impl).

replace_route_via_dev

Add or replace a route to dest/prefix_len that forwards via the interface named dev_name. Optional src sets the preferred source address.

set_link_up_by_name

Set the link identified by name to the “up” administrative state.

set_sysctl

Set a sysctl via the /proc/sys/... filesystem.

with_netns

Run a synchronous closure inside the network namespace of the given PID.

with_netns_async

Convenience wrapper around with_netns that builds a local current-thread tokio runtime inside the dedicated thread and drives the provided async future to completion.

with_netns_fd

Run a synchronous closure inside the network namespace referenced by the given OwnedFd.

with_netns_fd_async

Convenience wrapper around with_netns_fd that builds a local current-thread tokio runtime inside the dedicated thread and drives the provided async future to completion.