Refactors test setup and teardown logic to use `t.Cleanup` instead
of `defer`. This ensures that cleanup functions are correctly scoped
to each subtest's lifecycle, improving test isolation and reliability.
The `setUpNetlinkTest` helper function is also improved to correctly
save and restore the original network namespace, ensuring that tests
do not leak state.
To support this, a `Close()` method that returns an error is added to
the `Handle` struct, allowing for proper cleanup of underlying netlink
sockets. The test helpers are updated to use this new method,
preventing resource leaks between tests.
Additionally, a bug in the `netns` tests is fixed where a large
namespace ID could overflow a 32-bit integer, causing spurious
failures on some systems.
Currently, it's cumbersome to get a link by an IP addr - one needs to
list all links and then call AddrList() for each of them.
Considering that ifindex is already available to to the parseAddr()
helper function, we can expose it to a user via the newly added
Addr.LinkIndex field. This makes the retrieving link by IP addr much
more simple.
Signed-off-by: Martynas Pumputis <m@lambda.lt>
From libnl addr.c comment:
IPv6 sends the local address as IFA_ADDRESS with no
IFA_LOCAL, IPv4 sends both IFA_LOCAL and IFA_ADDRESS
with IFA_ADDRESS being the peer address if they differ
But obviously, IPv6 sends IFA_LOCAL in case of PtP.
From iproute2 manual:
If a peer address is specified, the local address
cannot have a prefix length. The network prefix is
associated with the peer rather than with the local
address.
For link, address, route, add a `WithOptions` variant to the
`*Subscribe()` function to specify a namespace and an error
callback. Those options can be extended in the future without adding
more functions. For example, it could be possible to subscribe only
for a given family by adding a `Family` member to the appropriate
struct.
As a minor change, the private function is always suffixed by `At`,
since it was the case for route and raw netlink functions (but not for
address and link).
The go get command and make both fail when executed on
non-linux platforms. Modified it so that there are no
compilation errors when developing in such an
environment.
