Cleanup and refactorings

[hulthe]

Fixing and refactorings of things I've encountered to hopefully make nftnl better

---

This change is 

[MarkusPettersson98]

@MarkusPettersson98 reviewed 14 of 24 files at r1, 2 of 3 files at r2, all commit messages.
Reviewable status: 16 of 24 files reviewed, 2 unresolved discussions (waiting on @hulthe)

---

nftnl/src/table.rs line 27 at r2 (raw file):

    /// Creates a new table instance with the given name and protocol family.
    pub fn new<T: AsRef<CStr>>(name: T, family: ProtoFamily) -> Table {
        let table = unsafe { try_alloc!(sys::nftnl_table_alloc()) };

Very minor nit: The unsafe scope could be kept down by moving it inside of the try_alloc! invocation. This is done in some places already, and not in other places.

Code quote:

let table = unsafe { try_alloc!(sys::nftnl_table_alloc()) };

---

nftnl/src/expr/counter.rs line 12 at r2 (raw file):

impl Expression for Counter {
    fn to_expr(&self, _rule: &Rule) -> ptr::NonNull<sys::nftnl_expr> {
        try_alloc!(unsafe { sys::nftnl_expr_alloc(c"counter".as_ptr()) })

Like here!

Code quote:

try_alloc!(unsafe { sys::nftnl_expr_alloc(c"counter".as_ptr()) })

[MarkusPettersson98]

🙌

@MarkusPettersson98 reviewed 7 of 24 files at r1, 1 of 3 files at r2.
Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @hulthe)

---

nftnl/examples/add-rules.rs line 195 at r2 (raw file):

    socket.send_all(batch)?;

    // TODO: this buffer must be aligned to nlmsghdr

TODO

Code quote:

// TODO: this buffer must be aligned to nlmsghdr

[hulthe]

Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @MarkusPettersson98 and @Serock3)

---

nftnl/src/table.rs line 27 at r2 (raw file):

Previously, MarkusPettersson98 (Markus Pettersson) wrote…

Very minor nit: The unsafe scope could be kept down by moving it inside of the try_alloc! invocation. This is done in some places already, and not in other places.

Done

[MarkusPettersson98]

@MarkusPettersson98 reviewed 2 of 2 files at r3, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @Serock3)

[MarkusPettersson98]

@MarkusPettersson98 reviewed 5 of 5 files at r4, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @Serock3)