Fix: FreeBSD Building

[splurge103]

This pull request will fix this building errors on FreeBSD 14:

$> cargo build --features local-redir,local-socks4

Compiling shadowsocks-service v1.18.5 (shadowsocks-rust/crates/shadowsocks-service)
error[E0432]: unresolved import `super::pfvar::pfsync_state`
  --> crates/shadowsocks-service/src/local/redir/sys/unix/bsd_pf.rs:22:5
   |
22 |     pfsync_state,
   |     ^^^^^^^^^^^^
   |     |
   |     no `pfsync_state` in `local::redir::sys::unix::pfvar`
   |     help: a similar name exists in the module: `pfioc_state`

error[E0405]: cannot find trait `UdpSocketRedir` in this scope
   --> crates/shadowsocks-service/src/local/redir/udprelay/sys/unix/bsd.rs:147:6
    |
147 | impl UdpSocketRedir for UdpRedirSocket {
    |      ^^^^^^^^^^^^^^
    |
   ::: crates/shadowsocks-service/src/local/redir/redir_ext.rs:49:1
    |
49  | pub trait UdpSocketRedirExt {
    | --------------------------- similarly named trait `UdpSocketRedirExt` defined here
    |
help: a trait with a similar name exists
    |
147 | impl UdpSocketRedirExt for UdpRedirSocket {
    |      ~~~~~~~~~~~~~~~~~
help: consider importing this trait
    |
1   + use crate::local::redir::redir_ext::UdpSocketRedir;
    |

error[E0425]: cannot find value `enable` in this scope
   --> crates/shadowsocks-service/src/local/redir/udprelay/sys/unix/bsd.rs:287:14
    |
287 |             &enable as *const _ as *const _,
    |              ^^^^^^ not found in this scope

error[E0425]: cannot find value `enable` in this scope
   --> crates/shadowsocks-service/src/local/redir/udprelay/sys/unix/bsd.rs:288:31
    |
288 |             mem::size_of_val(&enable) as libc::socklen_t,
    |                               ^^^^^^ not found in this scope

warning: unused import: `async_trait::async_trait`
  --> crates/shadowsocks-service/src/local/redir/udprelay/sys/unix/bsd.rs:10:5
   |
10 | use async_trait::async_trait;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `#[warn(unused_imports)]` on by default

warning: unused import: `UdpSocketRedirExt`
  --> crates/shadowsocks-service/src/local/redir/udprelay/sys/unix/bsd.rs:21:38
   |
21 |         redir_ext::{RedirSocketOpts, UdpSocketRedirExt},
   |                                      ^^^^^^^^^^^^^^^^^

error[E0599]: the method `recv_dest_from` exists for struct `UdpRedirSocket`, but its trait bounds were not satisfied
   --> crates/shadowsocks-service/src/local/redir/udprelay/mod.rs:294:45
    |
294 |                 recv_result = self.listener.recv_dest_from(&mut pkt_buf) => {
    |                                             ^^^^^^^^^^^^^^ method cannot be called on `UdpRedirSocket` due to unsatisfied trait bounds
    |
   ::: crates/shadowsocks-service/src/local/redir/udprelay/sys/unix/bsd.rs:30:1
    |
30  | pub struct UdpRedirSocket {
    | ------------------------- method `recv_dest_from` not found for this struct because it doesn't satisfy `_: UdpSocketRedirExt` or `_: UdpSocketRedir`
    |
note: trait bound `redir::udprelay::sys::unix::bsd::UdpRedirSocket: UdpSocketRedir` was not satisfied
   --> crates/shadowsocks-service/src/local/redir/redir_ext.rs:58:42
    |
58  | impl<S> UdpSocketRedirExt for S where S: UdpSocketRedir {}
    |         -----------------     -          ^^^^^^^^^^^^^^ unsatisfied trait bound introduced here
note: the trait `UdpSocketRedir` must be implemented
   --> crates/shadowsocks-service/src/local/redir/redir_ext.rs:35:1
    |
35  | pub trait UdpSocketRedir {
    | ^^^^^^^^^^^^^^^^^^^^^^^^
    = help: items from traits can only be used if the trait is implemented and in scope
note: `UdpSocketRedirExt` defines an item `recv_dest_from`, perhaps you need to implement it
   --> crates/shadowsocks-service/src/local/redir/redir_ext.rs:49:1
    |
49  | pub trait UdpSocketRedirExt {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^

Some errors have detailed explanations: E0405, E0425, E0432, E0599.
For more information about an error, try `rustc --explain E0405`.
warning: `shadowsocks-service` (lib) generated 2 warnings
error: could not compile `shadowsocks-service` (lib) due to 5 previous errors; 2 warnings emitted

[zonyitoo]

FreeBSD should have PF, hmm, but pfsync_state has another name in bindgen: pfsync_state_1301. Hmm.... Ugly.

[splurge103]

FreeBSD should have PF, hmm, but pfsync_state has another name in bindgen: pfsync_state_1301. Hmm.... Ugly.

In FreeBSD situation:
For TCP in TcpStreamRedirExt code use PF.tcp_natlook
PF.tcp_natlook don't need in pfsync_state_1301, they use only pfioc_natlook
For UDP code in UdpSocketRedir dont use PF.udp_natlook, they use recv_dest_from
Please check my last commit

[zonyitoo]

Your commit breaks macOS build.

Please fix it. I'm Ok with the other changes.

[splurge103]

Your commit breaks macOS build.

Please fix it. I'm Ok with the other changes.

Already