Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

To add extra statement to tcp/udp forward rule, example:

```
config ss_rules 'ss_rules'
    ...
    option nft_tcp_extra 'tcp dport { 80, 443 }' # tcp only forward connections with dport 80 or 443
    option nft_udp_extra 'udp dport { 53 }' # udp only forward connections with dport 53
```

This somewhat restores the old ipt_args functionality.

Signed-off-by: Zhong Jianxin <azuwis@gmail.com>
Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
(Amend README.md a bit)

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

It will be mostly implemented with ucode templates installed at
/usr/share/ss-rules and called from init script.  The generated nftables
rules will be stored at /etc/nftables.d/

Incompatible changes were introduced as described in the README.md file

 - Netfilter ipset was replaced with nftables sets
 - UCI options ipt_args and dst_forward_recentrst of section ss_rules
   are now deprecated.  The former does not apply to nftables.  The
   later not yet implemented with nftables.

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

Plugin options are properties of shadowsocks deployment as a whole,
including both server and each client components.  Multiple client
instances accessing the same server will need to share the same plugin
settings

With this change, plugin options will need to specified to "server" and
"ss-server" section, not to each component section.

Fixes: c19e949 ("shadowsocks-libev: add plugin options support")
Reference: https://github.com/openwrt/packages/issues/8903#issuecomment-489674137
Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

- New UCI options ifnames, dst_default
 - UCI options src_ips_xxx now accept cidr as their values
 - Export ipset names as part of the interface so that it can be
   depended on and used by other programs
 - Bypass only remote servers used ss-redir instances, so that it's
   possible to let other servers to go through existing re-redir
   instances

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

- Selecting only a single or subset of all components of shadowsocks-libev is
  now possible (this is the main motivation behind the rewrite)
- Configuring multiple instances of the same component is now also possible
- Same option names as with the json config
- Unified configuration generation method for each component
- Add support for ss-local, ss-tunnel, ss-server
- Most data validation is now done with validate_data
- USE_PROCD=1
- Update ss-rules with the one from shadowsocks/luci-app-shadowsocks
- Add README.md
- Set myself as the maintainer

Addresses #4435

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>