/ shadowsocks

optimize shadowsocks NAT rules

Few days ago, I upgraded my OpenWrt box to latest version, there is a new style(Bootstrap) interface and I like it very much(too long lived old world).

Also I found a shadowsocks special version for openwrt, it includs China main IP blocks, some requests within this IP range, you could bypass shadowsocks, and this IP blocks is from apnic, very precise but a little long for openwrt, 4000+lines.

I think the most counted IP block I would use it in the future very soon, so I can sort them desc.

iptables -t nat -xvnL SS_SPEC_WAN_AC | tail -n+12 | head -n -1 | sort -crnsk 1,1 | awk '{ print $NF }' > /etc/shadowsocks/ignore.list

tail -n+12 means display results from the first 12 row to the end, first 11 rows includes two lines heads, one line shadowsocks server IP, eight lines internal IP blocks;

head -n -1 means display results except last line(doesn't work on MacOS), and last line is default shadowsocks redirect rule, so keep it at the same place.

sort -crnsk 1,1 means check first, reverse result, numerical value(converted from input string), stable sort, k 1,1 sort key (start a key at POS1, end it at POS2 (origin 1))

awk print $NF, print the last column, that's very cool.

rewrite the results to ignore.list, and restart shadowsocks, it will use the sorted IP blocks, maybe fast than before 0.xx ms!