proxy all tcp traffic to a socks5t server use iptables and redsocks

iptables.sh

iptables -t nat -N REDSOCKS
iptables -t nat -A REDSOCKS -d 0.0.0.0/8 -j RETURN
iptables -t nat -A REDSOCKS -d 10.0.0.0/8 -j RETURN
iptables -t nat -A REDSOCKS -d 100.64.0.0/10 -j RETURN
iptables -t nat -A REDSOCKS -d 127.0.0.0/8 -j RETURN
iptables -t nat -A REDSOCKS -d 169.254.0.0/16 -j RETURN
iptables -t nat -A REDSOCKS -d 172.16.0.0/12 -j RETURN
iptables -t nat -A REDSOCKS -d 192.168.0.0/16 -j RETURN
iptables -t nat -A REDSOCKS -d 198.18.0.0/15 -j RETURN
iptables -t nat -A REDSOCKS -d 224.0.0.0/4 -j RETURN
iptables -t nat -A REDSOCKS -d 240.0.0.0/4 -j RETURN
iptables -t nat -A REDSOCKS -p tcp -j REDIRECT --to-ports 12345

iptables -t nat -I PREROUTING -p tcp -j REDSOCKS
iptables -t nat -A OUTPUT -p tcp -j REDSOCKS

iptables_new.sh

#!/bin/bash

function enable_proxy() {
    echo "[INFO] setting up iptables rules for redsocks...."    

    iptables -t nat -N REDSOCKS
    iptables -t nat -A REDSOCKS -d 0.0.0.0/8 -j RETURN
    iptables -t nat -A REDSOCKS -d 10.0.0.0/8 -j RETURN
    iptables -t nat -A REDSOCKS -d 100.64.0.0/10 -j RETURN
    iptables -t nat -A REDSOCKS -d 127.0.0.0/8 -j RETURN
    iptables -t nat -A REDSOCKS -d 169.254.0.0/16 -j RETURN
    iptables -t nat -A REDSOCKS -d 172.16.0.0/12 -j RETURN
    iptables -t nat -A REDSOCKS -d 192.168.0.0/16 -j RETURN
    iptables -t nat -A REDSOCKS -d 198.18.0.0/15 -j RETURN
    iptables -t nat -A REDSOCKS -d 224.0.0.0/4 -j RETURN
    iptables -t nat -A REDSOCKS -d 240.0.0.0/4 -j RETURN
    iptables -t nat -A REDSOCKS -p tcp -j REDIRECT --to-ports 12345

    iptables -t nat -I PREROUTING -p tcp -j REDSOCKS
    iptables -t nat -A OUTPUT -p tcp -j REDSOCKS
}

function disable_proxy() {
    echo "[INFO] clearing iptables nat rules..."
    iptables -t nat -F
    iptables -t nat -X REDSOCKS
}

function show_iptables_stat() {
    iptables -t nat -L -n -v
}

if [ "_$1" == "_1" ]; then
    enable_proxy
    show_iptables_stat
else
    disable_proxy
    show_iptables_stat
fi

redsocks.conf

base {
        // debug: connection progress & client list on SIGUSR1
        log_debug = on;

        // info: start and end of client session
        log_info = on;

        /* possible `log' values are:
         *   stderr
         *   "file:/path/to/file"
         *   syslog:FACILITY  facility is any of "daemon", "local0"..."local7"
         */
        log = "file:/var/log/redsocks.log";

        // detach from console
        daemon = on;

        /* Change uid, gid and root directory, these options require root
         * privilegies on startup.
         * Note, your chroot may requre /etc/localtime if you write log to syslog.
         * Log is opened before chroot & uid changing.
         */
        user = redsocks;
        group = redsocks;
        // chroot = "/var/chroot";

        /* possible `redirector' values are:
         *   iptables   - for Linux
         *   ipf        - for FreeBSD
         *   pf         - for OpenBSD
         *   generic    - some generic redirector that MAY work
         */
        redirector = iptables;
}

redsocks {
        /* `local_ip' defaults to 127.0.0.1 for security reasons,
         * use 0.0.0.0 if you want to listen on every interface.
         * `local_*' are used as port to redirect to.
         */
        local_ip = 127.0.0.1;
        local_port = 12345;

        // `ip' and `port' are IP and tcp-port of proxy-server
        // You can also use hostname instead of IP, only one (random)
        // address of multihomed host will be used.
        ip = 192.168.0.119;
        port = 1080;


        // known types: socks4, socks5, http-connect, http-relay
        type = socks5;

        // login = "foobar";
        // password = "baz";
}

the 'ip' and 'port' in redsocks {} should be set to a socks5 proxy server.