don't reset interface

Stop judging xt_comment by lsmod, which wasn't reliable
Users who want to disable iptables comment should set env var

NOTICE

@@ -1,42 +0,0 @@
-Copyright (c) 2013, oblique
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
-
-* Redistributions of source code must retain the above copyright notice, this
-  list of conditions and the following disclaimer.
-
-* Redistributions in binary form must reproduce the above copyright notice,
-  this list of conditions and the following disclaimer in the documentation
-  and/or other materials provided with the distribution.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
-FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
-OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-================================================================================
-
-linux-router
-Copyright (C) 2018  garywill
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Lesser General Public
-License as published by the Free Software Foundation; either
-version 2.1 of the License, or (at your option) any later version.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Lesser General Public License for more details.
-
-You should have received a copy of the GNU Lesser General Public
-License along with this library; if not, write to the Free Software
-Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

README.md

@@ -1,10 +1,10 @@
 # Linux-router
 
-Set Linux as router in one command. Able to Provide Internet, or create Wifi hotspot. Support transparent proxy (redsocks). Also useful for routing VM/containers.
+Set Linux as router in one command. Able to provide Internet, or create WiFi hotspot. Support transparent proxy (redsocks). Also useful for routing VM/containers.
 
 It wraps `iptables`, `dnsmasq` etc. stuff. Use in one command, restore in one command or by `control-c` (or even by closing terminal window).
 
-[Buy me a coffee](https://github.com/garywill/receiving/blob/master/receiving_methods.md) :)
+[Linux-Router News & Developer Notes 📰](https://github.com/garywill/linux-router/issues/28) | [More tools and projects 🛠️](https://garywill.github.io) | [🍻 Buy me a coffee ❤️](https://github.com/garywill/receiving/blob/master/receiving_methods.md)
 
 ## Features
 
@@ -12,16 +12,19 @@ Basic features:
 
 - Create a NATed sub-network
 - Provide Internet
-- DHCP server and RA
+- DHCP server (and RA)
+  - Specify what DNS the DHCP server assigns to clients
 - DNS server
+  - Specify upstream DNS (kind of a plain DNS proxy)
 - IPv6 (behind NATed LAN, like IPv4)
-- Creating Wifi hotspot:
+- Creating WiFi hotspot:
   - Channel selecting
   - Choose encryptions: WPA2/WPA, WPA2, WPA, No encryption
-  - Create AP on the same interface you are getting Internet (require same channel)
+  - Create AP on the same interface you are getting Internet (usually require same channel)
 - Transparent proxy (redsocks)
-- DNS proxy
+- Transparent DNS proxy (hijack port 53 packets)
-- Compatible with NetworkManager (automatically set interface as unmanaged)
+- Detect NetworkManager and make sure it won't interfere (handle interface (un)managed status)
+- You can run many instances, to create many different networks. Has instances managing feature.
 
 **For many other features, see below [CLI usage](#cli-usage-and-other-features)**
 
@@ -35,7 +38,7 @@ Internet----(eth0/wlan0)-Linux-(wlanX)AP
 
 ```
                                     Internet
-Wifi AP(no DHCP)                        |
+WiFi AP(no DHCP)                        |
     |----(wlan1)-Linux-(eth0/wlan0)------
     |           (DHCP)
     |--client
@@ -66,21 +69,39 @@ Internet----(eth0/wlan0)-Linux-(virtual interface)-----VM/container
 sudo lnxrouter -i eth1
 ```
 
-### Provide an interface's Internet to another interface
+no matter which interface (other than `eth1`) you're getting Internet from.
 
-```
+### Create WiFi hotspot
-sudo lnxrouter -i eth1 -o vpn0 --dhcp-dns 1.1.1.1 -6 --dhcp-dns6 [2606:4700:4700::1111]
-```
-> Read _Notice 1_
-
-### Create Wifi hotspot
 
 ```
 sudo lnxrouter --ap wlan0 MyAccessPoint -p MyPassPhrase
 ```
 
+no matter which interface you're getting Internet from (even from `wlan0`). Will create virtual Interface `x0wlan0` for hotspot.
+
+### Provide an interface's Internet to another interface
+
+Clients access Internet through only `isp5`
+
+<details>
+
+```
+sudo lnxrouter -i eth1 -o isp5  --no-dns  --dhcp-dns 1.1.1.1  -6 --dhcp-dns6 [2606:4700:4700::1111]
+```
+
+> In this case of usage, it's recommended to:
+> 
+> 1. Stop serving local DNS
+> 2. Tell clients which DNS to use (ISP5's DNS. Or, a safe public DNS, like above example)
+
+> Also, read *Notice 1*
+
+</details>
+
 ### LAN without Internet
 
+<details>
+
 ```
 sudo lnxrouter -n -i eth1
 sudo lnxrouter -n --ap wlan0 MyAccessPoint -p MyPassPhrase
@@ -88,9 +109,12 @@ sudo lnxrouter -n --ap wlan0 MyAccessPoint -p MyPassPhrase
 
 > Read _Notice 1_
 
+</details>
 
 ### Internet for LXC
 
+<details>
+
 Create a bridge
 
 ```
@@ -110,10 +134,16 @@ lxc.network.hwaddr = xx:xx:xx:xx:xx:xx
 sudo lnxrouter -i lxcbr5
 ```
 
-### Transparent proxy with Tor
+</details>
+
+### Transparent proxy
+
+All clients' Internet traffic go through, for example, Tor
+
+<details>
 
 ```
-sudo lnxrouter -i eth1 --tp 9040 --dns 9053 -g 192.168.55.1 --p6 fd00:5:6:7::
+sudo lnxrouter -i eth1 --tp 9040 --dns 9053 -g 192.168.55.1 -6 --p6 fd00:5:6:7::
 ```
 
 In `torrc`
@@ -125,9 +155,13 @@ TransPort [fd00:5:6:7::1]:9040
 DNSPort [fd00:5:6:7::1]:9053
 ```
 
+</details>
+
 ### Clients-in-sandbox network
 
-To not give our infomation to clients:
+To not give our infomation to clients. Clients can still access Internet.
+
+<details>
 
 ```
 sudo lnxrouter -i eth1 \
@@ -137,11 +171,14 @@ sudo lnxrouter -i eth1 \
     --catch-dns --log-dns   # optional
 ```
 
-> This script comes with no warrenty, use on your own risk
+</details>
 
+> This script comes with no warrenty. Use on your own risk
 
 ### Use as transparent proxy for LXD
 
+<details>
+
 Create a bridge
 
 ```
@@ -192,16 +229,24 @@ To remove the customized `eth0` to restore default `eth0`
 lxc config device remove <container> eth0
 ```
 
+</details>
+
 ### Use as transparent proxy for VirtualBox
 
+<details>
+
 In VirtualBox's global settings, create a host-only network `vboxnet5` with DHCP disabled.
 
 ```
 sudo lnxrouter -i vboxnet5 --tp 9040 --dns 9053
 ```
 
+</details>
+
 ### Use as transparent proxy for firejail
 
+<details>
+
 Create a bridge
 
 ```
@@ -213,8 +258,16 @@ sudo lnxrouter -i firejail5 -g 192.168.55.1 --tp 9040 --dns 9053
 firejail --net=firejail5 --dns=192.168.55.1 --blacklist=/var/run/nscd
 ```
 
+Firejail's `/etc/resolv.conf` doesn't obtain DNS from DHCP, so we need to assign.
+
+nscd is domain name cache service, which shouldn't be accessed from in jail here.
+
+</details>
+
 ### CLI usage and other features
 
+<details>
+
 ```
 Usage: lnxrouter <options>
 
@@ -224,20 +277,23 @@ Options:
 
     -i <interface>          Interface to make NATed sub-network,
                             and to provide Internet to
-                            (To create Wifi hotspot use '--ap' instead)
+                            (To create WiFi hotspot use '--ap' instead)
     -o <interface>          Specify an inteface to provide Internet from.
+                            (See Notice 1)
                             (Note using this with default DNS option may leak
                             queries to other interfaces)
     -n                      Do not provide Internet (See Notice 1)
     --ban-priv              Disallow clients to access my private network
 
     -g <ip>                 This host's IPv4 address in subnet (mask is /24)
+                            (example: '192.168.5.1' or '5' shortly)
     -6                      Enable IPv6 (NAT)
     --no4                   Disable IPv4 Internet (not forwarding IPv4)
                             (See Notice 1). Usually used with '-6'
 
     --p6 <prefix>           Set IPv6 LAN address prefix (length 64) 
-                            (example: fd00:1:2:3::) Using this enables '-6'
+                            (example: 'fd00:0:0:5::' or '5' shortly) 
+                            Using this enables '-6'
 
     --dns <ip>|<port>|<ip:port>
                             DNS server's upstream DNS.
@@ -248,13 +304,14 @@ Options:
     --no-dnsmasq            Disable dnsmasq server (DHCP, DNS, RA)
     --catch-dns             Transparent DNS proxy, redirect packets(TCP/UDP) 
                             whose destination port is 53 to this host
-    --log-dns               Show DNS query log
+    --log-dns               Show DNS query log (dnsmasq)
     --dhcp-dns <IP1[,IP2]>|no
-                            Set IPv4 DNS offered by DHCP (default: this host)
+                            Set IPv4 DNS offered by DHCP (default: this host).
     --dhcp-dns6 <IP1[,IP2]>|no
                             Set IPv6 DNS offered by DHCP (RA) 
                             (default: this host)
                             (Note IPv6 addresses need '[]' around)
+                            Using both above two will enable '--no-dns' 
     --hostname <name>       DNS server associate this name with this host.
                             Use '-' to read name from /etc/hostname
     -d                      DNS server will take into account /etc/hosts
@@ -268,12 +325,12 @@ Options:
                             redirect non-LAN TCP and UDP traffic to port.
                             (usually used with '--dns')
 
-  Wifi hotspot options:
+  WiFi hotspot options:
     --ap <wifi interface> <SSID>
-                            Create Wifi access point
+                            Create WiFi access point
     -p, --password <password>   
-                            Wifi password
+                            WiFi password
-    --qr                    Show Wifi QR code in terminal
+    --qr                    Show WiFi QR code in terminal
 
     --hidden                Hide access point (not broadcast SSID)
     --no-virt               Do not create virtual interface
@@ -288,8 +345,8 @@ Options:
                             (default: 2)
     --psk                   Use 64 hex digits pre-shared-key instead of
                             passphrase
-    --mac-filter            Enable Wifi hotspot MAC address filtering
+    --mac-filter            Enable WiFi hotspot MAC address filtering
-    --mac-filter-accept     Location of Wifi hotspot MAC address filter list
+    --mac-filter-accept     Location of WiFi hotspot MAC address filter list
                             (defaults to /etc/hostapd/hostapd.accept)
     --hostapd-debug <level> 1 or 2. Passes -d or -dd to hostapd
     --isolate-clients       Disable wifi communication between clients
@@ -303,28 +360,42 @@ Options:
 
   Instance managing:
     --daemon                Run in background
-    --list-running          Show running instances
+    -l, --list-running      Show running instances
-    --lc, --list-clients <id>     
+    --lc, --list-clients <id|interface>     
                             List clients of an instance. Or list neighbors of
-                            any interface, even if it isn't handled by us
+                            an interface, even if it isn't handled by us.
+                            (passive mode)
     --stop <id>             Stop a running instance
         For <id> you can use PID or subnet interface name.
         You can get them with '--list-running'
-
-    Notice 1:   This script assume your host's default policy won't forward
-                packets, so the script won't explictly ban forwarding in any
-                mode. In some unexpected case may cause unwanted packets 
-                leakage between 2 networks, which you should be aware of if you
-                want isolated network
 ```
 
-> These changes to system will not be restored by script's cleanup:
+</details>
-> 1. `/proc/sys/net/ipv4/ip_forward = 1` and `/proc/sys/net/ipv6/conf/all/forwarding = 1`
-> 1. dnsmasq in Apparmor complain mode
-> 1. Kernel module `nf_nat_pptp` loaded
-> 1. The wifi device which is used to create hotspot is `rfkill unblock`ed
-> 1. Wifi country code, if user specified
 
+## Notice
+
+<details>
+
+```
+    Notice 1:   This script assume your host's default policy won't forward
+                packets, so the script won't explictly ban forwarding in any
+                mode. In some unexpected case (eg. mistaken configurations) may
+                cause unwanted packets leakage between 2 networks, which you
+                should be aware of if you want isolated network
+```
+
+</details>
+
+## What changes are done to Linux system
+
+On exit of a linux-router instance, script **will do cleanup**, i.e. undo most changes to system. Though, **some** changes (if needed) will **not** be undone, which are:
+
+1. `/proc/sys/net/ipv4/ip_forward = 1` and `/proc/sys/net/ipv6/conf/all/forwarding = 1`
+2. dnsmasq in Apparmor complain mode
+3. hostapd in Apparmor complain mode
+4. Kernel module `nf_nat_pptp` loaded
+5. The wifi device which is used to create hotspot is `rfkill unblock`ed
+6. WiFi country code, if user assigns
 
 ## Dependencies
 
@@ -332,31 +403,92 @@ Options:
 - procps or procps-ng
 - iproute2
 - dnsmasq
-- iptables
+- iptables (or nftables with `iptables-nft` translation linked)
 - WiFi hotspot dependencies
-   - hostapd
+  - hostapd
-   - iw
+  - iw
-   - iwconfig (you only need this if 'iw' can not recognize your adapter)
+  - iwconfig (you only need this if 'iw' can not recognize your adapter)
-   - haveged (optional)
+  - haveged (optional)
-   - qrencode (opional)
+  - qrencode (optional)
 
 ## TODO
 
+Sooner is better:
+- Detect firewalld and make sure it won't interfere our interface
+
+Future:
 - WPA3
 - Global IPv6
 - Explictly ban forwarding if not needed
 - Bring bridging method back
 
-## Donate
+## License
 
-[Buy me a coffee](https://github.com/garywill/receiving/blob/master/receiving_methods.md) , this project took me lots of time!
+linux-router is LGPL licensed
 
-（ ^\_^）o自自o（^_^ ）
+<details>
 
-No? Okay, or just give me a star!
+```
+linux-router
+Copyright (C) 2018  garywill
 
-## For developers
+This library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License as published by the Free Software Foundation; either
+version 2.1 of the License, or (at your option) any later version.
 
-**Many thanks to project [create_ap](https://github.com/oblique/create_ap)**.
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Lesser General Public License for more details.
 
-This script was forked from create\_ap. Now it's quite different from it. (See `history` branch for how I modified create_ap)
+You should have received a copy of the GNU Lesser General Public
+License along with this library; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+```
+
+</details>
+
+Upstream create_ap was BSD licensed
+
+<details>
+
+```
+Copyright (c) 2013, oblique
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+```
+
+</details>
+
+## Meet developer(s) and become one of them
+
+Visit [**my homepage** 🏡](https://garywill.github.io) to see **more tools and projects** 🛠️.
+
+> [❤️ Buy me a coffee](https://github.com/garywill/receiving/blob/master/receiving_methods.md) , this project took me lots of time! ([❤️ 扫码领红包并打赏一个!](https://github.com/garywill/receiving/blob/master/receiving_methods.md))
+> 
+> 🥂 ( ^\_^) o自自o (^_^ ) 🍻
+
+🤝 Bisides, thank [create_ap](https://github.com/oblique/create_ap) by [oblique](https://github.com/oblique). This script was forked from create\_ap. Now they are quite different. (See `history` branch for how I modified create_ap). 🤝 Also thank those who contributed to that project.
+
+👨‍💻 You can be contributor, too! 🍃 There're some TO-DOs listed, at both [above](#todo) and [in the code file](https://github.com/garywill/linux-router/search?q=TODO&type=code). 🍃 Also some [unfulfilled enhancements in the Issues](https://github.com/garywill/linux-router/issues?q=is%3Aissue+is%3Aopen+label%3Aenhancement). Your name can be here!