Mesh/Firmware

Documentation for the sudo mesh firmware.

ToDo

Stuff we _need_ before beta launch:

• The production exit nodes intermittently stops working.
  • Until we figure out why, the script /root/scripts/check.sh is executed by cron every minute and if no nodes show up with "batctl o" the server reboot. It also saves syslog in /root/LAST_SYSLOG
• Get watchdog working on ar71xx (?)
• Better interface and security for node database
• Make analog hardware watchdog for old chipset and solder to devices.
• Set up a remote monitoring solution
• Run a node with serial monitoring to see if we can learn why it crashes.
• Detect ethernet being plugged/unplugged and send DHCP requests accordingly.
• Deal with situations where internet is not shared or not present. (juul)
  • Notes:
    • http://www.open-mesh.org/projects/batman-adv/wiki/Bridge-loop-avoidance-II
• Deal with situations where the node's eth0 is plugged into a 10.0.0.0/8 network (juul)
• Implement remote password reset (via h.sudomesh.org)
• Implement error reporting in web admin interface
• Implement a remote logging/monitoring solution (how far along is nodewatcher 2?)
  • Maybe with a script that checks for issues and reports back, e.g. "Ethernet is connected and DHCP server is present but DHCP server does not want to give me (the node) an IP. DHCP server probably has MAC address filtering enabled."
• Select a wifi channel, both 2.4 ghz and 5 ghz.
• Test if batman Internet gateway selection is working correctly (juul)
  • Currently DHCP hands out exit node IP as gateway, which means that the bandwidth specified in the batman gw_mode will be taken into account for DHCP server selection but not for gateway selection. Gateway selection will just happen based on normal batman-adv routing.
  • DHCP servers should maybe hand out node IP as gateway, but since both are on same subnet this will cause ICMP redirect messages to be generated.

Issues for later versions:

• IPv6 support (possibly switching to IPv6 entirely)
• Figure out how to legally use lower 5 ghz frequencies
• Figure out a solution for MAC address anonymizing.
• Set up OpenVPN on exit node.
• Implement statistics for web admin interface.
• Manual (or automatic?) speed and output power selection via web interface.
• Find better solution for batman/tunneldigger related MTU issues (Juul).
  • Currently setting client MTU with DHCP (does not work on e.g. Win 7) and using TCP MSS clamping on exit node (obviously only works for TCP).
• Support TDMA on Linux (Adri is working on FreeBSD support, maybe we can port).
• Make it possible to contribute to html/css without installing a dev environment (e.g. for luci)

Firmware generation features

It should be easy to generate a new firmware with the following custom config:

• Location and ownership information.

Contact info should be saved in a secure database but maybe not on the node itself?

• Randomly generated passwords set for wpa2, admin interface and ssh.

The SSH password should be stored securely and a couple of stickers with the wpa2 and admin password should be printed for the user.

• Web interface
• ssh key generation

Freifunk Meshkit is pretty neat!

We'll be dividing the image generation and node configuration aspects into two parts.

Sudomesh Firmware Image Builder Github Repo has our image builder and

Sudomesh Node Configurator Github Repo is our node configurator.

Sudomesh OpenWrt Packages has all of the sudomesh openwrt packages that we're using/we've written.

We flash nodes with the sudomesh image and then we use the node configurator to set them up with networking configs, ssh keys, etc. We also use the node-configurator to write pertinent info to a database.

Status: Pretty much finished! We're testing the last few issues!

Stuff the firmware should have

Ranked from most to least important

InternetIsDownRedirect

When the node doesn't have internet access, it will redirect traffic to our mesh hosted Splash Page.

We need something hosted on the node that can check if it has access to the internet. There's a bit of an issue where certain OSes won't connect to APs that don't have internet access. Juul will look into building a hack that properly manages these requests and redirects them to our node-hosted site.

InternetIsDownRedirect may also have to fake the expected captive portal detection responses? We need to figure out if android/iOS/Mac/Windows will connect to a wifi that does not have internet access.

Status: Implemented except for OS-specific captive portal requests.

Splash page

We can capture OS specific probes in order to specifically redirect captive portal requests without affecting any other network traffic.

Features:

• Brief info on the mesh
• Link to our website?

Status:

maxb has pretty much finished implementing this. We still need a services list page.

SSH server

The SSH server should be contactable from any interface. It should initially allow root access using a random generated password that the mesh group has and that the node owner can get and change if they are so inclined.

Status: Implemented. Mostly openwrt stock but we've added keygen features for the node-configurator

BATMAN-adv

The BATMAN-adv protocol is the mesh protocol. It's an application that we're installing onto OpenWRT and configured with batman-ctl.

Status: Implemented

Multiple virtual network interfaces with their own SSIDs

• One ad-hock mode, unencrypted interface for the mesh nodes, e.g. sudomesh-backchannel
• One access point mode, unencrypted interface, for non-mesh devices to connect to the mesh, e.g. sudomesh.
• One access point mode, private interface with WPA2, for the people who own the nodes. [optional]

Traffic on the private interface should be completely separated from traffic on the non-private interfaces unless a client connected to the private interface requests an IP on the mesh.

Maybe the last one is optional because some people may not need that feature (they already have another access point and they want to keep it), but then how do people administrate the router?

In order to serve a secure web admin config to home users, we'll probably always serve 3 APs with one private WPA encrypted home link so that users can access their admin page.

Status: Implemented

Web admin interface

Development information should be put in Web Admin Dev. This section can remain a wish-list.

A very simple one-page interface. It should do at least the following:

• Display some set of user statistics

Ideally we could list/graph the number of people who have associated with your mesh node.

We could also just list/graph the up/down data of people who have been using the mesh.

LightSquid (used by pfSense)

• Set location, name, description.

But do you want to know the location centrally as well so that you can display nodes on the map? Will people enter this information twice or will you pull this information from nodes and then display on the map? Same for name and description. I would suggest that information is stored only once. In your case on the node itself. So probably you can then pull this information through nodewatcher scripts on nodes and then display nodes the map. Just really should not require people to enter or maintain information on two places because it desyncs very fast. Mitar (talk) 22:20, 24 July 2013 (PDT)

• Let people select how much bandwidth they share.

They always share 100% when they're not using the connection themselves.

This works if people are using their private SSIDs on the node. But if the node is connected to their existing home network you might not easily configure such sharing. But maybe there is a way to detect that host network is free and can limits can be increased. Mitar (talk) 22:20, 24 July 2013 (PDT)

Do any ISPs have bandwidth caps around here? If so, let people specify how many MB to share per month.

Maybe also a button for temporary increase limits (make them more restrictive) which are then after some time automatically restored.

• Let people change the admin password and the private wifi wpa2 password.

Probably private SSID as well.

• Donate / "buy routers as presents for your friends"-button.

One idea we had (but this is probably better for splash screen) is "adopt a node". Where a neighbor who uses a node a lot and depends on the node can donate some money to keep it up, but can then give a nickname or avatar to the node. Or something. Mitar (talk) 22:20, 24 July 2013 (PDT)

Status: Maxb is implementing. Pretty much finished. Still needs graphs, etc. but has most of the other functionality including bandwidth shaping controls.

Source here:

https://github.com/sudomesh/luci-app-peopleswifi

Remote Updates

Once we deploy nodes, we'll want a way to update them as appropriate. The already built node configurator operates along similar lines, but we'd need to do some tweaking in order to make it work on the mesh. Also, we'd want to give the users the options to turn remote updates off. A somewhat decentralized system would be nice as well.

Status: Not yet

Watchdog script

Node tests itself to see if it has connectivity, etc and resets itself if necessary. OpenWrt supports the hardware watchdog on our PicoStations without any additional hacking, yay!

By default the hardware watchdog will automatically hard-reset the AP if /dev/watchdog is not written to at least once every 60 seconds. A Lua library has been written to interface with the batman-adv kernel module through the batctl command line utility. We need to identify a list of conditions that require a hard-reset and work them into the Lua watchdog script in the openwrt-firmware repository.

The Freifunk group has an awesome watchdog setup, details: http://wiki.freifunk.net/Kamikaze/LuCI/Watchdog

list of possible reset conditions: high sustained load, cron goes down, sshd goes down.

nodewatcher watchdog

Potential use of Quilt to update nodes.

QoS / bandwidth shaping

To support letting node owners select how much bandwidth they share. Allow users to block forwarded traffic based on type. There's an paper regarding layer 7 traffic shaping too.

• ipfirewall (ipfw) or netdummy
• ipfw-classifyd (used by pfSense)
• l7-filter
• ipp2p (p2p filtering)

Status: Juul is hacking on. Consider this hacked!

Internet VPN

The firmware should tunnel all Internet traffic from the mesh through a VPN server, unless this feature is specifically disabled.

This should not be a single VPN server, as that would be a single point of failure.

I suggest to use TunnelDigger. Mitar (talk) 21:50, 11 July 2013 (PDT)

Another tunneling option: OpenMesher jwentwistle

Network Topology

Status: Juul is implementing.

Mesh VPN

If the mesh does not see any other nodes (and maybe even if it does?), and it has internet, then it should connect to another node or two over VPN. The easy solution is to use the same VPN servers as for the internet.

Network Topology

Status: Implemented

DHCP and batman-adv gateway mode

Nodes with an internet connection should run DHCP and batman-adv gateway mode. We want to detect if the node can connect to a relay in which case it should configure as a batman-adv gateway server node. Otherwise they should configure as batman-adv gateway clients.

Staus: Implemented

Location and status reporting

Something that reports location and status when polled.

We developed this format and easy to publish status data from nodes for our nodewatcher. OpenWrt packages are here. Mitar (talk) 22:02, 11 July 2013 (PDT)

Nice to have:

• Status info: How many nodes is your node connected to. Is the internet link working.
• An "I don't know what my internet bandwidth is, test it for me"-function.
• Usage statistics (so people can see how many people they helped get internet!)

This is the most important thing! Mitar (talk) 22:20, 24 July 2013 (PDT)

You should add as well graphs on how much bandwidth was consumed by the node. This is useful when hosts see that their Internet is slow and believe that it was because of the node. Then they can check and see if it is really node (which often is not) or maybe just ISP has problems. Important because people like to attribute issues they have to nodes they don't understand. Mitar (talk) 22:20, 24 July 2013 (PDT)

• Let people put up a bit of info about their node / house / co-op, on a simple web page that people can access only if they're connected to that node. It could be shown as part of the splash page.

Status: Waiting for nodewatcher project to finish

Intelligent Wifi Channel Switching

It would be nice to be able to have the network intelligently determine channels

IPv6 support

We should have IPv6 support, but I am ok with launching the mesh with only IPv4 and adding in IPv6 later. (Juul (talk))

Stuff the firmware could have

DNS server

Each node could run its own (caching) DNS server.

For now, if you're logged into the private network on a node, going to http://my.node will take you to the web admin interface

Status:

Implemented web admin URL, but no caching DNS server yet.

RSSI Testing and Logging

At intervals, the nodes could conduct RSSI tests and log them with some way to compare and visualize signal strengths over time.

Caching web proxy

We could use Polipo to improve people's browsing experience. Not sure how much cpu and memory this would need. We may not be able to run it on the routers with less than 32 MB ram (e.g. the Bullet 2 HPs).

Block ads and tracking

We could use e.g. Polipo with the sources from both adblock plus and ghostery. If we implement this, it should be an optional (default off) feature that you can select on the splash page, with a "remember this" that remembers either using a cookie or using your MAC (but then we'd be logging people's MAC addresses :-S). The block should probably be time-limited (e.g. 30 days).

Compatible devices

We should have ready-made images for:

• One really cheap indoor router (with 3G usb stick support?) like TP-Link TL-WR703N
• One nice high-speed indoor router (300 mbps 802.11n)
• Ubiquiti hardware. Most of the AirMAX stuff.