Merge branch 'wifi-ap'

README.md

@@ -15,20 +15,20 @@ West Bengal.
 <!-- UNCOMMENT WHEN NECESSARY
 
 **Disclaimer**:
-In case you are either 1) a complete idiot; or 2) a member of parliament;
+In case you are either 1) a complete idiot; or 2) a member of the saffron
-or 3) both, please be aware that this project is not affiliated with
+brigade; or 3) both, please be aware that this project is not affiliated
-any groups designated as "terrorist" groups in India.
+with any groups designated as "terrorist" groups in India.
 
 Using the name Naxal does not imply any form of connection
-with anyone the government collectively calles Urban Naxals (human rights
+with anyone the government of India collectively calles Urban
-activists, lawyers, poets, writers, journalists or anyone else
+Naxals (human rights activists, lawyers, poets, writers, journalists
-advocating the constitutional rights).
+or anyone else advocating for their rights).
 
 -->
 
 ## Requirements
 
-- systemd v248 or more (for batman support)
+- systemd{,-networkd} v248 or more (for batman support)
 - Linux kernel with batman-adv module (if `modinfo batman-adv` shows
   no error then you already have it)
 - iwd (for starting ad-hoc network)
@@ -36,17 +36,22 @@ advocating the constitutional rights).
 - [python-dasbus][]
 - wifi adapter with ad-hoc support
 - two or more computers with wifi adapter
+- systemd-resolved (optional, for DNS)
+- batctl (optional, for debugging)
 
 ## Installing
 
 ### Arch Linux
 
-Install [naxalnet-git][] from the AUR:
+Install [naxalnet-git][] from the AUR with your favourite helper:
 
 ```sh
 yay -S naxalnet-git
 ```
 
+Optionally, [setup systemd-resolved][arch-resolved] if any of the
+computers have internet access.
+
 ### Manually
 
 Clone the repo and cd into it.
@@ -61,15 +66,41 @@ without rebooting:
 sudo systemctl daemon-reload
 ```
 
-## Running the program
+## How to use
 
 You need more than one computer running for the connection to work.
-Start the naxalnet service:
+
+### Communicate between peers
+
+Connect a wifi adapter to all the computers you intend to run
+naxalnet.
+Start the naxalnet service on all of them:
 
 ```sh
 sudo systemctl start naxalnet.service
 ```
 
+To test if it works, run `ip addr` to find out your address.
+Note the `inet` or `inet6` address of `bridge0`. Ping the address
+from another computer (example: `ping 169.254.62.90`) to find out
+if it is online. Press Ctrl-C to stop.
+
+### Getting internet access
+
+Connect an ethernet to any of the peers and start naxalnet.
+Now all the peers should be able to connect after renewing
+their DHCP connection (`sudo networkctl renew bridge0`).
+
+### Tethering via WiFi AP
+
+Connect two wifi adapters on a device and start naxalnet.
+Now an ap will be created on one of the devices with
+SSID `NaxalNet` and password `naxalnet256`.
+If you had set up internet access on one of the peers, internet
+can be accessed from the AP.
+
+### Running at boot
+
 Starting the service will stop `NetworkManager.service` and
 `wpa_supplicant.service` if it is running. If you start either of these
 services after naxalnet is started, systemd will stop naxalnet.
@@ -125,3 +156,4 @@ This project is in alpha stage. Documentation is incomplete.
 [ssb]: https://scuttlebutt.nz
 [python-dasbus]: https://github.com/rhinstaller/dasbus
 [naxalnet-git]: https://aur.archlinux.org/packages/naxalnet-git
+[arch-resolved]: https://wiki.archlinux.org/title/Systemd-resolved#DNS

naxalnet

@@ -22,7 +22,6 @@ with systemd-networkd and iwd
 
 
 import sys
-import time
 from pathlib import Path
 from shutil import copy
 from dasbus.connection import SystemMessageBus
@@ -30,12 +29,13 @@ from dasbus.error import DBusError
 
 NETWORKD_CONFIGS = "/usr/share/naxalnet/networkd"
 NETWORKD_VOLATILE_DIR = "/run/systemd/network"
-RESOLVED_STUB_RESOLVE = "/run/systemd/resolve/stub-resolv.conf"
-RESOLV_CONF = "/etc/resolv.conf"
 ADHOC_SSID = "HelloWorld"
-
+AP_SSID = "NaxalNet"
+AP_PASSWD = "naxalnet256"
 # Copy networkd configs to volatile dir.
-# See man:systemd.networkm(5)
+# The D-Bus API does not support creating new interfaces
+# or linking to bridges. So we use config files.
+# See man:systemd.network(5)
 try:
     print("Copying network config files")
     dest = Path(NETWORKD_VOLATILE_DIR)
@@ -51,36 +51,6 @@ except PermissionError as error:
     print(error)
     sys.exit("Make sure you are root")
 
-
-# Symlink resolvd.conf to systemd's stub-resolvd.conf
-# This is needed for DNS resolution to work.
-# see https://wiki.archlinux.org/title/Systemd-resolved#DNS
-try:
-    print("Checking resolv.conf")
-    r = Path(RESOLV_CONF)
-    if r.is_symlink():
-        # Naxalnet will be started before resolved, so the destination
-        # is unlikely to exist at the time
-        # If r is linked to resolved's resolv.conf, dont change it
-        if r.samefile(RESOLVED_STUB_RESOLVE):
-            print(r, "is already linked to stub-resolv.conf. Not changing")
-        # Else if the destination exists
-        elif r.exists():
-            print(r, "is a symlink that exists. Not removing")
-        else:
-            print(r, "is a symlink to a destination that doesn't exist. Removing")
-            r.unlink()
-    elif r.exists():
-        print(r, "is not a symlink")
-        x = r.rename(RESOLV_CONF + ".naxalnet-bkp")
-        print(r, "was moved to", x)
-        print("Linking resolv.conf")
-        r.symlink_to(RESOLVED_STUB_RESOLVE)
-except PermissionError as error:
-    print(error)
-    sys.exit("An error occured while linking resolv.conf")
-
-
 # Now, the iwd part
 try:
     # connect to the System bus
@@ -90,47 +60,75 @@ try:
     # Get list of all devices
     print("Finding connected devices")
     objects = iwd.GetManagedObjects()
-    devices = []
+    # devices that support ad-hoc
-    for name, obj in objects.items():
+    adhoc_devices = []
+    # devices that support ap
+    ap_devices = []
+    for path, obj in objects.items():
         if "net.connman.iwd.Device" in obj:
             # add all devices to the list
-            print("Found device:", obj["net.connman.iwd.Device"]["Name"])
+            name = obj["net.connman.iwd.Device"]["Name"]
-            devices.append(name)
+            print("Found device", name)
+            adapter_path = obj["net.connman.iwd.Device"]["Adapter"].get_string()
+            adapter = objects[adapter_path]["net.connman.iwd.Adapter"]
+            if "ad-hoc" in adapter["SupportedModes"]:
+                print(name, "supports ad-hoc")
+                adhoc_devices.append(path)
+            if "ap" in adapter["SupportedModes"]:
+                print(name, "supports ap")
+                ap_devices.append(path)
 
-    # Start ad-hoc on first device
+    if len(adhoc_devices) != 0:
-    devpath = devices.pop()
+        # Start ad-hoc on first device supporting ad-hoc
-    print("Working on first device", devpath)
+        dev1path = adhoc_devices.pop()
-    dev1 = bus.get_proxy("net.connman.iwd", devpath)
+        # The same device is likely to have ap support too.
-    if not dev1.Powered:
+        # But we can't start ad-hoc and ap on the same interface.
-        print("Device is off. Turning on")
+        # Remove dev1 from ap_devices if it exists there
-        dev1.Powered = True
+        if dev1path in ap_devices:
-    if dev1.Mode != "ad-hoc":
+            ap_devices.remove(dev1path)
-        print("Device is in", dev1.Mode)
+        print("Working on ad-hoc")
-        print("Switching to ad-hoc")
+        dev1 = bus.get_proxy("net.connman.iwd", dev1path)
-        dev1.Mode = "ad-hoc"
+        print("Starting ad-hoc on", dev1.Name)
-        # Changing Mode requires connecting to the proxy again
+        if not dev1.Powered:
-        dev1 = bus.get_proxy("net.connman.iwd", devpath)
+            print("Device is off. Turning on")
-    print("Starting ad-hoc network")
+            dev1.Powered = True
-    dev1.StartOpen(ADHOC_SSID)
+        if dev1.Mode != "ad-hoc":
-    # TODO: If there is a second device, start AP
+            print("Device is in", dev1.Mode)
-    # in it
+            print("Switching to ad-hoc")
+            dev1.Mode = "ad-hoc"
+            # Changing Mode needs connecting to the proxy again
+            dev1 = bus.get_proxy("net.connman.iwd", dev1path)
+        # If already connected to ad-hoc, stop it
+        if dev1.Started is True:
+            print("Already connected to ad-hoc. Stopping")
+            dev1.Stop()
+            # Reconnect to proxy or StartOpen won't work
+            dev1 = bus.get_proxy("net.connman.iwd", dev1path)
+        print("Starting ad-hoc network")
+        dev1.StartOpen(ADHOC_SSID)
+
+        # Start Access point if ap_device is not empty,
+        # ie, we have more devices
+        if len(ap_devices) != 0:
+            print("Working on AP")
+            dev2path = ap_devices.pop()
+            dev2 = bus.get_proxy("net.connman.iwd", dev2path)
+            if not dev1.Powered:
+                print("Device is off. Turning on")
+                dev1.Powered = True
+            if dev2.Mode != "ap":
+                print(dev2.Name, "is in", dev2.Mode)
+                print("Switching to ap")
+                dev2.Mode = "ap"
+                dev2 = bus.get_proxy("net.connman.iwd", dev2path)
+            if dev2.Started is True:
+                print("An AP is already started on", dev2.Name)
+                print("Stopping")
+                dev2.Stop()
+                dev2 = bus.get_proxy("net.connman.iwd", dev2path)
+            print("Starting AP on", dev2.Name)
+            dev2.Start(AP_SSID, AP_PASSWD)
 except DBusError:
     sys.exit("An error occured while communicating with iwd")
 
-# Sleep my little baby-oh
-# Sleep until you waken
-# When you wake you'll see the world
-# If I'm not mistaken...
-#
-# Kiss a lover
-# Dance a measure,
-# Find your name
-# And buried treasure...
-#
-# Face your life
-# Its pain,
-# Its pleasure,
-# Leave no path untaken.
-#
-# -- Neil Gaiman, The Graveyard Book
 print("Bye")

naxalnet.service

@@ -15,9 +15,12 @@ After=wpa_supplicant.service
 [Service]
 Type=oneshot
 RemainAfterExit=yes
-# Temporary (maybe permanent) fix to aborting after changing to ad-hoc
 Restart=on-failure
 RestartSec=5sec
+# IWD takes some time to find devices.
+# Without the sleep 5, naxalnet could not detect the second
+# device while testing.
+ExecStartPre=/usr/bin/sleep 5
 ExecStart=/usr/bin/naxalnet
 
 [Install]