# wake on wireless LAN # developed for the PinePhone (rtl8723cs), but may work on other systems. # key info was found from this chat between Peetz0r and megi: # additionally in the Realtek "Quick Guide For Wake on WLAN": # megi's devlog which enabled WOWLAN: # driver lives in Megi's kernel tree, at drivers/staging/rtl8723cs/Makefile # # wowlan configuration can be inspected with: # - `iw phy0 wowlan` # - `cat /proc/net/rtl8723cs/wlan0/wow_pattern_info` # - the "pattern mask" is a bitfield, where each bit `i` indicates if the "pattern content" byte at index `i` must match, or should be treated as Don't Care (`-`) # # wakeup sources can be monitored with: # - `cat /proc/interrupts | rg rtw_wifi_gpio_wakeup` # - e.g. `cat /sys/kernel/irq/25/actions` (if the above points to irq 25) # # caveats: # - can take 15s or more from when the packet is broadcast to when an application services it. # - WiFi doesn't respond to arp queries, so the sender might not actually know how to route # the packet to WiFi device at all. # - run `arp -s ` on the sender to hardcode an arp association. # - driver Makefile mentions ARP support though: # - #bit3: ARP enable, bit2: deauth, bit1: unicast, bit0: magic pkt. # - CONFIG_WAKEUP_TYPE = 0xf # - CONFIG_IP_R_MONITOR = n #arp VOQ and high rate # - #bit0: disBBRF off, #bit1: Wireless remote controller (WRC) # - CONFIG_SUSPEND_TYPE = 0 (i think this is correct) # - CONFIG_LPS_MODE = 1 (setting to 0 would disable LPS) # - maybe ARP gets disabled as part of the power saving features (iw phy ... power-save; CONFIG_POWER_SAVING=y)? # - driver code hints that some things like wake on arp are conditional on the state of AP association at the `wowlan enable` call. # so maybe it's proper to call `iw wowlan enable` immediately before *every* suspend instead of just once at boot # - packet matching happens below the OS, so it's not generic over virtual network devices like tunnels. # Wake On Lan with a VPN effectively requires that you wake on *every* packet routed via that VPN # since the meaning within any packet isn't obvious to the chipset. # # known problems: # - may fail to wake on LAN, with the following signature after power-button wake: # ``` # wpa_supplicant: wlan0: CTRL-EVENT-DISCONNECTED bssid=xx:xx:xx:xx:xx:xx reason=6 # wpa_supplicant: wlan0: Trying to associate with xx:xx:xx:xx:xx:xx (SSID='xx' freq=2437 MHz) # wpa_supplicant: wlan0: CTRL-EVENT-REGDOM-CHANGE init=CORE type=WORLD # wpa_supplicant: wlan0: CTRL-EVENT-STARTED-CHANNEL-SWITCH freq=2437 ht_enabled=1 ch_offset=0 ch_width=20 MHz cf1=2437 cf2=0 # wpa_supplicant: wlan0: Associated with xx:xx:xx:xx:xx:xx # wpa_supplicant: wlan0: CTRL-EVENT-SUBNET-STATUS-UPDATE status=0 # wpa_supplicant: wlan0: WPA: Key negotiation completed with xx:xx:xx:xx:xx:xx [PTK=CCMP GTK=CCMP] # wpa_supplicant: wlan0: CTRL-EVENT-CONNECTED - Connection to xx:xx:xx:xx:xx:xx completed [id=0 id_str=] # ``` # - observed after a suspension of 67 minutes. # - but also observed after a suspension of just 5 minutes. # - WiFi chip *should* have a way to wake on connection state change, i just need to enable it? # - `iw phy phy0 wowlan enable disconnect` => Invalid argument (-22) # - `iw phy0 wowlan enable net-detect ...` (from man example) => Operation not supported (-95) # - Realtek Quick Start guide claims "CONFIG_WAKEUP_TYPE = 0x7" enables deauth wake up (bit 2), unicast wake up (bit 1), magic packet (bit 0) # - driver Makefile: # - #bit0: ROAM_ON_EXPIRED, #bit1: ROAM_ON_RESUME, #bit2: ROAM_ACTIVE # - CONFIG_ROAMING_FLAG = 0x3 # - may fail to wake on LAN, even without any signature like the above # - observed after a suspension of 10 minutes, trying to contact from laptop (laptop would have previously not contacted moby) # - in many cases the wake reason is still 0x23, even as it sleeps for the whole alloted 300s. # - then it's likely a race condition with the WiFi chip raising the wake signal *as* the CPU is falling asleep, and the CPU misses it. # - this is testable: phone would wake 100% if all networked services are disabled (so it's not receiving packets near the time it enters sleep) # - TODO: change the wake event from edge-triggered to level-triggered. # - may disassociate from WiFi and *refuse to reassociate even via nmtui, restarting NetworkManager/wpa_supplicant/polkit* # - solution is `modprobe -r 8723cs && modprobe 8723cs`, then way a couple minutes. # - possible this only happens when the driver is compiled with CONFIG_GTK_OL (or CONFIG_ARP_KEEP_ALIVE). # - signature: # - `Oct 10 14:42:40 moby sxmo_autosuspend-start[1312366]: DEBUG:__main__:invoking: iwpriv wlan0 wow_set_pattern pattern=-:-:-:-:-:-:-:-:-:-:-:-:08:00:-:-:-:-:-:-:-:-:-:06:-:-:-:-:-:-:-:-:-:-:-:-:00:16` # - `Oct 10 14:42:40 moby kernel: [Warning] Error C2H ID=128, len=126` # - `Oct 10 14:42:55 moby NetworkManager[2750]: [1696948975.4162] device (wlan0): link timed out.` # - `Oct 10 14:42:55 moby NetworkManager[2750]: [1696948975.4749] device (wlan0): Activation: failed for connection 'xx'` # - `Oct 10 14:42:59 moby wpa_supplicant[2845]: wlan0: CTRL-EVENT-STARTED-CHANNEL-SWITCH freq=2437 ht_enabled=1 ch_offset=0 ch_width=20 MHz cf1=2437 cf2=0` # - `Oct 10 14:43:00 moby wpa_supplicant[2845]: wlan0: CTRL-EVENT-ASSOC-REJECT status_code=1` # - `Oct 10 14:43:00 moby wpa_supplicant[2845]: wlan0: CTRL-EVENT-SSID-TEMP-DISABLED id=0 ssid="xx" auth_failures=1 duration=10 reason=CONN_FAILED` # - `Oct 10 14:43:00 moby wpa_supplicant[2845]: wlan0: CTRL-EVENT-REGDOM-CHANGE init=CORE type=WORLD` # - (then wpa_supplicant tries again) # - `Oct 10 14:43:24 moby NetworkManager[2750]: [1696949004.4165] device (wlan0): Activation: (wifi) association took too long` # - `Oct 10 14:43:24 moby NetworkManager[2750]: [1696949004.4201] device (wlan0): Activation: (wifi) asking for new secrets` # - (above wpa_supplicant entries and these last two NM entries then repeat multiple times per minute, until driver reprobe) # # TODO: remove this file # it's been obsoleted by hosts/modules/gui/sxmo/hooks/sxmo_suspend.sh { config, lib, pkgs, ... }: let cfg = config.sane.wowlan; patternOpts = with lib; types.submodule { options = { tcp.destPort = mkOption { type = types.nullOr types.port; default = null; description = '' IP port from which the packet was *sent*. use this if you want to wake when an outbound connection shows activity (e.g. this machine made a long-running HTTP request, and the other side finally has data for us). ''; }; tcp.sourcePort = mkOption { type = types.nullOr types.port; default = null; description = '' IP port on which the packet was *received*. use this if you want to wake on inbound connections (e.g. sshing *into* this machine). ''; }; arp.destIp = mkOption { type = types.nullOr types.str; default = null; description = '' IP address being queried. e.g. `"192.168.0.100"` ''; }; }; }; in { options = with lib; { sane.wowlan.enable = mkOption { default = false; type = types.bool; }; sane.wowlan.patterns = mkOption { default = []; type = types.listOf patternOpts; description = '' each entry represents a pattern which if seen in a packet should wake the system. if any pattern matches, the system will wake. for a pattern to match, all of its non-null fields must match. ''; }; }; config = lib.mkIf cfg.enable { systemd.services.wowlan = { description = "configure the WiFi chip to wake the system on specific activity"; path = [ pkgs.rtl8723cs-wowlan ]; script = let tcpArgs = { destPort, sourcePort }: [ "tcp" ] ++ lib.optionals (destPort != null) [ "--dest-port" (builtins.toString destPort) ] ++ lib.optionals (sourcePort != null) [ "--source-port" (builtins.toString sourcePort) ] ; arpArgs = { destIp }: [ "arp" ] ++ lib.optionals (destIp != null) [ "--dest-ip" (builtins.toString destIp) ] ; maybeCallHelper = maybe: args: lib.optionalString maybe ((lib.escapeShellArgs ([ "rtl8723cs-wowlan" ] ++ args)) + "\n") ; applyPattern = pat: (maybeCallHelper (pat.tcp != { destPort = null; sourcePort = null; }) (tcpArgs pat.tcp)) + (maybeCallHelper (pat.arp != { destIp = null; }) (arpArgs pat.arp)) ; appliedPatterns = lib.concatStringsSep "" (builtins.map applyPattern cfg.patterns); in '' rtl8723cs-wowlan enable-clean ${appliedPatterns} ''; serviceConfig = { # TODO: re-run this periodically, just to be sure? # it's kinda bad if this fails or gets undone unexpectedly. Type = "oneshot"; RemainAfterExit = true; Restart = "on-failure"; RestartSec = "30s"; }; after = [ "network-online.target" ]; wantedBy = [ "multi-user.target" ]; }; }; }