From bfac21d5dee36b25cf9696a71332e737d6ec0532 Mon Sep 17 00:00:00 2001
From: Colin <colin@uninsane.org>
Date: Sat, 9 Dec 2023 18:14:27 +0000
Subject: [PATCH] mobile-linux-push-notifications: show how to integrate with
 SXMO

---
 .../index.md                                  | 55 ++++++++++++++++++-
 1 file changed, 54 insertions(+), 1 deletion(-)

diff --git a/content/blog/2023-12-09-mobile-linux-push-notifications/index.md b/content/blog/2023-12-09-mobile-linux-push-notifications/index.md
index 4334568..d891b64 100644
--- a/content/blog/2023-12-09-mobile-linux-push-notifications/index.md
+++ b/content/blog/2023-12-09-mobile-linux-push-notifications/index.md
@@ -240,7 +240,60 @@ i've only authored this module to alert me on jingle calls. one could presumably
 [mod_ntfy_push]: https://git.uninsane.org/colin/nix-files/src/commit/01de6f84cfc2291092a6809e61339e992f9b97b4/hosts/by-name/servo/services/prosody/modules/mod_sane_ntfy.lua
 [mod_ntfy_push_mirror]: mod_sane_notify.lua
 
-### Pinephone Wowlan Race Condition
+
+## SXMO Integration
+
+[SXMO][sxmo] is a mobile-friendly Linux desktop notable for being extremely hackable (it's really just a collection of shell scripts layered over [sway][sway]), and as such we can integrate all the client-side work we did above into something the desktop environment handles for us transparently.
+
+SXMO includes an [`autosuspend`][sxmo_autosuspend.sh] service. it's just a bash `while` loop that periodically checks if conditions are suitable to sleep the phone (is the screen off, is the user not in a call, are no media players active, and so on) and if so, calls out to `sxmo_suspend.sh`.
+
+[`sxmo_suspend.sh`][sxmo_suspend.sh] looks like this (simplified -- it does a little more to make cronjobs reliable)
+
+```bash
+suspend_time=99999999 # far away
+sxmo_log "calling suspend with suspend_time <$suspend_time>"
+
+doas rtcwake -m mem -s "$suspend_time" || exit 1
+
+sxmo_hook_postwake.sh
+```
+
+since the different components of SXMO communicate by shelling out to each other, we can patch it just by putting our own `sxmo_suspend.sh` script somewhere on the PATH. that's intentional behavior: SXMO goes out of its way to add `~/.config/sxmo/hooks` as a PATH entry to its services, so we can just drop a file like this into `~/.config/sxmo/hooks/sxmo_suspend.sh`:
+
+```bash
+ntfy sub TEST_WOWLAN_TOPIC &
+NTFY_PID=$!
+
+port=
+while [ -z "$port" ]; do
+  # netstat output will look like:
+  #   tcp 0 0 127.0.0.1:12345 10.11.12.13:443 ESTABLISHED 2798004/ntfy
+  # pipe through sed/cut to extract the `12345` local port component
+  # do this in a loop to allow time for ntfy to establish the connection
+  port="$(netstat --tcp --program --numeric-ports | grep ntfy | sed 's/  */ /g' | cut -d' ' -f 4 | cut -d':' -f2)"
+done
+
+# configure to wake on any traffic to that ntfy connection
+rtl8723cs-wowlan enable-clean
+rtl8723cs-wowlan tcp --src-port "$port"
+
+sxmo_log "calling suspend with suspend_time 600"
+doas rtcwake -m mem -s 600 || exit 1
+kill $NTFY_PID
+sxmo_hook_postwake.sh
+
+wait  # for ntfy to exit
+```
+
+and that's it. use your phone as you normally would, and everything should be the same except that now it'll wake up whenever you get a Matrix/XMPP/ntfy notification.
+
+[sxmo]: https://sxmo.org/
+[sway]: https://swaywm.org/
+[sxmo_autosuspend.sh]: https://git.sr.ht/~mil/sxmo-utils/tree/master/item/scripts/core/sxmo_autosuspend.sh
+[sxmo_suspend.sh]: https://git.sr.ht/~mil/sxmo-utils/tree/master/item/scripts/core/sxmo_suspend.sh
+
+
+## Pinephone Wowlan Race Condition
 
 as alluded, sending a wake packet within about a second of sending the SoC to sleep will fail to wake the system. worse, the SoC will be _stuck_ in the sleep state, not waking on any _future_ wake packets (you can still wake it via the power button, and it should behave correctly during the next sleep cycle). one can imagine lots of ways an edge-triggered interrupt could be misimplemented to cause this type of race, but i wasn't able to diagnose it any more than this.