From 0a6af46364d8991bbeda2e2c5c5bdcaaea028895 Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Mon, 4 Sep 2023 22:06:53 +0100
Subject: [PATCH] support dhcp static leases

---
 THOUGHTS.txt                | 96 +++++++++++++++++++++++++++++++++++++
 modules/dnsmasq/default.nix | 31 ++++++++++++
 modules/dnsmasq/service.nix |  7 ++-
 3 files changed, 133 insertions(+), 1 deletion(-)

diff --git a/THOUGHTS.txt b/THOUGHTS.txt
index c6c9f8cb..0f11f6b3 100644
--- a/THOUGHTS.txt
+++ b/THOUGHTS.txt
@@ -2151,3 +2151,99 @@ Thu Aug 31 23:53:54 BST 2023
 - [done] ntp is not setting the time
 - static dhcp(6) lease support reqd for dogfooding
 
+Sat Sep  2 21:35:41 BST 2023
+
+Considerations for "mount" service: each filesystem needs to depend on
+any mount points for its parent directories, and maybe also on other
+services (e.g. filesystem modules, network devices, routes)
+
+mountpoints = {
+ mnt = {
+   media = svc.mountpoint.build {
+     fstype = "msdos";
+     device = "/dev/sda1";
+     options = [ ...];
+   };
+   archive = svc.mountpoint.build {
+     fstype = "ext4";
+     device = "/dev/sda2";
+     options = [ ...];
+     mountpoints = {
+       remote = svc.mountpoint.build {
+         fstype = "nfs";
+	 device = "doc.ic.ac.uk:/public";
+       };
+     };
+   };
+  };
+}
+
+services.somethingelse = svc.ftpd.build {
+  # ...
+  dependencies = [ mountpoints.mnt.archive ];
+}
+
+what don't we like about this? we have to walk the nested attrset in a
+weird way, because the services may contain other mountpoints. Maybe
+just keep it simple and do
+
+
+services.mountpoints = bundle {
+ name = "mountpoints";
+ contents = [
+   svc.mountpoint.build {
+     device = "/dev/sda2"; fstype = "ext4"; directory = "/mnt/isos";
+   };
+   svc.mountpoint.build {
+     device = "/dev/sdb1"; fstype = "msdos"; directory = "/mnt/backup";
+     dependencies = [ load-vfat-module ];
+   };
+ ];
+}
+
+Sun Sep  3 17:34:36 BST 2023
+
+how to dogfood
+
+DHCP6 server: static lease support
+DHCP client and acquire-{lan-prefix,wan-address}
+
+The emergency boot thingy in glinet u-boot won't help because it
+expects to flash from its tftp request instead of booting it. So we
+could use kexec instead except that the openwrt install doesn't have
+it.  So we could swap the hardware devices, the only downside of that
+being that then I don't have a test system any more. Or we could YOLO it.
+
+Sun Sep  3 22:11:02 BST 2023
+
+I think we should rejigger the documentation ...
+
+- "getting started": worked example, building and installing Liminix
+with a very simple config (wifi AP with ssh daemon)
+
+- using modules
+  - link to module reference
+
+- creating custom services
+  - longrun or oneshot
+  - dependencies
+  - outputs
+
+- creating your own modules
+
+- hacking on Liminix itself
+
+- contributing
+
+- external links and resources
+
+- module reference
+
+- hardware device reference
+
+---
+
+I think we might rename wlan_24 to wlan and wlan_5 to wlan1.
+This is on the assumption that almost no device is 5GHz only, so
+would make it easier to write a basic wlan example that works
+both on 2.4GHz boards and dual radio boards
diff --git a/modules/dnsmasq/default.nix b/modules/dnsmasq/default.nix
index 59c39b7c..b8ad7535 100644
--- a/modules/dnsmasq/default.nix
+++ b/modules/dnsmasq/default.nix
@@ -42,6 +42,37 @@ in {
       ranges = mkOption {
         type = types.listOf types.str;
       };
+      hosts = mkOption {
+        type = types.attrsOf (types.submodule {
+          options = {
+            mac = mkOption {
+              description = ''
+                MAC or other hardware address to match on. For Ethernet
+                this is a 48 bit address represented as colon-separated
+                hex bytes, or "id:clientid" to match a presented
+                client id (IPv6 DUID)
+              '';
+              type = types.str;
+              example = "01:20:31:4a:50";
+            };
+            v4 = mkOption  {
+              description = "IPv4 address to assign to this client";
+              example = "192.0.2.1";
+              type = types.str;
+            };
+            v6 = mkOption  {
+              type = types.listOf types.str;
+              description = "IPv6 addresses or interface-ids to assign to this client";
+              default = [];
+              example = [ "fe80::42:1eff:fefd:b341" "::1234"];
+            };
+            leasetime = mkOption {
+              type = types.int;
+              default = 86400;
+            };
+          };
+        });
+      };
       domain = mkOption {
         # this can be given multiple times so probably should be
         # domains plural and list of string
diff --git a/modules/dnsmasq/service.nix b/modules/dnsmasq/service.nix
index 02cf4764..aa1a2608 100644
--- a/modules/dnsmasq/service.nix
+++ b/modules/dnsmasq/service.nix
@@ -10,13 +10,17 @@
 , domain
 , group
 , ranges
+, hosts
 , upstreams
 , resolvconf
 }:
 let
   name = "${interface.name}.dnsmasq";
   inherit (liminix.services) longrun;
-  inherit (lib) concatStringsSep;
+  inherit (lib) concatStrings concatStringsSep mapAttrsToList;
+  hostOpt = name : { mac, v4, v6, leasetime } @ attrs:
+    let v6s = concatStrings (map (a : ",[${a}]") v6);
+    in "--dhcp-host=${mac},${v4}${v6s},${name},${builtins.toString leasetime}";
 in
 longrun {
   inherit name;
@@ -33,6 +37,7 @@ longrun {
     --keep-in-foreground \
     --dhcp-authoritative \
     ${if resolvconf != null then "--resolv-file=$(output_path ${resolvconf} resolv.conf)" else "--no-resolv"} \
+    ${lib.concatStringsSep " " (mapAttrsToList hostOpt hosts)} \
     --no-hosts \
     --log-dhcp \
     --enable-ra \