odhcpd lease sharing via shared-state

packages/shared-state-odhcpd_leases/Makefile

@@ -0,0 +1,17 @@
+include ../../libremesh.mk  
+
+define Package/$(PKG_NAME)
+  SECTION:=lime
+  CATEGORY:=LibreMesh
+  TITLE:=odhcpd leases module for shared-state
+  DEPENDS:=+lua +luci-lib-jsonc +shared-state-async +odhcpd
+  PKGARCH:=all
+endef
+
+define Package/$(PKG_NAME)/description
+Synchronize external DHCP leases between LibreMesh nodes by
+watching odhcpd’s lease file, publishing updates over shared-state-async
+and injecting remote leases locally.
+endef
+
+$(eval $(call BuildPackage,$(PKG_NAME)))

packages/shared-state-odhcpd_leases/files/etc/uci-defaults/90_odhcpd-lease-share

@@ -0,0 +1,20 @@
+#!/bin/sh
+CRDT='odhcpd-leases'
+LEASEFILE='/tmp/ethers.mesh'
+TRIGGERFILE='usr/share/shared-state/publishers/shared-state-publish_odhcpd_leases'
+mSc='odhcpd_leases'
+
+uci -q set shared-state.$mSc=dataType          
+uci -q set shared-state.$mSc.name="$CRDT"   
+uci -q set shared-state.$mSc.scope='community'      
+uci -q set shared-state.$mSc.update_interval='120'  
+uci -q set shared-state.$mSc.ttl='1200'             
+uci commit shared-state  
+
+uci -q set dhcp.odhcpd.leasetrigger="$TRIGGERFILE"
+uci -q set dhcp.odhcpd.maindhcp='1'
+uci commit dhcp
+
+[ -e /etc/ethers ] || ln -s "$LEASEFILE" /etc/ethers
+
+/etc/init.d/odhcpd reload

packages/shared-state-odhcpd_leases/files/usr/share/shared-state/hooks/odhcpd-leases/shared-state-generate_odhcpd_leases

@@ -0,0 +1,25 @@
+#!/usr/bin/lua
+
+local JSON = require('luci.jsonc')
+
+local OUTPUT_FILE = '/tmp/ethers.mesh'
+local TMP_FILE = OUTPUT_FILE .. '.new' 
+
+local leases = JSON.parse(io.stdin:read('*a')) or {}
+
+local hostname_file = io.open('/proc/sys/kernel/hostname')
+local node_hostname = hostname_file:read('*l')
+hostname_file:close()
+
+local out_handle = io.open(TMP_FILE, 'w')
+
+for ip, data in pairs(leases) do
+
+  if data and data.mData and data.mData.mac and data.mAuthor ~= node_hostname then
+    out_handle:write(string.format('%s %s\n', data.mData.mac, ip)) -- Format: MAC IP
+  end
+end
+out_handle:close() 
+os.execute('mv "' .. TMP_FILE .. '" "' .. OUTPUT_FILE .. '"')
+
+os.execute('/etc/init.d/odhcpd reload')

packages/shared-state-odhcpd_leases/files/usr/share/shared-state/publishers/shared-state-publish_odhcpd_leases

@@ -0,0 +1,47 @@
+#!/usr/bin/lua
+
+local JSON = require("luci.jsonc")
+local CRDT = "odhcpd-leases"
+
+
+local handle = io.popen("ubus call dhcp ipv4leases '{}' 2>/dev/null")
+local ubus_output = handle:read("*a")
+handle:close()
+
+
+local ubus_data = JSON.parse(ubus_output or "{}")
+
+local output_table = {}
+
+
+if ubus_data and ubus_data.device then
+
+  for device_name, device_data in pairs(ubus_data.device) do
+    if device_data and device_data.leases then
+
+      for _, lease in ipairs(device_data.leases) do
+
+        if lease.address and lease.mac then
+
+          output_table[lease.address] = {
+            hostname = lease.hostname or "", 
+            mac = lease.mac
+          }
+        end
+      end
+    end
+  end
+end
+
+
+local final_json_string = JSON.stringify(output_table)
+
+
+local pipe = io.popen("shared-state-async insert " .. CRDT, "w")
+if pipe then
+  pipe:write(final_json_string)
+  pipe:close()
+end
+
+
+os.execute("/usr/sbin/odhcpd-update >/dev/null 2>&1")

packages/shared-state-odhcpd_leases/tests/test_publish_odhcpd_leases.lua

@@ -0,0 +1,101 @@
+local testUtils = require "tests.utils"
+local stub      = require "luassert.stub"
+
+local publisher_file =
+  "packages/shared-state-odhcpd_leases/files/usr/share/shared-state/publishers/" ..
+  "shared-state-publish_odhcpd_leases"
+local run_publisher = testUtils.load_lua_file_as_function(publisher_file)
+
+local captured_json
+local ubus_reply
+
+local popen_stub, execute_stub
+
+local function stub_system_calls()
+  popen_stub = stub(io, "popen", function(cmd, _)
+    if cmd:match("^ubus call dhcp ipv4leases") then
+      return { read = function() return "" end, close = function() end }
+
+    elseif cmd:match("^shared%-state%-async insert") then
+      return {
+        write = function(_, s) captured_json = s end,
+        close = function() end
+      }
+
+    else
+      return { read = function() return "" end, close = function() end }
+    end
+  end)
+
+  execute_stub = stub(os, "execute", function() return true end)
+end
+
+local function revert_system_stubs()
+  if popen_stub   then popen_stub:revert()   end
+  if execute_stub then execute_stub:revert() end
+end
+
+describe("shared-state-odhcpd_leases publisher #odhcpd-leases", function()
+
+  before_each(function()
+    captured_json = nil
+    ubus_reply    = nil
+
+    package.loaded["luci.jsonc"]  = nil
+    package.preload["luci.jsonc"] = function()
+      return {
+        parse = function() return ubus_reply end,
+        stringify = function(tbl)
+          if next(tbl) == nil then return "[]" end
+          local parts = {}
+          for ip, info in pairs(tbl) do
+            parts[#parts + 1] = string.format(
+              '"%s":{"mac":"%s","hostname":"%s"}',
+              ip, info.mac or "", info.hostname or "")
+          end
+          return "{" .. table.concat(parts, ",") .. "}"
+        end
+      }
+    end
+
+    stub_system_calls()
+  end)
+
+  after_each(function()
+    revert_system_stubs()
+    package.preload["luci.jsonc"] = nil
+  end)
+
+  it("#happy_path publishes every lease", function()
+    ubus_reply = {
+      device = {
+        eth0 = {
+          leases = {
+            { address = "10.0.0.5", mac = "aa:bb", hostname = "h1" },
+            { address = "10.0.0.6", mac = "cc:dd", hostname = "h2" }
+          }
+        }
+      }
+    }
+
+    run_publisher()
+
+    assert.is_string(captured_json, "Expected JSON")
+    assert.matches('"10%.0%.0%.5"%s*:%s*{[^}]-"mac"%s*:%s*"aa:bb"', captured_json)
+    assert.matches('"10%.0%.0%.6"%s*:%s*{[^}]-"mac"%s*:%s*"cc:dd"', captured_json)
+    assert.matches('"hostname"%s*:%s*"h1"', captured_json)
+    assert.matches('"hostname"%s*:%s*"h2"', captured_json)
+  end)
+
+  it("#empty with zero leases publishes '[]'", function()
+    ubus_reply = {}
+    run_publisher()
+    assert.equals("[]", captured_json)
+  end)
+
+  it("#malformed when parse returns nil publishes '[]'", function()
+    ubus_reply = nil
+    run_publisher()
+    assert.equals("[]", captured_json)
+  end)
+end)