Enhance Wake-on-LAN functionality by forcing IPv4 UDP socket and adding source IP binding

scripts/auto-boot-ollama-host.lua

@@ -47,25 +47,33 @@ local function send_wol(mac_str, bcast_ip, port)
   if not mb then return false, "invalid MAC" end
   local packet = string.rep(string.char(0xFF), 6) .. mb:rep(16)
 
-  local udp = assert(socket.udp())
+  -- 1) Force an IPv4 UDP socket (fallback to udp() if udp4() is not available)
+  local udp_ctor = socket.udp4 or socket.udp
+  local udp = assert(udp_ctor())
   udp:settimeout(2)
 
-  -- Optional: bind to a specific source IP (helps in host network with multi-NIC)
-  local WOL_SRC_IP = os.getenv("WOL_SRC_IP")
-  if WOL_SRC_IP and WOL_SRC_IP ~= "" then
-    assert(udp:setsockname(WOL_SRC_IP, 0))
+  -- 2) Bind to an IPv4 source to lock the address family
+  --    If you have WOL_SRC_IP set, bind to that; otherwise 0.0.0.0.
+  local src_ip = os.getenv("WOL_SRC_IP")
+  if src_ip and src_ip ~= "" then
+    assert(udp:setsockname(src_ip, 0))
+  else
+    assert(udp:setsockname("0.0.0.0", 0))
   end
 
-  -- IMPORTANT: must be true or Linux will return EACCES on broadcast sendto()
+  -- 3) Enable broadcast. This will fail on AF_INET6, so do it *after* binding IPv4.
   assert(udp:setoption("broadcast", true))
 
+  -- 4) Send to directed broadcast (recommended) or 255.255.255.255 if you must.
   local ok, err = udp:sendto(packet, bcast_ip, port)
+
   udp:close()
   if not ok then return false, err end
   return true
 end
 
 
+
 -- Kept for reference; not used to keep parity with your minimal bash
 -- local function port_is_up(host, port, timeout_sec)
 --   local deadline = socket.gettime() + (timeout_sec or 1)