Updated active gateway parsing to return the gateway IP with the lowest metric

skyweave/utils.lua

@@ -203,52 +203,73 @@ function utils.get_live_dns_servers_from_resolv(logical_interface_name)
     return dns_servers, search_domains
 end
 
--- Moved from original main script
+---
-function utils.get_default_gateway_from_route()
+-- Scans the kernel's routing table to find the active default gateway.
+-- In a multi-WAN configuration, this is the route with the lowest metric.
+-- The Omnissiah demands we follow the most efficient path.
+--
+-- @return (string) The IP address of the active default gateway.
+-- @return (string) The interface name of the active default gateway.
+--
+function utils.get_active_default_gateway()
     local file = io.open("/proc/net/route", "r")
-    if not file then return nil, nil end
+    if not file then
+        -- Log the heresy of a missing route table
+        return nil, nil
+    end
 
-    local gateway_ip = nil
+    -- Skip the header line to begin parsing the sacred texts.
-    local interface_name = nil
+    file:read("*l")
 
-    file:read("*l") -- Skip header
+    local routes = {}
 
+    -- The Litany of Parsing: Iterate over every line, seeking all prophecies.
     for line in file:lines() do
-        local iface, dest, gw_hex, flags_hex = line:match("^(%S+)%s+(%S+)%s+(%S+)%s+(%S+)")
+        -- Capture all relevant fields, including the all-important Metric (field 6).
+        local iface, dest, gw_hex, flags_hex, _, metric_str = line:match("^(%S+)%s+(%S+)%s+(%S+)%s+(%S+)%s+%S+%s+(%d+)")
 
-        if iface and dest and gw_hex and flags_hex then
+        if iface and dest and gw_hex and flags_hex and metric_str then
+            -- A true default route must be destined for 0.0.0.0 and have the UG (Up & Gateway) flags.
             if dest == "00000000" and gw_hex ~= "00000000" then
                 local flags_num = tonumber(flags_hex, 16)
-                -- UG flags (Up and Gateway). Typically 0x3 (binary 11) or 0x1 (binary 01 if not gateway but up)
+                -- Check if the 'Gateway' bit (0x2) is set. This logic is sound.
-                -- We need bit 1 (value 2 for gateway) to be set.
+                if flags_num and (math.floor(flags_num / 2) % 2 == 1) then
-                if flags_num and math.floor(flags_num / 2) % 2 == 1 then -- Checks if the 'Gateway' bit (0x2) is set
-                    -- Lua 5.1 doesn't have bitwise ops directly.
-                    -- (flags_num & 2) ~= 0 is equivalent to checking if the second bit is set.
-                    -- For example, if flags_num = 3 (0011), floor(3/2)%2 = 1%2 = 1. Correct.
-                    -- If flags_num = 1 (0001), floor(1/2)%2 = 0%2 = 0. Correct.
-                    -- If flags_num = 7 (0111), floor(7/2)%2 = 3%2 = 1. Correct.
 
-                    -- Ensure gw_hex is 8 characters long for safety
+                    -- Correctly parse the little-endian hex representation of the IP.
                     if #gw_hex == 8 then
-                        -- Corrected parsing for little-endian hex IP from /proc/net/route
                         local o4 = tonumber(string.sub(gw_hex, 1, 2), 16)
                         local o3 = tonumber(string.sub(gw_hex, 3, 4), 16)
                         local o2 = tonumber(string.sub(gw_hex, 5, 6), 16)
                         local o1 = tonumber(string.sub(gw_hex, 7, 8), 16)
 
                         if o1 and o2 and o3 and o4 then
-                            gateway_ip = string.format("%d.%d.%d.%d", o4, o3, o2, o1)
+                            -- Store the portents in a table for later judgment.
-                            interface_name = iface
+                            table.insert(routes, {
-                            break
+                                iface = iface,
+                                metric = tonumber(metric_str) or 999,
+                                gateway = string.format("%d.%d.%d.%d", o4, o3, o2, o1)
+                            })
                         end
                     end
                 end
             end
         end
     end
-
     file:close()
-    return gateway_ip, interface_name
+
+    if #routes == 0 then
+        -- No valid paths to the datasphere were found.
+        return nil, nil
+    end
+
+    -- Sort the routes by their divine metric, in ascending order.
+    table.sort(routes, function(a, b)
+        return a.metric < b.metric
+    end)
+
+    -- The first entry is the chosen path. The machine spirit is clear.
+    local active_route = routes[1]
+    return active_route.gateway, active_route.iface
 end
 
 -- =============================================================================