bring back functions generate_host(), generate_address() and helpers,…

… killed by Gio with 'Human understandable address generation' and 'Begin code razionalization and cleaning'

packages/lime-system/files/usr/lib/lua/lime/network.lua

@@ -2,6 +2,7 @@
 
 network = {}
 
+local bit = require("bit")
 local ip = require("luci.ip")
 local libuci = require("uci")
 local fs = require("nixio.fs")
@@ -34,6 +35,43 @@ function network.primary_address()
 	return ip.IPv4(ipv4_template), ip.IPv6(ipv6_template) 
 end
 
+function network.generate_host(ipprefix, hexsuffix)
+    -- use only the 8 rightmost nibbles for IPv4, or 32 nibbles for IPv6
+    hexsuffix = hexsuffix:sub((ipprefix[1] == 4) and -8 or -32)
+
+    -- convert hexsuffix into a cidr instance, using same prefix and family of ipprefix
+    local ipsuffix = ip.Hex(hexsuffix, ipprefix:prefix(), ipprefix[1])
+
+    local ipaddress = ipprefix
+    -- if it's a network prefix, fill in host bits with ipsuffix
+    if ipprefix:equal(ipprefix:network()) then
+        for i in ipairs(ipprefix[2]) do
+            -- reset ipsuffix netmask bits to 0
+            ipsuffix[2][i] = bit.bxor(ipsuffix[2][i],ipsuffix:network()[2][i])
+            -- fill in ipaddress host part, with ipsuffix bits
+            ipaddress[2][i] = bit.bor(ipaddress[2][i],ipsuffix[2][i])
+        end
+    end
+
+    return ipaddress
+end
+
+function network.generate_address(n)
+    local id = n or 0
+    local m4, m5, m6 = utils.node_id()
+    local n1, n2, n3 = utils.network_id()
+    local ipv4_template = config.get("network", "main_ipv4_address")
+    local ipv6_template = config.get("network", "main_ipv6_address")
+
+    local hex = utils.hex
+    ipv6_template = ipv6_template:gsub("N1", hex(n1)):gsub("N2", hex(n2)):gsub("N3", hex(n3))
+    ipv4_template = ipv4_template:gsub("N1", n1):gsub("N2", n2):gsub("N3", n3)
+
+    hexsuffix = hex((m4 * 256*256 + m5 * 256 + m6) + id)
+    return network.generate_host(ip.IPv4(ipv4_template), hexsuffix),
+           network.generate_host(ip.IPv6(ipv6_template), hexsuffix)
+end
+
 function network.setup_rp_filter()
 	local sysctl_file_path = "/etc/sysctl.conf";
 	local sysctl_options = "";

packages/lime-system/files/usr/lib/lua/lime/utils.lua

@@ -2,6 +2,8 @@
 
 utils = {}
 
+local config = require("lime.config")
+
 function utils.split(string, sep)
     local ret = {}
     for token in string.gmatch(string, "[^"..sep.."]+") do table.insert(ret, token) end
@@ -41,4 +43,23 @@ function utils.applyMacTemplate10(template, mac)
 	return template
 end
 
+function utils.node_id()
+    local m = network.primary_mac()
+    return tonumber(m[4], 16), tonumber(m[5], 16), tonumber(m[6], 16)
+end
+
+function utils.network_id()
+    local network_essid = config.get("wifi", "ap_ssid")
+    local n1, n2, n3
+    local fd = io.popen('echo "' .. network_essid .. '" | md5sum')
+    if fd then
+        local md5 = fd:read("*a")
+        n1 = tonumber(md5:match("^(..)"), 16)
+        n2 = tonumber(md5:match("^..(..)"), 16)
+        n3 = tonumber(md5:match("^....(..)"), 16)
+        fd:close()
+    end
+    return n1, n2, n3
+end
+
 return utils