Fix ralink-rt305x/vocore mac schema generation.

The VIF mac addresses in the ralink-rt305x chip must be sequential in
the last bit, since they are using a hardware mac filter.

1. Hash the original primary mac, since the addresses of devices bought
   together could be sequential in the last byte.

2. Increment the last byte for the VIF on the vocore (generate_mac routine)

Implements #648

package/gluon-core/files/lib/gluon/upgrade/010-primary-mac

@@ -10,8 +10,9 @@ end
 
 local platform = require 'gluon.platform'
 
-local fs = require 'nixio.fs'
+local sys = require 'luci.sys'
 local util = require 'luci.util'
+local nixio = require 'nixio'
 
 
 local try_files = {
@@ -32,9 +33,15 @@ end
 
 
 for _, file in ipairs(try_files) do
-  local addr = fs.readfile(file)
+  local addr = nixio.fs.readfile(file)
 
   if addr then
+    if platform.match('ramips', 'rt305x', {'vocore'}) then
+      -- Hash the mac address since we need to iterate in the last bits for
+      -- the VIF. (This chip uses a hardware mac filter)
+      addr = util.hash_mac(addr)
+    end
+
     sysconfig.primary_mac = util.trim(addr)
     break
   end

package/gluon-core/files/usr/lib/lua/gluon/util.lua

@@ -31,6 +31,7 @@ local table = table
 
 local nixio = require 'nixio'
 local sysconfig = require 'gluon.sysconfig'
+local platform = require 'gluon.platform'
 local site = require 'gluon.site_config'
 local uci = require('luci.model.uci').cursor()
 
@@ -83,10 +84,34 @@ end
 function generate_mac(f, i)
   local m1, m2, m3, m4, m5, m6 = string.match(sysconfig.primary_mac, '(%x%x):(%x%x):(%x%x):(%x%x):(%x%x):(%x%x)')
   m1 = nixio.bit.bor(tonumber(m1, 16), 0x02)
-  m2 = (tonumber(m2, 16)+f) % 0x100
+  m2 = tonumber(m2, 16)
   m3 = (tonumber(m3, 16)+i) % 0x100
+  m6 = tonumber(m6, 16)
 
-  return string.format('%02x:%02x:%02x:%s:%s:%s', m1, m2, m3, m4, m5, m6)
+  if platform.match('ramips', 'rt305x', {'vocore'}) then
+    -- We need to iterate in the last byte, since the vocore does
+    -- hardware mac filtering on the wlan interface.
+    m6 = (m6+f) % 0x100
+  else
+    m2 = (m2+f) % 0x100
+  end
+
+  return string.format('%02x:%02x:%02x:%s:%s:%02x', m1, m2, m3, m4, m5, m6)
+end
+
+-- Generates a mac hashed from the original
+-- The last three bits will be zeroed, since these bits are
+-- iterated on some devices for the VIF.
+function hash_mac(original)
+  local hashed = string.sub(sys.exec('echo -n "' .. original .. '" | sha512sum'),0,12)
+  local m1, m2, m3, m4, m5, m6 = string.match(hashed, '(%x%x)(%x%x)(%x%x)(%x%x)(%x%x)(%x%x)')
+  local m1 = nixio.bit.bor(tonumber(m1, 16), 0x02)
+  local m6 = nixio.bit.band(tonumber(m6, 16), 0xF8) -- zero the last three bits
+  -- It's necessary that the upper bits of the mac do
+  -- not vary on a single interface, since they are using
+  -- a hardware mac filter. (e.g 'ramips-rt305x')
+
+  return string.format('%02x:%s:%s:%s:%s:%02x', m1, m2, m3, m4, m5, m6)
 end
 
 -- Iterate over all radios defined in UCI calling