CP, refactor arp list, closes #1344

(cherry picked from commit 3151c87)
(cherry picked from commit 2981b66)

src/opnsense/scripts/OPNsense/CaptivePortal/lib/arp.py

@@ -51,22 +51,28 @@ def _fetch_arp_table(self):
             subprocess.check_call(['/usr/sbin/arp', '-an'], stdout=output_stream, stderr=subprocess.STDOUT)
             output_stream.seek(0)
             for line in output_stream.read().split('\n'):
-                if line.find('(') > -1 and line.find(')') > -1:
-                    if line.find('expires in') > -1:
-                        expires = line.split('expires in')[1:][0].strip().split(' ')[0]
-                        if expires.isdigit():
-                            expires = int(expires)
-                        else:
-                            expires = -1
-                    else:
-                        expires = -1
-                    address = line.split(')')[0].split('(')[-1]
-                    mac = line.split('at')[-1].split('on')[0].strip()
-                    physical_intf = line.split('on')[-1].strip().split(' ')[0]
-                    if address in self._arp_table:
-                        self._arp_table[address]['intf'].append(physical_intf)
-                    elif mac.find('incomplete') == -1:
-                        self._arp_table[address] = {'mac': mac, 'intf': [physical_intf], 'expires': expires}
+                line_parts = line.split()
+
+                if len(line_parts) < 6 or line_parts[2] != 'at' or line_parts[4] != 'on':
+                    continue
+
+                if len(line_parts[1]) < 2 or line_parts[1][0] != '(' or line_parts[1][-1] != ')':
+                    continue
+
+                address = line_parts[1][1:-1]
+                physical_intf = line_parts[5]
+                mac = line_parts[3]
+                expires = -1
+
+                for index in range(len(line_parts) - 3):
+                    if line_parts[index] == 'expires' and line_parts[index + 1] == 'in':
+                        if line_parts[index + 2].isdigit():
+                            expires = int(line_parts[index + 2])
+
+                if address in self._arp_table:
+                    self._arp_table[address]['intf'].append(physical_intf)
+                elif mac.find('incomplete') == -1:
+                    self._arp_table[address] = {'mac': mac, 'intf': [physical_intf], 'expires': expires}
 
     def list_items(self):
         """ return parsed arp list