Add hop-limit-except to Juniper

Author: nward

capirca/lib/juniper.py

@@ -313,6 +313,7 @@ def __str__(self):
                           self.term.forwarding_class_except or
                           self.term.fragment_offset or
                           self.term.hop_limit or
+                          self.term.hop_limit_except or
                           self.term.next_ip or
                           self.term.port or
                           self.term.precedence or
@@ -544,6 +545,11 @@ def __str__(self):
         if self.term_type == 'inet6':
           config.Append('hop-limit %s;' % (self.term.hop_limit))
 
+      if self.term.hop_limit_except:
+        # Only generate a hop-limit-except if inet6, inet4 has not hop-limit-except.
+        if self.term_type == 'inet6':
+          config.Append('hop-limit-except %s;' % (self.term.hop_limit_except))
+
       # flexible-match
       if self.term.flexible_match_range:
         config.Append('flexible-match-range {')
@@ -911,6 +917,7 @@ def _BuildTokens(self):
                          'forwarding_class_except',
                          'fragment_offset',
                          'hop_limit',
+                         'hop_limit_except',
                          'icmp_code',
                          'logging',
                          'loss_priority',

capirca/lib/policy.py

@@ -444,6 +444,7 @@ def __init__(self, obj):
     self.packet_length = None
     self.fragment_offset = None
     self.hop_limit = None
+    self.hop_limit_except = None
     self.icmp_type = []
     self.icmp_code = []
     self.ether_type = []
@@ -904,6 +905,8 @@ def __eq__(self, other):
       return False
     if self.hop_limit != other.hop_limit:
       return False
+    if self.hop_limit_except != other.hop_limit_except:
+      return False
     if sorted(self.icmp_type) != sorted(other.icmp_type):
       return False
     if sorted(self.icmp_code) != sorted(other.icmp_code):
@@ -1240,6 +1243,8 @@ def AddObject(self, obj):
         self.fragment_offset = obj.value
       elif obj.var_type is VarType.HOP_LIMIT:
         self.hop_limit = obj.value
+      elif obj.var_type is VarType.HOP_LIMIT_EXCEPT:
+        self.hop_limit_except = obj.value
       elif obj.var_type is VarType.SINTERFACE:
         self.source_interface = obj.value
       elif obj.var_type is VarType.DINTERFACE:
@@ -1582,6 +1587,7 @@ class VarType:
   SZONE = 65
   DZONE = 66
   TTL_EXCEPT = 67
+  HOP_LIMIT_EXCEPT = 68
 
   def __init__(self, var_type, value):
     self.var_type = var_type
@@ -1766,6 +1772,7 @@ def __ne__(self, other):
     'FORWARDING_CLASS_EXCEPT',
     'FRAGMENT_OFFSET',
     'HOP_LIMIT',
+    'HOP_LIMIT_EXCEPT',
     'APPLY_GROUPS',
     'APPLY_GROUPS_EXCEPT',
     'HEADER',
@@ -1854,6 +1861,7 @@ def __ne__(self, other):
     'fragment-offset': 'FRAGMENT_OFFSET',
     'hex': 'HEX',
     'hop-limit': 'HOP_LIMIT',
+    'hop-limit-except': 'HOP_LIMIT_EXCEPT',
     'apply-groups': 'APPLY_GROUPS',
     'apply-groups-except': 'APPLY_GROUPS_EXCEPT',
     'header': 'HEADER',
@@ -2039,6 +2047,7 @@ def p_term_spec(p):
                 | term_spec forwarding_class_except_spec
                 | term_spec fragment_offset_spec
                 | term_spec hop_limit_spec
+                | term_spec hop_limit_except_spec
                 | term_spec icmp_type_spec
                 | term_spec icmp_code_spec
                 | term_spec interface_spec
@@ -2207,6 +2216,9 @@ def p_hop_limit_spec(p):
   else:
     p[0] = VarType(VarType.HOP_LIMIT, str(p[4]) + '-' + str(p[6]))
 
+def p_hop_limit_except_spec(p):
+  """ hop_limit_except_spec : HOP_LIMIT_EXCEPT ':' ':' INTEGER"""
+  p[0] = VarType(VarType.HOP_LIMIT_EXCEPT, p[4])
 
 def p_one_or_more_dscps(p):
   """ one_or_more_dscps : one_or_more_dscps DSCP_RANGE

doc/generators/juniper.md

@@ -54,6 +54,7 @@ The default format is _inet4_, and is implied if not other argument is given.
 * _forwarding-class_except::_ Do not match the specified forwarding classes.
 * _fragement-offset::_ specify a fragment offset of a fragmented packet
 * _hop-limit::_ Match the hop limit to the specified hop limit or set of hop limits.
+* _hop-limit-except::_ Allow all hop limits "except" the one specified.
 * _icmp-code::_ Specifies the ICMP code to filter on.
 * _icmp-type::_ Specify icmp-type code to match, see section [ICMP TYPES](PolicyFormat#ICMP_TYPES.md) for list of valid arguments
 * _logging::_ Specify that this packet should be logged via syslog.

tests/lib/juniper_test.py

@@ -251,6 +251,12 @@
   action:: accept
 }
 """
+GOOD_TERM_V6_HOP_LIMIT_EXCEPT = """
+term good-term-v6-hl {
+  hop-limit-except:: 25
+  action:: accept
+}
+"""
 GOOD_TERM_20_V6 = """
 term good-term-20-v6 {
   protocol-except:: icmpv6
@@ -588,7 +594,6 @@
   action:: deny
 }
 """
-
 MIXED_TESTING_TERM = """
 term good-term {
   protocol:: tcp
@@ -621,6 +626,7 @@
     'forwarding_class_except',
     'fragment_offset',
     'hop_limit',
+    'hop_limit_except',
     'icmp_code',
     'icmp_type',
     'stateless_reply',
@@ -926,6 +932,20 @@ def testHopLimitInet(self):
     output = str(jcl)
     self.assertNotIn('hop-limit 25;', output, output)
 
+  def testHopLimitExcept(self):
+    jcl = juniper.Juniper(policy.ParsePolicy(GOOD_HEADER_V6 +
+                                             GOOD_TERM_V6_HOP_LIMIT_EXCEPT,
+                                             self.naming), EXP_INFO)
+    output = str(jcl)
+    self.assertIn('hop-limit-except 25;', output, output)
+
+  def testHopLimitExceptInet(self):
+    jcl = juniper.Juniper(policy.ParsePolicy(GOOD_HEADER +
+                                             GOOD_TERM_V6_HOP_LIMIT_EXCEPT,
+                                             self.naming), EXP_INFO)
+    output = str(jcl)
+    self.assertNotIn('hop-limit-except 25;', output, output)
+
   def testProtocolExcept(self):
     jcl = juniper.Juniper(policy.ParsePolicy(GOOD_HEADER_V6 + GOOD_TERM_7,
                                              self.naming), EXP_INFO)

tests/lib/policy_test.py

@@ -457,6 +457,12 @@
   action:: accept
 }
 """
+GOOD_TERM_V6_HOP_LIMIT_EXCEPT = """
+term good-term-v6-1 {
+  hop-limit-except:: 5
+  action:: accept
+}
+"""
 
 TERM_SUPER_2 = """
 term term-super {
@@ -695,6 +701,13 @@ def testHopLimitRange(self):
     _, terms = ret.filters[0]
     self.assertEqual(str(terms[0].hop_limit[2]), '7')
 
+  def testHopLimitExcept(self):
+    pol = HEADER_V6 + GOOD_TERM_V6_HOP_LIMIT_EXCEPT
+    ret = policy.ParsePolicy(pol, self.naming)
+    self.assertEqual(len(ret.filters), 1)
+    _, terms = ret.filters[0]
+    self.assertEqual(str(terms[0].hop_limit_except[0]), '5')
+
   def testBadPortProtocols(self):
     pol = HEADER + BAD_TERM_3
     self.naming.GetServiceByProto('SNMP', 'tcp').AndReturn([])