[Typing] Initial Pcap typing (aerleon#269)

* Initial pcap typing.

* .

* Fixing some typing in pcap.py

* Reformatted pcap.py.

* Removing more Any usage in typing.

* Formatting.

aerleon/lib/pcap.py

@@ -29,9 +29,13 @@
 """
 
 
+from typing import Dict, List, Set, Tuple, Union
+
 from absl import logging
 
 from aerleon.lib import aclgenerator
+from aerleon.lib.nacaddr import IPv4, IPv6
+from aerleon.lib.policy import Policy, Term
 
 
 class Error(aclgenerator.Error):
@@ -86,7 +90,9 @@ class Term(aclgenerator.Term):
  'hopopt': 'ip6 protochain 0',
  }
 
- def __init__(self, term, filter_name, af='inet', direction=''):
+ def __init__(
+ self, term: Term, filter_name: str, af: str = 'inet', direction: str = ''
+ ) -> None:
  """Setup a new term.
 
  Args:
@@ -106,7 +112,7 @@ def __init__(self, term, filter_name, af='inet', direction=''):
  self.af = af
  self.direction = direction
 
- def __str__(self):
+ def __str__(self) -> str:
  """Render config output from this term object."""
  conditions = []
 
@@ -192,7 +198,7 @@ def __str__(self):
 
  return cond + '\n'
 
- def _CheckAddressAf(self, addrs):
+ def _CheckAddressAf(self, addrs: List[Union[IPv4, IPv6]]) -> List[Union[str, IPv4, IPv6]]:
  """Verify that the requested address-family matches the address's family."""
  if not addrs:
  return ['any']
@@ -206,7 +212,7 @@ def _CheckAddressAf(self, addrs):
  return af_addrs
 
  @staticmethod
- def JoinConditionals(condition_list, operator):
+ def JoinConditionals(condition_list: List[str], operator: str) -> str:
  """Join conditionals using the specified operator.
 
  Filters out empty elements and blank strings.
@@ -228,7 +234,9 @@ def JoinConditionals(condition_list, operator):
  res = '(%s)' % (op.join(condition_list))
  return res
 
- def _GenerateAddrStatement(self, addrs, exclude_addrs):
+ def _GenerateAddrStatement(
+ self, addrs: List[Union[str, IPv6, IPv4]], exclude_addrs: List[Union[str, IPv6, IPv4]]
+ ) -> str:
  addrlist = []
  for d in addrs:
  if d != 'any' and str(d) != '::/0':
@@ -251,10 +259,10 @@ def _GenerateAddrStatement(self, addrs, exclude_addrs):
  else:
  return Term.JoinConditionals(addrlist, 'or')
 
- def _GenerateProtoStatement(self, protocols):
+ def _GenerateProtoStatement(self, protocols: List[str]) -> str:
  return Term.JoinConditionals([self._PROTO_TABLE[p] for p in protocols], 'or')
 
- def _GeneratePortStatement(self, ports, direction):
+ def _GeneratePortStatement(self, ports: List[Tuple[int, int]], direction: str) -> str:
  conditions = []
  # term.destination_port is a list of tuples containing the start and end
  # ports of the port range. In the event it is a single port, the start
@@ -266,7 +274,7 @@ def _GeneratePortStatement(self, ports, direction):
  conditions.append('%s portrange %s-%s' % (direction, port_tuple[0], port_tuple[1]))
  return Term.JoinConditionals(conditions, 'or')
 
- def _GenerateTcpOptions(self, options):
+ def _GenerateTcpOptions(self, options: List[str]) -> str:
  opts = [str(x) for x in options]
  tcp_flags_set = []
  tcp_flags_check = []
@@ -289,7 +297,7 @@ def _GenerateTcpOptions(self, options):
  )
  return ''
 
- def _GenerateIcmpType(self, icmp_types, icmp_code):
+ def _GenerateIcmpType(self, icmp_types: List[int], icmp_code: List[int]) -> str:
  rtr_str = ''
  if icmp_types:
  code_strings = ['']
@@ -314,7 +322,7 @@ class PcapFilter(aclgenerator.ACLGenerator):
  SUFFIX = '.pcap'
  _TERM = Term
 
- def __init__(self, *args, **kwargs):
+ def __init__(self, *args, **kwargs) -> None:
  """Initialize a PcapFilter generator.
 
  Takes standard ACLGenerator arguments, as well as an 'invert' kwarg. If
@@ -332,7 +340,7 @@ def __init__(self, *args, **kwargs):
  del kwargs['invert']
  super().__init__(*args, **kwargs)
 
- def _BuildTokens(self):
+ def _BuildTokens(self) -> Tuple[Set[str], Dict[str, Set[str]]]:
  """Build supported tokens for platform.
 
  Returns:
@@ -363,7 +371,7 @@ def _BuildTokens(self):
 
  return supported_tokens, supported_sub_tokens
 
- def _TranslatePolicy(self, pol, exp_info):
+ def _TranslatePolicy(self, pol: Policy, exp_info: int) -> None:
  self.pcap_policies = []
  good_afs = ['inet', 'inet6', 'mixed']
  good_options = ['in', 'out']
@@ -430,7 +438,7 @@ def _TranslatePolicy(self, pol, exp_info):
 
  self.pcap_policies.append((header, filter_name, filter_type, accept_terms, deny_terms))
 
- def __str__(self):
+ def __str__(self) -> str:
  """Render the output of the PF policy into config."""
  target = []