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authorVratko Polak <vrpolak@cisco.com>2022-02-15 10:59:14 +0100
committerVratko Polak <vrpolak@cisco.com>2022-02-15 10:59:14 +0100
commitf9abe8e4e17faf59ae72113f4f11960dcd57b7cc (patch)
tree907c764c69c6142d0222ceaad0aa9bcfb752a450 /resources/libraries/python
parentd6199f77dc6d8d110adb8ac0680ef81eff88e069 (diff)
fix(nat): parse new show nat44 summary output
+ Keep support for VPP 22.02 CLI output. + Keep tolerating "timed out" sessions for 2202 output. + Subtract timed-out sessions for post-2202 output. + Explain the logic differences in docstring. + Convert the return value to int. Change-Id: I8a119e1034848bfd0fb131cb633e2441b44634a2 Signed-off-by: Vratko Polak <vrpolak@cisco.com>
Diffstat (limited to 'resources/libraries/python')
-rw-r--r--resources/libraries/python/NATUtil.py67
1 files changed, 54 insertions, 13 deletions
diff --git a/resources/libraries/python/NATUtil.py b/resources/libraries/python/NATUtil.py
index e771637b37..0116306e6c 100644
--- a/resources/libraries/python/NATUtil.py
+++ b/resources/libraries/python/NATUtil.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2021 Cisco and/or its affiliates.
+# Copyright (c) 2022 Cisco and/or its affiliates.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at:
@@ -289,27 +289,68 @@ class NATUtil:
@staticmethod
def get_nat44_sessions_number(node, proto):
- """Get number of established NAT44 sessions from actual NAT44 mapping
- data.
+ """Get number of established NAT44 sessions from NAT44 mapping data.
+
+ This keyword uses output from a CLI command,
+ so it can start failing when VPP changes the output format.
+ TODO: Switch to API (or stat segment) when available.
+
+ The current implementation supports both 2202 and post-2202 format.
+ (The Gerrit number changing the output format is 34877.)
+
+ For TCP proto, the post-2202 format includes "timed out"
+ established sessions into its count of total sessions.
+ As the tests should fail if a session is timed-out,
+ the logic substracts timed out sessions for the resturned value.
+
+ The 2202 output reports most of TCP sessions as in "transitory" state,
+ as opposed to "established", but the previous CSIT logic tolerated that.
+ Ideally, whis keyword would add establised and transitory sessions
+ (but without CLOSED and WAIT_CLOSED sessions) and return that.
+ The current implementation simply returns "total tcp sessions" value,
+ to preserve the previous CSIT behavior for 2202 output.
:param node: DUT node.
:param proto: Required protocol - TCP/UDP/ICMP.
:type node: dict
:type proto: str
- :returns: Number of established NAT44 sessions.
+ :returns: Number of active established NAT44 sessions.
:rtype: int
:raises ValueError: If not supported protocol.
+ :raises RuntimeError: If output is not formatted as expected.
"""
- nat44_data = dict()
- if proto in [u"UDP", u"TCP", u"ICMP"]:
- for line in NATUtil.show_nat44_summary(node).splitlines():
- sum_k, sum_v = line.split(u":") if u":" in line \
- else (line, None)
- nat44_data[sum_k] = sum_v.strip() if isinstance(sum_v, str) \
- else sum_v
- else:
+ proto_l = proto.strip().lower()
+ if proto_l not in [u"udp", u"tcp", u"icmp"]:
raise ValueError(f"Unsupported protocol: {proto}!")
- return nat44_data.get(f"total {proto.lower()} sessions", 0)
+ summary_text = NATUtil.show_nat44_summary(node)
+ summary_lines = summary_text.splitlines()
+ # Output from VPP v22.02 and before, delete when no longer needed.
+ pattern_2202 = f"total {proto_l} sessions:"
+ if pattern_2202 in summary_text:
+ for line in summary_lines:
+ if pattern_2202 not in line:
+ continue
+ return int(line.split(u":", 1)[1].strip())
+ # Post-2202, the proto info and session info are not on the same line.
+ found = False
+ for line in summary_lines:
+ if not found:
+ if f"{proto_l} sessions:" in line:
+ found = True
+ continue
+ # Proto is found, find the line we are interested in.
+ if proto_l == u"tcp" and u"established" not in line:
+ continue
+ if u"total" not in line and u"established" not in line:
+ raise RuntimeError(f"show nat summary: no {proto} total.")
+ # We have the line with relevant numbers.
+ total_part, timed_out_part = line.split(u"(", 1)
+ timed_out_part = timed_out_part.split(u")", 1)[0]
+ total_count = int(total_part.split(u":", 1)[1].strip())
+ timed_out_count = int(timed_out_part.split(u":", 1)[1].strip())
+ active_count = total_count - timed_out_count
+ return active_count
+ raise RuntimeError(u"Unknown format of show nat44 summary")
# DET44 PAPI calls
# DET44 means deterministic mode of NAT44