From c934087b627f7d368458781944f990b0eb479634 Mon Sep 17 00:00:00 2001
From: 0xb10c <0xb10c@gmail.com>
Date: Thu, 3 Feb 2022 11:25:30 +0100
Subject: test: checks for tracepoint tests

For testing the USDT tracepoint API in the functional tests we
require:
 - that we are on a Linux system*
 - that Bitcoin Core is compiled with tracepoints
 - that bcc and the the Python bcc module [0] is installed
 - that we run the tests with the required permissions**
otherwise we skip the tests.

*:  We currently only support tracepoints on Linux. Tracepoints are
    not compiled on other platforms.
**: Currently, we check for root permissions via getuid == 0. It's
    unclear if it's even possible to run the tests a non-root user
    with e.g. CAP_BPF, CAP_PERFMON, and access to /sys/kernel/debug/
    tracing/. Anyone running these tests as root should carefully
    review them first and then run them in a disposable VM.

[0]: https://github.com/iovisor/bcc/blob/master/INSTALL.md
---
 test/functional/test_framework/test_framework.py | 28 ++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

(limited to 'test/functional/test_framework')

diff --git a/test/functional/test_framework/test_framework.py b/test/functional/test_framework/test_framework.py
index 8f75255caf..165c5b8d83 100755
--- a/test/functional/test_framework/test_framework.py
+++ b/test/functional/test_framework/test_framework.py
@@ -9,6 +9,7 @@ from enum import Enum
 import argparse
 import logging
 import os
+import platform
 import pdb
 import random
 import re
@@ -821,6 +822,29 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
         except ImportError:
             raise SkipTest("python3-zmq module not available.")
 
+    def skip_if_no_python_bcc(self):
+        """Attempt to import the bcc package and skip the tests if the import fails."""
+        try:
+            import bcc  # type: ignore[import] # noqa: F401
+        except ImportError:
+            raise SkipTest("bcc python module not available")
+
+    def skip_if_no_bitcoind_tracepoints(self):
+        """Skip the running test if bitcoind has not been compiled with USDT tracepoint support."""
+        if not self.is_usdt_compiled():
+            raise SkipTest("bitcoind has not been built with USDT tracepoints enabled.")
+
+    def skip_if_no_bpf_permissions(self):
+        """Skip the running test if we don't have permissions to do BPF syscalls and load BPF maps."""
+        # check for 'root' permissions
+        if os.geteuid() != 0:
+            raise SkipTest("no permissions to use BPF (please review the tests carefully before running them with higher privileges)")
+
+    def skip_if_platform_not_linux(self):
+        """Skip the running test if we are not on a Linux platform"""
+        if platform.system() != "Linux":
+            raise SkipTest("not on a Linux system")
+
     def skip_if_no_bitcoind_zmq(self):
         """Skip the running test if bitcoind has not been compiled with zmq support."""
         if not self.is_zmq_compiled():
@@ -902,6 +926,10 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
         """Checks whether the zmq module was compiled."""
         return self.config["components"].getboolean("ENABLE_ZMQ")
 
+    def is_usdt_compiled(self):
+        """Checks whether the USDT tracepoints were compiled."""
+        return self.config["components"].getboolean("ENABLE_USDT_TRACEPOINTS")
+
     def is_sqlite_compiled(self):
         """Checks whether the wallet module was compiled with Sqlite support."""
         return self.config["components"].getboolean("USE_SQLITE")
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