test: use ephemeral ports in p2p_private_broadcast.py
What the developer wrote
Authored by w0xlt
test: use ephemeral ports in p2p_private_broadcast.py
The test `p2p_private_broadcast.py` gets some Python P2P nodes to listen
and instructs the SOCKS5 proxy to redirect connections to them instead
of to the requested addresses. This way the `bitcoind` which uses the
proxy is tricked to think it has connected to real routable internet
IP addresses or `.onion` addresses.
Picking the ports where to Python P2P nodes to listen however is tricky
to be done in a non-conflicting way, given that other tests may run in
parallel. https://github.com/bitcoin/bitcoin/pull/34186 made it possible
to let the OS select a free port, so use that in
`p2p_private_broadcast.py`.
What changed, and why it matters
This is a minor test-only change. It updates one Bitcoin Core functional test to let the operating system pick a free network port automatically, instead of the test guessing a port number. This prevents the test from failing when another test is already using the guessed port. It does not change the Bitcoin Core software that users run, and it has no security impact on the live Bitcoin network or user wallets.
No security action needed. This is a routine test improvement. Reviewers may verify the test still passes in parallel test runs.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The commit modifies test/functional/p2p_private_broadcast.py to bind Python P2P listener nodes with port=0 so the OS assigns an ephemeral port. Previously the test computed a base port from tor_port(MAX_NODES)+1 and assigned sequential ports, which could collide with other concurrently running tests or TIME_WAIT sockets. The change removes the MAX_NODES import and the ports_base calculation, and adds a callback/on_listen_done mechanism to discover the assigned port. This is purely a test-framework robustness improvement.
Changed components
test/functional/p2p_private_broadcast.pyInspect captured patch +4 / −5
diff --git a/test/functional/p2p_private_broadcast.py b/test/functional/p2p_private_broadcast.py
index 4c3739d8..803444cc 100755
--- a/test/functional/p2p_private_broadcast.py
+++ b/test/functional/p2p_private_broadcast.py
@@ -36,7 +36,6 @@ from test_framework.test_framework import (
BitcoinTestFramework,
)
from test_framework.util import (
- MAX_NODES,
assert_equal,
assert_not_equal,
assert_raises_rpc_error,
@@ -181,9 +180,6 @@ class P2PPrivateBroadcast(BitcoinTestFramework):
self.socks5_server = Socks5Server(socks5_server_config)
self.socks5_server.start()
- # Tor ports are the highest among p2p/rpc/tor, so this should be the first available port.
- ports_base = tor_port(MAX_NODES) + 1
-
self.destinations = []
self.destinations_lock = threading.Lock()
@@ -215,9 +211,12 @@ class P2PPrivateBroadcast(BitcoinTestFramework):
actual_to_addr = addr
actual_to_port = port
+ # Use port=0 to let the OS assign an available port. This
+ # avoids "address already in use" errors when tests run
+ # concurrently or ports are still in TIME_WAIT state.
self.network_thread.listen(
addr="127.0.0.1",
- port=ports_base + i,
+ port=0,
p2p=listener,
callback=on_listen_done)
# Wait until the callback has been called.
Why this scored 15/100
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