#!/usr/bin/env python3
# Copyright (c) 2022 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
""" Tests the mempool:* tracepoint API interface.
See https://github.com/bitcoin/bitcoin/blob/master/doc/tracing.md#context-mempool
"""
import ctypes
from decimal import Decimal
# Test will be skipped if we don't have bcc installed
try:
from bcc import BPF, USDT # type: ignore[import]
except ImportError:
pass
from test_framework.blocktools import COINBASE_MATURITY
from test_framework.messages import COIN, DEFAULT_MEMPOOL_EXPIRY_HOURS
from test_framework.p2p import P2PDataStore
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import assert_equal
from test_framework.wallet import MiniWallet
MEMPOOL_TRACEPOINTS_PROGRAM = """
# include <uapi/linux/ptrace.h>
// The longest rejection reason is 118 chars and is generated in case of SCRIPT_ERR_EVAL_FALSE by
// strprintf("mandatory-script-verify-flag-failed (%s)", ScriptErrorString(check.GetScriptError()))
#define MAX_REJECT_REASON_LENGTH 118
// The longest string returned by RemovalReasonToString() is 'sizelimit'
#define MAX_REMOVAL_REASON_LENGTH 9
#define HASH_LENGTH 32
struct added_event
{
u8 hash[HASH_LENGTH];
s32 vsize;
s64 fee;
};
struct removed_event
{
u8 hash[HASH_LENGTH];
char reason[MAX_REMOVAL_REASON_LENGTH];
s32 vsize;
s64 fee;
u64 entry_time;
};
struct rejected_event
{
u8 hash[HASH_LENGTH];
char reason[MAX_REJECT_REASON_LENGTH];
};
struct replaced_event
{
u8 replaced_hash[HASH_LENGTH];
s32 replaced_vsize;
s64 replaced_fee;
u64 replaced_entry_time;
u8 replacement_hash[HASH_LENGTH];
s32 replacement_vsize;
s64 replacement_fee;
bool replaced_by_transaction;
};
// BPF perf buffer to push the data to user space.
BPF_PERF_OUTPUT(added_events);
BPF_PERF_OUTPUT(removed_events);
BPF_PERF_OUTPUT(rejected_events);
BPF_PERF_OUTPUT(replaced_events);
int trace_added(struct pt_regs *ctx) {
struct added_event added = {};
bpf_usdt_readarg_p(1, ctx, &added.hash, HASH_LENGTH);
bpf_usdt_readarg(2, ctx, &added.vsize);
bpf_usdt_readarg(3, ctx, &added.fee);
added_events.perf_submit(ctx, &added, sizeof(added));
return 0;
}
int trace_removed(struct pt_regs *ctx) {
struct removed_event removed = {};
bpf_usdt_readarg_p(1, ctx, &removed.hash, HASH_LENGTH);
bpf_usdt_readarg_p(2, ctx, &removed.reason, MAX_REMOVAL_REASON_LENGTH);
bpf_usdt_readarg(3, ctx, &removed.vsize);
bpf_usdt_readarg(4, ctx, &removed.fee);
bpf_usdt_readarg(5, ctx, &removed.entry_time);
removed_events.perf_submit(ctx, &removed, sizeof(removed));
return 0;
}
int trace_rejected(struct pt_regs *ctx) {
struct rejected_event rejected = {};
bpf_usdt_readarg_p(1, ctx, &rejected.hash, HASH_LENGTH);
bpf_usdt_readarg_p(2, ctx, &rejected.reason, MAX_REJECT_REASON_LENGTH);
rejected_events.perf_submit(ctx, &rejected, sizeof(rejected));
return 0;
}
int trace_replaced(struct pt_regs *ctx) {
struct replaced_event replaced = {};
bpf_usdt_readarg_p(1, ctx, &replaced.replaced_hash, HASH_LENGTH);
bpf_usdt_readarg(2, ctx, &replaced.replaced_vsize);
bpf_usdt_readarg(3, ctx, &replaced.replaced_fee);
bpf_usdt_readarg(4, ctx, &replaced.replaced_entry_time);
bpf_usdt_readarg_p(5, ctx, &replaced.replacement_hash, HASH_LENGTH);
bpf_usdt_readarg(6, ctx, &replaced.replacement_vsize);
bpf_usdt_readarg(7, ctx, &replaced.replacement_fee);
bpf_usdt_readarg(8, ctx, &replaced.replaced_by_transaction);
replaced_events.perf_submit(ctx, &replaced, sizeof(replaced));
return 0;
}
"""
class MempoolReplaced(ctypes.Structure):
_fields_ = [
("replaced_hash", ctypes.c_ubyte * 32),
("replaced_vsize", ctypes.c_int32),
("replaced_fee", ctypes.c_int64),
("replaced_entry_time", ctypes.c_uint64),
("replacement_hash", ctypes.c_ubyte * 32),
("replacement_vsize", ctypes.c_int32),
("replacement_fee", ctypes.c_int64),
("replaced_by_transaction", ctypes.c_bool),
]
class MempoolTracepointTest(BitcoinTestFramework):
def set_test_params(self):
self.num_nodes = 1
self.setup_clean_chain = True
def skip_test_if_missing_module(self):
self.skip_if_platform_not_linux()
self.skip_if_no_bitcoind_tracepoints()
self.skip_if_no_python_bcc()
self.skip_if_no_bpf_permissions()
def added_test(self):
"""Add a transaction to the mempool and make sure the tracepoint returns
the expected txid, vsize, and fee."""
events = []
self.log.info("Hooking into mempool:added tracepoint...")
node = self.nodes[0]
ctx = USDT(pid=node.process.pid)
ctx.enable_probe(probe="mempool:added", fn_name="trace_added")
bpf = BPF(text=MEMPOOL_TRACEPOINTS_PROGRAM, usdt_contexts=[ctx], debug=0, cflags=["-Wno-error=implicit-function-declaration"])
def handle_added_event(_, data, __):
events.append(bpf["added_events"].event(data))
bpf["added_events"].open_perf_buffer(handle_added_event)
self.log.info("Sending transaction...")
fee = Decimal(31200)
tx = self.wallet.send_self_transfer(from_node=node, fee=fee / COIN)
self.log.info("Polling buffer...")
bpf.perf_buffer_poll(timeout=200)
self.log.info("Cleaning up mempool...")
self.generate(node, 1)
self.log.info("Ensuring mempool:added event was handled successfully...")
assert_equal(1, len(events))
event = events[0]
assert_equal(bytes(event.hash)[::-1].hex(), tx["txid"])
assert_equal(event.vsize, tx["tx"].get_vsize())
assert_equal(event.fee, fee)
bpf.cleanup()
self.generate(self.wallet, 1)
def removed_test(self):
"""Expire a transaction from the mempool and make sure the tracepoint returns
the expected txid, expiry reason, vsize, and fee."""
events = []
self.log.info("Hooking into mempool:removed tracepoint...")
node = self.nodes[0]
ctx = USDT(pid=node.process.pid)
ctx.enable_probe(probe="mempool:removed", fn_name="trace_removed")
bpf = BPF(text=MEMPOOL_TRACEPOINTS_PROGRAM, usdt_contexts=[ctx], debug=0, cflags=["-Wno-error=implicit-function-declaration"])
def handle_removed_event(_, data, __):
events.append(bpf["removed_events"].event(data))
bpf["removed_events"].open_perf_buffer(handle_removed_event)
self.log.info("Sending transaction...")
fee = Decimal(31200)
tx = self.wallet.send_self_transfer(from_node=node, fee=fee / COIN)
txid = tx["txid"]
self.log.info("Fast-forwarding time to mempool expiry...")
entry_time = node.getmempoolentry(txid)["time"]
expiry_time = entry_time + 60 * 60 * DEFAULT_MEMPOOL_EXPIRY_HOURS + 5
node.setmocktime(expiry_time)
self.log.info("Triggering expiry...")
self.wallet.get_utxo(txid=txid)
self.wallet.send_self_transfer(from_node=node)
self.log.info("Polling buffer...")
bpf.perf_buffer_poll(timeout=200)
self.log.info("Ensuring mempool:removed event was handled successfully...")
assert_equal(1, len(events))
event = events[0]
assert_equal(bytes(event.hash)[::-1].hex(), txid)
assert_equal(event.reason.decode("UTF-8"), "expiry")
assert_equal(event.vsize, tx["tx"].get_vsize())
assert_equal(event.fee, fee)
assert_equal(event.entry_time, entry_time)
bpf.cleanup()
self.generate(self.wallet, 1)
def replaced_test(self):
"""Replace one and two transactions in the mempool and make sure the tracepoint
returns the expected txids, vsizes, and fees."""
events = []
self.log.info("Hooking into mempool:replaced tracepoint...")
node = self.nodes[0]
ctx = USDT(pid=node.process.pid)
ctx.enable_probe(probe="mempool:replaced", fn_name="trace_replaced")
bpf = BPF(text=MEMPOOL_TRACEPOINTS_PROGRAM, usdt_contexts=[ctx], debug=0, cflags=["-Wno-error=implicit-function-declaration"])
def handle_replaced_event(_, data, __):
event = ctypes.cast(data, ctypes.POINTER(MempoolReplaced)).contents
events.append(event)
bpf["replaced_events"].open_perf_buffer(handle_replaced_event)
self.log.info("Sending RBF transaction...")
utxo = self.wallet.get_utxo(mark_as_spent=True)
original_fee = Decimal(40000)
original_tx = self.wallet.send_self_transfer(
from_node=node, utxo_to_spend=utxo, fee=original_fee / COIN
)
entry_time = node.getmempoolentry(original_tx["txid"])["time"]
self.log.info("Sending replacement transaction...")
replacement_fee = Decimal(45000)
replacement_tx = self.wallet.send_self_transfer(
from_node=node, utxo_to_spend=utxo, fee=replacement_fee / COIN
)
self.log.info("Polling buffer...")
bpf.perf_buffer_poll(timeout=200)
self.log.info("Ensuring mempool:replaced event was handled successfully...")
assert_equal(1, len(events))
event = events[0]
assert_equal(bytes(event.replaced_hash)[::-1].hex(), original_tx["txid"])
assert_equal(event.replaced_vsize, original_tx["tx"].get_vsize())
assert_equal(event.replaced_fee, original_fee)
assert_equal(event.replaced_entry_time, entry_time)
assert_equal(bytes(event.replacement_hash)[::-1].hex(), replacement_tx["txid"])
assert_equal(event.replacement_vsize, replacement_tx["tx"].get_vsize())
assert_equal(event.replacement_fee, replacement_fee)
assert_equal(event.replaced_by_transaction, True)
bpf.cleanup()
self.generate(self.wallet, 1)
def rejected_test(self):
"""Create an invalid transaction and make sure the tracepoint returns
the expected txid, rejection reason, peer id, and peer address."""
events = []
self.log.info("Adding P2P connection...")
node = self.nodes[0]
node.add_p2p_connection(P2PDataStore())
self.log.info("Hooking into mempool:rejected tracepoint...")
ctx = USDT(pid=node.process.pid)
ctx.enable_probe(probe="mempool:rejected", fn_name="trace_rejected")
bpf = BPF(text=MEMPOOL_TRACEPOINTS_PROGRAM, usdt_contexts=[ctx], debug=0, cflags=["-Wno-error=implicit-function-declaration"])
def handle_rejected_event(_, data, __):
events.append(bpf["rejected_events"].event(data))
bpf["rejected_events"].open_perf_buffer(handle_rejected_event)
self.log.info("Sending invalid transaction...")
tx = self.wallet.create_self_transfer(fee_rate=Decimal(0))
node.p2ps[0].send_txs_and_test([tx["tx"]], node, success=False)
self.log.info("Polling buffer...")
bpf.perf_buffer_poll(timeout=200)
self.log.info("Ensuring mempool:rejected event was handled successfully...")
assert_equal(1, len(events))
event = events[0]
assert_equal(bytes(event.hash)[::-1].hex(), tx["tx"].hash)
# The next test is already known to fail, so disable it to avoid
# wasting CPU time and developer time. See
# https://github.com/bitcoin/bitcoin/issues/27380
#assert_equal(event.reason.decode("UTF-8"), "min relay fee not met")
bpf.cleanup()
self.generate(self.wallet, 1)
def run_test(self):
"""Tests the mempool:added, mempool:removed, mempool:replaced,
and mempool:rejected tracepoints."""
# Create some coinbase transactions and mature them so they can be spent
node = self.nodes[0]
self.wallet = MiniWallet(node)
self.generate(self.wallet, 4)
self.generate(node, COINBASE_MATURITY)
# Test individual tracepoints
self.added_test()
self.removed_test()
self.replaced_test()
self.rejected_test()
if __name__ == "__main__":
MempoolTracepointTest(__file__).main()