contrib/tracing/p2p_monitor.py
#!/usr/bin/env python3
# Copyright (c) 2021 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
""" Interactive bitcoind P2P network traffic monitor utilizing USDT and the
net:inbound_message and net:outbound_message tracepoints. """
# This script demonstrates what USDT for Bitcoin Core can enable. It uses BCC
# (https://github.com/iovisor/bcc) to load a sandboxed eBPF program into the
# Linux kernel (root privileges are required). The eBPF program attaches to two
# statically defined tracepoints. The tracepoint 'net:inbound_message' is called
# when a new P2P message is received, and 'net:outbound_message' is called on
# outbound P2P messages. The eBPF program submits the P2P messages to
# this script via a BPF ring buffer.
import sys
import curses
from curses import wrapper, panel
from bcc import BPF, USDT
# BCC: The C program to be compiled to an eBPF program (by BCC) and loaded into
# a sandboxed Linux kernel VM.
program = """
#include <uapi/linux/ptrace.h>
// Tor v3 addresses are 62 chars + 6 chars for the port (':12345').
// I2P addresses are 60 chars + 6 chars for the port (':12345').
#define MAX_PEER_ADDR_LENGTH 62 + 6
#define MAX_PEER_CONN_TYPE_LENGTH 20
#define MAX_MSG_TYPE_LENGTH 20
struct p2p_message
{
u64 peer_id;
char peer_addr[MAX_PEER_ADDR_LENGTH];
char peer_conn_type[MAX_PEER_CONN_TYPE_LENGTH];
char msg_type[MAX_MSG_TYPE_LENGTH];
u64 msg_size;
};
// Two BPF perf buffers for pushing data (here P2P messages) to user space.
BPF_PERF_OUTPUT(inbound_messages);
BPF_PERF_OUTPUT(outbound_messages);
int trace_inbound_message(struct pt_regs *ctx) {
struct p2p_message msg = {};
bpf_usdt_readarg(1, ctx, &msg.peer_id);
bpf_usdt_readarg_p(2, ctx, &msg.peer_addr, MAX_PEER_ADDR_LENGTH);
bpf_usdt_readarg_p(3, ctx, &msg.peer_conn_type, MAX_PEER_CONN_TYPE_LENGTH);
bpf_usdt_readarg_p(4, ctx, &msg.msg_type, MAX_MSG_TYPE_LENGTH);
bpf_usdt_readarg(5, ctx, &msg.msg_size);
inbound_messages.perf_submit(ctx, &msg, sizeof(msg));
return 0;
};
int trace_outbound_message(struct pt_regs *ctx) {
struct p2p_message msg = {};
bpf_usdt_readarg(1, ctx, &msg.peer_id);
bpf_usdt_readarg_p(2, ctx, &msg.peer_addr, MAX_PEER_ADDR_LENGTH);
bpf_usdt_readarg_p(3, ctx, &msg.peer_conn_type, MAX_PEER_CONN_TYPE_LENGTH);
bpf_usdt_readarg_p(4, ctx, &msg.msg_type, MAX_MSG_TYPE_LENGTH);
bpf_usdt_readarg(5, ctx, &msg.msg_size);
outbound_messages.perf_submit(ctx, &msg, sizeof(msg));
return 0;
};
"""
class Message:
""" A P2P network message. """
msg_type = ""
size = 0
data = bytes()
inbound = False
def __init__(self, msg_type, size, inbound):
self.msg_type = msg_type
self.size = size
self.inbound = inbound
class Peer:
""" A P2P network peer. """
id = 0
address = ""
connection_type = ""
last_messages = list()
total_inbound_msgs = 0
total_inbound_bytes = 0
total_outbound_msgs = 0
total_outbound_bytes = 0
def __init__(self, id, address, connection_type):
self.id = id
self.address = address
self.connection_type = connection_type
self.last_messages = list()
def add_message(self, message):
self.last_messages.append(message)
if len(self.last_messages) > 25:
self.last_messages.pop(0)
if message.inbound:
self.total_inbound_bytes += message.size
self.total_inbound_msgs += 1
else:
self.total_outbound_bytes += message.size
self.total_outbound_msgs += 1
def main(bitcoind_path):
peers = dict()
bitcoind_with_usdts = USDT(path=str(bitcoind_path))
# attaching the trace functions defined in the BPF program to the tracepoints
bitcoind_with_usdts.enable_probe(
probe="inbound_message", fn_name="trace_inbound_message")
bitcoind_with_usdts.enable_probe(
probe="outbound_message", fn_name="trace_outbound_message")
bpf = BPF(text=program, usdt_contexts=[bitcoind_with_usdts])
# BCC: perf buffer handle function for inbound_messages
def handle_inbound(_, data, size):
""" Inbound message handler.
Called each time a message is submitted to the inbound_messages BPF table."""
event = bpf["inbound_messages"].event(data)
if event.peer_id not in peers:
peer = Peer(event.peer_id, event.peer_addr.decode(
"utf-8"), event.peer_conn_type.decode("utf-8"))
peers[peer.id] = peer
peers[event.peer_id].add_message(
Message(event.msg_type.decode("utf-8"), event.msg_size, True))
# BCC: perf buffer handle function for outbound_messages
def handle_outbound(_, data, size):
""" Outbound message handler.
Called each time a message is submitted to the outbound_messages BPF table."""
event = bpf["outbound_messages"].event(data)
if event.peer_id not in peers:
peer = Peer(event.peer_id, event.peer_addr.decode(
"utf-8"), event.peer_conn_type.decode("utf-8"))
peers[peer.id] = peer
peers[event.peer_id].add_message(
Message(event.msg_type.decode("utf-8"), event.msg_size, False))
# BCC: add handlers to the inbound and outbound perf buffers
bpf["inbound_messages"].open_perf_buffer(handle_inbound)
bpf["outbound_messages"].open_perf_buffer(handle_outbound)
wrapper(loop, bpf, peers)
def loop(screen, bpf, peers):
screen.nodelay(1)
cur_list_pos = 0
win = curses.newwin(30, 70, 2, 7)
win.erase()
win.border(ord("|"), ord("|"), ord("-"), ord("-"),
ord("-"), ord("-"), ord("-"), ord("-"))
info_panel = panel.new_panel(win)
info_panel.hide()
ROWS_AVALIABLE_FOR_LIST = curses.LINES - 5
scroll = 0
while True:
try:
# BCC: poll the perf buffers for new events or timeout after 50ms
bpf.perf_buffer_poll(timeout=50)
ch = screen.getch()
if (ch == curses.KEY_DOWN or ch == ord("j")) and cur_list_pos < len(
peers.keys()) -1 and info_panel.hidden():
cur_list_pos += 1
if cur_list_pos >= ROWS_AVALIABLE_FOR_LIST:
scroll += 1
if (ch == curses.KEY_UP or ch == ord("k")) and cur_list_pos > 0 and info_panel.hidden():
cur_list_pos -= 1
if scroll > 0:
scroll -= 1
if ch == ord('\n') or ch == ord(' '):
if info_panel.hidden():
info_panel.show()
else:
info_panel.hide()
screen.erase()
render(screen, peers, cur_list_pos, scroll, ROWS_AVALIABLE_FOR_LIST, info_panel)
curses.panel.update_panels()
screen.refresh()
except KeyboardInterrupt:
exit()
def render(screen, peers, cur_list_pos, scroll, ROWS_AVALIABLE_FOR_LIST, info_panel):
""" renders the list of peers and details panel
This code is unrelated to USDT, BCC and BPF.
"""
header_format = "%6s %-20s %-20s %-22s %-67s"
row_format = "%6s %-5d %9d byte %-5d %9d byte %-22s %-67s"
screen.addstr(0, 1, (" P2P Message Monitor "), curses.A_REVERSE)
screen.addstr(
1, 0, (" Navigate with UP/DOWN or J/K and select a peer with ENTER or SPACE to see individual P2P messages"), curses.A_NORMAL)
screen.addstr(3, 0,
header_format % ("PEER", "OUTBOUND", "INBOUND", "TYPE", "ADDR"), curses.A_BOLD | curses.A_UNDERLINE)
peer_list = sorted(peers.keys())[scroll:ROWS_AVALIABLE_FOR_LIST+scroll]
for i, peer_id in enumerate(peer_list):
peer = peers[peer_id]
screen.addstr(i + 4, 0,
row_format % (peer.id, peer.total_outbound_msgs, peer.total_outbound_bytes,
peer.total_inbound_msgs, peer.total_inbound_bytes,
peer.connection_type, peer.address),
curses.A_REVERSE if i + scroll == cur_list_pos else curses.A_NORMAL)
if i + scroll == cur_list_pos:
info_window = info_panel.window()
info_window.erase()
info_window.border(
ord("|"), ord("|"), ord("-"), ord("-"),
ord("-"), ord("-"), ord("-"), ord("-"))
info_window.addstr(
1, 1, f"PEER {peer.id} ({peer.address})".center(68), curses.A_REVERSE | curses.A_BOLD)
info_window.addstr(
2, 1, f" OUR NODE{peer.connection_type:^54}PEER ",
curses.A_BOLD)
for i, msg in enumerate(peer.last_messages):
if msg.inbound:
info_window.addstr(
i + 3, 1, "%68s" %
(f"<--- {msg.msg_type} ({msg.size} bytes) "), curses.A_NORMAL)
else:
info_window.addstr(
i + 3, 1, " %s (%d byte) --->" %
(msg.msg_type, msg.size), curses.A_NORMAL)
if __name__ == "__main__":
if len(sys.argv) < 2:
print("USAGE:", sys.argv[0], "path/to/bitcoind")
exit()
path = sys.argv[1]
main(path)