| import argparse |
|
|
| import multiaddr |
| import trio |
|
|
| from libp2p import ( |
| new_host, |
| ) |
| from libp2p.crypto.secp256k1 import ( |
| create_new_key_pair, |
| ) |
| from libp2p.network.stream.net_stream_interface import ( |
| INetStream, |
| ) |
| from libp2p.peer.peerinfo import ( |
| info_from_p2p_addr, |
| ) |
| from libp2p.typing import ( |
| TProtocol, |
| ) |
|
|
| PROTOCOL_ID = TProtocol("/echo/1.0.0") |
|
|
|
|
| async def _echo_stream_handler(stream: INetStream) -> None: |
| |
| msg = await stream.read() |
| await stream.write(msg) |
| await stream.close() |
|
|
|
|
| async def run(port: int, destination: str, seed: int = None) -> None: |
| localhost_ip = "127.0.0.1" |
| listen_addr = multiaddr.Multiaddr(f"/ip4/0.0.0.0/tcp/{port}") |
|
|
| if seed: |
| import random |
|
|
| random.seed(seed) |
| secret_number = random.getrandbits(32 * 8) |
| secret = secret_number.to_bytes(length=32, byteorder="big") |
| else: |
| import secrets |
|
|
| secret = secrets.token_bytes(32) |
|
|
| host = new_host(key_pair=create_new_key_pair(secret)) |
| async with host.run(listen_addrs=[listen_addr]): |
| print(f"I am {host.get_id().to_string()}") |
|
|
| if not destination: |
| host.set_stream_handler(PROTOCOL_ID, _echo_stream_handler) |
|
|
| print( |
| "Run this from the same folder in another console:\n\n" |
| f"python echo.py -p {int(port) + 1} " |
| f"-d /ip4/{localhost_ip}/tcp/{port}/p2p/{host.get_id().pretty()}\n" |
| ) |
| print("Waiting for incoming connections...") |
| await trio.sleep_forever() |
|
|
| else: |
| maddr = multiaddr.Multiaddr(destination) |
| info = info_from_p2p_addr(maddr) |
| |
| await host.connect(info) |
|
|
| |
| |
| |
| stream = await host.new_stream(info.peer_id, [PROTOCOL_ID]) |
|
|
| msg = b"hi, there!\n" |
|
|
| await stream.write(msg) |
| |
| await stream.close() |
| response = await stream.read() |
|
|
| print(f"Sent: {msg.decode('utf-8')}") |
| print(f"Got: {response.decode('utf-8')}") |
|
|
|
|
| def main() -> None: |
| description = """ |
| This program demonstrates a simple echo protocol where a peer listens for |
| connections and copies back any input received on a stream. |
| |
| To use it, first run 'python ./echo -p <PORT>', where <PORT> is the port number. |
| Then, run another host with 'python ./chat -p <ANOTHER_PORT> -d <DESTINATION>', |
| where <DESTINATION> is the multiaddress of the previous listener host. |
| """ |
| example_maddr = ( |
| "/ip4/127.0.0.1/tcp/8000/p2p/QmQn4SwGkDZKkUEpBRBvTmheQycxAHJUNmVEnjA2v1qe8Q" |
| ) |
| parser = argparse.ArgumentParser(description=description) |
| parser.add_argument( |
| "-p", "--port", default=8000, type=int, help="source port number" |
| ) |
| parser.add_argument( |
| "-d", |
| "--destination", |
| type=str, |
| help=f"destination multiaddr string, e.g. {example_maddr}", |
| ) |
| parser.add_argument( |
| "-s", |
| "--seed", |
| type=int, |
| help="provide a seed to the random number generator (e.g. to fix peer IDs across runs)", |
| ) |
| args = parser.parse_args() |
|
|
| if not args.port: |
| raise RuntimeError("was not able to determine a local port") |
|
|
| try: |
| trio.run(run, args.port, args.destination, args.seed) |
| except KeyboardInterrupt: |
| pass |
|
|
|
|
| if __name__ == "__main__": |
| main() |
|
|
