feat: add identify protocol example

libp2p/identity/identify/identify.py

@@ -0,0 +1,114 @@
+import logging
+from typing import (
+    Optional,
+)
+
+from multiaddr import (
+    Multiaddr,
+)
+
+from libp2p.abc import (
+    IHost,
+    INetStream,
+)
+from libp2p.custom_types import (
+    StreamHandlerFn,
+    TProtocol,
+)
+from libp2p.network.stream.exceptions import (
+    StreamClosed,
+)
+from libp2p.utils import (
+    get_agent_version,
+)
+
+from .pb.identify_pb2 import (
+    Identify,
+)
+
+# Not sure I can do this or I break a pattern
+# logger = logging.getLogger("libp2p.identity.identify")
+logger = logging.getLogger(__name__)
+
+ID = TProtocol("/ipfs/id/1.0.0")
+PROTOCOL_VERSION = "ipfs/0.1.0"
+AGENT_VERSION = get_agent_version()
+
+
+def _multiaddr_to_bytes(maddr: Multiaddr) -> bytes:
+    return maddr.to_bytes()
+
+
+def _remote_address_to_multiaddr(
+    remote_address: Optional[tuple[str, int]]
+) -> Optional[Multiaddr]:
+    """Convert a (host, port) tuple to a Multiaddr."""
+    if remote_address is None:
+        return None
+
+    host, port = remote_address
+
+    # Check if the address is IPv6 (contains ':')
+    if ":" in host:
+        # IPv6 address
+        return Multiaddr(f"/ip6/{host}/tcp/{port}")
+    else:
+        # IPv4 address
+        return Multiaddr(f"/ip4/{host}/tcp/{port}")
+
+
+def _mk_identify_protobuf(
+    host: IHost, observed_multiaddr: Optional[Multiaddr]
+) -> Identify:
+    public_key = host.get_public_key()
+    laddrs = host.get_addrs()
+    protocols = host.get_mux().get_protocols()
+
+    observed_addr = observed_multiaddr.to_bytes() if observed_multiaddr else b""
+    return Identify(
+        protocol_version=PROTOCOL_VERSION,
+        agent_version=AGENT_VERSION,
+        public_key=public_key.serialize(),
+        listen_addrs=map(_multiaddr_to_bytes, laddrs),
+        observed_addr=observed_addr,
+        protocols=protocols,
+    )
+
+
+def identify_handler_for(host: IHost) -> StreamHandlerFn:
+    async def handle_identify(stream: INetStream) -> None:
+        # get observed address from ``stream``
+        peer_id = (
+            stream.muxed_conn.peer_id
+        )  # remote peer_id is in class Mplex (mplex.py )
+
+        # Get the remote address
+        try:
+            remote_address = stream.get_remote_address()
+            # Convert to multiaddr
+            if remote_address:
+                observed_multiaddr = _remote_address_to_multiaddr(remote_address)
+            else:
+                observed_multiaddr = None
+            logger.debug(
+                "Connection from remote peer %s, address: %s, multiaddr: %s",
+                peer_id,
+                remote_address,
+                observed_multiaddr,
+            )
+        except Exception as e:
+            logger.error("Error getting remote address: %s", e)
+            remote_address = None
+
+        protobuf = _mk_identify_protobuf(host, observed_multiaddr)
+        response = protobuf.SerializeToString()
+
+        try:
+            await stream.write(response)
+        except StreamClosed:
+            logger.debug("Fail to respond to %s request: stream closed", ID)
+        else:
+            await stream.close()
+            logger.debug("successfully handled request for %s from %s", ID, peer_id)
+
+    return handle_identify