Merge remote-tracking branch 'imurx/custom-port-range' into active/rc-site

WebHostLib/customserver.py

@@ -4,6 +4,7 @@ import asyncio
 import collections
 import datetime
 import functools
+import itertools
 import logging
 import multiprocessing
 import pickle
@@ -15,6 +16,7 @@ import typing
 import sys
 from asyncio import AbstractEventLoop
 
+import psutil
 import websockets
 from pony.orm import commit, db_session, select
 
@@ -133,7 +135,7 @@ class WebHostContext(Context):
         if room.last_port:
             self.port = room.last_port
         else:
-            self.port = get_random_port()
+            self.port = 0
 
         multidata = self.decompress(room.seed.multidata)
         return self._load(multidata, True)
@@ -171,8 +173,98 @@ class WebHostContext(Context):
         return d
 
 
-def get_random_port():
-    return random.randint(49152, 65535)
+class GameRangePorts(typing.NamedTuple):
+    parsed_ports: list[range]
+    weights: list[int]
+    ephemeral_allowed: bool
+
+
+@functools.cache
+def parse_game_ports(game_ports: tuple[str | int, ...]) -> GameRangePorts:
+    parsed_ports: list[range] = []
+    weights: list[int] = []
+    ephemeral_allowed = False
+    total_length = 0
+
+    for item in game_ports:
+        if isinstance(item, str) and "-" in item:
+            start, end = map(int, item.split("-"))
+            x = range(start, end + 1)
+            total_length += len(x)
+            weights.append(total_length)
+            parsed_ports.append(x)
+        elif int(item) == 0:
+            ephemeral_allowed = True
+        else:
+            total_length += 1
+            weights.append(total_length)
+            num = int(item)
+            parsed_ports.append(range(num, num + 1))
+
+    return GameRangePorts(parsed_ports, weights, ephemeral_allowed)
+
+
+def weighted_random(ranges: list[range], cum_weights: list[int]) -> int:
+    [picked] = random.choices(ranges, cum_weights=cum_weights)
+    return random.randrange(picked.start, picked.stop, picked.step)
+
+
+def create_random_port_socket(game_ports: tuple[str | int, ...], host: str) -> socket.socket:
+    parsed_ports, weights, ephemeral_allowed = parse_game_ports(game_ports)
+    used_ports = get_used_ports()
+    i = 1024 if len(parsed_ports) > 0 else 0
+    while i > 0:
+        port_num = weighted_random(parsed_ports, weights)
+        if port_num in used_ports:
+            used_ports = get_used_ports()
+            continue
+
+        i -= 0
+
+        try:
+            return socket.create_server((host, port_num))
+        except OSError:
+            pass
+
+    if ephemeral_allowed:
+        return socket.create_server((host, 0))
+
+    raise OSError(98, "No available ports")
+
+
+def try_conns_per_process(p: psutil.Process) -> typing.Iterable[int]:
+    try:
+        return (c.laddr.port for c in p.net_connections("tcp4"))
+    except psutil.AccessDenied:
+        return ()
+
+
+def get_active_net_connections() -> typing.Iterable[int]:
+    # Don't even try to check if system using AIX
+    if psutil.AIX:
+        return ()
+
+    try:
+        return (c.laddr.port for c in psutil.net_connections("tcp4"))
+    # raises AccessDenied when done on macOS
+    except psutil.AccessDenied:
+        # flatten the list of iterables
+        return itertools.chain.from_iterable(map(
+            # get the net connections of the process and then map its ports
+            try_conns_per_process,
+            # this method has caching handled by psutil
+            psutil.process_iter(["net_connections"])
+        ))
+
+
+def get_used_ports():
+    last_used_ports: tuple[frozenset[int], float] | None = getattr(get_used_ports, "last", None)
+    t_hash = round(time.time() / 90)  # cache for 90 seconds
+    if last_used_ports is None or last_used_ports[1] != t_hash:
+        last_used_ports = (frozenset(get_active_net_connections()), t_hash)
+        setattr(get_used_ports, "last", last_used_ports)
+
+    return last_used_ports[0]
 
 
 class StaticServerData(typing.TypedDict, total=True):
@@ -231,6 +323,7 @@ def run_server_process(
         cert_file: typing.Optional[str],
         cert_key_file: typing.Optional[str],
         host: str,
+        game_ports: typing.Iterable[str | int],
         rooms_to_run: multiprocessing.Queue,
         rooms_shutting_down: multiprocessing.Queue,
 ) -> None:
@@ -253,6 +346,8 @@ def run_server_process(
 
     # prime the data package cache with static data
     games_package_cache = DBGamesPackageCache(static_server_data["games_package"])
+    # convert to tuple because its hashable
+    game_ports = tuple(game_ports)
 
     # establish DB connection for multidata and multisave
     db.bind(**ponyconfig)
@@ -289,20 +384,26 @@ def run_server_process(
                 ctx.load(room_id)
                 ctx.init_save()
                 assert ctx.server is None
-                try:
+                if ctx.port != 0:
+                    try:
+                        ctx.server = websockets.serve(
+                            functools.partial(server, ctx=ctx),
+                            ctx.host,
+                            ctx.port,
+                            ssl=get_ssl_context(),
+                            extensions=[server_per_message_deflate_factory],
+                        )
+                        await ctx.server
+                    except OSError:
+                        ctx.port = 0
+                if ctx.port == 0:
                     ctx.server = websockets.serve(
                         functools.partial(server, ctx=ctx),
-                        ctx.host,
-                        ctx.port,
+                        sock=create_random_port_socket(game_ports, ctx.host),
                         ssl=get_ssl_context(),
                         extensions=[server_per_message_deflate_factory],
                     )
                     await ctx.server
-                except OSError:  # likely port in use
-                    ctx.server = websockets.serve(
-                        functools.partial(server, ctx=ctx), ctx.host, 0, ssl=get_ssl_context())
-
-                    await ctx.server
                 port = 0
                 for wssocket in ctx.server.ws_server.sockets:
                     socketname = wssocket.getsockname()
@@ -377,7 +478,7 @@ def run_server_process(
 
         def run(self):
             while 1:
-                next_room = rooms_to_run.get(block=True,  timeout=None)
+                next_room = rooms_to_run.get(block=True, timeout=None)
                 gc.collect()
                 task = asyncio.run_coroutine_threadsafe(start_room(next_room), loop)
                 self._tasks.append(task)