3 files changed, 36 insertions, 0 deletions
diff --git a/synapse_topology/controller/server/schemas.py b/synapse_topology/controller/server/schemas.py
index 8420ef62eb..f3774777b2 100644
--- a/synapse_topology/controller/server/schemas.py
+++ b/synapse_topology/controller/server/schemas.py
@@ -33,3 +33,9 @@ CERTS_SCHEMA = {
     },
     "required": ["cert", "cert_key"],
 }
+
+PORTS_SCHEMA = {
+    "type": "object",
+    "properties": {"ports": {"type": "array"}},
+    "required": ["ports"],
+}
diff --git a/synapse_topology/controller/server/server.py b/synapse_topology/controller/server/server.py
index bb8af0c553..713bec9714 100644
--- a/synapse_topology/controller/server/server.py
+++ b/synapse_topology/controller/server/server.py
@@ -5,12 +5,15 @@ from synapse_topology import model
 
 from twisted.web.static import File
 
+from .utils import port_checker
+
 from . import error_handlers
 from .schemas import (
     BASE_CONFIG_SCHEMA,
     SERVERNAME_SCHEMA,
     CERT_PATHS_SCHEMA,
     CERTS_SCHEMA,
+    PORTS_SCHEMA,
 )
 from .utils import validate_schema
 
@@ -85,3 +88,13 @@ def test_cert_paths(request, body):
 @validate_schema(CERTS_SCHEMA)
 def upload_certs(request, body):
     model.add_certs(**body)
+
+
+@app.route("/ports", methods=["POST"])
+@validate_schema(PORTS_SCHEMA)
+def check_ports(request, body):
+    results = []
+    for port in body["ports"]:
+        results.append(port_checker(port))
+    return json.dumps({"ports": results})
+
diff --git a/synapse_topology/controller/server/utils.py b/synapse_topology/controller/server/utils.py
index 009a1a1c79..3d7134a43a 100644
--- a/synapse_topology/controller/server/utils.py
+++ b/synapse_topology/controller/server/utils.py
@@ -3,6 +3,9 @@ from functools import wraps
 from canonicaljson import json
 from jsonschema import validate
 
+from contextlib import closing
+import socket
+
 
 def validate_schema(schema):
     def _wrap_validate(func):
@@ -15,3 +18,17 @@ def validate_schema(schema):
         return _do_validate
 
     return _wrap_validate
+
+
+def port_checker(port):
+    if port < 0 or 65535 < port:
+        return False
+
+    with closing(socket.socket(socket.AF_INET, socket.SOCK_STREAM)) as sock:
+        try:
+            sock.bind((socket.gethostname(), port))
+            sock.listen()
+            sock.close()
+            return True
+        except:
+            return False