error out if server gives a "sorry we're closed" error

src/wormhole/blocking/transcribe.py

@@ -7,6 +7,7 @@ from nacl.exceptions import CryptoError
 from nacl import utils
 from .. import __version__
 from .. import codes
+from ..errors import ServerError
 from ..util.hkdf import HKDF
 
 SECOND = 1
@@ -98,12 +99,14 @@ class Common:
     version_warning_displayed = False
 
     def handle_welcome(self, welcome):
-        if self.version_warning_displayed:
-            return
+        if "error" in welcome:
+            raise ServerError(welcome["error"], self.relay)
         if "-" in __version__:
             # only warn if we're running a release version (e.g. 0.0.6, not
             # 0.0.6-DISTANCE-gHASH)
             return
+        if self.version_warning_displayed:
+            return
         if welcome["current_version"] != __version__:
             print("Warning: errors may occur unless both sides are running the same version", file=sys.stderr)
             print("Server claims %s is current, but ours is %s"
@@ -139,7 +142,10 @@ class Common:
     def _allocate(self):
         r = requests.post(self.relay + "allocate")
         r.raise_for_status()
-        channel_id = r.json()["channel-id"]
+        data = r.json()
+        if "welcome" in data:
+            self.handle_welcome(data["welcome"])
+        channel_id = data["channel-id"]
         return channel_id
 
     def _post_pake(self):

src/wormhole/errors.py

@@ -0,0 +1,18 @@
+import functools
+
+class ServerError(Exception):
+    def __init__(self, message, relay):
+        self.message = message
+        self.relay = relay
+    def __str__(self):
+        return self.message
+
+def handle_server_error(func):
+    @functools.wraps(func)
+    def _wrap(*args, **kwargs):
+        try:
+            return func(*args, **kwargs)
+        except ServerError as e:
+            print("Server error (from %s):\n%s" % (e.relay, e.message))
+            return 1
+    return _wrap

src/wormhole/scripts/cmd_receive_file.py

@@ -1,12 +1,14 @@
 from __future__ import print_function
+import sys, os, json, binascii
+from ..errors import handle_server_error
 
 APPID = "lothar.com/wormhole/file-xfer"
 
+@handle_server_error
 def receive_file(args):
     # we're receiving
-    import sys, os, json, binascii
-    from wormhole.blocking.transcribe import Receiver, WrongPasswordError
-    from wormhole.blocking.transit import TransitReceiver, TransitError
+    from ..blocking.transcribe import Receiver, WrongPasswordError
+    from ..blocking.transit import TransitReceiver, TransitError
     from .progress import start_progress, update_progress, finish_progress
 
     transit_receiver = TransitReceiver(args.transit_helper)

src/wormhole/scripts/cmd_receive_text.py

@@ -1,11 +1,13 @@
 from __future__ import print_function
+import sys, json, binascii
+from ..errors import handle_server_error
 
 APPID = "lothar.com/wormhole/text-xfer"
 
+@handle_server_error
 def receive_text(args):
     # we're receiving
-    import sys, json, binascii
-    from wormhole.blocking.transcribe import Receiver, WrongPasswordError
+    from ..blocking.transcribe import Receiver, WrongPasswordError
 
     r = Receiver(APPID, args.relay_url)
     code = args.code

src/wormhole/scripts/cmd_send_file.py

@@ -1,12 +1,14 @@
 from __future__ import print_function
+import os, sys, json, binascii
+from ..errors import handle_server_error
 
 APPID = "lothar.com/wormhole/file-xfer"
 
+@handle_server_error
 def send_file(args):
     # we're sending
-    import os, sys, json, binascii
-    from wormhole.blocking.transcribe import Initiator, WrongPasswordError
-    from wormhole.blocking.transit import TransitSender
+    from ..blocking.transcribe import Initiator, WrongPasswordError
+    from ..blocking.transit import TransitSender
     from .progress import start_progress, update_progress, finish_progress
 
     filename = args.filename

src/wormhole/scripts/cmd_send_text.py

@@ -1,11 +1,13 @@
 from __future__ import print_function
+import sys, json, binascii
+from ..errors import handle_server_error
 
 APPID = "lothar.com/wormhole/text-xfer"
 
+@handle_server_error
 def send_text(args):
     # we're sending
-    import sys, json, binascii
-    from wormhole.blocking.transcribe import Initiator, WrongPasswordError
+    from ..blocking.transcribe import Initiator, WrongPasswordError
 
     i = Initiator(APPID, args.relay_url)
     code = i.get_code(args.code_length)

src/wormhole/servers/relay.py

@@ -49,6 +49,8 @@ class EventsProtocol:
 WELCOME = {
     "current_version": __version__,
     "motd": "Welcome to the public relay.",
+    # adding .error will cause all clients to fail, with this message
+    #"error": "This server has been disabled, see URL for details.",
     }
 
 # relay URLs are: