Fix #985 - Handle -V prefix even for IRRD commands

docs/releases/4.4.0.rst

@@ -140,6 +140,9 @@ Other changes
 * The deployment documentation now also suggests pipx for
   installing IRRD, which can be easier than managing the virtualenv
   manually.
+* All IRRD style queries may be prepended with ``-V <user-agent>``,
+  even though that is a RIPE style flag, for backwards compatibility
+  with whois clients that always prepend this to the user's query.
 
 Upgrading to IRRd 4.4.0 from 4.3.x
 ----------------------------------

docs/spelling_wordlist.txt

@@ -110,3 +110,4 @@ whois
 dummified
 dummify
 dummification
+prepended

docs/users/queries/whois.rst

@@ -41,6 +41,12 @@ IRRd supports two styles of queries:
 The two styles can not be combined in a single query, but can be mixed in
 a single TCP connection.
 
+There is one special case: if a query starts
+with the RIPE style flag ``-V <user-agent>``, followed by an IRRD style query,
+the IRRD style query will be processed, e.g. ``-V my-client !aAS-EXAMPLE``.
+This is for backward compatibility with whois clients that assume only
+RIPE style queries exist, and always prepend this flag to the user's query.
+
 IRRd style queries
 ------------------
 * ``!!`` activates multiple command mode for raw TCP sockets. The connection

irrd/server/whois/query_parser.py

@@ -73,6 +73,17 @@ def handle_query(self, query: str) -> WhoisQueryResponse:
                 result="Queries may not contain null bytes",
             )
 
+        if query.startswith("-V "):
+            # Special case for https://github.com/irrdnet/irrd/issues/985 - strip the user agent,
+            # then process remainder as normal.
+            try:
+                _, user_agent, remainder = query.split(" ", 2)
+                if remainder.startswith("!"):
+                    query = remainder
+                    self.handle_user_agent(user_agent)
+            except ValueError:
+                pass
+
         if query.startswith("!"):
             try:
                 return self.handle_irrd_command(query[1:])

irrd/server/whois/tests/test_query_parser.py

@@ -246,7 +246,8 @@ def test_sources_list(self, prepare_parser):
         mock_query_resolver, mock_dh, parser = prepare_parser
         mock_query_resolver.set_query_sources = Mock()
 
-        response = parser.handle_query("-s test1")
+        # Includes user-agent for variation
+        response = parser.handle_query("-V user-agent -s test1")
         assert response.response_type == WhoisQueryResponseType.SUCCESS
         assert response.mode == WhoisQueryResponseMode.RIPE
         assert not response.result
@@ -952,6 +953,17 @@ def test_irrd_version(self, prepare_parser):
         assert response.mode == WhoisQueryResponseMode.IRRD
         assert response.result.startswith("IRRd")
 
+    def test_irrd_command_prefixed_V(self, prepare_parser):
+        # https://github.com/irrdnet/irrd/issues/985
+        # Note that -V is for communicating the user-agent, but !v is to ask the server version.
+        # We just use !v here as it's the simplest command.
+        mock_query_resolver, mock_dh, parser = prepare_parser
+
+        response = parser.handle_query("-V user-agent !v")
+        assert response.response_type == WhoisQueryResponseType.SUCCESS
+        assert response.mode == WhoisQueryResponseMode.IRRD
+        assert response.result.startswith("IRRd")
+
     def test_disable_filters(self, prepare_parser):
         mock_query_resolver, mock_dh, parser = prepare_parser