test_p2p now deliberately selects ICE implementation

Our implementation honors the mock network.  We know that webrtc has
their own very robust mocking framework they put their own implementation
through.

(cherry picked from commit 7515a9e00c)

tests/test_p2p.cpp

@@ -46,6 +46,7 @@ void PrintUsage()
 		"  --spewlevel <level>                 Console spew level: msg, verbose, debug\n"
 		"  --loglevel-p2prendezvous <level>    P2P rendezvous log level: msg, verbose, debug\n"
 		"  --stun-server <host:port>           STUN server address (default: " DEFAULT_STUN_SERVER ")\n"
+		"  --ice-implementation <n>            ICE implementation: 0=default, 1=native\n"
 #ifdef STEAMNETWORKINGSOCKETS_ENABLE_MOCK
 		"\n"
 		"Mock network options:\n"
@@ -222,6 +223,7 @@ int main( int argc, const char **argv )
 	SteamNetworkingIdentity identityRemote; identityRemote.Clear();
 	const char *pszTrivialSignalingService = "localhost:10000";
 	const char *pszSTUNServer = DEFAULT_STUN_SERVER;
+	int g_nICEImplementation = -1; // -1 = not set, use library default
 #ifdef STEAMNETWORKINGSOCKETS_ENABLE_MOCK
 	TEST_mocknetwork_config_t mockConfig;
 #endif
@@ -250,6 +252,8 @@ int main( int argc, const char **argv )
 			pszTrivialSignalingService = GetArg();
 		else if ( !strcmp( pszSwitch, "--stun-server" ) )
 			pszSTUNServer = GetArg();
+		else if ( !strcmp( pszSwitch, "--ice-implementation" ) )
+			g_nICEImplementation = atoi( GetArg() );
 		else if ( !strcmp( pszSwitch, "--client" ) )
 			g_eTestRole = k_ETestRole_Client;
 		else if ( !strcmp( pszSwitch, "--server" ) )
@@ -360,6 +364,8 @@ int main( int argc, const char **argv )
 	TEST_Init( &identityLocal );
 
 	SteamNetworkingUtils()->SetGlobalConfigValueString( k_ESteamNetworkingConfig_P2P_STUN_ServerList, pszSTUNServer );
+	if ( g_nICEImplementation >= 0 )
+		SteamNetworkingUtils()->SetGlobalConfigValueInt32( k_ESteamNetworkingConfig_P2P_Transport_ICE_Implementation, g_nICEImplementation );
 
 	// Hardcode TURN servers
 	// comma seperated setting lists

tests/test_p2p.py

@@ -174,22 +174,30 @@ def _disabled_adapter( ip ):
 def _slow_nat( internal, gateway, nat_type, latency_ms ):
     return [ '--mock-gateway', gateway, '--mock-nat', nat_type, '--mock-adapter', internal, '--mock-latency', str(latency_ms) ]
 
-# Each entry: ( description, server_extra_args, client_extra_args, expected_route )
+# Each entry: ( description, server_extra_args, client_extra_args, expected_route, ice_impl )
 # Both sides must report the same route type — ICE nominates one candidate pair
 # and both ends classify the same path, so agreement is guaranteed by the protocol.
 # Route types: 'local' = Fast flag set: both host candidates on the same private /24 LAN subnet
 #              'udp'   = direct UDP but not same-LAN (NAT traversal, or public IPs)
 #              'relay' = TURN relay
+# ice_impl: 0 = default (WebRTC if compiled in), 1 = force native ICE client.
+# All mocked tests must use 1: the mock network is only wired into the native ICE path.
+# The two no-mock entries exercise both implementations on the real loopback network.
 CLIENT_SERVER_TEST_CASES = [
-    ( 'no-mock',
+    # No-mock tests: run on real network (same host), both implementations.
+    # We verify the route is 'local' (same-host loopback) but do not check the IP.
+    ( 'no-mock, default ICE implementation',
       [], [],
-      'local' ),
+      'local', 0 ),
+    ( 'no-mock, native ICE implementation',
+      [], [],
+      'local', 1 ),
 
     # Both on the same private /24 LAN: the core case for 'local' classification.
     ( 'same LAN (private subnet, no NAT)',
       [ '--mock-adapter', _SRV_INT ],
       [ '--mock-adapter', _CLI_SAME_LAN ],
-      'local' ),
+      'local', 1 ),
 
     # Both on the same LAN but each also has a NAT to the public internet via the
     # same shared gateway — the typical home/office scenario.  Both a direct host path
@@ -198,46 +206,46 @@ CLIENT_SERVER_TEST_CASES = [
     ( 'same LAN, shared gateway (hairpin)',
       _nat( _SRV_INT, _SRV_GW, 'full-cone' ),
       _nat( _CLI_SAME_LAN, _SRV_GW, 'full-cone' ),
-      'local' ),
+      'local', 1 ),
 
     # Both on the public network: direct host-to-host but NOT 'local' — public IPs
     # are not classified as fast even when they share a subnet.
     ( 'no-nat (both public)',
       [ '--mock-adapter', _SRV_GW ],
       [ '--mock-adapter', _CLI_GW ],
-      'udp' ),
+      'udp', 1 ),
 
     ( 'full-cone NAT',
       _nat( _SRV_INT, _SRV_GW, 'full-cone' ),
       _nat( _CLI_INT, _CLI_GW, 'full-cone' ),
-      'udp' ),
+      'udp', 1 ),
     ( 'restricted-cone NAT',
       _nat( _SRV_INT, _SRV_GW, 'restricted-cone' ),
       _nat( _CLI_INT, _CLI_GW, 'restricted-cone' ),
-      'udp' ),
+      'udp', 1 ),
     ( 'port-restricted-cone NAT',
       _nat( _SRV_INT, _SRV_GW, 'port-restricted-cone' ),
       _nat( _CLI_INT, _CLI_GW, 'port-restricted-cone' ),
-      'udp' ),
+      'udp', 1 ),
     # symmetric-vs-symmetric requires TURN relay; ICE alone cannot traverse it
     ( 'asymmetric: server public, client full-cone',
       [ '--mock-adapter', _SRV_GW ],
       _nat( _CLI_INT, _CLI_GW, 'full-cone' ),
-      'udp' ),  # client host (127.0.2.x) to server host (127.0.100.x): different subnets
+      'udp', 1 ),  # client host (127.0.2.x) to server host (127.0.100.x): different subnets
     ( 'asymmetric: server full-cone, client symmetric',
       _nat( _SRV_INT, _SRV_GW, 'full-cone' ),
       _nat( _CLI_INT, _CLI_GW, 'symmetric' ),
-      'udp' ),
+      'udp', 1 ),
 
     # Disabled adapter: verify connection still succeeds when one adapter is down
     ( 'server has disabled second adapter',
       [ '--mock-adapter', _SRV_GW ] + _disabled_adapter( _DEAD_INT ),
       _nat( _CLI_INT, _CLI_GW, 'full-cone' ),
-      'udp' ),
+      'udp', 1 ),
     ( 'client has disabled second adapter',
       [ '--mock-adapter', _SRV_GW ],
       _nat( _CLI_INT, _CLI_GW, 'full-cone' ) + _disabled_adapter( _DEAD_INT ),
-      'udp' ),
+      'udp', 1 ),
 
     # Multi-adapter with latency: fast public adapter + slow NATd adapter.
     # ICE should prefer the low-latency host-to-host path.  Both public adapters
@@ -245,13 +253,14 @@ CLIENT_SERVER_TEST_CASES = [
     ( 'both multi-adapter: fast public + slow NATd',
       [ '--mock-adapter', _SRV_GW ] + _slow_nat( _SRV_INT2, _SRV_GW2, 'full-cone', 50 ),
       [ '--mock-adapter', _CLI_GW ] + _slow_nat( _CLI_INT2, _CLI_GW2, 'full-cone', 50 ),
-      'udp' ),
+      'udp', 1 ),
 ]
 
-def ClientServerTest( server_extra_args=[], client_extra_args=[], expected_route=None ):
+def ClientServerTest( server_extra_args=[], client_extra_args=[], expected_route=None, ice_impl=1 ):
     global g_failed
-    server = StartClientInThread( "server", "peer_server", "peer_client", server_extra_args )
-    client = StartClientInThread( "client", "peer_client", "peer_server", client_extra_args )
+    impl_args = [ '--ice-implementation', str(ice_impl) ]
+    server = StartClientInThread( "server", "peer_server", "peer_client", server_extra_args + impl_args )
+    client = StartClientInThread( "client", "peer_client", "peer_server", client_extra_args + impl_args )
 
     # Wait for clients to shutdown.  Nuke them if necessary
     server.join( timeout=20 )
@@ -315,11 +324,11 @@ if not g_server_ready.wait( timeout=g_server_startup_timeout ):
 print( "Signaling server is ready, starting test clients" )
 
 # Run the tests
-for desc, srv_args, cli_args, exp_route in CLIENT_SERVER_TEST_CASES:
+for desc, srv_args, cli_args, exp_route, ice_impl in CLIENT_SERVER_TEST_CASES:
     print( "=================================================================" )
     print( "Test: " + desc )
     print( "=================================================================" )
-    ClientServerTest( srv_args, cli_args, exp_route )
+    ClientServerTest( srv_args, cli_args, exp_route, ice_impl )
     if g_failed:
         break