Bug 899757: Make nsServerSocket::InitWithAddress provide more detailed error results. r=mayhemer, r=ted

I looked through the NSPR socket creation functions that InitWithAddress
uses to see which errors they could return, and placed appropriate comments
in ErrorAccordingToNSPR.

The test coverage is not great; in particular, I wasn't able to find a way
to elicit "address in use" errors from Windows (although I could from
Linux); the web says that Windows is much more relaxed about binding
listening sockets than Unix derivatives. I'm interested in suggestions.

js/xpconnect/src/xpc.msg

@@ -167,6 +167,7 @@ XPC_MSG_DEF(NS_ERROR_UNKNOWN_PROXY_HOST             , "The lookup of the proxy h
 XPC_MSG_DEF(NS_ERROR_UNKNOWN_SOCKET_TYPE            , "The specified socket type does not exist")
 XPC_MSG_DEF(NS_ERROR_SOCKET_CREATE_FAILED           , "The specified socket type could not be created")
 XPC_MSG_DEF(NS_ERROR_SOCKET_ADDRESS_NOT_SUPPORTED   , "The specified socket address type is not supported")
+XPC_MSG_DEF(NS_ERROR_SOCKET_ADDRESS_IN_USE          , "Some other socket is already using the specified address.")
 XPC_MSG_DEF(NS_ERROR_CACHE_KEY_NOT_FOUND            , "Cache key could not be found")
 XPC_MSG_DEF(NS_ERROR_CACHE_DATA_IS_STREAM           , "Cache data is a stream")
 XPC_MSG_DEF(NS_ERROR_CACHE_DATA_IS_NOT_STREAM       , "Cache data is not a stream")

netwerk/base/src/nsServerSocket.cpp

@@ -289,7 +289,7 @@ nsServerSocket::InitWithAddress(const PRNetAddr *aAddr, int32_t aBackLog)
   if (!mFD)
   {
     NS_WARNING("unable to create server socket");
-    return NS_ERROR_FAILURE;
+    return ErrorAccordingToNSPR(PR_GetError());
   }
 
   PRSocketOptionData opt;
@@ -330,8 +330,9 @@ nsServerSocket::InitWithAddress(const PRNetAddr *aAddr, int32_t aBackLog)
   return NS_OK;
 
 fail:
+  nsresult rv = ErrorAccordingToNSPR(PR_GetError());
   Close();
-  return NS_ERROR_FAILURE;
+  return rv;
 }
 
 NS_IMETHODIMP

netwerk/base/src/nsSocketTransport2.cpp

@@ -155,8 +155,13 @@ ErrorAccordingToNSPR(PRErrorCode errorCode)
         rv = NS_ERROR_NET_INTERRUPT;
         break;
     case PR_CONNECT_REFUSED_ERROR:
-    case PR_NETWORK_UNREACHABLE_ERROR: // XXX need new nsresult for this!
-    case PR_HOST_UNREACHABLE_ERROR:    // XXX and this!
+    // We lump the following NSPR codes in with PR_CONNECT_REFUSED_ERROR. We
+    // could get better diagnostics by adding distinct XPCOM error codes for
+    // each of these, but there are a lot of places in Gecko that check
+    // specifically for NS_ERROR_CONNECTION_REFUSED, all of which would need to
+    // be checked.
+    case PR_NETWORK_UNREACHABLE_ERROR:
+    case PR_HOST_UNREACHABLE_ERROR:
     case PR_ADDRESS_NOT_AVAILABLE_ERROR:
     // Treat EACCES as a soft error since (at least on Linux) connect() returns
     // EACCES when an IPv6 connection is blocked by a firewall. See bug 270784.
@@ -170,10 +175,68 @@ ErrorAccordingToNSPR(PRErrorCode errorCode)
     case PR_CONNECT_TIMEOUT_ERROR:
         rv = NS_ERROR_NET_TIMEOUT;
         break;
+    case PR_OUT_OF_MEMORY_ERROR:
+    // These really indicate that the descriptor table filled up, or that the
+    // kernel ran out of network buffers - but nobody really cares which part of
+    // the system ran out of memory.
+    case PR_PROC_DESC_TABLE_FULL_ERROR:
+    case PR_SYS_DESC_TABLE_FULL_ERROR:
+    case PR_INSUFFICIENT_RESOURCES_ERROR:
+        rv = NS_ERROR_OUT_OF_MEMORY;
+        break;
+    case PR_ADDRESS_IN_USE_ERROR:
+        rv = NS_ERROR_SOCKET_ADDRESS_IN_USE;
+        break;
+    // These filename-related errors can arise when using Unix-domain sockets.
+    case PR_FILE_NOT_FOUND_ERROR:
+        rv = NS_ERROR_FILE_NOT_FOUND;
+        break;
+    case PR_IS_DIRECTORY_ERROR:
+        rv = NS_ERROR_FILE_IS_DIRECTORY;
+        break;
+    case PR_LOOP_ERROR:
+        rv = NS_ERROR_FILE_UNRESOLVABLE_SYMLINK;
+        break;
+    case PR_NAME_TOO_LONG_ERROR:
+        rv = NS_ERROR_FILE_NAME_TOO_LONG;
+        break;
+    case PR_NO_DEVICE_SPACE_ERROR:
+        rv = NS_ERROR_FILE_NO_DEVICE_SPACE;
+        break;
+    case PR_NOT_DIRECTORY_ERROR:
+        rv = NS_ERROR_FILE_NOT_DIRECTORY;
+        break;
+    case PR_READ_ONLY_FILESYSTEM_ERROR:
+        rv = NS_ERROR_FILE_READ_ONLY;
+        break;
     default:
         if (IsNSSErrorCode(errorCode))
             rv = GetXPCOMFromNSSError(errorCode);
         break;
+
+    // NSPR's socket code can return these, but they're not worth breaking out
+    // into their own error codes, distinct from NS_ERROR_FAILURE:
+    //
+    // PR_BAD_DESCRIPTOR_ERROR
+    // PR_INVALID_ARGUMENT_ERROR
+    // PR_NOT_SOCKET_ERROR
+    // PR_NOT_TCP_SOCKET_ERROR
+    //   These would indicate a bug internal to the component.
+    //
+    // PR_PROTOCOL_NOT_SUPPORTED_ERROR
+    //   This means that we can't use the given "protocol" (like
+    //   IPPROTO_TCP or IPPROTO_UDP) with a socket of the given type. As
+    //   above, this indicates an internal bug.
+    //
+    // PR_IS_CONNECTED_ERROR
+    //   This indicates that we've applied a system call like 'bind' or
+    //   'connect' to a socket that is already connected. The socket
+    //   components manage each file descriptor's state, and in some cases
+    //   handle this error result internally. We shouldn't be returning
+    //   this to our callers.
+    //
+    // PR_IO_ERROR
+    //   This is so vague that NS_ERROR_FAILURE is just as good.
     }
     SOCKET_LOG(("ErrorAccordingToNSPR [in=%d out=%x]\n", errorCode, rv));
     return rv;

netwerk/test/unit/test_addr_in_use_error.js

@@ -0,0 +1,32 @@
+// Opening a second listening socket on the same address as an extant
+// socket should elicit NS_ERROR_SOCKET_ADDRESS_IN_USE on non-Windows
+// machines.
+
+const { classes: Cc, interfaces: Ci, results: Cr, Constructor: CC } = Components;
+
+const ServerSocket = CC("@mozilla.org/network/server-socket;1",
+                        "nsIServerSocket",
+                        "init");
+
+function testAddrInUse()
+{
+  // Windows lets us have as many sockets listening on the same address as
+  // we like, evidently.
+  if ("@mozilla.org/windows-registry-key;1" in Cc) {
+    return;
+  }
+
+  // Create listening socket:
+  // any port (-1), loopback only (true), default backlog (-1)
+  let listener = ServerSocket(-1, true, -1);
+  do_check_true(listener instanceof Ci.nsIServerSocket);
+
+  // Try to create another listening socket on the same port, whatever that was.
+  do_check_throws_nsIException(() => ServerSocket(listener.port, true, -1),
+                               "NS_ERROR_SOCKET_ADDRESS_IN_USE");
+}
+
+function run_test()
+{
+  testAddrInUse();
+}

netwerk/test/unit/xpcshell.ini

@@ -2,6 +2,7 @@
 head = head_channels.js head_cache.js
 tail =
 
+[test_addr_in_use_error.js]
 [test_304_responses.js]
 # Bug 675039: test hangs on Android-armv6 
 skip-if = os == "android"

testing/xpcshell/example/unit/test_check_nsIException.js

@@ -0,0 +1,11 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function run_test() {
+  let env = Components.classes["@mozilla.org/process/environment;1"]
+                      .getService(Components.interfaces.nsIEnvironment);
+  do_check_throws_nsIException(function () {
+    env.QueryInterface(Components.interfaces.nsIFile);
+  }, "NS_NOINTERFACE");
+}
+

testing/xpcshell/example/unit/test_check_nsIException_failing.js

@@ -0,0 +1,9 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function run_test() {
+  do_check_throws_nsIException(function () {
+    throw Error("I find your relaxed dishabille unpalatable");
+  }, "NS_NOINTERFACE");
+}
+

testing/xpcshell/example/unit/xpcshell.ini

@@ -6,6 +6,10 @@
 head =
 tail =
 
+[test_check_nsIException.js]
+[test_check_nsIException_failing.js]
+fail-if = true
+
 [test_do_get_tempdir.js]
 [test_execute_soon.js]
 [test_get_file.js]

testing/xpcshell/head.js

@@ -868,6 +868,63 @@ function format_pattern_match_failure(diagnosis, indent="") {
   return indent + a;
 }
 
+// Check that |func| throws an nsIException that has
+// |Components.results[resultName]| as the value of its 'result' property.
+function do_check_throws_nsIException(func, resultName,
+                                      stack=Components.stack.caller, todo=false)
+{
+  let expected = Components.results[resultName];
+  if (typeof expected !== 'number') {
+    do_throw("do_check_throws_nsIException requires a Components.results" +
+             " property name, not " + uneval(resultName), stack);
+  }
+
+  let msg = ("do_check_throws_nsIException: func should throw" +
+             " an nsIException whose 'result' is Components.results." +
+             resultName);
+
+  try {
+    func();
+  } catch (ex) {
+    if (!(ex instanceof Components.interfaces.nsIException) ||
+        ex.result !== expected) {
+      do_report_result(false, msg + ", threw " + legible_exception(ex) +
+                       " instead", stack, todo);
+    }
+
+    do_report_result(true, msg, stack, todo);
+    return;
+  }
+
+  // Call this here, not in the 'try' clause, so do_report_result's own
+  // throw doesn't get caught by our 'catch' clause.
+  do_report_result(false, msg + ", but returned normally", stack, todo);
+}
+
+// Produce a human-readable form of |exception|. This looks up
+// Components.results values, tries toString methods, and so on.
+function legible_exception(exception)
+{
+  switch (typeof exception) {
+    case 'object':
+    if (exception instanceof Components.interfaces.nsIException) {
+      return "nsIException instance: " + uneval(exception.toString());
+    }
+    return exception.toString();
+
+    case 'number':
+    for (let name in Components.results) {
+      if (exception === Components.results[name]) {
+        return "Components.results." + name;
+      }
+    }
+
+    // Fall through.
+    default:
+    return uneval(exception);
+  }
+}
+
 function do_test_pending(aName) {
   ++_tests_pending;
 

xpcom/base/ErrorList.h

@@ -253,6 +253,8 @@
   ERROR(NS_ERROR_SOCKET_CREATE_FAILED,  FAILURE(52)),
   /* The operating system doesn't support the given type of address. */
   ERROR(NS_ERROR_SOCKET_ADDRESS_NOT_SUPPORTED, FAILURE(53)),
+  /* The address to which we tried to bind the socket was busy. */
+  ERROR(NS_ERROR_SOCKET_ADDRESS_IN_USE, FAILURE(54)),
 
   /* Cache specific error codes: */
   ERROR(NS_ERROR_CACHE_KEY_NOT_FOUND,        FAILURE(61)),