Add ChildPortServer, a MachMessageServer::Interface implementation for the child_port subsystem

util/mach/child_port_server.cc

Index: util/mach/child_port_server.cc
diff --git a/util/mach/child_port_server.cc b/util/mach/child_port_server.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b263b9049f3acfefcad71a081551d3ea05ab330f
--- /dev/null
+++ b/util/mach/child_port_server.cc
@@ -0,0 +1,110 @@
+// Copyright 2014 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "util/mach/child_port_server.h"
+
+#include "base/logging.h"
+#include "util/mach/child_portServer.h"
+#include "util/mach/mach_message_util.h"
+
+extern "C" {
+
+// This function is not used, and is in fact obsoleted by the other
+// functionality implemented in this file. The standard MIG-generated
+// child_port_server() (in child_portServer.c) server dispatch routine usable
+// with the standard mach_msg_server() function calls out to this function.
+// child_port_server() is unused and is replaced by the more flexible
+// ChildPortServer, but the linker still needs to see this function definition.
+
+kern_return_t handle_child_port_check_in(child_port_server_t server,
+                                         child_port_token_t token,
+                                         mach_port_t port,
+                                         mach_msg_type_name_t right_type) {
+  NOTREACHED();
+  return KERN_FAILURE;
+}
+
+}  // extern "C"
+
+namespace {
+
+// There is no predefined constant for this.
+enum MachMessageID : mach_msg_id_t {
+  kMachMessageIDChildPortCheckIn = 10011,
+};
+
+// The MIG-generated __MIG_check__Request__*() functions are not declared as
+// accepting const data, but they could have been because they in fact do not
+// modify the data. This wrapper function is provided to bridge the const gap
+// between the code in this file, which is const-correct and treats request
+// message data as const, and the generated function.
+
+kern_return_t MIGCheckRequestChildPortCheckIn(
+    const __Request__child_port_check_in_t* in_request) {
+  using Request = __Request__child_port_check_in_t;
+  return __MIG_check__Request__child_port_check_in_t(
+      const_cast<Request*>(in_request));
+}
+
+}  // namespace
+
+namespace crashpad {
+
+ChildPortServer::ChildPortServer(ChildPortServer::Interface* interface)
+    : MachMessageServer::Interface(),
+      interface_(interface) {
+}
+
+bool ChildPortServer::MachMessageServerFunction(
+    const mach_msg_header_t* in_header,
+    mach_msg_header_t* out_header,
+    bool* destroy_complex_request) {
+  PrepareMIGReplyFromRequest(in_header, out_header);
+
+  switch (in_header->msgh_id) {
+    case kMachMessageIDChildPortCheckIn: {
+      // child_port_check_in(), handle_child_port_check_in().
+      using Request = __Request__child_port_check_in_t;
+      const Request* in_request = reinterpret_cast<const Request*>(in_header);
+      kern_return_t kr = MIGCheckRequestChildPortCheckIn(in_request);
+      if (kr != MACH_MSG_SUCCESS) {
+        SetMIGReplyError(out_header, kr);
+        return true;
+      }
+
+      using Reply = __Reply__child_port_check_in_t;
+      Reply* out_reply = reinterpret_cast<Reply*>(out_header);
+      out_reply->RetCode =
+          interface_->HandleChildPortCheckIn(in_header->msgh_local_port,
+                                             in_request->token,
+                                             in_request->port.name,
+                                             in_request->port.disposition,
+                                             destroy_complex_request);
+      return true;
+    }
+  }
+
+  SetMIGReplyError(out_header, MIG_BAD_ID);
+  return false;
+}
+
+mach_msg_size_t ChildPortServer::MachMessageServerRequestSize() {
+  return sizeof(__RequestUnion__handle_child_port_subsystem);
+}
+
+mach_msg_size_t ChildPortServer::MachMessageServerReplySize() {
+  return sizeof(__ReplyUnion__handle_child_port_subsystem);
+}
+
+}  // namespace crashpad