ppapi/nacl_irt/manifest_service.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ppapi/nacl_irt/manifest_service.h"
   6
   7 #include "base/message_loop/message_loop_proxy.h"
   8 #include "ipc/ipc_channel_handle.h"
   9 #include "ipc/ipc_channel_proxy.h"
  10 #include "ipc/ipc_sync_message_filter.h"
  11 #include "native_client/src/trusted/service_runtime/include/sys/errno.h"
  12 #include "ppapi/nacl_irt/irt_manifest.h"
  13 #include "ppapi/nacl_irt/plugin_startup.h"
  14 #include "ppapi/proxy/ppapi_messages.h"
  15
  16 #if !defined(OS_NACL_SFI)
  17 #include <pthread.h>
  18 #include <map>
  19 #include <string>
  20 #endif
  21
  22 namespace ppapi {
  23
  24 const char kFilePrefix[] = "files/";
  25
  26 // IPC channel is asynchronously set up. So, the NaCl process may try to
  27 // send a OpenResource message to the host before the connection is
  28 // established. In such a case, it is necessary to wait for the set up
  29 // completion.
  30 class ManifestMessageFilter : public IPC::SyncMessageFilter {
  31  public:
  32   ManifestMessageFilter(base::WaitableEvent* shutdown_event)
  33       : SyncMessageFilter(shutdown_event),
  34         connected_event_(
  35             true /* manual_reset */, false /* initially_signaled */) {
  36   }
  37
  38   virtual bool Send(IPC::Message* message) override {
  39     // Wait until set up is actually done.
  40     connected_event_.Wait();
  41     return SyncMessageFilter::Send(message);
  42   }
  43
  44   // When set up is done, OnFilterAdded is called on IO thread. Unblocks the
  45   // Send().
  46   virtual void OnFilterAdded(IPC::Sender* sender) override {
  47     SyncMessageFilter::OnFilterAdded(sender);
  48     connected_event_.Signal();
  49   }
  50
  51   // If an error is found, unblocks the Send(), too, to return an error.
  52   virtual void OnChannelError() override {
  53     SyncMessageFilter::OnChannelError();
  54     connected_event_.Signal();
  55   }
  56
  57   // Similar to OnChannelError, unblocks the Send() on the channel closing.
  58   virtual void OnChannelClosing() override {
  59     SyncMessageFilter::OnChannelClosing();
  60     connected_event_.Signal();
  61   }
  62
  63  private:
  64   base::WaitableEvent connected_event_;
  65
  66   DISALLOW_COPY_AND_ASSIGN(ManifestMessageFilter);
  67 };
  68
  69 ManifestService::ManifestService(
  70     const IPC::ChannelHandle& handle,
  71     scoped_refptr<base::MessageLoopProxy> io_message_loop,
  72     base::WaitableEvent* shutdown_event) {
  73   filter_ = new ManifestMessageFilter(shutdown_event);
  74   channel_ = IPC::ChannelProxy::Create(handle,
  75                                        IPC::Channel::MODE_SERVER,
  76                                        NULL,  // Listener
  77                                        io_message_loop.get());
  78   channel_->AddFilter(filter_.get());
  79 }
  80
  81 ManifestService::~ManifestService() {
  82 }
  83
  84 void ManifestService::StartupInitializationComplete() {
  85   filter_->Send(new PpapiHostMsg_StartupInitializationComplete);
  86 }
  87
  88 bool ManifestService::OpenResource(const char* file, int* fd) {
  89   // We currently restrict to only allow one concurrent open_resource() call
  90   // per plugin. This could be fixed by doing a token lookup with
  91   // NaClProcessMsg_ResolveFileTokenAsyncReply instead of using a
  92   // global inside components/nacl/loader/nacl_listener.cc
  93   base::AutoLock lock(open_resource_lock_);
  94
  95   // OpenResource will return INVALID SerializedHandle, if it is not supported.
  96   // Specifically, PNaCl doesn't support open resource.
  97   ppapi::proxy::SerializedHandle ipc_fd;
  98
  99   // File tokens are ignored here, but needed when the message is processed
 100   // inside NaClIPCAdapter.
 101   uint64_t file_token_lo = 0;
 102   uint64_t file_token_hi = 0;
 103   if (!filter_->Send(new PpapiHostMsg_OpenResource(
 104           std::string(kFilePrefix) + file,
 105           &ipc_fd,
 106           &file_token_lo,
 107           &file_token_hi))) {
 108     LOG(ERROR) << "ManifestService::OpenResource failed:" << file;
 109     *fd = -1;
 110     return false;
 111   }
 112
 113   // File tokens are used internally by NaClIPCAdapter and should have
 114   // been cleared from the message when it is received here.
 115   // These tokens should never be set for Non-SFI mode.
 116   CHECK(file_token_lo == 0);
 117   CHECK(file_token_hi == 0);
 118
 119   // Copy the file if we received a valid file descriptor. Otherwise, if we got
 120   // a reply, the file doesn't exist, so provide an fd of -1.
 121   // See IrtOpenResource() for how this function's result is interpreted.
 122   if (ipc_fd.is_file())
 123     *fd = ipc_fd.descriptor().fd;
 124   else
 125     *fd = -1;
 126   return true;
 127 }
 128
 129 #if !defined(OS_NACL_SFI)
 130 namespace {
 131
 132 pthread_mutex_t g_mu = PTHREAD_MUTEX_INITIALIZER;
 133 std::map<std::string, int>* g_prefetched_fds;
 134
 135 }  // namespace
 136
 137 void RegisterPreopenedDescriptorsNonSfi(
 138     std::map<std::string, int>* key_fd_map) {
 139   pthread_mutex_lock(&g_mu);
 140   DCHECK(!g_prefetched_fds);
 141   g_prefetched_fds = key_fd_map;
 142   pthread_mutex_unlock(&g_mu);
 143 }
 144 #endif
 145
 146 int IrtOpenResource(const char* file, int* fd) {
 147   // Remove leading '/' character.
 148   if (file[0] == '/')
 149     ++file;
 150
 151 #if !defined(OS_NACL_SFI)
 152   // Fast path for prefetched FDs.
 153   pthread_mutex_lock(&g_mu);
 154   if (g_prefetched_fds) {
 155     std::map<std::string, int>::iterator it = g_prefetched_fds->find(file);
 156     if (it != g_prefetched_fds->end()) {
 157       *fd = it->second;
 158       g_prefetched_fds->erase(it);
 159       pthread_mutex_unlock(&g_mu);
 160       return 0;
 161     }
 162   }
 163   pthread_mutex_unlock(&g_mu);
 164 #endif
 165
 166   ManifestService* manifest_service = GetManifestService();
 167   if (manifest_service == NULL ||
 168       !manifest_service->OpenResource(file, fd)) {
 169     return NACL_ABI_EIO;
 170   }
 171   return (*fd == -1) ? NACL_ABI_ENOENT : 0;
 172 }
 173
 174 }  // namespace ppapi