mojo/shell/network_fetcher.cc

   1 // Copyright 2015 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 "mojo/shell/network_fetcher.h"
   6
   7 #include "base/bind.h"
   8 #include "base/command_line.h"
   9 #include "base/files/file.h"
  10 #include "base/files/file_path.h"
  11 #include "base/files/file_util.h"
  12 #include "base/message_loop/message_loop.h"
  13 #include "base/process/process.h"
  14 #include "base/stl_util.h"
  15 #include "base/strings/string_number_conversions.h"
  16 #include "base/strings/string_util.h"
  17 #include "base/strings/stringprintf.h"
  18 #include "base/strings/utf_string_conversions.h"
  19 #include "base/trace_event/trace_event.h"
  20 #include "crypto/secure_hash.h"
  21 #include "crypto/sha2.h"
  22 #include "mojo/common/common_type_converters.h"
  23 #include "mojo/common/data_pipe_utils.h"
  24 #include "mojo/common/url_type_converters.h"
  25 #include "mojo/services/network/public/interfaces/url_loader_factory.mojom.h"
  26 #include "mojo/shell/data_pipe_peek.h"
  27 #include "mojo/shell/switches.h"
  28
  29 namespace mojo {
  30 namespace shell {
  31
  32 NetworkFetcher::NetworkFetcher(bool disable_cache,
  33                                mojo::URLRequestPtr request,
  34                                URLLoaderFactory* url_loader_factory,
  35                                const FetchCallback& loader_callback)
  36     : Fetcher(loader_callback),
  37       disable_cache_(false),
  38       url_(request->url.To<GURL>()),
  39       weak_ptr_factory_(this) {
  40   StartNetworkRequest(request.Pass(), url_loader_factory);
  41 }
  42
  43 NetworkFetcher::~NetworkFetcher() {
  44 }
  45
  46 const GURL& NetworkFetcher::GetURL() const {
  47   return url_;
  48 }
  49
  50 GURL NetworkFetcher::GetRedirectURL() const {
  51   if (!response_)
  52     return GURL::EmptyGURL();
  53
  54   if (response_->redirect_url.is_null())
  55     return GURL::EmptyGURL();
  56
  57   return GURL(response_->redirect_url);
  58 }
  59
  60 GURL NetworkFetcher::GetRedirectReferer() const {
  61   if (!response_)
  62     return GURL::EmptyGURL();
  63
  64   if (response_->redirect_referrer.is_null())
  65     return GURL::EmptyGURL();
  66
  67   return GURL(response_->redirect_referrer);
  68 }
  69 URLResponsePtr NetworkFetcher::AsURLResponse(base::TaskRunner* task_runner,
  70                                              uint32_t skip) {
  71   if (skip != 0) {
  72     MojoResult result = ReadDataRaw(
  73         response_->body.get(), nullptr, &skip,
  74         MOJO_READ_DATA_FLAG_ALL_OR_NONE | MOJO_READ_DATA_FLAG_DISCARD);
  75     DCHECK_EQ(result, MOJO_RESULT_OK);
  76   }
  77   return response_.Pass();
  78 }
  79
  80 void NetworkFetcher::RecordCacheToURLMapping(const base::FilePath& path,
  81                                              const GURL& url) {
  82   // This is used to extract symbols on android.
  83   // TODO(eseidel): All users of this log should move to using the map file.
  84   VLOG(1) << "Caching mojo app " << url << " at " << path.value();
  85
  86   base::FilePath temp_dir;
  87   base::GetTempDir(&temp_dir);
  88   base::ProcessId pid = base::Process::Current().Pid();
  89   std::string map_name = base::StringPrintf("mojo_shell.%d.maps", pid);
  90   base::FilePath map_path = temp_dir.AppendASCII(map_name);
  91
  92   // TODO(eseidel): Paths or URLs with spaces will need quoting.
  93   std::string map_entry =
  94       base::StringPrintf("%s %s\n", path.value().c_str(), url.spec().c_str());
  95   // TODO(eseidel): AppendToFile is missing O_CREAT, crbug.com/450696
  96   if (!PathExists(map_path)) {
  97     base::WriteFile(map_path, map_entry.data(),
  98                     static_cast<int>(map_entry.length()));
  99   } else {
 100     base::AppendToFile(map_path, map_entry.data(),
 101                        static_cast<int>(map_entry.length()));
 102   }
 103 }
 104
 105 // For remote debugging, GDB needs to be, a apriori, aware of the filename a
 106 // library will be loaded from. AppIds should be be both predictable and unique,
 107 // but any hash would work. Currently we use sha256 from crypto/secure_hash.h
 108 bool NetworkFetcher::ComputeAppId(const base::FilePath& path,
 109                                   std::string* digest_string) {
 110   scoped_ptr<crypto::SecureHash> ctx(
 111       crypto::SecureHash::Create(crypto::SecureHash::SHA256));
 112   base::File file(path, base::File::FLAG_OPEN | base::File::FLAG_READ);
 113   if (!file.IsValid()) {
 114     LOG(ERROR) << "Failed to open " << path.value() << " for computing AppId";
 115     return false;
 116   }
 117   char buf[1024];
 118   while (file.IsValid()) {
 119     int bytes_read = file.ReadAtCurrentPos(buf, sizeof(buf));
 120     if (bytes_read == 0)
 121       break;
 122     ctx->Update(buf, bytes_read);
 123   }
 124   if (!file.IsValid()) {
 125     LOG(ERROR) << "Error reading " << path.value();
 126     return false;
 127   }
 128   // The output is really a vector of unit8, we're cheating by using a string.
 129   std::string output(crypto::kSHA256Length, 0);
 130   ctx->Finish(string_as_array(&output), output.size());
 131   output = base::HexEncode(output.c_str(), output.size());
 132   // Using lowercase for compatiblity with sha256sum output.
 133   *digest_string = base::StringToLowerASCII(output);
 134   return true;
 135 }
 136
 137 bool NetworkFetcher::RenameToAppId(const GURL& url,
 138                                    const base::FilePath& old_path,
 139                                    base::FilePath* new_path) {
 140   std::string app_id;
 141   if (!ComputeAppId(old_path, &app_id))
 142     return false;
 143
 144   // Using a hash of the url as a directory to prevent a race when the same
 145   // bytes are downloaded from 2 different urls. In particular, if the same
 146   // application is connected to twice concurrently with different query
 147   // parameters, the directory will be different, which will prevent the
 148   // collision.
 149   std::string dirname = base::HexEncode(
 150       crypto::SHA256HashString(url.spec()).data(), crypto::kSHA256Length);
 151
 152   base::FilePath temp_dir;
 153   base::GetTempDir(&temp_dir);
 154   base::FilePath app_dir = temp_dir.AppendASCII(dirname);
 155   // The directory is leaked, because it can be reused at any time if the same
 156   // application is downloaded. Deleting it would be racy. This is only
 157   // happening when --predictable-app-filenames is used.
 158   bool result = base::CreateDirectoryAndGetError(app_dir, nullptr);
 159   DCHECK(result);
 160   std::string unique_name = base::StringPrintf("%s.mojo", app_id.c_str());
 161   *new_path = app_dir.AppendASCII(unique_name);
 162   return base::Move(old_path, *new_path);
 163 }
 164
 165 void NetworkFetcher::CopyCompleted(
 166     base::Callback<void(const base::FilePath&, bool)> callback,
 167     bool success) {
 168   if (success) {
 169     if (base::CommandLine::ForCurrentProcess()->HasSwitch(
 170             switches::kPredictableAppFilenames)) {
 171       // The copy completed, now move to $TMP/$APP_ID.mojo before the dlopen.
 172       success = false;
 173       base::FilePath new_path;
 174       if (RenameToAppId(url_, path_, &new_path)) {
 175         if (base::PathExists(new_path)) {
 176           path_ = new_path;
 177           success = true;
 178         }
 179       }
 180     }
 181   }
 182
 183   if (success)
 184     RecordCacheToURLMapping(path_, url_);
 185
 186   base::MessageLoop::current()->PostTask(FROM_HERE,
 187                                          base::Bind(callback, path_, success));
 188 }
 189
 190 void NetworkFetcher::AsPath(
 191     base::TaskRunner* task_runner,
 192     base::Callback<void(const base::FilePath&, bool)> callback) {
 193   if (!path_.empty() || !response_) {
 194     base::MessageLoop::current()->PostTask(
 195         FROM_HERE, base::Bind(callback, path_, base::PathExists(path_)));
 196     return;
 197   }
 198
 199   base::CreateTemporaryFile(&path_);
 200   common::CopyToFile(response_->body.Pass(), path_, task_runner,
 201                      base::Bind(&NetworkFetcher::CopyCompleted,
 202                                 weak_ptr_factory_.GetWeakPtr(), callback));
 203 }
 204
 205 std::string NetworkFetcher::MimeType() {
 206   return response_->mime_type;
 207 }
 208
 209 bool NetworkFetcher::HasMojoMagic() {
 210   std::string magic;
 211   return BlockingPeekNBytes(response_->body.get(), &magic, strlen(kMojoMagic),
 212                             kPeekTimeout) &&
 213          magic == kMojoMagic;
 214 }
 215
 216 bool NetworkFetcher::PeekFirstLine(std::string* line) {
 217   return BlockingPeekLine(response_->body.get(), line, kMaxShebangLength,
 218                           kPeekTimeout);
 219 }
 220
 221 void NetworkFetcher::StartNetworkRequest(mojo::URLRequestPtr request,
 222                                          URLLoaderFactory* url_loader_factory) {
 223   TRACE_EVENT_ASYNC_BEGIN1("mojo_shell", "NetworkFetcher::NetworkRequest", this,
 224                            "url", request->url.To<std::string>());
 225   request->auto_follow_redirects = false;
 226   request->bypass_cache = disable_cache_;
 227
 228   url_loader_factory->CreateURLLoader(GetProxy(&url_loader_));
 229   url_loader_->Start(request.Pass(),
 230                      base::Bind(&NetworkFetcher::OnLoadComplete,
 231                                 weak_ptr_factory_.GetWeakPtr()));
 232 }
 233
 234 void NetworkFetcher::OnLoadComplete(URLResponsePtr response) {
 235   TRACE_EVENT_ASYNC_END0("mojo_shell", "NetworkFetcher::NetworkRequest", this);
 236   scoped_ptr<Fetcher> owner(this);
 237   if (response->error) {
 238     LOG(ERROR) << "Error (" << response->error->code << ": "
 239                << response->error->description << ") while fetching "
 240                << response->url;
 241     loader_callback_.Run(nullptr);
 242     return;
 243   }
 244
 245   if (response->status_code >= 400 && response->status_code < 600) {
 246     LOG(ERROR) << "Error (" << response->status_code << ": "
 247                << response->status_line << "): "
 248                << "while fetching " << response->url;
 249     loader_callback_.Run(nullptr);
 250     return;
 251   }
 252
 253   response_ = response.Pass();
 254   loader_callback_.Run(owner.Pass());
 255 }
 256
 257 }  // namespace shell
 258 }  // namespace mojo