Move the rest of the core files in chrome\browser to content\browser.

TBR=avi
Review URL: http://codereview.chromium.org/6538111

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@75711 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 362 insertions, 0 deletions

diff --git a/content/browser/zygote_host_linux.cc b/content/browser/zygote_host_linux.cc
new file mode 100644
index 0000000..3b6f1fb
--- /dev/null
+++ b/content/browser/zygote_host_linux.cc
@@ -0,0 +1,362 @@
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/browser/zygote_host_linux.h"
+
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "base/command_line.h"
+#include "base/eintr_wrapper.h"
+#include "base/environment.h"
+#include "base/linux_util.h"
+#include "base/logging.h"
+#include "base/path_service.h"
+#include "base/pickle.h"
+#include "base/process_util.h"
+#include "base/string_number_conversions.h"
+#include "base/string_util.h"
+#include "base/scoped_ptr.h"
+#include "base/utf_string_conversions.h"
+#include "chrome/common/chrome_constants.h"
+#include "chrome/common/chrome_switches.h"
+#include "chrome/common/process_watcher.h"
+#include "chrome/common/result_codes.h"
+#include "chrome/common/unix_domain_socket_posix.h"
+#include "content/browser/renderer_host/render_sandbox_host_linux.h"
+#include "sandbox/linux/suid/suid_unsafe_environment_variables.h"
+
+static void SaveSUIDUnsafeEnvironmentVariables() {
+  // The ELF loader will clear many environment variables so we save them to
+  // different names here so that the SUID sandbox can resolve them for the
+  // renderer.
+
+  for (unsigned i = 0; kSUIDUnsafeEnvironmentVariables[i]; ++i) {
+    const char* const envvar = kSUIDUnsafeEnvironmentVariables[i];
+    char* const saved_envvar = SandboxSavedEnvironmentVariable(envvar);
+    if (!saved_envvar)
+      continue;
+
+    scoped_ptr<base::Environment> env(base::Environment::Create());
+    std::string value;
+    if (env->GetVar(envvar, &value))
+      env->SetVar(saved_envvar, value);
+    else
+      env->UnSetVar(saved_envvar);
+
+    free(saved_envvar);
+  }
+}
+
+ZygoteHost::ZygoteHost()
+    : control_fd_(-1),
+      pid_(-1),
+      init_(false),
+      using_suid_sandbox_(false),
+      have_read_sandbox_status_word_(false),
+      sandbox_status_(0) {
+}
+
+ZygoteHost::~ZygoteHost() {
+  if (init_)
+    close(control_fd_);
+}
+
+// static
+ZygoteHost* ZygoteHost::GetInstance() {
+  return Singleton<ZygoteHost>::get();
+}
+
+void ZygoteHost::Init(const std::string& sandbox_cmd) {
+  DCHECK(!init_);
+  init_ = true;
+
+  FilePath chrome_path;
+  CHECK(PathService::Get(base::FILE_EXE, &chrome_path));
+  CommandLine cmd_line(chrome_path);
+
+  cmd_line.AppendSwitchASCII(switches::kProcessType, switches::kZygoteProcess);
+
+  int fds[2];
+  CHECK(socketpair(PF_UNIX, SOCK_SEQPACKET, 0, fds) == 0);
+  base::file_handle_mapping_vector fds_to_map;
+  fds_to_map.push_back(std::make_pair(fds[1], 3));
+
+  const CommandLine& browser_command_line = *CommandLine::ForCurrentProcess();
+  if (browser_command_line.HasSwitch(switches::kZygoteCmdPrefix)) {
+    cmd_line.PrependWrapper(
+        browser_command_line.GetSwitchValueNative(switches::kZygoteCmdPrefix));
+  }
+  // Append any switches from the browser process that need to be forwarded on
+  // to the zygote/renderers.
+  // Should this list be obtained from browser_render_process_host.cc?
+  static const char* kForwardSwitches[] = {
+    switches::kAllowSandboxDebugging,
+    switches::kLoggingLevel,
+    switches::kEnableLogging,  // Support, e.g., --enable-logging=stderr.
+    switches::kV,
+    switches::kVModule,
+    switches::kUserDataDir,  // Make logs go to the right file.
+    // Load (in-process) Pepper plugins in-process in the zygote pre-sandbox.
+    switches::kRegisterPepperPlugins,
+    switches::kDisableSeccompSandbox,
+    switches::kEnableSeccompSandbox,
+  };
+  cmd_line.CopySwitchesFrom(browser_command_line, kForwardSwitches,
+                            arraysize(kForwardSwitches));
+
+  sandbox_binary_ = sandbox_cmd.c_str();
+  struct stat st;
+
+  if (!sandbox_cmd.empty() && stat(sandbox_binary_.c_str(), &st) == 0) {
+    if (access(sandbox_binary_.c_str(), X_OK) == 0 &&
+        (st.st_uid == 0) &&
+        (st.st_mode & S_ISUID) &&
+        (st.st_mode & S_IXOTH)) {
+      using_suid_sandbox_ = true;
+      cmd_line.PrependWrapper(sandbox_binary_);
+
+      SaveSUIDUnsafeEnvironmentVariables();
+    } else {
+      LOG(FATAL) << "The SUID sandbox helper binary was found, but is not "
+                    "configured correctly. Rather than run without sandboxing "
+                    "I'm aborting now. You need to make sure that "
+                 << sandbox_binary_ << " is mode 4755 and owned by root.";
+    }
+  }
+
+  // Start up the sandbox host process and get the file descriptor for the
+  // renderers to talk to it.
+  const int sfd = RenderSandboxHostLinux::GetInstance()->GetRendererSocket();
+  fds_to_map.push_back(std::make_pair(sfd, 5));
+
+  int dummy_fd = -1;
+  if (using_suid_sandbox_) {
+    dummy_fd = socket(PF_UNIX, SOCK_DGRAM, 0);
+    CHECK(dummy_fd >= 0);
+    fds_to_map.push_back(std::make_pair(dummy_fd, 7));
+  }
+
+  base::ProcessHandle process;
+  base::LaunchApp(cmd_line.argv(), fds_to_map, false, &process);
+  CHECK(process != -1) << "Failed to launch zygote process";
+
+  if (using_suid_sandbox_) {
+    // In the SUID sandbox, the real zygote is forked from the sandbox.
+    // We need to look for it.
+    // But first, wait for the zygote to tell us it's running.
+    // The sending code is in chrome/browser/zygote_main_linux.cc.
+    std::vector<int> fds_vec;
+    const int kExpectedLength = sizeof(kZygoteMagic);
+    char buf[kExpectedLength];
+    const ssize_t len = UnixDomainSocket::RecvMsg(fds[0], buf, sizeof(buf),
+                                                  &fds_vec);
+    CHECK(len == kExpectedLength) << "Incorrect zygote magic length";
+    CHECK(0 == strcmp(buf, kZygoteMagic)) << "Incorrect zygote magic";
+
+    std::string inode_output;
+    ino_t inode = 0;
+    // Figure out the inode for |dummy_fd|, close |dummy_fd| on our end,
+    // and find the zygote process holding |dummy_fd|.
+    if (base::FileDescriptorGetInode(&inode, dummy_fd)) {
+      close(dummy_fd);
+      std::vector<std::string> get_inode_cmdline;
+      get_inode_cmdline.push_back(sandbox_binary_);
+      get_inode_cmdline.push_back(base::kFindInodeSwitch);
+      get_inode_cmdline.push_back(base::Int64ToString(inode));
+      CommandLine get_inode_cmd(get_inode_cmdline);
+      if (base::GetAppOutput(get_inode_cmd, &inode_output)) {
+        base::StringToInt(inode_output, &pid_);
+      }
+    }
+    CHECK(pid_ > 0) << "Did not find zygote process (using sandbox binary "
+        << sandbox_binary_ << ")";
+
+    if (process != pid_) {
+      // Reap the sandbox.
+      ProcessWatcher::EnsureProcessGetsReaped(process);
+    }
+  } else {
+    // Not using the SUID sandbox.
+    pid_ = process;
+  }
+
+  close(fds[1]);
+  control_fd_ = fds[0];
+
+  Pickle pickle;
+  pickle.WriteInt(kCmdGetSandboxStatus);
+  std::vector<int> empty_fds;
+  if (!UnixDomainSocket::SendMsg(control_fd_, pickle.data(), pickle.size(),
+                                 empty_fds))
+    LOG(FATAL) << "Cannot communicate with zygote";
+  // We don't wait for the reply. We'll read it in ReadReply.
+}
+
+ssize_t ZygoteHost::ReadReply(void* buf, size_t buf_len) {
+  // At startup we send a kCmdGetSandboxStatus request to the zygote, but don't
+  // wait for the reply. Thus, the first time that we read from the zygote, we
+  // get the reply to that request.
+  if (!have_read_sandbox_status_word_) {
+    if (HANDLE_EINTR(read(control_fd_, &sandbox_status_,
+                          sizeof(sandbox_status_))) !=
+        sizeof(sandbox_status_)) {
+      return -1;
+    }
+    have_read_sandbox_status_word_ = true;
+  }
+
+  return HANDLE_EINTR(read(control_fd_, buf, buf_len));
+}
+
+pid_t ZygoteHost::ForkRenderer(
+    const std::vector<std::string>& argv,
+    const base::GlobalDescriptors::Mapping& mapping) {
+  DCHECK(init_);
+  Pickle pickle;
+
+  pickle.WriteInt(kCmdFork);
+  pickle.WriteInt(argv.size());
+  for (std::vector<std::string>::const_iterator
+       i = argv.begin(); i != argv.end(); ++i)
+    pickle.WriteString(*i);
+
+  pickle.WriteInt(mapping.size());
+
+  std::vector<int> fds;
+  for (base::GlobalDescriptors::Mapping::const_iterator
+       i = mapping.begin(); i != mapping.end(); ++i) {
+    pickle.WriteUInt32(i->first);
+    fds.push_back(i->second);
+  }
+
+  pid_t pid;
+  {
+    base::AutoLock lock(control_lock_);
+    if (!UnixDomainSocket::SendMsg(control_fd_, pickle.data(), pickle.size(),
+                                   fds))
+      return base::kNullProcessHandle;
+
+    if (ReadReply(&pid, sizeof(pid)) != sizeof(pid))
+      return base::kNullProcessHandle;
+    if (pid <= 0)
+      return base::kNullProcessHandle;
+  }
+
+  const int kRendererScore = 5;
+  AdjustRendererOOMScore(pid, kRendererScore);
+
+  return pid;
+}
+
+void ZygoteHost::AdjustRendererOOMScore(base::ProcessHandle pid, int score) {
+  // 1) You can't change the oom_adj of a non-dumpable process (EPERM) unless
+  //    you're root. Because of this, we can't set the oom_adj from the browser
+  //    process.
+  //
+  // 2) We can't set the oom_adj before entering the sandbox because the
+  //    zygote is in the sandbox and the zygote is as critical as the browser
+  //    process. Its oom_adj value shouldn't be changed.
+  //
+  // 3) A non-dumpable process can't even change its own oom_adj because it's
+  //    root owned 0644. The sandboxed processes don't even have /proc, but one
+  //    could imagine passing in a descriptor from outside.
+  //
+  // So, in the normal case, we use the SUID binary to change it for us.
+  // However, Fedora (and other SELinux systems) don't like us touching other
+  // process's oom_adj values
+  // (https://bugzilla.redhat.com/show_bug.cgi?id=581256).
+  //
+  // The offical way to get the SELinux mode is selinux_getenforcemode, but I
+  // don't want to add another library to the build as it's sure to cause
+  // problems with other, non-SELinux distros.
+  //
+  // So we just check for /selinux. This isn't foolproof, but it's not bad
+  // and it's easy.
+
+  static bool selinux;
+  static bool selinux_valid = false;
+
+  if (!selinux_valid) {
+    selinux = access("/selinux", X_OK) == 0;
+    selinux_valid = true;
+  }
+
+  if (using_suid_sandbox_ && !selinux) {
+    base::ProcessHandle sandbox_helper_process;
+    std::vector<std::string> adj_oom_score_cmdline;
+
+    adj_oom_score_cmdline.push_back(sandbox_binary_);
+    adj_oom_score_cmdline.push_back(base::kAdjustOOMScoreSwitch);
+    adj_oom_score_cmdline.push_back(base::Int64ToString(pid));
+    adj_oom_score_cmdline.push_back(base::IntToString(score));
+    CommandLine adj_oom_score_cmd(adj_oom_score_cmdline);
+    if (base::LaunchApp(adj_oom_score_cmd, false, true,
+                        &sandbox_helper_process)) {
+      ProcessWatcher::EnsureProcessGetsReaped(sandbox_helper_process);
+    }
+  } else if (!using_suid_sandbox_) {
+    if (!base::AdjustOOMScore(pid, score))
+      PLOG(ERROR) << "Failed to adjust OOM score of renderer with pid " << pid;
+  }
+}
+
+void ZygoteHost::EnsureProcessTerminated(pid_t process) {
+  DCHECK(init_);
+  Pickle pickle;
+
+  pickle.WriteInt(kCmdReap);
+  pickle.WriteInt(process);
+
+  if (HANDLE_EINTR(write(control_fd_, pickle.data(), pickle.size())) < 0)
+    PLOG(ERROR) << "write";
+}
+
+base::TerminationStatus ZygoteHost::GetTerminationStatus(
+    base::ProcessHandle handle,
+    int* exit_code) {
+  DCHECK(init_);
+  Pickle pickle;
+  pickle.WriteInt(kCmdGetTerminationStatus);
+  pickle.WriteInt(handle);
+
+  // Set this now to handle the early termination cases.
+  if (exit_code)
+    *exit_code = ResultCodes::NORMAL_EXIT;
+
+  static const unsigned kMaxMessageLength = 128;
+  char buf[kMaxMessageLength];
+  ssize_t len;
+  {
+    base::AutoLock lock(control_lock_);
+    if (HANDLE_EINTR(write(control_fd_, pickle.data(), pickle.size())) < 0)
+      PLOG(ERROR) << "write";
+
+    len = ReadReply(buf, sizeof(buf));
+  }
+
+  if (len == -1) {
+    LOG(WARNING) << "Error reading message from zygote: " << errno;
+    return base::TERMINATION_STATUS_NORMAL_TERMINATION;
+  } else if (len == 0) {
+    LOG(WARNING) << "Socket closed prematurely.";
+    return base::TERMINATION_STATUS_NORMAL_TERMINATION;
+  }
+
+  Pickle read_pickle(buf, len);
+  int status, tmp_exit_code;
+  void* iter = NULL;
+  if (!read_pickle.ReadInt(&iter, &status) ||
+      !read_pickle.ReadInt(&iter, &tmp_exit_code)) {
+    LOG(WARNING) << "Error parsing GetTerminationStatus response from zygote.";
+    return base::TERMINATION_STATUS_NORMAL_TERMINATION;
+  }
+
+  if (exit_code)
+    *exit_code = tmp_exit_code;
+
+  return static_cast<base::TerminationStatus>(status);
+}