blob: e5ee01a3c5168490811a5cf68c073557db4b5f40 [file] [log] [blame]
// Copyright (c) 2011 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 "chrome/common/nacl_fork_delegate_linux.h"
#include <signal.h>
#include <stdlib.h>
#include <sys/socket.h>
#include "base/basictypes.h"
#include "base/command_line.h"
#include "base/eintr_wrapper.h"
#include "base/logging.h"
#include "base/file_path.h"
#include "base/path_service.h"
#include "base/process_util.h"
#include "content/common/unix_domain_socket_posix.h"
#include "content/common/zygote_fork_delegate_linux.h"
#include "chrome/common/chrome_paths.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/nacl_helper_linux.h"
NaClForkDelegate::NaClForkDelegate()
: ready_(false),
sandboxed_(false),
fd_(-1) {}
void NaClForkDelegate::Init(const bool sandboxed,
const int browserdesc,
const int sandboxdesc) {
VLOG(1) << "NaClForkDelegate::Init()";
int fds[2];
sandboxed_ = sandboxed;
// Confirm a couple hard-wired assumptions.
// The NaCl constants are from chrome/nacl/nacl_linux_helper.h
DCHECK(kNaClBrowserDescriptor == browserdesc);
DCHECK(kNaClSandboxDescriptor == sandboxdesc);
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], kNaClZygoteDescriptor));
fds_to_map.push_back(std::make_pair(sandboxdesc, kNaClSandboxDescriptor));
// TODO(bradchen): To make this the default for release builds,
// remove command line switch.
ready_ = false;
const bool use_helper = CommandLine::ForCurrentProcess()->HasSwitch(
switches::kNaClLinuxHelper);
FilePath helper_exe;
if (use_helper && PathService::Get(chrome::FILE_NACL_HELPER, &helper_exe)) {
CommandLine::StringVector argv = CommandLine::ForCurrentProcess()->argv();
argv[0] = helper_exe.value();
base::LaunchOptions options;
options.fds_to_remap = &fds_to_map;
options.clone_flags = CLONE_FS | SIGCHLD;
// LD_BIND_NOW forces non-lazy binding in the dynamic linker, to
// prevent the linker from trying to look at the text of the nacl_helper
// program after it has been replaced by the nacl module.
base::environment_vector env;
env.push_back(std::make_pair("LD_BIND_NOW", "1"));
options.environ = &env;
ready_ = base::LaunchProcess(argv, options, NULL);
// parent and error cases are handled below
}
if (HANDLE_EINTR(close(fds[1])) != 0)
LOG(ERROR) << "close(fds[1]) failed";
if (ready_) {
const ssize_t kExpectedLength = strlen(kNaClHelperStartupAck);
char buf[kExpectedLength];
// Wait for ack from nacl_helper, indicating it is ready to help
const ssize_t nread = HANDLE_EINTR(read(fds[0], buf, sizeof(buf)));
if (nread == kExpectedLength &&
memcmp(buf, kNaClHelperStartupAck, nread) == 0) {
// all is well
fd_ = fds[0];
return;
}
LOG(ERROR) << "Bad NaCl helper startup ack (" << nread << " bytes)";
}
// TODO(bradchen): Make this LOG(ERROR) when the NaCl helper
// becomes the default.
ready_ = false;
fd_ = -1;
if (HANDLE_EINTR(close(fds[0])) != 0)
LOG(ERROR) << "close(fds[0]) failed";
}
NaClForkDelegate::~NaClForkDelegate() {
// side effect of close: delegate process will terminate
if (ready_) {
if (HANDLE_EINTR(close(fd_)) != 0)
LOG(ERROR) << "close(fd_) failed";
}
}
bool NaClForkDelegate::CanHelp(const std::string& process_type) {
return (process_type == switches::kNaClLoaderProcess && ready_);
}
pid_t NaClForkDelegate::Fork(const std::vector<int>& fds) {
base::ProcessId naclchild;
VLOG(1) << "NaClForkDelegate::Fork";
DCHECK(fds.size() == kNaClParentFDIndex + 1);
if (!UnixDomainSocket::SendMsg(fd_, kNaClForkRequest,
strlen(kNaClForkRequest), fds)) {
LOG(ERROR) << "NaClForkDelegate::Fork: SendMsg failed";
return -1;
}
int nread = HANDLE_EINTR(read(fd_, &naclchild, sizeof(naclchild)));
if (nread != sizeof(naclchild)) {
LOG(ERROR) << "NaClForkDelegate::Fork: read failed";
return -1;
}
VLOG(1) << "nacl_child is " << naclchild << " (" << nread << " bytes)";
return naclchild;
}
bool NaClForkDelegate::AckChild(const int fd,
const std::string& channel_switch) {
int nwritten = HANDLE_EINTR(write(fd, channel_switch.c_str(),
channel_switch.length()));
if (nwritten != static_cast<int>(channel_switch.length())) {
return false;
}
return true;
}