blob: b9f9cd8fc512d68c0e820a45231e8d9bcd3b7c9a [file] [log] [blame]
// Copyright 2017 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 "sandbox/mac/seatbelt_exec.h"
#include <fcntl.h>
#include <inttypes.h>
#include <stdarg.h>
#include <stdio.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <unistd.h>
#include <vector>
#include "base/posix/eintr_wrapper.h" //nogncheck
#include "sandbox/mac/sandbox_logging.h"
#include "sandbox/mac/seatbelt.h"
namespace sandbox {
namespace {
struct ReadTraits {
using BufferType = uint8_t*;
static constexpr char kNameString[] = "read";
static ssize_t Operate(int fd, BufferType buffer, size_t size) {
return read(fd, buffer, size);
}
};
constexpr char ReadTraits::kNameString[];
struct WriteTraits {
using BufferType = const uint8_t*;
static constexpr char kNameString[] = "write";
static ssize_t Operate(int fd, BufferType buffer, size_t size) {
return write(fd, buffer, size);
}
};
constexpr char WriteTraits::kNameString[];
template <typename Traits>
bool ReadOrWrite(int fd,
const typename Traits::BufferType buffer,
const size_t size) {
if (size > std::numeric_limits<ssize_t>::max()) {
logging::Error("request size is greater than ssize_t::max");
return false;
}
ssize_t bytes_to_transact = static_cast<ssize_t>(size);
while (bytes_to_transact > 0) {
ssize_t offset = size - bytes_to_transact;
ssize_t transacted_bytes =
HANDLE_EINTR(Traits::Operate(fd, buffer + offset, bytes_to_transact));
if (transacted_bytes < 0) {
logging::PError("%s failed", Traits::kNameString);
return false;
} else if (transacted_bytes == 0) {
// A short read from the sender, perhaps the sender process died.
logging::Error("%s failed", Traits::kNameString);
return false;
}
bytes_to_transact -= transacted_bytes;
}
return true;
}
} // namespace
namespace switches {
const char kSeatbeltClient[] = "--seatbelt-client=";
const char kSeatbeltClientName[] = "seatbelt-client";
} // namespace switches
SeatbeltExecClient::SeatbeltExecClient() {
if (pipe(pipe_) != 0)
logging::PFatal("SeatbeltExecClient: pipe failed");
}
SeatbeltExecClient::~SeatbeltExecClient() {
if (pipe_[0] != -1)
IGNORE_EINTR(close(pipe_[0]));
if (pipe_[1] != -1)
IGNORE_EINTR(close(pipe_[1]));
}
bool SeatbeltExecClient::SetBooleanParameter(const std::string& key,
bool value) {
google::protobuf::MapPair<std::string, std::string> pair(
key, value ? "TRUE" : "FALSE");
return policy_.mutable_params()->insert(pair).second;
}
bool SeatbeltExecClient::SetParameter(const std::string& key,
const std::string& value) {
google::protobuf::MapPair<std::string, std::string> pair(key, value);
return policy_.mutable_params()->insert(pair).second;
}
void SeatbeltExecClient::SetProfile(const std::string& policy) {
policy_.set_profile(policy);
}
int SeatbeltExecClient::GetReadFD() {
return pipe_[0];
}
bool SeatbeltExecClient::SendProfile() {
IGNORE_EINTR(close(pipe_[0]));
pipe_[0] = -1;
std::string serialized_protobuf;
if (!policy_.SerializeToString(&serialized_protobuf)) {
logging::Error("SeatbeltExecClient: Serializing the profile failed.");
return false;
}
if (!WriteString(serialized_protobuf)) {
logging::Error(
"SeatbeltExecClient: Writing the serialized profile failed.");
return false;
}
IGNORE_EINTR(close(pipe_[1]));
pipe_[1] = -1;
return true;
}
bool SeatbeltExecClient::WriteString(const std::string& str) {
uint64_t str_len = static_cast<uint64_t>(str.size());
if (!ReadOrWrite<WriteTraits>(pipe_[1], reinterpret_cast<uint8_t*>(&str_len),
sizeof(str_len))) {
logging::Error("SeatbeltExecClient: write buffer length failed.");
return false;
}
if (!ReadOrWrite<WriteTraits>(
pipe_[1], reinterpret_cast<const uint8_t*>(&str[0]), str_len)) {
logging::Error("SeatbeltExecClient: write buffer failed.");
return false;
}
return true;
}
SeatbeltExecServer::SeatbeltExecServer(int fd) : fd_(fd), extra_params_() {}
SeatbeltExecServer::~SeatbeltExecServer() {
close(fd_);
}
sandbox::SeatbeltExecServer::CreateFromArgumentsResult::
CreateFromArgumentsResult() = default;
sandbox::SeatbeltExecServer::CreateFromArgumentsResult::
CreateFromArgumentsResult(CreateFromArgumentsResult&&) = default;
sandbox::SeatbeltExecServer::CreateFromArgumentsResult::
~CreateFromArgumentsResult() = default;
// static
sandbox::SeatbeltExecServer::CreateFromArgumentsResult
SeatbeltExecServer::CreateFromArguments(const char* executable_path,
int argc,
char** argv) {
CreateFromArgumentsResult result;
int seatbelt_client_fd = -1;
for (int i = 1; i < argc; ++i) {
if (strncmp(argv[i], switches::kSeatbeltClient,
strlen(switches::kSeatbeltClient)) == 0) {
result.sandbox_required = true;
std::string arg(argv[i]);
std::string fd_string = arg.substr(strlen(switches::kSeatbeltClient));
seatbelt_client_fd = std::stoi(fd_string);
}
}
if (!result.sandbox_required)
return result;
if (seatbelt_client_fd < 0) {
logging::Error("Must pass a valid file descriptor to %s",
switches::kSeatbeltClient);
return result;
}
char full_exec_path[MAXPATHLEN];
if (realpath(executable_path, full_exec_path) == NULL) {
logging::PError("realpath");
return result;
}
auto server = std::make_unique<SeatbeltExecServer>(seatbelt_client_fd);
// These parameters are provided for every profile to use.
if (!server->SetParameter("EXECUTABLE_PATH", full_exec_path) ||
!server->SetParameter("CURRENT_PID", std::to_string(getpid()))) {
logging::Error("Failed to set up parameters for sandbox.");
return result;
}
result.server = std::move(server);
return result;
}
bool SeatbeltExecServer::InitializeSandbox() {
std::string policy_string;
if (!ReadString(&policy_string))
return false;
mac::SandboxPolicy policy;
if (!policy.ParseFromString(policy_string)) {
logging::Error("SeatbeltExecServer: ParseFromString failed");
return false;
}
return ApplySandboxProfile(policy);
}
bool SeatbeltExecServer::ApplySandboxProfile(const mac::SandboxPolicy& policy) {
std::vector<const char*> weak_params;
for (const auto& pair : policy.params()) {
weak_params.push_back(pair.first.c_str());
weak_params.push_back(pair.second.c_str());
}
for (const auto& pair : extra_params_) {
weak_params.push_back(pair.first.c_str());
weak_params.push_back(pair.second.c_str());
}
weak_params.push_back(nullptr);
char* error = nullptr;
int rv = Seatbelt::InitWithParams(policy.profile().c_str(), 0,
weak_params.data(), &error);
if (error) {
logging::Error("SeatbeltExecServer: Failed to initialize sandbox: %d %s",
rv, error);
Seatbelt::FreeError(error);
return false;
}
return rv == 0;
}
bool SeatbeltExecServer::ReadString(std::string* str) {
uint64_t buf_len = 0;
if (!ReadOrWrite<ReadTraits>(fd_, reinterpret_cast<uint8_t*>(&buf_len),
sizeof(buf_len))) {
logging::Error("SeatbeltExecServer: failed to read buffer length.");
return false;
}
str->resize(buf_len);
if (!ReadOrWrite<ReadTraits>(fd_, reinterpret_cast<uint8_t*>(&(*str)[0]),
buf_len)) {
logging::Error("SeatbeltExecServer: failed to read buffer.");
return false;
}
return true;
}
bool SeatbeltExecServer::SetParameter(const std::string& key,
const std::string& value) {
return extra_params_.insert(std::make_pair(key, value)).second;
}
} // namespace sandbox