blob: 615701ccc123780c0d42d10674a599505fc98294 [file] [log] [blame]
/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "dumpstate"
#include "DumpstateUtil.h"
#include <dirent.h>
#include <fcntl.h>
#include <sys/prctl.h>
#include <sys/wait.h>
#include <unistd.h>
#include <vector>
#include <android-base/file.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <android-base/unique_fd.h>
#include <log/log.h>
#include "DumpstateInternal.h"
namespace android {
namespace os {
namespace dumpstate {
namespace {
static constexpr const char* kSuPath = "/system/xbin/su";
static bool waitpid_with_timeout(pid_t pid, int timeout_ms, int* status) {
sigset_t child_mask, old_mask;
sigemptyset(&child_mask);
sigaddset(&child_mask, SIGCHLD);
// block SIGCHLD before we check if a process has exited
if (sigprocmask(SIG_BLOCK, &child_mask, &old_mask) == -1) {
printf("*** sigprocmask failed: %s\n", strerror(errno));
return false;
}
// if the child has exited already, handle and reset signals before leaving
pid_t child_pid = waitpid(pid, status, WNOHANG);
if (child_pid != pid) {
if (child_pid > 0) {
printf("*** Waiting for pid %d, got pid %d instead\n", pid, child_pid);
sigprocmask(SIG_SETMASK, &old_mask, nullptr);
return false;
}
} else {
sigprocmask(SIG_SETMASK, &old_mask, nullptr);
return true;
}
// wait for a SIGCHLD
timespec ts;
ts.tv_sec = MSEC_TO_SEC(timeout_ms);
ts.tv_nsec = (timeout_ms % 1000) * 1000000;
int ret = TEMP_FAILURE_RETRY(sigtimedwait(&child_mask, nullptr, &ts));
int saved_errno = errno;
// Set the signals back the way they were.
if (sigprocmask(SIG_SETMASK, &old_mask, nullptr) == -1) {
printf("*** sigprocmask failed: %s\n", strerror(errno));
if (ret == 0) {
return false;
}
}
if (ret == -1) {
errno = saved_errno;
if (errno == EAGAIN) {
errno = ETIMEDOUT;
} else {
printf("*** sigtimedwait failed: %s\n", strerror(errno));
}
return false;
}
child_pid = waitpid(pid, status, WNOHANG);
if (child_pid != pid) {
if (child_pid != -1) {
printf("*** Waiting for pid %d, got pid %d instead\n", pid, child_pid);
} else {
printf("*** waitpid failed: %s\n", strerror(errno));
}
return false;
}
return true;
}
} // unnamed namespace
CommandOptions CommandOptions::DEFAULT = CommandOptions::WithTimeout(10).Build();
CommandOptions CommandOptions::AS_ROOT = CommandOptions::WithTimeout(10).AsRoot().Build();
CommandOptions::CommandOptionsBuilder::CommandOptionsBuilder(int64_t timeout_ms) : values(timeout_ms) {
}
CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::Always() {
values.always_ = true;
return *this;
}
CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::AsRoot() {
if (!PropertiesHelper::IsUnroot()) {
values.account_mode_ = SU_ROOT;
}
return *this;
}
CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::AsRootIfAvailable() {
if (!PropertiesHelper::IsUserBuild()) {
return AsRoot();
}
return *this;
}
CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::DropRoot() {
values.account_mode_ = DROP_ROOT;
return *this;
}
CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::RedirectStderr() {
values.output_mode_ = REDIRECT_TO_STDERR;
return *this;
}
CommandOptions::CommandOptionsBuilder&
CommandOptions::CommandOptionsBuilder::CloseAllFileDescriptorsOnExec() {
values.close_all_fds_on_exec_ = true;
return *this;
}
CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::Log(
const std::string& message) {
values.logging_message_ = message;
return *this;
}
CommandOptions CommandOptions::CommandOptionsBuilder::Build() {
return CommandOptions(values);
}
CommandOptions::CommandOptionsValues::CommandOptionsValues(int64_t timeout_ms)
: timeout_ms_(timeout_ms),
always_(false),
close_all_fds_on_exec_(false),
account_mode_(DONT_DROP_ROOT),
output_mode_(NORMAL_OUTPUT),
logging_message_("") {
}
CommandOptions::CommandOptions(const CommandOptionsValues& values) : values(values) {
}
int64_t CommandOptions::Timeout() const {
return MSEC_TO_SEC(values.timeout_ms_);
}
int64_t CommandOptions::TimeoutInMs() const {
return values.timeout_ms_;
}
bool CommandOptions::Always() const {
return values.always_;
}
bool CommandOptions::ShouldCloseAllFileDescriptorsOnExec() const {
return values.close_all_fds_on_exec_;
}
PrivilegeMode CommandOptions::PrivilegeMode() const {
return values.account_mode_;
}
OutputMode CommandOptions::OutputMode() const {
return values.output_mode_;
}
std::string CommandOptions::LoggingMessage() const {
return values.logging_message_;
}
CommandOptions::CommandOptionsBuilder CommandOptions::WithTimeout(int64_t timeout_sec) {
return CommandOptions::CommandOptionsBuilder(SEC_TO_MSEC(timeout_sec));
}
CommandOptions::CommandOptionsBuilder CommandOptions::WithTimeoutInMs(int64_t timeout_ms) {
return CommandOptions::CommandOptionsBuilder(timeout_ms);
}
std::string PropertiesHelper::build_type_ = "";
int PropertiesHelper::dry_run_ = -1;
int PropertiesHelper::unroot_ = -1;
int PropertiesHelper::parallel_run_ = -1;
int PropertiesHelper::strict_run_ = -1;
bool PropertiesHelper::IsUserBuild() {
if (build_type_.empty()) {
build_type_ = android::base::GetProperty("ro.build.type", "user");
}
return "user" == build_type_;
}
bool PropertiesHelper::IsDryRun() {
if (dry_run_ == -1) {
dry_run_ = android::base::GetBoolProperty("dumpstate.dry_run", false) ? 1 : 0;
}
return dry_run_ == 1;
}
bool PropertiesHelper::IsUnroot() {
if (unroot_ == -1) {
unroot_ = android::base::GetBoolProperty("dumpstate.unroot", false) ? 1 : 0;
}
return unroot_ == 1;
}
bool PropertiesHelper::IsParallelRun() {
if (parallel_run_ == -1) {
parallel_run_ = android::base::GetBoolProperty("dumpstate.parallel_run",
/* default_value = */true) ? 1 : 0;
}
return parallel_run_ == 1;
}
bool PropertiesHelper::IsStrictRun() {
if (strict_run_ == -1) {
// Defaults to using stricter timeouts.
strict_run_ = android::base::GetBoolProperty("dumpstate.strict_run", true) ? 1 : 0;
}
return strict_run_ == 1;
}
int DumpFileToFd(int out_fd, const std::string& title, const std::string& path) {
android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(path.c_str(), O_RDONLY | O_NONBLOCK | O_CLOEXEC)));
if (fd.get() < 0) {
int err = errno;
if (title.empty()) {
dprintf(out_fd, "*** Error dumping %s: %s\n", path.c_str(), strerror(err));
} else {
dprintf(out_fd, "*** Error dumping %s (%s): %s\n", path.c_str(), title.c_str(),
strerror(err));
}
return -1;
}
return DumpFileFromFdToFd(title, path, fd.get(), out_fd, PropertiesHelper::IsDryRun());
}
int RunCommandToFd(int fd, const std::string& title, const std::vector<std::string>& full_command,
const CommandOptions& options) {
if (full_command.empty()) {
MYLOGE("No arguments on RunCommandToFd(%s)\n", title.c_str());
return -1;
}
int size = full_command.size() + 1; // null terminated
int starting_index = 0;
if (options.PrivilegeMode() == SU_ROOT) {
starting_index = 2; // "su" "root"
size += starting_index;
}
std::vector<const char*> args;
args.resize(size);
std::string command_string;
if (options.PrivilegeMode() == SU_ROOT) {
args[0] = kSuPath;
command_string += kSuPath;
args[1] = "root";
command_string += " root ";
}
for (size_t i = 0; i < full_command.size(); i++) {
args[i + starting_index] = full_command[i].data();
command_string += args[i + starting_index];
if (i != full_command.size() - 1) {
command_string += " ";
}
}
args[size - 1] = nullptr;
const char* command = command_string.c_str();
if (options.PrivilegeMode() == SU_ROOT && PropertiesHelper::IsUserBuild()) {
dprintf(fd, "Skipping '%s' on user build.\n", command);
return 0;
}
if (!title.empty()) {
dprintf(fd, "------ %s (%s) ------\n", title.c_str(), command);
}
const std::string& logging_message = options.LoggingMessage();
if (!logging_message.empty()) {
MYLOGI(logging_message.c_str(), command_string.c_str());
}
bool silent = (options.OutputMode() == REDIRECT_TO_STDERR ||
options.ShouldCloseAllFileDescriptorsOnExec());
bool redirecting_to_fd = STDOUT_FILENO != fd;
if (PropertiesHelper::IsDryRun() && !options.Always()) {
if (!title.empty()) {
dprintf(fd, "\t(skipped on dry run)\n");
} else if (redirecting_to_fd) {
// There is no title, but we should still print a dry-run message
dprintf(fd, "%s: skipped on dry run\n", command_string.c_str());
}
return 0;
}
const char* path = args[0];
uint64_t start = Nanotime();
pid_t pid = vfork();
/* handle error case */
if (pid < 0) {
if (!silent) dprintf(fd, "*** fork: %s\n", strerror(errno));
MYLOGE("*** fork: %s\n", strerror(errno));
return pid;
}
/* handle child case */
if (pid == 0) {
if (options.PrivilegeMode() == DROP_ROOT && !DropRootUser()) {
if (!silent) {
dprintf(fd, "*** failed to drop root before running %s: %s\n", command,
strerror(errno));
}
MYLOGE("*** could not drop root before running %s: %s\n", command, strerror(errno));
_exit(EXIT_FAILURE);
}
if (options.ShouldCloseAllFileDescriptorsOnExec()) {
int devnull_fd = TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
TEMP_FAILURE_RETRY(dup2(devnull_fd, STDIN_FILENO));
close(devnull_fd);
devnull_fd = TEMP_FAILURE_RETRY(open("/dev/null", O_WRONLY));
TEMP_FAILURE_RETRY(dup2(devnull_fd, STDOUT_FILENO));
TEMP_FAILURE_RETRY(dup2(devnull_fd, STDERR_FILENO));
close(devnull_fd);
// This is to avoid leaking FDs that, accidentally, have not been
// marked as O_CLOEXEC. Leaking FDs across exec can cause failures
// when execing a process that has a SELinux auto_trans rule.
// Here we assume that the dumpstate process didn't open more than
// 1000 FDs. In theory we could iterate through /proc/self/fd/, but
// doing that in a fork-safe way is too complex and not worth it
// (opendir()/readdir() do heap allocations and take locks).
for (int i = 0; i < 1000; i++) {
if (i != STDIN_FILENO && i!= STDOUT_FILENO && i != STDERR_FILENO) {
close(i);
}
}
} else if (silent) {
// Redirects stdout to stderr
TEMP_FAILURE_RETRY(dup2(STDERR_FILENO, STDOUT_FILENO));
} else if (redirecting_to_fd) {
// Redirect stdout to fd
TEMP_FAILURE_RETRY(dup2(fd, STDOUT_FILENO));
close(fd);
}
/* make sure the child dies when dumpstate dies */
prctl(PR_SET_PDEATHSIG, SIGKILL);
/* just ignore SIGPIPE, will go down with parent's */
struct sigaction sigact;
memset(&sigact, 0, sizeof(sigact));
sigact.sa_handler = SIG_IGN;
sigaction(SIGPIPE, &sigact, nullptr);
execvp(path, (char**)args.data());
// execvp's result will be handled after waitpid_with_timeout() below, but
// if it failed, it's safer to exit dumpstate.
MYLOGD("execvp on command '%s' failed (error: %s)\n", command, strerror(errno));
// Must call _exit (instead of exit), otherwise it will corrupt the zip
// file.
_exit(EXIT_FAILURE);
}
/* handle parent case */
int status;
bool ret = waitpid_with_timeout(pid, options.TimeoutInMs(), &status);
uint64_t elapsed = Nanotime() - start;
if (!ret) {
if (errno == ETIMEDOUT) {
if (!silent)
dprintf(fd, "*** command '%s' timed out after %.3fs (killing pid %d)\n", command,
static_cast<float>(elapsed) / NANOS_PER_SEC, pid);
MYLOGE("*** command '%s' timed out after %.3fs (killing pid %d)\n", command,
static_cast<float>(elapsed) / NANOS_PER_SEC, pid);
} else {
if (!silent)
dprintf(fd, "*** command '%s': Error after %.4fs (killing pid %d)\n", command,
static_cast<float>(elapsed) / NANOS_PER_SEC, pid);
MYLOGE("command '%s': Error after %.4fs (killing pid %d)\n", command,
static_cast<float>(elapsed) / NANOS_PER_SEC, pid);
}
kill(pid, SIGTERM);
if (!waitpid_with_timeout(pid, 5000, nullptr)) {
kill(pid, SIGKILL);
if (!waitpid_with_timeout(pid, 5000, nullptr)) {
if (!silent)
dprintf(fd, "could not kill command '%s' (pid %d) even with SIGKILL.\n",
command, pid);
MYLOGE("could not kill command '%s' (pid %d) even with SIGKILL.\n", command, pid);
}
}
return -1;
}
if (WIFSIGNALED(status)) {
if (!silent)
dprintf(fd, "*** command '%s' failed: killed by signal %d\n", command, WTERMSIG(status));
MYLOGE("*** command '%s' failed: killed by signal %d\n", command, WTERMSIG(status));
} else if (WIFEXITED(status) && WEXITSTATUS(status) > 0) {
status = WEXITSTATUS(status);
if (!silent) dprintf(fd, "*** command '%s' failed: exit code %d\n", command, status);
MYLOGE("*** command '%s' failed: exit code %d\n", command, status);
}
return status;
}
} // namespace dumpstate
} // namespace os
} // namespace android