blob: 4ec525a01da597d5780c53060a2222276683b5d9 [file] [log] [blame]
/*
* Copyright (C) 2018 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.
*/
#ifdef _WIN32
// nothing to see here
#else
#include <memory>
#include <string>
#include <vector>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include "android-base/logging.h"
#include "androidfw/PosixUtils.h"
namespace {
std::unique_ptr<std::string> ReadFile(int fd) {
std::unique_ptr<std::string> str(new std::string());
char buf[1024];
ssize_t r;
while ((r = read(fd, buf, sizeof(buf))) > 0) {
str->append(buf, r);
}
if (r != 0) {
return nullptr;
}
return str;
}
}
namespace android {
namespace util {
std::unique_ptr<ProcResult> ExecuteBinary(const std::vector<std::string>& argv) {
int stdout[2]; // stdout[0] read, stdout[1] write
if (pipe(stdout) != 0) {
PLOG(ERROR) << "pipe";
return nullptr;
}
int stderr[2]; // stdout[0] read, stdout[1] write
if (pipe(stderr) != 0) {
PLOG(ERROR) << "pipe";
close(stdout[0]);
close(stdout[1]);
return nullptr;
}
auto gid = getgid();
auto uid = getuid();
char const** argv0 = (char const**)malloc(sizeof(char*) * (argv.size() + 1));
for (size_t i = 0; i < argv.size(); i++) {
argv0[i] = argv[i].c_str();
}
argv0[argv.size()] = nullptr;
int pid = fork();
switch (pid) {
case -1: // error
free(argv0);
PLOG(ERROR) << "fork";
return nullptr;
case 0: // child
if (setgid(gid) != 0) {
PLOG(ERROR) << "setgid";
exit(1);
}
if (setuid(uid) != 0) {
PLOG(ERROR) << "setuid";
exit(1);
}
close(stdout[0]);
if (dup2(stdout[1], STDOUT_FILENO) == -1) {
abort();
}
close(stderr[0]);
if (dup2(stderr[1], STDERR_FILENO) == -1) {
abort();
}
execvp(argv0[0], const_cast<char* const*>(argv0));
PLOG(ERROR) << "execv";
abort();
default: // parent
free(argv0);
close(stdout[1]);
close(stderr[1]);
int status;
waitpid(pid, &status, 0);
if (!WIFEXITED(status)) {
close(stdout[0]);
close(stderr[0]);
return nullptr;
}
std::unique_ptr<ProcResult> result(new ProcResult());
result->status = status;
const auto out = ReadFile(stdout[0]);
result->stdout = out ? *out : "";
close(stdout[0]);
const auto err = ReadFile(stderr[0]);
result->stderr = err ? *err : "";
close(stderr[0]);
return result;
}
}
} // namespace util
} // namespace android
#endif