96 lines
2.6 KiB
C++
96 lines
2.6 KiB
C++
// Copyright 2014 The Crashpad Authors
|
||
//
|
||
// 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.
|
||
|
||
#include <errno.h>
|
||
#include <limits.h>
|
||
#include <stdio.h>
|
||
#include <sys/types.h>
|
||
|
||
#include <algorithm>
|
||
|
||
#include "base/logging.h"
|
||
#include "build/build_config.h"
|
||
|
||
#if BUILDFLAG(IS_POSIX)
|
||
#if !BUILDFLAG(IS_FUCHSIA)
|
||
#include <sys/resource.h>
|
||
#endif // !BUILDFLAG(IS_FUCHSIA)
|
||
#include <unistd.h>
|
||
#elif BUILDFLAG(IS_WIN)
|
||
#include <windows.h>
|
||
#endif
|
||
|
||
int main(int argc, char* argv[]) {
|
||
#if BUILDFLAG(IS_POSIX)
|
||
|
||
#if BUILDFLAG(IS_FUCHSIA)
|
||
// getrlimit() is not implemented on Fuchsia. By construction, the child only
|
||
// receieves specific fds that it's given, but check low values as mild
|
||
// verification.
|
||
int last_fd = 1024;
|
||
#else
|
||
rlimit rlimit_nofile;
|
||
if (getrlimit(RLIMIT_NOFILE, &rlimit_nofile) != 0) {
|
||
LOG(FATAL) << "getrlimit";
|
||
}
|
||
int last_fd = static_cast<int>(rlimit_nofile.rlim_cur);
|
||
#endif // BUILDFLAG(IS_FUCHSIA)
|
||
|
||
// Make sure that there’s nothing open at any FD higher than 3. All FDs other
|
||
// than stdin, stdout, and stderr should have been closed prior to or at
|
||
// exec().
|
||
for (int fd = STDERR_FILENO + 1; fd < last_fd; ++fd) {
|
||
if (close(fd) == 0 || errno != EBADF) {
|
||
LOG(FATAL) << "close";
|
||
}
|
||
}
|
||
|
||
// Read a byte from stdin, expecting it to be a specific value.
|
||
char c;
|
||
ssize_t rv = read(STDIN_FILENO, &c, 1);
|
||
if (rv != 1 || c != 'z') {
|
||
LOG(FATAL) << "read";
|
||
}
|
||
|
||
// Write a byte to stdout.
|
||
c = 'Z';
|
||
rv = write(STDOUT_FILENO, &c, 1);
|
||
if (rv != 1) {
|
||
LOG(FATAL) << "write";
|
||
}
|
||
#elif BUILDFLAG(IS_WIN)
|
||
// TODO(scottmg): Verify that only the handles we expect to be open, are.
|
||
|
||
// Read a byte from stdin, expecting it to be a specific value.
|
||
char c;
|
||
DWORD bytes_read;
|
||
HANDLE stdin_handle = GetStdHandle(STD_INPUT_HANDLE);
|
||
if (!ReadFile(stdin_handle, &c, 1, &bytes_read, nullptr) ||
|
||
bytes_read != 1 || c != 'z') {
|
||
LOG(FATAL) << "ReadFile";
|
||
}
|
||
|
||
// Write a byte to stdout.
|
||
c = 'Z';
|
||
DWORD bytes_written;
|
||
if (!WriteFile(
|
||
GetStdHandle(STD_OUTPUT_HANDLE), &c, 1, &bytes_written, nullptr) ||
|
||
bytes_written != 1) {
|
||
LOG(FATAL) << "WriteFile";
|
||
}
|
||
#endif // BUILDFLAG(IS_POSIX)
|
||
|
||
return 0;
|
||
}
|