sandboxed-api/contrib/libzip/wrapper/wrapper_zip.cc
Mariusz Zaborski e49318571b Sandbox zip
2022-02-22 10:51:53 -05:00

121 lines
2.7 KiB
C++

// Copyright 2022 Google LLC
//
// 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
//
// https://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 "contrib/libzip/wrapper/wrapper_zip.h"
#include <fcntl.h>
#include <unistd.h>
#include <iostream>
#include "absl/cleanup/cleanup.h"
constexpr size_t kFileMaxSize = 1024 * 1024 * 1024; // 1GB
void* zip_source_filefd(zip_t* archive, int fd, const char* mode,
zip_uint64_t start, zip_int64_t len) {
FILE* pfile;
// The file stream is closed when the source is being freed,
// usually by zip_close(3).
pfile = fdopen(fd, mode);
if (pfile == nullptr) {
return nullptr;
}
return zip_source_filep(archive, pfile, start, len);
}
void* zip_source_filefd_create(int fd, const char* mode, zip_uint64_t start,
zip_int64_t len, zip_error_t* ze) {
FILE* pfile;
pfile = fdopen(fd, mode);
if (pfile == nullptr) {
return nullptr;
}
return zip_source_filep_create(pfile, start, len, ze);
}
off_t FDGetSize(int fd) {
off_t size = lseek(fd, 0, SEEK_END);
if (size < 0) {
return -1;
}
if (lseek(fd, 0, SEEK_SET) < 0) {
return -1;
}
return size;
}
void* zip_read_fd_to_source(int fd, zip_error_t* ze) {
off_t sizein = FDGetSize(fd);
if (sizein > kFileMaxSize) {
return nullptr;
}
int8_t* buf = reinterpret_cast<int8_t*>(malloc(sizein));
if (buf == nullptr) {
return nullptr;
}
if (read(fd, buf, sizein) != sizein) {
free(buf);
return nullptr;
}
zip_source_t* src = zip_source_buffer_create(buf, sizein, 1, ze);
if (src == nullptr) {
free(buf);
return nullptr;
}
return src;
}
// This function is not atomic. Maybe it should be?
bool zip_source_to_fd(zip_source_t* src, int fd) {
if (lseek(fd, 0, SEEK_SET) < 0) {
return false;
}
if (ftruncate(fd, 0) < 0) {
return false;
}
if (zip_source_open(src) < 0) {
return false;
}
absl::Cleanup src_cleanup = [&src] { zip_source_close(src); };
if (zip_source_seek(src, 0, SEEK_SET) < 0) {
return false;
}
int8_t buf[4096];
size_t size;
while (true) {
size = zip_source_read(src, &buf, sizeof(buf));
if (size <= 0) {
break;
}
if (write(fd, &buf, size) != size) {
return false;
}
}
return size == 0;
}