1 /*
2 * Copyright (C) 2019 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "fuse_provider.h"
18
19 #include <errno.h>
20 #include <fcntl.h>
21 #include <inttypes.h>
22 #include <stdio.h>
23 #include <string.h>
24 #include <sys/stat.h>
25 #include <unistd.h>
26
27 #include <functional>
28
29 #include <android-base/file.h>
30
31 #include "fuse_sideload.h"
32
FuseFileDataProvider(const std::string & path,uint32_t block_size)33 FuseFileDataProvider::FuseFileDataProvider(const std::string& path, uint32_t block_size) {
34 struct stat sb;
35 if (stat(path.c_str(), &sb) == -1) {
36 fprintf(stderr, "failed to stat %s: %s\n", path.c_str(), strerror(errno));
37 return;
38 }
39
40 fd_.reset(open(path.c_str(), O_RDONLY));
41 if (fd_ == -1) {
42 fprintf(stderr, "failed to open %s: %s\n", path.c_str(), strerror(errno));
43 return;
44 }
45 file_size_ = sb.st_size;
46 fuse_block_size_ = block_size;
47 }
48
ReadBlockAlignedData(uint8_t * buffer,uint32_t fetch_size,uint32_t start_block) const49 bool FuseFileDataProvider::ReadBlockAlignedData(uint8_t* buffer, uint32_t fetch_size,
50 uint32_t start_block) const {
51 uint64_t offset = static_cast<uint64_t>(start_block) * fuse_block_size_;
52 if (fetch_size > file_size_ || offset > file_size_ - fetch_size) {
53 fprintf(stderr,
54 "Out of bound read, start block: %" PRIu32 ", fetch size: %" PRIu32
55 ", file size %" PRIu64 "\n",
56 start_block, fetch_size, file_size_);
57 return false;
58 }
59
60 if (!android::base::ReadFullyAtOffset(fd_, buffer, fetch_size, offset)) {
61 fprintf(stderr, "Failed to read fetch size: %" PRIu32 " bytes data at offset %" PRIu64 ": %s\n",
62 fetch_size, offset, strerror(errno));
63 return false;
64 }
65
66 return true;
67 }
68
Close()69 void FuseFileDataProvider::Close() {
70 fd_.reset();
71 }
72