1 /*
2 * Copyright (C) 2023 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 <limits.h>
18 #include <string.h>
19 #include <sys/inotify.h>
20 #include <unistd.h>
21 #include <string>
22 #include <vector>
23
24 #include <android-base/logging.h>
25
26 #include "inotify.h"
27
28 namespace cuttlefish {
29
GetCreatedFileListFromInotifyFd(int fd)30 std::vector<std::string> GetCreatedFileListFromInotifyFd(int fd) {
31 return GetFileListFromInotifyFd(fd, IN_CREATE);
32 }
33
34 #define INOTIFY_MAX_EVENT_SIZE (sizeof(struct inotify_event) + NAME_MAX + 1)
35
GetFileListFromInotifyFd(int fd,uint32_t mask)36 std::vector<std::string> GetFileListFromInotifyFd(int fd, uint32_t mask) {
37 char event_readout[INOTIFY_MAX_EVENT_SIZE];
38 int bytes_parsed = 0;
39 std::vector<std::string> result;
40 // Each successful read can contain one or more of inotify_event events
41 // Note: read() on inotify returns 'whole' events, will never partially
42 // populate the buffer.
43 int event_read_out_length = read(fd, event_readout, INOTIFY_MAX_EVENT_SIZE);
44
45 if (event_read_out_length == -1) {
46 LOG(ERROR) << __FUNCTION__
47 << ": Couldn't read out inotify event due to error: '"
48 << strerror(errno) << "' (" << errno << ")";
49 return std::vector<std::string>();
50 }
51
52 while (bytes_parsed < event_read_out_length) {
53 struct inotify_event* event =
54 reinterpret_cast<inotify_event*>(event_readout + bytes_parsed);
55 bytes_parsed += sizeof(struct inotify_event) + event->len;
56
57 // No file name was present
58 if (event->len == 0) {
59 LOG(ERROR) << __FUNCTION__ << ": inotify event didn't contain filename";
60 continue;
61 }
62 if (!(event->mask & mask)) {
63 LOG(ERROR) << __FUNCTION__
64 << ": inotify event didn't pertain to the event";
65 continue;
66 }
67 result.push_back(std::string(event->name));
68 }
69
70 return result;
71 }
72
73 } // namespace cuttlefish
74