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 "common.h"
18 
19 #include <android-base/logging.h>
20 
21 #include <net/if.h>
22 
23 namespace android::nl {
24 
nametoindex(const std::string & ifname)25 unsigned int nametoindex(const std::string& ifname) {
26     const auto ifidx = if_nametoindex(ifname.c_str());
27     if (ifidx != 0) return ifidx;
28 
29     if (errno != ENODEV) {
30         PLOG(ERROR) << "if_nametoindex(" << ifname << ") failed";
31     }
32     return 0;
33 }
34 
printableOnly(std::string str)35 std::string printableOnly(std::string str) {
36     const auto isInvalid = [](char c) { return !isprint(c); };
37     std::replace_if(str.begin(), str.end(), isInvalid, '?');
38 
39     return str;
40 }
41 
crc16(const Buffer<uint8_t> data,uint16_t crc)42 uint16_t crc16(const Buffer<uint8_t> data, uint16_t crc) {
43     for (const auto byte : data.getRaw()) {
44         crc ^= byte;
45         for (unsigned i = 0; i < 8; i++) {
46             if (crc & 1) {
47                 crc = (crc >> 1) ^ 0xA001;
48             } else {
49                 crc >>= 1;
50             }
51         }
52     }
53     return crc;
54 }
55 
56 }  // namespace android::nl
57