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 #pragma once 18 19 #include <libnl++/Buffer.h> 20 21 #include <linux/can.h> 22 #include <net/if.h> 23 24 #include <string> 25 26 namespace android::nl { 27 28 /** 29 * Returns the index of a given network interface. 30 * 31 * If the syscall to check the index fails with other error than ENODEV, it gets logged and the 32 * return value indicates the interface doesn't exists. 33 * 34 * \param ifname Interface to check 35 * \return Interface index, or 0 if the interface doesn't exist 36 */ 37 unsigned int nametoindex(const std::string& ifname); 38 39 /** 40 * Filter a string against non-printable characters. 41 * 42 * Replaces all non-printable characters with '?'. 43 * 44 * \param str String to filter. 45 * \return Filtered string. 46 */ 47 std::string printableOnly(std::string str); 48 49 /** 50 * Calculates a (optionally running) CRC16 checksum. 51 * 52 * CRC16 isn't a strong checksum, but is good for quick comparison purposes. 53 * One benefit (and also a drawback too) is that all-zero payloads with any length will 54 * always have a checksum of 0x0000. 55 * 56 * \param data Buffer to calculate checksum for 57 * \param crc Previous CRC16 value to continue calculating running checksum 58 * \return CRC16 checksum 59 */ 60 uint16_t crc16(const Buffer<uint8_t> data, uint16_t crc = 0); 61 62 } // namespace android::nl 63