1 /****************************************************************************** 2 * 3 * Copyright (C) 2012 Broadcom Corporation 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at: 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 ******************************************************************************/ 18 #include "OverrideLog.h" 19 #include "CrcChecksum.h" 20 #include <sys/types.h> 21 #include <sys/stat.h> 22 #include <fcntl.h> 23 #include <errno.h> 24 #include <string> 25 #define LOG_TAG "NfcNciHal" 26 27 28 static const unsigned short crctab [256] = 29 { 30 0x0000, 0xc0c1, 0xc181, 0x0140, 0xc301, 0x03c0, 0x0280, 0xc241, 31 0xc601, 0x06c0, 0x0780, 0xc741, 0x0500, 0xc5c1, 0xc481, 0x0440, 32 0xcc01, 0x0cc0, 0x0d80, 0xcd41, 0x0f00, 0xcfc1, 0xce81, 0x0e40, 33 0x0a00, 0xcac1, 0xcb81, 0x0b40, 0xc901, 0x09c0, 0x0880, 0xc841, 34 0xd801, 0x18c0, 0x1980, 0xd941, 0x1b00, 0xdbc1, 0xda81, 0x1a40, 35 0x1e00, 0xdec1, 0xdf81, 0x1f40, 0xdd01, 0x1dc0, 0x1c80, 0xdc41, 36 0x1400, 0xd4c1, 0xd581, 0x1540, 0xd701, 0x17c0, 0x1680, 0xd641, 37 0xd201, 0x12c0, 0x1380, 0xd341, 0x1100, 0xd1c1, 0xd081, 0x1040, 38 0xf001, 0x30c0, 0x3180, 0xf141, 0x3300, 0xf3c1, 0xf281, 0x3240, 39 0x3600, 0xf6c1, 0xf781, 0x3740, 0xf501, 0x35c0, 0x3480, 0xf441, 40 0x3c00, 0xfcc1, 0xfd81, 0x3d40, 0xff01, 0x3fc0, 0x3e80, 0xfe41, 41 0xfa01, 0x3ac0, 0x3b80, 0xfb41, 0x3900, 0xf9c1, 0xf881, 0x3840, 42 0x2800, 0xe8c1, 0xe981, 0x2940, 0xeb01, 0x2bc0, 0x2a80, 0xea41, 43 0xee01, 0x2ec0, 0x2f80, 0xef41, 0x2d00, 0xedc1, 0xec81, 0x2c40, 44 0xe401, 0x24c0, 0x2580, 0xe541, 0x2700, 0xe7c1, 0xe681, 0x2640, 45 0x2200, 0xe2c1, 0xe381, 0x2340, 0xe101, 0x21c0, 0x2080, 0xe041, 46 0xa001, 0x60c0, 0x6180, 0xa141, 0x6300, 0xa3c1, 0xa281, 0x6240, 47 0x6600, 0xa6c1, 0xa781, 0x6740, 0xa501, 0x65c0, 0x6480, 0xa441, 48 0x6c00, 0xacc1, 0xad81, 0x6d40, 0xaf01, 0x6fc0, 0x6e80, 0xae41, 49 0xaa01, 0x6ac0, 0x6b80, 0xab41, 0x6900, 0xa9c1, 0xa881, 0x6840, 50 0x7800, 0xb8c1, 0xb981, 0x7940, 0xbb01, 0x7bc0, 0x7a80, 0xba41, 51 0xbe01, 0x7ec0, 0x7f80, 0xbf41, 0x7d00, 0xbdc1, 0xbc81, 0x7c40, 52 0xb401, 0x74c0, 0x7580, 0xb541, 0x7700, 0xb7c1, 0xb681, 0x7640, 53 0x7200, 0xb2c1, 0xb381, 0x7340, 0xb101, 0x71c0, 0x7080, 0xb041, 54 0x5000, 0x90c1, 0x9181, 0x5140, 0x9301, 0x53c0, 0x5280, 0x9241, 55 0x9601, 0x56c0, 0x5780, 0x9741, 0x5500, 0x95c1, 0x9481, 0x5440, 56 0x9c01, 0x5cc0, 0x5d80, 0x9d41, 0x5f00, 0x9fc1, 0x9e81, 0x5e40, 57 0x5a00, 0x9ac1, 0x9b81, 0x5b40, 0x9901, 0x59c0, 0x5880, 0x9841, 58 0x8801, 0x48c0, 0x4980, 0x8941, 0x4b00, 0x8bc1, 0x8a81, 0x4a40, 59 0x4e00, 0x8ec1, 0x8f81, 0x4f40, 0x8d01, 0x4dc0, 0x4c80, 0x8c41, 60 0x4400, 0x84c1, 0x8581, 0x4540, 0x8701, 0x47c0, 0x4680, 0x8641, 61 0x8201, 0x42c0, 0x4380, 0x8341, 0x4100, 0x81c1, 0x8081, 0x4040, 62 }; 63 64 65 /******************************************************************************* 66 ** 67 ** Function crcChecksumCompute 68 ** 69 ** Description Compute a checksum on a buffer of data. 70 ** 71 ** Returns 2-byte checksum. 72 ** 73 *******************************************************************************/ 74 unsigned short crcChecksumCompute (const unsigned char *buffer, int bufferLen) 75 { 76 register unsigned short crc = 0; 77 const register unsigned char *cp = buffer; 78 register int cnt = bufferLen; 79 80 while (cnt--) 81 { 82 crc = ((crc >> 8) & 0xff) ^ crctab[(crc & 0xff) ^ *cp++]; 83 } 84 return(crc); 85 } 86 87 88 /******************************************************************************* 89 ** 90 ** Function crcChecksumVerifyIntegrity 91 ** 92 ** Description Detect any corruption in a file by computing a checksum. 93 ** filename: file name. 94 ** 95 ** Returns True if file is good. 96 ** 97 *******************************************************************************/ 98 BOOLEAN crcChecksumVerifyIntegrity (const char* filename) 99 { 100 ALOGD ("%s: filename=%s", __FUNCTION__, filename); 101 BOOLEAN isGood = FALSE; 102 int fileStream = open (filename, O_RDONLY); 103 if (fileStream >= 0) 104 { 105 unsigned short checksum = 0; 106 std::string data; 107 size_t actualReadCrc = read (fileStream, &checksum, sizeof(checksum)); 108 while (true) 109 { 110 char buffer [1024]; 111 ssize_t actualReadData = read (fileStream, buffer, sizeof(buffer)); 112 if (actualReadData > 0) 113 data.append (buffer, actualReadData); 114 else 115 break; 116 } 117 close (fileStream); 118 if ((actualReadCrc == sizeof(checksum)) && (data.size() > 0)) 119 { 120 ALOGD ("%s: data size=%u", __FUNCTION__, data.size()); 121 if (checksum == crcChecksumCompute ((const unsigned char*) data.data(), data.size())) 122 isGood = TRUE; 123 else 124 ALOGE ("%s: checksum mismatch", __FUNCTION__); 125 } 126 else 127 ALOGE ("%s: invalid length", __FUNCTION__); 128 } 129 else 130 isGood = TRUE; //assume file does not exist 131 return isGood; 132 } 133
