1 /* mbr.cc -- Functions for loading, saving, and manipulating legacy MBR partition 2 data. */ 3 4 /* Initial coding by Rod Smith, January to February, 2009 */ 5 6 /* This program is copyright (c) 2009-2013 by Roderick W. Smith. It is distributed 7 under the terms of the GNU GPL version 2, as detailed in the COPYING file. */ 8 9 #define __STDC_LIMIT_MACROS 10 #define __STDC_CONSTANT_MACROS 11 12 #include <stdio.h> 13 #include <stdlib.h> 14 #include <stdint.h> 15 #include <fcntl.h> 16 #include <string.h> 17 #include <time.h> 18 #include <sys/stat.h> 19 #include <errno.h> 20 #include <iostream> 21 #include "mbr.h" 22 23 using namespace std; 24 25 /**************************************** 26 * * 27 * MBRData class and related structures * 28 * * 29 ****************************************/ 30 31 /* // Assignment operator -- copy entire set of MBR data. 32 MBRData & MBRData::operator=(const MBRData & orig) { 33 BasicMBRData::operator=(orig); 34 return *this; 35 } // MBRData::operator=() */ 36 37 // Assignment operator -- copy entire set of MBR data. 38 MBRData & MBRData::operator=(const BasicMBRData & orig) { 39 BasicMBRData::operator=(orig); 40 return *this; 41 } // MBRData::operator=() 42 43 /***************************************************** 44 * * 45 * Functions to create, delete, or change partitions * 46 * * 47 *****************************************************/ 48 49 // Create a protective MBR. Clears the boot loader area if clearBoot > 0. 50 void MBRData::MakeProtectiveMBR(int clearBoot) { 51 52 EmptyMBR(clearBoot); 53 54 // Initialize variables 55 nulls = 0; 56 MBRSignature = MBR_SIGNATURE; 57 diskSignature = UINT32_C(0); 58 59 partitions[0].SetStatus(0); // Flag the protective part. as unbootable 60 61 partitions[0].SetType(UINT8_C(0xEE)); 62 if (diskSize < UINT32_MAX) { // If the disk is under 2TiB 63 partitions[0].SetLocation(UINT32_C(1), (uint32_t) diskSize - UINT32_C(1)); 64 } else { // disk is too big to represent, so fake it... 65 partitions[0].SetLocation(UINT32_C(1), UINT32_MAX); 66 } // if/else 67 partitions[0].SetInclusion(PRIMARY); 68 69 state = gpt; 70 } // MBRData::MakeProtectiveMBR() 71 72 // Optimizes the size of the 0xEE (EFI GPT) partition 73 void MBRData::OptimizeEESize(void) { 74 int i, typeFlag = 0; 75 uint64_t after; 76 77 for (i = 0; i < 4; i++) { 78 // Check for non-empty and non-0xEE partitions 79 if ((partitions[i].GetType() != 0xEE) && (partitions[i].GetType() != 0x00)) 80 typeFlag++; 81 if (partitions[i].GetType() == 0xEE) { 82 // Blank space before this partition; fill it.... 83 if (SectorUsedAs(partitions[i].GetStartLBA() - 1, 4) == NONE) { 84 partitions[i].SetStartLBA(FindFirstInFree(partitions[i].GetStartLBA() - 1)); 85 } // if 86 // Blank space after this partition; fill it.... 87 after = partitions[i].GetStartLBA() + partitions[i].GetLengthLBA(); 88 if (SectorUsedAs(after, 4) == NONE) { 89 partitions[i].SetLengthLBA(FindLastInFree(after) - partitions[i].GetStartLBA() + 1); 90 } // if free space after 91 if (after > diskSize) { 92 if (diskSize < UINT32_MAX) { // If the disk is under 2TiB 93 partitions[i].SetLengthLBA((uint32_t) diskSize - partitions[i].GetStartLBA()); 94 } else { // disk is too big to represent, so fake it... 95 partitions[i].SetLengthLBA(UINT32_MAX - partitions[i].GetStartLBA()); 96 } // if/else 97 } // if protective partition is too big 98 RecomputeCHS(i); 99 } // if partition is 0xEE 100 } // for partition loop 101 if (typeFlag == 0) { // No non-hybrid partitions found 102 MakeProtectiveMBR(); // ensure it's a fully compliant protective MBR. 103 } // if 104 } // MBRData::OptimizeEESize() 105 106 // Delete a partition if one exists at the specified location. 107 // Returns 1 if a partition was deleted, 0 otherwise.... 108 // Used to help keep GPT & hybrid MBR partitions in sync.... 109 int MBRData::DeleteByLocation(uint64_t start64, uint64_t length64) { 110 uint32_t start32, length32; 111 int i, deleted = 0; 112 113 if ((start64 < UINT32_MAX) && (length64 < UINT32_MAX)) { 114 start32 = (uint32_t) start64; 115 length32 = (uint32_t) length64; 116 for (i = 0; i < MAX_MBR_PARTS; i++) { 117 if ((partitions[i].GetType() != 0xEE) && (partitions[i].GetStartLBA() == start32) 118 && (partitions[i].GetLengthLBA() == length32)) { 119 DeletePartition(i); 120 if (state == hybrid) 121 OptimizeEESize(); 122 deleted = 1; 123 } // if (match found) 124 } // for i (partition scan) 125 } // if (hybrid & GPT partition < 2TiB) 126 return deleted; 127 } // MBRData::DeleteByLocation() 128 129 /****************************************************** 130 * * 131 * Functions that extract data on specific partitions * 132 * * 133 ******************************************************/ 134 135 // Return the MBR data as a GPT partition.... 136 GPTPart MBRData::AsGPT(int i) { 137 MBRPart* origPart; 138 GPTPart newPart; 139 uint8_t origType; 140 uint64_t firstSector, lastSector; 141 142 newPart.BlankPartition(); 143 origPart = GetPartition(i); 144 if (origPart != NULL) { 145 origType = origPart->GetType(); 146 147 // don't convert extended, hybrid protective, or null (non-existent) 148 // partitions (Note similar protection is in GPTData::XFormPartitions(), 149 // but I want it here too in case I call this function in another 150 // context in the future....) 151 if ((origType != 0x05) && (origType != 0x0f) && (origType != 0x85) && 152 (origType != 0x00) && (origType != 0xEE)) { 153 firstSector = (uint64_t) origPart->GetStartLBA(); 154 newPart.SetFirstLBA(firstSector); 155 lastSector = (uint64_t) origPart->GetLastLBA(); 156 newPart.SetLastLBA(lastSector); 157 newPart.SetType(((uint16_t) origType) * 0x0100); 158 newPart.RandomizeUniqueGUID(); 159 newPart.SetAttributes(0); 160 newPart.SetName(newPart.GetTypeName()); 161 } // if not extended, protective, or non-existent 162 } // if (origPart != NULL) 163 return newPart; 164 } // MBRData::AsGPT() 165 166
