| 1 | // |
| 2 | // ELFManager.cpp: ELF format manager |
| 3 | // |
| 4 | // by Jean-Paul Mari |
| 5 | // |
| 6 | // JPM = Jean-Paul Mari <djipi.mari@gmail.com> |
| 7 | // |
| 8 | // WHO WHEN WHAT |
| 9 | // --- ---------- ------------------------------------------------------------ |
| 10 | // JPM Jan./2016 Created this file and added ELF format support |
| 11 | // JPM 07/13/2017 ELF DWARF format support improvement |
| 12 | // JPM 10/20/2018 Added function name support from ELF structure |
| 13 | // |
| 14 | |
| 15 | #include <stdlib.h> |
| 16 | #include <string.h> |
| 17 | #include "libelf/libelf.h" |
| 18 | #include "libelf/gelf.h" |
| 19 | #include "libdwarf.h" |
| 20 | #include "log.h" |
| 21 | #include "ELFManager.h" |
| 22 | #include "DwarfManager.h" |
| 23 | |
| 24 | |
| 25 | //#define LOG_SUPPORT // Support log |
| 26 | |
| 27 | |
| 28 | typedef struct { |
| 29 | const char *SectionName; |
| 30 | size_t SectionType; |
| 31 | }ELFSectionType; |
| 32 | |
| 33 | typedef struct { |
| 34 | size_t Type; |
| 35 | size_t Size; |
| 36 | union { |
| 37 | Elf_Data *PtrDataTab; |
| 38 | void *PtrTab; |
| 39 | }; |
| 40 | }ELFTab; |
| 41 | |
| 42 | |
| 43 | // Section type list |
| 44 | ELFSectionType ELFTabSectionType[] = { |
| 45 | { "", ELF_NULL_TYPE }, |
| 46 | { ".text", ELF_text_TYPE }, |
| 47 | { ".rodata", ELF_rodata_TYPE }, |
| 48 | { ".data", ELF_data_TYPE }, |
| 49 | { ".bss", ELF_bss_TYPE }, |
| 50 | { ".heap", ELF_heap_TYPE }, |
| 51 | { ".debug_aranges", ELF_debug_aranges_TYPE }, |
| 52 | { ".debug_info", ELF_debug_info_TYPE }, |
| 53 | { ".debug_abbrev", ELF_debug_abbrev_TYPE }, |
| 54 | { ".debug_line", ELF_debug_line_TYPE }, |
| 55 | { ".debug_frame", ELF_debug_frame_TYPE }, |
| 56 | { ".debug_str", ELF_debug_str_TYPE }, |
| 57 | { ".debug_loc", ELF_debug_loc_TYPE }, |
| 58 | { ".debug_ranges", ELF_debug_ranges_TYPE }, |
| 59 | { ".comment", ELF_comment_TYPE }, |
| 60 | { ".shstrtab", ELF_shstrtab_TYPE }, |
| 61 | { ".symtab", ELF_symtab_TYPE }, |
| 62 | { ".strtab", ELF_strtab_TYPE } |
| 63 | }; |
| 64 | |
| 65 | |
| 66 | // ELF management |
| 67 | Elf *ElfMem; |
| 68 | void *PtrExec; // ELF executable |
| 69 | |
| 70 | // ELF Dwarf management |
| 71 | bool ElfDwarf; |
| 72 | |
| 73 | // TAB structure |
| 74 | size_t NbELFtabStruct; |
| 75 | ELFTab **ELFtab; |
| 76 | |
| 77 | |
| 78 | char *ELFManager_GetSymbolnameFromSymbolindex(size_t Index); |
| 79 | |
| 80 | |
| 81 | // ELF section type detection |
| 82 | size_t ELFManager_GetSectionType(char *SectionName) |
| 83 | { |
| 84 | size_t i; |
| 85 | |
| 86 | for (i = 0; i < ELF_END_TYPE; i++) |
| 87 | { |
| 88 | if (!strcmp(ELFTabSectionType[i].SectionName, SectionName)) |
| 89 | { |
| 90 | return (ELFTabSectionType[i].SectionType); |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | return (size_t)ELF_NO_TYPE; |
| 95 | } |
| 96 | |
| 97 | |
| 98 | // ELF manager executable copy |
| 99 | void *ELFManager_ExeCopy(void *src, size_t size) |
| 100 | { |
| 101 | if ((PtrExec = malloc(size)) != NULL) |
| 102 | { |
| 103 | memcpy(PtrExec, src, size); |
| 104 | } |
| 105 | |
| 106 | return PtrExec; |
| 107 | } |
| 108 | |
| 109 | |
| 110 | Elf *ELFManager_MemOpen(char *PtrELFExe, size_t Size) |
| 111 | { |
| 112 | return(ElfMem = elf_memory(PtrELFExe, Size)); |
| 113 | } |
| 114 | |
| 115 | |
| 116 | int ELFManager_MemEnd(void) |
| 117 | { |
| 118 | int err = 0; |
| 119 | |
| 120 | if (ElfMem) |
| 121 | { |
| 122 | err = elf_end(ElfMem); |
| 123 | ElfMem = NULL; |
| 124 | } |
| 125 | |
| 126 | return (err); |
| 127 | } |
| 128 | |
| 129 | |
| 130 | // ELF manager Initialisation |
| 131 | void ELFManager_Init(void) |
| 132 | { |
| 133 | PtrExec = NULL; |
| 134 | NbELFtabStruct = 0; |
| 135 | ELFtab = NULL; |
| 136 | ElfMem = NULL; |
| 137 | ElfDwarf = false; |
| 138 | } |
| 139 | |
| 140 | |
| 141 | // ELF manager Dwarf Initialisation |
| 142 | bool ELFManager_DwarfInit(Elf *PtrElfMem) |
| 143 | { |
| 144 | return (ElfDwarf = (DWARFManager_ElfInit(PtrElfMem) == DW_DLV_OK) ? true : false); |
| 145 | } |
| 146 | |
| 147 | |
| 148 | // ELF manager Reset |
| 149 | void ELFManager_Reset(void) |
| 150 | { |
| 151 | if (ElfDwarf) |
| 152 | { |
| 153 | DWARFManager_Reset(); |
| 154 | ElfDwarf = false; |
| 155 | } |
| 156 | |
| 157 | if (PtrExec != NULL) |
| 158 | { |
| 159 | free(PtrExec); |
| 160 | PtrExec = NULL; |
| 161 | } |
| 162 | |
| 163 | if (ELFtab != NULL) |
| 164 | { |
| 165 | while (NbELFtabStruct) |
| 166 | { |
| 167 | free(ELFtab[--NbELFtabStruct]); |
| 168 | } |
| 169 | |
| 170 | free(ELFtab); |
| 171 | ELFtab = NULL; |
| 172 | } |
| 173 | |
| 174 | ELFManager_MemEnd(); |
| 175 | } |
| 176 | |
| 177 | |
| 178 | // ELF manager Closing |
| 179 | void ELFManager_Close(void) |
| 180 | { |
| 181 | ELFManager_Reset(); |
| 182 | } |
| 183 | |
| 184 | |
| 185 | // Save the ELF tab in memory |
| 186 | bool ELFManager_AddTab(void *Ptr, size_t type) |
| 187 | { |
| 188 | if (!NbELFtabStruct) |
| 189 | { |
| 190 | if ((ELFtab = (ELFTab **)calloc(1, sizeof(ELFTab *))) == NULL) |
| 191 | { |
| 192 | return false; |
| 193 | } |
| 194 | } |
| 195 | else |
| 196 | { |
| 197 | if ((ELFtab = (ELFTab **)realloc(ELFtab, sizeof(ELFTab *)*(NbELFtabStruct+1))) == NULL) |
| 198 | { |
| 199 | return false; |
| 200 | } |
| 201 | } |
| 202 | |
| 203 | if ((ELFtab[NbELFtabStruct] = (ELFTab *)calloc(1, sizeof(ELFTab))) == NULL) |
| 204 | { |
| 205 | return false; |
| 206 | } |
| 207 | else |
| 208 | { |
| 209 | ELFtab[NbELFtabStruct]->Type = type; |
| 210 | ELFtab[NbELFtabStruct]->PtrTab = Ptr; |
| 211 | NbELFtabStruct++; |
| 212 | return true; |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | |
| 217 | // Get Address from his Symbol Name |
| 218 | // Return 0 if Symbol name is not found |
| 219 | size_t ELFManager_GetAdrFromSymbolName(char *SymbolName) |
| 220 | { |
| 221 | size_t Adr = 0; |
| 222 | GElf_Sym *PtrST, ST; |
| 223 | |
| 224 | if (ELFtab && SymbolName) |
| 225 | { |
| 226 | for (size_t i = 0; i < NbELFtabStruct; i++) |
| 227 | { |
| 228 | if ((ELFtab[i]->Type == ELF_symtab_TYPE) && ((ELFtab[i]->PtrDataTab) != NULL)) |
| 229 | { |
| 230 | int j = 0; |
| 231 | |
| 232 | while ((PtrST = gelf_getsym(ELFtab[i]->PtrDataTab, j++, &ST)) != NULL) |
| 233 | { |
| 234 | if (!strcmp(ELFManager_GetSymbolnameFromSymbolindex(PtrST->st_name), SymbolName)) |
| 235 | { |
| 236 | Adr = PtrST->st_value; |
| 237 | } |
| 238 | } |
| 239 | } |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | return Adr; |
| 244 | } |
| 245 | |
| 246 | |
| 247 | // Get function name from his address |
| 248 | // Return NULL if function name is not found |
| 249 | char *ELFManager_GetFunctionName(size_t Adr) |
| 250 | { |
| 251 | char *SymbolName = NULL; |
| 252 | GElf_Sym *PtrST, ST; |
| 253 | |
| 254 | if (ELFtab != NULL) |
| 255 | { |
| 256 | for (size_t i = 0; i < NbELFtabStruct; i++) |
| 257 | { |
| 258 | if ((ELFtab[i]->Type == ELF_symtab_TYPE) && ((ELFtab[i]->PtrDataTab) != NULL)) |
| 259 | { |
| 260 | int j = 0; |
| 261 | |
| 262 | while ((PtrST = gelf_getsym(ELFtab[i]->PtrDataTab, j++, &ST)) != NULL) |
| 263 | { |
| 264 | if (PtrST->st_value == Adr) |
| 265 | { |
| 266 | if (ELF32_ST_TYPE(PtrST->st_info) == STT_FUNC) |
| 267 | { |
| 268 | SymbolName = ELFManager_GetSymbolnameFromSymbolindex(PtrST->st_name); |
| 269 | } |
| 270 | } |
| 271 | } |
| 272 | } |
| 273 | } |
| 274 | } |
| 275 | |
| 276 | return SymbolName; |
| 277 | } |
| 278 | |
| 279 | |
| 280 | // Get Symbol name from his address |
| 281 | // Return NULL if Symbol name is not found |
| 282 | char *ELFManager_GetSymbolnameFromAdr(size_t Adr) |
| 283 | { |
| 284 | char *SymbolName = NULL; |
| 285 | GElf_Sym *PtrST, ST; |
| 286 | |
| 287 | if (ELFtab != NULL) |
| 288 | { |
| 289 | for (size_t i = 0; i < NbELFtabStruct; i++) |
| 290 | { |
| 291 | if ((ELFtab[i]->Type == ELF_symtab_TYPE) && ((ELFtab[i]->PtrDataTab) != NULL)) |
| 292 | { |
| 293 | int j = 0; |
| 294 | |
| 295 | while ((PtrST = gelf_getsym(ELFtab[i]->PtrDataTab, j++, &ST)) != NULL) |
| 296 | { |
| 297 | if (PtrST->st_value == Adr) |
| 298 | { |
| 299 | #ifdef LOG_SUPPORT |
| 300 | WriteLog("ELF: .symtab: DATA: st_info=%0x, st_name=%0x, st_other=%0x, st_shndx=%0x, st_size=%0x, st_value=%0x\n", PtrST->st_info, PtrST->st_name, PtrST->st_other, PtrST->st_shndx, PtrST->st_size, PtrST->st_value); |
| 301 | #endif |
| 302 | SymbolName = ELFManager_GetSymbolnameFromSymbolindex(PtrST->st_name); |
| 303 | } |
| 304 | } |
| 305 | } |
| 306 | } |
| 307 | } |
| 308 | |
| 309 | return SymbolName; |
| 310 | } |
| 311 | |
| 312 | |
| 313 | // Get Symbol name from his Symbol index |
| 314 | char *ELFManager_GetSymbolnameFromSymbolindex(size_t Index) |
| 315 | { |
| 316 | if (ELFtab != NULL) |
| 317 | { |
| 318 | for (size_t i = 0; i < NbELFtabStruct; i++) |
| 319 | { |
| 320 | if ((ELFtab[i]->Type == ELF_strtab_TYPE) && ((ELFtab[i]->PtrDataTab) != NULL)) |
| 321 | { |
| 322 | return ((char *)(ELFtab[i]->PtrDataTab->d_buf) + Index); |
| 323 | } |
| 324 | } |
| 325 | } |
| 326 | |
| 327 | return NULL; |
| 328 | } |