| 1 | // |
| 2 | // ELFManager.cpp: ELF format manager |
| 3 | // |
| 4 | // by Jean-Paul Mari |
| 5 | // |
| 6 | // JPM = Jean-Paul Mari <djipi.mari@gmail.com> |
| 7 | // RG = Richard Goedeken |
| 8 | // |
| 9 | // WHO WHEN WHAT |
| 10 | // --- ---------- ------------------------------------------------------------ |
| 11 | // JPM Jan./2016 Created this file and added ELF format support |
| 12 | // JPM 07/13/2017 ELF DWARF format support improvement |
| 13 | // JPM 10/20/2018 Added function name support from ELF structure |
| 14 | // JPM 03/13/2020 Added ELF & DWARF .debug* types |
| 15 | // RG Jan./2021 Linux build fixes |
| 16 | // |
| 17 | |
| 18 | #include <stdlib.h> |
| 19 | #include <string.h> |
| 20 | #include <sys/types.h> |
| 21 | #include <sys/stat.h> |
| 22 | #include "libelf.h" |
| 23 | #include "gelf.h" |
| 24 | #include "libdwarf.h" |
| 25 | #include "log.h" |
| 26 | #include "ELFManager.h" |
| 27 | #include "DWARFManager.h" |
| 28 | |
| 29 | |
| 30 | //#define LOG_SUPPORT // Support log |
| 31 | |
| 32 | |
| 33 | typedef struct { |
| 34 | const char *SectionName; |
| 35 | size_t SectionType; |
| 36 | }ELFSectionType; |
| 37 | |
| 38 | typedef struct { |
| 39 | size_t Type; |
| 40 | size_t Size; |
| 41 | union { |
| 42 | Elf_Data *PtrDataTab; |
| 43 | void *PtrTab; |
| 44 | }; |
| 45 | }ELFTab; |
| 46 | |
| 47 | |
| 48 | // Section type list |
| 49 | ELFSectionType ELFTabSectionType[] = { |
| 50 | { "", ELF_NULL_TYPE }, |
| 51 | { ".text", ELF_text_TYPE }, |
| 52 | { ".rodata", ELF_rodata_TYPE }, |
| 53 | { ".data", ELF_data_TYPE }, |
| 54 | { ".bss", ELF_bss_TYPE }, |
| 55 | { ".heap", ELF_heap_TYPE }, |
| 56 | { ".debug", ELF_debug_TYPE }, |
| 57 | { ".comment", ELF_comment_TYPE }, |
| 58 | { ".shstrtab", ELF_shstrtab_TYPE }, |
| 59 | { ".symtab", ELF_symtab_TYPE }, |
| 60 | { ".strtab", ELF_strtab_TYPE }, |
| 61 | { ".debug_abbrev", ELF_debug_abbrev_TYPE }, |
| 62 | { ".debug_aranges", ELF_debug_aranges_TYPE }, |
| 63 | { ".debug_frame", ELF_debug_frame_TYPE }, |
| 64 | { ".debug_info", ELF_debug_info_TYPE }, |
| 65 | { ".debug_line", ELF_debug_line_TYPE }, |
| 66 | { ".debug_loc", ELF_debug_loc_TYPE }, |
| 67 | { ".debug_macinfo", ELF_debug_macinfo_TYPE }, |
| 68 | { ".debug_pubnames", ELF_debug_pubnames_TYPE }, |
| 69 | { ".debug_pubtypes", ELF_debug_pubtypes_TYPE }, |
| 70 | { ".debug_ranges", ELF_debug_ranges_TYPE }, |
| 71 | { ".debug_str", ELF_debug_str_TYPE }, |
| 72 | { ".debug_types", ELF_debug_types_TYPE } |
| 73 | }; |
| 74 | |
| 75 | |
| 76 | // ELF management |
| 77 | Elf *ElfMem; |
| 78 | void *PtrExec; // ELF executable |
| 79 | |
| 80 | // ELF Dwarf management |
| 81 | bool ElfDwarf; |
| 82 | |
| 83 | // TAB structure |
| 84 | size_t NbELFtabStruct; |
| 85 | ELFTab **ELFtab; |
| 86 | |
| 87 | |
| 88 | char *ELFManager_GetSymbolnameFromSymbolindex(size_t Index); |
| 89 | |
| 90 | |
| 91 | // ELF section type detection |
| 92 | size_t ELFManager_GetSectionType(char *SectionName) |
| 93 | { |
| 94 | size_t i; |
| 95 | |
| 96 | for (i = 0; i < ELF_END_TYPE; i++) |
| 97 | { |
| 98 | if (!strcmp(ELFTabSectionType[i].SectionName, SectionName)) |
| 99 | { |
| 100 | return (ELFTabSectionType[i].SectionType); |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | return (size_t)ELF_NO_TYPE; |
| 105 | } |
| 106 | |
| 107 | |
| 108 | // ELF manager executable copy |
| 109 | void *ELFManager_ExeCopy(void *src, size_t size) |
| 110 | { |
| 111 | if ((PtrExec = malloc(size)) != NULL) |
| 112 | { |
| 113 | memcpy(PtrExec, src, size); |
| 114 | } |
| 115 | |
| 116 | return PtrExec; |
| 117 | } |
| 118 | |
| 119 | |
| 120 | Elf *ELFManager_MemOpen(char *PtrELFExe, size_t Size) |
| 121 | { |
| 122 | return(ElfMem = elf_memory(PtrELFExe, Size)); |
| 123 | } |
| 124 | |
| 125 | |
| 126 | int ELFManager_MemEnd(void) |
| 127 | { |
| 128 | int err = 0; |
| 129 | |
| 130 | if (ElfMem) |
| 131 | { |
| 132 | err = elf_end(ElfMem); |
| 133 | ElfMem = NULL; |
| 134 | } |
| 135 | |
| 136 | return (err); |
| 137 | } |
| 138 | |
| 139 | |
| 140 | // ELF manager Initialisation |
| 141 | void ELFManager_Init(void) |
| 142 | { |
| 143 | PtrExec = NULL; |
| 144 | NbELFtabStruct = 0; |
| 145 | ELFtab = NULL; |
| 146 | ElfMem = NULL; |
| 147 | ElfDwarf = false; |
| 148 | } |
| 149 | |
| 150 | |
| 151 | // ELF manager Dwarf Initialisation |
| 152 | bool ELFManager_DwarfInit(Elf *PtrElfMem, struct stat FileElfInfo) |
| 153 | { |
| 154 | return (ElfDwarf = (DWARFManager_ElfInit(PtrElfMem, FileElfInfo) == DW_DLV_OK) ? true : false); |
| 155 | } |
| 156 | |
| 157 | |
| 158 | // ELF manager Reset |
| 159 | void ELFManager_Reset(void) |
| 160 | { |
| 161 | if (ElfDwarf) |
| 162 | { |
| 163 | DWARFManager_Reset(); |
| 164 | ElfDwarf = false; |
| 165 | } |
| 166 | |
| 167 | if (PtrExec != NULL) |
| 168 | { |
| 169 | free(PtrExec); |
| 170 | PtrExec = NULL; |
| 171 | } |
| 172 | |
| 173 | if (ELFtab != NULL) |
| 174 | { |
| 175 | while (NbELFtabStruct) |
| 176 | { |
| 177 | free(ELFtab[--NbELFtabStruct]); |
| 178 | } |
| 179 | |
| 180 | free(ELFtab); |
| 181 | ELFtab = NULL; |
| 182 | } |
| 183 | |
| 184 | ELFManager_MemEnd(); |
| 185 | } |
| 186 | |
| 187 | |
| 188 | // ELF manager Closing |
| 189 | void ELFManager_Close(void) |
| 190 | { |
| 191 | ELFManager_Reset(); |
| 192 | } |
| 193 | |
| 194 | |
| 195 | // Save the ELF tab in memory |
| 196 | bool ELFManager_AddTab(void *Ptr, size_t type) |
| 197 | { |
| 198 | if (!NbELFtabStruct) |
| 199 | { |
| 200 | if ((ELFtab = (ELFTab **)calloc(1, sizeof(ELFTab *))) == NULL) |
| 201 | { |
| 202 | return false; |
| 203 | } |
| 204 | } |
| 205 | else |
| 206 | { |
| 207 | if ((ELFtab = (ELFTab **)realloc(ELFtab, sizeof(ELFTab *)*(NbELFtabStruct+1))) == NULL) |
| 208 | { |
| 209 | return false; |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | if ((ELFtab[NbELFtabStruct] = (ELFTab *)calloc(1, sizeof(ELFTab))) == NULL) |
| 214 | { |
| 215 | return false; |
| 216 | } |
| 217 | else |
| 218 | { |
| 219 | ELFtab[NbELFtabStruct]->Type = type; |
| 220 | ELFtab[NbELFtabStruct]->PtrTab = Ptr; |
| 221 | NbELFtabStruct++; |
| 222 | return true; |
| 223 | } |
| 224 | } |
| 225 | |
| 226 | |
| 227 | // Get Address from his Symbol Name |
| 228 | // Return 0 if Symbol name is not found |
| 229 | size_t ELFManager_GetAdrFromSymbolName(char *SymbolName) |
| 230 | { |
| 231 | size_t Adr = 0; |
| 232 | GElf_Sym *PtrST, ST; |
| 233 | |
| 234 | if (ELFtab && SymbolName) |
| 235 | { |
| 236 | for (size_t i = 0; i < NbELFtabStruct; i++) |
| 237 | { |
| 238 | if ((ELFtab[i]->Type == ELF_symtab_TYPE) && ((ELFtab[i]->PtrDataTab) != NULL)) |
| 239 | { |
| 240 | int j = 0; |
| 241 | |
| 242 | while ((PtrST = gelf_getsym(ELFtab[i]->PtrDataTab, j++, &ST)) != NULL) |
| 243 | { |
| 244 | if (!strcmp(ELFManager_GetSymbolnameFromSymbolindex(PtrST->st_name), SymbolName)) |
| 245 | { |
| 246 | Adr = PtrST->st_value; |
| 247 | } |
| 248 | } |
| 249 | } |
| 250 | } |
| 251 | } |
| 252 | |
| 253 | return Adr; |
| 254 | } |
| 255 | |
| 256 | |
| 257 | // Get function name from his address |
| 258 | // Return NULL if function name is not found |
| 259 | char *ELFManager_GetFunctionName(size_t Adr) |
| 260 | { |
| 261 | char *SymbolName = NULL; |
| 262 | GElf_Sym *PtrST, ST; |
| 263 | |
| 264 | if (ELFtab != NULL) |
| 265 | { |
| 266 | for (size_t i = 0; i < NbELFtabStruct; i++) |
| 267 | { |
| 268 | if ((ELFtab[i]->Type == ELF_symtab_TYPE) && ((ELFtab[i]->PtrDataTab) != NULL)) |
| 269 | { |
| 270 | int j = 0; |
| 271 | |
| 272 | while ((PtrST = gelf_getsym(ELFtab[i]->PtrDataTab, j++, &ST)) != NULL) |
| 273 | { |
| 274 | if (PtrST->st_value == Adr) |
| 275 | { |
| 276 | if (ELF32_ST_TYPE(PtrST->st_info) == STT_FUNC) |
| 277 | { |
| 278 | SymbolName = ELFManager_GetSymbolnameFromSymbolindex(PtrST->st_name); |
| 279 | } |
| 280 | } |
| 281 | } |
| 282 | } |
| 283 | } |
| 284 | } |
| 285 | |
| 286 | return SymbolName; |
| 287 | } |
| 288 | |
| 289 | |
| 290 | // Get Symbol name from his address |
| 291 | // Return NULL if Symbol name is not found |
| 292 | char *ELFManager_GetSymbolnameFromAdr(size_t Adr) |
| 293 | { |
| 294 | char *SymbolName = NULL; |
| 295 | GElf_Sym *PtrST, ST; |
| 296 | |
| 297 | if (ELFtab != NULL) |
| 298 | { |
| 299 | for (size_t i = 0; i < NbELFtabStruct; i++) |
| 300 | { |
| 301 | if ((ELFtab[i]->Type == ELF_symtab_TYPE) && ((ELFtab[i]->PtrDataTab) != NULL)) |
| 302 | { |
| 303 | int j = 0; |
| 304 | |
| 305 | while ((PtrST = gelf_getsym(ELFtab[i]->PtrDataTab, j++, &ST)) != NULL) |
| 306 | { |
| 307 | if (PtrST->st_value == Adr) |
| 308 | { |
| 309 | #ifdef LOG_SUPPORT |
| 310 | 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); |
| 311 | #endif |
| 312 | SymbolName = ELFManager_GetSymbolnameFromSymbolindex(PtrST->st_name); |
| 313 | } |
| 314 | } |
| 315 | } |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | return SymbolName; |
| 320 | } |
| 321 | |
| 322 | |
| 323 | // Get Symbol name from his Symbol index |
| 324 | char *ELFManager_GetSymbolnameFromSymbolindex(size_t Index) |
| 325 | { |
| 326 | if (ELFtab != NULL) |
| 327 | { |
| 328 | for (size_t i = 0; i < NbELFtabStruct; i++) |
| 329 | { |
| 330 | if ((ELFtab[i]->Type == ELF_strtab_TYPE) && ((ELFtab[i]->PtrDataTab) != NULL)) |
| 331 | { |
| 332 | return ((char *)(ELFtab[i]->PtrDataTab->d_buf) + Index); |
| 333 | } |
| 334 | } |
| 335 | } |
| 336 | |
| 337 | return NULL; |
| 338 | } |