/* * Copyright (c) 2020, the SerenityOS developers. * * SPDX-License-Identifier: BSD-2-Clause */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include static const char* object_file_type_to_string(ElfW(Half) type) { switch (type) { case ET_NONE: return "None"; case ET_REL: return "Relocatable"; case ET_EXEC: return "Executable"; case ET_DYN: return "Shared object"; case ET_CORE: return "Core"; default: return "(?)"; } } static const char* object_machine_type_to_string(ElfW(Half) type) { switch (type) { case ET_NONE: return "None"; case EM_M32: return "AT&T WE 32100"; case EM_SPARC: return "SPARC"; case EM_386: return "Intel 80386"; case EM_68K: return "Motorola 68000"; case EM_88K: return "Motorola 88000"; case EM_486: return "Intel 80486"; case EM_860: return "Intel 80860"; case EM_MIPS: return "MIPS R3000 Big-Endian only"; default: return "(?)"; } } static const char* object_program_header_type_to_string(ElfW(Word) type) { switch (type) { case PT_NULL: return "NULL"; case PT_LOAD: return "LOAD"; case PT_DYNAMIC: return "DYNAMIC"; case PT_INTERP: return "INTERP"; case PT_NOTE: return "NOTE"; case PT_SHLIB: return "SHLIB"; case PT_PHDR: return "PHDR"; case PT_TLS: return "TLS"; case PT_LOOS: return "LOOS"; case PT_HIOS: return "HIOS"; case PT_LOPROC: return "LOPROC"; case PT_HIPROC: return "HIPROC"; case PT_GNU_EH_FRAME: return "GNU_EH_FRAME"; case PT_GNU_RELRO: return "GNU_RELRO"; case PT_GNU_STACK: return "GNU_STACK"; case PT_OPENBSD_RANDOMIZE: return "OPENBSD_RANDOMIZE"; case PT_OPENBSD_WXNEEDED: return "OPENBSD_WXNEEDED"; case PT_OPENBSD_BOOTDATA: return "OPENBSD_BOOTDATA"; default: return "(?)"; } } static const char* object_section_header_type_to_string(ElfW(Word) type) { switch (type) { case SHT_NULL: return "NULL"; case SHT_PROGBITS: return "PROGBITS"; case SHT_SYMTAB: return "SYMTAB"; case SHT_STRTAB: return "STRTAB"; case SHT_RELA: return "RELA"; case SHT_HASH: return "HASH"; case SHT_DYNAMIC: return "DYNAMIC"; case SHT_NOTE: return "NOTE"; case SHT_NOBITS: return "NOBITS"; case SHT_REL: return "REL"; case SHT_SHLIB: return "SHLIB"; case SHT_DYNSYM: return "DYNSYM"; case SHT_NUM: return "NUM"; case SHT_INIT_ARRAY: return "INIT_ARRAY"; case SHT_FINI_ARRAY: return "FINI_ARRAY"; case SHT_PREINIT_ARRAY: return "PREINIT_ARRAY"; case SHT_GROUP: return "GROUP"; case SHT_SYMTAB_SHNDX: return "SYMTAB_SHNDX"; case SHT_LOOS: return "SOOS"; case SHT_SUNW_dof: return "SUNW_dof"; case SHT_GNU_LIBLIST: return "GNU_LIBLIST"; case SHT_SUNW_move: return "SUNW_move"; case SHT_SUNW_syminfo: return "SUNW_syminfo"; case SHT_SUNW_verdef: return "SUNW_verdef"; case SHT_SUNW_verneed: return "SUNW_verneed"; case SHT_SUNW_versym: // or SHT_HIOS return "SUNW_versym"; case SHT_LOPROC: return "LOPROC"; case SHT_HIPROC: return "HIPROC"; case SHT_LOUSER: return "LOUSER"; case SHT_HIUSER: return "HIUSER"; case SHT_GNU_HASH: return "GNU_HASH"; default: return "(?)"; } } static const char* object_symbol_type_to_string(ElfW(Word) type) { switch (type) { case STT_NOTYPE: return "NOTYPE"; case STT_OBJECT: return "OBJECT"; case STT_FUNC: return "FUNC"; case STT_SECTION: return "SECTION"; case STT_FILE: return "FILE"; case STT_TLS: return "TLS"; case STT_LOPROC: return "LOPROC"; case STT_HIPROC: return "HIPROC"; default: return "(?)"; } } static const char* object_symbol_binding_to_string(ElfW(Word) type) { switch (type) { case STB_LOCAL: return "LOCAL"; case STB_GLOBAL: return "GLOBAL"; case STB_WEAK: return "WEAK"; case STB_NUM: return "NUM"; case STB_LOPROC: return "LOPROC"; case STB_HIPROC: return "HIPROC"; default: return "(?)"; } } static const char* object_relocation_type_to_string(ElfW(Word) type) { switch (type) { case R_386_NONE: return "R_386_NONE"; case R_386_32: return "R_386_32"; case R_386_PC32: return "R_386_PC32"; case R_386_GOT32: return "R_386_GOT32"; case R_386_PLT32: return "R_386_PLT32"; case R_386_COPY: return "R_386_COPY"; case R_386_GLOB_DAT: return "R_386_GLOB_DAT"; case R_386_JMP_SLOT: return "R_386_JMP_SLOT"; case R_386_RELATIVE: return "R_386_RELATIVE"; case R_386_TLS_TPOFF: return "R_386_TLS_TPOFF"; case R_386_TLS_TPOFF32: return "R_386_TLS_TPOFF32"; default: return "(?)"; } } static const char* object_tag_to_string(ElfW(Sword) dt_tag) { switch (dt_tag) { case DT_NULL: return "NULL"; /* marks end of _DYNAMIC array */ case DT_NEEDED: return "NEEDED"; /* string table offset of needed lib */ case DT_PLTRELSZ: return "PLTRELSZ"; /* size of relocation entries in PLT */ case DT_PLTGOT: return "PLTGOT"; /* address PLT/GOT */ case DT_HASH: return "HASH"; /* address of symbol hash table */ case DT_STRTAB: return "STRTAB"; /* address of string table */ case DT_SYMTAB: return "SYMTAB"; /* address of symbol table */ case DT_RELA: return "RELA"; /* address of relocation table */ case DT_RELASZ: return "RELASZ"; /* size of relocation table */ case DT_RELAENT: return "RELAENT"; /* size of relocation entry */ case DT_STRSZ: return "STRSZ"; /* size of string table */ case DT_SYMENT: return "SYMENT"; /* size of symbol table entry */ case DT_INIT: return "INIT"; /* address of initialization func. */ case DT_FINI: return "FINI"; /* address of termination function */ case DT_SONAME: return "SONAME"; /* string table offset of shared obj */ case DT_RPATH: return "RPATH"; /* string table offset of library search path */ case DT_SYMBOLIC: return "SYMBOLIC"; /* start sym search in shared obj. */ case DT_REL: return "REL"; /* address of rel. tbl. w addends */ case DT_RELSZ: return "RELSZ"; /* size of DT_REL relocation table */ case DT_RELENT: return "RELENT"; /* size of DT_REL relocation entry */ case DT_PLTREL: return "PLTREL"; /* PLT referenced relocation entry */ case DT_DEBUG: return "DEBUG"; /* bugger */ case DT_TEXTREL: return "TEXTREL"; /* Allow rel. mod. to unwritable seg */ case DT_JMPREL: return "JMPREL"; /* add. of PLT's relocation entries */ case DT_BIND_NOW: return "BIND_NOW"; /* Bind now regardless of env setting */ case DT_INIT_ARRAY: return "INIT_ARRAY"; /* address of array of init func */ case DT_FINI_ARRAY: return "FINI_ARRAY"; /* address of array of term func */ case DT_INIT_ARRAYSZ: return "INIT_ARRAYSZ"; /* size of array of init func */ case DT_FINI_ARRAYSZ: return "FINI_ARRAYSZ"; /* size of array of term func */ case DT_RUNPATH: return "RUNPATH"; /* strtab offset of lib search path */ case DT_FLAGS: return "FLAGS"; /* Set of DF_* flags */ case DT_ENCODING: return "ENCODING"; /* further DT_* follow encoding rules */ case DT_PREINIT_ARRAY: return "PREINIT_ARRAY"; /* address of array of preinit func */ case DT_PREINIT_ARRAYSZ: return "PREINIT_ARRAYSZ"; /* size of array of preinit func */ case DT_LOOS: return "LOOS"; /* reserved range for OS */ case DT_HIOS: return "HIOS"; /* specific dynamic array tags */ case DT_LOPROC: return "LOPROC"; /* reserved range for processor */ case DT_HIPROC: return "HIPROC"; /* specific dynamic array tags */ case DT_GNU_HASH: return "GNU_HASH"; /* address of GNU hash table */ case DT_RELACOUNT: return "RELACOUNT"; /* if present, number of RELATIVE */ case DT_RELCOUNT: return "RELCOUNT"; /* relocs, which must come first */ case DT_FLAGS_1: return "FLAGS_1"; default: return "??"; } } int main(int argc, char** argv) { if (pledge("stdio rpath", nullptr) < 0) { perror("pledge"); return 1; } const char* path; static bool display_all = false; static bool display_elf_header = false; static bool display_program_headers = false; static bool display_section_headers = false; static bool display_headers = false; static bool display_symbol_table = false; static bool display_dynamic_symbol_table = false; static bool display_core_notes = false; static bool display_relocations = false; static bool display_unwind_info = false; static bool display_dynamic_section = false; static bool display_hardening = false; Core::ArgsParser args_parser; args_parser.add_option(display_all, "Display all", "all", 'a'); args_parser.add_option(display_elf_header, "Display ELF header", "file-header", 'h'); args_parser.add_option(display_program_headers, "Display program headers", "program-headers", 'l'); args_parser.add_option(display_section_headers, "Display section headers", "section-headers", 'S'); args_parser.add_option(display_headers, "Equivalent to: -h -l -S -s -r -d -n -u -c", "headers", 'e'); args_parser.add_option(display_symbol_table, "Display the symbol table", "syms", 's'); args_parser.add_option(display_dynamic_symbol_table, "Display the dynamic symbol table", "dyn-syms", '\0'); args_parser.add_option(display_dynamic_section, "Display the dynamic section", "dynamic", 'd'); args_parser.add_option(display_core_notes, "Display core notes", "notes", 'n'); args_parser.add_option(display_relocations, "Display relocations", "relocs", 'r'); args_parser.add_option(display_unwind_info, "Display unwind info", "unwind", 'u'); args_parser.add_option(display_hardening, "Display security hardening info", "checksec", 'c'); args_parser.add_positional_argument(path, "ELF path", "path"); args_parser.parse(argc, argv); if (argc < 3) { args_parser.print_usage(stderr, argv[0]); return -1; } if (display_headers) { display_elf_header = true; display_program_headers = true; display_section_headers = true; } if (display_all) { display_elf_header = true; display_program_headers = true; display_section_headers = true; display_core_notes = true; display_relocations = true; display_unwind_info = true; display_symbol_table = true; display_hardening = true; } auto file_or_error = MappedFile::map(path); if (file_or_error.is_error()) { warnln("Unable to map file {}: {}", path, file_or_error.error()); return -1; } auto elf_image_data = file_or_error.value()->bytes(); ELF::Image elf_image(elf_image_data); if (!elf_image.is_valid()) { warnln("File is not a valid ELF object"); return -1; } String interpreter_path; if (!ELF::validate_program_headers(*(const ElfW(Ehdr)*)elf_image_data.data(), elf_image_data.size(), (const u8*)elf_image_data.data(), elf_image_data.size(), &interpreter_path)) { warnln("Invalid ELF headers"); return -1; } auto& header = *reinterpret_cast(elf_image_data.data()); RefPtr object = nullptr; if (elf_image.is_dynamic()) { if (interpreter_path.is_null()) { interpreter_path = "/usr/lib/Loader.so"; warnln("Warning: Dynamic ELF object has no interpreter path. Using: {}", interpreter_path); } auto interpreter_file_or_error = MappedFile::map(interpreter_path); if (interpreter_file_or_error.is_error()) { warnln("Unable to map interpreter file {}: {}", interpreter_path, interpreter_file_or_error.error()); return -1; } auto interpreter_image_data = interpreter_file_or_error.value()->bytes(); ELF::Image interpreter_image(interpreter_image_data); if (!interpreter_image.is_valid()) { warnln("ELF interpreter image is invalid"); return -1; } int fd = open(path, O_RDONLY); if (fd < 0) { outln("Unable to open file {}", path); return 1; } auto result = ELF::DynamicLoader::try_create(fd, path); if (result.is_error()) { outln("{}", result.error().text); return 1; } auto& loader = result.value(); if (!loader->is_valid()) { outln("{} is not a valid ELF dynamic shared object!", path); return 1; } object = loader->map(); if (!object) { outln("Failed to map dynamic ELF object {}", path); return 1; } } if (display_elf_header) { outln("ELF header:"); out(" Magic: "); for (char i : StringView { header.e_ident, sizeof(header.e_ident) }) { if (isprint(i)) { out("{:c} ", i); } else { out("{:02x} ", i); } } outln(); outln(" Type: {} ({})", header.e_type, object_file_type_to_string(header.e_type)); outln(" Machine: {} ({})", header.e_machine, object_machine_type_to_string(header.e_machine)); outln(" Version: {:#x}", header.e_version); outln(" Entry point address: {:#x}", header.e_entry); outln(" Start of program headers: {} (bytes into file)", header.e_phoff); outln(" Start of section headers: {} (bytes into file)", header.e_shoff); outln(" Flags: {:#x}", header.e_flags); outln(" Size of this header: {} (bytes)", header.e_ehsize); outln(" Size of program headers: {} (bytes)", header.e_phentsize); outln(" Number of program headers: {}", header.e_phnum); outln(" Size of section headers: {} (bytes)", header.e_shentsize); outln(" Number of section headers: {}", header.e_shnum); outln(" Section header string table index: {}", header.e_shstrndx); outln(); } if (display_section_headers) { if (!display_all) { outln("There are {} section headers, starting at offset {:#x}:", header.e_shnum, header.e_shoff); outln(); } if (!elf_image.section_count()) { outln("There are no sections in this file."); } else { outln("Section Headers:"); outln(" Name Type Address Offset Size Flags"); elf_image.for_each_section([](const ELF::Image::Section& section) { out(" {:19} ", section.name()); out("{:15} ", object_section_header_type_to_string(section.type())); out("{:08x} ", section.address()); out("{:08x} ", section.offset()); out("{:08x} ", section.size()); out("{}", section.flags()); outln(); }); } outln(); } if (display_program_headers) { if (!display_all) { outln("ELF file type is {} ({})", header.e_type, object_file_type_to_string(header.e_type)); outln("Entry point {:#x}\n", header.e_entry); outln("There are {} program headers, starting at offset {}", header.e_phnum, header.e_phoff); outln(); } if (!elf_image.program_header_count()) { outln("There are no program headers in this file."); } else { outln("Program Headers:"); outln(" Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align"); elf_image.for_each_program_header([](const ELF::Image::ProgramHeader& program_header) { out(" "); out("{:14} ", object_program_header_type_to_string(program_header.type())); out("{:#08x} ", program_header.offset()); out("{:p} ", program_header.vaddr().as_ptr()); out("{:p} ", program_header.vaddr().as_ptr()); // FIXME: assumes PhysAddr = VirtAddr out("{:#08x} ", program_header.size_in_image()); out("{:#08x} ", program_header.size_in_memory()); out("{:04x} ", program_header.flags()); out("{:#08x}", program_header.alignment()); outln(); if (program_header.type() == PT_INTERP) outln(" [Interpreter: {}]", program_header.raw_data()); }); } // TODO: Display section to segment mapping outln(); } if (display_dynamic_section) { auto found_dynamic_section = false; if (elf_image.is_dynamic()) { elf_image.for_each_section([&found_dynamic_section](const ELF::Image::Section& section) { if (section.name() != ELF_DYNAMIC) return IterationDecision::Continue; found_dynamic_section = true; if (section.entry_count()) { outln("Dynamic section '{}' at offset {:#08x} contains {} entries.", section.name().to_string(), section.offset(), section.entry_count()); } else { outln("Dynamic section '{}' at offset {:#08x} contains zero entries.", section.name().to_string(), section.offset()); } return IterationDecision::Break; }); Vector libraries; object->for_each_needed_library([&libraries](StringView entry) { libraries.append(String::formatted("{}", entry)); }); auto library_index = 0; outln(" Tag Type Name / Value"); object->for_each_dynamic_entry([&library_index, &libraries, &object](const ELF::DynamicObject::DynamicEntry& entry) { out(" {:#08x} ", entry.tag()); out("{:17} ", object_tag_to_string(entry.tag())); if (entry.tag() == DT_NEEDED) { outln("Shared library: {}", libraries[library_index]); library_index++; } else if (entry.tag() == DT_RPATH) { outln("Library rpath: {}", object->rpath()); } else if (entry.tag() == DT_RUNPATH) { outln("Library runpath: {}", object->runpath()); } else if (entry.tag() == DT_SONAME) { outln("Library soname: {}", object->soname()); } else { outln("{:#08x}", entry.val()); } }); } if (!found_dynamic_section) outln("No dynamic section in this file."); outln(); } if (display_relocations) { if (elf_image.is_dynamic()) { if (!object->relocation_section().entry_count()) { outln("Relocation section '{}' at offset {:#08x} contains zero entries:", object->relocation_section().name(), object->relocation_section().offset()); } else { outln("Relocation section '{}' at offset {:#08x} contains {} entries:", object->relocation_section().name(), object->relocation_section().offset(), object->relocation_section().entry_count()); outln(" Offset Type Sym Value Sym Name"); object->relocation_section().for_each_relocation([](const ELF::DynamicObject::Relocation& reloc) { out(" {:#08x} ", reloc.offset()); out(" {:17} ", object_relocation_type_to_string(reloc.type())); out(" {:#08x} ", reloc.symbol().value()); out(" {}", reloc.symbol().name()); outln(); }); } outln(); if (!object->plt_relocation_section().entry_count()) { outln("Relocation section '{}' at offset {:#08x} contains zero entries:", object->plt_relocation_section().name(), object->plt_relocation_section().offset()); } else { outln("Relocation section '{}' at offset {:#08x} contains {} entries:", object->plt_relocation_section().name(), object->plt_relocation_section().offset(), object->plt_relocation_section().entry_count()); outln(" Offset Type Sym Value Sym Name"); object->plt_relocation_section().for_each_relocation([](const ELF::DynamicObject::Relocation& reloc) { out(" {:#08x} ", reloc.offset()); out(" {:17} ", object_relocation_type_to_string(reloc.type())); out(" {:#08x} ", reloc.symbol().value()); out(" {}", reloc.symbol().name()); outln(); }); } } else { outln("No relocations in this file."); } outln(); } if (display_unwind_info) { // TODO: Unwind info outln("Decoding of unwind sections for machine type {} is not supported.", object_machine_type_to_string(header.e_machine)); outln(); } if (display_core_notes) { auto found_notes = false; elf_image.for_each_program_header([&found_notes](const ELF::Image::ProgramHeader& program_header) { if (program_header.type() != PT_NOTE) return; found_notes = true; outln("Displaying notes section '{}' at offset {:#08x} of length {:#08x}:", object_program_header_type_to_string(program_header.type()), program_header.offset(), program_header.size_in_image()); // FIXME: Parse CORE notes. Notes are in JSON format on SerenityOS, but vary between systems. outln("{}", program_header.raw_data()); }); if (!found_notes) outln("No core notes in this file."); outln(); } if (display_dynamic_symbol_table || display_symbol_table) { auto found_dynamic_symbol_table = false; if (elf_image.is_dynamic()) { elf_image.for_each_section([&found_dynamic_symbol_table](const ELF::Image::Section& section) { if (section.name() != ELF_DYNSYM) return IterationDecision::Continue; found_dynamic_symbol_table = true; if (!section.entry_count()) { outln("Symbol table '{}' contains zero entries.", ELF_DYNSYM); } else { outln("Symbol table '{}' contains {} entries.", ELF_DYNSYM, section.entry_count()); } return IterationDecision::Break; }); if (object->symbol_count()) { // FIXME: Add support for init/fini/start/main sections outln(" Num: Value Size Type Bind Name"); object->for_each_symbol([](const ELF::DynamicObject::Symbol& sym) { out(" {:>4}: ", sym.index()); out("{:08x} ", sym.value()); out("{:08x} ", sym.size()); out("{:8} ", object_symbol_type_to_string(sym.type())); out("{:8} ", object_symbol_binding_to_string(sym.bind())); out("{}", sym.name()); outln(); }); } } if (!found_dynamic_symbol_table) outln("No dynamic symbol information for this file."); outln(); } if (display_symbol_table) { if (elf_image.symbol_count()) { outln("Symbol table '{}' contains {} entries:", ELF_SYMTAB, elf_image.symbol_count()); outln(" Num: Value Size Type Bind Name"); elf_image.for_each_symbol([](const ELF::Image::Symbol& sym) { out(" {:>4}: ", sym.index()); out("{:08x} ", sym.value()); out("{:08x} ", sym.size()); out("{:8} ", object_symbol_type_to_string(sym.type())); out("{:8} ", object_symbol_binding_to_string(sym.bind())); out("{}", sym.name()); outln(); }); } else { outln("Symbol table '{}' contains zero entries.", ELF_SYMTAB); } outln(); } if (display_hardening) { outln("Security Hardening:"); outln("RELRO Stack Canary NX PIE RPATH RUNPATH Symbols "); bool relro = false; elf_image.for_each_program_header([&relro](const ELF::Image::ProgramHeader& program_header) { if (program_header.type() == PT_GNU_RELRO) { relro = true; return IterationDecision::Break; } return IterationDecision::Continue; }); bool full_relro = false; if (relro) { object->for_each_dynamic_entry([&full_relro](const ELF::DynamicObject::DynamicEntry& entry) { if (entry.tag() == DT_BIND_NOW) { full_relro = true; return IterationDecision::Break; } return IterationDecision::Continue; }); if (full_relro) out("\033[0;32m{:13}\033[0m ", "Full RELRO"); else out("\033[0;33m{:13}\033[0m ", "Partial RELRO"); } else { out("\033[0;31m{:13}\033[0m ", "No RELRO"); } bool canary = false; elf_image.for_each_symbol([&canary](const ELF::Image::Symbol& sym) { if (sym.name() == "__stack_chk_fail" || sym.name() == "__intel_security_cookie") { canary = true; return IterationDecision::Break; } return IterationDecision::Continue; }); if (canary) out("\033[0;32m{:12}\033[0m ", "Canary found"); else out("\033[0;31m{:12}\033[0m ", "No canary"); bool nx = false; elf_image.for_each_program_header([&nx](const ELF::Image::ProgramHeader& program_header) { if (program_header.type() == PT_GNU_STACK) { if (program_header.flags() & PF_X) nx = false; else nx = true; return IterationDecision::Break; } return IterationDecision::Continue; }); if (nx) out("\033[0;32m{:12}\033[0m ", "NX enabled"); else out("\033[0;31m{:12}\033[0m ", "NX disabled"); bool pie = false; if (header.e_type == ET_REL || header.e_type == ET_DYN) pie = true; if (pie) out("\033[0;32m{:12}\033[0m ", "PIE enabled"); else out("\033[0;31m{:12}\033[0m ", "No PIE"); StringView rpath; if (elf_image.is_dynamic()) rpath = object->rpath(); if (rpath.is_empty()) out("\033[0;32m{:12}\033[0m ", "No RPATH"); else out("\033[0;31m{:12}\033[0m ", rpath); StringView runpath; if (elf_image.is_dynamic()) runpath = object->runpath(); if (runpath.is_empty()) out("\033[0;32m{:12}\033[0m ", "No RUNPATH"); else out("\033[0;31m{:12}\033[0m ", runpath); out("{} symbols", elf_image.symbol_count()); outln(); } return 0; }