From 9aabbe7720b3c315048f977642e4bb8e387b572a Mon Sep 17 00:00:00 2001 From: CNLohr Date: Tue, 14 Mar 2017 21:12:18 -0400 Subject: Add a symbol enumerator for systems that don't support __contructor__. --- redist/symbol_enumerator.c | 243 +++++++++++++++++++++++++++++++++++++++++++++ redist/symbol_enumerator.h | 12 +++ 2 files changed, 255 insertions(+) create mode 100644 redist/symbol_enumerator.c create mode 100644 redist/symbol_enumerator.h (limited to 'redist') diff --git a/redist/symbol_enumerator.c b/redist/symbol_enumerator.c new file mode 100644 index 0000000..756a1ca --- /dev/null +++ b/redist/symbol_enumerator.c @@ -0,0 +1,243 @@ +#include +#include "symbol_enumerator.h" + +#if defined( WIN32 ) || defined( WINDOWS ) || defined( USE_WINDOWS ) + +#include + +typedef struct _SYMBOL_INFO { + ULONG SizeOfStruct; + ULONG TypeIndex; + ULONG64 Reserved[2]; + ULONG Index; + ULONG Size; + ULONG64 ModBase; + ULONG Flags; + ULONG64 Value; + ULONG64 Address; + ULONG Register; + ULONG Scope; + ULONG Tag; + ULONG NameLen; + ULONG MaxNameLen; + TCHAR Name[1]; +} SYMBOL_INFO, *PSYMBOL_INFO; +typedef struct _IMAGEHLP_STACK_FRAME { + ULONG64 InstructionOffset; + ULONG64 ReturnOffset; + ULONG64 FrameOffset; + ULONG64 StackOffset; + ULONG64 BackingStoreOffset; + ULONG64 FuncTableEntry; + ULONG64 Params[4]; + ULONG64 Reserved[5]; + BOOL Virtual; + ULONG Reserved2; +} IMAGEHLP_STACK_FRAME, *PIMAGEHLP_STACK_FRAME; + + +typedef BOOL (*PSYM_ENUMERATESYMBOLS_CALLBACK)( + PSYMBOL_INFO pSymInfo, + ULONG SymbolSize, + PVOID UserContext + ); + +BOOL WINAPI SymEnumSymbols( + HANDLE hProcess, + ULONG64 BaseOfDll, + PCTSTR Mask, + PSYM_ENUMERATESYMBOLS_CALLBACK EnumSymbolsCallback, + const PVOID UserContext +); + +BOOL WINAPI SymInitialize( + HANDLE hProcess, + PCTSTR UserSearchPath, + BOOL fInvadeProcess +); + +BOOL CALLBACK __cdecl mycb( + PSYMBOL_INFO pSymInfo, + ULONG SymbolSize, + PVOID UserContext + ){ + SymEnumeratorCallback cb = (SymEnumeratorCallback)UserContext; + return !cb( "", &pSymInfo->Name[0], (void*)pSymInfo->Address, (long) pSymInfo->Size ); + } + +int EnumerateSymbols( SymEnumeratorCallback cb ) +{ + HANDLE proc = GetCurrentProcess(); + if( !SymInitialize( proc, 0, 1 ) ) return -1; + if( !SymEnumSymbols( proc, 0, "*!*", &mycb, (void*)cb ) ) + { + SymCleanup(proc); + return -2; + } + SymCleanup(proc); + return 0; +} + +#else + + +#include +#include +#include +#include +#include + +#include "elf_enum.h" + +#ifndef __GNUC__ +#define __int128_t long long long +#endif + +#include +#include + +#define UINTS_PER_WORD (__WORDSIZE / (CHAR_BIT * sizeof (unsigned int))) + + + struct dl_phdr_info { + ElfW(Addr) dlpi_addr; /* Base address of object */ + const char *dlpi_name; /* (Null-terminated) name of + object */ + const ElfW(Phdr) *dlpi_phdr; /* Pointer to array of + ELF program headers + for this object */ + ElfW(Half) dlpi_phnum; /* # of items in dlpi_phdr */ + }; + + + +void dl_iterate_phdr( void*, void*); + + +static ElfW(Word) gnu_hashtab_symbol_count(const unsigned int *const table) +{ + const unsigned int *const bucket = table + 4 + table[2] * (unsigned int)(UINTS_PER_WORD); + unsigned int b = table[0]; + unsigned int max = 0U; + + while (b-->0U) + if (bucket[b] > max) + max = bucket[b]; + + return (ElfW(Word))max; +} + +static static void *dynamic_pointer(const ElfW(Addr) addr, + const ElfW(Addr) base, const ElfW(Phdr) *const header, const ElfW(Half) headers) +{ + if (addr) { + ElfW(Half) h; + + for (h = 0; h < headers; h++) + if (header[h].p_type == PT_LOAD) + if (addr >= base + header[h].p_vaddr && + addr < base + header[h].p_vaddr + header[h].p_memsz) + return (void *)addr; + } + + return NULL; +} + +//Mostly based off of http://stackoverflow.com/questions/29903049/get-names-and-addresses-of-exported-functions-from-in-linux +static int callback(struct dl_phdr_info *info, + size_t size, void *data) +{ + SymEnumeratorCallback cb = (SymEnumeratorCallback)data; + const ElfW(Addr) base = info->dlpi_addr; + const ElfW(Phdr) *const header = info->dlpi_phdr; + const ElfW(Half) headers = info->dlpi_phnum; + const char *libpath, *libname; + ElfW(Half) h; + + if (info->dlpi_name && info->dlpi_name[0]) + libpath = info->dlpi_name; + else + libpath = ""; + + libname = strrchr(libpath, '/'); + + if (libname && libname[0] == '/' && libname[1]) + libname++; + else + libname = libpath; + + for (h = 0; h < headers; h++) + { + if (header[h].p_type == PT_DYNAMIC) + { + const ElfW(Dyn) *entry = (const ElfW(Dyn) *)(base + header[h].p_vaddr); + const ElfW(Word) *hashtab; + const ElfW(Sym) *symtab = NULL; + const char *strtab = NULL; + ElfW(Word) symbol_count = 0; + + for (; entry->d_tag != DT_NULL; entry++) + { + switch (entry->d_tag) + { + case DT_HASH: + hashtab = dynamic_pointer(entry->d_un.d_ptr, base, header, headers); + if (hashtab) + symbol_count = hashtab[1]; + break; + case DT_GNU_HASH: + hashtab = dynamic_pointer(entry->d_un.d_ptr, base, header, headers); + if (hashtab) + { + ElfW(Word) count = gnu_hashtab_symbol_count(hashtab); + if (count > symbol_count) + symbol_count = count; + } + break; + case DT_STRTAB: + strtab = dynamic_pointer(entry->d_un.d_ptr, base, header, headers); + break; + case DT_SYMTAB: + symtab = dynamic_pointer(entry->d_un.d_ptr, base, header, headers); + break; + } + } + + if (symtab && strtab && symbol_count > 0) { + ElfW(Word) s; + + for (s = 0; s < symbol_count; s++) { + const char *name; + void *const ptr = dynamic_pointer(base + symtab[s].st_value, base, header, headers); + int result; + + if (!ptr) + continue; + + if (symtab[s].st_name) + name = strtab + symtab[s].st_name; + else + name = ""; + + result = cb( libpath, name, ptr, symtab[s].st_size ); + if( result ) return result; //Bail early. + } + } + } + } + return 0; +} + + + + + +int EnumerateSymbols( SymEnumeratorCallback cb ) +{ + dl_iterate_phdr( callback, cb ); +} + + + + +#endif \ No newline at end of file diff --git a/redist/symbol_enumerator.h b/redist/symbol_enumerator.h new file mode 100644 index 0000000..87e033b --- /dev/null +++ b/redist/symbol_enumerator.h @@ -0,0 +1,12 @@ +#ifndef _SYMBOL_ENUMERATOR_H +#define _SYMBOL_ENUMERATOR_H + +//Enumerates all symbols in the currently loaded excutable. +//Don't forget to compile with -rdynamic! + +//Return 0 to continue search. 1 to stop. +typedef int (*SymEnumeratorCallback)( const char * path, const char * name, void * location, long size ); + +int EnumerateSymbols( SymEnumeratorCallback cb ); + +#endif -- cgit v1.2.3