static void
dlsym_doit (void *a)
{
struct dlsym_args *args = (struct dlsym_args *) a;
args->sym = _dl_sym (args->handle, args->name, args->who);
}
unsigned long do_rel(struct _dl_handle * tmp_dl, unsigned long off)
{
Elf_Rel *tmp = ((void*)tmp_dl->plt_rel)+off;
int sym=ELF_R_SYM(tmp->r_info);
register unsigned long sym_val;
#ifdef DEBUG
pf(__func__": "); ph((unsigned long)tmp_dl); pf(" "); ph(off); pf(" on ");
ph((long)tmp_dl->plt_rel); pf("\n");
pf(__func__": @ "); ph((long)tmp->r_offset); pf(" with type ");
ph(ELF_R_TYPE(tmp->r_info)); pf(" and sym "); ph(sym);
pf(" symval "); ph(tmp_dl->dyn_sym_tab[sym].st_value); pf("\n");
#endif
/* modify GOT for REAL symbol */
//sym_val=((unsigned long)(tmp_dl->mem_base+tmp_dl->dyn_sym_tab[sym].st_value));
sym_val=(unsigned long)_dl_sym(tmp_dl,sym);
*((unsigned long*)(tmp_dl->mem_base+tmp->r_offset))=sym_val;
#ifdef DEBUG
pf(__func__": sym "); ph(sym_val); pf("\n");
#endif
/* JUMP (arg sysdep...) */
if (sym_val) return sym_val;
/* can't find symbol -> die now */
return (unsigned long)exit_now;
}
extern void * dlsym(void * handle, const char * symbol){
if(!real_dlsym){
real_dlsym = _dl_sym(RTLD_NEXT, "dlsym", dlsym);
}
void *ret = NULL;
if(symbol && string_testEqual(symbol, "dlsym")) return dlsym;
if(!(ret = real_dlsym(handle, symbol))) return ret;
printf("hooked dlsym, %s\n", symbol);
if(string_testEqualN(symbol, "glXGetProcAddress", 17)){
// printf("--- HOOK GLXGETPROCADDRESS\n");
glXGetProcAddress_orig = real_dlsym(handle, "glXGetProcAddress");
return glXGetProcAddress;
} else if(string_testEqualN(symbol, "glutGetProcAddress", 18)){
// printf("--- HOOK GLXGETPROCADDRESS\n");
glutGetProcAddress_orig = real_dlsym(handle, "glutGetProcAddress");
return glutGetProcAddress;
} else if(string_testEqualN(symbol, "glXSwapBuffers", 14)){
glXSwapBuffers_orig = real_dlsym(handle, "glXSwapBuffers");
// printf("replaced %s\n", symbol);
return (__GLXextFuncPtr)glXSwapBuffers;
} else if(string_testEqualN(symbol, "glXChooseFBConfig", 17)){
glXChooseFBConfig_orig = real_dlsym(handle, "glXChooseFBConfig");
// printf("replaced %s\n", symbol);
return (__GLXextFuncPtr)glXChooseFBConfig;
} else if(string_testEqualN(symbol, "glfwCreateWindow", 16)){
glfwCreateWindow_orig = real_dlsym(handle, "glfwCreateWindow");
// printf("replaced %s\n", symbol);
return glfwCreateWindow;
}
return ret;
}
/* check which symbols the program looks up */
void *
dlsym(void *handle, const char *symbol)
{
static void *(*orig_dlsym)(void *, const char *);
void *orig_ptr, *ptr = NULL;
if (orig_dlsym == NULL)
orig_dlsym = _dl_sym(RTLD_NEXT, "dlsym", dlsym);
if (!_env_ignored) {
/* try to resolve the symbol to an internal one first to avoid issues
* with dlerror().
*/
ptr = _env_dump_resolve_local_symbol_by_name(symbol);
/* resolve the symbol as expected by the client */
orig_ptr = orig_dlsym(handle, symbol);
if (!orig_ptr)
return orig_ptr;
/* add the symbol to our DB */
_env_dump_replace_symbol(symbol, orig_ptr);
if (ptr)
return ptr;
else
return orig_ptr;
} else
return orig_dlsym(handle, symbol);
}
void *
_env_dump_resolve_local_symbol_by_name(const char *symbol)
{
static void *(*orig_dlsym)(void *, const char *);
static void *handle_env_dump;
if (orig_dlsym == NULL)
orig_dlsym = _dl_sym(RTLD_NEXT, "dlsym", dlsym);
if (handle_env_dump == NULL ) {
void *(*orig_dlopen)(const char *, int);
char *fullpath = find_Linked_library("env_dump.so");
orig_dlopen = _dl_sym(RTLD_NEXT, "dlopen", dlsym);
handle_env_dump = orig_dlopen(fullpath, RTLD_LAZY);
free(fullpath);
}
return orig_dlsym(handle_env_dump, symbol);
}
void *
_env_dump_resolve_symbol_by_id(enum symbol_key_t symbol)
{
void *ret = NULL;
pthread_mutex_lock(&symbols_mp);
if (symbol < SYMB_END && symbols_len > symbol && symbols[symbol].name)
ret = symbols[symbol].ptr;
pthread_mutex_unlock(&symbols_mp);
/* Then try to see if there is another version somewhere else */
if (ret == NULL) {
ret = _dl_sym(RTLD_NEXT, symbol_key_str[symbol], _env_dump_resolve_symbol_by_name);
_env_dump_replace_symbol(symbol_key_str[symbol], ret);
}
return ret;
}
/* Wrapper function called in place of dlsym(), since we intercept dlsym().
* We use this ONLY to get the original dlsym() itself, all other symbol
* resolutions are done via that original function, then.
*/
static void *GH_dlsym_internal(void *handle, const char *name)
{
void *ptr;
/* ARGH: we are bypassing glibc's locking for dlsym(), so we
* must do this on our own */
pthread_mutex_lock(&GH_mutex);
/* Third argument is the address of the caller, (glibc uses stack
* unwinding internally to get this), we just use the address of our
* wrapper function itself, which is wrong when this is called on
* behalf of the real application doing a dlsycm, but we do not
* care... */
ptr=_dl_sym(handle, name, (void (*)())GH_dlsym_internal);
pthread_mutex_unlock(&GH_mutex);
return ptr;
}
void *
__libc_dlsym (void *map, const char *name)
{
return _dl_sym (map, name, NULL);
}
