/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 2006-2016. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* %CopyrightEnd%
*/
/*
* Interface functions to the dynamic linker using dl* functions.
* (As far as I know it works on SunOS 4, 5, Linux and FreeBSD. /Seb)
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "sys.h"
#include "erl_vm.h"
#include "global.h"
#ifdef HAVE_DLFCN_H
#include <dlfcn.h>
#endif
/* some systems do not have RTLD_NOW defined, and require the "mode"
* argument to dload() always be 1.
*/
#ifndef RTLD_NOW
# define RTLD_NOW 1
#endif
#define MAX_NAME_LEN 255 /* XXX should we get the system path size? */
#define EXT_LEN 3
#define FILE_EXT ".so" /* extension appended to the filename */
static char **errcodes = NULL;
static int num_errcodes = 0;
static int num_errcodes_allocated = 0;
#define my_strdup(WHAT) my_strdup_in(ERTS_ALC_T_DDLL_ERRCODES, WHAT);
static char *my_strdup_in(ErtsAlcType_t type, char *what)
{
char *res = erts_alloc(type, strlen(what) + 1);
strcpy(res, what);
return res;
}
static int find_errcode(char *string, ErtsSysDdllError* err)
{
int i;
if (err != NULL) {
erts_sys_ddll_free_error(err); /* in case we ignored an earlier error */
err->str = my_strdup_in(ERTS_ALC_T_DDLL_TMP_BUF, string);
return 0;
}
for(i=0;i<num_errcodes;++i) {
if (!strcmp(string, errcodes[i])) {
return i;
}
}
if (num_errcodes_allocated == num_errcodes) {
errcodes = (num_errcodes_allocated == 0)
? erts_alloc(ERTS_ALC_T_DDLL_ERRCODES,
(num_errcodes_allocated = 10) * sizeof(char *))
: erts_realloc(ERTS_ALC_T_DDLL_ERRCODES, errcodes,
(num_errcodes_allocated += 10) * sizeof(char *));
}
errcodes[num_errcodes++] = my_strdup(string);
return (num_errcodes - 1);
}
void erl_sys_ddll_init(void) {
#if defined(HAVE_DLOPEN) && defined(ERTS_NEED_DLOPEN_BEFORE_DLERROR)
/*
* dlopen() needs to be called before we make the first call to
* dlerror(); otherwise, dlerror() might dump core. At least
* some versions of linuxthread suffer from this bug.
*/
void *handle = dlopen("/nonexistinglib", RTLD_NOW);
if (handle)
dlclose(handle);
#endif
return;
}
/*
* Open a shared object
*/
int erts_sys_ddll_open(const char *full_name, void **handle, ErtsSysDdllError* err)
{
#if defined(HAVE_DLOPEN)
char* dlname;
int len = sys_strlen(full_name);
int ret;
dlname = erts_alloc(ERTS_ALC_T_TMP, len + EXT_LEN + 1);
sys_strcpy(dlname, full_name);
sys_strcpy(dlname+len, FILE_EXT);
ret = erts_sys_ddll_open_noext(dlname, handle, err);
erts_free(ERTS_ALC_T_TMP, (void *) dlname);
return ret;
#else
return ERL_DE_ERROR_NO_DDLL_FUNCTIONALITY;
#endif
}
int erts_sys_ddll_open_noext(char *dlname, void **handle, ErtsSysDdllError* err)
{
#if defined(HAVE_DLOPEN)
int ret = ERL_DE_NO_ERROR;
char *str;
dlerror();
if ((*handle = dlopen(dlname, RTLD_NOW)) == NULL) {
str = dlerror();
if (err == NULL) {
/*
* Remove prefix filename to avoid exploading number of
* error codes on extreme usage.
*/
if (strstr(str,dlname) == str) {
char *save_str = str;
str += strlen(dlname);
while (*str == ':' || *str == ' ') {
++str;
}
if (*str == '\0') { /* Better with filename than nothing... */
str = save_str;
}
}
}
ret = ERL_DE_DYNAMIC_ERROR_OFFSET - find_errcode(str, err);
}
return ret;
#else
return ERL_DE_ERROR_NO_DDLL_FUNCTIONALITY;
#endif
}
/*
* Find a symbol in the shared object
*/
int erts_sys_ddll_sym2(void *handle, const char *func_name, void **function,
ErtsSysDdllError* err)
{
#if defined(HAVE_DLOPEN)
void *sym;
char *e;
int ret;
dlerror();
sym = dlsym(handle, func_name);
if ((e = dlerror()) != NULL) {
ret = ERL_DE_DYNAMIC_ERROR_OFFSET - find_errcode(e, err);
} else {
*function = sym;
ret = ERL_DE_NO_ERROR;
}
return ret;
#else
return ERL_DE_ERROR_NO_DDLL_FUNCTIONALITY;
#endif
}
/* XXX:PaN These two will be changed with new driver interface! */
/*
* Load the driver init function, might appear under different names depending on object arch...
*/
int erts_sys_ddll_load_driver_init(void *handle, void **function)
{
void *fn;
int res;
if ((res = erts_sys_ddll_sym2(handle, "driver_init", &fn, NULL)) != ERL_DE_NO_ERROR) {
res = erts_sys_ddll_sym2(handle, "_driver_init", &fn, NULL);
}
if (res == ERL_DE_NO_ERROR) {
*function = fn;
}
return res;
}
int erts_sys_ddll_load_nif_init(void *handle, void **function, ErtsSysDdllError* err)
{
void *fn;
int res;
if ((res = erts_sys_ddll_sym2(handle, "nif_init", &fn, err)) != ERL_DE_NO_ERROR) {
res = erts_sys_ddll_sym2(handle, "_nif_init", &fn, err);
}
if (res == ERL_DE_NO_ERROR) {
*function = fn;
}
return res;
}
/*
* Call the driver_init function, whatever it's really called, simple on unix...
*/
void *erts_sys_ddll_call_init(void *function) {
void *(*initfn)(void) = function;
return (*initfn)();
}
void *erts_sys_ddll_call_nif_init(void *function) {
return erts_sys_ddll_call_init(function);
}
/*
* Close a chared object
*/
int erts_sys_ddll_close2(void *handle, ErtsSysDdllError* err)
{
#if defined(HAVE_DLOPEN)
int ret;
char *s;
dlerror();
if (dlclose(handle) == 0) {
ret = ERL_DE_NO_ERROR;
} else {
if ((s = dlerror()) == NULL) {
find_errcode("unspecified error", err);
ret = ERL_DE_ERROR_UNSPECIFIED;
} else {
ret = ERL_DE_DYNAMIC_ERROR_OFFSET - find_errcode(s, err);
}
}
return ret;
#else
return ERL_DE_ERROR_NO_DDLL_FUNCTIONALITY;
#endif
}
/*
* Return string that describes the (current) error
*/
char *erts_sys_ddll_error(int code)
{
int actual_code;
if (code > ERL_DE_DYNAMIC_ERROR_OFFSET) {
return "Unspecified error";
}
actual_code = -1*(code - ERL_DE_DYNAMIC_ERROR_OFFSET);
#if defined(HAVE_DLOPEN)
{
char *msg;
if (actual_code >= num_errcodes) {
msg = "Unknown dlload error";
} else {
msg = errcodes[actual_code];
}
return msg;
}
#endif
return "no error";
}
void erts_sys_ddll_free_error(ErtsSysDdllError* err)
{
if (err->str != NULL) {
erts_free(ERTS_ALC_T_DDLL_TMP_BUF, err->str);
}
}
