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authorSverker Eriksson <[email protected]>2012-10-05 11:52:52 +0200
committerSverker Eriksson <[email protected]>2012-10-09 22:05:11 +0200
commite5c1d346e29e5b1227ed30ee4d725a09eca0e532 (patch)
treeb5c8114a810459e855d4a81ec918c40e240c82d9 /erts/emulator/beam
parent54e7cc9086908a0e5642caa6ac3680557acc5a67 (diff)
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crypto: Make unloading of crypto safer
Facts: crypto nif-lib registers callback functions that openssl uses for memory management and thread synchronization. The callback functions can only be set once, openssl does not allow changing the callback functions. Problem: If openssl is dynamicly linked to crypto, you might get s scenario where the crypto lib is unloaded while leaving openssl loaded with its old pointers to the unloaded crypto code intact. If crypto is then reloaded (by init:restart() for example), the crypto nif-lib might get relocated at a different address. crypto calls openssl which in turn calls the old invalid callback functions...kaboom. Solution: Break apart the callback functions into a separate dynamic lib that crypto loads with dlopen. When crypto is unloaded the callback lib is left in place to be reused if/when crypto is loaded again.
Diffstat (limited to 'erts/emulator/beam')
-rw-r--r--erts/emulator/beam/erl_nif.c38
-rw-r--r--erts/emulator/beam/erl_nif_api_funcs.h4
-rw-r--r--erts/emulator/beam/sys.h4
3 files changed, 44 insertions, 2 deletions
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index 0dca588847..632d756481 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -1396,6 +1396,44 @@ size_t enif_sizeof_resource(void* obj)
return ERTS_MAGIC_BIN_DATA_SIZE(bin) - offsetof(ErlNifResource,data);
}
+
+void* enif_dlopen(const char* lib,
+ void (*err_handler)(void*,const char*), void* err_arg)
+{
+ ErtsSysDdllError errdesc = ERTS_SYS_DDLL_ERROR_INIT;
+ void* handle;
+ void* init_func;
+ if (erts_sys_ddll_open2(lib, &handle, &errdesc) == ERL_DE_NO_ERROR) {
+ if (erts_sys_ddll_load_nif_init(handle, &init_func, &errdesc) == ERL_DE_NO_ERROR) {
+ erts_sys_ddll_call_nif_init(init_func);
+ }
+ }
+ else {
+ if (err_handler != NULL) {
+ (*err_handler)(err_arg, errdesc.str);
+ }
+ handle = NULL;
+ }
+ erts_sys_ddll_free_error(&errdesc);
+ return handle;
+}
+
+void* enif_dlsym(void* handle, const char* symbol,
+ void (*err_handler)(void*,const char*), void* err_arg)
+{
+ ErtsSysDdllError errdesc = ERTS_SYS_DDLL_ERROR_INIT;
+ void* ret;
+ if (erts_sys_ddll_sym2(handle, symbol, &ret, &errdesc) != ERL_DE_NO_ERROR) {
+ if (err_handler != NULL) {
+ (*err_handler)(err_arg, errdesc.str);
+ }
+ erts_sys_ddll_free_error(&errdesc);
+ return NULL;
+ }
+ return ret;
+}
+
+
/***************************************************************************
** load_nif/2 **
***************************************************************************/
diff --git a/erts/emulator/beam/erl_nif_api_funcs.h b/erts/emulator/beam/erl_nif_api_funcs.h
index 6396af09d0..51ff1eaa48 100644
--- a/erts/emulator/beam/erl_nif_api_funcs.h
+++ b/erts/emulator/beam/erl_nif_api_funcs.h
@@ -138,6 +138,8 @@ ERL_NIF_API_FUNC_DECL(ERL_NIF_TERM,enif_make_uint64,(ErlNifEnv*, ErlNifUInt64));
ERL_NIF_API_FUNC_DECL(int,enif_is_exception,(ErlNifEnv*, ERL_NIF_TERM term));
ERL_NIF_API_FUNC_DECL(int,enif_make_reverse_list,(ErlNifEnv*, ERL_NIF_TERM term, ERL_NIF_TERM *list));
ERL_NIF_API_FUNC_DECL(int,enif_is_number,(ErlNifEnv*, ERL_NIF_TERM term));
+ERL_NIF_API_FUNC_DECL(void*,enif_dlopen,(const char* lib, void (*err_handler)(void*,const char*), void* err_arg));
+ERL_NIF_API_FUNC_DECL(void*,enif_dlsym,(void* handle, const char* symbol, void (*err_handler)(void*,const char*), void* err_arg));
/*
** Add new entries here to keep compatibility on Windows!!!
@@ -260,6 +262,8 @@ ERL_NIF_API_FUNC_DECL(int,enif_is_number,(ErlNifEnv*, ERL_NIF_TERM term));
# define enif_is_exception ERL_NIF_API_FUNC_MACRO(enif_is_exception)
# define enif_make_reverse_list ERL_NIF_API_FUNC_MACRO(enif_make_reverse_list)
# define enif_is_number ERL_NIF_API_FUNC_MACRO(enif_is_number)
+# define enif_dlopen ERL_NIF_API_FUNC_MACRO(enif_dlopen)
+# define enif_dlsym ERL_NIF_API_FUNC_MACRO(enif_dlsym)
/*
** Add new entries here
diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h
index 0e6bec352e..743da4ca3a 100644
--- a/erts/emulator/beam/sys.h
+++ b/erts/emulator/beam/sys.h
@@ -618,7 +618,7 @@ typedef struct {
#define ERTS_SYS_DDLL_ERROR_INIT {NULL}
extern void erts_sys_ddll_free_error(ErtsSysDdllError*);
extern void erl_sys_ddll_init(void); /* to initialize mutexes etc */
-extern int erts_sys_ddll_open2(char *path, void **handle, ErtsSysDdllError*);
+extern int erts_sys_ddll_open2(const char *path, void **handle, ErtsSysDdllError*);
#define erts_sys_ddll_open(P,H) erts_sys_ddll_open2(P,H,NULL)
extern int erts_sys_ddll_open_noext(char *path, void **handle, ErtsSysDdllError*);
extern int erts_sys_ddll_load_driver_init(void *handle, void **function);
@@ -627,7 +627,7 @@ extern int erts_sys_ddll_close2(void *handle, ErtsSysDdllError*);
#define erts_sys_ddll_close(H) erts_sys_ddll_close2(H,NULL)
extern void *erts_sys_ddll_call_init(void *function);
extern void *erts_sys_ddll_call_nif_init(void *function);
-extern int erts_sys_ddll_sym2(void *handle, char *name, void **function, ErtsSysDdllError*);
+extern int erts_sys_ddll_sym2(void *handle, const char *name, void **function, ErtsSysDdllError*);
#define erts_sys_ddll_sym(H,N,F) erts_sys_ddll_sym2(H,N,F,NULL)
extern char *erts_sys_ddll_error(int code);