osmith
/
wireshark
forked from osmocom/wireshark
1
0
Fork 0
Code Pull Requests Releases Wiki Activity
wireshark/epan/except.c

482 lines
13 KiB
C
Raw Permalink Blame History

/*
* Portable Exception Handling for ANSI C.
* Copyright (C) 1999 Kaz Kylheku <kaz@ashi.footprints.net>
*
* Free Software License:
*
* All rights are reserved by the author, with the following exceptions:
* Permission is granted to freely reproduce and distribute this software,
* possibly in exchange for a fee, provided that this copyright notice appears
* intact. Permission is also granted to adapt this software to produce
* derivative works, as long as the modified versions carry this copyright
* notice and additional notices stating that the work has been modified.
* This source code may be translated into executable form and incorporated
* into proprietary software; there is no requirement for such software to
* contain a copyright notice related to this source.
*/
/*
* Modified to support throwing an exception with a null message pointer,
* and to have the message not be const (as we generate messages with
* "ws_strdup_printf()", which means they need to be freed; using
* a null message means that we don't have to use a special string
* for exceptions with no message, and don't have to worry about
* not freeing that).
*/
#include "config.h"
#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <limits.h>
#include <glib.h>
#include "except.h"
#ifdef _WIN32
#include <windows.h>
#include "exceptions.h"
#endif
#define XCEPT_BUFFER_SIZE 1024
#ifdef KAZLIB_POSIX_THREADS
#include <pthread.h>
static pthread_mutex_t init_mtx = PTHREAD_MUTEX_INITIALIZER;
static int init_counter;
static pthread_key_t top_key;
static pthread_key_t uh_key;
static pthread_key_t alloc_key;
static pthread_key_t dealloc_key;
static void unhandled_catcher(except_t *);
#define get_top() ((struct except_stacknode *) pthread_getspecific(top_key))
#define set_top(T) (pthread_setspecific(top_key, (T)), (void)((T) == (struct except_stacknode *) 0))
#define set_catcher(C) (pthread_setspecific(uh_key, (void *) (C)), (void)((C) == (void (*)(except_t *)) 0))
#define set_alloc(A) (pthread_setspecific(alloc_key, (void *) (A)), (void)((A) == (void *(*)(size_t)) 0))
#define set_dealloc(D) (pthread_setspecific(dealloc_key, (void *) (D)), (void)((D) == (void (*)(void *)) 0))
static void (*get_catcher(void))(except_t *)
{
void (*catcher)(except_t *) = (void (*)(except_t *)) pthread_getspecific(uh_key);
return (catcher == 0) ? unhandled_catcher : catcher;
}
static void *(*get_alloc(void))(size_t)
{
void *(*alloc)(size_t) = (void *(*)(size_t)) pthread_getspecific(alloc_key);
return (alloc == 0) ? malloc : alloc;
}
static void (*get_dealloc(void))(void *)
{
void (*dealloc)(void *) = (void (*)(void *)) pthread_getspecific(dealloc_key);
return (dealloc == 0) ? free : dealloc;
}
int except_init(void)
{
int retval = 1;
pthread_mutex_lock(&init_mtx);
assert (init_counter < INT_MAX);
if (init_counter++ == 0) {
int top_ok = (pthread_key_create(&top_key, 0) == 0);
int uh_ok = (pthread_key_create(&uh_key, 0) == 0);
int alloc_ok = (pthread_key_create(&alloc_key, 0) == 0);
int dealloc_ok = (pthread_key_create(&dealloc_key, 0) == 0);
if (!top_ok || !uh_ok || !alloc_ok || !dealloc_ok) {
retval = 0;
init_counter = 0;
if (top_ok)
pthread_key_delete(top_key);
if (uh_ok)
pthread_key_delete(uh_key);
if (alloc_ok)
pthread_key_delete(alloc_key);
if (dealloc_ok)
pthread_key_delete(dealloc_key);
}
}
pthread_mutex_unlock(&init_mtx);
return retval;
}
void except_deinit(void)
{
pthread_mutex_lock(&init_mtx);
assert (init_counter > 0);
if (--init_counter == 0) {
pthread_key_delete(top_key);
pthread_key_delete(uh_key);
pthread_key_delete(alloc_key);
pthread_key_delete(dealloc_key);
}
pthread_mutex_unlock(&init_mtx);
}
#else /* not using POSIX thread support */
/*
* We make the catcher stack per-thread, because we must.
*
* We don't make the unhandled-exception-catcher, the allocator, or the
* deallocator thread-specific, as we don't need to.
*
* We don't protext the init level with a mutex, as we only initialize
* it and de-initialize it once.
*/
static int init_counter;
static void unhandled_catcher(except_t *);
static void (*uh_catcher_ptr)(except_t *) = unhandled_catcher;
/* We need this 'size_t' cast due to a glitch in GLib where g_malloc was prototyped
* as 'gpointer g_malloc (gulong n_bytes)'. This was later fixed to the correct prototype
* 'gpointer g_malloc (gsize n_bytes)'. In Wireshark we use the latter prototype
* throughout the code. We can get away with this even with older versions of GLib by
* adding a '(void *(*)(size_t))' cast whenever we refer to g_malloc. The only platform
* supported by Wireshark where this isn't safe (sizeof size_t != sizeof gulong) is Win64.
* However, we _always_ bundle the newest version of GLib on this platform so
* the size_t issue doesn't exists here. Pheew.. */
static void *(*allocator)(size_t) = (void *(*)(size_t)) g_malloc;
static void (*deallocator)(void *) = g_free;
static WS_THREAD_LOCAL struct except_stacknode *stack_top;
#define get_top() (stack_top)
#define set_top(T) (stack_top = (T))
#define get_catcher() (uh_catcher_ptr)
#define set_catcher(C) (uh_catcher_ptr = (C))
#define get_alloc() (allocator)
#define set_alloc(A) (allocator = (A))
#define get_dealloc() (deallocator)
#define set_dealloc(D) (deallocator = (D))
int except_init(void)
{
assert (init_counter < INT_MAX);
init_counter++;
return 1;
}
void except_deinit(void)
{
assert (init_counter > 0);
init_counter--;
}
#endif
static int match(const volatile except_id_t *thrown, const except_id_t *caught)
{
int group_match = (caught->except_group == XCEPT_GROUP_ANY ||
caught->except_group == thrown->except_group);
int code_match = (caught->except_code == XCEPT_CODE_ANY ||
caught->except_code == thrown->except_code);
return group_match && code_match;
}
WS_NORETURN static void do_throw(except_t *except)
{
struct except_stacknode *top;
assert (except->except_id.except_group != 0 &&
except->except_id.except_code != 0);
for (top = get_top(); top != 0; top = top->except_down) {
if (top->except_type == XCEPT_CLEANUP) {
top->except_info.except_cleanup->except_func(top->except_info.except_cleanup->except_context);
} else {
struct except_catch *catcher = top->except_info.except_catcher;
const except_id_t *pi = catcher->except_id;
size_t i;
assert (top->except_type == XCEPT_CATCHER);
except_free(catcher->except_obj.except_dyndata);
for (i = 0; i < catcher->except_size; pi++, i++) {
if (match(&except->except_id, pi)) {
catcher->except_obj = *except;
set_top(top);
longjmp(catcher->except_jmp, 1);
}
}
}
}
set_top(top);
get_catcher()(except); /* unhandled exception */
abort();
}
static void unhandled_catcher(except_t *except)
{
if (except->except_message == NULL) {
fprintf(stderr, "Unhandled exception (group=%lu, code=%lu)\n",
except->except_id.except_group,
except->except_id.except_code);
} else {
fprintf(stderr, "Unhandled exception (\"%s\", group=%lu, code=%lu)\n",
except->except_message, except->except_id.except_group,
except->except_id.except_code);
}
abort();
}
static void stack_push(struct except_stacknode *node)
{
node->except_down = get_top();
set_top(node);
}
void except_setup_clean(struct except_stacknode *esn,
struct except_cleanup *ecl, void (*cleanf)(void *), void *context)
{
esn->except_type = XCEPT_CLEANUP;
ecl->except_func = cleanf;
ecl->except_context = context;
esn->except_info.except_cleanup = ecl;
stack_push(esn);
}
void except_setup_try(struct except_stacknode *esn,
struct except_catch *ech, const except_id_t id[], size_t size)
{
ech->except_id = id;
ech->except_size = size;
ech->except_obj.except_dyndata = 0;
esn->except_type = XCEPT_CATCHER;
esn->except_info.except_catcher = ech;
stack_push(esn);
}
struct except_stacknode *except_pop(void)
{
struct except_stacknode *top = get_top();
assert (top->except_type == XCEPT_CLEANUP || top->except_type == XCEPT_CATCHER);
set_top(top->except_down);
return top;
}
WS_NORETURN void except_rethrow(except_t *except)
{
struct except_stacknode *top = get_top();
assert (top != 0);
assert (top->except_type == XCEPT_CATCHER);
assert (&top->except_info.except_catcher->except_obj == except);
set_top(top->except_down);
do_throw(except);
}
WS_NORETURN void except_throw(long group, long code, const char *msg)
{
except_t except;
except.except_id.except_group = group;
except.except_id.except_code = code;
except.except_message = msg;
except.except_dyndata = 0;
#ifdef _WIN32
if (code == DissectorError && IsDebuggerPresent()) {
DebugBreak();
}
#endif
do_throw(&except);
}
WS_NORETURN void except_throwd(long group, long code, const char *msg, void *data)
{
except_t except;
except.except_id.except_group = group;
except.except_id.except_code = code;
except.except_message = msg;
except.except_dyndata = data;
do_throw(&except);
}
/*
* XXX - should we use ws_strdup_printf() here, so we're not limited by
* XCEPT_BUFFER_SIZE? We could then just use this to generate formatted
* messages.
*/
WS_NORETURN void except_vthrowf(long group, long code, const char *fmt,
va_list vl)
{
char *buf = (char *)except_alloc(XCEPT_BUFFER_SIZE);
vsnprintf(buf, XCEPT_BUFFER_SIZE, fmt, vl);
except_throwd(group, code, buf, buf);
}
WS_NORETURN void except_throwf(long group, long code, const char *fmt, ...)
{
va_list vl;
va_start (vl, fmt);
except_vthrowf(group, code, fmt, vl);
va_end (vl);
}
void (*except_unhandled_catcher(void (*new_catcher)(except_t *)))(except_t *)
{
void (*old_catcher)(except_t *) = get_catcher();
set_catcher(new_catcher);
return old_catcher;
}
#undef except_code
#undef except_group
#undef except_message
#undef except_data
unsigned long except_code(except_t *ex)
{
return ex->except_id.except_code;
}
unsigned long except_group(except_t *ex)
{
return ex->except_id.except_group;
}
const char *except_message(except_t *ex)
{
return ex->except_message;
}
void *except_data(except_t *ex)
{
return ex->except_dyndata;
}
void *except_take_data(except_t *ex)
{
void *data = ex->except_dyndata;
ex->except_dyndata = 0;
return data;
}
void except_set_allocator(void *(*alloc)(size_t), void (*dealloc)(void *))
{
set_alloc(alloc);
set_dealloc(dealloc);
}
void *except_alloc(size_t size)
{
void *ptr = get_alloc()(size);
if (ptr == 0)
except_throw(XCEPT_BAD_ALLOC, 0, "out of memory");
return ptr;
}
void except_free(void *ptr)
{
get_dealloc()(ptr);
}
#ifdef KAZLIB_TEST_MAIN
static void cleanup(void *arg)
{
printf("cleanup(\"%s\") called\n", (char *) arg);
}
static void bottom_level(void)
{
char buf[256];
printf("throw exception? "); fflush(stdout);
fgets(buf, sizeof buf, stdin);
if (buf[0] >= 0 && (buf[0] == 'Y' || buf[0] == 'y'))
except_throw(1, 1, "nasty exception");
}
static void top_level(void)
{
except_cleanup_push(cleanup, "argument");
bottom_level();
except_cleanup_pop(0);
}
int main(int argc, char **argv)
{
static const except_id_t catch[] = { { 1, 1 }, { 1, 2 } };
except_t *ex;
char *msg;
/*
* Nested exception ``try blocks''
*/
/* outer */
except_try_push(catch, 2, &ex);
if (!ex) {
/* inner */
except_try_push(catch, 2, &ex);
if (!ex) {
top_level();
} else {
/* inner catch */
msg = except_message(ex);
if (msg == NULL) {
printf("caught exception (inner): s=%lu, c=%lu\n",
except_group(ex), except_code(ex));
} else {
printf("caught exception (inner): \"%s\", s=%lu, c=%lu\n",
msg, except_group(ex), except_code(ex));
}
except_rethrow(ex);
}
except_try_pop();
} else {
/* outer catch */
msg = except_message(ex);
if (msg == NULL) {
printf("caught exception (outer): s=%lu, c=%lu\n",
except_group(ex), except_code(ex));
} else {
printf("caught exception (outer): \"%s\", s=%lu, c=%lu\n",
except_message(ex), except_group(ex), except_code(ex));
}
}
except_try_pop();
except_throw(99, 99, "exception in main");
return 0;
}
#endif /* KAZLIB_TEST_MAIN */
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
View Git Blame Copy Permalink