int
_ftrylockfile(FILE *fp)
{
pthread_t curthread = _pthread_self();
int ret = 0;
if (fp->_lock->fl_owner == curthread)
fp->_lock->fl_count++;
/*
* Make sure this mutex is treated as a private
* internal mutex:
*/
else if (_pthread_mutex_trylock(&fp->_lock->fl_mutex) == 0) {
fp->_lock->fl_owner = curthread;
fp->_lock->fl_count = 1;
}
else
ret = -1;
return (ret);
}
/*
* The first time nsdispatch is called (during a process's lifetime,
* or after nsswitch.conf has been updated), nss_configure will
* prepare global data needed by NSS.
*/
static int
nss_configure(void)
{
static pthread_mutex_t conf_lock = PTHREAD_MUTEX_INITIALIZER;
static time_t confmod;
struct stat statbuf;
int result, isthreaded;
const char *path;
#ifdef NS_CACHING
void *handle;
#endif
result = 0;
isthreaded = __isthreaded;
#if defined(_NSS_DEBUG) && defined(_NSS_SHOOT_FOOT)
/* NOTE WELL: THIS IS A SECURITY HOLE. This must only be built
* for debugging purposes and MUST NEVER be used in production.
*/
path = getenv("NSSWITCH_CONF");
if (path == NULL)
#endif
path = _PATH_NS_CONF;
if (stat(path, &statbuf) != 0)
return (0);
if (statbuf.st_mtime <= confmod)
return (0);
if (isthreaded) {
result = _pthread_mutex_trylock(&conf_lock);
if (result != 0)
return (0);
_pthread_rwlock_unlock(&nss_lock);
result = _pthread_rwlock_wrlock(&nss_lock);
if (result != 0)
goto fin2;
}
_nsyyin = fopen(path, "r");
if (_nsyyin == NULL)
goto fin;
VECTOR_FREE(_nsmap, &_nsmapsize, sizeof(*_nsmap),
(vector_free_elem)ns_dbt_free);
VECTOR_FREE(_nsmod, &_nsmodsize, sizeof(*_nsmod),
(vector_free_elem)ns_mod_free);
nss_load_builtin_modules();
_nsyyparse();
fclose(_nsyyin);
vector_sort(_nsmap, _nsmapsize, sizeof(*_nsmap), string_compare);
if (confmod == 0)
atexit(nss_atexit);
confmod = statbuf.st_mtime;
#ifdef NS_CACHING
handle = dlopen(NULL, RTLD_LAZY | RTLD_GLOBAL);
if (handle != NULL) {
nss_cache_cycle_prevention_func = dlsym(handle,
"_nss_cache_cycle_prevention_function");
dlclose(handle);
}
#endif
fin:
if (isthreaded) {
_pthread_rwlock_unlock(&nss_lock);
if (result == 0)
result = _pthread_rwlock_rdlock(&nss_lock);
}
fin2:
if (isthreaded)
_pthread_mutex_unlock(&conf_lock);
return (result);
}
