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lib.c
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lib.c
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/* Copyright (c) 2001-2017 Dovecot authors, see the included COPYING file */
#include "lib.h"
#include "dovecot-version.h"
#include "array.h"
#include "env-util.h"
#include "hostpid.h"
#include "fd-close-on-exec.h"
#include "ipwd.h"
#include "process-title.h"
#include "var-expand-private.h"
#include "randgen.h"
#include <fcntl.h>
#include <unistd.h>
#include <sys/time.h>
/* Mainly for including the full version information in core dumps.
NOTE: Don't set this const - otherwise it won't end up in core dumps. */
char dovecot_build_info[] = DOVECOT_BUILD_INFO;
static bool lib_initialized = FALSE;
int dev_null_fd = -1;
struct atexit_callback {
int priority;
lib_atexit_callback_t *callback;
};
static ARRAY(struct atexit_callback) atexit_callbacks = ARRAY_INIT;
int close_keep_errno(int *fd)
{
int ret, old_errno = errno;
i_assert(*fd != -1);
ret = close(*fd);
*fd = -1;
errno = old_errno;
return ret;
}
void i_close_fd_real(int *fd, const char *arg, const char *func,
const char *file, int line)
{
int saved_errno;
if (*fd == -1)
return;
i_assert(*fd > 0);
saved_errno = errno;
if (unlikely(close(*fd) < 0))
i_error("%s: close(%s) @ %s:%d failed (fd=%d): %m",
func, arg, file, line, *fd);
errno = saved_errno;
*fd = -1;
}
void fd_close_maybe_stdio(int *fd_in, int *fd_out)
{
int *fdp[2] = { fd_in, fd_out };
if (*fd_in == *fd_out)
*fd_in = -1;
for (unsigned int i = 0; i < N_ELEMENTS(fdp); i++) {
if (*fdp[i] == -1)
;
else if (*fdp[i] > 1)
i_close_fd(fdp[i]);
else if (dup2(dev_null_fd, *fdp[i]) == *fdp[i])
*fdp[i] = -1;
else
i_fatal("dup2(/dev/null, %d) failed: %m", *fdp[i]);
}
}
#undef i_unlink
int i_unlink(const char *path, const char *source_fname,
unsigned int source_linenum)
{
if (unlink(path) < 0) {
i_error("unlink(%s) failed: %m (in %s:%u)",
path, source_fname, source_linenum);
return -1;
}
return 0;
}
#undef i_unlink_if_exists
int i_unlink_if_exists(const char *path, const char *source_fname,
unsigned int source_linenum)
{
if (unlink(path) == 0)
return 1;
else if (errno == ENOENT)
return 0;
else {
i_error("unlink(%s) failed: %m (in %s:%u)",
path, source_fname, source_linenum);
return -1;
}
}
void i_getopt_reset(void)
{
#ifdef __GLIBC__
/* a) for subcommands allow -options anywhere in command line
b) this is actually required for the reset to work (glibc bug?) */
optind = 0;
#else
optind = 1;
#endif
}
void lib_atexit(lib_atexit_callback_t *callback)
{
lib_atexit_priority(callback, 0);
}
void lib_atexit_priority(lib_atexit_callback_t *callback, int priority)
{
struct atexit_callback *cb;
const struct atexit_callback *callbacks;
unsigned int i, count;
if (!array_is_created(&atexit_callbacks))
i_array_init(&atexit_callbacks, 8);
else {
/* skip if it's already added */
callbacks = array_get(&atexit_callbacks, &count);
for (i = count; i > 0; i--) {
if (callbacks[i-1].callback == callback) {
i_assert(callbacks[i-1].priority == priority);
return;
}
}
}
cb = array_append_space(&atexit_callbacks);
cb->priority = priority;
cb->callback = callback;
}
static int atexit_callback_priority_cmp(const struct atexit_callback *cb1,
const struct atexit_callback *cb2)
{
return cb1->priority - cb2->priority;
}
void lib_atexit_run(void)
{
const struct atexit_callback *cb;
if (array_is_created(&atexit_callbacks)) {
array_sort(&atexit_callbacks, atexit_callback_priority_cmp);
array_foreach(&atexit_callbacks, cb)
(*cb->callback)();
array_free(&atexit_callbacks);
}
}
static void lib_open_non_stdio_dev_null(void)
{
dev_null_fd = open("/dev/null", O_WRONLY);
if (dev_null_fd == -1)
i_fatal("open(/dev/null) failed: %m");
/* Make sure stdin, stdout and stderr fds exist. We especially rely on
stderr being available and a lot of code doesn't like fd being 0.
We'll open /dev/null as write-only also for stdin, since if any
reads are attempted from it we'll want them to fail. */
while (dev_null_fd < STDERR_FILENO) {
dev_null_fd = dup(dev_null_fd);
if (dev_null_fd == -1)
i_fatal("dup(/dev/null) failed: %m");
}
/* close the actual /dev/null fd on exec*(), but keep it in stdio fds */
fd_close_on_exec(dev_null_fd, TRUE);
}
void lib_init(void)
{
i_assert(!lib_initialized);
random_init();
data_stack_init();
hostpid_init();
lib_open_non_stdio_dev_null();
var_expand_extensions_init();
lib_initialized = TRUE;
}
bool lib_is_initialized(void)
{
return lib_initialized;
}
void lib_deinit(void)
{
i_assert(lib_initialized);
lib_initialized = FALSE;
lib_atexit_run();
ipwd_deinit();
hostpid_deinit();
var_expand_extensions_deinit();
i_close_fd(&dev_null_fd);
data_stack_deinit();
env_deinit();
failures_deinit();
process_title_deinit();
random_deinit();
}