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/* MIT License
*
* Copyright (c) 2024 Brad House
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* SPDX-License-Identifier: MIT
*/
#include "ares_private.h"
#include "ares_event.h"
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#endif
#ifdef HAVE_PIPE
typedef struct {
int filedes[2];
} ares_pipeevent_t;
static void ares_pipeevent_destroy(ares_pipeevent_t *p)
{
if (p->filedes[0] != -1) {
close(p->filedes[0]);
}
if (p->filedes[1] != -1) {
close(p->filedes[1]);
}
ares_free(p);
}
static void ares_pipeevent_destroy_cb(void *arg)
{
ares_pipeevent_destroy(arg);
}
static ares_pipeevent_t *ares_pipeevent_init(void)
{
ares_pipeevent_t *p = ares_malloc_zero(sizeof(*p));
if (p == NULL) {
return NULL; /* LCOV_EXCL_LINE: OutOfMemory */
}
p->filedes[0] = -1;
p->filedes[1] = -1;
# ifdef HAVE_PIPE2
if (pipe2(p->filedes, O_NONBLOCK | O_CLOEXEC) != 0) {
ares_pipeevent_destroy(p); /* LCOV_EXCL_LINE: UntestablePath */
return NULL; /* LCOV_EXCL_LINE: UntestablePath */
}
# else
if (pipe(p->filedes) != 0) {
ares_pipeevent_destroy(p);
return NULL;
}
# ifdef O_NONBLOCK
{
int val;
val = fcntl(p->filedes[0], F_GETFL, 0);
if (val >= 0) {
val |= O_NONBLOCK;
}
fcntl(p->filedes[0], F_SETFL, val);
val = fcntl(p->filedes[1], F_GETFL, 0);
if (val >= 0) {
val |= O_NONBLOCK;
}
fcntl(p->filedes[1], F_SETFL, val);
}
# endif
# ifdef FD_CLOEXEC
fcntl(p->filedes[0], F_SETFD, FD_CLOEXEC);
fcntl(p->filedes[1], F_SETFD, FD_CLOEXEC);
# endif
# endif
# ifdef F_SETNOSIGPIPE
fcntl(p->filedes[0], F_SETNOSIGPIPE, 1);
fcntl(p->filedes[1], F_SETNOSIGPIPE, 1);
# endif
return p;
}
static void ares_pipeevent_signal(const ares_event_t *e)
{
const ares_pipeevent_t *p;
if (e == NULL || e->data == NULL) {
return; /* LCOV_EXCL_LINE: DefensiveCoding */
}
p = e->data;
(void)write(p->filedes[1], "1", 1);
}
static void ares_pipeevent_cb(ares_event_thread_t *e, ares_socket_t fd,
void *data, ares_event_flags_t flags)
{
unsigned char buf[32];
const ares_pipeevent_t *p = NULL;
(void)e;
(void)fd;
(void)flags;
if (data == NULL) {
return; /* LCOV_EXCL_LINE: DefensiveCoding */
}
p = data;
while (read(p->filedes[0], buf, sizeof(buf)) == sizeof(buf)) {
/* Do nothing */
}
}
ares_event_t *ares_pipeevent_create(ares_event_thread_t *e)
{
ares_event_t *event = NULL;
ares_pipeevent_t *p = NULL;
ares_status_t status;
p = ares_pipeevent_init();
if (p == NULL) {
return NULL;
}
status = ares_event_update(&event, e, ARES_EVENT_FLAG_READ, ares_pipeevent_cb,
p->filedes[0], p, ares_pipeevent_destroy_cb,
ares_pipeevent_signal);
if (status != ARES_SUCCESS) {
ares_pipeevent_destroy(p); /* LCOV_EXCL_LINE: DefensiveCoding */
return NULL; /* LCOV_EXCL_LINE: DefensiveCoding */
}
return event;
}
#endif
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