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| | /* SPDX-License-Identifier: LGPL-2.1-or-later */
/* Copied and adapted from systemd source code. */
#define _GNU_SOURCE 1
#include <assert.h>
#include <errno.h>
#include <signal.h>
#include <stddef.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include "sd-socket.h"
#define _cleanup_(f) __attribute__((cleanup(f)))
int sd_is_socket(int fd, int type, int listening) {
struct stat st_fd;
assert(fd >= 0);
assert(type >= 0);
if (fstat(fd, &st_fd) < 0)
return -errno;
if (!S_ISSOCK(st_fd.st_mode))
return 0;
if (type != 0) {
int other_type = 0;
socklen_t l = sizeof(other_type);
if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &other_type, &l) < 0)
return -errno;
if (l != sizeof(other_type))
return -EINVAL;
if (other_type != type)
return 0;
}
if (listening >= 0) {
int accepting = 0;
socklen_t l = sizeof(accepting);
if (getsockopt(fd, SOL_SOCKET, SO_ACCEPTCONN, &accepting, &l) < 0)
return -errno;
if (l != sizeof(accepting))
return -EINVAL;
if (!accepting != !listening)
return 0;
}
return 1;
}
/* SPDX-License-Identifier: MIT-0 */
/* Implement the systemd notify protocol without external dependencies.
* Supports both readiness notification on startup and on reloading,
* according to the protocol defined at:
* https://www.freedesktop.org/software/systemd/man/latest/sd_notify.html
* This protocol is guaranteed to be stable as per:
* https://systemd.io/PORTABILITY_AND_STABILITY/ */
static void closep(int *fd) {
if (!fd || *fd < 0)
return;
close(*fd);
*fd = -1;
}
static int sd_notify(const char *message) {
union sockaddr_union {
struct sockaddr sa;
struct sockaddr_un sun;
} socket_addr = {
.sun.sun_family = AF_UNIX,
};
size_t path_length, message_length;
_cleanup_(closep) int fd = -1;
const char *socket_path;
/* Verify the argument first */
if (!message)
return -EINVAL;
message_length = strlen(message);
if (message_length == 0)
return -EINVAL;
/* If the variable is not set, the protocol is a noop */
socket_path = getenv("NOTIFY_SOCKET");
if (!socket_path)
return 0; /* Not set? Nothing to do */
/* Only AF_UNIX is supported, with path or abstract sockets */
if (socket_path[0] != '/' && socket_path[0] != '@')
return -EAFNOSUPPORT;
path_length = strlen(socket_path);
/* Ensure there is room for NUL byte */
if (path_length >= sizeof(socket_addr.sun.sun_path))
return -E2BIG;
memcpy(socket_addr.sun.sun_path, socket_path, path_length);
/* Support for abstract socket */
if (socket_addr.sun.sun_path[0] == '@')
socket_addr.sun.sun_path[0] = 0;
fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
if (fd < 0)
return -errno;
if (connect(fd, &socket_addr.sa, offsetof(struct sockaddr_un, sun_path) + path_length) != 0)
return -errno;
ssize_t written = write(fd, message, message_length);
if (written != (ssize_t) message_length)
return written < 0 ? -errno : -EPROTO;
return 1; /* Notified! */
}
int sd_notify_ready(void) {
return sd_notify("READY=1");
}
int sd_notify_stopping(void) {
return sd_notify("STOPPING=1");
}
|