Files
xen/tools/include/xen-sd-notify.h
T
Andrew Cooper 8efff5a69a tools/sd-notify.h: Include string.h too
Alpine Linux, when using --enable-systemd to get the init files, fails with:

  tools/include/xen-sd-notify.h:69:3: error: call to undeclared library
  function 'memcpy' with type 'void *(void *, const void *, unsigned long)';
  ISO C99 and later do not support implicit function declarations
  [-Wimplicit-function-declaration]
     69 |   memcpy(socket_addr.sun.sun_path, socket_path, path_length);
        |   ^

This will be down to using musl rather than glibc.  Include the appropriate
header.

Fixes: 78510f3a15 ("tools: Import stand-alone sd_notify() implementation from systemd")
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Anthony PERARD <anthony.perard@vates.tech>
2025-12-12 03:04:48 +00:00

100 lines
2.5 KiB
C

/* 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/
*
* Differences from the upstream copy:
* - Rename/rework as a drop-in replacement for systemd/sd-daemon.h
* - Only take the subset Xen cares about
* - Respect -Wdeclaration-after-statement
*/
#ifndef XEN_SD_NOTIFY
#define XEN_SD_NOTIFY
#include <errno.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
static inline void xen_sd_closep(int *fd) {
if (!fd || *fd < 0)
return;
close(*fd);
*fd = -1;
}
static inline int xen_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;
ssize_t written;
const char *socket_path;
int __attribute__((cleanup(xen_sd_closep))) fd = -1;
/* 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;
written = write(fd, message, message_length);
if (written != (ssize_t) message_length)
return written < 0 ? -errno : -EPROTO;
return 1; /* Notified! */
}
static inline int sd_notify(int unset_environment, const char *message) {
int r = xen_sd_notify(message);
if (unset_environment)
unsetenv("NOTIFY_SOCKET");
return r;
}
#endif /* XEN_SD_NOTIFY */