mirror of
https://gitlab.com/qemu-project/qemu
synced 2024-09-06 18:05:37 +00:00
![Eric Blake](/assets/img/avatar_default.png)
Blindly setting FD_CLOEXEC without a read-modify-write will inadvertently clear any other intentionally-set bits, such as a proposed new bit for designating a fd that must behave in 32-bit mode. However, we cannot use our wrapper qemu_set_cloexec(), because that wrapper intentionally abort()s on failure, whereas the probe here intentionally tolerates failure to deal with incorrect socket activation gracefully. Instead, fix the code to do the proper read-modify-write. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200420175309.75894-3-eblake@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
80 lines
1.9 KiB
C
80 lines
1.9 KiB
C
/*
|
|
* systemd socket activation support
|
|
*
|
|
* Copyright 2017 Red Hat, Inc. and/or its affiliates
|
|
*
|
|
* Authors:
|
|
* Richard W.M. Jones <rjones@redhat.com>
|
|
*
|
|
* This work is licensed under the terms of the GNU GPL, version 2 or later.
|
|
* See the COPYING file in the top-level directory.
|
|
*/
|
|
|
|
#include "qemu/osdep.h"
|
|
#include "qemu/systemd.h"
|
|
#include "qemu/cutils.h"
|
|
#include "qemu/error-report.h"
|
|
|
|
#ifndef _WIN32
|
|
unsigned int check_socket_activation(void)
|
|
{
|
|
const char *s;
|
|
unsigned long pid;
|
|
unsigned long nr_fds;
|
|
unsigned int i;
|
|
int fd;
|
|
int f;
|
|
int err;
|
|
|
|
s = getenv("LISTEN_PID");
|
|
if (s == NULL) {
|
|
return 0;
|
|
}
|
|
err = qemu_strtoul(s, NULL, 10, &pid);
|
|
if (err) {
|
|
return 0;
|
|
}
|
|
if (pid != getpid()) {
|
|
return 0;
|
|
}
|
|
|
|
s = getenv("LISTEN_FDS");
|
|
if (s == NULL) {
|
|
return 0;
|
|
}
|
|
err = qemu_strtoul(s, NULL, 10, &nr_fds);
|
|
if (err) {
|
|
return 0;
|
|
}
|
|
assert(nr_fds <= UINT_MAX);
|
|
|
|
/* So these are not passed to any child processes we might start. */
|
|
unsetenv("LISTEN_FDS");
|
|
unsetenv("LISTEN_PID");
|
|
|
|
/* So the file descriptors don't leak into child processes. */
|
|
for (i = 0; i < nr_fds; ++i) {
|
|
fd = FIRST_SOCKET_ACTIVATION_FD + i;
|
|
f = fcntl(fd, F_GETFD);
|
|
if (f == -1 || fcntl(fd, F_SETFD, f | FD_CLOEXEC) == -1) {
|
|
/* If we cannot set FD_CLOEXEC then it probably means the file
|
|
* descriptor is invalid, so socket activation has gone wrong
|
|
* and we should exit.
|
|
*/
|
|
error_report("Socket activation failed: "
|
|
"invalid file descriptor fd = %d: %s",
|
|
fd, g_strerror(errno));
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
}
|
|
|
|
return (unsigned int) nr_fds;
|
|
}
|
|
|
|
#else /* !_WIN32 */
|
|
unsigned int check_socket_activation(void)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|