libvirt/src/util/virvsock.c
Michal Privoznik 95b9db4ee2 lib: Prefer WITH_* prefix for #if conditionals
Currently, we are mixing: #if HAVE_BLAH with #if WITH_BLAH.
Things got way better with Pavel's work on meson, but apparently,
mixing these two lead to confusing and easy to miss bugs (see
31fb929eca for instance). While we were forced to use HAVE_
prefix with autotools, we are free to chose our own prefix with
meson and since WITH_ prefix appears to be more popular let's use
it everywhere.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2020-09-02 10:28:10 +02:00

108 lines
2.5 KiB
C

/*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*
*/
#include <config.h>
#ifdef WITH_SYS_IOCTL_H
# include <sys/ioctl.h>
#endif
#if WITH_DECL_VHOST_VSOCK_SET_GUEST_CID
# include <linux/vhost.h>
#endif
#include "virvsock.h"
#include "virerror.h"
#include "virlog.h"
#define VIR_FROM_THIS VIR_FROM_NONE
VIR_LOG_INIT("util.vsock");
#if WITH_DECL_VHOST_VSOCK_SET_GUEST_CID
static int
virVsockSetGuestCidQuiet(int fd,
unsigned int guest_cid)
{
uint64_t val = guest_cid;
return ioctl(fd, VHOST_VSOCK_SET_GUEST_CID, &val);
}
#else
static int
virVsockSetGuestCidQuiet(int fd G_GNUC_UNUSED,
unsigned int guest_cid G_GNUC_UNUSED)
{
errno = ENOSYS;
return -1;
}
#endif
/**
* virVsockSetGuestCid:
* @fd: file descriptor of a vsock interface
* @guest_cid: guest CID to be set
*
* Wrapper for VHOST_VSOCK_SET_GUEST_CID ioctl.
* Returns: 0 on success, -1 on error.
*/
int
virVsockSetGuestCid(int fd,
unsigned int guest_cid)
{
if (virVsockSetGuestCidQuiet(fd, guest_cid) < 0) {
virReportSystemError(errno, "%s",
_("failed to set guest cid"));
return -1;
}
return 0;
}
#define VIR_VSOCK_GUEST_CID_MIN 3
/**
* virVsockAcquireGuestCid:
* @fd: file descriptor of a vsock interface
* @guest_cid: where to store the guest CID
*
* Iterates over usable CIDs until a free one is found.
* Returns: 0 on success, with the acquired CID stored in guest_cid
* -1 on error.
*/
int
virVsockAcquireGuestCid(int fd,
unsigned int *guest_cid)
{
unsigned int cid = VIR_VSOCK_GUEST_CID_MIN;
for (; virVsockSetGuestCidQuiet(fd, cid) < 0; cid++) {
if (errno != EADDRINUSE) {
virReportSystemError(errno, "%s",
_("failed to acquire guest cid"));
return -1;
}
}
*guest_cid = cid;
return 0;
}