forked from pool/libvirt
131 lines
4.6 KiB
Diff
131 lines
4.6 KiB
Diff
commit ba196952f57f2cb22be75fa5a4f363035a111103
|
|
Author: Jim Fehlig <jfehlig@novell.com>
|
|
Date: Fri May 21 07:52:09 2010 -0600
|
|
|
|
Fix race in finding available vnc port
|
|
|
|
The qemu driver contains a subtle race in the logic to find next
|
|
available vnc port. Currently it iterates through all available ports
|
|
and returns the first for which bind(2) succeeds. However it is possible
|
|
that a previously issued port has not yet been bound by qemu, resulting
|
|
in the same port used for a subsequent domain.
|
|
|
|
This patch addresses the race by using a simple bitmap to "reserve" the
|
|
ports allocated by libvirt.
|
|
|
|
V2:
|
|
- Put port bitmap in struct qemud_driver
|
|
- Initialize bitmap in qemudStartup
|
|
|
|
V3:
|
|
- Check for failure of virBitmapGetBit
|
|
- Additional check for port != -1 before calling virbitmapClearBit
|
|
|
|
V4:
|
|
- Check for failure of virBitmap{Set,Clear}Bit
|
|
|
|
Index: libvirt-0.8.1/src/qemu/qemu_conf.h
|
|
===================================================================
|
|
--- libvirt-0.8.1.orig/src/qemu/qemu_conf.h
|
|
+++ libvirt-0.8.1/src/qemu/qemu_conf.h
|
|
@@ -39,6 +39,7 @@
|
|
# include "pci.h"
|
|
# include "cpu_conf.h"
|
|
# include "driver.h"
|
|
+# include "bitmap.h"
|
|
|
|
# define qemudDebug(fmt, ...) do {} while(0)
|
|
|
|
@@ -153,6 +154,8 @@ struct qemud_driver {
|
|
char *saveImageFormat;
|
|
|
|
pciDeviceList *activePciHostdevs;
|
|
+
|
|
+ virBitmapPtr reservedVNCPorts;
|
|
};
|
|
|
|
typedef struct _qemuDomainPCIAddressSet qemuDomainPCIAddressSet;
|
|
Index: libvirt-0.8.1/src/qemu/qemu_driver.c
|
|
===================================================================
|
|
--- libvirt-0.8.1.orig/src/qemu/qemu_driver.c
|
|
+++ libvirt-0.8.1/src/qemu/qemu_driver.c
|
|
@@ -1479,6 +1479,11 @@ qemudStartup(int privileged) {
|
|
virEventAddTimeout(-1, qemuDomainEventFlush, qemu_driver, NULL)) < 0)
|
|
goto error;
|
|
|
|
+ /* Allocate bitmap for vnc port reservation */
|
|
+ if ((qemu_driver->reservedVNCPorts =
|
|
+ virBitmapAlloc(QEMU_VNC_PORT_MAX - QEMU_VNC_PORT_MIN)) == NULL)
|
|
+ goto out_of_memory;
|
|
+
|
|
if (privileged) {
|
|
if (virAsprintf(&qemu_driver->logDir,
|
|
"%s/log/libvirt/qemu", LOCAL_STATE_DIR) == -1)
|
|
@@ -1775,6 +1780,7 @@ qemudShutdown(void) {
|
|
virCapabilitiesFree(qemu_driver->caps);
|
|
|
|
virDomainObjListDeinit(&qemu_driver->domains);
|
|
+ virBitmapFree(qemu_driver->reservedVNCPorts);
|
|
|
|
VIR_FREE(qemu_driver->securityDriverName);
|
|
VIR_FREE(qemu_driver->logDir);
|
|
@@ -2607,13 +2613,22 @@ qemuInitPCIAddresses(struct qemud_driver
|
|
return ret;
|
|
}
|
|
|
|
-static int qemudNextFreeVNCPort(struct qemud_driver *driver ATTRIBUTE_UNUSED) {
|
|
+static int qemudNextFreeVNCPort(struct qemud_driver *driver) {
|
|
int i;
|
|
|
|
for (i = QEMU_VNC_PORT_MIN; i < QEMU_VNC_PORT_MAX; i++) {
|
|
int fd;
|
|
int reuse = 1;
|
|
struct sockaddr_in addr;
|
|
+ bool used = false;
|
|
+
|
|
+ if (virBitmapGetBit(driver->reservedVNCPorts,
|
|
+ i - QEMU_VNC_PORT_MIN, &used) < 0)
|
|
+ VIR_DEBUG("virBitmapGetBit failed on bit %d", i - QEMU_VNC_PORT_MIN);
|
|
+
|
|
+ if (used)
|
|
+ continue;
|
|
+
|
|
addr.sin_family = AF_INET;
|
|
addr.sin_port = htons(i);
|
|
addr.sin_addr.s_addr = htonl(INADDR_ANY);
|
|
@@ -2629,6 +2644,12 @@ static int qemudNextFreeVNCPort(struct q
|
|
if (bind(fd, (struct sockaddr*)&addr, sizeof(addr)) == 0) {
|
|
/* Not in use, lets grab it */
|
|
close(fd);
|
|
+ /* Add port to bitmap of reserved ports */
|
|
+ if (virBitmapSetBit(driver->reservedVNCPorts,
|
|
+ i - QEMU_VNC_PORT_MIN) < 0) {
|
|
+ VIR_DEBUG("virBitmapSetBit failed on bit %d",
|
|
+ i - QEMU_VNC_PORT_MIN);
|
|
+ }
|
|
return i;
|
|
}
|
|
close(fd);
|
|
@@ -3608,6 +3629,21 @@ retry:
|
|
|
|
qemudRemoveDomainStatus(driver, vm);
|
|
|
|
+ /* Remove VNC port from port reservation bitmap, but only if it was
|
|
+ reserved by the driver (autoport=yes)
|
|
+ */
|
|
+ if ((vm->def->ngraphics == 1) &&
|
|
+ vm->def->graphics[0]->type == VIR_DOMAIN_GRAPHICS_TYPE_VNC &&
|
|
+ vm->def->graphics[0]->data.vnc.autoport &&
|
|
+ vm->def->graphics[0]->data.vnc.port != -1) {
|
|
+ if (virBitmapClearBit(driver->reservedVNCPorts,
|
|
+ vm->def->graphics[0]->data.vnc.port - \
|
|
+ QEMU_VNC_PORT_MIN) < 0) {
|
|
+ VIR_DEBUG("virBitmapClearBit failed on bit %d",
|
|
+ vm->def->graphics[0]->data.vnc.port - QEMU_VNC_PORT_MIN);
|
|
+ }
|
|
+ }
|
|
+
|
|
vm->pid = -1;
|
|
vm->def->id = -1;
|
|
vm->state = VIR_DOMAIN_SHUTOFF;
|