V2: - Move bitmap impl to src/util/bitmap.[ch] - Use CHAR_BIT instead of explicit '8' - Use size_t instead of unsigned int - Fix calculation of bitmap size in virBitmapAlloc - Ensure bit is within range of map in the set, clear, and get operations - Use bool in virBitmapGetBit - Add virBitmapFree to free-like funcs in cfg.mk --- cfg.mk | 1 + src/Makefile.am | 1 + src/libvirt_private.syms | 8 +++ src/util/bitmap.c | 155 ++++++++++++++++++++++++++++++++++++++++++++++ src/util/bitmap.h | 60 ++++++++++++++++++ 5 files changed, 225 insertions(+), 0 deletions(-) create mode 100644 src/util/bitmap.c create mode 100644 src/util/bitmap.h diff --git a/cfg.mk b/cfg.mk index 04719d4..18a83df 100644 --- a/cfg.mk +++ b/cfg.mk @@ -67,6 +67,7 @@ local-checks-to-skip = \ useless_free_options = \ --name=VIR_FREE \ --name=sexpr_free \ + --name=virBitmapFree \ --name=virCPUDefFree \ --name=virCapabilitiesFree \ --name=virCapabilitiesFreeGuest \ diff --git a/src/Makefile.am b/src/Makefile.am index 889de8e..fad1bc4 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -50,6 +50,7 @@ augeastest_DATA = # helper APIs for various purposes UTIL_SOURCES = \ util/authhelper.c util/authhelper.h \ + util/bitmap.c util/bitmap.h \ util/bridge.c util/bridge.h \ util/buf.c util/buf.h \ util/conf.c util/conf.h \ diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index bdeab0f..8149719 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -4,6 +4,14 @@ # +# bitmap.h +virBitmapAlloc; +virBitmapFree; +virBitmapSetBit; +virBitmapClearBit; +virBitmapGetBit; + + # buf.h virBufferVSprintf; virBufferEscapeString; diff --git a/src/util/bitmap.c b/src/util/bitmap.c new file mode 100644 index 0000000..d733373 --- /dev/null +++ b/src/util/bitmap.c @@ -0,0 +1,155 @@ +/* + * bitmap.h: Simple bitmap operations + * + * Copyright (C) 2010 Novell, Inc. + * + * 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, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Jim Fehlig <jfehlig(a)novell.com&gt; + */ + +#include <config.h> + +#include <limits.h> +#include <stdint.h> +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <sys/types.h> + +#include "bitmap.h" +#include "memory.h" + + +struct _virBitmap { + size_t size; + uint32_t *map; +}; + + +#define VIR_BITMAP_BITS_PER_UNIT (sizeof(uint32_t) * CHAR_BIT) +#define VIR_BITMAP_UNIT_OFFSET(b) ((b) / VIR_BITMAP_BITS_PER_UNIT) +#define VIR_BITMAP_BIT_OFFSET(b) ((b) % VIR_BITMAP_BITS_PER_UNIT) + + +/** + * virBitmapAlloc: + * @size: number of bits + * + * Allocate a bitmap capable of containing @size bits. + * + * Returns a pointer to the allocated bitmap or NULL if + * memory cannot be allocated. + */ +virBitmapPtr virBitmapAlloc(size_t size) +{ + virBitmapPtr bitmap; + size_t sz = (size + VIR_BITMAP_BITS_PER_UNIT - 1) / + VIR_BITMAP_BITS_PER_UNIT; + + if (VIR_ALLOC_N(bitmap, sizeof(virBitmap)) < 0) + return NULL; + + if (VIR_ALLOC_N(bitmap->map, sz) < 0) { + VIR_FREE(bitmap); + return NULL; + } + + return bitmap; +} + +/** + * virBitmapFree: + * @bitmap: previously allocated bitmap + * + * Free @bitmap previously allocated by virBitmapAlloc. + */ +void virBitmapFree(virBitmapPtr bitmap) +{ + if (bitmap) { + VIR_FREE(bitmap->map); + VIR_FREE(bitmap); + } +} + +/** + * virBitmapSetBit: + * @bitmap: Pointer to bitmap + * @b: bit position to set + * + * Set bit position @b in @bitmap + * + * Returns 0 on if bit is successfully set, -1 on error. + */ +int virBitmapSetBit(virBitmapPtr bitmap, unsigned int b) +{ + if (bitmap == NULL) + return -1; + + if (b > bitmap->size - 1) + return -1; + + bitmap->map[VIR_BITMAP_UNIT_OFFSET(b)] |= (1 << VIR_BITMAP_BIT_OFFSET(b)); + return 0; +} + +/** + * virBitmapClearBit: + * @bitmap: Pointer to bitmap + * @b: bit position to clear + * + * Clear bit position @b in @bitmap + * + * Returns 0 on if bit is successfully clear, -1 on error. + */ +int virBitmapClearBit(virBitmapPtr bitmap, unsigned int b) +{ + if (bitmap == NULL) + return -1; + + if (b > bitmap->size - 1) + return -1; + + bitmap->map[VIR_BITMAP_UNIT_OFFSET(b)] &= ~(1 << VIR_BITMAP_BIT_OFFSET(b)); + return 0; +} + +/** + * virBitmapGetBit: + * @bitmap: Pointer to bitmap + * @b: bit position to get + * @result: bool pointer to receive bit setting + * + * Get setting of bit position @b in @bitmap and store in @result + * + * On success, @result will contain the setting of @b and 0 is + * returned. On failure, -1 is returned and @result is unchanged. + */ +int virBitmapGetBit(virBitmapPtr bitmap, unsigned int b, bool *result) +{ + uint32_t bit; + + if (bitmap == NULL) + return -1; + + if (b > bitmap->size - 1) + return -1; + + bit = bitmap->map[VIR_BITMAP_UNIT_OFFSET(b)] & + (1 << VIR_BITMAP_BIT_OFFSET(b)); + + *result = bit != 0; + return 0; +} diff --git a/src/util/bitmap.h b/src/util/bitmap.h new file mode 100644 index 0000000..0143b0e --- /dev/null +++ b/src/util/bitmap.h @@ -0,0 +1,60 @@ +/* + * bitmap.h: Simple bitmap operations + * + * Copyright (C) 2010 Novell, Inc. + * + * 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, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Jim Fehlig <jfehlig(a)novell.com&gt; + */ + +#ifndef __BITMAP_H__ +# define __BITMAP_H__ + +#include "internal.h" + +#include <stdbool.h> +#include <sys/types.h> + + +typedef struct _virBitmap virBitmap; +typedef virBitmap *virBitmapPtr; + +/* + * Allocate a bitmap capable of containing @size bits. + */ +virBitmapPtr virBitmapAlloc(size_t size); + +/* + * Free previously allocated bitmap + */ +void virBitmapFree(virBitmapPtr bitmap); + +/* + * Set bit position @b in @bitmap + */ +int virBitmapSetBit(virBitmapPtr bitmap, unsigned int b); + +/* + * Clear bit position @b in @bitmap + */ +int virBitmapClearBit(virBitmapPtr bitmap, unsigned int b); + +/* + * Get setting of bit position @b in @bitmap and store in @result + */ +int virBitmapGetBit(virBitmapPtr bitmap, unsigned int b, bool *result); + +#endif -- 1.6.0.2

--- src/qemu/qemu_driver.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 65ca117..06cf660 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -88,6 +88,9 @@ #define VIR_FROM_THIS VIR_FROM_QEMU +#define QEMU_VNC_PORT_MIN 5900 +#define QEMU_VNC_PORT_MAX 65535 + /* Only 1 job is allowed at any time * A job includes *all* monitor commands, even those just querying * information, not merely actions */ @@ -2632,7 +2635,7 @@ qemuInitPCIAddresses(struct qemud_driver *driver, static int qemudNextFreeVNCPort(struct qemud_driver *driver ATTRIBUTE_UNUSED) { int i; - for (i = 5900 ; i < 65535 ; i++) { + for (i = QEMU_VNC_PORT_MIN; i < QEMU_VNC_PORT_MAX; i++) { int fd; int reuse = 1; struct sockaddr_in addr; -- 1.6.0.2

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 --- src/qemu/qemu_conf.h | 3 +++ src/qemu/qemu_driver.c | 34 ++++++++++++++++++++++++++++++++-- 2 files changed, 35 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h index a101e47..d7d4c57 100644 --- a/src/qemu/qemu_conf.h +++ b/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; diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 06cf660..01867db 100644 --- a/src/qemu/qemu_driver.c +++ b/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); @@ -2632,13 +2638,19 @@ qemuInitPCIAddresses(struct qemud_driver *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; + + virBitmapGetBit(driver->reservedVNCPorts, i - QEMU_VNC_PORT_MIN, &used); + if (used) + continue; + addr.sin_family = AF_INET; addr.sin_port = htons(i); addr.sin_addr.s_addr = htonl(INADDR_ANY); @@ -2654,6 +2666,8 @@ static int qemudNextFreeVNCPort(struct qemud_driver *driver ATTRIBUTE_UNUSED) { if (bind(fd, (struct sockaddr*)&addr, sizeof(addr)) == 0) { /* Not in use, lets grab it */ close(fd); + /* Add port to bitmap of reserved ports */ + virBitmapSetBit(driver->reservedVNCPorts, i - QEMU_VNC_PORT_MIN); return i; } close(fd); @@ -3582,8 +3596,13 @@ cleanup: qemuRemoveCgroup(driver, vm, 1); 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.autoport) { + virBitmapClearBit(driver->reservedVNCPorts, + vm->def->graphics[0]->data.vnc.port - \ + QEMU_VNC_PORT_MIN); vm->def->graphics[0]->data.vnc.port = -1; + } + if (logfile != -1) close(logfile); vm->def->id = -1; @@ -3716,6 +3735,17 @@ 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) { + virBitmapClearBit(driver->reservedVNCPorts, + vm->def->graphics[0]->data.vnc.port - \ + QEMU_VNC_PORT_MIN); + } + vm->pid = -1; vm->def->id = -1; vm->state = VIR_DOMAIN_SHUTOFF; -- 1.6.0.2