6:47 a.m.
From: Chen Hanxiao <chenhanxiao(a)gmail.com>
We may overwrite existed save image by
'virsh save' command.
This patch will check qemu save headers
before trying to rewrite it.
Signed-off-by: Chen Hanxiao <chenhanxiao(a)gmail.com>
---
src/qemu/qemu_driver.c | 141 +++++++++++++++++++++++++++++++------------------
1 file changed, 89 insertions(+), 52 deletions(-)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index a0ac2ef..56aa079 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -2806,6 +2806,73 @@ bswap_header(virQEMUSaveHeaderPtr hdr)
}
+static int
+qemuSaveHeaderCheck(int fd,
+ virQEMUSaveHeaderPtr header,
+ const char *path,
+ bool unlink_corrupt)
+{
+ int ret = -1;
+
+ if (saferead(fd, header, sizeof(*header)) != sizeof(*header)) {
+ if (unlink_corrupt) {
+ if (VIR_CLOSE(fd) < 0 || unlink(path) < 0) {
+ virReportSystemError(errno,
+ _("cannot remove corrupt file: %s"),
+ path);
+ goto error;
+ }
+ return -3;
+ }
+ virReportError(VIR_ERR_OPERATION_FAILED,
+ "%s", _("failed to read qemu header"));
+ goto error;
+ }
+
+ if (memcmp((*header).magic, QEMU_SAVE_MAGIC, sizeof((*header).magic)) != 0) {
+ const char *msg = _("image magic is incorrect");
+
+ if (memcmp((*header).magic, QEMU_SAVE_PARTIAL,
+ sizeof((*header).magic)) == 0) {
+ msg = _("save image is incomplete");
+ if (unlink_corrupt) {
+ if (VIR_CLOSE(fd) < 0 || unlink(path) < 0) {
+ virReportSystemError(errno,
+ _("cannot remove corrupt file: %s"),
+ path);
+ goto error;
+ }
+ return -3;
+ }
+ }
+ virReportError(VIR_ERR_OPERATION_FAILED, "%s", msg);
+ goto error;
+ }
+
+ if ((*header).version > QEMU_SAVE_VERSION) {
+ /* convert endianess and try again */
+ bswap_header(header);
+ }
+
+ if ((*header).version > QEMU_SAVE_VERSION) {
+ virReportError(VIR_ERR_OPERATION_FAILED,
+ _("image version is not supported (%d > %d)"),
+ (*header).version, QEMU_SAVE_VERSION);
+ goto error;
+ }
+
+ if ((*header).xml_len <= 0) {
+ virReportError(VIR_ERR_OPERATION_FAILED,
+ _("invalid XML length: %d"), (*header).xml_len);
+ goto error;
+ }
+
+ ret = 0;
+
+ error:
+ return ret;
+}
+
/* return -errno on failure, or 0 on success */
static int
qemuDomainSaveHeader(int fd, const char *path, const char *xml,
@@ -2827,6 +2894,7 @@ qemuDomainSaveHeader(int fd, const char *path, const char *xml,
_("failed to write xml to '%s'"), path);
goto endjob;
}
+
endjob:
return ret;
}
@@ -3067,6 +3135,24 @@ qemuDomainSaveMemory(virQEMUDriverPtr driver,
goto cleanup;
}
}
+
+ /* don't overwrite exsited save files */
+ if (virFileExists(path)) {
+ virQEMUSaveHeader header_tmp;
+ fd = qemuOpenFile(driver, NULL, path, O_RDONLY, NULL, NULL);
+ if (fd < 0)
+ goto cleanup;
+
+ if (qemuSaveHeaderCheck(fd, &header_tmp, path, false) >= 0) {
+ ret = -EEXIST;
+ virReportError(VIR_ERR_OPERATION_FAILED,
+ _("failed to write existed image file
'%s'"),
+ path);
+ goto cleanup;
+ }
+ VIR_FORCE_CLOSE(fd);
+ }
+
fd = qemuOpenFile(driver, vm, path,
O_WRONLY | O_TRUNC | O_CREAT | directFlag,
&needUnlink, &bypassSecurityDriver);
@@ -6327,6 +6413,7 @@ qemuDomainSaveImageOpen(virQEMUDriverPtr driver,
bool unlink_corrupt)
{
int fd = -1;
+ int ret = -1;
virQEMUSaveHeader header;
char *xml = NULL;
virDomainDefPtr def = NULL;
@@ -6353,58 +6440,8 @@ qemuDomainSaveImageOpen(virQEMUDriverPtr driver,
VIR_FILE_WRAPPER_BYPASS_CACHE)))
goto error;
- if (saferead(fd, &header, sizeof(header)) != sizeof(header)) {
- if (unlink_corrupt) {
- if (VIR_CLOSE(fd) < 0 || unlink(path) < 0) {
- virReportSystemError(errno,
- _("cannot remove corrupt file: %s"),
- path);
- goto error;
- }
- return -3;
- }
- virReportError(VIR_ERR_OPERATION_FAILED,
- "%s", _("failed to read qemu header"));
+ if ((ret = qemuSaveHeaderCheck(fd, &header, path, unlink_corrupt)) < 0)
goto error;
- }
-
- if (memcmp(header.magic, QEMU_SAVE_MAGIC, sizeof(header.magic)) != 0) {
- const char *msg = _("image magic is incorrect");
-
- if (memcmp(header.magic, QEMU_SAVE_PARTIAL,
- sizeof(header.magic)) == 0) {
- msg = _("save image is incomplete");
- if (unlink_corrupt) {
- if (VIR_CLOSE(fd) < 0 || unlink(path) < 0) {
- virReportSystemError(errno,
- _("cannot remove corrupt file: %s"),
- path);
- goto error;
- }
- return -3;
- }
- }
- virReportError(VIR_ERR_OPERATION_FAILED, "%s", msg);
- goto error;
- }
-
- if (header.version > QEMU_SAVE_VERSION) {
- /* convert endianess and try again */
- bswap_header(&header);
- }
-
- if (header.version > QEMU_SAVE_VERSION) {
- virReportError(VIR_ERR_OPERATION_FAILED,
- _("image version is not supported (%d > %d)"),
- header.version, QEMU_SAVE_VERSION);
- goto error;
- }
-
- if (header.xml_len <= 0) {
- virReportError(VIR_ERR_OPERATION_FAILED,
- _("invalid XML length: %d"), header.xml_len);
- goto error;
- }
if (VIR_ALLOC_N(xml, header.xml_len) < 0)
goto error;
@@ -6439,7 +6476,7 @@ qemuDomainSaveImageOpen(virQEMUDriverPtr driver,
VIR_FORCE_CLOSE(fd);
virObjectUnref(caps);
- return -1;
+ return ret;
}
static int ATTRIBUTE_NONNULL(4) ATTRIBUTE_NONNULL(5) ATTRIBUTE_NONNULL(6)
--
1.8.3.1