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b7d1bee2b9
libvirt/src/util/virstoragefile.c
Peter Krempa b7d1bee2b9 storage: rbd: Implement support for passing config file option 
To be able to express some use cases of the RBD backing with libvirt, we
need to be able to specify a config file for the RBD client to qemu as
that is one of the commonly used options.
2014-11-21 14:37:03 +01:00

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/*
* virstoragefile.c: file utility functions for FS storage backend
*
* Copyright (C) 2007-2014 Red Hat, Inc.
* Copyright (C) 2007-2008 Daniel P. Berrange
*
* 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/>.
*
* Author: Daniel P. Berrange <berrange@redhat.com>
*/
#include <config.h>
#include "virstoragefile.h"
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include "viralloc.h"
#include "virxml.h"
#include "viruuid.h"
#include "virerror.h"
#include "virlog.h"
#include "virfile.h"
#include "c-ctype.h"
#include "vircommand.h"
#include "virhash.h"
#include "virendian.h"
#include "virstring.h"
#include "virutil.h"
#include "viruri.h"
#include "dirname.h"
#include "virbuffer.h"
#if HAVE_SYS_SYSCALL_H
# include <sys/syscall.h>
#endif
#define VIR_FROM_THIS VIR_FROM_STORAGE
VIR_LOG_INIT("util.storagefile");
VIR_ENUM_IMPL(virStorage, VIR_STORAGE_TYPE_LAST,
"none",
"file",
"block",
"dir",
"network",
"volume")
VIR_ENUM_IMPL(virStorageFileFormat,
VIR_STORAGE_FILE_LAST,
"none",
"raw", "dir", "bochs",
"cloop", "dmg", "iso",
"vpc", "vdi",
/* Not direct file formats, but used for various drivers */
"fat", "vhd", "ploop",
/* Formats with backing file below here */
"cow", "qcow", "qcow2", "qed", "vmdk")
VIR_ENUM_IMPL(virStorageFileFeature,
VIR_STORAGE_FILE_FEATURE_LAST,
"lazy_refcounts",
)
VIR_ENUM_IMPL(virStorageNetProtocol, VIR_STORAGE_NET_PROTOCOL_LAST,
"none",
"nbd",
"rbd",
"sheepdog",
"gluster",
"iscsi",
"http",
"https",
"ftp",
"ftps",
"tftp")
VIR_ENUM_IMPL(virStorageNetHostTransport, VIR_STORAGE_NET_HOST_TRANS_LAST,
"tcp",
"unix",
"rdma")
VIR_ENUM_IMPL(virStorageSourcePoolMode,
VIR_STORAGE_SOURCE_POOL_MODE_LAST,
"default",
"host",
"direct")
VIR_ENUM_IMPL(virStorageAuth,
VIR_STORAGE_AUTH_TYPE_LAST,
"none", "chap", "ceph")
enum lv_endian {
LV_LITTLE_ENDIAN = 1, /* 1234 */
LV_BIG_ENDIAN /* 4321 */
};
enum {
BACKING_STORE_OK,
BACKING_STORE_INVALID,
BACKING_STORE_ERROR,
};
#define FILE_TYPE_VERSIONS_LAST 2
/* Either 'magic' or 'extension' *must* be provided */
struct FileTypeInfo {
int magicOffset; /* Byte offset of the magic */
const char *magic; /* Optional string of file magic
* to check at head of file */
const char *extension; /* Optional file extension to check */
enum lv_endian endian; /* Endianness of file format */
int versionOffset; /* Byte offset from start of file
* where we find version number,
* -1 to always fail the version test,
* -2 to always pass the version test */
int versionNumbers[FILE_TYPE_VERSIONS_LAST];
/* Version numbers to validate. Zeroes are ignored. */
int sizeOffset; /* Byte offset from start of file
* where we find capacity info,
* -1 to use st_size as capacity */
int sizeBytes; /* Number of bytes for size field */
int sizeMultiplier; /* A scaling factor if size is not in bytes */
/* Store a COW base image path (possibly relative),
* or NULL if there is no COW base image, to RES;
* return BACKING_STORE_* */
int qcowCryptOffset; /* Byte offset from start of file
* where to find encryption mode,
* -1 if encryption is not used */
int (*getBackingStore)(char **res, int *format,
const char *buf, size_t buf_size);
int (*getFeatures)(virBitmapPtr *features, int format,
char *buf, ssize_t len);
};
static int cowGetBackingStore(char **, int *,
const char *, size_t);
static int qcow1GetBackingStore(char **, int *,
const char *, size_t);
static int qcow2GetBackingStore(char **, int *,
const char *, size_t);
static int qcow2GetFeatures(virBitmapPtr *features, int format,
char *buf, ssize_t len);
static int vmdk4GetBackingStore(char **, int *,
const char *, size_t);
static int
qedGetBackingStore(char **, int *, const char *, size_t);
#define QCOWX_HDR_VERSION (4)
#define QCOWX_HDR_BACKING_FILE_OFFSET (QCOWX_HDR_VERSION+4)
#define QCOWX_HDR_BACKING_FILE_SIZE (QCOWX_HDR_BACKING_FILE_OFFSET+8)
#define QCOWX_HDR_IMAGE_SIZE (QCOWX_HDR_BACKING_FILE_SIZE+4+4)
#define QCOW1_HDR_CRYPT (QCOWX_HDR_IMAGE_SIZE+8+1+1)
#define QCOW2_HDR_CRYPT (QCOWX_HDR_IMAGE_SIZE+8)
#define QCOW1_HDR_TOTAL_SIZE (QCOW1_HDR_CRYPT+4+8)
#define QCOW2_HDR_TOTAL_SIZE (QCOW2_HDR_CRYPT+4+4+8+8+4+4+8)
#define QCOW2_HDR_EXTENSION_END 0
#define QCOW2_HDR_EXTENSION_BACKING_FORMAT 0xE2792ACA
#define QCOW2v3_HDR_FEATURES_INCOMPATIBLE (QCOW2_HDR_TOTAL_SIZE)
#define QCOW2v3_HDR_FEATURES_COMPATIBLE (QCOW2v3_HDR_FEATURES_INCOMPATIBLE+8)
#define QCOW2v3_HDR_FEATURES_AUTOCLEAR (QCOW2v3_HDR_FEATURES_COMPATIBLE+8)
/* The location of the header size [4 bytes] */
#define QCOW2v3_HDR_SIZE (QCOW2_HDR_TOTAL_SIZE+8+8+8+4)
#define QED_HDR_FEATURES_OFFSET (4+4+4+4)
#define QED_HDR_IMAGE_SIZE (QED_HDR_FEATURES_OFFSET+8+8+8+8)
#define QED_HDR_BACKING_FILE_OFFSET (QED_HDR_IMAGE_SIZE+8)
#define QED_HDR_BACKING_FILE_SIZE (QED_HDR_BACKING_FILE_OFFSET+4)
#define QED_F_BACKING_FILE 0x01
#define QED_F_BACKING_FORMAT_NO_PROBE 0x04
static struct FileTypeInfo const fileTypeInfo[] = {
[VIR_STORAGE_FILE_NONE] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
-1, {0}, 0, 0, 0, 0, NULL, NULL },
[VIR_STORAGE_FILE_RAW] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
-1, {0}, 0, 0, 0, 0, NULL, NULL },
[VIR_STORAGE_FILE_DIR] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
-1, {0}, 0, 0, 0, 0, NULL, NULL },
[VIR_STORAGE_FILE_BOCHS] = {
/*"Bochs Virtual HD Image", */ /* Untested */
0, NULL, NULL,
LV_LITTLE_ENDIAN, 64, {0x20000},
32+16+16+4+4+4+4+4, 8, 1, -1, NULL, NULL
},
[VIR_STORAGE_FILE_CLOOP] = {
/* #!/bin/sh
#V2.0 Format
modprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1
*/ /* Untested */
0, NULL, NULL,
LV_LITTLE_ENDIAN, -1, {0},
-1, 0, 0, -1, NULL, NULL
},
[VIR_STORAGE_FILE_DMG] = {
/* XXX QEMU says there's no magic for dmg,
* /usr/share/misc/magic lists double magic (both offsets
* would have to match) but then disables that check. */
0, NULL, ".dmg",
0, -1, {0},
-1, 0, 0, -1, NULL, NULL
},
[VIR_STORAGE_FILE_ISO] = {
32769, "CD001", ".iso",
LV_LITTLE_ENDIAN, -2, {0},
-1, 0, 0, -1, NULL, NULL
},
[VIR_STORAGE_FILE_VPC] = {
0, "conectix", NULL,
LV_BIG_ENDIAN, 12, {0x10000},
8 + 4 + 4 + 8 + 4 + 4 + 2 + 2 + 4, 8, 1, -1, NULL, NULL
},
/* TODO: add getBackingStore function */
[VIR_STORAGE_FILE_VDI] = {
64, "\x7f\x10\xda\xbe", ".vdi",
LV_LITTLE_ENDIAN, 68, {0x00010001},
64 + 5 * 4 + 256 + 7 * 4, 8, 1, -1, NULL, NULL},
/* Not direct file formats, but used for various drivers */
[VIR_STORAGE_FILE_FAT] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
-1, {0}, 0, 0, 0, 0, NULL, NULL },
[VIR_STORAGE_FILE_VHD] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
-1, {0}, 0, 0, 0, 0, NULL, NULL },
[VIR_STORAGE_FILE_PLOOP] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
-1, {0}, 0, 0, 0, 0, NULL, NULL },
/* All formats with a backing store probe below here */
[VIR_STORAGE_FILE_COW] = {
0, "OOOM", NULL,
LV_BIG_ENDIAN, 4, {2},
4+4+1024+4, 8, 1, -1, cowGetBackingStore, NULL
},
[VIR_STORAGE_FILE_QCOW] = {
0, "QFI", NULL,
LV_BIG_ENDIAN, 4, {1},
QCOWX_HDR_IMAGE_SIZE, 8, 1, QCOW1_HDR_CRYPT, qcow1GetBackingStore, NULL
},
[VIR_STORAGE_FILE_QCOW2] = {
0, "QFI", NULL,
LV_BIG_ENDIAN, 4, {2, 3},
QCOWX_HDR_IMAGE_SIZE, 8, 1, QCOW2_HDR_CRYPT, qcow2GetBackingStore,
qcow2GetFeatures
},
[VIR_STORAGE_FILE_QED] = {
/* http://wiki.qemu.org/Features/QED */
0, "QED", NULL,
LV_LITTLE_ENDIAN, -2, {0},
QED_HDR_IMAGE_SIZE, 8, 1, -1, qedGetBackingStore, NULL
},
[VIR_STORAGE_FILE_VMDK] = {
0, "KDMV", NULL,
LV_LITTLE_ENDIAN, 4, {1, 2},
4+4+4, 8, 512, -1, vmdk4GetBackingStore, NULL
},
};
verify(ARRAY_CARDINALITY(fileTypeInfo) == VIR_STORAGE_FILE_LAST);
/* qcow2 compatible features in the order they appear on-disk */
enum qcow2CompatibleFeature {
QCOW2_COMPATIBLE_FEATURE_LAZY_REFCOUNTS = 0,
QCOW2_COMPATIBLE_FEATURE_LAST
};
/* conversion to virStorageFileFeature */
static const int qcow2CompatibleFeatureArray[] = {
VIR_STORAGE_FILE_FEATURE_LAZY_REFCOUNTS,
};
verify(ARRAY_CARDINALITY(qcow2CompatibleFeatureArray) ==
QCOW2_COMPATIBLE_FEATURE_LAST);
static int
cowGetBackingStore(char **res,
int *format,
const char *buf,
size_t buf_size)
{
#define COW_FILENAME_MAXLEN 1024
*res = NULL;
*format = VIR_STORAGE_FILE_AUTO;
if (buf_size < 4+4+ COW_FILENAME_MAXLEN)
return BACKING_STORE_INVALID;
if (buf[4+4] == '\0') { /* cow_header_v2.backing_file[0] */
*format = VIR_STORAGE_FILE_NONE;
return BACKING_STORE_OK;
}
if (VIR_STRNDUP(*res, (const char*)buf + 4 + 4, COW_FILENAME_MAXLEN) < 0)
return BACKING_STORE_ERROR;
return BACKING_STORE_OK;
}
static int
qcow2GetBackingStoreFormat(int *format,
const char *buf,
size_t buf_size,
size_t extension_start,
size_t extension_end)
{
size_t offset = extension_start;
/*
* The extensions take format of
*
* int32: magic
* int32: length
* byte[length]: payload
*
* Unknown extensions can be ignored by skipping
* over "length" bytes in the data stream.
*/
while (offset < (buf_size-8) &&
offset < (extension_end-8)) {
unsigned int magic = virReadBufInt32BE(buf + offset);
unsigned int len = virReadBufInt32BE(buf + offset + 4);
offset += 8;
if ((offset + len) < offset)
break;
if ((offset + len) > buf_size)
break;
switch (magic) {
case QCOW2_HDR_EXTENSION_END:
goto done;
case QCOW2_HDR_EXTENSION_BACKING_FORMAT:
if (buf[offset+len] != '\0')
break;
*format = virStorageFileFormatTypeFromString(
((const char *)buf)+offset);
if (*format <= VIR_STORAGE_FILE_NONE)
return -1;
}
offset += len;
}
done:
return 0;
}
static int
qcowXGetBackingStore(char **res,
int *format,
const char *buf,
size_t buf_size,
bool isQCow2)
{
unsigned long long offset;
unsigned int size;
unsigned long long start;
int version;
*res = NULL;
if (format)
*format = VIR_STORAGE_FILE_AUTO;
if (buf_size < QCOWX_HDR_BACKING_FILE_OFFSET+8+4)
return BACKING_STORE_INVALID;
offset = virReadBufInt64BE(buf + QCOWX_HDR_BACKING_FILE_OFFSET);
if (offset > buf_size)
return BACKING_STORE_INVALID;
if (offset == 0) {
if (format)
*format = VIR_STORAGE_FILE_NONE;
return BACKING_STORE_OK;
}
size = virReadBufInt32BE(buf + QCOWX_HDR_BACKING_FILE_SIZE);
if (size == 0) {
if (format)
*format = VIR_STORAGE_FILE_NONE;
return BACKING_STORE_OK;
}
if (size > 1023)
return BACKING_STORE_INVALID;
if (offset + size > buf_size || offset + size < offset)
return BACKING_STORE_INVALID;
if (VIR_ALLOC_N(*res, size + 1) < 0)
return BACKING_STORE_ERROR;
memcpy(*res, buf + offset, size);
(*res)[size] = '\0';
/*
* Traditionally QCow2 files had a layout of
*
* [header]
* [backingStoreName]
*
* Although the backingStoreName typically followed
* the header immediately, this was not required by
* the format. By specifying a higher byte offset for
* the backing file offset in the header, it was
* possible to leave space between the header and
* start of backingStore.
*
* This hack is now used to store extensions to the
* qcow2 format:
*
* [header]
* [extensions]
* [backingStoreName]
*
* Thus the file region to search for extensions is
* between the end of the header (QCOW2_HDR_TOTAL_SIZE)
* and the start of the backingStoreName (offset)
*
* for qcow2 v3 images, the length of the header
* is stored at QCOW2v3_HDR_SIZE
*/
if (isQCow2 && format) {
version = virReadBufInt32BE(buf + QCOWX_HDR_VERSION);
if (version == 2)
start = QCOW2_HDR_TOTAL_SIZE;
else
start = virReadBufInt32BE(buf + QCOW2v3_HDR_SIZE);
if (qcow2GetBackingStoreFormat(format, buf, buf_size,
start, offset) < 0)
return BACKING_STORE_INVALID;
}
return BACKING_STORE_OK;
}
static int
qcow1GetBackingStore(char **res,
int *format,
const char *buf,
size_t buf_size)
{
int ret;
/* QCow1 doesn't have the extensions capability
* used to store backing format */
*format = VIR_STORAGE_FILE_AUTO;
ret = qcowXGetBackingStore(res, NULL, buf, buf_size, false);
if (ret == 0 && *buf == '\0')
*format = VIR_STORAGE_FILE_NONE;
return ret;
}
static int
qcow2GetBackingStore(char **res,
int *format,
const char *buf,
size_t buf_size)
{
return qcowXGetBackingStore(res, format, buf, buf_size, true);
}
static int
vmdk4GetBackingStore(char **res,
int *format,
const char *buf,
size_t buf_size)
{
static const char prefix[] = "parentFileNameHint=\"";
char *desc, *start, *end;
size_t len;
int ret = BACKING_STORE_ERROR;
if (VIR_ALLOC_N(desc, VIR_STORAGE_MAX_HEADER) < 0)
goto cleanup;
*res = NULL;
/*
* Technically this should have been VMDK, since
* VMDK spec / VMWare impl only support VMDK backed
* by VMDK. QEMU isn't following this though and
* does probing on VMDK backing files, hence we set
* AUTO
*/
*format = VIR_STORAGE_FILE_AUTO;
if (buf_size <= 0x200) {
ret = BACKING_STORE_INVALID;
goto cleanup;
}
len = buf_size - 0x200;
if (len > VIR_STORAGE_MAX_HEADER)
len = VIR_STORAGE_MAX_HEADER;
memcpy(desc, buf + 0x200, len);
desc[len] = '\0';
start = strstr(desc, prefix);
if (start == NULL) {
*format = VIR_STORAGE_FILE_NONE;
ret = BACKING_STORE_OK;
goto cleanup;
}
start += strlen(prefix);
end = strchr(start, '"');
if (end == NULL) {
ret = BACKING_STORE_INVALID;
goto cleanup;
}
if (end == start) {
*format = VIR_STORAGE_FILE_NONE;
ret = BACKING_STORE_OK;
goto cleanup;
}
*end = '\0';
if (VIR_STRDUP(*res, start) < 0)
goto cleanup;
ret = BACKING_STORE_OK;
cleanup:
VIR_FREE(desc);
return ret;
}
static int
qedGetBackingStore(char **res,
int *format,
const char *buf,
size_t buf_size)
{
unsigned long long flags;
unsigned long offset, size;
*res = NULL;
/* Check if this image has a backing file */
if (buf_size < QED_HDR_FEATURES_OFFSET+8)
return BACKING_STORE_INVALID;
flags = virReadBufInt64LE(buf + QED_HDR_FEATURES_OFFSET);
if (!(flags & QED_F_BACKING_FILE)) {
*format = VIR_STORAGE_FILE_NONE;
return BACKING_STORE_OK;
}
/* Parse the backing file */
if (buf_size < QED_HDR_BACKING_FILE_OFFSET+8)
return BACKING_STORE_INVALID;
offset = virReadBufInt32LE(buf + QED_HDR_BACKING_FILE_OFFSET);
if (offset > buf_size)
return BACKING_STORE_INVALID;
size = virReadBufInt32LE(buf + QED_HDR_BACKING_FILE_SIZE);
if (size == 0)
return BACKING_STORE_OK;
if (offset + size > buf_size || offset + size < offset)
return BACKING_STORE_INVALID;
if (VIR_ALLOC_N(*res, size + 1) < 0)
return BACKING_STORE_ERROR;
memcpy(*res, buf + offset, size);
(*res)[size] = '\0';
if (flags & QED_F_BACKING_FORMAT_NO_PROBE)
*format = VIR_STORAGE_FILE_RAW;
else
*format = VIR_STORAGE_FILE_AUTO_SAFE;
return BACKING_STORE_OK;
}
static bool
virStorageFileMatchesMagic(int format,
char *buf,
size_t buflen)
{
int mlen;
int magicOffset = fileTypeInfo[format].magicOffset;
const char *magic = fileTypeInfo[format].magic;
if (magic == NULL)
return false;
/* Validate magic data */
mlen = strlen(magic);
if (magicOffset + mlen > buflen)
return false;
if (memcmp(buf + magicOffset, magic, mlen) != 0)
return false;
return true;
}
static bool
virStorageFileMatchesExtension(int format,
const char *path)
{
if (fileTypeInfo[format].extension == NULL)
return false;
if (virFileHasSuffix(path, fileTypeInfo[format].extension))
return true;
return false;
}
static bool
virStorageFileMatchesVersion(int format,
char *buf,
size_t buflen)
{
int version;
size_t i;
/* Validate version number info */
if (fileTypeInfo[format].versionOffset == -1)
return false;
/* -2 == non-versioned file format, so trivially match */
if (fileTypeInfo[format].versionOffset == -2)
return true;
if ((fileTypeInfo[format].versionOffset + 4) > buflen)
return false;
if (fileTypeInfo[format].endian == LV_LITTLE_ENDIAN)
version = virReadBufInt32LE(buf + fileTypeInfo[format].versionOffset);
else
version = virReadBufInt32BE(buf + fileTypeInfo[format].versionOffset);
for (i = 0;
i < FILE_TYPE_VERSIONS_LAST && fileTypeInfo[format].versionNumbers[i];
i++) {
VIR_DEBUG("Compare detected version %d vs one of the expected versions %d",
version, fileTypeInfo[format].versionNumbers[i]);
if (version == fileTypeInfo[format].versionNumbers[i])
return true;
}
return false;
}
bool
virStorageIsFile(const char *backing)
{
char *colon;
char *slash;
if (!backing)
return false;
colon = strchr(backing, ':');
slash = strchr(backing, '/');
/* Reject anything that looks like a protocol (such as nbd: or
* rbd:); if someone really does want a relative file name that
* includes ':', they can always prefix './'. */
if (colon && (!slash || colon < slash))
return false;
return true;
}
static bool
virStorageIsRelative(const char *backing)
{
if (backing[0] == '/')
return false;
if (!virStorageIsFile(backing))
return false;
return true;
}
int
virStorageFileProbeFormatFromBuf(const char *path,
char *buf,
size_t buflen)
{
int format = VIR_STORAGE_FILE_RAW;
size_t i;
int possibleFormat = VIR_STORAGE_FILE_RAW;
VIR_DEBUG("path=%s, buf=%p, buflen=%zu", path, buf, buflen);
/* First check file magic */
for (i = 0; i < VIR_STORAGE_FILE_LAST; i++) {
if (virStorageFileMatchesMagic(i, buf, buflen)) {
if (!virStorageFileMatchesVersion(i, buf, buflen)) {
possibleFormat = i;
continue;
}
format = i;
goto cleanup;
}
}
if (possibleFormat != VIR_STORAGE_FILE_RAW)
VIR_WARN("File %s matches %s magic, but version is wrong. "
"Please report new version to libvir-list@redhat.com",
path, virStorageFileFormatTypeToString(possibleFormat));
/* No magic, so check file extension */
for (i = 0; i < VIR_STORAGE_FILE_LAST; i++) {
if (virStorageFileMatchesExtension(i, path)) {
format = i;
goto cleanup;
}
}
cleanup:
VIR_DEBUG("format=%d", format);
return format;
}
static int
qcow2GetFeatures(virBitmapPtr *features,
int format,
char *buf,
ssize_t len)
{
int version = -1;
virBitmapPtr feat = NULL;
uint64_t bits;
size_t i;
version = virReadBufInt32BE(buf + fileTypeInfo[format].versionOffset);
if (version == 2)
return 0;
if (len < QCOW2v3_HDR_SIZE)
return -1;
if (!(feat = virBitmapNew(VIR_STORAGE_FILE_FEATURE_LAST)))
return -1;
/* todo: check for incompatible or autoclear features? */
bits = virReadBufInt64BE(buf + QCOW2v3_HDR_FEATURES_COMPATIBLE);
for (i = 0; i < QCOW2_COMPATIBLE_FEATURE_LAST; i++) {
if (bits & ((uint64_t) 1 << i))
ignore_value(virBitmapSetBit(feat, qcow2CompatibleFeatureArray[i]));
}
*features = feat;
return 0;
}
/* Given a header in BUF with length LEN, as parsed from the storage file
* assuming it has the given FORMAT, populate information into META
* with information about the file and its backing store. Return format
* of the backing store as BACKING_FORMAT. PATH and FORMAT have to be
* pre-populated in META */
int
virStorageFileGetMetadataInternal(virStorageSourcePtr meta,
char *buf,
size_t len,
int *backingFormat)
{
int ret = -1;
VIR_DEBUG("path=%s, buf=%p, len=%zu, meta->format=%d",
meta->path, buf, len, meta->format);
if (meta->format == VIR_STORAGE_FILE_AUTO)
meta->format = virStorageFileProbeFormatFromBuf(meta->path, buf, len);
if (meta->format <= VIR_STORAGE_FILE_NONE ||
meta->format >= VIR_STORAGE_FILE_LAST) {
virReportSystemError(EINVAL, _("unknown storage file meta->format %d"),
meta->format);
goto cleanup;
}
/* XXX we should consider moving virStorageBackendUpdateVolInfo
* code into this method, for non-magic files
*/
if (!fileTypeInfo[meta->format].magic)
goto done;
/* Optionally extract capacity from file */
if (fileTypeInfo[meta->format].sizeOffset != -1) {
if ((fileTypeInfo[meta->format].sizeOffset + 8) > len)
goto done;
if (fileTypeInfo[meta->format].endian == LV_LITTLE_ENDIAN)
meta->capacity = virReadBufInt64LE(buf +
fileTypeInfo[meta->format].sizeOffset);
else
meta->capacity = virReadBufInt64BE(buf +
fileTypeInfo[meta->format].sizeOffset);
/* Avoid unlikely, but theoretically possible overflow */
if (meta->capacity > (ULLONG_MAX /
fileTypeInfo[meta->format].sizeMultiplier))
goto done;
meta->capacity *= fileTypeInfo[meta->format].sizeMultiplier;
}
if (fileTypeInfo[meta->format].qcowCryptOffset != -1) {
int crypt_format;
crypt_format = virReadBufInt32BE(buf +
fileTypeInfo[meta->format].qcowCryptOffset);
if (crypt_format && !meta->encryption &&
VIR_ALLOC(meta->encryption) < 0)
goto cleanup;
}
VIR_FREE(meta->backingStoreRaw);
if (fileTypeInfo[meta->format].getBackingStore != NULL) {
int store = fileTypeInfo[meta->format].getBackingStore(&meta->backingStoreRaw,
backingFormat,
buf, len);
if (store == BACKING_STORE_INVALID)
goto done;
if (store == BACKING_STORE_ERROR)
goto cleanup;
}
if (fileTypeInfo[meta->format].getFeatures != NULL &&
fileTypeInfo[meta->format].getFeatures(&meta->features, meta->format, buf, len) < 0)
goto cleanup;
if (meta->format == VIR_STORAGE_FILE_QCOW2 && meta->features &&
VIR_STRDUP(meta->compat, "1.1") < 0)
goto cleanup;
done:
ret = 0;
cleanup:
return ret;
}
/**
* virStorageFileProbeFormat:
*
* Probe for the format of 'path', returning the detected
* disk format.
*
* Callers are advised never to trust the returned 'format'
* unless it is listed as VIR_STORAGE_FILE_RAW, since a
* malicious guest can turn a raw file into any other non-raw
* format at will.
*
* Best option: Don't use this function
*/
int
virStorageFileProbeFormat(const char *path, uid_t uid, gid_t gid)
{
int fd;
int ret = -1;
struct stat sb;
ssize_t len = VIR_STORAGE_MAX_HEADER;
char *header = NULL;
if ((fd = virFileOpenAs(path, O_RDONLY, 0, uid, gid, 0)) < 0) {
virReportSystemError(-fd, _("Failed to open file '%s'"), path);
return -1;
}
if (fstat(fd, &sb) < 0) {
virReportSystemError(errno, _("cannot stat file '%s'"), path);
goto cleanup;
}
/* No header to probe for directories */
if (S_ISDIR(sb.st_mode)) {
ret = VIR_STORAGE_FILE_DIR;
goto cleanup;
}
if (lseek(fd, 0, SEEK_SET) == (off_t)-1) {
virReportSystemError(errno, _("cannot set to start of '%s'"), path);
goto cleanup;
}
if ((len = virFileReadHeaderFD(fd, len, &header)) < 0) {
virReportSystemError(errno, _("cannot read header '%s'"), path);
goto cleanup;
}
ret = virStorageFileProbeFormatFromBuf(path, header, len);
cleanup:
VIR_FREE(header);
VIR_FORCE_CLOSE(fd);
return ret;
}
static virStorageSourcePtr
virStorageFileMetadataNew(const char *path,
int format)
{
virStorageSourcePtr ret = NULL;
if (VIR_ALLOC(ret) < 0)
return NULL;
ret->format = format;
ret->type = VIR_STORAGE_TYPE_FILE;
if (VIR_STRDUP(ret->path, path) < 0)
goto error;
return ret;
error:
virStorageSourceFree(ret);
return NULL;
}
/**
* virStorageFileGetMetadataFromBuf:
* @path: name of file, for error messages
* @buf: header bytes from @path
* @len: length of @buf
* @format: format of the storage file
* @backingFormat: format of @backing
*
* Extract metadata about the storage volume with the specified image format.
* If image format is VIR_STORAGE_FILE_AUTO, it will probe to automatically
* identify the format. Does not recurse.
*
* Callers are advised never to use VIR_STORAGE_FILE_AUTO as a format on a file
* that might be raw if that file will then be passed to a guest, since a
* malicious guest can turn a raw file into any other non-raw format at will.
*
* If the returned @backingFormat is VIR_STORAGE_FILE_AUTO it indicates the
* image didn't specify an explicit format for its backing store. Callers are
* advised against probing for the backing store format in this case.
*
* Caller MUST free the result after use via virStorageSourceFree.
*/
virStorageSourcePtr
virStorageFileGetMetadataFromBuf(const char *path,
char *buf,
size_t len,
int format,
int *backingFormat)
{
virStorageSourcePtr ret = NULL;
int dummy;
if (!backingFormat)
backingFormat = &dummy;
if (!(ret = virStorageFileMetadataNew(path, format)))
return NULL;
if (virStorageFileGetMetadataInternal(ret, buf, len,
backingFormat) < 0) {
virStorageSourceFree(ret);
return NULL;
}
return ret;
}
/**
* virStorageFileGetMetadataFromFD:
*
* Extract metadata about the storage volume with the specified
* image format. If image format is VIR_STORAGE_FILE_AUTO, it
* will probe to automatically identify the format. Does not recurse.
*
* Callers are advised never to use VIR_STORAGE_FILE_AUTO as a
* format, since a malicious guest can turn a raw file into any
* other non-raw format at will.
*
* Caller MUST free the result after use via virStorageSourceFree.
*/
virStorageSourcePtr
virStorageFileGetMetadataFromFD(const char *path,
int fd,
int format,
int *backingFormat)
{
virStorageSourcePtr ret = NULL;
virStorageSourcePtr meta = NULL;
char *buf = NULL;
ssize_t len = VIR_STORAGE_MAX_HEADER;
struct stat sb;
int dummy;
if (!backingFormat)
backingFormat = &dummy;
*backingFormat = VIR_STORAGE_FILE_NONE;
if (fstat(fd, &sb) < 0) {
virReportSystemError(errno,
_("cannot stat file '%s'"), path);
return NULL;
}
if (!(meta = virStorageFileMetadataNew(path, format)))
return NULL;
if (S_ISDIR(sb.st_mode)) {
/* No header to probe for directories, but also no backing file. Just
* update the metadata.*/
meta->type = VIR_STORAGE_TYPE_DIR;
meta->format = VIR_STORAGE_FILE_DIR;
ret = meta;
meta = NULL;
goto cleanup;
}
if (lseek(fd, 0, SEEK_SET) == (off_t)-1) {
virReportSystemError(errno, _("cannot seek to start of '%s'"), meta->relPath);
goto cleanup;
}
if ((len = virFileReadHeaderFD(fd, len, &buf)) < 0) {
virReportSystemError(errno, _("cannot read header '%s'"), meta->relPath);
goto cleanup;
}
if (virStorageFileGetMetadataInternal(meta, buf, len, backingFormat) < 0)
goto cleanup;
if (S_ISREG(sb.st_mode))
meta->type = VIR_STORAGE_TYPE_FILE;
else if (S_ISBLK(sb.st_mode))
meta->type = VIR_STORAGE_TYPE_BLOCK;
ret = meta;
meta = NULL;
cleanup:
virStorageSourceFree(meta);
VIR_FREE(buf);
return ret;
}
/**
* virStorageFileChainCheckBroken
*
* If CHAIN is broken, set *brokenFile to the broken file name,
* otherwise set it to NULL. Caller MUST free *brokenFile after use.
* Return 0 on success (including when brokenFile is set), negative on
* error (allocation failure).
*/
int
virStorageFileChainGetBroken(virStorageSourcePtr chain,
char **brokenFile)
{
virStorageSourcePtr tmp;
*brokenFile = NULL;
if (!chain)
return 0;
for (tmp = chain; tmp; tmp = tmp->backingStore) {
/* Break when we hit end of chain; report error if we detected
* a missing backing file, infinite loop, or other error */
if (!tmp->backingStore && tmp->backingStoreRaw) {
if (VIR_STRDUP(*brokenFile, tmp->backingStoreRaw) < 0)
return -1;
return 0;
}
}
return 0;
}
/**
* virStorageFileResize:
*
* Change the capacity of the raw storage file at 'path'.
*/
int
virStorageFileResize(const char *path,
unsigned long long capacity,
unsigned long long orig_capacity,
bool pre_allocate)
{
int fd = -1;
int ret = -1;
int rc ATTRIBUTE_UNUSED;
off_t offset ATTRIBUTE_UNUSED;
off_t len ATTRIBUTE_UNUSED;
offset = orig_capacity;
len = capacity - orig_capacity;
if ((fd = open(path, O_RDWR)) < 0) {
virReportSystemError(errno, _("Unable to open '%s'"), path);
goto cleanup;
}
if (pre_allocate) {
#if HAVE_POSIX_FALLOCATE
if ((rc = posix_fallocate(fd, offset, len)) != 0) {
virReportSystemError(rc,
_("Failed to pre-allocate space for "
"file '%s'"), path);
goto cleanup;
}
#elif HAVE_SYS_SYSCALL_H && defined(SYS_fallocate)
if (syscall(SYS_fallocate, fd, 0, offset, len) != 0) {
virReportSystemError(errno,
_("Failed to pre-allocate space for "
"file '%s'"), path);
goto cleanup;
}
#else
virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
_("preallocate is not supported on this platform"));
goto cleanup;
#endif
} else {
if (ftruncate(fd, capacity) < 0) {
virReportSystemError(errno,
_("Failed to truncate file '%s'"), path);
goto cleanup;
}
}
if (VIR_CLOSE(fd) < 0) {
virReportSystemError(errno, _("Unable to save '%s'"), path);
goto cleanup;
}
ret = 0;
cleanup:
VIR_FORCE_CLOSE(fd);
return ret;
}
int virStorageFileIsClusterFS(const char *path)
{
/* These are coherent cluster filesystems known to be safe for
* migration with cache != none
*/
return virFileIsSharedFSType(path,
VIR_FILE_SHFS_GFS2 |
VIR_FILE_SHFS_OCFS);
}
#ifdef LVS
int virStorageFileGetLVMKey(const char *path,
char **key)
{
/*
* # lvs --noheadings --unbuffered --nosuffix --options "uuid" LVNAME
* 06UgP5-2rhb-w3Bo-3mdR-WeoL-pytO-SAa2ky
*/
int status;
virCommandPtr cmd = virCommandNewArgList(
LVS,
"--noheadings", "--unbuffered", "--nosuffix",
"--options", "uuid", path,
NULL
);
int ret = -1;
*key = NULL;
/* Run the program and capture its output */
virCommandSetOutputBuffer(cmd, key);
if (virCommandRun(cmd, &status) < 0)
goto cleanup;
/* Explicitly check status == 0, rather than passing NULL
* to virCommandRun because we don't want to raise an actual
* error in this scenario, just return a NULL key.
*/
if (status == 0 && *key) {
char *nl;
char *tmp = *key;
/* Find first non-space character */
while (*tmp && c_isspace(*tmp))
tmp++;
/* Kill leading spaces */
if (tmp != *key)
memmove(*key, tmp, strlen(tmp)+1);
/* Kill trailing newline */
if ((nl = strchr(*key, '\n')))
*nl = '\0';
}
ret = 0;
cleanup:
if (*key && STREQ(*key, ""))
VIR_FREE(*key);
virCommandFree(cmd);
return ret;
}
#else
int virStorageFileGetLVMKey(const char *path,
char **key ATTRIBUTE_UNUSED)
{
virReportSystemError(ENOSYS, _("Unable to get LVM key for %s"), path);
return -1;
}
#endif
#ifdef WITH_UDEV
int virStorageFileGetSCSIKey(const char *path,
char **key)
{
int status;
virCommandPtr cmd = virCommandNewArgList(
"/lib/udev/scsi_id",
"--replace-whitespace",
"--whitelisted",
"--device", path,
NULL
);
int ret = -1;
*key = NULL;
/* Run the program and capture its output */
virCommandSetOutputBuffer(cmd, key);
if (virCommandRun(cmd, &status) < 0)
goto cleanup;
/* Explicitly check status == 0, rather than passing NULL
* to virCommandRun because we don't want to raise an actual
* error in this scenario, just return a NULL key.
*/
if (status == 0 && *key) {
char *nl = strchr(*key, '\n');
if (nl)
*nl = '\0';
}
ret = 0;
cleanup:
if (*key && STREQ(*key, ""))
VIR_FREE(*key);
virCommandFree(cmd);
return ret;
}
#else
int virStorageFileGetSCSIKey(const char *path,
char **key ATTRIBUTE_UNUSED)
{
virReportSystemError(ENOSYS, _("Unable to get SCSI key for %s"), path);
return -1;
}
#endif
int
virStorageFileParseChainIndex(const char *diskTarget,
const char *name,
unsigned int *chainIndex)
{
char **strings = NULL;
unsigned int idx = 0;
char *suffix;
int ret = 0;
*chainIndex = 0;
if (name && diskTarget)
strings = virStringSplit(name, "[", 2);
if (virStringListLength(strings) != 2)
goto cleanup;
if (virStrToLong_uip(strings[1], &suffix, 10, &idx) < 0 ||
STRNEQ(suffix, "]"))
goto cleanup;
if (STRNEQ(diskTarget, strings[0])) {
virReportError(VIR_ERR_INVALID_ARG,
_("requested target '%s' does not match target '%s'"),
strings[0], diskTarget);
ret = -1;
goto cleanup;
}
*chainIndex = idx;
cleanup:
virStringFreeList(strings);
return ret;
}
/* Given a @chain, look for the backing store @name that is a backing file
* of @startFrom (or any member of @chain if @startFrom is NULL) and return
* that location within the chain. @chain must always point to the top of
* the chain. Pass NULL for @name and 0 for @idx to find the base of the
* chain. Pass nonzero @idx to find the backing source according to its
* position in the backing chain. If @parent is not NULL, set *@parent to
* the preferred name of the parent (or to NULL if @name matches the start
* of the chain). Since the results point within @chain, they must not be
* independently freed. Reports an error and returns NULL if @name is not
* found.
*/
virStorageSourcePtr
virStorageFileChainLookup(virStorageSourcePtr chain,
virStorageSourcePtr startFrom,
const char *name,
unsigned int idx,
virStorageSourcePtr *parent)
{
virStorageSourcePtr prev;
const char *start = chain->path;
char *parentDir = NULL;
bool nameIsFile = virStorageIsFile(name);
size_t i = 0;
if (!parent)
parent = &prev;
*parent = NULL;
if (startFrom) {
while (chain && chain != startFrom->backingStore) {
chain = chain->backingStore;
i++;
}
*parent = startFrom;
}
while (chain) {
if (!name && !idx) {
if (!chain->backingStore)
break;
} else if (idx) {
VIR_DEBUG("%zu: %s", i, chain->path);
if (idx == i)
break;
} else {
if (STREQ_NULLABLE(name, chain->relPath) ||
STREQ(name, chain->path))
break;
if (nameIsFile && virStorageSourceIsLocalStorage(chain)) {
if (*parent && virStorageSourceIsLocalStorage(*parent))
parentDir = mdir_name((*parent)->path);
else
ignore_value(VIR_STRDUP_QUIET(parentDir, "."));
if (!parentDir) {
virReportOOMError();
goto error;
}
int result = virFileRelLinkPointsTo(parentDir, name,
chain->path);
VIR_FREE(parentDir);
if (result < 0)
goto error;
if (result > 0)
break;
}
}
*parent = chain;
chain = chain->backingStore;
i++;
}
if (!chain)
goto error;
return chain;
error:
if (idx) {
virReportError(VIR_ERR_INVALID_ARG,
_("could not find backing store %u in chain for '%s'"),
idx, start);
} else if (name) {
if (startFrom)
virReportError(VIR_ERR_INVALID_ARG,
_("could not find image '%s' beneath '%s' in "
"chain for '%s'"), name, startFrom->path, start);
else
virReportError(VIR_ERR_INVALID_ARG,
_("could not find image '%s' in chain for '%s'"),
name, start);
} else {
virReportError(VIR_ERR_INVALID_ARG,
_("could not find base image in chain for '%s'"),
start);
}
*parent = NULL;
return NULL;
}
void
virStorageNetHostDefClear(virStorageNetHostDefPtr def)
{
if (!def)
return;
VIR_FREE(def->name);
VIR_FREE(def->port);
VIR_FREE(def->socket);
}
void
virStorageNetHostDefFree(size_t nhosts,
virStorageNetHostDefPtr hosts)
{
size_t i;
if (!hosts)
return;
for (i = 0; i < nhosts; i++)
virStorageNetHostDefClear(&hosts[i]);
VIR_FREE(hosts);
}
static void
virStoragePermsFree(virStoragePermsPtr def)
{
if (!def)
return;
VIR_FREE(def->label);
VIR_FREE(def);
}
virStorageNetHostDefPtr
virStorageNetHostDefCopy(size_t nhosts,
virStorageNetHostDefPtr hosts)
{
virStorageNetHostDefPtr ret = NULL;
size_t i;
if (VIR_ALLOC_N(ret, nhosts) < 0)
goto error;
for (i = 0; i < nhosts; i++) {
virStorageNetHostDefPtr src = &hosts[i];
virStorageNetHostDefPtr dst = &ret[i];
dst->transport = src->transport;
if (VIR_STRDUP(dst->name, src->name) < 0)
goto error;
if (VIR_STRDUP(dst->port, src->port) < 0)
goto error;
if (VIR_STRDUP(dst->socket, src->socket) < 0)
goto error;
}
return ret;
error:
virStorageNetHostDefFree(nhosts, ret);
return NULL;
}
void
virStorageAuthDefFree(virStorageAuthDefPtr authdef)
{
if (!authdef)
return;
VIR_FREE(authdef->username);
VIR_FREE(authdef->secrettype);
if (authdef->secretType == VIR_STORAGE_SECRET_TYPE_USAGE)
VIR_FREE(authdef->secret.usage);
VIR_FREE(authdef);
}
virStorageAuthDefPtr
virStorageAuthDefCopy(const virStorageAuthDef *src)
{
virStorageAuthDefPtr ret;
if (VIR_ALLOC(ret) < 0)
return NULL;
if (VIR_STRDUP(ret->username, src->username) < 0)
goto error;
/* Not present for storage pool, but used for disk source */
if (VIR_STRDUP(ret->secrettype, src->secrettype) < 0)
goto error;
ret->authType = src->authType;
ret->secretType = src->secretType;
if (ret->secretType == VIR_STORAGE_SECRET_TYPE_UUID) {
memcpy(ret->secret.uuid, src->secret.uuid, sizeof(ret->secret.uuid));
} else if (ret->secretType == VIR_STORAGE_SECRET_TYPE_USAGE) {
if (VIR_STRDUP(ret->secret.usage, src->secret.usage) < 0)
goto error;
}
return ret;
error:
virStorageAuthDefFree(ret);
return NULL;
}
static int
virStorageAuthDefParseSecret(xmlXPathContextPtr ctxt,
virStorageAuthDefPtr authdef)
{
char *uuid;
char *usage;
int ret = -1;
/* Used by the domain disk xml parsing in order to ensure the
* <secret type='%s' value matches the expected secret type for
* the style of disk (iscsi is chap, nbd is ceph). For some reason
* the virSecretUsageType{From|To}String() cannot be linked here
* and because only the domain parsing code cares - just keep
* it as a string.
*/
authdef->secrettype = virXPathString("string(./secret/@type)", ctxt);
uuid = virXPathString("string(./secret/@uuid)", ctxt);
usage = virXPathString("string(./secret/@usage)", ctxt);
if (uuid == NULL && usage == NULL) {
virReportError(VIR_ERR_XML_ERROR, "%s",
_("missing auth secret uuid or usage attribute"));
goto cleanup;
}
if (uuid && usage) {
virReportError(VIR_ERR_XML_ERROR, "%s",
_("either auth secret uuid or usage expected"));
goto cleanup;
}
if (uuid) {
if (virUUIDParse(uuid, authdef->secret.uuid) < 0) {
virReportError(VIR_ERR_XML_ERROR, "%s",
_("invalid auth secret uuid"));
goto cleanup;
}
authdef->secretType = VIR_STORAGE_SECRET_TYPE_UUID;
} else {
authdef->secret.usage = usage;
usage = NULL;
authdef->secretType = VIR_STORAGE_SECRET_TYPE_USAGE;
}
ret = 0;
cleanup:
VIR_FREE(uuid);
VIR_FREE(usage);
return ret;
}
static virStorageAuthDefPtr
virStorageAuthDefParseXML(xmlXPathContextPtr ctxt)
{
virStorageAuthDefPtr authdef = NULL;
char *username = NULL;
char *authtype = NULL;
if (VIR_ALLOC(authdef) < 0)
return NULL;
if (!(username = virXPathString("string(./@username)", ctxt))) {
virReportError(VIR_ERR_XML_ERROR, "%s",
_("missing username for auth"));
goto error;
}
authdef->username = username;
username = NULL;
authdef->authType = VIR_STORAGE_AUTH_TYPE_NONE;
authtype = virXPathString("string(./@type)", ctxt);
if (authtype) {
/* Used by the storage pool instead of the secret type field
* to define whether chap or ceph being used
*/
if ((authdef->authType = virStorageAuthTypeFromString(authtype)) < 0) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("unknown auth type '%s'"), authtype);
goto error;
}
VIR_FREE(authtype);
}
authdef->secretType = VIR_STORAGE_SECRET_TYPE_NONE;
if (virStorageAuthDefParseSecret(ctxt, authdef) < 0)
goto error;
return authdef;
error:
VIR_FREE(authtype);
VIR_FREE(username);
virStorageAuthDefFree(authdef);
return NULL;
}
virStorageAuthDefPtr
virStorageAuthDefParse(xmlDocPtr xml, xmlNodePtr root)
{
xmlXPathContextPtr ctxt = NULL;
virStorageAuthDefPtr authdef = NULL;
ctxt = xmlXPathNewContext(xml);
if (ctxt == NULL) {
virReportOOMError();
goto cleanup;
}
ctxt->node = root;
authdef = virStorageAuthDefParseXML(ctxt);
cleanup:
xmlXPathFreeContext(ctxt);
return authdef;
}
int
virStorageAuthDefFormat(virBufferPtr buf,
virStorageAuthDefPtr authdef)
{
char uuidstr[VIR_UUID_STRING_BUFLEN];
if (authdef->authType == VIR_STORAGE_AUTH_TYPE_NONE) {
virBufferEscapeString(buf, "<auth username='%s'>\n", authdef->username);
} else {
virBufferAsprintf(buf, "<auth type='%s' ",
virStorageAuthTypeToString(authdef->authType));
virBufferEscapeString(buf, "username='%s'>\n", authdef->username);
}
virBufferAdjustIndent(buf, 2);
if (authdef->secrettype)
virBufferAsprintf(buf, "<secret type='%s'", authdef->secrettype);
else
virBufferAddLit(buf, "<secret");
if (authdef->secretType == VIR_STORAGE_SECRET_TYPE_UUID) {
virUUIDFormat(authdef->secret.uuid, uuidstr);
virBufferAsprintf(buf, " uuid='%s'/>\n", uuidstr);
} else if (authdef->secretType == VIR_STORAGE_SECRET_TYPE_USAGE) {
virBufferEscapeString(buf, " usage='%s'/>\n",
authdef->secret.usage);
} else {
virBufferAddLit(buf, "/>\n");
}
virBufferAdjustIndent(buf, -2);
virBufferAddLit(buf, "</auth>\n");
return 0;
}
virSecurityDeviceLabelDefPtr
virStorageSourceGetSecurityLabelDef(virStorageSourcePtr src,
const char *model)
{
size_t i;
for (i = 0; i < src->nseclabels; i++) {
if (STREQ_NULLABLE(src->seclabels[i]->model, model))
return src->seclabels[i];
}
return NULL;
}
static void
virStorageSourceSeclabelsClear(virStorageSourcePtr def)
{
size_t i;
if (def->seclabels) {
for (i = 0; i < def->nseclabels; i++)
virSecurityDeviceLabelDefFree(def->seclabels[i]);
VIR_FREE(def->seclabels);
}
}
static int
virStorageSourceSeclabelsCopy(virStorageSourcePtr to,
const virStorageSource *from)
{
size_t i;
if (from->nseclabels == 0)
return 0;
if (VIR_ALLOC_N(to->seclabels, from->nseclabels) < 0)
return -1;
to->nseclabels = from->nseclabels;
for (i = 0; i < to->nseclabels; i++) {
if (!(to->seclabels[i] = virSecurityDeviceLabelDefCopy(from->seclabels[i])))
goto error;
}
return 0;
error:
virStorageSourceSeclabelsClear(to);
return -1;
}
static virStorageTimestampsPtr
virStorageTimestampsCopy(const virStorageTimestamps *src)
{
virStorageTimestampsPtr ret;
if (VIR_ALLOC(ret) < 0)
return NULL;
memcpy(ret, src, sizeof(*src));
return ret;
}
static virStoragePermsPtr
virStoragePermsCopy(const virStoragePerms *src)
{
virStoragePermsPtr ret;
if (VIR_ALLOC(ret) < 0)
return NULL;
ret->mode = src->mode;
ret->uid = src->uid;
ret->gid = src->gid;
if (VIR_STRDUP(ret->label, src->label))
goto error;
return ret;
error:
virStoragePermsFree(ret);
return NULL;
}
static virStorageSourcePoolDefPtr
virStorageSourcePoolDefCopy(const virStorageSourcePoolDef *src)
{
virStorageSourcePoolDefPtr ret;
if (VIR_ALLOC(ret) < 0)
return NULL;
ret->voltype = src->voltype;
ret->pooltype = src->pooltype;
ret->actualtype = src->actualtype;
ret->mode = src->mode;
if (VIR_STRDUP(ret->pool, src->pool) < 0 ||
VIR_STRDUP(ret->volume, src->volume) < 0)
goto error;
return ret;
error:
virStorageSourcePoolDefFree(ret);
return NULL;
}
/**
* virStorageSourcePtr:
*
* Deep-copies a virStorageSource structure. If @backing chain is true
* then also copies the backing chain recursively, otherwise just
* the top element is copied. This function doesn't copy the
* storage driver access structure and thus the struct needs to be initialized
* separately.
*/
virStorageSourcePtr
virStorageSourceCopy(const virStorageSource *src,
bool backingChain)
{
virStorageSourcePtr ret = NULL;
if (VIR_ALLOC(ret) < 0)
return NULL;
ret->type = src->type;
ret->protocol = src->protocol;
ret->format = src->format;
ret->allocation = src->allocation;
ret->capacity = src->capacity;
ret->readonly = src->readonly;
ret->shared = src->shared;
/* storage driver metadata are not copied */
ret->drv = NULL;
if (VIR_STRDUP(ret->path, src->path) < 0 ||
VIR_STRDUP(ret->volume, src->volume) < 0 ||
VIR_STRDUP(ret->driverName, src->driverName) < 0 ||
VIR_STRDUP(ret->relPath, src->relPath) < 0 ||
VIR_STRDUP(ret->backingStoreRaw, src->backingStoreRaw) < 0 ||
VIR_STRDUP(ret->snapshot, src->snapshot) < 0 ||
VIR_STRDUP(ret->configFile, src->configFile) < 0 ||
VIR_STRDUP(ret->compat, src->compat) < 0)
goto error;
if (src->nhosts) {
if (!(ret->hosts = virStorageNetHostDefCopy(src->nhosts, src->hosts)))
goto error;
ret->nhosts = src->nhosts;
}
if (src->srcpool &&
!(ret->srcpool = virStorageSourcePoolDefCopy(src->srcpool)))
goto error;
if (src->features &&
!(ret->features = virBitmapNewCopy(src->features)))
goto error;
if (src->encryption &&
!(ret->encryption = virStorageEncryptionCopy(src->encryption)))
goto error;
if (src->perms &&
!(ret->perms = virStoragePermsCopy(src->perms)))
goto error;
if (src->timestamps &&
!(ret->timestamps = virStorageTimestampsCopy(src->timestamps)))
goto error;
if (virStorageSourceSeclabelsCopy(ret, src) < 0)
goto error;
if (src->auth &&
!(ret->auth = virStorageAuthDefCopy(src->auth)))
goto error;
if (backingChain && src->backingStore) {
if (!(ret->backingStore = virStorageSourceCopy(src->backingStore,
true)))
goto error;
}
return ret;
error:
virStorageSourceFree(ret);
return NULL;
}
/**
* virStorageSourceInitChainElement:
* @newelem: New backing chain element disk source
* @old: Existing top level disk source
* @transferLabels: Transfer security lables.
*
* Transfers relevant information from the existing disk source to the new
* backing chain element if they weren't supplied so that labelling info
* and possibly other stuff is correct.
*
* If @transferLabels is true, security labels from the existing disk are copied
* to the new disk. Otherwise the default domain imagelabel label will be used.
*
* Returns 0 on success, -1 on error.
*/
int
virStorageSourceInitChainElement(virStorageSourcePtr newelem,
virStorageSourcePtr old,
bool transferLabels)
{
int ret = -1;
if (transferLabels &&
!newelem->seclabels &&
virStorageSourceSeclabelsCopy(newelem, old) < 0)
goto cleanup;
if (!newelem->driverName &&
VIR_STRDUP(newelem->driverName, old->driverName) < 0)
goto cleanup;
newelem->shared = old->shared;
newelem->readonly = old->readonly;
ret = 0;
cleanup:
return ret;
}
void
virStorageSourcePoolDefFree(virStorageSourcePoolDefPtr def)
{
if (!def)
return;
VIR_FREE(def->pool);
VIR_FREE(def->volume);
VIR_FREE(def);
}
int
virStorageSourceGetActualType(virStorageSourcePtr def)
{
if (def->type == VIR_STORAGE_TYPE_VOLUME && def->srcpool)
return def->srcpool->actualtype;
return def->type;
}
bool
virStorageSourceIsLocalStorage(virStorageSourcePtr src)
{
virStorageType type = virStorageSourceGetActualType(src);
switch (type) {
case VIR_STORAGE_TYPE_FILE:
case VIR_STORAGE_TYPE_BLOCK:
case VIR_STORAGE_TYPE_DIR:
return true;
case VIR_STORAGE_TYPE_NETWORK:
case VIR_STORAGE_TYPE_VOLUME:
case VIR_STORAGE_TYPE_LAST:
case VIR_STORAGE_TYPE_NONE:
return false;
}
return false;
}
/**
* virStorageSourceIsEmpty:
*
* @src: disk source to check
*
* Returns true if the guest disk has no associated host storage source
* (such as an empty cdrom drive).
*/
bool
virStorageSourceIsEmpty(virStorageSourcePtr src)
{
if (virStorageSourceIsLocalStorage(src) && !src->path)
return true;
if (src->type == VIR_STORAGE_TYPE_NONE)
return true;
return false;
}
/**
* virStorageSourceBackingStoreClear:
*
* @src: disk source to clear
*
* Clears information about backing store of the current storage file.
*/
void
virStorageSourceBackingStoreClear(virStorageSourcePtr def)
{
if (!def)
return;
VIR_FREE(def->relPath);
VIR_FREE(def->backingStoreRaw);
/* recursively free backing chain */
virStorageSourceFree(def->backingStore);
def->backingStore = NULL;
}
void
virStorageSourceClear(virStorageSourcePtr def)
{
if (!def)
return;
VIR_FREE(def->path);
VIR_FREE(def->volume);
virStorageSourcePoolDefFree(def->srcpool);
VIR_FREE(def->driverName);
virBitmapFree(def->features);
VIR_FREE(def->compat);
virStorageEncryptionFree(def->encryption);
virStorageSourceSeclabelsClear(def);
virStoragePermsFree(def->perms);
VIR_FREE(def->timestamps);
virStorageNetHostDefFree(def->nhosts, def->hosts);
virStorageAuthDefFree(def->auth);
virStorageSourceBackingStoreClear(def);
}
void
virStorageSourceFree(virStorageSourcePtr def)
{
if (!def)
return;
virStorageSourceClear(def);
VIR_FREE(def);
}
static virStorageSourcePtr
virStorageSourceNewFromBackingRelative(virStorageSourcePtr parent,
const char *rel)
{
char *dirname = NULL;
virStorageSourcePtr ret;
if (VIR_ALLOC(ret) < 0)
return NULL;
/* store relative name */
if (VIR_STRDUP(ret->relPath, parent->backingStoreRaw) < 0)
goto error;
if (!(dirname = mdir_name(parent->path))) {
virReportOOMError();
goto error;
}
if (STRNEQ(dirname, "/")) {
if (virAsprintf(&ret->path, "%s/%s", dirname, rel) < 0)
goto error;
} else {
if (virAsprintf(&ret->path, "/%s", rel) < 0)
goto error;
}
if (virStorageSourceGetActualType(parent) == VIR_STORAGE_TYPE_NETWORK) {
ret->type = VIR_STORAGE_TYPE_NETWORK;
/* copy the host network part */
ret->protocol = parent->protocol;
if (parent->nhosts) {
if (!(ret->hosts = virStorageNetHostDefCopy(parent->nhosts,
parent->hosts)))
goto error;
ret->nhosts = parent->nhosts;
}
if (VIR_STRDUP(ret->volume, parent->volume) < 0)
goto error;
} else {
/* set the type to _FILE, the caller shall update it to the actual type */
ret->type = VIR_STORAGE_TYPE_FILE;
}
cleanup:
VIR_FREE(dirname);
return ret;
error:
virStorageSourceFree(ret);
ret = NULL;
goto cleanup;
}
static int
virStorageSourceParseBackingURI(virStorageSourcePtr src,
const char *path)
{
virURIPtr uri = NULL;
char **scheme = NULL;
int ret = -1;
if (!(uri = virURIParse(path))) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("failed to parse backing file location '%s'"),
path);
goto cleanup;
}
if (VIR_ALLOC(src->hosts) < 0)
goto cleanup;
src->nhosts = 1;
if (!(scheme = virStringSplit(uri->scheme, "+", 2)))
goto cleanup;
if (!scheme[0] ||
(src->protocol = virStorageNetProtocolTypeFromString(scheme[0])) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("invalid backing protocol '%s'"),
NULLSTR(scheme[0]));
goto cleanup;
}
if (scheme[1] &&
(src->hosts->transport = virStorageNetHostTransportTypeFromString(scheme[1])) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("invalid protocol transport type '%s'"),
scheme[1]);
goto cleanup;
}
/* handle socket stored as a query */
if (uri->query) {
if (VIR_STRDUP(src->hosts->socket, STRSKIP(uri->query, "socket=")) < 0)
goto cleanup;
}
/* XXX We currently don't support auth, so don't bother parsing it */
/* possibly skip the leading slash */
if (VIR_STRDUP(src->path,
*uri->path == '/' ? uri->path + 1 : uri->path) < 0)
goto cleanup;
if (src->protocol == VIR_STORAGE_NET_PROTOCOL_GLUSTER) {
char *tmp;
if (!(tmp = strchr(src->path, '/')) ||
tmp == src->path) {
virReportError(VIR_ERR_XML_ERROR,
_("missing volume name or file name in "
"gluster source path '%s'"), src->path);
goto cleanup;
}
src->volume = src->path;
if (VIR_STRDUP(src->path, tmp) < 0)
goto cleanup;
tmp[0] = '\0';
}
if (uri->port > 0) {
if (virAsprintf(&src->hosts->port, "%d", uri->port) < 0)
goto cleanup;
}
if (VIR_STRDUP(src->hosts->name, uri->server) < 0)
goto cleanup;
ret = 0;
cleanup:
virURIFree(uri);
virStringFreeList(scheme);
return ret;
}
static int
virStorageSourceRBDAddHost(virStorageSourcePtr src,
char *hostport)
{
char *port;
size_t skip;
char **parts;
if (VIR_EXPAND_N(src->hosts, src->nhosts, 1) < 0)
return -1;
if ((port = strchr(hostport, ']'))) {
/* ipv6, strip brackets */
hostport += 1;
skip = 3;
} else {
port = strstr(hostport, "\\:");
skip = 2;
}
if (port) {
*port = '\0';
port += skip;
if (VIR_STRDUP(src->hosts[src->nhosts - 1].port, port) < 0)
goto error;
} else {
if (VIR_STRDUP(src->hosts[src->nhosts - 1].port, "6789") < 0)
goto error;
}
parts = virStringSplit(hostport, "\\:", 0);
if (!parts)
goto error;
src->hosts[src->nhosts-1].name = virStringJoin((const char **)parts, ":");
virStringFreeList(parts);
if (!src->hosts[src->nhosts-1].name)
goto error;
src->hosts[src->nhosts-1].transport = VIR_STORAGE_NET_HOST_TRANS_TCP;
src->hosts[src->nhosts-1].socket = NULL;
return 0;
error:
VIR_FREE(src->hosts[src->nhosts-1].port);
VIR_FREE(src->hosts[src->nhosts-1].name);
return -1;
}
int
virStorageSourceParseRBDColonString(const char *rbdstr,
virStorageSourcePtr src)
{
char *options = NULL;
char *p, *e, *next;
virStorageAuthDefPtr authdef = NULL;
/* optionally skip the "rbd:" prefix if provided */
if (STRPREFIX(rbdstr, "rbd:"))
rbdstr += strlen("rbd:");
if (VIR_STRDUP(src->path, rbdstr) < 0)
goto error;
p = strchr(src->path, ':');
if (p) {
if (VIR_STRDUP(options, p + 1) < 0)
goto error;
*p = '\0';
}
/* snapshot name */
if ((p = strchr(src->path, '@'))) {
if (VIR_STRDUP(src->snapshot, p + 1) < 0)
goto error;
*p = '\0';
}
/* options */
if (!options)
return 0; /* all done */
p = options;
while (*p) {
/* find : delimiter or end of string */
for (e = p; *e && *e != ':'; ++e) {
if (*e == '\\') {
e++;
if (*e == '\0')
break;
}
}
if (*e == '\0') {
next = e; /* last kv pair */
} else {
next = e + 1;
*e = '\0';
}
if (STRPREFIX(p, "id=")) {
/* formulate authdef for src->auth */
if (VIR_ALLOC(authdef) < 0)
goto error;
if (VIR_STRDUP(authdef->username, p + strlen("id=")) < 0)
goto error;
if (VIR_STRDUP(authdef->secrettype,
virStorageAuthTypeToString(VIR_STORAGE_AUTH_TYPE_CEPHX)) < 0)
goto error;
src->auth = authdef;
authdef = NULL;
/* Cannot formulate a secretType (eg, usage or uuid) given
* what is provided.
*/
}
if (STRPREFIX(p, "mon_host=")) {
char *h, *sep;
h = p + strlen("mon_host=");
while (h < e) {
for (sep = h; sep < e; ++sep) {
if (*sep == '\\' && (sep[1] == ',' ||
sep[1] == ';' ||
sep[1] == ' ')) {
*sep = '\0';
sep += 2;
break;
}
}
if (virStorageSourceRBDAddHost(src, h) < 0)
goto error;
h = sep;
}
}
if (STRPREFIX(p, "conf=") &&
VIR_STRDUP(src->configFile, p + strlen("conf=")) < 0)
goto error;
p = next;
}
VIR_FREE(options);
return 0;
error:
VIR_FREE(options);
virStorageAuthDefFree(authdef);
return -1;
}
static int
virStorageSourceParseNBDColonString(const char *nbdstr,
virStorageSourcePtr src)
{
char **backing = NULL;
int ret = -1;
if (!(backing = virStringSplit(nbdstr, ":", 0)))
goto cleanup;
/* we know that backing[0] now equals to "nbd" */
if (VIR_ALLOC_N(src->hosts, 1) < 0)
goto cleanup;
src->nhosts = 1;
src->hosts->transport = VIR_STORAGE_NET_HOST_TRANS_TCP;
/* format: [] denotes optional sections, uppercase are variable strings
* nbd:unix:/PATH/TO/SOCKET[:exportname=EXPORTNAME]
* nbd:HOSTNAME:PORT[:exportname=EXPORTNAME]
*/
if (!backing[1]) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("missing remote information in '%s' for protocol nbd"),
nbdstr);
goto cleanup;
} else if (STREQ(backing[1], "unix")) {
if (!backing[2]) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("missing unix socket path in nbd backing string %s"),
nbdstr);
goto cleanup;
}
if (VIR_STRDUP(src->hosts->socket, backing[2]) < 0)
goto cleanup;
} else {
if (!backing[1]) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("missing host name in nbd string '%s'"),
nbdstr);
goto cleanup;
}
if (VIR_STRDUP(src->hosts->name, backing[1]) < 0)
goto cleanup;
if (!backing[2]) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("missing port in nbd string '%s'"),
nbdstr);
goto cleanup;
}
if (VIR_STRDUP(src->hosts->port, backing[2]) < 0)
goto cleanup;
}
if (backing[3] && STRPREFIX(backing[3], "exportname=")) {
if (VIR_STRDUP(src->path, backing[3] + strlen("exportname=")) < 0)
goto cleanup;
}
ret = 0;
cleanup:
virStringFreeList(backing);
return ret;
}
static int
virStorageSourceParseBackingColon(virStorageSourcePtr src,
const char *path)
{
char *protocol = NULL;
const char *p;
int ret = -1;
if (!(p = strchr(path, ':'))) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("invalid backing protocol string '%s'"),
path);
goto cleanup;
}
if (VIR_STRNDUP(protocol, path, p - path) < 0)
goto cleanup;
if ((src->protocol = virStorageNetProtocolTypeFromString(protocol)) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("invalid backing protocol '%s'"),
protocol);
goto cleanup;
}
switch ((virStorageNetProtocol) src->protocol) {
case VIR_STORAGE_NET_PROTOCOL_NBD:
if (virStorageSourceParseNBDColonString(path, src) < 0)
goto cleanup;
break;
case VIR_STORAGE_NET_PROTOCOL_RBD:
if (virStorageSourceParseRBDColonString(path, src) < 0)
goto cleanup;
break;
case VIR_STORAGE_NET_PROTOCOL_SHEEPDOG:
case VIR_STORAGE_NET_PROTOCOL_LAST:
case VIR_STORAGE_NET_PROTOCOL_NONE:
virReportError(VIR_ERR_INTERNAL_ERROR,
_("backing store parser is not implemented for protocol %s"),
protocol);
goto cleanup;
case VIR_STORAGE_NET_PROTOCOL_HTTP:
case VIR_STORAGE_NET_PROTOCOL_HTTPS:
case VIR_STORAGE_NET_PROTOCOL_FTP:
case VIR_STORAGE_NET_PROTOCOL_FTPS:
case VIR_STORAGE_NET_PROTOCOL_TFTP:
case VIR_STORAGE_NET_PROTOCOL_ISCSI:
case VIR_STORAGE_NET_PROTOCOL_GLUSTER:
virReportError(VIR_ERR_INTERNAL_ERROR,
_("malformed backing store path for protocol %s"),
protocol);
goto cleanup;
}
ret = 0;
cleanup:
VIR_FREE(protocol);
return ret;
}
static virStorageSourcePtr
virStorageSourceNewFromBackingAbsolute(const char *path)
{
virStorageSourcePtr ret;
if (VIR_ALLOC(ret) < 0)
return NULL;
if (virStorageIsFile(path)) {
ret->type = VIR_STORAGE_TYPE_FILE;
if (VIR_STRDUP(ret->path, path) < 0)
goto error;
} else {
ret->type = VIR_STORAGE_TYPE_NETWORK;
/* handle URI formatted backing stores */
if (strstr(path, "://")) {
if (virStorageSourceParseBackingURI(ret, path) < 0)
goto error;
} else {
if (virStorageSourceParseBackingColon(ret, path) < 0)
goto error;
}
}
return ret;
error:
virStorageSourceFree(ret);
return NULL;
}
virStorageSourcePtr
virStorageSourceNewFromBacking(virStorageSourcePtr parent)
{
struct stat st;
virStorageSourcePtr ret;
if (virStorageIsRelative(parent->backingStoreRaw))
ret = virStorageSourceNewFromBackingRelative(parent,
parent->backingStoreRaw);
else
ret = virStorageSourceNewFromBackingAbsolute(parent->backingStoreRaw);
if (ret) {
/* possibly update local type */
if (ret->type == VIR_STORAGE_TYPE_FILE) {
if (stat(ret->path, &st) == 0) {
if (S_ISDIR(st.st_mode)) {
ret->type = VIR_STORAGE_TYPE_DIR;
ret->format = VIR_STORAGE_FILE_DIR;
} else if (S_ISBLK(st.st_mode)) {
ret->type = VIR_STORAGE_TYPE_BLOCK;
}
}
}
/* copy parent's labelling and other top level stuff */
if (virStorageSourceInitChainElement(ret, parent, true) < 0)
goto error;
}
return ret;
error:
virStorageSourceFree(ret);
return NULL;
}
static char *
virStorageFileCanonicalizeFormatPath(char **components,
size_t ncomponents,
bool beginSlash,
bool beginDoubleSlash)
{
virBuffer buf = VIR_BUFFER_INITIALIZER;
size_t i;
char *ret = NULL;
if (beginSlash)
virBufferAddLit(&buf, "/");
if (beginDoubleSlash)
virBufferAddLit(&buf, "/");
for (i = 0; i < ncomponents; i++) {
if (i != 0)
virBufferAddLit(&buf, "/");
virBufferAdd(&buf, components[i], -1);
}
if (virBufferCheckError(&buf) < 0)
return NULL;
/* if the output string is empty just return an empty string */
if (!(ret = virBufferContentAndReset(&buf)))
ignore_value(VIR_STRDUP(ret, ""));
return ret;
}
static int
virStorageFileCanonicalizeInjectSymlink(const char *path,
size_t at,
char ***components,
size_t *ncomponents)
{
char **tmp = NULL;
char **next;
size_t ntmp = 0;
int ret = -1;
if (!(tmp = virStringSplitCount(path, "/", 0, &ntmp)))
goto cleanup;
/* prepend */
for (next = tmp; *next; next++) {
if (VIR_INSERT_ELEMENT(*components, at, *ncomponents, *next) < 0)
goto cleanup;
at++;
}
ret = 0;
cleanup:
virStringFreeListCount(tmp, ntmp);
return ret;
}
char *
virStorageFileCanonicalizePath(const char *path,
virStorageFileSimplifyPathReadlinkCallback cb,
void *cbdata)
{
virHashTablePtr cycle = NULL;
bool beginSlash = false;
bool beginDoubleSlash = false;
char **components = NULL;
size_t ncomponents = 0;
char *linkpath = NULL;
char *currentpath = NULL;
size_t i = 0;
size_t j = 0;
int rc;
char *ret = NULL;
if (path[0] == '/') {
beginSlash = true;
if (path[1] == '/' && path[2] != '/')
beginDoubleSlash = true;
}
if (!(cycle = virHashCreate(10, NULL)))
goto cleanup;
if (!(components = virStringSplitCount(path, "/", 0, &ncomponents)))
goto cleanup;
j = 0;
while (j < ncomponents) {
/* skip slashes */
if (STREQ(components[j], "")) {
VIR_FREE(components[j]);
VIR_DELETE_ELEMENT(components, j, ncomponents);
continue;
}
j++;
}
while (i < ncomponents) {
/* skip '.'s unless it's the last one remaining */
if (STREQ(components[i], ".") &&
(beginSlash || ncomponents > 1)) {
VIR_FREE(components[i]);
VIR_DELETE_ELEMENT(components, i, ncomponents);
continue;
}
/* resolve changes to parent directory */
if (STREQ(components[i], "..")) {
if (!beginSlash &&
(i == 0 || STREQ(components[i - 1], ".."))) {
i++;
continue;
}
VIR_FREE(components[i]);
VIR_DELETE_ELEMENT(components, i, ncomponents);
if (i != 0) {
VIR_FREE(components[i - 1]);
VIR_DELETE_ELEMENT(components, i - 1, ncomponents);
i--;
}
continue;
}
/* check if the actual path isn't resulting into a symlink */
if (!(currentpath = virStorageFileCanonicalizeFormatPath(components,
i + 1,
beginSlash,
beginDoubleSlash)))
goto cleanup;
if ((rc = cb(currentpath, &linkpath, cbdata)) < 0)
goto cleanup;
if (rc == 0) {
if (virHashLookup(cycle, currentpath)) {
virReportSystemError(ELOOP,
_("Failed to canonicalize path '%s'"), path);
goto cleanup;
}
if (virHashAddEntry(cycle, currentpath, (void *) 1) < 0)
goto cleanup;
if (linkpath[0] == '/') {
/* kill everything from the beginning including the actual component */
i++;
while (i--) {
VIR_FREE(components[0]);
VIR_DELETE_ELEMENT(components, 0, ncomponents);
}
beginSlash = true;
if (linkpath[1] == '/' && linkpath[2] != '/')
beginDoubleSlash = true;
else
beginDoubleSlash = false;
i = 0;
} else {
VIR_FREE(components[i]);
VIR_DELETE_ELEMENT(components, i, ncomponents);
}
if (virStorageFileCanonicalizeInjectSymlink(linkpath,
i,
&components,
&ncomponents) < 0)
goto cleanup;
j = 0;
while (j < ncomponents) {
/* skip slashes */
if (STREQ(components[j], "")) {
VIR_FREE(components[j]);
VIR_DELETE_ELEMENT(components, j, ncomponents);
continue;
}
j++;
}
VIR_FREE(linkpath);
VIR_FREE(currentpath);
continue;
}
VIR_FREE(currentpath);
i++;
}
ret = virStorageFileCanonicalizeFormatPath(components, ncomponents,
beginSlash, beginDoubleSlash);
cleanup:
virHashFree(cycle);
virStringFreeListCount(components, ncomponents);
VIR_FREE(linkpath);
VIR_FREE(currentpath);
return ret;
}
/**
* virStorageFileRemoveLastPathComponent:
*
* @path: Path string to remove the last component from
*
* Removes the last path component of a path. This function is designed to be
* called on file paths only (no trailing slashes in @path). Caller is
* responsible to free the returned string.
*/
static char *
virStorageFileRemoveLastPathComponent(const char *path)
{
char *tmp;
char *ret;
if (VIR_STRDUP(ret, path ? path : "") < 0)
return NULL;
if ((tmp = strrchr(ret, '/')))
tmp[1] = '\0';
else
ret[0] = '\0';
return ret;
}
/*
* virStorageFileGetRelativeBackingPath:
*
* Resolve relative path to be written to the overlay of @top image when
* collapsing the backing chain between @top and @base.
*
* Returns 0 on success; 1 if backing chain isn't relative and -1 on error.
*/
int
virStorageFileGetRelativeBackingPath(virStorageSourcePtr top,
virStorageSourcePtr base,
char **relpath)
{
virStorageSourcePtr next;
char *tmp = NULL;
char *path = NULL;
char ret = -1;
*relpath = NULL;
for (next = top; next; next = next->backingStore) {
if (!next->relPath) {
ret = 1;
goto cleanup;
}
if (!(tmp = virStorageFileRemoveLastPathComponent(path)))
goto cleanup;
VIR_FREE(path);
if (virAsprintf(&path, "%s%s", tmp, next->relPath) < 0)
goto cleanup;
VIR_FREE(tmp);
if (next == base)
break;
}
if (next != base) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("failed to resolve relative backing name: "
"base image is not in backing chain"));
goto cleanup;
}
*relpath = path;
path = NULL;
ret = 0;
cleanup:
VIR_FREE(path);
VIR_FREE(tmp);
return ret;
}
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