virstoragefile.c 66.3 KB
Newer Older
1
/*
2
 * virstoragefile.c: file utility functions for FS storage backend
3
 *
4
 * Copyright (C) 2007-2014 Red Hat, Inc.
5 6 7 8 9 10 11 12 13 14 15 16 17
 * 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
18
 * License along with this library.  If not, see
O
Osier Yang 已提交
19
 * <http://www.gnu.org/licenses/>.
20 21 22 23 24
 *
 * Author: Daniel P. Berrange <berrange@redhat.com>
 */

#include <config.h>
25
#include "virstoragefile.h"
26

27
#include <sys/stat.h>
28
#include <unistd.h>
29
#include <fcntl.h>
30
#include <stdlib.h>
31
#include "viralloc.h"
32 33
#include "virxml.h"
#include "viruuid.h"
34
#include "virerror.h"
35
#include "virlog.h"
E
Eric Blake 已提交
36
#include "virfile.h"
37
#include "c-ctype.h"
38
#include "vircommand.h"
39
#include "virhash.h"
E
Eric Blake 已提交
40
#include "virendian.h"
41 42
#include "virstring.h"
#include "virutil.h"
43 44
#include "viruri.h"
#include "dirname.h"
45
#include "virbuffer.h"
46 47 48
#if HAVE_SYS_SYSCALL_H
# include <sys/syscall.h>
#endif
49 50 51

#define VIR_FROM_THIS VIR_FROM_STORAGE

52 53
VIR_LOG_INIT("util.storagefile");

E
Eric Blake 已提交
54
VIR_ENUM_IMPL(virStorage, VIR_STORAGE_TYPE_LAST,
55
              "none",
E
Eric Blake 已提交
56
              "file",
57
              "block",
E
Eric Blake 已提交
58 59 60 61
              "dir",
              "network",
              "volume")

62 63
VIR_ENUM_IMPL(virStorageFileFormat,
              VIR_STORAGE_FILE_LAST,
E
Eric Blake 已提交
64
              "none",
65
              "raw", "dir", "bochs",
66 67 68
              "cloop", "dmg", "iso",
              "vpc", "vdi",
              /* Not direct file formats, but used for various drivers */
69
              "fat", "vhd", "ploop",
70 71
              /* Formats with backing file below here */
              "cow", "qcow", "qcow2", "qed", "vmdk")
72

73 74 75 76 77
VIR_ENUM_IMPL(virStorageFileFeature,
              VIR_STORAGE_FILE_FEATURE_LAST,
              "lazy_refcounts",
              )

78
VIR_ENUM_IMPL(virStorageNetProtocol, VIR_STORAGE_NET_PROTOCOL_LAST,
79
              "none",
80 81 82 83 84 85 86 87 88 89
              "nbd",
              "rbd",
              "sheepdog",
              "gluster",
              "iscsi",
              "http",
              "https",
              "ftp",
              "ftps",
              "tftp")
90 91 92 93 94 95

VIR_ENUM_IMPL(virStorageNetHostTransport, VIR_STORAGE_NET_HOST_TRANS_LAST,
              "tcp",
              "unix",
              "rdma")

96 97 98 99 100
VIR_ENUM_IMPL(virStorageSourcePoolMode,
              VIR_STORAGE_SOURCE_POOL_MODE_LAST,
              "default",
              "host",
              "direct")
101

102 103 104 105
VIR_ENUM_IMPL(virStorageAuth,
              VIR_STORAGE_AUTH_TYPE_LAST,
              "none", "chap", "ceph")

106 107 108 109 110 111 112 113 114 115 116
enum lv_endian {
    LV_LITTLE_ENDIAN = 1, /* 1234 */
    LV_BIG_ENDIAN         /* 4321 */
};

enum {
    BACKING_STORE_OK,
    BACKING_STORE_INVALID,
    BACKING_STORE_ERROR,
};

117 118
#define FILE_TYPE_VERSIONS_LAST 2

119 120
/* Either 'magic' or 'extension' *must* be provided */
struct FileTypeInfo {
121
    int magicOffset;    /* Byte offset of the magic */
122 123 124 125 126 127
    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,
128 129
                           * -1 to always fail the version test,
                           * -2 to always pass the version test */
130 131
    int versionNumbers[FILE_TYPE_VERSIONS_LAST];
                          /* Version numbers to validate. Zeroes are ignored. */
132 133 134 135 136 137 138 139 140 141 142
    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 */
143
    int (*getBackingStore)(char **res, int *format,
E
Eric Blake 已提交
144
                           const char *buf, size_t buf_size);
145
    int (*getFeatures)(virBitmapPtr *features, int format,
E
Eric Blake 已提交
146
                       char *buf, ssize_t len);
147 148
};

149
static int cowGetBackingStore(char **, int *,
E
Eric Blake 已提交
150
                              const char *, size_t);
151
static int qcow1GetBackingStore(char **, int *,
E
Eric Blake 已提交
152
                                const char *, size_t);
153
static int qcow2GetBackingStore(char **, int *,
E
Eric Blake 已提交
154
                                const char *, size_t);
155
static int qcow2GetFeatures(virBitmapPtr *features, int format,
E
Eric Blake 已提交
156
                            char *buf, ssize_t len);
157
static int vmdk4GetBackingStore(char **, int *,
E
Eric Blake 已提交
158
                                const char *, size_t);
159
static int
E
Eric Blake 已提交
160
qedGetBackingStore(char **, int *, const char *, size_t);
161 162 163 164 165 166 167 168 169 170 171 172 173 174 175

#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

176 177 178 179 180 181 182
#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)

183
#define QED_HDR_FEATURES_OFFSET (4+4+4+4)
184 185
#define QED_HDR_IMAGE_SIZE (QED_HDR_FEATURES_OFFSET+8+8+8+8)
#define QED_HDR_BACKING_FILE_OFFSET (QED_HDR_IMAGE_SIZE+8)
186 187 188
#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
A
Adam Litke 已提交
189

190 191

static struct FileTypeInfo const fileTypeInfo[] = {
192
    [VIR_STORAGE_FILE_NONE] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
193
                                -1, {0}, 0, 0, 0, 0, NULL, NULL },
194
    [VIR_STORAGE_FILE_RAW] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
195
                               -1, {0}, 0, 0, 0, 0, NULL, NULL },
196
    [VIR_STORAGE_FILE_DIR] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
197
                               -1, {0}, 0, 0, 0, 0, NULL, NULL },
198
    [VIR_STORAGE_FILE_BOCHS] = {
199 200
        /*"Bochs Virtual HD Image", */ /* Untested */
        0, NULL, NULL,
201 202
        LV_LITTLE_ENDIAN, 64, {0x20000},
        32+16+16+4+4+4+4+4, 8, 1, -1, NULL, NULL
203 204
    },
    [VIR_STORAGE_FILE_CLOOP] = {
205 206 207 208 209
        /* #!/bin/sh
           #V2.0 Format
           modprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1
        */ /* Untested */
        0, NULL, NULL,
210 211
        LV_LITTLE_ENDIAN, -1, {0},
        -1, 0, 0, -1, NULL, NULL
212 213
    },
    [VIR_STORAGE_FILE_DMG] = {
214 215 216 217
        /* 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",
218 219
        0, -1, {0},
        -1, 0, 0, -1, NULL, NULL
220 221
    },
    [VIR_STORAGE_FILE_ISO] = {
222
        32769, "CD001", ".iso",
223 224
        LV_LITTLE_ENDIAN, -2, {0},
        -1, 0, 0, -1, NULL, NULL
225
    },
226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241
    [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 },
242 243
    [VIR_STORAGE_FILE_PLOOP] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
                               -1, {0}, 0, 0, 0, 0, NULL, NULL },
244 245 246 247 248 249 250

    /* 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
    },
251
    [VIR_STORAGE_FILE_QCOW] = {
252
        0, "QFI", NULL,
253 254
        LV_BIG_ENDIAN, 4, {1},
        QCOWX_HDR_IMAGE_SIZE, 8, 1, QCOW1_HDR_CRYPT, qcow1GetBackingStore, NULL
255 256
    },
    [VIR_STORAGE_FILE_QCOW2] = {
257
        0, "QFI", NULL,
258
        LV_BIG_ENDIAN, 4, {2, 3},
259
        QCOWX_HDR_IMAGE_SIZE, 8, 1, QCOW2_HDR_CRYPT, qcow2GetBackingStore,
260
        qcow2GetFeatures
261
    },
A
Adam Litke 已提交
262 263
    [VIR_STORAGE_FILE_QED] = {
        /* http://wiki.qemu.org/Features/QED */
264
        0, "QED", NULL,
265 266
        LV_LITTLE_ENDIAN, -2, {0},
        QED_HDR_IMAGE_SIZE, 8, 1, -1, qedGetBackingStore, NULL
A
Adam Litke 已提交
267
    },
268
    [VIR_STORAGE_FILE_VMDK] = {
269
        0, "KDMV", NULL,
270
        LV_LITTLE_ENDIAN, 4, {1, 2},
271
        4+4+4, 8, 512, -1, vmdk4GetBackingStore, NULL
272
    },
273
};
274
verify(ARRAY_CARDINALITY(fileTypeInfo) == VIR_STORAGE_FILE_LAST);
275

276 277 278 279 280 281 282 283 284 285 286 287 288 289
/* 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);

290
static int
291
cowGetBackingStore(char **res,
292
                   int *format,
E
Eric Blake 已提交
293
                   const char *buf,
294 295 296 297
                   size_t buf_size)
{
#define COW_FILENAME_MAXLEN 1024
    *res = NULL;
298 299
    *format = VIR_STORAGE_FILE_AUTO;

300 301
    if (buf_size < 4+4+ COW_FILENAME_MAXLEN)
        return BACKING_STORE_INVALID;
E
Eric Blake 已提交
302 303
    if (buf[4+4] == '\0') { /* cow_header_v2.backing_file[0] */
        *format = VIR_STORAGE_FILE_NONE;
304
        return BACKING_STORE_OK;
E
Eric Blake 已提交
305
    }
306

307
    if (VIR_STRNDUP(*res, (const char*)buf + 4 + 4, COW_FILENAME_MAXLEN) < 0)
308 309 310 311
        return BACKING_STORE_ERROR;
    return BACKING_STORE_OK;
}

312 313 314

static int
qcow2GetBackingStoreFormat(int *format,
E
Eric Blake 已提交
315
                           const char *buf,
316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333
                           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)) {
E
Eric Blake 已提交
334 335
        unsigned int magic = virReadBufInt32BE(buf + offset);
        unsigned int len = virReadBufInt32BE(buf + offset + 4);
336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353

        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);
E
Eric Blake 已提交
354 355
            if (*format <= VIR_STORAGE_FILE_NONE)
                return -1;
356 357 358 359 360
        }

        offset += len;
    }

361
 done:
362 363 364 365 366

    return 0;
}


367
static int
368
qcowXGetBackingStore(char **res,
369
                     int *format,
E
Eric Blake 已提交
370
                     const char *buf,
371 372
                     size_t buf_size,
                     bool isQCow2)
373 374
{
    unsigned long long offset;
375
    unsigned int size;
376 377
    unsigned long long start;
    int version;
378 379

    *res = NULL;
380 381 382 383
    if (format)
        *format = VIR_STORAGE_FILE_AUTO;

    if (buf_size < QCOWX_HDR_BACKING_FILE_OFFSET+8+4)
384
        return BACKING_STORE_INVALID;
E
Eric Blake 已提交
385
    offset = virReadBufInt64BE(buf + QCOWX_HDR_BACKING_FILE_OFFSET);
386 387
    if (offset > buf_size)
        return BACKING_STORE_INVALID;
E
Eric Blake 已提交
388
    size = virReadBufInt32BE(buf + QCOWX_HDR_BACKING_FILE_SIZE);
E
Eric Blake 已提交
389 390 391
    if (size == 0) {
        if (format)
            *format = VIR_STORAGE_FILE_NONE;
392
        return BACKING_STORE_OK;
E
Eric Blake 已提交
393
    }
394 395 396 397
    if (offset + size > buf_size || offset + size < offset)
        return BACKING_STORE_INVALID;
    if (size + 1 == 0)
        return BACKING_STORE_INVALID;
398
    if (VIR_ALLOC_N(*res, size + 1) < 0)
399 400 401
        return BACKING_STORE_ERROR;
    memcpy(*res, buf + offset, size);
    (*res)[size] = '\0';
402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425

    /*
     * 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)
426 427 428
     *
     * for qcow2 v3 images, the length of the header
     * is stored at QCOW2v3_HDR_SIZE
429
     */
430 431 432 433 434 435 436 437 438 439
    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;
    }
440

441 442 443 444
    return BACKING_STORE_OK;
}


445 446 447
static int
qcow1GetBackingStore(char **res,
                     int *format,
E
Eric Blake 已提交
448
                     const char *buf,
449 450
                     size_t buf_size)
{
E
Eric Blake 已提交
451 452
    int ret;

453 454 455
    /* QCow1 doesn't have the extensions capability
     * used to store backing format */
    *format = VIR_STORAGE_FILE_AUTO;
E
Eric Blake 已提交
456 457 458 459
    ret = qcowXGetBackingStore(res, NULL, buf, buf_size, false);
    if (ret == 0 && *buf == '\0')
        *format = VIR_STORAGE_FILE_NONE;
    return ret;
460 461 462 463 464
}

static int
qcow2GetBackingStore(char **res,
                     int *format,
E
Eric Blake 已提交
465
                     const char *buf,
466 467 468 469 470 471
                     size_t buf_size)
{
    return qcowXGetBackingStore(res, format, buf, buf_size, true);
}


472
static int
473
vmdk4GetBackingStore(char **res,
474
                     int *format,
E
Eric Blake 已提交
475
                     const char *buf,
476 477 478
                     size_t buf_size)
{
    static const char prefix[] = "parentFileNameHint=\"";
479
    char *desc, *start, *end;
480
    size_t len;
481 482
    int ret = BACKING_STORE_ERROR;

483
    if (VIR_ALLOC_N(desc, VIR_STORAGE_MAX_HEADER) < 0)
484
        goto cleanup;
485 486

    *res = NULL;
487 488 489 490 491 492 493 494
    /*
     * 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;
495

496 497 498 499
    if (buf_size <= 0x200) {
        ret = BACKING_STORE_INVALID;
        goto cleanup;
    }
500
    len = buf_size - 0x200;
501 502
    if (len > VIR_STORAGE_MAX_HEADER)
        len = VIR_STORAGE_MAX_HEADER;
503 504 505
    memcpy(desc, buf + 0x200, len);
    desc[len] = '\0';
    start = strstr(desc, prefix);
506
    if (start == NULL) {
E
Eric Blake 已提交
507
        *format = VIR_STORAGE_FILE_NONE;
508 509 510
        ret = BACKING_STORE_OK;
        goto cleanup;
    }
511 512
    start += strlen(prefix);
    end = strchr(start, '"');
513 514 515 516 517
    if (end == NULL) {
        ret = BACKING_STORE_INVALID;
        goto cleanup;
    }
    if (end == start) {
E
Eric Blake 已提交
518
        *format = VIR_STORAGE_FILE_NONE;
519 520 521
        ret = BACKING_STORE_OK;
        goto cleanup;
    }
522
    *end = '\0';
523
    if (VIR_STRDUP(*res, start) < 0)
524 525 526 527
        goto cleanup;

    ret = BACKING_STORE_OK;

528
 cleanup:
529 530
    VIR_FREE(desc);
    return ret;
531 532
}

533 534 535
static int
qedGetBackingStore(char **res,
                   int *format,
E
Eric Blake 已提交
536
                   const char *buf,
537 538 539 540 541 542 543 544 545
                   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;
E
Eric Blake 已提交
546
    flags = virReadBufInt64LE(buf + QED_HDR_FEATURES_OFFSET);
E
Eric Blake 已提交
547 548
    if (!(flags & QED_F_BACKING_FILE)) {
        *format = VIR_STORAGE_FILE_NONE;
549
        return BACKING_STORE_OK;
E
Eric Blake 已提交
550
    }
551 552 553 554

    /* Parse the backing file */
    if (buf_size < QED_HDR_BACKING_FILE_OFFSET+8)
        return BACKING_STORE_INVALID;
E
Eric Blake 已提交
555
    offset = virReadBufInt32LE(buf + QED_HDR_BACKING_FILE_OFFSET);
556 557
    if (offset > buf_size)
        return BACKING_STORE_INVALID;
E
Eric Blake 已提交
558
    size = virReadBufInt32LE(buf + QED_HDR_BACKING_FILE_SIZE);
559 560 561 562
    if (size == 0)
        return BACKING_STORE_OK;
    if (offset + size > buf_size || offset + size < offset)
        return BACKING_STORE_INVALID;
563
    if (VIR_ALLOC_N(*res, size + 1) < 0)
564 565 566 567
        return BACKING_STORE_ERROR;
    memcpy(*res, buf + offset, size);
    (*res)[size] = '\0';

E
Eric Blake 已提交
568 569 570 571
    if (flags & QED_F_BACKING_FORMAT_NO_PROBE)
        *format = VIR_STORAGE_FILE_RAW;
    else
        *format = VIR_STORAGE_FILE_AUTO_SAFE;
572 573 574 575

    return BACKING_STORE_OK;
}

576 577 578

static bool
virStorageFileMatchesMagic(int format,
E
Eric Blake 已提交
579
                           char *buf,
580
                           size_t buflen)
581
{
582
    int mlen;
583 584
    int magicOffset = fileTypeInfo[format].magicOffset;
    const char *magic = fileTypeInfo[format].magic;
585

586
    if (magic == NULL)
587
        return false;
588

589
    /* Validate magic data */
590 591
    mlen = strlen(magic);
    if (magicOffset + mlen > buflen)
592
        return false;
593

594
    if (memcmp(buf + magicOffset, magic, mlen) != 0)
595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616
        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,
E
Eric Blake 已提交
617
                             char *buf,
618 619
                             size_t buflen)
{
620 621
    int version;
    size_t i;
622 623 624

    /* Validate version number info */
    if (fileTypeInfo[format].versionOffset == -1)
E
Eric Blake 已提交
625
        return false;
626

627 628 629 630
    /* -2 == non-versioned file format, so trivially match */
    if (fileTypeInfo[format].versionOffset == -2)
        return true;

631 632 633
    if ((fileTypeInfo[format].versionOffset + 4) > buflen)
        return false;

E
Eric Blake 已提交
634 635 636 637
    if (fileTypeInfo[format].endian == LV_LITTLE_ENDIAN)
        version = virReadBufInt32LE(buf + fileTypeInfo[format].versionOffset);
    else
        version = virReadBufInt32BE(buf + fileTypeInfo[format].versionOffset);
638

639 640 641 642 643 644 645 646
    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;
    }
647

648
    return false;
649
}
650

651 652
bool
virStorageIsFile(const char *backing)
A
Adam Litke 已提交
653
{
654 655 656 657 658 659 660 661
    char *colon;
    char *slash;

    if (!backing)
        return false;

    colon = strchr(backing, ':');
    slash = strchr(backing, '/');
662 663 664 665 666

    /* 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))
A
Adam Litke 已提交
667 668 669
        return false;
    return true;
}
670

E
Eric Blake 已提交
671

672 673 674 675 676 677 678 679 680 681 682 683 684
static bool
virStorageIsRelative(const char *backing)
{
    if (backing[0] == '/')
        return false;

    if (!virStorageIsFile(backing))
        return false;

    return true;
}


E
Eric Blake 已提交
685
static int
E
Eric Blake 已提交
686
virStorageFileProbeFormatFromBuf(const char *path,
E
Eric Blake 已提交
687
                                 char *buf,
E
Eric Blake 已提交
688 689 690
                                 size_t buflen)
{
    int format = VIR_STORAGE_FILE_RAW;
691
    size_t i;
E
Eric Blake 已提交
692
    int possibleFormat = VIR_STORAGE_FILE_RAW;
693
    VIR_DEBUG("path=%s, buf=%p, buflen=%zu", path, buf, buflen);
E
Eric Blake 已提交
694 695

    /* First check file magic */
696
    for (i = 0; i < VIR_STORAGE_FILE_LAST; i++) {
E
Eric Blake 已提交
697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712
        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 */
713
    for (i = 0; i < VIR_STORAGE_FILE_LAST; i++) {
E
Eric Blake 已提交
714 715 716 717 718 719
        if (virStorageFileMatchesExtension(i, path)) {
            format = i;
            goto cleanup;
        }
    }

720
 cleanup:
E
Eric Blake 已提交
721 722 723 724 725
    VIR_DEBUG("format=%d", format);
    return format;
}


726 727 728
static int
qcow2GetFeatures(virBitmapPtr *features,
                 int format,
E
Eric Blake 已提交
729
                 char *buf,
730 731 732 733 734
                 ssize_t len)
{
    int version = -1;
    virBitmapPtr feat = NULL;
    uint64_t bits;
735
    size_t i;
736 737 738 739 740 741 742 743 744

    version = virReadBufInt32BE(buf + fileTypeInfo[format].versionOffset);

    if (version == 2)
        return 0;

    if (len < QCOW2v3_HDR_SIZE)
        return -1;

745
    if (!(feat = virBitmapNew(VIR_STORAGE_FILE_FEATURE_LAST)))
746 747 748 749 750 751 752 753 754 755 756 757 758 759
        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;
}


760 761 762 763 764
/* 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 */
765
int
766
virStorageFileGetMetadataInternal(virStorageSourcePtr meta,
767 768
                                  char *buf,
                                  size_t len,
769
                                  int *backingFormat)
770
{
771
    int ret = -1;
E
Eric Blake 已提交
772

773 774
    VIR_DEBUG("path=%s, buf=%p, len=%zu, meta->format=%d",
              meta->path, buf, len, meta->format);
E
Eric Blake 已提交
775

776
    if (meta->format == VIR_STORAGE_FILE_AUTO)
777
        meta->format = virStorageFileProbeFormatFromBuf(meta->path, buf, len);
778

779 780 781 782
    if (meta->format <= VIR_STORAGE_FILE_NONE ||
        meta->format >= VIR_STORAGE_FILE_LAST) {
        virReportSystemError(EINVAL, _("unknown storage file meta->format %d"),
                             meta->format);
E
Eric Blake 已提交
783 784
        goto cleanup;
    }
785

786 787 788
    /* XXX we should consider moving virStorageBackendUpdateVolInfo
     * code into this method, for non-magic files
     */
789
    if (!fileTypeInfo[meta->format].magic)
E
Eric Blake 已提交
790
        goto done;
791

792
    /* Optionally extract capacity from file */
793 794
    if (fileTypeInfo[meta->format].sizeOffset != -1) {
        if ((fileTypeInfo[meta->format].sizeOffset + 8) > len)
E
Eric Blake 已提交
795
            goto done;
796

797
        if (fileTypeInfo[meta->format].endian == LV_LITTLE_ENDIAN)
E
Eric Blake 已提交
798
            meta->capacity = virReadBufInt64LE(buf +
799
                                               fileTypeInfo[meta->format].sizeOffset);
E
Eric Blake 已提交
800 801
        else
            meta->capacity = virReadBufInt64BE(buf +
802
                                               fileTypeInfo[meta->format].sizeOffset);
803
        /* Avoid unlikely, but theoretically possible overflow */
E
Eric Blake 已提交
804
        if (meta->capacity > (ULLONG_MAX /
805
                              fileTypeInfo[meta->format].sizeMultiplier))
E
Eric Blake 已提交
806
            goto done;
807
        meta->capacity *= fileTypeInfo[meta->format].sizeMultiplier;
808
    }
809

810
    if (fileTypeInfo[meta->format].qcowCryptOffset != -1) {
811
        int crypt_format;
812

E
Eric Blake 已提交
813
        crypt_format = virReadBufInt32BE(buf +
814
                                         fileTypeInfo[meta->format].qcowCryptOffset);
815 816
        if (crypt_format && !meta->encryption &&
            VIR_ALLOC(meta->encryption) < 0)
817
            goto cleanup;
818
    }
819

820 821
    if (fileTypeInfo[meta->format].getBackingStore != NULL) {
        int store = fileTypeInfo[meta->format].getBackingStore(&meta->backingStoreRaw,
822
                                                         backingFormat,
E
Eric Blake 已提交
823 824 825
                                                         buf, len);
        if (store == BACKING_STORE_INVALID)
            goto done;
826

E
Eric Blake 已提交
827 828
        if (store == BACKING_STORE_ERROR)
            goto cleanup;
829 830
    }

831 832
    if (fileTypeInfo[meta->format].getFeatures != NULL &&
        fileTypeInfo[meta->format].getFeatures(&meta->features, meta->format, buf, len) < 0)
833 834
        goto cleanup;

835
    if (meta->format == VIR_STORAGE_FILE_QCOW2 && meta->features &&
836 837 838
        VIR_STRDUP(meta->compat, "1.1") < 0)
        goto cleanup;

839
 done:
840
    ret = 0;
E
Eric Blake 已提交
841

842
 cleanup:
E
Eric Blake 已提交
843
    return ret;
844 845 846 847
}


/**
848
 * virStorageFileProbeFormat:
849
 *
850 851
 * Probe for the format of 'path', returning the detected
 * disk format.
852 853 854
 *
 * Callers are advised never to trust the returned 'format'
 * unless it is listed as VIR_STORAGE_FILE_RAW, since a
855
 * malicious guest can turn a raw file into any other non-raw
856 857 858 859 860
 * format at will.
 *
 * Best option: Don't use this function
 */
int
861
virStorageFileProbeFormat(const char *path, uid_t uid, gid_t gid)
862
{
863
    int fd;
864
    int ret = -1;
865
    struct stat sb;
866 867
    ssize_t len = VIR_STORAGE_MAX_HEADER;
    char *header = NULL;
868

869 870
    if ((fd = virFileOpenAs(path, O_RDONLY, 0, uid, gid, 0)) < 0) {
        virReportSystemError(-fd, _("Failed to open file '%s'"), path);
871 872 873
        return -1;
    }

874 875 876 877 878
    if (fstat(fd, &sb) < 0) {
        virReportSystemError(errno, _("cannot stat file '%s'"), path);
        goto cleanup;
    }

879 880
    /* No header to probe for directories */
    if (S_ISDIR(sb.st_mode)) {
881 882
        ret = VIR_STORAGE_FILE_DIR;
        goto cleanup;
883
    }
884 885 886 887 888 889

    if (lseek(fd, 0, SEEK_SET) == (off_t)-1) {
        virReportSystemError(errno, _("cannot set to start of '%s'"), path);
        goto cleanup;
    }

890
    if ((len = virFileReadHeaderFD(fd, len, &header)) < 0) {
891 892 893 894
        virReportSystemError(errno, _("cannot read header '%s'"), path);
        goto cleanup;
    }

895
    ret = virStorageFileProbeFormatFromBuf(path, header, len);
896

897
 cleanup:
898
    VIR_FREE(header);
899
    VIR_FORCE_CLOSE(fd);
900 901 902 903

    return ret;
}

904

905
static virStorageSourcePtr
906 907 908
virStorageFileMetadataNew(const char *path,
                          int format)
{
909
    virStorageSourcePtr ret = NULL;
910 911 912 913 914 915 916

    if (VIR_ALLOC(ret) < 0)
        return NULL;

    ret->format = format;
    ret->type = VIR_STORAGE_TYPE_FILE;

917 918
    if (VIR_STRDUP(ret->path, path) < 0)
        goto error;
919 920 921 922

    return ret;

 error:
923
    virStorageSourceFree(ret);
924 925 926 927
    return NULL;
}


928 929 930 931 932
/**
 * virStorageFileGetMetadataFromBuf:
 * @path: name of file, for error messages
 * @buf: header bytes from @path
 * @len: length of @buf
933 934
 * @backing: output malloc'd name of backing image, if any
 * @backingFormat: format of @backing
935
 *
E
Eric Blake 已提交
936 937 938 939
 * Extract metadata about the storage volume, including probing its
 * format.  Does not recurse.  Callers are advised not to trust the
 * learned format if a guest has ever used the volume when it was
 * raw, since a malicious guest can turn a raw file into any
940 941
 * other non-raw format at will.
 *
942
 * If the returned @backingFormat is VIR_STORAGE_FILE_AUTO
943 944 945 946
 * 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.
 *
947
 * Caller MUST free the result after use via virStorageSourceFree.
948
 */
949
virStorageSourcePtr
950 951 952
virStorageFileGetMetadataFromBuf(const char *path,
                                 char *buf,
                                 size_t len,
953 954
                                 char **backing,
                                 int *backingFormat)
955
{
956
    virStorageSourcePtr ret = NULL;
957
    virStorageSourcePtr meta = NULL;
958

E
Eric Blake 已提交
959
    if (!(meta = virStorageFileMetadataNew(path, VIR_STORAGE_FILE_AUTO)))
960
        return NULL;
961

962 963 964 965 966
    if (virStorageFileGetMetadataInternal(meta, buf, len,
                                          backingFormat) < 0)
        goto cleanup;
    if (VIR_STRDUP(*backing, meta->backingStoreRaw) < 0)
        goto cleanup;
967

968 969 970 971
    ret = meta;
    meta = NULL;
 cleanup:
    virStorageSourceFree(meta);
972
    return ret;
973 974 975 976
}


/* Internal version that also supports a containing directory name.  */
977
static int
978
virStorageFileGetMetadataFromFDInternal(virStorageSourcePtr meta,
979
                                        int fd,
980
                                        int *backingFormat)
981 982
{
    char *buf = NULL;
983
    ssize_t len = VIR_STORAGE_MAX_HEADER;
984
    struct stat sb;
985
    int ret = -1;
986
    int dummy;
987

988 989
    if (!backingFormat)
        backingFormat = &dummy;
990

991
    *backingFormat = VIR_STORAGE_FILE_NONE;
992

993 994 995
    if (fstat(fd, &sb) < 0) {
        virReportSystemError(errno,
                             _("cannot stat file '%s'"),
996
                             meta->relPath);
997
        return -1;
998 999 1000
    }

    if (S_ISDIR(sb.st_mode)) {
1001 1002
        /* No header to probe for directories, but also no backing file. Just
         * update the metadata.*/
1003 1004
        meta->type = VIR_STORAGE_TYPE_DIR;
        meta->format = VIR_STORAGE_FILE_DIR;
1005
        ret = 0;
1006 1007 1008 1009
        goto cleanup;
    }

    if (lseek(fd, 0, SEEK_SET) == (off_t)-1) {
1010
        virReportSystemError(errno, _("cannot seek to start of '%s'"), meta->relPath);
1011 1012 1013 1014
        goto cleanup;
    }

    if ((len = virFileReadHeaderFD(fd, len, &buf)) < 0) {
1015
        virReportSystemError(errno, _("cannot read header '%s'"), meta->relPath);
1016 1017 1018
        goto cleanup;
    }

1019
    ret = virStorageFileGetMetadataInternal(meta, buf, len, backingFormat);
1020

1021 1022 1023 1024 1025 1026
    if (ret == 0) {
        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;
    }
1027
 cleanup:
1028 1029 1030 1031 1032
    VIR_FREE(buf);
    return ret;
}


1033 1034 1035
/**
 * virStorageFileGetMetadataFromFD:
 *
1036 1037
 * Extract metadata about the storage volume with the specified
 * image format. If image format is VIR_STORAGE_FILE_AUTO, it
1038
 * will probe to automatically identify the format.  Does not recurse.
1039
 *
1040 1041 1042 1043
 * 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.
 *
1044
 * Caller MUST free the result after use via virStorageSourceFree.
1045
 */
1046
virStorageSourcePtr
1047 1048
virStorageFileGetMetadataFromFD(const char *path,
                                int fd,
1049 1050 1051
                                int format,
                                int *backingFormat)

1052
{
1053
    virStorageSourcePtr ret;
1054

1055 1056
    if (!(ret = virStorageFileMetadataNew(path, format)))
        return NULL;
1057

1058

1059
    if (virStorageFileGetMetadataFromFDInternal(ret, fd, backingFormat) < 0) {
1060
        virStorageSourceFree(ret);
1061
        return NULL;
1062 1063
    }

1064
    return ret;
1065 1066
}

1067

1068 1069 1070 1071 1072
/**
 * virStorageFileChainCheckBroken
 *
 * If CHAIN is broken, set *brokenFile to the broken file name,
 * otherwise set it to NULL. Caller MUST free *brokenFile after use.
1073 1074
 * Return 0 on success (including when brokenFile is set), negative on
 * error (allocation failure).
1075 1076
 */
int
1077
virStorageFileChainGetBroken(virStorageSourcePtr chain,
1078 1079
                             char **brokenFile)
{
1080
    virStorageSourcePtr tmp;
1081

1082 1083
    *brokenFile = NULL;

1084 1085 1086
    if (!chain)
        return 0;

1087
    for (tmp = chain; tmp; tmp = tmp->backingStore) {
1088 1089
        /* Break when we hit end of chain; report error if we detected
         * a missing backing file, infinite loop, or other error */
1090
        if (!tmp->backingStore && tmp->backingStoreRaw) {
1091 1092
            if (VIR_STRDUP(*brokenFile, tmp->backingStoreRaw) < 0)
                return -1;
1093

1094 1095 1096
           return 0;
        }
    }
1097

1098
    return 0;
1099 1100 1101
}


1102 1103 1104 1105 1106 1107
/**
 * virStorageFileResize:
 *
 * Change the capacity of the raw storage file at 'path'.
 */
int
1108 1109 1110 1111
virStorageFileResize(const char *path,
                     unsigned long long capacity,
                     unsigned long long orig_capacity,
                     bool pre_allocate)
1112
{
1113 1114
    int fd = -1;
    int ret = -1;
1115 1116 1117 1118 1119 1120
    int rc ATTRIBUTE_UNUSED;
    off_t offset ATTRIBUTE_UNUSED;
    off_t len ATTRIBUTE_UNUSED;

    offset = orig_capacity;
    len = capacity - orig_capacity;
1121 1122 1123 1124 1125 1126

    if ((fd = open(path, O_RDWR)) < 0) {
        virReportSystemError(errno, _("Unable to open '%s'"), path);
        goto cleanup;
    }

1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137
    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,
1138
                                 _("Failed to pre-allocate space for "
1139 1140 1141 1142 1143
                                   "file '%s'"), path);
            goto cleanup;
        }
#else
        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
1144
                       _("preallocate is not supported on this platform"));
1145
        goto cleanup;
1146 1147 1148 1149 1150 1151 1152
#endif
    } else {
        if (ftruncate(fd, capacity) < 0) {
            virReportSystemError(errno,
                                 _("Failed to truncate file '%s'"), path);
            goto cleanup;
        }
1153 1154
    }

1155 1156 1157 1158 1159 1160 1161
    if (VIR_CLOSE(fd) < 0) {
        virReportSystemError(errno, _("Unable to save '%s'"), path);
        goto cleanup;
    }

    ret = 0;

1162
 cleanup:
1163 1164
    VIR_FORCE_CLOSE(fd);
    return ret;
1165 1166
}

1167 1168 1169 1170 1171 1172

int virStorageFileIsClusterFS(const char *path)
{
    /* These are coherent cluster filesystems known to be safe for
     * migration with cache != none
     */
1173 1174 1175
    return virFileIsSharedFSType(path,
                                 VIR_FILE_SHFS_GFS2 |
                                 VIR_FILE_SHFS_OCFS);
1176
}
1177 1178

#ifdef LVS
1179 1180
int virStorageFileGetLVMKey(const char *path,
                            char **key)
1181 1182 1183 1184 1185
{
    /*
     *  # lvs --noheadings --unbuffered --nosuffix --options "uuid" LVNAME
     *    06UgP5-2rhb-w3Bo-3mdR-WeoL-pytO-SAa2ky
     */
1186
    int status;
1187 1188 1189 1190 1191 1192
    virCommandPtr cmd = virCommandNewArgList(
        LVS,
        "--noheadings", "--unbuffered", "--nosuffix",
        "--options", "uuid", path,
        NULL
        );
1193 1194 1195
    int ret = -1;

    *key = NULL;
1196 1197

    /* Run the program and capture its output */
1198 1199
    virCommandSetOutputBuffer(cmd, key);
    if (virCommandRun(cmd, &status) < 0)
1200 1201
        goto cleanup;

1202 1203 1204 1205 1206 1207
    /* 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) {
1208
        char *nl;
1209
        char *tmp = *key;
1210 1211 1212 1213 1214 1215

        /* Find first non-space character */
        while (*tmp && c_isspace(*tmp)) {
            tmp++;
        }
        /* Kill leading spaces */
1216 1217
        if (tmp != *key)
            memmove(*key, tmp, strlen(tmp)+1);
1218 1219

        /* Kill trailing newline */
1220
        if ((nl = strchr(*key, '\n')))
1221 1222 1223
            *nl = '\0';
    }

1224
    ret = 0;
1225

1226
 cleanup:
1227 1228 1229
    if (*key && STREQ(*key, ""))
        VIR_FREE(*key);

1230 1231
    virCommandFree(cmd);

1232
    return ret;
1233 1234
}
#else
1235 1236
int virStorageFileGetLVMKey(const char *path,
                            char **key ATTRIBUTE_UNUSED)
1237 1238
{
    virReportSystemError(ENOSYS, _("Unable to get LVM key for %s"), path);
1239
    return -1;
1240 1241 1242
}
#endif

1243
#ifdef WITH_UDEV
1244 1245
int virStorageFileGetSCSIKey(const char *path,
                             char **key)
1246
{
1247
    int status;
1248 1249 1250 1251 1252 1253 1254
    virCommandPtr cmd = virCommandNewArgList(
        "/lib/udev/scsi_id",
        "--replace-whitespace",
        "--whitelisted",
        "--device", path,
        NULL
        );
1255 1256 1257
    int ret = -1;

    *key = NULL;
1258 1259

    /* Run the program and capture its output */
1260 1261
    virCommandSetOutputBuffer(cmd, key);
    if (virCommandRun(cmd, &status) < 0)
1262 1263
        goto cleanup;

1264 1265 1266 1267 1268 1269
    /* 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');
1270 1271 1272 1273
        if (nl)
            *nl = '\0';
    }

1274 1275
    ret = 0;

1276
 cleanup:
1277 1278 1279
    if (*key && STREQ(*key, ""))
        VIR_FREE(*key);

1280 1281
    virCommandFree(cmd);

1282
    return ret;
1283 1284
}
#else
1285 1286
int virStorageFileGetSCSIKey(const char *path,
                             char **key ATTRIBUTE_UNUSED)
1287 1288
{
    virReportSystemError(ENOSYS, _("Unable to get SCSI key for %s"), path);
1289
    return -1;
1290 1291
}
#endif
1292

1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310
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;

E
Eric Blake 已提交
1311
    if (virStrToLong_uip(strings[1], &suffix, 10, &idx) < 0 ||
1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329
        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;
}

E
Eric Blake 已提交
1330 1331 1332 1333 1334 1335 1336 1337 1338 1339
/* 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.
1340
 */
1341
virStorageSourcePtr
1342
virStorageFileChainLookup(virStorageSourcePtr chain,
1343
                          virStorageSourcePtr startFrom,
1344
                          const char *name,
1345
                          unsigned int idx,
1346 1347
                          const char **parent)
{
1348
    virStorageSourcePtr prev = NULL;
1349
    const char *start = chain->path;
1350
    const char *tmp;
1351
    char *parentDir = NULL;
E
Eric Blake 已提交
1352
    bool nameIsFile = virStorageIsFile(name);
1353
    size_t i;
1354 1355 1356 1357

    if (!parent)
        parent = &tmp;
    *parent = NULL;
1358 1359 1360

    i = 0;
    if (startFrom) {
E
Eric Blake 已提交
1361
        while (chain && chain != startFrom->backingStore) {
1362 1363 1364
            chain = chain->backingStore;
            i++;
        }
E
Eric Blake 已提交
1365
        *parent = startFrom->path;
1366 1367
    }

E
Eric Blake 已提交
1368
    while (chain) {
1369
        if (!name && !idx) {
1370
            if (!chain->backingStore)
1371
                break;
1372 1373 1374 1375
        } else if (idx) {
            VIR_DEBUG("%zu: %s", i, chain->path);
            if (idx == i)
                break;
E
Eric Blake 已提交
1376
        } else {
1377 1378
            if (STREQ_NULLABLE(name, chain->relPath) ||
                STREQ(name, chain->path))
1379
                break;
E
Eric Blake 已提交
1380 1381
            if (nameIsFile && (chain->type == VIR_STORAGE_TYPE_FILE ||
                               chain->type == VIR_STORAGE_TYPE_BLOCK)) {
1382 1383 1384 1385 1386 1387 1388 1389 1390 1391
                if (prev) {
                    if (!(parentDir = mdir_name(prev->path))) {
                        virReportOOMError();
                        goto error;
                    }
                } else {
                    if (VIR_STRDUP(parentDir, ".") < 0)
                        goto error;
                }

E
Eric Blake 已提交
1392
                int result = virFileRelLinkPointsTo(parentDir, name,
1393
                                                    chain->path);
1394 1395

                VIR_FREE(parentDir);
E
Eric Blake 已提交
1396 1397 1398 1399 1400
                if (result < 0)
                    goto error;
                if (result > 0)
                    break;
            }
1401
        }
1402
        *parent = chain->path;
1403
        prev = chain;
1404
        chain = chain->backingStore;
1405
        i++;
1406
    }
1407

E
Eric Blake 已提交
1408
    if (!chain)
1409
        goto error;
1410
    return chain;
1411

1412
 error:
1413 1414 1415 1416 1417
    if (idx) {
        virReportError(VIR_ERR_INVALID_ARG,
                       _("could not find backing store %u in chain for '%s'"),
                       idx, start);
    } else if (name) {
E
Eric Blake 已提交
1418 1419 1420 1421 1422 1423 1424 1425
        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);
1426
    } else {
1427 1428 1429
        virReportError(VIR_ERR_INVALID_ARG,
                       _("could not find base image in chain for '%s'"),
                       start);
1430
    }
1431 1432 1433
    *parent = NULL;
    return NULL;
}
1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463


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);
}


1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474
static void
virStoragePermsFree(virStoragePermsPtr def)
{
    if (!def)
        return;

    VIR_FREE(def->label);
    VIR_FREE(def);
}


1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506
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;
}
1507 1508


1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706
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;
}


1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721
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;
}


1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734
void
virStorageSourcePoolDefFree(virStorageSourcePoolDefPtr def)
{
    if (!def)
        return;

    VIR_FREE(def->pool);
    VIR_FREE(def->volume);

    VIR_FREE(def);
}


1735 1736 1737 1738 1739 1740 1741 1742 1743 1744
int
virStorageSourceGetActualType(virStorageSourcePtr def)
{
    if (def->type == VIR_STORAGE_TYPE_VOLUME && def->srcpool)
        return def->srcpool->actualtype;

    return def->type;
}


1745 1746 1747 1748 1749 1750 1751
bool
virStorageSourceIsLocalStorage(virStorageSourcePtr src)
{
    return virStorageSourceGetActualType(src) != VIR_STORAGE_TYPE_NETWORK;
}


1752
/**
1753
 * virStorageSourceBackingStoreClear:
1754 1755 1756 1757 1758 1759
 *
 * @src: disk source to clear
 *
 * Clears information about backing store of the current storage file.
 */
void
1760
virStorageSourceBackingStoreClear(virStorageSourcePtr def)
1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773
{
    if (!def)
        return;

    VIR_FREE(def->relPath);
    VIR_FREE(def->backingStoreRaw);

    /* recursively free backing chain */
    virStorageSourceFree(def->backingStore);
    def->backingStore = NULL;
}


1774 1775 1776 1777 1778 1779 1780 1781 1782
void
virStorageSourceClear(virStorageSourcePtr def)
{
    size_t i;

    if (!def)
        return;

    VIR_FREE(def->path);
1783
    VIR_FREE(def->volume);
1784 1785
    virStorageSourcePoolDefFree(def->srcpool);
    VIR_FREE(def->driverName);
E
Eric Blake 已提交
1786 1787
    virBitmapFree(def->features);
    VIR_FREE(def->compat);
1788 1789 1790 1791 1792 1793 1794
    virStorageEncryptionFree(def->encryption);

    if (def->seclabels) {
        for (i = 0; i < def->nseclabels; i++)
            virSecurityDeviceLabelDefFree(def->seclabels[i]);
        VIR_FREE(def->seclabels);
    }
1795
    virStoragePermsFree(def->perms);
E
Eric Blake 已提交
1796
    VIR_FREE(def->timestamps);
1797 1798

    virStorageNetHostDefFree(def->nhosts, def->hosts);
1799
    virStorageAuthDefFree(def->auth);
1800

1801
    virStorageSourceBackingStoreClear(def);
1802
}
1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813


void
virStorageSourceFree(virStorageSourcePtr def)
{
    if (!def)
        return;

    virStorageSourceClear(def);
    VIR_FREE(def);
}
1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825


static virStorageSourcePtr
virStorageSourceNewFromBackingRelative(virStorageSourcePtr parent,
                                       const char *rel)
{
    char *dirname = NULL;
    virStorageSourcePtr ret;

    if (VIR_ALLOC(ret) < 0)
        return NULL;

1826 1827 1828 1829
    /* store relative name */
    if (VIR_STRDUP(ret->relPath, parent->backingStoreRaw) < 0)
        goto error;

1830 1831
    if (!(dirname = mdir_name(parent->path))) {
        virReportOOMError();
1832
        goto error;
1833
    }
1834

1835 1836
    if (STRNEQ(dirname, "/")) {
        if (virAsprintf(&ret->path, "%s/%s", dirname, rel) < 0)
1837 1838
            goto error;
    } else {
1839 1840 1841 1842 1843
        if (virAsprintf(&ret->path, "/%s", rel) < 0)
            goto error;
    }

    if (virStorageSourceGetActualType(parent) == VIR_STORAGE_TYPE_NETWORK) {
1844 1845 1846 1847 1848 1849 1850 1851 1852 1853
        ret->type = VIR_STORAGE_TYPE_NETWORK;

        /* copy the host network part */
        ret->protocol = parent->protocol;
        if (!(ret->hosts = virStorageNetHostDefCopy(parent->nhosts, parent->hosts)))
            goto error;
        ret->nhosts = parent->nhosts;

        if (VIR_STRDUP(ret->volume, parent->volume) < 0)
            goto error;
1854 1855 1856
    } else {
        /* set the type to _FILE, the caller shall update it to the actual type */
        ret->type = VIR_STORAGE_TYPE_FILE;
1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071
    }

 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 (!(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 (VIR_ALLOC(src->hosts) < 0)
        goto cleanup;

    src->nhosts = 1;

    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
virStorageSourceParseBackingColon(virStorageSourcePtr src,
                                  const char *path)
{
    char **backing = NULL;
    int ret = -1;

    if (!(backing = virStringSplit(path, ":", 0)))
        goto cleanup;

    if (!backing[0] ||
        (src->protocol = virStorageNetProtocolTypeFromString(backing[0])) < 0) {
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("invalid backing protocol '%s'"),
                       NULLSTR(backing[0]));
        goto cleanup;
    }

    switch ((virStorageNetProtocol) src->protocol) {
    case VIR_STORAGE_NET_PROTOCOL_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"),
                           path);
            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"),
                               path);
                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'"),
                               path);
                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'"),
                               path);
                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;
        }
     break;

    case VIR_STORAGE_NET_PROTOCOL_SHEEPDOG:
    case VIR_STORAGE_NET_PROTOCOL_RBD:
    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"),
                       backing[0]);
        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"),
                       backing[0]);
        goto cleanup;
    }

    ret = 0;

 cleanup:
    virStringFreeList(backing);
    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;

2072 2073
        if (VIR_STRDUP(ret->path, path) < 0)
            goto error;
2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122
    } 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;
                }
            }
        }
    }

    return ret;
}
2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147


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);
    }

2148
    if (virBufferCheckError(&buf) < 0)
2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337
        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;
}
2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387


/**
 * 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) {
2388
        if (!next->relPath) {
2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423
            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;
}