/* BlockDriver implementation for "raw" format driver * * Copyright (C) 2010-2016 Red Hat, Inc. * Copyright (C) 2010, Blue Swirl <blauwirbel@gmail.com> * Copyright (C) 2009, Anthony Liguori <aliguori@us.ibm.com> * * Author: * Laszlo Ersek <lersek@redhat.com> * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to * deal in the Software without restriction, including without limitation the * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or * sell copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. */ #include "qemu/osdep.h" #include "block/block_int.h" #include "qapi/error.h" #include "qemu/option.h" typedef struct BDRVRawState { uint64_t offset; uint64_t size; bool has_size; } BDRVRawState; static QemuOptsList raw_runtime_opts = { .name = "raw", .head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head), .desc = { { .name = "offset", .type = QEMU_OPT_SIZE, .help = "offset in the disk where the image starts", }, { .name = "size", .type = QEMU_OPT_SIZE, .help = "virtual disk size", }, { /* end of list */ } }, }; static QemuOptsList raw_create_opts = { .name = "raw-create-opts", .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head), .desc = { { .name = BLOCK_OPT_SIZE, .type = QEMU_OPT_SIZE, .help = "Virtual disk size" }, { /* end of list */ } } }; static int raw_read_options(QDict *options, BlockDriverState *bs, BDRVRawState *s, Error **errp) { Error *local_err = NULL; QemuOpts *opts = NULL; int64_t real_size = 0; int ret; real_size = bdrv_getlength(bs->file->bs); if (real_size < 0) { error_setg_errno(errp, -real_size, "Could not get image size"); return real_size; } opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort); qemu_opts_absorb_qdict(opts, options, &local_err); if (local_err) { error_propagate(errp, local_err); ret = -EINVAL; goto end; } s->offset = qemu_opt_get_size(opts, "offset", 0); if (s->offset > real_size) { error_setg(errp, "Offset (%" PRIu64 ") cannot be greater than " "size of the containing file (%" PRId64 ")", s->offset, real_size); ret = -EINVAL; goto end; } if (qemu_opt_find(opts, "size") != NULL) { s->size = qemu_opt_get_size(opts, "size", 0); s->has_size = true; } else { s->has_size = false; s->size = real_size - s->offset; } /* Check size and offset */ if ((real_size - s->offset) < s->size) { error_setg(errp, "The sum of offset (%" PRIu64 ") and size " "(%" PRIu64 ") has to be smaller or equal to the " " actual size of the containing file (%" PRId64 ")", s->offset, s->size, real_size); ret = -EINVAL; goto end; } /* Make sure size is multiple of BDRV_SECTOR_SIZE to prevent rounding * up and leaking out of the specified area. */ if (s->has_size && !QEMU_IS_ALIGNED(s->size, BDRV_SECTOR_SIZE)) { error_setg(errp, "Specified size is not multiple of %llu", BDRV_SECTOR_SIZE); ret = -EINVAL; goto end; } ret = 0; end: qemu_opts_del(opts); return ret; } static int raw_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, Error **errp) { assert(reopen_state != NULL); assert(reopen_state->bs != NULL); reopen_state->opaque = g_new0(BDRVRawState, 1); return raw_read_options( reopen_state->options, reopen_state->bs, reopen_state->opaque, errp); } static void raw_reopen_commit(BDRVReopenState *state) { BDRVRawState *new_s = state->opaque; BDRVRawState *s = state->bs->opaque; memcpy(s, new_s, sizeof(BDRVRawState)); g_free(state->opaque); state->opaque = NULL; } static void raw_reopen_abort(BDRVReopenState *state) { g_free(state->opaque); state->opaque = NULL; } static int coroutine_fn raw_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) { BDRVRawState *s = bs->opaque; if (offset > UINT64_MAX - s->offset) { return -EINVAL; } offset += s->offset; BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags); } static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) { BDRVRawState *s = bs->opaque; void *buf = NULL; BlockDriver *drv; QEMUIOVector local_qiov; int ret; if (s->has_size && (offset > s->size || bytes > (s->size - offset))) { /* There's not enough space for the data. Don't write anything and just * fail to prevent leaking out of the size specified in options. */ return -ENOSPC; } if (offset > UINT64_MAX - s->offset) { ret = -EINVAL; goto fail; } if (bs->probed && offset < BLOCK_PROBE_BUF_SIZE && bytes) { /* Handling partial writes would be a pain - so we just * require that guests have 512-byte request alignment if * probing occurred */ QEMU_BUILD_BUG_ON(BLOCK_PROBE_BUF_SIZE != 512); QEMU_BUILD_BUG_ON(BDRV_SECTOR_SIZE != 512); assert(offset == 0 && bytes >= BLOCK_PROBE_BUF_SIZE); buf = qemu_try_blockalign(bs->file->bs, 512); if (!buf) { ret = -ENOMEM; goto fail; } ret = qemu_iovec_to_buf(qiov, 0, buf, 512); if (ret != 512) { ret = -EINVAL; goto fail; } drv = bdrv_probe_all(buf, 512, NULL); if (drv != bs->drv) { ret = -EPERM; goto fail; } /* Use the checked buffer, a malicious guest might be overwriting its * original buffer in the background. */ qemu_iovec_init(&local_qiov, qiov->niov + 1); qemu_iovec_add(&local_qiov, buf, 512); qemu_iovec_concat(&local_qiov, qiov, 512, qiov->size - 512); qiov = &local_qiov; } offset += s->offset; BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); ret = bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags); fail: if (qiov == &local_qiov) { qemu_iovec_destroy(&local_qiov); } qemu_vfree(buf); return ret; } static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file) { BDRVRawState *s = bs->opaque; *pnum = nb_sectors; *file = bs->file->bs; sector_num += s->offset / BDRV_SECTOR_SIZE; return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA | (sector_num << BDRV_SECTOR_BITS); } static int coroutine_fn raw_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int count, BdrvRequestFlags flags) { BDRVRawState *s = bs->opaque; if (offset > UINT64_MAX - s->offset) { return -EINVAL; } offset += s->offset; return bdrv_co_pwrite_zeroes(bs->file, offset, count, flags); } static int coroutine_fn raw_co_pdiscard(BlockDriverState *bs, int64_t offset, int count) { BDRVRawState *s = bs->opaque; if (offset > UINT64_MAX - s->offset) { return -EINVAL; } offset += s->offset; return bdrv_co_pdiscard(bs->file->bs, offset, count); } static int64_t raw_getlength(BlockDriverState *bs) { int64_t len; BDRVRawState *s = bs->opaque; /* Update size. It should not change unless the file was externally * modified. */ len = bdrv_getlength(bs->file->bs); if (len < 0) { return len; } if (len < s->offset) { s->size = 0; } else { if (s->has_size) { /* Try to honour the size */ s->size = MIN(s->size, len - s->offset); } else { s->size = len - s->offset; } } return s->size; } static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) { return bdrv_get_info(bs->file->bs, bdi); } static void raw_refresh_limits(BlockDriverState *bs, Error **errp) { if (bs->probed) { /* To make it easier to protect the first sector, any probed * image is restricted to read-modify-write on sub-sector * operations. */ bs->bl.request_alignment = BDRV_SECTOR_SIZE; } } static int raw_truncate(BlockDriverState *bs, int64_t offset, Error **errp) { BDRVRawState *s = bs->opaque; if (s->has_size) { error_setg(errp, "Cannot resize fixed-size raw disks"); return -ENOTSUP; } if (INT64_MAX - offset < s->offset) { error_setg(errp, "Disk size too large for the chosen offset"); return -EINVAL; } s->size = offset; offset += s->offset; return bdrv_truncate(bs->file, offset, errp); } static int raw_media_changed(BlockDriverState *bs) { return bdrv_media_changed(bs->file->bs); } static void raw_eject(BlockDriverState *bs, bool eject_flag) { bdrv_eject(bs->file->bs, eject_flag); } static void raw_lock_medium(BlockDriverState *bs, bool locked) { bdrv_lock_medium(bs->file->bs, locked); } static int raw_co_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) { BDRVRawState *s = bs->opaque; if (s->offset || s->has_size) { return -ENOTSUP; } return bdrv_co_ioctl(bs->file->bs, req, buf); } static int raw_has_zero_init(BlockDriverState *bs) { return bdrv_has_zero_init(bs->file->bs); } static int raw_create(const char *filename, QemuOpts *opts, Error **errp) { return bdrv_create_file(filename, opts, errp); } static int raw_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { BDRVRawState *s = bs->opaque; int ret; bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, false, errp); if (!bs->file) { return -EINVAL; } bs->sg = bs->file->bs->sg; bs->supported_write_flags = BDRV_REQ_FUA & bs->file->bs->supported_write_flags; bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) & bs->file->bs->supported_zero_flags; if (bs->probed && !bdrv_is_read_only(bs)) { fprintf(stderr, "WARNING: Image format was not specified for '%s' and probing " "guessed raw.\n" " Automatically detecting the format is dangerous for " "raw images, write operations on block 0 will be restricted.\n" " Specify the 'raw' format explicitly to remove the " "restrictions.\n", bs->file->bs->filename); } ret = raw_read_options(options, bs, s, errp); if (ret < 0) { return ret; } if (bs->sg && (s->offset || s->has_size)) { error_setg(errp, "Cannot use offset/size with SCSI generic devices"); return -EINVAL; } return 0; } static void raw_close(BlockDriverState *bs) { } static int raw_probe(const uint8_t *buf, int buf_size, const char *filename) { /* smallest possible positive score so that raw is used if and only if no * other block driver works */ return 1; } static int raw_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz) { BDRVRawState *s = bs->opaque; int ret; ret = bdrv_probe_blocksizes(bs->file->bs, bsz); if (ret < 0) { return ret; } if (!QEMU_IS_ALIGNED(s->offset, MAX(bsz->log, bsz->phys))) { return -ENOTSUP; } return 0; } static int raw_probe_geometry(BlockDriverState *bs, HDGeometry *geo) { BDRVRawState *s = bs->opaque; if (s->offset || s->has_size) { return -ENOTSUP; } return bdrv_probe_geometry(bs->file->bs, geo); } BlockDriver bdrv_raw = { .format_name = "raw", .instance_size = sizeof(BDRVRawState), .bdrv_probe = &raw_probe, .bdrv_reopen_prepare = &raw_reopen_prepare, .bdrv_reopen_commit = &raw_reopen_commit, .bdrv_reopen_abort = &raw_reopen_abort, .bdrv_open = &raw_open, .bdrv_close = &raw_close, .bdrv_child_perm = bdrv_filter_default_perms, .bdrv_create = &raw_create, .bdrv_co_preadv = &raw_co_preadv, .bdrv_co_pwritev = &raw_co_pwritev, .bdrv_co_pwrite_zeroes = &raw_co_pwrite_zeroes, .bdrv_co_pdiscard = &raw_co_pdiscard, .bdrv_co_get_block_status = &raw_co_get_block_status, .bdrv_truncate = &raw_truncate, .bdrv_getlength = &raw_getlength, .has_variable_length = true, .bdrv_get_info = &raw_get_info, .bdrv_refresh_limits = &raw_refresh_limits, .bdrv_probe_blocksizes = &raw_probe_blocksizes, .bdrv_probe_geometry = &raw_probe_geometry, .bdrv_media_changed = &raw_media_changed, .bdrv_eject = &raw_eject, .bdrv_lock_medium = &raw_lock_medium, .bdrv_co_ioctl = &raw_co_ioctl, .create_opts = &raw_create_opts, .bdrv_has_zero_init = &raw_has_zero_init }; static void bdrv_raw_init(void) { bdrv_register(&bdrv_raw); } block_init(bdrv_raw_init);