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-rw-r--r--block/dmg.c228
1 files changed, 133 insertions, 95 deletions
diff --git a/block/dmg.c b/block/dmg.c
index cdad28fe14..c571ac9121 100644
--- a/block/dmg.c
+++ b/block/dmg.c
@@ -171,19 +171,138 @@ static int64_t dmg_find_koly_offset(BlockDriverState *file_bs, Error **errp)
return -EINVAL;
}
+/* used when building the sector table */
+typedef struct DmgHeaderState {
+ /* used internally by dmg_read_mish_block to remember offsets of blocks
+ * across calls */
+ uint64_t last_in_offset;
+ uint64_t last_out_offset;
+ /* exported for dmg_open */
+ uint32_t max_compressed_size;
+ uint32_t max_sectors_per_chunk;
+} DmgHeaderState;
+
+static int dmg_read_mish_block(BlockDriverState *bs, DmgHeaderState *ds,
+ int64_t offset, uint32_t count)
+{
+ BDRVDMGState *s = bs->opaque;
+ uint32_t type, i;
+ int ret;
+ size_t new_size;
+ uint32_t chunk_count;
+
+ ret = read_uint32(bs, offset, &type);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ /* skip data that is not a valid MISH block (invalid magic or too small) */
+ if (type != 0x6d697368 || count < 244) {
+ /* assume success for now */
+ return 0;
+ }
+
+ offset += 4;
+ offset += 200;
+
+ chunk_count = (count - 204) / 40;
+ new_size = sizeof(uint64_t) * (s->n_chunks + chunk_count);
+ s->types = g_realloc(s->types, new_size / 2);
+ s->offsets = g_realloc(s->offsets, new_size);
+ s->lengths = g_realloc(s->lengths, new_size);
+ s->sectors = g_realloc(s->sectors, new_size);
+ s->sectorcounts = g_realloc(s->sectorcounts, new_size);
+
+ for (i = s->n_chunks; i < s->n_chunks + chunk_count; i++) {
+ ret = read_uint32(bs, offset, &s->types[i]);
+ if (ret < 0) {
+ goto fail;
+ }
+ offset += 4;
+ if (s->types[i] != 0x80000005 && s->types[i] != 1 &&
+ s->types[i] != 2) {
+ if (s->types[i] == 0xffffffff && i > 0) {
+ ds->last_in_offset = s->offsets[i - 1] + s->lengths[i - 1];
+ ds->last_out_offset = s->sectors[i - 1] +
+ s->sectorcounts[i - 1];
+ }
+ chunk_count--;
+ i--;
+ offset += 36;
+ continue;
+ }
+ offset += 4;
+
+ ret = read_uint64(bs, offset, &s->sectors[i]);
+ if (ret < 0) {
+ goto fail;
+ }
+ s->sectors[i] += ds->last_out_offset;
+ offset += 8;
+
+ ret = read_uint64(bs, offset, &s->sectorcounts[i]);
+ if (ret < 0) {
+ goto fail;
+ }
+ offset += 8;
+
+ if (s->sectorcounts[i] > DMG_SECTORCOUNTS_MAX) {
+ error_report("sector count %" PRIu64 " for chunk %" PRIu32
+ " is larger than max (%u)",
+ s->sectorcounts[i], i, DMG_SECTORCOUNTS_MAX);
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ ret = read_uint64(bs, offset, &s->offsets[i]);
+ if (ret < 0) {
+ goto fail;
+ }
+ s->offsets[i] += ds->last_in_offset;
+ offset += 8;
+
+ ret = read_uint64(bs, offset, &s->lengths[i]);
+ if (ret < 0) {
+ goto fail;
+ }
+ offset += 8;
+
+ if (s->lengths[i] > DMG_LENGTHS_MAX) {
+ error_report("length %" PRIu64 " for chunk %" PRIu32
+ " is larger than max (%u)",
+ s->lengths[i], i, DMG_LENGTHS_MAX);
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ update_max_chunk_size(s, i, &ds->max_compressed_size,
+ &ds->max_sectors_per_chunk);
+ }
+ s->n_chunks += chunk_count;
+ return 0;
+
+fail:
+ return ret;
+}
+
static int dmg_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
BDRVDMGState *s = bs->opaque;
- uint64_t info_begin, info_end, last_in_offset, last_out_offset;
- uint32_t count, tmp;
- uint32_t max_compressed_size = 1, max_sectors_per_chunk = 1, i;
+ DmgHeaderState ds;
+ uint64_t info_begin, info_end;
+ uint32_t count, rsrc_data_offset;
int64_t offset;
int ret;
bs->read_only = 1;
s->n_chunks = 0;
s->offsets = s->lengths = s->sectors = s->sectorcounts = NULL;
+ /* used by dmg_read_mish_block to keep track of the current I/O position */
+ ds.last_in_offset = 0;
+ ds.last_out_offset = 0;
+ ds.max_compressed_size = 1;
+ ds.max_sectors_per_chunk = 1;
/* locate the UDIF trailer */
offset = dmg_find_koly_offset(bs->file, errp);
@@ -200,10 +319,10 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags,
goto fail;
}
- ret = read_uint32(bs, info_begin, &tmp);
+ ret = read_uint32(bs, info_begin, &rsrc_data_offset);
if (ret < 0) {
goto fail;
- } else if (tmp != 0x100) {
+ } else if (rsrc_data_offset != 0x100) {
ret = -EINVAL;
goto fail;
}
@@ -215,15 +334,15 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags,
ret = -EINVAL;
goto fail;
}
+ /* end of resource data, ignoring the following resource map */
info_end = info_begin + count;
+ /* begin of resource data (consisting of one or more resources) */
offset = info_begin + 0x100;
- /* read offsets */
- last_in_offset = last_out_offset = 0;
+ /* read offsets (mish blocks) from one or more resources in resource data */
while (offset < info_end) {
- uint32_t type;
-
+ /* size of following resource */
ret = read_uint32(bs, offset, &count);
if (ret < 0) {
goto fail;
@@ -233,100 +352,19 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags,
}
offset += 4;
- ret = read_uint32(bs, offset, &type);
+ ret = dmg_read_mish_block(bs, &ds, offset, count);
if (ret < 0) {
goto fail;
}
-
- if (type == 0x6d697368 && count >= 244) {
- size_t new_size;
- uint32_t chunk_count;
-
- offset += 4;
- offset += 200;
-
- chunk_count = (count - 204) / 40;
- new_size = sizeof(uint64_t) * (s->n_chunks + chunk_count);
- s->types = g_realloc(s->types, new_size / 2);
- s->offsets = g_realloc(s->offsets, new_size);
- s->lengths = g_realloc(s->lengths, new_size);
- s->sectors = g_realloc(s->sectors, new_size);
- s->sectorcounts = g_realloc(s->sectorcounts, new_size);
-
- for (i = s->n_chunks; i < s->n_chunks + chunk_count; i++) {
- ret = read_uint32(bs, offset, &s->types[i]);
- if (ret < 0) {
- goto fail;
- }
- offset += 4;
- if (s->types[i] != 0x80000005 && s->types[i] != 1 &&
- s->types[i] != 2) {
- if (s->types[i] == 0xffffffff && i > 0) {
- last_in_offset = s->offsets[i - 1] + s->lengths[i - 1];
- last_out_offset = s->sectors[i - 1] +
- s->sectorcounts[i - 1];
- }
- chunk_count--;
- i--;
- offset += 36;
- continue;
- }
- offset += 4;
-
- ret = read_uint64(bs, offset, &s->sectors[i]);
- if (ret < 0) {
- goto fail;
- }
- s->sectors[i] += last_out_offset;
- offset += 8;
-
- ret = read_uint64(bs, offset, &s->sectorcounts[i]);
- if (ret < 0) {
- goto fail;
- }
- offset += 8;
-
- if (s->sectorcounts[i] > DMG_SECTORCOUNTS_MAX) {
- error_report("sector count %" PRIu64 " for chunk %" PRIu32
- " is larger than max (%u)",
- s->sectorcounts[i], i, DMG_SECTORCOUNTS_MAX);
- ret = -EINVAL;
- goto fail;
- }
-
- ret = read_uint64(bs, offset, &s->offsets[i]);
- if (ret < 0) {
- goto fail;
- }
- s->offsets[i] += last_in_offset;
- offset += 8;
-
- ret = read_uint64(bs, offset, &s->lengths[i]);
- if (ret < 0) {
- goto fail;
- }
- offset += 8;
-
- if (s->lengths[i] > DMG_LENGTHS_MAX) {
- error_report("length %" PRIu64 " for chunk %" PRIu32
- " is larger than max (%u)",
- s->lengths[i], i, DMG_LENGTHS_MAX);
- ret = -EINVAL;
- goto fail;
- }
-
- update_max_chunk_size(s, i, &max_compressed_size,
- &max_sectors_per_chunk);
- }
- s->n_chunks += chunk_count;
- }
+ /* advance offset by size of resource */
+ offset += count;
}
/* initialize zlib engine */
s->compressed_chunk = qemu_try_blockalign(bs->file,
- max_compressed_size + 1);
+ ds.max_compressed_size + 1);
s->uncompressed_chunk = qemu_try_blockalign(bs->file,
- 512 * max_sectors_per_chunk);
+ 512 * ds.max_sectors_per_chunk);
if (s->compressed_chunk == NULL || s->uncompressed_chunk == NULL) {
ret = -ENOMEM;
goto fail;
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-02 19:42:10 +0000