[mirror_qemu.git] / block / dmg.c

/*
 * QEMU Block driver for DMG images
 *
 * Copyright (c) 2004 Johannes E. Schindelin
 *
 * 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-common.h"
#include "block/block_int.h"
#include "qemu/bswap.h"
#include "qemu/module.h"
#include <zlib.h>

enum {
    /* Limit chunk sizes to prevent unreasonable amounts of memory being used
     * or truncating when converting to 32-bit types
     */
    DMG_LENGTHS_MAX = 64 * 1024 * 1024, /* 64 MB */
    DMG_SECTORCOUNTS_MAX = DMG_LENGTHS_MAX / 512,
};

typedef struct BDRVDMGState {
    CoMutex lock;
    /* each chunk contains a certain number of sectors,
     * offsets[i] is the offset in the .dmg file,
     * lengths[i] is the length of the compressed chunk,
     * sectors[i] is the sector beginning at offsets[i],
     * sectorcounts[i] is the number of sectors in that chunk,
     * the sectors array is ordered
     * 0<=i<n_chunks */

    uint32_t n_chunks;
    uint32_t* types;
    uint64_t* offsets;
    uint64_t* lengths;
    uint64_t* sectors;
    uint64_t* sectorcounts;
    uint32_t current_chunk;
    uint8_t *compressed_chunk;
    uint8_t *uncompressed_chunk;
    z_stream zstream;
} BDRVDMGState;

static int dmg_probe(const uint8_t *buf, int buf_size, const char *filename)
{
    int len;

    if (!filename) {
        return 0;
    }

    len = strlen(filename);
    if (len > 4 && !strcmp(filename + len - 4, ".dmg")) {
        return 2;
    }
    return 0;
}

static int read_uint64(BlockDriverState *bs, int64_t offset, uint64_t *result)
{
    uint64_t buffer;
    int ret;

    ret = bdrv_pread(bs->file, offset, &buffer, 8);
    if (ret < 0) {
        return ret;
    }

    *result = be64_to_cpu(buffer);
    return 0;
}

static int read_uint32(BlockDriverState *bs, int64_t offset, uint32_t *result)
{
    uint32_t buffer;
    int ret;

    ret = bdrv_pread(bs->file, offset, &buffer, 4);
    if (ret < 0) {
        return ret;
    }

    *result = be32_to_cpu(buffer);
    return 0;
}

/* Increase max chunk sizes, if necessary.  This function is used to calculate
 * the buffer sizes needed for compressed/uncompressed chunk I/O.
 */
static void update_max_chunk_size(BDRVDMGState *s, uint32_t chunk,
                                  uint32_t *max_compressed_size,
                                  uint32_t *max_sectors_per_chunk)
{
    uint32_t compressed_size = 0;
    uint32_t uncompressed_sectors = 0;

    switch (s->types[chunk]) {
    case 0x80000005: /* zlib compressed */
        compressed_size = s->lengths[chunk];
        uncompressed_sectors = s->sectorcounts[chunk];
        break;
    case 1: /* copy */
        uncompressed_sectors = (s->lengths[chunk] + 511) / 512;
        break;
    case 2: /* zero */
        uncompressed_sectors = s->sectorcounts[chunk];
        break;
    }

    if (compressed_size > *max_compressed_size) {
        *max_compressed_size = compressed_size;
    }
    if (uncompressed_sectors > *max_sectors_per_chunk) {
        *max_sectors_per_chunk = uncompressed_sectors;
    }
}

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;
    int64_t offset;
    int ret;

    bs->read_only = 1;
    s->n_chunks = 0;
    s->offsets = s->lengths = s->sectors = s->sectorcounts = NULL;

    /* read offset of info blocks */
    offset = bdrv_getlength(bs->file);
    if (offset < 0) {
        ret = offset;
        goto fail;
    }
    offset -= 0x1d8;

    ret = read_uint64(bs, offset, &info_begin);
    if (ret < 0) {
        goto fail;
    } else if (info_begin == 0) {
        ret = -EINVAL;
        goto fail;
    }

    ret = read_uint32(bs, info_begin, &tmp);
    if (ret < 0) {
        goto fail;
    } else if (tmp != 0x100) {
        ret = -EINVAL;
        goto fail;
    }

    ret = read_uint32(bs, info_begin + 4, &count);
    if (ret < 0) {
        goto fail;
    } else if (count == 0) {
        ret = -EINVAL;
        goto fail;
    }
    info_end = info_begin + count;

    offset = info_begin + 0x100;

    /* read offsets */
    last_in_offset = last_out_offset = 0;
    while (offset < info_end) {
        uint32_t type;

        ret = read_uint32(bs, offset, &count);
        if (ret < 0) {
            goto fail;
        } else if (count == 0) {
            ret = -EINVAL;
            goto fail;
        }
        offset += 4;

        ret = read_uint32(bs, offset, &type);
        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;
        }
    }

    /* initialize zlib engine */
    s->compressed_chunk = g_malloc(max_compressed_size + 1);
    s->uncompressed_chunk = g_malloc(512 * max_sectors_per_chunk);
    if (inflateInit(&s->zstream) != Z_OK) {
        ret = -EINVAL;
        goto fail;
    }

    s->current_chunk = s->n_chunks;

    qemu_co_mutex_init(&s->lock);
    return 0;

fail:
    g_free(s->types);
    g_free(s->offsets);
    g_free(s->lengths);
    g_free(s->sectors);
    g_free(s->sectorcounts);
    g_free(s->compressed_chunk);
    g_free(s->uncompressed_chunk);
    return ret;
}

static inline int is_sector_in_chunk(BDRVDMGState* s,
                uint32_t chunk_num, uint64_t sector_num)
{
    if (chunk_num >= s->n_chunks || s->sectors[chunk_num] > sector_num ||
            s->sectors[chunk_num] + s->sectorcounts[chunk_num] <= sector_num) {
        return 0;
    } else {
        return -1;
    }
}

static inline uint32_t search_chunk(BDRVDMGState *s, uint64_t sector_num)
{
    /* binary search */
    uint32_t chunk1 = 0, chunk2 = s->n_chunks, chunk3;
    while (chunk1 != chunk2) {
        chunk3 = (chunk1 + chunk2) / 2;
        if (s->sectors[chunk3] > sector_num) {
            chunk2 = chunk3;
        } else if (s->sectors[chunk3] + s->sectorcounts[chunk3] > sector_num) {
            return chunk3;
        } else {
            chunk1 = chunk3;
        }
    }
    return s->n_chunks; /* error */
}

static inline int dmg_read_chunk(BlockDriverState *bs, uint64_t sector_num)
{
    BDRVDMGState *s = bs->opaque;

    if (!is_sector_in_chunk(s, s->current_chunk, sector_num)) {
        int ret;
        uint32_t chunk = search_chunk(s, sector_num);

        if (chunk >= s->n_chunks) {
            return -1;
        }

        s->current_chunk = s->n_chunks;
        switch (s->types[chunk]) {
        case 0x80000005: { /* zlib compressed */
            /* we need to buffer, because only the chunk as whole can be
             * inflated. */
            ret = bdrv_pread(bs->file, s->offsets[chunk],
                             s->compressed_chunk, s->lengths[chunk]);
            if (ret != s->lengths[chunk]) {
                return -1;
            }

            s->zstream.next_in = s->compressed_chunk;
            s->zstream.avail_in = s->lengths[chunk];
            s->zstream.next_out = s->uncompressed_chunk;
            s->zstream.avail_out = 512 * s->sectorcounts[chunk];
            ret = inflateReset(&s->zstream);
            if (ret != Z_OK) {
                return -1;
            }
            ret = inflate(&s->zstream, Z_FINISH);
            if (ret != Z_STREAM_END ||
                s->zstream.total_out != 512 * s->sectorcounts[chunk]) {
                return -1;
            }
            break; }
        case 1: /* copy */
            ret = bdrv_pread(bs->file, s->offsets[chunk],
                             s->uncompressed_chunk, s->lengths[chunk]);
            if (ret != s->lengths[chunk]) {
                return -1;
            }
            break;
        case 2: /* zero */
            memset(s->uncompressed_chunk, 0, 512 * s->sectorcounts[chunk]);
            break;
        }
        s->current_chunk = chunk;
    }
    return 0;
}

static int dmg_read(BlockDriverState *bs, int64_t sector_num,
                    uint8_t *buf, int nb_sectors)
{
    BDRVDMGState *s = bs->opaque;
    int i;

    for (i = 0; i < nb_sectors; i++) {
        uint32_t sector_offset_in_chunk;
        if (dmg_read_chunk(bs, sector_num + i) != 0) {
            return -1;
        }
        sector_offset_in_chunk = sector_num + i - s->sectors[s->current_chunk];
        memcpy(buf + i * 512,
               s->uncompressed_chunk + sector_offset_in_chunk * 512, 512);
    }
    return 0;
}

static coroutine_fn int dmg_co_read(BlockDriverState *bs, int64_t sector_num,
                                    uint8_t *buf, int nb_sectors)
{
    int ret;
    BDRVDMGState *s = bs->opaque;
    qemu_co_mutex_lock(&s->lock);
    ret = dmg_read(bs, sector_num, buf, nb_sectors);
    qemu_co_mutex_unlock(&s->lock);
    return ret;
}

static void dmg_close(BlockDriverState *bs)
{
    BDRVDMGState *s = bs->opaque;

    g_free(s->types);
    g_free(s->offsets);
    g_free(s->lengths);
    g_free(s->sectors);
    g_free(s->sectorcounts);
    g_free(s->compressed_chunk);
    g_free(s->uncompressed_chunk);

    inflateEnd(&s->zstream);
}

static BlockDriver bdrv_dmg = {
    .format_name    = "dmg",
    .instance_size  = sizeof(BDRVDMGState),
    .bdrv_probe     = dmg_probe,
    .bdrv_open      = dmg_open,
    .bdrv_read      = dmg_co_read,
    .bdrv_close     = dmg_close,
};

static void bdrv_dmg_init(void)
{
    bdrv_register(&bdrv_dmg);
}

block_init(bdrv_dmg_init);
Commit	Line	Data
585d0ed9 FB	1	/*
585d0ed9 FB	2	* QEMU Block driver for DMG images
5fafdf24	3	*
585d0ed9	4	* Copyright (c) 2004 Johannes E. Schindelin
5fafdf24	5	*
585d0ed9 FB	6	* Permission is hereby granted, free of charge, to any person obtaining a copy
	7	* of this software and associated documentation files (the "Software"), to deal
	8	* in the Software without restriction, including without limitation the rights
	9	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	10	* copies of the Software, and to permit persons to whom the Software is
	11	* furnished to do so, subject to the following conditions:
	12	*
	13	* The above copyright notice and this permission notice shall be included in
	14	* all copies or substantial portions of the Software.
	15	*
	16	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	17	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	18	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	19	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	20	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	21	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	22	* THE SOFTWARE.
	23	*/
faf07963	24	#include "qemu-common.h"
737e150e	25	#include "block/block_int.h"
1de7afc9 PB	26	#include "qemu/bswap.h"
1de7afc9 PB	27	#include "qemu/module.h"
585d0ed9 FB	28	#include <zlib.h>
585d0ed9 FB	29
c165f775 SH	30	enum {
	31	/* Limit chunk sizes to prevent unreasonable amounts of memory being used
	32	* or truncating when converting to 32-bit types
	33	*/
	34	DMG_LENGTHS_MAX = 64 * 1024 * 1024, /* 64 MB */
	35	DMG_SECTORCOUNTS_MAX = DMG_LENGTHS_MAX / 512,
	36	};
	37
585d0ed9	38	typedef struct BDRVDMGState {
848c66e8	39	CoMutex lock;
585d0ed9 FB	40	/* each chunk contains a certain number of sectors,
	41	* offsets[i] is the offset in the .dmg file,
	42	* lengths[i] is the length of the compressed chunk,
	43	* sectors[i] is the sector beginning at offsets[i],
	44	* sectorcounts[i] is the number of sectors in that chunk,
	45	* the sectors array is ordered
	46	* 0<=i<n_chunks */
	47
	48	uint32_t n_chunks;
	49	uint32_t* types;
	50	uint64_t* offsets;
	51	uint64_t* lengths;
	52	uint64_t* sectors;
	53	uint64_t* sectorcounts;
	54	uint32_t current_chunk;
28a5c9c8 FB	55	uint8_t *compressed_chunk;
28a5c9c8 FB	56	uint8_t *uncompressed_chunk;
585d0ed9 FB	57	z_stream zstream;
	58	} BDRVDMGState;
	59
	60	static int dmg_probe(const uint8_t buf, int buf_size, const char filename)
	61	{
f5866fa4 KW	62	int len;
	63
	64	if (!filename) {
	65	return 0;
	66	}
	67
	68	len = strlen(filename);
	69	if (len > 4 && !strcmp(filename + len - 4, ".dmg")) {
	70	return 2;
	71	}
585d0ed9 FB	72	return 0;
	73	}
	74
69d34a36	75	static int read_uint64(BlockDriverState bs, int64_t offset, uint64_t result)
585d0ed9	76	{
69d34a36 KW	77	uint64_t buffer;
	78	int ret;
	79
	80	ret = bdrv_pread(bs->file, offset, &buffer, 8);
	81	if (ret < 0) {
	82	return ret;
	83	}
	84
	85	*result = be64_to_cpu(buffer);
	86	return 0;
585d0ed9 FB	87	}
585d0ed9 FB	88
69d34a36	89	static int read_uint32(BlockDriverState bs, int64_t offset, uint32_t result)
585d0ed9	90	{
69d34a36 KW	91	uint32_t buffer;
	92	int ret;
	93
	94	ret = bdrv_pread(bs->file, offset, &buffer, 4);
	95	if (ret < 0) {
	96	return ret;
	97	}
	98
	99	*result = be32_to_cpu(buffer);
	100	return 0;
585d0ed9 FB	101	}
585d0ed9 FB	102
f0dce234 SH	103	/* Increase max chunk sizes, if necessary. This function is used to calculate
	104	* the buffer sizes needed for compressed/uncompressed chunk I/O.
	105	*/
	106	static void update_max_chunk_size(BDRVDMGState *s, uint32_t chunk,
	107	uint32_t *max_compressed_size,
	108	uint32_t *max_sectors_per_chunk)
	109	{
	110	uint32_t compressed_size = 0;
	111	uint32_t uncompressed_sectors = 0;
	112
	113	switch (s->types[chunk]) {
	114	case 0x80000005: /* zlib compressed */
	115	compressed_size = s->lengths[chunk];
	116	uncompressed_sectors = s->sectorcounts[chunk];
	117	break;
	118	case 1: /* copy */
	119	uncompressed_sectors = (s->lengths[chunk] + 511) / 512;
	120	break;
	121	case 2: /* zero */
	122	uncompressed_sectors = s->sectorcounts[chunk];
	123	break;
	124	}
	125
	126	if (compressed_size > *max_compressed_size) {
	127	*max_compressed_size = compressed_size;
	128	}
	129	if (uncompressed_sectors > *max_sectors_per_chunk) {
	130	*max_sectors_per_chunk = uncompressed_sectors;
	131	}
	132	}
	133
015a1036 HR	134	static int dmg_open(BlockDriverState bs, QDict options, int flags,
015a1036 HR	135	Error **errp)
585d0ed9 FB	136	{
585d0ed9 FB	137	BDRVDMGState *s = bs->opaque;
2c1885ad	138	uint64_t info_begin, info_end, last_in_offset, last_out_offset;
69d34a36	139	uint32_t count, tmp;
2c1885ad	140	uint32_t max_compressed_size = 1, max_sectors_per_chunk = 1, i;
16cdf7ce	141	int64_t offset;
69d34a36	142	int ret;
585d0ed9	143
585d0ed9 FB	144	bs->read_only = 1;
585d0ed9 FB	145	s->n_chunks = 0;
511d2b14	146	s->offsets = s->lengths = s->sectors = s->sectorcounts = NULL;
3b46e624	147
585d0ed9	148	/* read offset of info blocks */
64a31d5c	149	offset = bdrv_getlength(bs->file);
16cdf7ce	150	if (offset < 0) {
69d34a36	151	ret = offset;
1559ca00	152	goto fail;
585d0ed9	153	}
64a31d5c	154	offset -= 0x1d8;
1559ca00	155
69d34a36 KW	156	ret = read_uint64(bs, offset, &info_begin);
	157	if (ret < 0) {
	158	goto fail;
	159	} else if (info_begin == 0) {
	160	ret = -EINVAL;
	161	goto fail;
16cdf7ce CH	162	}
16cdf7ce CH	163
69d34a36 KW	164	ret = read_uint32(bs, info_begin, &tmp);
	165	if (ret < 0) {
	166	goto fail;
	167	} else if (tmp != 0x100) {
	168	ret = -EINVAL;
16cdf7ce CH	169	goto fail;
	170	}
	171
69d34a36 KW	172	ret = read_uint32(bs, info_begin + 4, &count);
	173	if (ret < 0) {
	174	goto fail;
	175	} else if (count == 0) {
	176	ret = -EINVAL;
16cdf7ce CH	177	goto fail;
	178	}
	179	info_end = info_begin + count;
	180
	181	offset = info_begin + 0x100;
585d0ed9 FB	182
	183	/* read offsets */
	184	last_in_offset = last_out_offset = 0;
16cdf7ce	185	while (offset < info_end) {
995179f1 FB	186	uint32_t type;
995179f1 FB	187
69d34a36 KW	188	ret = read_uint32(bs, offset, &count);
	189	if (ret < 0) {
	190	goto fail;
	191	} else if (count == 0) {
	192	ret = -EINVAL;
	193	goto fail;
	194	}
16cdf7ce CH	195	offset += 4;
16cdf7ce CH	196
69d34a36 KW	197	ret = read_uint32(bs, offset, &type);
	198	if (ret < 0) {
	199	goto fail;
	200	}
	201
2c1885ad	202	if (type == 0x6d697368 && count >= 244) {
eb71803b SH	203	size_t new_size;
eb71803b SH	204	uint32_t chunk_count;
16cdf7ce CH	205
	206	offset += 4;
	207	offset += 200;
	208
2c1885ad SH	209	chunk_count = (count - 204) / 40;
	210	new_size = sizeof(uint64_t) * (s->n_chunks + chunk_count);
	211	s->types = g_realloc(s->types, new_size / 2);
	212	s->offsets = g_realloc(s->offsets, new_size);
	213	s->lengths = g_realloc(s->lengths, new_size);
	214	s->sectors = g_realloc(s->sectors, new_size);
	215	s->sectorcounts = g_realloc(s->sectorcounts, new_size);
585d0ed9	216
69d34a36 KW	217	for (i = s->n_chunks; i < s->n_chunks + chunk_count; i++) {
	218	ret = read_uint32(bs, offset, &s->types[i]);
	219	if (ret < 0) {
	220	goto fail;
	221	}
2c1885ad SH	222	offset += 4;
	223	if (s->types[i] != 0x80000005 && s->types[i] != 1 &&
	224	s->types[i] != 2) {
73ed27ec	225	if (s->types[i] == 0xffffffff && i > 0) {
2c1885ad SH	226	last_in_offset = s->offsets[i - 1] + s->lengths[i - 1];
	227	last_out_offset = s->sectors[i - 1] +
	228	s->sectorcounts[i - 1];
	229	}
	230	chunk_count--;
	231	i--;
	232	offset += 36;
	233	continue;
	234	}
	235	offset += 4;
16cdf7ce	236
69d34a36 KW	237	ret = read_uint64(bs, offset, &s->sectors[i]);
	238	if (ret < 0) {
	239	goto fail;
	240	}
	241	s->sectors[i] += last_out_offset;
	242	offset += 8;
16cdf7ce	243
69d34a36 KW	244	ret = read_uint64(bs, offset, &s->sectorcounts[i]);
	245	if (ret < 0) {
	246	goto fail;
	247	}
	248	offset += 8;
16cdf7ce	249
c165f775	250	if (s->sectorcounts[i] > DMG_SECTORCOUNTS_MAX) {
521b2b5d HR	251	error_report("sector count %" PRIu64 " for chunk %" PRIu32
521b2b5d HR	252	" is larger than max (%u)",
c165f775 SH	253	s->sectorcounts[i], i, DMG_SECTORCOUNTS_MAX);
	254	ret = -EINVAL;
	255	goto fail;
	256	}
	257
69d34a36 KW	258	ret = read_uint64(bs, offset, &s->offsets[i]);
	259	if (ret < 0) {
	260	goto fail;
	261	}
	262	s->offsets[i] += last_in_offset;
	263	offset += 8;
16cdf7ce	264
69d34a36 KW	265	ret = read_uint64(bs, offset, &s->lengths[i]);
	266	if (ret < 0) {
	267	goto fail;
	268	}
	269	offset += 8;
16cdf7ce	270
c165f775	271	if (s->lengths[i] > DMG_LENGTHS_MAX) {
521b2b5d HR	272	error_report("length %" PRIu64 " for chunk %" PRIu32
521b2b5d HR	273	" is larger than max (%u)",
c165f775 SH	274	s->lengths[i], i, DMG_LENGTHS_MAX);
	275	ret = -EINVAL;
	276	goto fail;
	277	}
	278
f0dce234 SH	279	update_max_chunk_size(s, i, &max_compressed_size,
f0dce234 SH	280	&max_sectors_per_chunk);
2c1885ad SH	281	}
	282	s->n_chunks += chunk_count;
	283	}
585d0ed9 FB	284	}
	285
	286	/* initialize zlib engine */
2c1885ad SH	287	s->compressed_chunk = g_malloc(max_compressed_size + 1);
	288	s->uncompressed_chunk = g_malloc(512 * max_sectors_per_chunk);
	289	if (inflateInit(&s->zstream) != Z_OK) {
69d34a36 KW	290	ret = -EINVAL;
	291	goto fail;
	292	}
585d0ed9 FB	293
585d0ed9 FB	294	s->current_chunk = s->n_chunks;
3b46e624	295
848c66e8	296	qemu_co_mutex_init(&s->lock);
585d0ed9	297	return 0;
69d34a36	298
1559ca00	299	fail:
69d34a36 KW	300	g_free(s->types);
	301	g_free(s->offsets);
	302	g_free(s->lengths);
	303	g_free(s->sectors);
	304	g_free(s->sectorcounts);
	305	g_free(s->compressed_chunk);
	306	g_free(s->uncompressed_chunk);
	307	return ret;
585d0ed9 FB	308	}
	309
	310	static inline int is_sector_in_chunk(BDRVDMGState* s,
686d7148	311	uint32_t chunk_num, uint64_t sector_num)
585d0ed9	312	{
2c1885ad SH	313	if (chunk_num >= s->n_chunks \|\| s->sectors[chunk_num] > sector_num \|\|
	314	s->sectors[chunk_num] + s->sectorcounts[chunk_num] <= sector_num) {
	315	return 0;
	316	} else {
	317	return -1;
	318	}
585d0ed9 FB	319	}
585d0ed9 FB	320
686d7148	321	static inline uint32_t search_chunk(BDRVDMGState *s, uint64_t sector_num)
585d0ed9 FB	322	{
585d0ed9 FB	323	/* binary search */
2c1885ad SH	324	uint32_t chunk1 = 0, chunk2 = s->n_chunks, chunk3;
	325	while (chunk1 != chunk2) {
	326	chunk3 = (chunk1 + chunk2) / 2;
	327	if (s->sectors[chunk3] > sector_num) {
	328	chunk2 = chunk3;
	329	} else if (s->sectors[chunk3] + s->sectorcounts[chunk3] > sector_num) {
	330	return chunk3;
	331	} else {
	332	chunk1 = chunk3;
	333	}
585d0ed9 FB	334	}
	335	return s->n_chunks; /* error */
	336	}
	337
686d7148	338	static inline int dmg_read_chunk(BlockDriverState *bs, uint64_t sector_num)
585d0ed9	339	{
64a31d5c CH	340	BDRVDMGState *s = bs->opaque;
64a31d5c CH	341
2c1885ad SH	342	if (!is_sector_in_chunk(s, s->current_chunk, sector_num)) {
	343	int ret;
	344	uint32_t chunk = search_chunk(s, sector_num);
585d0ed9	345
2c1885ad SH	346	if (chunk >= s->n_chunks) {
	347	return -1;
	348	}
585d0ed9	349
2c1885ad SH	350	s->current_chunk = s->n_chunks;
	351	switch (s->types[chunk]) {
	352	case 0x80000005: { /* zlib compressed */
2c1885ad SH	353	/* we need to buffer, because only the chunk as whole can be
2c1885ad SH	354	* inflated. */
b404bf85 SH	355	ret = bdrv_pread(bs->file, s->offsets[chunk],
b404bf85 SH	356	s->compressed_chunk, s->lengths[chunk]);
2c1885ad SH	357	if (ret != s->lengths[chunk]) {
	358	return -1;
	359	}
	360
	361	s->zstream.next_in = s->compressed_chunk;
	362	s->zstream.avail_in = s->lengths[chunk];
	363	s->zstream.next_out = s->uncompressed_chunk;
	364	s->zstream.avail_out = 512 * s->sectorcounts[chunk];
	365	ret = inflateReset(&s->zstream);
	366	if (ret != Z_OK) {
	367	return -1;
	368	}
	369	ret = inflate(&s->zstream, Z_FINISH);
	370	if (ret != Z_STREAM_END \|\|
	371	s->zstream.total_out != 512 * s->sectorcounts[chunk]) {
	372	return -1;
	373	}
	374	break; }
	375	case 1: /* copy */
	376	ret = bdrv_pread(bs->file, s->offsets[chunk],
64a31d5c	377	s->uncompressed_chunk, s->lengths[chunk]);
2c1885ad SH	378	if (ret != s->lengths[chunk]) {
	379	return -1;
	380	}
	381	break;
	382	case 2: /* zero */
	383	memset(s->uncompressed_chunk, 0, 512 * s->sectorcounts[chunk]);
	384	break;
	385	}
	386	s->current_chunk = chunk;
585d0ed9 FB	387	}
	388	return 0;
	389	}
	390
5fafdf24	391	static int dmg_read(BlockDriverState *bs, int64_t sector_num,
585d0ed9 FB	392	uint8_t *buf, int nb_sectors)
	393	{
	394	BDRVDMGState *s = bs->opaque;
	395	int i;
	396
2c1885ad SH	397	for (i = 0; i < nb_sectors; i++) {
	398	uint32_t sector_offset_in_chunk;
	399	if (dmg_read_chunk(bs, sector_num + i) != 0) {
	400	return -1;
	401	}
	402	sector_offset_in_chunk = sector_num + i - s->sectors[s->current_chunk];
	403	memcpy(buf + i * 512,
	404	s->uncompressed_chunk + sector_offset_in_chunk * 512, 512);
585d0ed9 FB	405	}
	406	return 0;
	407	}
	408
2914caa0 PB	409	static coroutine_fn int dmg_co_read(BlockDriverState *bs, int64_t sector_num,
	410	uint8_t *buf, int nb_sectors)
	411	{
	412	int ret;
	413	BDRVDMGState *s = bs->opaque;
	414	qemu_co_mutex_lock(&s->lock);
	415	ret = dmg_read(bs, sector_num, buf, nb_sectors);
	416	qemu_co_mutex_unlock(&s->lock);
	417	return ret;
	418	}
	419
585d0ed9 FB	420	static void dmg_close(BlockDriverState *bs)
	421	{
	422	BDRVDMGState *s = bs->opaque;
4f8aa2e1 KW	423
	424	g_free(s->types);
	425	g_free(s->offsets);
	426	g_free(s->lengths);
	427	g_free(s->sectors);
	428	g_free(s->sectorcounts);
	429	g_free(s->compressed_chunk);
	430	g_free(s->uncompressed_chunk);
	431
585d0ed9 FB	432	inflateEnd(&s->zstream);
	433	}
	434
5efa9d5a	435	static BlockDriver bdrv_dmg = {
2c1885ad SH	436	.format_name = "dmg",
	437	.instance_size = sizeof(BDRVDMGState),
	438	.bdrv_probe = dmg_probe,
	439	.bdrv_open = dmg_open,
	440	.bdrv_read = dmg_co_read,
	441	.bdrv_close = dmg_close,
585d0ed9	442	};
5efa9d5a AL	443
	444	static void bdrv_dmg_init(void)
	445	{
	446	bdrv_register(&bdrv_dmg);
	447	}
	448
	449	block_init(bdrv_dmg_init);