[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_int.h"
#include "bswap.h"
#include "module.h"
#include <zlib.h>

typedef struct BDRVDMGState {
    int fd;

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

static off_t read_off(int fd)
{
	uint64_t buffer;
	if(read(fd,&buffer,8)<8)
		return 0;
	return be64_to_cpu(buffer);
}

static off_t read_uint32(int fd)
{
	uint32_t buffer;
	if(read(fd,&buffer,4)<4)
		return 0;
	return be32_to_cpu(buffer);
}

static int dmg_open(BlockDriverState *bs, const char *filename, int flags)
{
    BDRVDMGState *s = bs->opaque;
    off_t info_begin,info_end,last_in_offset,last_out_offset;
    uint32_t count;
    uint32_t max_compressed_size=1,max_sectors_per_chunk=1,i;

    s->fd = open(filename, O_RDONLY | O_BINARY);
    if (s->fd < 0)
        return -errno;
    bs->read_only = 1;
    s->n_chunks = 0;
    s->offsets = s->lengths = s->sectors = s->sectorcounts = NULL;

    /* read offset of info blocks */
    if(lseek(s->fd,-0x1d8,SEEK_END)<0) {
dmg_close:
	close(s->fd);
	/* open raw instead */
	bs->drv=bdrv_find_format("raw");
	return bs->drv->bdrv_open(bs, filename, flags);
    }
    info_begin=read_off(s->fd);
    if(info_begin==0)
	goto dmg_close;
    if(lseek(s->fd,info_begin,SEEK_SET)<0)
	goto dmg_close;
    if(read_uint32(s->fd)!=0x100)
	goto dmg_close;
    if((count = read_uint32(s->fd))==0)
	goto dmg_close;
    info_end = info_begin+count;
    if(lseek(s->fd,0xf8,SEEK_CUR)<0)
	goto dmg_close;

    /* read offsets */
    last_in_offset = last_out_offset = 0;
    while(lseek(s->fd,0,SEEK_CUR)<info_end) {
        uint32_t type;

	count = read_uint32(s->fd);
	if(count==0)
	    goto dmg_close;
	type = read_uint32(s->fd);
	if(type!=0x6d697368 || count<244)
	    lseek(s->fd,count-4,SEEK_CUR);
	else {
	    int new_size, chunk_count;
	    if(lseek(s->fd,200,SEEK_CUR)<0)
	        goto dmg_close;
	    chunk_count = (count-204)/40;
	    new_size = sizeof(uint64_t) * (s->n_chunks + chunk_count);
	    s->types = qemu_realloc(s->types, new_size/2);
	    s->offsets = qemu_realloc(s->offsets, new_size);
	    s->lengths = qemu_realloc(s->lengths, new_size);
	    s->sectors = qemu_realloc(s->sectors, new_size);
	    s->sectorcounts = qemu_realloc(s->sectorcounts, new_size);

	    for(i=s->n_chunks;i<s->n_chunks+chunk_count;i++) {
		s->types[i] = read_uint32(s->fd);
		if(s->types[i]!=0x80000005 && s->types[i]!=1 && s->types[i]!=2) {
		    if(s->types[i]==0xffffffff) {
			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--;
		    if(lseek(s->fd,36,SEEK_CUR)<0)
			goto dmg_close;
		    continue;
		}
		read_uint32(s->fd);
		s->sectors[i] = last_out_offset+read_off(s->fd);
		s->sectorcounts[i] = read_off(s->fd);
		s->offsets[i] = last_in_offset+read_off(s->fd);
		s->lengths[i] = read_off(s->fd);
		if(s->lengths[i]>max_compressed_size)
		    max_compressed_size = s->lengths[i];
		if(s->sectorcounts[i]>max_sectors_per_chunk)
		    max_sectors_per_chunk = s->sectorcounts[i];
	    }
	    s->n_chunks+=chunk_count;
	}
    }

    /* initialize zlib engine */
    s->compressed_chunk = qemu_malloc(max_compressed_size+1);
    s->uncompressed_chunk = qemu_malloc(512*max_sectors_per_chunk);
    if(inflateInit(&s->zstream) != Z_OK)
	goto dmg_close;

    s->current_chunk = s->n_chunks;

    return 0;
}

static inline int is_sector_in_chunk(BDRVDMGState* s,
		uint32_t chunk_num,int 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,int 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(BDRVDMGState *s,int sector_num)
{
    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 */
	    int i;

	    ret = lseek(s->fd, s->offsets[chunk], SEEK_SET);
	    if(ret<0)
		return -1;

	    /* we need to buffer, because only the chunk as whole can be
	     * inflated. */
	    i=0;
	    do {
		ret = read(s->fd, s->compressed_chunk+i, s->lengths[chunk]-i);
		if(ret<0 && errno==EINTR)
		    ret=0;
		i+=ret;
	    } while(ret>=0 && ret+i<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 = read(s->fd, 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(s, 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 void dmg_close(BlockDriverState *bs)
{
    BDRVDMGState *s = bs->opaque;
    close(s->fd);
    if(s->n_chunks>0) {
	free(s->types);
	free(s->offsets);
	free(s->lengths);
	free(s->sectors);
	free(s->sectorcounts);
    }
    free(s->compressed_chunk);
    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_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"
585d0ed9 FB	25	#include "block_int.h"
585d0ed9 FB	26	#include "bswap.h"
5efa9d5a	27	#include "module.h"
585d0ed9 FB	28	#include <zlib.h>
	29
	30	typedef struct BDRVDMGState {
	31	int fd;
3b46e624	32
585d0ed9 FB	33	/* each chunk contains a certain number of sectors,
	34	* offsets[i] is the offset in the .dmg file,
	35	* lengths[i] is the length of the compressed chunk,
	36	* sectors[i] is the sector beginning at offsets[i],
	37	* sectorcounts[i] is the number of sectors in that chunk,
	38	* the sectors array is ordered
	39	* 0<=i<n_chunks */
	40
	41	uint32_t n_chunks;
	42	uint32_t* types;
	43	uint64_t* offsets;
	44	uint64_t* lengths;
	45	uint64_t* sectors;
	46	uint64_t* sectorcounts;
	47	uint32_t current_chunk;
28a5c9c8 FB	48	uint8_t *compressed_chunk;
28a5c9c8 FB	49	uint8_t *uncompressed_chunk;
585d0ed9 FB	50	z_stream zstream;
	51	} BDRVDMGState;
	52
	53	static int dmg_probe(const uint8_t buf, int buf_size, const char filename)
	54	{
	55	int len=strlen(filename);
	56	if(len>4 && !strcmp(filename+len-4,".dmg"))
	57	return 2;
	58	return 0;
	59	}
	60
	61	static off_t read_off(int fd)
	62	{
	63	uint64_t buffer;
	64	if(read(fd,&buffer,8)<8)
	65	return 0;
	66	return be64_to_cpu(buffer);
	67	}
	68
	69	static off_t read_uint32(int fd)
	70	{
	71	uint32_t buffer;
	72	if(read(fd,&buffer,4)<4)
	73	return 0;
	74	return be32_to_cpu(buffer);
	75	}
	76
83f64091	77	static int dmg_open(BlockDriverState bs, const char filename, int flags)
585d0ed9 FB	78	{
	79	BDRVDMGState *s = bs->opaque;
	80	off_t info_begin,info_end,last_in_offset,last_out_offset;
	81	uint32_t count;
	82	uint32_t max_compressed_size=1,max_sectors_per_chunk=1,i;
	83
83f64091	84	s->fd = open(filename, O_RDONLY \| O_BINARY);
585d0ed9	85	if (s->fd < 0)
83f64091	86	return -errno;
585d0ed9 FB	87	bs->read_only = 1;
585d0ed9 FB	88	s->n_chunks = 0;
511d2b14	89	s->offsets = s->lengths = s->sectors = s->sectorcounts = NULL;
3b46e624	90
585d0ed9 FB	91	/* read offset of info blocks */
	92	if(lseek(s->fd,-0x1d8,SEEK_END)<0) {
	93	dmg_close:
	94	close(s->fd);
7c35359c	95	/* open raw instead */
5efa9d5a	96	bs->drv=bdrv_find_format("raw");
83f64091	97	return bs->drv->bdrv_open(bs, filename, flags);
585d0ed9 FB	98	}
	99	info_begin=read_off(s->fd);
	100	if(info_begin==0)
	101	goto dmg_close;
	102	if(lseek(s->fd,info_begin,SEEK_SET)<0)
	103	goto dmg_close;
	104	if(read_uint32(s->fd)!=0x100)
	105	goto dmg_close;
	106	if((count = read_uint32(s->fd))==0)
	107	goto dmg_close;
	108	info_end = info_begin+count;
	109	if(lseek(s->fd,0xf8,SEEK_CUR)<0)
	110	goto dmg_close;
	111
	112	/* read offsets */
	113	last_in_offset = last_out_offset = 0;
	114	while(lseek(s->fd,0,SEEK_CUR)<info_end) {
995179f1 FB	115	uint32_t type;
995179f1 FB	116
585d0ed9 FB	117	count = read_uint32(s->fd);
	118	if(count==0)
	119	goto dmg_close;
995179f1	120	type = read_uint32(s->fd);
585d0ed9 FB	121	if(type!=0x6d697368 \|\| count<244)
	122	lseek(s->fd,count-4,SEEK_CUR);
	123	else {
	124	int new_size, chunk_count;
	125	if(lseek(s->fd,200,SEEK_CUR)<0)
	126	goto dmg_close;
	127	chunk_count = (count-204)/40;
	128	new_size = sizeof(uint64_t) * (s->n_chunks + chunk_count);
2137b4cc TS	129	s->types = qemu_realloc(s->types, new_size/2);
	130	s->offsets = qemu_realloc(s->offsets, new_size);
	131	s->lengths = qemu_realloc(s->lengths, new_size);
	132	s->sectors = qemu_realloc(s->sectors, new_size);
	133	s->sectorcounts = qemu_realloc(s->sectorcounts, new_size);
585d0ed9 FB	134
	135	for(i=s->n_chunks;i<s->n_chunks+chunk_count;i++) {
	136	s->types[i] = read_uint32(s->fd);
	137	if(s->types[i]!=0x80000005 && s->types[i]!=1 && s->types[i]!=2) {
	138	if(s->types[i]==0xffffffff) {
	139	last_in_offset = s->offsets[i-1]+s->lengths[i-1];
	140	last_out_offset = s->sectors[i-1]+s->sectorcounts[i-1];
	141	}
	142	chunk_count--;
	143	i--;
	144	if(lseek(s->fd,36,SEEK_CUR)<0)
	145	goto dmg_close;
	146	continue;
	147	}
	148	read_uint32(s->fd);
	149	s->sectors[i] = last_out_offset+read_off(s->fd);
	150	s->sectorcounts[i] = read_off(s->fd);
	151	s->offsets[i] = last_in_offset+read_off(s->fd);
	152	s->lengths[i] = read_off(s->fd);
	153	if(s->lengths[i]>max_compressed_size)
	154	max_compressed_size = s->lengths[i];
	155	if(s->sectorcounts[i]>max_sectors_per_chunk)
	156	max_sectors_per_chunk = s->sectorcounts[i];
	157	}
	158	s->n_chunks+=chunk_count;
	159	}
	160	}
	161
	162	/* initialize zlib engine */
3ec88e80 AL	163	s->compressed_chunk = qemu_malloc(max_compressed_size+1);
3ec88e80 AL	164	s->uncompressed_chunk = qemu_malloc(512*max_sectors_per_chunk);
585d0ed9 FB	165	if(inflateInit(&s->zstream) != Z_OK)
	166	goto dmg_close;
	167
	168	s->current_chunk = s->n_chunks;
3b46e624	169
585d0ed9 FB	170	return 0;
	171	}
	172
	173	static inline int is_sector_in_chunk(BDRVDMGState* s,
	174	uint32_t chunk_num,int sector_num)
	175	{
	176	if(chunk_num>=s->n_chunks \|\| s->sectors[chunk_num]>sector_num \|\|
	177	s->sectors[chunk_num]+s->sectorcounts[chunk_num]<=sector_num)
	178	return 0;
	179	else
	180	return -1;
	181	}
	182
	183	static inline uint32_t search_chunk(BDRVDMGState* s,int sector_num)
	184	{
	185	/* binary search */
	186	uint32_t chunk1=0,chunk2=s->n_chunks,chunk3;
	187	while(chunk1!=chunk2) {
	188	chunk3 = (chunk1+chunk2)/2;
	189	if(s->sectors[chunk3]>sector_num)
	190	chunk2 = chunk3;
	191	else if(s->sectors[chunk3]+s->sectorcounts[chunk3]>sector_num)
	192	return chunk3;
	193	else
	194	chunk1 = chunk3;
	195	}
	196	return s->n_chunks; /* error */
	197	}
	198
	199	static inline int dmg_read_chunk(BDRVDMGState *s,int sector_num)
	200	{
	201	if(!is_sector_in_chunk(s,s->current_chunk,sector_num)) {
	202	int ret;
	203	uint32_t chunk = search_chunk(s,sector_num);
	204
	205	if(chunk>=s->n_chunks)
	206	return -1;
	207
	208	s->current_chunk = s->n_chunks;
	209	switch(s->types[chunk]) {
	210	case 0x80000005: { /* zlib compressed */
	211	int i;
	212
	213	ret = lseek(s->fd, s->offsets[chunk], SEEK_SET);
	214	if(ret<0)
	215	return -1;
	216
	217	/* we need to buffer, because only the chunk as whole can be
	218	* inflated. */
	219	i=0;
	220	do {
	221	ret = read(s->fd, s->compressed_chunk+i, s->lengths[chunk]-i);
	222	if(ret<0 && errno==EINTR)
	223	ret=0;
	224	i+=ret;
	225	} while(ret>=0 && ret+i<s->lengths[chunk]);
	226
	227	if (ret != s->lengths[chunk])
	228	return -1;
5fafdf24	229
585d0ed9 FB	230	s->zstream.next_in = s->compressed_chunk;
	231	s->zstream.avail_in = s->lengths[chunk];
	232	s->zstream.next_out = s->uncompressed_chunk;
	233	s->zstream.avail_out = 512*s->sectorcounts[chunk];
	234	ret = inflateReset(&s->zstream);
	235	if(ret != Z_OK)
	236	return -1;
	237	ret = inflate(&s->zstream, Z_FINISH);
	238	if(ret != Z_STREAM_END \|\| s->zstream.total_out != 512*s->sectorcounts[chunk])
	239	return -1;
	240	break; }
	241	case 1: /* copy */
	242	ret = read(s->fd, s->uncompressed_chunk, s->lengths[chunk]);
	243	if (ret != s->lengths[chunk])
	244	return -1;
	245	break;
	246	case 2: /* zero */
	247	memset(s->uncompressed_chunk, 0, 512*s->sectorcounts[chunk]);
	248	break;
	249	}
	250	s->current_chunk = chunk;
	251	}
	252	return 0;
	253	}
	254
5fafdf24	255	static int dmg_read(BlockDriverState *bs, int64_t sector_num,
585d0ed9 FB	256	uint8_t *buf, int nb_sectors)
	257	{
	258	BDRVDMGState *s = bs->opaque;
	259	int i;
	260
	261	for(i=0;i<nb_sectors;i++) {
	262	uint32_t sector_offset_in_chunk;
	263	if(dmg_read_chunk(s, sector_num+i) != 0)
	264	return -1;
	265	sector_offset_in_chunk = sector_num+i-s->sectors[s->current_chunk];
	266	memcpy(buf+i512,s->uncompressed_chunk+sector_offset_in_chunk512,512);
	267	}
	268	return 0;
	269	}
	270
	271	static void dmg_close(BlockDriverState *bs)
	272	{
	273	BDRVDMGState *s = bs->opaque;
	274	close(s->fd);
	275	if(s->n_chunks>0) {
	276	free(s->types);
	277	free(s->offsets);
	278	free(s->lengths);
	279	free(s->sectors);
	280	free(s->sectorcounts);
	281	}
	282	free(s->compressed_chunk);
	283	free(s->uncompressed_chunk);
	284	inflateEnd(&s->zstream);
	285	}
	286
5efa9d5a	287	static BlockDriver bdrv_dmg = {
e60f469c AJ	288	.format_name = "dmg",
	289	.instance_size = sizeof(BDRVDMGState),
	290	.bdrv_probe = dmg_probe,
	291	.bdrv_open = dmg_open,
	292	.bdrv_read = dmg_read,
	293	.bdrv_close = dmg_close,
585d0ed9	294	};
5efa9d5a AL	295
	296	static void bdrv_dmg_init(void)
	297	{
	298	bdrv_register(&bdrv_dmg);
	299	}
	300
	301	block_init(bdrv_dmg_init);