qed: Refuse to create images on block devices

[qemu.git] / block / dmg.c

diff --git a/block/dmg.c b/block/dmg.c
index 262560ffd371d5f5f8d389deacb6d73ffa6afaf6..a3c815b862c6600eb68be4d112feaab4fb28b596 100644 (file)
--- a/block/dmg.c
+++ b/block/dmg.c
@@ -28,8 +28,6 @@
 #include <zlib.h>
 
 typedef struct BDRVDMGState {
 #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,
     /* 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,


@@ -58,72 +56,75 @@ static int dmg_probe(const uint8_t *buf, int buf_size, const char *filename)
     return 0;
 }
 
     return 0;
 }
 

-static off_t read_off(int fd)
+static off_t read_off(BlockDriverState *bs, int64_t offset)

 {
        uint64_t buffer;
 {
        uint64_t buffer;

-       if(read(fd,&buffer,8)<8)
+       if (bdrv_pread(bs->file, offset, &buffer, 8) < 8)

                return 0;
        return be64_to_cpu(buffer);
 }
 
                return 0;
        return be64_to_cpu(buffer);
 }
 

-static off_t read_uint32(int fd)
+static off_t read_uint32(BlockDriverState *bs, int64_t offset)

 {
        uint32_t buffer;
 {
        uint32_t buffer;

-       if(read(fd,&buffer,4)<4)
+       if (bdrv_pread(bs->file, offset, &buffer, 4) < 4)

                return 0;
        return be32_to_cpu(buffer);
 }
 
                return 0;
        return be32_to_cpu(buffer);
 }
 

-static int dmg_open(BlockDriverState *bs, const char *filename, int flags)
+static int dmg_open(BlockDriverState *bs, 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;
 {
     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;

+    int64_t offset;

 
 

-    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 */
     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);
+    offset = bdrv_getlength(bs->file);
+    if (offset < 0) {
+        goto fail;
+    }
+    offset -= 0x1d8;
+
+    info_begin = read_off(bs, offset);
+    if (info_begin == 0) {
+       goto fail;
+    }
+
+    if (read_uint32(bs, info_begin) != 0x100) {
+        goto fail;

     }
     }

-    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;
+
+    count = read_uint32(bs, info_begin + 4);
+    if (count == 0) {
+        goto fail;
+    }
+    info_end = info_begin + count;
+
+    offset = info_begin + 0x100;

 
     /* read offsets */
     last_in_offset = last_out_offset = 0;
 
     /* read offsets */
     last_in_offset = last_out_offset = 0;

-    while(lseek(s->fd,0,SEEK_CUR)<info_end) {
+    while (offset < info_end) {

         uint32_t type;
 
         uint32_t type;
 

-       count = read_uint32(s->fd);
+       count = read_uint32(bs, offset);

        if(count==0)
        if(count==0)

-           goto dmg_close;
-       type = read_uint32(s->fd);
-       if(type!=0x6d697368 || count<244)
-           lseek(s->fd,count-4,SEEK_CUR);
-       else {
+           goto fail;
+        offset += 4;
+
+       type = read_uint32(bs, offset);
+       if (type == 0x6d697368 && count >= 244) {

            int new_size, chunk_count;
            int new_size, chunk_count;

-           if(lseek(s->fd,200,SEEK_CUR)<0)
-               goto dmg_close;
+
+            offset += 4;
+            offset += 200;
+

            chunk_count = (count-204)/40;
            new_size = sizeof(uint64_t) * (s->n_chunks + chunk_count);
            s->types = qemu_realloc(s->types, new_size/2);
            chunk_count = (count-204)/40;
            new_size = sizeof(uint64_t) * (s->n_chunks + chunk_count);
            s->types = qemu_realloc(s->types, new_size/2);


@@ -133,7 +134,8 @@ dmg_close:
            s->sectorcounts = qemu_realloc(s->sectorcounts, new_size);
 
            for(i=s->n_chunks;i<s->n_chunks+chunk_count;i++) {
            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);
+               s->types[i] = read_uint32(bs, offset);
+               offset += 4;

                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];
                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];


@@ -141,15 +143,23 @@ dmg_close:
                    }
                    chunk_count--;
                    i--;
                    }
                    chunk_count--;
                    i--;

-                   if(lseek(s->fd,36,SEEK_CUR)<0)
-                       goto dmg_close;
+                   offset += 36;

                    continue;
                }
                    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);
+               offset += 4;
+
+               s->sectors[i] = last_out_offset+read_off(bs, offset);
+               offset += 8;
+
+               s->sectorcounts[i] = read_off(bs, offset);
+               offset += 8;
+
+               s->offsets[i] = last_in_offset+read_off(bs, offset);
+               offset += 8;
+
+               s->lengths[i] = read_off(bs, offset);
+               offset += 8;
+

                if(s->lengths[i]>max_compressed_size)
                    max_compressed_size = s->lengths[i];
                if(s->sectorcounts[i]>max_sectors_per_chunk)
                if(s->lengths[i]>max_compressed_size)
                    max_compressed_size = s->lengths[i];
                if(s->sectorcounts[i]>max_sectors_per_chunk)


@@ -163,11 +173,13 @@ dmg_close:
     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)
     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;
+       goto fail;

 
     s->current_chunk = s->n_chunks;
 
     return 0;
 
     s->current_chunk = s->n_chunks;
 
     return 0;

+fail:
+    return -1;

 }
 
 static inline int is_sector_in_chunk(BDRVDMGState* s,
 }
 
 static inline int is_sector_in_chunk(BDRVDMGState* s,


@@ -196,8 +208,10 @@ static inline uint32_t search_chunk(BDRVDMGState* s,int sector_num)
     return s->n_chunks; /* error */
 }
 
     return s->n_chunks; /* error */
 }
 

-static inline int dmg_read_chunk(BDRVDMGState *s,int sector_num)
+static inline int dmg_read_chunk(BlockDriverState *bs, int 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(!is_sector_in_chunk(s,s->current_chunk,sector_num)) {
        int ret;
        uint32_t chunk = search_chunk(s,sector_num);


@@ -210,15 +224,12 @@ static inline int dmg_read_chunk(BDRVDMGState *s,int sector_num)
        case 0x80000005: { /* zlib compressed */
            int i;
 
        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 {
            /* 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);
+                ret = bdrv_pread(bs->file, s->offsets[chunk] + i,
+                                 s->compressed_chunk+i, s->lengths[chunk]-i);

                if(ret<0 && errno==EINTR)
                    ret=0;
                i+=ret;
                if(ret<0 && errno==EINTR)
                    ret=0;
                i+=ret;


@@ -239,7 +250,8 @@ static inline int dmg_read_chunk(BDRVDMGState *s,int sector_num)
                return -1;
            break; }
        case 1: /* copy */
                return -1;
            break; }
        case 1: /* copy */

-           ret = read(s->fd, s->uncompressed_chunk, s->lengths[chunk]);
+           ret = bdrv_pread(bs->file, s->offsets[chunk],
+                             s->uncompressed_chunk, s->lengths[chunk]);

            if (ret != s->lengths[chunk])
                return -1;
            break;
            if (ret != s->lengths[chunk])
                return -1;
            break;


@@ -260,7 +272,7 @@ static int dmg_read(BlockDriverState *bs, int64_t sector_num,
 
     for(i=0;i<nb_sectors;i++) {
        uint32_t sector_offset_in_chunk;
 
     for(i=0;i<nb_sectors;i++) {
        uint32_t sector_offset_in_chunk;

-       if(dmg_read_chunk(s, sector_num+i) != 0)
+       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 -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);


@@ -271,7 +283,6 @@ static int dmg_read(BlockDriverState *bs, int64_t sector_num,
 static void dmg_close(BlockDriverState *bs)
 {
     BDRVDMGState *s = bs->opaque;
 static void dmg_close(BlockDriverState *bs)
 {
     BDRVDMGState *s = bs->opaque;

-    close(s->fd);

     if(s->n_chunks>0) {
        free(s->types);
        free(s->offsets);
     if(s->n_chunks>0) {
        free(s->types);
        free(s->offsets);