]> Git Repo - qemu.git/blobdiff - block/dmg.c
qed: Drop qed_aiocb_info.cancel
[qemu.git] / block / dmg.c
index d5c1a687e443192716c3fb40d3df35d62f4abfaa..e455886d2bc3d7d3f363e0d95244cca96c7b1a1b 100644 (file)
  * THE SOFTWARE.
  */
 #include "qemu-common.h"
-#include "block_int.h"
-#include "bswap.h"
-#include "module.h"
+#include "block/block_int.h"
+#include "qemu/bswap.h"
+#include "qemu/module.h"
 #include <zlib.h>
 
-typedef struct BDRVDMGState {
-    int fd;
+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,
@@ -52,202 +59,338 @@ typedef struct 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;
+    int len;
+
+    if (!filename) {
+        return 0;
+    }
+
+    len = strlen(filename);
+    if (len > 4 && !strcmp(filename + len - 4, ".dmg")) {
+        return 2;
+    }
     return 0;
 }
 
-static off_t read_off(int fd)
+static int read_uint64(BlockDriverState *bs, int64_t offset, uint64_t *result)
 {
-       uint64_t buffer;
-       if(read(fd,&buffer,8)<8)
-               return 0;
-       return be64_to_cpu(buffer);
+    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;
 }
 
-static off_t read_uint32(int fd)
+/* 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 buffer;
-       if(read(fd,&buffer,4)<4)
-               return 0;
-       return be32_to_cpu(buffer);
+    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, const char *filename, int flags)
+static int dmg_open(BlockDriverState *bs, QDict *options, int flags,
+                    Error **errp)
 {
     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;
+    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;
 
-    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) {
+    offset = bdrv_getlength(bs->file);
+    if (offset < 0) {
+        ret = offset;
         goto fail;
     }
+    offset -= 0x1d8;
 
-    info_begin=read_off(s->fd);
-    if(info_begin==0)
-       goto fail;
-    if(lseek(s->fd,info_begin,SEEK_SET)<0)
-       goto fail;
-    if(read_uint32(s->fd)!=0x100)
-       goto fail;
-    if((count = read_uint32(s->fd))==0)
-       goto fail;
-    info_end = info_begin+count;
-    if(lseek(s->fd,0xf8,SEEK_CUR)<0)
-       goto fail;
+    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(lseek(s->fd,0,SEEK_CUR)<info_end) {
+    while (offset < info_end) {
         uint32_t type;
 
-       count = read_uint32(s->fd);
-       if(count==0)
-           goto fail;
-       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 fail;
-           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 fail;
-                   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;
-       }
+        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 = qemu_malloc(max_compressed_size+1);
-    s->uncompressed_chunk = qemu_malloc(512*max_sectors_per_chunk);
-    if(inflateInit(&s->zstream) != Z_OK)
-       goto fail;
+    s->compressed_chunk = qemu_try_blockalign(bs->file,
+                                              max_compressed_size + 1);
+    s->uncompressed_chunk = qemu_try_blockalign(bs->file,
+                                                512 * max_sectors_per_chunk);
+    if (s->compressed_chunk == NULL || s->uncompressed_chunk == NULL) {
+        ret = -ENOMEM;
+        goto fail;
+    }
+
+    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:
-    close(s->fd);
-    return -1;
+    g_free(s->types);
+    g_free(s->offsets);
+    g_free(s->lengths);
+    g_free(s->sectors);
+    g_free(s->sectorcounts);
+    qemu_vfree(s->compressed_chunk);
+    qemu_vfree(s->uncompressed_chunk);
+    return ret;
 }
 
 static inline int is_sector_in_chunk(BDRVDMGState* s,
-               uint32_t chunk_num,int sector_num)
+                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;
+    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)
+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;
+    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)
+static inline int dmg_read_chunk(BlockDriverState *bs, uint64_t 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;
+    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;
 }
@@ -258,39 +401,51 @@ static int dmg_read(BlockDriverState *bs, int64_t sector_num,
     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);
+    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;
-    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);
+
+    g_free(s->types);
+    g_free(s->offsets);
+    g_free(s->lengths);
+    g_free(s->sectors);
+    g_free(s->sectorcounts);
+    qemu_vfree(s->compressed_chunk);
+    qemu_vfree(s->uncompressed_chunk);
+
     inflateEnd(&s->zstream);
 }
 
 static BlockDriver bdrv_dmg = {
-    .format_name       = "dmg",
-    .instance_size     = sizeof(BDRVDMGState),
-    .bdrv_probe                = dmg_probe,
-    .bdrv_file_open    = dmg_open,
-    .bdrv_read         = dmg_read,
-    .bdrv_close                = dmg_close,
+    .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)
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