--- /dev/null
+/*
+ * QEMU Block driver for virtual VFAT (shadows a local directory)
+ *
+ * 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 <sys/stat.h>
+#include <dirent.h>
+#include <assert.h>
+#include "vl.h"
+#include "block_int.h"
+
+// TODO: new file
+// TODO: delete file
+// TODO: make root directory larger
+// TODO: make directory clusters connected, so they are reserved anyway... add a member which tells how many clusters are reserved after a directory
+// TODO: introduce another member in mapping_t which says where the directory resides in s->directory (for mkdir and rmdir)
+// in _read and _write, before treating direntries or file contents, get_mapping to know what it is.
+// TODO: mkdir
+// TODO: rmdir
+
+// TODO: when commit_data'ing a direntry and is_consistent, commit_remove
+// TODO: reset MODE_MODIFIED when commit_remove'ing
+
+#define DEBUG
+
+/* dynamic array functions */
+typedef struct array_t {
+ char* pointer;
+ unsigned int size,next,item_size;
+} array_t;
+
+static inline void array_init(array_t* array,unsigned int item_size)
+{
+ array->pointer=0;
+ array->size=0;
+ array->next=0;
+ array->item_size=item_size;
+}
+
+static inline void array_free(array_t* array)
+{
+ if(array->pointer)
+ free(array->pointer);
+ array->size=array->next=0;
+}
+
+/* make sure that memory is reserved at pointer[index*item_size] */
+static inline void* array_get(array_t* array,unsigned int index) {
+ if((index+1)*array->item_size>array->size) {
+ int new_size=(index+32)*array->item_size;
+ array->pointer=realloc(array->pointer,new_size);
+ if(!array->pointer)
+ return 0;
+ array->size=new_size;
+ array->next=index+1;
+ }
+ return array->pointer+index*array->item_size;
+}
+
+static inline void* array_get_next(array_t* array) {
+ unsigned int next=array->next;
+ void* result=array_get(array,next);
+ array->next=next+1;
+ return result;
+}
+
+static inline void* array_insert(array_t* array,unsigned int index,unsigned int count) {
+ if((array->next+count)*array->item_size>array->size) {
+ int increment=count*array->item_size;
+ array->pointer=realloc(array->pointer,array->size+increment);
+ if(!array->pointer)
+ return 0;
+ array->size+=increment;
+ }
+ memmove(array->pointer+(index+count)*array->item_size,
+ array->pointer+index*array->item_size,
+ (array->next-index)*array->item_size);
+ array->next+=count;
+ return array->pointer+index*array->item_size;
+}
+
+/* this performs a "roll", so that the element which was at index_from becomes
+ * index_to, but the order of all other elements is preserved. */
+static inline int array_roll(array_t* array,int index_to,int index_from,int count)
+{
+ char* buf;
+ char* from;
+ char* to;
+ int is;
+
+ if(!array ||
+ index_to<0 || index_to>=array->next ||
+ index_from<0 || index_from>=array->next)
+ return -1;
+
+ if(index_to==index_from)
+ return 0;
+
+ is=array->item_size;
+ from=array->pointer+index_from*is;
+ to=array->pointer+index_to*is;
+ buf=malloc(is*count);
+ memcpy(buf,from,is*count);
+
+ if(index_to<index_from)
+ memmove(to+is*count,to,from-to);
+ else
+ memmove(from,from+is*count,to-from);
+
+ memcpy(to,buf,is*count);
+
+ free(buf);
+
+ return 0;
+}
+
+int array_remove(array_t* array,int index)
+{
+ if(array_roll(array,array->next-1,index,1))
+ return -1;
+ array->next--;
+ return 0;
+}
+
+/* These structures are used to fake a disk and the VFAT filesystem.
+ * For this reason we need to use __attribute__((packed)). */
+
+typedef struct bootsector_t {
+ uint8_t jump[3];
+ uint8_t name[8];
+ uint16_t sector_size;
+ uint8_t sectors_per_cluster;
+ uint16_t reserved_sectors;
+ uint8_t number_of_fats;
+ uint16_t root_entries;
+ uint16_t zero;
+ uint8_t media_type;
+ uint16_t sectors_per_fat;
+ uint16_t sectors_per_track;
+ uint16_t number_of_heads;
+ uint32_t hidden_sectors;
+ uint32_t total_sectors;
+ union {
+ struct {
+ uint8_t drive_number;
+ uint8_t current_head;
+ uint8_t signature;
+ uint32_t id;
+ uint8_t volume_label[11];
+ } __attribute__((packed)) fat16;
+ struct {
+ uint32_t sectors_per_fat;
+ uint16_t flags;
+ uint8_t major,minor;
+ uint32_t first_cluster_of_root_directory;
+ uint16_t info_sector;
+ uint16_t backup_boot_sector;
+ uint16_t ignored;
+ } __attribute__((packed)) fat32;
+ } u;
+ uint8_t fat_type[8];
+ uint8_t ignored[0x1c0];
+ uint8_t magic[2];
+} __attribute__((packed)) bootsector_t;
+
+typedef struct partition_t {
+ uint8_t attributes; /* 0x80 = bootable */
+ uint8_t start_head;
+ uint8_t start_sector;
+ uint8_t start_cylinder;
+ uint8_t fs_type; /* 0x6 = FAT16, 0xb = FAT32 */
+ uint8_t end_head;
+ uint8_t end_sector;
+ uint8_t end_cylinder;
+ uint32_t start_sector_long;
+ uint32_t end_sector_long;
+} __attribute__((packed)) partition_t;
+
+typedef struct mbr_t {
+ uint8_t ignored[0x1be];
+ partition_t partition[4];
+ uint8_t magic[2];
+} __attribute__((packed)) mbr_t;
+
+typedef struct direntry_t {
+ uint8_t name[8];
+ uint8_t extension[3];
+ uint8_t attributes;
+ uint8_t reserved[2];
+ uint16_t ctime;
+ uint16_t cdate;
+ uint16_t adate;
+ uint16_t begin_hi;
+ uint16_t mtime;
+ uint16_t mdate;
+ uint16_t begin;
+ uint32_t size;
+} __attribute__((packed)) direntry_t;
+
+/* this structure are used to transparently access the files */
+
+typedef struct mapping_t {
+ /* begin is the first cluster, end is the last+1,
+ * offset is the offset in the file in clusters of this slice */
+ off_t begin,end,offset;
+ char* filename;
+
+ /* as s->directory is growable, no pointer may be used here */
+ unsigned int dir_index;
+ enum { MODE_NORMAL,MODE_UNDEFINED,MODE_MODIFIED,MODE_DELETED,MODE_DIRECTORY } mode;
+} mapping_t;
+
+/* this structure is used to hold sectors which need to be written, but it's
+ * not known yet where to write them. */
+
+typedef struct commit_t {
+ uint32_t cluster_num;
+ uint8_t* buf;
+} commit_t;
+
+/* write support exists for fat, direntry and file contents */
+typedef enum {
+ WRITE_UNDEFINED,WRITE_FAT,WRITE_DIRENTRY,WRITE_DATA
+} write_action_t;
+
+/* here begins the real VVFAT driver */
+
+typedef struct BDRVVVFATState {
+ unsigned int first_sectors_number; /* 1 for a single partition, 0x40 for a disk with partition table */
+ unsigned char first_sectors[0x40*0x200];
+
+ int fat_type; /* 16 or 32 */
+ array_t fat,directory,mapping;
+
+ unsigned int cluster_size;
+ unsigned int sectors_per_cluster;
+ unsigned int sectors_per_fat;
+ unsigned int sectors_of_root_directory;
+ unsigned int sectors_for_directory;
+ unsigned int faked_sectors; /* how many sectors are faked before file data */
+ uint32_t sector_count; /* total number of sectors of the partition */
+ uint32_t cluster_count; /* total number of clusters of this partition */
+ unsigned int first_file_mapping; /* index of the first mapping which is not a directory, but a file */
+ uint32_t max_fat_value;
+
+ int current_fd;
+ char current_fd_is_writable; /* =0 if read only, !=0 if read/writable */
+ mapping_t* current_mapping;
+ unsigned char* cluster;
+ unsigned int current_cluster;
+
+ /* write support */
+ array_t commit;
+ /* for each file, the file contents, the direntry, and the fat entries are
+ * written, but not necessarily in that order */
+ write_action_t action[3];
+} BDRVVVFATState;
+
+
+static int vvfat_probe(const uint8_t *buf, int buf_size, const char *filename)
+{
+ if (strstart(filename, "fat:", NULL) ||
+ strstart(filename, "fatrw:", NULL))
+ return 100;
+ return 0;
+}
+
+static void init_mbr(BDRVVVFATState* s)
+{
+ /* TODO: if the files mbr.img and bootsect.img exist, use them */
+ mbr_t* real_mbr=(mbr_t*)s->first_sectors;
+ partition_t* partition=&(real_mbr->partition[0]);
+
+ memset(s->first_sectors,0,512);
+
+ partition->attributes=0x80; /* bootable */
+ partition->start_head=1;
+ partition->start_sector=1;
+ partition->start_cylinder=0;
+ partition->fs_type=(s->fat_type==16?0x6:0xb); /* FAT16/FAT32 */
+ partition->end_head=0xf;
+ partition->end_sector=0xff; /* end sector & upper 2 bits of cylinder */;
+ partition->end_cylinder=0xff; /* lower 8 bits of end cylinder */;
+ partition->start_sector_long=cpu_to_le32(0x3f);
+ partition->end_sector_long=cpu_to_le32(s->sector_count);
+
+ real_mbr->magic[0]=0x55; real_mbr->magic[1]=0xaa;
+}
+
+/* dest is assumed to hold 258 bytes, and pads with 0xffff up to next multiple of 26 */
+static inline int short2long_name(unsigned char* dest,const char* src)
+{
+ int i;
+ for(i=0;i<129 && src[i];i++) {
+ dest[2*i]=src[i];
+ dest[2*i+1]=0;
+ }
+ dest[2*i]=dest[2*i+1]=0;
+ for(i=2*i+2;(i%26);i++)
+ dest[i]=0xff;
+ return i;
+}
+
+static inline direntry_t* create_long_filename(BDRVVVFATState* s,const char* filename)
+{
+ char buffer[258];
+ int length=short2long_name(buffer,filename),
+ number_of_entries=(length+25)/26,i;
+ direntry_t* entry;
+
+ for(i=0;i<number_of_entries;i++) {
+ entry=array_get_next(&(s->directory));
+ entry->attributes=0xf;
+ entry->reserved[0]=0;
+ entry->begin=0;
+ entry->name[0]=(number_of_entries-i)|(i==0?0x40:0);
+ }
+ for(i=0;i<length;i++) {
+ int offset=(i%26);
+ if(offset<10) offset=1+offset;
+ else if(offset<22) offset=14+offset-10;
+ else offset=28+offset-22;
+ entry=array_get(&(s->directory),s->directory.next-1-(i/26));
+ entry->name[offset]=buffer[i];
+ }
+ return array_get(&(s->directory),s->directory.next-number_of_entries);
+}
+
+/* fat functions */
+
+static inline uint8_t fat_chksum(direntry_t* entry)
+{
+ uint8_t chksum=0;
+ int i;
+
+ for(i=0;i<11;i++)
+ chksum=(((chksum&0xfe)>>1)|((chksum&0x01)?0x80:0))
+ +(unsigned char)entry->name[i];
+
+ return chksum;
+}
+
+/* if return_time==0, this returns the fat_date, else the fat_time */
+static uint16_t fat_datetime(time_t time,int return_time) {
+ struct tm* t;
+#ifdef _WIN32
+ t=localtime(&time); /* this is not thread safe */
+#else
+ struct tm t1;
+ t=&t1;
+ localtime_r(&time,t);
+#endif
+ if(return_time)
+ return cpu_to_le16((t->tm_sec/2)|(t->tm_min<<5)|(t->tm_hour<<11));
+ return cpu_to_le16((t->tm_mday)|((t->tm_mon+1)<<5)|((t->tm_year-80)<<9));
+}
+
+static inline void fat_set(BDRVVVFATState* s,unsigned int cluster,uint32_t value)
+{
+ if(s->fat_type==12) {
+ assert(0); /* TODO */
+ } else if(s->fat_type==16) {
+ uint16_t* entry=array_get(&(s->fat),cluster);
+ *entry=cpu_to_le16(value&0xffff);
+ } else {
+ uint32_t* entry=array_get(&(s->fat),cluster);
+ *entry=cpu_to_le32(value);
+ }
+}
+
+static inline uint32_t fat_get(BDRVVVFATState* s,unsigned int cluster)
+{
+ //fprintf(stderr,"want to get fat for cluster %d\n",cluster);
+ if(s->fat_type==12) {
+ const uint8_t* x=s->fat.pointer+cluster*3/2;
+ return ((x[0]|(x[1]<<8))>>(cluster&1?4:0))&0x0fff;
+ } else if(s->fat_type==16) {
+ uint16_t* entry=array_get(&(s->fat),cluster);
+ return le16_to_cpu(*entry);
+ } else {
+ uint32_t* entry=array_get(&(s->fat),cluster);
+ return le32_to_cpu(*entry);
+ }
+}
+
+static inline int fat_eof(BDRVVVFATState* s,uint32_t fat_entry)
+{
+ if(fat_entry>s->max_fat_value-8)
+ return -1;
+ return 0;
+}
+
+static inline void init_fat(BDRVVVFATState* s)
+{
+ int i;
+
+ array_init(&(s->fat),(s->fat_type==32?4:2));
+ array_get(&(s->fat),s->sectors_per_fat*0x200/s->fat.item_size-1);
+ memset(s->fat.pointer,0,s->fat.size);
+ fat_set(s,0,0x7ffffff8);
+
+ for(i=1;i<s->sectors_for_directory/s->sectors_per_cluster-1;i++)
+ fat_set(s,i,i+1);
+ fat_set(s,i,0x7fffffff);
+
+ switch(s->fat_type) {
+ case 12: s->max_fat_value=0xfff; break;
+ case 16: s->max_fat_value=0xffff; break;
+ case 32: s->max_fat_value=0xfffffff; break;
+ default: s->max_fat_value=0; /* error... */
+ }
+
+}
+
+static inline int long2unix_name(unsigned char* dest,int dest_size,direntry_t* direntry_short) {
+ int i=-1,j;
+ int chksum=fat_chksum(direntry_short);
+ while(1) {
+ char* buf=(char*)(direntry_short+i);
+ if((buf[0]&0x3f)!=-i || direntry_short[i].reserved[1]!=chksum ||
+ direntry_short[i].attributes!=0xf) {
+ if(i<-1)
+ return -3;
+ /* take short name */
+ for(j=7;j>0 && direntry_short->name[j]==' ';j--);
+ if(j+1>dest_size)
+ return -1;
+ strncpy(dest,direntry_short->name,j+1);
+ dest+=j+1; dest_size-=j+1;
+ for(j=2;j>=0 && direntry_short->extension[j]==' ';j--);
+ if(j>=0) {
+ if(j+2>dest_size)
+ return -1;
+ dest[0]='.';
+ strncpy(dest+1,direntry_short->extension,j+1);
+ }
+ return 0;
+ }
+ for(j=0;j<13;j++) {
+ dest_size--;
+ if(dest_size<0)
+ return -2;
+ dest[0]=buf[2*j+((j<5)?1:(j<11)?4:6)];
+ if(dest[0]==0 && (buf[0]&0x40)!=0)
+ return 0;
+ dest++;
+ }
+ /* last entry, but no trailing \0? */
+ if(buf[0]&0x40)
+ return -3;
+ i--;
+ }
+}
+
+static inline direntry_t* create_short_filename(BDRVVVFATState* s,unsigned int directory_start,const char* filename,int is_dot)
+{
+ int i,long_index=s->directory.next;
+ direntry_t* entry=0;
+ direntry_t* entry_long=0;
+
+ if(is_dot) {
+ entry=array_get_next(&(s->directory));
+ memset(entry->name,0x20,11);
+ memcpy(entry->name,filename,strlen(filename));
+ return entry;
+ }
+
+ for(i=1;i<8 && filename[i] && filename[i]!='.';i++);
+
+ entry_long=create_long_filename(s,filename);
+
+ entry=array_get_next(&(s->directory));
+ memset(entry->name,0x20,11);
+ strncpy(entry->name,filename,i);
+
+ if(filename[i]) {
+ int len=strlen(filename);
+ for(i=len;i>0 && filename[i-1]!='.';i--);
+ if(i>0)
+ memcpy(entry->extension,filename+i,(len-i>3?3:len-i));
+ }
+
+ /* upcase & remove unwanted characters */
+ for(i=10;i>=0;i--) {
+ if(i==10 || i==7) for(;i>1 && entry->name[i]==' ';i--);
+ if(entry->name[i]<=' ' || entry->name[i]>0x7f
+ || strchr("*?<>|\":/\\[];,+='",entry->name[i]))
+ entry->name[i]='_';
+ else if(entry->name[i]>='a' && entry->name[i]<='z')
+ entry->name[i]+='A'-'a';
+ }
+
+ /* mangle duplicates */
+ while(1) {
+ direntry_t* entry1=array_get(&(s->directory),directory_start);
+ int j;
+
+ for(;entry1<entry;entry1++)
+ if(!(entry1->attributes&0xf) && !memcmp(entry1->name,entry->name,11))
+ break; /* found dupe */
+ if(entry1==entry) /* no dupe found */
+ break;
+
+ /* use all 8 characters of name */
+ if(entry->name[7]==' ') {
+ int j;
+ for(j=6;j>0 && entry->name[j]==' ';j--)
+ entry->name[j]='~';
+ }
+
+ /* increment number */
+ for(j=7;j>0 && entry->name[j]=='9';j--)
+ entry->name[j]='0';
+ if(j>0) {
+ if(entry->name[j]<'0' || entry->name[j]>'9')
+ entry->name[j]='0';
+ else
+ entry->name[j]++;
+ }
+ }
+
+ /* calculate checksum; propagate to long name */
+ if(entry_long) {
+ uint8_t chksum=fat_chksum(entry);
+
+ /* calculate anew, because realloc could have taken place */
+ entry_long=array_get(&(s->directory),long_index);
+ while(entry_long<entry
+ && entry_long->attributes==0xf) {
+ entry_long->reserved[1]=chksum;
+ entry_long++;
+ }
+ }
+
+ return entry;
+}
+
+static int read_directory(BDRVVVFATState* s,const char* dirname,
+ int first_cluster_of_parent)
+{
+
+ DIR* dir=opendir(dirname);
+ struct dirent* entry;
+ struct stat st;
+ unsigned int start_of_directory=s->directory.next;
+ /* mappings before first_file_mapping are directories */
+ unsigned int first_directory_mapping=s->first_file_mapping;
+ unsigned int first_cluster=(start_of_directory/0x10/s->sectors_per_cluster);
+ int i;
+
+ if(!dir)
+ return -1;
+
+ while((entry=readdir(dir))) {
+ unsigned int length=strlen(dirname)+2+strlen(entry->d_name);
+ char* buffer;
+ direntry_t* direntry;
+ int is_dot=!strcmp(entry->d_name,".");
+ int is_dotdot=!strcmp(entry->d_name,"..");
+
+ if(start_of_directory==1 && (is_dotdot || is_dot))
+ continue;
+
+ buffer=(char*)malloc(length);
+ snprintf(buffer,length,"%s/%s",dirname,entry->d_name);
+
+ if(stat(buffer,&st)<0) {
+ free(buffer);
+ continue;
+ }
+
+ /* create directory entry for this file */
+ //fprintf(stderr,"create direntry at %d (cluster %d) for %s\n",s->directory.next,s->directory.next/0x10/s->sectors_per_cluster,entry->d_name);
+ direntry=create_short_filename(s,start_of_directory,entry->d_name,is_dot||is_dotdot);
+ direntry->attributes=(S_ISDIR(st.st_mode)?0x10:0x20);
+ direntry->reserved[0]=direntry->reserved[1]=0;
+ direntry->ctime=fat_datetime(st.st_ctime,1);
+ direntry->cdate=fat_datetime(st.st_ctime,0);
+ direntry->adate=fat_datetime(st.st_atime,0);
+ direntry->begin_hi=0;
+ direntry->mtime=fat_datetime(st.st_mtime,1);
+ direntry->mdate=fat_datetime(st.st_mtime,0);
+ if(is_dotdot)
+ direntry->begin=cpu_to_le16(first_cluster_of_parent);
+ else if(is_dot)
+ direntry->begin=cpu_to_le16(first_cluster);
+ else
+ direntry->begin=cpu_to_le16(0); /* do that later */
+ direntry->size=cpu_to_le32(st.st_size);
+
+ /* create mapping for this file */
+ if(!is_dot && !is_dotdot) {
+ if(S_ISDIR(st.st_mode))
+ s->current_mapping=(mapping_t*)array_insert(&(s->mapping),s->first_file_mapping++,1);
+ else
+ s->current_mapping=(mapping_t*)array_get_next(&(s->mapping));
+ s->current_mapping->begin=0;
+ s->current_mapping->end=st.st_size;
+ s->current_mapping->offset=0;
+ s->current_mapping->filename=buffer;
+ s->current_mapping->dir_index=s->directory.next-1;
+ s->current_mapping->mode=(S_ISDIR(st.st_mode)?MODE_DIRECTORY:MODE_UNDEFINED);
+ }
+ }
+ closedir(dir);
+
+ /* fill with zeroes up to the end of the cluster */
+ while(s->directory.next%(0x10*s->sectors_per_cluster)) {
+ direntry_t* direntry=array_get_next(&(s->directory));
+ memset(direntry,0,sizeof(direntry_t));
+ }
+
+ /* reserve next cluster also (for new files) */
+ for(i=0;i<0x10*s->sectors_per_cluster;i++) {
+ direntry_t* direntry=array_get_next(&(s->directory));
+ memset(direntry,0,sizeof(direntry_t));
+ }
+
+ /* was it the first directory? */
+ if(start_of_directory==1) {
+ mapping_t* mapping=array_insert(&(s->mapping),0,1);
+ mapping->filename=strdup(dirname);
+ mapping->mode=MODE_DIRECTORY;
+ mapping->begin=0;
+ mapping->end=1;
+ mapping->offset=0;
+ mapping->dir_index=0xffffffff;
+ s->sectors_of_root_directory=s->directory.next/0x10;
+ }
+
+ /* recurse directories */
+ {
+ int i;
+
+ //fprintf(stderr,"iterating subdirectories of %s (first cluster %d): %d to %d\n",dirname,first_cluster,first_directory_mapping,last_directory_mapping);
+ for(i=first_directory_mapping;i<s->first_file_mapping;i++) {
+ mapping_t* mapping=array_get(&(s->mapping),i);
+ direntry_t* direntry=array_get(&(s->directory),mapping->dir_index);
+ /* the directory to be read can add more subdirectories */
+ int last_dir_mapping=s->first_file_mapping;
+
+ assert(mapping->mode==MODE_DIRECTORY);
+ /* first, tell the mapping where the directory will start */
+ mapping->begin=s->directory.next/0x10/s->sectors_per_cluster;
+ if(i>0) {
+ mapping[-1].end=mapping->begin;
+ assert(mapping[-1].begin<mapping->begin);
+ }
+ /* then tell the direntry */
+ direntry->begin=cpu_to_le16(mapping->begin);
+ //fprintf(stderr,"read directory %s (begin %d)\n",mapping->filename,(int)mapping->begin);
+ /* then read it */
+ if(read_directory(s,mapping->filename,first_cluster))
+ return -1;
+
+ if(last_dir_mapping!=s->first_file_mapping) {
+ int diff=s->first_file_mapping-last_dir_mapping;
+ assert(diff>0);
+
+ if(last_dir_mapping!=i+1) {
+ int count=last_dir_mapping-i-1;
+ int to=s->first_file_mapping-count;
+
+ assert(count>0);
+ assert(to>i+1);
+ array_roll(&(s->mapping),to,i+1,count);
+ /* could have changed due to realloc */
+ mapping=array_get(&(s->mapping),i);
+ mapping->end=mapping[1].begin;
+ }
+ i+=diff;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static int init_directory(BDRVVVFATState* s,const char* dirname)
+{
+ bootsector_t* bootsector=(bootsector_t*)&(s->first_sectors[(s->first_sectors_number-1)*0x200]);
+ unsigned int i;
+ unsigned int cluster;
+
+ memset(&(s->first_sectors[0]),0,0x40*0x200);
+
+ /* TODO: if FAT32, this is probably wrong */
+ s->sectors_per_fat=0xfc;
+ s->sectors_per_cluster=0x10;
+ s->cluster_size=s->sectors_per_cluster*0x200;
+ s->cluster=malloc(s->cluster_size);
+
+ array_init(&(s->mapping),sizeof(mapping_t));
+ array_init(&(s->directory),sizeof(direntry_t));
+ array_init(&(s->commit),sizeof(commit_t));
+
+ /* add volume label */
+ {
+ direntry_t* entry=array_get_next(&(s->directory));
+ entry->attributes=0x28; /* archive | volume label */
+ snprintf(entry->name,11,"QEMU VVFAT");
+ }
+
+ if(read_directory(s,dirname,0))
+ return -1;
+
+ /* make sure that the number of directory entries is multiple of 0x200/0x20 (to fit the last sector exactly) */
+ s->sectors_for_directory=s->directory.next/0x10;
+
+ s->faked_sectors=s->first_sectors_number+s->sectors_per_fat*2+s->sectors_for_directory;
+ s->cluster_count=(s->sector_count-s->faked_sectors)/s->sectors_per_cluster;
+
+ /* Now build FAT, and write back information into directory */
+ init_fat(s);
+
+ cluster=s->sectors_for_directory/s->sectors_per_cluster;
+ assert(s->sectors_for_directory%s->sectors_per_cluster==0);
+
+ /* set the end of the last read directory */
+ if(s->first_file_mapping>0) {
+ mapping_t* mapping=array_get(&(s->mapping),s->first_file_mapping-1);
+ mapping->end=cluster;
+ }
+
+ for(i=1;i<s->mapping.next;i++) {
+ mapping_t* mapping=array_get(&(s->mapping),i);
+ direntry_t* direntry=array_get(&(s->directory),mapping->dir_index);
+ if(mapping->mode==MODE_DIRECTORY) {
+ /* directory */
+ int i;
+#ifdef DEBUG
+ fprintf(stderr,"assert: %s %d < %d\n",mapping->filename,(int)mapping->begin,(int)mapping->end);
+#endif
+ assert(mapping->begin<mapping->end);
+ for(i=mapping->begin;i<mapping->end-1;i++)
+ fat_set(s,i,i+1);
+ fat_set(s,i,0x7fffffff);
+ } else {
+ /* as the space is virtual, we can be sloppy about it */
+ unsigned int end_cluster=cluster+mapping->end/s->cluster_size;
+
+ if(end_cluster>=s->cluster_count) {
+ fprintf(stderr,"Directory does not fit in FAT%d\n",s->fat_type);
+ return -1;
+ }
+ mapping->begin=cluster;
+ mapping->mode=MODE_NORMAL;
+ mapping->offset=0;
+ direntry->size=cpu_to_le32(mapping->end);
+ if(direntry->size==0) {
+ direntry->begin=0;
+ mapping->end=cluster;
+ continue;
+ }
+
+ direntry->begin=cpu_to_le16(cluster);
+ mapping->end=end_cluster+1;
+ for(;cluster<end_cluster;cluster++)
+ fat_set(s,cluster,cluster+1);
+ fat_set(s,cluster,0x7fffffff);
+ cluster++;
+ }
+ }
+
+ s->current_mapping=0;
+
+ bootsector->jump[0]=0xeb;
+ bootsector->jump[1]=0x3e;
+ bootsector->jump[2]=0x90;
+ memcpy(bootsector->name,"QEMU ",8);
+ bootsector->sector_size=cpu_to_le16(0x200);
+ bootsector->sectors_per_cluster=s->sectors_per_cluster;
+ bootsector->reserved_sectors=cpu_to_le16(1);
+ bootsector->number_of_fats=0x2; /* number of FATs */
+ bootsector->root_entries=cpu_to_le16(s->sectors_of_root_directory*0x10);
+ bootsector->zero=0;
+ bootsector->media_type=(s->first_sectors_number==1?0xf0:0xf8); /* media descriptor */
+ bootsector->sectors_per_fat=cpu_to_le16(s->sectors_per_fat);
+ bootsector->sectors_per_track=cpu_to_le16(0x3f);
+ bootsector->number_of_heads=cpu_to_le16(0x10);
+ bootsector->hidden_sectors=cpu_to_le32(s->first_sectors_number==1?0:0x3f);
+ /* TODO: if FAT32, adjust */
+ bootsector->total_sectors=cpu_to_le32(s->sector_count);
+
+ /* TODO: if FAT32, this is wrong */
+ bootsector->u.fat16.drive_number=0x80; /* assume this is hda (TODO) */
+ bootsector->u.fat16.current_head=0;
+ bootsector->u.fat16.signature=0x29;
+ bootsector->u.fat16.id=cpu_to_le32(0xfabe1afd);
+
+ memcpy(bootsector->u.fat16.volume_label,"QEMU VVFAT ",11);
+ memcpy(bootsector->fat_type,(s->fat_type==12?"FAT12 ":s->fat_type==16?"FAT16 ":"FAT32 "),8);
+ bootsector->magic[0]=0x55; bootsector->magic[1]=0xaa;
+
+ return 0;
+}
+
+static int vvfat_open(BlockDriverState *bs, const char* dirname)
+{
+ BDRVVVFATState *s = bs->opaque;
+ int i;
+
+ /* TODO: automatically determine which FAT type */
+ s->fat_type=16;
+ s->sector_count=0xec04f;
+
+ s->current_cluster=0xffffffff;
+ s->first_file_mapping=0;
+
+ /* TODO: if simulating a floppy, this is 1, because there is no partition table */
+ s->first_sectors_number=0x40;
+
+ if (strstart(dirname, "fat:", &dirname)) {
+ /* read only is the default for safety */
+ bs->read_only = 1;
+ } else if (strstart(dirname, "fatrw:", &dirname)) {
+ /* development only for now */
+ bs->read_only = 0;
+ } else {
+ return -1;
+ }
+ if(init_directory(s,dirname))
+ return -1;
+
+ if(s->first_sectors_number==0x40)
+ init_mbr(s);
+
+ /* TODO: this could be wrong for FAT32 */
+ bs->cyls=1023; bs->heads=15; bs->secs=63;
+ bs->total_sectors=bs->cyls*bs->heads*bs->secs;
+
+ /* write support */
+ for(i=0;i<3;i++)
+ s->action[i]=WRITE_UNDEFINED;
+ return 0;
+}
+
+static inline void vvfat_close_current_file(BDRVVVFATState *s)
+{
+ if(s->current_mapping) {
+ s->current_mapping = 0;
+ close(s->current_fd);
+ }
+}
+
+/* mappings between index1 and index2-1 are supposed to be ordered
+ * return value is the index of the last mapping for which end>cluster_num
+ */
+static inline int find_mapping_for_cluster_aux(BDRVVVFATState* s,int cluster_num,int index1,int index2)
+{
+ int index3=index1+1;
+ //fprintf(stderr,"find_aux: cluster_num=%d, index1=%d,index2=%d\n",cluster_num,index1,index2);
+ while(1) {
+ mapping_t* mapping;
+ index3=(index1+index2)/2;
+ mapping=array_get(&(s->mapping),index3);
+ //fprintf(stderr,"index3: %d = (%d+%d)/2, end: %d\n",index3,index1,index2,(int)mapping->end);
+ if(mapping->end>cluster_num) {
+ assert(index2!=index3 || index2==0);
+ if(index2==index3)
+ return index2;
+ index2=index3;
+ } else {
+ if(index1==index3)
+ return index2;
+ index1=index3;
+ }
+ assert(index1<=index2);
+ }
+}
+
+static inline mapping_t* find_mapping_for_cluster(BDRVVVFATState* s,int cluster_num)
+{
+ int index=find_mapping_for_cluster_aux(s,cluster_num,0,s->mapping.next);
+ mapping_t* mapping;
+ if(index>=s->mapping.next)
+ return 0;
+ mapping=array_get(&(s->mapping),index);
+ if(mapping->begin>cluster_num)
+ return 0;
+ return mapping;
+}
+
+static int open_file(BDRVVVFATState* s,mapping_t* mapping,int flags)
+{
+ if(!mapping)
+ return -1;
+ assert(flags==O_RDONLY || flags==O_RDWR);
+ if(!s->current_mapping ||
+ strcmp(s->current_mapping->filename,mapping->filename) ||
+ (flags==O_RDWR && !s->current_fd_is_writable)) {
+ /* open file */
+ int fd = open(mapping->filename, flags | O_BINARY | O_LARGEFILE);
+ if(fd<0)
+ return -1;
+ vvfat_close_current_file(s);
+ s->current_fd = fd;
+ s->current_fd_is_writable = (flags==O_RDWR?-1:0);
+ s->current_mapping = mapping;
+ }
+ return 0;
+}
+
+static inline int read_cluster(BDRVVVFATState *s,int cluster_num)
+{
+ if(s->current_cluster != cluster_num) {
+ int result=0;
+ off_t offset;
+ if(!s->current_mapping
+ || s->current_mapping->begin>cluster_num
+ || s->current_mapping->end<=cluster_num) {
+ /* binary search of mappings for file */
+ mapping_t* mapping=find_mapping_for_cluster(s,cluster_num);
+ if(open_file(s,mapping,O_RDONLY))
+ return -2;
+ }
+
+ offset=s->cluster_size*(cluster_num-s->current_mapping->begin+s->current_mapping->offset);
+ if(lseek(s->current_fd, offset, SEEK_SET)!=offset)
+ return -3;
+ result=read(s->current_fd,s->cluster,s->cluster_size);
+ if(result<0) {
+ s->current_cluster = -1;
+ return -1;
+ }
+ s->current_cluster = cluster_num;
+ }
+ return 0;
+}
+
+static int vvfat_read(BlockDriverState *bs, int64_t sector_num,
+ uint8_t *buf, int nb_sectors)
+{
+ BDRVVVFATState *s = bs->opaque;
+ int i;
+
+ // fprintf(stderr,"vvfat_read: sector %d+%d\n",(int)sector_num,nb_sectors);
+
+ for(i=0;i<nb_sectors;i++,sector_num++) {
+ if(sector_num<s->faked_sectors) {
+ if(sector_num<s->first_sectors_number)
+ memcpy(buf+i*0x200,&(s->first_sectors[sector_num*0x200]),0x200);
+ else if(sector_num-s->first_sectors_number<s->sectors_per_fat)
+ memcpy(buf+i*0x200,&(s->fat.pointer[(sector_num-s->first_sectors_number)*0x200]),0x200);
+ else if(sector_num-s->first_sectors_number-s->sectors_per_fat<s->sectors_per_fat)
+ memcpy(buf+i*0x200,&(s->fat.pointer[(sector_num-s->first_sectors_number-s->sectors_per_fat)*0x200]),0x200);
+ else if(sector_num-s->first_sectors_number-s->sectors_per_fat*2<s->sectors_for_directory)
+ memcpy(buf+i*0x200,&(s->directory.pointer[(sector_num-s->first_sectors_number-s->sectors_per_fat*2)*0x200]),0x200);
+ } else {
+ uint32_t sector=sector_num-s->first_sectors_number-s->sectors_per_fat*2,
+ sector_offset_in_cluster=(sector%s->sectors_per_cluster),
+ cluster_num=sector/s->sectors_per_cluster;
+ if(read_cluster(s, cluster_num) != 0) {
+ //fprintf(stderr,"failed to read cluster %d\n",(int)cluster_num);
+ // TODO: strict: return -1;
+ memset(buf+i*0x200,0,0x200);
+ continue;
+ }
+ memcpy(buf+i*0x200,s->cluster+sector_offset_in_cluster*0x200,0x200);
+ }
+ }
+ return 0;
+}
+
+static void print_direntry(direntry_t* direntry)
+{
+ if(!direntry)
+ return;
+ if(direntry->attributes==0xf) {
+ unsigned char* c=(unsigned char*)direntry;
+ int i;
+ for(i=1;i<11 && c[i] && c[i]!=0xff;i+=2)
+ fputc(c[i],stderr);
+ for(i=14;i<26 && c[i] && c[i]!=0xff;i+=2)
+ fputc(c[i],stderr);
+ for(i=28;i<32 && c[i] && c[i]!=0xff;i+=2)
+ fputc(c[i],stderr);
+ fputc('\n',stderr);
+ } else {
+ int i;
+ for(i=0;i<11;i++)
+ fputc(direntry->name[i],stderr);
+ fprintf(stderr,"attributes=0x%02x begin=%d size=%d\n",
+ direntry->attributes,
+ direntry->begin,direntry->size);
+ }
+}
+
+static void print_changed_sector(BlockDriverState *bs,int64_t sector_num,const uint8_t *buf)
+{
+ BDRVVVFATState *s = bs->opaque;
+
+ if(sector_num<s->first_sectors_number)
+ return;
+ if(sector_num<s->first_sectors_number+s->sectors_per_fat*2) {
+ int first=((sector_num-s->first_sectors_number)%s->sectors_per_fat);
+ int first_fat_entry=first*0x200/2;
+ int i;
+
+ fprintf(stderr, "fat:\n");
+ for(i=0;i<0x200;i+=2) {
+ uint16_t* f=array_get(&(s->fat),first_fat_entry+i/2);
+ if(memcmp(buf+i,f,2))
+ fprintf(stderr,"%d(%d->%d) ",first_fat_entry+i/2,*f,*(uint16_t*)(buf+i));
+ }
+ fprintf(stderr, "\n");
+ } else if(sector_num<s->faked_sectors) {
+ direntry_t* d=(direntry_t*)buf;
+ int i;
+ fprintf(stderr, "directory:\n");
+ for(i=0;i<0x200/sizeof(direntry_t);i++) {
+ direntry_t* d_old=(direntry_t*)(s->directory.pointer+0x200*(sector_num-s->first_sectors_number-s->sectors_per_fat*2)+i*sizeof(direntry_t));
+ if(memcmp(d+i,d_old,sizeof(direntry_t))) {
+ fprintf(stderr, "old: "); print_direntry(d_old);
+ fprintf(stderr, "new: "); print_direntry(d+i);
+ fprintf(stderr, "\n");
+ }
+ }
+ } else {
+ int sec=(sector_num-s->first_sectors_number-2*s->sectors_per_fat);
+ fprintf(stderr, "\tcluster: %d(+%d sectors)\n",sec/s->sectors_per_cluster,sec%s->sectors_per_cluster);
+ }
+}
+
+char direntry_is_free(const direntry_t* direntry)
+{
+ return direntry->name[0]==0 || direntry->name[0]==0xe5;
+}
+
+/* TODO: use this everywhere */
+static inline uint32_t begin_of_direntry(direntry_t* direntry)
+{
+ return le16_to_cpu(direntry->begin)|(le16_to_cpu(direntry->begin_hi)<<16);
+}
+
+int consistency_check1(BDRVVVFATState *s) {
+ /* check all mappings */
+ int i;
+ for(i=0;i<s->mapping.next;i++) {
+ mapping_t* mapping=array_get(&(s->mapping),i);
+ int j;
+ for(j=mapping->begin;j<mapping->end-1;j++)
+ assert(fat_get(s,j)==j+1);
+ assert(fat_get(s,j)==(0x7fffffff&s->max_fat_value));
+ }
+ return 0;
+}
+
+int consistency_check2(BDRVVVFATState *s) {
+ /* check fat entries: consecutive fat entries should be mapped in one mapping */
+ int i;
+ /* TODO: i=0 (mappings for direntries have to be sorted) */
+ for(i=s->sectors_for_directory/s->sectors_per_cluster;i<s->fat.next-1;i++) {
+ uint32_t j=fat_get(s,i);
+ if(j!=i+1 && j!=0 && !fat_eof(s,j)) {
+ mapping_t* mapping=find_mapping_for_cluster(s,i+1);
+ assert(mapping->begin==i+1);
+ }
+ }
+ return 0;
+}
+
+int consistency_check3(BDRVVVFATState *s) {
+ /* check that for each file there is exactly one mapping per cluster */
+ int i,count_non_next=0;
+ for(i=0;i<s->mapping.next;i++) {
+ mapping_t* mapping=array_get(&(s->mapping),i);
+ /* TODO: when directories are correctly adapted, add them here */
+ assert(mapping->begin<mapping->end);
+ if(mapping->mode==MODE_NORMAL) {
+ int j,count=0,count_next=0;
+ for(j=0;j<s->mapping.next;j++) {
+ mapping_t* other=array_get(&(s->mapping),j);
+ if(mapping->begin<other->end&&mapping->end>other->begin)
+ count++;
+ if(mapping->end==other->begin)
+ count_next++;
+ }
+ assert(count==1); /* no overlapping mappings */
+ assert(count_next==1 || count_next==0); /* every mapping except the last one has a successor */
+ if(!count_next)
+ count_non_next++;
+ }
+ }
+ assert(count_non_next==1); /* only one last mapping */
+ return 0;
+}
+
+static inline commit_t* commit_get_next(BDRVVVFATState* s)
+{
+ commit_t* commit=array_get_next(&(s->commit));
+ if((commit->buf=malloc(s->cluster_size))==0) {
+ /* out of memory */
+ s->commit.next--;
+ return 0;
+ }
+ return commit;
+}
+
+int commit_remove(BDRVVVFATState* s,commit_t* commit)
+{
+ int index=commit-(commit_t*)s->commit.pointer;
+ free(commit->buf);
+ if(array_roll(&(s->commit),s->commit.next-1,index,1))
+ return -1;
+ s->commit.next--;
+ return 0;
+}
+
+/* TODO: the plan for write support:
+ *
+ * it seems that the direntries are written first, then the data is committed
+ * to the free sectors, then fat 1 is updated, then fat2.
+ *
+ * Plan: when sectors are written, do the following:
+ *
+ * - if they are in a directory, check if the entry has changed. if yes,
+ * look what has changed (different strategies for name, begin & size).
+ *
+ * if it is new (old entry is only 0's or has E5 at the start), create it,
+ * and also create mapping, but in a special mode "undefined" (TODO),
+ * because we cannot know which clusters belong to it yet.
+ *
+ * if it is zeroed, or has E5 at the start, look if has just moved. If yes,
+ * copy the entry to the new position. If no, delete the file.
+ *
+ * - if they are in data, and the cluster is undefined, add it to the commit
+ * list. if the cluster is defined (find_mapping), then write it into the
+ * corresponding file.
+ *
+ * If it is the last cluster (TODO: add a function
+ * fat_get(s,cluster); ), make sure not to write a complete cluster_size.
+ *
+ * If the data is in current_cluster, update s->cluster.
+ *
+ * - if they are in fat 1, update mappings, look in the commit list
+ * (assertions!) and if the cluster is now known (or changed from undefined
+ * state to defined state, like when begin or size changed in a direntry),
+ * write it.
+ *
+ * - if they are in fat 2, make sure they match with current fat.
+ *
+ */
+
+void mapping_modify_from_direntry(BDRVVVFATState* s,mapping_t* mapping,direntry_t* direntry)
+{
+ int begin=le16_to_cpu(direntry->begin),
+ end=begin+le32_to_cpu(direntry->size)/s->cluster_size+1,
+ i;
+ mapping->mode = MODE_MODIFIED;
+ /* TODO: what if begin==0 (size==0)? */
+ mapping->begin = begin;
+ /* TODO: why not just mapping->end = begin+1 ? */
+ for(i=begin+1;i<end && (fat_get(s,i)==0 || fat_get(s,i)==i+1);i++);
+ mapping->end = i;
+}
+
+mapping_t* find_mapping_for_direntry(BDRVVVFATState* s,direntry_t* direntry)
+{
+ int i;
+ int dir_index=direntry-((direntry_t*)s->directory.pointer);
+
+ /* TODO: support allocation for new clusters for directories (new/larger directory */
+ assert(dir_index<0x200/0x20*s->sectors_for_directory);
+
+ for(i=0;i<s->mapping.next;i++) {
+ mapping_t* mapping=array_get(&(s->mapping),i);
+ if(mapping->dir_index==dir_index && mapping->offset==0 &&
+ mapping->mode!=MODE_UNDEFINED)
+ return mapping;
+ }
+ return 0;
+}
+
+static inline uint32_t sector2cluster(BDRVVVFATState* s,off_t sector_num)
+{
+ return (sector_num-s->first_sectors_number-2*s->sectors_per_fat)/s->sectors_per_cluster;
+}
+
+static inline uint32_t sector_offset_in_cluster(BDRVVVFATState* s,off_t sector_num)
+{
+ return (sector_num-s->first_sectors_number-2*s->sectors_per_fat)%s->sectors_per_cluster;
+}
+
+static commit_t* get_commit_for_cluster(BDRVVVFATState* s,uint32_t cluster_num)
+{
+ int i;
+ for(i=0;i<s->commit.next;i++) {
+ commit_t* commit=array_get(&(s->commit),i);
+ if(commit->cluster_num==cluster_num)
+ return commit;
+ }
+ return 0;
+}
+
+static inline commit_t* create_or_get_commit_for_sector(BDRVVVFATState* s,off_t sector_num)
+{
+ int i;
+ commit_t* commit;
+ uint32_t cluster_num=sector2cluster(s,sector_num);
+
+ for(i=0;i<s->commit.next;i++) {
+ commit=array_get(&(s->commit),i);
+ if(commit->cluster_num==cluster_num)
+ return commit;
+ }
+
+ commit=commit_get_next(s);
+ commit->cluster_num=cluster_num;
+ /* we can ignore read errors here */
+ read_cluster(s,cluster_num);
+ memcpy(commit->buf,s->cluster,s->cluster_size);
+ return commit;
+}
+
+static direntry_t* get_direntry_for_mapping(BDRVVVFATState* s,mapping_t* mapping)
+{
+ if(mapping->mode==MODE_UNDEFINED)
+ return 0;
+ if(mapping->dir_index>=0x200/0x20*s->sectors_for_directory)
+ return 0;
+ return (direntry_t*)(s->directory.pointer+sizeof(direntry_t)*mapping->dir_index);
+}
+
+static void print_mappings(BDRVVVFATState* s)
+{
+ int i;
+ fprintf(stderr,"mapping:\n");
+ for(i=0;i<s->mapping.next;i++) {
+ mapping_t* m=array_get(&(s->mapping),i);
+ direntry_t* d=get_direntry_for_mapping(s,m);
+ fprintf(stderr,"%02d %d-%d (%d) %s (dir: %d)",i,(int)m->begin,(int)m->end,(int)m->offset,m->filename,m->dir_index);
+ print_direntry(d);
+ fprintf(stderr,"\n");
+ }
+ fprintf(stderr,"mappings end.\n");
+}
+
+/* TODO: statify all functions */
+
+/* This function is only meant for file contents.
+ * It will return an error if used for other sectors. */
+static int write_cluster(BDRVVVFATState* s,uint32_t cluster_num,const uint8_t* buf)
+{
+ /* sector_offset is the sector_num relative to the first cluster */
+ mapping_t* mapping=find_mapping_for_cluster(s,cluster_num);
+ direntry_t* direntry;
+ int next_cluster,write_size,last_cluster;
+ off_t offset;
+
+ /* if this cluster is free, return error */
+ next_cluster=fat_get(s,cluster_num);
+ if(next_cluster<2)
+ return -1;
+
+ /* TODO: MODE_DIRECTORY */
+ if(!mapping || mapping->mode==MODE_UNDEFINED || mapping->mode==MODE_DIRECTORY)
+ return -1;
+ direntry=get_direntry_for_mapping(s,mapping);
+ if(!direntry)
+ return -2;
+
+ /* get size to write */
+ last_cluster=fat_eof(s,next_cluster);
+ write_size=!last_cluster?s->cluster_size:
+ (le32_to_cpu(direntry->size)%s->cluster_size);
+ if(write_size<=0)
+ return 0;
+ //fprintf(stderr,"next_cluster: %d (%d), write_size: %d, %d, %d\n",next_cluster,s->max_fat_value-8,write_size,direntry->size,s->cluster_size);
+
+ if(open_file(s,mapping,O_RDWR))
+ return -4;
+
+ offset=(cluster_num-mapping->begin+mapping->offset)*s->cluster_size;
+ if(lseek(s->current_fd,offset,SEEK_SET)!=offset)
+ return -3;
+ if(write(s->current_fd,buf,write_size)!=write_size) {
+ lseek(s->current_fd,0,SEEK_END);
+ vvfat_close_current_file(s);
+ return -2;
+ }
+
+ /* seek to end of file, so it doesn't get truncated */
+ if(!last_cluster)
+ lseek(s->current_fd,0,SEEK_END);
+ else {
+ ftruncate(s->current_fd,le32_to_cpu(direntry->size));
+ vvfat_close_current_file(s);
+ }
+
+ /* update s->cluster if necessary */
+ if(cluster_num==s->current_cluster && s->cluster!=buf)
+ memcpy(s->cluster,buf,s->cluster_size);
+
+ return 0;
+}
+
+/* this function returns !=0 on error */
+int mapping_is_consistent(BDRVVVFATState* s,mapping_t* mapping)
+{
+ direntry_t* direntry=get_direntry_for_mapping(s,mapping);
+ uint32_t cluster_count=0;
+ int commit_count=0; /* number of commits for this file (we also write incomplete files; think "append") */
+ //fprintf(stderr,"check direntry for %s\n",mapping->filename);
+ while(mapping) {
+ int i;
+ assert(mapping->begin<mapping->end);
+ for(i=mapping->begin;i<mapping->end-1;i++) {
+ if(i<=0 || fat_get(s,i)!=i+1) {
+ /*fprintf(stderr,"the fat mapping of %d is not %d, but %d\n",
+ i,i+1,fat_get(s,i));*/
+ return -1;
+ }
+ if(get_commit_for_cluster(s,i))
+ commit_count++;
+ }
+ if(get_commit_for_cluster(s,i))
+ commit_count++;
+
+ cluster_count+=mapping->end-mapping->begin;
+
+ i=fat_get(s,mapping->end-1);
+ if(fat_eof(s,i))
+ break;
+
+ mapping=find_mapping_for_cluster(s,i);
+ if(!mapping) {
+ //fprintf(stderr,"No mapping found for %d\n",i);
+ print_mappings(s);
+ return -2;
+ }
+ }
+
+ if(cluster_count!=(le32_to_cpu(direntry->size)+s->cluster_size-1)/s->cluster_size) {
+ //fprintf(stderr,"cluster_count is %d, but size is %d\n",cluster_count,le32_to_cpu(direntry->size));
+ return -3;
+ }
+
+ if(commit_count==0)
+ return -4;
+
+ //fprintf(stderr,"okay\n");
+ return 0;
+}
+
+/* TODO: remember what comes third, and what's first in this OS:
+ * FAT, direntry or data.
+ * If the last written sector is either last in cluster or sector_num+nb_sectors-1,
+ * - commit every cluster for this file if mapping_is_consistent()==0
+ * - if the last written sector is first_action, and last_action=third_action, clear commit
+ */
+
+static int commit_cluster_aux(BDRVVVFATState* s,commit_t* commit)
+{
+ int result=write_cluster(s,commit->cluster_num,commit->buf);
+ return result;
+}
+
+
+static int commit_cluster(BDRVVVFATState* s,uint32_t cluster_num)
+{
+ commit_t* commit;
+
+ /* commit the sectors of this cluster */
+ commit=get_commit_for_cluster(s,cluster_num);
+ if(commit)
+ return commit_cluster_aux(s,commit);
+ return 0;
+}
+
+/* this function checks the consistency for the direntry which belongs to
+ * the mapping. if everything is found consistent, the data is committed.
+ * this returns 0 if no error occurred (even if inconsistencies were found) */
+static inline int commit_data_if_consistent(BDRVVVFATState* s,mapping_t* mapping,write_action_t action)
+{
+ direntry_t* direntry;
+
+ if(!mapping)
+ return 0;
+
+ //fprintf(stderr,"7\n");
+#define d(x) fprintf(stderr,#x "\n")
+ direntry=get_direntry_for_mapping(s,mapping);
+
+ //d(8);
+
+ assert(action==WRITE_FAT || action==WRITE_DIRENTRY || action==WRITE_DATA);
+
+ //d(9);
+ //fprintf(stderr,"mapping: 0x%x s=0x%x\n",(uint32_t)mapping,(uint32_t)s);
+ /*fprintf(stderr,"commit? file=%s, action=%s\n",
+ mapping->filename,action==WRITE_FAT?"fat":action==WRITE_DIRENTRY?"direntry":"data");*/
+
+ //d(10);
+ if(s->action[2]==WRITE_UNDEFINED) {
+ int i;
+ for(i=2;i>0 && s->action[i-1]==WRITE_UNDEFINED;i--);
+ if(i>0 && action!=s->action[i-1])
+ s->action[i]=action;
+ assert(i<2 || s->action[0]!=s->action[2]);
+ }
+ //d(11);
+
+ if(mapping_is_consistent(s,mapping)==0) {
+ uint32_t cluster_num=begin_of_direntry(direntry);
+ off_t remaining_bytes=le32_to_cpu(direntry->size);
+ //fprintf(stderr,"the data for %s was found consistent\n",mapping->filename);
+ while(remaining_bytes>0) {
+ commit_t* commit=get_commit_for_cluster(s,cluster_num);
+ if(!commit)
+ continue;
+
+ //fprintf(stderr,"commit_cluster %d (%d), remaining: %d\n",cluster_num,s->max_fat_value-15,(int)remaining_bytes);
+ assert(cluster_num>1);
+ assert(cluster_num<s->max_fat_value-15);
+ if(commit_cluster(s,cluster_num)) {
+ fprintf(stderr,"error committing cluster %d\n",cluster_num);
+ return -1;
+ }
+ cluster_num=fat_get(s,cluster_num);
+ remaining_bytes-=s->cluster_size;
+ /* TODO: if(action==s->action[2]) {
+ commit_t* commit=get_commit_for_cluster(s,cluster_num);
+ commit_remove(s,commit);
+ } */
+ }
+ }
+ //print_mappings(s);
+ //fprintf(stderr,"finish vvfat_write\n");
+ return 0;
+}
+
+static int vvfat_write(BlockDriverState *bs, int64_t sector_num,
+ const uint8_t *buf, int nb_sectors)
+{
+ BDRVVVFATState *s = bs->opaque;
+ int i;
+
+ /* fprintf(stderr,"vvfat_write %d+%d (%s)\n",(int)sector_num,nb_sectors,
+ (sector_num>=s->faked_sectors?"data":
+ (sector_num>=s->first_sectors_number+2*s->sectors_per_fat?"directory":
+ (sector_num>=s->first_sectors_number+s->sectors_per_fat?"fat 2":
+ (sector_num>=s->first_sectors_number?"fat 1":"boot sector"))))); */
+
+ for(i=0;i<nb_sectors;i++,sector_num++,buf+=0x200) {
+ print_changed_sector(bs,sector_num,buf);
+
+ if(sector_num<s->first_sectors_number) {
+ /* change the bootsector or partition table? no! */
+ return -1;
+ } else if(sector_num<s->first_sectors_number+s->sectors_per_fat) {
+ /* FAT 1 */
+ int fat_entries_per_cluster=s->cluster_size*8/s->fat_type;
+ int first_cluster=(sector_num-s->first_sectors_number)*fat_entries_per_cluster,i;
+ mapping_t* mapping=0;
+
+ /* write back */
+ memcpy(s->fat.pointer+0x200*(sector_num-s->first_sectors_number),
+ buf,0x200);
+
+ /* for each changed FAT entry, */
+ for(i=0;i<fat_entries_per_cluster;i++) {
+ int new_value;
+
+ /* TODO: MODE_DIRENTRY */
+ if(first_cluster+i<s->sectors_for_directory/s->sectors_per_cluster)
+ continue;
+
+ new_value=fat_get(s,first_cluster+i);
+
+ /* check the current fat entry */
+ if(new_value<2 || (new_value>=s->max_fat_value-0xf && !fat_eof(s,new_value))) {
+ /* free, reserved or bad cluster */
+ mapping=find_mapping_for_cluster(s,first_cluster+i);
+ //assert(!mapping || mapping->mode==MODE_DELETED);
+ if(mapping && mapping->mode==MODE_DELETED &&
+ first_cluster+i+1==mapping->end)
+ array_remove(&(s->mapping),mapping-(mapping_t*)s->mapping.pointer);
+ mapping=0;
+ continue;
+ }
+
+ /* get the mapping for the current entry */
+ if(!mapping || mapping->begin>new_value || mapping->end<=new_value) {
+ mapping=find_mapping_for_cluster(s,first_cluster+i);
+ }
+
+ print_mappings(s);
+ fprintf(stderr,"fat_get(%d)=%d\n",first_cluster+i,new_value);
+ /* TODO: what if there's no mapping? this is valid. */
+ /* TODO: refactor the rest of this clause so it can be called when the direntry changes, too */
+ assert(mapping);
+
+ if(new_value>1 && new_value<s->max_fat_value-0xf) {
+ /* the cluster new_value points to is valid */
+
+ if(first_cluster+i+1==new_value) {
+ /* consecutive cluster */
+ if(mapping->end<=new_value)
+ mapping->end=new_value+1;
+ } else {
+ mapping_t* next_mapping;
+
+ /* the current mapping ends here */
+ mapping->end=first_cluster+i+1;
+
+ /* the next mapping */
+ next_mapping=find_mapping_for_cluster(s,new_value);
+ if(next_mapping) {
+ assert(mapping!=next_mapping);
+ /* assert next mapping's filename is the same */
+ assert(next_mapping->filename==mapping->filename);
+ assert(next_mapping->dir_index==mapping->dir_index);
+ /* assert next mapping is MODIFIED or UNDEFINED */
+ assert(next_mapping->mode==MODE_MODIFIED || next_mapping->mode==MODE_UNDEFINED);
+ } else {
+ int index=find_mapping_for_cluster_aux(s,new_value,0,s->mapping.next);
+ next_mapping=array_insert(&(s->mapping),index,1);
+ next_mapping->filename=mapping->filename;
+ next_mapping->dir_index=mapping->dir_index;
+ next_mapping->mode=MODE_MODIFIED;
+ next_mapping->begin=0;
+ }
+ /* adjust offset of next mapping */
+ next_mapping->offset=mapping->offset+mapping->end-mapping->begin;
+ /* set begin and possible end */
+ if(next_mapping->begin!=new_value) {
+ next_mapping->begin=new_value;
+ next_mapping->end=new_value+1;
+ }
+ if(commit_data_if_consistent(s,mapping,WRITE_FAT))
+ return -4;
+ mapping=0;
+ }
+ } else if(fat_eof(s,new_value)) {
+ /* the last cluster of the file */
+ mapping->end=first_cluster+i+1;
+ if(commit_data_if_consistent(s,mapping,WRITE_FAT))
+ return -4;
+ mapping=0;
+ }
+ }
+ } else if(sector_num<s->first_sectors_number+2*s->sectors_per_fat) {
+ /* FAT 2: check if it is the same as FAT 1 */
+ if(memcmp(array_get(&(s->fat),sector_num-s->first_sectors_number),buf,0x200))
+ return -1; /* mismatch */
+ } else if(sector_num<s->faked_sectors) {
+ /* direntry */
+ /* - if they are in a directory, check if the entry has changed.
+ * if yes, look what has changed (different strategies for name,
+ * begin & size).
+ *
+ * if it is new (old entry is only 0's or has E5 at the start),
+ * create it, and also create mapping, but in a special mode
+ * "undefined", because we cannot know which clusters belong
+ * to it yet.
+ *
+ * if it is zeroed, or has E5 at the start, look if has just
+ * moved. If yes, copy the entry to the new position. If no,
+ * delete the file.
+ */
+ mapping_t* dir_mapping=find_mapping_for_cluster(s,sector2cluster(s,sector_num));
+ direntry_t *original=array_get(&(s->directory),sector_num-s->first_sectors_number-2*s->sectors_per_fat);
+ direntry_t *new_=(direntry_t*)buf;
+ int first_dir_index=(sector_num-s->first_sectors_number-2*s->sectors_per_fat)*0x200/0x20;
+ int j;
+
+#if 0
+ fprintf(stderr,"direntry: consistency check\n");
+
+ if(s->commit.next==0) {
+ consistency_check1(s);
+ consistency_check2(s);
+ consistency_check3(s);
+ }
+#endif
+
+ assert(sizeof(direntry_t)==0x20);
+
+ for(j=0;j<0x200/0x20;j++) {
+ //fprintf(stderr,"compare direntry %d: 0x%x,0x%x\n",j,(uint32_t)original+j,(uint32_t)new_+j);
+ if(memcmp(original+j,new_+j,sizeof(direntry_t))) {
+ //fprintf(stderr,"different\n");
+ /* TODO: in create_short_filename, 0xe5->0x05 is not yet handled! */
+ if(direntry_is_free(original+j)) {
+ mapping_t* mapping;
+ char buffer[4096];
+ int fd,i;
+
+ if(new_[j].attributes==0xf)
+ continue; /* long entry */
+
+ print_mappings(s);
+ //fprintf(stderr,"sector: %d cluster: %d\n",(int)sector_num,(int)sector2cluster(s,sector_num));
+
+ /* construct absolute path */
+ strncpy(buffer,dir_mapping->filename,4096);
+ i=strlen(buffer);
+ if(i+2>=4096)
+ return -1;
+ buffer[i]='/';
+ if(long2unix_name(buffer+i+1,4096-i-1,new_+j))
+ return -2;
+
+ /* new file/directory */
+ if(new_[j].attributes&0x10) {
+#ifdef _WIN32
+#define SEVENFIVEFIVE
+#else
+#define SEVENFIVEFIVE ,0755
+#endif
+ if(mkdir(buffer SEVENFIVEFIVE))
+ return -3;
+ /* TODO: map direntry.begin as directory, together with new array_t direntries */
+ assert(0);
+ } else {
+ fd=open(buffer,O_CREAT|O_EXCL,0644);
+ if(!fd)
+ return -3;
+ close(fd);
+ }
+
+ /* create mapping */
+ i=find_mapping_for_cluster_aux(s,begin_of_direntry(new_+j),0,s->mapping.next);
+ mapping=array_insert(&(s->mapping),i,1);
+ mapping->filename=strdup(buffer);
+ mapping->offset=0;
+ /* back pointer to direntry */
+ mapping->dir_index=first_dir_index+j;
+ /* set mode to modified */
+ mapping->mode=MODE_MODIFIED;
+ /* set begin to direntry.begin */
+ mapping->begin=begin_of_direntry(new_+j);
+ /* set end to begin+1 */
+ mapping->end=mapping->begin+1;
+ /* commit file contents */
+ if(commit_data_if_consistent(s,mapping,WRITE_DIRENTRY)) {
+ fprintf(stderr,"error committing file contents for new file %s!\n",buffer);
+ return -4;
+ }
+ } else if(direntry_is_free(new_+j)) {
+ assert(0);
+ /* TODO: delete file */
+ /* TODO: write direntry */
+ /* TODO: modify mapping: set mode=deleted */
+ } else {
+ /* modified file */
+ mapping_t* mapping=0;
+ /* if direntry.begin has changed,
+ * set mode to modified,
+ * adapt begin,
+ * adapt end */
+ /* TODO: handle rename */
+ assert(!memcmp(new_[j].name,original[j].name,11));
+ //fprintf(stderr,"1\n");
+ if(new_[j].begin!=original[j].begin || new_[j].size/s->cluster_size!=original[j].size/s->cluster_size) {
+ //fprintf(stderr,"2\n");
+ mapping = find_mapping_for_direntry(s,original+j);
+ //fprintf(stderr,"3\n");
+ if(!mapping) /* this should never happen! */
+ return -2;
+ mapping_modify_from_direntry(s,mapping,new_+j);
+ //fprintf(stderr,"4\n");
+ if(commit_data_if_consistent(s,mapping,WRITE_DIRENTRY)) {
+ fprintf(stderr,"big error\n");
+ return -4;
+ }
+ }
+ /* TODO: handle modified times and other attributes */
+
+ //fprintf(stderr,"5: mapping=0x%x, s=0x%x, s->mapping.pointer=0x%x\n",(uint32_t)mapping,(uint32_t)s,(uint32_t)s->mapping.pointer);
+ //fprintf(stderr,"6\n");
+ }
+ }
+ }
+ /* write back direntries */
+ memcpy(original,new_,0x200);
+ } else {
+ /* data */
+ off_t sector=sector_num-s->first_sectors_number-2*s->sectors_per_fat;
+ off_t cluster=sector/s->sectors_per_cluster;
+ mapping_t* mapping=find_mapping_for_cluster(s,cluster);
+ if(mapping && mapping->mode==MODE_DELETED)
+ return -3; /* this is an error: no writes to these clusters before committed */
+ {
+ /* as of yet, undefined: put into commits */
+ commit_t* commit=create_or_get_commit_for_sector(s,sector_num);
+
+ if(!commit)
+ return -1; /* out of memory */
+ memcpy(commit->buf+0x200*sector_offset_in_cluster(s,sector_num),buf,0x200);
+
+ //fprintf(stderr,"mapping: 0x%x\n",(uint32_t)mapping);
+ if(commit_data_if_consistent(s,mapping,WRITE_DATA))
+ return -4;
+ }
+ }
+ }
+ return 0;
+}
+
+static void vvfat_close(BlockDriverState *bs)
+{
+ BDRVVVFATState *s = bs->opaque;
+
+ vvfat_close_current_file(s);
+ array_free(&(s->fat));
+ array_free(&(s->directory));
+ array_free(&(s->mapping));
+ if(s->cluster)
+ free(s->cluster);
+}
+
+BlockDriver bdrv_vvfat = {
+ "vvfat",
+ sizeof(BDRVVVFATState),
+ vvfat_probe,
+ vvfat_open,
+ vvfat_read,
+ vvfat_write,
+ vvfat_close,
+};
+
+
projects / qemu.git / commitdiff