path: root/src/mcdmsdos.c

/*

mcdmsdos.c

DMSDOS: external filesystem interface for Midnight Commander

******************************************************************************
DMSDOS (compressed MSDOS filesystem support) for Linux
written 1995-1998 by Frank Gockel and Pavel Pisa

    (C) Copyright 1995-1998 by Frank Gockel
    (C) Copyright 1996-1998 by Pavel Pisa

Some code of dmsdos has been copied from the msdos filesystem
so there are the following additional copyrights:

    (C) Copyright 1992,1993 by Werner Almesberger (msdos filesystem)
    (C) Copyright 1994,1995 by Jacques Gelinas (mmap code)
    (C) Copyright 1992-1995 by Linus Torvalds

DMSDOS was inspired by the THS filesystem (a simple doublespace
DS-0-2 compressed read-only filesystem) written 1994 by Thomas Scheuermann.

The DMSDOS code is distributed under the Gnu General Public Licence.
See file COPYING for details.
******************************************************************************

*/

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<ctype.h>

#include"dmsdos.h"
#include"lib_interface.h"

#define M_LIST 1
#define M_OUT 2
#define M_IN 3

/*this is not good - but currently we have only one CVF open at a time*/
struct super_block*sb;
Dblsb*dblsb;

int scan(char*text)
{ int v=0;
  if(strncmp(text,"0x",2)==0||strncmp(text,"0X",2)==0)
    sscanf(text+2,"%x",&v);
  else
    sscanf(text,"%d",&v);
  return v;
}

unsigned char* get_root_dir(void)
{ unsigned char* data;
  struct buffer_head*bh;
  int i;
  
  data=malloc(dblsb->s_rootdirentries*32);
  if(data==NULL)return NULL;
  
  for(i=0;i<dblsb->s_rootdirentries*32/512;++i)
  { bh=raw_bread(sb,dblsb->s_rootdir+i);
    if(bh==NULL){free(data);return NULL;}
    memcpy(data+i*512,bh->b_data,512);
    raw_brelse(sb,bh);
  }
  return data;
}

int copy_cluster_out(int nr, int len, FILE*f)
{ unsigned char*data;
  int i,j;
  
  if(nr==0)
  { data=get_root_dir();
    if(data==NULL)return -1;
    i=dblsb->s_rootdirentries*32;
  }
  else
  { data=malloc(dblsb->s_sectperclust*512);
    if(data==NULL)return -1; 
    i=dmsdos_read_cluster(sb,data,nr);
    if(i<0){free(data);return -1;}
  }
  if(len<=0||len>i)len=i;
 
  for(j=0;j<len;++j)fputc(data[j],f);
  
  free(data);
  return ferror(f);
}

int handle_dir_chain(int start,int rek,char*prefix);

int display_dir_cluster(int nr, int rek, char*prefix)
{ unsigned char*data;
  int i,j;

  /*printf("display_dir_cluster called with nr=%d rek=%d prefix=%s\n",
         nr,rek,prefix);*/

  if(nr==0)
  { data=get_root_dir();
    if(data==NULL)return -1;
    i=dblsb->s_rootdirentries*32;
  }
  else
  { data=malloc(dblsb->s_sectperclust*512);
    if(data==NULL)return -1; 
    i=dmsdos_read_cluster(sb,data,nr);
    if(i<0){free(data);return -1;}
  }
  
  for(j=0;j<dblsb->s_sectperclust*512;j+=32)
  { unsigned char*pp;
    unsigned int x;
    char filename[15]="";
    int nstart;
    long size;
    char datestr[16][4]={"?00","Jan","Feb","Mar","Apr","May","Jun",
                         "Jul","Aug","Sep","Oct","Nov","Dec",
                         "?13","?14","?15"};  
    if(data[j]==0)break;
    if(data[j]==0xe5)continue;
    if(data[j+11]&8)continue;
    if(data[j]=='.')continue;
    
    for(i=0;i<11;++i)
    { if(i==8&&data[j+i]!=' ')strcat(filename,".");
      if(data[j+i]!=' ')strncat(filename,&(data[j+i]),1);
    }
    for(i=0;i<strlen(filename);++i)filename[i]=tolower(filename[i]);
    
    if(data[j+11]&16)printf("dr");else printf("-r");
    if(data[j+11]&1)printf("-");else printf("w");
    printf("xr-xr-x 1 0 0"); /* bogus values :) */
  
    /*
    printf("  ");
    if(data[j+11]&1)printf("R");else printf(" ");
    if(data[j+11]&2)printf("H");else printf(" ");
    if(data[j+11]&4)printf("S");else printf(" ");
    if(data[j+11]&8)printf("V");else printf(" ");
    if(data[j+11]&16)printf("D");else printf(" ");
    if(data[j+11]&32)printf("A");else printf(" ");
    if(data[j+11]&64)printf("?");else printf(" ");
    if(data[j+11]&128)printf("?");else printf(" ");
    */

    pp=&(data[j+28]);
    size=CHL(pp);
    printf(" %7lu",size);

    pp=&(data[j+24]);
    x=CHS(pp);
    /*printf(" %02d.%02d.%02d",x&31,(x>>5)&15,(x>>9)+80);*/
    printf(" %s",datestr[(x>>5)&15]);
    printf(" %02d",x&31);
    printf(" %04d",(x>>9)+1980); /* y2k compliant :) */
    
    pp=&(data[j+22]);
    x=CHS(pp);
    /*printf("  %02d:%02d:%02d",x>>11,(x>>5)&63,(x&31)<<1);*/
    printf(" %02d:%02d",x>>11,(x>>5)&63);
    
    pp=&(data[j+26]);
    nstart=CHS(pp);
    /*printf(" %5d",nstart);*/

    printf(" %s%s\n",prefix,filename);
        
    if((data[j+11]&16)!=0&&rek!=0&&filename[0]!='.')
    { char *nprefix;
      nprefix=malloc(strlen(prefix)+20);
      if(nprefix==NULL)
      { fprintf(stderr,"out of memory\n");
        exit(3);
      }
      strcpy(nprefix,prefix);
      strcat(nprefix,filename);
      strcat(nprefix,"/");
      handle_dir_chain(nstart,rek,nprefix);
      free(nprefix);
    }

  }
  
  free(data);
  return 0;
}

int handle_dir_chain(int start,int rek,char*prefix)
{ int i,next;

  if(start==0)return display_dir_cluster(0,rek,prefix);
  if(start==1||start<0||start>dblsb->s_max_cluster)return -1;
  
  do
  {
    next=dbl_fat_nextcluster(sb,start,NULL);
    i=display_dir_cluster(start,rek,prefix);
    if(i<0)return i;
    start=next;
  }
  while(next>1&&next<=dblsb->s_max_cluster);

  if(next>=0)
  { return -1;
  }
  
  return 0;
}

int handle_file_chain(int start, int len, FILE*f)
{ int i,next;

  if(start==0)return -1; /* never a file :) */
  if(start==1||start<0||start>dblsb->s_max_cluster)return -1;
  
  do
  {
    next=dbl_fat_nextcluster(sb,start,NULL);
    i=copy_cluster_out(start,len,f);
    if(i<0)return i;
    len-=dblsb->s_sectperclust*512;
    if(len<=0)break;
    start=next;
  }
  while(next>1&&next<=dblsb->s_max_cluster);

  if(next>=0)
  { return -1;
  }
  
  return 0;
}

int scan_dir(char*entry,int start,int*len)
{ char buf[]="           ";
            /*12345678EXT*/
  int i;
  int size;
  unsigned char*data;
  int next;
  
  if(strcmp(entry,".")==0)return start;
  else if(strcmp(entry,"..")==0)strncpy(buf,"..",2);
  else if(*entry=='.') return -1;
  else
  for(i=0;i<11;++i)
  { if(*entry=='.'&&i<=7){i=7;++entry;continue;}
    if(*entry=='.'&&i==8){i=7;++entry;continue;}
    if(*entry=='.')break;
    if(*entry=='\0')break;
    buf[i]=toupper(*entry);
    ++entry;
  }
  
  do
  {
    /*printf("scan_dir: searching for %s in %d\n",buf,start);*/
    
    if(start==0)
    { data=get_root_dir();
      size=dblsb->s_rootdirentries;
      next=-1;
    }
    else
    { data=malloc(dblsb->s_sectperclust*512);
      if(data!=NULL)
      { i=dmsdos_read_cluster(sb,data,start);
        if(i<0){free(data);data=NULL;}
        size=i/32;
        next=dbl_fat_nextcluster(sb,start,NULL);
        if(next==0)
          fprintf(stderr,"warning: cluster %d is marked as unused in FAT\n",
                  next);
      }
    }
    if(data==NULL)return -1;
    
    for(i=0;i<size;++i)
    { if(strncmp(&(data[i*32]),buf,11)==0)
      { unsigned char*pp;
        int cluster;
        
        pp=&(data[i*32+26]);
        cluster=CHS(pp);
        pp=&(data[i*32+28]);
        if(len)*len=CHL(pp);
        free(data);
        return cluster;
      }
    }
    
    free(data);
    start=next;
  }
  while(next>0&&next<=dblsb->s_max_cluster);
  return -1;
}

int scan_path(char*path,int start, int*len)
{ int i;
  char*p;
  
  for(p=strtok(path,"/");p;p=strtok(NULL,"/"))
  { i=scan_dir(p,start,len);
    if(i<0)
    { fprintf(stderr,"path component %s not found\n",p);
      return -1;
    }
    start=i;
  }
  
  return start;
}

int main(int argc, char*argv[])
{ int mode=0;
  int cluster;
  int i;
  char*p;
  int len;
  FILE*f;
  
  fprintf(stderr,"mcdmsdos version 0.2.0 (for libdmsdos 0.9.x and newer)\n");
  if(argc<2)
  { fprintf(stderr,"\nusage: mcdmsdos <mc-extfs-command> ...\n");
    fprintf(stderr,"where <mc-extfs-command> can be:\n");
    fprintf(stderr,"        list <CVF>\n");
    fprintf(stderr,"        copyout <CVF> <path/name_in_CVF> <outfile>\n");
    fprintf(stderr,"        copyin <CVF> <path/name_in_CVF> <infile> [*]\n");
    fprintf(stderr,"      [*] currently not implemented\n");
    return 1;
  }
  
  /* check syntax */
  if(strcmp(argv[1],"list")==0)
  { mode=M_LIST;
    if(argc!=3)
    { fprintf(stderr,"wrong number of arguments\n");
      return 1;
    }
  }
  else if(strcmp(argv[1],"copyout")==0)
  { mode=M_OUT;
    if(argc!=5)    
    { fprintf(stderr,"wrong number of arguments\n");
      return 1;
    }
  }
  else if(strcmp(argv[1],"copyin")==0)
  { mode=M_IN;
    if(argc!=5)    
    { fprintf(stderr,"wrong number of arguments\n");
      return 1;
    }
    fprintf(stderr,"copyin command is not implemented\n");
    return -2;
  }
  else
  { fprintf(stderr,"unknown command\n");
    return -1;
  }
  
  sb=open_cvf(argv[2],0/*read-only*/);
  if(sb==NULL)
  { printf("open CVF %s failed\n",argv[1]);
    return 2;
  }
  dblsb=MSDOS_SB(sb)->private_data; 
  
  
  if(mode==M_LIST)
  { i=handle_dir_chain(0,1,"");
  }
  
  else if(mode==M_OUT)
  { p=malloc(strlen(argv[3])+1);
    strcpy(p,argv[3]);
#ifdef _WIN32
    /* convert to Unix style path */
    for(i=0;i<strlen(p);++i){if(p[i]=='\\')p[i]='/';}
#endif
    if(*p=='/')++p;
    cluster=scan_path(p,0,&len);
    if(cluster<0)
    { fprintf(stderr,"%s not found\n",argv[3]);
      return 1;
    }

    f=fopen(argv[4],"wb");
    if(f==NULL)
    { perror("open write failed");
      i=-1;
    }
    else
    { i=handle_file_chain(cluster,len,f);
      fclose(f);
    }
  }
  
  close_cvf(sb);
  
  return i;
}