efp_extract.c

   1 /*
   2  * extract elecard efp files
   3  *
   4  * author: hackbard@hackdaworld.org
   5  *
   6  * build: gcc -Wall efp_extract.c -o efp_extract
   7  * usage: ./efp_extract file.efp
   8  *        chmod 640 file_??
   9  *
  10  * based on info from Muart232
  11  * http://www.mikrocontroller.net/topic/210759
  12  *
  13  * elecard:
  14  * http://www.elecard.com/forum/index.php?topic=4174.0
  15  *
  16  */
  17
  18 #include <stdio.h>
  19 #include <unistd.h>
  20 #include <sys/types.h>
  21 #include <sys/stat.h>
  22 #include <fcntl.h>
  23 #include <sys/mman.h>
  24
  25 int getbytes(int fd,char *buf,int len) {
  26
  27         int cnt,ret;
  28
  29         cnt=len;
  30         while(cnt) {
  31                 ret=read(fd,buf+len-cnt,cnt);
  32                 cnt-=ret;
  33         }
  34
  35         return 0;
  36 }
  37
  38 int hexprint(char *buf,int len) {
  39
  40         int i;
  41
  42         for(i=0;i<len;i++)
  43                 printf("%02x ",*(buf+i));
  44         printf("\n");
  45
  46         return 0;
  47
  48 }
  49
  50 int main(int argc,char **argv) {
  51
  52         int ret,cnt,i,fd,wfd;
  53         char buf[128];
  54         int nof;
  55         unsigned int index[16],offset[16],len[16],wtf[16];
  56         char filename[128];
  57         char *map;
  58
  59         fd=open(argv[1],O_RDONLY);
  60         if(fd<=0) {
  61                 perror("fd open");
  62                 return fd;
  63         }
  64
  65         lseek(fd,12,SEEK_CUR);
  66         // ignore first 12 bytes
  67
  68         getbytes(fd,buf,4);
  69         nof=*((unsigned int *)buf);
  70
  71         printf("number of files: %d\n",nof);
  72
  73         lseek(fd,6,SEEK_CUR);
  74
  75         for(i=0;i<nof;i++) {
  76
  77                 getbytes(fd,buf,4);
  78                 index[i]=*((unsigned int *)buf);
  79
  80                 getbytes(fd,buf,4);
  81                 wtf[i]=*((unsigned int *)buf);
  82
  83                 getbytes(fd,buf,4);
  84                 len[i]=*((unsigned int *)buf);
  85
  86                 getbytes(fd,buf,4);
  87                 offset[i]=*((unsigned int *)buf);
  88
  89                 lseek(fd,8,SEEK_CUR);
  90                 // ignore
  91
  92                 printf("file %u:\n",index[i]);
  93                 printf(" - wtf: %u\n",wtf[i]);
  94                 printf(" - len: %u\n",len[i]);
  95                 printf(" - offset: %u\n",offset[i]);
  96                 printf(" - next estimated offset: %u\n",len[i]+offset[i]);
  97
  98         }
  99
 100         printf("mapping file into memory ...\n");
 101         map=mmap(0,offset[nof-1]+len[nof-1],PROT_READ,MAP_SHARED,fd,0);
 102         if(map==MAP_FAILED) {
 103                 perror("mmap");
 104                 return -1;
 105         }
 106
 107         for(i=0;i<nof;i++) {
 108
 109                 snprintf(filename,128,"file_%02d",index[i]);
 110
 111                 wfd=open(filename,O_WRONLY|O_CREAT);
 112                 if(wfd<=0) {
 113                         perror("wfd open");
 114                         return wfd;
 115                 }
 116
 117                 cnt=len[i];
 118                 while(cnt) {
 119                         ret=write(wfd,map+offset[i]+len[i]-cnt,cnt);
 120                         cnt-=ret;
 121                 }
 122
 123                 close(wfd);
 124
 125         }
 126
 127         close(fd);
 128
 129         return 0;
 130
 131 }