modules/psionapp.c

   1 // This file is part of Deark.
   2 // Copyright (C) 2016 Jason Summers
   3 // See the file COPYING for terms of use.
   4
   5 // Psion APP/IMG
   6
   7 #include <deark-config.h>
   8 #include <deark-private.h>
   9 DE_DECLARE_MODULE(de_module_psionapp);
  10
  11 typedef struct localctx_struct {
  12         int convert_images; // 0=extract PIC, 1=convert PIC
  13 } lctx;
  14
  15 static void handle_embedded_file(deark *c, lctx *d, i64 offset, i64 len)
  16 {
  17         u8 buf[16];
  18         const char *ext;
  19         int extract_this_file;
  20         int is_pic;
  21
  22         de_dbg(c, "embedded file at %d, len=%d", (int)offset, (int)len);
  23         is_pic = 0;
  24         ext = "bin";
  25         extract_this_file = 0;
  26
  27         if(len>0 && c->extract_level>=2)
  28                 extract_this_file = 1;
  29
  30         // As far as I can tell, there's no way to tell the type of an
  31         // embedded file, except by sniffing it.
  32         de_read(buf, offset, 16);
  33         if(len>=8) {
  34                 if(!de_memcmp(buf, "PIC\xdc\x30\x30", 6)) {
  35                         // Looks like a PIC file
  36                         is_pic = 1;
  37                         ext = "pic";
  38                         extract_this_file = 1;
  39                 }
  40         }
  41
  42         if(extract_this_file) {
  43                 if(is_pic && d->convert_images) {
  44                         // Convert PIC to PNG.
  45                         // For consistency, this option shouldn't exist. But I'm not sure that
  46                         // PIC files embedded in APP files are really the same as PIC files on
  47                         // their own. They might need special handling. Until I'm sure they don't,
  48                         // I'll leave this option here.
  49                         de_run_module_by_id_on_slice(c, "psionpic", NULL, c->infile, offset, len);
  50                 }
  51                 else {
  52                         // Just extract the file
  53                         dbuf_create_file_from_slice(c->infile, offset, len, ext, NULL, is_pic?0:DE_CREATEFLAG_IS_AUX);
  54                 }
  55         }
  56         else {
  57                 de_dbg(c, "(not extracting this file)");
  58         }
  59 }
  60
  61 static void do_opo_opa(deark *c, lctx *d)
  62 {
  63         i64 offset_2ndheader;
  64         i64 pos;
  65         i64 n;
  66         i64 len;
  67
  68         de_declare_fmt(c, "Psion OPO/OPA");
  69
  70         // The second header marks the end of the embedded files section, I guess.
  71         offset_2ndheader = de_getu16le(18);
  72         de_dbg(c, "offset of second header: %d", (int)offset_2ndheader);
  73         pos = 20;
  74
  75         // Read length of source filename
  76         n = (i64)de_getbyte(pos);
  77         pos++;
  78         pos+=n;
  79         while(pos<offset_2ndheader) {
  80                 // Read length of this embedded file
  81                 len = de_getu16le(pos);
  82                 pos+=2;
  83                 handle_embedded_file(c, d, pos, len);
  84                 pos+=len;
  85         }
  86 }
  87
  88 static void do_img_app(deark *c, lctx *d)
  89 {
  90         i64 i;
  91         i64 offset;
  92         i64 len;
  93
  94         de_declare_fmt(c, "Psion IMG/APP");
  95
  96         for(i=0; i<4; i++) {
  97                 offset = de_getu16le(40 + 4*i);
  98                 len = de_getu16le(40 + 4*i + 2);
  99                 if(offset==0) break;
 100                 handle_embedded_file(c, d, offset, len);
 101         }
 102 }
 103
 104 static void de_run_psionapp(deark *c, de_module_params *mparams)
 105 {
 106         u8 b;
 107         const char *s;
 108         lctx *d = NULL;
 109
 110         d = de_malloc(c, sizeof(lctx));
 111
 112         s = de_get_ext_option(c, "psionapp:convertpic");
 113         if(s) {
 114                 d->convert_images = 1;
 115         }
 116
 117         b = de_getbyte(0);
 118         if(b=='O') {
 119                 do_opo_opa(c, d);
 120         }
 121         else {
 122                 do_img_app(c, d);
 123         }
 124
 125         de_free(c, d);
 126 }
 127
 128 static int de_identify_psionapp(deark *c)
 129 {
 130         u8 b[16];
 131         de_read(b, 0, 16);
 132         if(!de_memcmp(b, "ImageFileType**\0", 16))
 133                 return 100;
 134         if(!de_memcmp(b, "OPLObjectFile**\0", 16))
 135                 return 100;
 136         return 0;
 137 }
 138
 139 void de_module_psionapp(deark *c, struct deark_module_info *mi)
 140 {
 141         mi->id = "psionapp";
 142         mi->desc = "Psion .APP/.IMG and .OPA/.OPO";
 143         mi->desc2 = "extract images";
 144         mi->run_fn = de_run_psionapp;
 145         mi->identify_fn = de_identify_psionapp;
 146 }