FS#11828: Fix in core mod parser to blindly accept any .mod you throw at it. Based on MikMod.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29105 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 52 insertions, 10 deletions

diff --git a/apps/metadata/mod.c b/apps/metadata/mod.c
index dbedc6e62f..9595729c0b 100644
--- a/apps/metadata/mod.c
+++ b/apps/metadata/mod.c
@@ -19,40 +19,82 @@
  *
  ****************************************************************************/
 #include <stdio.h>
-#include <string.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <inttypes.h>
 
 #include "system.h"
 #include "metadata.h"
+#include <string-extra.h>
 #include "metadata_common.h"
 #include "metadata_parsers.h"
 #include "rbunicode.h"
 
+#define MODULEHEADERSIZE 0x438
+
 bool get_mod_metadata(int fd, struct mp3entry* id3)
 {    
     /* Use the trackname part of the id3 structure as a temporary buffer */
-    unsigned char buf[1084];
-    int read_bytes;
+    unsigned char buf[MODULEHEADERSIZE];
+    unsigned char id[4];
+    bool is_mod_file = false;
     char *p;
-      
 
     if ((lseek(fd, 0, SEEK_SET) < 0) 
-         || ((read_bytes = read(fd, buf, sizeof(buf))) < 1084))
+        || (read(fd, buf, sizeof(buf)) < MODULEHEADERSIZE))
     {
         return false;
     }
-    
-    /* We don't do file format checking here
-     * There can be .mod files without any signatures out there */
+
+    if (read(fd, id, sizeof(id)) < (ssize_t)sizeof(id))
+        return false;
+
+    /* Mod type checking based on MikMod */
+        /* Protracker and variants */
+        if ((!memcmp(id, "M.K.", 4)) || (!memcmp(id, "M!K!", 4))) {
+        is_mod_file = true;
+        }
+        
+        /* Star Tracker */
+        if (((!memcmp(id, "FLT", 3)) || (!memcmp(id, "EXO", 3))) &&
+                (isdigit(id[3]))) {
+                char numchn = id[3] - '0';
+                if (numchn == 4 || numchn == 8)
+            is_mod_file = true;
+        }
+
+        /* Oktalyzer (Amiga) */
+        if (!memcmp(id, "OKTA", 4)) {
+        is_mod_file = true;
+        }
+
+        /* Oktalyser (Atari) */
+        if (!memcmp(id, "CD81", 4)) {
+        is_mod_file = true;
+        }
+
+        /* Fasttracker */
+        if ((!memcmp(id + 1, "CHN", 3)) && (isdigit(id[0]))) {
+        is_mod_file = true;
+        }
+        /* Fasttracker or Taketracker */
+        if (((!memcmp(id + 2, "CH", 2)) || (!memcmp(id + 2, "CN", 2)))
+                && (isdigit(id[0])) && (isdigit(id[1]))) {
+        is_mod_file = true;
+        }
+
+    /* Don't try to play if we can't find a known mod type
+     * (there are mod files which have nothing to do with music) */
+    if (!is_mod_file)
+        return false;
 
     p = id3->id3v2buf;
     
     /* Copy Title */
-    strcpy(p, &buf[0x00]);
+    if (strlcpy(p, buf, sizeof(id3->id3v2buf)) >= sizeof(id3->id3v2buf))
+        return false;
+
     id3->title = p;
-    p += strlen(p)+1;
 
     id3->bitrate = filesize(fd)/1024; /* size in kb */
     id3->frequency = 44100;