added debruijn offset to ragg2

binr/ragg2/ragg2.c

@@ -31,7 +31,8 @@ static int usage (int v) {
 	" -p [padding]    add padding after compilation (padding=n10s32)\n"
 	"                 ntas : begin nop, trap, 'a', sequence\n"
 	"                 NTAS : same as above, but at the end\n"
-	" -P [size]       prepend debrujn pattern\n"
+	" -P [size]       prepend debruijn pattern\n"
+	" -q [fragment]   debruijn pattern offset\n"
 	" -r              show raw bytes instead of hexpairs\n"
 	" -s              show assembler\n"
 	" -v              show version\n"
@@ -105,8 +106,10 @@ int main(int argc, char **argv) {
 	int show_raw = 0;
 	int append = 0;
 	int show_str = 0;
+	ut64 get_offset  = 0;
 	char *shellcode = NULL;
 	char *encoder = NULL;
+	char *sequence = NULL;
 	int bits = (R_SYS_BITS & R_SYS_BITS_64)? 64: 32;
 	int fmt = 0;
 	const char *ofile = NULL;
@@ -117,7 +120,7 @@ int main(int argc, char **argv) {
 
 	//egg->bin = r_buf_new ();
 
-        while ((c = getopt (argc, argv, "n:N:he:a:b:f:o:sxrk:FOI:Li:c:p:P:B:C:vd:D:w:z")) != -1) {
+        while ((c = getopt (argc, argv, "n:N:he:a:b:f:o:sxrk:FOI:Li:c:p:P:B:C:vd:D:w:zq:")) != -1) {
                 switch (c) {
 		case 'a':
 			arch = optarg;
@@ -257,12 +260,16 @@ int main(int argc, char **argv) {
 		case 'z':
 			show_str = 1;
 			break;
+		case 'q':
+			get_offset = 1;
+			sequence = strdup (optarg);
+			break;
 		default:
 			return 1;
 		}
 	}
 
-	if (optind == argc && !shellcode && !bytes && !contents && !encoder && !padding && !pattern && !append) {
+	if (optind == argc && !shellcode && !bytes && !contents && !encoder && !padding && !pattern && !append && !get_offset) {
 		return usage (0);
 	} else file = argv[optind];
 
@@ -273,6 +280,17 @@ int main(int argc, char **argv) {
 			format = "elf64";
 	}
 
+	// catch this first
+	if (get_offset) {
+		get_offset = r_num_math (0, sequence);
+		printf ("Little endian: %d\n",
+			r_debruijn_offset (get_offset, 1));
+		printf ("Big endian: %d\n",
+			r_debruijn_offset (get_offset, 0));
+		free (sequence);
+		return 0;
+	}
+
 	// initialize egg
 	r_egg_setup (egg, arch, bits, 0, os);
 	if (file) {

man/ragg2.1

@@ -72,6 +72,8 @@ Append a 64bit number in little endian
 Specify generic paddings with a format string.
 .It Fl P Ar size
 Prepend debruijn sequence of given length.
+.It Fl q Ar fragment
+Output offset of debruijn sequence fragment.
 .It Fl F
 autodetect native file format (osx=mach0, linux=elf, ..)
 .It Fl O