--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/simtool/bfsearch.c	Thu Feb 25 06:03:13 2021 +0000
@@ -0,0 +1,96 @@
+/*
+ * This module implements a brute force search of file ID space at a given
+ * file system directory level.
+ */
+
+#include <sys/types.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "simresp.h"
+
+static
+parse_skip_ids(argv, array, total)
+	char **argv;
+	unsigned *array, total;
+{
+	unsigned n;
+
+	for (n = 0; n < total; n++) {
+		if (!isxdigit(argv[n][0]) || !isxdigit(argv[n][1]) ||
+		    !isxdigit(argv[n][2]) || !isxdigit(argv[n][3]) ||
+		    argv[n][4]) {
+			fprintf(stderr, "error: argument is not 4-digit hex\n");
+			return(-1);
+		}
+		array[n] = strtoul(argv[n], 0, 16);
+	}
+	return(0);
+}
+
+cmd_bfsearch(argc, argv, outf)
+	char **argv;
+	FILE *outf;
+{
+	unsigned skip_ids[8], num_skip_ids;
+	unsigned bfs, n;
+	int rc;
+
+	num_skip_ids = argc - 1;
+	rc = parse_skip_ids(argv + 1, skip_ids, num_skip_ids);
+	if (rc < 0)
+		return(rc);
+	rc = elem_select_op(skip_ids[0]);
+	if (rc < 0)
+		return(rc);
+	if (!rc) {
+		fprintf(stderr, "error: starting file ID 0x%04X not found\n",
+			skip_ids[0]);
+		return(-1);
+	}
+	for (bfs = 0; bfs <= 0xFFFF; bfs++) {
+		for (n = 0; n < num_skip_ids; n++) {
+			if (bfs == skip_ids[n])
+				break;
+		}
+		if (n < num_skip_ids)
+			continue;
+		rc = elem_select_op(bfs);
+		if (rc < 0)
+			return(rc);
+		if (!rc)
+			continue;
+		rc = get_response_op();
+		if (rc < 0)
+			return(rc);
+		if (sim_resp_data_len < 14)
+			printf("%04X: too-short response struct\n", bfs);
+		else {
+			switch (sim_resp_data[6]) {
+			case 0x01:
+				printf("%04X: MF\n", bfs);
+				break;
+			case 0x02:
+				printf("%04X: DF\n", bfs);
+				break;
+			case 0x04:
+				printf("%04X: EF (struct %02X)\n", bfs,
+					sim_resp_data[13]);
+				break;
+			default:
+				printf("%04X: unknown file type %02X\n", bfs,
+					sim_resp_data[6]);
+			}
+		}
+		rc = elem_select_op(skip_ids[0]);
+		if (rc < 0)
+			return(rc);
+		if (!rc) {
+			fprintf(stderr,
+			"reselecting starting file ID 0x%04X not-found error\n",
+				skip_ids[0]);
+			return(-1);
+		}
+	}
+	return(0);
+}