--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ater/dbits.c	Thu Sep 12 09:33:55 2024 +0000
@@ -0,0 +1,62 @@
+/*
+ * Here we implement the command for setting Dn bit patterns
+ * in data-mode TRAU-UL frames.
+ */
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <osmocom/core/bits.h>
+#include <osmocom/core/select.h>
+#include <osmocom/isdn/i460_mux.h>
+#include <osmocom/trau/trau_frame.h>
+
+#include "globals.h"
+#include "submux.h"
+
+void cmd_set_dbits(int argc, char **argv)
+{
+	int nr;
+	struct ater_subslot *at;
+	struct osmo_trau_frame *fr;
+	unsigned d_offset;
+	char *bits;
+
+	if (argc != 4) {
+usage:		fprintf(stderr, "usage: %s 0|1|2|3 D-offset bits\n", argv[0]);
+		return;
+	}
+	if (argv[1][0] < '0' || argv[1][0] > '3' || argv[1][1])
+		goto usage;
+	nr = argv[1][0] - '0';
+	at = &subslots[nr];
+	if (!at->is_active) {
+		fprintf(stderr, "error: subslot %d is not active\n", nr);
+		return;
+	}
+	if (!at->is_data) {
+		fprintf(stderr, "error: subslot %d is not in data mode\n", nr);
+		return;
+	}
+	fr = &at->ul_frame;
+	d_offset = atoi(argv[2]);
+	if (d_offset >= 252) {
+		fprintf(stderr, "error: specified offset is out of range\n");
+		return;
+	}
+	for (bits = argv[3]; *bits; bits++) {
+		if (*bits < '0' || *bits > '1') {
+			fprintf(stderr, "error: invalid bit string argument\n");
+			return;
+		}
+		if (d_offset >= 252) {
+			fprintf(stderr,
+		"error: given bit string extends past the end of Dn bits\n");
+			return;
+		}
+		fr->d_bits[d_offset++] = *bits - '0';
+	}
+}