1 files changed, 29 insertions, 0 deletions
diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c
index 4879f6395c7e..e916ff25697f 100644
--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c
@@ -117,6 +117,35 @@ bool is_prefix(const char *pfx, const char *str)
 	return !memcmp(str, pfx, strlen(pfx));
 }
 
+/* Last argument MUST be NULL pointer */
+int detect_common_prefix(const char *arg, ...)
+{
+	unsigned int count = 0;
+	const char *ref;
+	char msg[256];
+	va_list ap;
+
+	snprintf(msg, sizeof(msg), "ambiguous prefix: '%s' could be '", arg);
+	va_start(ap, arg);
+	while ((ref = va_arg(ap, const char *))) {
+		if (!is_prefix(arg, ref))
+			continue;
+		count++;
+		if (count > 1)
+			strncat(msg, "' or '", sizeof(msg) - strlen(msg) - 1);
+		strncat(msg, ref, sizeof(msg) - strlen(msg) - 1);
+	}
+	va_end(ap);
+	strncat(msg, "'", sizeof(msg) - strlen(msg) - 1);
+
+	if (count >= 2) {
+		p_err(msg);
+		return -1;
+	}
+
+	return 0;
+}
+
 void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep)
 {
 	unsigned char *data = arg;