1 files changed, 70 insertions, 0 deletions
diff --git a/test/packetdrill/tcp_options.c b/test/packetdrill/tcp_options.c
new file mode 100644
index 0000000..b7def9d
--- /dev/null
+++ b/test/packetdrill/tcp_options.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+/*
+ * Author: ncardwell@google.com (Neal Cardwell)
+ *
+ * Implementation for reading and writing TCP options in their wire format.
+ */
+
+#include "tcp_options.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include "packet.h"
+
+struct tcp_options *tcp_options_new(void)
+{
+	return calloc(1, sizeof(struct tcp_options));
+}
+
+struct tcp_option *tcp_option_new(u8 kind, u8 length)
+{
+	struct tcp_option *option = calloc(1, sizeof(struct tcp_option));
+	option->kind = kind;
+	option->length = length;
+	return option;
+}
+
+int tcp_options_append(struct tcp_options *options,
+			       struct tcp_option *option)
+{
+	if (options->length + option->length > sizeof(options->data))
+		return STATUS_ERR;
+	memcpy(options->data + options->length, option, option->length);
+	options->length += option->length;
+	assert(options->length <= sizeof(options->data));
+	free(option);
+	return STATUS_OK;
+}
+
+int num_sack_blocks(u8 opt_len, int *num_blocks, char **error)
+{
+	if (opt_len <= 2) {
+		asprintf(error, "TCP SACK option too short");
+		return STATUS_ERR;
+	}
+	const int num_bytes = opt_len - 2;
+	if (num_bytes % sizeof(struct sack_block) != 0) {
+		asprintf(error,
+			 "TCP SACK option not a multiple of SACK block size");
+		return STATUS_ERR;
+	}
+	*num_blocks = num_bytes / sizeof(struct sack_block);
+	return STATUS_OK;
+}