1 files changed, 89 insertions, 10 deletions

diff --git a/tcp_internal.h b/tcp_internal.h
index 8b60aab..94e5780 100644
--- a/tcp_internal.h
+++ b/tcp_internal.h
@@ -33,9 +33,7 @@
 #define OPT_EOL		0
 #define OPT_NOP		1
 #define OPT_MSS		2
-#define OPT_MSS_LEN	4
 #define OPT_WS		3
-#define OPT_WS_LEN	3
 #define OPT_SACKP	4
 #define OPT_SACK	5
 #define OPT_TS		8
@@ -44,7 +42,7 @@
 #define TAPFLOW(conn_)	(&((conn_)->f.side[TAPSIDE(conn_)]))
 #define TAP_SIDX(conn_)	(FLOW_SIDX((conn_), TAPSIDE(conn_)))
 
-#define CONN_V4(conn)		(!!inany_v4(&TAPFLOW(conn)->faddr))
+#define CONN_V4(conn)		(!!inany_v4(&TAPFLOW(conn)->oaddr))
 #define CONN_V6(conn)		(!CONN_V4(conn))
 
 /*
@@ -63,6 +61,79 @@ enum tcp_iov_parts {
 	TCP_NUM_IOVS
 };
 
+/**
+ * struct tcp_payload_t - TCP header and data to send segments with payload
+ * @th:		TCP header
+ * @data:	TCP data
+ */
+struct tcp_payload_t {
+	struct tcphdr th;
+	uint8_t data[IP_MAX_MTU - sizeof(struct tcphdr)];
+#ifdef __AVX2__
+} __attribute__ ((packed, aligned(32)));    /* For AVX2 checksum routines */
+#else
+} __attribute__ ((packed, aligned(__alignof__(unsigned int))));
+#endif
+
+/** struct tcp_opt_nop - TCP NOP option
+ * @kind:	Option kind (OPT_NOP = 1)
+ */
+struct tcp_opt_nop {
+	uint8_t kind;
+} __attribute__ ((packed));
+#define TCP_OPT_NOP		((struct tcp_opt_nop){ .kind = OPT_NOP, })
+
+/** struct tcp_opt_mss - TCP MSS option
+ * @kind:	Option kind (OPT_MSS == 2)
+ * @len:	Option length (4)
+ * @mss:	Maximum Segment Size
+ */
+struct tcp_opt_mss {
+	uint8_t kind;
+	uint8_t len;
+	uint16_t mss;
+} __attribute__ ((packed));
+#define TCP_OPT_MSS(mss_)				\
+	((struct tcp_opt_mss) {				\
+		.kind = OPT_MSS,			\
+		.len = sizeof(struct tcp_opt_mss),	\
+		.mss = htons(mss_),			\
+	})
+
+/** struct tcp_opt_ws - TCP Window Scaling option
+ * @kind:	Option kind (OPT_WS == 3)
+ * @len:	Option length (3)
+ * @shift:	Window scaling shift
+ */
+struct tcp_opt_ws {
+	uint8_t kind;
+	uint8_t len;
+	uint8_t shift;
+} __attribute__ ((packed));
+#define TCP_OPT_WS(shift_)				\
+	((struct tcp_opt_ws) {				\
+		.kind = OPT_WS,				\
+		.len = sizeof(struct tcp_opt_ws),	\
+		.shift = (shift_),			\
+	})
+
+/** struct tcp_syn_opts - TCP options we apply to SYN packets
+ * @mss:	Maximum Segment Size (MSS) option
+ * @nop:	NOP opt (for alignment)
+ * @ws:		Window Scaling (WS) option
+ */
+struct tcp_syn_opts {
+	struct tcp_opt_mss mss;
+	struct tcp_opt_nop nop;
+	struct tcp_opt_ws ws;
+} __attribute__ ((packed));
+#define TCP_SYN_OPTS(mss_, ws_)				\
+	((struct tcp_syn_opts){				\
+		.mss = TCP_OPT_MSS(mss_),		\
+		.nop = TCP_OPT_NOP,			\
+		.ws = TCP_OPT_WS(ws_),			\
+	})
+
 extern char tcp_buf_discard [MAX_WINDOW];
 
 void conn_flag_do(const struct ctx *c, struct tcp_tap_conn *conn,
@@ -82,19 +153,27 @@ void conn_event_do(const struct ctx *c, struct tcp_tap_conn *conn,
 		conn_event_do(c, conn, event);				\
 	} while (0)
 
-void tcp_rst_do(struct ctx *c, struct tcp_tap_conn *conn);
+void tcp_rst_do(const struct ctx *c, struct tcp_tap_conn *conn);
 #define tcp_rst(c, conn)						\
 	do {								\
 		flow_dbg((conn), "TCP reset at %s:%i", __func__, __LINE__); \
 		tcp_rst_do(c, conn);					\
 	} while (0)
 
-size_t tcp_l2_buf_fill_headers(const struct tcp_tap_conn *conn,
-			       struct iovec *iov, size_t dlen,
-			       const uint16_t *check, uint32_t seq);
+struct tcp_info_linux;
+
+void tcp_update_csum(uint32_t psum, struct tcphdr *th,
+		     struct iov_tail *payload);
+void tcp_fill_headers(const struct tcp_tap_conn *conn,
+		      struct tap_hdr *taph,
+		      struct iphdr *ip4h, struct ipv6hdr *ip6h,
+		      struct tcphdr *th, struct iov_tail *payload,
+		      const uint16_t *ip4_check, uint32_t seq, bool no_tcp_csum);
+
 int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn,
-			  int force_seq, struct tcp_info *tinfo);
-int tcp_prepare_flags(struct ctx *c, struct tcp_tap_conn *conn, int flags,
-		      struct tcphdr *th, char *data, size_t *optlen);
+			  bool force_seq, struct tcp_info_linux *tinfo);
+int tcp_prepare_flags(const struct ctx *c, struct tcp_tap_conn *conn,
+		      int flags, struct tcphdr *th, struct tcp_syn_opts *opts,
+		      size_t *optlen);
 
 #endif /* TCP_INTERNAL_H */