[PATCH 2/7] tcp: Move tcp_l2_buf_fill_headers() to tcp_buf.c

[David Gibson <david@gibson.dropbear.id.au>]

This function only has callers in tcp_buf.c.  More importantly, it's
inherently tied to the "buf" path, because it uses internal knowledge of
how we lay out the various headers across our locally allocated buffers.

Therefore, move it to tcp_buf.c.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 tcp.c          | 49 ++++++++-----------------------------------------
 tcp_buf.c      | 32 ++++++++++++++++++++++++++++++++
 tcp_internal.h | 12 ++++++++----
 3 files changed, 48 insertions(+), 45 deletions(-)

diff --git a/tcp.c b/tcp.c
index f2898ff..7c6f51a 100644
--- a/tcp.c
+++ b/tcp.c
@@ -922,11 +922,10 @@ static void tcp_fill_header(struct tcphdr *th,
  *
  * Return: The IPv4 payload length, host order
  */
-static size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
-				struct tap_hdr *taph,
-				struct iphdr *iph, struct tcp_payload_t *bp,
-				size_t dlen, const uint16_t *check,
-				uint32_t seq, bool no_tcp_csum)
+size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
+			 struct tap_hdr *taph, struct iphdr *iph,
+			 struct tcp_payload_t *bp, size_t dlen,
+			 const uint16_t *check, uint32_t seq, bool no_tcp_csum)
 {
 	const struct flowside *tapside = TAPFLOW(conn);
 	const struct in_addr *src4 = inany_v4(&tapside->oaddr);
@@ -974,10 +973,10 @@ static size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
  *
  * Return: The IPv6 payload length, host order
  */
-static size_t tcp_fill_headers6(const struct tcp_tap_conn *conn,
-				struct tap_hdr *taph,
-				struct ipv6hdr *ip6h, struct tcp_payload_t *bp,
-				size_t dlen, uint32_t seq, bool no_tcp_csum)
+size_t tcp_fill_headers6(const struct tcp_tap_conn *conn,
+			 struct tap_hdr *taph, struct ipv6hdr *ip6h,
+			 struct tcp_payload_t *bp, size_t dlen,
+			 uint32_t seq, bool no_tcp_csum)
 {
 	const struct flowside *tapside = TAPFLOW(conn);
 	size_t l4len = dlen + sizeof(bp->th);
@@ -1012,38 +1011,6 @@ static size_t tcp_fill_headers6(const struct tcp_tap_conn *conn,
 	return l4len;
 }
 
-/**
- * tcp_l2_buf_fill_headers() - Fill 802.3, IP, TCP headers in pre-cooked buffers
- * @conn:	Connection pointer
- * @iov:	Pointer to an array of iovec of TCP pre-cooked buffers
- * @dlen:	TCP payload length
- * @check:	Checksum, if already known
- * @seq:	Sequence number for this segment
- * @no_tcp_csum: Do not set TCP checksum
- *
- * Return: IP payload length, host order
- */
-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,
-			       bool no_tcp_csum)
-{
-	const struct flowside *tapside = TAPFLOW(conn);
-	const struct in_addr *a4 = inany_v4(&tapside->oaddr);
-
-	if (a4) {
-		return tcp_fill_headers4(conn, iov[TCP_IOV_TAP].iov_base,
-					 iov[TCP_IOV_IP].iov_base,
-					 iov[TCP_IOV_PAYLOAD].iov_base, dlen,
-					 check, seq, no_tcp_csum);
-	}
-
-	return tcp_fill_headers6(conn, iov[TCP_IOV_TAP].iov_base,
-				 iov[TCP_IOV_IP].iov_base,
-				 iov[TCP_IOV_PAYLOAD].iov_base, dlen,
-				 seq, no_tcp_csum);
-}
-
 /**
  * tcp_update_seqack_wnd() - Update ACK sequence and window to guest/tap
  * @c:		Execution context
diff --git a/tcp_buf.c b/tcp_buf.c
index cb6742c..dbe565c 100644
--- a/tcp_buf.c
+++ b/tcp_buf.c
@@ -256,6 +256,38 @@ void tcp_payload_flush(const struct ctx *c)
 	tcp4_payload_used = 0;
 }
 
+/**
+ * tcp_buf_fill_headers() - Fill 802.3, IP, TCP headers in pre-cooked buffers
+ * @conn:	Connection pointer
+ * @iov:	Pointer to an array of iovec of TCP pre-cooked buffers
+ * @dlen:	TCP payload length
+ * @check:	Checksum, if already known
+ * @seq:	Sequence number for this segment
+ * @no_tcp_csum: Do not set TCP checksum
+ *
+ * Return: IP payload length, host order
+ */
+static 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,
+				      bool no_tcp_csum)
+{
+	const struct flowside *tapside = TAPFLOW(conn);
+	const struct in_addr *a4 = inany_v4(&tapside->oaddr);
+
+	if (a4) {
+		return tcp_fill_headers4(conn, iov[TCP_IOV_TAP].iov_base,
+					 iov[TCP_IOV_IP].iov_base,
+					 iov[TCP_IOV_PAYLOAD].iov_base, dlen,
+					 check, seq, no_tcp_csum);
+	}
+
+	return tcp_fill_headers6(conn, iov[TCP_IOV_TAP].iov_base,
+				 iov[TCP_IOV_IP].iov_base,
+				 iov[TCP_IOV_PAYLOAD].iov_base, dlen,
+				 seq, no_tcp_csum);
+}
+
 /**
  * tcp_buf_send_flag() - Send segment with flags to tap (no payload)
  * @c:         Execution context
diff --git a/tcp_internal.h b/tcp_internal.h
index a5a47df..0034b22 100644
--- a/tcp_internal.h
+++ b/tcp_internal.h
@@ -177,10 +177,14 @@ void tcp_rst_do(const struct ctx *c, struct tcp_tap_conn *conn);
 
 struct tcp_info_linux;
 
-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,
-			       bool no_tcp_csum);
+size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
+			 struct tap_hdr *taph, struct iphdr *iph,
+			 struct tcp_payload_t *bp, size_t dlen,
+			 const uint16_t *check, uint32_t seq, bool no_tcp_csum);
+size_t tcp_fill_headers6(const struct tcp_tap_conn *conn,
+			 struct tap_hdr *taph, struct ipv6hdr *ip6h,
+			 struct tcp_payload_t *bp, size_t dlen,
+			 uint32_t seq, bool no_tcp_csum);
 int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn,
 			  bool force_seq, struct tcp_info_linux *tinfo);
 int tcp_prepare_flags(const struct ctx *c, struct tcp_tap_conn *conn,
-- 
@@ -177,10 +177,14 @@ void tcp_rst_do(const struct ctx *c, struct tcp_tap_conn *conn);
 
 struct tcp_info_linux;
 
-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,
-			       bool no_tcp_csum);
+size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
+			 struct tap_hdr *taph, struct iphdr *iph,
+			 struct tcp_payload_t *bp, size_t dlen,
+			 const uint16_t *check, uint32_t seq, bool no_tcp_csum);
+size_t tcp_fill_headers6(const struct tcp_tap_conn *conn,
+			 struct tap_hdr *taph, struct ipv6hdr *ip6h,
+			 struct tcp_payload_t *bp, size_t dlen,
+			 uint32_t seq, bool no_tcp_csum);
 int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn,
 			  bool force_seq, struct tcp_info_linux *tinfo);
 int tcp_prepare_flags(const struct ctx *c, struct tcp_tap_conn *conn,
-- 
2.47.0