[PATCH v9 15/20] 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.

Slightly reformat the prototypes while we're at it.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 tcp.c          | 45 ++++++---------------------------------------
 tcp_buf.c      | 32 ++++++++++++++++++++++++++++++++
 tcp_internal.h | 17 ++++++-----------
 3 files changed, 44 insertions(+), 50 deletions(-)

diff --git a/tcp.c b/tcp.c
index af23921..345f65c 100644
--- a/tcp.c
+++ b/tcp.c
@@ -981,10 +981,9 @@ static void tcp_fill_header(struct tcphdr *th,
  * Return: The IPv4 payload length, host order
  */
 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)
+			 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);
@@ -1033,9 +1032,9 @@ size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
  * Return: The IPv6 payload length, host order
  */
 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)
+			 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);
@@ -1070,38 +1069,6 @@ 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 d17ba48..6f8f5bb 100644
--- a/tcp_buf.c
+++ b/tcp_buf.c
@@ -186,6 +186,38 @@ void tcp_payload_flush(const struct ctx *c)
 	tcp_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 d5d5d06..21e31a0 100644
--- a/tcp_internal.h
+++ b/tcp_internal.h
@@ -184,18 +184,13 @@ void tcp_update_check_tcp6(const struct ipv6hdr *ip6h,
 			   const struct iovec *iov, int iov_cnt,
 			   size_t l4offset);
 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);
+			 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);
-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);
+			 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