[gPXE-devel] [PATCH 5/6] [tcp] Port tcp sequence helper functions from Linux

[cooldavid at cooldavid.org]

From: Guo-Fu Tseng <cooldavid at cooldavid.org>


Signed-off-by: Guo-Fu Tseng <cooldavid at cooldavid.org>
---
 src/include/gpxe/tcp.h |   20 ++++++++++++++++++++
 1 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/src/include/gpxe/tcp.h b/src/include/gpxe/tcp.h
index aa493a7..aabd4d6 100644
--- a/src/include/gpxe/tcp.h
+++ b/src/include/gpxe/tcp.h
@@ -28,6 +28,26 @@ struct tcp_header {
 	uint16_t urg;		/* Urgent pointer */
 };
 
+/** @Sequence helper functions ported from Linux
+ * @{
+ */
+
+/*
+ * The next routines deal with comparing 32 bit unsigned ints
+ * and worry about wraparound (automatic with unsigned arithmetic).
+ */
+static inline int before ( uint32_t seq1, uint32_t seq2 ) {
+	        return ( int32_t ) ( seq1 - seq2 ) < 0;
+}
+#define after(seq2,seq1)	before(seq1,seq2)
+
+/* is s2<=s1<=s3 ? */
+static inline int between ( uint32_t seq1, uint32_t seq2, uint32_t seq3) {
+	        return seq3 - seq2 >= seq1 - seq2;
+}
+
+/** @} */
+
 /** @defgroup tcpopts TCP options
  * @{
  */
-- 
1.7.1