Rfc9293 WIP

net/tcp.lisp

@@ -490,16 +490,15 @@ Set to a value near 2^32 to test SND sequence number wrapping.")
 (defun tcp-packet-data-length (packet start end)
   (- end (+ start (tcp-packet-header-length packet start end))))
 
-(defun acceptable-segment-p (connection packet start end)
+(defun acceptable-segment-p (connection seg.seq seg.len)
   (let ((rcv.wnd (tcp-connection-rcv.wnd connection))
-        (rcv.nxt (tcp-connection-rcv.nxt connection))
-        (seg.seq (tcp-packet-sequence-number packet start end))
-        (seg.len (tcp-packet-data-length packet start end)))
+        (rcv.nxt (tcp-connection-rcv.nxt connection)))
     (if (eql rcv.wnd 0)
         (and (eql seg.len 0)
              (eql seg.seq rcv.nxt))
         ;; Arithmetic here is not wrapping, so as to avoid wrap-around problems.
-        (and (and (<= rcv.nxt seg.seq) (< seg.seq (+ rcv.nxt rcv.wnd)))
+        (and (<= rcv.nxt seg.seq)
+             (< seg.seq (+ rcv.nxt rcv.wnd))
              (or (eql seg.len 0)
                  (let ((seq-end (+ seg.seq seg.len -1)))
                    (and (<= rcv.nxt seq-end) (< seq-end (+ rcv.nxt rcv.wnd)))))))))
@@ -626,7 +625,7 @@ Set to a value near 2^32 to test SND sequence number wrapping.")
                   (remhash connection (tcp-listener-pending-connections listener))
                   (decf (tcp-listener-n-pending-connections listener))))))
         (:established
-         (cond ((not (acceptable-segment-p connection packet start end))
+         (cond ((not (acceptable-segment-p connection seq data-length))
                 (when (not (logtest flags +tcp4-flag-rst+))
                   (tcp4-send-packet connection
                                     (tcp-connection-snd.nxt connection)