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-rw-r--r--pkg/tcpip/header/tcp.go10
-rw-r--r--pkg/tcpip/transport/tcp/accept.go2
-rw-r--r--pkg/tcpip/transport/tcp/connect.go28
-rw-r--r--pkg/tcpip/transport/tcp/protocol.go4
-rw-r--r--pkg/tcpip/transport/tcp/rcv.go18
-rw-r--r--pkg/tcpip/transport/tcp/segment.go14
-rw-r--r--pkg/tcpip/transport/tcp/snd.go2
7 files changed, 39 insertions, 39 deletions
diff --git a/pkg/tcpip/header/tcp.go b/pkg/tcpip/header/tcp.go
index 0df517000..8dabe3354 100644
--- a/pkg/tcpip/header/tcp.go
+++ b/pkg/tcpip/header/tcp.go
@@ -48,6 +48,16 @@ const (
// TCPFlags is the dedicated type for TCP flags.
type TCPFlags uint8
+// Intersects returns true iff there are flags common to both f and o.
+func (f TCPFlags) Intersects(o TCPFlags) bool {
+ return f&o != 0
+}
+
+// Contains returns true iff all the flags in o are contained within f.
+func (f TCPFlags) Contains(o TCPFlags) bool {
+ return f&o == o
+}
+
// String implements Stringer.String.
func (f TCPFlags) String() string {
flagsStr := []byte("FSRPAU")
diff --git a/pkg/tcpip/transport/tcp/accept.go b/pkg/tcpip/transport/tcp/accept.go
index 4a33fbc24..db75228a1 100644
--- a/pkg/tcpip/transport/tcp/accept.go
+++ b/pkg/tcpip/transport/tcp/accept.go
@@ -550,7 +550,7 @@ func (e *endpoint) handleListenSegment(ctx *listenContext, s *segment) tcpip.Err
e.rcvQueueInfo.rcvQueueMu.Lock()
rcvClosed := e.rcvQueueInfo.RcvClosed
e.rcvQueueInfo.rcvQueueMu.Unlock()
- if rcvClosed || s.flagsAreSet(header.TCPFlagSyn|header.TCPFlagAck) {
+ if rcvClosed || s.flags.Contains(header.TCPFlagSyn|header.TCPFlagAck) {
// If the endpoint is shutdown, reply with reset.
//
// RFC 793 section 3.4 page 35 (figure 12) outlines that a RST
diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go
index 2fcdf1cda..08849d0cc 100644
--- a/pkg/tcpip/transport/tcp/connect.go
+++ b/pkg/tcpip/transport/tcp/connect.go
@@ -212,7 +212,7 @@ func (h *handshake) resetToSynRcvd(iss seqnum.Value, irs seqnum.Value, opts *hea
// a TCP 3-way handshake is valid. If it's not, a RST segment is sent back in
// response.
func (h *handshake) checkAck(s *segment) bool {
- if s.flagIsSet(header.TCPFlagAck) && s.ackNumber != h.iss+1 {
+ if s.flags.Contains(header.TCPFlagAck) && s.ackNumber != h.iss+1 {
// RFC 793, page 36, states that a reset must be generated when
// the connection is in any non-synchronized state and an
// incoming segment acknowledges something not yet sent. The
@@ -230,8 +230,8 @@ func (h *handshake) checkAck(s *segment) bool {
func (h *handshake) synSentState(s *segment) tcpip.Error {
// RFC 793, page 37, states that in the SYN-SENT state, a reset is
// acceptable if the ack field acknowledges the SYN.
- if s.flagIsSet(header.TCPFlagRst) {
- if s.flagIsSet(header.TCPFlagAck) && s.ackNumber == h.iss+1 {
+ if s.flags.Contains(header.TCPFlagRst) {
+ if s.flags.Contains(header.TCPFlagAck) && s.ackNumber == h.iss+1 {
// RFC 793, page 67, states that "If the RST bit is set [and] If the ACK
// was acceptable then signal the user "error: connection reset", drop
// the segment, enter CLOSED state, delete TCB, and return."
@@ -249,7 +249,7 @@ func (h *handshake) synSentState(s *segment) tcpip.Error {
// We are in the SYN-SENT state. We only care about segments that have
// the SYN flag.
- if !s.flagIsSet(header.TCPFlagSyn) {
+ if !s.flags.Contains(header.TCPFlagSyn) {
return nil
}
@@ -270,7 +270,7 @@ func (h *handshake) synSentState(s *segment) tcpip.Error {
// If this is a SYN ACK response, we only need to acknowledge the SYN
// and the handshake is completed.
- if s.flagIsSet(header.TCPFlagAck) {
+ if s.flags.Contains(header.TCPFlagAck) {
h.state = handshakeCompleted
h.ep.transitionToStateEstablishedLocked(h)
@@ -316,7 +316,7 @@ func (h *handshake) synSentState(s *segment) tcpip.Error {
// synRcvdState handles a segment received when the TCP 3-way handshake is in
// the SYN-RCVD state.
func (h *handshake) synRcvdState(s *segment) tcpip.Error {
- if s.flagIsSet(header.TCPFlagRst) {
+ if s.flags.Contains(header.TCPFlagRst) {
// RFC 793, page 37, states that in the SYN-RCVD state, a reset
// is acceptable if the sequence number is in the window.
if s.sequenceNumber.InWindow(h.ackNum, h.rcvWnd) {
@@ -340,13 +340,13 @@ func (h *handshake) synRcvdState(s *segment) tcpip.Error {
return nil
}
- if s.flagIsSet(header.TCPFlagSyn) && s.sequenceNumber != h.ackNum-1 {
+ if s.flags.Contains(header.TCPFlagSyn) && s.sequenceNumber != h.ackNum-1 {
// We received two SYN segments with different sequence
// numbers, so we reset this and restart the whole
// process, except that we don't reset the timer.
ack := s.sequenceNumber.Add(s.logicalLen())
seq := seqnum.Value(0)
- if s.flagIsSet(header.TCPFlagAck) {
+ if s.flags.Contains(header.TCPFlagAck) {
seq = s.ackNumber
}
h.ep.sendRaw(buffer.VectorisedView{}, header.TCPFlagRst|header.TCPFlagAck, seq, ack, 0)
@@ -378,7 +378,7 @@ func (h *handshake) synRcvdState(s *segment) tcpip.Error {
// We have previously received (and acknowledged) the peer's SYN. If the
// peer acknowledges our SYN, the handshake is completed.
- if s.flagIsSet(header.TCPFlagAck) {
+ if s.flags.Contains(header.TCPFlagAck) {
// If deferAccept is not zero and this is a bare ACK and the
// timeout is not hit then drop the ACK.
if h.deferAccept != 0 && s.data.Size() == 0 && h.ep.stack.Clock().NowMonotonic().Sub(h.startTime) < h.deferAccept {
@@ -426,7 +426,7 @@ func (h *handshake) synRcvdState(s *segment) tcpip.Error {
func (h *handshake) handleSegment(s *segment) tcpip.Error {
h.sndWnd = s.window
- if !s.flagIsSet(header.TCPFlagSyn) && h.sndWndScale > 0 {
+ if !s.flags.Contains(header.TCPFlagSyn) && h.sndWndScale > 0 {
h.sndWnd <<= uint8(h.sndWndScale)
}
@@ -634,7 +634,7 @@ func (bt *backoffTimer) stop() {
}
func parseSynSegmentOptions(s *segment) header.TCPSynOptions {
- synOpts := header.ParseSynOptions(s.options, s.flagIsSet(header.TCPFlagAck))
+ synOpts := header.ParseSynOptions(s.options, s.flags.Contains(header.TCPFlagAck))
if synOpts.TS {
s.parsedOptions.TSVal = synOpts.TSVal
s.parsedOptions.TSEcr = synOpts.TSEcr
@@ -1188,11 +1188,11 @@ func (e *endpoint) handleSegmentLocked(s *segment) (cont bool, err tcpip.Error)
// the TCPEndpointState after the segment is processed.
defer e.probeSegmentLocked()
- if s.flagIsSet(header.TCPFlagRst) {
+ if s.flags.Contains(header.TCPFlagRst) {
if ok, err := e.handleReset(s); !ok {
return false, err
}
- } else if s.flagIsSet(header.TCPFlagSyn) {
+ } else if s.flags.Contains(header.TCPFlagSyn) {
// See: https://tools.ietf.org/html/rfc5961#section-4.1
// 1) If the SYN bit is set, irrespective of the sequence number, TCP
// MUST send an ACK (also referred to as challenge ACK) to the remote
@@ -1216,7 +1216,7 @@ func (e *endpoint) handleSegmentLocked(s *segment) (cont bool, err tcpip.Error)
// should then rely on SYN retransmission from the remote end to
// re-establish the connection.
e.snd.maybeSendOutOfWindowAck(s)
- } else if s.flagIsSet(header.TCPFlagAck) {
+ } else if s.flags.Contains(header.TCPFlagAck) {
// Patch the window size in the segment according to the
// send window scale.
s.window <<= e.snd.SndWndScale
diff --git a/pkg/tcpip/transport/tcp/protocol.go b/pkg/tcpip/transport/tcp/protocol.go
index c970dcecc..7c38ad480 100644
--- a/pkg/tcpip/transport/tcp/protocol.go
+++ b/pkg/tcpip/transport/tcp/protocol.go
@@ -149,7 +149,7 @@ func (p *protocol) HandleUnknownDestinationPacket(id stack.TransportEndpointID,
return stack.UnknownDestinationPacketMalformed
}
- if !s.flagIsSet(header.TCPFlagRst) {
+ if !s.flags.Contains(header.TCPFlagRst) {
replyWithReset(p.stack, s, stack.DefaultTOS, 0)
}
@@ -181,7 +181,7 @@ func replyWithReset(st *stack.Stack, s *segment, tos, ttl uint8) tcpip.Error {
// reset has sequence number zero and the ACK field is set to the sum
// of the sequence number and segment length of the incoming segment.
// The connection remains in the CLOSED state.
- if s.flagIsSet(header.TCPFlagAck) {
+ if s.flags.Contains(header.TCPFlagAck) {
seq = s.ackNumber
} else {
flags |= header.TCPFlagAck
diff --git a/pkg/tcpip/transport/tcp/rcv.go b/pkg/tcpip/transport/tcp/rcv.go
index b46f8320e..661ca604a 100644
--- a/pkg/tcpip/transport/tcp/rcv.go
+++ b/pkg/tcpip/transport/tcp/rcv.go
@@ -244,7 +244,7 @@ func (r *receiver) consumeSegment(s *segment, segSeq seqnum.Value, segLen seqnum
TrimSACKBlockList(&r.ep.sack, r.RcvNxt)
// Handle FIN or FIN-ACK.
- if s.flagIsSet(header.TCPFlagFin) {
+ if s.flags.Contains(header.TCPFlagFin) {
r.RcvNxt++
// Send ACK immediately.
@@ -260,7 +260,7 @@ func (r *receiver) consumeSegment(s *segment, segSeq seqnum.Value, segLen seqnum
case StateEstablished:
r.ep.setEndpointState(StateCloseWait)
case StateFinWait1:
- if s.flagIsSet(header.TCPFlagAck) && s.ackNumber == r.ep.snd.SndNxt {
+ if s.flags.Contains(header.TCPFlagAck) && s.ackNumber == r.ep.snd.SndNxt {
// FIN-ACK, transition to TIME-WAIT.
r.ep.setEndpointState(StateTimeWait)
} else {
@@ -295,7 +295,7 @@ func (r *receiver) consumeSegment(s *segment, segSeq seqnum.Value, segLen seqnum
// Handle ACK (not FIN-ACK, which we handled above) during one of the
// shutdown states.
- if s.flagIsSet(header.TCPFlagAck) && s.ackNumber == r.ep.snd.SndNxt {
+ if s.flags.Contains(header.TCPFlagAck) && s.ackNumber == r.ep.snd.SndNxt {
switch r.ep.EndpointState() {
case StateFinWait1:
r.ep.setEndpointState(StateFinWait2)
@@ -423,7 +423,7 @@ func (r *receiver) handleRcvdSegmentClosing(s *segment, state EndpointState, clo
// while the FIN is considered to occur after
// the last actual data octet in a segment in
// which it occurs.
- if closed && (!s.flagIsSet(header.TCPFlagFin) || s.sequenceNumber.Add(s.logicalLen()) != r.RcvNxt+1) {
+ if closed && (!s.flags.Contains(header.TCPFlagFin) || s.sequenceNumber.Add(s.logicalLen()) != r.RcvNxt+1) {
return true, &tcpip.ErrConnectionAborted{}
}
}
@@ -470,7 +470,7 @@ func (r *receiver) handleRcvdSegment(s *segment) (drop bool, err tcpip.Error) {
// Defer segment processing if it can't be consumed now.
if !r.consumeSegment(s, segSeq, segLen) {
- if segLen > 0 || s.flagIsSet(header.TCPFlagFin) {
+ if segLen > 0 || s.flags.Contains(header.TCPFlagFin) {
// We only store the segment if it's within our buffer size limit.
//
// Only use 75% of the receive buffer queue for out-of-order
@@ -538,7 +538,7 @@ func (r *receiver) handleTimeWaitSegment(s *segment) (resetTimeWait bool, newSyn
//
// As we do not yet support PAWS, we are being conservative in ignoring
// RSTs by default.
- if s.flagIsSet(header.TCPFlagRst) {
+ if s.flags.Contains(header.TCPFlagRst) {
return false, false
}
@@ -558,13 +558,13 @@ func (r *receiver) handleTimeWaitSegment(s *segment) (resetTimeWait bool, newSyn
// (2) returns to TIME-WAIT state if the SYN turns out
// to be an old duplicate".
- if s.flagIsSet(header.TCPFlagSyn) && r.RcvNxt.LessThan(segSeq) {
+ if s.flags.Contains(header.TCPFlagSyn) && r.RcvNxt.LessThan(segSeq) {
return false, true
}
// Drop the segment if it does not contain an ACK.
- if !s.flagIsSet(header.TCPFlagAck) {
+ if !s.flags.Contains(header.TCPFlagAck) {
return false, false
}
@@ -573,7 +573,7 @@ func (r *receiver) handleTimeWaitSegment(s *segment) (resetTimeWait bool, newSyn
r.ep.updateRecentTimestamp(s.parsedOptions.TSVal, r.ep.snd.MaxSentAck, segSeq)
}
- if segSeq.Add(1) == r.RcvNxt && s.flagIsSet(header.TCPFlagFin) {
+ if segSeq.Add(1) == r.RcvNxt && s.flags.Contains(header.TCPFlagFin) {
// If it's a FIN-ACK then resetTimeWait and send an ACK, as it
// indicates our final ACK could have been lost.
r.ep.snd.sendAck()
diff --git a/pkg/tcpip/transport/tcp/segment.go b/pkg/tcpip/transport/tcp/segment.go
index e5c0d52fa..ca78c96f2 100644
--- a/pkg/tcpip/transport/tcp/segment.go
+++ b/pkg/tcpip/transport/tcp/segment.go
@@ -148,16 +148,6 @@ func (s *segment) merge(oth *segment) {
oth.dataMemSize = oth.data.Size()
}
-// flagIsSet checks if at least one flag in flags is set in s.flags.
-func (s *segment) flagIsSet(flags header.TCPFlags) bool {
- return s.flags&flags != 0
-}
-
-// flagsAreSet checks if all flags in flags are set in s.flags.
-func (s *segment) flagsAreSet(flags header.TCPFlags) bool {
- return s.flags&flags == flags
-}
-
// setOwner sets the owning endpoint for this segment. Its required
// to be called to ensure memory accounting for receive/send buffer
// queues is done properly.
@@ -197,10 +187,10 @@ func (s *segment) incRef() {
// as the data length plus one for each of the SYN and FIN bits set.
func (s *segment) logicalLen() seqnum.Size {
l := seqnum.Size(s.data.Size())
- if s.flagIsSet(header.TCPFlagSyn) {
+ if s.flags.Contains(header.TCPFlagSyn) {
l++
}
- if s.flagIsSet(header.TCPFlagFin) {
+ if s.flags.Contains(header.TCPFlagFin) {
l++
}
return l
diff --git a/pkg/tcpip/transport/tcp/snd.go b/pkg/tcpip/transport/tcp/snd.go
index ccff9ca8d..72d58dcff 100644
--- a/pkg/tcpip/transport/tcp/snd.go
+++ b/pkg/tcpip/transport/tcp/snd.go
@@ -1132,7 +1132,7 @@ func (s *sender) isDupAck(seg *segment) bool {
// (b) The incoming acknowledgment carries no data.
seg.logicalLen() == 0 &&
// (c) The SYN and FIN bits are both off.
- !seg.flagIsSet(header.TCPFlagFin) && !seg.flagIsSet(header.TCPFlagSyn) &&
+ !seg.flags.Intersects(header.TCPFlagFin|header.TCPFlagSyn) &&
// (d) the ACK number is equal to the greatest acknowledgment received on
// the given connection (TCP.UNA from RFC793).
seg.ackNumber == s.SndUna &&
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-21 10:58:24 +0000