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-rw-r--r--pkg/tcpip/network/internal/ip/generic_multicast_protocol_test.go10
-rw-r--r--pkg/tcpip/stack/addressable_endpoint_state.go2
-rw-r--r--pkg/tcpip/stack/conntrack.go4
-rw-r--r--pkg/tcpip/transport/icmp/endpoint.go5
-rw-r--r--pkg/tcpip/transport/tcp/accept.go9
-rw-r--r--pkg/tcpip/transport/tcp/connect.go74
-rw-r--r--pkg/tcpip/transport/tcp/dispatcher.go2
-rw-r--r--pkg/tcpip/transport/tcp/endpoint.go140
-rw-r--r--pkg/tcpip/transport/tcp/forwarder.go5
-rw-r--r--pkg/tcpip/transport/udp/endpoint.go150
10 files changed, 220 insertions, 181 deletions
diff --git a/pkg/tcpip/network/internal/ip/generic_multicast_protocol_test.go b/pkg/tcpip/network/internal/ip/generic_multicast_protocol_test.go
index 0b51563cd..1261ad414 100644
--- a/pkg/tcpip/network/internal/ip/generic_multicast_protocol_test.go
+++ b/pkg/tcpip/network/internal/ip/generic_multicast_protocol_test.go
@@ -126,7 +126,7 @@ func (m *mockMulticastGroupProtocol) sendQueuedReports() {
// Precondition: m.mu must be read locked.
func (m *mockMulticastGroupProtocol) Enabled() bool {
if m.mu.TryLock() {
- m.mu.Unlock()
+ m.mu.Unlock() // +checklocksforce: TryLock.
m.t.Fatal("got write lock, expected to not take the lock; generic multicast protocol must take the read or write lock before calling Enabled")
}
@@ -138,11 +138,11 @@ func (m *mockMulticastGroupProtocol) Enabled() bool {
// Precondition: m.mu must be locked.
func (m *mockMulticastGroupProtocol) SendReport(groupAddress tcpip.Address) (bool, tcpip.Error) {
if m.mu.TryLock() {
- m.mu.Unlock()
+ m.mu.Unlock() // +checklocksforce: TryLock.
m.t.Fatalf("got write lock, expected to not take the lock; generic multicast protocol must take the write lock before sending report for %s", groupAddress)
}
if m.mu.TryRLock() {
- m.mu.RUnlock()
+ m.mu.RUnlock() // +checklocksforce: TryLock.
m.t.Fatalf("got read lock, expected to not take the lock; generic multicast protocol must take the write lock before sending report for %s", groupAddress)
}
@@ -155,11 +155,11 @@ func (m *mockMulticastGroupProtocol) SendReport(groupAddress tcpip.Address) (boo
// Precondition: m.mu must be locked.
func (m *mockMulticastGroupProtocol) SendLeave(groupAddress tcpip.Address) tcpip.Error {
if m.mu.TryLock() {
- m.mu.Unlock()
+ m.mu.Unlock() // +checklocksforce: TryLock.
m.t.Fatalf("got write lock, expected to not take the lock; generic multicast protocol must take the write lock before sending leave for %s", groupAddress)
}
if m.mu.TryRLock() {
- m.mu.RUnlock()
+ m.mu.RUnlock() // +checklocksforce: TryLock.
m.t.Fatalf("got read lock, expected to not take the lock; generic multicast protocol must take the write lock before sending leave for %s", groupAddress)
}
diff --git a/pkg/tcpip/stack/addressable_endpoint_state.go b/pkg/tcpip/stack/addressable_endpoint_state.go
index ce9cebdaa..ae0bb4ace 100644
--- a/pkg/tcpip/stack/addressable_endpoint_state.go
+++ b/pkg/tcpip/stack/addressable_endpoint_state.go
@@ -249,7 +249,7 @@ func (a *AddressableEndpointState) addAndAcquireAddressLocked(addr tcpip.Address
// or we are adding a new temporary or permanent address.
//
// The address MUST be write locked at this point.
- defer addrState.mu.Unlock()
+ defer addrState.mu.Unlock() // +checklocksforce
if permanent {
if addrState.mu.kind.IsPermanent() {
diff --git a/pkg/tcpip/stack/conntrack.go b/pkg/tcpip/stack/conntrack.go
index 782e74b24..068dab7ce 100644
--- a/pkg/tcpip/stack/conntrack.go
+++ b/pkg/tcpip/stack/conntrack.go
@@ -363,7 +363,7 @@ func (ct *ConnTrack) insertConn(conn *conn) {
// Unlocking can happen in any order.
ct.buckets[tupleBucket].mu.Unlock()
if tupleBucket != replyBucket {
- ct.buckets[replyBucket].mu.Unlock()
+ ct.buckets[replyBucket].mu.Unlock() // +checklocksforce
}
}
@@ -626,7 +626,7 @@ func (ct *ConnTrack) reapTupleLocked(tuple *tuple, bucket int, now time.Time) bo
// Don't re-unlock if both tuples are in the same bucket.
if differentBuckets {
- ct.buckets[replyBucket].mu.Unlock()
+ ct.buckets[replyBucket].mu.Unlock() // +checklocksforce
}
return true
diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go
index cb316d27a..f9a15efb2 100644
--- a/pkg/tcpip/transport/icmp/endpoint.go
+++ b/pkg/tcpip/transport/icmp/endpoint.go
@@ -213,6 +213,7 @@ func (e *endpoint) Read(dst io.Writer, opts tcpip.ReadOptions) (tcpip.ReadResult
// reacquire the mutex in exclusive mode.
//
// Returns true for retry if preparation should be retried.
+// +checklocks:e.mu
func (e *endpoint) prepareForWrite(to *tcpip.FullAddress) (retry bool, err tcpip.Error) {
switch e.state {
case stateInitial:
@@ -229,10 +230,8 @@ func (e *endpoint) prepareForWrite(to *tcpip.FullAddress) (retry bool, err tcpip
}
e.mu.RUnlock()
- defer e.mu.RLock()
-
e.mu.Lock()
- defer e.mu.Unlock()
+ defer e.mu.DowngradeLock()
// The state changed when we released the shared locked and re-acquired
// it in exclusive mode. Try again.
diff --git a/pkg/tcpip/transport/tcp/accept.go b/pkg/tcpip/transport/tcp/accept.go
index d807b13b7..aa413ad05 100644
--- a/pkg/tcpip/transport/tcp/accept.go
+++ b/pkg/tcpip/transport/tcp/accept.go
@@ -330,7 +330,9 @@ func (l *listenContext) performHandshake(s *segment, opts *header.TCPSynOptions,
}
ep := h.ep
- if err := h.complete(); err != nil {
+ // N.B. the endpoint is generated above by startHandshake, and will be
+ // returned locked. This first call is forced.
+ if err := h.complete(); err != nil { // +checklocksforce
ep.stack.Stats().TCP.FailedConnectionAttempts.Increment()
ep.stats.FailedConnectionAttempts.Increment()
l.cleanupFailedHandshake(h)
@@ -364,6 +366,7 @@ func (l *listenContext) closeAllPendingEndpoints() {
}
// Precondition: h.ep.mu must be held.
+// +checklocks:h.ep.mu
func (l *listenContext) cleanupFailedHandshake(h *handshake) {
e := h.ep
e.mu.Unlock()
@@ -504,7 +507,9 @@ func (e *endpoint) handleSynSegment(ctx *listenContext, s *segment, opts *header
}
go func() {
- if err := h.complete(); err != nil {
+ // Note that startHandshake returns a locked endpoint. The
+ // force call here just makes it so.
+ if err := h.complete(); err != nil { // +checklocksforce
e.stack.Stats().TCP.FailedConnectionAttempts.Increment()
e.stats.FailedConnectionAttempts.Increment()
ctx.cleanupFailedHandshake(h)
diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go
index e39d1623d..93ed161f9 100644
--- a/pkg/tcpip/transport/tcp/connect.go
+++ b/pkg/tcpip/transport/tcp/connect.go
@@ -511,6 +511,7 @@ func (h *handshake) start() {
}
// complete completes the TCP 3-way handshake initiated by h.start().
+// +checklocks:h.ep.mu
func (h *handshake) complete() tcpip.Error {
// Set up the wakers.
var s sleep.Sleeper
@@ -1283,42 +1284,45 @@ func (e *endpoint) disableKeepaliveTimer() {
e.keepalive.Unlock()
}
-// protocolMainLoop is the main loop of the TCP protocol. It runs in its own
-// goroutine and is responsible for sending segments and handling received
-// segments.
-func (e *endpoint) protocolMainLoop(handshake bool, wakerInitDone chan<- struct{}) tcpip.Error {
- e.mu.Lock()
- var closeTimer tcpip.Timer
- var closeWaker sleep.Waker
-
- epilogue := func() {
- // e.mu is expected to be hold upon entering this section.
- if e.snd != nil {
- e.snd.resendTimer.cleanup()
- e.snd.probeTimer.cleanup()
- e.snd.reorderTimer.cleanup()
- }
+// protocolMainLoopDone is called at the end of protocolMainLoop.
+// +checklocksrelease:e.mu
+func (e *endpoint) protocolMainLoopDone(closeTimer tcpip.Timer, closeWaker *sleep.Waker) {
+ if e.snd != nil {
+ e.snd.resendTimer.cleanup()
+ e.snd.probeTimer.cleanup()
+ e.snd.reorderTimer.cleanup()
+ }
- if closeTimer != nil {
- closeTimer.Stop()
- }
+ if closeTimer != nil {
+ closeTimer.Stop()
+ }
- e.completeWorkerLocked()
+ e.completeWorkerLocked()
- if e.drainDone != nil {
- close(e.drainDone)
- }
+ if e.drainDone != nil {
+ close(e.drainDone)
+ }
- e.mu.Unlock()
+ e.mu.Unlock()
- e.drainClosingSegmentQueue()
+ e.drainClosingSegmentQueue()
- // When the protocol loop exits we should wake up our waiters.
- e.waiterQueue.Notify(waiter.EventHUp | waiter.EventErr | waiter.ReadableEvents | waiter.WritableEvents)
- }
+ // When the protocol loop exits we should wake up our waiters.
+ e.waiterQueue.Notify(waiter.EventHUp | waiter.EventErr | waiter.ReadableEvents | waiter.WritableEvents)
+}
+// protocolMainLoop is the main loop of the TCP protocol. It runs in its own
+// goroutine and is responsible for sending segments and handling received
+// segments.
+func (e *endpoint) protocolMainLoop(handshake bool, wakerInitDone chan<- struct{}) tcpip.Error {
+ var (
+ closeTimer tcpip.Timer
+ closeWaker sleep.Waker
+ )
+
+ e.mu.Lock()
if handshake {
- if err := e.h.complete(); err != nil {
+ if err := e.h.complete(); err != nil { // +checklocksforce
e.lastErrorMu.Lock()
e.lastError = err
e.lastErrorMu.Unlock()
@@ -1327,8 +1331,7 @@ func (e *endpoint) protocolMainLoop(handshake bool, wakerInitDone chan<- struct{
e.hardError = err
e.workerCleanup = true
- // Lock released below.
- epilogue()
+ e.protocolMainLoopDone(closeTimer, &closeWaker)
return err
}
}
@@ -1472,7 +1475,7 @@ func (e *endpoint) protocolMainLoop(handshake bool, wakerInitDone chan<- struct{
// Only block the worker if the endpoint
// is not in closed state or error state.
close(e.drainDone)
- e.mu.Unlock()
+ e.mu.Unlock() // +checklocksforce
<-e.undrain
e.mu.Lock()
}
@@ -1533,8 +1536,6 @@ func (e *endpoint) protocolMainLoop(handshake bool, wakerInitDone chan<- struct{
if err != nil {
e.resetConnectionLocked(err)
}
- // Lock released below.
- epilogue()
}
loop:
@@ -1558,6 +1559,7 @@ loop:
// just want to terminate the loop and cleanup the
// endpoint.
cleanupOnError(nil)
+ e.protocolMainLoopDone(closeTimer, &closeWaker)
return nil
case StateTimeWait:
fallthrough
@@ -1566,6 +1568,7 @@ loop:
default:
if err := funcs[v].f(); err != nil {
cleanupOnError(err)
+ e.protocolMainLoopDone(closeTimer, &closeWaker)
return nil
}
}
@@ -1589,13 +1592,13 @@ loop:
// Handle any StateError transition from StateTimeWait.
if e.EndpointState() == StateError {
cleanupOnError(nil)
+ e.protocolMainLoopDone(closeTimer, &closeWaker)
return nil
}
e.transitionToStateCloseLocked()
- // Lock released below.
- epilogue()
+ e.protocolMainLoopDone(closeTimer, &closeWaker)
// A new SYN was received during TIME_WAIT and we need to abort
// the timewait and redirect the segment to the listener queue
@@ -1665,6 +1668,7 @@ func (e *endpoint) handleTimeWaitSegments() (extendTimeWait bool, reuseTW func()
// should be executed after releasing the endpoint registrations. This is
// done in cases where a new SYN is received during TIME_WAIT that carries
// a sequence number larger than one see on the connection.
+// +checklocks:e.mu
func (e *endpoint) doTimeWait() (twReuse func()) {
// Trigger a 2 * MSL time wait state. During this period
// we will drop all incoming segments.
diff --git a/pkg/tcpip/transport/tcp/dispatcher.go b/pkg/tcpip/transport/tcp/dispatcher.go
index dff7cb89c..7d110516b 100644
--- a/pkg/tcpip/transport/tcp/dispatcher.go
+++ b/pkg/tcpip/transport/tcp/dispatcher.go
@@ -127,7 +127,7 @@ func (p *processor) start(wg *sync.WaitGroup) {
case !ep.segmentQueue.empty():
p.epQ.enqueue(ep)
}
- ep.mu.Unlock()
+ ep.mu.Unlock() // +checklocksforce
} else {
ep.newSegmentWaker.Assert()
}
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index 4acddc959..1ed4ba419 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -664,6 +664,7 @@ func calculateAdvertisedMSS(userMSS uint16, r *stack.Route) uint16 {
// The assumption behind spinning here being that background packet processing
// should not be holding the lock for long and spinning reduces latency as we
// avoid an expensive sleep/wakeup of of the syscall goroutine).
+// +checklocksacquire:e.mu
func (e *endpoint) LockUser() {
for {
// Try first if the sock is locked then check if it's owned
@@ -683,7 +684,7 @@ func (e *endpoint) LockUser() {
continue
}
atomic.StoreUint32(&e.ownedByUser, 1)
- return
+ return // +checklocksforce
}
}
@@ -700,7 +701,7 @@ func (e *endpoint) LockUser() {
// protocol goroutine altogether.
//
// Precondition: e.LockUser() must have been called before calling e.UnlockUser()
-// +checklocks:e.mu
+// +checklocksrelease:e.mu
func (e *endpoint) UnlockUser() {
// Lock segment queue before checking so that we avoid a race where
// segments can be queued between the time we check if queue is empty
@@ -736,12 +737,13 @@ func (e *endpoint) UnlockUser() {
}
// StopWork halts packet processing. Only to be used in tests.
+// +checklocksacquire:e.mu
func (e *endpoint) StopWork() {
e.mu.Lock()
}
// ResumeWork resumes packet processing. Only to be used in tests.
-// +checklocks:e.mu
+// +checklocksrelease:e.mu
func (e *endpoint) ResumeWork() {
e.mu.Unlock()
}
@@ -1480,86 +1482,95 @@ func (e *endpoint) isEndpointWritableLocked() (int, tcpip.Error) {
return avail, nil
}
-// Write writes data to the endpoint's peer.
-func (e *endpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, tcpip.Error) {
- // Linux completely ignores any address passed to sendto(2) for TCP sockets
- // (without the MSG_FASTOPEN flag). Corking is unimplemented, so opts.More
- // and opts.EndOfRecord are also ignored.
+// readFromPayloader reads a slice from the Payloader.
+// +checklocks:e.mu
+// +checklocks:e.sndQueueInfo.sndQueueMu
+func (e *endpoint) readFromPayloader(p tcpip.Payloader, opts tcpip.WriteOptions, avail int) ([]byte, tcpip.Error) {
+ // We can release locks while copying data.
+ //
+ // This is not possible if atomic is set, because we can't allow the
+ // available buffer space to be consumed by some other caller while we
+ // are copying data in.
+ if !opts.Atomic {
+ e.sndQueueInfo.sndQueueMu.Unlock()
+ defer e.sndQueueInfo.sndQueueMu.Lock()
- e.LockUser()
- defer e.UnlockUser()
+ e.UnlockUser()
+ defer e.LockUser()
+ }
- nextSeg, n, err := func() (*segment, int, tcpip.Error) {
- e.sndQueueInfo.sndQueueMu.Lock()
- defer e.sndQueueInfo.sndQueueMu.Unlock()
+ // Fetch data.
+ if l := p.Len(); l < avail {
+ avail = l
+ }
+ if avail == 0 {
+ return nil, nil
+ }
+ v := make([]byte, avail)
+ n, err := p.Read(v)
+ if err != nil && err != io.EOF {
+ return nil, &tcpip.ErrBadBuffer{}
+ }
+ return v[:n], nil
+}
+
+// queueSegment reads data from the payloader and returns a segment to be sent.
+// +checklocks:e.mu
+func (e *endpoint) queueSegment(p tcpip.Payloader, opts tcpip.WriteOptions) (*segment, int, tcpip.Error) {
+ e.sndQueueInfo.sndQueueMu.Lock()
+ defer e.sndQueueInfo.sndQueueMu.Unlock()
+
+ avail, err := e.isEndpointWritableLocked()
+ if err != nil {
+ e.stats.WriteErrors.WriteClosed.Increment()
+ return nil, 0, err
+ }
+ v, err := e.readFromPayloader(p, opts, avail)
+ if err != nil {
+ return nil, 0, err
+ }
+ if !opts.Atomic {
+ // Since we released locks in between it's possible that the
+ // endpoint transitioned to a CLOSED/ERROR states so make
+ // sure endpoint is still writable before trying to write.
avail, err := e.isEndpointWritableLocked()
if err != nil {
e.stats.WriteErrors.WriteClosed.Increment()
return nil, 0, err
}
- v, err := func() ([]byte, tcpip.Error) {
- // We can release locks while copying data.
- //
- // This is not possible if atomic is set, because we can't allow the
- // available buffer space to be consumed by some other caller while we
- // are copying data in.
- if !opts.Atomic {
- e.sndQueueInfo.sndQueueMu.Unlock()
- defer e.sndQueueInfo.sndQueueMu.Lock()
-
- e.UnlockUser()
- defer e.LockUser()
- }
-
- // Fetch data.
- if l := p.Len(); l < avail {
- avail = l
- }
- if avail == 0 {
- return nil, nil
- }
- v := make([]byte, avail)
- n, err := p.Read(v)
- if err != nil && err != io.EOF {
- return nil, &tcpip.ErrBadBuffer{}
- }
- return v[:n], nil
- }()
- if len(v) == 0 || err != nil {
- return nil, 0, err
+ // Discard any excess data copied in due to avail being reduced due
+ // to a simultaneous write call to the socket.
+ if avail < len(v) {
+ v = v[:avail]
}
+ }
- if !opts.Atomic {
- // Since we released locks in between it's possible that the
- // endpoint transitioned to a CLOSED/ERROR states so make
- // sure endpoint is still writable before trying to write.
- avail, err := e.isEndpointWritableLocked()
- if err != nil {
- e.stats.WriteErrors.WriteClosed.Increment()
- return nil, 0, err
- }
+ // Add data to the send queue.
+ s := newOutgoingSegment(e.TransportEndpointInfo.ID, e.stack.Clock(), v)
+ e.sndQueueInfo.SndBufUsed += len(v)
+ e.snd.writeList.PushBack(s)
- // Discard any excess data copied in due to avail being reduced due
- // to a simultaneous write call to the socket.
- if avail < len(v) {
- v = v[:avail]
- }
- }
+ return s, len(v), nil
+}
- // Add data to the send queue.
- s := newOutgoingSegment(e.TransportEndpointInfo.ID, e.stack.Clock(), v)
- e.sndQueueInfo.SndBufUsed += len(v)
- e.snd.writeList.PushBack(s)
+// Write writes data to the endpoint's peer.
+func (e *endpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, tcpip.Error) {
+ // Linux completely ignores any address passed to sendto(2) for TCP sockets
+ // (without the MSG_FASTOPEN flag). Corking is unimplemented, so opts.More
+ // and opts.EndOfRecord are also ignored.
+
+ e.LockUser()
+ defer e.UnlockUser()
- return s, len(v), nil
- }()
// Return if either we didn't queue anything or if an error occurred while
// attempting to queue data.
+ nextSeg, n, err := e.queueSegment(p, opts)
if n == 0 || err != nil {
return 0, err
}
+
e.sendData(nextSeg)
return int64(n), nil
}
@@ -2504,6 +2515,7 @@ func (e *endpoint) listen(backlog int) tcpip.Error {
// startAcceptedLoop sets up required state and starts a goroutine with the
// main loop for accepted connections.
+// +checklocksrelease:e.mu
func (e *endpoint) startAcceptedLoop() {
e.workerRunning = true
e.mu.Unlock()
diff --git a/pkg/tcpip/transport/tcp/forwarder.go b/pkg/tcpip/transport/tcp/forwarder.go
index 65c86823a..2e709ed78 100644
--- a/pkg/tcpip/transport/tcp/forwarder.go
+++ b/pkg/tcpip/transport/tcp/forwarder.go
@@ -164,8 +164,9 @@ func (r *ForwarderRequest) CreateEndpoint(queue *waiter.Queue) (tcpip.Endpoint,
return nil, err
}
- // Start the protocol goroutine.
- ep.startAcceptedLoop()
+ // Start the protocol goroutine. Note that the endpoint is returned
+ // from performHandshake locked.
+ ep.startAcceptedLoop() // +checklocksforce
return ep, nil
}
diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go
index def9d7186..82a3f2287 100644
--- a/pkg/tcpip/transport/udp/endpoint.go
+++ b/pkg/tcpip/transport/udp/endpoint.go
@@ -364,6 +364,7 @@ func (e *endpoint) Read(dst io.Writer, opts tcpip.ReadOptions) (tcpip.ReadResult
// reacquire the mutex in exclusive mode.
//
// Returns true for retry if preparation should be retried.
+// +checklocks:e.mu
func (e *endpoint) prepareForWrite(to *tcpip.FullAddress) (retry bool, err tcpip.Error) {
switch e.EndpointState() {
case StateInitial:
@@ -380,10 +381,8 @@ func (e *endpoint) prepareForWrite(to *tcpip.FullAddress) (retry bool, err tcpip
}
e.mu.RUnlock()
- defer e.mu.RLock()
-
e.mu.Lock()
- defer e.mu.Unlock()
+ defer e.mu.DowngradeLock()
// The state changed when we released the shared locked and re-acquired
// it in exclusive mode. Try again.
@@ -449,37 +448,20 @@ func (e *endpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, tcp
return n, err
}
-func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, tcpip.Error) {
- if err := e.LastError(); err != nil {
- return 0, err
- }
-
- // MSG_MORE is unimplemented. (This also means that MSG_EOR is a no-op.)
- if opts.More {
- return 0, &tcpip.ErrInvalidOptionValue{}
- }
-
- to := opts.To
-
+func (e *endpoint) buildUDPPacketInfo(p tcpip.Payloader, opts tcpip.WriteOptions) (udpPacketInfo, tcpip.Error) {
e.mu.RLock()
- lockReleased := false
- defer func() {
- if lockReleased {
- return
- }
- e.mu.RUnlock()
- }()
+ defer e.mu.RUnlock()
// If we've shutdown with SHUT_WR we are in an invalid state for sending.
if e.shutdownFlags&tcpip.ShutdownWrite != 0 {
- return 0, &tcpip.ErrClosedForSend{}
+ return udpPacketInfo{}, &tcpip.ErrClosedForSend{}
}
// Prepare for write.
for {
- retry, err := e.prepareForWrite(to)
+ retry, err := e.prepareForWrite(opts.To)
if err != nil {
- return 0, err
+ return udpPacketInfo{}, err
}
if !retry {
@@ -489,34 +471,34 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, tcp
route := e.route
dstPort := e.dstPort
- if to != nil {
+ if opts.To != nil {
// Reject destination address if it goes through a different
// NIC than the endpoint was bound to.
- nicID := to.NIC
+ nicID := opts.To.NIC
if nicID == 0 {
nicID = tcpip.NICID(e.ops.GetBindToDevice())
}
if e.BindNICID != 0 {
if nicID != 0 && nicID != e.BindNICID {
- return 0, &tcpip.ErrNoRoute{}
+ return udpPacketInfo{}, &tcpip.ErrNoRoute{}
}
nicID = e.BindNICID
}
- if to.Port == 0 {
+ if opts.To.Port == 0 {
// Port 0 is an invalid port to send to.
- return 0, &tcpip.ErrInvalidEndpointState{}
+ return udpPacketInfo{}, &tcpip.ErrInvalidEndpointState{}
}
- dst, netProto, err := e.checkV4MappedLocked(*to)
+ dst, netProto, err := e.checkV4MappedLocked(*opts.To)
if err != nil {
- return 0, err
+ return udpPacketInfo{}, err
}
r, _, err := e.connectRoute(nicID, dst, netProto)
if err != nil {
- return 0, err
+ return udpPacketInfo{}, err
}
defer r.Release()
@@ -525,12 +507,12 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, tcp
}
if !e.ops.GetBroadcast() && route.IsOutboundBroadcast() {
- return 0, &tcpip.ErrBroadcastDisabled{}
+ return udpPacketInfo{}, &tcpip.ErrBroadcastDisabled{}
}
v := make([]byte, p.Len())
if _, err := io.ReadFull(p, v); err != nil {
- return 0, &tcpip.ErrBadBuffer{}
+ return udpPacketInfo{}, &tcpip.ErrBadBuffer{}
}
if len(v) > header.UDPMaximumPacketSize {
// Payload can't possibly fit in a packet.
@@ -548,24 +530,39 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, tcp
v,
)
}
- return 0, &tcpip.ErrMessageTooLong{}
+ return udpPacketInfo{}, &tcpip.ErrMessageTooLong{}
}
ttl := e.ttl
useDefaultTTL := ttl == 0
-
if header.IsV4MulticastAddress(route.RemoteAddress()) || header.IsV6MulticastAddress(route.RemoteAddress()) {
ttl = e.multicastTTL
// Multicast allows a 0 TTL.
useDefaultTTL = false
}
- localPort := e.ID.LocalPort
- sendTOS := e.sendTOS
- owner := e.owner
- noChecksum := e.SocketOptions().GetNoChecksum()
- lockReleased = true
- e.mu.RUnlock()
+ return udpPacketInfo{
+ route: route,
+ data: buffer.View(v),
+ localPort: e.ID.LocalPort,
+ remotePort: dstPort,
+ ttl: ttl,
+ useDefaultTTL: useDefaultTTL,
+ tos: e.sendTOS,
+ owner: e.owner,
+ noChecksum: e.SocketOptions().GetNoChecksum(),
+ }, nil
+}
+
+func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, tcpip.Error) {
+ if err := e.LastError(); err != nil {
+ return 0, err
+ }
+
+ // MSG_MORE is unimplemented. (This also means that MSG_EOR is a no-op.)
+ if opts.More {
+ return 0, &tcpip.ErrInvalidOptionValue{}
+ }
// Do not hold lock when sending as loopback is synchronous and if the UDP
// datagram ends up generating an ICMP response then it can result in a
@@ -577,10 +574,15 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, tcp
//
// See: https://golang.org/pkg/sync/#RWMutex for details on why recursive read
// locking is prohibited.
- if err := sendUDP(route, buffer.View(v).ToVectorisedView(), localPort, dstPort, ttl, useDefaultTTL, sendTOS, owner, noChecksum); err != nil {
+ u, err := e.buildUDPPacketInfo(p, opts)
+ if err != nil {
return 0, err
}
- return int64(len(v)), nil
+ n, err := u.send()
+ if err != nil {
+ return 0, err
+ }
+ return int64(n), nil
}
// OnReuseAddressSet implements tcpip.SocketOptionsHandler.
@@ -817,14 +819,30 @@ func (e *endpoint) GetSockOpt(opt tcpip.GettableSocketOption) tcpip.Error {
return nil
}
-// sendUDP sends a UDP segment via the provided network endpoint and under the
-// provided identity.
-func sendUDP(r *stack.Route, data buffer.VectorisedView, localPort, remotePort uint16, ttl uint8, useDefaultTTL bool, tos uint8, owner tcpip.PacketOwner, noChecksum bool) tcpip.Error {
+// udpPacketInfo contains all information required to send a UDP packet.
+//
+// This should be used as a value-only type, which exists in order to simplify
+// return value syntax. It should not be exported or extended.
+type udpPacketInfo struct {
+ route *stack.Route
+ data buffer.View
+ localPort uint16
+ remotePort uint16
+ ttl uint8
+ useDefaultTTL bool
+ tos uint8
+ owner tcpip.PacketOwner
+ noChecksum bool
+}
+
+// send sends the given packet.
+func (u *udpPacketInfo) send() (int, tcpip.Error) {
+ vv := u.data.ToVectorisedView()
pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
- ReserveHeaderBytes: header.UDPMinimumSize + int(r.MaxHeaderLength()),
- Data: data,
+ ReserveHeaderBytes: header.UDPMinimumSize + int(u.route.MaxHeaderLength()),
+ Data: vv,
})
- pkt.Owner = owner
+ pkt.Owner = u.owner
// Initialize the UDP header.
udp := header.UDP(pkt.TransportHeader().Push(header.UDPMinimumSize))
@@ -832,8 +850,8 @@ func sendUDP(r *stack.Route, data buffer.VectorisedView, localPort, remotePort u
length := uint16(pkt.Size())
udp.Encode(&header.UDPFields{
- SrcPort: localPort,
- DstPort: remotePort,
+ SrcPort: u.localPort,
+ DstPort: u.remotePort,
Length: length,
})
@@ -841,30 +859,30 @@ func sendUDP(r *stack.Route, data buffer.VectorisedView, localPort, remotePort u
// On IPv4, UDP checksum is optional, and a zero value indicates the
// transmitter skipped the checksum generation (RFC768).
// On IPv6, UDP checksum is not optional (RFC2460 Section 8.1).
- if r.RequiresTXTransportChecksum() &&
- (!noChecksum || r.NetProto() == header.IPv6ProtocolNumber) {
- xsum := r.PseudoHeaderChecksum(ProtocolNumber, length)
- for _, v := range data.Views() {
+ if u.route.RequiresTXTransportChecksum() &&
+ (!u.noChecksum || u.route.NetProto() == header.IPv6ProtocolNumber) {
+ xsum := u.route.PseudoHeaderChecksum(ProtocolNumber, length)
+ for _, v := range vv.Views() {
xsum = header.Checksum(v, xsum)
}
udp.SetChecksum(^udp.CalculateChecksum(xsum))
}
- if useDefaultTTL {
- ttl = r.DefaultTTL()
+ if u.useDefaultTTL {
+ u.ttl = u.route.DefaultTTL()
}
- if err := r.WritePacket(stack.NetworkHeaderParams{
+ if err := u.route.WritePacket(stack.NetworkHeaderParams{
Protocol: ProtocolNumber,
- TTL: ttl,
- TOS: tos,
+ TTL: u.ttl,
+ TOS: u.tos,
}, pkt); err != nil {
- r.Stats().UDP.PacketSendErrors.Increment()
- return err
+ u.route.Stats().UDP.PacketSendErrors.Increment()
+ return 0, err
}
// Track count of packets sent.
- r.Stats().UDP.PacketsSent.Increment()
- return nil
+ u.route.Stats().UDP.PacketsSent.Increment()
+ return len(u.data), nil
}
// checkV4MappedLocked determines the effective network protocol and converts
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-25 18:34:15 +0000