diff options
Diffstat (limited to 'pkg/tcpip/network/fragmentation')
| -rw-r--r-- | pkg/tcpip/network/fragmentation/fragmentation.go | 28 | ||||
| -rw-r--r-- | pkg/tcpip/network/fragmentation/fragmentation_test.go | 104 | ||||
| -rw-r--r-- | pkg/tcpip/network/fragmentation/reassembler.go | 22 | ||||
| -rw-r--r-- | pkg/tcpip/network/fragmentation/reassembler_test.go | 23 |
4 files changed, 162 insertions, 15 deletions
diff --git a/pkg/tcpip/network/fragmentation/fragmentation.go b/pkg/tcpip/network/fragmentation/fragmentation.go index bb31ef61a..936601287 100644 --- a/pkg/tcpip/network/fragmentation/fragmentation.go +++ b/pkg/tcpip/network/fragmentation/fragmentation.go @@ -136,8 +136,16 @@ func NewFragmentation(blockSize uint16, highMemoryLimit, lowMemoryLimit int, rea // proto is the protocol number marked in the fragment being processed. It has // to be given here outside of the FragmentID struct because IPv6 should not use // the protocol to identify a fragment. +// +// releaseCB is a callback that will run when the fragment reassembly of a +// packet is complete or cancelled. releaseCB take a a boolean argument which is +// true iff the reassembly is cancelled due to timeout. releaseCB should be +// passed only with the first fragment of a packet. If more than one releaseCB +// are passed for the same packet, only the first releaseCB will be saved for +// the packet and the succeeding ones will be dropped by running them +// immediately with a false argument. func (f *Fragmentation) Process( - id FragmentID, first, last uint16, more bool, proto uint8, vv buffer.VectorisedView) ( + id FragmentID, first, last uint16, more bool, proto uint8, vv buffer.VectorisedView, releaseCB func(bool)) ( buffer.VectorisedView, uint8, bool, error) { if first > last { return buffer.VectorisedView{}, 0, false, fmt.Errorf("first=%d is greater than last=%d: %w", first, last, ErrInvalidArgs) @@ -171,6 +179,12 @@ func (f *Fragmentation) Process( f.releaseReassemblersLocked() } } + if releaseCB != nil { + if !r.setCallback(releaseCB) { + // We got a duplicate callback. Release it immediately. + releaseCB(false /* timedOut */) + } + } f.mu.Unlock() res, firstFragmentProto, done, consumed, err := r.process(first, last, more, proto, vv) @@ -178,14 +192,14 @@ func (f *Fragmentation) Process( // We probably got an invalid sequence of fragments. Just // discard the reassembler and move on. f.mu.Lock() - f.release(r) + f.release(r, false /* timedOut */) f.mu.Unlock() return buffer.VectorisedView{}, 0, false, fmt.Errorf("fragmentation processing error: %w", err) } f.mu.Lock() f.size += consumed if done { - f.release(r) + f.release(r, false /* timedOut */) } // Evict reassemblers if we are consuming more memory than highLimit until // we reach lowLimit. @@ -195,14 +209,14 @@ func (f *Fragmentation) Process( if tail == nil { break } - f.release(tail) + f.release(tail, false /* timedOut */) } } f.mu.Unlock() return res, firstFragmentProto, done, nil } -func (f *Fragmentation) release(r *reassembler) { +func (f *Fragmentation) release(r *reassembler, timedOut bool) { // Before releasing a fragment we need to check if r is already marked as done. // Otherwise, we would delete it twice. if r.checkDoneOrMark() { @@ -216,6 +230,8 @@ func (f *Fragmentation) release(r *reassembler) { log.Printf("memory counter < 0 (%d), this is an accounting bug that requires investigation", f.size) f.size = 0 } + + r.release(timedOut) // releaseCB may run. } // releaseReassemblersLocked releases already-expired reassemblers, then @@ -238,7 +254,7 @@ func (f *Fragmentation) releaseReassemblersLocked() { break } // If the oldest reassembler has already expired, release it. - f.release(r) + f.release(r, true /* timedOut*/) } } diff --git a/pkg/tcpip/network/fragmentation/fragmentation_test.go b/pkg/tcpip/network/fragmentation/fragmentation_test.go index a1eb1e243..5dcd10730 100644 --- a/pkg/tcpip/network/fragmentation/fragmentation_test.go +++ b/pkg/tcpip/network/fragmentation/fragmentation_test.go @@ -105,7 +105,7 @@ func TestFragmentationProcess(t *testing.T) { f := NewFragmentation(minBlockSize, 1024, 512, reassembleTimeout, &faketime.NullClock{}) firstFragmentProto := c.in[0].proto for i, in := range c.in { - vv, proto, done, err := f.Process(in.id, in.first, in.last, in.more, in.proto, in.vv) + vv, proto, done, err := f.Process(in.id, in.first, in.last, in.more, in.proto, in.vv, nil) if err != nil { t.Fatalf("f.Process(%+v, %d, %d, %t, %d, %X) failed: %s", in.id, in.first, in.last, in.more, in.proto, in.vv.ToView(), err) @@ -240,7 +240,7 @@ func TestReassemblingTimeout(t *testing.T) { for _, event := range test.events { clock.Advance(event.clockAdvance) if frag := event.fragment; frag != nil { - _, _, done, err := f.Process(FragmentID{}, frag.first, frag.last, frag.more, protocol, vv(len(frag.data), frag.data)) + _, _, done, err := f.Process(FragmentID{}, frag.first, frag.last, frag.more, protocol, vv(len(frag.data), frag.data), nil) if err != nil { t.Fatalf("%s: f.Process failed: %s", event.name, err) } @@ -259,15 +259,15 @@ func TestReassemblingTimeout(t *testing.T) { func TestMemoryLimits(t *testing.T) { f := NewFragmentation(minBlockSize, 3, 1, reassembleTimeout, &faketime.NullClock{}) // Send first fragment with id = 0. - f.Process(FragmentID{ID: 0}, 0, 0, true, 0xFF, vv(1, "0")) + f.Process(FragmentID{ID: 0}, 0, 0, true, 0xFF, vv(1, "0"), nil) // Send first fragment with id = 1. - f.Process(FragmentID{ID: 1}, 0, 0, true, 0xFF, vv(1, "1")) + f.Process(FragmentID{ID: 1}, 0, 0, true, 0xFF, vv(1, "1"), nil) // Send first fragment with id = 2. - f.Process(FragmentID{ID: 2}, 0, 0, true, 0xFF, vv(1, "2")) + f.Process(FragmentID{ID: 2}, 0, 0, true, 0xFF, vv(1, "2"), nil) // Send first fragment with id = 3. This should caused id = 0 and id = 1 to be // evicted. - f.Process(FragmentID{ID: 3}, 0, 0, true, 0xFF, vv(1, "3")) + f.Process(FragmentID{ID: 3}, 0, 0, true, 0xFF, vv(1, "3"), nil) if _, ok := f.reassemblers[FragmentID{ID: 0}]; ok { t.Errorf("Memory limits are not respected: id=0 has not been evicted.") @@ -283,9 +283,9 @@ func TestMemoryLimits(t *testing.T) { func TestMemoryLimitsIgnoresDuplicates(t *testing.T) { f := NewFragmentation(minBlockSize, 1, 0, reassembleTimeout, &faketime.NullClock{}) // Send first fragment with id = 0. - f.Process(FragmentID{}, 0, 0, true, 0xFF, vv(1, "0")) + f.Process(FragmentID{}, 0, 0, true, 0xFF, vv(1, "0"), nil) // Send the same packet again. - f.Process(FragmentID{}, 0, 0, true, 0xFF, vv(1, "0")) + f.Process(FragmentID{}, 0, 0, true, 0xFF, vv(1, "0"), nil) got := f.size want := 1 @@ -377,7 +377,7 @@ func TestErrors(t *testing.T) { for _, test := range tests { t.Run(test.name, func(t *testing.T) { f := NewFragmentation(test.blockSize, HighFragThreshold, LowFragThreshold, reassembleTimeout, &faketime.NullClock{}) - _, _, done, err := f.Process(FragmentID{}, test.first, test.last, test.more, 0, vv(len(test.data), test.data)) + _, _, done, err := f.Process(FragmentID{}, test.first, test.last, test.more, 0, vv(len(test.data), test.data), nil) if !errors.Is(err, test.err) { t.Errorf("got Process(_, %d, %d, %t, _, %q) = (_, _, _, %v), want = (_, _, _, %v)", test.first, test.last, test.more, test.data, err, test.err) } @@ -497,3 +497,89 @@ func TestPacketFragmenter(t *testing.T) { }) } } + +func TestReleaseCallback(t *testing.T) { + const ( + proto = 99 + ) + + var result int + var callbackReasonIsTimeout bool + cb1 := func(timedOut bool) { result = 1; callbackReasonIsTimeout = timedOut } + cb2 := func(timedOut bool) { result = 2; callbackReasonIsTimeout = timedOut } + + tests := []struct { + name string + callbacks []func(bool) + timeout bool + wantResult int + wantCallbackReasonIsTimeout bool + }{ + { + name: "callback runs on release", + callbacks: []func(bool){cb1}, + timeout: false, + wantResult: 1, + wantCallbackReasonIsTimeout: false, + }, + { + name: "first callback is nil", + callbacks: []func(bool){nil, cb2}, + timeout: false, + wantResult: 2, + wantCallbackReasonIsTimeout: false, + }, + { + name: "two callbacks - first one is set", + callbacks: []func(bool){cb1, cb2}, + timeout: false, + wantResult: 1, + wantCallbackReasonIsTimeout: false, + }, + { + name: "callback runs on timeout", + callbacks: []func(bool){cb1}, + timeout: true, + wantResult: 1, + wantCallbackReasonIsTimeout: true, + }, + { + name: "no callbacks", + callbacks: []func(bool){nil}, + timeout: false, + wantResult: 0, + wantCallbackReasonIsTimeout: false, + }, + } + + id := FragmentID{ID: 0} + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + result = 0 + callbackReasonIsTimeout = false + + f := NewFragmentation(minBlockSize, HighFragThreshold, LowFragThreshold, reassembleTimeout, &faketime.NullClock{}) + + for i, cb := range test.callbacks { + _, _, _, err := f.Process(id, uint16(i), uint16(i), true, proto, vv(1, "0"), cb) + if err != nil { + t.Errorf("f.Process error = %s", err) + } + } + + r, ok := f.reassemblers[id] + if !ok { + t.Fatalf("Reassemberr not found") + } + f.release(r, test.timeout) + + if result != test.wantResult { + t.Errorf("got result = %d, want = %d", result, test.wantResult) + } + if callbackReasonIsTimeout != test.wantCallbackReasonIsTimeout { + t.Errorf("got callbackReasonIsTimeout = %t, want = %t", callbackReasonIsTimeout, test.wantCallbackReasonIsTimeout) + } + }) + } +} diff --git a/pkg/tcpip/network/fragmentation/reassembler.go b/pkg/tcpip/network/fragmentation/reassembler.go index 9bb051a30..c0cc0bde0 100644 --- a/pkg/tcpip/network/fragmentation/reassembler.go +++ b/pkg/tcpip/network/fragmentation/reassembler.go @@ -41,6 +41,7 @@ type reassembler struct { heap fragHeap done bool creationTime int64 + callback func(bool) } func newReassembler(id FragmentID, clock tcpip.Clock) *reassembler { @@ -123,3 +124,24 @@ func (r *reassembler) checkDoneOrMark() bool { r.mu.Unlock() return prev } + +func (r *reassembler) setCallback(c func(bool)) bool { + r.mu.Lock() + defer r.mu.Unlock() + if r.callback != nil { + return false + } + r.callback = c + return true +} + +func (r *reassembler) release(timedOut bool) { + r.mu.Lock() + callback := r.callback + r.callback = nil + r.mu.Unlock() + + if callback != nil { + callback(timedOut) + } +} diff --git a/pkg/tcpip/network/fragmentation/reassembler_test.go b/pkg/tcpip/network/fragmentation/reassembler_test.go index a0a04a027..fa2a70dc8 100644 --- a/pkg/tcpip/network/fragmentation/reassembler_test.go +++ b/pkg/tcpip/network/fragmentation/reassembler_test.go @@ -105,3 +105,26 @@ func TestUpdateHoles(t *testing.T) { } } } + +func TestSetCallback(t *testing.T) { + result := 0 + reasonTimeout := false + + cb1 := func(timedOut bool) { result = 1; reasonTimeout = timedOut } + cb2 := func(timedOut bool) { result = 2; reasonTimeout = timedOut } + + r := newReassembler(FragmentID{}, &faketime.NullClock{}) + if !r.setCallback(cb1) { + t.Errorf("setCallback failed") + } + if r.setCallback(cb2) { + t.Errorf("setCallback should fail if one is already set") + } + r.release(true) + if result != 1 { + t.Errorf("got result = %d, want = 1", result) + } + if !reasonTimeout { + t.Errorf("got reasonTimeout = %t, want = true", reasonTimeout) + } +} |