59 lines
998 B
Go
59 lines
998 B
Go
package seccomp
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import (
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"os"
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"runtime"
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"sync"
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)
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type exporter struct {
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opts SyscallOpts
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r, w *os.File
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prepareOnce sync.Once
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prepareErr error
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closeOnce sync.Once
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closeErr error
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exportErr <-chan error
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}
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func (e *exporter) prepare() error {
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e.prepareOnce.Do(func() {
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if r, w, err := os.Pipe(); err != nil {
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e.prepareErr = err
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return
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} else {
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e.r, e.w = r, w
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}
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ec := make(chan error, 1)
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go func(fd uintptr) {
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ec <- buildFilter(int(fd), e.opts)
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close(ec)
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_ = e.closeWrite()
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runtime.KeepAlive(e.w)
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}(e.w.Fd())
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e.exportErr = ec
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runtime.SetFinalizer(e, (*exporter).closeWrite)
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})
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return e.prepareErr
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}
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func (e *exporter) closeWrite() error {
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e.closeOnce.Do(func() {
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if e.w == nil {
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panic("closeWrite called on invalid exporter")
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}
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e.closeErr = e.w.Close()
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// no need for a finalizer anymore
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runtime.SetFinalizer(e, nil)
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})
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return e.closeErr
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}
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func newExporter(opts SyscallOpts) *exporter {
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return &exporter{opts: opts}
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}
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