nuclei/v2/pkg/protocols/http/race/syncedreadcloser.go

106 lines
2.3 KiB
Go

package race
import (
"fmt"
"io"
"io/ioutil"
"time"
)
// SyncedReadCloser is compatible with io.ReadSeeker and performs
// gate-based synced writes to enable race condition testing.
type SyncedReadCloser struct {
data []byte
p int64
length int64
opengate chan struct{}
enableBlocking bool
}
// NewSyncedReadCloser creates a new SyncedReadCloser instance.
func NewSyncedReadCloser(r io.ReadCloser) *SyncedReadCloser {
var (
s SyncedReadCloser
err error
)
s.data, err = ioutil.ReadAll(r)
if err != nil {
return nil
}
r.Close()
s.length = int64(len(s.data))
s.opengate = make(chan struct{})
s.enableBlocking = true
return &s
}
// NewOpenGateWithTimeout creates a new open gate with a timeout
func NewOpenGateWithTimeout(r io.ReadCloser, d time.Duration) *SyncedReadCloser {
s := NewSyncedReadCloser(r)
s.OpenGateAfter(d)
return s
}
// SetOpenGate sets the status of the blocking gate
func (s *SyncedReadCloser) SetOpenGate(status bool) {
s.enableBlocking = status
}
// OpenGate opens the gate allowing all requests to be completed
func (s *SyncedReadCloser) OpenGate() {
s.opengate <- struct{}{}
}
// OpenGateAfter schedules gate to be opened after a duration
func (s *SyncedReadCloser) OpenGateAfter(d time.Duration) {
time.AfterFunc(d, func() {
s.opengate <- struct{}{}
})
}
// Seek implements seek method for io.ReadSeeker
func (s *SyncedReadCloser) Seek(offset int64, whence int) (int64, error) {
var err error
switch whence {
case io.SeekStart:
s.p = 0
case io.SeekCurrent:
if s.p+offset < s.length {
s.p += offset
break
}
err = fmt.Errorf("offset is too big")
case io.SeekEnd:
if s.length-offset >= 0 {
s.p = s.length - offset
break
}
err = fmt.Errorf("offset is too big")
}
return s.p, err
}
// Read implements read method for io.ReadSeeker
func (s *SyncedReadCloser) Read(p []byte) (n int, err error) {
// If the data fits in the buffer blocks awaiting the sync instruction
if s.p+int64(len(p)) >= s.length && s.enableBlocking {
<-s.opengate
}
n = copy(p, s.data[s.p:])
s.p += int64(n)
if s.p == s.length {
err = io.EOF
}
return n, err
}
// Close implements close method for io.ReadSeeker
func (s *SyncedReadCloser) Close() error {
return nil
}
// Len returns the length of data in reader
func (s *SyncedReadCloser) Len() int {
return int(s.length)
}