mirror of
https://github.com/amigan/aim-oscar-server.git
synced 2024-11-21 03:59:47 -05:00
115 lines
2.4 KiB
Go
115 lines
2.4 KiB
Go
package oscar
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import (
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"aim-oscar/util"
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"encoding"
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"encoding/binary"
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"fmt"
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"io"
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"github.com/pkg/errors"
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)
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var _ encoding.BinaryUnmarshaler = &TLV{}
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var _ encoding.BinaryMarshaler = &TLV{}
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type TLV struct {
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Type uint16
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DataLength uint16
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Data []byte
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}
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func NewTLV(tlvType uint16, data []byte) *TLV {
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return &TLV{
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Type: tlvType,
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DataLength: uint16(len(data)),
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Data: data,
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}
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}
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func (t *TLV) Len() int {
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return 4 + int(t.DataLength)
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}
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func (t *TLV) MarshalBinary() ([]byte, error) {
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buf := make([]byte, 4+t.DataLength)
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binary.BigEndian.PutUint16(buf[:2], t.Type)
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binary.BigEndian.PutUint16(buf[2:4], t.DataLength)
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copy(buf[4:], t.Data)
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return buf, nil
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}
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func (t *TLV) UnmarshalBinary(data []byte) error {
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if len(data) < 4 {
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return io.ErrUnexpectedEOF
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}
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t.Type = binary.BigEndian.Uint16(data[:2])
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t.DataLength = binary.BigEndian.Uint16(data[2:4])
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if len(data) < 4+int(t.DataLength) {
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return io.ErrUnexpectedEOF
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}
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t.Data = make([]byte, int(t.DataLength))
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copy(t.Data, data[4:4+int(t.DataLength)])
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return nil
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}
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func (t *TLV) String() string {
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return fmt.Sprintf("TLV(%#x):\n%s", t.Type, util.PrettyBytes(t.Data))
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}
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func UnmarshalTLVs(data []byte) ([]*TLV, error) {
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tlvs := make([]*TLV, 0)
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d := make([]byte, len(data))
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copy(d, data)
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for len(d) > 0 {
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tlv := &TLV{}
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if err := tlv.UnmarshalBinary(d); err != nil {
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return nil, errors.Wrap(err, "enexpected end to unmarshalling TLVs")
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}
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tlvs = append(tlvs, tlv)
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d = d[tlv.Len():]
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}
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return tlvs, nil
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}
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func FindTLV(tlvs []*TLV, tlvType uint16) *TLV {
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for _, tlv := range tlvs {
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if tlv.Type == tlvType {
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return tlv
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}
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}
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return nil
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}
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// type TLVReader struct {
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// buf []byte
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// pos int
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// }
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// func (r *TLVReader) ReadNextTLV() (*TLV, error) {
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// if len(r.buf) < 4 {
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// return nil, io.ErrUnexpectedEOF
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// }
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// t := &TLV{}
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// t.Type = Word(r.buf[r.pos:r.pos+2])
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// r.pos = r.pos + 2
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// t.DataLength = Word(r.buf[r.pos : r.pos+2])
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// r.pos = r.pos + 2
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// copy(p[2:4], r.buf[r.pos:r.pos+2])
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// r.pos = r.pos + 2
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// // If there is not enough space to write the expected amount of data, error
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// if dataLength > len(p)+4 {
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// return 0, io.ErrUnexpectedEOF
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// }
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// n = n + copy(p[4:dataLength], r.buf[r.pos:r.pos+dataLength])
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// r.pos = r.pos + dataLength
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// return n, nil
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// }
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// func NewTLVReader(data []byte) *TLVReader {
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// return &TLVReader{buf: data, pos: 0}
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// }
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