dns: check bytes length in unmarshal message

This commit is contained in:
nadoo 2018-08-06 08:03:07 +08:00
parent 5467e4bbc1
commit b27f153426
2 changed files with 9 additions and 0 deletions

View File

@ -134,6 +134,7 @@ func (c *Client) exchange(qname string, reqBytes []byte, preferTCP bool) (server
if err == nil {
break
}
log.F("[dns] failed to exchange with server %v: %v", server, err)
}

View File

@ -119,6 +119,10 @@ func (m *Message) Marshal() ([]byte, error) {
// UnmarshalMessage unmarshals []bytes to Message
func UnmarshalMessage(b []byte) (*Message, error) {
if len(b) <= 2+HeaderLen {
return nil, errors.New("UnmarshalMessage: not enough data")
}
m := &Message{unMarshaled: b}
err := UnmarshalHeader(b[:HeaderLen], &m.Header)
if err != nil {
@ -280,6 +284,10 @@ func (m *Message) UnmarshalQuestion(b []byte, q *Question) (n int, err error) {
return 0, errors.New("unmarshal question must not be nil")
}
if len(b) <= 5 {
return 0, errors.New("UnmarshalQuestion: not enough data")
}
domain, idx, err := m.UnmarshalDomain(b)
if err != nil {
return 0, err