bughz/glider
1
0
Fork 0
mirror of https://github.com/nadoo/glider.git synced 2025-11-04 15:52:38 +08:00
Code Issues Actions Packages Projects Releases Wiki Activity

dns: parse answers only when query type is A or AAAA

Browse Source
This commit is contained in:
nadoo 2018-01-05 12:29:06 +08:00
parent 8e8361bc42
commit 52a1c35b01
1 changed files with 7 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
dns.go
View File

@ -139,7 +139,8 @@ func (s *DNS) ListenAndServe() {
// SEE RFC1035, section 4.2.2 TCP: The message is prefixed with a two byte length field which gives the message length, excluding the two byte length field.
if respLen > 0 {
query := parseQuery(respMsg)
if len(respMsg) > query.Offset {
if (query.QueryType == DNSQueryTypeA || query.QueryType == DNSQueryTypeAAAA) &&
len(respMsg) > query.Offset {
answers := parseAnswers(respMsg[query.Offset:])
for _, answer := range answers {
if answer.IP != "" {
@ -160,7 +161,7 @@ func (s *DNS) ListenAndServe() {
}
}
logf("proxy-dns %s <-> %s, %s: %s", clientAddr.String(), dnsServer, domain, ip)
logf("proxy-dns %s <-> %s, type: %d, %s: %s", clientAddr.String(), dnsServer, query.QueryType, domain, ip)
}()
}
@ -231,6 +232,10 @@ func parseAnswers(p []byte) []*dnsAnswer {
}
answer := &dnsAnswer{}
// https://tools.ietf.org/html/rfc1035#section-4.1.4
// i+2 assumes the ANSWER always using "Message compression", start with 2 bytes offset of the query domain.
// TODO: check here
answer.QueryType = binary.BigEndian.Uint16(p[i+2:])
answer.QueryClass = binary.BigEndian.Uint16(p[i+4:])
answer.TTL = binary.BigEndian.Uint32(p[i+6:])