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fuzzzz

This commit is contained in:
Miek Gieben 2015-07-27 21:48:46 +01:00
parent fcf516f280
commit 14e381d23e
1 changed files with 42 additions and 13 deletions
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55
msg.go
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@ -1691,17 +1691,26 @@ func (dns *Msg) Unpack(msg []byte) (err error) {
dns.CheckingDisabled = (dh.Bits & _CD) != 0
dns.Rcode = int(dh.Bits & 0xF)
// Arrays.
dns.Question = make([]Question, dh.Qdcount)
dns.Answer = make([]RR, dh.Ancount)
dns.Ns = make([]RR, dh.Nscount)
dns.Extra = make([]RR, dh.Arcount)
// Don't pre-alloc these arrays, the incoming lengths are from the network.
dns.Question = make([]Question, 0, 1)
dns.Answer = make([]RR, 0, 10)
dns.Ns = make([]RR, 0, 10)
dns.Extra = make([]RR, 0, 10)
for i := 0; i < len(dns.Question); i++ {
off, err = UnpackStruct(&dns.Question[i], msg, off)
var q Question
for i := 0; i < int(dh.Qdcount); i++ {
off1 := off
off, err = UnpackStruct(&q, msg, off)
if err != nil {
return err
}
if off1 == off { // Offset does not increase anymore, dh.Qdcount is a lie!
dh.Qdcount = uint16(i)
break
}
dns.Question = append(dns.Question, q)
}
// If we see a TC bit being set we return here, without
// an error, because technically it isn't an error. So return
@ -1713,23 +1722,43 @@ func (dns *Msg) Unpack(msg []byte) (err error) {
dns.Extra = nil
return nil
}
for i := 0; i < len(dns.Answer); i++ {
dns.Answer[i], off, err = UnpackRR(msg, off)
var r RR
for i := 0; i < int(dh.Ancount); i++ {
off1 := off
r, off, err = UnpackRR(msg, off)
if err != nil {
return err
}
if off1 == off { // Offset does not increase anymore, dh.Ancount is a lie!
dh.Ancount = uint16(i)
break
}
dns.Answer = append(dns.Answer, r)
}
for i := 0; i < len(dns.Ns); i++ {
dns.Ns[i], off, err = UnpackRR(msg, off)
for i := 0; i < int(dh.Nscount); i++ {
off1 := off
r, off, err = UnpackRR(msg, off)
if err != nil {
return err
}
if off1 == off { // Offset does not increase anymore, dh.Nscount is a lie!
dh.Nscount = uint16(i)
break
}
dns.Ns = append(dns.Ns, r)
}
for i := 0; i < len(dns.Extra); i++ {
dns.Extra[i], off, err = UnpackRR(msg, off)
for i := 0; i < int(dh.Arcount); i++ {
off1 := off
r, off, err = UnpackRR(msg, off)
if err != nil {
return err
}
if off1 == off { // Offset does not increase anymore, dh.Arcount is a lie!
dh.Arcount = uint16(i)
break
}
dns.Extra = append(dns.Extra, r)
}
if off != len(msg) {
// TODO(miek) make this an error?