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caddy/vendor/github.com/miekg/dns/rawmsg.go
Matthew Holt 6fde3632ef
Vendor all dependencies (Warning: Huge changeset.)
The vendor/ folder was created with the help of @FiloSottile's gvt and
vendorcheck.

Any dependencies of Caddy plugins outside this repo are not vendored.

We do not remove any unused, vendored packages because vendorcheck -u
only checks using the current build configuration; i.e. packages that
may be imported by files toggled by build tags of other systems.

CI tests have been updated to ignore the vendor/ folder. When Go 1.9 is
released, a few of the go commands should be revised to again use ./...
as it will ignore the vendor folder by default.
2017-05-27 13:30:11 -06:00

49 lines
1.1 KiB
Go

package dns
import "encoding/binary"
// rawSetRdlength sets the rdlength in the header of
// the RR. The offset 'off' must be positioned at the
// start of the header of the RR, 'end' must be the
// end of the RR.
func rawSetRdlength(msg []byte, off, end int) bool {
l := len(msg)
Loop:
for {
if off+1 > l {
return false
}
c := int(msg[off])
off++
switch c & 0xC0 {
case 0x00:
if c == 0x00 {
// End of the domainname
break Loop
}
if off+c > l {
return false
}
off += c
case 0xC0:
// pointer, next byte included, ends domainname
off++
break Loop
}
}
// The domainname has been seen, we at the start of the fixed part in the header.
// Type is 2 bytes, class is 2 bytes, ttl 4 and then 2 bytes for the length.
off += 2 + 2 + 4
if off+2 > l {
return false
}
//off+1 is the end of the header, 'end' is the end of the rr
//so 'end' - 'off+2' is the length of the rdata
rdatalen := end - (off + 2)
if rdatalen > 0xFFFF {
return false
}
binary.BigEndian.PutUint16(msg[off:], uint16(rdatalen))
return true
}