open-nomad/vendor/github.com/miekg/dns/format.go
Seth Hoenig 435c0d9fc8 deps: Switch to Go modules for dependency management
This PR switches the Nomad repository from using govendor to Go modules
for managing dependencies. Aspects of the Nomad workflow remain pretty
much the same. The usual Makefile targets should continue to work as
they always did. The API submodule simply defers to the parent Nomad
version on the repository, keeping the semantics of API versioning that
currently exists.
2020-06-02 14:30:36 -05:00

94 lines
2.4 KiB
Go

package dns
import (
"net"
"reflect"
"strconv"
)
// NumField returns the number of rdata fields r has.
func NumField(r RR) int {
return reflect.ValueOf(r).Elem().NumField() - 1 // Remove RR_Header
}
// Field returns the rdata field i as a string. Fields are indexed starting from 1.
// RR types that holds slice data, for instance the NSEC type bitmap will return a single
// string where the types are concatenated using a space.
// Accessing non existing fields will cause a panic.
func Field(r RR, i int) string {
if i == 0 {
return ""
}
d := reflect.ValueOf(r).Elem().Field(i)
switch d.Kind() {
case reflect.String:
return d.String()
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return strconv.FormatInt(d.Int(), 10)
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
return strconv.FormatUint(d.Uint(), 10)
case reflect.Slice:
switch reflect.ValueOf(r).Elem().Type().Field(i).Tag {
case `dns:"a"`:
// TODO(miek): Hmm store this as 16 bytes
if d.Len() < net.IPv4len {
return ""
}
if d.Len() < net.IPv6len {
return net.IPv4(byte(d.Index(0).Uint()),
byte(d.Index(1).Uint()),
byte(d.Index(2).Uint()),
byte(d.Index(3).Uint())).String()
}
return net.IPv4(byte(d.Index(12).Uint()),
byte(d.Index(13).Uint()),
byte(d.Index(14).Uint()),
byte(d.Index(15).Uint())).String()
case `dns:"aaaa"`:
if d.Len() < net.IPv6len {
return ""
}
return net.IP{
byte(d.Index(0).Uint()),
byte(d.Index(1).Uint()),
byte(d.Index(2).Uint()),
byte(d.Index(3).Uint()),
byte(d.Index(4).Uint()),
byte(d.Index(5).Uint()),
byte(d.Index(6).Uint()),
byte(d.Index(7).Uint()),
byte(d.Index(8).Uint()),
byte(d.Index(9).Uint()),
byte(d.Index(10).Uint()),
byte(d.Index(11).Uint()),
byte(d.Index(12).Uint()),
byte(d.Index(13).Uint()),
byte(d.Index(14).Uint()),
byte(d.Index(15).Uint()),
}.String()
case `dns:"nsec"`:
if d.Len() == 0 {
return ""
}
s := Type(d.Index(0).Uint()).String()
for i := 1; i < d.Len(); i++ {
s += " " + Type(d.Index(i).Uint()).String()
}
return s
default:
// if it does not have a tag its a string slice
fallthrough
case `dns:"txt"`:
if d.Len() == 0 {
return ""
}
s := d.Index(0).String()
for i := 1; i < d.Len(); i++ {
s += " " + d.Index(i).String()
}
return s
}
}
return ""
}