coredns/plugin/loop/setup.go
Miek Gieben 5f41d8eb1f
reverse zone: fix Normalize (#4621)
Make normalize return multiple "hosts" (= reverse zones) when a
non-octet boundary cidr is given.

Added pkg/cidr package that holds the cidr calculation routines; felt
they didn't really fit dnsutil.

This change means the IPNet return parameter isn't needed, the hosts are
all correct. The tests that tests this is also removed: TestSplitHostPortReverse
The fallout was that zoneAddr _also_ doesn't need the IPNet member, that
in turn make it visible that zoneAddr in address.go duplicated a bunch
of stuff from register.go; removed/refactored that too.

Created a plugin.OriginsFromArgsOrServerBlock to help plugins do the
right things, by consuming ZONE arguments; this now expands reverse
zones correctly. This is mostly mechanical.

Remove the reverse test in plugin/kubernetes which is a copy-paste from
a core test (which has since been fixed).

Remove MustNormalize as it has no plugin users.

This change is not backwards compatible to plugins that have a ZONE
argument that they parse in the setup util.

All in-tree plugins have been updated.

Signed-off-by: Miek Gieben <miek@miek.nl>
2021-05-17 13:19:54 -07:00

87 lines
1.7 KiB
Go

package loop
import (
"math/rand"
"net"
"strconv"
"time"
"github.com/coredns/caddy"
"github.com/coredns/coredns/core/dnsserver"
"github.com/coredns/coredns/plugin"
"github.com/coredns/coredns/plugin/pkg/dnsutil"
)
func init() { plugin.Register("loop", setup) }
func setup(c *caddy.Controller) error {
l, err := parse(c)
if err != nil {
return plugin.Error("loop", err)
}
dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
l.Next = next
return l
})
// Send query to ourselves and see if it end up with us again.
c.OnStartup(func() error {
// Another Go function, otherwise we block startup and can't send the packet.
go func() {
deadline := time.Now().Add(30 * time.Second)
conf := dnsserver.GetConfig(c)
lh := conf.ListenHosts[0]
addr := net.JoinHostPort(lh, conf.Port)
for time.Now().Before(deadline) {
l.setAddress(addr)
if _, err := l.exchange(addr); err != nil {
l.reset()
time.Sleep(1 * time.Second)
continue
}
go func() {
time.Sleep(2 * time.Second)
l.setDisabled()
}()
break
}
l.setDisabled()
}()
return nil
})
return nil
}
func parse(c *caddy.Controller) (*Loop, error) {
i := 0
zones := []string{"."}
for c.Next() {
if i > 0 {
return nil, plugin.ErrOnce
}
i++
if c.NextArg() {
return nil, c.ArgErr()
}
if len(c.ServerBlockKeys) > 0 {
zones = plugin.Host(c.ServerBlockKeys[0]).Normalize()
}
}
return New(zones[0]), nil
}
// qname returns a random name. <rand.Int()>.<rand.Int().<zone>.
func qname(zone string) string {
l1 := strconv.Itoa(r.Int())
l2 := strconv.Itoa(r.Int())
return dnsutil.Join(l1, l2, zone)
}
var r = rand.New(rand.NewSource(time.Now().UnixNano()))