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package nftables_test
import (
"fmt"
"log"
"net"
"sync"
"sync/atomic"
"testing"
"github.com/google/nftables"
"github.com/google/nftables/expr"
"github.com/google/nftables/internal/nftest"
)
func ExampleNewMonitor() {
conn, err := nftables.New()
if err != nil {
log.Fatal(err)
}
mon := nftables.NewMonitor()
defer mon.Close()
events, err := conn.AddMonitor(mon)
if err != nil {
log.Fatal(err)
}
for ev := range events {
log.Printf("ev: %+v, data = %T", ev, ev.Data)
switch ev.Type {
case nftables.MonitorEventTypeNewTable:
log.Printf("data = %+v", ev.Data.(*nftables.Table))
// …more cases if needed…
}
}
}
func TestMonitor(t *testing.T) {
// Create a new network namespace to test these operations,
// and tear down the namespace at test completion.
c, newNS := nftest.OpenSystemConn(t, *enableSysTests)
defer nftest.CleanupSystemConn(t, newNS)
// Clear all rules at the beginning + end of the test.
c.FlushRuleset()
defer c.FlushRuleset()
// default to monitor all
monitor := nftables.NewMonitor()
events, err := c.AddMonitor(monitor)
if err != nil {
t.Fatal(err)
}
defer monitor.Close()
var gotTable *nftables.Table
var gotChain *nftables.Chain
var gotRule *nftables.Rule
wg := sync.WaitGroup{}
wg.Add(1)
go func() {
defer wg.Done()
count := int32(0)
for {
select {
case event, ok := <-events:
if !ok {
return
}
if event.Error != nil {
err = fmt.Errorf("monitor err: %s", event.Error)
return
}
switch event.Type {
case nftables.MonitorEventTypeNewTable:
gotTable = event.Data.(*nftables.Table)
atomic.AddInt32(&count, 1)
case nftables.MonitorEventTypeNewChain:
gotChain = event.Data.(*nftables.Chain)
atomic.AddInt32(&count, 1)
case nftables.MonitorEventTypeNewRule:
gotRule = event.Data.(*nftables.Rule)
atomic.AddInt32(&count, 1)
}
if atomic.LoadInt32(&count) == 3 {
return
}
}
}
}()
nat := c.AddTable(&nftables.Table{
Family: nftables.TableFamilyIPv4,
Name: "nat",
})
postrouting := c.AddChain(&nftables.Chain{
Name: "postrouting",
Hooknum: nftables.ChainHookPostrouting,
Priority: nftables.ChainPriorityNATSource,
Table: nat,
Type: nftables.ChainTypeNAT,
})
rule := c.AddRule(&nftables.Rule{
Table: nat,
Chain: postrouting,
Exprs: []expr.Any{
// payload load 4b @ network header + 12 => reg 1
&expr.Payload{
DestRegister: 1,
Base: expr.PayloadBaseNetworkHeader,
Offset: 12,
Len: 4,
},
// cmp eq reg 1 0x0245a8c0
&expr.Cmp{
Op: expr.CmpOpEq,
Register: 1,
Data: net.ParseIP("192.168.69.2").To4(),
},
// masq
&expr.Masq{},
},
})
if err := c.Flush(); err != nil {
t.Fatal(err)
}
wg.Wait()
if gotTable.Family != nat.Family || gotTable.Name != nat.Name {
t.Fatal("no want table", gotTable.Family, gotTable.Name)
}
if gotChain.Type != postrouting.Type || gotChain.Name != postrouting.Name ||
*gotChain.Hooknum != *postrouting.Hooknum {
t.Fatal("no want chain", gotChain.Type, gotChain.Name, gotChain.Hooknum)
}
if len(gotRule.Exprs) != len(rule.Exprs) {
t.Fatal("no want rule")
}
}
|
