Add ebtables rule delete function + broute table + brouting chain

pkg/util/ebtables/ebtables.go

@@ -43,6 +43,7 @@ type Table string
 const (
 	TableNAT    Table = "nat"
 	TableFilter Table = "filter"
+	TableBroute Table = "broute"
 )
 
 type Chain string
@@ -52,6 +53,7 @@ const (
 	ChainPrerouting  Chain = "PREROUTING"
 	ChainOutput      Chain = "OUTPUT"
 	ChainInput       Chain = "INPUT"
+	ChainBrouting    Chain = "BROUTING"
 )
 
 type operation string
@@ -75,6 +77,8 @@ type Interface interface {
 	// Input args must follow the format and sequence of ebtables list output. Otherwise, EnsureRule will always create
 	// new rules and causing duplicates.
 	EnsureRule(position RulePosition, table Table, chain Chain, args ...string) (bool, error)
+	// DeleteRule checks if the specified rule is present and, if so, deletes it.
+	DeleteRule(table Table, chain Chain, args ...string) error
 	// EnsureChain checks if the specified chain is present and, if not, creates it.  If the rule existed, return true.
 	EnsureChain(table Table, chain Chain) (bool, error)
 	// DeleteChain deletes the specified chain.  If the chain did not exist, return error.
@@ -139,6 +143,27 @@ func (runner *runner) EnsureRule(position RulePosition, table Table, chain Chain
 	return exist, nil
 }
 
+func (runner *runner) DeleteRule(table Table, chain Chain, args ...string) error {
+	exist := true
+	fullArgs := makeFullArgs(table, opListChain, chain, fullMac)
+	out, err := runner.exec.Command(cmdebtables, fullArgs...).CombinedOutput()
+	if err != nil {
+		exist = false
+	} else {
+		exist = checkIfRuleExists(string(out), args...)
+	}
+
+	if !exist {
+		return nil
+	}
+	fullArgs = makeFullArgs(table, opDeleteRule, chain, args...)
+	out, err = runner.exec.Command(cmdebtables, fullArgs...).CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("Failed to delete rule: %v, output: %s", err, out)
+	}
+	return nil
+}
+
 func (runner *runner) EnsureChain(table Table, chain Chain) (bool, error) {
 	exist := true