mirror of
https://github.com/netbirdio/netbird.git
synced 2024-11-07 08:44:07 +01:00
[client] Add table filter rules using iptables (#2727)
This specifically concerns the established/related rule since this one is not compatible with iptables-nft even if it is generated the same way by iptables-translate.
This commit is contained in:
parent
da3a053e2b
commit
3a88ac78ff
@ -315,28 +315,33 @@ func insertReturnTrafficRule(conn *nftables.Conn, table *nftables.Table, chain *
|
||||
rule := &nftables.Rule{
|
||||
Table: table,
|
||||
Chain: chain,
|
||||
Exprs: []expr.Any{
|
||||
&expr.Ct{
|
||||
Key: expr.CtKeySTATE,
|
||||
Register: 1,
|
||||
},
|
||||
&expr.Bitwise{
|
||||
SourceRegister: 1,
|
||||
DestRegister: 1,
|
||||
Len: 4,
|
||||
Mask: binaryutil.NativeEndian.PutUint32(expr.CtStateBitESTABLISHED | expr.CtStateBitRELATED),
|
||||
Xor: binaryutil.NativeEndian.PutUint32(0),
|
||||
},
|
||||
&expr.Cmp{
|
||||
Op: expr.CmpOpNeq,
|
||||
Register: 1,
|
||||
Data: []byte{0, 0, 0, 0},
|
||||
},
|
||||
&expr.Verdict{
|
||||
Kind: expr.VerdictAccept,
|
||||
},
|
||||
},
|
||||
Exprs: getEstablishedExprs(1),
|
||||
}
|
||||
|
||||
conn.InsertRule(rule)
|
||||
}
|
||||
|
||||
func getEstablishedExprs(register uint32) []expr.Any {
|
||||
return []expr.Any{
|
||||
&expr.Ct{
|
||||
Key: expr.CtKeySTATE,
|
||||
Register: register,
|
||||
},
|
||||
&expr.Bitwise{
|
||||
SourceRegister: register,
|
||||
DestRegister: register,
|
||||
Len: 4,
|
||||
Mask: binaryutil.NativeEndian.PutUint32(expr.CtStateBitESTABLISHED | expr.CtStateBitRELATED),
|
||||
Xor: binaryutil.NativeEndian.PutUint32(0),
|
||||
},
|
||||
&expr.Cmp{
|
||||
Op: expr.CmpOpNeq,
|
||||
Register: register,
|
||||
Data: []byte{0, 0, 0, 0},
|
||||
},
|
||||
&expr.Counter{},
|
||||
&expr.Verdict{
|
||||
Kind: expr.VerdictAccept,
|
||||
},
|
||||
}
|
||||
}
|
||||
|
@ -109,6 +109,7 @@ func TestNftablesManager(t *testing.T) {
|
||||
Register: 1,
|
||||
Data: []byte{0, 0, 0, 0},
|
||||
},
|
||||
&expr.Counter{},
|
||||
&expr.Verdict{
|
||||
Kind: expr.VerdictAccept,
|
||||
},
|
||||
|
@ -10,6 +10,7 @@ import (
|
||||
"net/netip"
|
||||
"strings"
|
||||
|
||||
"github.com/coreos/go-iptables/iptables"
|
||||
"github.com/davecgh/go-spew/spew"
|
||||
"github.com/google/nftables"
|
||||
"github.com/google/nftables/binaryutil"
|
||||
@ -81,7 +82,7 @@ func newRouter(parentCtx context.Context, workTable *nftables.Table, wgIface iFa
|
||||
}
|
||||
}
|
||||
|
||||
err = r.cleanUpDefaultForwardRules()
|
||||
err = r.removeAcceptForwardRules()
|
||||
if err != nil {
|
||||
log.Errorf("failed to clean up rules from FORWARD chain: %s", err)
|
||||
}
|
||||
@ -98,40 +99,7 @@ func (r *router) Reset() error {
|
||||
// clear without deleting the ipsets, the nf table will be deleted by the caller
|
||||
r.ipsetCounter.Clear()
|
||||
|
||||
return r.cleanUpDefaultForwardRules()
|
||||
}
|
||||
|
||||
func (r *router) cleanUpDefaultForwardRules() error {
|
||||
if r.filterTable == nil {
|
||||
return nil
|
||||
}
|
||||
|
||||
chains, err := r.conn.ListChainsOfTableFamily(nftables.TableFamilyIPv4)
|
||||
if err != nil {
|
||||
return fmt.Errorf("list chains: %v", err)
|
||||
}
|
||||
|
||||
for _, chain := range chains {
|
||||
if chain.Table.Name != r.filterTable.Name || chain.Name != chainNameForward {
|
||||
continue
|
||||
}
|
||||
|
||||
rules, err := r.conn.GetRules(r.filterTable, chain)
|
||||
if err != nil {
|
||||
return fmt.Errorf("get rules: %v", err)
|
||||
}
|
||||
|
||||
for _, rule := range rules {
|
||||
if bytes.Equal(rule.UserData, []byte(userDataAcceptForwardRuleIif)) ||
|
||||
bytes.Equal(rule.UserData, []byte(userDataAcceptForwardRuleOif)) {
|
||||
if err := r.conn.DelRule(rule); err != nil {
|
||||
return fmt.Errorf("delete rule: %v", err)
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return r.conn.Flush()
|
||||
return r.removeAcceptForwardRules()
|
||||
}
|
||||
|
||||
func (r *router) loadFilterTable() (*nftables.Table, error) {
|
||||
@ -167,7 +135,9 @@ func (r *router) createContainers() error {
|
||||
Type: nftables.ChainTypeNAT,
|
||||
})
|
||||
|
||||
r.acceptForwardRules()
|
||||
if err := r.acceptForwardRules(); err != nil {
|
||||
log.Errorf("failed to add accept rules for the forward chain: %s", err)
|
||||
}
|
||||
|
||||
if err := r.refreshRulesMap(); err != nil {
|
||||
log.Errorf("failed to clean up rules from FORWARD chain: %s", err)
|
||||
@ -577,19 +547,60 @@ func (r *router) RemoveAllLegacyRouteRules() error {
|
||||
// that our traffic is not dropped by existing rules there.
|
||||
// The existing FORWARD rules/policies decide outbound traffic towards our interface.
|
||||
// In case the FORWARD policy is set to "drop", we add an established/related rule to allow return traffic for the inbound rule.
|
||||
func (r *router) acceptForwardRules() {
|
||||
func (r *router) acceptForwardRules() error {
|
||||
if r.filterTable == nil {
|
||||
log.Debugf("table 'filter' not found for forward rules, skipping accept rules")
|
||||
return
|
||||
return nil
|
||||
}
|
||||
|
||||
fw := "iptables"
|
||||
|
||||
defer func() {
|
||||
log.Debugf("Used %s to add accept forward rules", fw)
|
||||
}()
|
||||
|
||||
// Try iptables first and fallback to nftables if iptables is not available
|
||||
ipt, err := iptables.New()
|
||||
if err != nil {
|
||||
// filter table exists but iptables is not
|
||||
log.Warnf("Will use nftables to manipulate the filter table because iptables is not available: %v", err)
|
||||
|
||||
fw = "nftables"
|
||||
return r.acceptForwardRulesNftables()
|
||||
}
|
||||
|
||||
return r.acceptForwardRulesIptables(ipt)
|
||||
}
|
||||
|
||||
func (r *router) acceptForwardRulesIptables(ipt *iptables.IPTables) error {
|
||||
var merr *multierror.Error
|
||||
for _, rule := range r.getAcceptForwardRules() {
|
||||
if err := ipt.Insert("filter", chainNameForward, 1, rule...); err != nil {
|
||||
merr = multierror.Append(err, fmt.Errorf("add iptables rule: %v", err))
|
||||
} else {
|
||||
log.Debugf("added iptables rule: %v", rule)
|
||||
}
|
||||
}
|
||||
|
||||
return nberrors.FormatErrorOrNil(merr)
|
||||
}
|
||||
|
||||
func (r *router) getAcceptForwardRules() [][]string {
|
||||
intf := r.wgIface.Name()
|
||||
return [][]string{
|
||||
{"-i", intf, "-j", "ACCEPT"},
|
||||
{"-o", intf, "-m", "conntrack", "--ctstate", "RELATED,ESTABLISHED", "-j", "ACCEPT"},
|
||||
}
|
||||
}
|
||||
|
||||
func (r *router) acceptForwardRulesNftables() error {
|
||||
intf := ifname(r.wgIface.Name())
|
||||
|
||||
// Rule for incoming interface (iif) with counter
|
||||
iifRule := &nftables.Rule{
|
||||
Table: r.filterTable,
|
||||
Chain: &nftables.Chain{
|
||||
Name: "FORWARD",
|
||||
Name: chainNameForward,
|
||||
Table: r.filterTable,
|
||||
Type: nftables.ChainTypeFilter,
|
||||
Hooknum: nftables.ChainHookForward,
|
||||
@ -609,6 +620,15 @@ func (r *router) acceptForwardRules() {
|
||||
}
|
||||
r.conn.InsertRule(iifRule)
|
||||
|
||||
oifExprs := []expr.Any{
|
||||
&expr.Meta{Key: expr.MetaKeyOIFNAME, Register: 1},
|
||||
&expr.Cmp{
|
||||
Op: expr.CmpOpEq,
|
||||
Register: 1,
|
||||
Data: intf,
|
||||
},
|
||||
}
|
||||
|
||||
// Rule for outgoing interface (oif) with counter
|
||||
oifRule := &nftables.Rule{
|
||||
Table: r.filterTable,
|
||||
@ -619,36 +639,72 @@ func (r *router) acceptForwardRules() {
|
||||
Hooknum: nftables.ChainHookForward,
|
||||
Priority: nftables.ChainPriorityFilter,
|
||||
},
|
||||
Exprs: []expr.Any{
|
||||
&expr.Meta{Key: expr.MetaKeyOIFNAME, Register: 1},
|
||||
&expr.Cmp{
|
||||
Op: expr.CmpOpEq,
|
||||
Register: 1,
|
||||
Data: intf,
|
||||
},
|
||||
&expr.Ct{
|
||||
Key: expr.CtKeySTATE,
|
||||
Register: 2,
|
||||
},
|
||||
&expr.Bitwise{
|
||||
SourceRegister: 2,
|
||||
DestRegister: 2,
|
||||
Len: 4,
|
||||
Mask: binaryutil.NativeEndian.PutUint32(expr.CtStateBitESTABLISHED | expr.CtStateBitRELATED),
|
||||
Xor: binaryutil.NativeEndian.PutUint32(0),
|
||||
},
|
||||
&expr.Cmp{
|
||||
Op: expr.CmpOpNeq,
|
||||
Register: 2,
|
||||
Data: []byte{0, 0, 0, 0},
|
||||
},
|
||||
&expr.Counter{},
|
||||
&expr.Verdict{Kind: expr.VerdictAccept},
|
||||
},
|
||||
Exprs: append(oifExprs, getEstablishedExprs(2)...),
|
||||
UserData: []byte(userDataAcceptForwardRuleOif),
|
||||
}
|
||||
|
||||
r.conn.InsertRule(oifRule)
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
func (r *router) removeAcceptForwardRules() error {
|
||||
if r.filterTable == nil {
|
||||
return nil
|
||||
}
|
||||
|
||||
// Try iptables first and fallback to nftables if iptables is not available
|
||||
ipt, err := iptables.New()
|
||||
if err != nil {
|
||||
log.Warnf("Will use nftables to manipulate the filter table because iptables is not available: %v", err)
|
||||
return r.removeAcceptForwardRulesNftables()
|
||||
}
|
||||
|
||||
return r.removeAcceptForwardRulesIptables(ipt)
|
||||
}
|
||||
|
||||
func (r *router) removeAcceptForwardRulesNftables() error {
|
||||
chains, err := r.conn.ListChainsOfTableFamily(nftables.TableFamilyIPv4)
|
||||
if err != nil {
|
||||
return fmt.Errorf("list chains: %v", err)
|
||||
}
|
||||
|
||||
for _, chain := range chains {
|
||||
if chain.Table.Name != r.filterTable.Name || chain.Name != chainNameForward {
|
||||
continue
|
||||
}
|
||||
|
||||
rules, err := r.conn.GetRules(r.filterTable, chain)
|
||||
if err != nil {
|
||||
return fmt.Errorf("get rules: %v", err)
|
||||
}
|
||||
|
||||
for _, rule := range rules {
|
||||
if bytes.Equal(rule.UserData, []byte(userDataAcceptForwardRuleIif)) ||
|
||||
bytes.Equal(rule.UserData, []byte(userDataAcceptForwardRuleOif)) {
|
||||
if err := r.conn.DelRule(rule); err != nil {
|
||||
return fmt.Errorf("delete rule: %v", err)
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if err := r.conn.Flush(); err != nil {
|
||||
return fmt.Errorf(flushError, err)
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
func (r *router) removeAcceptForwardRulesIptables(ipt *iptables.IPTables) error {
|
||||
var merr *multierror.Error
|
||||
for _, rule := range r.getAcceptForwardRules() {
|
||||
if err := ipt.DeleteIfExists("filter", chainNameForward, rule...); err != nil {
|
||||
merr = multierror.Append(err, fmt.Errorf("remove iptables rule: %v", err))
|
||||
}
|
||||
}
|
||||
|
||||
return nberrors.FormatErrorOrNil(merr)
|
||||
}
|
||||
|
||||
// RemoveNatRule removes a nftables rule pair from nat chains
|
||||
|
Loading…
Reference in New Issue
Block a user