mirror of
https://github.com/netbirdio/netbird.git
synced 2024-12-17 04:10:44 +01:00
474 lines
13 KiB
Go
474 lines
13 KiB
Go
package iptables
|
|
|
|
import (
|
|
"fmt"
|
|
"net"
|
|
"strconv"
|
|
|
|
"github.com/coreos/go-iptables/iptables"
|
|
"github.com/google/uuid"
|
|
"github.com/nadoo/ipset"
|
|
log "github.com/sirupsen/logrus"
|
|
|
|
firewall "github.com/netbirdio/netbird/client/firewall/manager"
|
|
)
|
|
|
|
const (
|
|
tableName = "filter"
|
|
|
|
// rules chains contains the effective ACL rules
|
|
chainNameInputRules = "NETBIRD-ACL-INPUT"
|
|
chainNameOutputRules = "NETBIRD-ACL-OUTPUT"
|
|
|
|
postRoutingMark = "0x000007e4"
|
|
)
|
|
|
|
type aclManager struct {
|
|
iptablesClient *iptables.IPTables
|
|
wgIface iFaceMapper
|
|
routeingFwChainName string
|
|
|
|
entries map[string][][]string
|
|
ipsetStore *ipsetStore
|
|
}
|
|
|
|
func newAclManager(iptablesClient *iptables.IPTables, wgIface iFaceMapper, routeingFwChainName string) (*aclManager, error) {
|
|
m := &aclManager{
|
|
iptablesClient: iptablesClient,
|
|
wgIface: wgIface,
|
|
routeingFwChainName: routeingFwChainName,
|
|
|
|
entries: make(map[string][][]string),
|
|
ipsetStore: newIpsetStore(),
|
|
}
|
|
|
|
err := ipset.Init()
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to init ipset: %w", err)
|
|
}
|
|
|
|
m.seedInitialEntries()
|
|
|
|
err = m.cleanChains()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
err = m.createDefaultChains()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return m, nil
|
|
}
|
|
|
|
func (m *aclManager) AddFiltering(
|
|
ip net.IP,
|
|
protocol firewall.Protocol,
|
|
sPort *firewall.Port,
|
|
dPort *firewall.Port,
|
|
direction firewall.RuleDirection,
|
|
action firewall.Action,
|
|
ipsetName string,
|
|
) ([]firewall.Rule, error) {
|
|
var dPortVal, sPortVal string
|
|
if dPort != nil && dPort.Values != nil {
|
|
// TODO: we support only one port per rule in current implementation of ACLs
|
|
dPortVal = strconv.Itoa(dPort.Values[0])
|
|
}
|
|
if sPort != nil && sPort.Values != nil {
|
|
sPortVal = strconv.Itoa(sPort.Values[0])
|
|
}
|
|
|
|
var chain string
|
|
if direction == firewall.RuleDirectionOUT {
|
|
chain = chainNameOutputRules
|
|
} else {
|
|
chain = chainNameInputRules
|
|
}
|
|
|
|
ipsetName = transformIPsetName(ipsetName, sPortVal, dPortVal)
|
|
specs := filterRuleSpecs(ip, string(protocol), sPortVal, dPortVal, direction, action, ipsetName)
|
|
if ipsetName != "" {
|
|
if ipList, ipsetExists := m.ipsetStore.ipset(ipsetName); ipsetExists {
|
|
if err := ipset.Add(ipsetName, ip.String()); err != nil {
|
|
return nil, fmt.Errorf("failed to add IP to ipset: %w", err)
|
|
}
|
|
// if ruleset already exists it means we already have the firewall rule
|
|
// so we need to update IPs in the ruleset and return new fw.Rule object for ACL manager.
|
|
ipList.addIP(ip.String())
|
|
return []firewall.Rule{&Rule{
|
|
ruleID: uuid.New().String(),
|
|
ipsetName: ipsetName,
|
|
ip: ip.String(),
|
|
chain: chain,
|
|
specs: specs,
|
|
}}, nil
|
|
}
|
|
|
|
if err := ipset.Flush(ipsetName); err != nil {
|
|
log.Errorf("flush ipset %s before use it: %s", ipsetName, err)
|
|
}
|
|
if err := ipset.Create(ipsetName); err != nil {
|
|
return nil, fmt.Errorf("failed to create ipset: %w", err)
|
|
}
|
|
if err := ipset.Add(ipsetName, ip.String()); err != nil {
|
|
return nil, fmt.Errorf("failed to add IP to ipset: %w", err)
|
|
}
|
|
|
|
ipList := newIpList(ip.String())
|
|
m.ipsetStore.addIpList(ipsetName, ipList)
|
|
}
|
|
|
|
ok, err := m.iptablesClient.Exists("filter", chain, specs...)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to check rule: %w", err)
|
|
}
|
|
if ok {
|
|
return nil, fmt.Errorf("rule already exists")
|
|
}
|
|
|
|
if err := m.iptablesClient.Insert("filter", chain, 1, specs...); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
rule := &Rule{
|
|
ruleID: uuid.New().String(),
|
|
specs: specs,
|
|
ipsetName: ipsetName,
|
|
ip: ip.String(),
|
|
chain: chain,
|
|
}
|
|
|
|
if !shouldAddToPrerouting(protocol, dPort, direction) {
|
|
return []firewall.Rule{rule}, nil
|
|
}
|
|
|
|
rulePrerouting, err := m.addPreroutingFilter(ipsetName, string(protocol), dPortVal, ip)
|
|
if err != nil {
|
|
return []firewall.Rule{rule}, err
|
|
}
|
|
return []firewall.Rule{rule, rulePrerouting}, nil
|
|
}
|
|
|
|
// DeleteRule from the firewall by rule definition
|
|
func (m *aclManager) DeleteRule(rule firewall.Rule) error {
|
|
r, ok := rule.(*Rule)
|
|
if !ok {
|
|
return fmt.Errorf("invalid rule type")
|
|
}
|
|
|
|
if r.chain == "PREROUTING" {
|
|
goto DELETERULE
|
|
}
|
|
|
|
if ipsetList, ok := m.ipsetStore.ipset(r.ipsetName); ok {
|
|
// delete IP from ruleset IPs list and ipset
|
|
if _, ok := ipsetList.ips[r.ip]; ok {
|
|
if err := ipset.Del(r.ipsetName, r.ip); err != nil {
|
|
return fmt.Errorf("failed to delete ip from ipset: %w", err)
|
|
}
|
|
delete(ipsetList.ips, r.ip)
|
|
}
|
|
|
|
// if after delete, set still contains other IPs,
|
|
// no need to delete firewall rule and we should exit here
|
|
if len(ipsetList.ips) != 0 {
|
|
return nil
|
|
}
|
|
|
|
// we delete last IP from the set, that means we need to delete
|
|
// set itself and associated firewall rule too
|
|
m.ipsetStore.deleteIpset(r.ipsetName)
|
|
|
|
if err := ipset.Destroy(r.ipsetName); err != nil {
|
|
log.Errorf("delete empty ipset: %v", err)
|
|
}
|
|
}
|
|
|
|
DELETERULE:
|
|
var table string
|
|
if r.chain == "PREROUTING" {
|
|
table = "mangle"
|
|
} else {
|
|
table = "filter"
|
|
}
|
|
err := m.iptablesClient.Delete(table, r.chain, r.specs...)
|
|
if err != nil {
|
|
log.Debugf("failed to delete rule, %s, %v: %s", r.chain, r.specs, err)
|
|
}
|
|
return err
|
|
}
|
|
|
|
func (m *aclManager) Reset() error {
|
|
return m.cleanChains()
|
|
}
|
|
|
|
func (m *aclManager) addPreroutingFilter(ipsetName string, protocol string, port string, ip net.IP) (*Rule, error) {
|
|
var src []string
|
|
if ipsetName != "" {
|
|
src = []string{"-m", "set", "--set", ipsetName, "src"}
|
|
} else {
|
|
src = []string{"-s", ip.String()}
|
|
}
|
|
specs := []string{
|
|
"-d", m.wgIface.Address().IP.String(),
|
|
"-p", protocol,
|
|
"--dport", port,
|
|
"-j", "MARK", "--set-mark", postRoutingMark,
|
|
}
|
|
|
|
specs = append(src, specs...)
|
|
|
|
ok, err := m.iptablesClient.Exists("mangle", "PREROUTING", specs...)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to check rule: %w", err)
|
|
}
|
|
if ok {
|
|
return nil, fmt.Errorf("rule already exists")
|
|
}
|
|
|
|
if err := m.iptablesClient.Insert("mangle", "PREROUTING", 1, specs...); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
rule := &Rule{
|
|
ruleID: uuid.New().String(),
|
|
specs: specs,
|
|
ipsetName: ipsetName,
|
|
ip: ip.String(),
|
|
chain: "PREROUTING",
|
|
}
|
|
return rule, nil
|
|
}
|
|
|
|
// todo write less destructive cleanup mechanism
|
|
func (m *aclManager) cleanChains() error {
|
|
ok, err := m.iptablesClient.ChainExists(tableName, chainNameOutputRules)
|
|
if err != nil {
|
|
log.Debugf("failed to list chains: %s", err)
|
|
return err
|
|
}
|
|
if ok {
|
|
rules := m.entries["OUTPUT"]
|
|
for _, rule := range rules {
|
|
err := m.iptablesClient.DeleteIfExists(tableName, "OUTPUT", rule...)
|
|
if err != nil {
|
|
log.Errorf("failed to delete rule: %v, %s", rule, err)
|
|
}
|
|
}
|
|
|
|
err = m.iptablesClient.ClearAndDeleteChain(tableName, chainNameOutputRules)
|
|
if err != nil {
|
|
log.Debugf("failed to clear and delete %s chain: %s", chainNameOutputRules, err)
|
|
return err
|
|
}
|
|
}
|
|
|
|
ok, err = m.iptablesClient.ChainExists(tableName, chainNameInputRules)
|
|
if err != nil {
|
|
log.Debugf("failed to list chains: %s", err)
|
|
return err
|
|
}
|
|
if ok {
|
|
for _, rule := range m.entries["INPUT"] {
|
|
err := m.iptablesClient.DeleteIfExists(tableName, "INPUT", rule...)
|
|
if err != nil {
|
|
log.Errorf("failed to delete rule: %v, %s", rule, err)
|
|
}
|
|
}
|
|
|
|
for _, rule := range m.entries["FORWARD"] {
|
|
err := m.iptablesClient.DeleteIfExists(tableName, "FORWARD", rule...)
|
|
if err != nil {
|
|
log.Errorf("failed to delete rule: %v, %s", rule, err)
|
|
}
|
|
}
|
|
|
|
err = m.iptablesClient.ClearAndDeleteChain(tableName, chainNameInputRules)
|
|
if err != nil {
|
|
log.Debugf("failed to clear and delete %s chain: %s", chainNameInputRules, err)
|
|
return err
|
|
}
|
|
}
|
|
|
|
ok, err = m.iptablesClient.ChainExists("mangle", "PREROUTING")
|
|
if err != nil {
|
|
log.Debugf("failed to list chains: %s", err)
|
|
return err
|
|
}
|
|
if ok {
|
|
for _, rule := range m.entries["PREROUTING"] {
|
|
err := m.iptablesClient.DeleteIfExists("mangle", "PREROUTING", rule...)
|
|
if err != nil {
|
|
log.Errorf("failed to delete rule: %v, %s", rule, err)
|
|
}
|
|
}
|
|
err = m.iptablesClient.ClearChain("mangle", "PREROUTING")
|
|
if err != nil {
|
|
log.Debugf("failed to clear %s chain: %s", "PREROUTING", err)
|
|
return err
|
|
}
|
|
}
|
|
|
|
for _, ipsetName := range m.ipsetStore.ipsetNames() {
|
|
if err := ipset.Flush(ipsetName); err != nil {
|
|
log.Errorf("flush ipset %q during reset: %v", ipsetName, err)
|
|
}
|
|
if err := ipset.Destroy(ipsetName); err != nil {
|
|
log.Errorf("delete ipset %q during reset: %v", ipsetName, err)
|
|
}
|
|
m.ipsetStore.deleteIpset(ipsetName)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (m *aclManager) createDefaultChains() error {
|
|
// chain netbird-acl-input-rules
|
|
if err := m.iptablesClient.NewChain(tableName, chainNameInputRules); err != nil {
|
|
log.Debugf("failed to create '%s' chain: %s", chainNameInputRules, err)
|
|
return err
|
|
}
|
|
|
|
// chain netbird-acl-output-rules
|
|
if err := m.iptablesClient.NewChain(tableName, chainNameOutputRules); err != nil {
|
|
log.Debugf("failed to create '%s' chain: %s", chainNameOutputRules, err)
|
|
return err
|
|
}
|
|
|
|
for chainName, rules := range m.entries {
|
|
for _, rule := range rules {
|
|
if chainName == "FORWARD" {
|
|
// position 2 because we add it after router's, jump rule
|
|
if err := m.iptablesClient.InsertUnique(tableName, "FORWARD", 2, rule...); err != nil {
|
|
log.Debugf("failed to create input chain jump rule: %s", err)
|
|
return err
|
|
}
|
|
} else {
|
|
if err := m.iptablesClient.AppendUnique(tableName, chainName, rule...); err != nil {
|
|
log.Debugf("failed to create input chain jump rule: %s", err)
|
|
return err
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (m *aclManager) seedInitialEntries() {
|
|
m.appendToEntries("INPUT",
|
|
[]string{"-i", m.wgIface.Name(), "!", "-s", m.wgIface.Address().String(), "-d", m.wgIface.Address().String(), "-j", "ACCEPT"})
|
|
|
|
m.appendToEntries("INPUT",
|
|
[]string{"-i", m.wgIface.Name(), "-s", m.wgIface.Address().String(), "!", "-d", m.wgIface.Address().String(), "-j", "ACCEPT"})
|
|
|
|
m.appendToEntries("INPUT",
|
|
[]string{"-i", m.wgIface.Name(), "-s", m.wgIface.Address().String(), "-d", m.wgIface.Address().String(), "-j", chainNameInputRules})
|
|
|
|
m.appendToEntries("INPUT", []string{"-i", m.wgIface.Name(), "-j", "DROP"})
|
|
|
|
m.appendToEntries("OUTPUT",
|
|
[]string{"-o", m.wgIface.Name(), "!", "-s", m.wgIface.Address().String(), "-d", m.wgIface.Address().String(), "-j", "ACCEPT"})
|
|
|
|
m.appendToEntries("OUTPUT",
|
|
[]string{"-o", m.wgIface.Name(), "-s", m.wgIface.Address().String(), "!", "-d", m.wgIface.Address().String(), "-j", "ACCEPT"})
|
|
|
|
m.appendToEntries("OUTPUT",
|
|
[]string{"-o", m.wgIface.Name(), "-s", m.wgIface.Address().String(), "-d", m.wgIface.Address().String(), "-j", chainNameOutputRules})
|
|
|
|
m.appendToEntries("OUTPUT", []string{"-o", m.wgIface.Name(), "-j", "DROP"})
|
|
|
|
m.appendToEntries("FORWARD", []string{"-i", m.wgIface.Name(), "-j", "DROP"})
|
|
m.appendToEntries("FORWARD", []string{"-i", m.wgIface.Name(), "-j", chainNameInputRules})
|
|
m.appendToEntries("FORWARD",
|
|
[]string{"-o", m.wgIface.Name(), "-m", "mark", "--mark", postRoutingMark, "-j", "ACCEPT"})
|
|
m.appendToEntries("FORWARD",
|
|
[]string{"-i", m.wgIface.Name(), "-m", "mark", "--mark", postRoutingMark, "-j", "ACCEPT"})
|
|
m.appendToEntries("FORWARD", []string{"-o", m.wgIface.Name(), "-j", m.routeingFwChainName})
|
|
m.appendToEntries("FORWARD", []string{"-i", m.wgIface.Name(), "-j", m.routeingFwChainName})
|
|
|
|
m.appendToEntries("PREROUTING",
|
|
[]string{"-t", "mangle", "-i", m.wgIface.Name(), "!", "-s", m.wgIface.Address().String(), "-d", m.wgIface.Address().IP.String(), "-m", "mark", "--mark", postRoutingMark})
|
|
}
|
|
|
|
func (m *aclManager) appendToEntries(chainName string, spec []string) {
|
|
m.entries[chainName] = append(m.entries[chainName], spec)
|
|
}
|
|
|
|
// filterRuleSpecs returns the specs of a filtering rule
|
|
func filterRuleSpecs(
|
|
ip net.IP, protocol string, sPort, dPort string, direction firewall.RuleDirection, action firewall.Action, ipsetName string,
|
|
) (specs []string) {
|
|
matchByIP := true
|
|
// don't use IP matching if IP is ip 0.0.0.0
|
|
if ip.String() == "0.0.0.0" {
|
|
matchByIP = false
|
|
}
|
|
switch direction {
|
|
case firewall.RuleDirectionIN:
|
|
if matchByIP {
|
|
if ipsetName != "" {
|
|
specs = append(specs, "-m", "set", "--set", ipsetName, "src")
|
|
} else {
|
|
specs = append(specs, "-s", ip.String())
|
|
}
|
|
}
|
|
case firewall.RuleDirectionOUT:
|
|
if matchByIP {
|
|
if ipsetName != "" {
|
|
specs = append(specs, "-m", "set", "--set", ipsetName, "dst")
|
|
} else {
|
|
specs = append(specs, "-d", ip.String())
|
|
}
|
|
}
|
|
}
|
|
if protocol != "all" {
|
|
specs = append(specs, "-p", protocol)
|
|
}
|
|
if sPort != "" {
|
|
specs = append(specs, "--sport", sPort)
|
|
}
|
|
if dPort != "" {
|
|
specs = append(specs, "--dport", dPort)
|
|
}
|
|
return append(specs, "-j", actionToStr(action))
|
|
}
|
|
|
|
func actionToStr(action firewall.Action) string {
|
|
if action == firewall.ActionAccept {
|
|
return "ACCEPT"
|
|
}
|
|
return "DROP"
|
|
}
|
|
|
|
func transformIPsetName(ipsetName string, sPort, dPort string) string {
|
|
switch {
|
|
case ipsetName == "":
|
|
return ""
|
|
case sPort != "" && dPort != "":
|
|
return ipsetName + "-sport-dport"
|
|
case sPort != "":
|
|
return ipsetName + "-sport"
|
|
case dPort != "":
|
|
return ipsetName + "-dport"
|
|
default:
|
|
return ipsetName
|
|
}
|
|
}
|
|
|
|
func shouldAddToPrerouting(proto firewall.Protocol, dPort *firewall.Port, direction firewall.RuleDirection) bool {
|
|
if proto == "all" {
|
|
return false
|
|
}
|
|
|
|
if direction != firewall.RuleDirectionIN {
|
|
return false
|
|
}
|
|
|
|
if dPort == nil {
|
|
return false
|
|
}
|
|
return true
|
|
}
|