func reexecSetupResolver() {
runtime.LockOSThread()
defer runtime.UnlockOSThread()
if len(os.Args) < 4 {
log.Error("invalid number of arguments..")
os.Exit(1)
}
resolverIP, ipPort, _ := net.SplitHostPort(os.Args[2])
_, tcpPort, _ := net.SplitHostPort(os.Args[3])
rules := [][]string{
{"-t", "nat", "-I", outputChain, "-d", resolverIP, "-p", "udp", "--dport", dnsPort, "-j", "DNAT", "--to-destination", os.Args[2]},
{"-t", "nat", "-I", postroutingchain, "-s", resolverIP, "-p", "udp", "--sport", ipPort, "-j", "SNAT", "--to-source", ":" + dnsPort},
{"-t", "nat", "-I", outputChain, "-d", resolverIP, "-p", "tcp", "--dport", dnsPort, "-j", "DNAT", "--to-destination", os.Args[3]},
{"-t", "nat", "-I", postroutingchain, "-s", resolverIP, "-p", "tcp", "--sport", tcpPort, "-j", "SNAT", "--to-source", ":" + dnsPort},
}
f, err := os.OpenFile(os.Args[1], os.O_RDONLY, 0)
if err != nil {
log.Errorf("failed get network namespace %q: %v", os.Args[1], err)
os.Exit(2)
}
defer f.Close()
nsFD := f.Fd()
if err = netns.Set(netns.NsHandle(nsFD)); err != nil {
log.Errorf("setting into container net ns %v failed, %v", os.Args[1], err)
os.Exit(3)
}
// insert outputChain and postroutingchain
err = iptables.RawCombinedOutputNative("-t", "nat", "-C", "OUTPUT", "-d", resolverIP, "-j", outputChain)
if err == nil {
iptables.RawCombinedOutputNative("-t", "nat", "-F", outputChain)
} else {
iptables.RawCombinedOutputNative("-t", "nat", "-N", outputChain)
iptables.RawCombinedOutputNative("-t", "nat", "-I", "OUTPUT", "-d", resolverIP, "-j", outputChain)
}
err = iptables.RawCombinedOutputNative("-t", "nat", "-C", "POSTROUTING", "-d", resolverIP, "-j", postroutingchain)
if err == nil {
iptables.RawCombinedOutputNative("-t", "nat", "-F", postroutingchain)
} else {
iptables.RawCombinedOutputNative("-t", "nat", "-N", postroutingchain)
iptables.RawCombinedOutputNative("-t", "nat", "-I", "POSTROUTING", "-d", resolverIP, "-j", postroutingchain)
}
for _, rule := range rules {
if iptables.RawCombinedOutputNative(rule...) != nil {
log.Errorf("setting up rule failed, %v", rule)
}
}
}
// Redirecter reexec function.
func redirecter() {
runtime.LockOSThread()
defer runtime.UnlockOSThread()
if len(os.Args) < 4 {
logrus.Error("invalid number of arguments..")
os.Exit(1)
}
var ingressPorts []*PortConfig
if os.Args[3] != "" {
var err error
ingressPorts, err = readPortsFromFile(os.Args[3])
if err != nil {
logrus.Errorf("Failed reading ingress ports file: %v", err)
os.Exit(2)
}
}
eIP, _, err := net.ParseCIDR(os.Args[2])
if err != nil {
logrus.Errorf("Failed to parse endpoint IP %s: %v", os.Args[2], err)
os.Exit(3)
}
rules := [][]string{}
for _, iPort := range ingressPorts {
rule := strings.Fields(fmt.Sprintf("-t nat -A PREROUTING -d %s -p %s --dport %d -j REDIRECT --to-port %d",
eIP.String(), strings.ToLower(PortConfig_Protocol_name[int32(iPort.Protocol)]), iPort.PublishedPort, iPort.TargetPort))
rules = append(rules, rule)
}
ns, err := netns.GetFromPath(os.Args[1])
if err != nil {
logrus.Errorf("failed get network namespace %q: %v", os.Args[1], err)
os.Exit(4)
}
defer ns.Close()
if err := netns.Set(ns); err != nil {
logrus.Errorf("setting into container net ns %v failed, %v", os.Args[1], err)
os.Exit(5)
}
for _, rule := range rules {
if err := iptables.RawCombinedOutputNative(rule...); err != nil {
logrus.Errorf("setting up rule failed, %v: %v", rule, err)
os.Exit(5)
}
}
}
func (r *resolver) SetupFunc() func() {
return (func() {
var err error
// DNS operates primarily on UDP
addr := &net.UDPAddr{
IP: net.ParseIP(resolverIP),
}
r.conn, err = net.ListenUDP("udp", addr)
if err != nil {
r.err = fmt.Errorf("error in opening name server socket %v", err)
return
}
laddr := r.conn.LocalAddr()
_, ipPort, _ := net.SplitHostPort(laddr.String())
// Listen on a TCP as well
tcpaddr := &net.TCPAddr{
IP: net.ParseIP(resolverIP),
}
r.tcpListen, err = net.ListenTCP("tcp", tcpaddr)
if err != nil {
r.err = fmt.Errorf("error in opening name TCP server socket %v", err)
return
}
ltcpaddr := r.tcpListen.Addr()
_, tcpPort, _ := net.SplitHostPort(ltcpaddr.String())
rules := [][]string{
{"-t", "nat", "-A", "OUTPUT", "-d", resolverIP, "-p", "udp", "--dport", dnsPort, "-j", "DNAT", "--to-destination", laddr.String()},
{"-t", "nat", "-A", "POSTROUTING", "-s", resolverIP, "-p", "udp", "--sport", ipPort, "-j", "SNAT", "--to-source", ":" + dnsPort},
{"-t", "nat", "-A", "OUTPUT", "-d", resolverIP, "-p", "tcp", "--dport", dnsPort, "-j", "DNAT", "--to-destination", ltcpaddr.String()},
{"-t", "nat", "-A", "POSTROUTING", "-s", resolverIP, "-p", "tcp", "--sport", tcpPort, "-j", "SNAT", "--to-source", ":" + dnsPort},
}
for _, rule := range rules {
r.err = iptables.RawCombinedOutputNative(rule...)
if r.err != nil {
return
}
}
r.err = nil
})
}
// Firewall marker reexec function.
func fwMarker() {
runtime.LockOSThread()
defer runtime.UnlockOSThread()
if len(os.Args) < 7 {
logrus.Error("invalid number of arguments..")
os.Exit(1)
}
var ingressPorts []*PortConfig
if os.Args[5] != "" {
buf, err := ioutil.ReadFile(os.Args[5])
if err != nil {
logrus.Errorf("Failed to read ports config file: %v", err)
os.Exit(6)
}
var epRec EndpointRecord
err = proto.Unmarshal(buf, &epRec)
if err != nil {
logrus.Errorf("Failed to unmarshal ports config data: %v", err)
os.Exit(7)
}
ingressPorts = epRec.IngressPorts
}
vip := os.Args[2]
fwMark, err := strconv.ParseUint(os.Args[3], 10, 32)
if err != nil {
logrus.Errorf("bad fwmark value(%s) passed: %v", os.Args[3], err)
os.Exit(2)
}
addDelOpt := os.Args[4]
rules := [][]string{}
for _, iPort := range ingressPorts {
rule := strings.Fields(fmt.Sprintf("-t nat %s PREROUTING -p %s --dport %d -j REDIRECT --to-port %d",
addDelOpt, strings.ToLower(PortConfig_Protocol_name[int32(iPort.Protocol)]), iPort.PublishedPort, iPort.TargetPort))
rules = append(rules, rule)
rule = strings.Fields(fmt.Sprintf("-t mangle %s PREROUTING -p %s --dport %d -j MARK --set-mark %d",
addDelOpt, strings.ToLower(PortConfig_Protocol_name[int32(iPort.Protocol)]), iPort.PublishedPort, fwMark))
rules = append(rules, rule)
}
ns, err := netns.GetFromPath(os.Args[1])
if err != nil {
logrus.Errorf("failed get network namespace %q: %v", os.Args[1], err)
os.Exit(3)
}
defer ns.Close()
if err := netns.Set(ns); err != nil {
logrus.Errorf("setting into container net ns %v failed, %v", os.Args[1], err)
os.Exit(4)
}
if len(ingressPorts) != 0 && addDelOpt == "-A" {
ruleParams := strings.Fields(fmt.Sprintf("-m ipvs --ipvs -j SNAT --to-source %s", os.Args[6]))
if !iptables.Exists("nat", "POSTROUTING", ruleParams...) {
rule := append(strings.Fields("-t nat -A POSTROUTING"), ruleParams...)
rules = append(rules, rule)
err := ioutil.WriteFile("/proc/sys/net/ipv4/vs/conntrack", []byte{'1', '\n'}, 0644)
if err != nil {
logrus.Errorf("Failed to write to /proc/sys/net/ipv4/vs/conntrack: %v", err)
os.Exit(8)
}
}
}
rule := strings.Fields(fmt.Sprintf("-t mangle %s OUTPUT -d %s/32 -j MARK --set-mark %d", addDelOpt, vip, fwMark))
rules = append(rules, rule)
for _, rule := range rules {
if err := iptables.RawCombinedOutputNative(rule...); err != nil {
logrus.Errorf("setting up rule failed, %v: %v", rule, err)
os.Exit(5)
}
}
}
// Redirecter reexec function.
func redirecter() {
runtime.LockOSThread()
defer runtime.UnlockOSThread()
if len(os.Args) < 4 {
logrus.Error("invalid number of arguments..")
os.Exit(1)
}
var ingressPorts []*PortConfig
if os.Args[3] != "" {
var err error
ingressPorts, err = readPortsFromFile(os.Args[3])
if err != nil {
logrus.Errorf("Failed reading ingress ports file: %v", err)
os.Exit(2)
}
}
eIP, _, err := net.ParseCIDR(os.Args[2])
if err != nil {
logrus.Errorf("Failed to parse endpoint IP %s: %v", os.Args[2], err)
os.Exit(3)
}
rules := [][]string{}
for _, iPort := range ingressPorts {
rule := strings.Fields(fmt.Sprintf("-t nat -A PREROUTING -d %s -p %s --dport %d -j REDIRECT --to-port %d",
eIP.String(), strings.ToLower(PortConfig_Protocol_name[int32(iPort.Protocol)]), iPort.PublishedPort, iPort.TargetPort))
rules = append(rules, rule)
// Allow only incoming connections to exposed ports
iRule := strings.Fields(fmt.Sprintf("-I INPUT -d %s -p %s --dport %d -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT",
eIP.String(), strings.ToLower(PortConfig_Protocol_name[int32(iPort.Protocol)]), iPort.TargetPort))
rules = append(rules, iRule)
// Allow only outgoing connections from exposed ports
oRule := strings.Fields(fmt.Sprintf("-I OUTPUT -s %s -p %s --sport %d -m conntrack --ctstate ESTABLISHED -j ACCEPT",
eIP.String(), strings.ToLower(PortConfig_Protocol_name[int32(iPort.Protocol)]), iPort.TargetPort))
rules = append(rules, oRule)
}
ns, err := netns.GetFromPath(os.Args[1])
if err != nil {
logrus.Errorf("failed get network namespace %q: %v", os.Args[1], err)
os.Exit(4)
}
defer ns.Close()
if err := netns.Set(ns); err != nil {
logrus.Errorf("setting into container net ns %v failed, %v", os.Args[1], err)
os.Exit(5)
}
for _, rule := range rules {
if err := iptables.RawCombinedOutputNative(rule...); err != nil {
logrus.Errorf("setting up rule failed, %v: %v", rule, err)
os.Exit(6)
}
}
if len(ingressPorts) == 0 {
return
}
// Ensure blocking rules for anything else in/to ingress network
for _, rule := range [][]string{
{"-d", eIP.String(), "-p", "udp", "-j", "DROP"},
{"-d", eIP.String(), "-p", "tcp", "-j", "DROP"},
} {
if !iptables.ExistsNative(iptables.Filter, "INPUT", rule...) {
if err := iptables.RawCombinedOutputNative(append([]string{"-A", "INPUT"}, rule...)...); err != nil {
logrus.Errorf("setting up rule failed, %v: %v", rule, err)
os.Exit(7)
}
}
rule[0] = "-s"
if !iptables.ExistsNative(iptables.Filter, "OUTPUT", rule...) {
if err := iptables.RawCombinedOutputNative(append([]string{"-A", "OUTPUT"}, rule...)...); err != nil {
logrus.Errorf("setting up rule failed, %v: %v", rule, err)
os.Exit(8)
}
}
}
}
// Firewall marker reexec function.
func fwMarker() {
runtime.LockOSThread()
defer runtime.UnlockOSThread()
if len(os.Args) < 7 {
logrus.Error("invalid number of arguments..")
os.Exit(1)
}
var ingressPorts []*PortConfig
if os.Args[5] != "" {
var err error
ingressPorts, err = readPortsFromFile(os.Args[5])
if err != nil {
logrus.Errorf("Failed reading ingress ports file: %v", err)
os.Exit(6)
}
}
vip := os.Args[2]
fwMark, err := strconv.ParseUint(os.Args[3], 10, 32)
if err != nil {
logrus.Errorf("bad fwmark value(%s) passed: %v", os.Args[3], err)
os.Exit(2)
}
addDelOpt := os.Args[4]
rules := [][]string{}
for _, iPort := range ingressPorts {
rule := strings.Fields(fmt.Sprintf("-t mangle %s PREROUTING -p %s --dport %d -j MARK --set-mark %d",
addDelOpt, strings.ToLower(PortConfig_Protocol_name[int32(iPort.Protocol)]), iPort.PublishedPort, fwMark))
rules = append(rules, rule)
}
ns, err := netns.GetFromPath(os.Args[1])
if err != nil {
logrus.Errorf("failed get network namespace %q: %v", os.Args[1], err)
os.Exit(3)
}
defer ns.Close()
if err := netns.Set(ns); err != nil {
logrus.Errorf("setting into container net ns %v failed, %v", os.Args[1], err)
os.Exit(4)
}
if addDelOpt == "-A" {
eIP, subnet, err := net.ParseCIDR(os.Args[6])
if err != nil {
logrus.Errorf("Failed to parse endpoint IP %s: %v", os.Args[6], err)
os.Exit(9)
}
ruleParams := strings.Fields(fmt.Sprintf("-m ipvs --ipvs -d %s -j SNAT --to-source %s", subnet, eIP))
if !iptables.Exists("nat", "POSTROUTING", ruleParams...) {
rule := append(strings.Fields("-t nat -A POSTROUTING"), ruleParams...)
rules = append(rules, rule)
err := ioutil.WriteFile("/proc/sys/net/ipv4/vs/conntrack", []byte{'1', '\n'}, 0644)
if err != nil {
logrus.Errorf("Failed to write to /proc/sys/net/ipv4/vs/conntrack: %v", err)
os.Exit(8)
}
}
}
rule := strings.Fields(fmt.Sprintf("-t mangle %s OUTPUT -d %s/32 -j MARK --set-mark %d", addDelOpt, vip, fwMark))
rules = append(rules, rule)
rule = strings.Fields(fmt.Sprintf("-t nat %s OUTPUT -p icmp --icmp echo-request -d %s -j DNAT --to 127.0.0.1", addDelOpt, vip))
rules = append(rules, rule)
for _, rule := range rules {
if err := iptables.RawCombinedOutputNative(rule...); err != nil {
logrus.Errorf("setting up rule failed, %v: %v", rule, err)
os.Exit(5)
}
}
}