Commit 686492c9 authored by Dmitry Smirnov's avatar Dmitry Smirnov

Imported Upstream version 0.1.0+dfsg

parent 8eb0651b
// Copyright 2015 CoreOS, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package iptables
import (
"bytes"
"fmt"
"log"
"os/exec"
"regexp"
"strconv"
"strings"
"syscall"
)
// Adds the output of stderr to exec.ExitError
type Error struct {
exec.ExitError
msg string
}
func (e *Error) ExitStatus() int {
return e.Sys().(syscall.WaitStatus).ExitStatus()
}
func (e *Error) Error() string {
return fmt.Sprintf("exit status %v: %v", e.ExitStatus(), e.msg)
}
type IPTables struct {
path string
}
func New() (*IPTables, error) {
path, err := exec.LookPath("iptables")
if err != nil {
return nil, err
}
return &IPTables{path}, nil
}
// Exists checks if given rulespec in specified table/chain exists
func (ipt *IPTables) Exists(table, chain string, rulespec...string) (bool, error) {
checkPresent, err := getIptablesHasCheckCommand()
if err != nil {
log.Printf("Error checking iptables version, assuming version at least 1.4.11: %v", err)
checkPresent = true
}
if !checkPresent {
cmd := append([]string{"-A", chain}, rulespec...)
return existsForOldIpTables(table, strings.Join(cmd, " "))
} else {
cmd := append([]string{"-t", table, "-C", chain}, rulespec...)
err := ipt.run(cmd...)
switch {
case err == nil:
return true, nil
case err.(*Error).ExitStatus() == 1:
return false, nil
default:
return false, err
}
}
}
// Insert inserts rulespec to specified table/chain (in specified pos)
func (ipt *IPTables) Insert(table, chain string, pos int, rulespec ...string) error {
cmd := append([]string{"-t", table, "-I", chain, strconv.Itoa(pos)}, rulespec...)
return ipt.run(cmd...)
}
// Append appends rulespec to specified table/chain
func (ipt *IPTables) Append(table, chain string, rulespec ...string) error {
cmd := append([]string{"-t", table, "-A", chain}, rulespec...)
return ipt.run(cmd...)
}
// AppendUnique acts like Append except that it won't add a duplicate
func (ipt *IPTables) AppendUnique(table, chain string, rulespec ...string) error {
exists, err := ipt.Exists(table, chain, rulespec...)
if err != nil {
return err
}
if !exists {
return ipt.Append(table, chain, rulespec...)
}
return nil
}
// Delete removes rulespec in specified table/chain
func (ipt *IPTables) Delete(table, chain string, rulespec ...string) error {
cmd := append([]string{"-t", table, "-D", chain}, rulespec...)
return ipt.run(cmd...)
}
// List rules in specified table/chain
func (ipt *IPTables) List(table, chain string) ([]string, error) {
var stdout, stderr bytes.Buffer
cmd := exec.Cmd{
Path: ipt.path,
Args: []string{ipt.path, "-t", table, "-S", chain},
Stdout: &stdout,
Stderr: &stderr,
}
if err := cmd.Run(); err != nil {
return nil, &Error{*(err.(*exec.ExitError)), stderr.String()}
}
rules := strings.Split(stdout.String(), "\n")
if len(rules) > 0 && rules[len(rules)-1] == "" {
rules = rules[:len(rules)-1]
}
return rules, nil
}
func (ipt *IPTables) NewChain(table, chain string) error {
return ipt.run("-t", table, "-N", chain)
}
// ClearChain flushed (deletes all rules) in the specifed table/chain.
// If the chain does not exist, new one will be created
func (ipt *IPTables) ClearChain(table, chain string) error {
err := ipt.NewChain(table, chain)
switch {
case err == nil:
return nil
case err.(*Error).ExitStatus() == 1:
// chain already exists. Flush (clear) it.
return ipt.run("-t", table, "-F", chain)
default:
return err
}
}
// DeleteChain deletes the chain in the specified table.
// The chain must be empty
func (ipt *IPTables) DeleteChain(table, chain string) error {
return ipt.run("-t", table, "-X", chain)
}
func (ipt *IPTables) run(args... string) error {
var stderr bytes.Buffer
cmd := exec.Cmd{
Path: ipt.path,
Args: append([]string{ipt.path}, args...),
Stderr: &stderr,
}
if err := cmd.Run(); err != nil {
return &Error{*(err.(*exec.ExitError)), stderr.String()}
}
return nil
}
// Checks if iptables has the "-C" flag
func getIptablesHasCheckCommand() (bool, error) {
vstring, err := getIptablesVersionString()
if err != nil {
return false, err
}
v1, v2, v3, err := extractIptablesVersion(vstring)
if err != nil {
return false, err
}
return iptablesHasCheckCommand(v1, v2, v3), nil
}
// getIptablesVersion returns the first three components of the iptables version.
// e.g. "iptables v1.3.66" would return (1, 3, 66, nil)
func extractIptablesVersion(str string) (int, int, int, error) {
versionMatcher := regexp.MustCompile("v([0-9]+)\\.([0-9]+)\\.([0-9]+)")
result := versionMatcher.FindStringSubmatch(str)
if result == nil {
return 0, 0, 0, fmt.Errorf("no iptables version found in string: %s", str)
}
v1, err := strconv.Atoi(result[1])
if err != nil {
return 0, 0, 0, err
}
v2, err := strconv.Atoi(result[2])
if err != nil {
return 0, 0, 0, err
}
v3, err := strconv.Atoi(result[3])
if err != nil {
return 0, 0, 0, err
}
return v1, v2, v3, nil
}
// Runs "iptables --version" to get the version string
func getIptablesVersionString() (string, error) {
cmd := exec.Command("iptables", "--version")
var out bytes.Buffer
cmd.Stdout = &out
err := cmd.Run()
if err != nil {
return "", err
}
return out.String(), nil
}
// Checks if an iptables version is after 1.4.11, when --check was added
func iptablesHasCheckCommand(v1 int, v2 int, v3 int) bool {
if v1 > 1 {
return true
}
if v1 == 1 && v2 > 4 {
return true
}
if v1 == 1 && v2 == 4 && v3 >= 11 {
return true
}
return false
}
// Checks if a rule specification exists for a table
func existsForOldIpTables(table string, ruleSpec string) (bool, error) {
cmd := exec.Command("iptables", "-t", table, "-S")
var out bytes.Buffer
cmd.Stdout = &out
err := cmd.Run()
if err != nil {
return false, err
}
rules := out.String()
return strings.Contains(rules, ruleSpec), nil
}
// Copyright 2015 CoreOS, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package iptables
import (
"crypto/rand"
"math/big"
"reflect"
"testing"
)
func randChain(t *testing.T) string {
n, err := rand.Int(rand.Reader, big.NewInt(1000000))
if err != nil {
t.Fatalf("Failed to generate random chain name: %v", err)
}
return "TEST-" + n.String()
}
func TestChain(t *testing.T) {
chain := randChain(t)
ipt, err := New()
if err != nil {
t.Fatalf("New failed: %v", err)
}
// chain shouldn't exist, this will create new
err = ipt.ClearChain("filter", chain)
if err != nil {
t.Fatalf("ClearChain (of missing) failed: %v", err)
}
// chain now exists
err = ipt.ClearChain("filter", chain)
if err != nil {
t.Fatalf("ClearChain (of empty) failed: %v", err)
}
// put a simple rule in
err = ipt.Append("filter", chain, "-s", "0.0.0.0/0", "-j", "ACCEPT")
if err != nil {
t.Fatalf("Append failed: %v", err)
}
// can't delete non-empty chain
err = ipt.DeleteChain("filter", chain)
if err == nil {
t.Fatalf("DeleteChain of non-empty chain did not fail")
}
err = ipt.ClearChain("filter", chain)
if err != nil {
t.Fatalf("ClearChain (of non-empty) failed: %v", err)
}
// chain empty, should be ok
err = ipt.DeleteChain("filter", chain)
if err != nil {
t.Fatalf("DeleteChain of empty chain failed: %v", err)
}
}
func TestRules(t *testing.T) {
chain := randChain(t)
ipt, err := New()
if err != nil {
t.Fatalf("New failed: %v", err)
}
// chain shouldn't exist, this will create new
err = ipt.ClearChain("filter", chain)
if err != nil {
t.Fatalf("ClearChain (of missing) failed: %v", err)
}
err = ipt.Append("filter", chain, "-s", "10.1.0.0/16", "-d", "8.8.8.8/32", "-j", "ACCEPT")
if err != nil {
t.Fatalf("Append failed: %v", err)
}
err = ipt.AppendUnique("filter", chain, "-s", "10.1.0.0/16", "-d", "8.8.8.8/32", "-j", "ACCEPT")
if err != nil {
t.Fatalf("AppendUnique failed: %v", err)
}
err = ipt.Append("filter", chain, "-s", "10.2.0.0/16", "-d", "8.8.8.8/32", "-j", "ACCEPT")
if err != nil {
t.Fatalf("Append failed: %v", err)
}
err = ipt.Insert("filter", chain, 2, "-s", "10.2.0.0/16", "-d", "9.9.9.9/32", "-j", "ACCEPT")
if err != nil {
t.Fatalf("Insert failed: %v", err)
}
err = ipt.Insert("filter", chain, 1, "-s", "10.1.0.0/16", "-d", "9.9.9.9/32", "-j", "ACCEPT")
if err != nil {
t.Fatalf("Insert failed: %v", err)
}
err = ipt.Delete("filter", chain, "-s", "10.1.0.0/16", "-d", "9.9.9.9/32", "-j", "ACCEPT")
if err != nil {
t.Fatalf("Insert failed: %v", err)
}
rules, err := ipt.List("filter", chain)
if err != nil {
t.Fatalf("List failed: %v", err)
}
expected := []string{
"-N " + chain,
"-A " + chain + " -s 10.1.0.0/16 -d 8.8.8.8/32 -j ACCEPT",
"-A " + chain + " -s 10.2.0.0/16 -d 9.9.9.9/32 -j ACCEPT",
"-A " + chain + " -s 10.2.0.0/16 -d 8.8.8.8/32 -j ACCEPT",
}
if !reflect.DeepEqual(rules, expected) {
t.Fatalf("List mismatch: \ngot %#v \nneed %#v", rules, expected)
}
}
// Copyright 2015 CoreOS, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package activation implements primitives for systemd socket activation.
package activation
import (
"os"
"strconv"
"syscall"
)
// based on: https://gist.github.com/alberts/4640792
const (
listenFdsStart = 3
)
func Files(unsetEnv bool) []*os.File {
if unsetEnv {
defer os.Unsetenv("LISTEN_PID")
defer os.Unsetenv("LISTEN_FDS")
}
pid, err := strconv.Atoi(os.Getenv("LISTEN_PID"))
if err != nil || pid != os.Getpid() {
return nil
}
nfds, err := strconv.Atoi(os.Getenv("LISTEN_FDS"))
if err != nil || nfds == 0 {
return nil
}
files := make([]*os.File, 0, nfds)
for fd := listenFdsStart; fd < listenFdsStart+nfds; fd++ {
syscall.CloseOnExec(fd)
files = append(files, os.NewFile(uintptr(fd), "LISTEN_FD_"+strconv.Itoa(fd)))
}
return files
}
// Copyright 2015 CoreOS, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package activation
import (
"bytes"
"io"
"os"
"os/exec"
"testing"
)
// correctStringWritten fails the text if the correct string wasn't written
// to the other side of the pipe.
func correctStringWritten(t *testing.T, r *os.File, expected string) bool {
bytes := make([]byte, len(expected))
io.ReadAtLeast(r, bytes, len(expected))
if string(bytes) != expected {
t.Fatalf("Unexpected string %s", string(bytes))
}
return true
}
// TestActivation forks out a copy of activation.go example and reads back two
// strings from the pipes that are passed in.
func TestActivation(t *testing.T) {
cmd := exec.Command("go", "run", "../examples/activation/activation.go")
r1, w1, _ := os.Pipe()
r2, w2, _ := os.Pipe()
cmd.ExtraFiles = []*os.File{
w1,
w2,
}
cmd.Env = os.Environ()
cmd.Env = append(cmd.Env, "LISTEN_FDS=2", "FIX_LISTEN_PID=1")
err := cmd.Run()
if err != nil {
t.Fatalf(err.Error())
}
correctStringWritten(t, r1, "Hello world")
correctStringWritten(t, r2, "Goodbye world")
}
func TestActivationNoFix(t *testing.T) {
cmd := exec.Command("go", "run", "../examples/activation/activation.go")
cmd.Env = os.Environ()
cmd.Env = append(cmd.Env, "LISTEN_FDS=2")
out, _ := cmd.CombinedOutput()
if bytes.Contains(out, []byte("No files")) == false {
t.Fatalf("Child didn't error out as expected")
}
}
func TestActivationNoFiles(t *testing.T) {
cmd := exec.Command("go", "run", "../examples/activation/activation.go")
cmd.Env = os.Environ()
cmd.Env = append(cmd.Env, "LISTEN_FDS=0", "FIX_LISTEN_PID=1")
out, _ := cmd.CombinedOutput()
if bytes.Contains(out, []byte("No files")) == false {
t.Fatalf("Child didn't error out as expected")
}
}
// Copyright 2015 CoreOS, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package activation
import (
"net"
)
// Listeners returns a slice containing a net.Listener for each matching socket type
// passed to this process.
//
// The order of the file descriptors is preserved in the returned slice.
// Nil values are used to fill any gaps. For example if systemd were to return file descriptors
// corresponding with "udp, tcp, tcp", then the slice would contain {nil, net.Listener, net.Listener}
func Listeners(unsetEnv bool) ([]net.Listener, error) {
files := Files(unsetEnv)
listeners := make([]net.Listener, len(files))
for i, f := range files {
if pc, err := net.FileListener(f); err == nil {
listeners[i] = pc
}
}
return listeners, nil
}
// Copyright 2015 CoreOS, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package activation
import (
"io"
"net"
"os"