Initial import into Github

cmd/filter-rbl/main.go

@@ -0,0 +1,161 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"net"
+	"os"
+	"strings"
+
+	lru "github.com/hashicorp/golang-lru"
+
+	"gopkg.in/opensmtpd.v0"
+)
+
+var (
+	prog = os.Args[0]
+	skip = []*net.IPNet{}
+	rbls = []string{
+		"b.barracudacentral.org",
+		"bl.spamcop.net",
+		"virbl.bit.nl",
+		"xbl.spamhaus.org",
+	}
+	debug bool
+	masq  bool
+	cache *lru.Cache
+)
+
+func debugf(fmt string, args ...interface{}) {
+	if !debug {
+		return
+	}
+	log.Printf("debug: "+fmt, args...)
+}
+
+func reverse(ip net.IP) string {
+	if ip.To4() == nil {
+		return ""
+	}
+
+	splitAddress := strings.Split(ip.String(), ".")
+
+	for i, j := 0, len(splitAddress)-1; i < len(splitAddress)/2; i, j = i+1, j-1 {
+		splitAddress[i], splitAddress[j] = splitAddress[j], splitAddress[i]
+	}
+
+	return strings.Join(splitAddress, ".")
+}
+
+func lookup(rbl string, host string) (result string, listed bool, err error) {
+	host = fmt.Sprintf("%s.%s", host, rbl)
+
+	var res []string
+	res, err = net.LookupHost(host)
+	if listed = len(res) > 0; listed {
+		txt, _ := net.LookupTXT(host)
+		if len(txt) > 0 {
+			result = txt[0]
+		}
+	}
+
+	// Expected error
+	if err != nil && strings.HasSuffix(err.Error(), ": no such host") {
+		err = nil
+	}
+
+	return
+}
+
+func onConnect(s *opensmtpd.Session, query *opensmtpd.ConnectQuery) error {
+	ip := query.Remote.(opensmtpd.Sockaddr).IP()
+	if ip == nil {
+		return nil
+	}
+
+	debugf("%s: connect from %s\n", prog, ip)
+
+	for _, ipnet := range skip {
+		if ipnet.Contains(ip) {
+			debugf("%s: skip %s, IP ignored", prog, ip)
+			return s.Accept()
+		}
+	}
+
+	var (
+		result string
+		lsited bool
+		host   = reverse(ip)
+		err    error
+	)
+	for _, rbl := range rbls {
+		if result, listed, err = lookup(rbl, host); err != nil {
+			log.Printf("%s: %s failed %s: %v\n", prog, rbl, ip, err)
+		} else if listed {
+			log.Printf("%s: %s listed %s: %v\n", prog, rbl, ip, result)
+			cache.Add(s.ID, result)
+			break
+		}
+	}
+
+	debugf("%s: pass: %s\n", prog, ip)
+
+	if !listed {
+		// Add negative hit
+		cache.Add(s.ID, "")
+	}
+
+	return s.Accept()
+}
+
+func onDATA(s *opensmtpd.Session) error {
+	debugf("%s: %s DATA\n", prog, s)
+
+	if result, block := cache.Get(s.ID); block && result.(string) != "" {
+		return s.RejectCode(opensmtpd.FilterClose, 421, result.(string))
+	}
+
+	return s.Accept()
+}
+
+func main() {
+	cacheSize := flag.Int("cache-size", 1024, "LRU cache size")
+	rblServer := flag.String("servers", strings.Join(rbls, ","), "RBL servers")
+	ignoreIPs := flag.String("ignore", "127.0.0.0/8,10.0.0.0/8,172.16.0.0/12,192.168.0.0/16,fe80::/64", "ignore IPs")
+	debugging := flag.Bool("d", false, "be verbose")
+	verbosity := flag.Bool("v", false, "be verbose")
+	flag.BoolVar(&masq, "masq", true, "masquerade SMTP banner")
+	flag.Parse()
+
+	debug = *debugging || *verbosity
+
+	var err error
+	if cache, err = lru.New(*cacheSize); err != nil {
+		log.Fatalln(err)
+	}
+
+	rbls = strings.Split(*rblServer, ",")
+
+	for _, prefix := range strings.Split(*ignoreIPs, ",") {
+		var ipnet *net.IPNet
+		if _, ipnet, err = net.ParseCIDR(prefix); err != nil {
+			log.Fatalln(err)
+		}
+		skip = append(skip, ipnet)
+		debugf("ignore: %s\n", ipnet)
+	}
+
+	f := new(opensmtpd.Filter)
+
+	f.OnConnect(onConnect)
+	f.OnDATA(onDATA)
+
+	if err = f.Register(); err != nil {
+		log.Fatalln(err)
+	}
+
+	if err = f.Serve(); err != nil {
+		log.Fatalln(err)
+	}
+}

conn.go

@@ -0,0 +1,11 @@
+package opensmtpd
+
+import (
+	"net"
+	"os"
+)
+
+func NewConn(fd int) (net.Conn, error) {
+	f := os.NewFile(uintptr(fd), "")
+	return net.FileConn(f)
+}

filter.go

@@ -0,0 +1,488 @@
+package opensmtpd
+
+import (
+	"fmt"
+	"log"
+	"net"
+	"os"
+	"strings"
+
+	lru "github.com/hashicorp/golang-lru"
+)
+
+const (
+	FilterVersion = 51
+)
+
+const (
+	TypeFilterRegister uint32 = iota
+	TypeFilterEvent
+	TypeFilterQuery
+	TypeFilterPipe
+	TypeFilterResponse
+)
+
+var filterTypeName = map[uint32]string{
+	TypeFilterRegister: "IMSG_FILTER_REGISTER",
+	TypeFilterEvent:    "IMSG_FILTER_EVENT",
+	TypeFilterQuery:    "IMSG_FILTER_QUERY",
+	TypeFilterPipe:     "IMSG_FILTER_PIPE",
+	TypeFilterResponse: "IMSG_FILTER_RESPONSE",
+}
+
+func filterName(t uint32) string {
+	if s, ok := filterTypeName[t]; ok {
+		return s
+	}
+	return fmt.Sprintf("UNKNOWN %d", t)
+}
+
+const (
+	HookConnect = 1 << iota
+	HookHELO
+	HookMAIL
+	HookRCPT
+	HookDATA
+	HookEOM
+	HookReset
+	HookDisconnect
+	HookCommit
+	HookRollback
+	HookDataLine
+)
+
+var hookTypeName = map[uint16]string{
+	HookConnect:    "HOOK_CONNECT",
+	HookHELO:       "HOOK_HELO",
+	HookMAIL:       "HOOK_MAIL",
+	HookRCPT:       "HOOK_RCPT",
+	HookDATA:       "HOOK_DATA",
+	HookEOM:        "HOOK_EOM",
+	HookReset:      "HOOK_RESET",
+	HookDisconnect: "HOOK_DISCONNECT",
+	HookCommit:     "HOOK_COMMIT",
+	HookRollback:   "HOOK_ROLLBACK",
+	HookDataLine:   "HOOK_DATALINE",
+}
+
+func hookName(h uint16) string {
+	var s []string
+	for i := uint(0); i < 11; i++ {
+		if h&(1<<i) != 0 {
+			s = append(s, hookTypeName[(1<<i)])
+		}
+	}
+	return strings.Join(s, ",")
+}
+
+const (
+	EventConnect = iota
+	EventReset
+	EventDisconnect
+	EventTXBegin
+	EventTXCommit
+	EventTXRollback
+)
+
+var eventTypeName = map[int]string{
+	EventConnect:    "EVENT_CONNECT",
+	EventReset:      "EVENT_RESET",
+	EventDisconnect: "EVENT_DISCONNECT",
+	EventTXBegin:    "EVENT_TX_BEGIN",
+	EventTXCommit:   "EVENT_TX_COMMIT",
+	EventTXRollback: "EVENT_TX_ROLLBACK",
+}
+
+func eventName(t int) string {
+	if s, ok := eventTypeName[t]; ok {
+		return s
+	}
+	return fmt.Sprintf("UNKNOWN %d", int(t))
+}
+
+const (
+	QueryConnect = iota
+	QueryHELO
+	QueryMAIL
+	QueryRCPT
+	QueryDATA
+	QueryEOM
+	QueryDataLine
+)
+
+var queryTypeName = map[int]string{
+	QueryConnect:  "QUERY_CONNECT",
+	QueryHELO:     "QUERY_HELO",
+	QueryMAIL:     "QUERY_MAIL",
+	QueryRCPT:     "QUERY_RCPT",
+	QueryDATA:     "QUERY_DATA",
+	QueryEOM:      "QUERY_EOM",
+	QueryDataLine: "QUERY_DATALINE",
+}
+
+func queryName(t int) string {
+	if s, ok := queryTypeName[t]; ok {
+		return s
+	}
+	return fmt.Sprintf("UNKNOWN %d", int(t))
+}
+
+const (
+	FilterOK = iota
+	FilterFail
+	FilterClose
+)
+
+var responseTypeName = map[int]string{
+	FilterOK:    "FILTER_OK",
+	FilterFail:  "FILTER_FAIL",
+	FilterClose: "FILTER_CLOSE",
+}
+
+func responseName(c int) string {
+	if s, ok := responseTypeName[c]; ok {
+		return s
+	}
+	return fmt.Sprintf("UNKNOWN %d", c)
+}
+
+type Filter struct {
+	Name    string
+	Version uint32
+
+	c net.Conn
+	m *Message
+
+	hooks int
+	flags int
+	ready bool
+
+	hook struct {
+		connect    func(*Session, *ConnectQuery) error
+		helo       func(*Session, string) error
+		mail       func(*Session, string, string) error
+		rcpt       func(*Session, string, string) error
+		data       func(*Session) error
+		dataline   func(*Session, string) error
+		eom        func(*Session, uint32) error
+		reset      func(*Session) error
+		disconnect func(*Session) error
+		commit     func(*Session) error
+	}
+	session *lru.Cache
+}
+
+func (f *Filter) OnConnect(fn func(*Session, *ConnectQuery) error) {
+	f.hook.connect = fn
+	f.hooks |= HookConnect
+}
+
+func (f *Filter) OnHELO(fn func(*Session, string) error) {
+	f.hook.helo = fn
+	f.hooks |= HookHELO
+}
+
+func (f *Filter) OnMAIL(fn func(*Session, string, string) error) {
+	f.hook.mail = fn
+	f.hooks |= HookMAIL
+}
+
+func (f *Filter) OnRCPT(fn func(*Session, string, string) error) {
+	f.hook.rcpt = fn
+	f.hooks |= HookRCPT
+}
+
+func (f *Filter) OnDATA(fn func(*Session) error) {
+	f.hook.data = fn
+	f.hooks |= HookDATA
+}
+
+func (f *Filter) OnDataLine(fn func(*Session, string) error) {
+	f.hook.dataline = fn
+	f.hooks |= HookDataLine
+}
+
+func (f *Filter) Register() error {
+	var err error
+	if f.m == nil {
+		f.m = new(Message)
+	}
+	if f.c == nil {
+		if f.c, err = NewConn(0); err != nil {
+			return err
+		}
+	}
+	if err = f.m.ReadFrom(f.c); err != nil {
+		return err
+	}
+
+	if t, ok := filterTypeName[f.m.Type]; ok {
+		log.Printf("filter: imsg %s\n", t)
+	} else {
+		log.Printf("filter: imsg UNKNOWN %d\n", f.m.Type)
+	}
+
+	switch f.m.Type {
+	case TypeFilterRegister:
+		var err error
+		if f.Version, err = f.m.GetTypeUint32(); err != nil {
+			return err
+		}
+		if f.Name, err = f.m.GetTypeString(); err != nil {
+			return err
+		}
+		log.Printf("register version=%d,name=%q\n", f.Version, f.Name)
+
+		f.m.reset()
+		f.m.Type = TypeFilterRegister
+		f.m.PutTypeInt(f.hooks)
+		f.m.PutTypeInt(f.flags)
+		if err = f.m.SendTo(0); err != nil {
+			return err
+		}
+	default:
+		return fmt.Errorf("filter: unexpected imsg type=%s\n", filterTypeName[f.m.Type])
+	}
+
+	return nil
+}
+
+func (f *Filter) Serve() error {
+	var err error
+	if f.m == nil {
+		f.m = new(Message)
+	}
+	if f.session == nil {
+		if f.session, err = lru.New(1024); err != nil {
+			return err
+		}
+	}
+	if f.c == nil {
+		if f.c, err = NewConn(0); err != nil {
+			return err
+		}
+	}
+
+	for {
+		//log.Printf("fdcount: %d [pid=%d]\n", fdCount(), os.Getpid())
+		if err := f.m.ReadFrom(f.c); err != nil {
+			if err.Error() != "resource temporarily unavailable" {
+				return err
+			}
+		}
+		if err := f.handle(); err != nil {
+			return err
+		}
+	}
+}
+
+func (f *Filter) handle() (err error) {
+	if t, ok := filterTypeName[f.m.Type]; ok {
+		log.Printf("filter: imsg %s\n", t)
+	} else {
+		log.Printf("filter: imsg UNKNOWN %d\n", f.m.Type)
+	}
+
+	switch f.m.Type {
+	case TypeFilterEvent:
+		if err = f.handleEvent(); err != nil {
+			return
+		}
+
+	case TypeFilterQuery:
+		if err = f.handleQuery(); err != nil {
+			return
+		}
+	}
+
+	return
+}
+
+func fdCount() int {
+	d, err := os.Open("/proc/self/fd")
+	if err != nil {
+		log.Printf("fdcount open: %v\n", err)
+		return -1
+	}
+	defer d.Close()
+	fds, err := d.Readdirnames(-1)
+	if err != nil {
+		log.Printf("fdcount: %v\n", err)
+		return -1
+	}
+	return len(fds) - 1 // -1 for os.Open...
+}
+
+func (f *Filter) handleEvent() (err error) {
+	var (
+		id uint64
+		t  int
+	)
+
+	if id, err = f.m.GetTypeID(); err != nil {
+		return
+	}
+	if t, err = f.m.GetTypeInt(); err != nil {
+		return
+	}
+
+	log.Printf("imsg event: %s [id=%#x]\n", eventName(t), id)
+	log.Printf("imsg event data: %q\n", f.m.Data[14:])
+	log.Printf("fdcount: %d [pid=%d]\n", fdCount(), os.Getpid())
+
+	switch t {
+	case EventConnect:
+		f.session.Add(id, NewSession(f, id))
+	case EventDisconnect:
+		f.session.Remove(id)
+	}
+
+	return
+}
+
+func (f *Filter) handleQuery() (err error) {
+	var (
+		id, qid uint64
+		t       int
+	)
+
+	if id, err = f.m.GetTypeID(); err != nil {
+		return
+	}
+	if qid, err = f.m.GetTypeID(); err != nil {
+		return
+	}
+	if t, err = f.m.GetTypeInt(); err != nil {
+		return
+	}
+
+	log.Printf("imsg query: %s [id=%#x,qid=%#x]\n", queryName(t), id, qid)
+	//log.Printf("imsg query data (%d remaining): %q\n", len(f.m.Data[f.m.rpos:]), f.m.Data[f.m.rpos:])
+	//log.Printf("fdcount: %d [pid=%d]\n", fdCount(), os.Getpid())
+
+	var s *Session
+	if cached, ok := f.session.Get(id); ok {
+		s = cached.(*Session)
+	} else {
+		s = NewSession(f, id)
+		f.session.Add(id, s)
+	}
+	s.qtype = t
+	s.qid = qid
+
+	switch t {
+	case QueryConnect:
+		var query ConnectQuery
+		if query.Local, err = f.m.GetTypeSockaddr(); err != nil {
+			return
+		}
+		if query.Remote, err = f.m.GetTypeSockaddr(); err != nil {
+			return
+		}
+		if query.Hostname, err = f.m.GetTypeString(); err != nil {
+			return
+		}
+
+		log.Printf("query connect: %s\n", query)
+		if f.hook.connect != nil {
+			return f.hook.connect(s, &query)
+		}
+
+		log.Printf("filter: WARNING: no connect callback\n")
+
+	case QueryHELO:
+		var line string
+		if line, err = f.m.GetTypeString(); err != nil {
+			return
+		}
+
+		log.Printf("query HELO: %q\n", line)
+		if f.hook.helo != nil {
+			return f.hook.helo(s, line)
+		}
+
+		log.Printf("filter: WARNING: no HELO callback\n")
+		return f.respond(s, FilterOK, 0, "")
+
+	case QueryMAIL:
+		var user, domain string
+		if user, domain, err = f.m.GetTypeMailaddr(); err != nil {
+			return
+		}
+
+		log.Printf("query MAIL: %s\n", user+"@"+domain)
+		if f.hook.mail != nil {
+			return f.hook.mail(s, user, domain)
+		}
+
+		log.Printf("filter: WARNING: no MAIL callback\n")
+		return f.respond(s, FilterOK, 0, "")
+
+	case QueryRCPT:
+		var user, domain string
+		if user, domain, err = f.m.GetTypeMailaddr(); err != nil {
+			return
+		}
+
+		log.Printf("query RCPT: %s\n", user+"@"+domain)
+		if f.hook.rcpt != nil {
+			return f.hook.rcpt(s, user, domain)
+		}
+
+		log.Printf("filter: WARNING: no RCPT callback\n")
+		return f.respond(s, FilterOK, 0, "")
+
+	case QueryDATA:
+		if f.hook.data != nil {
+			return f.hook.data(s)
+		}
+
+		log.Printf("filter: WARNING: no DATA callback\n")
+		return f.respond(s, FilterOK, 0, "")
+
+	case QueryEOM:
+		var dataLen uint32
+		if dataLen, err = f.m.GetTypeUint32(); err != nil {
+			return
+		}
+
+		if f.hook.eom != nil {
+			return f.hook.eom(s, dataLen)
+		}
+
+		log.Printf("filter: WARNING: no EOM callback\n")
+		return f.respond(s, FilterOK, 0, "")
+	}
+
+	return
+}
+
+func (f *Filter) respond(s *Session, status, code int, line string) error {
+	log.Printf("filter: %s %s [code=%d,line=%q]\n", filterName(TypeFilterResponse), responseName(status), code, line)
+
+	if s.qtype == QueryEOM {
+		// Not implemented
+		return nil
+	}
+
+	m := new(Message)
+	m.Type = TypeFilterResponse
+	m.PutTypeID(s.qid)
+	m.PutTypeInt(s.qtype)
+	if s.qtype == QueryEOM {
+		// Not imlemented
+		return nil
+	}
+	m.PutTypeInt(status)
+	m.PutTypeInt(code)
+	if line != "" {
+		m.PutTypeString(line)
+	}
+
+	if err := m.WriteTo(f.c); err != nil {
+		log.Printf("filter: respond failed: %v\n", err)
+		return err
+	}
+
+	return nil
+}

imsg.go

@@ -0,0 +1,315 @@
+package opensmtpd
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"os"
+	"syscall"
+)
+
+const (
+	ibufReadSize   = 65535
+	imsgMaxSize    = 16384
+	imsgHeaderSize = 4 + 2 + 2 + 4 + 4
+	imsgVersion    = 14
+
+	maxLocalPartSize  = (255 + 1)
+	maxDomainPartSize = (255 + 1)
+)
+
+type MessageHeader struct {
+	Type   uint32
+	Len    uint16
+	Flags  uint16
+	PeerID uint32
+	PID    uint32
+}
+
+type Message struct {
+	MessageHeader
+	Data []byte
+
+	// rpos is the read position in the current Data
+	rpos int
+
+	// buf is what we read from the socket (and remains)
+	buf []byte
+}
+
+func (m *Message) reset() {
+	m.Type = 0
+	m.Len = 0
+	m.Flags = 0
+	m.PeerID = imsgVersion
+	m.PID = uint32(os.Getpid())
+	m.Data = m.Data[:0]
+	m.rpos = 0
+	m.buf = m.buf[:0]
+}
+
+func (m *Message) ReadFrom(c net.Conn) error {
+	m.reset()
+
+	head := make([]byte, imsgHeaderSize)
+	if _, err := c.Read(head); err != nil {
+		return err
+	}
+
+	r := bytes.NewBuffer(head)
+	if err := binary.Read(r, binary.LittleEndian, &m.MessageHeader); err != nil {
+		return err
+	}
+
+	data := make([]byte, m.MessageHeader.Len-imsgHeaderSize)
+	if _, err := c.Read(data); err != nil {
+		return err
+	}
+
+	m.Data = data
+	return nil
+}
+
+func (m *Message) SendTo(fd int) error {
+	m.Len = uint16(len(m.Data)) + imsgHeaderSize
+
+	buf := new(bytes.Buffer)
+	//log.Printf("imsg header: %+v\n", m.MessageHeader)
+	if err := binary.Write(buf, binary.LittleEndian, &m.MessageHeader); err != nil {
+		return err
+	}
+	buf.Write(m.Data)
+	//log.Printf("imsg send: %d / %q\n", buf.Len(), buf.Bytes())
+	return syscall.Sendmsg(fd, buf.Bytes(), nil, nil, 0)
+}
+
+func (m *Message) WriteTo(c net.Conn) error {
+	m.Len = uint16(len(m.Data)) + imsgHeaderSize
+
+	buf := new(bytes.Buffer)
+	//log.Printf("imsg header: %+v\n", m.MessageHeader)
+	if err := binary.Write(buf, binary.LittleEndian, &m.MessageHeader); err != nil {
+		return err
+	}
+	buf.Write(m.Data)
+	//log.Printf("imsg send: %d / %q\n", buf.Len(), buf.Bytes())
+
+	_, err := c.Write(buf.Bytes())
+	return err
+}
+
+func (m *Message) GetInt() (int, error) {
+	if m.rpos+4 > len(m.Data) {
+		return 0, io.ErrShortBuffer
+	}
+	i := binary.LittleEndian.Uint32(m.Data[m.rpos:])
+	m.rpos += 4
+	return int(i), nil
+}
+
+func (m *Message) GetUint32() (uint32, error) {
+	if m.rpos+4 > len(m.Data) {
+		return 0, io.ErrShortBuffer
+	}
+	u := binary.LittleEndian.Uint32(m.Data[m.rpos:])
+	m.rpos += 4
+	return u, nil
+}
+
+func (m *Message) GetSize() (uint64, error) {
+	if m.rpos+8 > len(m.Data) {
+		return 0, io.ErrShortBuffer
+	}
+	u := binary.LittleEndian.Uint64(m.Data[m.rpos:])
+	m.rpos += 8
+	return u, nil
+}
+
+func (m *Message) GetString() (string, error) {
+	o := bytes.IndexByte(m.Data[m.rpos:], 0)
+	if o < 0 {
+		return "", errors.New("imsg: string not NULL-terminated")
+	}
+
+	s := string(m.Data[m.rpos : m.rpos+o])
+	m.rpos += o
+	return s, nil
+}
+
+func (m *Message) GetID() (uint64, error) {
+	if m.rpos+8 > len(m.Data) {
+		return 0, io.ErrShortBuffer
+	}
+	u := binary.LittleEndian.Uint64(m.Data[m.rpos:])
+	m.rpos += 8
+	return u, nil
+}
+
+type Sockaddr []byte
+
+func (sa Sockaddr) IP() net.IP {
+	switch len(sa) {
+	case 16: // IPv4, sockaddr_in
+		return net.IP(sa[4:8])
+	case 28: // IPv6, sockaddr_in6
+		return net.IP(sa[8:24])
+	default:
+		return nil
+	}
+}
+
+func (sa Sockaddr) Port() uint16 {
+	switch len(sa) {
+	case 16: // IPv4, sockaddr_in
+		return binary.LittleEndian.Uint16(sa[2:4])
+	case 28: // IPv6, sockaddr_in6
+		return binary.LittleEndian.Uint16(sa[2:4])
+	default:
+		return 0
+	}
+}
+
+func (sa Sockaddr) Network() string {
+	return "bla"
+}
+
+func (sa Sockaddr) String() string {
+	return fmt.Sprintf("%s:%d", sa.IP(), sa.Port())
+}
+
+func (m *Message) GetSockaddr() (net.Addr, error) {
+	s, err := m.GetSize()
+	if err != nil {
+		return nil, err
+	}
+	if m.rpos+int(s) > len(m.Data) {
+		return nil, io.ErrShortBuffer
+	}
+
+	a := make(Sockaddr, s)
+	copy(a[:], m.Data[m.rpos:])
+	m.rpos += int(s)
+
+	return a, nil
+}
+
+func (m *Message) GetMailaddr() (user, domain string, err error) {
+	var buf [maxLocalPartSize + maxDomainPartSize]byte
+	if maxLocalPartSize+maxDomainPartSize > len(m.Data[m.rpos:]) {
+		return "", "", io.ErrShortBuffer
+	}
+	copy(buf[:], m.Data[m.rpos:])
+	m.rpos += maxLocalPartSize + maxDomainPartSize
+	user = string(buf[:maxLocalPartSize])
+	domain = string(buf[maxLocalPartSize:])
+	return
+}
+
+func (m *Message) GetType(t uint8) error {
+	if m.rpos >= len(m.Data) {
+		return io.ErrShortBuffer
+	}
+
+	b := m.Data[m.rpos]
+	m.rpos++
+	if b != t {
+		return MProcTypeErr{t, b}
+	}
+	return nil
+}
+
+func (m *Message) GetTypeInt() (int, error) {
+	if err := m.GetType(M_INT); err != nil {
+		return 0, err
+	}
+	return m.GetInt()
+}
+
+func (m *Message) GetTypeUint32() (uint32, error) {
+	if err := m.GetType(M_UINT32); err != nil {
+		return 0, err
+	}
+	return m.GetUint32()
+}
+
+func (m *Message) GetTypeString() (string, error) {
+	if err := m.GetType(M_STRING); err != nil {
+		return "", err
+	}
+	return m.GetString()
+}
+
+func (m *Message) GetTypeID() (uint64, error) {
+	if err := m.GetType(M_ID); err != nil {
+		return 0, err
+	}
+	return m.GetID()
+}
+
+func (m *Message) GetTypeSockaddr() (net.Addr, error) {
+	if err := m.GetType(M_SOCKADDR); err != nil {
+		return nil, err
+	}
+	return m.GetSockaddr()
+}
+
+func (m *Message) GetTypeMailaddr() (user, domain string, err error) {
+	if err = m.GetType(M_MAILADDR); err != nil {
+		return
+	}
+	return m.GetMailaddr()
+}
+
+func (m *Message) PutInt(v int) {
+	var b [4]byte
+	binary.LittleEndian.PutUint32(b[:], uint32(v))
+	m.Data = append(m.Data, b[:]...)
+	m.Len += 4
+}
+
+func (m *Message) PutUint32(v uint32) {
+	var b [4]byte
+	binary.LittleEndian.PutUint32(b[:], v)
+	m.Data = append(m.Data, b[:]...)
+	m.Len += 4
+}
+
+func (m *Message) PutString(s string) {
+	m.Data = append(m.Data, append([]byte(s), 0)...)
+	m.Len += uint16(len(s)) + 1
+}
+
+func (m *Message) PutID(id uint64) {
+	var b [8]byte
+	binary.LittleEndian.PutUint64(b[:], id)
+	m.Data = append(m.Data, b[:]...)
+	m.Len += 8
+}
+
+func (m *Message) PutType(t uint8) {
+	m.Data = append(m.Data, t)
+	m.Len += 1
+}
+
+func (m *Message) PutTypeInt(v int) {
+	m.PutType(M_INT)
+	m.PutInt(v)
+}
+
+func (m *Message) PutTypeUint32(v uint32) {
+	m.PutType(M_UINT32)
+	m.PutUint32(v)
+}
+
+func (m *Message) PutTypeString(s string) {
+	m.PutType(M_STRING)
+	m.PutString(s)
+}
+
+func (m *Message) PutTypeID(id uint64) {
+	m.PutType(M_ID)
+	m.PutID(id)
+}

mproc.go

@@ -0,0 +1,51 @@
+package opensmtpd
+
+import (
+	"fmt"
+)
+
+const (
+	M_INT = iota
+	M_UINT32
+	M_SIZET
+	M_TIME
+	M_STRING
+	M_DATA
+	M_ID
+	M_EVPID
+	M_MSGID
+	M_SOCKADDR
+	M_MAILADDR
+	M_ENVELOPE
+)
+
+var mprocTypeName = map[uint8]string{
+	M_INT:      "M_INT",
+	M_UINT32:   "M_UINT32",
+	M_SIZET:    "M_SIZET",
+	M_TIME:     "M_TIME",
+	M_STRING:   "M_STRING",
+	M_DATA:     "M_DATA",
+	M_ID:       "M_ID",
+	M_EVPID:    "M_EVPID",
+	M_MSGID:    "M_MSGID",
+	M_SOCKADDR: "M_SOCKADDR",
+	M_MAILADDR: "M_MAILADDR",
+	M_ENVELOPE: "M_ENVELOPE",
+}
+
+func mprocType(t uint8) string {
+	if s, ok := mprocTypeName[t]; ok {
+		return s
+	}
+	return fmt.Sprintf("UNKNOWN %d", t)
+}
+
+type MProcTypeErr struct {
+	want, got uint8
+}
+
+func (err MProcTypeErr) Error() string {
+	return fmt.Sprintf("mproc: expected type %s, got %s",
+		mprocType(err.want), mprocType(err.got))
+}

query.go

@@ -0,0 +1,15 @@
+package opensmtpd
+
+import (
+	"fmt"
+	"net"
+)
+
+type ConnectQuery struct {
+	Local, Remote net.Addr
+	Hostname      string
+}
+
+func (q ConnectQuery) String() string {
+	return fmt.Sprintf("%s -> %s [hostname=%s]", q.Remote, q.Local, q.Hostname)
+}

session.go

@@ -0,0 +1,40 @@
+package opensmtpd
+
+type Session struct {
+	ID uint64
+
+	filter *Filter
+	qtype  int
+	qid    uint64
+}
+
+func NewSession(f *Filter, id uint64) *Session {
+	return &Session{
+		ID:     id,
+		filter: f,
+	}
+}
+
+func (s *Session) Accept() error {
+	return s.filter.respond(s, FilterOK, 0, "")
+}
+
+func (s *Session) AcceptCode(code int, line string) error {
+	return s.filter.respond(s, FilterOK, code, line)
+}
+
+func (s *Session) Reject(status, code int) error {
+	if status == FilterOK {
+		status = FilterFail
+	}
+
+	return s.filter.respond(s, status, code, "")
+}
+
+func (s *Session) RejectCode(status, code int, line string) error {
+	if status == FilterOK {
+		status = FilterFail
+	}
+
+	return s.filter.respond(s, status, code, line)
+}

vendor/github.com/hashicorp/golang-lru/.gitignore

@@ -0,0 +1,23 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test

vendor/github.com/hashicorp/golang-lru/2q.go

@@ -0,0 +1,212 @@
+package lru
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/hashicorp/golang-lru/simplelru"
+)
+
+const (
+	// Default2QRecentRatio is the ratio of the 2Q cache dedicated
+	// to recently added entries that have only been accessed once.
+	Default2QRecentRatio = 0.25
+
+	// Default2QGhostEntries is the default ratio of ghost
+	// entries kept to track entries recently evicted
+	Default2QGhostEntries = 0.50
+)
+
+// TwoQueueCache is a thread-safe fixed size 2Q cache.
+// 2Q is an enhancement over the standard LRU cache
+// in that it tracks both frequently and recently used
+// entries separately. This avoids a burst in access to new
+// entries from evicting frequently used entries. It adds some
+// additional tracking overhead to the standard LRU cache, and is
+// computationally about 2x the cost, and adds some metadata over
+// head. The ARCCache is similar, but does not require setting any
+// parameters.
+type TwoQueueCache struct {
+	size       int
+	recentSize int
+
+	recent      *simplelru.LRU
+	frequent    *simplelru.LRU
+	recentEvict *simplelru.LRU
+	lock        sync.RWMutex
+}
+
+// New2Q creates a new TwoQueueCache using the default
+// values for the parameters.
+func New2Q(size int) (*TwoQueueCache, error) {
+	return New2QParams(size, Default2QRecentRatio, Default2QGhostEntries)
+}
+
+// New2QParams creates a new TwoQueueCache using the provided
+// parameter values.
+func New2QParams(size int, recentRatio float64, ghostRatio float64) (*TwoQueueCache, error) {
+	if size <= 0 {
+		return nil, fmt.Errorf("invalid size")
+	}
+	if recentRatio < 0.0 || recentRatio > 1.0 {
+		return nil, fmt.Errorf("invalid recent ratio")
+	}
+	if ghostRatio < 0.0 || ghostRatio > 1.0 {
+		return nil, fmt.Errorf("invalid ghost ratio")
+	}
+
+	// Determine the sub-sizes
+	recentSize := int(float64(size) * recentRatio)
+	evictSize := int(float64(size) * ghostRatio)
+
+	// Allocate the LRUs
+	recent, err := simplelru.NewLRU(size, nil)
+	if err != nil {
+		return nil, err
+	}
+	frequent, err := simplelru.NewLRU(size, nil)
+	if err != nil {
+		return nil, err
+	}
+	recentEvict, err := simplelru.NewLRU(evictSize, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	// Initialize the cache
+	c := &TwoQueueCache{
+		size:        size,
+		recentSize:  recentSize,
+		recent:      recent,
+		frequent:    frequent,
+		recentEvict: recentEvict,
+	}
+	return c, nil
+}
+
+func (c *TwoQueueCache) Get(key interface{}) (interface{}, bool) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	// Check if this is a frequent value
+	if val, ok := c.frequent.Get(key); ok {
+		return val, ok
+	}
+
+	// If the value is contained in recent, then we
+	// promote it to frequent
+	if val, ok := c.recent.Peek(key); ok {
+		c.recent.Remove(key)
+		c.frequent.Add(key, val)
+		return val, ok
+	}
+
+	// No hit
+	return nil, false
+}
+
+func (c *TwoQueueCache) Add(key, value interface{}) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	// Check if the value is frequently used already,
+	// and just update the value
+	if c.frequent.Contains(key) {
+		c.frequent.Add(key, value)
+		return
+	}
+
+	// Check if the value is recently used, and promote
+	// the value into the frequent list
+	if c.recent.Contains(key) {
+		c.recent.Remove(key)
+		c.frequent.Add(key, value)
+		return
+	}
+
+	// If the value was recently evicted, add it to the
+	// frequently used list
+	if c.recentEvict.Contains(key) {
+		c.ensureSpace(true)
+		c.recentEvict.Remove(key)
+		c.frequent.Add(key, value)
+		return
+	}
+
+	// Add to the recently seen list
+	c.ensureSpace(false)
+	c.recent.Add(key, value)
+	return
+}
+
+// ensureSpace is used to ensure we have space in the cache
+func (c *TwoQueueCache) ensureSpace(recentEvict bool) {
+	// If we have space, nothing to do
+	recentLen := c.recent.Len()
+	freqLen := c.frequent.Len()
+	if recentLen+freqLen < c.size {
+		return
+	}
+
+	// If the recent buffer is larger than
+	// the target, evict from there
+	if recentLen > 0 && (recentLen > c.recentSize || (recentLen == c.recentSize && !recentEvict)) {
+		k, _, _ := c.recent.RemoveOldest()
+		c.recentEvict.Add(k, nil)
+		return
+	}
+
+	// Remove from the frequent list otherwise
+	c.frequent.RemoveOldest()
+}
+
+func (c *TwoQueueCache) Len() int {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	return c.recent.Len() + c.frequent.Len()
+}
+
+func (c *TwoQueueCache) Keys() []interface{} {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	k1 := c.frequent.Keys()
+	k2 := c.recent.Keys()
+	return append(k1, k2...)
+}
+
+func (c *TwoQueueCache) Remove(key interface{}) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	if c.frequent.Remove(key) {
+		return
+	}
+	if c.recent.Remove(key) {
+		return
+	}
+	if c.recentEvict.Remove(key) {
+		return
+	}
+}
+
+func (c *TwoQueueCache) Purge() {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	c.recent.Purge()
+	c.frequent.Purge()
+	c.recentEvict.Purge()
+}
+
+func (c *TwoQueueCache) Contains(key interface{}) bool {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	return c.frequent.Contains(key) || c.recent.Contains(key)
+}
+
+func (c *TwoQueueCache) Peek(key interface{}) (interface{}, bool) {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	if val, ok := c.frequent.Peek(key); ok {
+		return val, ok
+	}
+	return c.recent.Peek(key)
+}

vendor/github.com/hashicorp/golang-lru/2q_test.go

@@ -0,0 +1,306 @@
+package lru
+
+import (
+	"math/rand"
+	"testing"
+)
+
+func Benchmark2Q_Rand(b *testing.B) {
+	l, err := New2Q(8192)
+	if err != nil {
+		b.Fatalf("err: %v", err)
+	}
+
+	trace := make([]int64, b.N*2)
+	for i := 0; i < b.N*2; i++ {
+		trace[i] = rand.Int63() % 32768
+	}
+
+	b.ResetTimer()
+
+	var hit, miss int
+	for i := 0; i < 2*b.N; i++ {
+		if i%2 == 0 {
+			l.Add(trace[i], trace[i])
+		} else {
+			_, ok := l.Get(trace[i])
+			if ok {
+				hit++
+			} else {
+				miss++
+			}
+		}
+	}
+	b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(miss))
+}
+
+func Benchmark2Q_Freq(b *testing.B) {
+	l, err := New2Q(8192)
+	if err != nil {
+		b.Fatalf("err: %v", err)
+	}
+
+	trace := make([]int64, b.N*2)
+	for i := 0; i < b.N*2; i++ {
+		if i%2 == 0 {
+			trace[i] = rand.Int63() % 16384
+		} else {
+			trace[i] = rand.Int63() % 32768
+		}
+	}
+
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		l.Add(trace[i], trace[i])
+	}
+	var hit, miss int
+	for i := 0; i < b.N; i++ {
+		_, ok := l.Get(trace[i])
+		if ok {
+			hit++
+		} else {
+			miss++
+		}
+	}
+	b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(miss))
+}
+
+func Test2Q_RandomOps(t *testing.T) {
+	size := 128
+	l, err := New2Q(128)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	n := 200000
+	for i := 0; i < n; i++ {
+		key := rand.Int63() % 512
+		r := rand.Int63()
+		switch r % 3 {
+		case 0:
+			l.Add(key, key)
+		case 1:
+			l.Get(key)
+		case 2:
+			l.Remove(key)
+		}
+
+		if l.recent.Len()+l.frequent.Len() > size {
+			t.Fatalf("bad: recent: %d freq: %d",
+				l.recent.Len(), l.frequent.Len())
+		}
+	}
+}
+
+func Test2Q_Get_RecentToFrequent(t *testing.T) {
+	l, err := New2Q(128)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Touch all the entries, should be in t1
+	for i := 0; i < 128; i++ {
+		l.Add(i, i)
+	}
+	if n := l.recent.Len(); n != 128 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.frequent.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Get should upgrade to t2
+	for i := 0; i < 128; i++ {
+		_, ok := l.Get(i)
+		if !ok {
+			t.Fatalf("missing: %d", i)
+		}
+	}
+	if n := l.recent.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.frequent.Len(); n != 128 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Get be from t2
+	for i := 0; i < 128; i++ {
+		_, ok := l.Get(i)
+		if !ok {
+			t.Fatalf("missing: %d", i)
+		}
+	}
+	if n := l.recent.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.frequent.Len(); n != 128 {
+		t.Fatalf("bad: %d", n)
+	}
+}
+
+func Test2Q_Add_RecentToFrequent(t *testing.T) {
+	l, err := New2Q(128)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Add initially to recent
+	l.Add(1, 1)
+	if n := l.recent.Len(); n != 1 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.frequent.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Add should upgrade to frequent
+	l.Add(1, 1)
+	if n := l.recent.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.frequent.Len(); n != 1 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Add should remain in frequent
+	l.Add(1, 1)
+	if n := l.recent.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.frequent.Len(); n != 1 {
+		t.Fatalf("bad: %d", n)
+	}
+}
+
+func Test2Q_Add_RecentEvict(t *testing.T) {
+	l, err := New2Q(4)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Add 1,2,3,4,5 -> Evict 1
+	l.Add(1, 1)
+	l.Add(2, 2)
+	l.Add(3, 3)
+	l.Add(4, 4)
+	l.Add(5, 5)
+	if n := l.recent.Len(); n != 4 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.recentEvict.Len(); n != 1 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.frequent.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Pull in the recently evicted
+	l.Add(1, 1)
+	if n := l.recent.Len(); n != 3 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.recentEvict.Len(); n != 1 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.frequent.Len(); n != 1 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Add 6, should cause another recent evict
+	l.Add(6, 6)
+	if n := l.recent.Len(); n != 3 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.recentEvict.Len(); n != 2 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.frequent.Len(); n != 1 {
+		t.Fatalf("bad: %d", n)
+	}
+}
+
+func Test2Q(t *testing.T) {
+	l, err := New2Q(128)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	for i := 0; i < 256; i++ {
+		l.Add(i, i)
+	}
+	if l.Len() != 128 {
+		t.Fatalf("bad len: %v", l.Len())
+	}
+
+	for i, k := range l.Keys() {
+		if v, ok := l.Get(k); !ok || v != k || v != i+128 {
+			t.Fatalf("bad key: %v", k)
+		}
+	}
+	for i := 0; i < 128; i++ {
+		_, ok := l.Get(i)
+		if ok {
+			t.Fatalf("should be evicted")
+		}
+	}
+	for i := 128; i < 256; i++ {
+		_, ok := l.Get(i)
+		if !ok {
+			t.Fatalf("should not be evicted")
+		}
+	}
+	for i := 128; i < 192; i++ {
+		l.Remove(i)
+		_, ok := l.Get(i)
+		if ok {
+			t.Fatalf("should be deleted")
+		}
+	}
+
+	l.Purge()
+	if l.Len() != 0 {
+		t.Fatalf("bad len: %v", l.Len())
+	}
+	if _, ok := l.Get(200); ok {
+		t.Fatalf("should contain nothing")
+	}
+}
+
+// Test that Contains doesn't update recent-ness
+func Test2Q_Contains(t *testing.T) {
+	l, err := New2Q(2)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	l.Add(1, 1)
+	l.Add(2, 2)
+	if !l.Contains(1) {
+		t.Errorf("1 should be contained")
+	}
+
+	l.Add(3, 3)
+	if l.Contains(1) {
+		t.Errorf("Contains should not have updated recent-ness of 1")
+	}
+}
+
+// Test that Peek doesn't update recent-ness
+func Test2Q_Peek(t *testing.T) {
+	l, err := New2Q(2)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	l.Add(1, 1)
+	l.Add(2, 2)
+	if v, ok := l.Peek(1); !ok || v != 1 {
+		t.Errorf("1 should be set to 1: %v, %v", v, ok)
+	}
+
+	l.Add(3, 3)
+	if l.Contains(1) {
+		t.Errorf("should not have updated recent-ness of 1")
+	}
+}

vendor/github.com/hashicorp/golang-lru/LICENSE

@@ -0,0 +1,362 @@
+Mozilla Public License, version 2.0
+
+1. Definitions
+
+1.1. "Contributor"
+
+     means each individual or legal entity that creates, contributes to the
+     creation of, or owns Covered Software.
+
+1.2. "Contributor Version"
+
+     means the combination of the Contributions of others (if any) used by a
+     Contributor and that particular Contributor's Contribution.
+
+1.3. "Contribution"
+
+     means Covered Software of a particular Contributor.
+
+1.4. "Covered Software"
+
+     means Source Code Form to which the initial Contributor has attached the
+     notice in Exhibit A, the Executable Form of such Source Code Form, and
+     Modifications of such Source Code Form, in each case including portions
+     thereof.
+
+1.5. "Incompatible With Secondary Licenses"
+     means
+
+     a. that the initial Contributor has attached the notice described in
+        Exhibit B to the Covered Software; or
+
+     b. that the Covered Software was made available under the terms of
+        version 1.1 or earlier of the License, but not also under the terms of
+        a Secondary License.
+
+1.6. "Executable Form"
+
+     means any form of the work other than Source Code Form.
+
+1.7. "Larger Work"
+
+     means a work that combines Covered Software with other material, in a
+     separate file or files, that is not Covered Software.
+
+1.8. "License"
+
+     means this document.
+
+1.9. "Licensable"
+
+     means having the right to grant, to the maximum extent possible, whether
+     at the time of the initial grant or subsequently, any and all of the
+     rights conveyed by this License.
+
+1.10. "Modifications"
+
+     means any of the following:
+
+     a. any file in Source Code Form that results from an addition to,
+        deletion from, or modification of the contents of Covered Software; or
+
+     b. any new file in Source Code Form that contains any Covered Software.
+
+1.11. "Patent Claims" of a Contributor
+
+      means any patent claim(s), including without limitation, method,
+      process, and apparatus claims, in any patent Licensable by such
+      Contributor that would be infringed, but for the grant of the License,
+      by the making, using, selling, offering for sale, having made, import,
+      or transfer of either its Contributions or its Contributor Version.
+
+1.12. "Secondary License"
+
+      means either the GNU General Public License, Version 2.0, the GNU Lesser
+      General Public License, Version 2.1, the GNU Affero General Public
+      License, Version 3.0, or any later versions of those licenses.
+
+1.13. "Source Code Form"
+
+      means the form of the work preferred for making modifications.
+
+1.14. "You" (or "Your")
+
+      means an individual or a legal entity exercising rights under this
+      License. For legal entities, "You" includes any entity that controls, is
+      controlled by, or is under common control with You. For purposes of this
+      definition, "control" means (a) the power, direct or indirect, to cause
+      the direction or management of such entity, whether by contract or
+      otherwise, or (b) ownership of more than fifty percent (50%) of the
+      outstanding shares or beneficial ownership of such entity.
+
+
+2. License Grants and Conditions
+
+2.1. Grants
+
+     Each Contributor hereby grants You a world-wide, royalty-free,
+     non-exclusive license:
+
+     a. under intellectual property rights (other than patent or trademark)
+        Licensable by such Contributor to use, reproduce, make available,
+        modify, display, perform, distribute, and otherwise exploit its
+        Contributions, either on an unmodified basis, with Modifications, or
+        as part of a Larger Work; and
+
+     b. under Patent Claims of such Contributor to make, use, sell, offer for
+        sale, have made, import, and otherwise transfer either its
+        Contributions or its Contributor Version.
+
+2.2. Effective Date
+
+     The licenses granted in Section 2.1 with respect to any Contribution
+     become effective for each Contribution on the date the Contributor first
+     distributes such Contribution.
+
+2.3. Limitations on Grant Scope
+
+     The licenses granted in this Section 2 are the only rights granted under
+     this License. No additional rights or licenses will be implied from the
+     distribution or licensing of Covered Software under this License.
+     Notwithstanding Section 2.1(b) above, no patent license is granted by a
+     Contributor:
+
+     a. for any code that a Contributor has removed from Covered Software; or
+
+     b. for infringements caused by: (i) Your and any other third party's
+        modifications of Covered Software, or (ii) the combination of its
+        Contributions with other software (except as part of its Contributor
+        Version); or
+
+     c. under Patent Claims infringed by Covered Software in the absence of
+        its Contributions.
+
+     This License does not grant any rights in the trademarks, service marks,
+     or logos of any Contributor (except as may be necessary to comply with
+     the notice requirements in Section 3.4).
+
+2.4. Subsequent Licenses
+
+     No Contributor makes additional grants as a result of Your choice to
+     distribute the Covered Software under a subsequent version of this
+     License (see Section 10.2) or under the terms of a Secondary License (if
+     permitted under the terms of Section 3.3).
+
+2.5. Representation
+
+     Each Contributor represents that the Contributor believes its
+     Contributions are its original creation(s) or it has sufficient rights to
+     grant the rights to its Contributions conveyed by this License.
+
+2.6. Fair Use
+
+     This License is not intended to limit any rights You have under
+     applicable copyright doctrines of fair use, fair dealing, or other
+     equivalents.
+
+2.7. Conditions
+
+     Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted in
+     Section 2.1.
+
+
+3. Responsibilities
+
+3.1. Distribution of Source Form
+
+     All distribution of Covered Software in Source Code Form, including any
+     Modifications that You create or to which You contribute, must be under
+     the terms of this License. You must inform recipients that the Source
+     Code Form of the Covered Software is governed by the terms of this
+     License, and how they can obtain a copy of this License. You may not
+     attempt to alter or restrict the recipients' rights in the Source Code
+     Form.
+
+3.2. Distribution of Executable Form
+
+     If You distribute Covered Software in Executable Form then:
+
+     a. such Covered Software must also be made available in Source Code Form,
+        as described in Section 3.1, and You must inform recipients of the
+        Executable Form how they can obtain a copy of such Source Code Form by
+        reasonable means in a timely manner, at a charge no more than the cost
+        of distribution to the recipient; and
+
+     b. You may distribute such Executable Form under the terms of this
+        License, or sublicense it under different terms, provided that the
+        license for the Executable Form does not attempt to limit or alter the
+        recipients' rights in the Source Code Form under this License.
+
+3.3. Distribution of a Larger Work
+
+     You may create and distribute a Larger Work under terms of Your choice,
+     provided that You also comply with the requirements of this License for
+     the Covered Software. If the Larger Work is a combination of Covered
+     Software with a work governed by one or more Secondary Licenses, and the
+     Covered Software is not Incompatible With Secondary Licenses, this
+     License permits You to additionally distribute such Covered Software
+     under the terms of such Secondary License(s), so that the recipient of
+     the Larger Work may, at their option, further distribute the Covered
+     Software under the terms of either this License or such Secondary
+     License(s).
+
+3.4. Notices
+
+     You may not remove or alter the substance of any license notices
+     (including copyright notices, patent notices, disclaimers of warranty, or
+     limitations of liability) contained within the Source Code Form of the
+     Covered Software, except that You may alter any license notices to the
+     extent required to remedy known factual inaccuracies.
+
+3.5. Application of Additional Terms
+
+     You may choose to offer, and to charge a fee for, warranty, support,
+     indemnity or liability obligations to one or more recipients of Covered
+     Software. However, You may do so only on Your own behalf, and not on
+     behalf of any Contributor. You must make it absolutely clear that any
+     such warranty, support, indemnity, or liability obligation is offered by
+     You alone, and You hereby agree to indemnify every Contributor for any
+     liability incurred by such Contributor as a result of warranty, support,
+     indemnity or liability terms You offer. You may include additional
+     disclaimers of warranty and limitations of liability specific to any
+     jurisdiction.
+
+4. Inability to Comply Due to Statute or Regulation
+
+   If it is impossible for You to comply with any of the terms of this License
+   with respect to some or all of the Covered Software due to statute,
+   judicial order, or regulation then You must: (a) comply with the terms of
+   this License to the maximum extent possible; and (b) describe the
+   limitations and the code they affect. Such description must be placed in a
+   text file included with all distributions of the Covered Software under
+   this License. Except to the extent prohibited by statute or regulation,
+   such description must be sufficiently detailed for a recipient of ordinary
+   skill to be able to understand it.
+
+5. Termination
+
+5.1. The rights granted under this License will terminate automatically if You
+     fail to comply with any of its terms. However, if You become compliant,
+     then the rights granted under this License from a particular Contributor
+     are reinstated (a) provisionally, unless and until such Contributor
+     explicitly and finally terminates Your grants, and (b) on an ongoing
+     basis, if such Contributor fails to notify You of the non-compliance by
+     some reasonable means prior to 60 days after You have come back into
+     compliance. Moreover, Your grants from a particular Contributor are
+     reinstated on an ongoing basis if such Contributor notifies You of the
+     non-compliance by some reasonable means, this is the first time You have
+     received notice of non-compliance with this License from such
+     Contributor, and You become compliant prior to 30 days after Your receipt
+     of the notice.
+
+5.2. If You initiate litigation against any entity by asserting a patent
+     infringement claim (excluding declaratory judgment actions,
+     counter-claims, and cross-claims) alleging that a Contributor Version
+     directly or indirectly infringes any patent, then the rights granted to
+     You by any and all Contributors for the Covered Software under Section
+     2.1 of this License shall terminate.
+
+5.3. In the event of termination under Sections 5.1 or 5.2 above, all end user
+     license agreements (excluding distributors and resellers) which have been
+     validly granted by You or Your distributors under this License prior to
+     termination shall survive termination.
+
+6. Disclaimer of Warranty
+
+   Covered Software is provided under this License on an "as is" basis,
+   without warranty of any kind, either expressed, implied, or statutory,
+   including, without limitation, warranties that the Covered Software is free
+   of defects, merchantable, fit for a particular purpose or non-infringing.
+   The entire risk as to the quality and performance of the Covered Software
+   is with You. Should any Covered Software prove defective in any respect,
+   You (not any Contributor) assume the cost of any necessary servicing,
+   repair, or correction. This disclaimer of warranty constitutes an essential
+   part of this License. No use of  any Covered Software is authorized under
+   this License except under this disclaimer.
+
+7. Limitation of Liability
+
+   Under no circumstances and under no legal theory, whether tort (including
+   negligence), contract, or otherwise, shall any Contributor, or anyone who
+   distributes Covered Software as permitted above, be liable to You for any
+   direct, indirect, special, incidental, or consequential damages of any
+   character including, without limitation, damages for lost profits, loss of
+   goodwill, work stoppage, computer failure or malfunction, or any and all
+   other commercial damages or losses, even if such party shall have been
+   informed of the possibility of such damages. This limitation of liability
+   shall not apply to liability for death or personal injury resulting from
+   such party's negligence to the extent applicable law prohibits such
+   limitation. Some jurisdictions do not allow the exclusion or limitation of
+   incidental or consequential damages, so this exclusion and limitation may
+   not apply to You.
+
+8. Litigation
+
+   Any litigation relating to this License may be brought only in the courts
+   of a jurisdiction where the defendant maintains its principal place of
+   business and such litigation shall be governed by laws of that
+   jurisdiction, without reference to its conflict-of-law provisions. Nothing
+   in this Section shall prevent a party's ability to bring cross-claims or
+   counter-claims.
+
+9. Miscellaneous
+
+   This License represents the complete agreement concerning the subject
+   matter hereof. If any provision of this License is held to be
+   unenforceable, such provision shall be reformed only to the extent
+   necessary to make it enforceable. Any law or regulation which provides that
+   the language of a contract shall be construed against the drafter shall not
+   be used to construe this License against a Contributor.
+
+
+10. Versions of the License
+
+10.1. New Versions
+
+      Mozilla Foundation is the license steward. Except as provided in Section
+      10.3, no one other than the license steward has the right to modify or
+      publish new versions of this License. Each version will be given a
+      distinguishing version number.
+
+10.2. Effect of New Versions
+
+      You may distribute the Covered Software under the terms of the version
+      of the License under which You originally received the Covered Software,
+      or under the terms of any subsequent version published by the license
+      steward.
+
+10.3. Modified Versions
+
+      If you create software not governed by this License, and you want to
+      create a new license for such software, you may create and use a
+      modified version of this License if you rename the license and remove
+      any references to the name of the license steward (except to note that
+      such modified license differs from this License).
+
+10.4. Distributing Source Code Form that is Incompatible With Secondary
+      Licenses If You choose to distribute Source Code Form that is
+      Incompatible With Secondary Licenses under the terms of this version of
+      the License, the notice described in Exhibit B of this License must be
+      attached.
+
+Exhibit A - Source Code Form License Notice
+
+      This Source Code Form is subject to the
+      terms of the Mozilla Public License, v.
+      2.0. If a copy of the MPL was not
+      distributed with this file, You can
+      obtain one at
+      http://mozilla.org/MPL/2.0/.
+
+If it is not possible or desirable to put the notice in a particular file,
+then You may include the notice in a location (such as a LICENSE file in a
+relevant directory) where a recipient would be likely to look for such a
+notice.
+
+You may add additional accurate notices of copyright ownership.
+
+Exhibit B - "Incompatible With Secondary Licenses" Notice
+
+      This Source Code Form is "Incompatible
+      With Secondary Licenses", as defined by
+      the Mozilla Public License, v. 2.0.

vendor/github.com/hashicorp/golang-lru/README.md

@@ -0,0 +1,25 @@
+golang-lru
+==========
+
+This provides the `lru` package which implements a fixed-size
+thread safe LRU cache. It is based on the cache in Groupcache.
+
+Documentation
+=============
+
+Full docs are available on [Godoc](http://godoc.org/github.com/hashicorp/golang-lru)
+
+Example
+=======
+
+Using the LRU is very simple:
+
+```go
+l, _ := New(128)
+for i := 0; i < 256; i++ {
+    l.Add(i, nil)
+}
+if l.Len() != 128 {
+    panic(fmt.Sprintf("bad len: %v", l.Len()))
+}
+```

vendor/github.com/hashicorp/golang-lru/arc.go

@@ -0,0 +1,257 @@
+package lru
+
+import (
+	"sync"
+
+	"github.com/hashicorp/golang-lru/simplelru"
+)
+
+// ARCCache is a thread-safe fixed size Adaptive Replacement Cache (ARC).
+// ARC is an enhancement over the standard LRU cache in that tracks both
+// frequency and recency of use. This avoids a burst in access to new
+// entries from evicting the frequently used older entries. It adds some
+// additional tracking overhead to a standard LRU cache, computationally
+// it is roughly 2x the cost, and the extra memory overhead is linear
+// with the size of the cache. ARC has been patented by IBM, but is
+// similar to the TwoQueueCache (2Q) which requires setting parameters.
+type ARCCache struct {
+	size int // Size is the total capacity of the cache
+	p    int // P is the dynamic preference towards T1 or T2
+
+	t1 *simplelru.LRU // T1 is the LRU for recently accessed items
+	b1 *simplelru.LRU // B1 is the LRU for evictions from t1
+
+	t2 *simplelru.LRU // T2 is the LRU for frequently accessed items
+	b2 *simplelru.LRU // B2 is the LRU for evictions from t2
+
+	lock sync.RWMutex
+}
+
+// NewARC creates an ARC of the given size
+func NewARC(size int) (*ARCCache, error) {
+	// Create the sub LRUs
+	b1, err := simplelru.NewLRU(size, nil)
+	if err != nil {
+		return nil, err
+	}
+	b2, err := simplelru.NewLRU(size, nil)
+	if err != nil {
+		return nil, err
+	}
+	t1, err := simplelru.NewLRU(size, nil)
+	if err != nil {
+		return nil, err
+	}
+	t2, err := simplelru.NewLRU(size, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	// Initialize the ARC
+	c := &ARCCache{
+		size: size,
+		p:    0,
+		t1:   t1,
+		b1:   b1,
+		t2:   t2,
+		b2:   b2,
+	}
+	return c, nil
+}
+
+// Get looks up a key's value from the cache.
+func (c *ARCCache) Get(key interface{}) (interface{}, bool) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	// Ff the value is contained in T1 (recent), then
+	// promote it to T2 (frequent)
+	if val, ok := c.t1.Peek(key); ok {
+		c.t1.Remove(key)
+		c.t2.Add(key, val)
+		return val, ok
+	}
+
+	// Check if the value is contained in T2 (frequent)
+	if val, ok := c.t2.Get(key); ok {
+		return val, ok
+	}
+
+	// No hit
+	return nil, false
+}
+
+// Add adds a value to the cache.
+func (c *ARCCache) Add(key, value interface{}) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	// Check if the value is contained in T1 (recent), and potentially
+	// promote it to frequent T2
+	if c.t1.Contains(key) {
+		c.t1.Remove(key)
+		c.t2.Add(key, value)
+		return
+	}
+
+	// Check if the value is already in T2 (frequent) and update it
+	if c.t2.Contains(key) {
+		c.t2.Add(key, value)
+		return
+	}
+
+	// Check if this value was recently evicted as part of the
+	// recently used list
+	if c.b1.Contains(key) {
+		// T1 set is too small, increase P appropriately
+		delta := 1
+		b1Len := c.b1.Len()
+		b2Len := c.b2.Len()
+		if b2Len > b1Len {
+			delta = b2Len / b1Len
+		}
+		if c.p+delta >= c.size {
+			c.p = c.size
+		} else {
+			c.p += delta
+		}
+
+		// Potentially need to make room in the cache
+		if c.t1.Len()+c.t2.Len() >= c.size {
+			c.replace(false)
+		}
+
+		// Remove from B1
+		c.b1.Remove(key)
+
+		// Add the key to the frequently used list
+		c.t2.Add(key, value)
+		return
+	}
+
+	// Check if this value was recently evicted as part of the
+	// frequently used list
+	if c.b2.Contains(key) {
+		// T2 set is too small, decrease P appropriately
+		delta := 1
+		b1Len := c.b1.Len()
+		b2Len := c.b2.Len()
+		if b1Len > b2Len {
+			delta = b1Len / b2Len
+		}
+		if delta >= c.p {
+			c.p = 0
+		} else {
+			c.p -= delta
+		}
+
+		// Potentially need to make room in the cache
+		if c.t1.Len()+c.t2.Len() >= c.size {
+			c.replace(true)
+		}
+
+		// Remove from B2
+		c.b2.Remove(key)
+
+		// Add the key to the frequntly used list
+		c.t2.Add(key, value)
+		return
+	}
+
+	// Potentially need to make room in the cache
+	if c.t1.Len()+c.t2.Len() >= c.size {
+		c.replace(false)
+	}
+
+	// Keep the size of the ghost buffers trim
+	if c.b1.Len() > c.size-c.p {
+		c.b1.RemoveOldest()
+	}
+	if c.b2.Len() > c.p {
+		c.b2.RemoveOldest()
+	}
+
+	// Add to the recently seen list
+	c.t1.Add(key, value)
+	return
+}
+
+// replace is used to adaptively evict from either T1 or T2
+// based on the current learned value of P
+func (c *ARCCache) replace(b2ContainsKey bool) {
+	t1Len := c.t1.Len()
+	if t1Len > 0 && (t1Len > c.p || (t1Len == c.p && b2ContainsKey)) {
+		k, _, ok := c.t1.RemoveOldest()
+		if ok {
+			c.b1.Add(k, nil)
+		}
+	} else {
+		k, _, ok := c.t2.RemoveOldest()
+		if ok {
+			c.b2.Add(k, nil)
+		}
+	}
+}
+
+// Len returns the number of cached entries
+func (c *ARCCache) Len() int {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	return c.t1.Len() + c.t2.Len()
+}
+
+// Keys returns all the cached keys
+func (c *ARCCache) Keys() []interface{} {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	k1 := c.t1.Keys()
+	k2 := c.t2.Keys()
+	return append(k1, k2...)
+}
+
+// Remove is used to purge a key from the cache
+func (c *ARCCache) Remove(key interface{}) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	if c.t1.Remove(key) {
+		return
+	}
+	if c.t2.Remove(key) {
+		return
+	}
+	if c.b1.Remove(key) {
+		return
+	}
+	if c.b2.Remove(key) {
+		return
+	}
+}
+
+// Purge is used to clear the cache
+func (c *ARCCache) Purge() {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	c.t1.Purge()
+	c.t2.Purge()
+	c.b1.Purge()
+	c.b2.Purge()
+}
+
+// Contains is used to check if the cache contains a key
+// without updating recency or frequency.
+func (c *ARCCache) Contains(key interface{}) bool {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	return c.t1.Contains(key) || c.t2.Contains(key)
+}
+
+// Peek is used to inspect the cache value of a key
+// without updating recency or frequency.
+func (c *ARCCache) Peek(key interface{}) (interface{}, bool) {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	if val, ok := c.t1.Peek(key); ok {
+		return val, ok
+	}
+	return c.t2.Peek(key)
+}

vendor/github.com/hashicorp/golang-lru/arc_test.go

@@ -0,0 +1,377 @@
+package lru
+
+import (
+	"math/rand"
+	"testing"
+	"time"
+)
+
+func init() {
+	rand.Seed(time.Now().Unix())
+}
+
+func BenchmarkARC_Rand(b *testing.B) {
+	l, err := NewARC(8192)
+	if err != nil {
+		b.Fatalf("err: %v", err)
+	}
+
+	trace := make([]int64, b.N*2)
+	for i := 0; i < b.N*2; i++ {
+		trace[i] = rand.Int63() % 32768
+	}
+
+	b.ResetTimer()
+
+	var hit, miss int
+	for i := 0; i < 2*b.N; i++ {
+		if i%2 == 0 {
+			l.Add(trace[i], trace[i])
+		} else {
+			_, ok := l.Get(trace[i])
+			if ok {
+				hit++
+			} else {
+				miss++
+			}
+		}
+	}
+	b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(miss))
+}
+
+func BenchmarkARC_Freq(b *testing.B) {
+	l, err := NewARC(8192)
+	if err != nil {
+		b.Fatalf("err: %v", err)
+	}
+
+	trace := make([]int64, b.N*2)
+	for i := 0; i < b.N*2; i++ {
+		if i%2 == 0 {
+			trace[i] = rand.Int63() % 16384
+		} else {
+			trace[i] = rand.Int63() % 32768
+		}
+	}
+
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		l.Add(trace[i], trace[i])
+	}
+	var hit, miss int
+	for i := 0; i < b.N; i++ {
+		_, ok := l.Get(trace[i])
+		if ok {
+			hit++
+		} else {
+			miss++
+		}
+	}
+	b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(miss))
+}
+
+func TestARC_RandomOps(t *testing.T) {
+	size := 128
+	l, err := NewARC(128)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	n := 200000
+	for i := 0; i < n; i++ {
+		key := rand.Int63() % 512
+		r := rand.Int63()
+		switch r % 3 {
+		case 0:
+			l.Add(key, key)
+		case 1:
+			l.Get(key)
+		case 2:
+			l.Remove(key)
+		}
+
+		if l.t1.Len()+l.t2.Len() > size {
+			t.Fatalf("bad: t1: %d t2: %d b1: %d b2: %d p: %d",
+				l.t1.Len(), l.t2.Len(), l.b1.Len(), l.b2.Len(), l.p)
+		}
+		if l.b1.Len()+l.b2.Len() > size {
+			t.Fatalf("bad: t1: %d t2: %d b1: %d b2: %d p: %d",
+				l.t1.Len(), l.t2.Len(), l.b1.Len(), l.b2.Len(), l.p)
+		}
+	}
+}
+
+func TestARC_Get_RecentToFrequent(t *testing.T) {
+	l, err := NewARC(128)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Touch all the entries, should be in t1
+	for i := 0; i < 128; i++ {
+		l.Add(i, i)
+	}
+	if n := l.t1.Len(); n != 128 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.t2.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Get should upgrade to t2
+	for i := 0; i < 128; i++ {
+		_, ok := l.Get(i)
+		if !ok {
+			t.Fatalf("missing: %d", i)
+		}
+	}
+	if n := l.t1.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.t2.Len(); n != 128 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Get be from t2
+	for i := 0; i < 128; i++ {
+		_, ok := l.Get(i)
+		if !ok {
+			t.Fatalf("missing: %d", i)
+		}
+	}
+	if n := l.t1.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.t2.Len(); n != 128 {
+		t.Fatalf("bad: %d", n)
+	}
+}
+
+func TestARC_Add_RecentToFrequent(t *testing.T) {
+	l, err := NewARC(128)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Add initially to t1
+	l.Add(1, 1)
+	if n := l.t1.Len(); n != 1 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.t2.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Add should upgrade to t2
+	l.Add(1, 1)
+	if n := l.t1.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.t2.Len(); n != 1 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Add should remain in t2
+	l.Add(1, 1)
+	if n := l.t1.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.t2.Len(); n != 1 {
+		t.Fatalf("bad: %d", n)
+	}
+}
+
+func TestARC_Adaptive(t *testing.T) {
+	l, err := NewARC(4)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Fill t1
+	for i := 0; i < 4; i++ {
+		l.Add(i, i)
+	}
+	if n := l.t1.Len(); n != 4 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Move to t2
+	l.Get(0)
+	l.Get(1)
+	if n := l.t2.Len(); n != 2 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Evict from t1
+	l.Add(4, 4)
+	if n := l.b1.Len(); n != 1 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Current state
+	// t1 : (MRU) [4, 3] (LRU)
+	// t2 : (MRU) [1, 0] (LRU)
+	// b1 : (MRU) [2] (LRU)
+	// b2 : (MRU) [] (LRU)
+
+	// Add 2, should cause hit on b1
+	l.Add(2, 2)
+	if n := l.b1.Len(); n != 1 {
+		t.Fatalf("bad: %d", n)
+	}
+	if l.p != 1 {
+		t.Fatalf("bad: %d", l.p)
+	}
+	if n := l.t2.Len(); n != 3 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Current state
+	// t1 : (MRU) [4] (LRU)
+	// t2 : (MRU) [2, 1, 0] (LRU)
+	// b1 : (MRU) [3] (LRU)
+	// b2 : (MRU) [] (LRU)
+
+	// Add 4, should migrate to t2
+	l.Add(4, 4)
+	if n := l.t1.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.t2.Len(); n != 4 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Current state
+	// t1 : (MRU) [] (LRU)
+	// t2 : (MRU) [4, 2, 1, 0] (LRU)
+	// b1 : (MRU) [3] (LRU)
+	// b2 : (MRU) [] (LRU)
+
+	// Add 4, should evict to b2
+	l.Add(5, 5)
+	if n := l.t1.Len(); n != 1 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.t2.Len(); n != 3 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.b2.Len(); n != 1 {
+		t.Fatalf("bad: %d", n)
+	}
+
+	// Current state
+	// t1 : (MRU) [5] (LRU)
+	// t2 : (MRU) [4, 2, 1] (LRU)
+	// b1 : (MRU) [3] (LRU)
+	// b2 : (MRU) [0] (LRU)
+
+	// Add 0, should decrease p
+	l.Add(0, 0)
+	if n := l.t1.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.t2.Len(); n != 4 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.b1.Len(); n != 2 {
+		t.Fatalf("bad: %d", n)
+	}
+	if n := l.b2.Len(); n != 0 {
+		t.Fatalf("bad: %d", n)
+	}
+	if l.p != 0 {
+		t.Fatalf("bad: %d", l.p)
+	}
+
+	// Current state
+	// t1 : (MRU) [] (LRU)
+	// t2 : (MRU) [0, 4, 2, 1] (LRU)
+	// b1 : (MRU) [5, 3] (LRU)
+	// b2 : (MRU) [0] (LRU)
+}
+
+func TestARC(t *testing.T) {
+	l, err := NewARC(128)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	for i := 0; i < 256; i++ {
+		l.Add(i, i)
+	}
+	if l.Len() != 128 {
+		t.Fatalf("bad len: %v", l.Len())
+	}
+
+	for i, k := range l.Keys() {
+		if v, ok := l.Get(k); !ok || v != k || v != i+128 {
+			t.Fatalf("bad key: %v", k)
+		}
+	}
+	for i := 0; i < 128; i++ {
+		_, ok := l.Get(i)
+		if ok {
+			t.Fatalf("should be evicted")
+		}
+	}
+	for i := 128; i < 256; i++ {
+		_, ok := l.Get(i)
+		if !ok {
+			t.Fatalf("should not be evicted")
+		}
+	}
+	for i := 128; i < 192; i++ {
+		l.Remove(i)
+		_, ok := l.Get(i)
+		if ok {
+			t.Fatalf("should be deleted")
+		}
+	}
+
+	l.Purge()
+	if l.Len() != 0 {
+		t.Fatalf("bad len: %v", l.Len())
+	}
+	if _, ok := l.Get(200); ok {
+		t.Fatalf("should contain nothing")
+	}
+}
+
+// Test that Contains doesn't update recent-ness
+func TestARC_Contains(t *testing.T) {
+	l, err := NewARC(2)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	l.Add(1, 1)
+	l.Add(2, 2)
+	if !l.Contains(1) {
+		t.Errorf("1 should be contained")
+	}
+
+	l.Add(3, 3)
+	if l.Contains(1) {
+		t.Errorf("Contains should not have updated recent-ness of 1")
+	}
+}
+
+// Test that Peek doesn't update recent-ness
+func TestARC_Peek(t *testing.T) {
+	l, err := NewARC(2)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	l.Add(1, 1)
+	l.Add(2, 2)
+	if v, ok := l.Peek(1); !ok || v != 1 {
+		t.Errorf("1 should be set to 1: %v, %v", v, ok)
+	}
+
+	l.Add(3, 3)
+	if l.Contains(1) {
+		t.Errorf("should not have updated recent-ness of 1")
+	}
+}

vendor/github.com/hashicorp/golang-lru/lru.go

@@ -0,0 +1,114 @@
+// This package provides a simple LRU cache. It is based on the
+// LRU implementation in groupcache:
+// https://github.com/golang/groupcache/tree/master/lru
+package lru
+
+import (
+	"sync"
+
+	"github.com/hashicorp/golang-lru/simplelru"
+)
+
+// Cache is a thread-safe fixed size LRU cache.
+type Cache struct {
+	lru  *simplelru.LRU
+	lock sync.RWMutex
+}
+
+// New creates an LRU of the given size
+func New(size int) (*Cache, error) {
+	return NewWithEvict(size, nil)
+}
+
+// NewWithEvict constructs a fixed size cache with the given eviction
+// callback.
+func NewWithEvict(size int, onEvicted func(key interface{}, value interface{})) (*Cache, error) {
+	lru, err := simplelru.NewLRU(size, simplelru.EvictCallback(onEvicted))
+	if err != nil {
+		return nil, err
+	}
+	c := &Cache{
+		lru: lru,
+	}
+	return c, nil
+}
+
+// Purge is used to completely clear the cache
+func (c *Cache) Purge() {