1 files changed, 169 insertions, 0 deletions
diff --git a/src/net/internal/socktest/switch.go b/src/net/internal/socktest/switch.go
new file mode 100644
index 0000000..3c37b6f
--- /dev/null
+++ b/src/net/internal/socktest/switch.go
@@ -0,0 +1,169 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package socktest provides utilities for socket testing.
+package socktest
+
+import (
+	"fmt"
+	"sync"
+)
+
+// A Switch represents a callpath point switch for socket system
+// calls.
+type Switch struct {
+	once sync.Once
+
+	fmu   sync.RWMutex
+	fltab map[FilterType]Filter
+
+	smu   sync.RWMutex
+	sotab Sockets
+	stats stats
+}
+
+func (sw *Switch) init() {
+	sw.fltab = make(map[FilterType]Filter)
+	sw.sotab = make(Sockets)
+	sw.stats = make(stats)
+}
+
+// Stats returns a list of per-cookie socket statistics.
+func (sw *Switch) Stats() []Stat {
+	var st []Stat
+	sw.smu.RLock()
+	for _, s := range sw.stats {
+		ns := *s
+		st = append(st, ns)
+	}
+	sw.smu.RUnlock()
+	return st
+}
+
+// Sockets returns mappings of socket descriptor to socket status.
+func (sw *Switch) Sockets() Sockets {
+	sw.smu.RLock()
+	tab := make(Sockets, len(sw.sotab))
+	for i, s := range sw.sotab {
+		tab[i] = s
+	}
+	sw.smu.RUnlock()
+	return tab
+}
+
+// A Cookie represents a 3-tuple of a socket; address family, socket
+// type and protocol number.
+type Cookie uint64
+
+// Family returns an address family.
+func (c Cookie) Family() int { return int(c >> 48) }
+
+// Type returns a socket type.
+func (c Cookie) Type() int { return int(c << 16 >> 32) }
+
+// Protocol returns a protocol number.
+func (c Cookie) Protocol() int { return int(c & 0xff) }
+
+func cookie(family, sotype, proto int) Cookie {
+	return Cookie(family)<<48 | Cookie(sotype)&0xffffffff<<16 | Cookie(proto)&0xff
+}
+
+// A Status represents the status of a socket.
+type Status struct {
+	Cookie    Cookie
+	Err       error // error status of socket system call
+	SocketErr error // error status of socket by SO_ERROR
+}
+
+func (so Status) String() string {
+	return fmt.Sprintf("(%s, %s, %s): syscallerr=%v socketerr=%v", familyString(so.Cookie.Family()), typeString(so.Cookie.Type()), protocolString(so.Cookie.Protocol()), so.Err, so.SocketErr)
+}
+
+// A Stat represents a per-cookie socket statistics.
+type Stat struct {
+	Family   int // address family
+	Type     int // socket type
+	Protocol int // protocol number
+
+	Opened    uint64 // number of sockets opened
+	Connected uint64 // number of sockets connected
+	Listened  uint64 // number of sockets listened
+	Accepted  uint64 // number of sockets accepted
+	Closed    uint64 // number of sockets closed
+
+	OpenFailed    uint64 // number of sockets open failed
+	ConnectFailed uint64 // number of sockets connect failed
+	ListenFailed  uint64 // number of sockets listen failed
+	AcceptFailed  uint64 // number of sockets accept failed
+	CloseFailed   uint64 // number of sockets close failed
+}
+
+func (st Stat) String() string {
+	return fmt.Sprintf("(%s, %s, %s): opened=%d connected=%d listened=%d accepted=%d closed=%d openfailed=%d connectfailed=%d listenfailed=%d acceptfailed=%d closefailed=%d", familyString(st.Family), typeString(st.Type), protocolString(st.Protocol), st.Opened, st.Connected, st.Listened, st.Accepted, st.Closed, st.OpenFailed, st.ConnectFailed, st.ListenFailed, st.AcceptFailed, st.CloseFailed)
+}
+
+type stats map[Cookie]*Stat
+
+func (st stats) getLocked(c Cookie) *Stat {
+	s, ok := st[c]
+	if !ok {
+		s = &Stat{Family: c.Family(), Type: c.Type(), Protocol: c.Protocol()}
+		st[c] = s
+	}
+	return s
+}
+
+// A FilterType represents a filter type.
+type FilterType int
+
+const (
+	FilterSocket        FilterType = iota // for Socket
+	FilterConnect                         // for Connect or ConnectEx
+	FilterListen                          // for Listen
+	FilterAccept                          // for Accept, Accept4 or AcceptEx
+	FilterGetsockoptInt                   // for GetsockoptInt
+	FilterClose                           // for Close or Closesocket
+)
+
+// A Filter represents a socket system call filter.
+//
+// It will only be executed before a system call for a socket that has
+// an entry in internal table.
+// If the filter returns a non-nil error, the execution of system call
+// will be canceled and the system call function returns the non-nil
+// error.
+// It can return a non-nil AfterFilter for filtering after the
+// execution of the system call.
+type Filter func(*Status) (AfterFilter, error)
+
+func (f Filter) apply(st *Status) (AfterFilter, error) {
+	if f == nil {
+		return nil, nil
+	}
+	return f(st)
+}
+
+// An AfterFilter represents a socket system call filter after an
+// execution of a system call.
+//
+// It will only be executed after a system call for a socket that has
+// an entry in internal table.
+// If the filter returns a non-nil error, the system call function
+// returns the non-nil error.
+type AfterFilter func(*Status) error
+
+func (f AfterFilter) apply(st *Status) error {
+	if f == nil {
+		return nil
+	}
+	return f(st)
+}
+
+// Set deploys the socket system call filter f for the filter type t.
+func (sw *Switch) Set(t FilterType, f Filter) {
+	sw.once.Do(sw.init)
+	sw.fmu.Lock()
+	sw.fltab[t] = f
+	sw.fmu.Unlock()
+}