1// Copyright 2015 The Go Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style 3// license that can be found in the LICENSE file. 4 5// Package socktest provides utilities for socket testing. 6package socktest 7 8import ( 9 "fmt" 10 "sync" 11) 12 13// A Switch represents a callpath point switch for socket system 14// calls. 15type Switch struct { 16 once sync.Once 17 18 fmu sync.RWMutex 19 fltab map[FilterType]Filter 20 21 smu sync.RWMutex 22 sotab Sockets 23 stats stats 24} 25 26func (sw *Switch) init() { 27 sw.fltab = make(map[FilterType]Filter) 28 sw.sotab = make(Sockets) 29 sw.stats = make(stats) 30} 31 32// Stats returns a list of per-cookie socket statistics. 33func (sw *Switch) Stats() []Stat { 34 var st []Stat 35 sw.smu.RLock() 36 for _, s := range sw.stats { 37 ns := *s 38 st = append(st, ns) 39 } 40 sw.smu.RUnlock() 41 return st 42} 43 44// Sockets returns mappings of socket descriptor to socket status. 45func (sw *Switch) Sockets() Sockets { 46 sw.smu.RLock() 47 tab := make(Sockets, len(sw.sotab)) 48 for i, s := range sw.sotab { 49 tab[i] = s 50 } 51 sw.smu.RUnlock() 52 return tab 53} 54 55// A Cookie represents a 3-tuple of a socket; address family, socket 56// type and protocol number. 57type Cookie uint64 58 59// Family returns an address family. 60func (c Cookie) Family() int { return int(c >> 48) } 61 62// Type returns a socket type. 63func (c Cookie) Type() int { return int(c << 16 >> 32) } 64 65// Protocol returns a protocol number. 66func (c Cookie) Protocol() int { return int(c & 0xff) } 67 68func cookie(family, sotype, proto int) Cookie { 69 return Cookie(family)<<48 | Cookie(sotype)&0xffffffff<<16 | Cookie(proto)&0xff 70} 71 72// A Status represents the status of a socket. 73type Status struct { 74 Cookie Cookie 75 Err error // error status of socket system call 76 SocketErr error // error status of socket by SO_ERROR 77} 78 79func (so Status) String() string { 80 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) 81} 82 83// A Stat represents a per-cookie socket statistics. 84type Stat struct { 85 Family int // address family 86 Type int // socket type 87 Protocol int // protocol number 88 89 Opened uint64 // number of sockets opened 90 Connected uint64 // number of sockets connected 91 Listened uint64 // number of sockets listened 92 Accepted uint64 // number of sockets accepted 93 Closed uint64 // number of sockets closed 94 95 OpenFailed uint64 // number of sockets open failed 96 ConnectFailed uint64 // number of sockets connect failed 97 ListenFailed uint64 // number of sockets listen failed 98 AcceptFailed uint64 // number of sockets accept failed 99 CloseFailed uint64 // number of sockets close failed 100} 101 102func (st Stat) String() string { 103 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) 104} 105 106type stats map[Cookie]*Stat 107 108func (st stats) getLocked(c Cookie) *Stat { 109 s, ok := st[c] 110 if !ok { 111 s = &Stat{Family: c.Family(), Type: c.Type(), Protocol: c.Protocol()} 112 st[c] = s 113 } 114 return s 115} 116 117// A FilterType represents a filter type. 118type FilterType int 119 120const ( 121 FilterSocket FilterType = iota // for Socket 122 FilterConnect // for Connect or ConnectEx 123 FilterListen // for Listen 124 FilterAccept // for Accept, Accept4 or AcceptEx 125 FilterGetsockoptInt // for GetsockoptInt 126 FilterClose // for Close or Closesocket 127) 128 129// A Filter represents a socket system call filter. 130// 131// It will only be executed before a system call for a socket that has 132// an entry in internal table. 133// If the filter returns a non-nil error, the execution of system call 134// will be canceled and the system call function returns the non-nil 135// error. 136// It can return a non-nil AfterFilter for filtering after the 137// execution of the system call. 138type Filter func(*Status) (AfterFilter, error) 139 140func (f Filter) apply(st *Status) (AfterFilter, error) { 141 if f == nil { 142 return nil, nil 143 } 144 return f(st) 145} 146 147// An AfterFilter represents a socket system call filter after an 148// execution of a system call. 149// 150// It will only be executed after a system call for a socket that has 151// an entry in internal table. 152// If the filter returns a non-nil error, the system call function 153// returns the non-nil error. 154type AfterFilter func(*Status) error 155 156func (f AfterFilter) apply(st *Status) error { 157 if f == nil { 158 return nil 159 } 160 return f(st) 161} 162 163// Set deploys the socket system call filter f for the filter type t. 164func (sw *Switch) Set(t FilterType, f Filter) { 165 sw.once.Do(sw.init) 166 sw.fmu.Lock() 167 sw.fltab[t] = f 168 sw.fmu.Unlock() 169} 170