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. 6 package socktest 7 8 import ( 9 "fmt" 10 "sync" 11 ) 12 13 // A Switch represents a callpath point switch for socket system 14 // calls. 15 type 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 26 func (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. 33 func (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. 45 func (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. 57 type Cookie uint64 58 59 // Family returns an address family. 60 func (c Cookie) Family() int { return int(c >> 48) } 61 62 // Type returns a socket type. 63 func (c Cookie) Type() int { return int(c << 16 >> 32) } 64 65 // Protocol returns a protocol number. 66 func (c Cookie) Protocol() int { return int(c & 0xff) } 67 68 func 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. 73 type 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 79 func (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. 84 type 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 } 101 102 func (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 } 105 106 type stats map[Cookie]*Stat 107 108 func (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. 118 type FilterType int 119 120 const ( 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. 138 type Filter func(*Status) (AfterFilter, error) 139 140 func (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. 154 type AfterFilter func(*Status) error 155 156 func (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. 164 func (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
