1// Copyright 2011 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// Plan 9 system calls. 6// This file is compiled as ordinary Go code, 7// but it is also input to mksyscall, 8// which parses the //sys lines and generates system call stubs. 9// Note that sometimes we use a lowercase //sys name and 10// wrap it in our own nicer implementation. 11 12package plan9 13 14import ( 15 "bytes" 16 "syscall" 17 "unsafe" 18) 19 20// A Note is a string describing a process note. 21// It implements the os.Signal interface. 22type Note string 23 24func (n Note) Signal() {} 25 26func (n Note) String() string { 27 return string(n) 28} 29 30var ( 31 Stdin = 0 32 Stdout = 1 33 Stderr = 2 34) 35 36// For testing: clients can set this flag to force 37// creation of IPv6 sockets to return EAFNOSUPPORT. 38var SocketDisableIPv6 bool 39 40func Syscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err syscall.ErrorString) 41func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err syscall.ErrorString) 42func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2, err uintptr) 43func RawSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) 44 45func atoi(b []byte) (n uint) { 46 n = 0 47 for i := 0; i < len(b); i++ { 48 n = n*10 + uint(b[i]-'0') 49 } 50 return 51} 52 53func cstring(s []byte) string { 54 i := bytes.IndexByte(s, 0) 55 if i == -1 { 56 i = len(s) 57 } 58 return string(s[:i]) 59} 60 61func errstr() string { 62 var buf [ERRMAX]byte 63 64 RawSyscall(SYS_ERRSTR, uintptr(unsafe.Pointer(&buf[0])), uintptr(len(buf)), 0) 65 66 buf[len(buf)-1] = 0 67 return cstring(buf[:]) 68} 69 70// Implemented in assembly to import from runtime. 71func exit(code int) 72 73func Exit(code int) { exit(code) } 74 75func readnum(path string) (uint, error) { 76 var b [12]byte 77 78 fd, e := Open(path, O_RDONLY) 79 if e != nil { 80 return 0, e 81 } 82 defer Close(fd) 83 84 n, e := Pread(fd, b[:], 0) 85 86 if e != nil { 87 return 0, e 88 } 89 90 m := 0 91 for ; m < n && b[m] == ' '; m++ { 92 } 93 94 return atoi(b[m : n-1]), nil 95} 96 97func Getpid() (pid int) { 98 n, _ := readnum("#c/pid") 99 return int(n) 100} 101 102func Getppid() (ppid int) { 103 n, _ := readnum("#c/ppid") 104 return int(n) 105} 106 107func Read(fd int, p []byte) (n int, err error) { 108 return Pread(fd, p, -1) 109} 110 111func Write(fd int, p []byte) (n int, err error) { 112 return Pwrite(fd, p, -1) 113} 114 115var ioSync int64 116 117//sys fd2path(fd int, buf []byte) (err error) 118func Fd2path(fd int) (path string, err error) { 119 var buf [512]byte 120 121 e := fd2path(fd, buf[:]) 122 if e != nil { 123 return "", e 124 } 125 return cstring(buf[:]), nil 126} 127 128//sys pipe(p *[2]int32) (err error) 129func Pipe(p []int) (err error) { 130 if len(p) != 2 { 131 return syscall.ErrorString("bad arg in system call") 132 } 133 var pp [2]int32 134 err = pipe(&pp) 135 p[0] = int(pp[0]) 136 p[1] = int(pp[1]) 137 return 138} 139 140// Underlying system call writes to newoffset via pointer. 141// Implemented in assembly to avoid allocation. 142func seek(placeholder uintptr, fd int, offset int64, whence int) (newoffset int64, err string) 143 144func Seek(fd int, offset int64, whence int) (newoffset int64, err error) { 145 newoffset, e := seek(0, fd, offset, whence) 146 147 if newoffset == -1 { 148 err = syscall.ErrorString(e) 149 } 150 return 151} 152 153func Mkdir(path string, mode uint32) (err error) { 154 fd, err := Create(path, O_RDONLY, DMDIR|mode) 155 156 if fd != -1 { 157 Close(fd) 158 } 159 160 return 161} 162 163type Waitmsg struct { 164 Pid int 165 Time [3]uint32 166 Msg string 167} 168 169func (w Waitmsg) Exited() bool { return true } 170func (w Waitmsg) Signaled() bool { return false } 171 172func (w Waitmsg) ExitStatus() int { 173 if len(w.Msg) == 0 { 174 // a normal exit returns no message 175 return 0 176 } 177 return 1 178} 179 180//sys await(s []byte) (n int, err error) 181func Await(w *Waitmsg) (err error) { 182 var buf [512]byte 183 var f [5][]byte 184 185 n, err := await(buf[:]) 186 187 if err != nil || w == nil { 188 return 189 } 190 191 nf := 0 192 p := 0 193 for i := 0; i < n && nf < len(f)-1; i++ { 194 if buf[i] == ' ' { 195 f[nf] = buf[p:i] 196 p = i + 1 197 nf++ 198 } 199 } 200 f[nf] = buf[p:] 201 nf++ 202 203 if nf != len(f) { 204 return syscall.ErrorString("invalid wait message") 205 } 206 w.Pid = int(atoi(f[0])) 207 w.Time[0] = uint32(atoi(f[1])) 208 w.Time[1] = uint32(atoi(f[2])) 209 w.Time[2] = uint32(atoi(f[3])) 210 w.Msg = cstring(f[4]) 211 if w.Msg == "''" { 212 // await() returns '' for no error 213 w.Msg = "" 214 } 215 return 216} 217 218func Unmount(name, old string) (err error) { 219 fixwd() 220 oldp, err := BytePtrFromString(old) 221 if err != nil { 222 return err 223 } 224 oldptr := uintptr(unsafe.Pointer(oldp)) 225 226 var r0 uintptr 227 var e syscall.ErrorString 228 229 // bind(2) man page: If name is zero, everything bound or mounted upon old is unbound or unmounted. 230 if name == "" { 231 r0, _, e = Syscall(SYS_UNMOUNT, _zero, oldptr, 0) 232 } else { 233 namep, err := BytePtrFromString(name) 234 if err != nil { 235 return err 236 } 237 r0, _, e = Syscall(SYS_UNMOUNT, uintptr(unsafe.Pointer(namep)), oldptr, 0) 238 } 239 240 if int32(r0) == -1 { 241 err = e 242 } 243 return 244} 245 246func Fchdir(fd int) (err error) { 247 path, err := Fd2path(fd) 248 249 if err != nil { 250 return 251 } 252 253 return Chdir(path) 254} 255 256type Timespec struct { 257 Sec int32 258 Nsec int32 259} 260 261type Timeval struct { 262 Sec int32 263 Usec int32 264} 265 266func NsecToTimeval(nsec int64) (tv Timeval) { 267 nsec += 999 // round up to microsecond 268 tv.Usec = int32(nsec % 1e9 / 1e3) 269 tv.Sec = int32(nsec / 1e9) 270 return 271} 272 273func nsec() int64 { 274 var scratch int64 275 276 r0, _, _ := Syscall(SYS_NSEC, uintptr(unsafe.Pointer(&scratch)), 0, 0) 277 // TODO(aram): remove hack after I fix _nsec in the pc64 kernel. 278 if r0 == 0 { 279 return scratch 280 } 281 return int64(r0) 282} 283 284func Gettimeofday(tv *Timeval) error { 285 nsec := nsec() 286 *tv = NsecToTimeval(nsec) 287 return nil 288} 289 290func Getpagesize() int { return 0x1000 } 291 292func Getegid() (egid int) { return -1 } 293func Geteuid() (euid int) { return -1 } 294func Getgid() (gid int) { return -1 } 295func Getuid() (uid int) { return -1 } 296 297func Getgroups() (gids []int, err error) { 298 return make([]int, 0), nil 299} 300 301//sys open(path string, mode int) (fd int, err error) 302func Open(path string, mode int) (fd int, err error) { 303 fixwd() 304 return open(path, mode) 305} 306 307//sys create(path string, mode int, perm uint32) (fd int, err error) 308func Create(path string, mode int, perm uint32) (fd int, err error) { 309 fixwd() 310 return create(path, mode, perm) 311} 312 313//sys remove(path string) (err error) 314func Remove(path string) error { 315 fixwd() 316 return remove(path) 317} 318 319//sys stat(path string, edir []byte) (n int, err error) 320func Stat(path string, edir []byte) (n int, err error) { 321 fixwd() 322 return stat(path, edir) 323} 324 325//sys bind(name string, old string, flag int) (err error) 326func Bind(name string, old string, flag int) (err error) { 327 fixwd() 328 return bind(name, old, flag) 329} 330 331//sys mount(fd int, afd int, old string, flag int, aname string) (err error) 332func Mount(fd int, afd int, old string, flag int, aname string) (err error) { 333 fixwd() 334 return mount(fd, afd, old, flag, aname) 335} 336 337//sys wstat(path string, edir []byte) (err error) 338func Wstat(path string, edir []byte) (err error) { 339 fixwd() 340 return wstat(path, edir) 341} 342 343//sys chdir(path string) (err error) 344//sys Dup(oldfd int, newfd int) (fd int, err error) 345//sys Pread(fd int, p []byte, offset int64) (n int, err error) 346//sys Pwrite(fd int, p []byte, offset int64) (n int, err error) 347//sys Close(fd int) (err error) 348//sys Fstat(fd int, edir []byte) (n int, err error) 349//sys Fwstat(fd int, edir []byte) (err error) 350