diff options
| -rw-r--r-- | src/os/env.go | 5 | ||||
| -rw-r--r-- | src/os/env_test.go | 26 | ||||
| -rw-r--r-- | src/runtime/cgo/gcc_setenv.c | 7 | ||||
| -rw-r--r-- | src/runtime/cgo/setenv.c | 3 | ||||
| -rw-r--r-- | src/runtime/env_posix.go | 13 | ||||
| -rw-r--r-- | src/runtime/thunk.s | 3 | ||||
| -rw-r--r-- | src/syscall/env_plan9.go | 38 | ||||
| -rw-r--r-- | src/syscall/env_unix.go | 44 | ||||
| -rw-r--r-- | src/syscall/env_windows.go | 8 |
9 files changed, 135 insertions, 12 deletions
diff --git a/src/os/env.go b/src/os/env.go index db7fc72b8..d0494a476 100644 --- a/src/os/env.go +++ b/src/os/env.go @@ -91,6 +91,11 @@ func Setenv(key, value string) error { return nil } +// Unsetenv unsets a single environment variable. +func Unsetenv(key string) error { + return syscall.Unsetenv(key) +} + // Clearenv deletes all environment variables. func Clearenv() { syscall.Clearenv() diff --git a/src/os/env_test.go b/src/os/env_test.go index 991fa4d05..e61806751 100644 --- a/src/os/env_test.go +++ b/src/os/env_test.go @@ -7,6 +7,7 @@ package os_test import ( . "os" "reflect" + "strings" "testing" ) @@ -68,3 +69,28 @@ func TestConsistentEnviron(t *testing.T) { } } } + +func TestUnsetenv(t *testing.T) { + const testKey = "GO_TEST_UNSETENV" + set := func() bool { + prefix := testKey + "=" + for _, key := range Environ() { + if strings.HasPrefix(key, prefix) { + return true + } + } + return false + } + if err := Setenv(testKey, "1"); err != nil { + t.Fatalf("Setenv: %v", err) + } + if !set() { + t.Error("Setenv didn't set TestUnsetenv") + } + if err := Unsetenv(testKey); err != nil { + t.Fatalf("Unsetenv: %v", err) + } + if set() { + t.Fatal("Unsetenv didn't clear TestUnsetenv") + } +} diff --git a/src/runtime/cgo/gcc_setenv.c b/src/runtime/cgo/gcc_setenv.c index 8b128b946..af0fc5d8d 100644 --- a/src/runtime/cgo/gcc_setenv.c +++ b/src/runtime/cgo/gcc_setenv.c @@ -14,3 +14,10 @@ x_cgo_setenv(char **arg) { setenv(arg[0], arg[1], 1); } + +/* Stub for calling unsetenv */ +void +x_cgo_unsetenv(char *arg) +{ + unsetenv(arg); +} diff --git a/src/runtime/cgo/setenv.c b/src/runtime/cgo/setenv.c index ee529904f..76d88cbf1 100644 --- a/src/runtime/cgo/setenv.c +++ b/src/runtime/cgo/setenv.c @@ -5,6 +5,9 @@ // +build darwin dragonfly freebsd linux netbsd openbsd #pragma cgo_import_static x_cgo_setenv +#pragma cgo_import_static x_cgo_unsetenv void x_cgo_setenv(char**); void (*runtime·_cgo_setenv)(char**) = x_cgo_setenv; +void x_cgo_unsetenv(char**); +void (*runtime·_cgo_unsetenv)(char**) = x_cgo_unsetenv; diff --git a/src/runtime/env_posix.go b/src/runtime/env_posix.go index 6c04f6cc7..dd57872d7 100644 --- a/src/runtime/env_posix.go +++ b/src/runtime/env_posix.go @@ -32,7 +32,8 @@ func gogetenv(key string) string { return "" } -var _cgo_setenv uintptr // pointer to C function +var _cgo_setenv uintptr // pointer to C function +var _cgo_unsetenv uintptr // pointer to C function // Update the C environment if cgo is loaded. // Called from syscall.Setenv. @@ -44,6 +45,16 @@ func syscall_setenv_c(k string, v string) { asmcgocall(unsafe.Pointer(_cgo_setenv), unsafe.Pointer(&arg)) } +// Update the C environment if cgo is loaded. +// Called from syscall.unsetenv. +func syscall_unsetenv_c(k string) { + if _cgo_unsetenv == 0 { + return + } + arg := [1]unsafe.Pointer{cstring(k)} + asmcgocall(unsafe.Pointer(_cgo_unsetenv), unsafe.Pointer(&arg)) +} + func cstring(s string) unsafe.Pointer { p := make([]byte, len(s)+1) sp := (*_string)(unsafe.Pointer(&s)) diff --git a/src/runtime/thunk.s b/src/runtime/thunk.s index d6a2d399e..0a0f147c4 100644 --- a/src/runtime/thunk.s +++ b/src/runtime/thunk.s @@ -110,6 +110,9 @@ TEXT net·runtime_pollUnblock(SB),NOSPLIT,$0-0 TEXT syscall·setenv_c(SB), NOSPLIT, $0-0 JMP runtime·syscall_setenv_c(SB) +TEXT syscall·unsetenv_c(SB), NOSPLIT, $0-0 + JMP runtime·syscall_unsetenv_c(SB) + TEXT reflect·makemap(SB),NOSPLIT,$0-0 JMP runtime·reflect_makemap(SB) diff --git a/src/syscall/env_plan9.go b/src/syscall/env_plan9.go index 9587ab5af..3044b410a 100644 --- a/src/syscall/env_plan9.go +++ b/src/syscall/env_plan9.go @@ -12,16 +12,22 @@ import ( ) var ( - // envOnce guards copyenv, which populates env. + // envOnce guards copyenv, which populates env, envi and envs. envOnce sync.Once - // envLock guards env and envs. + // envLock guards env, envi and envs. envLock sync.RWMutex // env maps from an environment variable to its value. + // TODO: remove this? golang.org/issue/8849 env = make(map[string]string) + // envi maps from an environment variable to its index in envs. + // TODO: remove this? golang.org/issue/8849 + envi = make(map[string]int) + // envs contains elements of env in the form "key=value". + // empty strings mean deleted. envs []string errZeroLengthKey = errors.New("zero length key") @@ -83,6 +89,7 @@ func copyenv() { } env[key] = v envs[i] = key + "=" + v + envi[key] = i i++ } } @@ -129,14 +136,39 @@ func Clearenv() { defer envLock.Unlock() env = make(map[string]string) + envi = make(map[string]int) envs = []string{} RawSyscall(SYS_RFORK, RFCENVG, 0, 0) } +func Unsetenv(key string) error { + if len(key) == 0 { + return errZeroLengthKey + } + + envLock.Lock() + defer envLock.Unlock() + + Remove("/env/" + key) + + if i, ok := envi[key]; ok { + delete(env, key) + delete(envi, key) + envs[i] = "" + } + return nil +} + func Environ() []string { envLock.RLock() defer envLock.RUnlock() envOnce.Do(copyenv) - return append([]string(nil), envs...) + ret := make([]string, 0, len(envs)) + for _, pair := range envs { + if pair != "" { + ret = append(ret, pair) + } + } + return ret } diff --git a/src/syscall/env_unix.go b/src/syscall/env_unix.go index 01ac38af1..b5ded9c76 100644 --- a/src/syscall/env_unix.go +++ b/src/syscall/env_unix.go @@ -20,16 +20,18 @@ var ( // env maps from an environment variable to its first occurrence in envs. env map[string]int - // envs is provided by the runtime. elements are expected to be - // of the form "key=value". + // envs is provided by the runtime. elements are expected to + // be of the form "key=value". An empty string means deleted + // (or a duplicate to be ignored). envs []string = runtime_envs() ) func runtime_envs() []string // in package runtime -// setenv_c is provided by the runtime, but is a no-op if cgo isn't -// loaded. +// setenv_c and unsetenv_c are provided by the runtime but are no-ops +// if cgo isn't loaded. func setenv_c(k, v string) +func unsetenv_c(k string) func copyenv() { env = make(map[string]int) @@ -38,7 +40,13 @@ func copyenv() { if s[j] == '=' { key := s[:j] if _, ok := env[key]; !ok { - env[key] = i + env[key] = i // first mention of key + } else { + // Clear duplicate keys. This permits Unsetenv to + // safely delete only the first item without + // worrying about unshadowing a later one, + // which might be a security problem. + envs[i] = "" } break } @@ -46,6 +54,20 @@ func copyenv() { } } +func Unsetenv(key string) error { + envOnce.Do(copyenv) + + envLock.Lock() + defer envLock.Unlock() + + if i, ok := env[key]; ok { + envs[i] = "" + delete(env, key) + } + unsetenv_c(key) + return nil +} + func Getenv(key string) (value string, found bool) { envOnce.Do(copyenv) if len(key) == 0 { @@ -106,16 +128,22 @@ func Clearenv() { envLock.Lock() defer envLock.Unlock() + for k := range env { + unsetenv_c(k) + } env = make(map[string]int) envs = []string{} - // TODO(bradfitz): pass through to C } func Environ() []string { envOnce.Do(copyenv) envLock.RLock() defer envLock.RUnlock() - a := make([]string, len(envs)) - copy(a, envs) + a := make([]string, 0, len(envs)) + for _, env := range envs { + if env != "" { + a = append(a, env) + } + } return a } diff --git a/src/syscall/env_windows.go b/src/syscall/env_windows.go index 420b38724..bc21690d9 100644 --- a/src/syscall/env_windows.go +++ b/src/syscall/env_windows.go @@ -47,6 +47,14 @@ func Setenv(key, value string) error { return nil } +func Unsetenv(key string) error { + keyp, err := UTF16PtrFromString(key) + if err != nil { + return err + } + return SetEnvironmentVariable(keyp, nil) +} + func Clearenv() { for _, s := range Environ() { // Environment variables can begin with = |