internal/syscall/unix: unify GetRandom implementation

The implementation of GetRandom for Linux, FreeBSD and DragonflyBSD can
be shared.

Also remove GRND_INSECURE on DragonflyBSD as pointed out by Ian in the
review of CL 269999.

Change-Id: I5bf4c1bd51ddb2ad600652a57e0bc1bafa1cf40d
Reviewed-on: https://go-review.googlesource.com/c/go/+/299133
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

diff --git a/src/internal/syscall/unix/getrandom.go b/src/internal/syscall/unix/getrandom.go
new file mode 100644 (file)
index 0000000..d2c58c0
--- /dev/null
+++ b/src/internal/syscall/unix/getrandom.go
@@ -0,0 +1,40 @@
+// Copyright 2021 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.
+
+//go:build dragonfly || freebsd || linux
+// +build dragonfly freebsd linux
+
+package unix
+
+import (
+       "sync/atomic"
+       "syscall"
+       "unsafe"
+)
+
+var getrandomUnsupported int32 // atomic
+
+// GetRandomFlag is a flag supported by the getrandom system call.
+type GetRandomFlag uintptr
+
+// GetRandom calls the getrandom system call.
+func GetRandom(p []byte, flags GetRandomFlag) (n int, err error) {
+       if len(p) == 0 {
+               return 0, nil
+       }
+       if atomic.LoadInt32(&getrandomUnsupported) != 0 {
+               return 0, syscall.ENOSYS
+       }
+       r1, _, errno := syscall.Syscall(getrandomTrap,
+               uintptr(unsafe.Pointer(&p[0])),
+               uintptr(len(p)),
+               uintptr(flags))
+       if errno != 0 {
+               if errno == syscall.ENOSYS {
+                       atomic.StoreInt32(&getrandomUnsupported, 1)
+               }
+               return 0, errno
+       }
+       return int(r1), nil
+}

diff --git a/src/internal/syscall/unix/getrandom_dragonfly.go b/src/internal/syscall/unix/getrandom_dragonfly.go
index b345b4c00c60e09e5af7ac21d150eeb84630ab18..fbf78f9de804f86375df034caa0b35bc9a2062ce 100644 (file)
--- a/src/internal/syscall/unix/getrandom_dragonfly.go
+++ b/src/internal/syscall/unix/getrandom_dragonfly.go
@@ -4,19 +4,8 @@
 
 package unix
 
-import (
-       "sync/atomic"
-       "syscall"
-       "unsafe"
-)
-
-var randomUnsupported int32 // atomic
-
 // DragonFlyBSD getrandom system call number.
-const randomTrap uintptr = 550
-
-// GetRandomFlag is a flag supported by the getrandom system call.
-type GetRandomFlag uintptr
+const getrandomTrap uintptr = 550
 
 const (
        // GRND_RANDOM is only set for portability purpose, no-op on DragonFlyBSD.
@@ -24,28 +13,4 @@ const (
 
        // GRND_NONBLOCK means return EAGAIN rather than blocking.
        GRND_NONBLOCK GetRandomFlag = 0x0002
-
-       // GRND_INSECURE is an GRND_NONBLOCK alias
-       GRND_INSECURE GetRandomFlag = 0x0004
 )
-
-// GetRandom calls the DragonFlyBSD getrandom system call.
-func GetRandom(p []byte, flags GetRandomFlag) (n int, err error) {
-       if len(p) == 0 {
-               return 0, nil
-       }
-       if atomic.LoadInt32(&randomUnsupported) != 0 {
-               return 0, syscall.ENOSYS
-       }
-       r1, _, errno := syscall.Syscall(randomTrap,
-               uintptr(unsafe.Pointer(&p[0])),
-               uintptr(len(p)),
-               uintptr(flags))
-       if errno != 0 {
-               if errno == syscall.ENOSYS {
-                       atomic.StoreInt32(&randomUnsupported, 1)
-               }
-               return 0, errno
-       }
-       return int(r1), nil
-}

diff --git a/src/internal/syscall/unix/getrandom_freebsd.go b/src/internal/syscall/unix/getrandom_freebsd.go
index f1ba5730c96953281b37c276d307aac548bf12da..8c4f3dff82377e5324c400fb98fd3f5a9b1b4681 100644 (file)
--- a/src/internal/syscall/unix/getrandom_freebsd.go
+++ b/src/internal/syscall/unix/getrandom_freebsd.go
@@ -4,19 +4,8 @@
 
 package unix
 
-import (
-       "sync/atomic"
-       "syscall"
-       "unsafe"
-)
-
-var randomUnsupported int32 // atomic
-
 // FreeBSD getrandom system call number.
-const randomTrap uintptr = 563
-
-// GetRandomFlag is a flag supported by the getrandom system call.
-type GetRandomFlag uintptr
+const getrandomTrap uintptr = 563
 
 const (
        // GRND_NONBLOCK means return EAGAIN rather than blocking.
@@ -25,24 +14,3 @@ const (
        // GRND_RANDOM is only set for portability purpose, no-op on FreeBSD.
        GRND_RANDOM GetRandomFlag = 0x0002
 )
-
-// GetRandom calls the FreeBSD getrandom system call.
-func GetRandom(p []byte, flags GetRandomFlag) (n int, err error) {
-       if len(p) == 0 {
-               return 0, nil
-       }
-       if atomic.LoadInt32(&randomUnsupported) != 0 {
-               return 0, syscall.ENOSYS
-       }
-       r1, _, errno := syscall.Syscall(randomTrap,
-               uintptr(unsafe.Pointer(&p[0])),
-               uintptr(len(p)),
-               uintptr(flags))
-       if errno != 0 {
-               if errno == syscall.ENOSYS {
-                       atomic.StoreInt32(&randomUnsupported, 1)
-               }
-               return 0, errno
-       }
-       return int(r1), nil
-}

diff --git a/src/internal/syscall/unix/getrandom_linux.go b/src/internal/syscall/unix/getrandom_linux.go
index 490d516978daea8b9e2f7facbfdc44a4e60d2df3..8ccd8d328af1feb980ac35c062f944ca3c0219f6 100644 (file)
--- a/src/internal/syscall/unix/getrandom_linux.go
+++ b/src/internal/syscall/unix/getrandom_linux.go
@@ -4,17 +4,6 @@
 
 package unix
 
-import (
-       "sync/atomic"
-       "syscall"
-       "unsafe"
-)
-
-var randomUnsupported int32 // atomic
-
-// GetRandomFlag is a flag supported by the getrandom system call.
-type GetRandomFlag uintptr
-
 const (
        // GRND_NONBLOCK means return EAGAIN rather than blocking.
        GRND_NONBLOCK GetRandomFlag = 0x0001
@@ -22,25 +11,3 @@ const (
        // GRND_RANDOM means use the /dev/random pool instead of /dev/urandom.
        GRND_RANDOM GetRandomFlag = 0x0002
 )
-
-// GetRandom calls the Linux getrandom system call.
-// See https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c6e9d6f38894798696f23c8084ca7edbf16ee895
-func GetRandom(p []byte, flags GetRandomFlag) (n int, err error) {
-       if len(p) == 0 {
-               return 0, nil
-       }
-       if atomic.LoadInt32(&randomUnsupported) != 0 {
-               return 0, syscall.ENOSYS
-       }
-       r1, _, errno := syscall.Syscall(getrandomTrap,
-               uintptr(unsafe.Pointer(&p[0])),
-               uintptr(len(p)),
-               uintptr(flags))
-       if errno != 0 {
-               if errno == syscall.ENOSYS {
-                       atomic.StoreInt32(&randomUnsupported, 1)
-               }
-               return 0, errno
-       }
-       return int(r1), nil
-}