Add non-AMD64 support to rawfile

PiperOrigin-RevId: 203499064
Change-Id: I2cd5189638e94ce926f1e82c1264a8d3ece9dfa5

6 files changed, 48 insertions, 16 deletions

diff --git a/pkg/tcpip/link/rawfile/BUILD b/pkg/tcpip/link/rawfile/BUILD
index 4c63af0ea..b43de5530 100644
--- a/pkg/tcpip/link/rawfile/BUILD
+++ b/pkg/tcpip/link/rawfile/BUILD
@@ -6,6 +6,8 @@ go_library(
     name = "rawfile",
     srcs = [
         "blockingpoll_amd64.s",
+        "blockingpoll_unsafe.go",
+        "blockingpoll_unsafe_amd64.go",
         "errors.go",
         "rawfile_unsafe.go",
     ],
diff --git a/pkg/tcpip/link/rawfile/blockingpoll_amd64.s b/pkg/tcpip/link/rawfile/blockingpoll_amd64.s
index d6778dafe..7635900a5 100644
--- a/pkg/tcpip/link/rawfile/blockingpoll_amd64.s
+++ b/pkg/tcpip/link/rawfile/blockingpoll_amd64.s
@@ -8,7 +8,7 @@
 // entersyscall that relinquishes the P so that other Gs can run. This is meant
 // to be called in cases when the syscall is expected to block.
 //
-// func blockingPoll(fds unsafe.Pointer, nfds int, timeout int64) (n int, err syscall.Errno)
+// func blockingPoll(fds *pollEvent, nfds int, timeout int64) (n int, err syscall.Errno)
 TEXT ·blockingPoll(SB),NOSPLIT,$0-40
 	CALL	runtime·entersyscallblock(SB)
 	MOVQ	fds+0(FP), DI
diff --git a/pkg/tcpip/link/rawfile/blockingpoll_unsafe.go b/pkg/tcpip/link/rawfile/blockingpoll_unsafe.go
new file mode 100644
index 000000000..659bfbe03
--- /dev/null
+++ b/pkg/tcpip/link/rawfile/blockingpoll_unsafe.go
@@ -0,0 +1,17 @@
+// Copyright 2018 The Netstack Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build linux,!amd64
+
+package rawfile
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func blockingPoll(fds *pollEvent, nfds int, timeout int64) (int, syscall.Errno) {
+	n, _, e := syscall.Syscall(syscall.SYS_POLL, uintptr(unsafe.Pointer(fds)), uintptr(nfds), uintptr(timeout))
+	return int(n), e
+}
diff --git a/pkg/tcpip/link/rawfile/blockingpoll_unsafe_amd64.go b/pkg/tcpip/link/rawfile/blockingpoll_unsafe_amd64.go
new file mode 100644
index 000000000..0d89ddc1d
--- /dev/null
+++ b/pkg/tcpip/link/rawfile/blockingpoll_unsafe_amd64.go
@@ -0,0 +1,14 @@
+// Copyright 2018 The Netstack Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build linux,amd64
+
+package rawfile
+
+import (
+	"syscall"
+)
+
+//go:noescape
+func blockingPoll(fds *pollEvent, nfds int, timeout int64) (int, syscall.Errno)
diff --git a/pkg/tcpip/link/rawfile/errors.go b/pkg/tcpip/link/rawfile/errors.go
index ce58ee975..8eae9252c 100644
--- a/pkg/tcpip/link/rawfile/errors.go
+++ b/pkg/tcpip/link/rawfile/errors.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build linux
+
 package rawfile
 
 import (
diff --git a/pkg/tcpip/link/rawfile/rawfile_unsafe.go b/pkg/tcpip/link/rawfile/rawfile_unsafe.go
index d3660e1b4..6e8d7f556 100644
--- a/pkg/tcpip/link/rawfile/rawfile_unsafe.go
+++ b/pkg/tcpip/link/rawfile/rawfile_unsafe.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build linux
+
 // Package rawfile contains utilities for using the netstack with raw host
 // files on Linux hosts.
 package rawfile
@@ -13,9 +15,6 @@ import (
 	"gvisor.googlesource.com/gvisor/pkg/tcpip"
 )
 
-//go:noescape
-func blockingPoll(fds unsafe.Pointer, nfds int, timeout int64) (n int, err syscall.Errno)
-
 // GetMTU determines the MTU of a network interface device.
 func GetMTU(name string) (uint32, error) {
 	fd, err := syscall.Socket(syscall.AF_UNIX, syscall.SOCK_DGRAM, 0)
@@ -108,6 +107,12 @@ func NonBlockingWriteN(fd int, bs ...[]byte) *tcpip.Error {
 	return nil
 }
 
+type pollEvent struct {
+	fd      int32
+	events  int16
+	revents int16
+}
+
 // BlockingRead reads from a file descriptor that is set up as non-blocking. If
 // no data is available, it will block in a poll() syscall until the file
 // descirptor becomes readable.
@@ -118,16 +123,12 @@ func BlockingRead(fd int, b []byte) (int, *tcpip.Error) {
 			return int(n), nil
 		}
 
-		event := struct {
-			fd      int32
-			events  int16
-			revents int16
-		}{
+		event := pollEvent{
 			fd:     int32(fd),
 			events: 1, // POLLIN
 		}
 
-		_, e = blockingPoll(unsafe.Pointer(&event), 1, -1)
+		_, e = blockingPoll(&event, 1, -1)
 		if e != 0 && e != syscall.EINTR {
 			return 0, TranslateErrno(e)
 		}
@@ -144,16 +145,12 @@ func BlockingReadv(fd int, iovecs []syscall.Iovec) (int, *tcpip.Error) {
 			return int(n), nil
 		}
 
-		event := struct {
-			fd      int32
-			events  int16
-			revents int16
-		}{
+		event := pollEvent{
 			fd:     int32(fd),
 			events: 1, // POLLIN
 		}
 
-		_, e = blockingPoll(unsafe.Pointer(&event), 1, -1)
+		_, e = blockingPoll(&event, 1, -1)
 		if e != 0 && e != syscall.EINTR {
 			return 0, TranslateErrno(e)
 		}