Files
netstack/tcpip/link/rawfile/rawfile_unsafe.go
2021-09-05 21:53:52 +08:00

117 lines
2.1 KiB
Go

package rawfile
import (
"syscall"
"unsafe"
"github.com/impact-eintr/netstack/tcpip"
)
func GetMTU(name string) (uint32, error) {
fd, err := syscall.Socket(syscall.AF_UNIX, syscall.SOCK_DGRAM, 0)
if err != nil {
return 0, err
}
defer syscall.Close(fd)
var ifreq struct {
name [16]byte
mtu int32
_ [20]byte
}
copy(ifreq.name[:], name)
_, _, errno := syscall.Syscall(syscall.SYS_IOCTL,
uintptr(fd), syscall.SIOCGIFMTU, uintptr(unsafe.Pointer(&ifreq)))
if errno != 0 {
return 0, errno
}
return uint32(ifreq.mtu), nil
}
func NonBlockingWrite(fd int, buf []byte) *tcpip.Error {
var ptr unsafe.Pointer
if len(buf) > 0 {
ptr = unsafe.Pointer(&buf[0])
}
_, _, e := syscall.RawSyscall(syscall.SYS_WRITE,
uintptr(fd), uintptr(ptr), uintptr(len(buf)))
if e != 0 {
return TranslationErrno(e)
}
return nil
}
func NonBlockingWrite2(fd int, b1, b2 []byte) *tcpip.Error {
if len(b2) == 0 {
return NonBlockingWrite(fd, b1)
}
iovec := [...]syscall.Iovec{
{
Base: &b1[0],
Len: uint64(len(b1)),
},
{
Base: &b2[0],
Len: uint64(len(b2)),
},
}
_, _, e := syscall.RawSyscall(syscall.SYS_WRITEV,
uintptr(fd), uintptr(unsafe.Pointer(&iovec[0])), uintptr(len(iovec)))
if e != 0 {
return TranslationErrno(e)
}
return nil
}
type pollEvent struct {
fd int32
events int16
revents int16
}
func BlockingRead(fd int, b []byte) (int, *tcpip.Error) {
for {
n, _, e := syscall.RawSyscall(syscall.SYS_READ,
uintptr(fd), uintptr(unsafe.Pointer(&b[0])), uintptr(len(b)))
if e == 0 {
return int(n), nil
}
event := pollEvent{
fd: int32(fd),
events: 1,
}
_, e = blockingPoll(&event, 1, -1)
if e != 0 && e != syscall.EINTR {
return 0, TranslationErrno(e)
}
}
}
func BlockingReadv(fd int, iovecs []syscall.Iovec) (int, *tcpip.Error) {
for {
n, _, e := syscall.RawSyscall(syscall.SYS_READV,
uintptr(fd), uintptr(unsafe.Pointer(&iovecs[0])), uintptr(len(iovecs)))
if e == 0 {
return int(n), nil
}
event := pollEvent{
fd: int32(fd),
events: 1,
}
_, e = blockingPoll(&event, 1, -1)
if e != 0 && e != syscall.EINTR {
return 0, TranslationErrno(e)
}
}
}