gcc/libgo/go/syscall/lsf_linux.go
Ian Lance Taylor de27caacfb Implement new syscall package.
Calls to library functions now use entersyscall and
exitsyscall as appropriate.  This is a first step toward
multiplexing goroutines onto threads.

From-SVN: r180345
2011-10-23 19:04:37 +00:00

79 lines
1.8 KiB
Go

// Copyright 2011 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.
// Linux socket filter
package syscall
import (
"unsafe"
)
func LsfStmt(code, k int) *SockFilter {
return &SockFilter{Code: uint16(code), K: uint32(k)}
}
func LsfJump(code, k, jt, jf int) *SockFilter {
return &SockFilter{Code: uint16(code), Jt: uint8(jt), Jf: uint8(jf), K: uint32(k)}
}
func LsfSocket(ifindex, proto int) (int, int) {
var lsall SockaddrLinklayer
s, e := Socket(AF_PACKET, SOCK_RAW, proto)
if e != 0 {
return 0, e
}
p := (*[2]byte)(unsafe.Pointer(&lsall.Protocol))
p[0] = byte(proto >> 8)
p[1] = byte(proto)
lsall.Ifindex = ifindex
e = Bind(s, &lsall)
if e != 0 {
Close(s)
return 0, e
}
return s, 0
}
type iflags struct {
name [IFNAMSIZ]byte
flags uint16
}
func SetLsfPromisc(name string, m bool) int {
s, e := Socket(AF_INET, SOCK_DGRAM, 0)
if e != 0 {
return e
}
defer Close(s)
var ifl iflags
copy(ifl.name[:], []byte(name))
_, _, ep := Syscall(SYS_IOCTL, uintptr(s), SIOCGIFFLAGS, uintptr(unsafe.Pointer(&ifl)))
if e := int(ep); e != 0 {
return e
}
if m {
ifl.flags |= uint16(IFF_PROMISC)
} else {
ifl.flags &= ^uint16(IFF_PROMISC)
}
_, _, ep = Syscall(SYS_IOCTL, uintptr(s), SIOCSIFFLAGS, uintptr(unsafe.Pointer(&ifl)))
if e := int(ep); e != 0 {
return e
}
return 0
}
func AttachLsf(fd int, i []SockFilter) int {
var p SockFprog
p.Len = uint16(len(i))
p.Filter = (*SockFilter)(unsafe.Pointer(&i[0]))
return setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, uintptr(unsafe.Pointer(&p)), unsafe.Sizeof(p))
}
func DetachLsf(fd int) int {
var dummy int
return setsockopt(fd, SOL_SOCKET, SO_DETACH_FILTER, uintptr(unsafe.Pointer(&dummy)), unsafe.Sizeof(dummy))
}