Files
sys/unix/lsf_linux.go
Rob Pike dc3c21c62b go.sys/unix: use syscall.Errno for errors
If we use a local type, it won't compare properly with errors from
the rest of the standard library. Errors are the one type from syscall
that propagates through the system, so it's important to have only
one type for them.

Ditto for syscall.Signal.

LGTM=dave
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/123490043
2014-08-15 09:57:24 -07:00

80 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 unix
import (
"syscall"
"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, error) {
var lsall SockaddrLinklayer
s, e := Socket(AF_PACKET, SOCK_RAW, proto)
if e != nil {
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 != nil {
Close(s)
return 0, e
}
return s, nil
}
type iflags struct {
name [IFNAMSIZ]byte
flags uint16
}
func SetLsfPromisc(name string, m bool) error {
s, e := Socket(AF_INET, SOCK_DGRAM, 0)
if e != nil {
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 ep != 0 {
return syscall.Errno(ep)
}
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 ep != 0 {
return syscall.Errno(ep)
}
return nil
}
func AttachLsf(fd int, i []SockFilter) error {
var p SockFprog
p.Len = uint16(len(i))
p.Filter = (*SockFilter)(unsafe.Pointer(&i[0]))
return setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, unsafe.Pointer(&p), unsafe.Sizeof(p))
}
func DetachLsf(fd int) error {
var dummy int
return setsockopt(fd, SOL_SOCKET, SO_DETACH_FILTER, unsafe.Pointer(&dummy), unsafe.Sizeof(dummy))
}