79 lines
1.8 KiB
Go
79 lines
1.8 KiB
Go
// Copyright 2011 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Linux socket filter
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package syscall
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import (
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"unsafe"
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)
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func LsfStmt(code, k int) *SockFilter {
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return &SockFilter{Code: uint16(code), K: uint32(k)}
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}
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func LsfJump(code, k, jt, jf int) *SockFilter {
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return &SockFilter{Code: uint16(code), Jt: uint8(jt), Jf: uint8(jf), K: uint32(k)}
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}
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func LsfSocket(ifindex, proto int) (int, error) {
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var lsall SockaddrLinklayer
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s, e := Socket(AF_PACKET, SOCK_RAW, proto)
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if e != nil {
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return 0, e
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}
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p := (*[2]byte)(unsafe.Pointer(&lsall.Protocol))
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p[0] = byte(proto >> 8)
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p[1] = byte(proto)
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lsall.Ifindex = ifindex
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e = Bind(s, &lsall)
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if e != nil {
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Close(s)
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return 0, e
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}
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return s, nil
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}
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type iflags struct {
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name [IFNAMSIZ]byte
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flags uint16
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}
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func SetLsfPromisc(name string, m bool) error {
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s, e := Socket(AF_INET, SOCK_DGRAM, 0)
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if e != nil {
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return e
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}
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defer Close(s)
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var ifl iflags
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copy(ifl.name[:], []byte(name))
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_, _, ep := Syscall(SYS_IOCTL, uintptr(s), SIOCGIFFLAGS, uintptr(unsafe.Pointer(&ifl)))
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if ep != 0 {
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return Errno(ep)
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}
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if m {
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ifl.flags |= uint16(IFF_PROMISC)
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} else {
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ifl.flags &= ^uint16(IFF_PROMISC)
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}
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_, _, ep = Syscall(SYS_IOCTL, uintptr(s), SIOCSIFFLAGS, uintptr(unsafe.Pointer(&ifl)))
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if ep != 0 {
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return Errno(ep)
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}
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return nil
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}
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func AttachLsf(fd int, i []SockFilter) error {
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var p SockFprog
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p.Len = uint16(len(i))
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p.Filter = (*SockFilter)(unsafe.Pointer(&i[0]))
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return setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, uintptr(unsafe.Pointer(&p)), unsafe.Sizeof(p))
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}
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func DetachLsf(fd int) error {
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var dummy int
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return setsockopt(fd, SOL_SOCKET, SO_DETACH_FILTER, uintptr(unsafe.Pointer(&dummy)), unsafe.Sizeof(dummy))
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}
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