lsf_linux.go

     1  // Copyright 2011 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Linux socket filter
     6  
     7  package syscall
     8  
     9  import (
    10  	"unsafe"
    11  )
    12  
    13  // Deprecated: Use golang.org/x/net/bpf instead.
    14  func LsfStmt(code, k int) *SockFilter {
    15  	return &SockFilter{Code: uint16(code), K: uint32(k)}
    16  }
    17  
    18  // Deprecated: Use golang.org/x/net/bpf instead.
    19  func LsfJump(code, k, jt, jf int) *SockFilter {
    20  	return &SockFilter{Code: uint16(code), Jt: uint8(jt), Jf: uint8(jf), K: uint32(k)}
    21  }
    22  
    23  // Deprecated: Use golang.org/x/net/bpf instead.
    24  func LsfSocket(ifindex, proto int) (int, error) {
    25  	var lsall SockaddrLinklayer
    26  	// This is missing SOCK_CLOEXEC, but adding the flag
    27  	// could break callers.
    28  	s, e := Socket(AF_PACKET, SOCK_RAW, proto)
    29  	if e != nil {
    30  		return 0, e
    31  	}
    32  	p := (*[2]byte)(unsafe.Pointer(&lsall.Protocol))
    33  	p[0] = byte(proto >> 8)
    34  	p[1] = byte(proto)
    35  	lsall.Ifindex = ifindex
    36  	e = Bind(s, &lsall)
    37  	if e != nil {
    38  		Close(s)
    39  		return 0, e
    40  	}
    41  	return s, nil
    42  }
    43  
    44  type iflags struct {
    45  	name  [IFNAMSIZ]byte
    46  	flags uint16
    47  }
    48  
    49  // Deprecated: Use golang.org/x/net/bpf instead.
    50  func SetLsfPromisc(name string, m bool) error {
    51  	s, e := cloexecSocket(AF_INET, SOCK_DGRAM, 0)
    52  	if e != nil {
    53  		return e
    54  	}
    55  	defer Close(s)
    56  	var ifl iflags
    57  	copy(ifl.name[:], []byte(name))
    58  	_, _, ep := Syscall(SYS_IOCTL, uintptr(s), SIOCGIFFLAGS, uintptr(unsafe.Pointer(&ifl)))
    59  	if ep != 0 {
    60  		return Errno(ep)
    61  	}
    62  	if m {
    63  		ifl.flags |= uint16(IFF_PROMISC)
    64  	} else {
    65  		ifl.flags &^= uint16(IFF_PROMISC)
    66  	}
    67  	_, _, ep = Syscall(SYS_IOCTL, uintptr(s), SIOCSIFFLAGS, uintptr(unsafe.Pointer(&ifl)))
    68  	if ep != 0 {
    69  		return Errno(ep)
    70  	}
    71  	return nil
    72  }
    73  
    74  // Deprecated: Use golang.org/x/net/bpf instead.
    75  func AttachLsf(fd int, i []SockFilter) error {
    76  	var p SockFprog
    77  	p.Len = uint16(len(i))
    78  	p.Filter = (*SockFilter)(unsafe.Pointer(&i[0]))
    79  	return setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, unsafe.Pointer(&p), unsafe.Sizeof(p))
    80  }
    81  
    82  // Deprecated: Use golang.org/x/net/bpf instead.
    83  func DetachLsf(fd int) error {
    84  	var dummy int
    85  	return setsockopt(fd, SOL_SOCKET, SO_DETACH_FILTER, unsafe.Pointer(&dummy), unsafe.Sizeof(dummy))
    86  }
    87
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