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| author | Mitja Felicijan <mitja.felicijan@gmail.com> | 2024-10-25 00:47:47 +0200 |
|---|---|---|
| committer | Mitja Felicijan <mitja.felicijan@gmail.com> | 2024-10-25 00:47:47 +0200 |
| commit | c6cc0108ca7738023b45e0eeac0fa2390532dd93 (patch) | |
| tree | 36890e6cd3091bbab8efbe686cc56f467f645bfd /vendor/golang.org/x/sys/unix/ifreq_linux.go | |
| parent | 0130404a1dc663d4aa68d780c9bcb23a4243e68d (diff) | |
| download | jbmafp-c6cc0108ca7738023b45e0eeac0fa2390532dd93.tar.gz | |
Diffstat (limited to 'vendor/golang.org/x/sys/unix/ifreq_linux.go')
| -rw-r--r-- | vendor/golang.org/x/sys/unix/ifreq_linux.go | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/vendor/golang.org/x/sys/unix/ifreq_linux.go b/vendor/golang.org/x/sys/unix/ifreq_linux.go new file mode 100644 index 0000000..15721a5 --- /dev/null +++ b/vendor/golang.org/x/sys/unix/ifreq_linux.go | |||
| @@ -0,0 +1,142 @@ | |||
| 1 | // Copyright 2021 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 | //go:build linux | ||
| 6 | // +build linux | ||
| 7 | |||
| 8 | package unix | ||
| 9 | |||
| 10 | import ( | ||
| 11 | "unsafe" | ||
| 12 | ) | ||
| 13 | |||
| 14 | // Helpers for dealing with ifreq since it contains a union and thus requires a | ||
| 15 | // lot of unsafe.Pointer casts to use properly. | ||
| 16 | |||
| 17 | // An Ifreq is a type-safe wrapper around the raw ifreq struct. An Ifreq | ||
| 18 | // contains an interface name and a union of arbitrary data which can be | ||
| 19 | // accessed using the Ifreq's methods. To create an Ifreq, use the NewIfreq | ||
| 20 | // function. | ||
| 21 | // | ||
| 22 | // Use the Name method to access the stored interface name. The union data | ||
| 23 | // fields can be get and set using the following methods: | ||
| 24 | // - Uint16/SetUint16: flags | ||
| 25 | // - Uint32/SetUint32: ifindex, metric, mtu | ||
| 26 | type Ifreq struct{ raw ifreq } | ||
| 27 | |||
| 28 | // NewIfreq creates an Ifreq with the input network interface name after | ||
| 29 | // validating the name does not exceed IFNAMSIZ-1 (trailing NULL required) | ||
| 30 | // bytes. | ||
| 31 | func NewIfreq(name string) (*Ifreq, error) { | ||
| 32 | // Leave room for terminating NULL byte. | ||
| 33 | if len(name) >= IFNAMSIZ { | ||
| 34 | return nil, EINVAL | ||
| 35 | } | ||
| 36 | |||
| 37 | var ifr ifreq | ||
| 38 | copy(ifr.Ifrn[:], name) | ||
| 39 | |||
| 40 | return &Ifreq{raw: ifr}, nil | ||
| 41 | } | ||
| 42 | |||
| 43 | // TODO(mdlayher): get/set methods for hardware address sockaddr, char array, etc. | ||
| 44 | |||
| 45 | // Name returns the interface name associated with the Ifreq. | ||
| 46 | func (ifr *Ifreq) Name() string { | ||
| 47 | return ByteSliceToString(ifr.raw.Ifrn[:]) | ||
| 48 | } | ||
| 49 | |||
| 50 | // According to netdevice(7), only AF_INET addresses are returned for numerous | ||
| 51 | // sockaddr ioctls. For convenience, we expose these as Inet4Addr since the Port | ||
| 52 | // field and other data is always empty. | ||
| 53 | |||
| 54 | // Inet4Addr returns the Ifreq union data from an embedded sockaddr as a C | ||
| 55 | // in_addr/Go []byte (4-byte IPv4 address) value. If the sockaddr family is not | ||
| 56 | // AF_INET, an error is returned. | ||
| 57 | func (ifr *Ifreq) Inet4Addr() ([]byte, error) { | ||
| 58 | raw := *(*RawSockaddrInet4)(unsafe.Pointer(&ifr.raw.Ifru[:SizeofSockaddrInet4][0])) | ||
| 59 | if raw.Family != AF_INET { | ||
| 60 | // Cannot safely interpret raw.Addr bytes as an IPv4 address. | ||
| 61 | return nil, EINVAL | ||
| 62 | } | ||
| 63 | |||
| 64 | return raw.Addr[:], nil | ||
| 65 | } | ||
| 66 | |||
| 67 | // SetInet4Addr sets a C in_addr/Go []byte (4-byte IPv4 address) value in an | ||
| 68 | // embedded sockaddr within the Ifreq's union data. v must be 4 bytes in length | ||
| 69 | // or an error will be returned. | ||
| 70 | func (ifr *Ifreq) SetInet4Addr(v []byte) error { | ||
| 71 | if len(v) != 4 { | ||
| 72 | return EINVAL | ||
| 73 | } | ||
| 74 | |||
| 75 | var addr [4]byte | ||
| 76 | copy(addr[:], v) | ||
| 77 | |||
| 78 | ifr.clear() | ||
| 79 | *(*RawSockaddrInet4)( | ||
| 80 | unsafe.Pointer(&ifr.raw.Ifru[:SizeofSockaddrInet4][0]), | ||
| 81 | ) = RawSockaddrInet4{ | ||
| 82 | // Always set IP family as ioctls would require it anyway. | ||
| 83 | Family: AF_INET, | ||
| 84 | Addr: addr, | ||
| 85 | } | ||
| 86 | |||
| 87 | return nil | ||
| 88 | } | ||
| 89 | |||
| 90 | // Uint16 returns the Ifreq union data as a C short/Go uint16 value. | ||
| 91 | func (ifr *Ifreq) Uint16() uint16 { | ||
| 92 | return *(*uint16)(unsafe.Pointer(&ifr.raw.Ifru[:2][0])) | ||
| 93 | } | ||
| 94 | |||
| 95 | // SetUint16 sets a C short/Go uint16 value as the Ifreq's union data. | ||
| 96 | func (ifr *Ifreq) SetUint16(v uint16) { | ||
| 97 | ifr.clear() | ||
| 98 | *(*uint16)(unsafe.Pointer(&ifr.raw.Ifru[:2][0])) = v | ||
| 99 | } | ||
| 100 | |||
| 101 | // Uint32 returns the Ifreq union data as a C int/Go uint32 value. | ||
| 102 | func (ifr *Ifreq) Uint32() uint32 { | ||
| 103 | return *(*uint32)(unsafe.Pointer(&ifr.raw.Ifru[:4][0])) | ||
| 104 | } | ||
| 105 | |||
| 106 | // SetUint32 sets a C int/Go uint32 value as the Ifreq's union data. | ||
| 107 | func (ifr *Ifreq) SetUint32(v uint32) { | ||
| 108 | ifr.clear() | ||
| 109 | *(*uint32)(unsafe.Pointer(&ifr.raw.Ifru[:4][0])) = v | ||
| 110 | } | ||
| 111 | |||
| 112 | // clear zeroes the ifreq's union field to prevent trailing garbage data from | ||
| 113 | // being sent to the kernel if an ifreq is reused. | ||
| 114 | func (ifr *Ifreq) clear() { | ||
| 115 | for i := range ifr.raw.Ifru { | ||
| 116 | ifr.raw.Ifru[i] = 0 | ||
| 117 | } | ||
| 118 | } | ||
| 119 | |||
| 120 | // TODO(mdlayher): export as IfreqData? For now we can provide helpers such as | ||
| 121 | // IoctlGetEthtoolDrvinfo which use these APIs under the hood. | ||
| 122 | |||
| 123 | // An ifreqData is an Ifreq which carries pointer data. To produce an ifreqData, | ||
| 124 | // use the Ifreq.withData method. | ||
| 125 | type ifreqData struct { | ||
| 126 | name [IFNAMSIZ]byte | ||
| 127 | // A type separate from ifreq is required in order to comply with the | ||
| 128 | // unsafe.Pointer rules since the "pointer-ness" of data would not be | ||
| 129 | // preserved if it were cast into the byte array of a raw ifreq. | ||
| 130 | data unsafe.Pointer | ||
| 131 | // Pad to the same size as ifreq. | ||
| 132 | _ [len(ifreq{}.Ifru) - SizeofPtr]byte | ||
| 133 | } | ||
| 134 | |||
| 135 | // withData produces an ifreqData with the pointer p set for ioctls which require | ||
| 136 | // arbitrary pointer data. | ||
| 137 | func (ifr Ifreq) withData(p unsafe.Pointer) ifreqData { | ||
| 138 | return ifreqData{ | ||
| 139 | name: ifr.raw.Ifrn, | ||
| 140 | data: p, | ||
| 141 | } | ||
| 142 | } | ||
