diff options
author | kali kaneko (leap communications) <kali@leap.se> | 2021-11-29 01:46:27 +0100 |
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committer | kali kaneko (leap communications) <kali@leap.se> | 2021-11-29 18:14:16 +0100 |
commit | 18f52af5be3a9a0c73811706108f790d65ee9c67 (patch) | |
tree | e13cbacb47d56919caa9c44a2b45dec1497a7860 /vendor/golang.org/x/net/ipv4/packet.go | |
parent | ebcef0d57b6ecb5a40c6579f6be07182dd3033ba (diff) |
[pkg] update vendor
Diffstat (limited to 'vendor/golang.org/x/net/ipv4/packet.go')
-rw-r--r-- | vendor/golang.org/x/net/ipv4/packet.go | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/ipv4/packet.go b/vendor/golang.org/x/net/ipv4/packet.go new file mode 100644 index 0000000..7d784e0 --- /dev/null +++ b/vendor/golang.org/x/net/ipv4/packet.go @@ -0,0 +1,117 @@ +// Copyright 2012 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. + +package ipv4 + +import ( + "net" + + "golang.org/x/net/internal/socket" +) + +// BUG(mikio): On Windows, the ReadFrom and WriteTo methods of RawConn +// are not implemented. + +// A packetHandler represents the IPv4 datagram handler. +type packetHandler struct { + *net.IPConn + *socket.Conn + rawOpt +} + +func (c *packetHandler) ok() bool { return c != nil && c.IPConn != nil && c.Conn != nil } + +// ReadFrom reads an IPv4 datagram from the endpoint c, copying the +// datagram into b. It returns the received datagram as the IPv4 +// header h, the payload p and the control message cm. +func (c *packetHandler) ReadFrom(b []byte) (h *Header, p []byte, cm *ControlMessage, err error) { + if !c.ok() { + return nil, nil, nil, errInvalidConn + } + c.rawOpt.RLock() + m := socket.Message{ + Buffers: [][]byte{b}, + OOB: NewControlMessage(c.rawOpt.cflags), + } + c.rawOpt.RUnlock() + if err := c.RecvMsg(&m, 0); err != nil { + return nil, nil, nil, &net.OpError{Op: "read", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Err: err} + } + var hs []byte + if hs, p, err = slicePacket(b[:m.N]); err != nil { + return nil, nil, nil, &net.OpError{Op: "read", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Err: err} + } + if h, err = ParseHeader(hs); err != nil { + return nil, nil, nil, &net.OpError{Op: "read", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Err: err} + } + if m.NN > 0 { + if compatFreeBSD32 { + adjustFreeBSD32(&m) + } + cm = new(ControlMessage) + if err := cm.Parse(m.OOB[:m.NN]); err != nil { + return nil, nil, nil, &net.OpError{Op: "read", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Err: err} + } + } + if src, ok := m.Addr.(*net.IPAddr); ok && cm != nil { + cm.Src = src.IP + } + return +} + +func slicePacket(b []byte) (h, p []byte, err error) { + if len(b) < HeaderLen { + return nil, nil, errHeaderTooShort + } + hdrlen := int(b[0]&0x0f) << 2 + return b[:hdrlen], b[hdrlen:], nil +} + +// WriteTo writes an IPv4 datagram through the endpoint c, copying the +// datagram from the IPv4 header h and the payload p. The control +// message cm allows the datagram path and the outgoing interface to be +// specified. Currently only Darwin and Linux support this. The cm +// may be nil if control of the outgoing datagram is not required. +// +// The IPv4 header h must contain appropriate fields that include: +// +// Version = <must be specified> +// Len = <must be specified> +// TOS = <must be specified> +// TotalLen = <must be specified> +// ID = platform sets an appropriate value if ID is zero +// FragOff = <must be specified> +// TTL = <must be specified> +// Protocol = <must be specified> +// Checksum = platform sets an appropriate value if Checksum is zero +// Src = platform sets an appropriate value if Src is nil +// Dst = <must be specified> +// Options = optional +func (c *packetHandler) WriteTo(h *Header, p []byte, cm *ControlMessage) error { + if !c.ok() { + return errInvalidConn + } + m := socket.Message{ + OOB: cm.Marshal(), + } + wh, err := h.Marshal() + if err != nil { + return err + } + m.Buffers = [][]byte{wh, p} + dst := new(net.IPAddr) + if cm != nil { + if ip := cm.Dst.To4(); ip != nil { + dst.IP = ip + } + } + if dst.IP == nil { + dst.IP = h.Dst + } + m.Addr = dst + if err := c.SendMsg(&m, 0); err != nil { + return &net.OpError{Op: "write", Net: c.IPConn.LocalAddr().Network(), Source: c.IPConn.LocalAddr(), Addr: opAddr(dst), Err: err} + } + return nil +} |