David K. Bainbridge | 215e024 | 2017-09-05 23:18:24 -0700 | [diff] [blame] | 1 | // Copyright 2017 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 | // +build go1.9 |
| 6 | |
| 7 | package ipv6 |
| 8 | |
| 9 | import ( |
| 10 | "net" |
| 11 | "runtime" |
| 12 | "syscall" |
| 13 | |
| 14 | "golang.org/x/net/internal/socket" |
| 15 | ) |
| 16 | |
| 17 | // BUG(mikio): On Windows, the ReadBatch and WriteBatch methods of |
| 18 | // PacketConn are not implemented. |
| 19 | |
| 20 | // A Message represents an IO message. |
| 21 | // |
| 22 | // type Message struct { |
| 23 | // Buffers [][]byte |
| 24 | // OOB []byte |
| 25 | // Addr net.Addr |
| 26 | // N int |
| 27 | // NN int |
| 28 | // Flags int |
| 29 | // } |
| 30 | // |
| 31 | // The Buffers fields represents a list of contiguous buffers, which |
| 32 | // can be used for vectored IO, for example, putting a header and a |
| 33 | // payload in each slice. |
| 34 | // When writing, the Buffers field must contain at least one byte to |
| 35 | // write. |
| 36 | // When reading, the Buffers field will always contain a byte to read. |
| 37 | // |
| 38 | // The OOB field contains protocol-specific control or miscellaneous |
| 39 | // ancillary data known as out-of-band data. |
| 40 | // It can be nil when not required. |
| 41 | // |
| 42 | // The Addr field specifies a destination address when writing. |
| 43 | // It can be nil when the underlying protocol of the endpoint uses |
| 44 | // connection-oriented communication. |
| 45 | // After a successful read, it may contain the source address on the |
| 46 | // received packet. |
| 47 | // |
| 48 | // The N field indicates the number of bytes read or written from/to |
| 49 | // Buffers. |
| 50 | // |
| 51 | // The NN field indicates the number of bytes read or written from/to |
| 52 | // OOB. |
| 53 | // |
| 54 | // The Flags field contains protocol-specific information on the |
| 55 | // received message. |
| 56 | type Message = socket.Message |
| 57 | |
| 58 | // ReadBatch reads a batch of messages. |
| 59 | // |
| 60 | // The provided flags is a set of platform-dependent flags, such as |
| 61 | // syscall.MSG_PEEK. |
| 62 | // |
| 63 | // On a successful read it returns the number of messages received, up |
| 64 | // to len(ms). |
| 65 | // |
| 66 | // On Linux, a batch read will be optimized. |
| 67 | // On other platforms, this method will read only a single message. |
| 68 | func (c *payloadHandler) ReadBatch(ms []Message, flags int) (int, error) { |
| 69 | if !c.ok() { |
| 70 | return 0, syscall.EINVAL |
| 71 | } |
| 72 | switch runtime.GOOS { |
| 73 | case "linux": |
| 74 | n, err := c.RecvMsgs([]socket.Message(ms), flags) |
| 75 | if err != nil { |
| 76 | err = &net.OpError{Op: "read", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Err: err} |
| 77 | } |
| 78 | return n, err |
| 79 | default: |
| 80 | n := 1 |
| 81 | err := c.RecvMsg(&ms[0], flags) |
| 82 | if err != nil { |
| 83 | n = 0 |
| 84 | err = &net.OpError{Op: "read", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Err: err} |
| 85 | } |
| 86 | return n, err |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | // WriteBatch writes a batch of messages. |
| 91 | // |
| 92 | // The provided flags is a set of platform-dependent flags, such as |
| 93 | // syscall.MSG_DONTROUTE. |
| 94 | // |
| 95 | // It returns the number of messages written on a successful write. |
| 96 | // |
| 97 | // On Linux, a batch write will be optimized. |
| 98 | // On other platforms, this method will write only a single message. |
| 99 | func (c *payloadHandler) WriteBatch(ms []Message, flags int) (int, error) { |
| 100 | if !c.ok() { |
| 101 | return 0, syscall.EINVAL |
| 102 | } |
| 103 | switch runtime.GOOS { |
| 104 | case "linux": |
| 105 | n, err := c.SendMsgs([]socket.Message(ms), flags) |
| 106 | if err != nil { |
| 107 | err = &net.OpError{Op: "write", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Err: err} |
| 108 | } |
| 109 | return n, err |
| 110 | default: |
| 111 | n := 1 |
| 112 | err := c.SendMsg(&ms[0], flags) |
| 113 | if err != nil { |
| 114 | n = 0 |
| 115 | err = &net.OpError{Op: "write", Net: c.PacketConn.LocalAddr().Network(), Source: c.PacketConn.LocalAddr(), Err: err} |
| 116 | } |
| 117 | return n, err |
| 118 | } |
| 119 | } |