-
Notifications
You must be signed in to change notification settings - Fork 0
/
util.go
108 lines (98 loc) · 3.29 KB
/
util.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
/* SPDX-License-Identifier: ISC
*
* Copyright (c) 2019-2024 Stanford University
* Copyright (c) 2024 Damian Peckett <[email protected]>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
package homa
import (
"encoding/binary"
"errors"
"fmt"
"net"
"unsafe"
"golang.org/x/sys/unix"
)
// htons converts a 16-bit host byte order number to network byte order.
func htons(host uint16) uint16 {
var buf [2]byte
binary.BigEndian.PutUint16(buf[:], host)
return *(*uint16)(unsafe.Pointer(&buf))
}
// ntohs converts a 16-bit network byte order number to host byte order.
func ntohs(net uint16) uint16 {
return binary.BigEndian.Uint16(unsafe.Slice((*byte)(unsafe.Pointer(&net)), 2))
}
// recvmsg is a wrapper around the recvmsg system call, this is not natively exposed to go but
// we need to make some tweaks to the msghdr struct so we'll define our own.
func recvmsg(s int, msg *unix.Msghdr, flags int) (n int, err error) {
err = unix.EINTR
for errors.Is(err, unix.EINTR) {
r0, _, e1 := unix.Syscall(unix.SYS_RECVMSG, uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
n = int(r0)
if e1 != 0 {
err = unix.Errno(e1)
} else {
err = nil
}
}
return
}
// sendmsg is a wrapper around the sendmsg system call, this is not natively exposed to go but
// we need to make some tweaks to the msghdr struct so we'll define our own.
func sendmsg(s int, msg *unix.Msghdr, flags int) (n int, err error) {
err = unix.EINTR
for errors.Is(err, unix.EINTR) {
r0, _, e1 := unix.Syscall(unix.SYS_SENDMSG, uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags))
n = int(r0)
if e1 != 0 {
err = unix.Errno(e1)
} else {
err = nil
}
}
return
}
func setsockoptHomaBuf(fd int, args SetBufArgs) (err error) {
err = unix.EINTR
for errors.Is(err, unix.EINTR) {
_, _, e1 := unix.Syscall6(unix.SYS_SETSOCKOPT, uintptr(fd), IPPROTO_HOMA, SO_HOMA_SET_BUF, uintptr(unsafe.Pointer(&args)), unsafe.Sizeof(args), 0)
if e1 != 0 {
err = unix.Errno(e1)
} else {
err = nil
}
}
return
}
// toRawSockAddr converts a net.Addr to a raw socket address.
func toRawSockAddr(addr net.Addr) (unsafe.Pointer, uint32, error) {
switch addr := addr.(type) {
case *net.UDPAddr:
if ipv4 := addr.IP.To4(); ipv4 != nil {
return unsafe.Pointer(&unix.RawSockaddrInet4{
Family: unix.AF_INET,
Port: htons(uint16(addr.Port)),
Addr: [4]byte(ipv4),
}), unix.SizeofSockaddrInet4, nil
}
return unsafe.Pointer(&unix.RawSockaddrInet6{
Family: unix.AF_INET6,
Port: htons(uint16(addr.Port)),
Addr: [16]byte(addr.IP),
}), unix.SizeofSockaddrInet6, nil
default:
return nil, 0, fmt.Errorf("unsupported address type: %T", addr)
}
}