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
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
// Copyright (C) 2015 Luke Shumaker <lukeshu@sbcglobal.net>
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
// 02110-1301 USA
package nslcd_proto
import (
"encoding/binary"
"fmt"
"io"
"net"
"reflect"
"syscall"
)
type NslcdError string
func (o NslcdError) Error() string {
return string(o)
}
type nslcdObject interface {
nslcdWrite(fd io.Writer)
}
type nslcdObjectPtr interface {
nslcdRead(fd io.Reader)
}
// Write an object to a stream. In the event of an error, this
// function may panic! Handle it!
func Write(fd io.Writer, data interface{}) {
switch data := data.(type) {
// basic data types
case nslcdObject:
data.nslcdWrite(fd)
case []byte:
_, err := fd.Write(data)
if err != nil {
panic(err)
}
case int32:
err := binary.Write(fd, binary.BigEndian, data)
if err != nil {
panic(err)
}
// composite datatypes
case string:
Write(fd, int32(len(data)))
Write(fd, []byte(data))
case []string:
Write(fd, int32(len(data)))
for _, item := range data {
Write(fd, item)
}
case net.IP:
var af int32 = -1
switch len(data) {
case net.IPv4len:
af = syscall.AF_INET
case net.IPv6len:
af = syscall.AF_INET6
}
var bytes []byte
if af < 0 {
bytes = make([]byte, 0)
} else {
bytes = data
}
Write(fd, af)
Write(fd, int32(len(bytes)))
Write(fd, bytes)
case []net.IP:
Write(fd, int32(len(data)))
for _, item := range data {
Write(fd, item)
}
default:
v := reflect.ValueOf(data)
switch v.Kind() {
case reflect.Struct:
for i, n := 0, v.NumField(); i < n; i++ {
Write(fd, v.Field(i).Interface())
}
default:
panic(fmt.Sprintf("Invalid structure to write NSLCD protocol data from: %T ( %#v )", data, data))
}
}
}
// Read an object from a stream. In the event of an error, this
// function may panic! Handle it!
func Read(fd io.Reader, data interface{}) {
switch data := data.(type) {
// basic data types
case nslcdObjectPtr:
data.nslcdRead(fd)
case *[]byte:
_, err := fd.Read(*data)
if err != nil {
panic(err)
}
case *int32:
err := binary.Read(fd, binary.BigEndian, data)
if err != nil {
panic(err)
}
// composite datatypes
case *string:
var len int32
Read(fd, &len)
buf := make([]byte, len)
Read(fd, &buf)
*data = string(buf)
case *[]string:
var num int32
Read(fd, &num)
*data = make([]string, num)
for i := 0; i < int(num); i++ {
Read(fd, &((*data)[i]))
}
case *net.IP:
var af int32
Read(fd, &af)
var _len int32
switch af {
case syscall.AF_INET:
_len = net.IPv4len
case syscall.AF_INET6:
_len = net.IPv6len
default:
panic(NslcdError(fmt.Sprintf("incorrect address family specified: %d", af)))
}
var len int32
Read(fd, &len)
if len != _len {
panic(NslcdError(fmt.Sprintf("address length incorrect: %d", len)))
}
buf := make([]byte, len)
Read(fd, &buf)
*data = buf
case *[]net.IP:
var num int32
Read(fd, &num)
*data = make([]net.IP, num)
for i := 0; i < int(num); i++ {
Read(fd, &((*data)[i]))
}
default:
p := reflect.ValueOf(data)
v := reflect.Indirect(p)
if p == v || v.Kind() != reflect.Struct {
panic(fmt.Sprintf("The argument to nslcd_proto/internal.Read() must be a pointer: %T ( %#v )", data, data))
}
for i, n := 0, v.NumField(); i < n; i++ {
Read(fd, v.Field(i).Addr().Interface())
}
}
}
|
