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
|
// Copyright 2019 Google LLC. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package expr
import (
"encoding/binary"
"github.com/google/nftables/binaryutil"
"github.com/mdlayher/netlink"
"golang.org/x/sys/unix"
)
type LogLevel uint32
const (
// See https://git.netfilter.org/nftables/tree/include/linux/netfilter/nf_tables.h?id=5b364657a35f4e4cd5d220ba2a45303d729c8eca#n1226
LogLevelEmerg LogLevel = iota
LogLevelAlert
LogLevelCrit
LogLevelErr
LogLevelWarning
LogLevelNotice
LogLevelInfo
LogLevelDebug
LogLevelAudit
)
type LogFlags uint32
const (
// See https://git.netfilter.org/nftables/tree/include/linux/netfilter/nf_log.h?id=5b364657a35f4e4cd5d220ba2a45303d729c8eca
LogFlagsTCPSeq LogFlags = 0x01 << iota
LogFlagsTCPOpt
LogFlagsIPOpt
LogFlagsUID
LogFlagsNFLog
LogFlagsMACDecode
LogFlagsMask LogFlags = 0x2f
)
// Log defines type for NFT logging
// See https://git.netfilter.org/libnftnl/tree/src/expr/log.c?id=09456c720e9c00eecc08e41ac6b7c291b3821ee5#n25
type Log struct {
Level LogLevel
// Refers to log flags (flags all, flags ip options, ...)
Flags LogFlags
// Equivalent to expression flags.
// Indicates that an option is set by setting a bit
// on index referred by the NFTA_LOG_* value.
// See https://cs.opensource.google/go/x/sys/+/3681064d:unix/ztypes_linux.go;l=2126;drc=3681064d51587c1db0324b3d5c23c2ddbcff6e8f
Key uint32
Snaplen uint32
Group uint16
QThreshold uint16
// Log prefix string content
Data []byte
}
func (e *Log) marshal(fam byte) ([]byte, error) {
// Per https://git.netfilter.org/libnftnl/tree/src/expr/log.c?id=09456c720e9c00eecc08e41ac6b7c291b3821ee5#n129
attrs := make([]netlink.Attribute, 0)
if e.Key&(1<<unix.NFTA_LOG_GROUP) != 0 {
attrs = append(attrs, netlink.Attribute{
Type: unix.NFTA_LOG_GROUP,
Data: binaryutil.BigEndian.PutUint16(e.Group),
})
}
if e.Key&(1<<unix.NFTA_LOG_PREFIX) != 0 {
prefix := append(e.Data, '\x00')
attrs = append(attrs, netlink.Attribute{
Type: unix.NFTA_LOG_PREFIX,
Data: prefix,
})
}
if e.Key&(1<<unix.NFTA_LOG_SNAPLEN) != 0 {
attrs = append(attrs, netlink.Attribute{
Type: unix.NFTA_LOG_SNAPLEN,
Data: binaryutil.BigEndian.PutUint32(e.Snaplen),
})
}
if e.Key&(1<<unix.NFTA_LOG_QTHRESHOLD) != 0 {
attrs = append(attrs, netlink.Attribute{
Type: unix.NFTA_LOG_QTHRESHOLD,
Data: binaryutil.BigEndian.PutUint16(e.QThreshold),
})
}
if e.Key&(1<<unix.NFTA_LOG_LEVEL) != 0 {
attrs = append(attrs, netlink.Attribute{
Type: unix.NFTA_LOG_LEVEL,
Data: binaryutil.BigEndian.PutUint32(uint32(e.Level)),
})
}
if e.Key&(1<<unix.NFTA_LOG_FLAGS) != 0 {
attrs = append(attrs, netlink.Attribute{
Type: unix.NFTA_LOG_FLAGS,
Data: binaryutil.BigEndian.PutUint32(uint32(e.Flags)),
})
}
data, err := netlink.MarshalAttributes(attrs)
if err != nil {
return nil, err
}
return netlink.MarshalAttributes([]netlink.Attribute{
{Type: unix.NFTA_EXPR_NAME, Data: []byte("log\x00")},
{Type: unix.NLA_F_NESTED | unix.NFTA_EXPR_DATA, Data: data},
})
}
func (e *Log) unmarshal(fam byte, data []byte) error {
ad, err := netlink.NewAttributeDecoder(data)
if err != nil {
return err
}
ad.ByteOrder = binary.BigEndian
for ad.Next() {
e.Key |= 1 << uint32(ad.Type())
data := ad.Bytes()
switch ad.Type() {
case unix.NFTA_LOG_GROUP:
e.Group = binaryutil.BigEndian.Uint16(data)
case unix.NFTA_LOG_PREFIX:
// Getting rid of \x00 at the end of string
e.Data = data[:len(data)-1]
case unix.NFTA_LOG_SNAPLEN:
e.Snaplen = binaryutil.BigEndian.Uint32(data)
case unix.NFTA_LOG_QTHRESHOLD:
e.QThreshold = binaryutil.BigEndian.Uint16(data)
case unix.NFTA_LOG_LEVEL:
e.Level = LogLevel(binaryutil.BigEndian.Uint32(data))
case unix.NFTA_LOG_FLAGS:
e.Flags = LogFlags(binaryutil.BigEndian.Uint32(data))
}
}
return ad.Err()
}
|
