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
173
174
175
176
177
178
179
|
package internal
import (
"fmt"
"path/filepath"
"runtime"
"unsafe"
"github.com/cilium/ebpf/internal/unix"
)
//go:generate stringer -output syscall_string.go -type=BPFCmd
// BPFCmd identifies a subcommand of the bpf syscall.
type BPFCmd int
// Well known BPF commands.
const (
BPF_MAP_CREATE BPFCmd = iota
BPF_MAP_LOOKUP_ELEM
BPF_MAP_UPDATE_ELEM
BPF_MAP_DELETE_ELEM
BPF_MAP_GET_NEXT_KEY
BPF_PROG_LOAD
BPF_OBJ_PIN
BPF_OBJ_GET
BPF_PROG_ATTACH
BPF_PROG_DETACH
BPF_PROG_TEST_RUN
BPF_PROG_GET_NEXT_ID
BPF_MAP_GET_NEXT_ID
BPF_PROG_GET_FD_BY_ID
BPF_MAP_GET_FD_BY_ID
BPF_OBJ_GET_INFO_BY_FD
BPF_PROG_QUERY
BPF_RAW_TRACEPOINT_OPEN
BPF_BTF_LOAD
BPF_BTF_GET_FD_BY_ID
BPF_TASK_FD_QUERY
BPF_MAP_LOOKUP_AND_DELETE_ELEM
BPF_MAP_FREEZE
BPF_BTF_GET_NEXT_ID
BPF_MAP_LOOKUP_BATCH
BPF_MAP_LOOKUP_AND_DELETE_BATCH
BPF_MAP_UPDATE_BATCH
BPF_MAP_DELETE_BATCH
BPF_LINK_CREATE
BPF_LINK_UPDATE
BPF_LINK_GET_FD_BY_ID
BPF_LINK_GET_NEXT_ID
BPF_ENABLE_STATS
BPF_ITER_CREATE
)
// BPF wraps SYS_BPF.
//
// Any pointers contained in attr must use the Pointer type from this package.
func BPF(cmd BPFCmd, attr unsafe.Pointer, size uintptr) (uintptr, error) {
r1, _, errNo := unix.Syscall(unix.SYS_BPF, uintptr(cmd), uintptr(attr), size)
runtime.KeepAlive(attr)
var err error
if errNo != 0 {
err = errNo
}
return r1, err
}
type BPFProgAttachAttr struct {
TargetFd uint32
AttachBpfFd uint32
AttachType uint32
AttachFlags uint32
ReplaceBpfFd uint32
}
func BPFProgAttach(attr *BPFProgAttachAttr) error {
_, err := BPF(BPF_PROG_ATTACH, unsafe.Pointer(attr), unsafe.Sizeof(*attr))
return err
}
type BPFProgDetachAttr struct {
TargetFd uint32
AttachBpfFd uint32
AttachType uint32
}
func BPFProgDetach(attr *BPFProgDetachAttr) error {
_, err := BPF(BPF_PROG_DETACH, unsafe.Pointer(attr), unsafe.Sizeof(*attr))
return err
}
type BPFEnableStatsAttr struct {
StatsType uint32
}
func BPFEnableStats(attr *BPFEnableStatsAttr) (*FD, error) {
ptr, err := BPF(BPF_ENABLE_STATS, unsafe.Pointer(attr), unsafe.Sizeof(*attr))
if err != nil {
return nil, fmt.Errorf("enable stats: %w", err)
}
return NewFD(uint32(ptr)), nil
}
type bpfObjAttr struct {
fileName Pointer
fd uint32
fileFlags uint32
}
const bpfFSType = 0xcafe4a11
// BPFObjPin wraps BPF_OBJ_PIN.
func BPFObjPin(fileName string, fd *FD) error {
dirName := filepath.Dir(fileName)
var statfs unix.Statfs_t
if err := unix.Statfs(dirName, &statfs); err != nil {
return err
}
if uint64(statfs.Type) != bpfFSType {
return fmt.Errorf("%s is not on a bpf filesystem", fileName)
}
value, err := fd.Value()
if err != nil {
return err
}
attr := bpfObjAttr{
fileName: NewStringPointer(fileName),
fd: value,
}
_, err = BPF(BPF_OBJ_PIN, unsafe.Pointer(&attr), unsafe.Sizeof(attr))
if err != nil {
return fmt.Errorf("pin object %s: %w", fileName, err)
}
return nil
}
// BPFObjGet wraps BPF_OBJ_GET.
func BPFObjGet(fileName string) (*FD, error) {
attr := bpfObjAttr{
fileName: NewStringPointer(fileName),
}
ptr, err := BPF(BPF_OBJ_GET, unsafe.Pointer(&attr), unsafe.Sizeof(attr))
if err != nil {
return nil, fmt.Errorf("get object %s: %w", fileName, err)
}
return NewFD(uint32(ptr)), nil
}
type bpfObjGetInfoByFDAttr struct {
fd uint32
infoLen uint32
info Pointer
}
// BPFObjGetInfoByFD wraps BPF_OBJ_GET_INFO_BY_FD.
//
// Available from 4.13.
func BPFObjGetInfoByFD(fd *FD, info unsafe.Pointer, size uintptr) error {
value, err := fd.Value()
if err != nil {
return err
}
attr := bpfObjGetInfoByFDAttr{
fd: value,
infoLen: uint32(size),
info: NewPointer(info),
}
_, err = BPF(BPF_OBJ_GET_INFO_BY_FD, unsafe.Pointer(&attr), unsafe.Sizeof(attr))
if err != nil {
return fmt.Errorf("fd %v: %w", fd, err)
}
return nil
}
|
