forked from cilium/ebpf
/
link_test.go
212 lines (178 loc) · 4.52 KB
/
link_test.go
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package link
import (
"errors"
"math"
"os"
"path/filepath"
"reflect"
"testing"
"github.com/cilium/ebpf"
"github.com/cilium/ebpf/asm"
"github.com/cilium/ebpf/internal/sys"
"github.com/cilium/ebpf/internal/testutils"
"github.com/cilium/ebpf/internal/unix"
)
func TestRawLink(t *testing.T) {
cgroup, prog := mustCgroupFixtures(t)
link, err := AttachRawLink(RawLinkOptions{
Target: int(cgroup.Fd()),
Program: prog,
Attach: ebpf.AttachCGroupInetEgress,
})
testutils.SkipIfNotSupported(t, err)
if err != nil {
t.Fatal("Can't create raw link:", err)
}
info, err := link.Info()
if err != nil {
t.Fatal("Can't get link info:", err)
}
pi, err := prog.Info()
if err != nil {
t.Fatal("Can't get program info:", err)
}
progID, ok := pi.ID()
if !ok {
t.Fatal("Program ID not available in program info")
}
if info.Program != progID {
t.Error("Link program ID doesn't match program ID")
}
testLink(t, &linkCgroup{*link}, prog)
}
func TestRawLinkLoadPinnedWithOptions(t *testing.T) {
cgroup, prog := mustCgroupFixtures(t)
link, err := AttachRawLink(RawLinkOptions{
Target: int(cgroup.Fd()),
Program: prog,
Attach: ebpf.AttachCGroupInetEgress,
})
testutils.SkipIfNotSupported(t, err)
if err != nil {
t.Fatal("Can't create raw link:", err)
}
path := filepath.Join(testutils.TempBPFFS(t), "link")
err = link.Pin(path)
testutils.SkipIfNotSupported(t, err)
if err != nil {
t.Fatal(err)
}
// It seems like the kernel ignores BPF_F_RDONLY when updating a link,
// so we can't test this.
_, err = loadPinnedRawLink(path, &ebpf.LoadPinOptions{
Flags: math.MaxUint32,
})
if !errors.Is(err, unix.EINVAL) {
t.Fatal("Invalid flags don't trigger an error:", err)
}
}
func mustCgroupFixtures(t *testing.T) (*os.File, *ebpf.Program) {
t.Helper()
testutils.SkipIfNotSupported(t, haveProgAttach())
return testutils.CreateCgroup(t), mustLoadProgram(t, ebpf.CGroupSKB, ebpf.AttachCGroupInetEgress, "")
}
func testLink(t *testing.T, link Link, prog *ebpf.Program) {
t.Helper()
tmp, err := os.MkdirTemp("/sys/fs/bpf", "ebpf-test")
if err != nil {
t.Fatal(err)
}
defer os.RemoveAll(tmp)
t.Run("link/pinning", func(t *testing.T) {
path := filepath.Join(tmp, "link")
err = link.Pin(path)
testutils.SkipIfNotSupported(t, err)
if err != nil {
t.Fatalf("Can't pin %T: %s", link, err)
}
link2, err := LoadPinnedLink(path, nil)
if err != nil {
t.Fatalf("Can't load pinned %T: %s", link, err)
}
link2.Close()
if reflect.TypeOf(link) != reflect.TypeOf(link2) {
t.Errorf("Loading a pinned %T returns a %T", link, link2)
}
_, err = LoadPinnedLink(path, &ebpf.LoadPinOptions{
Flags: math.MaxUint32,
})
if !errors.Is(err, unix.EINVAL) {
t.Errorf("Loading a pinned %T doesn't respect flags", link)
}
})
t.Run("link/update", func(t *testing.T) {
err := link.Update(prog)
testutils.SkipIfNotSupported(t, err)
if err != nil {
t.Fatal("Update returns an error:", err)
}
func() {
// Panicking is OK
defer func() {
_ = recover()
}()
if err := link.Update(nil); err == nil {
t.Fatalf("%T.Update accepts nil program", link)
}
}()
})
t.Run("link/info", func(t *testing.T) {
info, err := link.Info()
testutils.SkipIfNotSupported(t, err)
if err != nil {
t.Fatal("Link info returns an error:", err)
}
if info.Type == 0 {
t.Fatal("Failed to get link info type")
}
switch info.Type {
case sys.BPF_LINK_TYPE_TRACING:
if info.Tracing() == nil {
t.Fatalf("Failed to get link tracing extra info")
}
case sys.BPF_LINK_TYPE_CGROUP:
cg := info.Cgroup()
if cg.CgroupId == 0 {
t.Fatalf("Failed to get link Cgroup extra info")
}
case sys.BPF_LINK_TYPE_NETNS:
netns := info.NetNs()
if netns.AttachType == 0 {
t.Fatalf("Failed to get link NetNs extra info")
}
case sys.BPF_LINK_TYPE_XDP:
xdp := info.XDP()
if xdp.Ifindex == 0 {
t.Fatalf("Failed to get link XDP extra info")
}
}
})
if err := link.Close(); err != nil {
t.Fatalf("%T.Close returns an error: %s", link, err)
}
}
func mustLoadProgram(tb testing.TB, typ ebpf.ProgramType, attachType ebpf.AttachType, attachTo string) *ebpf.Program {
tb.Helper()
license := "MIT"
switch typ {
case ebpf.RawTracepoint, ebpf.LSM:
license = "GPL"
}
prog, err := ebpf.NewProgram(&ebpf.ProgramSpec{
Type: typ,
AttachType: attachType,
AttachTo: attachTo,
License: license,
Instructions: asm.Instructions{
asm.Mov.Imm(asm.R0, 0),
asm.Return(),
},
})
if err != nil {
tb.Fatal(err)
}
tb.Cleanup(func() {
prog.Close()
})
return prog
}