| // Copyright 2018 Google Inc. |
| // |
| // 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 stack |
| |
| import ( |
| "fmt" |
| "sync" |
| "testing" |
| "time" |
| |
| "github.com/google/netstack/sleep" |
| "github.com/google/netstack/tcpip" |
| ) |
| |
| type testaddr struct { |
| addr tcpip.FullAddress |
| linkAddr tcpip.LinkAddress |
| } |
| |
| var testaddrs []testaddr |
| |
| type testLinkAddressResolver struct { |
| cache *linkAddrCache |
| delay time.Duration |
| } |
| |
| func (r *testLinkAddressResolver) LinkAddressRequest(addr, _ tcpip.Address, _ LinkEndpoint) *tcpip.Error { |
| go func() { |
| if r.delay > 0 { |
| time.Sleep(r.delay) |
| } |
| r.fakeRequest(addr) |
| }() |
| return nil |
| } |
| |
| func (r *testLinkAddressResolver) fakeRequest(addr tcpip.Address) { |
| for _, ta := range testaddrs { |
| if ta.addr.Addr == addr { |
| r.cache.add(ta.addr, ta.linkAddr) |
| break |
| } |
| } |
| } |
| |
| func (*testLinkAddressResolver) ResolveStaticAddress(addr tcpip.Address) (tcpip.LinkAddress, bool) { |
| if addr == "broadcast" { |
| return "mac_broadcast", true |
| } |
| return "", false |
| } |
| |
| func (*testLinkAddressResolver) LinkAddressProtocol() tcpip.NetworkProtocolNumber { |
| return 1 |
| } |
| |
| func getBlocking(c *linkAddrCache, addr tcpip.FullAddress, linkRes LinkAddressResolver) (tcpip.LinkAddress, *tcpip.Error) { |
| w := sleep.Waker{} |
| s := sleep.Sleeper{} |
| s.AddWaker(&w, 123) |
| defer s.Done() |
| |
| for { |
| if got, err := c.get(addr, linkRes, "", nil, &w); err != tcpip.ErrWouldBlock { |
| return got, err |
| } |
| s.Fetch(true) |
| } |
| } |
| |
| func init() { |
| for i := 0; i < 4*linkAddrCacheSize; i++ { |
| addr := fmt.Sprintf("Addr%06d", i) |
| testaddrs = append(testaddrs, testaddr{ |
| addr: tcpip.FullAddress{NIC: 1, Addr: tcpip.Address(addr)}, |
| linkAddr: tcpip.LinkAddress("Link" + addr), |
| }) |
| } |
| } |
| |
| func TestCacheOverflow(t *testing.T) { |
| c := newLinkAddrCache(1<<63-1, 1*time.Second, 3) |
| for i := len(testaddrs) - 1; i >= 0; i-- { |
| e := testaddrs[i] |
| c.add(e.addr, e.linkAddr) |
| got, err := c.get(e.addr, nil, "", nil, nil) |
| if err != nil { |
| t.Errorf("insert %d, c.get(%q)=%q, got error: %v", i, string(e.addr.Addr), got, err) |
| } |
| if got != e.linkAddr { |
| t.Errorf("insert %d, c.get(%q)=%q, want %q", i, string(e.addr.Addr), got, e.linkAddr) |
| } |
| } |
| // Expect to find at least half of the most recent entries. |
| for i := 0; i < linkAddrCacheSize/2; i++ { |
| e := testaddrs[i] |
| got, err := c.get(e.addr, nil, "", nil, nil) |
| if err != nil { |
| t.Errorf("check %d, c.get(%q)=%q, got error: %v", i, string(e.addr.Addr), got, err) |
| } |
| if got != e.linkAddr { |
| t.Errorf("check %d, c.get(%q)=%q, want %q", i, string(e.addr.Addr), got, e.linkAddr) |
| } |
| } |
| // The earliest entries should no longer be in the cache. |
| for i := len(testaddrs) - 1; i >= len(testaddrs)-linkAddrCacheSize; i-- { |
| e := testaddrs[i] |
| if _, err := c.get(e.addr, nil, "", nil, nil); err != tcpip.ErrNoLinkAddress { |
| t.Errorf("check %d, c.get(%q), got error: %v, want: error ErrNoLinkAddress", i, string(e.addr.Addr), err) |
| } |
| } |
| } |
| |
| func TestCacheConcurrent(t *testing.T) { |
| c := newLinkAddrCache(1<<63-1, 1*time.Second, 3) |
| |
| var wg sync.WaitGroup |
| for r := 0; r < 16; r++ { |
| wg.Add(1) |
| go func() { |
| for _, e := range testaddrs { |
| c.add(e.addr, e.linkAddr) |
| c.get(e.addr, nil, "", nil, nil) // make work for gotsan |
| } |
| wg.Done() |
| }() |
| } |
| wg.Wait() |
| |
| // All goroutines add in the same order and add more values than |
| // can fit in the cache, so our eviction strategy requires that |
| // the last entry be present and the first be missing. |
| e := testaddrs[len(testaddrs)-1] |
| got, err := c.get(e.addr, nil, "", nil, nil) |
| if err != nil { |
| t.Errorf("c.get(%q)=%q, got error: %v", string(e.addr.Addr), got, err) |
| } |
| if got != e.linkAddr { |
| t.Errorf("c.get(%q)=%q, want %q", string(e.addr.Addr), got, e.linkAddr) |
| } |
| |
| e = testaddrs[0] |
| if _, err := c.get(e.addr, nil, "", nil, nil); err != tcpip.ErrNoLinkAddress { |
| t.Errorf("c.get(%q), got error: %v, want: error ErrNoLinkAddress", string(e.addr.Addr), err) |
| } |
| } |
| |
| func TestCacheAgeLimit(t *testing.T) { |
| c := newLinkAddrCache(1*time.Millisecond, 1*time.Second, 3) |
| e := testaddrs[0] |
| c.add(e.addr, e.linkAddr) |
| time.Sleep(50 * time.Millisecond) |
| if _, err := c.get(e.addr, nil, "", nil, nil); err != tcpip.ErrNoLinkAddress { |
| t.Errorf("c.get(%q), got error: %v, want: error ErrNoLinkAddress", string(e.addr.Addr), err) |
| } |
| } |
| |
| func TestCacheReplace(t *testing.T) { |
| c := newLinkAddrCache(1<<63-1, 1*time.Second, 3) |
| e := testaddrs[0] |
| l2 := e.linkAddr + "2" |
| c.add(e.addr, e.linkAddr) |
| got, err := c.get(e.addr, nil, "", nil, nil) |
| if err != nil { |
| t.Errorf("c.get(%q)=%q, got error: %v", string(e.addr.Addr), got, err) |
| } |
| if got != e.linkAddr { |
| t.Errorf("c.get(%q)=%q, want %q", string(e.addr.Addr), got, e.linkAddr) |
| } |
| |
| c.add(e.addr, l2) |
| got, err = c.get(e.addr, nil, "", nil, nil) |
| if err != nil { |
| t.Errorf("c.get(%q)=%q, got error: %v", string(e.addr.Addr), got, err) |
| } |
| if got != l2 { |
| t.Errorf("c.get(%q)=%q, want %q", string(e.addr.Addr), got, l2) |
| } |
| } |
| |
| func TestCacheResolution(t *testing.T) { |
| c := newLinkAddrCache(1<<63-1, 250*time.Millisecond, 1) |
| linkRes := &testLinkAddressResolver{cache: c} |
| for i, ta := range testaddrs { |
| got, err := getBlocking(c, ta.addr, linkRes) |
| if err != nil { |
| t.Errorf("check %d, c.get(%q)=%q, got error: %v", i, string(ta.addr.Addr), got, err) |
| } |
| if got != ta.linkAddr { |
| t.Errorf("check %d, c.get(%q)=%q, want %q", i, string(ta.addr.Addr), got, ta.linkAddr) |
| } |
| } |
| |
| // Check that after resolved, address stays in the cache and never returns WouldBlock. |
| for i := 0; i < 10; i++ { |
| e := testaddrs[len(testaddrs)-1] |
| got, err := c.get(e.addr, linkRes, "", nil, nil) |
| if err != nil { |
| t.Errorf("c.get(%q)=%q, got error: %v", string(e.addr.Addr), got, err) |
| } |
| if got != e.linkAddr { |
| t.Errorf("c.get(%q)=%q, want %q", string(e.addr.Addr), got, e.linkAddr) |
| } |
| } |
| } |
| |
| func TestCacheResolutionFailed(t *testing.T) { |
| c := newLinkAddrCache(1<<63-1, 10*time.Millisecond, 5) |
| linkRes := &testLinkAddressResolver{cache: c} |
| |
| // First, sanity check that resolution is working... |
| e := testaddrs[0] |
| got, err := getBlocking(c, e.addr, linkRes) |
| if err != nil { |
| t.Errorf("c.get(%q)=%q, got error: %v", string(e.addr.Addr), got, err) |
| } |
| if got != e.linkAddr { |
| t.Errorf("c.get(%q)=%q, want %q", string(e.addr.Addr), got, e.linkAddr) |
| } |
| |
| e.addr.Addr += "2" |
| if _, err := getBlocking(c, e.addr, linkRes); err != tcpip.ErrNoLinkAddress { |
| t.Errorf("c.get(%q), got error: %v, want: error ErrNoLinkAddress", string(e.addr.Addr), err) |
| } |
| } |
| |
| func TestCacheResolutionTimeout(t *testing.T) { |
| resolverDelay := 50 * time.Millisecond |
| expiration := resolverDelay / 2 |
| c := newLinkAddrCache(expiration, 1*time.Millisecond, 3) |
| linkRes := &testLinkAddressResolver{cache: c, delay: resolverDelay} |
| |
| e := testaddrs[0] |
| if _, err := getBlocking(c, e.addr, linkRes); err != tcpip.ErrNoLinkAddress { |
| t.Errorf("c.get(%q), got error: %v, want: error ErrNoLinkAddress", string(e.addr.Addr), err) |
| } |
| } |
| |
| // TestStaticResolution checks that static link addresses are resolved immediately and don't |
| // send resolution requests. |
| func TestStaticResolution(t *testing.T) { |
| c := newLinkAddrCache(1<<63-1, time.Millisecond, 1) |
| linkRes := &testLinkAddressResolver{cache: c, delay: time.Minute} |
| |
| addr := tcpip.Address("broadcast") |
| want := tcpip.LinkAddress("mac_broadcast") |
| got, err := c.get(tcpip.FullAddress{Addr: addr}, linkRes, "", nil, nil) |
| if err != nil { |
| t.Errorf("c.get(%q)=%q, got error: %v", string(addr), string(got), err) |
| } |
| if got != want { |
| t.Errorf("c.get(%q)=%q, want %q", string(addr), string(got), string(want)) |
| } |
| } |