| 1 | package discovery |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "crypto/tls" |
| 6 | "net/http" |
| 7 | "net/url" |
| 8 | "time" |
| 9 | |
| 10 | "github.com/rs/zerolog/log" |
| 11 | |
| 12 | "github.com/gosuda/portal-tunnel/v2/types" |
| 13 | "github.com/gosuda/portal-tunnel/v2/utils" |
| 14 | ) |
| 15 | |
| 16 | const ( |
| 17 | defaultRequestTimeout = 15 * time.Second |
| 18 | DiscoveryPollInterval = 30 * time.Second |
| 19 | defaultRecoveryFailures = 5 |
| 20 | ) |
| 21 | |
| 22 | type OverlayRuntime interface { |
| 23 | DiscoverRelay(context.Context, types.RelayDescriptor) (types.DiscoveryResponse, error) |
| 24 | Sync([]types.RelayDescriptor) error |
| 25 | } |
| 26 | |
| 27 | type Refresher struct { |
| 28 | relaySet *RelaySet |
| 29 | httpClient *http.Client |
| 30 | overlay OverlayRuntime |
| 31 | directRecoveryFailures int |
| 32 | lastAnnounceSuccess map[string]bool |
| 33 | } |
| 34 | |
| 35 | func NewRefresher(relaySet *RelaySet, overlay OverlayRuntime) *Refresher { |
| 36 | return &Refresher{ |
| 37 | relaySet: relaySet, |
| 38 | httpClient: utils.NewHTTPClient( |
| 39 | utils.WithHTTPTLSConfig(&tls.Config{ |
| 40 | MinVersion: tls.VersionTLS12, |
| 41 | NextProtos: []string{"http/1.1"}, |
| 42 | }), |
| 43 | utils.WithoutHTTP2(), |
| 44 | utils.WithHTTPTimeout(defaultRequestTimeout), |
| 45 | ), |
| 46 | overlay: overlay, |
| 47 | directRecoveryFailures: defaultRecoveryFailures, |
| 48 | lastAnnounceSuccess: make(map[string]bool), |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | func (r *Refresher) Refresh(ctx context.Context, self *types.RelayDescriptor) error { |
| 53 | if r.overlay != nil { |
| 54 | if err := r.refreshOverlay(ctx); err != nil && ctx.Err() == nil { |
| 55 | log.Warn(). |
| 56 | Err(err). |
| 57 | Msg("overlay discovery failed") |
| 58 | } |
| 59 | if ctx.Err() != nil { |
| 60 | return ctx.Err() |
| 61 | } |
| 62 | } |
| 63 | if err := r.refreshHTTPS(ctx); err != nil { |
| 64 | return err |
| 65 | } |
| 66 | if self != nil { |
| 67 | if err := r.announceSelf(ctx, *self); err != nil { |
| 68 | return err |
| 69 | } |
| 70 | } |
| 71 | return nil |
| 72 | } |
| 73 | |
| 74 | func (r *Refresher) announceSelf(ctx context.Context, descriptor types.RelayDescriptor) error { |
| 75 | req := types.DiscoveryAnnounceRequest{ |
| 76 | ProtocolVersion: types.DiscoveryVersion, |
| 77 | Descriptor: descriptor, |
| 78 | } |
| 79 | |
| 80 | for _, relayURL := range r.relaySet.BootstrapRelayURLs() { |
| 81 | if relayURL == descriptor.APIHTTPSAddr { |
| 82 | continue |
| 83 | } |
| 84 | baseURL, err := url.Parse(relayURL) |
| 85 | if err != nil { |
| 86 | if r.shouldLogAnnounce(relayURL, false) { |
| 87 | log.Warn(). |
| 88 | Err(err). |
| 89 | Str("relay", relayURL). |
| 90 | Msg("relay discovery announce target skipped") |
| 91 | } |
| 92 | continue |
| 93 | } |
| 94 | |
| 95 | if err := utils.HTTPDoAPIPath(ctx, r.httpClient, baseURL, http.MethodPost, types.PathDiscoveryAnnounce, req, nil, nil); err != nil { |
| 96 | if ctx.Err() != nil { |
| 97 | return ctx.Err() |
| 98 | } |
| 99 | if r.shouldLogAnnounce(relayURL, false) { |
| 100 | log.Warn(). |
| 101 | Err(err). |
| 102 | Str("relay", relayURL). |
| 103 | Msg("relay discovery announce failed") |
| 104 | } |
| 105 | continue |
| 106 | } |
| 107 | if r.shouldLogAnnounce(relayURL, true) { |
| 108 | log.Info(). |
| 109 | Str("relay", relayURL). |
| 110 | Msg("relay discovery announce succeeded") |
| 111 | } |
| 112 | } |
| 113 | return nil |
| 114 | } |
| 115 | |
| 116 | func (r *Refresher) shouldLogAnnounce(relayURL string, success bool) bool { |
| 117 | previous, ok := r.lastAnnounceSuccess[relayURL] |
| 118 | if ok && previous == success { |
| 119 | return false |
| 120 | } |
| 121 | r.lastAnnounceSuccess[relayURL] = success |
| 122 | return true |
| 123 | } |
| 124 | |
| 125 | func (r *Refresher) refreshHTTPS(ctx context.Context) error { |
| 126 | now := time.Now().UTC() |
| 127 | for _, state := range r.relaySet.refreshCandidates(now) { |
| 128 | relayURL := state.Descriptor.APIHTTPSAddr |
| 129 | |
| 130 | recoveryFailures := r.directRecoveryFailures |
| 131 | if state.Bootstrap { |
| 132 | recoveryFailures = 0 |
| 133 | } |
| 134 | |
| 135 | baseURL, err := url.Parse(relayURL) |
| 136 | if err != nil { |
| 137 | if recoveryFailures > 0 { |
| 138 | r.logDiscoveryFailure(relayURL, relayURL, recoveryFailures, err) |
| 139 | } |
| 140 | continue |
| 141 | } |
| 142 | client := r.httpClient |
| 143 | var closeClient func() |
| 144 | if utils.IsLocalRelayHost(baseURL.Hostname()) { |
| 145 | _, localClient, transport, err := utils.NewHTTPTLSClient(ctx, baseURL, defaultRequestTimeout) |
| 146 | if err != nil { |
| 147 | if recoveryFailures > 0 { |
| 148 | r.logDiscoveryFailure(relayURL, relayURL, recoveryFailures, err) |
| 149 | } |
| 150 | continue |
| 151 | } |
| 152 | client = localClient |
| 153 | closeClient = transport.CloseIdleConnections |
| 154 | } |
| 155 | |
| 156 | startedAt := time.Now() |
| 157 | var resp types.DiscoveryResponse |
| 158 | if err := utils.HTTPDoAPIPath(ctx, client, baseURL, http.MethodGet, types.PathDiscovery, nil, nil, &resp); err != nil { |
| 159 | if closeClient != nil { |
| 160 | closeClient() |
| 161 | } |
| 162 | if ctx.Err() != nil { |
| 163 | return ctx.Err() |
| 164 | } |
| 165 | if recoveryFailures > 0 { |
| 166 | r.logDiscoveryFailure(relayURL, relayURL, recoveryFailures, err) |
| 167 | } |
| 168 | continue |
| 169 | } |
| 170 | if closeClient != nil { |
| 171 | closeClient() |
| 172 | } |
| 173 | measuredAt := time.Now().UTC() |
| 174 | |
| 175 | if _, err := r.relaySet.ApplyRelayDiscoveryResponse(relayURL, resp, measuredAt); err != nil { |
| 176 | if recoveryFailures > 0 { |
| 177 | r.logDiscoveryFailure(relayURL, relayURL, recoveryFailures, err) |
| 178 | } |
| 179 | continue |
| 180 | } |
| 181 | r.relaySet.RecordDiscoveryRTT(relayURL, time.Since(startedAt), measuredAt) |
| 182 | } |
| 183 | return nil |
| 184 | } |
| 185 | |
| 186 | func (r *Refresher) refreshOverlay(ctx context.Context) error { |
| 187 | now := time.Now().UTC() |
| 188 | states := r.relaySet.overlayPeerRelayStates(now) |
| 189 | if len(states) == 0 { |
| 190 | return nil |
| 191 | } |
| 192 | descriptors := make([]types.RelayDescriptor, 0, len(states)) |
| 193 | for _, state := range states { |
| 194 | descriptors = append(descriptors, state.Descriptor) |
| 195 | } |
| 196 | if err := r.overlay.Sync(descriptors); err != nil { |
| 197 | return err |
| 198 | } |
| 199 | relaySetChanged := false |
| 200 | for _, state := range r.relaySet.overlayRefreshCandidates(now) { |
| 201 | relay := state.Descriptor |
| 202 | recoveryFailures := r.directRecoveryFailures |
| 203 | if state.Bootstrap { |
| 204 | recoveryFailures = 0 |
| 205 | } |
| 206 | startedAt := time.Now() |
| 207 | resp, err := r.overlay.DiscoverRelay(ctx, relay) |
| 208 | if err != nil { |
| 209 | if ctx.Err() != nil { |
| 210 | return ctx.Err() |
| 211 | } |
| 212 | if recoveryFailures > 0 { |
| 213 | r.logDiscoveryFailure(relay.APIHTTPSAddr, relay.APIHTTPSAddr, recoveryFailures, err) |
| 214 | } |
| 215 | continue |
| 216 | } |
| 217 | |
| 218 | measuredAt := time.Now().UTC() |
| 219 | changed, err := r.relaySet.ApplyRelayDiscoveryResponse(relay.APIHTTPSAddr, resp, measuredAt) |
| 220 | if err != nil { |
| 221 | if recoveryFailures > 0 { |
| 222 | r.logDiscoveryFailure(relay.APIHTTPSAddr, relay.APIHTTPSAddr, recoveryFailures, err) |
| 223 | } |
| 224 | continue |
| 225 | } |
| 226 | r.relaySet.RecordDiscoveryRTT(relay.APIHTTPSAddr, time.Since(startedAt), measuredAt) |
| 227 | if changed { |
| 228 | relaySetChanged = true |
| 229 | } |
| 230 | } |
| 231 | if !relaySetChanged { |
| 232 | return nil |
| 233 | } |
| 234 | if err := r.overlay.Sync(r.relaySet.OverlayPeerDescriptor()); err != nil { |
| 235 | return err |
| 236 | } |
| 237 | return nil |
| 238 | } |
| 239 | |
| 240 | func (r *Refresher) logDiscoveryFailure(targetRelayURL, sourceURL string, recoveryFailures int, err error) { |
| 241 | backedOff, backoffReason, failureCount := r.relaySet.RecordDiscoveryFailure(targetRelayURL, recoveryFailures) |
| 242 | if !backedOff { |
| 243 | return |
| 244 | } |
| 245 | |
| 246 | event := log.Warn(). |
| 247 | Err(err). |
| 248 | Str("relay", sourceURL). |
| 249 | Bool("backed_off", true). |
| 250 | Str("reason", backoffReason) |
| 251 | if failureCount > 0 { |
| 252 | event = event.Int("discovery_failures", failureCount) |
| 253 | } |
| 254 | if backoffReason == "unhealthy" { |
| 255 | event.Msg("discovery source removed from relay pool") |
| 256 | return |
| 257 | } |
| 258 | event.Msg("discovery source retry delayed") |
| 259 | } |