-
Notifications
You must be signed in to change notification settings - Fork 29
/
forwarder.go
405 lines (344 loc) · 10.9 KB
/
forwarder.go
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
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
package proxy
import (
"context"
"fmt"
"github.com/synapsecns/sanguine/ethergo/parser/rpc"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/trace"
"io"
"net/http"
"strconv"
"strings"
"sync"
"github.com/Soft/iter"
"github.com/gin-gonic/gin"
"github.com/goccy/go-json"
"github.com/puzpuzpuz/xsync"
"github.com/synapsecns/sanguine/core/threaditer"
"github.com/synapsecns/sanguine/services/omnirpc/chainmanager"
omniHTTP "github.com/synapsecns/sanguine/services/omnirpc/http"
"k8s.io/apimachinery/pkg/util/sets"
)
// Forwarder creates a request forwarder.
type Forwarder struct {
// r is the parent rpc proxy object
r *RPCProxy
// c is the gin context for the request
c *gin.Context
// chain is the chain from the chain manager
chain chainmanager.Chain
// body is the body of the request
body []byte
// requiredConfirmations is the number of required confirmations for the request to go through
requiredConfirmations uint16
// requestID is the request id
requestID []byte
// client is the client used for fasthttp
client omniHTTP.Client
// resMap is the res map
// Note: because we use an array here, this is not thread safe for writes
resMap *xsync.MapOf[string, []rawResponse]
// failedForwards is a map of failed forwards
failedForwards *xsync.MapOf[string, error]
// rpcRequest is the parsed rpc request
rpcRequest rpc.Requests
// mux is used to track the release of the forwarder. This should only be used in async methods
// as RLock
mux sync.RWMutex
// span is the span for the request
span trace.Span
// tracer is the tracer for the request
tracer trace.Tracer
}
// Reset resets the forwarder so it can be reused.
func (f *Forwarder) Reset() {
// try to acquire the lock. this is
f.mux.Lock()
defer f.mux.Unlock()
// client and forwarder can stay the same
f.c = nil
f.chain = nil
f.body = nil
f.requiredConfirmations = 0
f.requestID = nil
f.resMap = nil
f.failedForwards = nil
f.rpcRequest = nil
f.span = nil
}
// AcquireForwarder allocates a forwarder and allows it to be released when not in use
// this allows forwarder cycling reducing GC overhead.
func (r *RPCProxy) AcquireForwarder() *Forwarder {
v := r.forwarderPool.Get()
if v == nil {
return &Forwarder{
r: r,
client: r.client,
tracer: r.tracer,
}
}
//nolint: forcetypeassert
return v.(*Forwarder)
}
// ReleaseForwarder releases a forwarder object for reuse.
func (r *RPCProxy) ReleaseForwarder(f *Forwarder) {
f.Reset()
r.forwarderPool.Put(f)
}
// Forward forwards the rpc request to the servers and makes assertions around confirmation thresholds.
// required confirmations can be used to override the required confirmations count.
func (r *RPCProxy) Forward(c *gin.Context, chainID uint32, requiredConfirmationsOverride *uint16) {
ctx, span := r.tracer.Start(c, "rpcRequest",
trace.WithAttributes(attribute.Int("chainID", int(chainID))),
)
forwarder := r.AcquireForwarder()
defer func() {
span.End()
r.ReleaseForwarder(forwarder)
}()
forwarder.c = c
forwarder.span = span
forwarder.resMap = xsync.NewMapOf[[]rawResponse]()
forwarder.failedForwards = xsync.NewMapOf[error]()
if requiredConfirmationsOverride != nil {
forwarder.requiredConfirmations = *requiredConfirmationsOverride
}
if ok := forwarder.fillAndValidate(chainID); !ok {
return
}
forwarder.attemptForwardAndValidate(ctx)
}
// attemptForwardAndValidate attempts to forward the request and
// makes sure it is valid
// TODO: maybe the context shouldn't be used from a struct here?
//
//nolint:gocognit,cyclop
func (f *Forwarder) attemptForwardAndValidate(ctx context.Context) {
urlIter := threaditer.ThreadSafe(iter.Slice(f.chain.URLs()))
// setup the channels we use for confirmation
errChan := make(chan FailedForward)
resChan := make(chan rawResponse)
forwardCtx, cancel := context.WithCancel(ctx)
defer cancel()
// start requiredConfirmations workers
for i := uint16(0); i < f.requiredConfirmations; i++ {
go func() {
f.mux.RLock()
defer f.mux.RUnlock()
for {
select {
case <-forwardCtx.Done():
return
default:
done := f.attemptForward(forwardCtx, errChan, resChan, urlIter)
// if there's nothing else we can end the goroutine
if done {
return
}
}
}
}()
}
totalResponses := 0
for {
select {
// request timeout
case <-f.c.Done():
return
case failedForward := <-errChan:
totalResponses++
f.failedForwards.Store(failedForward.URL, failedForward.Err)
// if we've checked every url
if totalResponses == len(f.chain.URLs()) {
if done := f.checkResponses(totalResponses); done {
return
}
}
case res := <-resChan:
totalResponses++
// add the response to resmap
responses, _ := f.resMap.Load(res.hash)
responses = append(responses, res)
f.resMap.Store(res.hash, responses)
// if we've checked every url or the number of non-error responses is greater than or equal to the
// number of confirmations
if totalResponses == len(f.chain.URLs()) || uint16(f.resMap.Size()) >= f.requiredConfirmations {
if done := f.checkResponses(totalResponses); done {
return
}
}
}
}
}
// urlConfirmationsHeader is a header specifying which urls were checked.
const urlConfirmationsHeader = "x-checked-urls"
// jsonHashHeader is the hash of the returned json.
const jsonHashHeader = "x-json-hash"
// forwardedFrom the actual url the json was forwarded from.
const forwardedFrom = "x-forwarded-from"
// ErroredRPCResponse contains an errored rpc response
// this is mostly used for debugging.
type ErroredRPCResponse struct {
Raw json.RawMessage `json:"json_response"`
URL string `json:"url"`
}
// ErrorResponse contains error response used for debugging.
type ErrorResponse struct {
Hashes map[string][]ErroredRPCResponse `json:"hashes"`
Error string `json:"error"`
// ErroredURLS returned no response at all
ErroredURLS []string `json:"errored_urls"`
// FailedForwards stores lower level json errors where no response could be returned at all
FailedForwards map[string]string `json:"failed_forwards"`
}
// FailedForward contains a failed forward.
type FailedForward struct {
// Err is the error returned
Err error
// URL is the url of the error
URL string
}
func (f *Forwarder) checkResponses(responseCount int) (done bool) {
var valid bool
f.resMap.Range(func(key string, responses []rawResponse) bool {
if uint16(len(responses)) >= f.requiredConfirmations {
responseURLS := make([]string, len(responses))
for i, url := range responses {
responseURLS[i] = url.url
}
f.c.Header(urlConfirmationsHeader, strings.Join(responseURLS, ","))
f.c.Header(jsonHashHeader, responses[0].hash)
f.c.Header(forwardedFrom, responses[0].url)
f.c.Data(http.StatusOK, gin.MIMEJSON, responses[0].body)
valid = true
return false
}
return true
})
if valid {
return true
}
// every urls been checked, we need to error
if responseCount == len(f.chain.URLs()) {
erroredUrls := sets.NewString(f.chain.URLs()...)
errResponse := ErrorResponse{
Error: "could not get consistent response",
Hashes: make(map[string][]ErroredRPCResponse),
}
f.resMap.Range(func(key string, responses []rawResponse) bool {
for _, response := range responses {
erroredUrls.Delete(response.url)
rpcErr := ErroredRPCResponse{
URL: response.url,
Raw: response.body,
}
errResponse.Hashes[key] = append(errResponse.Hashes[key], rpcErr)
}
return true
})
errResponse.FailedForwards = make(map[string]string)
f.failedForwards.Range(func(key string, value error) bool {
errResponse.FailedForwards[key] = value.Error()
return true
})
errResponse.ErroredURLS = erroredUrls.List()
f.c.JSON(http.StatusBadGateway, errResponse)
return true
}
return false
}
// attemptForward attempts to forward a request. If it runs out of urls to process
// or context is canceled, done is returned as true
//
// otherwise errors are added to an errChan and responses are added to the response chan.
func (f *Forwarder) attemptForward(ctx context.Context, errChan chan FailedForward, resChan chan rawResponse, urlIter iter.Iterator[string]) (done bool) {
nextURL := urlIter.Next()
if nextURL.IsNone() {
return true
}
url := nextURL.Unwrap()
res, err := f.forwardRequest(ctx, url)
if err != nil {
// check if we're done, otherwise add to errchan
select {
case <-ctx.Done():
return true
case errChan <- FailedForward{Err: err, URL: url}:
return false
}
}
// request was successful, add the body to the raw response channel for processing
select {
case <-ctx.Done():
return true
case resChan <- *res:
return false
}
}
// fillAndValidate fills request fields and validates fields.
func (f *Forwarder) fillAndValidate(chainID uint32) (ok bool) {
var err error
f.chain = f.r.chainManager.GetChain(chainID)
if f.chain == nil {
f.c.JSON(http.StatusBadRequest, gin.H{
"error": fmt.Sprintf("chain %d not found", chainID),
})
return false
}
f.body, err = io.ReadAll(f.c.Request.Body)
if err != nil {
f.c.JSON(http.StatusBadRequest, gin.H{
"error": err,
})
return false
}
f.requestID = []byte(f.c.GetHeader(omniHTTP.XRequestIDString))
f.span.SetAttributes(attribute.String("request_id", string(f.requestID)))
if ok := f.checkAndSetConfirmability(); !ok {
return false
}
return true
}
// checkAndSetConfirmability checks the confirmability of the request body and makes sure
// we have enough urls to validate the request.
func (f *Forwarder) checkAndSetConfirmability() (ok bool) {
// if we overrided required confirmations above, use that
if f.requiredConfirmations == 0 {
f.requiredConfirmations = f.chain.ConfirmationsThreshold()
}
var err error
f.rpcRequest, err = rpc.ParseRPCPayload(f.body)
if err != nil {
f.c.JSON(http.StatusBadRequest, gin.H{
"error": err,
})
return false
}
// If any request ina batch is not confirmable, the entire batch is marks as non-confirmable
confirmable, err := areConfirmable(f.rpcRequest)
if err != nil {
f.c.JSON(http.StatusBadRequest, gin.H{
"error": err,
})
return false
}
// non-confirmable requests must use 1
if !confirmable {
f.requiredConfirmations = 1
}
// set the headers
f.c.Header("x-confirmable", strconv.FormatBool(confirmable))
// this will be 1 if not confirmable
f.c.Header("x-required-confirmations", strconv.Itoa(int(f.requiredConfirmations)))
f.span.SetAttributes(attribute.Int("required_confirmations", int(f.requiredConfirmations)))
f.span.SetAttributes(attribute.Bool("confirmable", confirmable))
f.span.SetAttributes(attribute.String("method", f.rpcRequest.Method()))
// make sure we have enough urls to hit the required confirmation threshold
if len(f.chain.URLs()) < int(f.requiredConfirmations) {
f.c.JSON(http.StatusBadRequest, gin.H{
"error": fmt.Sprintf("not enough endpoints for chain %d: found %d needed %d", f.chain.ID(), len(f.chain.URLs()), f.requiredConfirmations),
})
return false
}
return true
}