Files
higress/plugins/wasm-go/pkg/mcp/utils/json_rpc.go

210 lines
6.8 KiB
Go

// Copyright (c) 2022 Alibaba Group Holding Ltd.
//
// 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 utils
import (
"fmt"
"strconv"
"github.com/higress-group/proxy-wasm-go-sdk/proxywasm"
"github.com/higress-group/proxy-wasm-go-sdk/proxywasm/types"
"github.com/tidwall/gjson"
"github.com/tidwall/sjson"
"google.golang.org/protobuf/proto"
"github.com/higress-group/wasm-go/pkg/iface"
"github.com/higress-group/wasm-go/pkg/log"
pb "github.com/higress-group/wasm-go/pkg/protos"
"github.com/higress-group/wasm-go/pkg/wrapper"
)
const (
CtxJsonRpcID = "jsonRpcID"
CtxNeedPause = "needPause" // Context key to signal if the handler needs to pause
JError = "error"
JCode = "code"
JMessage = "message"
JResult = "result"
ErrParseError = -32700
ErrInvalidRequest = -32600
ErrMethodNotFound = -32601
ErrInvalidParams = -32602
ErrInternalError = -32603
)
// JsonRpcID represents a JSON-RPC ID which can be either a string or a number
type JsonRpcID struct {
StringValue string
IntValue int64
IsString bool
}
// NewJsonRpcIDFromGjson creates a JsonRpcID from a gjson.Result
func NewJsonRpcIDFromGjson(result gjson.Result) JsonRpcID {
if result.Type == gjson.String {
return JsonRpcID{
StringValue: result.String(),
IsString: true,
}
}
return JsonRpcID{
IntValue: result.Int(),
IsString: false,
}
}
type JsonRpcRequestHandler func(context wrapper.HttpContext, id JsonRpcID, method string, params gjson.Result, rawBody []byte) types.Action
type JsonRpcResponseHandler func(context wrapper.HttpContext, id JsonRpcID, result gjson.Result, error gjson.Result, rawBody []byte) types.Action
type JsonRpcMethodHandler func(context wrapper.HttpContext, id JsonRpcID, params gjson.Result) error
type MethodHandlers map[string]JsonRpcMethodHandler
func makeHttpResponse(ctx wrapper.HttpContext, code uint32, debugInfo string, headers [][2]string, body []byte) {
phase := ctx.GetExecutionPhase()
if phase < iface.EncodeHeader {
proxywasm.SendHttpResponseWithDetail(code, debugInfo, headers, body, -1)
return
}
if debugInfo != "" {
log.Infof("response detail info:%s", debugInfo)
}
proxywasm.RemoveHttpResponseHeader("content-length")
proxywasm.ReplaceHttpResponseHeader(":status", strconv.Itoa(int(code)))
for _, kv := range headers {
proxywasm.ReplaceHttpResponseHeader(kv[0], kv[1])
}
if phase == iface.EncodeData {
proxywasm.ReplaceHttpResponseBody(body)
return
}
// EncodeHeader phase
args := &pb.InjectEncodedDataToFilterChainArguments{
Body: string(body),
Endstream: true,
}
argsStr, _ := proto.Marshal(args)
_, err := proxywasm.CallForeignFunction("inject_encoded_data_to_filter_chain_on_header", argsStr)
if err != nil {
log.Warnf("call inject_encoded_data_to_filter_chain_on_header failed, err:%v, fallback to send directly", err)
proxywasm.SendHttpResponseWithDetail(code, debugInfo, headers, body, -1)
return
}
}
func sendJsonRpcResponse(ctx wrapper.HttpContext, id JsonRpcID, extras map[string]any, debugInfo string) {
body := []byte(`{"jsonrpc": "2.0"}`)
if id.IsString {
body, _ = sjson.SetBytes(body, "id", id.StringValue)
} else {
body, _ = sjson.SetBytes(body, "id", id.IntValue)
}
for key, value := range extras {
body, _ = sjson.SetBytes(body, key, value)
}
makeHttpResponse(ctx, 200, debugInfo, [][2]string{{"Content-Type", "application/json; charset=utf-8"}}, body)
}
func OnJsonRpcResponseSuccess(ctx wrapper.HttpContext, result map[string]any, debugInfo ...string) {
var (
id JsonRpcID
ok bool
)
idRaw := ctx.GetContext(CtxJsonRpcID)
if id, ok = idRaw.(JsonRpcID); !ok {
makeHttpResponse(ctx, 500, "not_found_json_rpc_id", nil, []byte("not found json rpc id"))
return
}
responseDebugInfo := "json_rpc_success"
if len(debugInfo) > 0 {
responseDebugInfo = debugInfo[0]
}
sendJsonRpcResponse(ctx, id, map[string]any{JResult: result}, responseDebugInfo)
}
func OnJsonRpcResponseError(ctx wrapper.HttpContext, err error, errorCode int, debugInfo ...string) {
var (
id JsonRpcID
ok bool
)
idRaw := ctx.GetContext(CtxJsonRpcID)
if id, ok = idRaw.(JsonRpcID); !ok {
makeHttpResponse(ctx, 500, "not_found_json_rpc_id", nil, []byte("not found json rpc id"))
return
}
responseDebugInfo := fmt.Sprintf("json_rpc_error(%s)", err)
if len(debugInfo) > 0 {
responseDebugInfo = debugInfo[0]
}
sendJsonRpcResponse(ctx, id, map[string]any{JError: map[string]any{
JMessage: err.Error(),
JCode: errorCode,
}}, responseDebugInfo)
}
func HandleJsonRpcMethod(ctx wrapper.HttpContext, body []byte, handles MethodHandlers) types.Action {
idResult := gjson.GetBytes(body, "id")
id := NewJsonRpcIDFromGjson(idResult)
ctx.SetContext(CtxJsonRpcID, id)
method := gjson.GetBytes(body, "method").String()
params := gjson.GetBytes(body, "params")
if method != "" {
if handle, ok := handles[method]; ok {
log.Debugf("json rpc call method[%s] with params[%s]", method, params.Raw)
// Clear pause flag before calling handler
ctx.SetContext(CtxNeedPause, false)
err := handle(ctx, id, params)
if err != nil {
OnJsonRpcResponseError(ctx, err, ErrInvalidRequest)
return types.ActionContinue
}
// Check if the handler set the pause flag
if needPause := ctx.GetContext(CtxNeedPause); needPause != nil && needPause.(bool) {
return types.ActionPause
}
return types.ActionContinue
}
OnJsonRpcResponseError(ctx, fmt.Errorf("method not found:%s", method), ErrMethodNotFound)
} else {
proxywasm.SendHttpResponseWithDetail(202, "json_rpc_ack", nil, nil, -1)
}
return types.ActionContinue
}
func HandleJsonRpcRequest(ctx wrapper.HttpContext, body []byte, handle JsonRpcRequestHandler) types.Action {
idResult := gjson.GetBytes(body, "id")
id := NewJsonRpcIDFromGjson(idResult)
ctx.SetContext(CtxJsonRpcID, id)
method := gjson.GetBytes(body, "method").String()
params := gjson.GetBytes(body, "params")
log.Debugf("json rpc call method[%s] with params[%s]", method, params.Raw)
return handle(ctx, id, method, params, body)
}
func HandleJsonRpcResponse(ctx wrapper.HttpContext, body []byte, handle JsonRpcResponseHandler) types.Action {
idResult := gjson.GetBytes(body, "id")
id := NewJsonRpcIDFromGjson(idResult)
error := gjson.GetBytes(body, "error")
result := gjson.GetBytes(body, "result")
log.Debugf("json rpc response error[%s] result[%s]", error.Raw, result.Raw)
return handle(ctx, id, result, error, body)
}