/
rpcstack.go
162 lines (142 loc) · 4.47 KB
/
rpcstack.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
package node
import (
"compress/gzip"
"fmt"
"github.com/chenxifun/jsonrpc/rpc"
"io"
"io/ioutil"
"net"
"net/http"
"strings"
"sync"
"github.com/rs/cors"
)
// NewHTTPHandlerStack returns wrapped http-related handlers
func NewHTTPHandlerStack(srv http.Handler, cors []string, vhosts []string) http.Handler {
// Wrap the CORS-handler within a host-handler
handler := newCorsHandler(srv, cors)
handler = newVHostHandler(vhosts, handler)
return newGzipHandler(handler)
}
func newCorsHandler(srv http.Handler, allowedOrigins []string) http.Handler {
// disable CORS support if user has not specified a custom CORS configuration
if len(allowedOrigins) == 0 {
return srv
}
c := cors.New(cors.Options{
AllowedOrigins: allowedOrigins,
AllowedMethods: []string{http.MethodPost, http.MethodGet},
AllowedHeaders: []string{"*"},
MaxAge: 600,
})
return c.Handler(srv)
}
type virtualHostHandler struct {
vhosts map[string]struct{}
next http.Handler
}
func newVHostHandler(vhosts []string, next http.Handler) http.Handler {
vhostMap := make(map[string]struct{})
for _, allowedHost := range vhosts {
vhostMap[strings.ToLower(allowedHost)] = struct{}{}
}
return &virtualHostHandler{vhostMap, next}
}
// ServeHTTP serves JSON-RPC requests over HTTP, implements http.Handler
func (h *virtualHostHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
// if r.Host is not set, we can continue serving since a browser would set the Host header
if r.Host == "" {
h.next.ServeHTTP(w, r)
return
}
host, _, err := net.SplitHostPort(r.Host)
if err != nil {
// Either invalid (too many colons) or no port specified
host = r.Host
}
if ipAddr := net.ParseIP(host); ipAddr != nil {
// It's an IP address, we can serve that
h.next.ServeHTTP(w, r)
return
}
// Not an IP address, but a hostname. Need to validate
if _, exist := h.vhosts["*"]; exist {
h.next.ServeHTTP(w, r)
return
}
if _, exist := h.vhosts[host]; exist {
h.next.ServeHTTP(w, r)
return
}
http.Error(w, "invalid host specified", http.StatusForbidden)
}
var gzPool = sync.Pool{
New: func() interface{} {
w := gzip.NewWriter(ioutil.Discard)
return w
},
}
type gzipResponseWriter struct {
io.Writer
http.ResponseWriter
}
func (w *gzipResponseWriter) WriteHeader(status int) {
w.Header().Del("Content-Length")
w.ResponseWriter.WriteHeader(status)
}
func (w *gzipResponseWriter) Write(b []byte) (int, error) {
return w.Writer.Write(b)
}
func newGzipHandler(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if !strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
next.ServeHTTP(w, r)
return
}
w.Header().Set("Content-Encoding", "gzip")
gz := gzPool.Get().(*gzip.Writer)
defer gzPool.Put(gz)
gz.Reset(w)
defer gz.Close()
next.ServeHTTP(&gzipResponseWriter{ResponseWriter: w, Writer: gz}, r)
})
}
// checkModuleAvailability checks that all names given in modules are actually
// available API services. It assumes that the MetadataApi module ("rpc") is always available;
// the registration of this "rpc" module happens in NewServer() and is thus common to all endpoints.
func checkModuleAvailability(modules []string, apis []rpc.API) (bad, available []string) {
availableSet := make(map[string]struct{})
for _, api := range apis {
if _, ok := availableSet[api.Namespace]; !ok {
availableSet[api.Namespace] = struct{}{}
available = append(available, api.Namespace)
}
}
for _, name := range modules {
if _, ok := availableSet[name]; !ok && name != rpc.MetadataApi {
bad = append(bad, name)
}
}
return bad, available
}
// RegisterApisFromWhitelist checks the given modules' availability, generates a whitelist based on the allowed modules,
// and then registers all of the APIs exposed by the services.
func RegisterApisFromWhitelist(apis []rpc.API, modules []string, srv *rpc.Server, exposeAll bool) error {
if bad, available := checkModuleAvailability(modules, apis); len(bad) > 0 {
fmt.Println("Unavailable modules in HTTP API list", "unavailable", bad, "available", available)
}
// Generate the whitelist based on the allowed modules
whitelist := make(map[string]bool)
for _, module := range modules {
whitelist[module] = true
}
// Register all the APIs exposed by the services
for _, api := range apis {
if exposeAll || whitelist[api.Namespace] || (len(whitelist) == 0 && api.Public) {
if err := srv.RegisterName(api.Namespace, api.Version, api.Service); err != nil {
return err
}
}
}
return nil
}