1 /*
2 *
3 * Copyright 2014 gRPC authors.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18 19 // Package peer defines various peer information associated with RPCs and
20 // corresponding utils.
21 package peer
22 23 import (
24 "context"
25 "fmt"
26 "net"
27 "strings"
28 29 "google.golang.org/grpc/credentials"
30 )
31 32 // Peer contains the information of the peer for an RPC, such as the address
33 // and authentication information.
34 type Peer struct {
35 // Addr is the peer address.
36 Addr net.Addr
37 // LocalAddr is the local address.
38 LocalAddr net.Addr
39 // AuthInfo is the authentication information of the transport.
40 // It is nil if there is no transport security being used.
41 AuthInfo credentials.AuthInfo
42 }
43 44 // String ensures the Peer types implements the Stringer interface in order to
45 // allow to print a context with a peerKey value effectively.
46 func (p *Peer) String() string {
47 if p == nil {
48 return "Peer<nil>"
49 }
50 sb := &strings.Builder{}
51 sb.WriteString("Peer{")
52 if p.Addr != nil {
53 fmt.Fprintf(sb, "Addr: '%s', ", p.Addr.String())
54 } else {
55 fmt.Fprintf(sb, "Addr: <nil>, ")
56 }
57 if p.LocalAddr != nil {
58 fmt.Fprintf(sb, "LocalAddr: '%s', ", p.LocalAddr.String())
59 } else {
60 fmt.Fprintf(sb, "LocalAddr: <nil>, ")
61 }
62 if p.AuthInfo != nil {
63 fmt.Fprintf(sb, "AuthInfo: '%s'", p.AuthInfo.AuthType())
64 } else {
65 fmt.Fprintf(sb, "AuthInfo: <nil>")
66 }
67 sb.WriteString("}")
68 69 return sb.String()
70 }
71 72 type peerKey struct{}
73 74 // NewContext creates a new context with peer information attached.
75 func NewContext(ctx context.Context, p *Peer) context.Context {
76 return context.WithValue(ctx, peerKey{}, p)
77 }
78 79 // FromContext returns the peer information in ctx if it exists.
80 func FromContext(ctx context.Context) (p *Peer, ok bool) {
81 p, ok = ctx.Value(peerKey{}).(*Peer)
82 return
83 }
84