1 7583dd64 2022-04-13 o package mailmux
 2 7583dd64 2022-04-13 o 
 3 7583dd64 2022-04-13 o import (
 4 7583dd64 2022-04-13 o 	"encoding/json"
 5 7583dd64 2022-04-13 o 	"errors"
 6 7583dd64 2022-04-13 o 	"io"
 7 7583dd64 2022-04-13 o 	"time"
 8 a7e7d1d5 2022-04-13 o 
 9 a7e7d1d5 2022-04-13 o 	"mailmux.net/aliases"
10 7583dd64 2022-04-13 o )
11 7583dd64 2022-04-13 o 
12 7583dd64 2022-04-13 o const (
13 7583dd64 2022-04-13 o 	Tregister = 1 + iota
14 7583dd64 2022-04-13 o 	Rregister
15 7583dd64 2022-04-13 o 	Rerror
16 7583dd64 2022-04-13 o 	Tnew
17 7583dd64 2022-04-13 o 	Rnew
18 7583dd64 2022-04-13 o 	Tlist
19 7583dd64 2022-04-13 o 	Rlist
20 7583dd64 2022-04-13 o 	Tremove
21 7583dd64 2022-04-13 o )
22 7583dd64 2022-04-13 o 
23 c7ecbae7 2022-04-13 o // Mcall represents a message passed between mailmux clients and servers.
24 7583dd64 2022-04-13 o // Operations requested by clients are T-messages (such as Tregister).
25 c7ecbae7 2022-04-13 o // Servers respond with the corresponding R-message (such as Rregister).
26 c7ecbae7 2022-04-13 o // Servers may instead respond with Rerror to inform the client, with a diagnostic message,
27 c7ecbae7 2022-04-13 o // that the request was not completed successfully.
28 7583dd64 2022-04-13 o // This design is loosely based on the Plan 9 network file protocol 9P.
29 7583dd64 2022-04-13 o type Mcall struct {
30 5b8260a5 2022-04-13 o 	Type     uint
31 a7e7d1d5 2022-04-13 o 	Username string          // Tregister, Rregister
32 a7e7d1d5 2022-04-13 o 	Password string          // Tregister
33 a7e7d1d5 2022-04-13 o 	Error    string          // Rerror
34 a7e7d1d5 2022-04-13 o 	Aliases  aliases.Aliases // Rnew, Rlist, Tremove
35 a7e7d1d5 2022-04-13 o 	Expiry   time.Time       // Tnew, Rnew
36 7583dd64 2022-04-13 o }
37 7583dd64 2022-04-13 o 
38 c7ecbae7 2022-04-13 o // ParseMcall parses and validates a JSON-encoded Mcall from r.
39 7583dd64 2022-04-13 o func ParseMcall(r io.Reader) (*Mcall, error) {
40 7583dd64 2022-04-13 o 	var mc Mcall
41 7583dd64 2022-04-13 o 	if err := json.NewDecoder(r).Decode(&mc); err != nil {
42 7583dd64 2022-04-13 o 		return nil, err
43 7583dd64 2022-04-13 o 	}
44 a7e7d1d5 2022-04-13 o 	switch mc.Type {
45 a7e7d1d5 2022-04-13 o 	case Rerror:
46 a7e7d1d5 2022-04-13 o 		if mc.Error == "" {
47 a7e7d1d5 2022-04-13 o 			return nil, errors.New("empty error message")
48 a7e7d1d5 2022-04-13 o 		}
49 a7e7d1d5 2022-04-13 o 	case Tregister, Tnew, Tlist, Tremove:
50 a7e7d1d5 2022-04-13 o 		if mc.Username == "" {
51 a7e7d1d5 2022-04-13 o 			return nil, errors.New("empty username")
52 a7e7d1d5 2022-04-13 o 		} else if mc.Password == "" {
53 a7e7d1d5 2022-04-13 o 			return nil, errors.New("empty password")
54 a7e7d1d5 2022-04-13 o 		}
55 7583dd64 2022-04-13 o 	}
56 7583dd64 2022-04-13 o 	return &mc, nil
57 7583dd64 2022-04-13 o }