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
|
package dnsresolver
import (
"context"
"net"
"net/url"
"strings"
"gitlab.com/gitlab-org/gitaly/v16/internal/structerr"
)
// ValidateURL validates Gitaly address URL having dns scheme. The URL follows three forms:
// * dns://authority-port:authority-host/host:port
// * dns:///host:port
// * dns:host:port
// Either form, the real address is the URL's path
func ValidateURL(rawAddress string) error {
if rawAddress == "" {
return structerr.New("empty address")
}
uri, err := url.Parse(rawAddress)
if err != nil {
return structerr.New("fail to parse address: %w", err)
}
if uri.Scheme != "dns" {
return structerr.New("unexpected scheme: %s", uri.Scheme)
}
path := uri.Path
if path == "" {
// When "//" part is stripped
path = uri.Opaque
}
_, _, err = parseTarget(strings.TrimPrefix(path, "/"), "50051")
return err
}
// parseTarget takes the user input target string and default port, returns formatted host and port info.
// This is a shameless copy of built-in gRPC dns resolver, because we don't want to have any
// inconsistency between our resolver and dns resolver.
// Source: https://github.com/grpc/grpc-go/blob/eeb9afa1f6b6388152955eeca8926e36ca94c768/internal/resolver/dns/dns_resolver.go#L378-L378
func parseTarget(target, defaultPort string) (string, string, error) {
var err error
if target == "" {
return "", "", structerr.New("dns resolver: missing address")
}
if ip := net.ParseIP(target); ip != nil {
// target is an IPv4 or IPv6(without brackets) address
return target, defaultPort, nil
}
if host, port, err := net.SplitHostPort(target); err == nil {
if port == "" {
// If the port field is empty (target ends with colon), e.g. "[::1]:", this is an error.
return "", "", structerr.New("dns resolver: missing port after port-separator colon")
}
if host == "" {
host = "localhost"
}
return host, port, nil
}
host, port, err := net.SplitHostPort(target + ":" + defaultPort)
if err == nil {
return host, port, nil
}
return "", "", structerr.New("dns resolver: %w", err)
}
func tryParseIP(host, port string) (addr string, ok bool) {
ip := net.ParseIP(host)
if ip == nil {
return "", false
}
return net.JoinHostPort(host, port), true
}
func findDNSLookup(authority string) (dnsLookuper, error) {
if authority == "" {
return net.DefaultResolver, nil
}
host, port, err := parseTarget(authority, defaultDNSNameserverPort)
if err != nil {
return nil, err
}
addr := net.JoinHostPort(host, port)
return &net.Resolver{
PreferGo: true,
Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
var dialer net.Dialer
return dialer.DialContext(ctx, network, addr)
},
}, nil
}
|
