resolver: replace nopResolver with lookupStaticHost · saucelabs/forwarder@0b35f78

3 files changed

lines changed

Original file line number	Diff line number	Diff line change
`@@ -433,26 +433,8 @@ func (hp *HTTPProxy) directLocalhost(fn ProxyFunc) ProxyFunc {`
`433`	`433`	`}`
`434`	`434`	`}`
`435`	`435`
`436`		`-// nopResolver is a dns resolver that does not ever dial.`
`437`		`-// It uses only the local resolver.`
`438`		`-// It will look for the address in the /etc/hosts file.`
`439`		`-var localhostResolver = nopResolver() //nolint:gochecknoglobals // This is a local resolver.`
`440`		`-`
`441`	`436`	`func (hp HTTPProxy) isLocalhost(req http.Request) bool {`
`442`		`-h := req.URL.Hostname()`
`443`		`-`
`444`		`-// Plain old localhost.`
`445`		`-if h == "localhost" {`
`446`		`-return true`
`447`		`- }`
`448`		`-`
`449`		`-if addrs, err := localhostResolver.LookupHost(context.Background(), h); err == nil {`
`450`		`-if ip := net.ParseIP(addrs[0]); ip != nil {`
`451`		`-return ip.IsLoopback()`
`452`		`- }`
`453`		`- }`
`454`		`-`
`455`		`-return false`
	`437`	`+return isLocalhost(req.URL.Hostname())`
`456`	`438`	`}`
`457`	`439`
`458`	`440`	`func (hp HTTPProxy) setBasicAuth(req http.Request) error {`

Original file line number	Diff line number	Diff line change
`@@ -7,16 +7,31 @@`
`7`	`7`	`package forwarder`
`8`	`8`
`9`	`9`	`import (`
`10`		`-"context"`
`11`		`-"errors"`
`12`	`10`	`"net"`
	`11`	`+ _ "unsafe" // for go:linkname`
`13`	`12`	`)`
`14`	`13`
`15`		`-func nopResolver() *net.Resolver {`
`16`		`-return &net.Resolver{`
`17`		`-PreferGo: true,`
`18`		`-Dial: func(ctx context.Context, network, address string) (net.Conn, error) {`
`19`		`-return nil, errors.New("no DNS resolver configured")`
`20`		`- },`
	`14`	`+// lookupStaticHost looks up the addresses and the canonical name for the given host from /etc/hosts.`
	`15`	`+// It automatically updates the data cache.`
	`16`	`+//`
	`17`	`+//go:linkname lookupStaticHost net.lookupStaticHost`
	`18`	`+func lookupStaticHost(string) ([]string, string)`
	`19`	`+`
	`20`	`+func isLocalhost(host string) bool {`
	`21`	`+if host == "localhost" {`
	`22`	`+return true`
	`23`	`+ }`
	`24`	`+`
	`25`	`+if ip := net.ParseIP(host); ip != nil {`
	`26`	`+return ip.IsLoopback()`
`21`	`27`	`}`
	`28`	`+`
	`29`	`+addrs, _ := lookupStaticHost(host)`
	`30`	`+if len(addrs) > 0 {`
	`31`	`+if ip := net.ParseIP(addrs[0]); ip != nil {`
	`32`	`+return ip.IsLoopback()`
	`33`	`+ }`
	`34`	`+ }`
	`35`	`+`
	`36`	`+return false`
`22`	`37`	`}`

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,37 @@`
	`1`	`+// Copyright 2022-2024 Sauce Labs Inc., all rights reserved.`
	`2`	`+//`
	`3`	`+// This Source Code Form is subject to the terms of the Mozilla Public`
	`4`	`+// License, v. 2.0. If a copy of the MPL was not distributed with this`
	`5`	`+// file, You can obtain one at https://mozilla.org/MPL/2.0/.`
	`6`	`+`
	`7`	`+package forwarder`
	`8`	`+`
	`9`	`+import (`
	`10`	`+"testing"`
	`11`	`+)`
	`12`	`+`
	`13`	`+func TestIsLocalhost(t *testing.T) {`
	`14`	`+tests := []struct {`
	`15`	`+host string`
	`16`	`+localhost bool`
	`17`	`+ }{`
	`18`	`+ {"127.0.0.1", true},`
	`19`	`+ {"127.10.20.30", true},`
	`20`	`+ {"localhost", true},`
	`21`	`+`
	`22`	`+ {"notlocalhost", false},`
	`23`	`+ {"broadcasthost", false},`
	`24`	`+`
	`25`	`+ {"::1", true},`
	`26`	`+`
	`27`	`+ {"::10", false},`
	`28`	`+ {"2001:0db8:85a3:0000:0000:8a2e:0370:7334", false},`
	`29`	`+ }`
	`30`	`+`
	`31`	`+for i := range tests {`
	`32`	`+tc := tests[i]`
	`33`	`+if lh := isLocalhost(tc.host); lh != tc.localhost {`
	`34`	`+t.Errorf("isLocalhost(%q) = %v; want %v", tc.host, lh, tc.localhost)`
	`35`	`+ }`
	`36`	`+ }`
	`37`	`+}`