From: Jinwen Wo <wojinwen@huawei.com>
Date: Thu, 7 Oct 2021 17:24:47 +0000 (+0000)
Subject: cmd/go/internal/web: improve IP check testing on ipv6 env
X-Git-Tag: go1.18beta1~987
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=4ab3c1065eb38b90247f7ad46160fc5bb07ca2ed;p=gostls13.git

cmd/go/internal/web: improve IP check testing on ipv6 env

The existing implementation lacks consideration of running test on a
machine which has ipv6 address but no ipv4 address. Use net.IP.IsLoopback
and net.IP.IsUnspecified instead of hardcoded addresses.

Fixes: #48575

This PR will be imported into Gerrit with the title and first
comment (this text) used to generate the subject and body of
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Change-Id: I9c3c26d2ba13c7a24065751b59a1e002098ed654
GitHub-Last-Rev: fc45adbf7b944122d8f07bd451a8eeed1e69140c
GitHub-Pull-Request: golang/go#48850
Reviewed-on: https://go-review.googlesource.com/c/go/+/354609
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Jay Conrod <jayconrod@google.com>
---

diff --git a/src/cmd/go/internal/web/http.go b/src/cmd/go/internal/web/http.go
index f177278eba..81f841d2c6 100644
--- a/src/cmd/go/internal/web/http.go
+++ b/src/cmd/go/internal/web/http.go
@@ -17,6 +17,7 @@ import (
 	"errors"
 	"fmt"
 	"mime"
+	"net"
 	"net/http"
 	urlpkg "net/url"
 	"os"
@@ -84,8 +85,15 @@ func get(security SecurityMode, url *urlpkg.URL) (*Response, error) {
 	if url.Host == "localhost.localdev" {
 		return nil, fmt.Errorf("no such host localhost.localdev")
 	}
-	if os.Getenv("TESTGONETWORK") == "panic" && !strings.HasPrefix(url.Host, "127.0.0.1") && !strings.HasPrefix(url.Host, "0.0.0.0") {
-		panic("use of network: " + url.String())
+	if os.Getenv("TESTGONETWORK") == "panic" {
+		host := url.Host
+		if h, _, err := net.SplitHostPort(url.Host); err == nil && h != "" {
+			host = h
+		}
+		addr := net.ParseIP(host)
+		if addr == nil || (!addr.IsLoopback() && !addr.IsUnspecified()) {
+			panic("use of network: " + url.String())
+		}
 	}
 
 	fetch := func(url *urlpkg.URL) (*urlpkg.URL, *http.Response, error) {