net: remove redundant cgoLookupCNAME return parameter

`completed bool` just means `err == nil` after CL 446179.

While here, add a test for cgoLookupCNAME.

Co-authored-by: Mateusz Poliwczak <mpoliwczak34@gmail.com>
Change-Id: I6081a089fde3cb27af4fbde6f04301fc3755272c
Reviewed-on: https://go-review.googlesource.com/c/go/+/698615
Reviewed-by: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Sean Liao <sean@liao.dev>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Auto-Submit: Sean Liao <sean@liao.dev>
Reviewed-by: Mateusz Poliwczak <mpoliwczak34@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>

diff --git a/src/net/cgo_stub.go b/src/net/cgo_stub.go
index a4f6b4b0e8d8b7c5cf55248b69f2d9c0840edb53..640f5a4fd65a552a2503255a3117c8f02bde9339 100644 (file)
--- a/src/net/cgo_stub.go
+++ b/src/net/cgo_stub.go
@@ -31,7 +31,7 @@ func cgoLookupIP(ctx context.Context, network, name string) (addrs []IPAddr, err
        panic("cgo stub: cgo not available")
 }
 
-func cgoLookupCNAME(ctx context.Context, name string) (cname string, err error, completed bool) {
+func cgoLookupCNAME(ctx context.Context, name string) (cname string, err error) {
        panic("cgo stub: cgo not available")
 }
 

diff --git a/src/net/cgo_unix.go b/src/net/cgo_unix.go
index 1e170dbc0afb2432b16fef258a89dac5a04cff16..51efee6f872c53439db61e3b0252293df4bbb256 100644 (file)
--- a/src/net/cgo_unix.go
+++ b/src/net/cgo_unix.go
@@ -297,16 +297,16 @@ func cgoSockaddr(ip IP, zone string) (*_C_struct_sockaddr, _C_socklen_t) {
        return nil, 0
 }
 
-func cgoLookupCNAME(ctx context.Context, name string) (cname string, err error, completed bool) {
+func cgoLookupCNAME(ctx context.Context, name string) (cname string, err error) {
        resources, err := resSearch(ctx, name, int(dnsmessage.TypeCNAME), int(dnsmessage.ClassINET))
        if err != nil {
-               return
+               return "", err
        }
        cname, err = parseCNAMEFromResources(resources)
        if err != nil {
-               return "", err, false
+               return "", err
        }
-       return cname, nil, true
+       return cname, nil
 }
 
 // resSearch will make a call to the 'res_nsearch' routine in the C library

diff --git a/src/net/cgo_unix_test.go b/src/net/cgo_unix_test.go
index d8233dfaf229609551fd2bb635f20efe781ecae5..9aaeccc5f057090a3ee2bdc184c801b5f7b1cff2 100644 (file)
--- a/src/net/cgo_unix_test.go
+++ b/src/net/cgo_unix_test.go
@@ -8,6 +8,7 @@ package net
 
 import (
        "context"
+       "internal/testenv"
        "testing"
 )
 
@@ -67,3 +68,12 @@ func TestCgoLookupPTRWithCancel(t *testing.T) {
                t.Error(err)
        }
 }
+
+func TestCgoLookupCNAME(t *testing.T) {
+       mustHaveExternalNetwork(t)
+       testenv.SkipFlakyNet(t)
+       defer dnsWaitGroup.Wait()
+       if _, err := cgoLookupCNAME(t.Context(), "www.iana.org."); err != nil {
+               t.Error(err)
+       }
+}

diff --git a/src/net/lookup_unix.go b/src/net/lookup_unix.go
index 7416cb01f80efe7aa161b7164412ec7e85e2201e..86108939cd03d61dc5a52fb212dcc4508e7f89f6 100644 (file)
--- a/src/net/lookup_unix.go
+++ b/src/net/lookup_unix.go
@@ -87,8 +87,8 @@ func (r *Resolver) lookupPort(ctx context.Context, network, service string) (int
 func (r *Resolver) lookupCNAME(ctx context.Context, name string) (string, error) {
        order, conf := systemConf().hostLookupOrder(r, name)
        if order == hostLookupCgo {
-               if cname, err, ok := cgoLookupCNAME(ctx, name); ok {
-                       return cname, err
+               if cname, err := cgoLookupCNAME(ctx, name); err == nil {
+                       return cname, nil
                }
        }
        return r.goLookupCNAME(ctx, name, order, conf)