wgengine/magicsock, controlclient, net/dns: reduce some logspam

Updates #cleanup

Change-Id: I78b0697a01e94baa33f3de474b591e616fa5e6af
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

control/controlclient/direct.go

@@ -1501,7 +1501,7 @@ func (c *Direct) getNoiseClient() (*NoiseClient, error) {
 		if err != nil {
 			return nil, err
 		}
-		c.logf("creating new noise client")
+		c.logf("[v1] creating new noise client")
 		nc, err := NewNoiseClient(NoiseOpts{
 			PrivKey:      k,
 			ServerPubKey: serverNoiseKey,

net/dns/manager.go

@@ -97,7 +97,9 @@ func (m *Manager) Set(cfg Config) error {
 	m.logf("Resolvercfg: %v", logger.ArgWriter(func(w *bufio.Writer) {
 		rcfg.WriteToBufioWriter(w)
 	}))
-	m.logf("OScfg: %+v", ocfg)
+	m.logf("OScfg: %v", logger.ArgWriter(func(w *bufio.Writer) {
+		ocfg.WriteToBufioWriter(w)
+	}))
 
 	if err := m.resolver.SetConfig(rcfg); err != nil {
 		return err

net/dns/osconfig.go

@@ -8,6 +8,7 @@ import (
 	"errors"
 	"fmt"
 	"net/netip"
+	"strings"
 
 	"tailscale.com/types/logger"
 	"tailscale.com/util/dnsname"
@@ -65,6 +66,42 @@ type OSConfig struct {
 	MatchDomains []dnsname.FQDN
 }
 
+func (o *OSConfig) WriteToBufioWriter(w *bufio.Writer) {
+	if o == nil {
+		w.WriteString("<nil>")
+		return
+	}
+	w.WriteString("{")
+	if len(o.Hosts) > 0 {
+		fmt.Fprintf(w, "Hosts:%v ", o.Hosts)
+	}
+	if len(o.Nameservers) > 0 {
+		fmt.Fprintf(w, "Nameservers:%v ", o.Nameservers)
+	}
+	if len(o.SearchDomains) > 0 {
+		fmt.Fprintf(w, "SearchDomains:%v ", o.SearchDomains)
+	}
+	if len(o.MatchDomains) > 0 {
+		w.WriteString("SearchDomains:[")
+		sp := ""
+		var numARPA int
+		for _, s := range o.MatchDomains {
+			if strings.HasSuffix(string(s), ".arpa.") {
+				numARPA++
+				continue
+			}
+			w.WriteString(sp)
+			w.WriteString(string(s))
+			sp = " "
+		}
+		w.WriteString("]")
+		if numARPA > 0 {
+			fmt.Fprintf(w, "+%darpa", numARPA)
+		}
+	}
+	w.WriteString("}")
+}
+
 func (o OSConfig) IsZero() bool {
 	return len(o.Nameservers) == 0 && len(o.SearchDomains) == 0 && len(o.MatchDomains) == 0
 }

wgengine/magicsock/peermtu.go

@@ -48,12 +48,12 @@ func (c *Conn) ShouldPMTUD() bool {
 	return false // Until we feel confident PMTUD is solid.
 }
 
-// PeerMTUEnabled returns true if this Conn is has peer path MTU discovery enabled.
+// PeerMTUEnabled reports whether peer path MTU discovery is enabled.
 func (c *Conn) PeerMTUEnabled() bool {
 	return c.peerMTUEnabled.Load()
 }
 
-// UpdatePMTUD configures underlying sockets of this Conn to enable or disable
+// UpdatePMTUD configures the underlying sockets of this Conn to enable or disable
 // peer path MTU discovery according to the current configuration.
 //
 // Enabling or disabling peer path MTU discovery requires setting the don't
@@ -84,7 +84,7 @@ func (c *Conn) UpdatePMTUD() {
 
 	enable := c.ShouldPMTUD()
 	if c.peerMTUEnabled.Load() == enable {
-		c.logf("magicsock: peermtu: peer MTU status is %v", enable)
+		c.logf("[v1] magicsock: peermtu: peer MTU status is %v", enable)
 		return
 	}