Pull request 2338: AGDNS-2665-upstream-timeout

Merge in DNS/adguard-home from AGDNS-2665-upstream-timeout to master

Squashed commit of the following:

commit b4041c97f2ccd371a9cff8312bda72f4c18496b9
Merge: d939b3b3e b92a3cfb8
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Fri Feb 7 16:15:19 2025 +0300

    Merge branch 'master' into AGDNS-2665-upstream-timeout

commit d939b3b3ef2345d315c05a3730e81e1f1ea9f79f
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Fri Feb 7 16:10:06 2025 +0300

    client: imp i18n

commit 52089adb6c28d8c47f5a916d9df941c5fddea1fc
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Thu Feb 6 18:39:53 2025 +0300

    all: fix typo

commit aca08b1873c9f39b8c1da0439a9057117e1dacce
Author: Ildar Kamalov <ik@adguard.com>
Date:   Thu Feb 6 15:19:30 2025 +0300

    client: rearrange upstream timeout settings

commit 48e75fabe2f65aeac7156a020cce3d4c2412e5f9
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Tue Feb 4 20:48:53 2025 +0300

    github: upd actions cache

commit 64bac193fc834a975e6913bb86a6bf27e54c382a
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Tue Feb 4 20:28:54 2025 +0300

    all: imp code

commit 95c73698985dc528a4af6ff0d3b8a301da1f0d4a
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Mon Feb 3 16:25:35 2025 +0300

    all: upstream timeout

internal/dnsforward/http.go

@@ -18,6 +18,7 @@ import (
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/golibs/netutil"
 	"github.com/AdguardTeam/golibs/stringutil"
+	"github.com/AdguardTeam/golibs/validate"
 )
 
 // jsonDNSConfig is the JSON representation of the DNS server configuration.
@@ -53,6 +54,9 @@ type jsonDNSConfig struct {
 	// rate limiting requests.
 	RatelimitSubnetLenIPv6 *int `json:"ratelimit_subnet_len_ipv6"`
 
+	// UpstreamTimeout is an upstream timeout in seconds.
+	UpstreamTimeout *int `json:"upstream_timeout"`
+
 	// RatelimitWhitelist is a list of IP addresses excluded from rate limiting.
 	RatelimitWhitelist *[]netip.Addr `json:"ratelimit_whitelist"`
 
@@ -147,6 +151,7 @@ func (s *Server) getDNSConfig() (c *jsonDNSConfig) {
 	ratelimitSubnetLenIPv4 := s.conf.RatelimitSubnetLenIPv4
 	ratelimitSubnetLenIPv6 := s.conf.RatelimitSubnetLenIPv6
 	ratelimitWhitelist := append([]netip.Addr{}, s.conf.RatelimitWhitelist...)
+	upstreamTimeout := int(s.conf.UpstreamTimeout.Seconds())
 
 	customIP := s.conf.EDNSClientSubnet.CustomIP
 	enableEDNSClientSubnet := s.conf.EDNSClientSubnet.Enabled
@@ -192,6 +197,7 @@ func (s *Server) getDNSConfig() (c *jsonDNSConfig) {
 		RatelimitSubnetLenIPv4:   &ratelimitSubnetLenIPv4,
 		RatelimitSubnetLenIPv6:   &ratelimitSubnetLenIPv6,
 		RatelimitWhitelist:       &ratelimitWhitelist,
+		UpstreamTimeout:          &upstreamTimeout,
 		EDNSCSCustomIP:           customIP,
 		EDNSCSEnabled:            &enableEDNSClientSubnet,
 		EDNSCSUseCustom:          &useCustom,
@@ -302,6 +308,12 @@ func (req *jsonDNSConfig) validate(
 		return err
 	}
 
+	err = req.checkUpstreamTimeout()
+	if err != nil {
+		// Don't wrap the error since it's informative enough as is.
+		return err
+	}
+
 	return nil
 }
 
@@ -437,6 +449,16 @@ func (req *jsonDNSConfig) checkRatelimitSubnetMaskLen() (err error) {
 	return nil
 }
 
+// checkUpstreamTimeout returns an error if the configuration of the upstream
+// timeout is invalid.
+func (req *jsonDNSConfig) checkUpstreamTimeout() (err error) {
+	if req.UpstreamTimeout == nil {
+		return nil
+	}
+
+	return validate.NoLessThan("upstream_timeout", *req.UpstreamTimeout, 1)
+}
+
 // checkInclusion returns an error if a ptr is not nil and points to value,
 // that not in the inclusive range between minN and maxN.
 func checkInclusion(ptr *int, minN, maxN int) (err error) {
@@ -588,6 +610,14 @@ func (s *Server) setConfigRestartable(dc *jsonDNSConfig) (shouldRestart bool) {
 		shouldRestart = true
 	}
 
+	if dc.UpstreamTimeout != nil {
+		ut := time.Duration(*dc.UpstreamTimeout) * time.Second
+		if s.conf.UpstreamTimeout != ut {
+			s.conf.UpstreamTimeout = ut
+			shouldRestart = true
+		}
+	}
+
 	return shouldRestart
 }