1 files changed, 26 insertions, 41 deletions

diff --git a/modules/caddyhttp/reverseproxy/hosts.go b/modules/caddyhttp/reverseproxy/hosts.go
index a973ecb..83a39d8 100644
--- a/modules/caddyhttp/reverseproxy/hosts.go
+++ b/modules/caddyhttp/reverseproxy/hosts.go
@@ -17,8 +17,8 @@ package reverseproxy
 import (
 	"context"
 	"fmt"
-	"net"
 	"net/http"
+	"net/netip"
 	"strconv"
 	"sync/atomic"
 
@@ -47,15 +47,6 @@ type Upstream struct {
 	// backends is down. Also be aware of open proxy vulnerabilities.
 	Dial string `json:"dial,omitempty"`
 
-	// DEPRECATED: Use the SRVUpstreams module instead
-	// (http.reverse_proxy.upstreams.srv). This field will be
-	// removed in a future version of Caddy. TODO: Remove this field.
-	//
-	// If DNS SRV records are used for service discovery with this
-	// upstream, specify the DNS name for which to look up SRV
-	// records here, instead of specifying a dial address.
-	LookupSRV string `json:"lookup_srv,omitempty"`
-
 	// The maximum number of simultaneous requests to allow to
 	// this upstream. If set, overrides the global passive health
 	// check UnhealthyRequestCount value.
@@ -72,12 +63,10 @@ type Upstream struct {
 	unhealthy             int32 // accessed atomically; status from active health checker
 }
 
-func (u Upstream) String() string {
-	if u.LookupSRV != "" {
-		return u.LookupSRV
-	}
-	return u.Dial
-}
+// (pointer receiver necessary to avoid a race condition, since
+// copying the Upstream reads the 'unhealthy' field which is
+// accessed atomically)
+func (u *Upstream) String() string { return u.Dial }
 
 // Available returns true if the remote host
 // is available to receive requests. This is
@@ -109,35 +98,21 @@ func (u *Upstream) Full() bool {
 }
 
 // fillDialInfo returns a filled DialInfo for upstream u, using the request
-// context. If the upstream has a SRV lookup configured, that is done and a
-// returned address is chosen; otherwise, the upstream's regular dial address
-// field is used. Note that the returned value is not a pointer.
+// context. Note that the returned value is not a pointer.
 func (u *Upstream) fillDialInfo(r *http.Request) (DialInfo, error) {
 	repl := r.Context().Value(caddy.ReplacerCtxKey).(*caddy.Replacer)
 	var addr caddy.NetworkAddress
 
-	if u.LookupSRV != "" {
-		// perform DNS lookup for SRV records and choose one - TODO: deprecated
-		srvName := repl.ReplaceAll(u.LookupSRV, "")
-		_, records, err := net.DefaultResolver.LookupSRV(r.Context(), "", "", srvName)
-		if err != nil {
-			return DialInfo{}, err
-		}
-		addr.Network = "tcp"
-		addr.Host = records[0].Target
-		addr.StartPort, addr.EndPort = uint(records[0].Port), uint(records[0].Port)
-	} else {
-		// use provided dial address
-		var err error
-		dial := repl.ReplaceAll(u.Dial, "")
-		addr, err = caddy.ParseNetworkAddress(dial)
-		if err != nil {
-			return DialInfo{}, fmt.Errorf("upstream %s: invalid dial address %s: %v", u.Dial, dial, err)
-		}
-		if numPorts := addr.PortRangeSize(); numPorts != 1 {
-			return DialInfo{}, fmt.Errorf("upstream %s: dial address must represent precisely one socket: %s represents %d",
-				u.Dial, dial, numPorts)
-		}
+	// use provided dial address
+	var err error
+	dial := repl.ReplaceAll(u.Dial, "")
+	addr, err = caddy.ParseNetworkAddress(dial)
+	if err != nil {
+		return DialInfo{}, fmt.Errorf("upstream %s: invalid dial address %s: %v", u.Dial, dial, err)
+	}
+	if numPorts := addr.PortRangeSize(); numPorts != 1 {
+		return DialInfo{}, fmt.Errorf("upstream %s: dial address must represent precisely one socket: %s represents %d",
+			u.Dial, dial, numPorts)
 	}
 
 	return DialInfo{
@@ -259,3 +234,13 @@ var hosts = caddy.NewUsagePool()
 // dialInfoVarKey is the key used for the variable that holds
 // the dial info for the upstream connection.
 const dialInfoVarKey = "reverse_proxy.dial_info"
+
+// proxyProtocolInfoVarKey is the key used for the variable that holds
+// the proxy protocol info for the upstream connection.
+const proxyProtocolInfoVarKey = "reverse_proxy.proxy_protocol_info"
+
+// ProxyProtocolInfo contains information needed to write proxy protocol to a
+// connection to an upstream host.
+type ProxyProtocolInfo struct {
+	AddrPort netip.AddrPort
+}