caddytls,caddyhttp: Placeholders for some TLS and HTTP matchers (#6480)

* Runtime placeholders for caddytls matchers (1/3):

- remove IPs validation in UnmarshalCaddyfile

* Runtime placeholders for caddytls matchers (2/3):

- add placeholder replacement for IPs in Provision

* Runtime placeholders for caddytls matchers (3/3):

- add placeholder replacement for other strings

* Runtime placeholders for caddyhttp matchers (1/1):

- add placeholder replacement for IPs in Provision

* Runtime placeholders for caddyhttp/caddytls matchers:

- move PrivateRandesCIDR under internal

5 files changed, 57 insertions, 41 deletions

diff --git a/internal/ranges.go b/internal/ranges.go
new file mode 100644
index 000000000..e9429e263
--- /dev/null
+++ b/internal/ranges.go
@@ -0,0 +1,14 @@
+package internal
+
+// PrivateRangesCIDR returns a list of private CIDR range
+// strings, which can be used as a configuration shortcut.
+func PrivateRangesCIDR() []string {
+	return []string{
+		"192.168.0.0/16",
+		"172.16.0.0/12",
+		"10.0.0.0/8",
+		"127.0.0.1/8",
+		"fd00::/8",
+		"::1",
+	}
+}
diff --git a/modules/caddyhttp/ip_matchers.go b/modules/caddyhttp/ip_matchers.go
index 9101a0357..2e735cb69 100644
--- a/modules/caddyhttp/ip_matchers.go
+++ b/modules/caddyhttp/ip_matchers.go
@@ -29,6 +29,7 @@ import (
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
+	"github.com/caddyserver/caddy/v2/internal"
 )
 
 // MatchRemoteIP matches requests by the remote IP address,
@@ -79,7 +80,7 @@ func (m *MatchRemoteIP) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 				return d.Err("the 'forwarded' option is no longer supported; use the 'client_ip' matcher instead")
 			}
 			if d.Val() == "private_ranges" {
-				m.Ranges = append(m.Ranges, PrivateRangesCIDR()...)
+				m.Ranges = append(m.Ranges, internal.PrivateRangesCIDR()...)
 				continue
 			}
 			m.Ranges = append(m.Ranges, d.Val())
@@ -173,7 +174,7 @@ func (m *MatchClientIP) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 	for d.Next() {
 		for d.NextArg() {
 			if d.Val() == "private_ranges" {
-				m.Ranges = append(m.Ranges, PrivateRangesCIDR()...)
+				m.Ranges = append(m.Ranges, internal.PrivateRangesCIDR()...)
 				continue
 			}
 			m.Ranges = append(m.Ranges, d.Val())
@@ -250,7 +251,9 @@ func (m MatchClientIP) Match(r *http.Request) bool {
 func provisionCidrsZonesFromRanges(ranges []string) ([]*netip.Prefix, []string, error) {
 	cidrs := []*netip.Prefix{}
 	zones := []string{}
+	repl := caddy.NewReplacer()
 	for _, str := range ranges {
+		str = repl.ReplaceAll(str, "")
 		// Exclude the zone_id from the IP
 		if strings.Contains(str, "%") {
 			split := strings.Split(str, "%")
diff --git a/modules/caddyhttp/ip_range.go b/modules/caddyhttp/ip_range.go
index b1db25475..7632e460c 100644
--- a/modules/caddyhttp/ip_range.go
+++ b/modules/caddyhttp/ip_range.go
@@ -22,6 +22,7 @@ import (
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
+	"github.com/caddyserver/caddy/v2/internal"
 )
 
 func init() {
@@ -92,7 +93,7 @@ func (m *StaticIPRange) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 	}
 	for d.NextArg() {
 		if d.Val() == "private_ranges" {
-			m.Ranges = append(m.Ranges, PrivateRangesCIDR()...)
+			m.Ranges = append(m.Ranges, internal.PrivateRangesCIDR()...)
 			continue
 		}
 		m.Ranges = append(m.Ranges, d.Val())
@@ -121,19 +122,6 @@ func CIDRExpressionToPrefix(expr string) (netip.Prefix, error) {
 	return prefix, nil
 }
 
-// PrivateRangesCIDR returns a list of private CIDR range
-// strings, which can be used as a configuration shortcut.
-func PrivateRangesCIDR() []string {
-	return []string{
-		"192.168.0.0/16",
-		"172.16.0.0/12",
-		"10.0.0.0/8",
-		"127.0.0.1/8",
-		"fd00::/8",
-		"::1",
-	}
-}
-
 // Interface guards
 var (
 	_ caddy.Provisioner     = (*StaticIPRange)(nil)
diff --git a/modules/caddyhttp/reverseproxy/caddyfile.go b/modules/caddyhttp/reverseproxy/caddyfile.go
index 1c3b49447..4ca5d0e0d 100644
--- a/modules/caddyhttp/reverseproxy/caddyfile.go
+++ b/modules/caddyhttp/reverseproxy/caddyfile.go
@@ -28,6 +28,7 @@ import (
 	"github.com/caddyserver/caddy/v2/caddyconfig"
 	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
 	"github.com/caddyserver/caddy/v2/caddyconfig/httpcaddyfile"
+	"github.com/caddyserver/caddy/v2/internal"
 	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
 	"github.com/caddyserver/caddy/v2/modules/caddyhttp/headers"
 	"github.com/caddyserver/caddy/v2/modules/caddyhttp/rewrite"
@@ -688,7 +689,7 @@ func (h *Handler) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 		case "trusted_proxies":
 			for d.NextArg() {
 				if d.Val() == "private_ranges" {
-					h.TrustedProxies = append(h.TrustedProxies, caddyhttp.PrivateRangesCIDR()...)
+					h.TrustedProxies = append(h.TrustedProxies, internal.PrivateRangesCIDR()...)
 					continue
 				}
 				h.TrustedProxies = append(h.TrustedProxies, d.Val())
diff --git a/modules/caddytls/matchers.go b/modules/caddytls/matchers.go
index a23a19317..83a464713 100644
--- a/modules/caddytls/matchers.go
+++ b/modules/caddytls/matchers.go
@@ -26,6 +26,7 @@ import (
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
+	"github.com/caddyserver/caddy/v2/internal"
 )
 
 func init() {
@@ -49,8 +50,17 @@ func (MatchServerName) CaddyModule() caddy.ModuleInfo {
 
 // Match matches hello based on SNI.
 func (m MatchServerName) Match(hello *tls.ClientHelloInfo) bool {
+	// caddytls.TestServerNameMatcher calls this function without any context
+	var repl *caddy.Replacer
+	if ctx := hello.Context(); ctx != nil {
+		repl = ctx.Value(caddy.ReplacerCtxKey).(*caddy.Replacer)
+	} else {
+		repl = caddy.NewReplacer()
+	}
+
 	for _, name := range m {
-		if certmagic.MatchWildcard(hello.ServerName, name) {
+		rs := repl.ReplaceAll(name, "")
+		if certmagic.MatchWildcard(hello.ServerName, rs) {
 			return true
 		}
 	}
@@ -107,16 +117,19 @@ func (MatchRemoteIP) CaddyModule() caddy.ModuleInfo {
 
 // Provision parses m's IP ranges, either from IP or CIDR expressions.
 func (m *MatchRemoteIP) Provision(ctx caddy.Context) error {
+	repl := caddy.NewReplacer()
 	m.logger = ctx.Logger()
 	for _, str := range m.Ranges {
-		cidrs, err := m.parseIPRange(str)
+		rs := repl.ReplaceAll(str, "")
+		cidrs, err := m.parseIPRange(rs)
 		if err != nil {
 			return err
 		}
 		m.cidrs = append(m.cidrs, cidrs...)
 	}
 	for _, str := range m.NotRanges {
-		cidrs, err := m.parseIPRange(str)
+		rs := repl.ReplaceAll(str, "")
+		cidrs, err := m.parseIPRange(rs)
 		if err != nil {
 			return err
 		}
@@ -185,22 +198,18 @@ func (m *MatchRemoteIP) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 
 		for d.NextArg() {
 			val := d.Val()
+			var exclamation bool
 			if len(val) > 1 && val[0] == '!' {
-				prefixes, err := m.parseIPRange(val[1:])
-				if err != nil {
-					return err
-				}
-				for _, prefix := range prefixes {
-					m.NotRanges = append(m.NotRanges, prefix.String())
-				}
+				exclamation, val = true, val[1:]
+			}
+			ranges := []string{val}
+			if val == "private_ranges" {
+				ranges = internal.PrivateRangesCIDR()
+			}
+			if exclamation {
+				m.NotRanges = append(m.NotRanges, ranges...)
 			} else {
-				prefixes, err := m.parseIPRange(val)
-				if err != nil {
-					return err
-				}
-				for _, prefix := range prefixes {
-					m.Ranges = append(m.Ranges, prefix.String())
-				}
+				m.Ranges = append(m.Ranges, ranges...)
 			}
 		}
 
@@ -233,9 +242,11 @@ func (MatchLocalIP) CaddyModule() caddy.ModuleInfo {
 
 // Provision parses m's IP ranges, either from IP or CIDR expressions.
 func (m *MatchLocalIP) Provision(ctx caddy.Context) error {
+	repl := caddy.NewReplacer()
 	m.logger = ctx.Logger()
 	for _, str := range m.Ranges {
-		cidrs, err := m.parseIPRange(str)
+		rs := repl.ReplaceAll(str, "")
+		cidrs, err := m.parseIPRange(rs)
 		if err != nil {
 			return err
 		}
@@ -300,13 +311,12 @@ func (m *MatchLocalIP) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 		}
 
 		for d.NextArg() {
-			prefixes, err := m.parseIPRange(d.Val())
-			if err != nil {
-				return err
-			}
-			for _, prefix := range prefixes {
-				m.Ranges = append(m.Ranges, prefix.String())
+			val := d.Val()
+			if val == "private_ranges" {
+				m.Ranges = append(m.Ranges, internal.PrivateRangesCIDR()...)
+				continue
 			}
+			m.Ranges = append(m.Ranges, val)
 		}
 
 		// No blocks are supported