Clock matcher: initial commit

README.md

@@ -30,6 +30,7 @@ This app works similarly to the `http` app. You define servers, and each server
 
 Current matchers:
 
+- **layer4.matchers.clock** - matches connections on the time they are wrapped/matched.
 - **layer4.matchers.http** - matches connections that start with HTTP requests. In addition, any [`http.matchers` modules](https://caddyserver.com/docs/modules/) can be used for matching on HTTP-specific properties of requests, such as header or path. Note that only the first request of each connection can be used for matching.
 - **layer4.matchers.tls** - matches connections that start with TLS handshakes. In addition, any [`tls.handshake_match` modules](https://caddyserver.com/docs/modules/) can be used for matching on TLS-specific properties of the ClientHello, such as ServerName (SNI).
 - **layer4.matchers.ssh** - matches connections that look like SSH connections.

imports.go

@@ -17,6 +17,7 @@ package caddyl4
 import (
 	// plugging in the standard modules for the layer4 app
 	_ "github.com/mholt/caddy-l4/layer4"
+	_ "github.com/mholt/caddy-l4/modules/l4clock"
 	_ "github.com/mholt/caddy-l4/modules/l4echo"
 	_ "github.com/mholt/caddy-l4/modules/l4http"
 	_ "github.com/mholt/caddy-l4/modules/l4postgres"

integration/caddyfile_adapt/gd_matcher_clock.caddytest

@@ -0,0 +1,153 @@
+{
+	layer4 {
+		:8080 {
+			@night_m clock before 05:00:00
+			@morning clock 05:00:00 12:00:00
+			@afternoon clock 12:00:00 17:00:00
+			@evening clock 17:00:00 21:00:00
+			@night_e clock after 21:00:00
+			route @night_m @night_e {
+				proxy 00.upstream.local:8080
+			}
+			route @morning {
+				proxy 01.upstream.local:8080 02.upstream.local:8080
+			}
+			route @afternoon {
+				proxy 03.upstream.local:8080 04.upstream.local:8080 05.upstream.local:8080
+			}
+			route @evening {
+				proxy 06.upstream.local:8080 07.upstream.local:8080
+			}
+		}
+	}
+}
+----------
+{
+	"apps": {
+		"layer4": {
+			"servers": {
+				"srv0": {
+					"listen": [
+						":8080"
+					],
+					"routes": [
+						{
+							"match": [
+								{
+									"clock": {
+										"after": "00:00:00",
+										"before": "05:00:00"
+									}
+								},
+								{
+									"clock": {
+										"after": "21:00:00",
+										"before": "00:00:00"
+									}
+								}
+							],
+							"handle": [
+								{
+									"handler": "proxy",
+									"upstreams": [
+										{
+											"dial": [
+												"00.upstream.local:8080"
+											]
+										}
+									]
+								}
+							]
+						},
+						{
+							"match": [
+								{
+									"clock": {
+										"after": "05:00:00",
+										"before": "12:00:00"
+									}
+								}
+							],
+							"handle": [
+								{
+									"handler": "proxy",
+									"upstreams": [
+										{
+											"dial": [
+												"01.upstream.local:8080"
+											]
+										},
+										{
+											"dial": [
+												"02.upstream.local:8080"
+											]
+										}
+									]
+								}
+							]
+						},
+						{
+							"match": [
+								{
+									"clock": {
+										"after": "12:00:00",
+										"before": "17:00:00"
+									}
+								}
+							],
+							"handle": [
+								{
+									"handler": "proxy",
+									"upstreams": [
+										{
+											"dial": [
+												"03.upstream.local:8080"
+											]
+										},
+										{
+											"dial": [
+												"04.upstream.local:8080"
+											]
+										},
+										{
+											"dial": [
+												"05.upstream.local:8080"
+											]
+										}
+									]
+								}
+							]
+						},
+						{
+							"match": [
+								{
+									"clock": {
+										"after": "17:00:00",
+										"before": "21:00:00"
+									}
+								}
+							],
+							"handle": [
+								{
+									"handler": "proxy",
+									"upstreams": [
+										{
+											"dial": [
+												"06.upstream.local:8080"
+											]
+										},
+										{
+											"dial": [
+												"07.upstream.local:8080"
+											]
+										}
+									]
+								}
+							]
+						}
+					]
+				}
+			}
+		}
+	}
+}

layer4/connection.go

@@ -19,6 +19,7 @@ import (
 	"errors"
 	"net"
 	"sync"
+	"time"
 
 	"github.com/caddyserver/caddy/v2"
 	"go.uber.org/zap"
@@ -33,6 +34,7 @@ func WrapConnection(underlying net.Conn, buf []byte, logger *zap.Logger) *Connec
 	repl := caddy.NewReplacer()
 	repl.Set("l4.conn.remote_addr", underlying.RemoteAddr())
 	repl.Set("l4.conn.local_addr", underlying.LocalAddr())
+	repl.Set("l4.conn.wrap_time", time.Now())
 
 	ctx := context.Background()
 	ctx = context.WithValue(ctx, VarsCtxKey, make(map[string]interface{}))

modules/l4clock/matcher.go

@@ -0,0 +1,156 @@
+// Copyright 2024 VNXME
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package l4clock
+
+import (
+	"strings"
+	"time"
+
+	"github.com/caddyserver/caddy/v2"
+	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
+
+	"github.com/mholt/caddy-l4/layer4"
+)
+
+func init() {
+	caddy.RegisterModule(&MatchClock{})
+}
+
+// MatchClock is able to match any connections using the time when they are wrapped/matched.
+type MatchClock struct {
+	After  string `json:"after,omitempty"`
+	Before string `json:"before,omitempty"`
+
+	secondsAfter  int
+	secondsBefore int
+}
+
+// CaddyModule returns the Caddy module information.
+func (m *MatchClock) CaddyModule() caddy.ModuleInfo {
+	return caddy.ModuleInfo{
+		ID:  "layer4.matchers.clock",
+		New: func() caddy.Module { return new(MatchClock) },
+	}
+}
+
+// Match returns true if the connection wrapping/matching occurs within m's time points.
+func (m *MatchClock) Match(cx *layer4.Connection) (bool, error) {
+	repl := cx.Context.Value(caddy.ReplacerCtxKey).(*caddy.Replacer)
+	t, known := repl.Get(timeKey)
+	if !known {
+		t = time.Now()
+		repl.Set(timeKey, t)
+	}
+	secondsNow := timeToSeconds(t.(time.Time))
+	if secondsNow >= m.secondsAfter && secondsNow < m.secondsBefore {
+		return true, nil
+	}
+	return false, nil
+}
+
+// Provision parses m's time points.
+func (m *MatchClock) Provision(_ caddy.Context) (err error) {
+	repl := caddy.NewReplacer()
+	after, before := repl.ReplaceAll(m.After, ""), repl.ReplaceAll(m.Before, "")
+
+	if m.secondsAfter, err = timeParseSeconds(after, 0); err != nil {
+		return
+	}
+
+	if m.secondsBefore, err = timeParseSeconds(before, 0); err != nil {
+		return
+	}
+
+	// Treat secondsBefore of 00:00:00 as 24:00:00
+	if m.secondsBefore == 0 {
+		m.secondsBefore = 86400
+	}
+
+	// Swap time points, if secondsAfter is greater than secondsBefore
+	if m.secondsBefore < m.secondsAfter {
+		m.secondsAfter, m.secondsBefore = m.secondsBefore, m.secondsAfter
+	}
+
+	return nil
+}
+
+// UnmarshalCaddyfile sets up the MatchClock from Caddyfile tokens. Syntax:
+//
+//	clock <time_after> <time_before>
+//	clock <after|from> <time_after>
+//	clock <before|till|to|until> <time_before>
+//
+// Note: MatchClock checks if time_now is greater than or equal to time_after AND less than time_before.
+// The lowest value is 00:00:00. If time_before equals 00:00:00, it is treated as 24:00:00. If time_after is greater
+// than time_before, they are swapped. Both "after 00:00:00" and "before 00:00:00" match all day.
+func (m *MatchClock) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
+	_, wrapper := d.Next(), d.Val() // consume wrapper name
+
+	// Two same-line arguments must be provided
+	if d.CountRemainingArgs() != 2 {
+		return d.ArgErr()
+	}
+
+	_, first, _, second := d.NextArg(), d.Val(), d.NextArg(), d.Val()
+	switch strings.ToLower(first) {
+	case "before", "till", "to", "until":
+		first = timeMin
+		break
+	case "after", "from":
+		first = timeMax
+		second, first = first, second
+		break
+	}
+	m.After, m.Before = first, second
+
+	// No blocks are supported
+	if d.NextBlock(d.Nesting()) {
+		return d.Errf("malformed %s matcher: blocks are not supported", wrapper)
+	}
+
+	return nil
+}
+
+const (
+	timeKey    = "l4.conn.wrap_time"
+	timeLayout = time.TimeOnly
+	timeMax    = "00:00:00"
+	timeMin    = "00:00:00"
+)
+
+// Interface guards
+var (
+	_ caddy.Provisioner     = (*MatchClock)(nil)
+	_ caddyfile.Unmarshaler = (*MatchClock)(nil)
+	_ layer4.ConnMatcher    = (*MatchClock)(nil)
+)
+
+// timeToSeconds gets time and returns the number of seconds passed from the beginning of the current day.
+func timeToSeconds(t time.Time) int {
+	hh, mm, ss := t.Clock()
+	return hh*3600 + mm*60 + ss
+}
+
+// timeParseSeconds parses time string and returns seconds passed from the beginning of the current day.
+func timeParseSeconds(src string, def int) (int, error) {
+	if len(src) == 0 {
+		return def, nil
+	}
+	t, err := time.Parse(timeLayout, src)
+	if err != nil {
+		return def, err
+	}
+	return timeToSeconds(t), nil
+}