From 9294c9ecb2db05dab83b3e168df80c27be15f000 Mon Sep 17 00:00:00 2001
From: Eugene Bujak <hmage@hmage.net>
Date: Wed, 12 Dec 2018 20:22:45 +0300
Subject: [PATCH] Add DHCP API stubs for JS development.

---
 config.go  | 29 +++++++++++++++++++++++++++++
 control.go |  3 +++
 dhcp.go    | 45 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 77 insertions(+)
 create mode 100644 dhcp.go

diff --git a/config.go b/config.go
index 1f7464b2..8566de68 100644
--- a/config.go
+++ b/config.go
@@ -6,6 +6,7 @@ import (
 	"os"
 	"path/filepath"
 	"sync"
+	"time"
 
 	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
 	"github.com/AdguardTeam/AdGuardHome/dnsforward"
@@ -31,6 +32,7 @@ type configuration struct {
 	DNS       dnsConfig `yaml:"dns"`
 	Filters   []filter  `yaml:"filters"`
 	UserRules []string  `yaml:"user_rules"`
+	DHCP      dhcpState `yaml:"dhcp"`
 
 	sync.RWMutex `yaml:"-"`
 
@@ -48,6 +50,30 @@ type dnsConfig struct {
 
 var defaultDNS = []string{"tls://1.1.1.1", "tls://1.0.0.1"}
 
+// field ordering is important -- yaml fields will mirror ordering from here
+type dhcpState struct {
+	dhcpConfig
+	Leases []dhcpLease
+}
+
+// field ordering is important -- yaml fields will mirror ordering from here
+type dhcpConfig struct {
+	Enabled       bool
+	GatewayIP     string        `json:"gateway_ip" yaml:"gateway_ip"`
+	SubnetMask    string        `json:"subnet_mask" yaml:"subnet_mask"`
+	RangeStart    string        `json:"range_start" yaml:"range_start"`
+	RangeEnd      string        `json:"range_end" yaml:"range_end"`
+	LeaseDuration time.Duration `json:"lease_duration" yaml:"lease_duration"`
+}
+
+// field ordering is important -- yaml fields will mirror ordering from here
+type dhcpLease struct {
+	HWAddr   [6]byte `json:"mac" yaml:"hwaddr"`
+	IP       string  `json:"ip"` // json by default keeps IP uppercase but we need lowercase
+	Hostname string
+	Expires  time.Time
+}
+
 // initialize to default values, will be changed later when reading config or parsing command line
 var config = configuration{
 	ourConfigFilename: "AdGuardHome.yaml",
@@ -72,6 +98,9 @@ var config = configuration{
 		{Filter: dnsfilter.Filter{ID: 3}, Enabled: false, URL: "https://hosts-file.net/ad_servers.txt", Name: "hpHosts - Ad and Tracking servers only"},
 		{Filter: dnsfilter.Filter{ID: 4}, Enabled: false, URL: "http://www.malwaredomainlist.com/hostslist/hosts.txt", Name: "MalwareDomainList.com Hosts List"},
 	},
+	DHCP: dhcpState{dhcpConfig: dhcpConfig{
+		LeaseDuration: time.Hour * 12,
+	}},
 	SchemaVersion: currentSchemaVersion,
 }
 
diff --git a/control.go b/control.go
index 78235a48..0b00f08c 100644
--- a/control.go
+++ b/control.go
@@ -719,4 +719,7 @@ func registerControlHandlers() {
 	http.HandleFunc("/control/safesearch/enable", optionalAuth(ensurePOST(handleSafeSearchEnable)))
 	http.HandleFunc("/control/safesearch/disable", optionalAuth(ensurePOST(handleSafeSearchDisable)))
 	http.HandleFunc("/control/safesearch/status", optionalAuth(ensureGET(handleSafeSearchStatus)))
+	http.HandleFunc("/control/dhcp/status", optionalAuth(ensureGET(handleDHCPStatus)))
+	http.HandleFunc("/control/dhcp/set_config", optionalAuth(ensurePOST(handleDHCPSetConfig)))
+	http.HandleFunc("/control/dhcp/find_active_dhcp", optionalAuth(ensurePOST(handleDHCPFindActiveServer)))
 }
diff --git a/dhcp.go b/dhcp.go
new file mode 100644
index 00000000..5a6fc490
--- /dev/null
+++ b/dhcp.go
@@ -0,0 +1,45 @@
+package main
+
+import (
+	"encoding/json"
+	"math/rand"
+	"net/http"
+)
+
+func handleDHCPStatus(w http.ResponseWriter, r *http.Request) {
+	status := map[string]interface{}{
+		"config": config.DHCP.dhcpConfig,
+		"leases": config.DHCP.Leases,
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	err := json.NewEncoder(w).Encode(status)
+	if err != nil {
+		httpError(w, http.StatusInternalServerError, "Unable to marshal DHCP status json: %s", err)
+		return
+	}
+}
+
+func handleDHCPSetConfig(w http.ResponseWriter, r *http.Request) {
+	newconfig := dhcpConfig{}
+	err := json.NewDecoder(r.Body).Decode(&newconfig)
+	if err != nil {
+		httpError(w, http.StatusBadRequest, "Failed to parse new DHCP config json: %s", err)
+		return
+	}
+
+	config.DHCP.dhcpConfig = newconfig
+}
+
+// TODO: implement
+func handleDHCPFindActiveServer(w http.ResponseWriter, r *http.Request) {
+	found := map[string]bool{
+		"found": rand.Intn(2) == 1,
+	}
+	w.Header().Set("Content-Type", "application/json")
+	err := json.NewEncoder(w).Encode(found)
+	if err != nil {
+		httpError(w, http.StatusBadRequest, "Failed to marshal DHCP found json: %s", err)
+		return
+	}
+}