From 98a94c67ff3921210f69553673c2b3e843b1318e Mon Sep 17 00:00:00 2001
From: Jeff Carr <jcarr@wit.com>
Date: Sat, 18 Feb 2023 07:29:24 -0600
Subject: [PATCH] ready to pull DNS records

Signed-off-by: Jeff Carr <jcarr@wit.com>
---
 Makefile   |  3 +++
 args.go    |  1 +
 dns.go     | 47 +++++++++++++++++++++++++++++++++++++++++++----
 gui.go     | 10 +---------
 net.go     | 14 +++++++++++++-
 netlink.go |  2 ++
 6 files changed, 63 insertions(+), 14 deletions(-)

diff --git a/Makefile b/Makefile
index cc0c867..2c91975 100644
--- a/Makefile
+++ b/Makefile
@@ -4,6 +4,9 @@ run: build
 verbose: build
 	./control-panel-dns --verbose --verbose-net --gui-debug --toolkit-debug
 
+dns: build
+	./control-panel-dns --verbose-dns
+
 build-release:
 	reset
 	go get -v -u -x .
diff --git a/args.go b/args.go
index 40cf039..9a9680b 100644
--- a/args.go
+++ b/args.go
@@ -9,6 +9,7 @@ type LogOptions struct {
 	LogFile string `help:"write all output to a file"`
 	Verbose bool
 	VerboseNet bool  `arg:"--verbose-net" help:"debug network settings"`
+	VerboseDNS bool  `arg:"--verbose-dns" help:"debug dns settings"`
 	// GuiDebug bool `help:"open up the wit/gui Debugging Window"`
 	// GuiDemo bool `help:"open the wit/gui Demo Window"`
 	User string `arg:"env:USER"`
diff --git a/dns.go b/dns.go
index 93ffc8a..14b6683 100644
--- a/dns.go
+++ b/dns.go
@@ -5,13 +5,11 @@
 package main
 
 import 	(
-//	"os"
-//	"os/exec"
 	"net"
-//	"git.wit.org/wit/gui"
-//	"github.com/davecgh/go-spew/spew"
 )
 
+var dnsTTL int = 3600;	// Recheck DNS is working every TTL (in seconds)
+
 /*
 	Check a bunch of things. If they don't work right, then things are not correctly configured
 	They are things like:
@@ -33,3 +31,44 @@ func (h *Host) updateIPs(host string) {
                 log(host, ip)
         }
 }
+
+func (h *Host) setIPv4(ipv4s map[string]*IPtype) {
+        for ip, t := range ipv4s {
+		log("IPv4", ip, t)
+        }
+}
+
+func (h *Host) checkDNS() {
+	var ip4 bool = false
+	var ip6 bool = false
+
+	for s, t := range h.ipmap {
+		i := t.iface
+		ipt := "IPv4"
+		if (t.ipv6) {
+			ipt = "IPv6"
+		}
+		if (! t.IsReal()) {
+			log(args.VerboseDNS, "\tIP is not Real", ipt, i.Index, i.Name, s)
+			continue
+		}
+
+		log(args.VerboseDNS, "\tIP is Real    ", ipt, i.Index, i.Name, s)
+		if (t.ipv6) {
+			ip6 = true
+		} else {
+			ip4 = true
+		}
+	}
+
+	if (ip4 == true) {
+		log(args.VerboseDNS, "IPv4 should work. Wow. You actually have a real IPv4 address")
+	} else {
+		log(args.VerboseDNS, "IPv4 is broken. (be nice and setup ipv4-only.wit.com)")
+	}
+	if (ip6 == true) {
+		log(args.VerboseDNS, "IPv6 should be working. Need to test it here.")
+	} else {
+		log(args.VerboseDNS, "IPv6 is broken. Need to fix it here.")
+	}
+}
diff --git a/gui.go b/gui.go
index 5313100..46ccb2d 100644
--- a/gui.go
+++ b/gui.go
@@ -71,16 +71,8 @@ func addDNSTab(window *gui.Node, title string) {
 			log("int =", i, "name =", t.name, t.iface)
 		}
 	})
-	g2.NewButton("dump Host.ipmap", func () {
-		for s, t := range me.ipmap {
-			log("name =", s, "ipv4 =", t.ipv4)
-			log("name =", s, "ipv6 =", t.ipv6)
-			log("name =", s, "iface =", t.iface)
-			log("name =", s, "ip =", t.ip)
-		}
-	})
 	g2.NewButton("checkDNS()", func () {
-		checkDNS()
+		me.checkDNS()
 	})
 	g2.NewButton("os.Hostname()", func () {
 		name, err = os.Hostname()
diff --git a/net.go b/net.go
index 70ac155..b52d513 100644
--- a/net.go
+++ b/net.go
@@ -91,7 +91,13 @@ func checkInterface(i net.Interface) {
 	}
 }
 
-func checkDNS() {
+func checkDNS() (map[string]*IPtype, map[string]*IPtype) {
+	var ipv4s map[string]*IPtype
+	var ipv6s map[string]*IPtype
+
+	ipv4s = make(map[string]*IPtype)
+	ipv6s = make(map[string]*IPtype)
+
 	for s, t := range me.ipmap {
 		i := t.iface
 		ipt := "IPv4"
@@ -100,10 +106,16 @@ func checkDNS() {
 		}
 		if (t.IsReal()) {
 			log("\tIP is Real    ", ipt, i.Index, i.Name, s)
+			if (t.ipv6) {
+				ipv6s[s] = t
+			} else {
+				ipv4s[s] = t
+			}
 		} else {
 			log("\tIP is not Real", ipt, i.Index, i.Name, s)
 		}
 	}
+	return ipv6s, ipv4s
 }
 
 // Will figure out if an IP address is new
diff --git a/netlink.go b/netlink.go
index 8b2e14f..7d3c3f5 100644
--- a/netlink.go
+++ b/netlink.go
@@ -6,6 +6,8 @@ package main
 // from that page, a link to watch for any ip event:
 // https://github.com/angt/ipevent/blob/master/ipevent.c
 
+// https://github.com/mdlayher/talks : Linux, Netlink, and Go in 7 minutes or less! (GopherCon 2018, lightning talk) 
+
 /*
 	c example from ipevent.c :
 	int fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);