diff --git a/go.mod b/go.mod index 5ddcfb6..a1c9f87 100644 --- a/go.mod +++ b/go.mod @@ -14,6 +14,7 @@ require ( github.com/google/uuid v1.6.0 github.com/gwatts/rootcerts v0.0.0-20240401182218-3ab9db955caf github.com/hanwen/go-fuse/v2 v2.5.1 + github.com/hashicorp/go-envparse v0.1.0 github.com/openstadia/go-usb-gadget v0.0.0-20231115171102-aebd56bbb965 github.com/pion/logging v0.2.2 github.com/pion/mdns/v2 v2.0.7 diff --git a/go.sum b/go.sum index be21917..0b3c219 100644 --- a/go.sum +++ b/go.sum @@ -49,6 +49,8 @@ github.com/gwatts/rootcerts v0.0.0-20240401182218-3ab9db955caf h1:JO6ISZIvEUitto github.com/gwatts/rootcerts v0.0.0-20240401182218-3ab9db955caf/go.mod h1:5Kt9XkWvkGi2OHOq0QsGxebHmhCcqJ8KCbNg/a6+n+g= github.com/hanwen/go-fuse/v2 v2.5.1 h1:OQBE8zVemSocRxA4OaFJbjJ5hlpCmIWbGr7r0M4uoQQ= github.com/hanwen/go-fuse/v2 v2.5.1/go.mod h1:xKwi1cF7nXAOBCXujD5ie0ZKsxc8GGSA1rlMJc+8IJs= +github.com/hashicorp/go-envparse v0.1.0 h1:bE++6bhIsNCPLvgDZkYqo3nA+/PFI51pkrHdmPSDFPY= +github.com/hashicorp/go-envparse v0.1.0/go.mod h1:OHheN1GoygLlAkTlXLXvAdnXdZxy8JUweQ1rAXx1xnc= github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM= github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo= github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg= diff --git a/network.go b/network.go index c9ef919..ecc4069 100644 --- a/network.go +++ b/network.go @@ -1,14 +1,22 @@ package kvm import ( + "bytes" "fmt" - "github.com/pion/mdns/v2" - "golang.org/x/net/ipv4" - "golang.org/x/net/ipv6" + "net" + "os" + "strings" + "time" + "net" "os/exec" "time" + "github.com/hashicorp/go-envparse" + "github.com/pion/mdns/v2" + "golang.org/x/net/ipv4" + "golang.org/x/net/ipv6" + "github.com/vishvananda/netlink" "github.com/vishvananda/netlink/nl" ) @@ -28,27 +36,32 @@ type LocalIpInfo struct { MAC string } +const ( + NetIfName = "eth0" + DHCPLeaseFile = "/run/udhcpc.%s.info" +) + // setDhcpClientState sends signals to udhcpc to change it's current mode // of operation. Setting active to true will force udhcpc to renew the DHCP lease. // Setting active to false will put udhcpc into idle mode. func setDhcpClientState(active bool) { - var signal string; + var signal string if active { signal = "-SIGUSR1" } else { signal = "-SIGUSR2" } - cmd := exec.Command("/usr/bin/killall", signal, "udhcpc"); + cmd := exec.Command("/usr/bin/killall", signal, "udhcpc") if err := cmd.Run(); err != nil { fmt.Printf("network: setDhcpClientState: failed to change udhcpc state: %s\n", err) } } func checkNetworkState() { - iface, err := netlink.LinkByName("eth0") + iface, err := netlink.LinkByName(NetIfName) if err != nil { - fmt.Printf("failed to get eth0 interface: %v\n", err) + fmt.Printf("failed to get [%s] interface: %v\n", NetIfName, err) return } @@ -64,7 +77,13 @@ func checkNetworkState() { addrs, err := netlink.AddrList(iface, nl.FAMILY_ALL) if err != nil { - fmt.Printf("failed to get addresses for eth0: %v\n", err) + fmt.Printf("failed to get addresses for [%s]: %v\n", NetIfName, err) + } + + // If the link is going down, put udhcpc into idle mode. + // If the link is coming back up, activate udhcpc and force it to renew the lease. + if newState.Up != networkState.Up { + setDhcpClientState(newState.Up) } // If the link is going down, put udhcpc into idle mode. @@ -144,6 +163,39 @@ func startMDNS() error { return nil } +func getNTPServersFromDHCPInfo() ([]string, error) { + buf, err := os.ReadFile(fmt.Sprintf(DHCPLeaseFile, NetIfName)) + if err != nil { + // do not return error if file does not exist + if os.IsNotExist(err) { + return nil, nil + } + return nil, fmt.Errorf("failed to load udhcpc info: %w", err) + } + + // parse udhcpc info + env, err := envparse.Parse(bytes.NewReader(buf)) + if err != nil { + return nil, fmt.Errorf("failed to parse udhcpc info: %w", err) + } + + val, ok := env["ntpsrv"] + if !ok { + return nil, nil + } + + var servers []string + + for _, server := range strings.Fields(val) { + if net.ParseIP(server) == nil { + fmt.Printf("invalid NTP server IP: %s, ignoring ... \n", server) + } + servers = append(servers, server) + } + + return servers, nil +} + func init() { updates := make(chan netlink.LinkUpdate) done := make(chan struct{}) @@ -162,7 +214,7 @@ func init() { for { select { case update := <-updates: - if update.Link.Attrs().Name == "eth0" { + if update.Link.Attrs().Name == NetIfName { fmt.Printf("link update: %+v\n", update) checkNetworkState() } diff --git a/ntp.go b/ntp.go index f785d96..4150d96 100644 --- a/ntp.go +++ b/ntp.go @@ -12,9 +12,19 @@ import ( ) var timeSynced = false +var defaultNTPServers = []string{ + "time.cloudflare.com", + "time.apple.com", +} func TimeSyncLoop() { for { + if !networkState.Up { + fmt.Printf("Waiting for network to come up\n") + time.Sleep(3 * time.Second) + continue + } + fmt.Println("Syncing system time") start := time.Now() err := SyncSystemTime() @@ -41,10 +51,15 @@ func SyncSystemTime() (err error) { } func queryNetworkTime() (*time.Time, error) { - ntpServers := []string{ - "time.cloudflare.com", - "time.apple.com", + ntpServers, err := getNTPServersFromDHCPInfo() + if err != nil { + fmt.Printf("failed to get NTP servers from DHCP info: %v\n", err) } + + if ntpServers == nil { + ntpServers = defaultNTPServers + } + for _, server := range ntpServers { now, err := queryNtpServer(server, 2*time.Second) if err == nil {