Reservation lease time; reservations by MAC address or client ID

- A reservation can have its own lease time (--lease-time, the
  reservation dialog), over the subnet's. Schema migration 6.
- A reservation with a MAC address and a client ID matches either one
  (a dual-boot machine sends two client IDs from one MAC); before, it
  was found by MAC and then refused. A lease of the reserved address by
  the client's other identity counts as its own.
- The Leases page shows a client's client ID; reserving a lease uses
  both, or one with --by / the dialog's choice.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

cmd/steward/leases.go

@@ -126,13 +126,17 @@ gets a NAK when it next renews, and then asks for a new address.`,
 	}
 	del.Flags().BoolVarP(&yes, "yes", "y", false, "don't ask")
 	cmd.AddCommand(del)
-	var hostname, comment string
+	var hostname, comment, by string
 	reserve := &cobra.Command{
 		Use:   "reserve IP",
 		Short: "Make a lease's address its client's reservation",
 		Long: `Makes the address a client has now its reservation: it keeps it from
 then on. The host name the client sent becomes the reservation's, unless
---hostname gives another.`,
+--hostname gives another.
+
+The reservation knows the client by its MAC address and, if it sent one,
+its client ID (option 61): either one gets it the address. --by mac or
+--by client-id uses just one.`,
 		Args: cobra.ExactArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			c, err := newClient()
@@ -146,6 +150,9 @@ then on. The host name the client sent becomes the reservation's, unless
 			if comment != "" {
 				body["comment"] = comment
 			}
+			if by != "" {
+				body["by"] = by
+			}
 			var resp api.MutationResponse
 			if err := c.Do(ctx(), "POST", "/leases/"+args[0]+"/reserve", nil, body, &resp); err != nil {
 				return err
@@ -155,6 +162,7 @@ then on. The host name the client sent becomes the reservation's, unless
 	}
 	reserve.Flags().StringVar(&hostname, "hostname", "", "the reservation's host name")
 	reserve.Flags().StringVar(&comment, "comment", "", "a comment")
+	reserve.Flags().StringVar(&by, "by", "", "know the client by mac, client-id or both (the default)")
 	cmd.AddCommand(reserve)
 	return cmd
 }

cmd/steward/subnets.go

@@ -385,7 +385,7 @@ func reservationCmd() *cobra.Command {
 				for _, r := range rs {
 					who := r.MAC
 					if r.ClientID != "" {
-						who = "id " + r.ClientID
+						who = strings.TrimPrefix(r.MAC+" or id "+r.ClientID, " or ")
 					}
 					lease := "-"
 					if r.Lease != nil {
@@ -427,6 +427,11 @@ func reservationCmd() *cobra.Command {
 				}
 				fmt.Fprintf(w, "Host name:\t%s\n", orDash(r.Hostname))
 				fmt.Fprintln(w, "Options:\t"+optionsText(r.Options))
+				lt := "the subnet's"
+				if r.LeaseTime > 0 {
+					lt = fmtSeconds(r.LeaseTime)
+				}
+				fmt.Fprintf(w, "Lease time:\t%s\n", lt)
 				if r.Lease != nil {
 					fmt.Fprintf(w, "Lease:\tuntil %s, on %s\n", r.Lease.End.Local().Format("2006-01-02 15:04"), r.Lease.Interface)
 					if r.Lease.LastSeen != nil {
@@ -467,17 +472,18 @@ func reservationCmd() *cobra.Command {
 		})
 	}
 
-	var hostname, clientID, comment, ip, mac string
+	var hostname, clientID, comment, ip, mac, leaseTime string
 	var opts, unsetOpts []string
 	add := &cobra.Command{
 		Use:   "add IP MAC",
 		Short: "Reserve an address for a client",
-		Long: `Reserves an address for a client, known by its MAC address (or by its
-client identifier: give "-" for the MAC and --client-id). The address picks
-the subnet. An address inside a pool is fine: it is never handed out to
-anyone else.
+		Long: `Reserves an address for a client, known by its MAC address, its client
+identifier (option 61: give "-" for the MAC and --client-id), or both:
+then either one gets it the address, as for a machine that boots two
+systems. The address picks the subnet. An address inside a pool is fine:
+it is never handed out to anyone else.
 
-  steward reservation add 10.0.10.20 aa:bb:cc:dd:ee:01 --hostname nas`,
+  steward reservation add 10.0.10.20 aa:bb:cc:dd:ee:01 --hostname nas --lease-time 7d`,
 		Args: cobra.ExactArgs(2),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			c, err := newClient()
@@ -497,6 +503,13 @@ anyone else.
 			if comment != "" {
 				in.Comment = &comment
 			}
+			if leaseTime != "" {
+				n, err := parseSeconds(leaseTime)
+				if err != nil {
+					return err
+				}
+				in.LeaseTime = &n
+			}
 			if len(opts) > 0 {
 				o, err := optionsArg(opts)
 				if err != nil {
@@ -513,7 +526,8 @@ anyone else.
 	}
 	f := add.Flags()
 	f.StringVar(&hostname, "hostname", "", "the host name to send it")
-	f.StringVar(&clientID, "client-id", "", "match the client identifier (hex) instead of the MAC address")
+	f.StringVar(&clientID, "client-id", "", "the client identifier (hex): with a MAC address, either one matches")
+	f.StringVar(&leaseTime, "lease-time", "", "this client's lease time (12h, 7d; default: the subnet's)")
 	f.StringArrayVar(&opts, "option", nil, "an option NAME=VALUE for this client only")
 	f.StringVar(&comment, "comment", "", "a comment")
 	cmd.AddCommand(add)
@@ -547,6 +561,15 @@ anyone else.
 			if fl.Changed("comment") {
 				in.Comment = &comment
 			}
+			if fl.Changed("lease-time") {
+				n := 0
+				if leaseTime != "default" {
+					if n, err = parseSeconds(leaseTime); err != nil {
+						return err
+					}
+				}
+				in.LeaseTime = &n
+			}
 			if len(opts) > 0 || len(unsetOpts) > 0 {
 				set, err := optionsArg(opts)
 				if err != nil {
@@ -570,6 +593,7 @@ anyone else.
 	f.StringVar(&mac, "mac", "", "a new MAC address (\"\" for none)")
 	f.StringVar(&clientID, "client-id", "", "a client identifier (\"\" for none)")
 	f.StringVar(&hostname, "hostname", "", "a new host name")
+	f.StringVar(&leaseTime, "lease-time", "", "lease time (12h, 7d, or \"default\": the subnet's)")
 	f.StringArrayVar(&opts, "option", nil, "set an option NAME=VALUE")
 	f.StringArrayVar(&unsetOpts, "unset-option", nil, "remove an option")
 	f.StringVar(&comment, "comment", "", "a comment")