When the leaselease option is given, retain the lease when the DHCP lease

expires, which mirrors how dhcpcd works when it starts up.
However, if any ARP probe is for the address, drop the lease right away
and continue discovery.

diff --git a/dhcp.c b/dhcp.c
index d2a9678a3825882ac179e69b1bc78ae108ebd24e..e4baa03db086631901c9318b5e682839779a01dd 100644 (file)
--- a/dhcp.c
+++ b/dhcp.c
@@ -118,7 +118,8 @@ struct udp_dhcp_packet
 
 static const size_t udp_dhcp_len = sizeof(struct udp_dhcp_packet);
 
-static int dhcp_open(struct interface *ifp);
+static int dhcp_open(struct interface *);
+static void dhcp_arp_conflicted(struct arp_state *, const struct arp_msg *);
 
 void
 dhcp_printoptions(const struct dhcpcd_ctx *ctx,
@@ -1808,18 +1809,48 @@ dhcp_request(void *arg)
        send_request(ifp);
 }
 
+static int
+dhcp_leaseextend(struct interface *ifp)
+{
+       struct arp_state *astate;
+
+       if ((astate = arp_new(ifp, NULL)) == NULL)
+               return -1;
+
+       if (arp_open(ifp) == -1)
+               return -1;
+
+       astate->conflicted_cb = dhcp_arp_conflicted;
+       logger(ifp->ctx, LOG_WARNING,
+           "%s: keeping lease until DaD failure or DHCP", ifp->name);
+       return 0;
+}
+
 static void
-dhcp_expire(void *arg)
+dhcp_expire1(struct interface *ifp)
 {
-       struct interface *ifp = arg;
        struct dhcp_state *state = D_STATE(ifp);
 
-       logger(ifp->ctx, LOG_ERR, "%s: DHCP lease expired", ifp->name);
        eloop_timeout_delete(ifp->ctx->eloop, NULL, ifp);
        dhcp_drop(ifp, "EXPIRE");
        unlink(state->leasefile);
        state->interval = 0;
        dhcp_discover(ifp);
+
+}
+static void
+dhcp_expire(void *arg)
+{
+       struct interface *ifp = arg;
+
+       logger(ifp->ctx, LOG_ERR, "%s: DHCP lease expired", ifp->name);
+       if (ifp->options->options & DHCPCD_LASTLEASE) {
+               if (dhcp_leaseextend(ifp) == 0)
+                       return;
+               logger(ifp->ctx, LOG_ERR, "%s: dhcp_leaseextend: %m",
+                   ifp->name);
+       }
+       dhcp_expire1(ifp);
 }
 
 static void
@@ -2003,6 +2034,21 @@ dhcp_arp_conflicted(struct arp_state *astate, const struct arp_msg *amsg)
                eloop_timeout_add_sec(ifp->ctx->eloop,
                    DHCP_RAND_MAX, dhcp_discover, ifp);
        }
+
+       /* Bound address */
+       if (amsg &&
+           (amsg->sip.s_addr == state->addr.s_addr ||
+           (amsg->sip.s_addr == 0 && amsg->tip.s_addr == state->addr.s_addr)))
+       {
+               astate->failed = state->addr;
+               arp_report_conflicted(astate, amsg);
+               if (state->state == DHS_BOUND) {
+                       /* For now, just report the duplicated address */
+               } else {
+                       arp_free(astate);
+                       dhcp_expire1(ifp);
+               }
+       }
 }
 
 void
@@ -2123,7 +2169,7 @@ dhcp_bind(struct interface *ifp)
 }
 
 static void
-dhcp_timeout(void *arg)
+dhcp_lastlease(void *arg)
 {
        struct interface *ifp = arg;
        struct dhcp_state *state = D_STATE(ifp);
@@ -2133,6 +2179,11 @@ dhcp_timeout(void *arg)
        if (ifp->ctx->options & DHCPCD_FORKED)
                return;
        state->interval = 0;
+       if (dhcp_leaseextend(ifp) == -1) {
+               logger(ifp->ctx, LOG_ERR, "%s: dhcp_leaseextend: %m",
+                   ifp->name);
+               dhcp_expire(ifp);
+       }
        dhcp_discover(ifp);
 }
 
@@ -2368,7 +2419,7 @@ dhcp_reboot(struct interface *ifp)
 
        if (ifo->options & DHCPCD_LASTLEASE && state->lease.frominfo)
                eloop_timeout_add_sec(ifp->ctx->eloop,
-                   ifo->reboot, dhcp_timeout, ifp);
+                   ifo->reboot, dhcp_lastlease, ifp);
        else if (!(ifo->options & DHCPCD_INFORM))
                eloop_timeout_add_sec(ifp->ctx->eloop,
                    ifo->reboot, dhcp_expire, ifp);
@@ -3352,7 +3403,8 @@ dhcp_start1(void *arg)
                                free(state->offer);
                                state->offer = NULL;
                        }
-               } else if (state->lease.leasetime != ~0U &&
+               } else if (!(ifo->options & DHCPCD_LASTLEASE) &&
+                   state->lease.leasetime != ~0U &&
                    stat(state->leasefile, &st) == 0)
                {
                        time_t now;