Pass status option up.

If we are in state "renewing" and the DHCPv6 server returns an
unsuccessful status go to "rebinding", i.e. ask any DHCPv6 server for
a lease not just the one we got the lease from.

This likely fixes a problem reported by Brian Conway where the ISP
returned "NoBinding - Prefix not bound to this interface." for a renew.
dhcp6leased recovered once T1 expired and we went to "rebinding" after
some time.

diff --git a/sbin/dhcp6leased/engine.c b/sbin/dhcp6leased/engine.c
index 113be3c..c8997b3 100644 (file)
--- a/sbin/dhcp6leased/engine.c
+++ b/sbin/dhcp6leased/engine.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: engine.c,v 1.19 2024/07/10 12:44:46 florian Exp $     */
+/*     $OpenBSD: engine.c,v 1.20 2024/07/10 12:52:51 florian Exp $     */
 
 /*
  * Copyright (c) 2017, 2021, 2024 Florian Obser <florian@openbsd.org>
@@ -127,7 +127,7 @@ struct dhcp6leased_iface    *get_dhcp6leased_iface_by_id(uint32_t);
 void                    remove_dhcp6leased_iface(uint32_t);
 void                    parse_dhcp(struct dhcp6leased_iface *,
                             struct imsg_dhcp *);
-void                    parse_ia_pd_options(uint8_t *, size_t, struct prefix *);
+int                     parse_ia_pd_options(uint8_t *, size_t, struct prefix *);
 void                    state_transition(struct dhcp6leased_iface *, enum
                             if_state);
 void                    iface_timeout(int, short, void *);
@@ -812,11 +812,19 @@ parse_dhcp(struct dhcp6leased_iface *iface, struct imsg_dhcp *dhcp)
                        log_debug("%s: IA_PD, IAID: %08x, T1: %u, T2: %u",
                            __func__, ntohl(iapd.iaid), ntohl(iapd.t1),
                            ntohl(iapd.t2));
-                       if (ntohl(iapd.iaid) < iface_conf->ia_count)
-                               parse_ia_pd_options(p +
+                       if (ntohl(iapd.iaid) < iface_conf->ia_count) {
+                               int status_code;
+                               status_code = parse_ia_pd_options(p +
                                    sizeof(struct dhcp_iapd), opt_hdr.len -
                                    sizeof(struct dhcp_iapd),
                                    &iface->new_pds[ntohl(iapd.iaid)]);
+
+                               if (status_code != DHCP_STATUS_SUCCESS &&
+                                   iface->state == IF_RENEWING) {
+                                       state_transition(iface, IF_REBINDING);
+                                       goto out;
+                               }
+                       }
                        break;
                case DHO_RAPID_COMMIT:
                        if (opt_hdr.len != 0) {
@@ -932,7 +940,7 @@ parse_dhcp(struct dhcp6leased_iface *iface, struct imsg_dhcp *dhcp)
        return;
 }
 
-void
+int
 parse_ia_pd_options(uint8_t *p, size_t len, struct prefix *prefix)
 {
        struct dhcp_option_hdr   opt_hdr;
@@ -953,7 +961,7 @@ parse_ia_pd_options(uint8_t *p, size_t len, struct prefix *prefix)
                            dhcp_option_type2str(opt_hdr.code), opt_hdr.len);
                if (len < opt_hdr.len) {
                        log_warnx("%s: malformed packet, ignoring", __func__);
-                       return;
+                       return DHCP_STATUS_UNSPECFAIL;
                }
 
                switch (opt_hdr.code) {
@@ -961,7 +969,7 @@ parse_ia_pd_options(uint8_t *p, size_t len, struct prefix *prefix)
                        if (len < sizeof(struct dhcp_iaprefix)) {
                                log_warnx("%s: malformed packet, ignoring",
                                    __func__);
-                               return;
+                               return DHCP_STATUS_UNSPECFAIL;
                        }
 
                        memcpy(&iaprefix, p, sizeof(struct dhcp_iaprefix));
@@ -996,15 +1004,11 @@ parse_ia_pd_options(uint8_t *p, size_t len, struct prefix *prefix)
 
                        break;
                case DHO_STATUS_CODE:
-                       /*
-                        * XXX handle STATUS_CODE if not success
-                        * STATUS_CODE can also appear in other parts of
-                        * the packet.
-                        */
+                       /* XXX STATUS_CODE can also appear outside of options */
                        if (len < 2) {
                                log_warnx("%s: malformed packet, ignoring",
                                    __func__);
-                               return;
+                               return DHCP_STATUS_UNSPECFAIL;
                        }
                        memcpy(&status_code, p, sizeof(uint16_t));
                        status_code = ntohs(status_code);
@@ -1024,6 +1028,7 @@ parse_ia_pd_options(uint8_t *p, size_t len, struct prefix *prefix)
                p += opt_hdr.len;
                len -= opt_hdr.len;
        }
+       return status_code;
 }
 
 /* XXX check valid transitions */