File 0013-dhcp-4.2.x-dhcpv6-decline-on-DAD-failure.872609.patch of Package dhcp.24175
Author: Jiri Popelka <jpopelka@redhat.com>
References: bsc#872609, ISC-Bugs#21237
Upstream: yes
If the bound address failed DAD (is found to be in use on the link),
the dhcpv6 client sends a Decline message to the server as described
in section 18.1.7 of RFC-3315 (#559147)
(Submitted to dhcp-bugs@isc.org - [ISC-Bugs #26735])
diff --git a/client/dhc6.c b/client/dhc6.c
index 8974e7a..f8ad25d 100644
--- a/client/dhc6.c
+++ b/client/dhc6.c
@@ -96,6 +96,8 @@ void do_select6(void *input);
void do_refresh6(void *input);
static void do_release6(void *input);
static void start_bound(struct client_state *client);
+static void start_decline6(struct client_state *client);
+static void do_decline6(void *input);
static void start_informed(struct client_state *client);
void informed_handler(struct packet *packet, struct client_state *client);
void bound_handler(struct packet *packet, struct client_state *client);
@@ -2080,6 +2082,7 @@ start_release6(struct client_state *client)
cancel_timeout(do_select6, client);
cancel_timeout(do_refresh6, client);
cancel_timeout(do_release6, client);
+ cancel_timeout(do_decline6, client);
client->state = S_STOPPED;
/*
@@ -2713,6 +2716,7 @@ dhc6_check_reply(struct client_state *client, struct dhc6_lease *new)
break;
case S_STOPPED:
+ case S_DECLINED:
action = dhc6_stop_action;
break;
@@ -2814,6 +2818,7 @@ dhc6_check_reply(struct client_state *client, struct dhc6_lease *new)
break;
case S_STOPPED:
+ case S_DECLINED:
/* Nothing critical to do at this stage. */
break;
@@ -3804,17 +3809,23 @@ reply_handler(struct packet *packet, struct client_state *client)
cancel_timeout(do_select6, client);
cancel_timeout(do_refresh6, client);
cancel_timeout(do_release6, client);
+ cancel_timeout(do_decline6, client);
/* If this is in response to a Release/Decline, clean up and return. */
- if (client->state == S_STOPPED) {
- if (client->active_lease == NULL)
- return;
+ if ((client->state == S_STOPPED) ||
+ (client->state == S_DECLINED)) {
+
+ if (client->active_lease != NULL) {
+ dhc6_lease_destroy(&client->active_lease, MDL);
+ client->active_lease = NULL;
+ /* We should never wait for nothing!? */
+ if (stopping_finished())
+ exit(0);
+ }
+
+ if (client->state == S_DECLINED)
+ start_init6(client);
- dhc6_lease_destroy(&client->active_lease, MDL);
- client->active_lease = NULL;
- /* We should never wait for nothing!? */
- if (stopping_finished())
- exit(0);
return;
}
@@ -4342,7 +4353,11 @@ start_bound(struct client_state *client)
dhc6_marshall_values("new_", client, lease, ia, addr);
script_write_requested6(client);
- script_go(client);
+ // when script returns 3, DAD failed
+ if (script_go(client) == 3) {
+ start_decline6(client);
+ return;
+ }
}
/* XXX: maybe we should loop on the old values instead? */
@@ -4390,6 +4405,149 @@ start_bound(struct client_state *client)
dhc6_check_times(client);
}
+/*
+ * Decline addresses.
+ */
+void
+start_decline6(struct client_state *client)
+{
+ /* Cancel any pending transmissions */
+ cancel_timeout(do_confirm6, client);
+ cancel_timeout(do_select6, client);
+ cancel_timeout(do_refresh6, client);
+ cancel_timeout(do_release6, client);
+ cancel_timeout(do_decline6, client);
+ client->state = S_DECLINED;
+
+ if (client->active_lease == NULL)
+ return;
+
+ /* Set timers per RFC3315 section 18.1.7. */
+ client->IRT = DEC_TIMEOUT * 100;
+ client->MRT = 0;
+ client->MRC = DEC_MAX_RC;
+ client->MRD = 0;
+
+ dhc6_retrans_init(client);
+ client->v6_handler = reply_handler;
+
+ client->refresh_type = DHCPV6_DECLINE;
+ do_decline6(client);
+}
+
+/*
+ * do_decline6() creates a Decline packet and transmits it.
+ */
+static void
+do_decline6(void *input)
+{
+ struct client_state *client;
+ struct data_string ds;
+ int send_ret;
+ struct timeval elapsed, tv;
+
+ client = input;
+
+ if ((client->active_lease == NULL) || !active_prefix(client))
+ return;
+
+ if ((client->MRC != 0) && (client->txcount > client->MRC)) {
+ log_info("Max retransmission count exceeded.");
+ goto decline_done;
+ }
+
+ /*
+ * Start_time starts at the first transmission.
+ */
+ if (client->txcount == 0) {
+ client->start_time.tv_sec = cur_tv.tv_sec;
+ client->start_time.tv_usec = cur_tv.tv_usec;
+ }
+
+ /* elapsed = cur - start */
+ elapsed.tv_sec = cur_tv.tv_sec - client->start_time.tv_sec;
+ elapsed.tv_usec = cur_tv.tv_usec - client->start_time.tv_usec;
+ if (elapsed.tv_usec < 0) {
+ elapsed.tv_sec -= 1;
+ elapsed.tv_usec += 1000000;
+ }
+
+ memset(&ds, 0, sizeof(ds));
+ if (!buffer_allocate(&ds.buffer, 4, MDL)) {
+ log_error("Unable to allocate memory for Decline.");
+ goto decline_done;
+ }
+
+ ds.data = ds.buffer->data;
+ ds.len = 4;
+ ds.buffer->data[0] = DHCPV6_DECLINE;
+ memcpy(ds.buffer->data + 1, client->dhcpv6_transaction_id, 3);
+
+ /* Form an elapsed option. */
+ /* Maximum value is 65535 1/100s coded as 0xffff. */
+ if ((elapsed.tv_sec < 0) || (elapsed.tv_sec > 655) ||
+ ((elapsed.tv_sec == 655) && (elapsed.tv_usec > 350000))) {
+ client->elapsed = 0xffff;
+ } else {
+ client->elapsed = elapsed.tv_sec * 100;
+ client->elapsed += elapsed.tv_usec / 10000;
+ }
+
+ client->elapsed = htons(client->elapsed);
+
+ log_debug("XMT: Forming Decline.");
+ make_client6_options(client, &client->sent_options,
+ client->active_lease, DHCPV6_DECLINE);
+ dhcpv6_universe.encapsulate(&ds, NULL, NULL, client, NULL,
+ client->sent_options, &global_scope,
+ &dhcpv6_universe);
+
+ /* Append IA's (but don't release temporary addresses). */
+ if (wanted_ia_na &&
+ dhc6_add_ia_na(client, &ds, client->active_lease,
+ DHCPV6_DECLINE) != ISC_R_SUCCESS) {
+ data_string_forget(&ds, MDL);
+ goto decline_done;
+ }
+ if (wanted_ia_pd &&
+ dhc6_add_ia_pd(client, &ds, client->active_lease,
+ DHCPV6_DECLINE) != ISC_R_SUCCESS) {
+ data_string_forget(&ds, MDL);
+ goto decline_done;
+ }
+
+ /* Transmit and wait. */
+ log_info("XMT: Decline on %s, interval %ld0ms.",
+ client->name ? client->name : client->interface->name,
+ (long int)client->RT);
+
+ send_ret = send_packet6(client->interface, ds.data, ds.len,
+ &DHCPv6DestAddr);
+ if (send_ret != ds.len) {
+ log_error("dhc6: sendpacket6() sent %d of %d bytes",
+ send_ret, ds.len);
+ }
+
+ data_string_forget(&ds, MDL);
+
+ /* Wait RT */
+ tv.tv_sec = cur_tv.tv_sec + client->RT / 100;
+ tv.tv_usec = cur_tv.tv_usec + (client->RT % 100) * 10000;
+ if (tv.tv_usec >= 1000000) {
+ tv.tv_sec += 1;
+ tv.tv_usec -= 1000000;
+ }
+ add_timeout(&tv, do_decline6, client, NULL, NULL);
+ dhc6_retrans_advance(client);
+ return;
+
+decline_done:
+ dhc6_lease_destroy(&client->active_lease, MDL);
+ client->active_lease = NULL;
+ start_init6(client);
+ return;
+}
+
/* While bound, ignore packets. In the future we'll want to answer
* Reconfigure-Request messages and the like.
*/
diff --git a/includes/dhcpd.h b/includes/dhcpd.h
index a52992b..0eda51d 100644
--- a/includes/dhcpd.h
+++ b/includes/dhcpd.h
@@ -1060,7 +1060,8 @@ enum dhcp_state {
S_BOUND = 5,
S_RENEWING = 6,
S_REBINDING = 7,
- S_STOPPED = 8
+ S_STOPPED = 8,
+ S_DECLINED = 9
};
/* Authentication and BOOTP policy possibilities (not all values work