(void) event_source_disable(client->timeout_t1);
(void) event_source_disable(client->timeout_t2);
(void) event_source_disable(client->timeout_expire);
- (void) event_source_disable(client->timeout_ipv6_only_mode);
}
static void client_initialize(sd_dhcp_client *client) {
assert(client);
assert(client->event);
- (void) event_source_disable(client->timeout_ipv6_only_mode);
-
return event_reset_time_relative(
client->event,
&client->timeout_resend,
return 0;
}
-static int client_enter_requesting_now(sd_dhcp_client *client) {
- assert(client);
-
- client_set_state(client, DHCP_STATE_REQUESTING);
- client->discover_attempt = 0;
- client->request_attempt = 0;
-
- return event_reset_time(client->event, &client->timeout_resend,
- CLOCK_BOOTTIME, 0, 0,
- client_timeout_resend, client,
- client->event_priority, "dhcp4-resend-timer",
- /* force_reset= */ true);
-}
-
-static int client_enter_requesting_delayed(sd_event_source *s, uint64_t usec, void *userdata) {
- sd_dhcp_client *client = ASSERT_PTR(userdata);
- DHCP_CLIENT_DONT_DESTROY(client);
- int r;
-
- r = client_enter_requesting_now(client);
- if (r < 0)
- client_stop(client, r);
-
- return 0;
-}
-
static int client_enter_requesting(sd_dhcp_client *client) {
assert(client);
assert(client->lease);
client_disable_event_sources(client);
- if (client->lease->ipv6_only_preferred_usec > 0) {
+ client_set_state(client, DHCP_STATE_REQUESTING);
+ client->discover_attempt = 0;
+ client->request_attempt = 0;
+
+ if (sd_dhcp_client_is_waiting_for_ipv6_connectivity(client)) {
if (client->ipv6_acquired) {
log_dhcp_client(client,
"Received an OFFER with IPv6-only preferred option, and the host already acquired IPv6 connectivity, stopping DHCPv4 client.");
log_dhcp_client(client,
"Received an OFFER with IPv6-only preferred option, delaying to send REQUEST with %s.",
FORMAT_TIMESPAN(client->lease->ipv6_only_preferred_usec, USEC_PER_SEC));
-
- return event_reset_time_relative(client->event, &client->timeout_ipv6_only_mode,
- CLOCK_BOOTTIME,
- client->lease->ipv6_only_preferred_usec, 0,
- client_enter_requesting_delayed, client,
- client->event_priority, "dhcp4-ipv6-only-mode-timer",
- /* force_reset= */ true);
}
- return client_enter_requesting_now(client);
+ return event_reset_time_relative(
+ client->event,
+ &client->timeout_resend,
+ CLOCK_BOOTTIME,
+ client->lease->ipv6_only_preferred_usec,
+ /* accuracy= */ 0,
+ client_timeout_resend,
+ client,
+ client->event_priority,
+ "dhcp4-resend-timer",
+ /* force_reset= */ true);
}
static bool lease_equal(const sd_dhcp_lease *a, const sd_dhcp_lease *b) {
return 0;
}
-static int client_enter_bound_now(sd_dhcp_client *client, int notify_event) {
+static int client_enter_bound(sd_dhcp_client *client, int notify_event) {
int r;
assert(client);
+ assert(client->lease);
if (IN_SET(client->state, DHCP_STATE_REQUESTING, DHCP_STATE_REBOOTING))
notify_event = SD_DHCP_CLIENT_EVENT_IP_ACQUIRE;
+ client_disable_event_sources(client);
+
+ client->start_delay = 0;
+
client_set_state(client, DHCP_STATE_BOUND);
client->discover_attempt = 0;
client->request_attempt = 0;
r = client_set_lease_timeouts(client);
if (r < 0)
- log_dhcp_client_errno(client, r, "could not set lease timeouts: %m");
+ log_dhcp_client_errno(client, r, "Failed to set lease timeouts: %m");
client_notify(client, notify_event);
return 0;
}
-static int client_enter_bound_delayed(sd_event_source *s, uint64_t usec, void *userdata) {
- sd_dhcp_client *client = ASSERT_PTR(userdata);
- DHCP_CLIENT_DONT_DESTROY(client);
- int r;
-
- r = client_enter_bound_now(client, SD_DHCP_CLIENT_EVENT_IP_ACQUIRE);
- if (r < 0)
- client_stop(client, r);
-
- return 0;
-}
-
-static int client_enter_bound(sd_dhcp_client *client, int notify_event) {
- assert(client);
- assert(client->lease);
-
- client_disable_event_sources(client);
-
- client->start_delay = 0;
-
- /* RFC 8925 section 3.2
- * If the client is in the INIT-REBOOT state, it SHOULD stop the DHCPv4 configuration process or
- * disable the IPv4 stack completely for V6ONLY_WAIT seconds or until the network attachment event,
- * whichever happens first.
- *
- * In the below, the condition uses REBOOTING, instead of INIT-REBOOT, as the client state has
- * already transitioned from INIT-REBOOT to REBOOTING after sending a DHCPREQUEST message. */
- if (client->state == DHCP_STATE_REBOOTING && client->lease->ipv6_only_preferred_usec > 0) {
- if (client->ipv6_acquired) {
- log_dhcp_client(client,
- "Received an ACK with IPv6-only preferred option, and the host already acquired IPv6 connectivity, stopping DHCPv4 client.");
- return sd_dhcp_client_stop(client);
- }
-
- log_dhcp_client(client,
- "Received an ACK with IPv6-only preferred option, delaying to enter bound state with %s.",
- FORMAT_TIMESPAN(client->lease->ipv6_only_preferred_usec, USEC_PER_SEC));
-
- return event_reset_time_relative(client->event, &client->timeout_ipv6_only_mode,
- CLOCK_BOOTTIME,
- client->lease->ipv6_only_preferred_usec, 0,
- client_enter_bound_delayed, client,
- client->event_priority, "dhcp4-ipv6-only-mode",
- /* force_reset= */ true);
- }
-
- return client_enter_bound_now(client, notify_event);
-}
-
static int client_restart(sd_dhcp_client *client) {
int r;
assert(client);
assert_return(client->event, -EINVAL);
assert_return(client->ifindex > 0, -EINVAL);
- /* Note, do not reset the flag in client_initialize(), as it is also called on expire. */
- client->ipv6_acquired = false;
-
/* If no client identifier exists, construct an RFC 4361-compliant one */
if (!sd_dhcp_client_id_is_set(&client->client_id)) {
r = sd_dhcp_client_set_iaid_duid_en(client, /* iaid_set= */ false, /* iaid= */ 0);
return 0;
}
+int sd_dhcp_client_is_waiting_for_ipv6_connectivity(sd_dhcp_client *client) {
+ /* Note that we intentionally do not implement the following behavior:
+ *
+ * RFC 8925, section 3.2:
+ * If the client is in the INIT-REBOOT state, it SHOULD stop the DHCPv4 configuration process or
+ * disable the IPv4 stack completely for V6ONLY_WAIT seconds or until the next network attachment
+ * event, whichever occurs first.
+ *
+ * Delaying the application of an acquired IPv4 address after DHCPACK introduces several issues:
+ *
+ * - If T1 is reached before the address is assigned to the interface, the client cannot send a
+ * unicast DHCPREQUEST during RENEWING.
+ *
+ * - If the client is stopped before the address is configured, it cannot send a DHCPRELEASE message,
+ * which also requires a valid source address.
+ *
+ * While these issues could be worked around, doing so would significantly complicate the
+ * implementation and violate assumptions in the DHCP state machine as defined in RFC 2131.
+ *
+ * Instead, we only honor the IPv6-Only Preferred delay (Option 108) in the REQUESTING state, i.e.
+ * before any DHCPREQUEST has been sent. */
+
+ return
+ client &&
+ client->state == DHCP_STATE_REQUESTING &&
+ client->request_attempt == 0 &&
+ client->lease &&
+ client->lease->ipv6_only_preferred_usec > 0;
+}
+
int sd_dhcp_client_set_ipv6_connectivity(sd_dhcp_client *client, int have) {
if (!client)
return 0;
- /* We have already received a message with IPv6-Only preferred option, and are waiting for IPv6
- * connectivity or timeout, let's stop the client. */
- if (have && sd_event_source_get_enabled(client->timeout_ipv6_only_mode, NULL) > 0)
- return sd_dhcp_client_stop(client);
-
- /* Otherwise, save that the host already has IPv6 connectivity. */
client->ipv6_acquired = have;
- return 0;
-}
-
-int sd_dhcp_client_interrupt_ipv6_only_mode(sd_dhcp_client *client) {
- assert_return(client, -EINVAL);
- assert_return(sd_dhcp_client_is_running(client), -ESTALE);
- if (sd_event_source_get_enabled(client->timeout_ipv6_only_mode, NULL) <= 0)
- return 0;
+ if (have && sd_dhcp_client_is_waiting_for_ipv6_connectivity(client)) {
+ log_dhcp_client(client,
+ "Acquired IPv6 connectivity before sending REQUEST, stopping DHCPv4 client.");
+ return sd_dhcp_client_stop(client);
+ }
- return client_start(client);
+ return 0;
}
int sd_dhcp_client_attach_event(sd_dhcp_client *client, sd_event *event, int64_t priority) {
sd_event_source_unref(client->timeout_t1);
sd_event_source_unref(client->timeout_t2);
sd_event_source_unref(client->timeout_expire);
- sd_event_source_unref(client->timeout_ipv6_only_mode);
sd_dhcp_client_detach_event(client);
projects / thirdparty / systemd.git / commitdiff
