chiark / gitweb /
sd-dhcp-client: listen on UDP socket as soon as a lease is acquired
[elogind.git] / src / libsystemd-network / sd-dhcp-client.c
index f7a4018540508d316a15f0e8ed8b9462ce36a2c4..68bce5e45959c7a9ca0878ecffeff76ecf7b4ef3 100644 (file)
@@ -276,19 +276,10 @@ static void client_stop(sd_dhcp_client *client, int error) {
 
         if (error < 0)
                 log_dhcp_client(client, "STOPPED: %s", strerror(-error));
-        else {
-                switch(error) {
-                case DHCP_EVENT_STOP:
-                        log_dhcp_client(client, "STOPPED");
-                        break;
-                case DHCP_EVENT_NO_LEASE:
-                        log_dhcp_client(client, "STOPPED: No lease");
-                        break;
-                default:
-                        log_dhcp_client(client, "STOPPED: Unknown reason");
-                        break;
-                }
-        }
+        else if (error == DHCP_EVENT_STOP)
+                log_dhcp_client(client, "STOPPED");
+        else
+                log_dhcp_client(client, "STOPPED: Unknown event");
 
         client_notify(client, error);
 
@@ -412,7 +403,7 @@ static int client_send_discover(sd_dhcp_client *client) {
 
         /* See RFC2131 section 4.4.1 */
 
-        r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now);
+        r = sd_event_now(client->event, clock_boottime_or_monotonic(), &time_now);
         if (r < 0)
                 return r;
         assert(time_now >= client->start_time);
@@ -612,7 +603,7 @@ static int client_timeout_resend(sd_event_source *s, uint64_t usec,
         assert(client);
         assert(client->event);
 
-        r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now);
+        r = sd_event_now(client->event, clock_boottime_or_monotonic(), &time_now);
         if (r < 0)
                 goto error;
 
@@ -674,7 +665,7 @@ static int client_timeout_resend(sd_event_source *s, uint64_t usec,
 
         r = sd_event_add_time(client->event,
                               &client->timeout_resend,
-                              CLOCK_MONOTONIC,
+                              clock_boottime_or_monotonic(),
                               next_timeout, 10 * USEC_PER_MSEC,
                               client_timeout_resend, client);
         if (r < 0)
@@ -740,8 +731,8 @@ error:
         return 0;
 }
 
-static int client_initialize_events(sd_dhcp_client *client,
-                                    sd_event_io_handler_t io_callback) {
+static int client_initialize_io_events(sd_dhcp_client *client,
+                                       sd_event_io_handler_t io_callback) {
         int r;
 
         assert(client);
@@ -758,11 +749,24 @@ static int client_initialize_events(sd_dhcp_client *client,
         if (r < 0)
                 goto error;
 
+error:
+        if (r < 0)
+                client_stop(client, r);
+
+        return 0;
+}
+
+static int client_initialize_time_events(sd_dhcp_client *client) {
+        int r;
+
+        assert(client);
+        assert(client->event);
+
         client->timeout_resend = sd_event_source_unref(client->timeout_resend);
 
         r = sd_event_add_time(client->event,
                               &client->timeout_resend,
-                              CLOCK_MONOTONIC,
+                              clock_boottime_or_monotonic(),
                               0, 0,
                               client_timeout_resend, client);
         if (r < 0)
@@ -779,6 +783,14 @@ error:
 
 }
 
+static int client_initialize_events(sd_dhcp_client *client,
+                                    sd_event_io_handler_t io_callback) {
+        client_initialize_io_events(client, io_callback);
+        client_initialize_time_events(client);
+
+        return 0;
+}
+
 static int client_start(sd_dhcp_client *client) {
         int r;
 
@@ -800,7 +812,7 @@ static int client_start(sd_dhcp_client *client) {
         client->fd = r;
 
         if (client->state == DHCP_STATE_INIT) {
-                client->start_time = now(CLOCK_MONOTONIC);
+                client->start_time = now(clock_boottime_or_monotonic());
                 client->secs = 0;
         }
 
@@ -855,16 +867,7 @@ static int client_timeout_t1(sd_event_source *s, uint64_t usec,
         client->state = DHCP_STATE_RENEWING;
         client->attempt = 1;
 
-        r = dhcp_network_bind_udp_socket(client->lease->address,
-                                         DHCP_PORT_CLIENT);
-        if (r < 0) {
-                log_dhcp_client(client, "could not bind UDP socket");
-                return 0;
-        }
-
-        client->fd = r;
-
-        return client_initialize_events(client, client_receive_message_udp);
+        return client_initialize_time_events(client);
 }
 
 static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer,
@@ -925,7 +928,7 @@ static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack,
         r = dhcp_option_parse(ack, len, dhcp_lease_parse_options, lease);
         if (r == DHCP_NAK) {
                 log_dhcp_client(client, "NAK");
-                return DHCP_EVENT_NO_LEASE;
+                return -EADDRNOTAVAIL;
         }
 
         if (r != DHCP_ACK) {
@@ -1006,7 +1009,7 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) {
         if (client->lease->lifetime == 0xffffffff)
                 return 0;
 
-        r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now);
+        r = sd_event_now(client->event, clock_boottime_or_monotonic(), &time_now);
         if (r < 0)
                 return r;
         assert(client->request_sent <= time_now);
@@ -1057,7 +1060,7 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) {
 
         /* arm lifetime timeout */
         r = sd_event_add_time(client->event, &client->timeout_expire,
-                              CLOCK_MONOTONIC,
+                              clock_boottime_or_monotonic(),
                               lifetime_timeout, 10 * USEC_PER_MSEC,
                               client_timeout_expire, client);
         if (r < 0)
@@ -1079,7 +1082,7 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) {
         /* arm T2 timeout */
         r = sd_event_add_time(client->event,
                               &client->timeout_t2,
-                              CLOCK_MONOTONIC,
+                              clock_boottime_or_monotonic(),
                               t2_timeout,
                               10 * USEC_PER_MSEC,
                               client_timeout_t2, client);
@@ -1102,7 +1105,7 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) {
         /* arm T1 timeout */
         r = sd_event_add_time(client->event,
                               &client->timeout_t1,
-                              CLOCK_MONOTONIC,
+                              clock_boottime_or_monotonic(),
                               t1_timeout, 10 * USEC_PER_MSEC,
                               client_timeout_t1, client);
         if (r < 0)
@@ -1129,35 +1132,6 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
         assert(client->event);
         assert(message);
 
-        if (be32toh(message->magic) != DHCP_MAGIC_COOKIE) {
-                log_dhcp_client(client, "not a DHCP message: ignoring");
-                return 0;
-        }
-
-        if (message->op != BOOTREPLY) {
-                log_dhcp_client(client, "not a BOOTREPLY message: ignoring");
-                return 0;
-        }
-
-        if (be32toh(message->xid) != client->xid) {
-                log_dhcp_client(client, "received xid (%u) does not match "
-                                "expected (%u): ignoring",
-                                be32toh(message->xid), client->xid);
-                return 0;
-        }
-
-        if (message->htype != ARPHRD_ETHER || message->hlen != ETHER_ADDR_LEN) {
-                log_dhcp_client(client, "not an ethernet packet");
-                return 0;
-        }
-
-        if (memcmp(&message->chaddr[0], &client->client_id.mac_addr,
-                   ETH_ALEN)) {
-                log_dhcp_client(client, "received chaddr does not match "
-                                "expected: ignoring");
-                return 0;
-        }
-
         switch (client->state) {
         case DHCP_STATE_SELECTING:
 
@@ -1172,7 +1146,7 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
 
                         r = sd_event_add_time(client->event,
                                               &client->timeout_resend,
-                                              CLOCK_MONOTONIC,
+                                              clock_boottime_or_monotonic(),
                                               0, 0,
                                               client_timeout_resend, client);
                         if (r < 0)
@@ -1194,25 +1168,7 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
         case DHCP_STATE_REBINDING:
 
                 r = client_handle_ack(client, message, len);
-                if (r == DHCP_EVENT_NO_LEASE) {
-
-                        client->timeout_resend =
-                                sd_event_source_unref(client->timeout_resend);
-
-                        if (client->state == DHCP_STATE_REBOOTING) {
-                                r = client_initialize(client);
-                                if (r < 0)
-                                        goto error;
-
-                                r = client_start(client);
-                                if (r < 0)
-                                        goto error;
-
-                                log_dhcp_client(client, "REBOOTED");
-                        }
-
-                        goto error;
-                } else if (r >= 0) {
+                if (r >= 0) {
                         client->timeout_resend =
                                 sd_event_source_unref(client->timeout_resend);
 
@@ -1231,15 +1187,39 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
                         if (r < 0)
                                 goto error;
 
+                        r = dhcp_network_bind_udp_socket(client->lease->address,
+                                                         DHCP_PORT_CLIENT);
+                        if (r < 0) {
+                                log_dhcp_client(client, "could not bind UDP socket");
+                                goto error;
+                        }
+
+                        client->fd = r;
+
+                        client_initialize_io_events(client, client_receive_message_udp);
+
                         if (notify_event) {
                                 client_notify(client, notify_event);
                                 if (client->state == DHCP_STATE_STOPPED)
                                         return 0;
                         }
 
-                        client->receive_message =
-                                sd_event_source_unref(client->receive_message);
-                        client->fd = asynchronous_close(client->fd);
+                } else if (r == -EADDRNOTAVAIL) {
+                        /* got a NAK, let's restart the client */
+                        client->timeout_resend =
+                                sd_event_source_unref(client->timeout_resend);
+
+                        r = client_initialize(client);
+                        if (r < 0)
+                                goto error;
+
+                        r = client_start(client);
+                        if (r < 0)
+                                goto error;
+
+                        log_dhcp_client(client, "REBOOTED");
+
+                        return 0;
                 } else if (r == -ENOMSG)
                         /* invalid message, let's ignore it */
                         return 0;
@@ -1258,7 +1238,7 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
         }
 
 error:
-        if (r < 0 || r == DHCP_EVENT_NO_LEASE)
+        if (r < 0)
                 client_stop(client, r);
 
         return r;
@@ -1290,8 +1270,39 @@ static int client_receive_message_udp(sd_event_source *s, int fd,
                 log_dhcp_client(client, "could not receive message from UDP "
                                 "socket: %m");
                 return 0;
-        } else if ((size_t)len < sizeof(DHCPMessage))
+        } else if ((size_t)len < sizeof(DHCPMessage)) {
+                log_dhcp_client(client, "too small to be a DHCP message: ignoring");
                 return 0;
+        }
+
+        if (be32toh(message->magic) != DHCP_MAGIC_COOKIE) {
+                log_dhcp_client(client, "not a DHCP message: ignoring");
+                return 0;
+        }
+
+        if (message->op != BOOTREPLY) {
+                log_dhcp_client(client, "not a BOOTREPLY message: ignoring");
+                return 0;
+        }
+
+        if (be32toh(message->xid) != client->xid) {
+                log_dhcp_client(client, "received xid (%u) does not match "
+                                "expected (%u): ignoring",
+                                be32toh(message->xid), client->xid);
+                return 0;
+        }
+
+        if (message->htype != ARPHRD_ETHER || message->hlen != ETHER_ADDR_LEN) {
+                log_dhcp_client(client, "not an ethernet packet");
+                return 0;
+        }
+
+        if (memcmp(&message->chaddr[0], &client->client_id.mac_addr,
+                   ETH_ALEN)) {
+                log_dhcp_client(client, "received chaddr does not match "
+                                "expected: ignoring");
+                return 0;
+        }
 
         return client_handle_message(client, message, len);
 }