Merge branch 'lukeshu/linkdown'HEADmain

2 files changed, 55 insertions, 11 deletions

diff --git a/libdhcp/dhcp_client.c b/libdhcp/dhcp_client.c
index 359bd9f..208bc1c 100644
--- a/libdhcp/dhcp_client.c
+++ b/libdhcp/dhcp_client.c
@@ -461,10 +461,8 @@ static error dhcp_client_send(struct dhcp_client *client, uint8_t msgtyp, const
 	log_debugln("state ", state_strs[client->state], ": sending DHCP ", dhcp_msgtyp_str(msgtyp));
 	error err = LO_CALL(client->sock, sendto, scratch_msg, DHCP_MSG_BASE_SIZE + optlen,
 	                     client_broadcasts ? net_ip4_addr_broadcast : client->lease_server_id, DHCP_PORT_SERVER);
-	if (!ERROR_IS_NULL(err)) {
-		log_debugln("error: sendto: ", (error, err));
+	if (!ERROR_IS_NULL(err))
 		return err;
-	}
 	client->last_sent_msgtyp = msgtyp;
 	return ERROR_NULL;
 }
@@ -573,7 +571,6 @@ static error dhcp_client_recv(struct dhcp_client *client, struct dhcp_recv_msg *
  ignore:
 	size_t_or_error r = LO_CALL(client->sock, recvfrom, &ret->raw, sizeof(ret->raw), &srv_addr, &srv_port);
 	if (r.is_err)
-		/* msg_len is -errno */
 		return r.err;
 	msg_len = r.size_t;
 
@@ -743,8 +740,15 @@ static void dhcp_client_setstate(struct dhcp_client *client,
                                  uint8_t send_msgtyp, const char *errstr, struct dhcp_recv_msg *scratch_msg) {
 	if (send_msgtyp) {
 		error err = dhcp_client_send(client, send_msgtyp, errstr, &scratch_msg->raw);
+		if (!ERROR_IS_NULL(err)) {
+			log_errorln("error: sendto: ", (error, err));
+			if (err.num == E_POSIX_ENETDOWN)
+				newstate = STATE_INIT;
+		}
 		error_cleanup(&err);
 	}
+	if (newstate == STATE_INIT)
+		LO_CALL(client->iface, ifcfg, (struct net_iface_config){});
 	client->state = newstate;
 }
 
@@ -757,6 +761,17 @@ static void dhcp_client_setstate(struct dhcp_client *client,
 		log_debugln("loop: state=", state_strs[client->state]);
 		switch (client->state) {
 		case STATE_INIT:
+			log_debugln("state ", state_strs[client->state], ": wait for link up");
+			uint64_t start = LO_CALL(bootclock, get_time_ns);
+			LO_CALL(client->iface, wait_for_link_up);
+			uint64_t end = LO_CALL(bootclock, get_time_ns);
+			log_debugln("state ", state_strs[client->state], ": link up after ", (duration, end-start));
+			/* Just because we've processed link-up on our end
+			 * doesn't mean the router has; 500ms now is better than
+			 * the REQUEST packet getting dropped and us having to
+			 * wait an entire CONFIG_DHCP_SELECTING_NS before
+			 * realizing it.  */
+			sleep_for_ms(500);
 			client->xid = rand_uint32();
 			client->time_ns_init = LO_CALL(bootclock, get_time_ns);
 			dhcp_client_setstate(client, STATE_SELECTING, DHCP_MSGTYP_DISCOVER, NULL, scratch_msg);
@@ -776,10 +791,15 @@ static void dhcp_client_setstate(struct dhcp_client *client,
 				}
 				break;
 			case E_NET_ERECV_TIMEOUT:
+				log_errorln("error: recvfrom: ", (error, err), " (action: reset to state=INIT)");
+				dhcp_client_setstate(client, STATE_INIT, 0, NULL, scratch_msg);
+				break;
+			case E_POSIX_ENETDOWN:
+				log_errorln("error: recvfrom: ", (error, err), " (action: reset to state=INIT)");
 				dhcp_client_setstate(client, STATE_INIT, 0, NULL, scratch_msg);
 				break;
 			default:
-				log_debugln("error: recvfrom: ", (error, err));
+				log_errorln("error: recvfrom: ", (error, err), " (action: ignore)");
 			}
 			break;
 		case STATE_REQUESTING:
@@ -803,8 +823,12 @@ static void dhcp_client_setstate(struct dhcp_client *client,
 					/* ignore */
 				}
 				break;
+			case E_POSIX_ENETDOWN:
+				log_errorln("error: recvfrom: ", (error, err), " (action: reset to state=INIT)");
+				dhcp_client_setstate(client, STATE_INIT, 0, NULL, scratch_msg);
+				break;
 			default:
-				log_debugln("error: recvfrom: ", (error, err));
+				log_errorln("error: recvfrom: ", (error, err), " (action: ignore)");
 			}
 			break;
 		case STATE_BOUND:
@@ -814,10 +838,15 @@ static void dhcp_client_setstate(struct dhcp_client *client,
 				/* discard */
 				break;
 			case E_NET_ERECV_TIMEOUT:
+				/* Not logging the error here is intentional.  */
 				dhcp_client_setstate(client, STATE_RENEWING, DHCP_MSGTYP_REQUEST, NULL, scratch_msg);
 				break;
+			case E_POSIX_ENETDOWN:
+				log_errorln("error: recvfrom: ", (error, err), " (action: reset to state=INIT)");
+				dhcp_client_setstate(client, STATE_INIT, 0, NULL, scratch_msg);
+				break;
 			default:
-				log_debugln("error: recvfrom: ", (error, err));
+				log_errorln("error: recvfrom: ", (error, err), " (action: ignore)");
 			}
 			break;
 		case STATE_RENEWING:
@@ -841,11 +870,16 @@ static void dhcp_client_setstate(struct dhcp_client *client,
 				}
 				break;
 			case E_NET_ERECV_TIMEOUT:
+				log_errorln("error: recvfrom: ", (error, err), " (action: forget server, set state=REBINDING)");
 				client->lease_server_id = net_ip4_addr_zero;
 				dhcp_client_setstate(client, STATE_REBINDING, DHCP_MSGTYP_REQUEST, NULL, scratch_msg);
 				break;
+			case E_POSIX_ENETDOWN:
+				log_errorln("error: recvfrom: ", (error, err), " (action: reset to state=INIT)");
+				dhcp_client_setstate(client, STATE_INIT, 0, NULL, scratch_msg);
+				break;
 			default:
-				log_debugln("error: recvfrom: ", (error, err));
+				log_errorln("error: recvfrom: ", (error, err), " (action: ignore)");
 			}
 			break;
 		case STATE_REBINDING:
@@ -866,11 +900,15 @@ static void dhcp_client_setstate(struct dhcp_client *client,
 				}
 				break;
 			case E_NET_ERECV_TIMEOUT:
-				LO_CALL(client->iface, ifcfg, (struct net_iface_config){});
-				dhcp_client_setstate(client, STATE_BOUND, 0, NULL, scratch_msg);
+				log_errorln("error: recvfrom: ", (error, err), " (action: reset to state=INIT)");
+				dhcp_client_setstate(client, STATE_INIT, 0, NULL, scratch_msg);
+				break;
+			case E_POSIX_ENETDOWN:
+				log_errorln("error: recvfrom: ", (error, err), " (action: reset to state=INIT)");
+				dhcp_client_setstate(client, STATE_INIT, 0, NULL, scratch_msg);
 				break;
 			default:
-				log_debugln("error: recvfrom: ", (error, err));
+				log_errorln("error: recvfrom: ", (error, err), " (action: ignore)");
 			}
 			break;
 		case STATE_INIT_REBOOT:
diff --git a/libdhcp/tests/test_client.c b/libdhcp/tests/test_client.c
index 772d778..0112e76 100644
--- a/libdhcp/tests/test_client.c
+++ b/libdhcp/tests/test_client.c
@@ -99,6 +99,12 @@ static void test_ifcfg(struct test_iface *LM_UNUSED(self), struct net_iface_conf
 	cr_exit();
 }
 
+static bool test_is_link_up(struct test_iface *LM_UNUSED(self)) {
+	return true;
+}
+
+static void test_wait_for_link_up(struct test_iface *LM_UNUSED(self)) {}
+
 static bool test_arp_ping(struct test_iface *LM_UNUSED(self), struct net_ip4_addr LM_UNUSED(addr)) {
 	return false;
 }