From 5a3cdc27c8846e49d7fe0446642959fc8813833a Mon Sep 17 00:00:00 2001 From: Beniamino Galvani Date: Mon, 24 Feb 2020 09:55:13 +0100 Subject: n-dhcp4: keep trying after a failure in send() Currently if an error is encountered during a send() of a message, the client fails and there is no possibility of recover, since no timers are armed after a failed event dispatch. An easy way to reproduce a failure is to add a firewall rule like: iptables -A OUTPUT -p udp --dport 67 -j REJECT which makes the send() fail with EPERM during the renew. In such case, the client should continue (failing) until it reaches the rebind phase at T2, when it will be able to renew the lease using the packet socket. In general, a failure to send a packet should not cause the failure of the client. --- shared/n-dhcp4/src/n-dhcp4-c-connection.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/shared/n-dhcp4/src/n-dhcp4-c-connection.c b/shared/n-dhcp4/src/n-dhcp4-c-connection.c index d4354467d1..a5c8ea66fe 100644 --- a/shared/n-dhcp4/src/n-dhcp4-c-connection.c +++ b/shared/n-dhcp4/src/n-dhcp4-c-connection.c @@ -1006,6 +1006,7 @@ static int n_dhcp4_c_connection_send_request(NDhcp4CConnection *connection, uint64_t timestamp) { char server_addr[INET_ADDRSTRLEN]; char client_addr[INET_ADDRSTRLEN]; + char error_msg[128]; int r; bool broadcast = false; @@ -1045,45 +1046,45 @@ static int n_dhcp4_c_connection_send_request(NDhcp4CConnection *connection, case N_DHCP4_C_MESSAGE_REBIND: broadcast = true; r = n_dhcp4_c_connection_packet_broadcast(connection, request); - if (r) - return r; break; case N_DHCP4_C_MESSAGE_INFORM: broadcast = true; r = n_dhcp4_c_connection_udp_broadcast(connection, request); - if (r) - return r; - break; case N_DHCP4_C_MESSAGE_RENEW: case N_DHCP4_C_MESSAGE_RELEASE: r = n_dhcp4_c_connection_udp_send(connection, request); - if (r) - return r; - break; default: c_assert(0); } + if (r) { + snprintf(error_msg, sizeof(error_msg), ": error %d", r); + } else { + error_msg[0] = '\0'; + } + if (request->userdata.client_addr == INADDR_ANY) { n_dhcp4_c_log(connection->client_config, LOG_INFO, - "sent %s to %s", + "send %s to %s%s", message_type_to_str(request->userdata.message_type), broadcast ? "255.255.255.255" : inet_ntop(AF_INET, &connection->server_ip, - server_addr, sizeof(server_addr))); + server_addr, sizeof(server_addr)), + error_msg); } else { n_dhcp4_c_log(connection->client_config, LOG_INFO, - "sent %s of %s to %s", + "send %s of %s to %s%s", message_type_to_str(request->userdata.message_type), inet_ntop(AF_INET, &request->userdata.client_addr, client_addr, sizeof(client_addr)), broadcast ? "255.255.255.255" : inet_ntop(AF_INET, &connection->server_ip, - server_addr, sizeof(server_addr))); + server_addr, sizeof(server_addr)), + error_msg); } ++request->userdata.n_send; -- cgit v1.2.1