X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Flibsystemd-network%2Fsd-dhcp-client.c;h=489220326e90843872e246b7956ced1e6a6b24bd;hp=4be37a2389fef27912004f17a141df3c87ced973;hb=6e00a80641aaba814204c65365c2fd5a90768394;hpb=eb105b96d58a3ebfeedb76a5d421b13748e0395c diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c index 4be37a238..489220326 100644 --- a/src/libsystemd-network/sd-dhcp-client.c +++ b/src/libsystemd-network/sd-dhcp-client.c @@ -230,7 +230,7 @@ static int client_initialize(sd_dhcp_client *client) { static sd_dhcp_client *client_stop(sd_dhcp_client *client, int error) { assert_return(client, NULL); - log_dhcp_client(client, "STOPPED %d", error); + log_dhcp_client(client, "STOPPED: %s", strerror(-error)); client = client_notify(client, error); @@ -242,6 +242,7 @@ static sd_dhcp_client *client_stop(sd_dhcp_client *client, int error) { static int client_message_init(sd_dhcp_client *client, DHCPMessage *message, uint8_t type, uint8_t **opt, size_t *optlen) { + be16_t max_size; int r; assert(client); @@ -249,6 +250,7 @@ static int client_message_init(sd_dhcp_client *client, DHCPMessage *message, assert(message); assert(opt); assert(optlen); + assert(type == DHCP_DISCOVER || type == DHCP_REQUEST); r = dhcp_message_init(message, BOOTREQUEST, client->xid, type, opt, optlen); @@ -259,12 +261,12 @@ static int client_message_init(sd_dhcp_client *client, DHCPMessage *message, refuse to issue an DHCP lease if 'secs' is set to zero */ message->secs = htobe16(client->secs); + /* RFC2132 section 4.1.1: + The client MUST include its hardware address in the ’chaddr’ field, if + necessary for delivery of DHCP reply messages. + */ memcpy(&message->chaddr, &client->client_id.mac_addr, ETH_ALEN); - if (client->state == DHCP_STATE_RENEWING || - client->state == DHCP_STATE_REBINDING) - message->ciaddr = client->lease->address; - /* Some DHCP servers will refuse to issue an DHCP lease if the Client Identifier option is not set */ r = dhcp_option_append(opt, optlen, DHCP_OPTION_CLIENT_IDENTIFIER, @@ -272,27 +274,37 @@ static int client_message_init(sd_dhcp_client *client, DHCPMessage *message, if (r < 0) return r; - if (type == DHCP_DISCOVER || type == DHCP_REQUEST) { - be16_t max_size; - r = dhcp_option_append(opt, optlen, - DHCP_OPTION_PARAMETER_REQUEST_LIST, - client->req_opts_size, - client->req_opts); - if (r < 0) - return r; + /* RFC2131 section 3.5: + in its initial DHCPDISCOVER or DHCPREQUEST message, a + client may provide the server with a list of specific + parameters the client is interested in. If the client + includes a list of parameters in a DHCPDISCOVER message, + it MUST include that list in any subsequent DHCPREQUEST + messages. + */ + r = dhcp_option_append(opt, optlen, + DHCP_OPTION_PARAMETER_REQUEST_LIST, + client->req_opts_size, + client->req_opts); + if (r < 0) + return r; - /* Some DHCP servers will send bigger DHCP packets than the - defined default size unless the Maximum Messge Size option - is explicitely set */ - max_size = htobe16(DHCP_IP_UDP_SIZE + DHCP_MESSAGE_SIZE + - DHCP_MIN_OPTIONS_SIZE); - r = dhcp_option_append(opt, optlen, - DHCP_OPTION_MAXIMUM_MESSAGE_SIZE, - 2, &max_size); - if (r < 0) - return r; - } + /* RFC2131 section 3.5: + The client SHOULD include the ’maximum DHCP message size’ option to + let the server know how large the server may make its DHCP messages. + + Note (from ConnMan): Some DHCP servers will send bigger DHCP packets + than the defined default size unless the Maximum Messge Size option + is explicitely set + */ + max_size = htobe16(DHCP_IP_UDP_SIZE + DHCP_MESSAGE_SIZE + + DHCP_MIN_OPTIONS_SIZE); + r = dhcp_option_append(opt, optlen, + DHCP_OPTION_MAXIMUM_MESSAGE_SIZE, + 2, &max_size); + if (r < 0) + return r; return 0; } @@ -314,6 +326,10 @@ static int client_send_discover(sd_dhcp_client *client) { int r; assert(client); + assert(client->state == DHCP_STATE_INIT || + client->state == DHCP_STATE_SELECTING); + + /* See RFC2131 section 4.4.1 */ r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now); if (r < 0) @@ -336,6 +352,12 @@ static int client_send_discover(sd_dhcp_client *client) { if (r < 0) return r; + /* the client may suggest values for the network address + and lease time in the DHCPDISCOVER message. The client may include + the ’requested IP address’ option to suggest that a particular IP + address be assigned, and may include the ’IP address lease time’ + option to suggest the lease time it would like. + */ if (client->last_addr != INADDR_ANY) { r = dhcp_option_append(&opt, &optlen, DHCP_OPTION_REQUESTED_IP_ADDRESS, @@ -348,6 +370,10 @@ static int client_send_discover(sd_dhcp_client *client) { if (r < 0) return r; + /* We currently ignore: + The client SHOULD wait a random time between one and ten seconds to + desynchronize the use of DHCP at startup. + */ r = dhcp_client_send_raw(client, discover, len - optlen); if (r < 0) return r; @@ -376,38 +402,64 @@ static int client_send_request(sd_dhcp_client *client) { return r; switch (client->state) { + /* See RFC2131 section 4.3.2 (note that there is a typo in the RFC, + SELECTING should be REQUESTING) + */ + + case DHCP_STATE_REQUESTING: + /* Client inserts the address of the selected server in ’server + identifier’, ’ciaddr’ MUST be zero, ’requested IP address’ MUST be + filled in with the yiaddr value from the chosen DHCPOFFER. + */ - case DHCP_STATE_INIT_REBOOT: r = dhcp_option_append(&opt, &optlen, - DHCP_OPTION_REQUESTED_IP_ADDRESS, - 4, &client->last_addr); + DHCP_OPTION_SERVER_IDENTIFIER, + 4, &client->lease->server_address); if (r < 0) return r; - break; - case DHCP_STATE_REQUESTING: r = dhcp_option_append(&opt, &optlen, DHCP_OPTION_REQUESTED_IP_ADDRESS, 4, &client->lease->address); if (r < 0) return r; + break; + + case DHCP_STATE_INIT_REBOOT: + /* ’server identifier’ MUST NOT be filled in, ’requested IP address’ + option MUST be filled in with client’s notion of its previously + assigned address. ’ciaddr’ MUST be zero. + */ r = dhcp_option_append(&opt, &optlen, - DHCP_OPTION_SERVER_IDENTIFIER, - 4, &client->lease->server_address); + DHCP_OPTION_REQUESTED_IP_ADDRESS, + 4, &client->last_addr); if (r < 0) return r; break; - case DHCP_STATE_INIT: - case DHCP_STATE_SELECTING: - case DHCP_STATE_REBOOTING: - case DHCP_STATE_BOUND: case DHCP_STATE_RENEWING: + /* ’server identifier’ MUST NOT be filled in, ’requested IP address’ + option MUST NOT be filled in, ’ciaddr’ MUST be filled in with + client’s IP address. + */ + + /* fall through */ case DHCP_STATE_REBINDING: + /* ’server identifier’ MUST NOT be filled in, ’requested IP address’ + option MUST NOT be filled in, ’ciaddr’ MUST be filled in with + client’s IP address. + + This message MUST be broadcast to the 0xffffffff IP broadcast address. + */ + request->dhcp.ciaddr = client->lease->address; break; + case DHCP_STATE_INIT: + case DHCP_STATE_SELECTING: + case DHCP_STATE_REBOOTING: + case DHCP_STATE_BOUND: case DHCP_STATE_STOPPED: return -EINVAL; } @@ -428,11 +480,29 @@ static int client_send_request(sd_dhcp_client *client) { if (r < 0) return r; - log_dhcp_client(client, "REQUEST"); + switch (client->state) { + case DHCP_STATE_REQUESTING: + log_dhcp_client(client, "REQUEST (requesting)"); + break; + case DHCP_STATE_INIT_REBOOT: + log_dhcp_client(client, "REQUEST (init-reboot)"); + break; + case DHCP_STATE_RENEWING: + log_dhcp_client(client, "REQUEST (renewing)"); + break; + case DHCP_STATE_REBINDING: + log_dhcp_client(client, "REQUEST (rebinding)"); + break; + default: + log_dhcp_client(client, "REQUEST (invalid)"); + break; + } return 0; } +static int client_start(sd_dhcp_client *client); + static int client_timeout_resend(sd_event_source *s, uint64_t usec, void *userdata) { sd_dhcp_client *client = userdata; @@ -471,17 +541,18 @@ static int client_timeout_resend(sd_event_source *s, uint64_t usec, case DHCP_STATE_REBOOTING: /* start over as we did not receive a timely ack or nak */ - client->state = DHCP_STATE_INIT; - client->attempt = 1; + r = client_initialize(client); + if (r < 0) + goto error; - client->fd = safe_close(client->fd); - client->xid = random_u32(); - r = dhcp_network_bind_raw_socket(client->index, &client->link, client->xid); + r = client_start(client); if (r < 0) goto error; - client->fd = r; + else { + log_dhcp_client(client, "REBOOTED"); + return 0; + } - /* fall through */ case DHCP_STATE_INIT: case DHCP_STATE_INIT_REBOOT: case DHCP_STATE_SELECTING: @@ -625,7 +696,6 @@ static int client_start(sd_dhcp_client *client) { client->xid = random_u32(); r = dhcp_network_bind_raw_socket(client->index, &client->link, client->xid); - if (r < 0) { client_stop(client, r); return r; @@ -637,8 +707,6 @@ static int client_start(sd_dhcp_client *client) { client->secs = 0; } - log_dhcp_client(client, "STARTED"); - return client_initialize_events(client, client_receive_message_raw); } @@ -674,11 +742,8 @@ static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata) client_stop(client, r); return 0; } - client->fd = r; - log_dhcp_client(client, "TIMEOUT T2"); - return client_initialize_events(client, client_receive_message_raw); } @@ -700,8 +765,6 @@ static int client_timeout_t1(sd_event_source *s, uint64_t usec, client->fd = r; - log_dhcp_client(client, "TIMEOUT T1"); - return client_initialize_events(client, client_receive_message_udp); } @@ -742,6 +805,7 @@ static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer, } } + sd_dhcp_lease_unref(client->lease); client->lease = lease; lease = NULL; @@ -1042,6 +1106,8 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, r = client_start(client); if (r < 0) goto error; + + log_dhcp_client(client, "REBOOTED"); } goto error; @@ -1196,7 +1262,11 @@ int sd_dhcp_client_start(sd_dhcp_client *client) { if (client->last_addr) client->state = DHCP_STATE_INIT_REBOOT; - return client_start(client); + r = client_start(client); + if (r >= 0) + log_dhcp_client(client, "STARTED"); + + return r; } int sd_dhcp_client_stop(sd_dhcp_client *client) { @@ -1261,6 +1331,8 @@ sd_dhcp_client *sd_dhcp_client_unref(sd_dhcp_client *client) { sd_dhcp_client_detach_event(client); + sd_dhcp_lease_unref(client->lease); + free(client->req_opts); free(client);