X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Flibsystemd-network%2Fsd-dhcp-client.c;h=854c6711a8f82cd35ee82e53fad85edd79c6630c;hp=512bc9368df56e55f029a9dc1f54d766655c66f3;hb=6317519517210f703e20dc846b31d018845244cd;hpb=e5b04c8de83aa17e324bae95f18a822931fb8078 diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c index 512bc9368..854c6711a 100644 --- a/src/libsystemd-network/sd-dhcp-client.c +++ b/src/libsystemd-network/sd-dhcp-client.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -96,7 +97,8 @@ int sd_dhcp_client_set_request_option(sd_dhcp_client *client, uint8_t option) { size_t i; assert_return(client, -EINVAL); - assert_return (client->state == DHCP_STATE_INIT, -EBUSY); + assert_return (IN_SET(client->state, DHCP_STATE_INIT, + DHCP_STATE_STOPPED), -EBUSY); switch(option) { case DHCP_OPTION_PAD: @@ -126,7 +128,8 @@ int sd_dhcp_client_set_request_option(sd_dhcp_client *client, uint8_t option) { int sd_dhcp_client_set_request_address(sd_dhcp_client *client, const struct in_addr *last_addr) { assert_return(client, -EINVAL); - assert_return(client->state == DHCP_STATE_INIT, -EBUSY); + assert_return (IN_SET(client->state, DHCP_STATE_INIT, + DHCP_STATE_STOPPED), -EBUSY); if (last_addr) client->last_addr = last_addr->s_addr; @@ -138,7 +141,8 @@ int sd_dhcp_client_set_request_address(sd_dhcp_client *client, int sd_dhcp_client_set_index(sd_dhcp_client *client, int interface_index) { assert_return(client, -EINVAL); - assert_return(client->state == DHCP_STATE_INIT, -EBUSY); + assert_return (IN_SET(client->state, DHCP_STATE_INIT, + DHCP_STATE_STOPPED), -EBUSY); assert_return(interface_index >= -1, -EINVAL); client->index = interface_index; @@ -156,7 +160,7 @@ int sd_dhcp_client_set_mac(sd_dhcp_client *client, if (memcmp(&client->client_id.mac_addr, addr, ETH_ALEN) == 0) return 0; - if (client->state != DHCP_STATE_INIT) { + if (!IN_SET(client->state, DHCP_STATE_INIT, DHCP_STATE_STOPPED)) { log_dhcp_client(client, "Changing MAC address on running DHCP " "client, restarting"); need_restart = true; @@ -169,7 +173,7 @@ int sd_dhcp_client_set_mac(sd_dhcp_client *client, memcpy(&client->client_id.mac_addr, addr, ETH_ALEN); client->client_id.type = 0x01; - if (need_restart) + if (need_restart && client->state != DHCP_STATE_STOPPED) sd_dhcp_client_start(client); return 0; @@ -227,7 +231,7 @@ 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); @@ -239,6 +243,7 @@ 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); @@ -246,6 +251,7 @@ 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); @@ -256,12 +262,12 @@ 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, @@ -269,27 +275,37 @@ 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; } @@ -311,6 +327,10 @@ 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) @@ -333,6 +353,12 @@ 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, @@ -345,6 +371,10 @@ 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; @@ -373,37 +403,66 @@ 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; } r = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL); @@ -422,11 +481,29 @@ 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; @@ -465,11 +542,18 @@ 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; - client->xid = random_u32(); + r = client_initialize(client); + if (r < 0) + goto error; + + r = client_start(client); + if (r < 0) + goto error; + else { + log_dhcp_client(client, "REBOOTED"); + return 0; + } - /* fall through */ case DHCP_STATE_INIT: case DHCP_STATE_INIT_REBOOT: case DHCP_STATE_SELECTING: @@ -482,6 +566,10 @@ static int client_timeout_resend(sd_event_source *s, uint64_t usec, next_timeout = time_now + (client->attempt - 1) * USEC_PER_SEC; break; + + case DHCP_STATE_STOPPED: + r = -EINVAL; + goto error; } next_timeout += (random_u32() & 0x1fffff); @@ -540,6 +628,10 @@ static int client_timeout_resend(sd_event_source *s, uint64_t usec, case DHCP_STATE_BOUND: break; + + case DHCP_STATE_STOPPED: + r = -EINVAL; + goto error; } return 0; @@ -605,7 +697,6 @@ 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; @@ -617,8 +708,6 @@ 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); } @@ -630,8 +719,8 @@ static int client_timeout_expire(sd_event_source *s, uint64_t usec, client = client_notify(client, DHCP_EVENT_EXPIRED); - /* lease was lost, start over if not freed */ - if (client) { + /* lease was lost, start over if not freed or stopped in callback */ + if (client && client->state != DHCP_STATE_STOPPED) { client_initialize(client); client_start(client); } @@ -654,11 +743,8 @@ 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); } @@ -680,8 +766,6 @@ 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); } @@ -722,6 +806,7 @@ static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer, } } + sd_dhcp_lease_unref(client->lease); client->lease = lease; lease = NULL; @@ -1022,6 +1107,8 @@ 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; @@ -1046,7 +1133,8 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, if (notify_event) { client = client_notify(client, notify_event); - if (!client) + if (!client || + client->state == DHCP_STATE_STOPPED) return 0; } @@ -1064,6 +1152,10 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, case DHCP_STATE_BOUND: break; + + case DHCP_STATE_STOPPED: + r = -EINVAL; + goto error; } error: @@ -1171,13 +1263,20 @@ 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 on ifindex %u with address %s", + client->index, + ether_ntoa(&client->client_id.mac_addr)); + + return r; } int sd_dhcp_client_stop(sd_dhcp_client *client) { assert_return(client, -EINVAL); - client_stop(client, DHCP_EVENT_STOP); + if (client_stop(client, DHCP_EVENT_STOP)) + client->state = DHCP_STATE_STOPPED; return 0; } @@ -1235,6 +1334,8 @@ 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);