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=8205ad0e18e0bfb1b1525d8649a1f9ae9845879e;hp=aff4c21e95180f78302c2704d8af1f23608869a9;hb=615c1467c81411bf1d19fd7092e8995b5ebadc13;hpb=022446adf99b84c59a88c2e614033ccde13c395c diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c index aff4c21e9..8205ad0e1 100644 --- a/src/libsystemd-network/sd-dhcp-client.c +++ b/src/libsystemd-network/sd-dhcp-client.c @@ -22,11 +22,15 @@ #include #include #include +#include +#include #include #include #include "util.h" #include "list.h" +#include "refcnt.h" +#include "async.h" #include "dhcp-protocol.h" #include "dhcp-internal.h" @@ -34,6 +38,8 @@ #include "sd-dhcp-client.h" struct sd_dhcp_client { + RefCount n_ref; + DHCPState state; sd_event *event; int event_priority; @@ -42,6 +48,7 @@ struct sd_dhcp_client { int fd; union sockaddr_union link; sd_event_source *receive_message; + bool request_broadcast; uint8_t *req_opts; size_t req_opts_allocated; size_t req_opts_size; @@ -50,6 +57,8 @@ struct sd_dhcp_client { uint8_t type; struct ether_addr mac_addr; } _packed_ client_id; + char *hostname; + char *vendor_class_identifier; uint32_t xid; usec_t start_time; uint16_t secs; @@ -76,6 +85,7 @@ static int client_receive_message_raw(sd_event_source *s, int fd, uint32_t revents, void *userdata); static int client_receive_message_udp(sd_event_source *s, int fd, uint32_t revents, void *userdata); +static void client_stop(sd_dhcp_client *client, int error); int sd_dhcp_client_set_callback(sd_dhcp_client *client, sd_dhcp_client_cb_t cb, void *userdata) { @@ -87,11 +97,20 @@ int sd_dhcp_client_set_callback(sd_dhcp_client *client, sd_dhcp_client_cb_t cb, return 0; } +int sd_dhcp_client_set_request_broadcast(sd_dhcp_client *client, int broadcast) { + assert_return(client, -EINVAL); + + client->request_broadcast = !!broadcast; + + return 0; +} + 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: @@ -121,7 +140,8 @@ 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; @@ -133,8 +153,9 @@ 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(interface_index >= -1, -EINVAL); + assert_return (IN_SET(client->state, DHCP_STATE_INIT, + DHCP_STATE_STOPPED), -EBUSY); + assert_return(interface_index > 0, -EINVAL); client->index = interface_index; @@ -143,21 +164,66 @@ int sd_dhcp_client_set_index(sd_dhcp_client *client, int interface_index) { int sd_dhcp_client_set_mac(sd_dhcp_client *client, const struct ether_addr *addr) { + DHCP_CLIENT_DONT_DESTROY(client); + bool need_restart = false; + assert_return(client, -EINVAL); - assert_return(client->state == DHCP_STATE_INIT, -EBUSY); + assert_return(addr, -EINVAL); + + if (memcmp(&client->client_id.mac_addr, addr, ETH_ALEN) == 0) + return 0; - log_dhcp_client(client, "set MAC address to " - "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx", - addr->ether_addr_octet[0], - addr->ether_addr_octet[1], - addr->ether_addr_octet[2], - addr->ether_addr_octet[3], - addr->ether_addr_octet[4], - addr->ether_addr_octet[5]); + 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; + client_stop(client, DHCP_EVENT_STOP); + } memcpy(&client->client_id.mac_addr, addr, ETH_ALEN); client->client_id.type = 0x01; + if (need_restart && client->state != DHCP_STATE_STOPPED) + sd_dhcp_client_start(client); + + return 0; +} + +int sd_dhcp_client_set_hostname(sd_dhcp_client *client, + const char *hostname) { + char *new_hostname = NULL; + + assert_return(client, -EINVAL); + + if (streq_ptr(client->hostname, hostname)) + return 0; + + if (hostname) { + new_hostname = strdup(hostname); + if (!new_hostname) + return -ENOMEM; + } + + free(client->hostname); + client->hostname = new_hostname; + + return 0; +} + +int sd_dhcp_client_set_vendor_class_identifier(sd_dhcp_client *client, + const char *vci) { + char *new_vci = NULL; + + assert_return(client, -EINVAL); + + new_vci = strdup(vci); + if (!new_vci) + return -ENOMEM; + + free(client->vendor_class_identifier); + + client->vendor_class_identifier = new_vci; + return 0; } @@ -175,11 +241,9 @@ int sd_dhcp_client_get_lease(sd_dhcp_client *client, sd_dhcp_lease **ret) { return 0; } -static int client_notify(sd_dhcp_client *client, int event) { +static void client_notify(sd_dhcp_client *client, int event) { if (client->cb) client->cb(client, event, client->userdata); - - return 0; } static int client_initialize(sd_dhcp_client *client) { @@ -188,7 +252,7 @@ static int client_initialize(sd_dhcp_client *client) { client->receive_message = sd_event_source_unref(client->receive_message); - client->fd = safe_close(client->fd); + client->fd = asynchronous_close(client->fd); client->timeout_resend = sd_event_source_unref(client->timeout_resend); @@ -207,71 +271,113 @@ static int client_initialize(sd_dhcp_client *client) { return 0; } -static int client_stop(sd_dhcp_client *client, int error) { - assert_return(client, -EINVAL); +static void client_stop(sd_dhcp_client *client, int error) { + assert(client); + + if (error < 0) + log_dhcp_client(client, "STOPPED: %s", strerror(-error)); + else if (error == DHCP_EVENT_STOP) + log_dhcp_client(client, "STOPPED"); + else + log_dhcp_client(client, "STOPPED: Unknown event"); client_notify(client, error); client_initialize(client); - - log_dhcp_client(client, "STOPPED"); - - return 0; } -static int client_message_init(sd_dhcp_client *client, DHCPMessage *message, - uint8_t type, uint8_t **opt, size_t *optlen) { +static int client_message_init(sd_dhcp_client *client, DHCPPacket **ret, + uint8_t type, size_t *_optlen, size_t *_optoffset) { + _cleanup_free_ DHCPPacket *packet; + size_t optlen, optoffset, size; + be16_t max_size; int r; assert(client); assert(client->secs); - assert(message); - assert(opt); - assert(optlen); + assert(ret); + assert(_optlen); + assert(_optoffset); + assert(type == DHCP_DISCOVER || type == DHCP_REQUEST); + + optlen = DHCP_MIN_OPTIONS_SIZE; + size = sizeof(DHCPPacket) + optlen; - r = dhcp_message_init(message, BOOTREQUEST, client->xid, type, opt, - optlen); + packet = malloc0(size); + if (!packet) + return -ENOMEM; + + r = dhcp_message_init(&packet->dhcp, BOOTREQUEST, client->xid, type, + optlen, &optoffset); if (r < 0) return r; /* Although 'secs' field is a SHOULD in RFC 2131, certain DHCP servers refuse to issue an DHCP lease if 'secs' is set to zero */ - message->secs = htobe16(client->secs); - - 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; + packet->dhcp.secs = htobe16(client->secs); + + /* RFC2132 section 4.1 + A client that cannot receive unicast IP datagrams until its protocol + software has been configured with an IP address SHOULD set the + BROADCAST bit in the 'flags' field to 1 in any DHCPDISCOVER or + DHCPREQUEST messages that client sends. The BROADCAST bit will + provide a hint to the DHCP server and BOOTP relay agent to broadcast + any messages to the client on the client's subnet. + + Note: some interfaces needs this to be enabled, but some networks + needs this to be disabled as broadcasts are filteretd, so this + needs to be configurable */ + if (client->request_broadcast) + packet->dhcp.flags = htobe16(0x8000); + + /* 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(&packet->dhcp.chaddr, &client->client_id.mac_addr, ETH_ALEN); /* 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, + r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0, + DHCP_OPTION_CLIENT_IDENTIFIER, sizeof(client->client_id), &client->client_id); 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(&packet->dhcp, optlen, &optoffset, 0, + 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(size); + r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0, + DHCP_OPTION_MAXIMUM_MESSAGE_SIZE, + 2, &max_size); + if (r < 0) + return r; + + *_optlen = optlen; + *_optoffset = optoffset; + *ret = packet; + packet = NULL; return 0; } @@ -286,15 +392,18 @@ static int dhcp_client_send_raw(sd_dhcp_client *client, DHCPPacket *packet, } static int client_send_discover(sd_dhcp_client *client) { - _cleanup_free_ DHCPPacket *discover; - size_t optlen, len; - uint8_t *opt; + _cleanup_free_ DHCPPacket *discover = NULL; + size_t optoffset, optlen; usec_t time_now; int r; assert(client); + assert(client->state == DHCP_STATE_INIT || + client->state == DHCP_STATE_SELECTING); + + /* See RFC2131 section 4.4.1 */ - r = sd_event_get_now_monotonic(client->event, &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); @@ -303,31 +412,55 @@ static int client_send_discover(sd_dhcp_client *client) { * must always be strictly positive to deal with broken servers */ client->secs = ((time_now - client->start_time) / USEC_PER_SEC) ? : 1; - optlen = DHCP_MIN_OPTIONS_SIZE; - len = sizeof(DHCPPacket) + optlen; - - discover = malloc0(len); - if (!discover) - return -ENOMEM; - - r = client_message_init(client, &discover->dhcp, DHCP_DISCOVER, - &opt, &optlen); + r = client_message_init(client, &discover, DHCP_DISCOVER, + &optlen, &optoffset); 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, - 4, &client->last_addr); + r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0, + DHCP_OPTION_REQUESTED_IP_ADDRESS, + 4, &client->last_addr); if (r < 0) return r; } - r = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL); + /* it is unclear from RFC 2131 if client should send hostname in + DHCPDISCOVER but dhclient does and so we do as well + */ + if (client->hostname) { + r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0, + DHCP_OPTION_HOST_NAME, + strlen(client->hostname), client->hostname); + if (r < 0) + return r; + } + + if (client->vendor_class_identifier) { + r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0, + DHCP_OPTION_VENDOR_CLASS_IDENTIFIER, + strlen(client->vendor_class_identifier), + client->vendor_class_identifier); + if (r < 0) + return r; + } + + r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0, + DHCP_OPTION_END, 0, NULL); if (r < 0) return r; - r = dhcp_client_send_raw(client, discover, len - optlen); + /* 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, sizeof(DHCPPacket) + optoffset); if (r < 0) return r; @@ -337,58 +470,88 @@ static int client_send_discover(sd_dhcp_client *client) { } static int client_send_request(sd_dhcp_client *client) { - _cleanup_free_ DHCPPacket *request; - size_t optlen, len; - uint8_t *opt; + _cleanup_free_ DHCPPacket *request = NULL; + size_t optoffset, optlen; int r; - optlen = DHCP_MIN_OPTIONS_SIZE; - len = sizeof(DHCPPacket) + optlen; - - request = malloc0(len); - if (!request) - return -ENOMEM; - - r = client_message_init(client, &request->dhcp, DHCP_REQUEST, &opt, - &optlen); + r = client_message_init(client, &request, DHCP_REQUEST, + &optlen, &optoffset); if (r < 0) 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_INIT_REBOOT: - r = dhcp_option_append(&opt, &optlen, - DHCP_OPTION_REQUESTED_IP_ADDRESS, - 4, &client->last_addr); + 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. + */ + + r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0, + 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, + r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0, DHCP_OPTION_REQUESTED_IP_ADDRESS, 4, &client->lease->address); if (r < 0) return r; - r = dhcp_option_append(&opt, &optlen, - DHCP_OPTION_SERVER_IDENTIFIER, - 4, &client->lease->server_address); + 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(&request->dhcp, optlen, &optoffset, 0, + DHCP_OPTION_REQUESTED_IP_ADDRESS, + 4, &client->last_addr); if (r < 0) return r; break; + 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_RENEWING: - case DHCP_STATE_REBINDING: + case DHCP_STATE_STOPPED: + return -EINVAL; + } - break; + if (client->hostname) { + r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0, + DHCP_OPTION_HOST_NAME, + strlen(client->hostname), client->hostname); + if (r < 0) + return r; } - r = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL); + r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0, + DHCP_OPTION_END, 0, NULL); if (r < 0) return r; @@ -397,21 +560,40 @@ static int client_send_request(sd_dhcp_client *client) { client->lease->server_address, DHCP_PORT_SERVER, &request->dhcp, - len - optlen - DHCP_IP_UDP_SIZE); + sizeof(DHCPMessage) + optoffset); } else { - r = dhcp_client_send_raw(client, request, len - optlen); + r = dhcp_client_send_raw(client, request, sizeof(DHCPPacket) + optoffset); } 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; + DHCP_CLIENT_DONT_DESTROY(client); usec_t next_timeout = 0; uint64_t time_now; uint32_t time_left; @@ -421,7 +603,7 @@ static int client_timeout_resend(sd_event_source *s, uint64_t usec, assert(client); assert(client->event); - r = sd_event_get_now_monotonic(client->event, &time_now); + r = sd_event_now(client->event, clock_boottime_or_monotonic(), &time_now); if (r < 0) goto error; @@ -447,11 +629,18 @@ 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: @@ -464,17 +653,21 @@ 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); client->timeout_resend = sd_event_source_unref(client->timeout_resend); - r = sd_event_add_monotonic(client->event, - &client->timeout_resend, - next_timeout, - 10 * USEC_PER_MSEC, - client_timeout_resend, client); + r = sd_event_add_time(client->event, + &client->timeout_resend, + clock_boottime_or_monotonic(), + next_timeout, 10 * USEC_PER_MSEC, + client_timeout_resend, client); if (r < 0) goto error; @@ -522,6 +715,10 @@ 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; @@ -534,8 +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); @@ -552,11 +749,26 @@ 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_monotonic(client->event, - &client->timeout_resend, 0, 0, - client_timeout_resend, client); + r = sd_event_add_time(client->event, + &client->timeout_resend, + clock_boottime_or_monotonic(), + 0, 0, + client_timeout_resend, client); if (r < 0) goto error; @@ -571,6 +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; @@ -584,8 +804,7 @@ static int client_start(sd_dhcp_client *client) { client->xid = random_u32(); - r = dhcp_network_bind_raw_socket(client->index, &client->link); - + r = dhcp_network_bind_raw_socket(client->index, &client->link, client->xid, client->client_id.mac_addr); if (r < 0) { client_stop(client, r); return r; @@ -593,74 +812,61 @@ 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; } - log_dhcp_client(client, "STARTED"); - return client_initialize_events(client, client_receive_message_raw); } static int client_timeout_expire(sd_event_source *s, uint64_t usec, void *userdata) { sd_dhcp_client *client = userdata; + DHCP_CLIENT_DONT_DESTROY(client); log_dhcp_client(client, "EXPIRED"); client_notify(client, DHCP_EVENT_EXPIRED); - /* start over as the lease was lost */ - client_initialize(client); - client_start(client); + /* lease was lost, start over if not freed or stopped in callback */ + if (client->state != DHCP_STATE_STOPPED) { + client_initialize(client); + client_start(client); + } return 0; } static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata) { sd_dhcp_client *client = userdata; + DHCP_CLIENT_DONT_DESTROY(client); int r; client->receive_message = sd_event_source_unref(client->receive_message); - client->fd = safe_close(client->fd); + client->fd = asynchronous_close(client->fd); client->state = DHCP_STATE_REBINDING; client->attempt = 1; - r = dhcp_network_bind_raw_socket(client->index, &client->link); + r = dhcp_network_bind_raw_socket(client->index, &client->link, client->xid, client->client_id.mac_addr); if (r < 0) { client_stop(client, r); return 0; } - client->fd = r; - log_dhcp_client(client, "TIMEOUT T2"); - return client_initialize_events(client, client_receive_message_raw); } static int client_timeout_t1(sd_event_source *s, uint64_t usec, void *userdata) { sd_dhcp_client *client = userdata; - int r; + DHCP_CLIENT_DONT_DESTROY(client); client->state = DHCP_STATE_RENEWING; client->attempt = 1; - r = dhcp_network_bind_udp_socket(client->index, - client->lease->address, - DHCP_PORT_CLIENT); - if (r < 0) { - client_stop(client, r); - return 0; - } - - client->fd = r; - - log_dhcp_client(client, "TIMEOUT T1"); - - 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, @@ -673,8 +879,10 @@ static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer, return r; r = dhcp_option_parse(offer, len, dhcp_lease_parse_options, lease); - if (r != DHCP_OFFER) + if (r != DHCP_OFFER) { + log_dhcp_client(client, "receieved message was not an OFFER, ignoring"); return -ENOMSG; + } lease->next_server = offer->siaddr; @@ -682,10 +890,23 @@ static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer, if (lease->address == INADDR_ANY || lease->server_address == INADDR_ANY || - lease->subnet_mask == INADDR_ANY || - lease->lifetime == 0) + lease->lifetime == 0) { + log_dhcp_client(client, "receieved lease lacks address, server " + "address or lease lifetime, ignoring"); return -ENOMSG; + } + if (lease->subnet_mask == INADDR_ANY) { + r = dhcp_lease_set_default_subnet_mask(lease); + if (r < 0) { + log_dhcp_client(client, "receieved lease lacks subnet " + "mask, and a fallback one can not be " + "generated, ignoring"); + return -ENOMSG; + } + } + + sd_dhcp_lease_unref(client->lease); client->lease = lease; lease = NULL; @@ -694,6 +915,19 @@ static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer, return 0; } +static int client_handle_forcerenew(sd_dhcp_client *client, DHCPMessage *force, + size_t len) { + int r; + + r = dhcp_option_parse(force, len, NULL, NULL); + if (r != DHCP_FORCERENEW) + return -ENOMSG; + + log_dhcp_client(client, "FORCERENEW"); + + return 0; +} + static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack, size_t len) { _cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL; @@ -706,11 +940,13 @@ 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) + if (r != DHCP_ACK) { + log_dhcp_client(client, "receieved message was not an ACK, ignoring"); return -ENOMSG; + } lease->next_server = ack->siaddr; @@ -718,8 +954,21 @@ static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack, if (lease->address == INADDR_ANY || lease->server_address == INADDR_ANY || - lease->subnet_mask == INADDR_ANY || lease->lifetime == 0) + lease->lifetime == 0) { + log_dhcp_client(client, "receieved lease lacks address, server " + "address or lease lifetime, ignoring"); return -ENOMSG; + } + + if (lease->subnet_mask == INADDR_ANY) { + r = dhcp_lease_set_default_subnet_mask(lease); + if (r < 0) { + log_dhcp_client(client, "receieved lease lacks subnet " + "mask, and a fallback one can not be " + "generated, ignoring"); + return -ENOMSG; + } + } r = DHCP_EVENT_IP_ACQUIRE; if (client->lease) { @@ -727,7 +976,8 @@ static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack, client->lease->subnet_mask != lease->subnet_mask || client->lease->router != lease->router) { r = DHCP_EVENT_IP_CHANGE; - } + } else + r = DHCP_EVENT_RENEW; client->lease = sd_dhcp_lease_unref(client->lease); } @@ -771,7 +1021,7 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) { if (client->lease->lifetime == 0xffffffff) return 0; - r = sd_event_get_now_monotonic(client->event, &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); @@ -821,10 +1071,10 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) { } /* arm lifetime timeout */ - r = sd_event_add_monotonic(client->event, - &client->timeout_expire, lifetime_timeout, - 10 * USEC_PER_MSEC, - client_timeout_expire, client); + r = sd_event_add_time(client->event, &client->timeout_expire, + clock_boottime_or_monotonic(), + lifetime_timeout, 10 * USEC_PER_MSEC, + client_timeout_expire, client); if (r < 0) return r; @@ -842,11 +1092,12 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) { return 0; /* arm T2 timeout */ - r = sd_event_add_monotonic(client->event, - &client->timeout_t2, - t2_timeout, - 10 * USEC_PER_MSEC, - client_timeout_t2, client); + r = sd_event_add_time(client->event, + &client->timeout_t2, + clock_boottime_or_monotonic(), + t2_timeout, + 10 * USEC_PER_MSEC, + client_timeout_t2, client); if (r < 0) return r; @@ -864,11 +1115,11 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) { return 0; /* arm T1 timeout */ - r = sd_event_add_monotonic(client->event, - &client->timeout_t1, - t1_timeout, - 10 * USEC_PER_MSEC, - client_timeout_t1, client); + r = sd_event_add_time(client->event, + &client->timeout_t1, + clock_boottime_or_monotonic(), + t1_timeout, 10 * USEC_PER_MSEC, + client_timeout_t1, client); if (r < 0) return r; @@ -886,37 +1137,13 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) { static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, int len) { + DHCP_CLIENT_DONT_DESTROY(client); int r = 0, notify_event = 0; assert(client); assert(client->event); assert(message); - if (len < DHCP_MESSAGE_SIZE) { - log_dhcp_client(client, "message too small (%d bytes): " - "ignoring", len); - 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 (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: @@ -929,10 +1156,11 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, client->state = DHCP_STATE_REQUESTING; client->attempt = 1; - r = sd_event_add_monotonic(client->event, - &client->timeout_resend, 0, - 0, client_timeout_resend, - client); + r = sd_event_add_time(client->event, + &client->timeout_resend, + clock_boottime_or_monotonic(), + 0, 0, + client_timeout_resend, client); if (r < 0) goto error; @@ -940,7 +1168,9 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, client->event_priority); if (r < 0) goto error; - } + } else if (r == -ENOMSG) + /* invalid message, let's ignore it */ + return 0; break; @@ -950,25 +1180,6 @@ 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; - } - - goto error; - } - if (r >= 0) { client->timeout_resend = sd_event_source_unref(client->timeout_resend); @@ -988,30 +1199,72 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, if (r < 0) goto error; - if (notify_event) + 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 = safe_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 = 0; + 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; + + break; + + case DHCP_STATE_BOUND: + r = client_handle_forcerenew(client, message, len); + if (r >= 0) { + r = client_timeout_t1(NULL, 0, client); + if (r < 0) + goto error; + } else if (r == -ENOMSG) + /* invalid message, let's ignore it */ + return 0; break; case DHCP_STATE_INIT: case DHCP_STATE_INIT_REBOOT: - case DHCP_STATE_BOUND: break; + + case DHCP_STATE_STOPPED: + r = -EINVAL; + goto error; } error: - if (r < 0 || r == DHCP_EVENT_NO_LEASE) - return client_stop(client, r); + if (r < 0) + client_stop(client, r); - return 0; + return r; } static int client_receive_message_udp(sd_event_source *s, int fd, @@ -1024,16 +1277,58 @@ static int client_receive_message_udp(sd_event_source *s, int fd, assert(client); r = ioctl(fd, FIONREAD, &buflen); - if (r < 0 || buflen <= 0) - buflen = sizeof(DHCPMessage) + DHCP_MIN_OPTIONS_SIZE; + if (r < 0) + return r; + + if (buflen < 0) + /* this can't be right */ + return -EIO; message = malloc0(buflen); if (!message) return -ENOMEM; len = read(fd, message, buflen); - if (len < 0) + if (len < 0) { + log_dhcp_client(client, "could not receive message from UDP " + "socket: %m"); + return 0; + } 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 (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; + } + + if (client->state != DHCP_STATE_BOUND && + be32toh(message->xid) != client->xid) { + /* in BOUND state, we may receive FORCERENEW with xid set by server, + so ignore the xid in this case */ + log_dhcp_client(client, "received xid (%u) does not match " + "expected (%u): ignoring", + be32toh(message->xid), client->xid); + return 0; + } return client_handle_message(client, message, len); } @@ -1058,8 +1353,12 @@ static int client_receive_message_raw(sd_event_source *s, int fd, assert(client); r = ioctl(fd, FIONREAD, &buflen); - if (r < 0 || buflen <= 0) - buflen = sizeof(DHCPPacket) + DHCP_MIN_OPTIONS_SIZE; + if (r < 0) + return r; + + if (buflen < 0) + /* this can't be right */ + return -EIO; packet = malloc0(buflen); if (!packet) @@ -1071,13 +1370,16 @@ static int client_receive_message_raw(sd_event_source *s, int fd, len = recvmsg(fd, &msg, 0); if (len < 0) { log_dhcp_client(client, "could not receive message from raw " - "socket: %s", strerror(errno)); + "socket: %m"); + return 0; + } else if ((size_t)len < sizeof(DHCPPacket)) return 0; - } for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { - if (cmsg->cmsg_level == SOL_PACKET && cmsg->cmsg_type == PACKET_AUXDATA) { - struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg); + if (cmsg->cmsg_level == SOL_PACKET && + cmsg->cmsg_type == PACKET_AUXDATA && + cmsg->cmsg_len == CMSG_LEN(sizeof(struct tpacket_auxdata))) { + struct tpacket_auxdata *aux = (struct tpacket_auxdata*)CMSG_DATA(cmsg); checksum = !(aux->tp_status & TP_STATUS_CSUMNOTREADY); break; @@ -1105,11 +1407,24 @@ 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) { - return client_stop(client, DHCP_EVENT_STOP); + DHCP_CLIENT_DONT_DESTROY(client); + + assert_return(client, -EINVAL); + + client_stop(client, DHCP_EVENT_STOP); + client->state = DHCP_STATE_STOPPED; + + return 0; } int sd_dhcp_client_attach_event(sd_dhcp_client *client, sd_event *event, @@ -1147,22 +1462,37 @@ sd_event *sd_dhcp_client_get_event(sd_dhcp_client *client) { return client->event; } -void sd_dhcp_client_free(sd_dhcp_client *client) { - if (!client) - return; +sd_dhcp_client *sd_dhcp_client_ref(sd_dhcp_client *client) { + if (client) + assert_se(REFCNT_INC(client->n_ref) >= 2); - sd_dhcp_client_stop(client); - sd_dhcp_client_detach_event(client); - - free(client->req_opts); - free(client); + return client; } -DEFINE_TRIVIAL_CLEANUP_FUNC(sd_dhcp_client*, sd_dhcp_client_free); -#define _cleanup_dhcp_client_free_ _cleanup_(sd_dhcp_client_freep) +sd_dhcp_client *sd_dhcp_client_unref(sd_dhcp_client *client) { + if (client && REFCNT_DEC(client->n_ref) <= 0) { + log_dhcp_client(client, "FREE"); + + client_initialize(client); + + client->receive_message = + sd_event_source_unref(client->receive_message); + + sd_dhcp_client_detach_event(client); + + sd_dhcp_lease_unref(client->lease); + + free(client->req_opts); + free(client->hostname); + free(client->vendor_class_identifier); + free(client); + } + + return NULL; +} int sd_dhcp_client_new(sd_dhcp_client **ret) { - _cleanup_dhcp_client_free_ sd_dhcp_client *client = NULL; + _cleanup_dhcp_client_unref_ sd_dhcp_client *client = NULL; assert_return(ret, -EINVAL); @@ -1170,6 +1500,7 @@ int sd_dhcp_client_new(sd_dhcp_client **ret) { if (!client) return -ENOMEM; + client->n_ref = REFCNT_INIT; client->state = DHCP_STATE_INIT; client->index = -1; client->fd = -1;