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=392e294ae43e27fe404c30c03542347e201eb99b;hp=6e35ef403b81d7641b7c007f11fbea08eafbd302;hb=48a4612e6b67ae81b93ee8e8a4b3f8efa5324270;hpb=58ec2d3e6e7d2274f5bb5cb64b936f1dbac45168 diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c index 6e35ef403..392e294ae 100644 --- a/src/libsystemd-network/sd-dhcp-client.c +++ b/src/libsystemd-network/sd-dhcp-client.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include @@ -143,21 +144,27 @@ 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) { + 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 (client->state != DHCP_STATE_INIT) { + log_dhcp_client(client, "Changing MAC address on running DHCP " + "client, restarting"); + sd_dhcp_client_stop(client); + need_restart = true; + } memcpy(&client->client_id.mac_addr, addr, ETH_ALEN); client->client_id.type = 0x01; + if (need_restart) + sd_dhcp_client_start(client); + return 0; } @@ -286,7 +293,7 @@ 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; + _cleanup_free_ DHCPPacket *discover = NULL; size_t optlen, len; uint8_t *opt; usec_t time_now; @@ -294,7 +301,7 @@ static int client_send_discover(sd_dhcp_client *client) { assert(client); - r = sd_event_get_now_monotonic(client->event, &time_now); + r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now); if (r < 0) return r; assert(time_now >= client->start_time); @@ -421,7 +428,7 @@ 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_MONOTONIC, &time_now); if (r < 0) goto error; @@ -470,11 +477,11 @@ static int client_timeout_resend(sd_event_source *s, uint64_t usec, 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_MONOTONIC, + next_timeout, 10 * USEC_PER_MSEC, + client_timeout_resend, client); if (r < 0) goto error; @@ -554,9 +561,11 @@ static int client_initialize_events(sd_dhcp_client *client, 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_MONOTONIC, + 0, 0, + client_timeout_resend, client); if (r < 0) goto error; @@ -584,7 +593,7 @@ 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); if (r < 0) { client_stop(client, r); @@ -627,7 +636,7 @@ static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata) 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); if (r < 0) { client_stop(client, r); return 0; @@ -673,8 +682,10 @@ 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; @@ -682,9 +693,21 @@ 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; + } + } client->lease = lease; lease = NULL; @@ -709,8 +732,10 @@ static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack, return DHCP_EVENT_NO_LEASE; } - 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 +743,21 @@ 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) { @@ -740,70 +778,114 @@ static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack, return r; } -static uint64_t client_compute_timeout(uint64_t request_sent, - uint32_t lifetime) { - return request_sent + (lifetime - 3) * USEC_PER_SEC + +static uint64_t client_compute_timeout(sd_dhcp_client *client, + uint32_t lifetime, double factor) { + assert(client); + assert(client->request_sent); + assert(lifetime); + + return client->request_sent + ((lifetime - 3) * USEC_PER_SEC * factor) + + (random_u32() & 0x1fffff); } -static int client_set_lease_timeouts(sd_dhcp_client *client, uint64_t usec) { - uint64_t next_timeout; +static int client_set_lease_timeouts(sd_dhcp_client *client) { + usec_t time_now; + uint64_t lifetime_timeout; + uint64_t t2_timeout; + uint64_t t1_timeout; + char time_string[FORMAT_TIMESPAN_MAX]; int r; assert(client); assert(client->event); - - /* don't set timers for infinite leases */ - if (client->lease->lifetime == 0xffffffff) - return 0; - - if (client->lease->lifetime < 10) - return -EINVAL; + assert(client->lease); + assert(client->lease->lifetime); client->timeout_t1 = sd_event_source_unref(client->timeout_t1); client->timeout_t2 = sd_event_source_unref(client->timeout_t2); client->timeout_expire = sd_event_source_unref(client->timeout_expire); - if (!client->lease->t1) - client->lease->t1 = client->lease->lifetime / 2; + /* don't set timers for infinite leases */ + if (client->lease->lifetime == 0xffffffff) + return 0; - next_timeout = client_compute_timeout(client->request_sent, - client->lease->t1); - if (next_timeout < usec) - return -EINVAL; + r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now); + if (r < 0) + return r; + assert(client->request_sent <= time_now); + + /* convert the various timeouts from relative (secs) to absolute (usecs) */ + lifetime_timeout = client_compute_timeout(client, client->lease->lifetime, 1); + if (client->lease->t1 && client->lease->t2) { + /* both T1 and T2 are given */ + if (client->lease->t1 < client->lease->t2 && + client->lease->t2 < client->lease->lifetime) { + /* they are both valid */ + t2_timeout = client_compute_timeout(client, client->lease->t2, 1); + t1_timeout = client_compute_timeout(client, client->lease->t1, 1); + } else { + /* discard both */ + t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0); + client->lease->t2 = (client->lease->lifetime * 7) / 8; + t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5); + client->lease->t1 = client->lease->lifetime / 2; + } + } else if (client->lease->t2 && client->lease->t2 < client->lease->lifetime) { + /* only T2 is given, and it is valid */ + t2_timeout = client_compute_timeout(client, client->lease->t2, 1); + t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5); + client->lease->t1 = client->lease->lifetime / 2; + if (t2_timeout <= t1_timeout) { + /* the computed T1 would be invalid, so discard T2 */ + t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0); + client->lease->t2 = (client->lease->lifetime * 7) / 8; + } + } else if (client->lease->t1 && client->lease->t1 < client->lease->lifetime) { + /* only T1 is given, and it is valid */ + t1_timeout = client_compute_timeout(client, client->lease->t1, 1); + t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0); + client->lease->t2 = (client->lease->lifetime * 7) / 8; + if (t2_timeout <= t1_timeout) { + /* the computed T2 would be invalid, so discard T1 */ + t2_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5); + client->lease->t2 = client->lease->lifetime / 2; + } + } else { + /* fall back to the default timeouts */ + t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5); + client->lease->t1 = client->lease->lifetime / 2; + t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0); + client->lease->t2 = (client->lease->lifetime * 7) / 8; + } - r = sd_event_add_monotonic(client->event, - &client->timeout_t1, - next_timeout, - 10 * USEC_PER_MSEC, - client_timeout_t1, client); + /* arm lifetime timeout */ + r = sd_event_add_time(client->event, &client->timeout_expire, + CLOCK_MONOTONIC, + lifetime_timeout, 10 * USEC_PER_MSEC, + client_timeout_expire, client); if (r < 0) return r; - r = sd_event_source_set_priority(client->timeout_t1, + r = sd_event_source_set_priority(client->timeout_expire, client->event_priority); if (r < 0) return r; - if (!client->lease->t2) - client->lease->t2 = client->lease->lifetime * 7 / 8; - - if (client->lease->t2 < client->lease->t1) - return -EINVAL; - - if (client->lease->lifetime < client->lease->t2) - return -EINVAL; + log_dhcp_client(client, "lease expires in %s", + format_timespan(time_string, FORMAT_TIMESPAN_MAX, + lifetime_timeout - time_now, 0)); - next_timeout = client_compute_timeout(client->request_sent, - client->lease->t2); - if (next_timeout < usec) - return -EINVAL; + /* don't arm earlier timeouts if this has already expired */ + if (lifetime_timeout <= time_now) + return 0; - r = sd_event_add_monotonic(client->event, - &client->timeout_t2, - next_timeout, - 10 * USEC_PER_MSEC, - client_timeout_t2, client); + /* arm T2 timeout */ + r = sd_event_add_time(client->event, + &client->timeout_t2, + CLOCK_MONOTONIC, + t2_timeout, + 10 * USEC_PER_MSEC, + client_timeout_t2, client); if (r < 0) return r; @@ -812,37 +894,45 @@ static int client_set_lease_timeouts(sd_dhcp_client *client, uint64_t usec) { if (r < 0) return r; - next_timeout = client_compute_timeout(client->request_sent, - client->lease->lifetime); - if (next_timeout < usec) - return -EINVAL; + log_dhcp_client(client, "T2 expires in %s", + format_timespan(time_string, FORMAT_TIMESPAN_MAX, + t2_timeout - time_now, 0)); + + /* don't arm earlier timeout if this has already expired */ + if (t2_timeout <= time_now) + return 0; - r = sd_event_add_monotonic(client->event, - &client->timeout_expire, next_timeout, - 10 * USEC_PER_MSEC, - client_timeout_expire, client); + /* arm T1 timeout */ + r = sd_event_add_time(client->event, + &client->timeout_t1, + CLOCK_MONOTONIC, + t1_timeout, 10 * USEC_PER_MSEC, + client_timeout_t1, client); if (r < 0) return r; - r = sd_event_source_set_priority(client->timeout_expire, + r = sd_event_source_set_priority(client->timeout_t1, client->event_priority); if (r < 0) return r; + log_dhcp_client(client, "T1 expires in %s", + format_timespan(time_string, FORMAT_TIMESPAN_MAX, + t1_timeout - time_now, 0)); + return 0; } static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, - int len, usec_t time_now) { + int len) { 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); + if (be32toh(message->magic) != DHCP_MAGIC_COOKIE) { + log_dhcp_client(client, "not a DHCP message: ignoring"); return 0; } @@ -858,6 +948,11 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, 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 " @@ -877,10 +972,11 @@ 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_MONOTONIC, + 0, 0, + client_timeout_resend, client); if (r < 0) goto error; @@ -888,7 +984,9 @@ 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; @@ -898,7 +996,6 @@ 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 = @@ -915,9 +1012,7 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, } goto error; - } - - if (r >= 0) { + } else if (r >= 0) { client->timeout_resend = sd_event_source_unref(client->timeout_resend); @@ -932,7 +1027,7 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, client->last_addr = client->lease->address; - r = client_set_lease_timeouts(client, time_now); + r = client_set_lease_timeouts(client); if (r < 0) goto error; @@ -942,9 +1037,9 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, client->receive_message = sd_event_source_unref(client->receive_message); client->fd = safe_close(client->fd); - } - - r = 0; + } else if (r == -ENOMSG) + /* invalid message, let's ignore it */ + return 0; break; @@ -967,11 +1062,9 @@ static int client_receive_message_udp(sd_event_source *s, int fd, sd_dhcp_client *client = userdata; _cleanup_free_ DHCPMessage *message = NULL; int buflen = 0, len, r; - usec_t time_now; assert(s); assert(client); - assert(client->event); r = ioctl(fd, FIONREAD, &buflen); if (r < 0 || buflen <= 0) @@ -982,22 +1075,20 @@ static int client_receive_message_udp(sd_event_source *s, int fd, return -ENOMEM; len = read(fd, message, buflen); - if (len < 0) + if (len < 0) { + log_dhcp_client(client, "could not receive message from UDP " + "socket: %s", strerror(errno)); + return 0; + } else if ((size_t)len < sizeof(DHCPMessage)) return 0; - r = sd_event_get_now_monotonic(client->event, &time_now); - if (r < 0) - return client_stop(client, r); - - return client_handle_message(client, message, len, - time_now); + return client_handle_message(client, message, len); } static int client_receive_message_raw(sd_event_source *s, int fd, uint32_t revents, void *userdata) { sd_dhcp_client *client = userdata; _cleanup_free_ DHCPPacket *packet = NULL; - usec_t time_now; uint8_t cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))]; struct iovec iov = {}; struct msghdr msg = { @@ -1012,7 +1103,6 @@ static int client_receive_message_raw(sd_event_source *s, int fd, assert(s); assert(client); - assert(client->event); r = ioctl(fd, FIONREAD, &buflen); if (r < 0 || buflen <= 0) @@ -1030,11 +1120,14 @@ static int client_receive_message_raw(sd_event_source *s, int fd, log_dhcp_client(client, "could not receive message from raw " "socket: %s", strerror(errno)); 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; @@ -1047,11 +1140,7 @@ static int client_receive_message_raw(sd_event_source *s, int fd, len -= DHCP_IP_UDP_SIZE; - r = sd_event_get_now_monotonic(client->event, &time_now); - if (r < 0) - return client_stop(client, r); - - return client_handle_message(client, &packet->dhcp, len, time_now); + return client_handle_message(client, &packet->dhcp, len); } int sd_dhcp_client_start(sd_dhcp_client *client) {