diff options
Diffstat (limited to 'src/libsystemd-network/sd-dhcp-client.c')
| -rw-r--r-- | src/libsystemd-network/sd-dhcp-client.c | 1904 |
1 files changed, 0 insertions, 1904 deletions
diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c deleted file mode 100644 index 5ccb23922c..0000000000 --- a/src/libsystemd-network/sd-dhcp-client.c +++ /dev/null @@ -1,1904 +0,0 @@ -/*** - This file is part of systemd. - - Copyright (C) 2013 Intel Corporation. All rights reserved. - - systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU Lesser General Public License as published by - the Free Software Foundation; either version 2.1 of the License, or - (at your option) any later version. - - systemd is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. -***/ - -#include <errno.h> -#include <net/ethernet.h> -#include <net/if_arp.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <sys/ioctl.h> -#include <linux/if_infiniband.h> - -#include "sd-dhcp-client.h" - -#include "alloc-util.h" -#include "async.h" -#include "dhcp-identifier.h" -#include "dhcp-internal.h" -#include "dhcp-lease-internal.h" -#include "dhcp-protocol.h" -#include "dns-domain.h" -#include "hostname-util.h" -#include "random-util.h" -#include "string-util.h" -#include "util.h" - -#define MAX_CLIENT_ID_LEN (sizeof(uint32_t) + MAX_DUID_LEN) /* Arbitrary limit */ -#define MAX_MAC_ADDR_LEN CONST_MAX(INFINIBAND_ALEN, ETH_ALEN) - -#define RESTART_AFTER_NAK_MIN_USEC (1 * USEC_PER_SEC) -#define RESTART_AFTER_NAK_MAX_USEC (30 * USEC_PER_MINUTE) - -struct sd_dhcp_client { - unsigned n_ref; - - DHCPState state; - sd_event *event; - int event_priority; - sd_event_source *timeout_resend; - int ifindex; - 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; - be32_t last_addr; - uint8_t mac_addr[MAX_MAC_ADDR_LEN]; - size_t mac_addr_len; - uint16_t arp_type; - struct { - uint8_t type; - union { - struct { - /* 0: Generic (non-LL) (RFC 2132) */ - uint8_t data[MAX_CLIENT_ID_LEN]; - } _packed_ gen; - struct { - /* 1: Ethernet Link-Layer (RFC 2132) */ - uint8_t haddr[ETH_ALEN]; - } _packed_ eth; - struct { - /* 2 - 254: ARP/Link-Layer (RFC 2132) */ - uint8_t haddr[0]; - } _packed_ ll; - struct { - /* 255: Node-specific (RFC 4361) */ - be32_t iaid; - struct duid duid; - } _packed_ ns; - struct { - uint8_t data[MAX_CLIENT_ID_LEN]; - } _packed_ raw; - }; - } _packed_ client_id; - size_t client_id_len; - char *hostname; - char *vendor_class_identifier; - uint32_t mtu; - uint32_t xid; - usec_t start_time; - unsigned int attempt; - usec_t request_sent; - sd_event_source *timeout_t1; - sd_event_source *timeout_t2; - sd_event_source *timeout_expire; - sd_dhcp_client_callback_t callback; - void *userdata; - sd_dhcp_lease *lease; - usec_t start_delay; -}; - -static const uint8_t default_req_opts[] = { - SD_DHCP_OPTION_SUBNET_MASK, - SD_DHCP_OPTION_ROUTER, - SD_DHCP_OPTION_HOST_NAME, - SD_DHCP_OPTION_DOMAIN_NAME, - SD_DHCP_OPTION_DOMAIN_NAME_SERVER, -}; - -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_callback_t cb, - void *userdata) { - - assert_return(client, -EINVAL); - - client->callback = cb; - client->userdata = userdata; - - 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(IN_SET(client->state, DHCP_STATE_INIT, DHCP_STATE_STOPPED), -EBUSY); - - switch(option) { - - case SD_DHCP_OPTION_PAD: - case SD_DHCP_OPTION_OVERLOAD: - case SD_DHCP_OPTION_MESSAGE_TYPE: - case SD_DHCP_OPTION_PARAMETER_REQUEST_LIST: - case SD_DHCP_OPTION_END: - return -EINVAL; - - default: - break; - } - - for (i = 0; i < client->req_opts_size; i++) - if (client->req_opts[i] == option) - return -EEXIST; - - if (!GREEDY_REALLOC(client->req_opts, client->req_opts_allocated, - client->req_opts_size + 1)) - return -ENOMEM; - - client->req_opts[client->req_opts_size++] = option; - - return 0; -} - -int sd_dhcp_client_set_request_address( - sd_dhcp_client *client, - const struct in_addr *last_addr) { - - assert_return(client, -EINVAL); - assert_return(IN_SET(client->state, DHCP_STATE_INIT, DHCP_STATE_STOPPED), -EBUSY); - - if (last_addr) - client->last_addr = last_addr->s_addr; - else - client->last_addr = INADDR_ANY; - - return 0; -} - -int sd_dhcp_client_set_ifindex(sd_dhcp_client *client, int ifindex) { - - assert_return(client, -EINVAL); - assert_return(IN_SET(client->state, DHCP_STATE_INIT, DHCP_STATE_STOPPED), -EBUSY); - assert_return(ifindex > 0, -EINVAL); - - client->ifindex = ifindex; - return 0; -} - -int sd_dhcp_client_set_mac( - sd_dhcp_client *client, - const uint8_t *addr, - size_t addr_len, - uint16_t arp_type) { - - DHCP_CLIENT_DONT_DESTROY(client); - bool need_restart = false; - - assert_return(client, -EINVAL); - assert_return(addr, -EINVAL); - assert_return(addr_len > 0 && addr_len <= MAX_MAC_ADDR_LEN, -EINVAL); - assert_return(arp_type > 0, -EINVAL); - - if (arp_type == ARPHRD_ETHER) - assert_return(addr_len == ETH_ALEN, -EINVAL); - else if (arp_type == ARPHRD_INFINIBAND) - assert_return(addr_len == INFINIBAND_ALEN, -EINVAL); - else - return -EINVAL; - - if (client->mac_addr_len == addr_len && - memcmp(&client->mac_addr, addr, addr_len) == 0) - return 0; - - 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, SD_DHCP_CLIENT_EVENT_STOP); - } - - memcpy(&client->mac_addr, addr, addr_len); - client->mac_addr_len = addr_len; - client->arp_type = arp_type; - - if (need_restart && client->state != DHCP_STATE_STOPPED) - sd_dhcp_client_start(client); - - return 0; -} - -int sd_dhcp_client_get_client_id( - sd_dhcp_client *client, - uint8_t *type, - const uint8_t **data, - size_t *data_len) { - - assert_return(client, -EINVAL); - assert_return(type, -EINVAL); - assert_return(data, -EINVAL); - assert_return(data_len, -EINVAL); - - *type = 0; - *data = NULL; - *data_len = 0; - if (client->client_id_len) { - *type = client->client_id.type; - *data = client->client_id.raw.data; - *data_len = client->client_id_len - sizeof(client->client_id.type); - } - - return 0; -} - -int sd_dhcp_client_set_client_id( - sd_dhcp_client *client, - uint8_t type, - const uint8_t *data, - size_t data_len) { - - DHCP_CLIENT_DONT_DESTROY(client); - bool need_restart = false; - - assert_return(client, -EINVAL); - assert_return(data, -EINVAL); - assert_return(data_len > 0 && data_len <= MAX_CLIENT_ID_LEN, -EINVAL); - - switch (type) { - - case ARPHRD_ETHER: - if (data_len != ETH_ALEN) - return -EINVAL; - break; - - case ARPHRD_INFINIBAND: - if (data_len != INFINIBAND_ALEN) - return -EINVAL; - break; - - default: - break; - } - - if (client->client_id_len == data_len + sizeof(client->client_id.type) && - client->client_id.type == type && - memcmp(&client->client_id.raw.data, data, data_len) == 0) - return 0; - - if (!IN_SET(client->state, DHCP_STATE_INIT, DHCP_STATE_STOPPED)) { - log_dhcp_client(client, "Changing client ID on running DHCP " - "client, restarting"); - need_restart = true; - client_stop(client, SD_DHCP_CLIENT_EVENT_STOP); - } - - client->client_id.type = type; - memcpy(&client->client_id.raw.data, data, data_len); - client->client_id_len = data_len + sizeof (client->client_id.type); - - if (need_restart && client->state != DHCP_STATE_STOPPED) - sd_dhcp_client_start(client); - - return 0; -} - -/** - * Sets IAID and DUID. If duid is non-null, the DUID is set to duid_type + duid - * without further modification. Otherwise, if duid_type is supported, DUID - * is set based on that type. Otherwise, an error is returned. - */ -int sd_dhcp_client_set_iaid_duid( - sd_dhcp_client *client, - uint32_t iaid, - uint16_t duid_type, - const void *duid, - size_t duid_len) { - - DHCP_CLIENT_DONT_DESTROY(client); - int r; - size_t len; - - assert_return(client, -EINVAL); - assert_return(duid_len == 0 || duid != NULL, -EINVAL); - - if (duid != NULL) { - r = dhcp_validate_duid_len(duid_type, duid_len); - if (r < 0) - return r; - } - - zero(client->client_id); - client->client_id.type = 255; - - /* If IAID is not configured, generate it. */ - if (iaid == 0) { - r = dhcp_identifier_set_iaid(client->ifindex, client->mac_addr, - client->mac_addr_len, - &client->client_id.ns.iaid); - if (r < 0) - return r; - } else - client->client_id.ns.iaid = htobe32(iaid); - - if (duid != NULL) { - client->client_id.ns.duid.type = htobe16(duid_type); - memcpy(&client->client_id.ns.duid.raw.data, duid, duid_len); - len = sizeof(client->client_id.ns.duid.type) + duid_len; - } else if (duid_type == DUID_TYPE_EN) { - r = dhcp_identifier_set_duid_en(&client->client_id.ns.duid, &len); - if (r < 0) - return r; - } else - return -EOPNOTSUPP; - - client->client_id_len = sizeof(client->client_id.type) + len + - sizeof(client->client_id.ns.iaid); - - if (!IN_SET(client->state, DHCP_STATE_INIT, DHCP_STATE_STOPPED)) { - log_dhcp_client(client, "Configured IAID+DUID, restarting."); - client_stop(client, SD_DHCP_CLIENT_EVENT_STOP); - 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 (!hostname_is_valid(hostname, false) && !dns_name_is_valid(hostname)) - return -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; -} - -int sd_dhcp_client_set_mtu(sd_dhcp_client *client, uint32_t mtu) { - assert_return(client, -EINVAL); - assert_return(mtu >= DHCP_DEFAULT_MIN_SIZE, -ERANGE); - - client->mtu = mtu; - - return 0; -} - -int sd_dhcp_client_get_lease(sd_dhcp_client *client, sd_dhcp_lease **ret) { - assert_return(client, -EINVAL); - - if (client->state != DHCP_STATE_BOUND && - client->state != DHCP_STATE_RENEWING && - client->state != DHCP_STATE_REBINDING) - return -EADDRNOTAVAIL; - - if (ret) - *ret = client->lease; - - return 0; -} - -static void client_notify(sd_dhcp_client *client, int event) { - assert(client); - - if (client->callback) - client->callback(client, event, client->userdata); -} - -static int client_initialize(sd_dhcp_client *client) { - assert_return(client, -EINVAL); - - client->receive_message = sd_event_source_unref(client->receive_message); - - client->fd = asynchronous_close(client->fd); - - client->timeout_resend = sd_event_source_unref(client->timeout_resend); - - 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); - - client->attempt = 1; - - client->state = DHCP_STATE_INIT; - client->xid = 0; - - client->lease = sd_dhcp_lease_unref(client->lease); - - return 0; -} - -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 == SD_DHCP_CLIENT_EVENT_STOP) - log_dhcp_client(client, "STOPPED"); - else - log_dhcp_client(client, "STOPPED: Unknown event"); - - client_notify(client, error); - - client_initialize(client); -} - -static int client_message_init( - sd_dhcp_client *client, - DHCPPacket **ret, - uint8_t type, - size_t *_optlen, - size_t *_optoffset) { - - _cleanup_free_ DHCPPacket *packet = NULL; - size_t optlen, optoffset, size; - be16_t max_size; - usec_t time_now; - uint16_t secs; - int r; - - assert(client); - assert(client->start_time); - assert(ret); - assert(_optlen); - assert(_optoffset); - assert(type == DHCP_DISCOVER || type == DHCP_REQUEST); - - optlen = DHCP_MIN_OPTIONS_SIZE; - size = sizeof(DHCPPacket) + optlen; - - packet = malloc0(size); - if (!packet) - return -ENOMEM; - - r = dhcp_message_init(&packet->dhcp, BOOTREQUEST, client->xid, type, - client->arp_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 */ - r = sd_event_now(client->event, clock_boottime_or_monotonic(), &time_now); - if (r < 0) - return r; - assert(time_now >= client->start_time); - - /* seconds between sending first and last DISCOVER - * must always be strictly positive to deal with broken servers */ - secs = ((time_now - client->start_time) / USEC_PER_SEC) ? : 1; - packet->dhcp.secs = htobe16(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 || client->arp_type != ARPHRD_ETHER) - 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. Non-Ethernet - interfaces will leave 'chaddr' empty and use the client identifier - instead (eg, RFC 4390 section 2.1). - */ - if (client->arp_type == ARPHRD_ETHER) - memcpy(&packet->dhcp.chaddr, &client->mac_addr, ETH_ALEN); - - /* If no client identifier exists, construct an RFC 4361-compliant one */ - if (client->client_id_len == 0) { - size_t duid_len; - - client->client_id.type = 255; - - r = dhcp_identifier_set_iaid(client->ifindex, client->mac_addr, client->mac_addr_len, &client->client_id.ns.iaid); - if (r < 0) - return r; - - r = dhcp_identifier_set_duid_en(&client->client_id.ns.duid, &duid_len); - if (r < 0) - return r; - - client->client_id_len = sizeof(client->client_id.type) + sizeof(client->client_id.ns.iaid) + duid_len; - } - - /* Some DHCP servers will refuse to issue an DHCP lease if the Client - Identifier option is not set */ - if (client->client_id_len) { - r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0, - SD_DHCP_OPTION_CLIENT_IDENTIFIER, - client->client_id_len, - &client->client_id); - 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, - SD_DHCP_OPTION_PARAMETER_REQUEST_LIST, - client->req_opts_size, client->req_opts); - 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 explicitly set - - RFC3442 "Requirements to Avoid Sizing Constraints": - Because a full routing table can be quite large, the standard 576 - octet maximum size for a DHCP message may be too short to contain - some legitimate Classless Static Route options. Because of this, - clients implementing the Classless Static Route option SHOULD send a - Maximum DHCP Message Size [4] option if the DHCP client's TCP/IP - stack is capable of receiving larger IP datagrams. In this case, the - client SHOULD set the value of this option to at least the MTU of the - interface that the client is configuring. The client MAY set the - value of this option higher, up to the size of the largest UDP packet - it is prepared to accept. (Note that the value specified in the - Maximum DHCP Message Size option is the total maximum packet size, - including IP and UDP headers.) - */ - max_size = htobe16(size); - r = dhcp_option_append(&packet->dhcp, client->mtu, &optoffset, 0, - SD_DHCP_OPTION_MAXIMUM_MESSAGE_SIZE, - 2, &max_size); - if (r < 0) - return r; - - *_optlen = optlen; - *_optoffset = optoffset; - *ret = packet; - packet = NULL; - - return 0; -} - -static int client_append_fqdn_option( - DHCPMessage *message, - size_t optlen, - size_t *optoffset, - const char *fqdn) { - - uint8_t buffer[3 + DHCP_MAX_FQDN_LENGTH]; - int r; - - buffer[0] = DHCP_FQDN_FLAG_S | /* Request server to perform A RR DNS updates */ - DHCP_FQDN_FLAG_E; /* Canonical wire format */ - buffer[1] = 0; /* RCODE1 (deprecated) */ - buffer[2] = 0; /* RCODE2 (deprecated) */ - - r = dns_name_to_wire_format(fqdn, buffer + 3, sizeof(buffer) - 3, false); - if (r > 0) - r = dhcp_option_append(message, optlen, optoffset, 0, - SD_DHCP_OPTION_FQDN, 3 + r, buffer); - - return r; -} - -static int dhcp_client_send_raw( - sd_dhcp_client *client, - DHCPPacket *packet, - size_t len) { - - dhcp_packet_append_ip_headers(packet, INADDR_ANY, DHCP_PORT_CLIENT, - INADDR_BROADCAST, DHCP_PORT_SERVER, len); - - return dhcp_network_send_raw_socket(client->fd, &client->link, - packet, len); -} - -static int client_send_discover(sd_dhcp_client *client) { - _cleanup_free_ DHCPPacket *discover = NULL; - size_t optoffset, optlen; - int r; - - assert(client); - assert(client->state == DHCP_STATE_INIT || - client->state == DHCP_STATE_SELECTING); - - 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(&discover->dhcp, optlen, &optoffset, 0, - SD_DHCP_OPTION_REQUESTED_IP_ADDRESS, - 4, &client->last_addr); - if (r < 0) - return r; - } - - if (client->hostname) { - /* According to RFC 4702 "clients that send the Client FQDN option in - their messages MUST NOT also send the Host Name option". Just send - one of the two depending on the hostname type. - */ - if (dns_name_is_single_label(client->hostname)) { - /* it is unclear from RFC 2131 if client should send hostname in - DHCPDISCOVER but dhclient does and so we do as well - */ - r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0, - SD_DHCP_OPTION_HOST_NAME, - strlen(client->hostname), client->hostname); - } else - r = client_append_fqdn_option(&discover->dhcp, optlen, &optoffset, - client->hostname); - if (r < 0) - return r; - } - - if (client->vendor_class_identifier) { - r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0, - SD_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, - SD_DHCP_OPTION_END, 0, NULL); - 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, sizeof(DHCPPacket) + optoffset); - if (r < 0) - return r; - - log_dhcp_client(client, "DISCOVER"); - - return 0; -} - -static int client_send_request(sd_dhcp_client *client) { - _cleanup_free_ DHCPPacket *request = NULL; - size_t optoffset, optlen; - int r; - - assert(client); - - 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_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, - SD_DHCP_OPTION_SERVER_IDENTIFIER, - 4, &client->lease->server_address); - if (r < 0) - return r; - - r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0, - SD_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(&request->dhcp, optlen, &optoffset, 0, - SD_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_STOPPED: - return -EINVAL; - } - - if (client->hostname) { - if (dns_name_is_single_label(client->hostname)) - r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0, - SD_DHCP_OPTION_HOST_NAME, - strlen(client->hostname), client->hostname); - else - r = client_append_fqdn_option(&request->dhcp, optlen, &optoffset, - client->hostname); - if (r < 0) - return r; - } - - r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0, - SD_DHCP_OPTION_END, 0, NULL); - if (r < 0) - return r; - - if (client->state == DHCP_STATE_RENEWING) { - r = dhcp_network_send_udp_socket(client->fd, - client->lease->server_address, - DHCP_PORT_SERVER, - &request->dhcp, - sizeof(DHCPMessage) + optoffset); - } else { - r = dhcp_client_send_raw(client, request, sizeof(DHCPPacket) + optoffset); - } - if (r < 0) - return r; - - 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; - int r; - - assert(s); - assert(client); - assert(client->event); - - r = sd_event_now(client->event, clock_boottime_or_monotonic(), &time_now); - if (r < 0) - goto error; - - switch (client->state) { - - case DHCP_STATE_RENEWING: - - time_left = (client->lease->t2 - client->lease->t1) / 2; - if (time_left < 60) - time_left = 60; - - next_timeout = time_now + time_left * USEC_PER_SEC; - - break; - - case DHCP_STATE_REBINDING: - - time_left = (client->lease->lifetime - client->lease->t2) / 2; - if (time_left < 60) - time_left = 60; - - next_timeout = time_now + time_left * USEC_PER_SEC; - break; - - case DHCP_STATE_REBOOTING: - /* start over as we did not receive a timely ack or nak */ - 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; - } - - case DHCP_STATE_INIT: - case DHCP_STATE_INIT_REBOOT: - case DHCP_STATE_SELECTING: - case DHCP_STATE_REQUESTING: - case DHCP_STATE_BOUND: - - if (client->attempt < 64) - client->attempt *= 2; - - 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_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; - - r = sd_event_source_set_priority(client->timeout_resend, - client->event_priority); - if (r < 0) - goto error; - - r = sd_event_source_set_description(client->timeout_resend, "dhcp4-resend-timer"); - if (r < 0) - goto error; - - switch (client->state) { - case DHCP_STATE_INIT: - r = client_send_discover(client); - if (r >= 0) { - client->state = DHCP_STATE_SELECTING; - client->attempt = 1; - } else { - if (client->attempt >= 64) - goto error; - } - - break; - - case DHCP_STATE_SELECTING: - r = client_send_discover(client); - if (r < 0 && client->attempt >= 64) - goto error; - - break; - - case DHCP_STATE_INIT_REBOOT: - case DHCP_STATE_REQUESTING: - case DHCP_STATE_RENEWING: - case DHCP_STATE_REBINDING: - r = client_send_request(client); - if (r < 0 && client->attempt >= 64) - goto error; - - if (client->state == DHCP_STATE_INIT_REBOOT) - client->state = DHCP_STATE_REBOOTING; - - client->request_sent = time_now; - - break; - - case DHCP_STATE_REBOOTING: - case DHCP_STATE_BOUND: - - break; - - case DHCP_STATE_STOPPED: - r = -EINVAL; - goto error; - } - - return 0; - -error: - client_stop(client, r); - - /* Errors were dealt with when stopping the client, don't spill - errors into the event loop handler */ - return 0; -} - -static int client_initialize_io_events( - sd_dhcp_client *client, - sd_event_io_handler_t io_callback) { - - int r; - - assert(client); - assert(client->event); - - r = sd_event_add_io(client->event, &client->receive_message, - client->fd, EPOLLIN, io_callback, - client); - if (r < 0) - goto error; - - r = sd_event_source_set_priority(client->receive_message, - client->event_priority); - if (r < 0) - goto error; - - r = sd_event_source_set_description(client->receive_message, "dhcp4-receive-message"); - 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) { - uint64_t usec = 0; - int r; - - assert(client); - assert(client->event); - - client->timeout_resend = sd_event_source_unref(client->timeout_resend); - - if (client->start_delay) { - assert_se(sd_event_now(client->event, clock_boottime_or_monotonic(), &usec) >= 0); - usec += client->start_delay; - } - - r = sd_event_add_time(client->event, - &client->timeout_resend, - clock_boottime_or_monotonic(), - usec, 0, - client_timeout_resend, client); - if (r < 0) - goto error; - - r = sd_event_source_set_priority(client->timeout_resend, - client->event_priority); - if (r < 0) - goto error; - - r = sd_event_source_set_description(client->timeout_resend, "dhcp4-resend-timer"); - if (r < 0) - goto error; - -error: - if (r < 0) - client_stop(client, r); - - return 0; - -} - -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_delayed(sd_dhcp_client *client) { - int r; - - assert_return(client, -EINVAL); - assert_return(client->event, -EINVAL); - assert_return(client->ifindex > 0, -EINVAL); - assert_return(client->fd < 0, -EBUSY); - assert_return(client->xid == 0, -EINVAL); - assert_return(IN_SET(client->state, DHCP_STATE_INIT, DHCP_STATE_INIT_REBOOT), -EBUSY); - - client->xid = random_u32(); - - r = dhcp_network_bind_raw_socket(client->ifindex, &client->link, - client->xid, client->mac_addr, - client->mac_addr_len, client->arp_type); - if (r < 0) { - client_stop(client, r); - return r; - } - client->fd = r; - - if (client->state == DHCP_STATE_INIT || client->state == DHCP_STATE_INIT_REBOOT) - client->start_time = now(clock_boottime_or_monotonic()); - - return client_initialize_events(client, client_receive_message_raw); -} - -static int client_start(sd_dhcp_client *client) { - client->start_delay = 0; - return client_start_delayed(client); -} - -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, SD_DHCP_CLIENT_EVENT_EXPIRED); - - /* 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; - - assert(client); - - client->receive_message = sd_event_source_unref(client->receive_message); - client->fd = asynchronous_close(client->fd); - - client->state = DHCP_STATE_REBINDING; - client->attempt = 1; - - r = dhcp_network_bind_raw_socket(client->ifindex, &client->link, - client->xid, client->mac_addr, - client->mac_addr_len, client->arp_type); - if (r < 0) { - client_stop(client, r); - return 0; - } - client->fd = r; - - 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; - DHCP_CLIENT_DONT_DESTROY(client); - - client->state = DHCP_STATE_RENEWING; - client->attempt = 1; - - return client_initialize_time_events(client); -} - -static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer, size_t len) { - _cleanup_(sd_dhcp_lease_unrefp) sd_dhcp_lease *lease = NULL; - int r; - - r = dhcp_lease_new(&lease); - if (r < 0) - return r; - - if (client->client_id_len) { - r = dhcp_lease_set_client_id(lease, - (uint8_t *) &client->client_id, - client->client_id_len); - if (r < 0) - return r; - } - - r = dhcp_option_parse(offer, len, dhcp_lease_parse_options, lease, NULL); - if (r != DHCP_OFFER) { - log_dhcp_client(client, "received message was not an OFFER, ignoring"); - return -ENOMSG; - } - - lease->next_server = offer->siaddr; - lease->address = offer->yiaddr; - - if (lease->address == 0 || - lease->server_address == 0 || - lease->lifetime == 0) { - log_dhcp_client(client, "received lease lacks address, server address or lease lifetime, ignoring"); - return -ENOMSG; - } - - if (!lease->have_subnet_mask) { - r = dhcp_lease_set_default_subnet_mask(lease); - if (r < 0) { - log_dhcp_client(client, "received 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; - - log_dhcp_client(client, "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, 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_(sd_dhcp_lease_unrefp) sd_dhcp_lease *lease = NULL; - _cleanup_free_ char *error_message = NULL; - int r; - - r = dhcp_lease_new(&lease); - if (r < 0) - return r; - - if (client->client_id_len) { - r = dhcp_lease_set_client_id(lease, - (uint8_t *) &client->client_id, - client->client_id_len); - if (r < 0) - return r; - } - - r = dhcp_option_parse(ack, len, dhcp_lease_parse_options, lease, &error_message); - if (r == DHCP_NAK) { - log_dhcp_client(client, "NAK: %s", strna(error_message)); - return -EADDRNOTAVAIL; - } - - if (r != DHCP_ACK) { - log_dhcp_client(client, "received message was not an ACK, ignoring"); - return -ENOMSG; - } - - lease->next_server = ack->siaddr; - - lease->address = ack->yiaddr; - - if (lease->address == INADDR_ANY || - lease->server_address == INADDR_ANY || - lease->lifetime == 0) { - log_dhcp_client(client, "received 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, "received lease lacks subnet " - "mask, and a fallback one can not be " - "generated, ignoring"); - return -ENOMSG; - } - } - - r = SD_DHCP_CLIENT_EVENT_IP_ACQUIRE; - if (client->lease) { - if (client->lease->address != lease->address || - client->lease->subnet_mask != lease->subnet_mask || - client->lease->router != lease->router) { - r = SD_DHCP_CLIENT_EVENT_IP_CHANGE; - } else - r = SD_DHCP_CLIENT_EVENT_RENEW; - - client->lease = sd_dhcp_lease_unref(client->lease); - } - - client->lease = lease; - lease = NULL; - - log_dhcp_client(client, "ACK"); - - return r; -} - -static uint64_t client_compute_timeout(sd_dhcp_client *client, uint32_t lifetime, double factor) { - assert(client); - assert(client->request_sent); - assert(lifetime > 0); - - if (lifetime > 3) - lifetime -= 3; - else - lifetime = 0; - - return client->request_sent + (lifetime * USEC_PER_SEC * factor) + - + (random_u32() & 0x1fffff); -} - -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); - 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); - - /* don't set timers for infinite leases */ - if (client->lease->lifetime == 0xffffffff) - return 0; - - r = sd_event_now(client->event, clock_boottime_or_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 > 0 && client->lease->t2 > 0) { - /* 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 > 0 && 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 > 0 && 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; - } - - /* arm lifetime timeout */ - 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; - - r = sd_event_source_set_priority(client->timeout_expire, - client->event_priority); - if (r < 0) - return r; - - r = sd_event_source_set_description(client->timeout_expire, "dhcp4-lifetime"); - if (r < 0) - return r; - - log_dhcp_client(client, "lease expires in %s", - format_timespan(time_string, FORMAT_TIMESPAN_MAX, lifetime_timeout - time_now, USEC_PER_SEC)); - - /* don't arm earlier timeouts if this has already expired */ - if (lifetime_timeout <= time_now) - return 0; - - /* arm T2 timeout */ - 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; - - r = sd_event_source_set_priority(client->timeout_t2, - client->event_priority); - if (r < 0) - return r; - - r = sd_event_source_set_description(client->timeout_t2, "dhcp4-t2-timeout"); - if (r < 0) - return r; - - log_dhcp_client(client, "T2 expires in %s", - format_timespan(time_string, FORMAT_TIMESPAN_MAX, t2_timeout - time_now, USEC_PER_SEC)); - - /* don't arm earlier timeout if this has already expired */ - if (t2_timeout <= time_now) - return 0; - - /* arm T1 timeout */ - 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; - - r = sd_event_source_set_priority(client->timeout_t1, - client->event_priority); - if (r < 0) - return r; - - r = sd_event_source_set_description(client->timeout_t1, "dhcp4-t1-timer"); - if (r < 0) - return r; - - log_dhcp_client(client, "T1 expires in %s", - format_timespan(time_string, FORMAT_TIMESPAN_MAX, t1_timeout - time_now, USEC_PER_SEC)); - - return 0; -} - -static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, int len) { - DHCP_CLIENT_DONT_DESTROY(client); - char time_string[FORMAT_TIMESPAN_MAX]; - int r = 0, notify_event = 0; - - assert(client); - assert(client->event); - assert(message); - - switch (client->state) { - case DHCP_STATE_SELECTING: - - r = client_handle_offer(client, message, len); - if (r >= 0) { - - client->timeout_resend = - sd_event_source_unref(client->timeout_resend); - - client->state = DHCP_STATE_REQUESTING; - client->attempt = 1; - - 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; - - r = sd_event_source_set_priority(client->timeout_resend, - client->event_priority); - if (r < 0) - goto error; - - r = sd_event_source_set_description(client->timeout_resend, "dhcp4-resend-timer"); - if (r < 0) - goto error; - } else if (r == -ENOMSG) - /* invalid message, let's ignore it */ - return 0; - - break; - - case DHCP_STATE_REBOOTING: - case DHCP_STATE_REQUESTING: - case DHCP_STATE_RENEWING: - case DHCP_STATE_REBINDING: - - r = client_handle_ack(client, message, len); - if (r >= 0) { - client->start_delay = 0; - client->timeout_resend = - sd_event_source_unref(client->timeout_resend); - client->receive_message = - sd_event_source_unref(client->receive_message); - client->fd = asynchronous_close(client->fd); - - if (IN_SET(client->state, DHCP_STATE_REQUESTING, - DHCP_STATE_REBOOTING)) - notify_event = SD_DHCP_CLIENT_EVENT_IP_ACQUIRE; - else if (r != SD_DHCP_CLIENT_EVENT_IP_ACQUIRE) - notify_event = r; - - client->state = DHCP_STATE_BOUND; - client->attempt = 1; - - client->last_addr = client->lease->address; - - r = client_set_lease_timeouts(client); - if (r < 0) { - log_dhcp_client(client, "could not set lease timeouts"); - goto error; - } - - 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; - } - - } else if (r == -EADDRNOTAVAIL) { - /* got a NAK, let's restart the client */ - client->timeout_resend = - sd_event_source_unref(client->timeout_resend); - - r = client_initialize(client); - if (r < 0) - goto error; - - r = client_start_delayed(client); - if (r < 0) - goto error; - - log_dhcp_client(client, "REBOOT in %s", format_timespan(time_string, FORMAT_TIMESPAN_MAX, - client->start_delay, USEC_PER_SEC)); - - client->start_delay = CLAMP(client->start_delay * 2, - RESTART_AFTER_NAK_MIN_USEC, RESTART_AFTER_NAK_MAX_USEC); - - 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: - - break; - - case DHCP_STATE_STOPPED: - r = -EINVAL; - goto error; - } - -error: - if (r < 0) - client_stop(client, r); - - return r; -} - -static int client_receive_message_udp( - sd_event_source *s, - int fd, - uint32_t revents, - void *userdata) { - - sd_dhcp_client *client = userdata; - _cleanup_free_ DHCPMessage *message = NULL; - const struct ether_addr zero_mac = {}; - const struct ether_addr *expected_chaddr = NULL; - uint8_t expected_hlen = 0; - ssize_t len, buflen; - - assert(s); - assert(client); - - buflen = next_datagram_size_fd(fd); - if (buflen < 0) - return buflen; - - message = malloc0(buflen); - if (!message) - return -ENOMEM; - - len = recv(fd, message, buflen, 0); - if (len < 0) { - if (errno == EAGAIN || errno == EINTR) - return 0; - - return log_dhcp_client_errno(client, errno, "Could not receive message from UDP socket: %m"); - } - 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 != client->arp_type) { - log_dhcp_client(client, "Packet type does not match client type"); - return 0; - } - - if (client->arp_type == ARPHRD_ETHER) { - expected_hlen = ETH_ALEN; - expected_chaddr = (const struct ether_addr *) &client->mac_addr; - } else { - /* Non-Ethernet links expect zero chaddr */ - expected_hlen = 0; - expected_chaddr = &zero_mac; - } - - if (message->hlen != expected_hlen) { - log_dhcp_client(client, "Unexpected packet hlen %d", message->hlen); - return 0; - } - - if (memcmp(&message->chaddr[0], expected_chaddr, 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); -} - -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; - uint8_t cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))]; - struct iovec iov = {}; - struct msghdr msg = { - .msg_iov = &iov, - .msg_iovlen = 1, - .msg_control = cmsgbuf, - .msg_controllen = sizeof(cmsgbuf), - }; - struct cmsghdr *cmsg; - bool checksum = true; - ssize_t buflen, len; - int r; - - assert(s); - assert(client); - - buflen = next_datagram_size_fd(fd); - if (buflen < 0) - return buflen; - - packet = malloc0(buflen); - if (!packet) - return -ENOMEM; - - iov.iov_base = packet; - iov.iov_len = buflen; - - len = recvmsg(fd, &msg, 0); - if (len < 0) { - if (errno == EAGAIN || errno == EINTR) - return 0; - - log_dhcp_client(client, "Could not receive message from raw socket: %m"); - - return -errno; - } else if ((size_t)len < sizeof(DHCPPacket)) - return 0; - - CMSG_FOREACH(cmsg, &msg) { - 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; - } - } - - r = dhcp_packet_verify_headers(packet, len, checksum); - if (r < 0) - return 0; - - len -= DHCP_IP_UDP_SIZE; - - return client_handle_message(client, &packet->dhcp, len); -} - -int sd_dhcp_client_start(sd_dhcp_client *client) { - int r; - - assert_return(client, -EINVAL); - - r = client_initialize(client); - if (r < 0) - return r; - - if (client->last_addr) - client->state = DHCP_STATE_INIT_REBOOT; - - r = client_start(client); - if (r >= 0) - log_dhcp_client(client, "STARTED on ifindex %i", client->ifindex); - - return r; -} - -int sd_dhcp_client_stop(sd_dhcp_client *client) { - DHCP_CLIENT_DONT_DESTROY(client); - - assert_return(client, -EINVAL); - - client_stop(client, SD_DHCP_CLIENT_EVENT_STOP); - client->state = DHCP_STATE_STOPPED; - - return 0; -} - -int sd_dhcp_client_attach_event(sd_dhcp_client *client, sd_event *event, int64_t priority) { - int r; - - assert_return(client, -EINVAL); - assert_return(!client->event, -EBUSY); - - if (event) - client->event = sd_event_ref(event); - else { - r = sd_event_default(&client->event); - if (r < 0) - return 0; - } - - client->event_priority = priority; - - return 0; -} - -int sd_dhcp_client_detach_event(sd_dhcp_client *client) { - assert_return(client, -EINVAL); - - client->event = sd_event_unref(client->event); - - return 0; -} - -sd_event *sd_dhcp_client_get_event(sd_dhcp_client *client) { - assert_return(client, NULL); - - return client->event; -} - -sd_dhcp_client *sd_dhcp_client_ref(sd_dhcp_client *client) { - - if (!client) - return NULL; - - assert(client->n_ref >= 1); - client->n_ref++; - - return client; -} - -sd_dhcp_client *sd_dhcp_client_unref(sd_dhcp_client *client) { - - if (!client) - return NULL; - - assert(client->n_ref >= 1); - client->n_ref--; - - if (client->n_ref > 0) - return NULL; - - 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); - return mfree(client); -} - -int sd_dhcp_client_new(sd_dhcp_client **ret) { - _cleanup_(sd_dhcp_client_unrefp) sd_dhcp_client *client = NULL; - - assert_return(ret, -EINVAL); - - client = new0(sd_dhcp_client, 1); - if (!client) - return -ENOMEM; - - client->n_ref = 1; - client->state = DHCP_STATE_INIT; - client->ifindex = -1; - client->fd = -1; - client->attempt = 1; - client->mtu = DHCP_DEFAULT_MIN_SIZE; - - client->req_opts_size = ELEMENTSOF(default_req_opts); - client->req_opts = memdup(default_req_opts, client->req_opts_size); - if (!client->req_opts) - return -ENOMEM; - - *ret = client; - client = NULL; - - return 0; -} |