| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| /*** |
| Copyright © 2013 Intel Corporation. All rights reserved. |
| ***/ |
| |
| #include <net/if_arp.h> |
| #include <sys/ioctl.h> |
| |
| #include "sd-dhcp-server.h" |
| #include "sd-id128.h" |
| |
| #include "alloc-util.h" |
| #include "dhcp-internal.h" |
| #include "dhcp-server-internal.h" |
| #include "dns-domain.h" |
| #include "fd-util.h" |
| #include "in-addr-util.h" |
| #include "io-util.h" |
| #include "memory-util.h" |
| #include "network-common.h" |
| #include "ordered-set.h" |
| #include "siphash24.h" |
| #include "string-util.h" |
| #include "unaligned.h" |
| #include "utf8.h" |
| |
| #define DHCP_DEFAULT_LEASE_TIME_USEC USEC_PER_HOUR |
| #define DHCP_MAX_LEASE_TIME_USEC (USEC_PER_HOUR*12) |
| |
| static DHCPLease *dhcp_lease_free(DHCPLease *lease) { |
| if (!lease) |
| return NULL; |
| |
| if (lease->server) { |
| hashmap_remove_value(lease->server->bound_leases_by_address, UINT32_TO_PTR(lease->address), lease); |
| hashmap_remove_value(lease->server->bound_leases_by_client_id, &lease->client_id, lease); |
| hashmap_remove_value(lease->server->static_leases_by_address, UINT32_TO_PTR(lease->address), lease); |
| hashmap_remove_value(lease->server->static_leases_by_client_id, &lease->client_id, lease); |
| } |
| |
| free(lease->client_id.data); |
| return mfree(lease); |
| } |
| |
| DEFINE_TRIVIAL_CLEANUP_FUNC(DHCPLease*, dhcp_lease_free); |
| |
| /* configures the server's address and subnet, and optionally the pool's size and offset into the subnet |
| * the whole pool must fit into the subnet, and may not contain the first (any) nor last (broadcast) address |
| * moreover, the server's own address may be in the pool, and is in that case reserved in order not to |
| * accidentally hand it out */ |
| int sd_dhcp_server_configure_pool( |
| sd_dhcp_server *server, |
| const struct in_addr *address, |
| unsigned char prefixlen, |
| uint32_t offset, |
| uint32_t size) { |
| |
| struct in_addr netmask_addr; |
| be32_t netmask; |
| uint32_t server_off, broadcast_off, size_max; |
| |
| assert_return(server, -EINVAL); |
| assert_return(address, -EINVAL); |
| assert_return(address->s_addr != INADDR_ANY, -EINVAL); |
| assert_return(prefixlen <= 32, -ERANGE); |
| |
| assert_se(in4_addr_prefixlen_to_netmask(&netmask_addr, prefixlen)); |
| netmask = netmask_addr.s_addr; |
| |
| server_off = be32toh(address->s_addr & ~netmask); |
| broadcast_off = be32toh(~netmask); |
| |
| /* the server address cannot be the subnet address */ |
| assert_return(server_off != 0, -ERANGE); |
| |
| /* nor the broadcast address */ |
| assert_return(server_off != broadcast_off, -ERANGE); |
| |
| /* 0 offset means we should set a default, we skip the first (subnet) address |
| and take the next one */ |
| if (offset == 0) |
| offset = 1; |
| |
| size_max = (broadcast_off + 1) /* the number of addresses in the subnet */ |
| - offset /* exclude the addresses before the offset */ |
| - 1; /* exclude the last (broadcast) address */ |
| |
| /* The pool must contain at least one address */ |
| assert_return(size_max >= 1, -ERANGE); |
| |
| if (size != 0) |
| assert_return(size <= size_max, -ERANGE); |
| else |
| size = size_max; |
| |
| if (server->address != address->s_addr || server->netmask != netmask || server->pool_size != size || server->pool_offset != offset) { |
| |
| server->pool_offset = offset; |
| server->pool_size = size; |
| |
| server->address = address->s_addr; |
| server->netmask = netmask; |
| server->subnet = address->s_addr & netmask; |
| |
| /* Drop any leases associated with the old address range */ |
| hashmap_clear(server->bound_leases_by_address); |
| hashmap_clear(server->bound_leases_by_client_id); |
| |
| if (server->callback) |
| server->callback(server, SD_DHCP_SERVER_EVENT_LEASE_CHANGED, server->callback_userdata); |
| } |
| |
| return 0; |
| } |
| |
| int sd_dhcp_server_is_running(sd_dhcp_server *server) { |
| assert_return(server, false); |
| |
| return !!server->receive_message; |
| } |
| |
| int sd_dhcp_server_is_in_relay_mode(sd_dhcp_server *server) { |
| assert_return(server, -EINVAL); |
| |
| return in4_addr_is_set(&server->relay_target); |
| } |
| |
| void client_id_hash_func(const DHCPClientId *id, struct siphash *state) { |
| assert(id); |
| assert(id->length > 0); |
| assert(id->data); |
| |
| siphash24_compress(&id->length, sizeof(id->length), state); |
| siphash24_compress(id->data, id->length, state); |
| } |
| |
| int client_id_compare_func(const DHCPClientId *a, const DHCPClientId *b) { |
| int r; |
| |
| assert(a->length > 0); |
| assert(a->data); |
| assert(b->length > 0); |
| assert(b->data); |
| |
| r = CMP(a->length, b->length); |
| if (r != 0) |
| return r; |
| |
| return memcmp(a->data, b->data, a->length); |
| } |
| |
| DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR( |
| dhcp_lease_hash_ops, |
| DHCPClientId, |
| client_id_hash_func, |
| client_id_compare_func, |
| DHCPLease, |
| dhcp_lease_free); |
| |
| static sd_dhcp_server *dhcp_server_free(sd_dhcp_server *server) { |
| assert(server); |
| |
| sd_dhcp_server_stop(server); |
| |
| sd_event_unref(server->event); |
| |
| free(server->boot_server_name); |
| free(server->boot_filename); |
| free(server->timezone); |
| |
| for (sd_dhcp_lease_server_type_t i = 0; i < _SD_DHCP_LEASE_SERVER_TYPE_MAX; i++) |
| free(server->servers[i].addr); |
| |
| server->bound_leases_by_address = hashmap_free(server->bound_leases_by_address); |
| server->bound_leases_by_client_id = hashmap_free(server->bound_leases_by_client_id); |
| server->static_leases_by_address = hashmap_free(server->static_leases_by_address); |
| server->static_leases_by_client_id = hashmap_free(server->static_leases_by_client_id); |
| |
| ordered_set_free(server->extra_options); |
| ordered_set_free(server->vendor_options); |
| |
| free(server->agent_circuit_id); |
| free(server->agent_remote_id); |
| |
| free(server->ifname); |
| return mfree(server); |
| } |
| |
| DEFINE_TRIVIAL_REF_UNREF_FUNC(sd_dhcp_server, sd_dhcp_server, dhcp_server_free); |
| |
| int sd_dhcp_server_new(sd_dhcp_server **ret, int ifindex) { |
| _cleanup_(sd_dhcp_server_unrefp) sd_dhcp_server *server = NULL; |
| |
| assert_return(ret, -EINVAL); |
| assert_return(ifindex > 0, -EINVAL); |
| |
| server = new(sd_dhcp_server, 1); |
| if (!server) |
| return -ENOMEM; |
| |
| *server = (sd_dhcp_server) { |
| .n_ref = 1, |
| .fd_raw = -EBADF, |
| .fd = -EBADF, |
| .fd_broadcast = -EBADF, |
| .address = htobe32(INADDR_ANY), |
| .netmask = htobe32(INADDR_ANY), |
| .ifindex = ifindex, |
| .bind_to_interface = true, |
| .default_lease_time = DIV_ROUND_UP(DHCP_DEFAULT_LEASE_TIME_USEC, USEC_PER_SEC), |
| .max_lease_time = DIV_ROUND_UP(DHCP_MAX_LEASE_TIME_USEC, USEC_PER_SEC), |
| }; |
| |
| *ret = TAKE_PTR(server); |
| |
| return 0; |
| } |
| |
| int sd_dhcp_server_set_ifname(sd_dhcp_server *server, const char *ifname) { |
| assert_return(server, -EINVAL); |
| assert_return(ifname, -EINVAL); |
| |
| if (!ifname_valid_full(ifname, IFNAME_VALID_ALTERNATIVE)) |
| return -EINVAL; |
| |
| return free_and_strdup(&server->ifname, ifname); |
| } |
| |
| int sd_dhcp_server_get_ifname(sd_dhcp_server *server, const char **ret) { |
| int r; |
| |
| assert_return(server, -EINVAL); |
| |
| r = get_ifname(server->ifindex, &server->ifname); |
| if (r < 0) |
| return r; |
| |
| if (ret) |
| *ret = server->ifname; |
| |
| return 0; |
| } |
| |
| int sd_dhcp_server_attach_event(sd_dhcp_server *server, sd_event *event, int64_t priority) { |
| int r; |
| |
| assert_return(server, -EINVAL); |
| assert_return(!server->event, -EBUSY); |
| |
| if (event) |
| server->event = sd_event_ref(event); |
| else { |
| r = sd_event_default(&server->event); |
| if (r < 0) |
| return r; |
| } |
| |
| server->event_priority = priority; |
| |
| return 0; |
| } |
| |
| int sd_dhcp_server_detach_event(sd_dhcp_server *server) { |
| assert_return(server, -EINVAL); |
| |
| server->event = sd_event_unref(server->event); |
| |
| return 0; |
| } |
| |
| sd_event *sd_dhcp_server_get_event(sd_dhcp_server *server) { |
| assert_return(server, NULL); |
| |
| return server->event; |
| } |
| |
| int sd_dhcp_server_set_boot_server_address(sd_dhcp_server *server, const struct in_addr *address) { |
| assert_return(server, -EINVAL); |
| |
| if (address) |
| server->boot_server_address = *address; |
| else |
| server->boot_server_address = (struct in_addr) {}; |
| |
| return 0; |
| } |
| |
| int sd_dhcp_server_set_boot_server_name(sd_dhcp_server *server, const char *name) { |
| int r; |
| |
| assert_return(server, -EINVAL); |
| |
| if (name) { |
| r = dns_name_is_valid(name); |
| if (r < 0) |
| return r; |
| if (r == 0) |
| return -EINVAL; |
| } |
| |
| return free_and_strdup(&server->boot_server_name, name); |
| } |
| |
| int sd_dhcp_server_set_boot_filename(sd_dhcp_server *server, const char *filename) { |
| assert_return(server, -EINVAL); |
| |
| if (filename && (!string_is_safe(filename) || !ascii_is_valid(filename))) |
| return -EINVAL; |
| |
| return free_and_strdup(&server->boot_filename, filename); |
| } |
| |
| int sd_dhcp_server_stop(sd_dhcp_server *server) { |
| bool running; |
| |
| if (!server) |
| return 0; |
| |
| running = sd_dhcp_server_is_running(server); |
| |
| server->receive_message = sd_event_source_disable_unref(server->receive_message); |
| server->receive_broadcast = sd_event_source_disable_unref(server->receive_broadcast); |
| |
| server->fd_raw = safe_close(server->fd_raw); |
| server->fd = safe_close(server->fd); |
| server->fd_broadcast = safe_close(server->fd_broadcast); |
| |
| if (running) |
| log_dhcp_server(server, "STOPPED"); |
| |
| return 0; |
| } |
| |
| static int dhcp_server_send_unicast_raw( |
| sd_dhcp_server *server, |
| uint8_t hlen, |
| const uint8_t *chaddr, |
| DHCPPacket *packet, |
| size_t len) { |
| |
| union sockaddr_union link = { |
| .ll.sll_family = AF_PACKET, |
| .ll.sll_protocol = htobe16(ETH_P_IP), |
| .ll.sll_ifindex = server->ifindex, |
| .ll.sll_halen = hlen, |
| }; |
| |
| assert(server); |
| assert(server->ifindex > 0); |
| assert(server->address != 0); |
| assert(hlen > 0); |
| assert(chaddr); |
| assert(packet); |
| assert(len > sizeof(DHCPPacket)); |
| |
| memcpy(link.ll.sll_addr, chaddr, hlen); |
| |
| if (len > UINT16_MAX) |
| return -EOVERFLOW; |
| |
| dhcp_packet_append_ip_headers(packet, server->address, DHCP_PORT_SERVER, |
| packet->dhcp.yiaddr, |
| DHCP_PORT_CLIENT, len, -1); |
| |
| return dhcp_network_send_raw_socket(server->fd_raw, &link, packet, len); |
| } |
| |
| static int dhcp_server_send_udp(sd_dhcp_server *server, be32_t destination, |
| uint16_t destination_port, |
| DHCPMessage *message, size_t len) { |
| union sockaddr_union dest = { |
| .in.sin_family = AF_INET, |
| .in.sin_port = htobe16(destination_port), |
| .in.sin_addr.s_addr = destination, |
| }; |
| struct iovec iov = { |
| .iov_base = message, |
| .iov_len = len, |
| }; |
| CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct in_pktinfo))) control = {}; |
| struct msghdr msg = { |
| .msg_name = &dest, |
| .msg_namelen = sizeof(dest.in), |
| .msg_iov = &iov, |
| .msg_iovlen = 1, |
| }; |
| struct cmsghdr *cmsg; |
| struct in_pktinfo *pktinfo; |
| |
| assert(server); |
| assert(server->fd >= 0); |
| assert(message); |
| assert(len >= sizeof(DHCPMessage)); |
| |
| if (server->bind_to_interface) { |
| msg.msg_control = &control; |
| msg.msg_controllen = sizeof(control); |
| |
| cmsg = CMSG_FIRSTHDR(&msg); |
| assert(cmsg); |
| |
| cmsg->cmsg_level = IPPROTO_IP; |
| cmsg->cmsg_type = IP_PKTINFO; |
| cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo)); |
| |
| /* we attach source interface and address info to the message |
| rather than binding the socket. This will be mostly useful |
| when we gain support for arbitrary number of server addresses |
| */ |
| pktinfo = (struct in_pktinfo*) CMSG_DATA(cmsg); |
| assert(pktinfo); |
| |
| pktinfo->ipi_ifindex = server->ifindex; |
| pktinfo->ipi_spec_dst.s_addr = server->address; |
| } |
| |
| if (sendmsg(server->fd, &msg, 0) < 0) |
| return -errno; |
| |
| return 0; |
| } |
| |
| static bool requested_broadcast(DHCPMessage *message) { |
| assert(message); |
| return message->flags & htobe16(0x8000); |
| } |
| |
| static int dhcp_server_send( |
| sd_dhcp_server *server, |
| uint8_t hlen, |
| const uint8_t *chaddr, |
| be32_t destination, |
| uint16_t destination_port, |
| DHCPPacket *packet, |
| size_t optoffset, |
| bool l2_broadcast) { |
| |
| if (destination != INADDR_ANY) |
| return dhcp_server_send_udp(server, destination, |
| destination_port, &packet->dhcp, |
| sizeof(DHCPMessage) + optoffset); |
| else if (l2_broadcast) |
| return dhcp_server_send_udp(server, INADDR_BROADCAST, |
| destination_port, &packet->dhcp, |
| sizeof(DHCPMessage) + optoffset); |
| else |
| /* we cannot send UDP packet to specific MAC address when the |
| address is not yet configured, so must fall back to raw |
| packets */ |
| return dhcp_server_send_unicast_raw(server, hlen, chaddr, packet, |
| sizeof(DHCPPacket) + optoffset); |
| } |
| |
| int dhcp_server_send_packet(sd_dhcp_server *server, |
| DHCPRequest *req, DHCPPacket *packet, |
| int type, size_t optoffset) { |
| be32_t destination = INADDR_ANY; |
| uint16_t destination_port = DHCP_PORT_CLIENT; |
| int r; |
| |
| assert(server); |
| assert(req); |
| assert(req->max_optlen > 0); |
| assert(req->message); |
| assert(optoffset <= req->max_optlen); |
| assert(packet); |
| |
| r = dhcp_option_append(&packet->dhcp, req->max_optlen, &optoffset, 0, |
| SD_DHCP_OPTION_SERVER_IDENTIFIER, |
| 4, &server->address); |
| if (r < 0) |
| return r; |
| |
| if (req->agent_info_option) { |
| size_t opt_full_length = *(req->agent_info_option + 1) + 2; |
| /* there must be space left for SD_DHCP_OPTION_END */ |
| if (optoffset + opt_full_length < req->max_optlen) { |
| memcpy(packet->dhcp.options + optoffset, req->agent_info_option, opt_full_length); |
| optoffset += opt_full_length; |
| } |
| } |
| |
| r = dhcp_option_append(&packet->dhcp, req->max_optlen, &optoffset, 0, |
| SD_DHCP_OPTION_END, 0, NULL); |
| if (r < 0) |
| return r; |
| |
| /* RFC 2131 Section 4.1 |
| |
| If the ’giaddr’ field in a DHCP message from a client is non-zero, |
| the server sends any return messages to the ’DHCP server’ port on the |
| BOOTP relay agent whose address appears in ’giaddr’. If the ’giaddr’ |
| field is zero and the ’ciaddr’ field is nonzero, then the server |
| unicasts DHCPOFFER and DHCPACK messages to the address in ’ciaddr’. |
| If ’giaddr’ is zero and ’ciaddr’ is zero, and the broadcast bit is |
| set, then the server broadcasts DHCPOFFER and DHCPACK messages to |
| 0xffffffff. If the broadcast bit is not set and ’giaddr’ is zero and |
| ’ciaddr’ is zero, then the server unicasts DHCPOFFER and DHCPACK |
| messages to the client’s hardware address and ’yiaddr’ address. In |
| all cases, when ’giaddr’ is zero, the server broadcasts any DHCPNAK |
| messages to 0xffffffff. |
| |
| Section 4.3.2 |
| |
| If ’giaddr’ is set in the DHCPREQUEST message, the client is on a |
| different subnet. The server MUST set the broadcast bit in the |
| DHCPNAK, so that the relay agent will broadcast the DHCPNAK to the |
| client, because the client may not have a correct network address |
| or subnet mask, and the client may not be answering ARP requests. |
| */ |
| if (req->message->giaddr != 0) { |
| destination = req->message->giaddr; |
| destination_port = DHCP_PORT_SERVER; |
| if (type == DHCP_NAK) |
| packet->dhcp.flags = htobe16(0x8000); |
| } else if (req->message->ciaddr != 0 && type != DHCP_NAK) |
| destination = req->message->ciaddr; |
| |
| bool l2_broadcast = requested_broadcast(req->message) || type == DHCP_NAK; |
| return dhcp_server_send(server, req->message->hlen, req->message->chaddr, |
| destination, destination_port, packet, optoffset, l2_broadcast); |
| } |
| |
| static int server_message_init( |
| sd_dhcp_server *server, |
| DHCPPacket **ret, |
| uint8_t type, |
| size_t *ret_optoffset, |
| DHCPRequest *req) { |
| |
| _cleanup_free_ DHCPPacket *packet = NULL; |
| size_t optoffset = 0; |
| int r; |
| |
| assert(server); |
| assert(ret); |
| assert(ret_optoffset); |
| assert(IN_SET(type, DHCP_OFFER, DHCP_ACK, DHCP_NAK)); |
| assert(req); |
| |
| packet = malloc0(sizeof(DHCPPacket) + req->max_optlen); |
| if (!packet) |
| return -ENOMEM; |
| |
| r = dhcp_message_init(&packet->dhcp, BOOTREPLY, |
| be32toh(req->message->xid), type, |
| req->message->htype, req->message->hlen, req->message->chaddr, |
| req->max_optlen, &optoffset); |
| if (r < 0) |
| return r; |
| |
| packet->dhcp.flags = req->message->flags; |
| packet->dhcp.giaddr = req->message->giaddr; |
| |
| *ret_optoffset = optoffset; |
| *ret = TAKE_PTR(packet); |
| |
| return 0; |
| } |
| |
| static int server_send_offer_or_ack( |
| sd_dhcp_server *server, |
| DHCPRequest *req, |
| be32_t address, |
| uint8_t type) { |
| |
| _cleanup_free_ DHCPPacket *packet = NULL; |
| sd_dhcp_option *j; |
| be32_t lease_time; |
| size_t offset; |
| int r; |
| |
| assert(server); |
| assert(req); |
| assert(IN_SET(type, DHCP_OFFER, DHCP_ACK)); |
| |
| r = server_message_init(server, &packet, type, &offset, req); |
| if (r < 0) |
| return r; |
| |
| packet->dhcp.yiaddr = address; |
| packet->dhcp.siaddr = server->boot_server_address.s_addr; |
| |
| lease_time = htobe32(req->lifetime); |
| r = dhcp_option_append(&packet->dhcp, req->max_optlen, &offset, 0, |
| SD_DHCP_OPTION_IP_ADDRESS_LEASE_TIME, 4, |
| &lease_time); |
| if (r < 0) |
| return r; |
| |
| r = dhcp_option_append(&packet->dhcp, req->max_optlen, &offset, 0, |
| SD_DHCP_OPTION_SUBNET_MASK, 4, &server->netmask); |
| if (r < 0) |
| return r; |
| |
| if (server->emit_router) { |
| r = dhcp_option_append(&packet->dhcp, req->max_optlen, &offset, 0, |
| SD_DHCP_OPTION_ROUTER, 4, |
| in4_addr_is_set(&server->router_address) ? |
| &server->router_address.s_addr : |
| &server->address); |
| if (r < 0) |
| return r; |
| } |
| |
| if (server->boot_server_name) { |
| r = dhcp_option_append(&packet->dhcp, req->max_optlen, &offset, 0, |
| SD_DHCP_OPTION_BOOT_SERVER_NAME, |
| strlen(server->boot_server_name), server->boot_server_name); |
| if (r < 0) |
| return r; |
| } |
| |
| if (server->boot_filename) { |
| r = dhcp_option_append(&packet->dhcp, req->max_optlen, &offset, 0, |
| SD_DHCP_OPTION_BOOT_FILENAME, |
| strlen(server->boot_filename), server->boot_filename); |
| if (r < 0) |
| return r; |
| } |
| |
| if (type == DHCP_ACK) { |
| static const uint8_t option_map[_SD_DHCP_LEASE_SERVER_TYPE_MAX] = { |
| [SD_DHCP_LEASE_DNS] = SD_DHCP_OPTION_DOMAIN_NAME_SERVER, |
| [SD_DHCP_LEASE_NTP] = SD_DHCP_OPTION_NTP_SERVER, |
| [SD_DHCP_LEASE_SIP] = SD_DHCP_OPTION_SIP_SERVER, |
| [SD_DHCP_LEASE_POP3] = SD_DHCP_OPTION_POP3_SERVER, |
| [SD_DHCP_LEASE_SMTP] = SD_DHCP_OPTION_SMTP_SERVER, |
| [SD_DHCP_LEASE_LPR] = SD_DHCP_OPTION_LPR_SERVER, |
| }; |
| |
| for (sd_dhcp_lease_server_type_t k = 0; k < _SD_DHCP_LEASE_SERVER_TYPE_MAX; k++) { |
| if (server->servers[k].size <= 0) |
| continue; |
| |
| r = dhcp_option_append( |
| &packet->dhcp, req->max_optlen, &offset, 0, |
| option_map[k], |
| sizeof(struct in_addr) * server->servers[k].size, |
| server->servers[k].addr); |
| if (r < 0) |
| return r; |
| } |
| |
| |
| if (server->timezone) { |
| r = dhcp_option_append( |
| &packet->dhcp, req->max_optlen, &offset, 0, |
| SD_DHCP_OPTION_TZDB_TIMEZONE, |
| strlen(server->timezone), server->timezone); |
| if (r < 0) |
| return r; |
| } |
| } |
| |
| ORDERED_SET_FOREACH(j, server->extra_options) { |
| r = dhcp_option_append(&packet->dhcp, req->max_optlen, &offset, 0, |
| j->option, j->length, j->data); |
| if (r < 0) |
| return r; |
| } |
| |
| if (!ordered_set_isempty(server->vendor_options)) { |
| r = dhcp_option_append( |
| &packet->dhcp, req->max_optlen, &offset, 0, |
| SD_DHCP_OPTION_VENDOR_SPECIFIC, |
| ordered_set_size(server->vendor_options), server->vendor_options); |
| if (r < 0) |
| return r; |
| } |
| |
| return dhcp_server_send_packet(server, req, packet, type, offset); |
| } |
| |
| static int server_send_nak_or_ignore(sd_dhcp_server *server, bool init_reboot, DHCPRequest *req) { |
| _cleanup_free_ DHCPPacket *packet = NULL; |
| size_t offset; |
| int r; |
| |
| /* When a request is refused, RFC 2131, section 4.3.2 mentioned we should send NAK when the |
| * client is in INITREBOOT. If the client is in other state, there is nothing mentioned in the |
| * RFC whether we should send NAK or not. Hence, let's silently ignore the request. */ |
| |
| if (!init_reboot) |
| return 0; |
| |
| r = server_message_init(server, &packet, DHCP_NAK, &offset, req); |
| if (r < 0) |
| return log_dhcp_server_errno(server, r, "Failed to create NAK message: %m"); |
| |
| r = dhcp_server_send_packet(server, req, packet, DHCP_NAK, offset); |
| if (r < 0) |
| return log_dhcp_server_errno(server, r, "Could not send NAK message: %m"); |
| |
| log_dhcp_server(server, "NAK (0x%x)", be32toh(req->message->xid)); |
| return DHCP_NAK; |
| } |
| |
| static int server_send_forcerenew( |
| sd_dhcp_server *server, |
| be32_t address, |
| be32_t gateway, |
| uint8_t htype, |
| uint8_t hlen, |
| const uint8_t *chaddr) { |
| |
| _cleanup_free_ DHCPPacket *packet = NULL; |
| size_t optoffset = 0; |
| int r; |
| |
| assert(server); |
| assert(address != INADDR_ANY); |
| assert(chaddr); |
| |
| packet = malloc0(sizeof(DHCPPacket) + DHCP_MIN_OPTIONS_SIZE); |
| if (!packet) |
| return -ENOMEM; |
| |
| r = dhcp_message_init(&packet->dhcp, BOOTREPLY, 0, |
| DHCP_FORCERENEW, htype, hlen, chaddr, |
| DHCP_MIN_OPTIONS_SIZE, &optoffset); |
| if (r < 0) |
| return r; |
| |
| r = dhcp_option_append(&packet->dhcp, DHCP_MIN_OPTIONS_SIZE, |
| &optoffset, 0, SD_DHCP_OPTION_END, 0, NULL); |
| if (r < 0) |
| return r; |
| |
| return dhcp_server_send_udp(server, address, DHCP_PORT_CLIENT, |
| &packet->dhcp, |
| sizeof(DHCPMessage) + optoffset); |
| } |
| |
| static int parse_request(uint8_t code, uint8_t len, const void *option, void *userdata) { |
| DHCPRequest *req = ASSERT_PTR(userdata); |
| |
| switch (code) { |
| case SD_DHCP_OPTION_IP_ADDRESS_LEASE_TIME: |
| if (len == 4) |
| req->lifetime = unaligned_read_be32(option); |
| |
| break; |
| case SD_DHCP_OPTION_REQUESTED_IP_ADDRESS: |
| if (len == 4) |
| memcpy(&req->requested_ip, option, sizeof(be32_t)); |
| |
| break; |
| case SD_DHCP_OPTION_SERVER_IDENTIFIER: |
| if (len == 4) |
| memcpy(&req->server_id, option, sizeof(be32_t)); |
| |
| break; |
| case SD_DHCP_OPTION_CLIENT_IDENTIFIER: |
| if (len >= 2) { |
| uint8_t *data; |
| |
| data = memdup(option, len); |
| if (!data) |
| return -ENOMEM; |
| |
| free_and_replace(req->client_id.data, data); |
| req->client_id.length = len; |
| } |
| |
| break; |
| case SD_DHCP_OPTION_MAXIMUM_MESSAGE_SIZE: |
| |
| if (len == 2 && unaligned_read_be16(option) >= sizeof(DHCPPacket)) |
| req->max_optlen = unaligned_read_be16(option) - sizeof(DHCPPacket); |
| |
| break; |
| case SD_DHCP_OPTION_RELAY_AGENT_INFORMATION: |
| req->agent_info_option = (uint8_t*)option - 2; |
| |
| break; |
| } |
| |
| return 0; |
| } |
| |
| static DHCPRequest* dhcp_request_free(DHCPRequest *req) { |
| if (!req) |
| return NULL; |
| |
| free(req->client_id.data); |
| return mfree(req); |
| } |
| |
| DEFINE_TRIVIAL_CLEANUP_FUNC(DHCPRequest*, dhcp_request_free); |
| |
| static int ensure_sane_request(sd_dhcp_server *server, DHCPRequest *req, DHCPMessage *message) { |
| assert(req); |
| assert(message); |
| |
| req->message = message; |
| |
| if (message->hlen > sizeof(message->chaddr)) |
| return -EBADMSG; |
| |
| /* set client id based on MAC address if client did not send an explicit one */ |
| if (!req->client_id.data) { |
| uint8_t *data; |
| |
| if (message->hlen == 0) |
| return -EBADMSG; |
| |
| data = new0(uint8_t, message->hlen + 1); |
| if (!data) |
| return -ENOMEM; |
| |
| data[0] = 0x01; |
| memcpy(data + 1, message->chaddr, message->hlen); |
| |
| req->client_id.length = message->hlen + 1; |
| req->client_id.data = data; |
| } |
| |
| if (message->hlen == 0 || memeqzero(message->chaddr, message->hlen)) { |
| /* See RFC2131 section 4.1.1. |
| * hlen and chaddr may not be set for non-ethernet interface. |
| * Let's try to retrieve it from the client ID. */ |
| |
| if (!req->client_id.data) |
| return -EBADMSG; |
| |
| if (req->client_id.length <= 1 || req->client_id.length > sizeof(message->chaddr) + 1) |
| return -EBADMSG; |
| |
| if (req->client_id.data[0] != 0x01) |
| return -EBADMSG; |
| |
| message->hlen = req->client_id.length - 1; |
| memcpy(message->chaddr, req->client_id.data + 1, message->hlen); |
| } |
| |
| if (req->max_optlen < DHCP_MIN_OPTIONS_SIZE) |
| req->max_optlen = DHCP_MIN_OPTIONS_SIZE; |
| |
| if (req->lifetime <= 0) |
| req->lifetime = MAX(1ULL, server->default_lease_time); |
| |
| if (server->max_lease_time > 0 && req->lifetime > server->max_lease_time) |
| req->lifetime = server->max_lease_time; |
| |
| return 0; |
| } |
| |
| static bool address_is_in_pool(sd_dhcp_server *server, be32_t address) { |
| assert(server); |
| |
| if (server->pool_size == 0) |
| return false; |
| |
| if (address == server->address) |
| return false; |
| |
| if (be32toh(address) < (be32toh(server->subnet) | server->pool_offset) || |
| be32toh(address) >= (be32toh(server->subnet) | (server->pool_offset + server->pool_size))) |
| return false; |
| |
| if (hashmap_contains(server->static_leases_by_address, UINT32_TO_PTR(address))) |
| return false; |
| |
| return true; |
| } |
| |
| static int append_agent_information_option(sd_dhcp_server *server, DHCPMessage *message, size_t opt_length, size_t size) { |
| int r; |
| size_t offset; |
| |
| assert(server); |
| assert(message); |
| |
| r = dhcp_option_find_option(message->options, opt_length, SD_DHCP_OPTION_END, &offset); |
| if (r < 0) |
| return r; |
| |
| r = dhcp_option_append(message, size, &offset, 0, SD_DHCP_OPTION_RELAY_AGENT_INFORMATION, 0, server); |
| if (r < 0) |
| return r; |
| |
| r = dhcp_option_append(message, size, &offset, 0, SD_DHCP_OPTION_END, 0, NULL); |
| if (r < 0) |
| return r; |
| return offset; |
| } |
| |
| static int dhcp_server_relay_message(sd_dhcp_server *server, DHCPMessage *message, size_t opt_length, size_t buflen) { |
| _cleanup_free_ DHCPPacket *packet = NULL; |
| int r; |
| |
| assert(server); |
| assert(message); |
| assert(sd_dhcp_server_is_in_relay_mode(server)); |
| |
| if (message->hlen == 0 || message->hlen > sizeof(message->chaddr) || memeqzero(message->chaddr, message->hlen)) |
| return log_dhcp_server_errno(server, SYNTHETIC_ERRNO(EBADMSG), |
| "(relay agent) received message without/invalid hardware address, discarding."); |
| |
| if (message->op == BOOTREQUEST) { |
| log_dhcp_server(server, "(relay agent) BOOTREQUEST (0x%x)", be32toh(message->xid)); |
| if (message->hops >= 16) |
| return -ETIME; |
| message->hops++; |
| |
| /* https://tools.ietf.org/html/rfc1542#section-4.1.1 */ |
| if (message->giaddr == 0) |
| message->giaddr = server->address; |
| |
| if (server->agent_circuit_id || server->agent_remote_id) { |
| r = append_agent_information_option(server, message, opt_length, buflen - sizeof(DHCPMessage)); |
| if (r < 0) |
| return log_dhcp_server_errno(server, r, "could not append relay option: %m"); |
| opt_length = r; |
| } |
| |
| return dhcp_server_send_udp(server, server->relay_target.s_addr, DHCP_PORT_SERVER, message, sizeof(DHCPMessage) + opt_length); |
| } else if (message->op == BOOTREPLY) { |
| log_dhcp_server(server, "(relay agent) BOOTREPLY (0x%x)", be32toh(message->xid)); |
| if (message->giaddr != server->address) |
| return log_dhcp_server_errno(server, SYNTHETIC_ERRNO(EBADMSG), |
| "(relay agent) BOOTREPLY giaddr mismatch, discarding"); |
| |
| int message_type = dhcp_option_parse(message, sizeof(DHCPMessage) + opt_length, NULL, NULL, NULL); |
| if (message_type < 0) |
| return message_type; |
| |
| packet = malloc0(sizeof(DHCPPacket) + opt_length); |
| if (!packet) |
| return -ENOMEM; |
| memcpy(&packet->dhcp, message, sizeof(DHCPMessage) + opt_length); |
| |
| r = dhcp_option_remove_option(packet->dhcp.options, opt_length, SD_DHCP_OPTION_RELAY_AGENT_INFORMATION); |
| if (r > 0) |
| opt_length = r; |
| |
| bool l2_broadcast = requested_broadcast(message) || message_type == DHCP_NAK; |
| const be32_t destination = message_type == DHCP_NAK ? INADDR_ANY : message->ciaddr; |
| return dhcp_server_send(server, message->hlen, message->chaddr, destination, DHCP_PORT_CLIENT, packet, opt_length, l2_broadcast); |
| } |
| return -EBADMSG; |
| } |
| |
| static int prepare_new_lease( |
| DHCPLease **ret_lease, |
| be32_t address, |
| const DHCPClientId *client_id, |
| uint8_t htype, |
| uint8_t hlen, |
| const uint8_t *chaddr, |
| be32_t gateway, |
| usec_t expiration) { |
| |
| _cleanup_(dhcp_lease_freep) DHCPLease *lease = NULL; |
| |
| lease = new(DHCPLease, 1); |
| if (!lease) |
| return -ENOMEM; |
| |
| *lease = (DHCPLease) { |
| .address = address, |
| .client_id.length = client_id->length, |
| .htype = htype, |
| .hlen = hlen, |
| .gateway = gateway, |
| .expiration = expiration, |
| }; |
| lease->client_id.data = memdup(client_id->data, client_id->length); |
| if (!lease->client_id.data) |
| return -ENOMEM; |
| |
| memcpy(lease->chaddr, chaddr, hlen); |
| |
| *ret_lease = TAKE_PTR(lease); |
| |
| return 0; |
| } |
| |
| static int server_ack_request(sd_dhcp_server *server, DHCPRequest *req, DHCPLease *existing_lease, be32_t address) { |
| usec_t time_now, expiration; |
| int r; |
| |
| assert(server); |
| assert(req); |
| assert(address != 0); |
| |
| r = sd_event_now(server->event, CLOCK_BOOTTIME, &time_now); |
| if (r < 0) |
| return r; |
| |
| expiration = usec_add(req->lifetime * USEC_PER_SEC, time_now); |
| |
| if (existing_lease) { |
| assert(existing_lease->server); |
| assert(existing_lease->address == address); |
| existing_lease->expiration = expiration; |
| |
| } else { |
| _cleanup_(dhcp_lease_freep) DHCPLease *lease = NULL; |
| |
| r = prepare_new_lease(&lease, address, &req->client_id, |
| req->message->htype, req->message->hlen, |
| req->message->chaddr, req->message->giaddr, expiration); |
| if (r < 0) |
| return log_dhcp_server_errno(server, r, "Failed to create new lease: %m"); |
| |
| lease->server = server; /* This must be set just before hashmap_put(). */ |
| |
| r = hashmap_ensure_put(&server->bound_leases_by_client_id, &dhcp_lease_hash_ops, &lease->client_id, lease); |
| if (r < 0) |
| return log_dhcp_server_errno(server, r, "Could not save lease: %m"); |
| |
| r = hashmap_ensure_put(&server->bound_leases_by_address, NULL, UINT32_TO_PTR(lease->address), lease); |
| if (r < 0) |
| return log_dhcp_server_errno(server, r, "Could not save lease: %m"); |
| |
| TAKE_PTR(lease); |
| } |
| |
| r = server_send_offer_or_ack(server, req, address, DHCP_ACK); |
| if (r < 0) |
| return log_dhcp_server_errno(server, r, "Could not send ACK: %m"); |
| |
| log_dhcp_server(server, "ACK (0x%x)", be32toh(req->message->xid)); |
| |
| if (server->callback) |
| server->callback(server, SD_DHCP_SERVER_EVENT_LEASE_CHANGED, server->callback_userdata); |
| |
| return DHCP_ACK; |
| } |
| |
| static int dhcp_server_cleanup_expired_leases(sd_dhcp_server *server) { |
| DHCPLease *lease; |
| usec_t time_now; |
| int r; |
| |
| assert(server); |
| |
| r = sd_event_now(server->event, CLOCK_BOOTTIME, &time_now); |
| if (r < 0) |
| return r; |
| |
| HASHMAP_FOREACH(lease, server->bound_leases_by_client_id) |
| if (lease->expiration < time_now) { |
| log_dhcp_server(server, "CLEAN (0x%x)", be32toh(lease->address)); |
| dhcp_lease_free(lease); |
| } |
| |
| return 0; |
| } |
| |
| static bool address_available(sd_dhcp_server *server, be32_t address) { |
| assert(server); |
| |
| if (hashmap_contains(server->bound_leases_by_address, UINT32_TO_PTR(address)) || |
| hashmap_contains(server->static_leases_by_address, UINT32_TO_PTR(address)) || |
| address == server->address) |
| return false; |
| |
| return true; |
| } |
| |
| #define HASH_KEY SD_ID128_MAKE(0d,1d,fe,bd,f1,24,bd,b3,47,f1,dd,6e,73,21,93,30) |
| |
| int dhcp_server_handle_message(sd_dhcp_server *server, DHCPMessage *message, size_t length) { |
| _cleanup_(dhcp_request_freep) DHCPRequest *req = NULL; |
| _cleanup_free_ char *error_message = NULL; |
| DHCPLease *existing_lease, *static_lease; |
| int type, r; |
| |
| assert(server); |
| assert(message); |
| |
| if (message->op != BOOTREQUEST) |
| return 0; |
| |
| req = new0(DHCPRequest, 1); |
| if (!req) |
| return -ENOMEM; |
| |
| type = dhcp_option_parse(message, length, parse_request, req, &error_message); |
| if (type < 0) |
| return 0; |
| |
| r = ensure_sane_request(server, req, message); |
| if (r < 0) |
| return r; |
| |
| r = dhcp_server_cleanup_expired_leases(server); |
| if (r < 0) |
| return r; |
| |
| existing_lease = hashmap_get(server->bound_leases_by_client_id, &req->client_id); |
| static_lease = hashmap_get(server->static_leases_by_client_id, &req->client_id); |
| |
| switch (type) { |
| |
| case DHCP_DISCOVER: { |
| be32_t address = INADDR_ANY; |
| |
| log_dhcp_server(server, "DISCOVER (0x%x)", be32toh(req->message->xid)); |
| |
| if (server->pool_size == 0) |
| /* no pool allocated */ |
| return 0; |
| |
| /* for now pick a random free address from the pool */ |
| if (static_lease) |
| address = static_lease->address; |
| else if (existing_lease) |
| address = existing_lease->address; |
| else { |
| struct siphash state; |
| uint64_t hash; |
| |
| /* even with no persistence of leases, we try to offer the same client |
| the same IP address. we do this by using the hash of the client id |
| as the offset into the pool of leases when finding the next free one */ |
| |
| siphash24_init(&state, HASH_KEY.bytes); |
| client_id_hash_func(&req->client_id, &state); |
| hash = htole64(siphash24_finalize(&state)); |
| |
| for (unsigned i = 0; i < server->pool_size; i++) { |
| be32_t tmp_address; |
| |
| tmp_address = server->subnet | htobe32(server->pool_offset + (hash + i) % server->pool_size); |
| if (address_available(server, tmp_address)) { |
| address = tmp_address; |
| break; |
| } |
| } |
| } |
| |
| if (address == INADDR_ANY) |
| /* no free addresses left */ |
| return 0; |
| |
| r = server_send_offer_or_ack(server, req, address, DHCP_OFFER); |
| if (r < 0) |
| /* this only fails on critical errors */ |
| return log_dhcp_server_errno(server, r, "Could not send offer: %m"); |
| |
| log_dhcp_server(server, "OFFER (0x%x)", be32toh(req->message->xid)); |
| return DHCP_OFFER; |
| } |
| case DHCP_DECLINE: |
| log_dhcp_server(server, "DECLINE (0x%x): %s", be32toh(req->message->xid), strna(error_message)); |
| |
| /* TODO: make sure we don't offer this address again */ |
| |
| return 1; |
| |
| case DHCP_REQUEST: { |
| be32_t address; |
| bool init_reboot = false; |
| |
| /* see RFC 2131, section 4.3.2 */ |
| |
| if (req->server_id != 0) { |
| log_dhcp_server(server, "REQUEST (selecting) (0x%x)", |
| be32toh(req->message->xid)); |
| |
| /* SELECTING */ |
| if (req->server_id != server->address) |
| /* client did not pick us */ |
| return 0; |
| |
| if (req->message->ciaddr != 0) |
| /* this MUST be zero */ |
| return 0; |
| |
| if (req->requested_ip == 0) |
| /* this must be filled in with the yiaddr |
| from the chosen OFFER */ |
| return 0; |
| |
| address = req->requested_ip; |
| } else if (req->requested_ip != 0) { |
| log_dhcp_server(server, "REQUEST (init-reboot) (0x%x)", |
| be32toh(req->message->xid)); |
| |
| /* INIT-REBOOT */ |
| if (req->message->ciaddr != 0) |
| /* this MUST be zero */ |
| return 0; |
| |
| /* TODO: check more carefully if IP is correct */ |
| address = req->requested_ip; |
| init_reboot = true; |
| } else { |
| log_dhcp_server(server, "REQUEST (rebinding/renewing) (0x%x)", |
| be32toh(req->message->xid)); |
| |
| /* REBINDING / RENEWING */ |
| if (req->message->ciaddr == 0) |
| /* this MUST be filled in with clients IP address */ |
| return 0; |
| |
| address = req->message->ciaddr; |
| } |
| |
| /* disallow our own address */ |
| if (address == server->address) |
| return 0; |
| |
| if (static_lease) { |
| /* Found a static lease for the client ID. */ |
| |
| if (static_lease->address != address) |
| /* The client requested an address which is different from the static lease. Refuse. */ |
| return server_send_nak_or_ignore(server, init_reboot, req); |
| |
| return server_ack_request(server, req, existing_lease, address); |
| } |
| |
| if (address_is_in_pool(server, address)) { |
| /* The requested address is in the pool. */ |
| |
| if (existing_lease && existing_lease->address != address) |
| /* We previously assigned an address, but the client requested another one. Refuse. */ |
| return server_send_nak_or_ignore(server, init_reboot, req); |
| |
| return server_ack_request(server, req, existing_lease, address); |
| } |
| |
| return server_send_nak_or_ignore(server, init_reboot, req); |
| } |
| |
| case DHCP_RELEASE: { |
| log_dhcp_server(server, "RELEASE (0x%x)", |
| be32toh(req->message->xid)); |
| |
| if (!existing_lease) |
| return 0; |
| |
| if (existing_lease->address != req->message->ciaddr) |
| return 0; |
| |
| dhcp_lease_free(existing_lease); |
| |
| if (server->callback) |
| server->callback(server, SD_DHCP_SERVER_EVENT_LEASE_CHANGED, server->callback_userdata); |
| |
| return 0; |
| }} |
| |
| return 0; |
| } |
| |
| static size_t relay_agent_information_length(const char* agent_circuit_id, const char* agent_remote_id) { |
| size_t sum = 0; |
| if (agent_circuit_id) |
| sum += 2 + strlen(agent_circuit_id); |
| if (agent_remote_id) |
| sum += 2 + strlen(agent_remote_id); |
| return sum; |
| } |
| |
| static int server_receive_message(sd_event_source *s, int fd, |
| uint32_t revents, void *userdata) { |
| _cleanup_free_ DHCPMessage *message = NULL; |
| CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct in_pktinfo))) control; |
| sd_dhcp_server *server = ASSERT_PTR(userdata); |
| struct iovec iov = {}; |
| struct msghdr msg = { |
| .msg_iov = &iov, |
| .msg_iovlen = 1, |
| .msg_control = &control, |
| .msg_controllen = sizeof(control), |
| }; |
| struct cmsghdr *cmsg; |
| ssize_t datagram_size, len; |
| int r; |
| |
| datagram_size = next_datagram_size_fd(fd); |
| if (datagram_size < 0) { |
| if (ERRNO_IS_TRANSIENT(datagram_size) || ERRNO_IS_DISCONNECT(datagram_size)) |
| return 0; |
| |
| log_dhcp_server_errno(server, datagram_size, "Failed to determine datagram size to read, ignoring: %m"); |
| return 0; |
| } |
| |
| size_t buflen = datagram_size; |
| if (sd_dhcp_server_is_in_relay_mode(server)) |
| /* Preallocate the additional size for DHCP Relay Agent Information Option if needed */ |
| buflen += relay_agent_information_length(server->agent_circuit_id, server->agent_remote_id) + 2; |
| |
| message = malloc(buflen); |
| if (!message) |
| return -ENOMEM; |
| |
| iov = IOVEC_MAKE(message, datagram_size); |
| |
| len = recvmsg_safe(fd, &msg, 0); |
| if (len < 0) { |
| if (ERRNO_IS_TRANSIENT(len) || ERRNO_IS_DISCONNECT(len)) |
| return 0; |
| |
| log_dhcp_server_errno(server, len, "Could not receive message, ignoring: %m"); |
| return 0; |
| } |
| |
| if ((size_t) len < sizeof(DHCPMessage)) |
| return 0; |
| |
| CMSG_FOREACH(cmsg, &msg) |
| if (cmsg->cmsg_level == IPPROTO_IP && |
| cmsg->cmsg_type == IP_PKTINFO && |
| cmsg->cmsg_len == CMSG_LEN(sizeof(struct in_pktinfo))) { |
| struct in_pktinfo *info = (struct in_pktinfo*)CMSG_DATA(cmsg); |
| |
| /* TODO figure out if this can be done as a filter on |
| * the socket, like for IPv6 */ |
| if (server->ifindex != info->ipi_ifindex) |
| return 0; |
| |
| break; |
| } |
| |
| if (sd_dhcp_server_is_in_relay_mode(server)) { |
| r = dhcp_server_relay_message(server, message, len - sizeof(DHCPMessage), buflen); |
| if (r < 0) |
| log_dhcp_server_errno(server, r, "Couldn't relay message, ignoring: %m"); |
| } else { |
| r = dhcp_server_handle_message(server, message, (size_t) len); |
| if (r < 0) |
| log_dhcp_server_errno(server, r, "Couldn't process incoming message, ignoring: %m"); |
| } |
| return 0; |
| } |
| |
| static void dhcp_server_update_lease_servers(sd_dhcp_server *server) { |
| assert(server); |
| assert(server->address != 0); |
| |
| /* Convert null address -> server address */ |
| |
| for (sd_dhcp_lease_server_type_t k = 0; k < _SD_DHCP_LEASE_SERVER_TYPE_MAX; k++) |
| for (size_t i = 0; i < server->servers[k].size; i++) |
| if (in4_addr_is_null(&server->servers[k].addr[i])) |
| server->servers[k].addr[i].s_addr = server->address; |
| } |
| |
| int sd_dhcp_server_start(sd_dhcp_server *server) { |
| int r; |
| |
| assert_return(server, -EINVAL); |
| assert_return(server->event, -EINVAL); |
| |
| if (sd_dhcp_server_is_running(server)) |
| return 0; |
| |
| assert_return(!server->receive_message, -EBUSY); |
| assert_return(server->fd_raw < 0, -EBUSY); |
| assert_return(server->fd < 0, -EBUSY); |
| assert_return(server->address != htobe32(INADDR_ANY), -EUNATCH); |
| |
| dhcp_server_update_lease_servers(server); |
| |
| r = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0); |
| if (r < 0) { |
| r = -errno; |
| goto on_error; |
| } |
| server->fd_raw = r; |
| |
| if (server->bind_to_interface) |
| r = dhcp_network_bind_udp_socket(server->ifindex, INADDR_ANY, DHCP_PORT_SERVER, -1); |
| else |
| r = dhcp_network_bind_udp_socket(0, server->address, DHCP_PORT_SERVER, -1); |
| if (r < 0) |
| goto on_error; |
| server->fd = r; |
| |
| r = sd_event_add_io(server->event, &server->receive_message, |
| server->fd, EPOLLIN, |
| server_receive_message, server); |
| if (r < 0) |
| goto on_error; |
| |
| r = sd_event_source_set_priority(server->receive_message, |
| server->event_priority); |
| if (r < 0) |
| goto on_error; |
| |
| if (!server->bind_to_interface) { |
| r = dhcp_network_bind_udp_socket(server->ifindex, INADDR_BROADCAST, DHCP_PORT_SERVER, -1); |
| if (r < 0) |
| goto on_error; |
| |
| server->fd_broadcast = r; |
| |
| r = sd_event_add_io(server->event, &server->receive_broadcast, |
| server->fd_broadcast, EPOLLIN, |
| server_receive_message, server); |
| if (r < 0) |
| goto on_error; |
| |
| r = sd_event_source_set_priority(server->receive_broadcast, |
| server->event_priority); |
| if (r < 0) |
| goto on_error; |
| } |
| |
| log_dhcp_server(server, "STARTED"); |
| |
| return 0; |
| |
| on_error: |
| sd_dhcp_server_stop(server); |
| return r; |
| } |
| |
| int sd_dhcp_server_forcerenew(sd_dhcp_server *server) { |
| DHCPLease *lease; |
| int k, r = 0; |
| |
| assert_return(server, -EINVAL); |
| |
| log_dhcp_server(server, "FORCERENEW"); |
| |
| HASHMAP_FOREACH(lease, server->bound_leases_by_client_id) { |
| k = server_send_forcerenew(server, lease->address, lease->gateway, |
| lease->htype, lease->hlen, lease->chaddr); |
| if (k < 0) |
| r = k; |
| } |
| |
| return r; |
| } |
| |
| int sd_dhcp_server_set_bind_to_interface(sd_dhcp_server *server, int enabled) { |
| assert_return(server, -EINVAL); |
| assert_return(!sd_dhcp_server_is_running(server), -EBUSY); |
| |
| if (!!enabled == server->bind_to_interface) |
| return 0; |
| |
| server->bind_to_interface = enabled; |
| |
| return 1; |
| } |
| |
| int sd_dhcp_server_set_timezone(sd_dhcp_server *server, const char *tz) { |
| int r; |
| |
| assert_return(server, -EINVAL); |
| assert_return(timezone_is_valid(tz, LOG_DEBUG), -EINVAL); |
| |
| if (streq_ptr(tz, server->timezone)) |
| return 0; |
| |
| r = free_and_strdup(&server->timezone, tz); |
| if (r < 0) |
| return r; |
| |
| return 1; |
| } |
| |
| int sd_dhcp_server_set_max_lease_time(sd_dhcp_server *server, uint32_t t) { |
| assert_return(server, -EINVAL); |
| |
| if (t == server->max_lease_time) |
| return 0; |
| |
| server->max_lease_time = t; |
| return 1; |
| } |
| |
| int sd_dhcp_server_set_default_lease_time(sd_dhcp_server *server, uint32_t t) { |
| assert_return(server, -EINVAL); |
| |
| if (t == server->default_lease_time) |
| return 0; |
| |
| server->default_lease_time = t; |
| return 1; |
| } |
| |
| int sd_dhcp_server_set_servers( |
| sd_dhcp_server *server, |
| sd_dhcp_lease_server_type_t what, |
| const struct in_addr addresses[], |
| size_t n_addresses) { |
| |
| struct in_addr *c = NULL; |
| |
| assert_return(server, -EINVAL); |
| assert_return(!sd_dhcp_server_is_running(server), -EBUSY); |
| assert_return(addresses || n_addresses == 0, -EINVAL); |
| assert_return(what >= 0, -EINVAL); |
| assert_return(what < _SD_DHCP_LEASE_SERVER_TYPE_MAX, -EINVAL); |
| |
| if (server->servers[what].size == n_addresses && |
| memcmp(server->servers[what].addr, addresses, sizeof(struct in_addr) * n_addresses) == 0) |
| return 0; |
| |
| if (n_addresses > 0) { |
| c = newdup(struct in_addr, addresses, n_addresses); |
| if (!c) |
| return -ENOMEM; |
| } |
| |
| free_and_replace(server->servers[what].addr, c); |
| server->servers[what].size = n_addresses; |
| return 1; |
| } |
| |
| int sd_dhcp_server_set_dns(sd_dhcp_server *server, const struct in_addr dns[], size_t n) { |
| return sd_dhcp_server_set_servers(server, SD_DHCP_LEASE_DNS, dns, n); |
| } |
| int sd_dhcp_server_set_ntp(sd_dhcp_server *server, const struct in_addr ntp[], size_t n) { |
| return sd_dhcp_server_set_servers(server, SD_DHCP_LEASE_NTP, ntp, n); |
| } |
| int sd_dhcp_server_set_sip(sd_dhcp_server *server, const struct in_addr sip[], size_t n) { |
| return sd_dhcp_server_set_servers(server, SD_DHCP_LEASE_SIP, sip, n); |
| } |
| int sd_dhcp_server_set_pop3(sd_dhcp_server *server, const struct in_addr pop3[], size_t n) { |
| return sd_dhcp_server_set_servers(server, SD_DHCP_LEASE_POP3, pop3, n); |
| } |
| int sd_dhcp_server_set_smtp(sd_dhcp_server *server, const struct in_addr smtp[], size_t n) { |
| return sd_dhcp_server_set_servers(server, SD_DHCP_LEASE_SMTP, smtp, n); |
| } |
| int sd_dhcp_server_set_lpr(sd_dhcp_server *server, const struct in_addr lpr[], size_t n) { |
| return sd_dhcp_server_set_servers(server, SD_DHCP_LEASE_LPR, lpr, n); |
| } |
| |
| int sd_dhcp_server_set_router(sd_dhcp_server *server, const struct in_addr *router) { |
| assert_return(server, -EINVAL); |
| |
| /* router is NULL: router option will not be appended. |
| * router is null address (0.0.0.0): the server address will be used as the router address. |
| * otherwise: the specified address will be used as the router address. */ |
| |
| server->emit_router = router; |
| if (router) |
| server->router_address = *router; |
| |
| return 0; |
| } |
| |
| int sd_dhcp_server_add_option(sd_dhcp_server *server, sd_dhcp_option *v) { |
| int r; |
| |
| assert_return(server, -EINVAL); |
| assert_return(v, -EINVAL); |
| |
| r = ordered_set_ensure_put(&server->extra_options, &dhcp_option_hash_ops, v); |
| if (r < 0) |
| return r; |
| |
| sd_dhcp_option_ref(v); |
| return 0; |
| } |
| |
| int sd_dhcp_server_add_vendor_option(sd_dhcp_server *server, sd_dhcp_option *v) { |
| int r; |
| |
| assert_return(server, -EINVAL); |
| assert_return(v, -EINVAL); |
| |
| r = ordered_set_ensure_put(&server->vendor_options, &dhcp_option_hash_ops, v); |
| if (r < 0) |
| return r; |
| |
| sd_dhcp_option_ref(v); |
| |
| return 1; |
| } |
| |
| int sd_dhcp_server_set_callback(sd_dhcp_server *server, sd_dhcp_server_callback_t cb, void *userdata) { |
| assert_return(server, -EINVAL); |
| |
| server->callback = cb; |
| server->callback_userdata = userdata; |
| |
| return 0; |
| } |
| |
| int sd_dhcp_server_set_relay_target(sd_dhcp_server *server, const struct in_addr *address) { |
| assert_return(server, -EINVAL); |
| assert_return(!sd_dhcp_server_is_running(server), -EBUSY); |
| |
| if (memcmp(address, &server->relay_target, sizeof(struct in_addr)) == 0) |
| return 0; |
| |
| server->relay_target = *address; |
| return 1; |
| } |
| |
| int sd_dhcp_server_set_relay_agent_information( |
| sd_dhcp_server *server, |
| const char *agent_circuit_id, |
| const char *agent_remote_id) { |
| _cleanup_free_ char *circuit_id_dup = NULL, *remote_id_dup = NULL; |
| |
| assert_return(server, -EINVAL); |
| |
| if (relay_agent_information_length(agent_circuit_id, agent_remote_id) > UINT8_MAX) |
| return -ENOBUFS; |
| |
| if (agent_circuit_id) { |
| circuit_id_dup = strdup(agent_circuit_id); |
| if (!circuit_id_dup) |
| return -ENOMEM; |
| } |
| |
| if (agent_remote_id) { |
| remote_id_dup = strdup(agent_remote_id); |
| if (!remote_id_dup) |
| return -ENOMEM; |
| } |
| |
| free_and_replace(server->agent_circuit_id, circuit_id_dup); |
| free_and_replace(server->agent_remote_id, remote_id_dup); |
| return 0; |
| } |
| |
| int sd_dhcp_server_set_static_lease( |
| sd_dhcp_server *server, |
| const struct in_addr *address, |
| uint8_t *client_id, |
| size_t client_id_size) { |
| |
| _cleanup_(dhcp_lease_freep) DHCPLease *lease = NULL; |
| int r; |
| |
| assert_return(server, -EINVAL); |
| assert_return(client_id, -EINVAL); |
| assert_return(client_id_size > 0, -EINVAL); |
| assert_return(!sd_dhcp_server_is_running(server), -EBUSY); |
| |
| /* Static lease with an empty or omitted address is a valid entry, |
| * the server removes any static lease with the specified mac address. */ |
| if (!address || address->s_addr == 0) { |
| DHCPClientId c; |
| |
| c = (DHCPClientId) { |
| .length = client_id_size, |
| .data = client_id, |
| }; |
| |
| dhcp_lease_free(hashmap_get(server->static_leases_by_client_id, &c)); |
| return 0; |
| } |
| |
| lease = new(DHCPLease, 1); |
| if (!lease) |
| return -ENOMEM; |
| |
| *lease = (DHCPLease) { |
| .address = address->s_addr, |
| .client_id.length = client_id_size, |
| }; |
| lease->client_id.data = memdup(client_id, client_id_size); |
| if (!lease->client_id.data) |
| return -ENOMEM; |
| |
| lease->server = server; /* This must be set just before hashmap_put(). */ |
| |
| r = hashmap_ensure_put(&server->static_leases_by_client_id, &dhcp_lease_hash_ops, &lease->client_id, lease); |
| if (r < 0) |
| return r; |
| r = hashmap_ensure_put(&server->static_leases_by_address, NULL, UINT32_TO_PTR(lease->address), lease); |
| if (r < 0) |
| return r; |
| |
| TAKE_PTR(lease); |
| return 0; |
| } |
