+++ /dev/null
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
- This file is part of systemd.
-
- Copyright (C) 2013 Intel Corporation. All rights reserved.
- Copyright (C) 2014 Tom Gundersen
-
- 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 <sys/ioctl.h>
-
-#include "siphash24.h"
-
-#include "sd-dhcp-server.h"
-#include "dhcp-server-internal.h"
-#include "dhcp-internal.h"
-
-#define DHCP_DEFAULT_LEASE_TIME 3600 /* one hour */
-
-int sd_dhcp_server_set_lease_pool(sd_dhcp_server *server,
- struct in_addr *address,
- size_t size) {
- assert_return(server, -EINVAL);
- assert_return(address, -EINVAL);
- assert_return(address->s_addr, -EINVAL);
- assert_return(size, -EINVAL);
- assert_return(server->pool_start == htobe32(INADDR_ANY), -EBUSY);
- assert_return(!server->pool_size, -EBUSY);
- assert_return(!server->bound_leases, -EBUSY);
-
- server->bound_leases = new0(DHCPLease*, size);
- if (!server->bound_leases)
- return -ENOMEM;
-
- server->pool_start = address->s_addr;
- server->pool_size = size;
-
- return 0;
-}
-
-int sd_dhcp_server_set_address(sd_dhcp_server *server, struct in_addr *address,
- unsigned char prefixlen) {
- assert_return(server, -EINVAL);
- assert_return(address, -EINVAL);
- assert_return(address->s_addr, -EINVAL);
- assert_return(prefixlen <= 32, -ERANGE);
- assert_return(server->address == htobe32(INADDR_ANY), -EBUSY);
- assert_return(server->netmask == htobe32(INADDR_ANY), -EBUSY);
-
- server->address = address->s_addr;
- server->netmask = htobe32(0xfffffffflu << (32 - prefixlen));
-
- return 0;
-}
-
-bool sd_dhcp_server_is_running(sd_dhcp_server *server) {
- assert_return(server, -EINVAL);
-
- return !!server->receive_message;
-}
-
-sd_dhcp_server *sd_dhcp_server_ref(sd_dhcp_server *server) {
- if (server)
- assert_se(REFCNT_INC(server->n_ref) >= 2);
-
- return server;
-}
-
-unsigned long client_id_hash_func(const void *p,
- const uint8_t hash_key[HASH_KEY_SIZE]) {
- uint64_t u;
- const DHCPClientId *id = p;
-
- assert(id);
- assert(id->length);
- assert(id->data);
-
- siphash24((uint8_t*) &u, id->data, id->length, hash_key);
-
- return (unsigned long) u;
-}
-
-int client_id_compare_func(const void *_a, const void *_b) {
- const DHCPClientId *a, *b;
-
- a = _a;
- b = _b;
-
- assert(!a->length || a->data);
- assert(!b->length || b->data);
-
- if (a->length != b->length)
- return a->length < b->length ? -1 : 1;
-
- return memcmp(a->data, b->data, a->length);
-}
-
-static const struct hash_ops client_id_hash_ops = {
- .hash = client_id_hash_func,
- .compare = client_id_compare_func
-};
-
-static void dhcp_lease_free(DHCPLease *lease) {
- if (!lease)
- return;
-
- free(lease->client_id.data);
- free(lease);
-}
-
-sd_dhcp_server *sd_dhcp_server_unref(sd_dhcp_server *server) {
- DHCPLease *lease;
-
- if (!server)
- return NULL;
-
- if (REFCNT_DEC(server->n_ref) > 0)
- return NULL;
-
- log_dhcp_server(server, "UNREF");
-
- sd_dhcp_server_stop(server);
-
- sd_event_unref(server->event);
-
- while ((lease = hashmap_steal_first(server->leases_by_client_id)))
- dhcp_lease_free(lease);
- hashmap_free(server->leases_by_client_id);
-
- free(server->bound_leases);
- free(server);
-
- return NULL;
-}
-
-int sd_dhcp_server_new(sd_dhcp_server **ret, int ifindex) {
- _cleanup_dhcp_server_unref_ sd_dhcp_server *server = NULL;
-
- assert_return(ret, -EINVAL);
- assert_return(ifindex > 0, -EINVAL);
-
- server = new0(sd_dhcp_server, 1);
- if (!server)
- return -ENOMEM;
-
- server->n_ref = REFCNT_INIT;
- server->fd_raw = -1;
- server->fd = -1;
- server->address = htobe32(INADDR_ANY);
- server->netmask = htobe32(INADDR_ANY);
- server->index = ifindex;
- server->leases_by_client_id = hashmap_new(&client_id_hash_ops);
-
- *ret = server;
- server = NULL;
-
- return 0;
-}
-
-int sd_dhcp_server_attach_event(sd_dhcp_server *server, sd_event *event,
- int 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_stop(sd_dhcp_server *server) {
- assert_return(server, -EINVAL);
-
- server->receive_message =
- sd_event_source_unref(server->receive_message);
-
- server->fd_raw = safe_close(server->fd_raw);
- server->fd = safe_close(server->fd);
-
- log_dhcp_server(server, "STOPPED");
-
- return 0;
-}
-
-static int dhcp_server_send_unicast_raw(sd_dhcp_server *server,
- DHCPPacket *packet, size_t len) {
- union sockaddr_union link = {
- .ll.sll_family = AF_PACKET,
- .ll.sll_protocol = htons(ETH_P_IP),
- .ll.sll_ifindex = server->index,
- .ll.sll_halen = ETH_ALEN,
- };
- int r;
-
- assert(server);
- assert(server->index > 0);
- assert(server->address);
- assert(packet);
- assert(len > sizeof(DHCPPacket));
-
- memcpy(&link.ll.sll_addr, &packet->dhcp.chaddr, ETH_ALEN);
-
- dhcp_packet_append_ip_headers(packet, server->address, DHCP_PORT_SERVER,
- packet->dhcp.yiaddr,
- DHCP_PORT_CLIENT, len);
-
- r = dhcp_network_send_raw_socket(server->fd_raw, &link, packet, len);
- if (r < 0)
- return r;
-
- return 0;
-}
-
-static int dhcp_server_send_udp(sd_dhcp_server *server, be32_t destination,
- DHCPMessage *message, size_t len) {
- union sockaddr_union dest = {
- .in.sin_family = AF_INET,
- .in.sin_port = htobe16(DHCP_PORT_CLIENT),
- .in.sin_addr.s_addr = destination,
- };
- struct iovec iov = {
- .iov_base = message,
- .iov_len = len,
- };
- uint8_t cmsgbuf[CMSG_LEN(sizeof(struct in_pktinfo))] = {};
- struct msghdr msg = {
- .msg_name = &dest,
- .msg_namelen = sizeof(dest.in),
- .msg_iov = &iov,
- .msg_iovlen = 1,
- .msg_control = cmsgbuf,
- .msg_controllen = sizeof(cmsgbuf),
- };
- struct cmsghdr *cmsg;
- struct in_pktinfo *pktinfo;
- int r;
-
- assert(server);
- assert(server->fd > 0);
- assert(message);
- assert(len > sizeof(DHCPMessage));
-
- 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->index;
- pktinfo->ipi_spec_dst.s_addr = server->address;
-
- r = sendmsg(server->fd, &msg, 0);
- if (r < 0)
- return -errno;
-
- return 0;
-}
-
-static bool requested_broadcast(DHCPRequest *req) {
- assert(req);
-
- return req->message->flags & htobe16(0x8000);
-}
-
-int dhcp_server_send_packet(sd_dhcp_server *server,
- DHCPRequest *req, DHCPPacket *packet,
- int type, size_t optoffset) {
- be32_t destination = INADDR_ANY;
- int r;
-
- assert(server);
- assert(req);
- assert(req->max_optlen);
- assert(optoffset <= req->max_optlen);
- assert(packet);
-
- r = dhcp_option_append(&packet->dhcp, req->max_optlen, &optoffset, 0,
- DHCP_OPTION_SERVER_IDENTIFIER,
- 4, &server->address);
- if (r < 0)
- return r;
-
- r = dhcp_option_append(&packet->dhcp, req->max_optlen, &optoffset, 0,
- 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) {
- destination = req->message->giaddr;
- if (type == DHCP_NAK)
- packet->dhcp.flags = htobe16(0x8000);
- } else if (req->message->ciaddr && type != DHCP_NAK)
- destination = req->message->ciaddr;
-
- if (destination != INADDR_ANY)
- return dhcp_server_send_udp(server, destination, &packet->dhcp,
- sizeof(DHCPMessage) + optoffset);
- else if (requested_broadcast(req) || type == DHCP_NAK)
- return dhcp_server_send_udp(server, INADDR_BROADCAST,
- &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, packet,
- sizeof(DHCPPacket) + optoffset);
-}
-
-static int server_message_init(sd_dhcp_server *server, DHCPPacket **ret,
- uint8_t type, size_t *_optoffset,
- DHCPRequest *req) {
- _cleanup_free_ DHCPPacket *packet = NULL;
- size_t optoffset = 0;
- int r;
-
- assert(server);
- assert(ret);
- assert(_optoffset);
- assert(IN_SET(type, DHCP_OFFER, DHCP_ACK, DHCP_NAK));
-
- packet = malloc0(sizeof(DHCPPacket) + req->max_optlen);
- if (!packet)
- return -ENOMEM;
-
- r = dhcp_message_init(&packet->dhcp, BOOTREPLY,
- be32toh(req->message->xid), type, ARPHRD_ETHER,
- req->max_optlen, &optoffset);
- if (r < 0)
- return r;
-
- packet->dhcp.flags = req->message->flags;
- packet->dhcp.giaddr = req->message->giaddr;
- memcpy(&packet->dhcp.chaddr, &req->message->chaddr, ETH_ALEN);
-
- *_optoffset = optoffset;
- *ret = packet;
- packet = NULL;
-
- return 0;
-}
-
-static int server_send_offer(sd_dhcp_server *server, DHCPRequest *req,
- be32_t address) {
- _cleanup_free_ DHCPPacket *packet = NULL;
- size_t offset;
- be32_t lease_time;
- int r;
-
- r = server_message_init(server, &packet, DHCP_OFFER, &offset, req);
- if (r < 0)
- return r;
-
- packet->dhcp.yiaddr = address;
-
- lease_time = htobe32(req->lifetime);
- r = dhcp_option_append(&packet->dhcp, req->max_optlen, &offset, 0,
- 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,
- DHCP_OPTION_SUBNET_MASK, 4, &server->netmask);
- if (r < 0)
- return r;
-
- r = dhcp_option_append(&packet->dhcp, req->max_optlen, &offset, 0,
- DHCP_OPTION_ROUTER, 4, &server->address);
- if (r < 0)
- return r;
-
- r = dhcp_server_send_packet(server, req, packet, DHCP_OFFER, offset);
- if (r < 0)
- return r;
-
- return 0;
-}
-
-static int server_send_ack(sd_dhcp_server *server, DHCPRequest *req,
- be32_t address) {
- _cleanup_free_ DHCPPacket *packet = NULL;
- size_t offset;
- be32_t lease_time;
- int r;
-
- r = server_message_init(server, &packet, DHCP_ACK, &offset, req);
- if (r < 0)
- return r;
-
- packet->dhcp.yiaddr = address;
-
- lease_time = htobe32(req->lifetime);
- r = dhcp_option_append(&packet->dhcp, req->max_optlen, &offset, 0,
- 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,
- DHCP_OPTION_SUBNET_MASK, 4, &server->netmask);
- if (r < 0)
- return r;
-
- r = dhcp_option_append(&packet->dhcp, req->max_optlen, &offset, 0,
- DHCP_OPTION_ROUTER, 4, &server->address);
- if (r < 0)
- return r;
-
- r = dhcp_server_send_packet(server, req, packet, DHCP_ACK, offset);
- if (r < 0)
- return r;
-
- return 0;
-}
-
-static int server_send_nak(sd_dhcp_server *server, DHCPRequest *req) {
- _cleanup_free_ DHCPPacket *packet = NULL;
- size_t offset;
- int r;
-
- r = server_message_init(server, &packet, DHCP_NAK, &offset, req);
- if (r < 0)
- return r;
-
- r = dhcp_server_send_packet(server, req, packet, DHCP_NAK, offset);
- if (r < 0)
- return r;
-
- return 0;
-}
-
-static int server_send_forcerenew(sd_dhcp_server *server, be32_t address,
- be32_t gateway, 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, ARPHRD_ETHER,
- DHCP_MIN_OPTIONS_SIZE, &optoffset);
- if (r < 0)
- return r;
-
- r = dhcp_option_append(&packet->dhcp, DHCP_MIN_OPTIONS_SIZE,
- &optoffset, 0, DHCP_OPTION_END, 0, NULL);
- if (r < 0)
- return r;
-
- memcpy(&packet->dhcp.chaddr, chaddr, ETH_ALEN);
-
- r = dhcp_server_send_udp(server, address, &packet->dhcp,
- sizeof(DHCPMessage) + optoffset);
- if (r < 0)
- return r;
-
- return 0;
-}
-
-static int parse_request(uint8_t code, uint8_t len, const uint8_t *option,
- void *user_data) {
- DHCPRequest *req = user_data;
-
- assert(req);
-
- switch(code) {
- case DHCP_OPTION_IP_ADDRESS_LEASE_TIME:
- if (len == 4)
- req->lifetime = be32toh(*(be32_t*)option);
-
- break;
- case DHCP_OPTION_REQUESTED_IP_ADDRESS:
- if (len == 4)
- req->requested_ip = *(be32_t*)option;
-
- break;
- case DHCP_OPTION_SERVER_IDENTIFIER:
- if (len == 4)
- req->server_id = *(be32_t*)option;
-
- break;
- case DHCP_OPTION_CLIENT_IDENTIFIER:
- if (len >= 2) {
- uint8_t *data;
-
- data = memdup(option, len);
- if (!data)
- return -ENOMEM;
-
- free(req->client_id.data);
- req->client_id.data = data;
- req->client_id.length = len;
- }
-
- break;
- case DHCP_OPTION_MAXIMUM_MESSAGE_SIZE:
- if (len == 2)
- req->max_optlen = be16toh(*(be16_t*)option) -
- - sizeof(DHCPPacket);
-
- break;
- }
-
- return 0;
-}
-
-static void dhcp_request_free(DHCPRequest *req) {
- if (!req)
- return;
-
- free(req->client_id.data);
- free(req);
-}
-
-DEFINE_TRIVIAL_CLEANUP_FUNC(DHCPRequest*, dhcp_request_free);
-#define _cleanup_dhcp_request_free_ _cleanup_(dhcp_request_freep)
-
-static int ensure_sane_request(DHCPRequest *req, DHCPMessage *message) {
- assert(req);
- assert(message);
-
- req->message = message;
-
- /* set client id based on MAC address if client did not send an explicit
- one */
- if (!req->client_id.data) {
- uint8_t *data;
-
- data = new0(uint8_t, ETH_ALEN + 1);
- if (!data)
- return -ENOMEM;
-
- req->client_id.length = ETH_ALEN + 1;
- req->client_id.data = data;
- req->client_id.data[0] = 0x01;
- memcpy(&req->client_id.data[1], &message->chaddr, ETH_ALEN);
- }
-
- if (req->max_optlen < DHCP_MIN_OPTIONS_SIZE)
- req->max_optlen = DHCP_MIN_OPTIONS_SIZE;
-
- if (!req->lifetime)
- req->lifetime = DHCP_DEFAULT_LEASE_TIME;
-
- return 0;
-}
-
-static int get_pool_offset(sd_dhcp_server *server, be32_t requested_ip) {
- assert(server);
-
- if (!server->pool_size)
- return -EINVAL;
-
- if (be32toh(requested_ip) < be32toh(server->pool_start) ||
- be32toh(requested_ip) >= be32toh(server->pool_start) +
- + server->pool_size)
- return -EINVAL;
-
- return be32toh(requested_ip) - be32toh(server->pool_start);
-}
-
-int dhcp_server_handle_message(sd_dhcp_server *server, DHCPMessage *message,
- size_t length) {
- _cleanup_dhcp_request_free_ DHCPRequest *req = NULL;
- DHCPLease *existing_lease;
- int type, r;
-
- assert(server);
- assert(message);
-
- if (message->op != BOOTREQUEST ||
- message->htype != ARPHRD_ETHER ||
- message->hlen != ETHER_ADDR_LEN)
- return 0;
-
- req = new0(DHCPRequest, 1);
- if (!req)
- return -ENOMEM;
-
- type = dhcp_option_parse(message, length, parse_request, req);
- if (type < 0)
- return 0;
-
- r = ensure_sane_request(req, message);
- if (r < 0)
- /* this only fails on critical errors */
- return r;
-
- existing_lease = hashmap_get(server->leases_by_client_id,
- &req->client_id);
-
- switch(type) {
- case DHCP_DISCOVER:
- {
- be32_t address = INADDR_ANY;
- unsigned i;
-
- log_dhcp_server(server, "DISCOVER (0x%x)",
- be32toh(req->message->xid));
-
- if (!server->pool_size)
- /* no pool allocated */
- return 0;
-
- /* for now pick a random free address from the pool */
- if (existing_lease)
- address = existing_lease->address;
- else {
- for (i = 0; i < server->pool_size; i++) {
- if (!server->bound_leases[server->next_offer]) {
- address = htobe32(be32toh(server->pool_start) + server->next_offer);
- break;
- } else
- server->next_offer = (server->next_offer + 1) % server->pool_size;
- }
- }
-
- if (address == INADDR_ANY)
- /* no free addresses left */
- return 0;
-
- r = server_send_offer(server, req, address);
- if (r < 0) {
- /* this only fails on critical errors */
- log_dhcp_server(server, "could not send offer: %s",
- strerror(-r));
- return r;
- } else {
- log_dhcp_server(server, "OFFER (0x%x)",
- be32toh(req->message->xid));
- return DHCP_OFFER;
- }
-
- break;
- }
- case DHCP_DECLINE:
- log_dhcp_server(server, "DECLINE (0x%x)",
- be32toh(req->message->xid));
-
- /* TODO: make sure we don't offer this address again */
-
- return 1;
-
- break;
- case DHCP_REQUEST:
- {
- be32_t address;
- bool init_reboot = false;
- int pool_offset;
-
- /* see RFC 2131, section 4.3.2 */
-
- if (req->server_id) {
- 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)
- /* this MUST be zero */
- return 0;
-
- if (!req->requested_ip)
- /* this must be filled in with the yiaddr
- from the chosen OFFER */
- return 0;
-
- address = req->requested_ip;
- } else if (req->requested_ip) {
- log_dhcp_server(server, "REQUEST (init-reboot) (0x%x)",
- be32toh(req->message->xid));
-
- /* INIT-REBOOT */
- if (req->message->ciaddr)
- /* 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)
- /* this MUST be filled in with clients IP address */
- return 0;
-
- address = req->message->ciaddr;
- }
-
- pool_offset = get_pool_offset(server, address);
-
- /* verify that the requested address is from the pool, and either
- owned by the current client or free */
- if (pool_offset >= 0 &&
- server->bound_leases[pool_offset] == existing_lease) {
- DHCPLease *lease;
- usec_t time_now = 0;
-
- if (!existing_lease) {
- lease = new0(DHCPLease, 1);
- lease->address = req->requested_ip;
- lease->client_id.data = memdup(req->client_id.data,
- req->client_id.length);
- if (!lease->client_id.data) {
- free(lease);
- return -ENOMEM;
- }
- lease->client_id.length = req->client_id.length;
- memcpy(&lease->chaddr, &req->message->chaddr,
- ETH_ALEN);
- lease->gateway = req->message->giaddr;
- } else
- lease = existing_lease;
-
- r = sd_event_now(server->event,
- clock_boottime_or_monotonic(),
- &time_now);
- if (r < 0)
- time_now = now(clock_boottime_or_monotonic());
- lease->expiration = req->lifetime * USEC_PER_SEC + time_now;
-
- r = server_send_ack(server, req, address);
- if (r < 0) {
- /* this only fails on critical errors */
- log_dhcp_server(server, "could not send ack: %s",
- strerror(-r));
-
- if (!existing_lease)
- dhcp_lease_free(lease);
-
- return r;
- } else {
- log_dhcp_server(server, "ACK (0x%x)",
- be32toh(req->message->xid));
-
- server->bound_leases[pool_offset] = lease;
- hashmap_put(server->leases_by_client_id,
- &lease->client_id, lease);
-
- return DHCP_ACK;
- }
- } else if (init_reboot) {
- r = server_send_nak(server, req);
- if (r < 0) {
- /* this only fails on critical errors */
- log_dhcp_server(server, "could not send nak: %s",
- strerror(-r));
- return r;
- } else {
- log_dhcp_server(server, "NAK (0x%x)",
- be32toh(req->message->xid));
- return DHCP_NAK;
- }
- }
-
- break;
- }
- case DHCP_RELEASE: {
- int pool_offset;
-
- 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;
-
- pool_offset = get_pool_offset(server, req->message->ciaddr);
- if (pool_offset < 0)
- return 0;
-
- if (server->bound_leases[pool_offset] == existing_lease) {
- server->bound_leases[pool_offset] = NULL;
- hashmap_remove(server->leases_by_client_id, existing_lease);
- dhcp_lease_free(existing_lease);
-
- return 1;
- } else
- return 0;
- }
- }
-
- return 0;
-}
-
-static int server_receive_message(sd_event_source *s, int fd,
- uint32_t revents, void *userdata) {
- _cleanup_free_ DHCPMessage *message = NULL;
- uint8_t cmsgbuf[CMSG_LEN(sizeof(struct in_pktinfo))];
- sd_dhcp_server *server = userdata;
- struct iovec iov = {};
- struct msghdr msg = {
- .msg_iov = &iov,
- .msg_iovlen = 1,
- .msg_control = cmsgbuf,
- .msg_controllen = sizeof(cmsgbuf),
- };
- struct cmsghdr *cmsg;
- int buflen = 0, len, r;
-
- assert(server);
-
- r = ioctl(fd, FIONREAD, &buflen);
- if (r < 0)
- return r;
- if (buflen < 0)
- return -EIO;
-
- message = malloc0(buflen);
- if (!message)
- return -ENOMEM;
-
- iov.iov_base = message;
- iov.iov_len = buflen;
-
- len = recvmsg(fd, &msg, 0);
- if (len < buflen)
- return 0;
- else if ((size_t)len < sizeof(DHCPMessage))
- return 0;
-
- for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
- 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->index != info->ipi_ifindex)
- return 0;
-
- break;
- }
- }
-
- return dhcp_server_handle_message(server, message, (size_t)len);
-}
-
-int sd_dhcp_server_start(sd_dhcp_server *server) {
- int r;
-
- assert_return(server, -EINVAL);
- assert_return(server->event, -EINVAL);
- assert_return(!server->receive_message, -EBUSY);
- assert_return(server->fd_raw == -1, -EBUSY);
- assert_return(server->fd == -1, -EBUSY);
- assert_return(server->address != htobe32(INADDR_ANY), -EUNATCH);
-
- r = socket(AF_PACKET, SOCK_DGRAM | SOCK_NONBLOCK, 0);
- if (r < 0) {
- r = -errno;
- sd_dhcp_server_stop(server);
- return r;
- }
- server->fd_raw = r;
-
- r = dhcp_network_bind_udp_socket(INADDR_ANY, DHCP_PORT_SERVER);
- if (r < 0) {
- sd_dhcp_server_stop(server);
- return r;
- }
- server->fd = r;
-
- r = sd_event_add_io(server->event, &server->receive_message,
- server->fd, EPOLLIN,
- server_receive_message, server);
- if (r < 0) {
- sd_dhcp_server_stop(server);
- return r;
- }
-
- r = sd_event_source_set_priority(server->receive_message,
- server->event_priority);
- if (r < 0) {
- sd_dhcp_server_stop(server);
- return r;
- }
-
- log_dhcp_server(server, "STARTED");
-
- return 0;
-}
-
-int sd_dhcp_server_forcerenew(sd_dhcp_server *server) {
- unsigned i;
- int r = 0;
-
- assert_return(server, -EINVAL);
- assert(server->bound_leases);
-
- for (i = 0; i < server->pool_size; i++) {
- DHCPLease *lease = server->bound_leases[i];
-
- if (!lease)
- continue;
-
- r = server_send_forcerenew(server, lease->address,
- lease->gateway,
- lease->chaddr);
- if (r < 0)
- return r;
- else
- log_dhcp_server(server, "FORCERENEW");
- }
-
- return r;
-}
~ianmdlvl / elogind.git / blobdiff