2006-07-02 19:47:05 +00:00
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/* vi: set sw=4 ts=4: */
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2010-03-20 02:48:11 +00:00
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/*
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2010-03-26 09:09:34 +00:00
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* udhcp server
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2006-05-08 03:20:50 +00:00
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* Copyright (C) 1999 Matthew Ramsay <matthewr@moreton.com.au>
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* Chris Trew <ctrew@moreton.com.au>
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*
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* Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
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*
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2010-03-20 02:48:11 +00:00
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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2006-05-08 03:20:50 +00:00
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*/
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2011-04-11 01:29:49 +00:00
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//usage:#define udhcpd_trivial_usage
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2013-03-14 01:18:52 +00:00
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//usage: "[-fS] [-I ADDR]" IF_FEATURE_UDHCP_PORT(" [-P N]") " [CONFFILE]"
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2011-04-11 01:29:49 +00:00
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//usage:#define udhcpd_full_usage "\n\n"
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//usage: "DHCP server\n"
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//usage: "\n -f Run in foreground"
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//usage: "\n -S Log to syslog too"
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2013-03-13 21:27:37 +00:00
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//usage: "\n -I ADDR Local address"
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2014-10-30 10:59:04 +00:00
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//usage: "\n -a MSEC Timeout for ARP ping (default 2000)"
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2011-04-11 01:29:49 +00:00
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//usage: IF_FEATURE_UDHCP_PORT(
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//usage: "\n -P N Use port N (default 67)"
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//usage: )
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2007-03-26 13:22:35 +00:00
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#include <syslog.h>
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2006-11-18 19:51:32 +00:00
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#include "common.h"
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2008-02-04 13:12:16 +00:00
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#include "dhcpc.h"
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2006-05-08 03:20:50 +00:00
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#include "dhcpd.h"
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2010-03-21 05:15:28 +00:00
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/* Send a packet to a specific mac address and ip address by creating our own ip packet */
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static void send_packet_to_client(struct dhcp_packet *dhcp_pkt, int force_broadcast)
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2010-03-20 02:48:11 +00:00
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{
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const uint8_t *chaddr;
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uint32_t ciaddr;
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// Was:
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//if (force_broadcast) { /* broadcast */ }
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//else if (dhcp_pkt->ciaddr) { /* unicast to dhcp_pkt->ciaddr */ }
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//else if (dhcp_pkt->flags & htons(BROADCAST_FLAG)) { /* broadcast */ }
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//else { /* unicast to dhcp_pkt->yiaddr */ }
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// But this is wrong: yiaddr is _our_ idea what client's IP is
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// (for example, from lease file). Client may not know that,
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// and may not have UDP socket listening on that IP!
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// We should never unicast to dhcp_pkt->yiaddr!
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// dhcp_pkt->ciaddr, OTOH, comes from client's request packet,
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// and can be used.
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if (force_broadcast
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|| (dhcp_pkt->flags & htons(BROADCAST_FLAG))
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2010-03-21 05:46:09 +00:00
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|| dhcp_pkt->ciaddr == 0
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2010-03-20 02:48:11 +00:00
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) {
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log1("Broadcasting packet to client");
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ciaddr = INADDR_BROADCAST;
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chaddr = MAC_BCAST_ADDR;
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} else {
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log1("Unicasting packet to client ciaddr");
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ciaddr = dhcp_pkt->ciaddr;
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chaddr = dhcp_pkt->chaddr;
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}
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2010-03-21 05:15:28 +00:00
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udhcp_send_raw_packet(dhcp_pkt,
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2010-03-20 02:48:11 +00:00
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/*src*/ server_config.server_nip, SERVER_PORT,
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/*dst*/ ciaddr, CLIENT_PORT, chaddr,
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server_config.ifindex);
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}
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2010-03-21 05:15:28 +00:00
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/* Send a packet to gateway_nip using the kernel ip stack */
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static void send_packet_to_relay(struct dhcp_packet *dhcp_pkt)
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{
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log1("Forwarding packet to relay");
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udhcp_send_kernel_packet(dhcp_pkt,
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server_config.server_nip, SERVER_PORT,
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dhcp_pkt->gateway_nip, SERVER_PORT);
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}
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static void send_packet(struct dhcp_packet *dhcp_pkt, int force_broadcast)
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2010-03-20 02:48:11 +00:00
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{
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if (dhcp_pkt->gateway_nip)
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2010-03-21 05:15:28 +00:00
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send_packet_to_relay(dhcp_pkt);
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else
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send_packet_to_client(dhcp_pkt, force_broadcast);
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2010-03-20 02:48:11 +00:00
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}
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static void init_packet(struct dhcp_packet *packet, struct dhcp_packet *oldpacket, char type)
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{
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2010-03-21 05:15:28 +00:00
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/* Sets op, htype, hlen, cookie fields
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* and adds DHCP_MESSAGE_TYPE option */
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2010-03-20 02:48:11 +00:00
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udhcp_init_header(packet, type);
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2010-03-21 05:15:28 +00:00
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2010-03-20 02:48:11 +00:00
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packet->xid = oldpacket->xid;
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memcpy(packet->chaddr, oldpacket->chaddr, sizeof(oldpacket->chaddr));
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packet->flags = oldpacket->flags;
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packet->gateway_nip = oldpacket->gateway_nip;
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packet->ciaddr = oldpacket->ciaddr;
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2010-03-26 08:32:09 +00:00
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udhcp_add_simple_option(packet, DHCP_SERVER_ID, server_config.server_nip);
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2010-03-20 02:48:11 +00:00
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}
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2010-03-20 23:43:11 +00:00
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/* Fill options field, siaddr_nip, and sname and boot_file fields.
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* TODO: teach this code to use overload option.
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*/
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static void add_server_options(struct dhcp_packet *packet)
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2010-03-20 02:48:11 +00:00
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{
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2010-03-20 23:43:11 +00:00
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struct option_set *curr = server_config.options;
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while (curr) {
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if (curr->data[OPT_CODE] != DHCP_LEASE_TIME)
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2010-03-26 08:32:09 +00:00
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udhcp_add_binary_option(packet, curr->data);
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2010-03-20 23:43:11 +00:00
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curr = curr->next;
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}
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2010-03-20 02:48:11 +00:00
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packet->siaddr_nip = server_config.siaddr_nip;
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2010-03-20 23:43:11 +00:00
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2010-03-20 02:48:11 +00:00
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if (server_config.sname)
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strncpy((char*)packet->sname, server_config.sname, sizeof(packet->sname) - 1);
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if (server_config.boot_file)
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strncpy((char*)packet->file, server_config.boot_file, sizeof(packet->file) - 1);
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}
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static uint32_t select_lease_time(struct dhcp_packet *packet)
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{
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uint32_t lease_time_sec = server_config.max_lease_sec;
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2010-03-22 13:29:13 +00:00
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uint8_t *lease_time_opt = udhcp_get_option(packet, DHCP_LEASE_TIME);
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2010-03-20 02:48:11 +00:00
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if (lease_time_opt) {
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move_from_unaligned32(lease_time_sec, lease_time_opt);
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lease_time_sec = ntohl(lease_time_sec);
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if (lease_time_sec > server_config.max_lease_sec)
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lease_time_sec = server_config.max_lease_sec;
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if (lease_time_sec < server_config.min_lease_sec)
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lease_time_sec = server_config.min_lease_sec;
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}
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return lease_time_sec;
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}
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2010-03-21 05:15:28 +00:00
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/* We got a DHCP DISCOVER. Send an OFFER. */
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2010-10-21 10:33:10 +00:00
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/* NOINLINE: limit stack usage in caller */
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2010-11-28 00:10:51 +00:00
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static NOINLINE void send_offer(struct dhcp_packet *oldpacket,
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uint32_t static_lease_nip,
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struct dyn_lease *lease,
|
2014-10-30 10:59:04 +00:00
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uint8_t *requested_ip_opt,
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unsigned arpping_ms)
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2010-03-20 02:48:11 +00:00
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{
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struct dhcp_packet packet;
|
2010-03-21 05:15:28 +00:00
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uint32_t lease_time_sec;
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2010-03-20 02:48:11 +00:00
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struct in_addr addr;
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init_packet(&packet, oldpacket, DHCPOFFER);
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2010-03-21 05:15:28 +00:00
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/* If it is a static lease, use its IP */
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packet.yiaddr = static_lease_nip;
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/* Else: */
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2010-03-20 02:49:27 +00:00
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if (!static_lease_nip) {
|
2010-03-21 05:15:28 +00:00
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/* We have no static lease for client's chaddr */
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2010-03-20 23:43:11 +00:00
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uint32_t req_nip;
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2010-03-21 05:15:28 +00:00
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const char *p_host_name;
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2010-03-20 23:43:11 +00:00
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2010-03-20 02:48:11 +00:00
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if (lease) {
|
2010-03-21 05:15:28 +00:00
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/* We have a dynamic lease for client's chaddr.
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* Reuse its IP (even if lease is expired).
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* Note that we ignore requested IP in this case.
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*/
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2010-03-20 02:48:11 +00:00
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packet.yiaddr = lease->lease_nip;
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}
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2010-03-21 05:15:28 +00:00
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/* Or: if client has requested an IP */
|
2010-11-28 00:10:51 +00:00
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else if (requested_ip_opt != NULL
|
2010-03-20 02:48:11 +00:00
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/* (read IP) */
|
2010-11-28 00:10:51 +00:00
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&& (move_from_unaligned32(req_nip, requested_ip_opt), 1)
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2010-03-20 02:48:11 +00:00
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/* and the IP is in the lease range */
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&& ntohl(req_nip) >= server_config.start_ip
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&& ntohl(req_nip) <= server_config.end_ip
|
2010-03-20 23:43:11 +00:00
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/* and */
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&& ( !(lease = find_lease_by_nip(req_nip)) /* is not already taken */
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|| is_expired_lease(lease) /* or is taken, but expired */
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)
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2010-03-20 02:48:11 +00:00
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) {
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packet.yiaddr = req_nip;
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}
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else {
|
2010-03-21 05:15:28 +00:00
|
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/* Otherwise, find a free IP */
|
2014-10-30 10:59:04 +00:00
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packet.yiaddr = find_free_or_expired_nip(oldpacket->chaddr, arpping_ms);
|
2010-03-20 02:48:11 +00:00
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}
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if (!packet.yiaddr) {
|
2010-03-21 05:15:28 +00:00
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bb_error_msg("no free IP addresses. OFFER abandoned");
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return;
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2010-03-20 02:48:11 +00:00
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}
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2010-03-21 05:15:28 +00:00
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/* Reserve the IP for a short time hoping to get DHCPREQUEST soon */
|
2010-03-22 13:29:13 +00:00
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p_host_name = (const char*) udhcp_get_option(oldpacket, DHCP_HOST_NAME);
|
2010-03-21 05:15:28 +00:00
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lease = add_lease(packet.chaddr, packet.yiaddr,
|
2010-03-20 02:48:11 +00:00
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server_config.offer_time,
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p_host_name,
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p_host_name ? (unsigned char)p_host_name[OPT_LEN - OPT_DATA] : 0
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2010-03-21 05:15:28 +00:00
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);
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if (!lease) {
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bb_error_msg("no free IP addresses. OFFER abandoned");
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return;
|
2010-03-20 02:48:11 +00:00
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}
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}
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|
2010-03-21 05:15:28 +00:00
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lease_time_sec = select_lease_time(oldpacket);
|
2010-03-26 08:32:09 +00:00
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udhcp_add_simple_option(&packet, DHCP_LEASE_TIME, htonl(lease_time_sec));
|
2010-03-20 23:43:11 +00:00
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add_server_options(&packet);
|
2010-03-20 02:48:11 +00:00
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addr.s_addr = packet.yiaddr;
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bb_info_msg("Sending OFFER of %s", inet_ntoa(addr));
|
2010-03-21 05:15:28 +00:00
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/* send_packet emits error message itself if it detects failure */
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send_packet(&packet, /*force_bcast:*/ 0);
|
2010-03-20 02:48:11 +00:00
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}
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|
2010-10-21 10:33:10 +00:00
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|
|
/* NOINLINE: limit stack usage in caller */
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static NOINLINE void send_NAK(struct dhcp_packet *oldpacket)
|
2010-03-20 02:48:11 +00:00
|
|
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{
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struct dhcp_packet packet;
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init_packet(&packet, oldpacket, DHCPNAK);
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log1("Sending NAK");
|
2010-03-21 05:15:28 +00:00
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|
send_packet(&packet, /*force_bcast:*/ 1);
|
2010-03-20 02:48:11 +00:00
|
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|
}
|
|
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|
|
2010-10-21 10:33:10 +00:00
|
|
|
/* NOINLINE: limit stack usage in caller */
|
|
|
|
static NOINLINE void send_ACK(struct dhcp_packet *oldpacket, uint32_t yiaddr)
|
2010-03-20 02:48:11 +00:00
|
|
|
{
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|
|
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struct dhcp_packet packet;
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|
|
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uint32_t lease_time_sec;
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|
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struct in_addr addr;
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|
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const char *p_host_name;
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|
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|
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init_packet(&packet, oldpacket, DHCPACK);
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|
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packet.yiaddr = yiaddr;
|
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|
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|
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|
|
lease_time_sec = select_lease_time(oldpacket);
|
2010-03-26 08:32:09 +00:00
|
|
|
udhcp_add_simple_option(&packet, DHCP_LEASE_TIME, htonl(lease_time_sec));
|
2010-03-21 05:15:28 +00:00
|
|
|
|
2010-03-20 23:43:11 +00:00
|
|
|
add_server_options(&packet);
|
2010-03-20 02:48:11 +00:00
|
|
|
|
2010-03-21 05:15:28 +00:00
|
|
|
addr.s_addr = yiaddr;
|
2010-03-20 02:48:11 +00:00
|
|
|
bb_info_msg("Sending ACK to %s", inet_ntoa(addr));
|
2010-03-21 05:15:28 +00:00
|
|
|
send_packet(&packet, /*force_bcast:*/ 0);
|
2010-03-20 02:48:11 +00:00
|
|
|
|
2010-03-22 13:29:13 +00:00
|
|
|
p_host_name = (const char*) udhcp_get_option(oldpacket, DHCP_HOST_NAME);
|
2010-03-20 02:48:11 +00:00
|
|
|
add_lease(packet.chaddr, packet.yiaddr,
|
|
|
|
lease_time_sec,
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|
|
p_host_name,
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|
|
p_host_name ? (unsigned char)p_host_name[OPT_LEN - OPT_DATA] : 0
|
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|
);
|
|
|
|
if (ENABLE_FEATURE_UDHCPD_WRITE_LEASES_EARLY) {
|
|
|
|
/* rewrite the file with leases at every new acceptance */
|
|
|
|
write_leases();
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2010-10-21 10:33:10 +00:00
|
|
|
/* NOINLINE: limit stack usage in caller */
|
|
|
|
static NOINLINE void send_inform(struct dhcp_packet *oldpacket)
|
2010-03-20 02:48:11 +00:00
|
|
|
{
|
|
|
|
struct dhcp_packet packet;
|
|
|
|
|
2010-04-04 20:36:34 +00:00
|
|
|
/* "If a client has obtained a network address through some other means
|
|
|
|
* (e.g., manual configuration), it may use a DHCPINFORM request message
|
|
|
|
* to obtain other local configuration parameters. Servers receiving a
|
|
|
|
* DHCPINFORM message construct a DHCPACK message with any local
|
|
|
|
* configuration parameters appropriate for the client without:
|
|
|
|
* allocating a new address, checking for an existing binding, filling
|
|
|
|
* in 'yiaddr' or including lease time parameters. The servers SHOULD
|
|
|
|
* unicast the DHCPACK reply to the address given in the 'ciaddr' field
|
|
|
|
* of the DHCPINFORM message.
|
|
|
|
* ...
|
|
|
|
* The server responds to a DHCPINFORM message by sending a DHCPACK
|
2010-03-21 05:15:28 +00:00
|
|
|
* message directly to the address given in the 'ciaddr' field
|
|
|
|
* of the DHCPINFORM message. The server MUST NOT send a lease
|
|
|
|
* expiration time to the client and SHOULD NOT fill in 'yiaddr'."
|
|
|
|
*/
|
2010-04-04 20:36:34 +00:00
|
|
|
//TODO: do a few sanity checks: is ciaddr set?
|
|
|
|
//Better yet: is ciaddr == IP source addr?
|
2010-03-20 02:48:11 +00:00
|
|
|
init_packet(&packet, oldpacket, DHCPACK);
|
2010-03-20 23:43:11 +00:00
|
|
|
add_server_options(&packet);
|
2010-03-20 02:48:11 +00:00
|
|
|
|
2010-03-21 05:15:28 +00:00
|
|
|
send_packet(&packet, /*force_bcast:*/ 0);
|
2010-03-20 02:48:11 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
2006-05-08 03:20:50 +00:00
|
|
|
/* globals */
|
2009-06-17 11:24:03 +00:00
|
|
|
struct dyn_lease *g_leases;
|
2007-09-30 17:55:43 +00:00
|
|
|
/* struct server_config_t server_config is in bb_common_bufsiz1 */
|
2006-05-08 03:20:50 +00:00
|
|
|
|
|
|
|
|
2007-10-11 10:05:36 +00:00
|
|
|
int udhcpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
2008-07-05 09:18:54 +00:00
|
|
|
int udhcpd_main(int argc UNUSED_PARAM, char **argv)
|
2006-05-08 03:20:50 +00:00
|
|
|
{
|
2009-01-01 17:52:09 +00:00
|
|
|
int server_socket = -1, retval, max_sock;
|
2009-06-17 11:24:03 +00:00
|
|
|
uint8_t *state;
|
2007-07-03 15:47:50 +00:00
|
|
|
unsigned timeout_end;
|
|
|
|
unsigned num_ips;
|
2007-08-14 16:45:29 +00:00
|
|
|
unsigned opt;
|
2006-05-08 03:20:50 +00:00
|
|
|
struct option_set *option;
|
2013-03-13 21:27:37 +00:00
|
|
|
char *str_I = str_I;
|
2014-10-30 10:59:04 +00:00
|
|
|
const char *str_a = "2000";
|
|
|
|
unsigned arpping_ms;
|
2009-04-21 11:09:40 +00:00
|
|
|
IF_FEATURE_UDHCP_PORT(char *str_P;)
|
2006-05-08 03:20:50 +00:00
|
|
|
|
2008-02-04 13:12:16 +00:00
|
|
|
#if ENABLE_FEATURE_UDHCP_PORT
|
|
|
|
SERVER_PORT = 67;
|
|
|
|
CLIENT_PORT = 68;
|
|
|
|
#endif
|
|
|
|
|
2009-06-17 09:54:52 +00:00
|
|
|
#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
|
|
|
|
opt_complementary = "vv";
|
|
|
|
#endif
|
2014-10-30 10:59:04 +00:00
|
|
|
opt = getopt32(argv, "fSI:va:"
|
2013-03-13 21:27:37 +00:00
|
|
|
IF_FEATURE_UDHCP_PORT("P:")
|
|
|
|
, &str_I
|
2014-10-30 10:59:04 +00:00
|
|
|
, &str_a
|
2013-03-13 21:27:37 +00:00
|
|
|
IF_FEATURE_UDHCP_PORT(, &str_P)
|
2011-10-17 22:35:47 +00:00
|
|
|
IF_UDHCP_VERBOSE(, &dhcp_verbose)
|
2009-06-17 09:54:52 +00:00
|
|
|
);
|
2007-08-14 16:45:29 +00:00
|
|
|
if (!(opt & 1)) { /* no -f */
|
2007-07-01 17:05:57 +00:00
|
|
|
bb_daemonize_or_rexec(0, argv);
|
2009-03-11 14:40:00 +00:00
|
|
|
logmode = LOGMODE_NONE;
|
2007-03-26 13:22:35 +00:00
|
|
|
}
|
2010-06-04 17:24:50 +00:00
|
|
|
/* update argv after the possible vfork+exec in daemonize */
|
|
|
|
argv += optind;
|
2007-08-14 16:45:29 +00:00
|
|
|
if (opt & 2) { /* -S */
|
2009-03-08 23:46:48 +00:00
|
|
|
openlog(applet_name, LOG_PID, LOG_DAEMON);
|
2007-03-26 13:22:35 +00:00
|
|
|
logmode |= LOGMODE_SYSLOG;
|
|
|
|
}
|
2013-03-13 21:27:37 +00:00
|
|
|
if (opt & 4) { /* -I */
|
|
|
|
len_and_sockaddr *lsa = xhost_and_af2sockaddr(str_I, 0, AF_INET);
|
|
|
|
server_config.server_nip = lsa->u.sin.sin_addr.s_addr;
|
|
|
|
free(lsa);
|
|
|
|
}
|
2008-02-04 13:12:16 +00:00
|
|
|
#if ENABLE_FEATURE_UDHCP_PORT
|
2014-10-30 10:59:04 +00:00
|
|
|
if (opt & 32) { /* -P */
|
2008-02-04 13:12:16 +00:00
|
|
|
SERVER_PORT = xatou16(str_P);
|
|
|
|
CLIENT_PORT = SERVER_PORT + 1;
|
|
|
|
}
|
|
|
|
#endif
|
2014-10-30 10:59:04 +00:00
|
|
|
arpping_ms = xatou(str_a);
|
|
|
|
|
2007-03-26 13:22:35 +00:00
|
|
|
/* Would rather not do read_config before daemonization -
|
|
|
|
* otherwise NOMMU machines will parse config twice */
|
2007-08-15 20:03:36 +00:00
|
|
|
read_config(argv[0] ? argv[0] : DHCPD_CONF_FILE);
|
2006-05-08 03:20:50 +00:00
|
|
|
|
2007-08-02 22:31:05 +00:00
|
|
|
/* Make sure fd 0,1,2 are open */
|
|
|
|
bb_sanitize_stdio();
|
|
|
|
/* Equivalent of doing a fflush after every \n */
|
|
|
|
setlinebuf(stdout);
|
|
|
|
|
|
|
|
/* Create pidfile */
|
|
|
|
write_pidfile(server_config.pidfile);
|
2009-11-13 08:08:27 +00:00
|
|
|
/* if (!..) bb_perror_msg("can't create pidfile %s", pidfile); */
|
2007-08-02 22:31:05 +00:00
|
|
|
|
2007-10-07 17:06:01 +00:00
|
|
|
bb_info_msg("%s (v"BB_VER") started", applet_name);
|
2006-05-08 03:20:50 +00:00
|
|
|
|
2010-03-26 08:32:09 +00:00
|
|
|
option = udhcp_find_option(server_config.options, DHCP_LEASE_TIME);
|
2010-03-21 01:22:07 +00:00
|
|
|
server_config.max_lease_sec = DEFAULT_LEASE_TIME;
|
2007-03-26 13:22:35 +00:00
|
|
|
if (option) {
|
2009-06-17 11:24:03 +00:00
|
|
|
move_from_unaligned32(server_config.max_lease_sec, option->data + OPT_DATA);
|
|
|
|
server_config.max_lease_sec = ntohl(server_config.max_lease_sec);
|
2007-05-03 23:39:35 +00:00
|
|
|
}
|
2006-05-08 03:20:50 +00:00
|
|
|
|
|
|
|
/* Sanity check */
|
2007-07-01 17:05:57 +00:00
|
|
|
num_ips = server_config.end_ip - server_config.start_ip + 1;
|
2006-05-08 03:20:50 +00:00
|
|
|
if (server_config.max_leases > num_ips) {
|
2007-07-03 15:47:50 +00:00
|
|
|
bb_error_msg("max_leases=%u is too big, setting to %u",
|
|
|
|
(unsigned)server_config.max_leases, num_ips);
|
2006-05-08 03:20:50 +00:00
|
|
|
server_config.max_leases = num_ips;
|
|
|
|
}
|
|
|
|
|
2009-06-17 11:24:03 +00:00
|
|
|
g_leases = xzalloc(server_config.max_leases * sizeof(g_leases[0]));
|
2006-05-08 03:20:50 +00:00
|
|
|
read_leases(server_config.lease_file);
|
|
|
|
|
2009-06-16 10:04:23 +00:00
|
|
|
if (udhcp_read_interface(server_config.interface,
|
|
|
|
&server_config.ifindex,
|
2013-03-13 21:27:37 +00:00
|
|
|
(server_config.server_nip == 0 ? &server_config.server_nip : NULL),
|
2009-06-16 10:04:23 +00:00
|
|
|
server_config.server_mac)
|
|
|
|
) {
|
2007-05-03 23:39:35 +00:00
|
|
|
retval = 1;
|
|
|
|
goto ret;
|
|
|
|
}
|
2006-05-08 03:20:50 +00:00
|
|
|
|
|
|
|
/* Setup the signal pipe */
|
|
|
|
udhcp_sp_setup();
|
|
|
|
|
2012-07-24 15:21:26 +00:00
|
|
|
continue_with_autotime:
|
2007-07-03 15:47:50 +00:00
|
|
|
timeout_end = monotonic_sec() + server_config.auto_time;
|
2006-11-18 19:51:32 +00:00
|
|
|
while (1) { /* loop until universe collapses */
|
2010-11-28 00:10:51 +00:00
|
|
|
fd_set rfds;
|
|
|
|
struct dhcp_packet packet;
|
2009-01-01 17:52:09 +00:00
|
|
|
int bytes;
|
|
|
|
struct timeval tv;
|
2010-03-21 05:15:28 +00:00
|
|
|
uint8_t *server_id_opt;
|
2010-11-28 00:10:51 +00:00
|
|
|
uint8_t *requested_ip_opt;
|
2010-03-21 05:15:28 +00:00
|
|
|
uint32_t requested_nip = requested_nip; /* for compiler */
|
2010-11-28 00:10:51 +00:00
|
|
|
uint32_t static_lease_nip;
|
|
|
|
struct dyn_lease *lease, fake_lease;
|
2006-05-08 03:20:50 +00:00
|
|
|
|
2006-11-27 23:43:28 +00:00
|
|
|
if (server_socket < 0) {
|
2008-09-26 09:34:59 +00:00
|
|
|
server_socket = udhcp_listen_socket(/*INADDR_ANY,*/ SERVER_PORT,
|
2007-05-03 23:39:35 +00:00
|
|
|
server_config.interface);
|
2006-11-27 23:43:28 +00:00
|
|
|
}
|
2006-05-08 03:20:50 +00:00
|
|
|
|
|
|
|
max_sock = udhcp_sp_fd_set(&rfds, server_socket);
|
|
|
|
if (server_config.auto_time) {
|
2015-01-27 20:59:40 +00:00
|
|
|
/* cast to signed is essential if tv_sec is wider than int */
|
|
|
|
tv.tv_sec = (int)(timeout_end - monotonic_sec());
|
2006-05-08 03:20:50 +00:00
|
|
|
tv.tv_usec = 0;
|
|
|
|
}
|
2007-05-03 23:39:35 +00:00
|
|
|
retval = 0;
|
2006-05-08 03:20:50 +00:00
|
|
|
if (!server_config.auto_time || tv.tv_sec > 0) {
|
|
|
|
retval = select(max_sock + 1, &rfds, NULL, NULL,
|
|
|
|
server_config.auto_time ? &tv : NULL);
|
2007-05-03 23:39:35 +00:00
|
|
|
}
|
2006-05-08 03:20:50 +00:00
|
|
|
if (retval == 0) {
|
|
|
|
write_leases();
|
2012-07-24 15:21:26 +00:00
|
|
|
goto continue_with_autotime;
|
2007-05-03 23:39:35 +00:00
|
|
|
}
|
|
|
|
if (retval < 0 && errno != EINTR) {
|
2009-06-17 09:54:52 +00:00
|
|
|
log1("Error on select");
|
2006-05-08 03:20:50 +00:00
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
switch (udhcp_sp_read(&rfds)) {
|
|
|
|
case SIGUSR1:
|
2010-03-23 15:25:17 +00:00
|
|
|
bb_info_msg("Received SIGUSR1");
|
2006-05-08 03:20:50 +00:00
|
|
|
write_leases();
|
|
|
|
/* why not just reset the timeout, eh */
|
2012-07-24 15:21:26 +00:00
|
|
|
goto continue_with_autotime;
|
2006-05-08 03:20:50 +00:00
|
|
|
case SIGTERM:
|
2010-03-23 15:25:17 +00:00
|
|
|
bb_info_msg("Received SIGTERM");
|
2012-07-24 15:21:26 +00:00
|
|
|
write_leases();
|
2007-05-03 23:39:35 +00:00
|
|
|
goto ret0;
|
2010-10-28 16:57:19 +00:00
|
|
|
case 0: /* no signal: read a packet */
|
2009-01-01 17:52:09 +00:00
|
|
|
break;
|
|
|
|
default: /* signal or error (probably EINTR): back to select */
|
|
|
|
continue;
|
2006-05-08 03:20:50 +00:00
|
|
|
}
|
|
|
|
|
2009-01-01 17:52:09 +00:00
|
|
|
bytes = udhcp_recv_kernel_packet(&packet, server_socket);
|
2007-03-26 13:22:35 +00:00
|
|
|
if (bytes < 0) {
|
2009-01-01 17:52:09 +00:00
|
|
|
/* bytes can also be -2 ("bad packet data") */
|
2006-05-08 03:20:50 +00:00
|
|
|
if (bytes == -1 && errno != EINTR) {
|
2009-06-17 09:54:52 +00:00
|
|
|
log1("Read error: %s, reopening socket", strerror(errno));
|
2006-05-08 03:20:50 +00:00
|
|
|
close(server_socket);
|
|
|
|
server_socket = -1;
|
|
|
|
}
|
|
|
|
continue;
|
|
|
|
}
|
2009-06-17 09:57:09 +00:00
|
|
|
if (packet.hlen != 6) {
|
|
|
|
bb_error_msg("MAC length != 6, ignoring packet");
|
|
|
|
continue;
|
|
|
|
}
|
2010-03-21 05:15:28 +00:00
|
|
|
if (packet.op != BOOTREQUEST) {
|
|
|
|
bb_error_msg("not a REQUEST, ignoring packet");
|
|
|
|
continue;
|
|
|
|
}
|
2010-03-22 13:29:13 +00:00
|
|
|
state = udhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
|
2010-03-21 05:15:28 +00:00
|
|
|
if (state == NULL || state[0] < DHCP_MINTYPE || state[0] > DHCP_MAXTYPE) {
|
|
|
|
bb_error_msg("no or bad message type option, ignoring packet");
|
2006-05-08 03:20:50 +00:00
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
2010-11-28 00:10:51 +00:00
|
|
|
/* Get SERVER_ID if present */
|
|
|
|
server_id_opt = udhcp_get_option(&packet, DHCP_SERVER_ID);
|
|
|
|
if (server_id_opt) {
|
2010-11-28 20:51:44 +00:00
|
|
|
uint32_t server_id_network_order;
|
|
|
|
move_from_unaligned32(server_id_network_order, server_id_opt);
|
|
|
|
if (server_id_network_order != server_config.server_nip) {
|
2010-11-28 00:10:51 +00:00
|
|
|
/* client talks to somebody else */
|
|
|
|
log1("server ID doesn't match, ignoring");
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2010-03-21 05:15:28 +00:00
|
|
|
/* Look for a static/dynamic lease */
|
2010-03-20 02:49:27 +00:00
|
|
|
static_lease_nip = get_static_nip_by_mac(server_config.static_leases, &packet.chaddr);
|
|
|
|
if (static_lease_nip) {
|
|
|
|
bb_info_msg("Found static lease: %x", static_lease_nip);
|
2009-06-17 11:24:03 +00:00
|
|
|
memcpy(&fake_lease.lease_mac, &packet.chaddr, 6);
|
2010-03-20 02:49:27 +00:00
|
|
|
fake_lease.lease_nip = static_lease_nip;
|
2009-06-17 11:24:03 +00:00
|
|
|
fake_lease.expires = 0;
|
|
|
|
lease = &fake_lease;
|
2006-11-18 19:51:32 +00:00
|
|
|
} else {
|
2009-06-17 11:24:03 +00:00
|
|
|
lease = find_lease_by_mac(packet.chaddr);
|
2006-05-08 03:20:50 +00:00
|
|
|
}
|
|
|
|
|
2010-11-28 00:10:51 +00:00
|
|
|
/* Get REQUESTED_IP if present */
|
|
|
|
requested_ip_opt = udhcp_get_option(&packet, DHCP_REQUESTED_IP);
|
|
|
|
if (requested_ip_opt) {
|
|
|
|
move_from_unaligned32(requested_nip, requested_ip_opt);
|
2010-03-21 05:15:28 +00:00
|
|
|
}
|
|
|
|
|
2006-05-08 03:20:50 +00:00
|
|
|
switch (state[0]) {
|
2010-03-21 05:15:28 +00:00
|
|
|
|
2006-05-08 03:20:50 +00:00
|
|
|
case DHCPDISCOVER:
|
2009-06-17 09:54:52 +00:00
|
|
|
log1("Received DISCOVER");
|
2006-05-08 03:20:50 +00:00
|
|
|
|
2014-10-30 10:59:04 +00:00
|
|
|
send_offer(&packet, static_lease_nip, lease, requested_ip_opt, arpping_ms);
|
2006-05-08 03:20:50 +00:00
|
|
|
break;
|
|
|
|
|
2010-03-21 05:15:28 +00:00
|
|
|
case DHCPREQUEST:
|
2009-06-17 11:24:03 +00:00
|
|
|
log1("Received REQUEST");
|
2010-03-21 05:46:09 +00:00
|
|
|
/* RFC 2131:
|
|
|
|
|
|
|
|
o DHCPREQUEST generated during SELECTING state:
|
|
|
|
|
|
|
|
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.
|
|
|
|
|
|
|
|
Note that the client may choose to collect several DHCPOFFER
|
|
|
|
messages and select the "best" offer. The client indicates its
|
|
|
|
selection by identifying the offering server in the DHCPREQUEST
|
|
|
|
message. If the client receives no acceptable offers, the client
|
|
|
|
may choose to try another DHCPDISCOVER message. Therefore, the
|
|
|
|
servers may not receive a specific DHCPREQUEST from which they can
|
|
|
|
decide whether or not the client has accepted the offer.
|
|
|
|
|
|
|
|
o DHCPREQUEST generated during INIT-REBOOT state:
|
|
|
|
|
|
|
|
'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. The client is seeking to
|
|
|
|
verify a previously allocated, cached configuration. Server SHOULD
|
|
|
|
send a DHCPNAK message to the client if the 'requested IP address'
|
|
|
|
is incorrect, or is on the wrong network.
|
|
|
|
|
|
|
|
Determining whether a client in the INIT-REBOOT state is on the
|
|
|
|
correct network is done by examining the contents of 'giaddr', the
|
|
|
|
'requested IP address' option, and a database lookup. If the DHCP
|
|
|
|
server detects that the client is on the wrong net (i.e., the
|
|
|
|
result of applying the local subnet mask or remote subnet mask (if
|
|
|
|
'giaddr' is not zero) to 'requested IP address' option value
|
|
|
|
doesn't match reality), then the server SHOULD send a DHCPNAK
|
|
|
|
message to the client.
|
|
|
|
|
|
|
|
If the network is correct, then the DHCP server should check if
|
|
|
|
the client's notion of its IP address is correct. If not, then the
|
|
|
|
server SHOULD send a DHCPNAK message to the client. If the DHCP
|
|
|
|
server has no record of this client, then it MUST remain silent,
|
|
|
|
and MAY output a warning to the network administrator. This
|
|
|
|
behavior is necessary for peaceful coexistence of non-
|
|
|
|
communicating DHCP servers on the same wire.
|
|
|
|
|
|
|
|
If 'giaddr' is 0x0 in the DHCPREQUEST message, the client is on
|
|
|
|
the same subnet as the server. The server MUST broadcast the
|
|
|
|
DHCPNAK message to the 0xffffffff broadcast address because the
|
|
|
|
client may not have a correct network address or subnet mask, and
|
|
|
|
the client may not be answering ARP requests.
|
|
|
|
|
|
|
|
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.
|
|
|
|
|
|
|
|
o DHCPREQUEST generated during RENEWING state:
|
|
|
|
|
|
|
|
'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. In this situation, the client is completely
|
|
|
|
configured, and is trying to extend its lease. This message will
|
|
|
|
be unicast, so no relay agents will be involved in its
|
|
|
|
transmission. Because 'giaddr' is therefore not filled in, the
|
|
|
|
DHCP server will trust the value in 'ciaddr', and use it when
|
|
|
|
replying to the client.
|
|
|
|
|
|
|
|
A client MAY choose to renew or extend its lease prior to T1. The
|
|
|
|
server may choose not to extend the lease (as a policy decision by
|
|
|
|
the network administrator), but should return a DHCPACK message
|
|
|
|
regardless.
|
|
|
|
|
|
|
|
o DHCPREQUEST generated during REBINDING state:
|
|
|
|
|
|
|
|
'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. In this situation, the client is completely
|
|
|
|
configured, and is trying to extend its lease. This message MUST
|
|
|
|
be broadcast to the 0xffffffff IP broadcast address. The DHCP
|
|
|
|
server SHOULD check 'ciaddr' for correctness before replying to
|
|
|
|
the DHCPREQUEST.
|
|
|
|
|
|
|
|
The DHCPREQUEST from a REBINDING client is intended to accommodate
|
|
|
|
sites that have multiple DHCP servers and a mechanism for
|
|
|
|
maintaining consistency among leases managed by multiple servers.
|
|
|
|
A DHCP server MAY extend a client's lease only if it has local
|
|
|
|
administrative authority to do so.
|
|
|
|
*/
|
2010-11-28 00:10:51 +00:00
|
|
|
if (!requested_ip_opt) {
|
2010-03-21 05:46:09 +00:00
|
|
|
requested_nip = packet.ciaddr;
|
|
|
|
if (requested_nip == 0) {
|
|
|
|
log1("no requested IP and no ciaddr, ignoring");
|
|
|
|
break;
|
|
|
|
}
|
2010-03-21 05:15:28 +00:00
|
|
|
}
|
|
|
|
if (lease && requested_nip == lease->lease_nip) {
|
2010-03-21 05:46:09 +00:00
|
|
|
/* client requested or configured IP matches the lease.
|
2010-03-21 05:15:28 +00:00
|
|
|
* ACK it, and bump lease expiration time. */
|
|
|
|
send_ACK(&packet, lease->lease_nip);
|
|
|
|
break;
|
|
|
|
}
|
2010-11-28 20:51:44 +00:00
|
|
|
/* No lease for this MAC, or lease IP != requested IP */
|
|
|
|
|
|
|
|
if (server_id_opt /* client is in SELECTING state */
|
|
|
|
|| requested_ip_opt /* client is in INIT-REBOOT state */
|
|
|
|
) {
|
|
|
|
/* "No, we don't have this IP for you" */
|
2010-03-21 05:15:28 +00:00
|
|
|
send_NAK(&packet);
|
2010-11-28 20:51:44 +00:00
|
|
|
} /* else: client is in RENEWING or REBINDING, do not answer */
|
|
|
|
|
2006-05-08 03:20:50 +00:00
|
|
|
break;
|
2010-03-21 05:15:28 +00:00
|
|
|
|
2006-05-08 03:20:50 +00:00
|
|
|
case DHCPDECLINE:
|
2010-03-21 05:15:28 +00:00
|
|
|
/* RFC 2131:
|
|
|
|
* "If the server receives a DHCPDECLINE message,
|
|
|
|
* the client has discovered through some other means
|
|
|
|
* that the suggested network address is already
|
|
|
|
* in use. The server MUST mark the network address
|
|
|
|
* as not available and SHOULD notify the local
|
|
|
|
* sysadmin of a possible configuration problem."
|
|
|
|
*
|
|
|
|
* SERVER_ID must be present,
|
|
|
|
* REQUESTED_IP must be present,
|
|
|
|
* chaddr must be filled in,
|
|
|
|
* ciaddr must be 0 (we do not check this)
|
|
|
|
*/
|
2009-06-17 09:54:52 +00:00
|
|
|
log1("Received DECLINE");
|
2010-03-21 05:15:28 +00:00
|
|
|
if (server_id_opt
|
2010-11-28 00:10:51 +00:00
|
|
|
&& requested_ip_opt
|
2010-03-21 05:15:28 +00:00
|
|
|
&& lease /* chaddr matches this lease */
|
|
|
|
&& requested_nip == lease->lease_nip
|
|
|
|
) {
|
2009-06-17 09:57:09 +00:00
|
|
|
memset(lease->lease_mac, 0, sizeof(lease->lease_mac));
|
2009-02-02 10:48:06 +00:00
|
|
|
lease->expires = time(NULL) + server_config.decline_time;
|
2006-05-08 03:20:50 +00:00
|
|
|
}
|
|
|
|
break;
|
2010-03-21 05:15:28 +00:00
|
|
|
|
2006-05-08 03:20:50 +00:00
|
|
|
case DHCPRELEASE:
|
2010-03-21 05:15:28 +00:00
|
|
|
/* "Upon receipt of a DHCPRELEASE message, the server
|
|
|
|
* marks the network address as not allocated."
|
|
|
|
*
|
|
|
|
* SERVER_ID must be present,
|
|
|
|
* REQUESTED_IP must not be present (we do not check this),
|
|
|
|
* chaddr must be filled in,
|
|
|
|
* ciaddr must be filled in
|
|
|
|
*/
|
2009-06-17 09:54:52 +00:00
|
|
|
log1("Received RELEASE");
|
2010-03-21 05:15:28 +00:00
|
|
|
if (server_id_opt
|
|
|
|
&& lease /* chaddr matches this lease */
|
|
|
|
&& packet.ciaddr == lease->lease_nip
|
|
|
|
) {
|
2009-02-02 10:48:06 +00:00
|
|
|
lease->expires = time(NULL);
|
2010-03-21 05:15:28 +00:00
|
|
|
}
|
2006-05-08 03:20:50 +00:00
|
|
|
break;
|
2010-03-21 05:15:28 +00:00
|
|
|
|
2006-05-08 03:20:50 +00:00
|
|
|
case DHCPINFORM:
|
2009-06-17 09:54:52 +00:00
|
|
|
log1("Received INFORM");
|
2006-05-08 03:20:50 +00:00
|
|
|
send_inform(&packet);
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
2007-05-03 23:39:35 +00:00
|
|
|
ret0:
|
|
|
|
retval = 0;
|
|
|
|
ret:
|
2007-07-03 15:47:50 +00:00
|
|
|
/*if (server_config.pidfile) - server_config.pidfile is never NULL */
|
2007-05-03 23:39:35 +00:00
|
|
|
remove_pidfile(server_config.pidfile);
|
|
|
|
return retval;
|
2006-05-08 03:20:50 +00:00
|
|
|
}
|