initial cut at split out dhcrelay, whacked from usr.sbin/dhcp/ and sbin/dhclient

10 files changed, 2406 insertions, 0 deletions

diff --git a/usr.sbin/dhcrelay/Makefile b/usr.sbin/dhcrelay/Makefile
new file mode 100644
index 00000000000..3b17dd22241
--- /dev/null
+++ b/usr.sbin/dhcrelay/Makefile
@@ -0,0 +1,11 @@
+# $OpenBSD: Makefile,v 1.1 2004/04/12 21:10:28 henning Exp $
+
+.include <bsd.own.mk>
+
+SRCS=	dhcrelay.c dispatch.c errwarn.c bpf.c packet.c alloc.c
+PROG=	dhcrelay
+MAN=	dhcrelay.8
+
+CFLAGS+=-Wall
+
+.include <bsd.prog.mk>
diff --git a/usr.sbin/dhcrelay/bpf.c b/usr.sbin/dhcrelay/bpf.c
new file mode 100644
index 00000000000..657aad79af7
--- /dev/null
+++ b/usr.sbin/dhcrelay/bpf.c
@@ -0,0 +1,321 @@
+/*	$OpenBSD: bpf.c,v 1.1 2004/04/12 21:10:28 henning Exp $	*/
+
+/* BPF socket interface code, originally contributed by Archie Cobbs. */
+
+/*
+ * Copyright (c) 1995, 1996, 1998, 1999
+ * The Internet Software Consortium.    All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of The Internet Software Consortium nor the names
+ *    of its contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
+ * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This software has been written for the Internet Software Consortium
+ * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+ * Enterprises.  To learn more about the Internet Software Consortium,
+ * see ``http://www.vix.com/isc''.  To learn more about Vixie
+ * Enterprises, see ``http://www.vix.com''.
+ */
+
+#include "dhcpd.h"
+#include <sys/ioctl.h>
+#include <sys/uio.h>
+
+#include <net/bpf.h>
+#include <netinet/in_systm.h>
+#include <netinet/ip.h>
+#include <netinet/udp.h>
+#include <netinet/if_ether.h>
+
+#define BPF_FORMAT "/dev/bpf%d"
+
+/*
+ * Called by get_interface_list for each interface that's discovered.
+ * Opens a packet filter for each interface and adds it to the select
+ * mask.
+ */
+int
+if_register_bpf(struct interface_info *info)
+{
+	char filename[50];
+	int sock, b;
+
+	/* Open a BPF device */
+	for (b = 0; 1; b++) {
+		snprintf(filename, sizeof(filename), BPF_FORMAT, b);
+		sock = open(filename, O_RDWR, 0);
+		if (sock < 0) {
+			if (errno == EBUSY)
+				continue;
+			else
+				error("Can't find free bpf: %m");
+		} else
+			break;
+	}
+
+	/* Set the BPF device to point at this interface. */
+	if (ioctl(sock, BIOCSETIF, info->ifp) < 0)
+		error("Can't attach interface %s to bpf device %s: %m",
+		    info->name, filename);
+
+	return (sock);
+}
+
+void
+if_register_send(struct interface_info *info)
+{
+	/*
+	 * If we're using the bpf API for sending and receiving, we
+	 * don't need to register this interface twice.
+	 */
+	info->wfdesc = info->rfdesc;
+}
+
+/*
+ * Packet filter program...
+ *
+ * XXX: Changes to the filter program may require changes to the
+ * constant offsets used in if_register_send to patch the BPF program!
+ */
+struct bpf_insn dhcp_bpf_filter[] = {
+	/* Make sure this is an IP packet... */
+	BPF_STMT(BPF_LD + BPF_H + BPF_ABS, 12),
+	BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ETHERTYPE_IP, 0, 8),
+
+	/* Make sure it's a UDP packet... */
+	BPF_STMT(BPF_LD + BPF_B + BPF_ABS, 23),
+	BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_UDP, 0, 6),
+
+	/* Make sure this isn't a fragment... */
+	BPF_STMT(BPF_LD + BPF_H + BPF_ABS, 20),
+	BPF_JUMP(BPF_JMP + BPF_JSET + BPF_K, 0x1fff, 4, 0),
+
+	/* Get the IP header length... */
+	BPF_STMT(BPF_LDX + BPF_B + BPF_MSH, 14),
+
+	/* Make sure it's to the right port... */
+	BPF_STMT(BPF_LD + BPF_H + BPF_IND, 16),
+	BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 67, 0, 1),		/* patch */
+
+	/* If we passed all the tests, ask for the whole packet. */
+	BPF_STMT(BPF_RET+BPF_K, (u_int)-1),
+
+	/* Otherwise, drop it. */
+	BPF_STMT(BPF_RET+BPF_K, 0),
+};
+
+int dhcp_bpf_filter_len = sizeof(dhcp_bpf_filter) / sizeof(struct bpf_insn);
+
+void
+if_register_receive(struct interface_info *info)
+{
+	struct bpf_version v;
+	struct bpf_program p;
+	int flag = 1, sz;
+
+	/* Open a BPF device and hang it on this interface... */
+	info->rfdesc = if_register_bpf(info);
+
+	/* Make sure the BPF version is in range... */
+	if (ioctl(info->rfdesc, BIOCVERSION, &v) < 0)
+		error("Can't get BPF version: %m");
+
+	if (v.bv_major != BPF_MAJOR_VERSION ||
+	    v.bv_minor < BPF_MINOR_VERSION)
+		error("Kernel BPF version out of range - recompile dhcpd!");
+
+	/*
+	 * Set immediate mode so that reads return as soon as a packet
+	 * comes in, rather than waiting for the input buffer to fill
+	 * with packets.
+	 */
+	if (ioctl(info->rfdesc, BIOCIMMEDIATE, &flag) < 0)
+		error("Can't set immediate mode on bpf device: %m");
+
+	/* Get the required BPF buffer length from the kernel. */
+	if (ioctl(info->rfdesc, BIOCGBLEN, &sz) < 0)
+		error("Can't get bpf buffer length: %m");
+	info->rbuf_max = sz;
+	info->rbuf = malloc(info->rbuf_max);
+	if (!info->rbuf)
+		error("Can't allocate %lu bytes for bpf input buffer.",
+		    (unsigned long)info->rbuf_max);
+	info->rbuf_offset = 0;
+	info->rbuf_len = 0;
+
+	/* Set up the bpf filter program structure. */
+	p.bf_len = dhcp_bpf_filter_len;
+	p.bf_insns = dhcp_bpf_filter;
+
+	/* Patch the server port into the BPF program...
+	 *
+	 * XXX: changes to filter program may require changes to the
+	 * insn number(s) used below!
+	 */
+	dhcp_bpf_filter[8].k = LOCAL_PORT;
+
+	if (ioctl(info->rfdesc, BIOCSETF, &p) < 0)
+		error("Can't install packet filter program: %m");
+}
+
+ssize_t
+send_packet(struct interface_info *interface, struct packet *packet,
+    struct dhcp_packet *raw, size_t len, struct in_addr from,
+    struct sockaddr_in *to, struct hardware *hto)
+{
+	unsigned char buf[256];
+	struct iovec iov[2];
+	int result, bufp = 0;
+
+	/* Assemble the headers... */
+	assemble_hw_header(interface, buf, &bufp, hto);
+	assemble_udp_ip_header(interface, buf, &bufp, from.s_addr,
+	    to->sin_addr.s_addr, to->sin_port, (unsigned char *)raw, len);
+
+	/* Fire it off */
+	iov[0].iov_base = (char *)buf;
+	iov[0].iov_len = bufp;
+	iov[1].iov_base = (char *)raw;
+	iov[1].iov_len = len;
+
+	result = writev(interface->wfdesc, iov, 2);
+	if (result < 0)
+		warn("send_packet: %m");
+	return (result);
+}
+
+ssize_t
+receive_packet(struct interface_info *interface, unsigned char *buf,
+    size_t len, struct sockaddr_in *from, struct hardware *hfrom)
+{
+	int length = 0, offset = 0;
+	struct bpf_hdr hdr;
+
+	/*
+	 * All this complexity is because BPF doesn't guarantee that
+	 * only one packet will be returned at a time.  We're getting
+	 * what we deserve, though - this is a terrible abuse of the BPF
+	 * interface.  Sigh.
+	 */
+
+	/* Process packets until we get one we can return or until we've
+	 * done a read and gotten nothing we can return...
+	 */
+	do {
+		/* If the buffer is empty, fill it. */
+		if (interface->rbuf_offset == interface->rbuf_len) {
+			length = read(interface->rfdesc, interface->rbuf,
+			    interface->rbuf_max);
+			if (length <= 0)
+				return (length);
+			interface->rbuf_offset = 0;
+			interface->rbuf_len = length;
+		}
+
+		/*
+		 * If there isn't room for a whole bpf header, something
+		 * went wrong, but we'll ignore it and hope it goes
+		 * away... XXX
+		 */
+		if (interface->rbuf_len - interface->rbuf_offset <
+		    sizeof(hdr)) {
+			interface->rbuf_offset = interface->rbuf_len;
+			continue;
+		}
+
+		/* Copy out a bpf header... */
+		memcpy(&hdr, &interface->rbuf[interface->rbuf_offset],
+		    sizeof(hdr));
+
+		/*
+		 * If the bpf header plus data doesn't fit in what's
+		 * left of the buffer, stick head in sand yet again...
+		 */
+		if (interface->rbuf_offset + hdr.bh_hdrlen + hdr.bh_caplen >
+		    interface->rbuf_len) {
+			interface->rbuf_offset = interface->rbuf_len;
+			continue;
+		}
+
+		/*
+		 * If the captured data wasn't the whole packet, or if
+		 * the packet won't fit in the input buffer, all we can
+		 * do is drop it.
+		 */
+		if (hdr.bh_caplen != hdr.bh_datalen) {
+			interface->rbuf_offset += hdr.bh_hdrlen = hdr.bh_caplen;
+			continue;
+		}
+
+		/* Skip over the BPF header... */
+		interface->rbuf_offset += hdr.bh_hdrlen;
+
+		/* Decode the physical header... */
+		offset = decode_hw_header(interface,
+		    interface->rbuf, interface->rbuf_offset, hfrom);
+
+		/*
+		 * If a physical layer checksum failed (dunno of any
+		 * physical layer that supports this, but WTH), skip
+		 * this packet.
+		 */
+		if (offset < 0) {
+			interface->rbuf_offset += hdr.bh_caplen;
+			continue;
+		}
+		interface->rbuf_offset += offset;
+		hdr.bh_caplen -= offset;
+
+		/* Decode the IP and UDP headers... */
+		offset = decode_udp_ip_header(interface, interface->rbuf,
+		    interface->rbuf_offset, from, NULL, hdr.bh_caplen);
+
+		/* If the IP or UDP checksum was bad, skip the packet... */
+		if (offset < 0) {
+			interface->rbuf_offset += hdr.bh_caplen;
+			continue;
+		}
+		interface->rbuf_offset += offset;
+		hdr.bh_caplen -= offset;
+
+		/*
+		 * If there's not enough room to stash the packet data,
+		 * we have to skip it (this shouldn't happen in real
+		 * life, though).
+		 */
+		if (hdr.bh_caplen > len) {
+			interface->rbuf_offset += hdr.bh_caplen;
+			continue;
+		}
+
+		/* Copy out the data in the packet... */
+		memcpy(buf, interface->rbuf + interface->rbuf_offset,
+		    hdr.bh_caplen);
+		interface->rbuf_offset += hdr.bh_caplen;
+		return (hdr.bh_caplen);
+	} while (!length);
+	return (0);
+}
diff --git a/usr.sbin/dhcrelay/dhcp.h b/usr.sbin/dhcrelay/dhcp.h
new file mode 100644
index 00000000000..2b6278dc8e0
--- /dev/null
+++ b/usr.sbin/dhcrelay/dhcp.h
@@ -0,0 +1,168 @@
+/*	$OpenBSD: dhcp.h,v 1.1 2004/04/12 21:10:28 henning Exp $	*/
+
+/* Protocol structures... */
+
+/*
+ * Copyright (c) 1995, 1996 The Internet Software Consortium.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of The Internet Software Consortium nor the names
+ *    of its contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
+ * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This software has been written for the Internet Software Consortium
+ * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+ * Enterprises.  To learn more about the Internet Software Consortium,
+ * see ``http://www.vix.com/isc''.  To learn more about Vixie
+ * Enterprises, see ``http://www.vix.com''.
+ */
+
+#define DHCP_UDP_OVERHEAD	(14 + /* Ethernet header */	\
+				 20 + /* IP header */		\
+				 8)   /* UDP header */
+#define DHCP_SNAME_LEN		64
+#define DHCP_FILE_LEN		128
+#define DHCP_FIXED_NON_UDP	236
+#define DHCP_FIXED_LEN		(DHCP_FIXED_NON_UDP + DHCP_UDP_OVERHEAD)
+						/* Everything but options. */
+#define DHCP_MTU_MAX		1500
+#define DHCP_OPTION_LEN		(DHCP_MTU_MAX - DHCP_FIXED_LEN)
+
+#define BOOTP_MIN_LEN		300
+#define DHCP_MIN_LEN            548
+
+struct dhcp_packet {
+	u_int8_t  op;		/* Message opcode/type */
+	u_int8_t  htype;	/* Hardware addr type (see net/if_types.h) */
+	u_int8_t  hlen;		/* Hardware addr length */
+	u_int8_t  hops;		/* Number of relay agent hops from client */
+	u_int32_t xid;		/* Transaction ID */
+	u_int16_t secs;		/* Seconds since client started looking */
+	u_int16_t flags;	/* Flag bits */
+	struct in_addr ciaddr;	/* Client IP address (if already in use) */
+	struct in_addr yiaddr;	/* Client IP address */
+	struct in_addr siaddr;	/* IP address of next server to talk to */
+	struct in_addr giaddr;	/* DHCP relay agent IP address */
+	unsigned char chaddr[16];	/* Client hardware address */
+	char sname[DHCP_SNAME_LEN];	/* Server name */
+	char file[DHCP_FILE_LEN];	/* Boot filename */
+	unsigned char options[DHCP_OPTION_LEN];
+				/* Optional parameters
+				   (actual length dependent on MTU). */
+};
+
+/* BOOTP (rfc951) message types */
+#define BOOTREQUEST	1
+#define BOOTREPLY	2
+
+/* Possible values for flags field... */
+#define BOOTP_BROADCAST 32768L
+
+/* Possible values for hardware type (htype) field... */
+#define HTYPE_ETHER	1               /* Ethernet 10Mbps              */
+#define HTYPE_IEEE802	6               /* IEEE 802.2 Token Ring...	*/
+#define HTYPE_FDDI	8		/* FDDI...			*/
+
+/* Magic cookie validating dhcp options field (and bootp vendor
+   extensions field). */
+#define DHCP_OPTIONS_COOKIE	"\143\202\123\143"
+
+/* DHCP Option codes: */
+
+#define DHO_PAD				0
+#define DHO_SUBNET_MASK			1
+#define DHO_TIME_OFFSET			2
+#define DHO_ROUTERS			3
+#define DHO_TIME_SERVERS		4
+#define DHO_NAME_SERVERS		5
+#define DHO_DOMAIN_NAME_SERVERS		6
+#define DHO_LOG_SERVERS			7
+#define DHO_COOKIE_SERVERS		8
+#define DHO_LPR_SERVERS			9
+#define DHO_IMPRESS_SERVERS		10
+#define DHO_RESOURCE_LOCATION_SERVERS	11
+#define DHO_HOST_NAME			12
+#define DHO_BOOT_SIZE			13
+#define DHO_MERIT_DUMP			14
+#define DHO_DOMAIN_NAME			15
+#define DHO_SWAP_SERVER			16
+#define DHO_ROOT_PATH			17
+#define DHO_EXTENSIONS_PATH		18
+#define DHO_IP_FORWARDING		19
+#define DHO_NON_LOCAL_SOURCE_ROUTING	20
+#define DHO_POLICY_FILTER		21
+#define DHO_MAX_DGRAM_REASSEMBLY	22
+#define DHO_DEFAULT_IP_TTL		23
+#define DHO_PATH_MTU_AGING_TIMEOUT	24
+#define DHO_PATH_MTU_PLATEAU_TABLE	25
+#define DHO_INTERFACE_MTU		26
+#define DHO_ALL_SUBNETS_LOCAL		27
+#define DHO_BROADCAST_ADDRESS		28
+#define DHO_PERFORM_MASK_DISCOVERY	29
+#define DHO_MASK_SUPPLIER		30
+#define DHO_ROUTER_DISCOVERY		31
+#define DHO_ROUTER_SOLICITATION_ADDRESS	32
+#define DHO_STATIC_ROUTES		33
+#define DHO_TRAILER_ENCAPSULATION	34
+#define DHO_ARP_CACHE_TIMEOUT		35
+#define DHO_IEEE802_3_ENCAPSULATION	36
+#define DHO_DEFAULT_TCP_TTL		37
+#define DHO_TCP_KEEPALIVE_INTERVAL	38
+#define DHO_TCP_KEEPALIVE_GARBAGE	39
+#define DHO_NIS_DOMAIN			40
+#define DHO_NIS_SERVERS			41
+#define DHO_NTP_SERVERS			42
+#define DHO_VENDOR_ENCAPSULATED_OPTIONS	43
+#define DHO_NETBIOS_NAME_SERVERS	44
+#define DHO_NETBIOS_DD_SERVER		45
+#define DHO_NETBIOS_NODE_TYPE		46
+#define DHO_NETBIOS_SCOPE		47
+#define DHO_FONT_SERVERS		48
+#define DHO_X_DISPLAY_MANAGER		49
+#define DHO_DHCP_REQUESTED_ADDRESS	50
+#define DHO_DHCP_LEASE_TIME		51
+#define DHO_DHCP_OPTION_OVERLOAD	52
+#define DHO_DHCP_MESSAGE_TYPE		53
+#define DHO_DHCP_SERVER_IDENTIFIER	54
+#define DHO_DHCP_PARAMETER_REQUEST_LIST	55
+#define DHO_DHCP_MESSAGE		56
+#define DHO_DHCP_MAX_MESSAGE_SIZE	57
+#define DHO_DHCP_RENEWAL_TIME		58
+#define DHO_DHCP_REBINDING_TIME		59
+#define DHO_DHCP_CLASS_IDENTIFIER	60
+#define DHO_DHCP_CLIENT_IDENTIFIER	61
+#define DHO_DHCP_USER_CLASS_ID		77
+#define DHO_END				255
+
+/* DHCP message types. */
+#define DHCPDISCOVER	1
+#define DHCPOFFER	2
+#define DHCPREQUEST	3
+#define DHCPDECLINE	4
+#define DHCPACK		5
+#define DHCPNAK		6
+#define DHCPRELEASE	7
+#define DHCPINFORM	8
diff --git a/usr.sbin/dhcrelay/dhcpd.h b/usr.sbin/dhcrelay/dhcpd.h
new file mode 100644
index 00000000000..6b305814d71
--- /dev/null
+++ b/usr.sbin/dhcrelay/dhcpd.h
@@ -0,0 +1,290 @@
+/*	$OpenBSD: dhcpd.h,v 1.1 2004/04/12 21:10:28 henning Exp $	*/
+
+/*
+ * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
+ * Copyright (c) 1995, 1996, 1997, 1998, 1999
+ * The Internet Software Consortium.    All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of The Internet Software Consortium nor the names
+ *    of its contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
+ * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This software has been written for the Internet Software Consortium
+ * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+ * Enterprises.  To learn more about the Internet Software Consortium,
+ * see ``http://www.vix.com/isc''.  To learn more about Vixie
+ * Enterprises, see ``http://www.vix.com''.
+ */
+
+#include <sys/types.h>
+
+#include <sys/socket.h>
+#include <sys/sockio.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/un.h>
+#include <sys/wait.h>
+
+#include <net/if.h>
+#include <net/if_dl.h>
+#include <net/route.h>
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <netdb.h>
+#include <paths.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "dhcp.h"
+#include "tree.h"
+
+#define	LOCAL_PORT	68
+#define	REMOTE_PORT	67
+
+struct option_data {
+	int		 len;
+	u_int8_t	*data;
+};
+
+struct string_list {
+	struct string_list	*next;
+	char			*string;
+};
+
+struct iaddr {
+	int len;
+	unsigned char iabuf[16];
+};
+
+struct iaddrlist {
+	struct iaddrlist *next;
+	struct iaddr addr;
+};
+
+struct packet {
+	struct dhcp_packet	*raw;
+	int			 packet_length;
+	int			 packet_type;
+	int			 options_valid;
+	int			 client_port;
+	struct iaddr		 client_addr;
+	struct interface_info	*interface;
+	struct hardware		*haddr;
+	struct option_data	 options[256];
+	int			 got_requested_address;
+};
+
+struct hardware {
+	u_int8_t htype;
+	u_int8_t hlen;
+	u_int8_t haddr[16];
+};
+
+struct client_lease {
+	struct client_lease	*next;
+	time_t			 expiry, renewal, rebind;
+	struct iaddr		 address;
+	char			*server_name;
+	char			*filename;
+	struct string_list	*medium;
+	unsigned int		 is_static : 1;
+	unsigned int		 is_bootp : 1;
+	struct option_data	 options[256];
+};
+
+/* Possible states in which the client can be. */
+enum dhcp_state {
+	S_REBOOTING,
+	S_INIT,
+	S_SELECTING,
+	S_REQUESTING,
+	S_BOUND,
+	S_RENEWING,
+	S_REBINDING
+};
+
+struct client_config {
+	struct option_data	defaults[256];
+	enum {
+		ACTION_DEFAULT,
+		ACTION_SUPERSEDE,
+		ACTION_PREPEND,
+		ACTION_APPEND
+	} default_actions[256];
+
+	struct option_data	 send_options[256];
+	u_int8_t		 required_options[256];
+	u_int8_t		 requested_options[256];
+	int			 requested_option_count;
+	time_t			 timeout;
+	time_t			 initial_interval;
+	time_t			 retry_interval;
+	time_t			 select_interval;
+	time_t			 reboot_timeout;
+	time_t			 backoff_cutoff;
+	struct string_list	*media;
+	char			*script_name;
+	enum { IGNORE, ACCEPT, PREFER }
+				 bootp_policy;
+	struct string_list	*medium;
+	struct iaddrlist	*reject_list;
+};
+
+struct client_state {
+	struct client_lease	 *active;
+	struct client_lease	 *new;
+	struct client_lease	 *offered_leases;
+	struct client_lease	 *leases;
+	struct client_lease	 *alias;
+	enum dhcp_state		  state;
+	struct iaddr		  destination;
+	u_int32_t		  xid;
+	u_int16_t		  secs;
+	time_t			  first_sending;
+	time_t			  interval;
+	struct string_list	 *medium;
+	struct dhcp_packet	  packet;
+	int			  packet_length;
+	struct iaddr		  requested_address;
+	struct client_config	 *config;
+	char			**scriptEnv;
+	int			  scriptEnvsize;
+	struct string_list	 *env;
+	int			  envc;
+};
+
+struct interface_info {
+	struct interface_info	*next;
+	struct hardware		 hw_address;
+	struct in_addr		 primary_address;
+	char			 name[IFNAMSIZ];
+	int			 rfdesc;
+	int			 wfdesc;
+	unsigned char		*rbuf;
+	size_t			 rbuf_max;
+	size_t			 rbuf_offset;
+	size_t			 rbuf_len;
+	struct ifreq		*ifp;
+	struct client_state	*client;
+	int			 noifmedia;
+	int			 errors;
+	int			 dead;
+	u_int16_t		 index;
+};
+
+struct timeout {
+	struct timeout	*next;
+	time_t		 when;
+	void		 (*func)(void *);
+	void		*what;
+};
+
+struct protocol {
+	struct protocol	*next;
+	int fd;
+	void (*handler)(struct protocol *);
+	void *local;
+};
+
+#define DEFAULT_HASH_SIZE 97
+
+struct hash_bucket {
+	struct hash_bucket *next;
+	unsigned char *name;
+	int len;
+	unsigned char *value;
+};
+
+struct hash_table {
+	int hash_count;
+	struct hash_bucket *buckets[DEFAULT_HASH_SIZE];
+};
+
+/* Default path to dhcpd config file. */
+#define	DHCPD_LOG_FACILITY	LOG_DAEMON
+
+#define	MAX_TIME 0x7fffffff
+#define	MIN_TIME 0
+
+/* External definitions... */
+
+/* errwarn.c */
+extern int warnings_occurred;
+void error(char *, ...) __attribute__ ((__format__ (__printf__, 1, 2)));
+int warn(char *, ...) __attribute__ ((__format__ (__printf__, 1, 2)));
+int note(char *, ...) __attribute__ ((__format__ (__printf__, 1, 2)));
+int debug(char *, ...) __attribute__ ((__format__ (__printf__, 1, 2)));
+
+/* bpf.c */
+int if_register_bpf(struct interface_info *);
+void if_register_send(struct interface_info *);
+void if_register_receive(struct interface_info *);
+ssize_t send_packet(struct interface_info *,
+    struct packet *, struct dhcp_packet *, size_t, struct in_addr,
+    struct sockaddr_in *, struct hardware *);
+ssize_t receive_packet(struct interface_info *, unsigned char *, size_t,
+    struct sockaddr_in *, struct hardware *);
+
+/* dispatch.c */
+extern void (*bootp_packet_handler)(struct interface_info *,
+    struct dhcp_packet *, int, unsigned int, struct iaddr, struct hardware *);
+void discover_interfaces(struct interface_info *);
+void reinitialize_interfaces(void);
+void dispatch(void);
+void got_one(struct protocol *);
+void add_timeout(time_t, void (*)(void *), void *);
+void cancel_timeout(void (*)(void *), void *);
+void add_protocol(char *, int, void (*)(struct protocol *), void *);
+void remove_protocol(struct protocol *);
+int interface_link_status(char *);
+
+/* packet.c */
+void assemble_hw_header(struct interface_info *, unsigned char *,
+    int *, struct hardware *);
+void assemble_udp_ip_header(struct interface_info *, unsigned char *,
+    int *, u_int32_t, u_int32_t, unsigned int, unsigned char *, int);
+ssize_t decode_hw_header(struct interface_info *, unsigned char *,
+    int, struct hardware *);
+ssize_t decode_udp_ip_header(struct interface_info *, unsigned char *,
+    int, struct sockaddr_in *, unsigned char *, int);
+
+
+/* crap */
+extern time_t cur_time;
+extern int log_priority;
+extern int log_perror;
diff --git a/usr.sbin/dhcrelay/dhcrelay.8 b/usr.sbin/dhcrelay/dhcrelay.8
new file mode 100644
index 00000000000..cc814ff5bfd
--- /dev/null
+++ b/usr.sbin/dhcrelay/dhcrelay.8
@@ -0,0 +1,157 @@
+.\"	$OpenBSD: dhcrelay.8,v 1.1 2004/04/12 21:10:28 henning Exp $
+.\"
+.\" Copyright (c) 1997 The Internet Software Consortium.
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\"
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. Neither the name of The Internet Software Consortium nor the names
+.\"    of its contributors may be used to endorse or promote products derived
+.\"    from this software without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
+.\" CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+.\" DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
+.\" CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+.\" LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+.\" USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+.\" ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" This software has been written for the Internet Software Consortium
+.\" by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+.\" Enterprises.  To learn more about the Internet Software Consortium,
+.\" see ``http://www.isc.org/isc''.  To learn more about Vixie
+.\" Enterprises, see ``http://www.vix.com''.
+.\"
+.Dd January 1, 1997
+.Dt DHCRELAY 8
+.Os
+.Sh NAME
+.Nm dhcrelay
+.Nd Dynamic Host Configuration Protocol Relay Agent
+.Sh SYNOPSIS
+.Nm dhcrelay
+.Op Fl p Ar port
+.Op Fl d
+.Op Fl q
+.Xo
+.Oo Fl i Ar if0 Oo Ar ...
+.Fl i Ar ifN Oc Oc
+.Xc
+.Ar server0 Op Ar ... serverN
+.Sh DESCRIPTION
+The Internet Software Consortium DHCP Relay Agent,
+.Nm dhcrelay ,
+provides a means for relaying DHCP and BOOTP requests from a subnet to which
+no DHCP server is directly connected to one or more DHCP servers on other
+subnets.
+.Sh OPERATION
+The DHCP Relay Agent listens for DHCP requests on all interfaces
+attached to a host, unless one or more interfaces are specified on the
+command line with the
+.Fl i
+flag.
+.Pp
+When a query is received,
+.Nm
+forwards it to the list of DHCP servers specified on the command line.
+When a reply is received, it is broadcast or unicast on the network from
+whence the original request came.
+.Pp
+It is possible to specify a set of interfaces on which
+.Nm
+will listen, so that if
+.Nm
+is connected through one interface to a network on which there is no DHCP
+server, but is connected on another interface to a network on which there
+is a DHCP server, it will not relay DHCP and BOOTP requests from the network
+on which the server exists to that server.
+This is an imperfect solution.
+.Sh COMMAND LINE
+The names of the network interfaces that
+.Nm
+should attempt to configure may be specified on the command line using the
+.Fl i
+option.
+If no interface names are specified on the command line,
+.Nm
+will identify all network interfaces, eliminating non-broadcast interfaces
+if possible, and attempt to configure each interface.
+.Pp
+If
+.Nm
+should listen and transmit on a port other than the standard (port 67), the
+.Fl p
+flag may used.
+It should be followed by the UDP port number that
+.Nm
+should use.
+This is mostly useful for debugging purposes.
+If the
+.Fl p
+flag is specified, the relay agent will transmit responses to clients
+at a port number that is one greater than the one specified \- i.e., if
+you specify
+.Fl p
+67, then the relay agent will listen on port 67 and transmit to port 68.
+Transmissions to servers will be sent to the same port number
+that is specified with the
+.Fl p
+flag.
+.Pp
+.Nm
+will normally run in the foreground until it has configured
+an interface, and then will revert to running in the background.
+To force
+.Nm
+to always run as a foreground process, the
+.Fl d
+flag should be specified.
+This is useful when running
+.Nm
+under a debugger, or when running it out of inittab on System V systems.
+.Pp
+.Nm
+will normally print its network configuration on startup.
+This can be annoying in a system startup script \- to disable this
+behaviour, specify the
+.Fl q
+flag.
+.Pp
+The name of at least one DHCP server to which DHCP and BOOTP requests
+should be relayed must be specified on the command line.
+.Sh SEE ALSO
+.Xr dhclient 8 ,
+.Xr dhcpd 8
+.Pp
+RFC 2132, RFC 2131.
+.Sh AUTHORS
+.Nm
+has been written for the Internet Software Consortium by
+.An Ted Lemon Aq mellon@fugue.com
+in cooperation with Vixie Enterprises.
+To learn more about the Internet Software Consortium, see
+.Pa http://www.vix.com/isc .
+To learn more about Vixie Enterprises, see
+.Pa http://www.vix.com .
+.Sh BUGS
+Relayed DHCP traffic could actually safely be protected by IPsec, but
+like
+.Xr dhcpd 8
+and
+.Xr dhclient 8 ,
+.Nm
+will bypass IPsec for all its traffic.
diff --git a/usr.sbin/dhcrelay/dhcrelay.c b/usr.sbin/dhcrelay/dhcrelay.c
new file mode 100644
index 00000000000..6cc899cc72a
--- /dev/null
+++ b/usr.sbin/dhcrelay/dhcrelay.c
@@ -0,0 +1,402 @@
+/* dhcrelay.c
+
+   DHCP/BOOTP Relay Agent. */
+
+/*
+ * Copyright (c) 1997, 1998, 1999 The Internet Software Consortium.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of The Internet Software Consortium nor the names
+ *    of its contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
+ * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This software has been written for the Internet Software Consortium
+ * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+ * Enterprises.  To learn more about the Internet Software Consortium,
+ * see ``http://www.vix.com/isc''.  To learn more about Vixie
+ * Enterprises, see ``http://www.vix.com''.
+ */
+
+#include "dhcpd.h"
+
+void	 usage(char *);
+void	 relay(struct interface_info *, struct dhcp_packet *, int,
+	    unsigned int, struct iaddr, struct hardware *);
+char	*print_hw_addr(int, int, unsigned char *);
+
+time_t cur_time;
+time_t default_lease_time = 43200; /* 12 hours... */
+time_t max_lease_time = 86400; /* 24 hours... */
+struct tree_cache *global_options [256];
+
+int log_perror = 1;
+
+/* Needed to prevent linking against conflex.c. */
+#if 0
+int lexline;
+int lexchar;
+char *token_line;
+char *tlname;
+#endif
+
+char *path_dhcrelay_pid = "/var/run/dhcrelay.pid";
+
+u_int16_t local_port;
+u_int16_t remote_port;
+int log_priority;
+struct interface_info *interfaces = NULL;
+
+struct server_list {
+	struct server_list *next;
+	struct sockaddr_in to;
+} *servers;
+
+static char copyright [] =
+"Copyright 1997, 1998, 1999 The Internet Software Consortium.";
+static char arr [] = "All rights reserved.";
+static char message [] = "Internet Software Consortium DHCP Relay Agent";
+static char contrib [] = "Please contribute if you find this software useful.";
+static char url [] = "For info, please visit http://www.isc.org/dhcp-contrib.html";
+
+int main (argc, argv)
+	int argc;
+	char **argv;
+{
+	int i;
+	struct servent *ent;
+	struct server_list *sp = (struct server_list *)0;
+	int no_daemon = 0;
+	int quiet = 0;
+	char *s;
+
+	s = strrchr (argv [0], '/');
+	if (!s)
+		s = argv [0];
+	else
+		s++;
+
+	/* Initially, log errors to stderr as well as to syslogd. */
+	openlog (s, LOG_NDELAY, DHCPD_LOG_FACILITY);
+
+	setlogmask (LOG_UPTO (LOG_INFO));
+
+	for (i = 1; i < argc; i++) {
+		if (!strcmp (argv [i], "-p")) {
+			if (++i == argc)
+				usage (s);
+			local_port = htons (atoi (argv [i]));
+			debug ("binding to user-specified port %d",
+			       ntohs (local_port));
+		} else if (!strcmp (argv [i], "-pf")) {
+			if (++i == argc)
+				usage (s);
+			path_dhcrelay_pid = argv [i];
+		} else if (!strcmp (argv [i], "-d")) {
+			no_daemon = 1;
+ 		} else if (!strcmp (argv [i], "-i")) {
+			if (++i == argc || interfaces != NULL) {
+				usage (s);
+			}
+			if ((interfaces = calloc(1,
+			    sizeof(struct interface_info))) == NULL)
+				error("calloc");
+			strlcpy(interfaces -> name, argv [i],
+			    sizeof(interfaces->name));
+		} else if (!strcmp (argv [i], "-q")) {
+			quiet = 1;
+ 		} else if (argv [i][0] == '-') {
+ 		    usage (s);
+ 		} else {
+			struct hostent *he;
+			struct in_addr ia, *iap = (struct in_addr *)0;
+			if (inet_aton (argv [i], &ia)) {
+				iap = &ia;
+			} else {
+				he = gethostbyname (argv [i]);
+				if (!he) {
+					warn ("%s: host unknown", argv [i]);
+				} else {
+					iap = ((struct in_addr *)
+					       he -> h_addr_list [0]);
+				}
+			}
+			if (iap) {
+				sp = calloc(1, sizeof *sp);
+				if (!sp)
+					error ("no memory for server.\n");
+				sp -> next = servers;
+				servers = sp;
+				memcpy (&sp -> to.sin_addr,
+					iap, sizeof *iap);
+			}
+ 		}
+	}
+
+	if (!quiet)
+		log_perror = 0;
+
+	if (interfaces == NULL)
+		error("no interface given");
+
+	/* Default to the DHCP/BOOTP port. */
+	if (!local_port) {
+		ent = getservbyname ("dhcps", "udp");
+		if (!ent)
+			local_port = htons (67);
+		else
+			local_port = ent -> s_port;
+		endservent ();
+	}
+	remote_port = htons (ntohs (local_port) + 1);
+  
+	/* We need at least one server. */
+	if (!sp) {
+		usage (s);
+	}
+
+	/* Set up the server sockaddrs. */
+	for (sp = servers; sp; sp = sp -> next) {
+		sp -> to.sin_port = local_port;
+		sp -> to.sin_family = AF_INET;
+		sp -> to.sin_len = sizeof sp -> to;
+	}
+
+	/* Get the current time... */
+	time(&cur_time);
+
+	/* Discover all the network interfaces. */
+	discover_interfaces(interfaces);
+
+	/* Set up the bootp packet handler... */
+	bootp_packet_handler = relay;
+
+	/* Become a daemon... */
+	if (!no_daemon) {
+		int pid;
+		FILE *pf;
+		int pfdesc;
+
+		log_perror = 0;
+
+		if ((pid = fork()) < 0)
+			error ("can't fork daemon: %m");
+		else if (pid)
+			exit (0);
+
+		pfdesc = open (path_dhcrelay_pid,
+			       O_CREAT | O_TRUNC | O_WRONLY, 0644);
+
+		if (pfdesc < 0) {
+			warn ("Can't create %s: %m", path_dhcrelay_pid);
+		} else {
+			pf = fdopen (pfdesc, "w");
+			if (!pf)
+				warn ("Can't fdopen %s: %m",
+				      path_dhcrelay_pid);
+			else {
+				fprintf (pf, "%ld\n", (long)getpid ());
+				fclose (pf);
+			}	
+		}
+
+		close (0);
+		close (1);
+		close (2);
+		pid = setsid ();
+	}
+
+	/* Start dispatching packets and timeouts... */
+	dispatch ();
+
+	/*NOTREACHED*/
+	return 0;
+}
+
+void relay (ip, packet, length, from_port, from, hfrom)
+	struct interface_info *ip;
+	struct dhcp_packet *packet;
+	int length;
+	unsigned int from_port;
+	struct iaddr from;
+	struct hardware *hfrom;
+{
+	struct server_list *sp;
+	struct sockaddr_in to;
+	struct interface_info *out;
+	struct hardware hto;
+
+	if (packet -> hlen > sizeof packet -> chaddr) {
+		note ("Discarding packet with invalid hlen.");
+		return;
+	}
+
+	/* If it's a bootreply, forward it to the client. */
+	if (packet -> op == BOOTREPLY) {
+		memset(&to, 0, sizeof(to));
+		if (!(packet -> flags & htons (BOOTP_BROADCAST))) {
+			to.sin_addr = packet -> yiaddr;
+			to.sin_port = remote_port;
+		} else {
+			to.sin_addr.s_addr = htonl (INADDR_BROADCAST);
+			to.sin_port = remote_port;
+		}
+		to.sin_family = AF_INET;
+		to.sin_len = sizeof to;
+
+		/* Set up the hardware destination address. */
+		hto.hlen = packet -> hlen;
+		if (hto.hlen > sizeof hto.haddr)
+			hto.hlen = sizeof hto.haddr;
+		memcpy (hto.haddr, packet -> chaddr, hto.hlen);
+		hto.htype = packet -> htype;
+
+		/* Find the interface that corresponds to the giaddr
+		   in the packet. */
+		for (out = interfaces; out; out = out -> next) {
+			if (!memcmp (&out -> primary_address,
+				     &packet -> giaddr,
+				     sizeof packet -> giaddr))
+				break;
+		}
+		if (!out) {
+			warn ("packet to bogus giaddr %s.",
+			      inet_ntoa (packet -> giaddr));
+			return;
+		}
+
+		if (send_packet (out,
+				  (struct packet *)0,
+				  packet, length, out -> primary_address,
+				  &to, &hto) != -1)
+			debug ("forwarded BOOTREPLY for %s to %s",
+			       print_hw_addr (packet -> htype, packet -> hlen,
+					      packet -> chaddr),
+			       inet_ntoa (to.sin_addr));
+
+		return;
+	}
+
+	/* If giaddr is set on a BOOTREQUEST, ignore it - it's already
+	   been gatewayed. */
+	if (packet -> giaddr.s_addr) {
+		note ("ignoring BOOTREQUEST with giaddr of %s\n",
+		      inet_ntoa (packet -> giaddr));
+		return;
+	}
+
+	/* Set the giaddr so the server can figure out what net it's
+	   from and so that we can later forward the response to the
+	   correct net. */
+	packet -> giaddr = ip -> primary_address;
+
+	/* Otherwise, it's a BOOTREQUEST, so forward it to all the
+	   servers. */
+	for (sp = servers; sp; sp = sp -> next) {
+		if (send_packet (interfaces,
+				  (struct packet *)0,
+				  packet, length, ip -> primary_address,
+				  &sp -> to, (struct hardware *)0) != -1) {
+			debug ("forwarded BOOTREQUEST for %s to %s",
+			       print_hw_addr (packet -> htype, packet -> hlen,
+					      packet -> chaddr),
+			       inet_ntoa (sp -> to.sin_addr));
+		}
+	}
+				 
+}
+
+void usage (appname)
+	char *appname;
+{
+	note (message);
+	note (copyright);
+	note (arr);
+	note ("%s", "");
+	note (contrib);
+	note (url);
+	note ("%s", "");
+
+	warn ("Usage: %s [-q] [-d] [-i if0] [...-i ifN] [-p <port>]", appname);
+	error ("      [-pf pidfilename] [server1 [... serverN]]");
+}
+
+void cleanup ()
+{
+}
+
+int write_lease (lease)
+	struct lease *lease;
+{
+	return 1;
+}
+
+int commit_leases ()
+{
+	return 1;
+}
+
+void bootp (packet)
+	struct packet *packet;
+{
+}
+
+void dhcp (packet)
+	struct packet *packet;
+{
+}
+
+char *print_hw_addr (htype, hlen, data)
+	int htype;
+	int hlen;
+	unsigned char *data;
+{
+	static char habuf [49];
+	char *s;
+	int i;
+
+	if (htype == 0 || hlen == 0) {
+		goto bad;
+	} else {
+		int slen = sizeof(habuf);
+		s = habuf;
+		for (i = 0; i < hlen; i++) {
+			int j;
+			j = snprintf (s, slen, "%02x", data [i]);
+			if (j <= 0)
+				goto bad;
+
+			s += strlen (s);
+			slen -= (strlen(s) + 1);
+ 			*s++ = ':';
+		}
+		*--s = 0;
+	}
+	return habuf;
+ bad:	
+	strlcpy (habuf, "<null>", sizeof habuf);
+	return habuf;
+
+}
diff --git a/usr.sbin/dhcrelay/dispatch.c b/usr.sbin/dhcrelay/dispatch.c
new file mode 100644
index 00000000000..a38850842ad
--- /dev/null
+++ b/usr.sbin/dhcrelay/dispatch.c
@@ -0,0 +1,496 @@
+/*	$OpenBSD: dispatch.c,v 1.1 2004/04/12 21:10:28 henning Exp $	*/
+
+/*
+ * Copyright 2004 Henning Brauer <henning@openbsd.org>
+ * Copyright (c) 1995, 1996, 1997, 1998, 1999
+ * The Internet Software Consortium.   All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of The Internet Software Consortium nor the names
+ *    of its contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
+ * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This software has been written for the Internet Software Consortium
+ * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+ * Enterprises.  To learn more about the Internet Software Consortium,
+ * see ``http://www.vix.com/isc''.  To learn more about Vixie
+ * Enterprises, see ``http://www.vix.com''.
+ */
+
+#include "dhcpd.h"
+
+#include <sys/ioctl.h>
+
+#include <net/if_media.h>
+#include <ifaddrs.h>
+#include <poll.h>
+
+struct protocol *protocols;
+struct timeout *timeouts;
+static struct timeout *free_timeouts;
+static int interfaces_invalidated;
+void (*bootp_packet_handler)(struct interface_info *,
+    struct dhcp_packet *, int, unsigned int,
+    struct iaddr, struct hardware *);
+
+static int interface_status(struct interface_info *ifinfo);
+
+/*
+ * Use getifaddrs() to get a list of all the attached interfaces.  For
+ * each interface that's of type INET and not the loopback interface,
+ * register that interface with the network I/O software, figure out
+ * what subnet it's on, and add it to the list of interfaces.
+ */
+void
+discover_interfaces(struct interface_info *iface)
+{
+	struct sockaddr_in foo;
+	struct ifaddrs *ifap, *ifa;
+	struct ifreq *tif;
+
+	if (getifaddrs(&ifap) != 0)
+		error("getifaddrs failed");
+
+	for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
+		if ((ifa->ifa_flags & IFF_LOOPBACK) ||
+		    (ifa->ifa_flags & IFF_POINTOPOINT) ||
+		    (!(ifa->ifa_flags & IFF_UP)))
+			continue;
+
+		if (strcmp(iface->name, ifa->ifa_name))
+			continue;
+
+		/*
+		 * If we have the capability, extract link information
+		 * and record it in a linked list.
+		 */
+		if (ifa->ifa_addr->sa_family == AF_LINK) {
+			struct sockaddr_dl *foo =
+			    (struct sockaddr_dl *)ifa->ifa_addr;
+			iface->index = foo->sdl_index;
+			iface->hw_address.hlen = foo->sdl_alen;
+			iface->hw_address.htype = HTYPE_ETHER; /* XXX */
+			memcpy(iface->hw_address.haddr,
+			    LLADDR(foo), foo->sdl_alen);
+		} else if (ifa->ifa_addr->sa_family == AF_INET) {
+			struct iaddr addr;
+
+			memcpy(&foo, ifa->ifa_addr, sizeof(foo));
+			if (foo.sin_addr.s_addr == htonl(INADDR_LOOPBACK))
+				continue;
+			if (!iface->ifp) {
+				int len = IFNAMSIZ + ifa->ifa_addr->sa_len;
+				if ((tif = malloc(len)) == NULL)
+					error("no space to remember ifp");
+				strlcpy(tif->ifr_name, ifa->ifa_name, IFNAMSIZ);
+				memcpy(&tif->ifr_addr, ifa->ifa_addr,
+				    ifa->ifa_addr->sa_len);
+				iface->ifp = tif;
+				iface->primary_address = foo.sin_addr;
+			}
+			addr.len = 4;
+			memcpy(addr.iabuf, &foo.sin_addr.s_addr, addr.len);
+		}
+	}
+
+	if (!iface->ifp)
+		error("%s: not found", iface->name);
+
+	/* Register the interface... */
+	if_register_receive(iface);
+	if_register_send(iface);
+	add_protocol(iface->name, iface->rfdesc, got_one, iface);
+
+	freeifaddrs(ifap);
+}
+
+void
+reinitialize_interfaces(void)
+{
+	interfaces_invalidated = 1;
+}
+
+/*
+ * Wait for packets to come in using poll().  When a packet comes in,
+ * call receive_packet to receive the packet and possibly strip hardware
+ * addressing information from it, and then call through the
+ * bootp_packet_handler hook to try to do something with it.
+ */
+void
+dispatch(void)
+{
+	int count, i, to_msec, nfds = 0;
+	struct protocol *l;
+	struct pollfd *fds;
+	time_t howlong;
+
+	nfds = 0;
+	for (l = protocols; l; l = l->next)
+		nfds++;
+
+	fds = malloc(nfds * sizeof(struct pollfd));
+	if (fds == NULL)
+		error("Can't allocate poll structures.");
+
+	do {
+		/*
+		 * Call any expired timeouts, and then if there's still
+		 * a timeout registered, time out the select call then.
+		 */
+another:
+		if (timeouts) {
+			struct timeout *t;
+			if (timeouts->when <= cur_time) {
+				t = timeouts;
+				timeouts = timeouts->next;
+				(*(t->func))(t->what);
+				t->next = free_timeouts;
+				free_timeouts = t;
+				goto another;
+			}
+
+			/*
+			 * Figure timeout in milliseconds, and check for
+			 * potential overflow, so we can cram into an
+			 * int for poll, while not polling with a
+			 * negative timeout and blocking indefinetely.
+			 */
+			howlong = timeouts->when - cur_time;
+			if (howlong > INT_MAX / 1000)
+				howlong = INT_MAX / 1000;
+			to_msec = howlong * 1000;
+		} else
+			to_msec = -1;
+
+		/* Set up the descriptors to be polled. */
+		i = 0;
+
+		for (l = protocols; l; l = l->next) {
+			struct interface_info *ip = l->local;
+			if (ip && (l->handler != got_one || !ip->dead)) {
+				fds[i].fd = l->fd;
+				fds[i].events = POLLIN;
+				fds[i].revents = 0;
+				i++;
+			}
+		}
+
+		if (i == 0)
+			error("No live interfaces to poll on - exiting.");
+
+		/* Wait for a packet or a timeout... XXX */
+		count = poll(fds, nfds, to_msec);
+
+		/* Not likely to be transitory... */
+		if (count == -1) {
+			if (errno == EAGAIN || errno == EINTR) {
+				time(&cur_time);
+				continue;
+			}
+			else
+				error("poll: %m");
+		}
+
+		/* Get the current time... */
+		time(&cur_time);
+
+		i = 0;
+		for (l = protocols; l; l = l->next) {
+			struct interface_info *ip;
+			ip = l->local;
+			if ((fds[i].revents & POLLIN)) {
+				fds[i].revents = 0;
+				if (ip && (l->handler != got_one ||
+				    !ip->dead))
+					(*(l->handler))(l);
+				if (interfaces_invalidated)
+					break;
+			}
+			i++;
+		}
+		interfaces_invalidated = 0;
+	} while (1);
+}
+
+
+void
+got_one(struct protocol *l)
+{
+	struct sockaddr_in from;
+	struct hardware hfrom;
+	struct iaddr ifrom;
+	size_t result;
+	union {
+		/*
+		 * Packet input buffer.  Must be as large as largest
+		 * possible MTU.
+		 */
+		unsigned char packbuf[4095];
+		struct dhcp_packet packet;
+	} u;
+	struct interface_info *ip = l->local;
+
+	if ((result = receive_packet(ip, u.packbuf, sizeof(u), &from,
+	    &hfrom)) == -1) {
+		warn("receive_packet failed on %s: %s", ip->name,
+		    strerror(errno));
+		ip->errors++;
+		if ((!interface_status(ip)) ||
+		    (ip->noifmedia && ip->errors > 20)) {
+			/* our interface has gone away. */
+			warn("Interface %s no longer appears valid.",
+			    ip->name);
+			ip->dead = 1;
+			interfaces_invalidated = 1;
+			close(l->fd);
+			remove_protocol(l);
+			free(ip);
+		}
+		return;
+	}
+	if (result == 0)
+		return;
+
+	if (bootp_packet_handler) {
+		ifrom.len = 4;
+		memcpy(ifrom.iabuf, &from.sin_addr, ifrom.len);
+
+		(*bootp_packet_handler)(ip, &u.packet, result,
+		    from.sin_port, ifrom, &hfrom);
+	}
+}
+
+int
+interface_status(struct interface_info *ifinfo)
+{
+	char *ifname = ifinfo->name;
+	int ifsock = ifinfo->rfdesc;
+	struct ifreq ifr;
+	struct ifmediareq ifmr;
+
+	/* get interface flags */
+	memset(&ifr, 0, sizeof(ifr));
+	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+	if (ioctl(ifsock, SIOCGIFFLAGS, &ifr) < 0) {
+		syslog(LOG_ERR, "ioctl(SIOCGIFFLAGS) on %s: %m", ifname);
+		goto inactive;
+	}
+	/*
+	 * if one of UP and RUNNING flags is dropped,
+	 * the interface is not active.
+	 */
+	if ((ifr.ifr_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
+		goto inactive;
+	}
+	/* Next, check carrier on the interface, if possible */
+	if (ifinfo->noifmedia)
+		goto active;
+	memset(&ifmr, 0, sizeof(ifmr));
+	strlcpy(ifmr.ifm_name, ifname, sizeof(ifmr.ifm_name));
+	if (ioctl(ifsock, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0) {
+		if (errno != EINVAL) {
+			syslog(LOG_DEBUG, "ioctl(SIOCGIFMEDIA) on %s: %m",
+			    ifname);
+
+			ifinfo->noifmedia = 1;
+			goto active;
+		}
+		/*
+		 * EINVAL (or ENOTTY) simply means that the interface
+		 * does not support the SIOCGIFMEDIA ioctl. We regard it alive.
+		 */
+		ifinfo->noifmedia = 1;
+		goto active;
+	}
+	if (ifmr.ifm_status & IFM_AVALID) {
+		switch (ifmr.ifm_active & IFM_NMASK) {
+		case IFM_ETHER:
+			if (ifmr.ifm_status & IFM_ACTIVE)
+				goto active;
+			else
+				goto inactive;
+			break;
+		default:
+			goto inactive;
+		}
+	}
+inactive:
+	return (0);
+active:
+	return (1);
+}
+
+void
+add_timeout(time_t when, void (*where)(void *), void *what)
+{
+	struct timeout *t, *q;
+
+	/* See if this timeout supersedes an existing timeout. */
+	t = NULL;
+	for (q = timeouts; q; q = q->next) {
+		if (q->func == where && q->what == what) {
+			if (t)
+				t->next = q->next;
+			else
+				timeouts = q->next;
+			break;
+		}
+		t = q;
+	}
+
+	/* If we didn't supersede a timeout, allocate a timeout
+	   structure now. */
+	if (!q) {
+		if (free_timeouts) {
+			q = free_timeouts;
+			free_timeouts = q->next;
+			q->func = where;
+			q->what = what;
+		} else {
+			q = malloc(sizeof(struct timeout));
+			if (!q)
+				error("Can't allocate timeout structure!");
+			q->func = where;
+			q->what = what;
+		}
+	}
+
+	q->when = when;
+
+	/* Now sort this timeout into the timeout list. */
+
+	/* Beginning of list? */
+	if (!timeouts || timeouts->when > q->when) {
+		q->next = timeouts;
+		timeouts = q;
+		return;
+	}
+
+	/* Middle of list? */
+	for (t = timeouts; t->next; t = t->next) {
+		if (t->next->when > q->when) {
+			q->next = t->next;
+			t->next = q;
+			return;
+		}
+	}
+
+	/* End of list. */
+	t->next = q;
+	q->next = NULL;
+}
+
+void
+cancel_timeout(void (*where)(void *), void *what)
+{
+	struct timeout *t, *q;
+
+	/* Look for this timeout on the list, and unlink it if we find it. */
+	t = NULL;
+	for (q = timeouts; q; q = q->next) {
+		if (q->func == where && q->what == what) {
+			if (t)
+				t->next = q->next;
+			else
+				timeouts = q->next;
+			break;
+		}
+		t = q;
+	}
+
+	/* If we found the timeout, put it on the free list. */
+	if (q) {
+		q->next = free_timeouts;
+		free_timeouts = q;
+	}
+}
+
+/* Add a protocol to the list of protocols... */
+void
+add_protocol(char *name, int fd, void (*handler)(struct protocol *),
+    void *local)
+{
+	struct protocol *p;
+
+	p = malloc(sizeof(*p));
+	if (!p)
+		error("can't allocate protocol struct for %s", name);
+
+	p->fd = fd;
+	p->handler = handler;
+	p->local = local;
+	p->next = protocols;
+	protocols = p;
+}
+
+void
+remove_protocol(struct protocol *proto)
+{
+	struct protocol *p, *next, *prev;
+
+	prev = NULL;
+	for (p = protocols; p; p = next) {
+		next = p->next;
+		if (p == proto) {
+			if (prev)
+				prev->next = p->next;
+			else
+				protocols = p->next;
+			free(p);
+		}
+	}
+}
+
+int
+interface_link_status(char *ifname)
+{
+	struct ifmediareq ifmr;
+	int sock;
+
+	if ((sock = socket (AF_INET, SOCK_DGRAM, 0)) == -1)
+		error("Can't create socket");
+
+	memset(&ifmr, 0, sizeof(ifmr));
+	strlcpy(ifmr.ifm_name, ifname, sizeof(ifmr.ifm_name));
+	if (ioctl(sock, SIOCGIFMEDIA, (caddr_t)&ifmr) == -1) {
+		/* EINVAL -> link state unknown. treat as active */
+		if (errno != EINVAL)
+			syslog(LOG_DEBUG, "ioctl(SIOCGIFMEDIA) on %s: %m",
+			    ifname);
+		close(sock);
+		return (1);
+	}
+	close(sock);
+
+	if (ifmr.ifm_status & IFM_AVALID) {
+		if ((ifmr.ifm_active & IFM_NMASK) == IFM_ETHER) {
+			if (ifmr.ifm_status & IFM_ACTIVE)
+				return (1);
+			else
+				return (0);
+		}
+	}
+	return (1);
+}
diff --git a/usr.sbin/dhcrelay/errwarn.c b/usr.sbin/dhcrelay/errwarn.c
new file mode 100644
index 00000000000..081896720b5
--- /dev/null
+++ b/usr.sbin/dhcrelay/errwarn.c
@@ -0,0 +1,199 @@
+/*	$OpenBSD: errwarn.c,v 1.1 2004/04/12 21:10:28 henning Exp $	*/
+
+/* Errors and warnings... */
+
+/*
+ * Copyright (c) 1996 The Internet Software Consortium.
+ * All Rights Reserved.
+ * Copyright (c) 1995 RadioMail Corporation.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of RadioMail Corporation, the Internet Software
+ *    Consortium nor the names of its contributors may be used to endorse
+ *    or promote products derived from this software without specific
+ *    prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY RADIOMAIL CORPORATION, THE INTERNET
+ * SOFTWARE CONSORTIUM AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL RADIOMAIL CORPORATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software was written for RadioMail Corporation by Ted Lemon
+ * under a contract with Vixie Enterprises.   Further modifications have
+ * been made for the Internet Software Consortium under a contract
+ * with Vixie Laboratories.
+ */
+
+#include <errno.h>
+
+#include "dhcpd.h"
+
+static void do_percentm(char *obuf, size_t size, char *ibuf);
+
+static char mbuf[1024];
+static char fbuf[1024];
+
+int warnings_occurred;
+
+/*
+ * Log an error message, then exit.
+ */
+void
+error(char *fmt, ...)
+{
+	va_list list;
+
+	do_percentm(fbuf, sizeof(fbuf), fmt);
+
+	va_start(list, fmt);
+	vsnprintf(mbuf, sizeof(mbuf), fbuf, list);
+	va_end(list);
+
+#ifndef DEBUG
+	syslog(log_priority | LOG_ERR, "%s", mbuf);
+#endif
+
+	/* Also log it to stderr? */
+	if (log_perror) {
+		write(2, mbuf, strlen(mbuf));
+		write(2, "\n", 1);
+	}
+
+	syslog(LOG_CRIT, "exiting.");
+	if (log_perror) {
+		fprintf(stderr, "exiting.\n");
+		fflush(stderr);
+	}
+	exit(1);
+}
+
+/*
+ * Log a warning message...
+ */
+int
+warn(char *fmt, ...)
+{
+	va_list list;
+
+	do_percentm(fbuf, sizeof(fbuf), fmt);
+
+	va_start(list, fmt);
+	vsnprintf(mbuf, sizeof(mbuf), fbuf, list);
+	va_end(list);
+
+#ifndef DEBUG
+	syslog(log_priority | LOG_ERR, "%s", mbuf);
+#endif
+
+	if (log_perror) {
+		write(2, mbuf, strlen(mbuf));
+		write(2, "\n", 1);
+	}
+
+	return (0);
+}
+
+/*
+ * Log a note...
+ */
+int
+note(char *fmt, ...)
+{
+	va_list list;
+
+	do_percentm(fbuf, sizeof(fbuf), fmt);
+
+	va_start(list, fmt);
+	vsnprintf(mbuf, sizeof(mbuf), fbuf, list);
+	va_end(list);
+
+#ifndef DEBUG
+	syslog(log_priority | LOG_INFO, "%s", mbuf);
+#endif
+
+	if (log_perror) {
+		write(2, mbuf, strlen(mbuf));
+		write(2, "\n", 1);
+	}
+
+	return (0);
+}
+
+/*
+ * Log a debug message...
+ */
+int
+debug(char *fmt, ...)
+{
+	va_list list;
+
+	do_percentm(fbuf, sizeof(fbuf), fmt);
+
+	va_start(list, fmt);
+	vsnprintf(mbuf, sizeof(mbuf), fbuf, list);
+	va_end(list);
+
+#ifndef DEBUG
+	syslog(log_priority | LOG_DEBUG, "%s", mbuf);
+#endif
+
+	if (log_perror) {
+		write(2, mbuf, strlen(mbuf));
+		write(2, "\n", 1);
+	}
+
+	return (0);
+}
+
+/*
+ * Find %m in the input string and substitute an error message string.
+ */
+static void
+do_percentm(char *obuf, size_t size, char *ibuf)
+{
+	char ch;
+	char *s = ibuf;
+	char *t = obuf;
+	size_t prlen;
+	size_t fmt_left;
+	int saved_errno = errno;
+
+	/*
+	 * We wouldn't need this mess if printf handled %m, or if
+	 * strerror() had been invented before syslog().
+	 */
+	for (fmt_left = size; (ch = *s); ++s) {
+		if (ch == '%' && s[1] == 'm') {
+			++s;
+			prlen = snprintf(t, fmt_left, "%s",
+			    strerror(saved_errno));
+			if (prlen >= fmt_left)
+				prlen = fmt_left - 1;
+			t += prlen;
+			fmt_left -= prlen;
+		} else {
+			if (fmt_left > 1) {
+				*t++ = ch;
+				fmt_left--;
+			}
+		}
+	}
+	*t = '\0';
+}
+
diff --git a/usr.sbin/dhcrelay/packet.c b/usr.sbin/dhcrelay/packet.c
new file mode 100644
index 00000000000..925b3afe36a
--- /dev/null
+++ b/usr.sbin/dhcrelay/packet.c
@@ -0,0 +1,255 @@
+/*	$OpenBSD: packet.c,v 1.1 2004/04/12 21:10:28 henning Exp $	*/
+
+/* Packet assembly code, originally contributed by Archie Cobbs. */
+
+/*
+ * Copyright (c) 1995, 1996, 1999 The Internet Software Consortium.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of The Internet Software Consortium nor the names
+ *    of its contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
+ * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This software has been written for the Internet Software Consortium
+ * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+ * Enterprises.  To learn more about the Internet Software Consortium,
+ * see ``http://www.vix.com/isc''.  To learn more about Vixie
+ * Enterprises, see ``http://www.vix.com''.
+ */
+
+#include "dhcpd.h"
+
+#include <netinet/in_systm.h>
+#include <netinet/ip.h>
+#include <netinet/udp.h>
+#include <netinet/if_ether.h>
+
+#define ETHER_HEADER_SIZE (ETHER_ADDR_LEN * 2 + sizeof(u_int16_t))
+
+u_int32_t	checksum(unsigned char *, unsigned, u_int32_t);
+u_int32_t	wrapsum(u_int32_t);
+
+void	assemble_ethernet_header(struct interface_info *, unsigned char *,
+	    int *, struct hardware *);
+ssize_t	decode_ethernet_header(struct interface_info *, unsigned char *,
+	    int bufix, struct hardware *);
+
+u_int32_t
+checksum(unsigned char *buf, unsigned nbytes, u_int32_t sum)
+{
+	int i;
+
+	/* Checksum all the pairs of bytes first... */
+	for (i = 0; i < (nbytes & ~1U); i += 2) {
+		sum += (u_int16_t)ntohs(*((u_int16_t *)(buf + i)));
+		if (sum > 0xFFFF)
+			sum -= 0xFFFF;
+	}
+
+	/*
+	 * If there's a single byte left over, checksum it, too.
+	 * Network byte order is big-endian, so the remaining byte is
+	 * the high byte.
+	 */
+	if (i < nbytes) {
+		sum += buf[i] << 8;
+		if (sum > 0xFFFF)
+			sum -= 0xFFFF;
+	}
+
+	return (sum);
+}
+
+u_int32_t
+wrapsum(u_int32_t sum)
+{
+	sum = ~sum & 0xFFFF;
+	return (htons(sum));
+}
+
+void
+assemble_hw_header(struct interface_info *interface, unsigned char *buf,
+    int *bufix, struct hardware *to)
+{
+	struct ether_header eh;
+
+	if (to != NULL && to->hlen == 6) /* XXX */
+		memcpy(eh.ether_dhost, to->haddr, sizeof(eh.ether_dhost));
+	else
+		memset(eh.ether_dhost, 0xff, sizeof(eh.ether_dhost));
+	if (interface->hw_address.hlen == sizeof(eh.ether_shost))
+		memcpy(eh.ether_shost, interface->hw_address.haddr,
+		    sizeof(eh.ether_shost));
+	else
+		memset(eh.ether_shost, 0x00, sizeof(eh.ether_shost));
+
+	eh.ether_type = htons(ETHERTYPE_IP);
+
+	memcpy(&buf[*bufix], &eh, ETHER_HEADER_SIZE);
+	*bufix += ETHER_HEADER_SIZE;
+}
+
+void
+assemble_udp_ip_header(struct interface_info *interface, unsigned char *buf,
+    int *bufix, u_int32_t from, u_int32_t to, unsigned int port,
+    unsigned char *data, int len)
+{
+	struct ip ip;
+	struct udphdr udp;
+
+	ip.ip_v = 4;
+	ip.ip_hl = 5;
+	ip.ip_tos = IPTOS_LOWDELAY;
+	ip.ip_len = htons(sizeof(ip) + sizeof(udp) + len);
+	ip.ip_id = 0;
+	ip.ip_off = 0;
+	ip.ip_ttl = 16;
+	ip.ip_p = IPPROTO_UDP;
+	ip.ip_sum = 0;
+	ip.ip_src.s_addr = from;
+	ip.ip_dst.s_addr = to;
+
+	ip.ip_sum = wrapsum(checksum((unsigned char *)&ip, sizeof(ip), 0));
+	memcpy(&buf[*bufix], &ip, sizeof(ip));
+	*bufix += sizeof(ip);
+
+	udp.uh_sport = htons(LOCAL_PORT);	/* XXX */
+	udp.uh_dport = port;			/* XXX */
+	udp.uh_ulen = htons(sizeof(udp) + len);
+	memset(&udp.uh_sum, 0, sizeof(udp.uh_sum));
+
+	udp.uh_sum = wrapsum(checksum((unsigned char *)&udp, sizeof(udp),
+	    checksum(data, len, checksum((unsigned char *)&ip.ip_src,
+	    2 * sizeof(ip.ip_src),
+	    IPPROTO_UDP + (u_int32_t)ntohs(udp.uh_ulen)))));
+
+	memcpy(&buf[*bufix], &udp, sizeof(udp));
+	*bufix += sizeof(udp);
+}
+
+ssize_t
+decode_hw_header(struct interface_info *interface, unsigned char *buf,
+    int bufix, struct hardware *from)
+{
+	struct ether_header eh;
+
+	memcpy(&eh, buf + bufix, ETHER_HEADER_SIZE);
+
+	memcpy(from->haddr, eh.ether_shost, sizeof(eh.ether_shost));
+	from->htype = ARPHRD_ETHER;
+	from->hlen = sizeof(eh.ether_shost);
+
+	return (sizeof(eh));
+}
+
+ssize_t
+decode_udp_ip_header(struct interface_info *interface, unsigned char *buf,
+    int bufix, struct sockaddr_in *from, unsigned char *data, int buflen)
+{
+	struct ip *ip;
+	struct udphdr *udp;
+	u_int32_t ip_len = (buf[bufix] & 0xf) << 2;
+	u_int32_t sum, usum;
+	static int ip_packets_seen;
+	static int ip_packets_bad_checksum;
+	static int udp_packets_seen;
+	static int udp_packets_bad_checksum;
+	static int udp_packets_length_checked;
+	static int udp_packets_length_overflow;
+	int len = 0;
+
+	ip = (struct ip *)(buf + bufix);
+	udp = (struct udphdr *)(buf + bufix + ip_len);
+
+	/* Check the IP header checksum - it should be zero. */
+	ip_packets_seen++;
+	if (wrapsum(checksum(buf + bufix, ip_len, 0)) != 0) {
+		ip_packets_bad_checksum++;
+		if (ip_packets_seen > 4 &&
+		    (ip_packets_seen / ip_packets_bad_checksum) < 2) {
+			note("%d bad IP checksums seen in %d packets",
+			    ip_packets_bad_checksum, ip_packets_seen);
+			ip_packets_seen = ip_packets_bad_checksum = 0;
+		}
+		return (-1);
+	}
+
+	if (ntohs(ip->ip_len) != buflen)
+		debug("ip length %d disagrees with bytes received %d.",
+		    ntohs(ip->ip_len), buflen);
+
+	memcpy(&from->sin_addr, &ip->ip_src, 4);
+
+	/*
+	 * Compute UDP checksums, including the ``pseudo-header'', the
+	 * UDP header and the data.   If the UDP checksum field is zero,
+	 * we're not supposed to do a checksum.
+	 */
+	if (!data) {
+		data = buf + bufix + ip_len + sizeof(*udp);
+		len = ntohs(udp->uh_ulen) - sizeof(*udp);
+		udp_packets_length_checked++;
+		if (len + data > buf + bufix + buflen) {
+			udp_packets_length_overflow++;
+			if (udp_packets_length_checked > 4 &&
+			    (udp_packets_length_checked /
+			    udp_packets_length_overflow) < 2) {
+				note("%d udp packets in %d too long - dropped",
+				    udp_packets_length_overflow,
+				    udp_packets_length_checked);
+				udp_packets_length_overflow =
+				    udp_packets_length_checked = 0;
+			}
+			return (-1);
+		}
+		if (len + data != buf + bufix + buflen)
+			debug("accepting packet with data after udp payload.");
+	}
+
+	usum = udp->uh_sum;
+	udp->uh_sum = 0;
+
+	sum = wrapsum(checksum((unsigned char *)udp, sizeof(*udp),
+	    checksum(data, len, checksum((unsigned char *)&ip->ip_src,
+	    2 * sizeof(ip->ip_src),
+	    IPPROTO_UDP + (u_int32_t)ntohs(udp->uh_ulen)))));
+
+	udp_packets_seen++;
+	if (usum && usum != sum) {
+		udp_packets_bad_checksum++;
+		if (udp_packets_seen > 4 &&
+		    (udp_packets_seen / udp_packets_bad_checksum) < 2) {
+			note("%d bad udp checksums in %d packets",
+			    udp_packets_bad_checksum, udp_packets_seen);
+			udp_packets_seen = udp_packets_bad_checksum = 0;
+		}
+		return (-1);
+	}
+
+	memcpy(&from->sin_port, &udp->uh_sport, sizeof(udp->uh_sport));
+
+	return (ip_len + sizeof(*udp));
+}
diff --git a/usr.sbin/dhcrelay/tree.h b/usr.sbin/dhcrelay/tree.h
new file mode 100644
index 00000000000..a17c8888870
--- /dev/null
+++ b/usr.sbin/dhcrelay/tree.h
@@ -0,0 +1,107 @@
+/*	$OpenBSD: tree.h,v 1.1 2004/04/12 21:10:28 henning Exp $	*/
+
+/* Definitions for address trees... */
+
+/*
+ * Copyright (c) 1995 The Internet Software Consortium.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of The Internet Software Consortium nor the names
+ *    of its contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
+ * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This software has been written for the Internet Software Consortium
+ * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+ * Enterprises.  To learn more about the Internet Software Consortium,
+ * see ``http://www.vix.com/isc''.  To learn more about Vixie
+ * Enterprises, see ``http://www.vix.com''.
+ */
+
+/* A pair of pointers, suitable for making a linked list. */
+typedef struct _pair {
+	caddr_t car;
+	struct _pair *cdr;
+} *pair;
+
+/* Tree node types... */
+#define TREE_CONCAT		1
+#define TREE_HOST_LOOKUP	2
+#define TREE_CONST		3
+#define TREE_LIMIT		4
+
+/* Tree structure for deferred evaluation of changing values. */
+struct tree {
+	int op;
+	union {
+		struct concat {
+			struct tree *left;
+			struct tree *right;
+		} concat;
+		struct host_lookup {
+			struct dns_host_entry *host;
+		} host_lookup;
+		struct const_val {
+			unsigned char *data;
+			int len;
+		} const_val;
+		struct limit {
+			struct tree *tree;
+			int limit;
+		} limit;
+	} data;
+};
+
+/* DNS host entry structure... */
+struct dns_host_entry {
+	char *hostname;
+	unsigned char *data;
+	int data_len;
+	int buf_len;
+	time_t timeout;
+};
+
+struct tree_cache {
+	unsigned char *value;
+	int len;
+	int buf_size;
+	time_t timeout;
+	struct tree *tree;
+	int flags;
+#define	TC_AWAITING_RESOLUTION	1
+#define TC_TEMPORARY		2
+};
+
+struct universe {
+	char *name;
+	struct hash_table *hash;
+	struct option *options[256];
+};
+
+struct option {
+	char *name;
+	char *format;
+	struct universe *universe;
+	unsigned char code;
+};