[qemu.git] / slirp / bootp.c

/*
 * QEMU BOOTP/DHCP server
 *
 * Copyright (c) 2004 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include <slirp.h>

/* XXX: only DHCP is supported */

#define NB_ADDR 16

#define START_ADDR 15

#define LEASE_TIME (24 * 3600)

typedef struct {
    uint8_t allocated;
    uint8_t macaddr[6];
} BOOTPClient;

static BOOTPClient bootp_clients[NB_ADDR];

const char *bootp_filename;

static const uint8_t rfc1533_cookie[] = { RFC1533_COOKIE };

#ifdef DEBUG
#define dprintf(fmt, ...) \
if (slirp_debug & DBG_CALL) { fprintf(dfd, fmt, ##  __VA_ARGS__); fflush(dfd); }
#else
#define dprintf(fmt, ...)
#endif

static BOOTPClient *get_new_addr(struct in_addr *paddr,
                                 const uint8_t *macaddr)
{
    BOOTPClient *bc;
    int i;

    for(i = 0; i < NB_ADDR; i++) {
        bc = &bootp_clients[i];
        if (!bc->allocated || !memcmp(macaddr, bc->macaddr, 6))
            goto found;
    }
    return NULL;
 found:
    bc = &bootp_clients[i];
    bc->allocated = 1;
    paddr->s_addr = htonl(ntohl(special_addr.s_addr) | (i + START_ADDR));
    return bc;
}

static BOOTPClient *request_addr(const struct in_addr *paddr,
                                 const uint8_t *macaddr)
{
    uint32_t req_addr = ntohl(paddr->s_addr);
    uint32_t spec_addr = ntohl(special_addr.s_addr);
    BOOTPClient *bc;

    if (req_addr >= (spec_addr | START_ADDR) &&
        req_addr < (spec_addr | (NB_ADDR + START_ADDR))) {
        bc = &bootp_clients[(req_addr & 0xff) - START_ADDR];
        if (!bc->allocated || !memcmp(macaddr, bc->macaddr, 6)) {
            bc->allocated = 1;
            return bc;
        }
    }
    return NULL;
}

static BOOTPClient *find_addr(struct in_addr *paddr, const uint8_t *macaddr)
{
    BOOTPClient *bc;
    int i;

    for(i = 0; i < NB_ADDR; i++) {
        if (!memcmp(macaddr, bootp_clients[i].macaddr, 6))
            goto found;
    }
    return NULL;
 found:
    bc = &bootp_clients[i];
    bc->allocated = 1;
    paddr->s_addr = htonl(ntohl(special_addr.s_addr) | (i + START_ADDR));
    return bc;
}

static void dhcp_decode(const struct bootp_t *bp, int *pmsg_type,
                        const struct in_addr **preq_addr)
{
    const uint8_t *p, *p_end;
    int len, tag;

    *pmsg_type = 0;
    *preq_addr = NULL;

    p = bp->bp_vend;
    p_end = p + DHCP_OPT_LEN;
    if (memcmp(p, rfc1533_cookie, 4) != 0)
        return;
    p += 4;
    while (p < p_end) {
        tag = p[0];
        if (tag == RFC1533_PAD) {
            p++;
        } else if (tag == RFC1533_END) {
            break;
        } else {
            p++;
            if (p >= p_end)
                break;
            len = *p++;
            dprintf("dhcp: tag=%d len=%d\n", tag, len);

            switch(tag) {
            case RFC2132_MSG_TYPE:
                if (len >= 1)
                    *pmsg_type = p[0];
                break;
            case RFC2132_REQ_ADDR:
                if (len >= 4)
                    *preq_addr = (struct in_addr *)p;
                break;
            default:
                break;
            }
            p += len;
        }
    }
    if (*pmsg_type == DHCPREQUEST && !*preq_addr && bp->bp_ciaddr.s_addr) {
        *preq_addr = &bp->bp_ciaddr;
    }
}

static void bootp_reply(const struct bootp_t *bp)
{
    BOOTPClient *bc = NULL;
    struct mbuf *m;
    struct bootp_t *rbp;
    struct sockaddr_in saddr, daddr;
    struct in_addr dns_addr;
    const struct in_addr *preq_addr;
    int dhcp_msg_type, val;
    uint8_t *q;

    /* extract exact DHCP msg type */
    dhcp_decode(bp, &dhcp_msg_type, &preq_addr);
    dprintf("bootp packet op=%d msgtype=%d", bp->bp_op, dhcp_msg_type);
    if (preq_addr)
        dprintf(" req_addr=%08x\n", ntohl(preq_addr->s_addr));
    else
        dprintf("\n");

    if (dhcp_msg_type == 0)
        dhcp_msg_type = DHCPREQUEST; /* Force reply for old BOOTP clients */

    if (dhcp_msg_type != DHCPDISCOVER &&
        dhcp_msg_type != DHCPREQUEST)
        return;
    /* XXX: this is a hack to get the client mac address */
    memcpy(client_ethaddr, bp->bp_hwaddr, 6);

    if ((m = m_get()) == NULL)
        return;
    m->m_data += IF_MAXLINKHDR;
    rbp = (struct bootp_t *)m->m_data;
    m->m_data += sizeof(struct udpiphdr);
    memset(rbp, 0, sizeof(struct bootp_t));

    if (dhcp_msg_type == DHCPDISCOVER) {
        if (preq_addr) {
            bc = request_addr(preq_addr, client_ethaddr);
            if (bc) {
                daddr.sin_addr = *preq_addr;
            }
        }
        if (!bc) {
         new_addr:
            bc = get_new_addr(&daddr.sin_addr, client_ethaddr);
            if (!bc) {
                dprintf("no address left\n");
                return;
            }
        }
        memcpy(bc->macaddr, client_ethaddr, 6);
    } else if (preq_addr) {
        bc = request_addr(preq_addr, client_ethaddr);
        if (bc) {
            daddr.sin_addr = *preq_addr;
            memcpy(bc->macaddr, client_ethaddr, 6);
        } else {
            daddr.sin_addr.s_addr = 0;
        }
    } else {
        bc = find_addr(&daddr.sin_addr, bp->bp_hwaddr);
        if (!bc) {
            /* if never assigned, behaves as if it was already
               assigned (windows fix because it remembers its address) */
            goto new_addr;
        }
    }

    saddr.sin_addr.s_addr = htonl(ntohl(special_addr.s_addr) | CTL_ALIAS);
    saddr.sin_port = htons(BOOTP_SERVER);

    daddr.sin_port = htons(BOOTP_CLIENT);

    rbp->bp_op = BOOTP_REPLY;
    rbp->bp_xid = bp->bp_xid;
    rbp->bp_htype = 1;
    rbp->bp_hlen = 6;
    memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6);

    rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */
    rbp->bp_siaddr = saddr.sin_addr; /* Server IP address */

    q = rbp->bp_vend;
    memcpy(q, rfc1533_cookie, 4);
    q += 4;

    if (bc) {
        dprintf("%s addr=%08x\n",
                (dhcp_msg_type == DHCPDISCOVER) ? "offered" : "ack'ed",
                ntohl(daddr.sin_addr.s_addr));

        if (dhcp_msg_type == DHCPDISCOVER) {
            *q++ = RFC2132_MSG_TYPE;
            *q++ = 1;
            *q++ = DHCPOFFER;
        } else /* DHCPREQUEST */ {
            *q++ = RFC2132_MSG_TYPE;
            *q++ = 1;
            *q++ = DHCPACK;
        }

        if (bootp_filename)
            snprintf((char *)rbp->bp_file, sizeof(rbp->bp_file), "%s",
                     bootp_filename);

        *q++ = RFC2132_SRV_ID;
        *q++ = 4;
        memcpy(q, &saddr.sin_addr, 4);
        q += 4;

        *q++ = RFC1533_NETMASK;
        *q++ = 4;
        *q++ = 0xff;
        *q++ = 0xff;
        *q++ = 0xff;
        *q++ = 0x00;

        if (!slirp_restrict) {
            *q++ = RFC1533_GATEWAY;
            *q++ = 4;
            memcpy(q, &saddr.sin_addr, 4);
            q += 4;

            *q++ = RFC1533_DNS;
            *q++ = 4;
            dns_addr.s_addr = htonl(ntohl(special_addr.s_addr) | CTL_DNS);
            memcpy(q, &dns_addr, 4);
            q += 4;
        }

        *q++ = RFC2132_LEASE_TIME;
        *q++ = 4;
        val = htonl(LEASE_TIME);
        memcpy(q, &val, 4);
        q += 4;

        if (*slirp_hostname) {
            val = strlen(slirp_hostname);
            *q++ = RFC1533_HOSTNAME;
            *q++ = val;
            memcpy(q, slirp_hostname, val);
            q += val;
        }
    } else {
        static const char nak_msg[] = "requested address not available";

        dprintf("nak'ed addr=%08x\n", ntohl(preq_addr->s_addr));

        *q++ = RFC2132_MSG_TYPE;
        *q++ = 1;
        *q++ = DHCPNAK;

        *q++ = RFC2132_MESSAGE;
        *q++ = sizeof(nak_msg) - 1;
        memcpy(q, nak_msg, sizeof(nak_msg) - 1);
        q += sizeof(nak_msg) - 1;
    }
    *q++ = RFC1533_END;

    daddr.sin_addr.s_addr = 0xffffffffu;

    m->m_len = sizeof(struct bootp_t) -
        sizeof(struct ip) - sizeof(struct udphdr);
    udp_output2(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
}

void bootp_input(struct mbuf *m)
{
    struct bootp_t *bp = mtod(m, struct bootp_t *);

    if (bp->bp_op == BOOTP_REQUEST) {
        bootp_reply(bp);
    }
}
Commit	Line	Data
f0cbd3ec FB	1	/*
f0cbd3ec FB	2	* QEMU BOOTP/DHCP server
5fafdf24	3	*
f0cbd3ec	4	* Copyright (c) 2004 Fabrice Bellard
5fafdf24	5	*
f0cbd3ec FB	6	* Permission is hereby granted, free of charge, to any person obtaining a copy
	7	* of this software and associated documentation files (the "Software"), to deal
	8	* in the Software without restriction, including without limitation the rights
	9	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	10	* copies of the Software, and to permit persons to whom the Software is
	11	* furnished to do so, subject to the following conditions:
	12	*
	13	* The above copyright notice and this permission notice shall be included in
	14	* all copies or substantial portions of the Software.
	15	*
	16	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	17	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	18	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	19	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	20	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	21	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	22	* THE SOFTWARE.
	23	*/
	24	#include <slirp.h>
	25
	26	/* XXX: only DHCP is supported */
	27
	28	#define NB_ADDR 16
	29
	30	#define START_ADDR 15
	31
	32	#define LEASE_TIME (24 * 3600)
	33
	34	typedef struct {
	35	uint8_t allocated;
512176db	36	uint8_t macaddr[6];
f0cbd3ec FB	37	} BOOTPClient;
f0cbd3ec FB	38
7ca699c8	39	static BOOTPClient bootp_clients[NB_ADDR];
f0cbd3ec	40
47d5d01a TS	41	const char *bootp_filename;
47d5d01a TS	42
f0cbd3ec FB	43	static const uint8_t rfc1533_cookie[] = { RFC1533_COOKIE };
	44
	45	#ifdef DEBUG
001faf32 BS	46	#define dprintf(fmt, ...) \
001faf32 BS	47	if (slirp_debug & DBG_CALL) { fprintf(dfd, fmt, ## __VA_ARGS__); fflush(dfd); }
f0cbd3ec	48	#else
001faf32	49	#define dprintf(fmt, ...)
f0cbd3ec FB	50	#endif
f0cbd3ec FB	51
0928a95f JK	52	static BOOTPClient get_new_addr(struct in_addr paddr,
0928a95f JK	53	const uint8_t *macaddr)
f0cbd3ec FB	54	{
	55	BOOTPClient *bc;
	56	int i;
	57
	58	for(i = 0; i < NB_ADDR; i++) {
0928a95f JK	59	bc = &bootp_clients[i];
0928a95f JK	60	if (!bc->allocated \|\| !memcmp(macaddr, bc->macaddr, 6))
f0cbd3ec FB	61	goto found;
	62	}
	63	return NULL;
	64	found:
	65	bc = &bootp_clients[i];
	66	bc->allocated = 1;
	67	paddr->s_addr = htonl(ntohl(special_addr.s_addr) \| (i + START_ADDR));
	68	return bc;
	69	}
	70
b63c7f6b AL	71	static BOOTPClient request_addr(const struct in_addr paddr,
	72	const uint8_t *macaddr)
	73	{
	74	uint32_t req_addr = ntohl(paddr->s_addr);
	75	uint32_t spec_addr = ntohl(special_addr.s_addr);
	76	BOOTPClient *bc;
	77
	78	if (req_addr >= (spec_addr \| START_ADDR) &&
	79	req_addr < (spec_addr \| (NB_ADDR + START_ADDR))) {
	80	bc = &bootp_clients[(req_addr & 0xff) - START_ADDR];
	81	if (!bc->allocated \|\| !memcmp(macaddr, bc->macaddr, 6)) {
	82	bc->allocated = 1;
	83	return bc;
	84	}
	85	}
	86	return NULL;
	87	}
	88
512176db FB	89	static BOOTPClient find_addr(struct in_addr paddr, const uint8_t *macaddr)
	90	{
	91	BOOTPClient *bc;
	92	int i;
	93
	94	for(i = 0; i < NB_ADDR; i++) {
	95	if (!memcmp(macaddr, bootp_clients[i].macaddr, 6))
	96	goto found;
	97	}
	98	return NULL;
	99	found:
	100	bc = &bootp_clients[i];
	101	bc->allocated = 1;
	102	paddr->s_addr = htonl(ntohl(special_addr.s_addr) \| (i + START_ADDR));
	103	return bc;
	104	}
	105
b63c7f6b AL	106	static void dhcp_decode(const struct bootp_t bp, int pmsg_type,
b63c7f6b AL	107	const struct in_addr **preq_addr)
f0cbd3ec FB	108	{
	109	const uint8_t p, p_end;
	110	int len, tag;
	111
3b46e624	112	*pmsg_type = 0;
b63c7f6b	113	*preq_addr = NULL;
f0cbd3ec	114
b63c7f6b AL	115	p = bp->bp_vend;
b63c7f6b AL	116	p_end = p + DHCP_OPT_LEN;
f0cbd3ec FB	117	if (memcmp(p, rfc1533_cookie, 4) != 0)
	118	return;
	119	p += 4;
	120	while (p < p_end) {
	121	tag = p[0];
	122	if (tag == RFC1533_PAD) {
5fafdf24	123	p++;
f0cbd3ec FB	124	} else if (tag == RFC1533_END) {
	125	break;
	126	} else {
	127	p++;
	128	if (p >= p_end)
	129	break;
	130	len = *p++;
b63c7f6b	131	dprintf("dhcp: tag=%d len=%d\n", tag, len);
f0cbd3ec FB	132
	133	switch(tag) {
	134	case RFC2132_MSG_TYPE:
	135	if (len >= 1)
	136	*pmsg_type = p[0];
	137	break;
b63c7f6b AL	138	case RFC2132_REQ_ADDR:
	139	if (len >= 4)
	140	preq_addr = (struct in_addr )p;
	141	break;
f0cbd3ec FB	142	default:
	143	break;
	144	}
	145	p += len;
	146	}
	147	}
b63c7f6b AL	148	if (pmsg_type == DHCPREQUEST && !preq_addr && bp->bp_ciaddr.s_addr) {
	149	*preq_addr = &bp->bp_ciaddr;
	150	}
f0cbd3ec FB	151	}
f0cbd3ec FB	152
b63c7f6b	153	static void bootp_reply(const struct bootp_t *bp)
f0cbd3ec	154	{
b63c7f6b	155	BOOTPClient *bc = NULL;
f0cbd3ec FB	156	struct mbuf *m;
	157	struct bootp_t *rbp;
	158	struct sockaddr_in saddr, daddr;
	159	struct in_addr dns_addr;
b63c7f6b	160	const struct in_addr *preq_addr;
f0cbd3ec FB	161	int dhcp_msg_type, val;
	162	uint8_t *q;
	163
	164	/* extract exact DHCP msg type */
b63c7f6b AL	165	dhcp_decode(bp, &dhcp_msg_type, &preq_addr);
	166	dprintf("bootp packet op=%d msgtype=%d", bp->bp_op, dhcp_msg_type);
	167	if (preq_addr)
	168	dprintf(" req_addr=%08x\n", ntohl(preq_addr->s_addr));
	169	else
	170	dprintf("\n");
3b46e624	171
487be8a1 FB	172	if (dhcp_msg_type == 0)
487be8a1 FB	173	dhcp_msg_type = DHCPREQUEST; /* Force reply for old BOOTP clients */
3b46e624	174
5fafdf24	175	if (dhcp_msg_type != DHCPDISCOVER &&
f0cbd3ec FB	176	dhcp_msg_type != DHCPREQUEST)
	177	return;
	178	/* XXX: this is a hack to get the client mac address */
	179	memcpy(client_ethaddr, bp->bp_hwaddr, 6);
3b46e624	180
f0cbd3ec FB	181	if ((m = m_get()) == NULL)
f0cbd3ec FB	182	return;
9634d903	183	m->m_data += IF_MAXLINKHDR;
f0cbd3ec FB	184	rbp = (struct bootp_t *)m->m_data;
	185	m->m_data += sizeof(struct udpiphdr);
	186	memset(rbp, 0, sizeof(struct bootp_t));
	187
512176db	188	if (dhcp_msg_type == DHCPDISCOVER) {
b63c7f6b AL	189	if (preq_addr) {
	190	bc = request_addr(preq_addr, client_ethaddr);
	191	if (bc) {
	192	daddr.sin_addr = *preq_addr;
	193	}
	194	}
512176db	195	if (!bc) {
b63c7f6b	196	new_addr:
0928a95f	197	bc = get_new_addr(&daddr.sin_addr, client_ethaddr);
b63c7f6b AL	198	if (!bc) {
	199	dprintf("no address left\n");
	200	return;
	201	}
512176db FB	202	}
512176db FB	203	memcpy(bc->macaddr, client_ethaddr, 6);
b63c7f6b AL	204	} else if (preq_addr) {
	205	bc = request_addr(preq_addr, client_ethaddr);
	206	if (bc) {
	207	daddr.sin_addr = *preq_addr;
	208	memcpy(bc->macaddr, client_ethaddr, 6);
	209	} else {
	210	daddr.sin_addr.s_addr = 0;
	211	}
512176db FB	212	} else {
	213	bc = find_addr(&daddr.sin_addr, bp->bp_hwaddr);
	214	if (!bc) {
d981b883 FB	215	/* if never assigned, behaves as if it was already
	216	assigned (windows fix because it remembers its address) */
	217	goto new_addr;
512176db	218	}
f0cbd3ec	219	}
47d5d01a	220
f0cbd3ec FB	221	saddr.sin_addr.s_addr = htonl(ntohl(special_addr.s_addr) \| CTL_ALIAS);
	222	saddr.sin_port = htons(BOOTP_SERVER);
	223
	224	daddr.sin_port = htons(BOOTP_CLIENT);
	225
	226	rbp->bp_op = BOOTP_REPLY;
	227	rbp->bp_xid = bp->bp_xid;
	228	rbp->bp_htype = 1;
	229	rbp->bp_hlen = 6;
	230	memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6);
	231
e95c8d51 FB	232	rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */
e95c8d51 FB	233	rbp->bp_siaddr = saddr.sin_addr; /* Server IP address */
f0cbd3ec FB	234
	235	q = rbp->bp_vend;
	236	memcpy(q, rfc1533_cookie, 4);
	237	q += 4;
	238
b63c7f6b AL	239	if (bc) {
	240	dprintf("%s addr=%08x\n",
	241	(dhcp_msg_type == DHCPDISCOVER) ? "offered" : "ack'ed",
	242	ntohl(daddr.sin_addr.s_addr));
	243
	244	if (dhcp_msg_type == DHCPDISCOVER) {
	245	*q++ = RFC2132_MSG_TYPE;
	246	*q++ = 1;
	247	*q++ = DHCPOFFER;
	248	} else /* DHCPREQUEST */ {
	249	*q++ = RFC2132_MSG_TYPE;
	250	*q++ = 1;
	251	*q++ = DHCPACK;
	252	}
	253
	254	if (bootp_filename)
	255	snprintf((char *)rbp->bp_file, sizeof(rbp->bp_file), "%s",
	256	bootp_filename);
3b46e624	257
f0cbd3ec FB	258	*q++ = RFC2132_SRV_ID;
	259	*q++ = 4;
	260	memcpy(q, &saddr.sin_addr, 4);
	261	q += 4;
	262
	263	*q++ = RFC1533_NETMASK;
	264	*q++ = 4;
	265	*q++ = 0xff;
	266	*q++ = 0xff;
	267	*q++ = 0xff;
	268	*q++ = 0x00;
3b46e624	269
a9ba3a85 AL	270	if (!slirp_restrict) {
	271	*q++ = RFC1533_GATEWAY;
	272	*q++ = 4;
	273	memcpy(q, &saddr.sin_addr, 4);
	274	q += 4;
	275
	276	*q++ = RFC1533_DNS;
	277	*q++ = 4;
	278	dns_addr.s_addr = htonl(ntohl(special_addr.s_addr) \| CTL_DNS);
	279	memcpy(q, &dns_addr, 4);
	280	q += 4;
	281	}
f0cbd3ec FB	282
	283	*q++ = RFC2132_LEASE_TIME;
	284	*q++ = 4;
	285	val = htonl(LEASE_TIME);
	286	memcpy(q, &val, 4);
	287	q += 4;
115defd1 PB	288
	289	if (*slirp_hostname) {
	290	val = strlen(slirp_hostname);
	291	*q++ = RFC1533_HOSTNAME;
	292	*q++ = val;
	293	memcpy(q, slirp_hostname, val);
	294	q += val;
	295	}
b63c7f6b AL	296	} else {
	297	static const char nak_msg[] = "requested address not available";
	298
	299	dprintf("nak'ed addr=%08x\n", ntohl(preq_addr->s_addr));
	300
	301	*q++ = RFC2132_MSG_TYPE;
	302	*q++ = 1;
	303	*q++ = DHCPNAK;
	304
	305	*q++ = RFC2132_MESSAGE;
	306	*q++ = sizeof(nak_msg) - 1;
	307	memcpy(q, nak_msg, sizeof(nak_msg) - 1);
	308	q += sizeof(nak_msg) - 1;
f0cbd3ec FB	309	}
f0cbd3ec FB	310	*q++ = RFC1533_END;
3b46e624	311
b63c7f6b AL	312	daddr.sin_addr.s_addr = 0xffffffffu;
b63c7f6b AL	313
5fafdf24	314	m->m_len = sizeof(struct bootp_t) -
44bbf73f	315	sizeof(struct ip) - sizeof(struct udphdr);
f0cbd3ec FB	316	udp_output2(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
	317	}
	318
	319	void bootp_input(struct mbuf *m)
	320	{
101c5935	321	struct bootp_t bp = mtod(m, struct bootp_t );
f0cbd3ec FB	322
	323	if (bp->bp_op == BOOTP_REQUEST) {
	324	bootp_reply(bp);
	325	}
	326	}