2 * QEMU BOOTP/DHCP server
4 * Copyright (c) 2004 Fabrice Bellard
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:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
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
26 /* XXX: only DHCP is supported */
30 #define LEASE_TIME (24 * 3600)
37 static BOOTPClient bootp_clients[NB_ADDR];
41 static const uint8_t rfc1533_cookie[] = { RFC1533_COOKIE };
44 #define dprintf(fmt, ...) \
45 do if (slirp_debug & DBG_CALL) { fprintf(dfd, fmt, ## __VA_ARGS__); fflush(dfd); } while (0)
47 #define dprintf(fmt, ...)
50 static BOOTPClient *get_new_addr(struct in_addr *paddr,
51 const uint8_t *macaddr)
56 for(i = 0; i < NB_ADDR; i++) {
57 bc = &bootp_clients[i];
58 if (!bc->allocated || !memcmp(macaddr, bc->macaddr, 6))
63 bc = &bootp_clients[i];
65 paddr->s_addr = vdhcp_startaddr.s_addr + htonl(i);
69 static BOOTPClient *request_addr(const struct in_addr *paddr,
70 const uint8_t *macaddr)
72 uint32_t req_addr = ntohl(paddr->s_addr);
73 uint32_t dhcp_addr = ntohl(vdhcp_startaddr.s_addr);
76 if (req_addr >= dhcp_addr &&
77 req_addr < (dhcp_addr + NB_ADDR)) {
78 bc = &bootp_clients[req_addr - dhcp_addr];
79 if (!bc->allocated || !memcmp(macaddr, bc->macaddr, 6)) {
87 static BOOTPClient *find_addr(struct in_addr *paddr, const uint8_t *macaddr)
92 for(i = 0; i < NB_ADDR; i++) {
93 if (!memcmp(macaddr, bootp_clients[i].macaddr, 6))
98 bc = &bootp_clients[i];
100 paddr->s_addr = vdhcp_startaddr.s_addr + htonl(i);
104 static void dhcp_decode(const struct bootp_t *bp, int *pmsg_type,
105 const struct in_addr **preq_addr)
107 const uint8_t *p, *p_end;
114 p_end = p + DHCP_OPT_LEN;
115 if (memcmp(p, rfc1533_cookie, 4) != 0)
120 if (tag == RFC1533_PAD) {
122 } else if (tag == RFC1533_END) {
129 dprintf("dhcp: tag=%d len=%d\n", tag, len);
132 case RFC2132_MSG_TYPE:
136 case RFC2132_REQ_ADDR:
138 *preq_addr = (struct in_addr *)p;
146 if (*pmsg_type == DHCPREQUEST && !*preq_addr && bp->bp_ciaddr.s_addr) {
147 *preq_addr = &bp->bp_ciaddr;
151 static void bootp_reply(const struct bootp_t *bp)
153 BOOTPClient *bc = NULL;
156 struct sockaddr_in saddr, daddr;
157 const struct in_addr *preq_addr;
158 int dhcp_msg_type, val;
161 /* extract exact DHCP msg type */
162 dhcp_decode(bp, &dhcp_msg_type, &preq_addr);
163 dprintf("bootp packet op=%d msgtype=%d", bp->bp_op, dhcp_msg_type);
165 dprintf(" req_addr=%08x\n", ntohl(preq_addr->s_addr));
169 if (dhcp_msg_type == 0)
170 dhcp_msg_type = DHCPREQUEST; /* Force reply for old BOOTP clients */
172 if (dhcp_msg_type != DHCPDISCOVER &&
173 dhcp_msg_type != DHCPREQUEST)
175 /* XXX: this is a hack to get the client mac address */
176 memcpy(client_ethaddr, bp->bp_hwaddr, 6);
178 if ((m = m_get()) == NULL)
180 m->m_data += IF_MAXLINKHDR;
181 rbp = (struct bootp_t *)m->m_data;
182 m->m_data += sizeof(struct udpiphdr);
183 memset(rbp, 0, sizeof(struct bootp_t));
185 if (dhcp_msg_type == DHCPDISCOVER) {
187 bc = request_addr(preq_addr, client_ethaddr);
189 daddr.sin_addr = *preq_addr;
194 bc = get_new_addr(&daddr.sin_addr, client_ethaddr);
196 dprintf("no address left\n");
200 memcpy(bc->macaddr, client_ethaddr, 6);
201 } else if (preq_addr) {
202 bc = request_addr(preq_addr, client_ethaddr);
204 daddr.sin_addr = *preq_addr;
205 memcpy(bc->macaddr, client_ethaddr, 6);
207 daddr.sin_addr.s_addr = 0;
210 bc = find_addr(&daddr.sin_addr, bp->bp_hwaddr);
212 /* if never assigned, behaves as if it was already
213 assigned (windows fix because it remembers its address) */
218 saddr.sin_addr = vhost_addr;
219 saddr.sin_port = htons(BOOTP_SERVER);
221 daddr.sin_port = htons(BOOTP_CLIENT);
223 rbp->bp_op = BOOTP_REPLY;
224 rbp->bp_xid = bp->bp_xid;
227 memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6);
229 rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */
230 rbp->bp_siaddr = saddr.sin_addr; /* Server IP address */
233 memcpy(q, rfc1533_cookie, 4);
237 dprintf("%s addr=%08x\n",
238 (dhcp_msg_type == DHCPDISCOVER) ? "offered" : "ack'ed",
239 ntohl(daddr.sin_addr.s_addr));
241 if (dhcp_msg_type == DHCPDISCOVER) {
242 *q++ = RFC2132_MSG_TYPE;
245 } else /* DHCPREQUEST */ {
246 *q++ = RFC2132_MSG_TYPE;
252 snprintf((char *)rbp->bp_file, sizeof(rbp->bp_file), "%s",
255 *q++ = RFC2132_SRV_ID;
257 memcpy(q, &saddr.sin_addr, 4);
260 *q++ = RFC1533_NETMASK;
262 memcpy(q, &vnetwork_mask, 4);
265 if (!slirp_restrict) {
266 *q++ = RFC1533_GATEWAY;
268 memcpy(q, &saddr.sin_addr, 4);
273 memcpy(q, &vnameserver_addr, 4);
277 *q++ = RFC2132_LEASE_TIME;
279 val = htonl(LEASE_TIME);
283 if (*slirp_hostname) {
284 val = strlen(slirp_hostname);
285 *q++ = RFC1533_HOSTNAME;
287 memcpy(q, slirp_hostname, val);
291 static const char nak_msg[] = "requested address not available";
293 dprintf("nak'ed addr=%08x\n", ntohl(preq_addr->s_addr));
295 *q++ = RFC2132_MSG_TYPE;
299 *q++ = RFC2132_MESSAGE;
300 *q++ = sizeof(nak_msg) - 1;
301 memcpy(q, nak_msg, sizeof(nak_msg) - 1);
302 q += sizeof(nak_msg) - 1;
306 daddr.sin_addr.s_addr = 0xffffffffu;
308 m->m_len = sizeof(struct bootp_t) -
309 sizeof(struct ip) - sizeof(struct udphdr);
310 udp_output2(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
313 void bootp_input(struct mbuf *m)
315 struct bootp_t *bp = mtod(m, struct bootp_t *);
317 if (bp->bp_op == BOOTP_REQUEST) {