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Commit | Line | Data |
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f0cbd3ec FB |
1 | /* |
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; |
38 | ||
7ca699c8 | 39 | static BOOTPClient bootp_clients[NB_ADDR]; |
f0cbd3ec | 40 | |
47d5d01a TS |
41 | const char *bootp_filename; |
42 | ||
f0cbd3ec FB |
43 | static const uint8_t rfc1533_cookie[] = { RFC1533_COOKIE }; |
44 | ||
45 | #ifdef DEBUG | |
001faf32 BS |
46 | #define dprintf(fmt, ...) \ |
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 |
51 | ||
0928a95f JK |
52 | static BOOTPClient *get_new_addr(struct in_addr *paddr, |
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]; |
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, |
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; |
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 | } |
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) |
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) |
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 | } |
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 */ |
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 | } |
310 | *q++ = RFC1533_END; | |
3b46e624 | 311 | |
b63c7f6b AL |
312 | daddr.sin_addr.s_addr = 0xffffffffu; |
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 | } |