1 /* $NetBSD: bootp.c,v 1.40 2015/07/25 07:06:11 isaki Exp $ */
2
3 /*
4 * Copyright (c) 1992 Regents of the University of California.
5 * All rights reserved.
6 *
7 * This software was developed by the Computer Systems Engineering group
8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9 * contributed to Berkeley.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the University of
22 * California, Lawrence Berkeley Laboratory and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 * @(#) Header: bootp.c,v 1.4 93/09/11 03:13:51 leres Exp (LBL)
40 */
41
42 #include <sys/param.h>
43 #include <netinet/in.h>
44 #include <netinet/in_systm.h>
45
46 #ifdef _STANDALONE
47 #include <lib/libkern/libkern.h>
48 #else
49 #include <string.h>
50 #endif
51
52 #include "stand.h"
53 #include "net.h"
54 #include "bootp.h"
55
56 struct in_addr servip;
57 #ifdef SUPPORT_LINUX
58 char linuxcmdline[256];
59 #ifndef TAG_LINUX_CMDLINE
60 #define TAG_LINUX_CMDLINE 123
61 #endif
62 #endif
63
64 static n_long nmask, smask;
65
66 static satime_t bot;
67
68 static char vm_rfc1048[4] = VM_RFC1048;
69 #ifdef BOOTP_VEND_CMU
70 static char vm_cmu[4] = VM_CMU;
71 #endif
72
73 /* Local forwards */
74 static ssize_t bootpsend(struct iodesc *, void *, size_t);
75 static ssize_t bootprecv(struct iodesc *, void *, size_t, saseconds_t);
76 static int vend_rfc1048(u_char *, u_int);
77 #ifdef BOOTP_VEND_CMU
78 static void vend_cmu(u_char *);
79 #endif
80
81 #ifdef SUPPORT_DHCP
82 static char expected_dhcpmsgtype = -1, dhcp_ok;
83 struct in_addr dhcp_serverip;
84 #endif
85
86 /*
87 * Boot programs can patch this at run-time to change the behavior
88 * of bootp/dhcp.
89 */
90 int bootp_flags;
91
92 static void
bootp_addvend(u_char * area)93 bootp_addvend(u_char *area)
94 {
95 #ifdef SUPPORT_DHCP
96 char vci[64];
97 int vcilen;
98
99 *area++ = TAG_PARAM_REQ;
100 *area++ = 6;
101 *area++ = TAG_SUBNET_MASK;
102 *area++ = TAG_GATEWAY;
103 *area++ = TAG_HOSTNAME;
104 *area++ = TAG_DOMAINNAME;
105 *area++ = TAG_ROOTPATH;
106 *area++ = TAG_SWAPSERVER;
107
108 /* Insert a NetBSD Vendor Class Identifier option. */
109 snprintf(vci, sizeof(vci), "NetBSD:%s:libsa", MACHINE);
110 vcilen = strlen(vci);
111 *area++ = TAG_CLASSID;
112 *area++ = vcilen;
113 (void)memcpy(area, vci, vcilen);
114 area += vcilen;
115 #endif
116 *area = TAG_END;
117 }
118
119 /* Fetch required bootp information */
120 void
bootp(int sock)121 bootp(int sock)
122 {
123 struct iodesc *d;
124 struct bootp *bp;
125 struct {
126 u_char header[UDP_TOTAL_HEADER_SIZE];
127 struct bootp wbootp;
128 } wbuf;
129 struct {
130 u_char header[UDP_TOTAL_HEADER_SIZE];
131 struct bootp rbootp;
132 } rbuf;
133 unsigned int index;
134
135 #ifdef BOOTP_DEBUG
136 if (debug)
137 printf("bootp: socket=%d\n", sock);
138 #endif
139 if (!bot)
140 bot = getsecs();
141
142 if (!(d = socktodesc(sock))) {
143 printf("bootp: bad socket. %d\n", sock);
144 return;
145 }
146 #ifdef BOOTP_DEBUG
147 if (debug)
148 printf("bootp: d=%lx\n", (long)d);
149 #endif
150
151 bp = &wbuf.wbootp;
152 (void)memset(bp, 0, sizeof(*bp));
153
154 bp->bp_op = BOOTREQUEST;
155 bp->bp_htype = 1; /* 10Mb Ethernet (48 bits) */
156 bp->bp_hlen = 6;
157 bp->bp_xid = htonl(d->xid);
158 MACPY(d->myea, bp->bp_chaddr);
159 (void)strncpy((char *)bp->bp_file, bootfile, sizeof(bp->bp_file));
160 (void)memcpy(bp->bp_vend, vm_rfc1048, sizeof(vm_rfc1048));
161 index = 4;
162 #ifdef SUPPORT_DHCP
163 bp->bp_vend[index++] = TAG_DHCP_MSGTYPE;
164 bp->bp_vend[index++] = 1;
165 bp->bp_vend[index++] = DHCPDISCOVER;
166 #endif
167 bootp_addvend(&bp->bp_vend[index]);
168
169 d->myip.s_addr = INADDR_ANY;
170 d->myport = htons(IPPORT_BOOTPC);
171 d->destip.s_addr = INADDR_BROADCAST;
172 d->destport = htons(IPPORT_BOOTPS);
173
174 #ifdef SUPPORT_DHCP
175 expected_dhcpmsgtype = DHCPOFFER;
176 dhcp_ok = 0;
177 #endif
178
179 if (sendrecv(d,
180 bootpsend, bp, sizeof(*bp),
181 bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
182 == -1) {
183 printf("bootp: no reply\n");
184 return;
185 }
186
187 #ifdef SUPPORT_DHCP
188 if (dhcp_ok) {
189 u_int32_t leasetime;
190 index = 6;
191 bp->bp_vend[index++] = DHCPREQUEST;
192 bp->bp_vend[index++] = TAG_REQ_ADDR;
193 bp->bp_vend[index++] = 4;
194 (void)memcpy(&bp->bp_vend[9], &rbuf.rbootp.bp_yiaddr, 4);
195 index += 4;
196 bp->bp_vend[index++] = TAG_SERVERID;
197 bp->bp_vend[index++] = 4;
198 (void)memcpy(&bp->bp_vend[index], &dhcp_serverip.s_addr, 4);
199 index += 4;
200 bp->bp_vend[index++] = TAG_LEASETIME;
201 bp->bp_vend[index++] = 4;
202 leasetime = htonl(300);
203 (void)memcpy(&bp->bp_vend[index], &leasetime, 4);
204 index += 4;
205 bootp_addvend(&bp->bp_vend[index]);
206
207 expected_dhcpmsgtype = DHCPACK;
208
209 if (sendrecv(d,
210 bootpsend, bp, sizeof(*bp),
211 bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
212 == -1) {
213 printf("DHCPREQUEST failed\n");
214 return;
215 }
216 }
217 #endif
218
219 myip = d->myip = rbuf.rbootp.bp_yiaddr;
220 servip = rbuf.rbootp.bp_siaddr;
221 if (rootip.s_addr == INADDR_ANY)
222 rootip = servip;
223 (void)memcpy(bootfile, rbuf.rbootp.bp_file, sizeof(bootfile));
224 bootfile[sizeof(bootfile) - 1] = '\0';
225
226 if (IN_CLASSA(myip.s_addr))
227 nmask = IN_CLASSA_NET;
228 else if (IN_CLASSB(myip.s_addr))
229 nmask = IN_CLASSB_NET;
230 else
231 nmask = IN_CLASSC_NET;
232 #ifdef BOOTP_DEBUG
233 if (debug)
234 printf("'native netmask' is %s\n", intoa(nmask));
235 #endif
236
237 /* Get subnet (or natural net) mask */
238 netmask = nmask;
239 if (smask)
240 netmask = smask;
241 #ifdef BOOTP_DEBUG
242 if (debug)
243 printf("mask: %s\n", intoa(netmask));
244 #endif
245
246 /* We need a gateway if root is on a different net */
247 if (!SAMENET(myip, rootip, netmask)) {
248 #ifdef BOOTP_DEBUG
249 if (debug)
250 printf("need gateway for root ip\n");
251 #endif
252 }
253
254 /* Toss gateway if on a different net */
255 if (!SAMENET(myip, gateip, netmask)) {
256 #ifdef BOOTP_DEBUG
257 if (debug)
258 printf("gateway ip (%s) bad\n", inet_ntoa(gateip));
259 #endif
260 gateip.s_addr = 0;
261 }
262
263 #ifdef BOOTP_DEBUG
264 if (debug) {
265 printf("client addr: %s\n", inet_ntoa(myip));
266 if (smask)
267 printf("subnet mask: %s\n", intoa(smask));
268 if (gateip.s_addr != 0)
269 printf("net gateway: %s\n", inet_ntoa(gateip));
270 printf("server addr: %s\n", inet_ntoa(rootip));
271 if (rootpath[0] != '\0')
272 printf("server path: %s\n", rootpath);
273 if (bootfile[0] != '\0')
274 printf("file name: %s\n", bootfile);
275 }
276 #endif
277
278 /* Bump xid so next request will be unique. */
279 ++d->xid;
280 }
281
282 /* Transmit a bootp request */
283 static ssize_t
bootpsend(struct iodesc * d,void * pkt,size_t len)284 bootpsend(struct iodesc *d, void *pkt, size_t len)
285 {
286 struct bootp *bp;
287
288 #ifdef BOOTP_DEBUG
289 if (debug)
290 printf("bootpsend: d=%lx called.\n", (long)d);
291 #endif
292
293 bp = pkt;
294 bp->bp_secs = htons((u_short)(getsecs() - bot));
295
296 #ifdef BOOTP_DEBUG
297 if (debug)
298 printf("bootpsend: calling sendudp\n");
299 #endif
300
301 return sendudp(d, pkt, len);
302 }
303
304 static ssize_t
bootprecv(struct iodesc * d,void * pkt,size_t len,saseconds_t tleft)305 bootprecv(struct iodesc *d, void *pkt, size_t len, saseconds_t tleft)
306 {
307 ssize_t n;
308 struct bootp *bp;
309
310 #ifdef BOOTP_DEBUGx
311 if (debug)
312 printf("bootp_recvoffer: called\n");
313 #endif
314
315 n = readudp(d, pkt, len, tleft);
316 if (n == -1 || (size_t)n < sizeof(struct bootp) - BOOTP_VENDSIZE)
317 goto bad;
318
319 bp = (struct bootp *)pkt;
320
321 #ifdef BOOTP_DEBUG
322 if (debug)
323 printf("bootprecv: checked. bp = 0x%lx, n = %d\n",
324 (long)bp, (int)n);
325 #endif
326 if (bp->bp_xid != htonl(d->xid)) {
327 #ifdef BOOTP_DEBUG
328 if (debug) {
329 printf("bootprecv: expected xid 0x%lx, got 0x%x\n",
330 d->xid, ntohl(bp->bp_xid));
331 }
332 #endif
333 goto bad;
334 }
335
336 /* protect against bogus addresses sent by DHCP servers */
337 if (bp->bp_yiaddr.s_addr == INADDR_ANY ||
338 bp->bp_yiaddr.s_addr == INADDR_BROADCAST)
339 goto bad;
340
341 #ifdef BOOTP_DEBUG
342 if (debug)
343 printf("bootprecv: got one!\n");
344 #endif
345
346 /* Suck out vendor info */
347 if (memcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) {
348 if (vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend)) != 0)
349 goto bad;
350 }
351 #ifdef BOOTP_VEND_CMU
352 else if (memcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0)
353 vend_cmu(bp->bp_vend);
354 #endif
355 else
356 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend);
357
358 return n;
359 bad:
360 errno = 0;
361 return -1;
362 }
363
364 static int
vend_rfc1048(u_char * cp,u_int len)365 vend_rfc1048(u_char *cp, u_int len)
366 {
367 u_char *ep;
368 int size;
369 u_char tag;
370
371 #ifdef BOOTP_DEBUG
372 if (debug)
373 printf("vend_rfc1048 bootp info. len=%d\n", len);
374 #endif
375 ep = cp + len;
376
377 /* Step over magic cookie */
378 cp += sizeof(int);
379
380 while (cp < ep) {
381 tag = *cp++;
382 size = *cp++;
383 if (tag == TAG_END)
384 break;
385
386 if (tag == TAG_SUBNET_MASK && size >= sizeof(smask)) {
387 (void)memcpy(&smask, cp, sizeof(smask));
388 }
389 if (tag == TAG_GATEWAY && size >= sizeof(gateip.s_addr)) {
390 (void)memcpy(&gateip.s_addr, cp, sizeof(gateip.s_addr));
391 }
392 if (tag == TAG_SWAPSERVER && size >= sizeof(rootip.s_addr)) {
393 /* let it override bp_siaddr */
394 (void)memcpy(&rootip.s_addr, cp, sizeof(rootip.s_addr));
395 }
396 if (tag == TAG_ROOTPATH && size < sizeof(rootpath)) {
397 strncpy(rootpath, (char *)cp, sizeof(rootpath));
398 rootpath[size] = '\0';
399 }
400 if (tag == TAG_HOSTNAME && size < sizeof(hostname)) {
401 strncpy(hostname, (char *)cp, sizeof(hostname));
402 hostname[size] = '\0';
403 }
404 #ifdef SUPPORT_DHCP
405 if (tag == TAG_DHCP_MSGTYPE) {
406 if (*cp != expected_dhcpmsgtype)
407 return -1;
408 dhcp_ok = 1;
409 }
410 if (tag == TAG_SERVERID &&
411 size >= sizeof(dhcp_serverip.s_addr))
412 {
413 (void)memcpy(&dhcp_serverip.s_addr, cp,
414 sizeof(dhcp_serverip.s_addr));
415 }
416 #endif
417 #ifdef SUPPORT_LINUX
418 if (tag == TAG_LINUX_CMDLINE && size < sizeof(linuxcmdline)) {
419 strncpy(linuxcmdline, (char *)cp, sizeof(linuxcmdline));
420 linuxcmdline[size] = '\0';
421 }
422 #endif
423 cp += size;
424 }
425 return 0;
426 }
427
428 #ifdef BOOTP_VEND_CMU
429 static void
vend_cmu(u_char * cp)430 vend_cmu(u_char *cp)
431 {
432 struct cmu_vend *vp;
433
434 #ifdef BOOTP_DEBUG
435 if (debug)
436 printf("vend_cmu bootp info.\n");
437 #endif
438 vp = (struct cmu_vend *)cp;
439
440 if (vp->v_smask.s_addr != 0) {
441 smask = vp->v_smask.s_addr;
442 }
443 if (vp->v_dgate.s_addr != 0) {
444 gateip = vp->v_dgate;
445 }
446 }
447 #endif
448