1 /* $NetBSD: bootp.c,v 1.43 2019/04/05 20:09:29 christos 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("%s: socket=%d\n", __func__, sock);
138 #endif
139 if (!bot)
140 bot = getsecs();
141
142 if (!(d = socktodesc(sock))) {
143 printf("%s: bad socket. %d\n", __func__, sock);
144 return;
145 }
146 #ifdef BOOTP_DEBUG
147 if (debug)
148 printf("%s: d=%p\n", __func__, 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, bootpsend, bp, sizeof(*bp),
180 bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp)) == -1) {
181 printf("%s: no reply\n", __func__);
182 return;
183 }
184
185 #ifdef SUPPORT_DHCP
186 if (dhcp_ok) {
187 u_int32_t leasetime;
188 index = 6;
189 bp->bp_vend[index++] = DHCPREQUEST;
190 bp->bp_vend[index++] = TAG_REQ_ADDR;
191 bp->bp_vend[index++] = 4;
192 (void)memcpy(&bp->bp_vend[9], &rbuf.rbootp.bp_yiaddr, 4);
193 index += 4;
194 bp->bp_vend[index++] = TAG_SERVERID;
195 bp->bp_vend[index++] = 4;
196 (void)memcpy(&bp->bp_vend[index], &dhcp_serverip.s_addr, 4);
197 index += 4;
198 bp->bp_vend[index++] = TAG_LEASETIME;
199 bp->bp_vend[index++] = 4;
200 leasetime = htonl(300);
201 (void)memcpy(&bp->bp_vend[index], &leasetime, 4);
202 index += 4;
203 bootp_addvend(&bp->bp_vend[index]);
204
205 expected_dhcpmsgtype = DHCPACK;
206
207 if (sendrecv(d,
208 bootpsend, bp, sizeof(*bp),
209 bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
210 == -1) {
211 printf("DHCPREQUEST failed\n");
212 return;
213 }
214 }
215 #endif
216
217 myip = d->myip = rbuf.rbootp.bp_yiaddr;
218 servip = rbuf.rbootp.bp_siaddr;
219 if (rootip.s_addr == INADDR_ANY)
220 rootip = servip;
221 (void)memcpy(bootfile, rbuf.rbootp.bp_file, sizeof(bootfile));
222 bootfile[sizeof(bootfile) - 1] = '\0';
223
224 if (IN_CLASSA(myip.s_addr))
225 nmask = IN_CLASSA_NET;
226 else if (IN_CLASSB(myip.s_addr))
227 nmask = IN_CLASSB_NET;
228 else
229 nmask = IN_CLASSC_NET;
230 #ifdef BOOTP_DEBUG
231 if (debug)
232 printf("'native netmask' is %s\n", intoa(nmask));
233 #endif
234
235 /* Get subnet (or natural net) mask */
236 netmask = nmask;
237 if (smask)
238 netmask = smask;
239 #ifdef BOOTP_DEBUG
240 if (debug)
241 printf("mask: %s\n", intoa(netmask));
242 #endif
243
244 /* We need a gateway if root is on a different net */
245 if (!SAMENET(myip, rootip, netmask)) {
246 #ifdef BOOTP_DEBUG
247 if (debug)
248 printf("need gateway for root ip\n");
249 #endif
250 }
251
252 /* Toss gateway if on a different net */
253 if (!SAMENET(myip, gateip, netmask)) {
254 #ifdef BOOTP_DEBUG
255 if (debug)
256 printf("gateway ip (%s) bad\n", inet_ntoa(gateip));
257 #endif
258 gateip.s_addr = 0;
259 }
260
261 #ifdef BOOTP_DEBUG
262 if (debug) {
263 printf("client addr: %s\n", inet_ntoa(myip));
264 if (smask)
265 printf("subnet mask: %s\n", intoa(smask));
266 if (gateip.s_addr != 0)
267 printf("net gateway: %s\n", inet_ntoa(gateip));
268 printf("server addr: %s\n", inet_ntoa(rootip));
269 if (rootpath[0] != '\0')
270 printf("server path: %s\n", rootpath);
271 if (bootfile[0] != '\0')
272 printf("file name: %s\n", bootfile);
273 }
274 #endif
275
276 /* Bump xid so next request will be unique. */
277 ++d->xid;
278 }
279
280 /* Transmit a bootp request */
281 static ssize_t
bootpsend(struct iodesc * d,void * pkt,size_t len)282 bootpsend(struct iodesc *d, void *pkt, size_t len)
283 {
284 struct bootp *bp;
285
286 #ifdef BOOTP_DEBUG
287 if (debug)
288 printf("%s: d=%p called.\n", __func__, d);
289 #endif
290
291 bp = pkt;
292 bp->bp_secs = htons((u_short)(getsecs() - bot));
293
294 #ifdef BOOTP_DEBUG
295 if (debug)
296 printf("%s: calling sendudp\n", __func__);
297 #endif
298
299 return sendudp(d, pkt, len);
300 }
301
302 static ssize_t
bootprecv(struct iodesc * d,void * pkt,size_t len,saseconds_t tleft)303 bootprecv(struct iodesc *d, void *pkt, size_t len, saseconds_t tleft)
304 {
305 ssize_t n;
306 struct bootp *bp;
307
308 #ifdef BOOTP_DEBUG
309 if (debug)
310 printf("%s: called\n", __func__);
311 #endif
312
313 n = readudp(d, pkt, len, tleft);
314 if (n == -1 || (size_t)n < sizeof(struct bootp) - BOOTP_VENDSIZE)
315 goto bad;
316
317 bp = (struct bootp *)pkt;
318
319 #ifdef BOOTP_DEBUG
320 if (debug)
321 printf("%s: checked. bp = %p, n = %zd\n", __func__, bp, n);
322 #endif
323 if (bp->bp_xid != htonl(d->xid)) {
324 #ifdef BOOTP_DEBUG
325 if (debug) {
326 printf("%s: expected xid 0x%lx, got 0x%x\n", __func__,
327 d->xid, ntohl(bp->bp_xid));
328 }
329 #endif
330 goto bad;
331 }
332
333 /* protect against bogus addresses sent by DHCP servers */
334 if (bp->bp_yiaddr.s_addr == INADDR_ANY ||
335 bp->bp_yiaddr.s_addr == INADDR_BROADCAST)
336 goto bad;
337
338 #ifdef BOOTP_DEBUG
339 if (debug)
340 printf("%s: got one!\n", __func__);
341 #endif
342
343 /* Suck out vendor info */
344 if (memcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) {
345 if (vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend)) != 0)
346 goto bad;
347 }
348 #ifdef BOOTP_VEND_CMU
349 else if (memcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0)
350 vend_cmu(bp->bp_vend);
351 #endif
352 else
353 printf("%s: unknown vendor %p\n", __func__, bp->bp_vend);
354
355 return n;
356 bad:
357 errno = 0;
358 return -1;
359 }
360
361 static int
vend_rfc1048(u_char * cp,u_int len)362 vend_rfc1048(u_char *cp, u_int len)
363 {
364 u_char *ep;
365 size_t size;
366 u_char tag;
367
368 #ifdef BOOTP_DEBUG
369 if (debug)
370 printf("%s: bootp info. len=%d\n", __func__, len);
371 #endif
372 ep = cp + len;
373
374 /* Step over magic cookie */
375 cp += sizeof(int);
376
377 while (cp < ep) {
378 tag = *cp++;
379 size = *cp++;
380 if (tag == TAG_END)
381 break;
382
383 if (tag == TAG_SUBNET_MASK && size >= sizeof(smask)) {
384 (void)memcpy(&smask, cp, sizeof(smask));
385 }
386 if (tag == TAG_GATEWAY && size >= sizeof(gateip.s_addr)) {
387 (void)memcpy(&gateip.s_addr, cp, sizeof(gateip.s_addr));
388 }
389 if (tag == TAG_SWAPSERVER && size >= sizeof(rootip.s_addr)) {
390 /* let it override bp_siaddr */
391 (void)memcpy(&rootip.s_addr, cp, sizeof(rootip.s_addr));
392 }
393 if (tag == TAG_ROOTPATH && size < sizeof(rootpath)) {
394 strncpy(rootpath, (char *)cp, sizeof(rootpath));
395 rootpath[size] = '\0';
396 }
397 if (tag == TAG_HOSTNAME && size < sizeof(hostname)) {
398 strncpy(hostname, (char *)cp, sizeof(hostname));
399 hostname[size] = '\0';
400 }
401 #ifdef SUPPORT_DHCP
402 if (tag == TAG_DHCP_MSGTYPE) {
403 if (*cp != expected_dhcpmsgtype)
404 return -1;
405 dhcp_ok = 1;
406 }
407 if (tag == TAG_SERVERID &&
408 size >= sizeof(dhcp_serverip.s_addr))
409 {
410 (void)memcpy(&dhcp_serverip.s_addr, cp,
411 sizeof(dhcp_serverip.s_addr));
412 }
413 #endif
414 #ifdef SUPPORT_LINUX
415 if (tag == TAG_LINUX_CMDLINE && size < sizeof(linuxcmdline)) {
416 strncpy(linuxcmdline, (char *)cp, sizeof(linuxcmdline));
417 linuxcmdline[size] = '\0';
418 }
419 #endif
420 cp += size;
421 }
422 return 0;
423 }
424
425 #ifdef BOOTP_VEND_CMU
426 static void
vend_cmu(u_char * cp)427 vend_cmu(u_char *cp)
428 {
429 struct cmu_vend *vp;
430
431 #ifdef BOOTP_DEBUG
432 if (debug)
433 printf("%s: bootp info.\n", __func__);
434 #endif
435 vp = (struct cmu_vend *)cp;
436
437 if (vp->v_smask.s_addr != 0) {
438 smask = vp->v_smask.s_addr;
439 }
440 if (vp->v_dgate.s_addr != 0) {
441 gateip = vp->v_dgate;
442 }
443 }
444 #endif
445