1 /* $OpenBSD: bootp.c,v 1.15 2014/11/19 19:58:40 miod Exp $ */
2 /* $NetBSD: bootp.c,v 1.10 1996/10/13 02:28:59 christos Exp $ */
3
4 /*
5 * Copyright (c) 1992 Regents of the University of California.
6 * All rights reserved.
7 *
8 * This software was developed by the Computer Systems Engineering group
9 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
10 * contributed to Berkeley.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by the University of
23 * California, Lawrence Berkeley Laboratory and its contributors.
24 * 4. Neither the name of the University nor the names of its contributors
25 * may be used to endorse or promote products derived from this software
26 * without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
39 *
40 * @(#) Header: bootp.c,v 1.4 93/09/11 03:13:51 leres Exp (LBL)
41 */
42
43 #include <sys/types.h>
44 #include <sys/socket.h>
45 #include <netinet/in.h>
46
47 #include "stand.h"
48 #include "net.h"
49 #include "netif.h"
50 #include "bootp.h"
51
52 static u_int32_t nmask, smask;
53
54 static time_t bot;
55
56 static char vm_rfc1048[4] = VM_RFC1048;
57 static char vm_cmu[4] = VM_CMU;
58
59 /* Local forwards */
60 static ssize_t bootpsend(struct iodesc *, void *, size_t);
61 static ssize_t bootprecv(struct iodesc *, void *, size_t, time_t);
62 static void vend_cmu(const u_char *);
63 static void vend_rfc1048(const u_char *, u_int);
64
65 /* Fetch required bootp information */
66 void
bootp(int sock)67 bootp(int sock)
68 {
69 struct iodesc *d;
70 struct bootp *bp;
71 struct {
72 struct packet_header header;
73 struct bootp wbootp;
74 } wbuf;
75 struct {
76 struct packet_header header;
77 struct bootp rbootp;
78 } rbuf;
79
80 #ifdef BOOTP_DEBUG
81 if (debug)
82 printf("bootp: socket=%d\n", sock);
83 #endif
84 if (!bot)
85 bot = getsecs();
86
87 if (!(d = socktodesc(sock))) {
88 printf("bootp: bad socket. %d\n", sock);
89 return;
90 }
91 #ifdef BOOTP_DEBUG
92 if (debug)
93 printf("bootp: d=%x\n", (u_int)d);
94 #endif
95
96 bp = &wbuf.wbootp;
97 bzero(bp, sizeof(*bp));
98
99 bp->bp_op = BOOTREQUEST;
100 bp->bp_htype = HTYPE_ETHERNET; /* 10Mb Ethernet (48 bits) */
101 bp->bp_hlen = 6;
102 bp->bp_xid = htonl(d->xid);
103 MACPY(d->myea, bp->bp_chaddr);
104 bzero(bp->bp_file, sizeof(bp->bp_file));
105 bcopy(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048));
106
107 d->myip = myip;
108 d->myport = htons(IPPORT_BOOTPC);
109 d->destip.s_addr = INADDR_BROADCAST;
110 d->destport = htons(IPPORT_BOOTPS);
111
112 (void)sendrecv(d,
113 bootpsend, bp, sizeof(*bp),
114 bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp));
115
116 /* Bump xid so next request will be unique. */
117 ++d->xid;
118 }
119
120 /* Transmit a bootp request */
121 static ssize_t
bootpsend(struct iodesc * d,void * pkt,size_t len)122 bootpsend(struct iodesc *d, void *pkt, size_t len)
123 {
124 struct bootp *bp;
125
126 #ifdef BOOTP_DEBUG
127 if (debug)
128 printf("bootpsend: d=%x called.\n", (u_int)d);
129 #endif
130
131 bp = pkt;
132 bp->bp_secs = htons((u_short)(getsecs() - bot));
133
134 #ifdef BOOTP_DEBUG
135 if (debug)
136 printf("bootpsend: calling sendudp\n");
137 #endif
138
139 return (sendudp(d, pkt, len));
140 }
141
142 /* Returns 0 if this is the packet we're waiting for else -1 (and errno == 0) */
143 static ssize_t
bootprecv(struct iodesc * d,void * pkt,size_t len,time_t tleft)144 bootprecv(struct iodesc *d, void *pkt, size_t len, time_t tleft)
145 {
146 ssize_t n;
147 struct bootp *bp;
148
149 #ifdef BOOTP_DEBUG
150 if (debug)
151 printf("bootprecv: called\n");
152 #endif
153
154 n = readudp(d, pkt, len, tleft);
155 if (n < 0 || (size_t)n < sizeof(struct bootp))
156 goto bad;
157
158 bp = (struct bootp *)pkt;
159
160 #ifdef BOOTP_DEBUG
161 if (debug)
162 printf("bootprecv: checked. bp = 0x%x, n = %d\n",
163 (unsigned)bp, n);
164 #endif
165 if (bp->bp_xid != htonl(d->xid)) {
166 #ifdef BOOTP_DEBUG
167 if (debug) {
168 printf("bootprecv: expected xid 0x%lx, got 0x%lx\n",
169 d->xid, ntohl(bp->bp_xid));
170 }
171 #endif
172 goto bad;
173 }
174
175 #ifdef BOOTP_DEBUG
176 if (debug)
177 printf("bootprecv: got one!\n");
178 #endif
179
180 /* Pick up our ip address (and natural netmask) */
181 myip = d->myip = bp->bp_yiaddr;
182 #ifdef BOOTP_DEBUG
183 if (debug)
184 printf("our ip address is %s\n", inet_ntoa(d->myip));
185 #endif
186 if (IN_CLASSA(d->myip.s_addr))
187 nmask = IN_CLASSA_NET;
188 else if (IN_CLASSB(d->myip.s_addr))
189 nmask = IN_CLASSB_NET;
190 else
191 nmask = IN_CLASSC_NET;
192 #ifdef BOOTP_DEBUG
193 if (debug)
194 printf("'native netmask' is %s\n", intoa(nmask));
195 #endif
196
197 /* Pick up root or swap server address and file spec. */
198 if (bp->bp_siaddr.s_addr != 0)
199 rootip = bp->bp_siaddr;
200 if (bp->bp_file[0] != '\0') {
201 strncpy(bootfile, (char *)bp->bp_file, sizeof(bootfile));
202 bootfile[sizeof(bootfile) - 1] = '\0';
203 }
204
205 /* Suck out vendor info */
206 if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0)
207 vend_cmu(bp->bp_vend);
208 else if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0)
209 vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend));
210 else
211 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend);
212
213 /* Check subnet mask against net mask; toss if bogus */
214 if ((nmask & smask) != nmask) {
215 #ifdef BOOTP_DEBUG
216 if (debug)
217 printf("subnet mask (%s) bad\n", intoa(smask));
218 #endif
219 smask = 0;
220 }
221
222 /* Get subnet (or natural net) mask */
223 netmask = nmask;
224 if (smask)
225 netmask = smask;
226 #ifdef BOOTP_DEBUG
227 if (debug)
228 printf("mask: %s\n", intoa(netmask));
229 #endif
230
231 /* We need a gateway if root or swap is on a different net */
232 if (!SAMENET(d->myip, rootip, netmask)) {
233 #ifdef BOOTP_DEBUG
234 if (debug)
235 printf("need gateway for root ip\n");
236 #endif
237 }
238
239 if (!SAMENET(d->myip, swapip, netmask)) {
240 #ifdef BOOTP_DEBUG
241 if (debug)
242 printf("need gateway for swap ip\n");
243 #endif
244 }
245
246 /* Toss gateway if on a different net */
247 if (!SAMENET(d->myip, gateip, netmask)) {
248 #ifdef BOOTP_DEBUG
249 if (debug)
250 printf("gateway ip (%s) bad\n", inet_ntoa(gateip));
251 #endif
252 gateip.s_addr = 0;
253 }
254
255 return (n);
256
257 bad:
258 errno = 0;
259 return (-1);
260 }
261
262 static void
vend_cmu(const u_char * cp)263 vend_cmu(const u_char *cp)
264 {
265 const struct cmu_vend *vp;
266
267 #ifdef BOOTP_DEBUG
268 if (debug)
269 printf("vend_cmu bootp info.\n");
270 #endif
271 vp = (const struct cmu_vend *)cp;
272
273 if (vp->v_smask.s_addr != 0)
274 smask = vp->v_smask.s_addr;
275 if (vp->v_dgate.s_addr != 0)
276 gateip = vp->v_dgate;
277 }
278
279 static void
vend_rfc1048(const u_char * cp,u_int len)280 vend_rfc1048(const u_char *cp, u_int len)
281 {
282 const u_char *ep;
283 int size;
284 u_char tag;
285
286 #ifdef BOOTP_DEBUG
287 if (debug)
288 printf("vend_rfc1048 bootp info. len=%d\n", len);
289 #endif
290 ep = cp + len;
291
292 /* Step over magic cookie */
293 cp += sizeof(int);
294
295 while (cp < ep) {
296 tag = *cp++;
297 size = *cp++;
298 if (tag == TAG_END)
299 break;
300
301 if (tag == TAG_SUBNET_MASK)
302 bcopy(cp, &smask, sizeof(smask));
303 if (tag == TAG_GATEWAY)
304 bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr));
305 if (tag == TAG_SWAPSERVER)
306 bcopy(cp, &swapip.s_addr, sizeof(swapip.s_addr));
307 if (tag == TAG_DOMAIN_SERVER)
308 bcopy(cp, &nameip.s_addr, sizeof(nameip.s_addr));
309 if (tag == TAG_ROOTPATH) {
310 strncpy(rootpath, (char *)cp, sizeof(rootpath));
311 rootpath[size] = '\0';
312 }
313 if (tag == TAG_HOSTNAME) {
314 strncpy(hostname, (char *)cp, sizeof(hostname));
315 hostname[size] = '\0';
316 }
317 if (tag == TAG_DOMAINNAME) {
318 strncpy(domainname, (char *)cp, sizeof(domainname));
319 domainname[size] = '\0';
320 }
321 cp += size;
322 }
323 }
324