xref: /netbsd-src/sys/lib/libsa/bootp.c (revision fdecd6a253f999ae92b139670d9e15cc9df4497c)
1 /*	$NetBSD: bootp.c,v 1.11 1997/06/26 19:11:31 drochner 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/types.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 "netif.h"
55 #include "bootp.h"
56 
57 static n_long	nmask, smask;
58 
59 static time_t	bot;
60 
61 static	char vm_rfc1048[4] = VM_RFC1048;
62 static	char vm_cmu[4] = VM_CMU;
63 
64 /* Local forwards */
65 static	ssize_t bootpsend __P((struct iodesc *, void *, size_t));
66 static	ssize_t bootprecv __P((struct iodesc *, void *, size_t, time_t));
67 static	void vend_cmu __P((u_char *));
68 static	void vend_rfc1048 __P((u_char *, u_int));
69 
70 /* Fetch required bootp infomation */
71 void
72 bootp(sock)
73 	int sock;
74 {
75 	struct iodesc *d;
76 	register struct bootp *bp;
77 	struct {
78 		u_char header[HEADER_SIZE];
79 		struct bootp wbootp;
80 	} wbuf;
81 	struct {
82 		u_char header[HEADER_SIZE];
83 		struct bootp rbootp;
84 	} rbuf;
85 
86 #ifdef BOOTP_DEBUG
87  	if (debug)
88 		printf("bootp: socket=%d\n", sock);
89 #endif
90 	if (!bot)
91 		bot = getsecs();
92 
93 	if (!(d = socktodesc(sock))) {
94 		printf("bootp: bad socket. %d\n", sock);
95 		return;
96 	}
97 #ifdef BOOTP_DEBUG
98  	if (debug)
99 		printf("bootp: d=%x\n", (u_int)d);
100 #endif
101 
102 	bp = &wbuf.wbootp;
103 	bzero(bp, sizeof(*bp));
104 
105 	bp->bp_op = BOOTREQUEST;
106 	bp->bp_htype = 1;		/* 10Mb Ethernet (48 bits) */
107 	bp->bp_hlen = 6;
108 	bp->bp_xid = htonl(d->xid);
109 	MACPY(d->myea, bp->bp_chaddr);
110 	bzero(bp->bp_file, sizeof(bp->bp_file));
111 	bcopy(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048));
112 
113 	d->myip = myip;
114 	d->myport = htons(IPPORT_BOOTPC);
115 	d->destip.s_addr = INADDR_BROADCAST;
116 	d->destport = htons(IPPORT_BOOTPS);
117 
118 	(void)sendrecv(d,
119 	    bootpsend, bp, sizeof(*bp),
120 	    bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp));
121 
122 	/* Bump xid so next request will be unique. */
123 	++d->xid;
124 }
125 
126 /* Transmit a bootp request */
127 static ssize_t
128 bootpsend(d, pkt, len)
129 	register struct iodesc *d;
130 	register void *pkt;
131 	register size_t len;
132 {
133 	register struct bootp *bp;
134 
135 #ifdef BOOTP_DEBUG
136 	if (debug)
137 		printf("bootpsend: d=%x called.\n", (u_int)d);
138 #endif
139 
140 	bp = pkt;
141 	bp->bp_secs = htons((u_short)(getsecs() - bot));
142 
143 #ifdef BOOTP_DEBUG
144 	if (debug)
145 		printf("bootpsend: calling sendudp\n");
146 #endif
147 
148 	return (sendudp(d, pkt, len));
149 }
150 
151 /* Returns 0 if this is the packet we're waiting for else -1 (and errno == 0) */
152 static ssize_t
153 bootprecv(d, pkt, len, tleft)
154 	register struct iodesc *d;
155 	register void *pkt;
156 	register size_t len;
157 	time_t tleft;
158 {
159 	register ssize_t n;
160 	register struct bootp *bp;
161 
162 #ifdef BOOTP_DEBUG
163 	if (debug)
164 		printf("bootprecv: called\n");
165 #endif
166 
167 	n = readudp(d, pkt, len, tleft);
168 	if (n == -1 || n < sizeof(struct bootp))
169 		goto bad;
170 
171 	bp = (struct bootp *)pkt;
172 
173 #ifdef BOOTP_DEBUG
174 	if (debug)
175 		printf("bootprecv: checked.  bp = 0x%x, n = %d\n",
176 		    (unsigned)bp, n);
177 #endif
178 	if (bp->bp_xid != htonl(d->xid)) {
179 #ifdef BOOTP_DEBUG
180 		if (debug) {
181 			printf("bootprecv: expected xid 0x%x, got 0x%x\n",
182 			    d->xid, ntohl(bp->bp_xid));
183 		}
184 #endif
185 		goto bad;
186 	}
187 
188 #ifdef BOOTP_DEBUG
189 	if (debug)
190 		printf("bootprecv: got one!\n");
191 #endif
192 
193 	/* Pick up our ip address (and natural netmask) */
194 	myip = d->myip = bp->bp_yiaddr;
195 #ifdef BOOTP_DEBUG
196 	if (debug)
197 		printf("our ip address is %s\n", inet_ntoa(d->myip));
198 #endif
199 	if (IN_CLASSA(d->myip.s_addr))
200 		nmask = IN_CLASSA_NET;
201 	else if (IN_CLASSB(d->myip.s_addr))
202 		nmask = IN_CLASSB_NET;
203 	else
204 		nmask = IN_CLASSC_NET;
205 #ifdef BOOTP_DEBUG
206 	if (debug)
207 		printf("'native netmask' is %s\n", intoa(nmask));
208 #endif
209 
210 	/* Pick up root or swap server address and file spec. */
211 	if (bp->bp_siaddr.s_addr != 0)
212 		rootip = bp->bp_siaddr;
213 	if (bp->bp_file[0] != '\0') {
214 		strncpy(bootfile, (char *)bp->bp_file, sizeof(bootfile));
215 		bootfile[sizeof(bootfile) - 1] = '\0';
216 	}
217 
218 	/* Suck out vendor info */
219 	if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0)
220 		vend_cmu(bp->bp_vend);
221 	else if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0)
222 		vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend));
223 	else
224 		printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend);
225 
226 	/* Check subnet mask against net mask; toss if bogus */
227 	if ((nmask & smask) != nmask) {
228 #ifdef BOOTP_DEBUG
229 		if (debug)
230 			printf("subnet mask (%s) bad\n", intoa(smask));
231 #endif
232 		smask = 0;
233 	}
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 or swap is on a different net */
245 	if (!SAMENET(d->myip, rootip, netmask)) {
246 #ifdef BOOTP_DEBUG
247 		if (debug)
248 			printf("need gateway for root ip\n");
249 #endif
250 	}
251 
252 	if (!SAMENET(d->myip, swapip, netmask)) {
253 #ifdef BOOTP_DEBUG
254 		if (debug)
255 			printf("need gateway for swap ip\n");
256 #endif
257 	}
258 
259 	/* Toss gateway if on a different net */
260 	if (!SAMENET(d->myip, gateip, netmask)) {
261 #ifdef BOOTP_DEBUG
262 		if (debug)
263 			printf("gateway ip (%s) bad\n", inet_ntoa(gateip));
264 #endif
265 		gateip.s_addr = 0;
266 	}
267 
268 	return (n);
269 
270 bad:
271 	errno = 0;
272 	return (-1);
273 }
274 
275 static void
276 vend_cmu(cp)
277 	u_char *cp;
278 {
279 	register struct cmu_vend *vp;
280 
281 #ifdef BOOTP_DEBUG
282 	if (debug)
283 		printf("vend_cmu bootp info.\n");
284 #endif
285 	vp = (struct cmu_vend *)cp;
286 
287 	if (vp->v_smask.s_addr != 0) {
288 		smask = vp->v_smask.s_addr;
289 	}
290 	if (vp->v_dgate.s_addr != 0) {
291 		gateip = vp->v_dgate;
292 	}
293 }
294 
295 static void
296 vend_rfc1048(cp, len)
297 	register u_char *cp;
298 	u_int len;
299 {
300 	register u_char *ep;
301 	register int size;
302 	register u_char tag;
303 
304 #ifdef BOOTP_DEBUG
305 	if (debug)
306 		printf("vend_rfc1048 bootp info. len=%d\n", len);
307 #endif
308 	ep = cp + len;
309 
310 	/* Step over magic cookie */
311 	cp += sizeof(int);
312 
313 	while (cp < ep) {
314 		tag = *cp++;
315 		size = *cp++;
316 		if (tag == TAG_END)
317 			break;
318 
319 		if (tag == TAG_SUBNET_MASK) {
320 			bcopy(cp, &smask, sizeof(smask));
321 		}
322 		if (tag == TAG_GATEWAY) {
323 			bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr));
324 		}
325 		if (tag == TAG_SWAPSERVER) {
326 			bcopy(cp, &swapip.s_addr, sizeof(swapip.s_addr));
327 		}
328 		if (tag == TAG_DOMAIN_SERVER) {
329 			bcopy(cp, &nameip.s_addr, sizeof(nameip.s_addr));
330 		}
331 		if (tag == TAG_ROOTPATH) {
332 			strncpy(rootpath, (char *)cp, sizeof(rootpath));
333 			rootpath[size] = '\0';
334 		}
335 		if (tag == TAG_HOSTNAME) {
336 			strncpy(hostname, (char *)cp, sizeof(hostname));
337 			hostname[size] = '\0';
338 		}
339 		if (tag == TAG_DOMAINNAME) {
340 			strncpy(domainname, (char *)cp, sizeof(domainname));
341 			domainname[size] = '\0';
342 		}
343 		cp += size;
344 	}
345 }
346