xref: /freebsd/libexec/bootpd/dovend.c (revision 380a989b3223d455375b4fae70fd0b9bdd43bafb)
1 /*
2  * dovend.c : Inserts all but the first few vendor options.
3  *
4  *	$Id$
5  */
6 
7 #include <sys/types.h>
8 
9 #include <netinet/in.h>
10 #include <arpa/inet.h>			/* inet_ntoa */
11 
12 #include <stdlib.h>
13 #include <stdio.h>
14 #include <string.h>
15 #include <errno.h>
16 #include <syslog.h>
17 
18 #ifndef USE_BFUNCS
19 # include <memory.h>
20 /* Yes, memcpy is OK here (no overlapped copies). */
21 # define bcopy(a,b,c)    memcpy(b,a,c)
22 # define bzero(p,l)      memset(p,0,l)
23 # define bcmp(a,b,c)     memcmp(a,b,c)
24 # define index           strchr
25 #endif
26 
27 #include "bootp.h"
28 #include "bootpd.h"
29 #include "report.h"
30 #include "dovend.h"
31 
32 #ifdef	__STDC__
33 #define P(args) args
34 #else
35 #define P(args) ()
36 #endif
37 
38 PRIVATE int insert_generic P((struct shared_bindata *, byte **, int *));
39 
40 /*
41  * Insert the 2nd part of the options into an option buffer.
42  * Return amount of space used.
43  *
44  * This inserts everything EXCEPT:
45  *   magic cookie, subnet mask, gateway, bootsize, extension file
46  * Those are handled separately (in bootpd.c) to allow this function
47  * to be shared between bootpd and bootpef.
48  *
49  * When an "extension file" is in use, the options inserted by
50  * this function go into the exten_file, not the bootp response.
51  */
52 
53 int
54 dovend_rfc1497(hp, buf, len)
55 	struct host *hp;
56 	byte *buf;
57 	int len;
58 {
59 	int bytesleft = len;
60 	byte *vp = buf;
61 
62 	static char noroom[] = "%s: No room for \"%s\" option";
63 #define	NEED(LEN, MSG) do                       \
64 		if (bytesleft < (LEN)) {         	    \
65 			report(LOG_NOTICE, noroom,          \
66 				   hp->hostname->string, MSG);  \
67 			return (vp - buf);                  \
68 		} while (0)
69 
70 	/*
71 	 * Note that the following have already been inserted:
72 	 *   magic_cookie, subnet_mask, gateway, bootsize
73 	 *
74 	 * The remaining options are inserted in order of importance.
75 	 * (Of course the importance of each is a matter of opinion.)
76 	 * The option insertion order should probably be configurable.
77 	 *
78 	 * This is the order used in the NetBSD version.  Can anyone
79 	 * explain why the time_offset and swap_server are first?
80 	 * Also, why is the hostname so far down the list?  -gwr
81 	 */
82 
83 	if (hp->flags.time_offset) {
84 		NEED(6, "to");
85 		*vp++ = TAG_TIME_OFFSET;/* -1 byte  */
86 		*vp++ = 4;				/* -1 byte  */
87 		insert_u_long(htonl(hp->time_offset), &vp);	/* -4 bytes */
88 		bytesleft -= 6;
89 	}
90 	/*
91 	 * swap server, root path, dump path
92 	 */
93 	if (hp->flags.swap_server) {
94 		NEED(6, "sw");
95 		/* There is just one SWAP_SERVER, so it is not an iplist. */
96 		*vp++ = TAG_SWAP_SERVER;/* -1 byte  */
97 		*vp++ = 4;				/* -1 byte  */
98 		insert_u_long(hp->swap_server.s_addr, &vp);	/* -4 bytes */
99 		bytesleft -= 6;			/* Fix real count */
100 	}
101 	if (hp->flags.root_path) {
102 		/*
103 		 * Check for room for root_path.  Add 2 to account for
104 		 * TAG_ROOT_PATH and length.
105 		 */
106 		len = strlen(hp->root_path->string);
107 		NEED((len + 2), "rp");
108 		*vp++ = TAG_ROOT_PATH;
109 		*vp++ = (byte) (len & 0xFF);
110 		bcopy(hp->root_path->string, vp, len);
111 		vp += len;
112 		bytesleft -= len + 2;
113 	}
114 	if (hp->flags.dump_file) {
115 		/*
116 		 * Check for room for dump_file.  Add 2 to account for
117 		 * TAG_DUMP_FILE and length.
118 		 */
119 		len = strlen(hp->dump_file->string);
120 		NEED((len + 2), "df");
121 		*vp++ = TAG_DUMP_FILE;
122 		*vp++ = (byte) (len & 0xFF);
123 		bcopy(hp->dump_file->string, vp, len);
124 		vp += len;
125 		bytesleft -= len + 2;
126 	}
127 	/*
128 	 * DNS server and domain
129 	 */
130 	if (hp->flags.domain_server) {
131 		if (insert_ip(TAG_DOMAIN_SERVER,
132 					  hp->domain_server,
133 					  &vp, &bytesleft))
134 			NEED(8, "ds");
135 	}
136 	if (hp->flags.domain_name) {
137 		/*
138 		 * Check for room for domain_name.  Add 2 to account for
139 		 * TAG_DOMAIN_NAME and length.
140 		 */
141 		len = strlen(hp->domain_name->string);
142 		NEED((len + 2), "dn");
143 		*vp++ = TAG_DOMAIN_NAME;
144 		*vp++ = (byte) (len & 0xFF);
145 		bcopy(hp->domain_name->string, vp, len);
146 		vp += len;
147 		bytesleft -= len + 2;
148 	}
149 	/*
150 	 * NIS (YP) server and domain
151 	 */
152 	if (hp->flags.nis_server) {
153 		if (insert_ip(TAG_NIS_SERVER,
154 					  hp->nis_server,
155 					  &vp, &bytesleft))
156 			NEED(8, "ds");
157 	}
158 	if (hp->flags.nis_domain) {
159 		/*
160 		 * Check for room for nis_domain.  Add 2 to account for
161 		 * TAG_NIS_DOMAIN and length.
162 		 */
163 		len = strlen(hp->nis_domain->string);
164 		NEED((len + 2), "dn");
165 		*vp++ = TAG_NIS_DOMAIN;
166 		*vp++ = (byte) (len & 0xFF);
167 		bcopy(hp->nis_domain->string, vp, len);
168 		vp += len;
169 		bytesleft -= len + 2;
170 	}
171 	/* IEN 116 name server */
172 	if (hp->flags.name_server) {
173 		if (insert_ip(TAG_NAME_SERVER,
174 					  hp->name_server,
175 					  &vp, &bytesleft))
176 			NEED(8, "ns");
177 	}
178 	if (hp->flags.rlp_server) {
179 		if (insert_ip(TAG_RLP_SERVER,
180 					  hp->rlp_server,
181 					  &vp, &bytesleft))
182 			NEED(8, "rl");
183 	}
184 	/* Time server (RFC 868) */
185 	if (hp->flags.time_server) {
186 		if (insert_ip(TAG_TIME_SERVER,
187 					  hp->time_server,
188 					  &vp, &bytesleft))
189 			NEED(8, "ts");
190 	}
191 	/* NTP (time) Server (RFC 1129) */
192 	if (hp->flags.ntp_server) {
193 		if (insert_ip(TAG_NTP_SERVER,
194 					  hp->ntp_server,
195 					  &vp, &bytesleft))
196 			NEED(8, "ts");
197 	}
198 	/*
199 	 * I wonder:  If the hostname were "promoted" into the BOOTP
200 	 * response part, might these "extension" files possibly be
201 	 * shared between several clients?
202 	 *
203 	 * Also, why not just use longer BOOTP packets with all the
204 	 * additional length used as option data.  This bootpd version
205 	 * already supports that feature by replying with the same
206 	 * packet length as the client request packet. -gwr
207 	 */
208 	if (hp->flags.name_switch && hp->flags.send_name) {
209 		/*
210 		 * Check for room for hostname.  Add 2 to account for
211 		 * TAG_HOST_NAME and length.
212 		 */
213 		len = strlen(hp->hostname->string);
214 #if 0
215 		/*
216 		 * XXX - Too much magic.  The user can always set the hostname
217 		 * to the short version in the bootptab file. -gwr
218 		 */
219 		if ((len + 2) > bytesleft) {
220 			/*
221 			 * Not enough room for full (domain-qualified) hostname, try
222 			 * stripping it down to just the first field (host).
223 			 */
224 			char *tmpstr = hp->hostname->string;
225 			len = 0;
226 			while (*tmpstr && (*tmpstr != '.')) {
227 				tmpstr++;
228 				len++;
229 			}
230 		}
231 #endif
232 		NEED((len + 2), "hn");
233 		*vp++ = TAG_HOST_NAME;
234 		*vp++ = (byte) (len & 0xFF);
235 		bcopy(hp->hostname->string, vp, len);
236 		vp += len;
237 		bytesleft -= len + 2;
238 	}
239 	/*
240 	 * The rest of these are less important, so they go last.
241 	 */
242 	if (hp->flags.lpr_server) {
243 		if (insert_ip(TAG_LPR_SERVER,
244 					  hp->lpr_server,
245 					  &vp, &bytesleft))
246 			NEED(8, "lp");
247 	}
248 	if (hp->flags.cookie_server) {
249 		if (insert_ip(TAG_COOKIE_SERVER,
250 					  hp->cookie_server,
251 					  &vp, &bytesleft))
252 			NEED(8, "cs");
253 	}
254 	if (hp->flags.log_server) {
255 		if (insert_ip(TAG_LOG_SERVER,
256 					  hp->log_server,
257 					  &vp, &bytesleft))
258 			NEED(8, "lg");
259 	}
260 	/*
261 	 * XXX - Add new tags here (to insert options)
262 	 */
263 	if (hp->flags.generic) {
264 		if (insert_generic(hp->generic, &vp, &bytesleft))
265 			NEED(64, "(generic)");
266 	}
267 	/*
268 	 * The end marker is inserted by the caller.
269 	 */
270 	return (vp - buf);
271 #undef	NEED
272 }								/* dovend_rfc1497 */
273 
274 
275 
276 /*
277  * Insert a tag value, a length value, and a list of IP addresses into the
278  * memory buffer indirectly pointed to by "dest".  "tag" is the RFC1048 tag
279  * number to use, "iplist" is a pointer to a list of IP addresses
280  * (struct in_addr_list), and "bytesleft" points to an integer which
281  * indicates the size of the "dest" buffer.
282  *
283  * Return zero if everything fits.
284  *
285  * This is used to fill the vendor-specific area of a bootp packet in
286  * conformance to RFC1048.
287  */
288 
289 int
290 insert_ip(tag, iplist, dest, bytesleft)
291 	byte tag;
292 	struct in_addr_list *iplist;
293 	byte **dest;
294 	int *bytesleft;
295 {
296 	struct in_addr *addrptr;
297 	unsigned addrcount = 1;
298 	byte *d;
299 
300 	if (iplist == NULL)
301 		return (0);
302 
303 	if (*bytesleft >= 6) {
304 		d = *dest;				/* Save pointer for later */
305 		**dest = tag;
306 		(*dest) += 2;
307 		(*bytesleft) -= 2;		/* Account for tag and length */
308 		addrptr = iplist->addr;
309 		addrcount = iplist->addrcount;
310 		while ((*bytesleft >= 4) && (addrcount > 0)) {
311 			insert_u_long(addrptr->s_addr, dest);
312 			addrptr++;
313 			addrcount--;
314 			(*bytesleft) -= 4;	/* Four bytes per address */
315 		}
316 		d[1] = (byte) ((*dest - d - 2) & 0xFF);
317 	}
318 	return (addrcount);
319 }
320 
321 
322 
323 /*
324  * Insert generic data into a bootp packet.  The data is assumed to already
325  * be in RFC1048 format.  It is inserted using a first-fit algorithm which
326  * attempts to insert as many tags as possible.  Tags and data which are
327  * too large to fit are skipped; any remaining tags are tried until they
328  * have all been exhausted.
329  * Return zero if everything fits.
330  */
331 
332 static int
333 insert_generic(gendata, buff, bytesleft)
334 	struct shared_bindata *gendata;
335 	byte **buff;
336 	int *bytesleft;
337 {
338 	byte *srcptr;
339 	int length, numbytes;
340 	int skipped = 0;
341 
342 	if (gendata == NULL)
343 		return (0);
344 
345 	srcptr = gendata->data;
346 	length = gendata->length;
347 	while ((length > 0) && (*bytesleft > 0)) {
348 		switch (*srcptr) {
349 		case TAG_END:
350 			length = 0;			/* Force an exit on next iteration */
351 			break;
352 		case TAG_PAD:
353 			*(*buff)++ = *srcptr++;
354 			(*bytesleft)--;
355 			length--;
356 			break;
357 		default:
358 			numbytes = srcptr[1] + 2;
359 			if (*bytesleft < numbytes)
360 				skipped += numbytes;
361 			else {
362 				bcopy(srcptr, *buff, numbytes);
363 				(*buff) += numbytes;
364 				(*bytesleft) -= numbytes;
365 			}
366 			srcptr += numbytes;
367 			length -= numbytes;
368 			break;
369 		}
370 	} /* while */
371 	return (skipped);
372 }
373 
374 /*
375  * Insert the unsigned long "value" into memory starting at the byte
376  * pointed to by the byte pointer (*dest).  (*dest) is updated to
377  * point to the next available byte.
378  *
379  * Since it is desirable to internally store network addresses in network
380  * byte order (in struct in_addr's), this routine expects longs to be
381  * passed in network byte order.
382  *
383  * However, due to the nature of the main algorithm, the long must be in
384  * host byte order, thus necessitating the use of ntohl() first.
385  */
386 
387 void
388 insert_u_long(value, dest)
389 	u_int32 value;
390 	byte **dest;
391 {
392 	byte *temp;
393 	int n;
394 
395 	value = ntohl(value);		/* Must use host byte order here */
396 	temp = (*dest += 4);
397 	for (n = 4; n > 0; n--) {
398 		*--temp = (byte) (value & 0xFF);
399 		value >>= 8;
400 	}
401 	/* Final result is network byte order */
402 }
403 
404 /*
405  * Local Variables:
406  * tab-width: 4
407  * c-indent-level: 4
408  * c-argdecl-indent: 4
409  * c-continued-statement-offset: 4
410  * c-continued-brace-offset: -4
411  * c-label-offset: -4
412  * c-brace-offset: 0
413  * End:
414  */
415