1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
28 /* All Rights Reserved */
29
30 /*
31 * University Copyright- Copyright (c) 1982, 1986, 1988
32 * The Regents of the University of California
33 * All Rights Reserved
34 *
35 * University Acknowledgment- Portions of this document are derived from
36 * software developed by the University of California, Berkeley, and its
37 * contributors.
38 */
39
40 #pragma ident "%Z%%M% %I% %E% SMI"
41
42 #include <sys/types.h>
43 #include <stdio.h>
44 #include <arpa/nameser.h>
45
46 static int dn_find(u_char *exp_dn, u_char *msg, u_char **dnptrs,
47 u_char **lastdnptr);
48
49
50 /*
51 * Expand compressed domain name 'comp_dn' to full domain name.
52 * 'msg' is a pointer to the begining of the message,
53 * 'eomorig' points to the first location after the message,
54 * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
55 * Return size of compressed name or -1 if there was an error.
56 */
57 int
dn_expand(msg,eomorig,comp_dn,exp_dn,length)58 dn_expand(msg, eomorig, comp_dn, exp_dn, length)
59 u_char *msg, *eomorig, *comp_dn, *exp_dn;
60 int length;
61 {
62 register u_char *cp, *dn;
63 register int n, c;
64 u_char *eom;
65 int len = -1, checked = 0;
66
67 dn = exp_dn;
68 cp = comp_dn;
69 eom = exp_dn + length;
70 /*
71 * fetch next label in domain name
72 */
73 while (n = *cp++) {
74 /*
75 * Check for indirection
76 */
77 switch (n & INDIR_MASK) {
78 case 0:
79 if (dn != exp_dn) {
80 if (dn >= eom)
81 return (-1);
82 *dn++ = '.';
83 }
84 if (dn+n >= eom)
85 return (-1);
86 checked += n + 1;
87 while (--n >= 0) {
88 if ((c = *cp++) == '.') {
89 if (dn + n + 2 >= eom)
90 return (-1);
91 *dn++ = '\\';
92 }
93 *dn++ = c;
94 if (cp >= eomorig) /* out of range */
95 return (-1);
96 }
97 break;
98
99 case INDIR_MASK:
100 if (len < 0)
101 len = cp - comp_dn + 1;
102 cp = msg + (((n & 0x3f) << 8) | (*cp & 0xff));
103 if (cp < msg || cp >= eomorig) /* out of range */
104 return (-1);
105 checked += 2;
106 /*
107 * Check for loops in the compressed name;
108 * if we've looked at the whole message,
109 * there must be a loop.
110 */
111 if (checked >= eomorig - msg)
112 return (-1);
113 break;
114
115 default:
116 return (-1); /* flag error */
117 }
118 }
119 *dn = '\0';
120 if (len < 0)
121 len = cp - comp_dn;
122 return (len);
123 }
124
125 /*
126 * Compress domain name 'exp_dn' into 'comp_dn'.
127 * Return the size of the compressed name or -1.
128 * 'length' is the size of the array pointed to by 'comp_dn'.
129 * 'dnptrs' is a list of pointers to previous compressed names. dnptrs[0]
130 * is a pointer to the beginning of the message. The list ends with NULL.
131 * 'lastdnptr' is a pointer to the end of the arrary pointed to
132 * by 'dnptrs'. Side effect is to update the list of pointers for
133 * labels inserted into the message as we compress the name.
134 * If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr'
135 * is NULL, we don't update the list.
136 */
137 int
dn_comp(exp_dn,comp_dn,length,dnptrs,lastdnptr)138 dn_comp(exp_dn, comp_dn, length, dnptrs, lastdnptr)
139 u_char *exp_dn, *comp_dn;
140 int length;
141 u_char **dnptrs, **lastdnptr;
142 {
143 register u_char *cp, *dn;
144 register int c, l;
145 u_char **cpp, **lpp, *sp, *eob;
146 u_char *msg;
147
148 dn = exp_dn;
149 cp = comp_dn;
150 eob = cp + length;
151 if (dnptrs != NULL) {
152 if ((msg = *dnptrs++) != NULL) {
153 for (cpp = dnptrs; *cpp != NULL; cpp++)
154 ;
155 lpp = cpp; /* end of list to search */
156 }
157 } else
158 msg = NULL;
159 for (c = *dn++; c != '\0'; /*EMPTY*/) {
160 /* look to see if we can use pointers */
161 if (msg != NULL) {
162 if ((l = dn_find(dn-1, msg, dnptrs, lpp)) >= 0) {
163 if (cp+1 >= eob)
164 return (-1);
165 *cp++ = (l >> 8) | INDIR_MASK;
166 *cp++ = l % 256;
167 return (cp - comp_dn);
168 }
169 /* not found, save it */
170 if (lastdnptr != NULL && cpp < lastdnptr-1) {
171 *cpp++ = cp;
172 *cpp = NULL;
173 }
174 }
175 sp = cp++; /* save ptr to length byte */
176 do {
177 if (c == '.') {
178 c = *dn++;
179 break;
180 }
181 if (c == '\\') {
182 if ((c = *dn++) == '\0')
183 break;
184 }
185 if (cp >= eob) {
186 if (msg != NULL)
187 *lpp = NULL;
188 return (-1);
189 }
190 *cp++ = c;
191 } while ((c = *dn++) != '\0');
192 /* catch trailing '.'s but not '..' */
193 if ((l = cp - sp - 1) == 0 && c == '\0') {
194 cp--;
195 break;
196 }
197 if (l <= 0 || l > MAXLABEL) {
198 if (msg != NULL)
199 *lpp = NULL;
200 return (-1);
201 }
202 *sp = l;
203 }
204 if (cp >= eob) {
205 if (msg != NULL)
206 *lpp = NULL;
207 return (-1);
208 }
209 *cp++ = '\0';
210 return (cp - comp_dn);
211 }
212
213 /*
214 * Skip over a compressed domain name. Return the size or -1.
215 */
216 int
dn_skipname(comp_dn,eom)217 dn_skipname(comp_dn, eom)
218 u_char *comp_dn, *eom;
219 {
220 register u_char *cp;
221 register int n;
222
223 cp = comp_dn;
224 while (cp < eom && (n = *cp++)) {
225 /*
226 * check for indirection
227 */
228 switch (n & INDIR_MASK) {
229 case 0: /* normal case, n == len */
230 cp += n;
231 continue;
232 default: /* illegal type */
233 return (-1);
234 case INDIR_MASK: /* indirection */
235 cp++;
236 }
237 break;
238 }
239 return (cp - comp_dn);
240 }
241
242 /*
243 * Search for expanded name from a list of previously compressed names.
244 * Return the offset from msg if found or -1.
245 * dnptrs is the pointer to the first name on the list,
246 * not the pointer to the start of the message.
247 */
248 static int
dn_find(u_char * exp_dn,u_char * msg,u_char ** dnptrs,u_char ** lastdnptr)249 dn_find(u_char *exp_dn, u_char *msg, u_char **dnptrs, u_char **lastdnptr)
250 {
251 register u_char *dn, *cp, **cpp;
252 register int n;
253 u_char *sp;
254
255 for (cpp = dnptrs; cpp < lastdnptr; cpp++) {
256 dn = exp_dn;
257 sp = cp = *cpp;
258 while (n = *cp++) {
259 /*
260 * check for indirection
261 */
262 switch (n & INDIR_MASK) {
263 case 0: /* normal case, n == len */
264 while (--n >= 0) {
265 if (*dn == '.')
266 goto next;
267 if (*dn == '\\')
268 dn++;
269 if (*dn++ != *cp++)
270 goto next;
271 }
272 if ((n = *dn++) == '\0' && *cp == '\0')
273 return (sp - msg);
274 if (n == '.')
275 continue;
276 goto next;
277
278 default: /* illegal type */
279 return (-1);
280
281 case INDIR_MASK: /* indirection */
282 cp = msg + (((n & 0x3f) << 8) | *cp);
283 }
284 }
285 if (*dn == '\0')
286 return (sp - msg);
287 next: /*EMPTY*/;
288 }
289 return (-1);
290 }
291
292 /*
293 * Routines to insert/extract short/long's. Must account for byte
294 * order and non-alignment problems. This code at least has the
295 * advantage of being portable.
296 *
297 * used by sendmail.
298 */
299
300 u_short
_getshort(msgp)301 _getshort(msgp)
302 u_char *msgp;
303 {
304 register u_char *p = (u_char *) msgp;
305 #ifdef vax
306 /*
307 * vax compiler doesn't put shorts in registers
308 */
309 register u_long u;
310 #else
311 register u_short u;
312 #endif
313
314 u = *p++ << 8;
315 return ((u_short)(u | *p));
316 }
317
318 u_long
_getlong(msgp)319 _getlong(msgp)
320 u_char *msgp;
321 {
322 register u_char *p = (u_char *) msgp;
323 register u_long u;
324
325 u = *p++; u <<= 8;
326 u |= *p++; u <<= 8;
327 u |= *p++; u <<= 8;
328 return (u | *p);
329 }
330
331 void
putshort(s,msgp)332 putshort(s, msgp)
333 register u_short s;
334 register u_char *msgp;
335 {
336
337 msgp[1] = s;
338 msgp[0] = s >> 8;
339 }
340
341 void
putlong(l,msgp)342 putlong(l, msgp)
343 register u_long l;
344 register u_char *msgp;
345 {
346
347 msgp[3] = l;
348 msgp[2] = (l >>= 8);
349 msgp[1] = (l >>= 8);
350 msgp[0] = l >> 8;
351 }
352