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 #include <sys/types.h>
41 #include <stdio.h>
42 #include <arpa/nameser.h>
43
44 static int dn_find(u_char *exp_dn, u_char *msg, u_char **dnptrs,
45 u_char **lastdnptr);
46
47
48 /*
49 * Expand compressed domain name 'comp_dn' to full domain name.
50 * 'msg' is a pointer to the begining of the message,
51 * 'eomorig' points to the first location after the message,
52 * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
53 * Return size of compressed name or -1 if there was an error.
54 */
55 int
dn_expand(msg,eomorig,comp_dn,exp_dn,length)56 dn_expand(msg, eomorig, comp_dn, exp_dn, length)
57 u_char *msg, *eomorig, *comp_dn, *exp_dn;
58 int length;
59 {
60 register u_char *cp, *dn;
61 register int n, c;
62 u_char *eom;
63 int len = -1, checked = 0;
64
65 dn = exp_dn;
66 cp = comp_dn;
67 eom = exp_dn + length;
68 /*
69 * fetch next label in domain name
70 */
71 while (n = *cp++) {
72 /*
73 * Check for indirection
74 */
75 switch (n & INDIR_MASK) {
76 case 0:
77 if (dn != exp_dn) {
78 if (dn >= eom)
79 return (-1);
80 *dn++ = '.';
81 }
82 if (dn+n >= eom)
83 return (-1);
84 checked += n + 1;
85 while (--n >= 0) {
86 if ((c = *cp++) == '.') {
87 if (dn + n + 2 >= eom)
88 return (-1);
89 *dn++ = '\\';
90 }
91 *dn++ = c;
92 if (cp >= eomorig) /* out of range */
93 return (-1);
94 }
95 break;
96
97 case INDIR_MASK:
98 if (len < 0)
99 len = cp - comp_dn + 1;
100 cp = msg + (((n & 0x3f) << 8) | (*cp & 0xff));
101 if (cp < msg || cp >= eomorig) /* out of range */
102 return (-1);
103 checked += 2;
104 /*
105 * Check for loops in the compressed name;
106 * if we've looked at the whole message,
107 * there must be a loop.
108 */
109 if (checked >= eomorig - msg)
110 return (-1);
111 break;
112
113 default:
114 return (-1); /* flag error */
115 }
116 }
117 *dn = '\0';
118 if (len < 0)
119 len = cp - comp_dn;
120 return (len);
121 }
122
123 /*
124 * Compress domain name 'exp_dn' into 'comp_dn'.
125 * Return the size of the compressed name or -1.
126 * 'length' is the size of the array pointed to by 'comp_dn'.
127 * 'dnptrs' is a list of pointers to previous compressed names. dnptrs[0]
128 * is a pointer to the beginning of the message. The list ends with NULL.
129 * 'lastdnptr' is a pointer to the end of the arrary pointed to
130 * by 'dnptrs'. Side effect is to update the list of pointers for
131 * labels inserted into the message as we compress the name.
132 * If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr'
133 * is NULL, we don't update the list.
134 */
135 int
dn_comp(exp_dn,comp_dn,length,dnptrs,lastdnptr)136 dn_comp(exp_dn, comp_dn, length, dnptrs, lastdnptr)
137 u_char *exp_dn, *comp_dn;
138 int length;
139 u_char **dnptrs, **lastdnptr;
140 {
141 register u_char *cp, *dn;
142 register int c, l;
143 u_char **cpp, **lpp, *sp, *eob;
144 u_char *msg;
145
146 dn = exp_dn;
147 cp = comp_dn;
148 eob = cp + length;
149 if (dnptrs != NULL) {
150 if ((msg = *dnptrs++) != NULL) {
151 for (cpp = dnptrs; *cpp != NULL; cpp++)
152 ;
153 lpp = cpp; /* end of list to search */
154 }
155 } else
156 msg = NULL;
157 for (c = *dn++; c != '\0'; /*EMPTY*/) {
158 /* look to see if we can use pointers */
159 if (msg != NULL) {
160 if ((l = dn_find(dn-1, msg, dnptrs, lpp)) >= 0) {
161 if (cp+1 >= eob)
162 return (-1);
163 *cp++ = (l >> 8) | INDIR_MASK;
164 *cp++ = l % 256;
165 return (cp - comp_dn);
166 }
167 /* not found, save it */
168 if (lastdnptr != NULL && cpp < lastdnptr-1) {
169 *cpp++ = cp;
170 *cpp = NULL;
171 }
172 }
173 sp = cp++; /* save ptr to length byte */
174 do {
175 if (c == '.') {
176 c = *dn++;
177 break;
178 }
179 if (c == '\\') {
180 if ((c = *dn++) == '\0')
181 break;
182 }
183 if (cp >= eob) {
184 if (msg != NULL)
185 *lpp = NULL;
186 return (-1);
187 }
188 *cp++ = c;
189 } while ((c = *dn++) != '\0');
190 /* catch trailing '.'s but not '..' */
191 if ((l = cp - sp - 1) == 0 && c == '\0') {
192 cp--;
193 break;
194 }
195 if (l <= 0 || l > MAXLABEL) {
196 if (msg != NULL)
197 *lpp = NULL;
198 return (-1);
199 }
200 *sp = l;
201 }
202 if (cp >= eob) {
203 if (msg != NULL)
204 *lpp = NULL;
205 return (-1);
206 }
207 *cp++ = '\0';
208 return (cp - comp_dn);
209 }
210
211 /*
212 * Skip over a compressed domain name. Return the size or -1.
213 */
214 int
dn_skipname(comp_dn,eom)215 dn_skipname(comp_dn, eom)
216 u_char *comp_dn, *eom;
217 {
218 register u_char *cp;
219 register int n;
220
221 cp = comp_dn;
222 while (cp < eom && (n = *cp++)) {
223 /*
224 * check for indirection
225 */
226 switch (n & INDIR_MASK) {
227 case 0: /* normal case, n == len */
228 cp += n;
229 continue;
230 default: /* illegal type */
231 return (-1);
232 case INDIR_MASK: /* indirection */
233 cp++;
234 }
235 break;
236 }
237 return (cp - comp_dn);
238 }
239
240 /*
241 * Search for expanded name from a list of previously compressed names.
242 * Return the offset from msg if found or -1.
243 * dnptrs is the pointer to the first name on the list,
244 * not the pointer to the start of the message.
245 */
246 static int
dn_find(u_char * exp_dn,u_char * msg,u_char ** dnptrs,u_char ** lastdnptr)247 dn_find(u_char *exp_dn, u_char *msg, u_char **dnptrs, u_char **lastdnptr)
248 {
249 register u_char *dn, *cp, **cpp;
250 register int n;
251 u_char *sp;
252
253 for (cpp = dnptrs; cpp < lastdnptr; cpp++) {
254 dn = exp_dn;
255 sp = cp = *cpp;
256 while (n = *cp++) {
257 /*
258 * check for indirection
259 */
260 switch (n & INDIR_MASK) {
261 case 0: /* normal case, n == len */
262 while (--n >= 0) {
263 if (*dn == '.')
264 goto next;
265 if (*dn == '\\')
266 dn++;
267 if (*dn++ != *cp++)
268 goto next;
269 }
270 if ((n = *dn++) == '\0' && *cp == '\0')
271 return (sp - msg);
272 if (n == '.')
273 continue;
274 goto next;
275
276 default: /* illegal type */
277 return (-1);
278
279 case INDIR_MASK: /* indirection */
280 cp = msg + (((n & 0x3f) << 8) | *cp);
281 }
282 }
283 if (*dn == '\0')
284 return (sp - msg);
285 next: /*EMPTY*/;
286 }
287 return (-1);
288 }
289
290 /*
291 * Routines to insert/extract short/long's. Must account for byte
292 * order and non-alignment problems. This code at least has the
293 * advantage of being portable.
294 *
295 * used by sendmail.
296 */
297
298 u_short
_getshort(msgp)299 _getshort(msgp)
300 u_char *msgp;
301 {
302 register u_char *p = (u_char *) msgp;
303 #ifdef vax
304 /*
305 * vax compiler doesn't put shorts in registers
306 */
307 register u_long u;
308 #else
309 register u_short u;
310 #endif
311
312 u = *p++ << 8;
313 return ((u_short)(u | *p));
314 }
315
316 u_long
_getlong(msgp)317 _getlong(msgp)
318 u_char *msgp;
319 {
320 register u_char *p = (u_char *) msgp;
321 register u_long u;
322
323 u = *p++; u <<= 8;
324 u |= *p++; u <<= 8;
325 u |= *p++; u <<= 8;
326 return (u | *p);
327 }
328
329 void
putshort(s,msgp)330 putshort(s, msgp)
331 register u_short s;
332 register u_char *msgp;
333 {
334
335 msgp[1] = s;
336 msgp[0] = s >> 8;
337 }
338
339 void
putlong(l,msgp)340 putlong(l, msgp)
341 register u_long l;
342 register u_char *msgp;
343 {
344
345 msgp[3] = l;
346 msgp[2] = (l >>= 8);
347 msgp[1] = (l >>= 8);
348 msgp[0] = l >> 8;
349 }
350