1 /* $NetBSD: ttl.c,v 1.9 2022/09/23 12:15:30 christos Exp $ */
2
3 /*
4 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
5 *
6 * SPDX-License-Identifier: MPL-2.0
7 *
8 * This Source Code Form is subject to the terms of the Mozilla Public
9 * License, v. 2.0. If a copy of the MPL was not distributed with this
10 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
11 *
12 * See the COPYRIGHT file distributed with this work for additional
13 * information regarding copyright ownership.
14 */
15
16 /*! \file */
17
18 #include <ctype.h>
19 #include <errno.h>
20 #include <inttypes.h>
21 #include <stdbool.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24
25 #include <isc/buffer.h>
26 #include <isc/parseint.h>
27 #include <isc/print.h>
28 #include <isc/region.h>
29 #include <isc/string.h>
30 #include <isc/util.h>
31
32 #include <dns/result.h>
33 #include <dns/ttl.h>
34
35 #define RETERR(x) \
36 do { \
37 isc_result_t _r = (x); \
38 if (_r != ISC_R_SUCCESS) \
39 return ((_r)); \
40 } while (0)
41
42 static isc_result_t
43 bind_ttl(isc_textregion_t *source, uint32_t *ttl);
44
45 /*
46 * Helper for dns_ttl_totext().
47 */
48 static isc_result_t
ttlfmt(unsigned int t,const char * s,bool verbose,bool space,isc_buffer_t * target)49 ttlfmt(unsigned int t, const char *s, bool verbose, bool space,
50 isc_buffer_t *target) {
51 char tmp[60];
52 unsigned int len;
53 isc_region_t region;
54
55 if (verbose) {
56 len = snprintf(tmp, sizeof(tmp), "%s%u %s%s", space ? " " : "",
57 t, s, t == 1 ? "" : "s");
58 } else {
59 len = snprintf(tmp, sizeof(tmp), "%u%c", t, s[0]);
60 }
61
62 INSIST(len + 1 <= sizeof(tmp));
63 isc_buffer_availableregion(target, ®ion);
64 if (len > region.length) {
65 return (ISC_R_NOSPACE);
66 }
67 memmove(region.base, tmp, len);
68 isc_buffer_add(target, len);
69
70 return (ISC_R_SUCCESS);
71 }
72
73 /*
74 * Derived from bind8 ns_format_ttl().
75 */
76 isc_result_t
dns_ttl_totext(uint32_t src,bool verbose,bool upcase,isc_buffer_t * target)77 dns_ttl_totext(uint32_t src, bool verbose, bool upcase, isc_buffer_t *target) {
78 unsigned secs, mins, hours, days, weeks, x;
79
80 secs = src % 60;
81 src /= 60;
82 mins = src % 60;
83 src /= 60;
84 hours = src % 24;
85 src /= 24;
86 days = src % 7;
87 src /= 7;
88 weeks = src;
89 src = 0;
90 POST(src);
91
92 x = 0;
93 if (weeks != 0) {
94 RETERR(ttlfmt(weeks, "week", verbose, (x > 0), target));
95 x++;
96 }
97 if (days != 0) {
98 RETERR(ttlfmt(days, "day", verbose, (x > 0), target));
99 x++;
100 }
101 if (hours != 0) {
102 RETERR(ttlfmt(hours, "hour", verbose, (x > 0), target));
103 x++;
104 }
105 if (mins != 0) {
106 RETERR(ttlfmt(mins, "minute", verbose, (x > 0), target));
107 x++;
108 }
109 if (secs != 0 || (weeks == 0 && days == 0 && hours == 0 && mins == 0)) {
110 RETERR(ttlfmt(secs, "second", verbose, (x > 0), target));
111 x++;
112 }
113 INSIST(x > 0);
114 /*
115 * If only a single unit letter is printed, print it
116 * in upper case. (Why? Because BIND 8 does that.
117 * Presumably it has a reason.)
118 */
119 if (x == 1 && upcase && !verbose) {
120 isc_region_t region;
121 /*
122 * The unit letter is the last character in the
123 * used region of the buffer.
124 *
125 * toupper() does not need its argument to be masked of cast
126 * here because region.base is type unsigned char *.
127 */
128 isc_buffer_usedregion(target, ®ion);
129 region.base[region.length - 1] =
130 toupper(region.base[region.length - 1]);
131 }
132 return (ISC_R_SUCCESS);
133 }
134
135 isc_result_t
dns_counter_fromtext(isc_textregion_t * source,uint32_t * ttl)136 dns_counter_fromtext(isc_textregion_t *source, uint32_t *ttl) {
137 return (bind_ttl(source, ttl));
138 }
139
140 isc_result_t
dns_ttl_fromtext(isc_textregion_t * source,uint32_t * ttl)141 dns_ttl_fromtext(isc_textregion_t *source, uint32_t *ttl) {
142 isc_result_t result;
143
144 result = bind_ttl(source, ttl);
145 if (result != ISC_R_SUCCESS && result != ISC_R_RANGE) {
146 result = DNS_R_BADTTL;
147 }
148 return (result);
149 }
150
151 static isc_result_t
bind_ttl(isc_textregion_t * source,uint32_t * ttl)152 bind_ttl(isc_textregion_t *source, uint32_t *ttl) {
153 uint64_t tmp = 0ULL;
154 uint32_t n;
155 char *s;
156 char buf[64];
157 char nbuf[64]; /* Number buffer */
158
159 /*
160 * Copy the buffer as it may not be NULL terminated.
161 * No legal counter / ttl is longer that 63 characters.
162 */
163 if (source->length > sizeof(buf) - 1) {
164 return (DNS_R_SYNTAX);
165 }
166 /* Copy source->length bytes and NUL terminate. */
167 snprintf(buf, sizeof(buf), "%.*s", (int)source->length, source->base);
168 s = buf;
169
170 do {
171 isc_result_t result;
172
173 char *np = nbuf;
174 while (*s != '\0' && isdigit((unsigned char)*s)) {
175 *np++ = *s++;
176 }
177 *np++ = '\0';
178 INSIST(np - nbuf <= (int)sizeof(nbuf));
179 result = isc_parse_uint32(&n, nbuf, 10);
180 if (result != ISC_R_SUCCESS) {
181 return (DNS_R_SYNTAX);
182 }
183 switch (*s) {
184 case 'w':
185 case 'W':
186 tmp += (uint64_t)n * 7 * 24 * 3600;
187 s++;
188 break;
189 case 'd':
190 case 'D':
191 tmp += (uint64_t)n * 24 * 3600;
192 s++;
193 break;
194 case 'h':
195 case 'H':
196 tmp += (uint64_t)n * 3600;
197 s++;
198 break;
199 case 'm':
200 case 'M':
201 tmp += (uint64_t)n * 60;
202 s++;
203 break;
204 case 's':
205 case 'S':
206 tmp += (uint64_t)n;
207 s++;
208 break;
209 case '\0':
210 /* Plain number? */
211 if (tmp != 0ULL) {
212 return (DNS_R_SYNTAX);
213 }
214 tmp = n;
215 break;
216 default:
217 return (DNS_R_SYNTAX);
218 }
219 } while (*s != '\0');
220
221 if (tmp > 0xffffffffULL) {
222 return (ISC_R_RANGE);
223 }
224
225 *ttl = (uint32_t)(tmp & 0xffffffffUL);
226 return (ISC_R_SUCCESS);
227 }
228