1 /* $NetBSD: defined.c,v 1.2 2019/11/16 12:26:54 tkusumi Exp $ */
2
3 /*-
4 * Copyright (c) 2017 The NetBSD Foundation, Inc.
5 * Copyright (c) 2016 The DragonFly Project
6 * Copyright (c) 2014 The FreeBSD Foundation
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to The NetBSD Foundation
10 * by Tomohiro Kusumi <kusumi.tomohiro@gmail.com>.
11 *
12 * This software was developed by Edward Tomasz Napierala under sponsorship
13 * from the FreeBSD Foundation.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 */
37 #include <sys/cdefs.h>
38 __RCSID("$NetBSD: defined.c,v 1.2 2019/11/16 12:26:54 tkusumi Exp $");
39
40 /*
41 * All the "defined" stuff is for handling variables,
42 * such as ${OSNAME}, in maps.
43 */
44
45 #include <sys/types.h>
46 #include <sys/utsname.h>
47 #include <assert.h>
48 #include <ctype.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.h>
52 #include <unistd.h>
53
54 #include "common.h"
55
56 static TAILQ_HEAD(, defined_value) defined_values;
57
58 static const char *
defined_find(const char * name)59 defined_find(const char *name)
60 {
61 struct defined_value *d;
62
63 TAILQ_FOREACH(d, &defined_values, d_next) {
64 if (strcmp(d->d_name, name) == 0)
65 return d->d_value;
66 }
67
68 return NULL;
69 }
70
71 char *
defined_expand(const char * string)72 defined_expand(const char *string)
73 {
74 const char *value;
75 char c, *expanded, *name;
76 int ret;
77 size_t i, before_len = 0, name_off = 0, name_len = 0, after_off = 0;
78 bool backslashed = false, bracketed = false;
79
80 expanded = checked_strdup(string);
81
82 for (i = 0; string[i] != '\0'; i++) {
83 c = string[i];
84 if (c == '\\' && backslashed == false) {
85 backslashed = true;
86 continue;
87 }
88 if (backslashed) {
89 backslashed = false;
90 continue;
91 }
92 backslashed = false;
93 if (c != '$')
94 continue;
95
96 /*
97 * The 'before_len' variable contains the number
98 * of characters before the '$'.
99 */
100 before_len = i;
101 assert(i + 1 < strlen(string));
102 if (string[i + 1] == '{')
103 bracketed = true;
104
105 if (string[i + 1] == '\0') {
106 log_warnx("truncated variable");
107 return NULL;
108 }
109
110 /*
111 * Skip '$'.
112 */
113 i++;
114
115 if (bracketed) {
116 if (string[i + 1] == '\0') {
117 log_warnx("truncated variable");
118 return NULL;
119 }
120
121 /*
122 * Skip '{'.
123 */
124 i++;
125 }
126
127 /*
128 * The 'name_off' variable contains the number
129 * of characters before the variable name,
130 * including the "$" or "${".
131 */
132 name_off = i;
133
134 for (; string[i] != '\0'; i++) {
135 c = string[i];
136 /*
137 * XXX: Decide on the set of characters that can be
138 * used in a variable name.
139 */
140 if (isalnum((unsigned char)c) || c == '_')
141 continue;
142
143 /*
144 * End of variable name.
145 */
146 if (bracketed) {
147 if (c != '}')
148 continue;
149
150 /*
151 * The 'after_off' variable contains the number
152 * of characters before the rest of the string,
153 * i.e. after the variable name.
154 */
155 after_off = i + 1;
156 assert(i > 1);
157 assert(i - 1 > name_off);
158 name_len = i - name_off;
159 break;
160 }
161
162 after_off = i;
163 assert(i > 1);
164 assert(i > name_off);
165 name_len = i - name_off;
166 break;
167 }
168
169 name = strndup(string + name_off, name_len);
170 if (name == NULL)
171 log_err(1, "strndup");
172 value = defined_find(name);
173 if (value == NULL) {
174 log_warnx("undefined variable ${%s}", name);
175 return NULL;
176 }
177
178 /*
179 * Concatenate it back.
180 */
181 ret = asprintf(&expanded, "%.*s%s%s",
182 (int)before_len, string, value, string + after_off);
183 if (ret < 0)
184 log_err(1, "asprintf");
185
186 //log_debugx("\"%s\" expanded to \"%s\"", string, expanded);
187 free(name);
188
189 /*
190 * Figure out where to start searching for next variable.
191 */
192 string = expanded;
193 i = before_len + strlen(value);
194 backslashed = bracketed = false;
195 before_len = name_off = name_len = after_off = 0;
196 assert(i <= strlen(string));
197 }
198
199 if (before_len != 0 || name_off != 0 || name_len != 0
200 || after_off != 0) {
201 log_warnx("truncated variable");
202 return NULL;
203 }
204
205 return expanded;
206 }
207
208 static void
defined_add(const char * name,const char * value)209 defined_add(const char *name, const char *value)
210 {
211 struct defined_value *d;
212 const char *found;
213
214 found = defined_find(name);
215 if (found != NULL)
216 log_errx(1, "variable %s already defined", name);
217
218 log_debugx("defining variable %s=%s", name, value);
219
220 d = calloc(1, sizeof(*d));
221 if (d == NULL)
222 log_err(1, "calloc");
223 d->d_name = checked_strdup(name);
224 d->d_value = checked_strdup(value);
225
226 TAILQ_INSERT_TAIL(&defined_values, d, d_next);
227 }
228
229 void
defined_parse_and_add(char * def)230 defined_parse_and_add(char *def)
231 {
232 char *name, *value;
233
234 value = def;
235 name = strsep(&value, "=");
236
237 if (value == NULL || value[0] == '\0')
238 log_errx(1, "missing variable value");
239 if (name == NULL || name[0] == '\0')
240 log_errx(1, "missing variable name");
241
242 defined_add(name, value);
243 }
244
245 void
defined_init(void)246 defined_init(void)
247 {
248 struct utsname name;
249 int error;
250
251 TAILQ_INIT(&defined_values);
252
253 error = uname(&name);
254 if (error != 0)
255 log_err(1, "uname");
256
257 defined_add("ARCH", name.machine);
258 defined_add("CPU", name.machine);
259 defined_add("DOLLAR", "$");
260 defined_add("HOST", name.nodename);
261 defined_add("OSNAME", name.sysname);
262 defined_add("OSREL", name.release);
263 defined_add("OSVERS", name.version);
264 }
265