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