1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2014 The FreeBSD Foundation
5 *
6 * This software was developed by Edward Tomasz Napierala under sponsorship
7 * from the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 */
31
32 /*
33 * All the "defined" stuff is for handling variables,
34 * such as ${OSNAME}, in maps.
35 */
36
37 #include <sys/types.h>
38 #include <sys/time.h>
39 #include <sys/ioctl.h>
40 #include <sys/param.h>
41 #include <sys/linker.h>
42 #include <sys/mount.h>
43 #include <sys/socket.h>
44 #include <sys/stat.h>
45 #include <sys/wait.h>
46 #include <sys/utsname.h>
47 #include <assert.h>
48 #include <ctype.h>
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <libgen.h>
52 #include <libutil.h>
53 #include <netdb.h>
54 #include <signal.h>
55 #include <stdbool.h>
56 #include <stdint.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61
62 #include "common.h"
63
64 static TAILQ_HEAD(, defined_value) defined_values;
65
66 static const char *
defined_find(const char * name)67 defined_find(const char *name)
68 {
69 struct defined_value *d;
70
71 TAILQ_FOREACH(d, &defined_values, d_next) {
72 if (strcmp(d->d_name, name) == 0)
73 return (d->d_value);
74 }
75
76 return (NULL);
77 }
78
79 char *
defined_expand(const char * string)80 defined_expand(const char *string)
81 {
82 const char *value;
83 char c, *expanded, *name;
84 int i, ret, before_len = 0, name_off = 0, name_len = 0, after_off = 0;
85 bool backslashed = false, bracketed = false;
86
87 expanded = checked_strdup(string);
88
89 for (i = 0; string[i] != '\0'; i++) {
90 c = string[i];
91 if (c == '\\' && backslashed == false) {
92 backslashed = true;
93 continue;
94 }
95 if (backslashed) {
96 backslashed = false;
97 continue;
98 }
99 backslashed = false;
100 if (c != '$')
101 continue;
102
103 /*
104 * The 'before_len' variable contains the number
105 * of characters before the '$'.
106 */
107 before_len = i;
108 assert(i + 1 < (int)strlen(string));
109 if (string[i + 1] == '{')
110 bracketed = true;
111
112 if (string[i + 1] == '\0') {
113 log_warnx("truncated variable");
114 return (NULL);
115 }
116
117 /*
118 * Skip '$'.
119 */
120 i++;
121
122 if (bracketed) {
123 if (string[i + 1] == '\0') {
124 log_warnx("truncated variable");
125 return (NULL);
126 }
127
128 /*
129 * Skip '{'.
130 */
131 i++;
132 }
133
134 /*
135 * The 'name_off' variable contains the number
136 * of characters before the variable name,
137 * including the "$" or "${".
138 */
139 name_off = i;
140
141 for (; string[i] != '\0'; i++) {
142 c = string[i];
143 /*
144 * XXX: Decide on the set of characters that can be
145 * used in a variable name.
146 */
147 if (isalnum(c) || c == '_')
148 continue;
149
150 /*
151 * End of variable name.
152 */
153 if (bracketed) {
154 if (c != '}')
155 continue;
156
157 /*
158 * The 'after_off' variable contains the number
159 * of characters before the rest of the string,
160 * i.e. after the variable name.
161 */
162 after_off = i + 1;
163 assert(i > 1);
164 assert(i - 1 > name_off);
165 name_len = i - name_off;
166 break;
167 }
168
169 after_off = i;
170 assert(i > 1);
171 assert(i > name_off);
172 name_len = i - name_off;
173 break;
174 }
175
176 name = strndup(string + name_off, name_len);
177 if (name == NULL)
178 log_err(1, "strndup");
179 value = defined_find(name);
180 if (value == NULL) {
181 log_warnx("undefined variable ${%s}", name);
182 return (NULL);
183 }
184
185 /*
186 * Concatenate it back.
187 */
188 ret = asprintf(&expanded, "%.*s%s%s",
189 before_len, string, value, string + after_off);
190 if (ret < 0)
191 log_err(1, "asprintf");
192
193 //log_debugx("\"%s\" expanded to \"%s\"", string, expanded);
194 free(name);
195
196 /*
197 * Figure out where to start searching for next variable.
198 */
199 string = expanded;
200 i = before_len + strlen(value);
201 backslashed = bracketed = false;
202 before_len = name_off = name_len = after_off = 0;
203 assert(i <= (int)strlen(string));
204 }
205
206 if (before_len != 0 || name_off != 0 || name_len != 0 || after_off != 0) {
207 log_warnx("truncated variable");
208 return (NULL);
209 }
210
211 return (expanded);
212 }
213
214 static void
defined_add(const char * name,const char * value)215 defined_add(const char *name, const char *value)
216 {
217 struct defined_value *d;
218 const char *found;
219
220 found = defined_find(name);
221 if (found != NULL)
222 log_errx(1, "variable %s already defined", name);
223
224 log_debugx("defining variable %s=%s", name, value);
225
226 d = calloc(1, sizeof(*d));
227 if (d == NULL)
228 log_err(1, "calloc");
229 d->d_name = checked_strdup(name);
230 d->d_value = checked_strdup(value);
231
232 TAILQ_INSERT_TAIL(&defined_values, d, d_next);
233 }
234
235 void
defined_parse_and_add(char * def)236 defined_parse_and_add(char *def)
237 {
238 char *name, *value;
239
240 value = def;
241 name = strsep(&value, "=");
242
243 if (value == NULL || value[0] == '\0')
244 log_errx(1, "missing variable value");
245 if (name == NULL || name[0] == '\0')
246 log_errx(1, "missing variable name");
247
248 defined_add(name, value);
249 }
250
251 void
defined_init(void)252 defined_init(void)
253 {
254 struct utsname name;
255 int error;
256
257 TAILQ_INIT(&defined_values);
258
259 error = uname(&name);
260 if (error != 0)
261 log_err(1, "uname");
262
263 defined_add("ARCH", name.machine);
264 defined_add("CPU", name.machine);
265 defined_add("DOLLAR", "$");
266 defined_add("HOST", name.nodename);
267 defined_add("OSNAME", name.sysname);
268 defined_add("OSREL", name.release);
269 defined_add("OSVERS", name.version);
270 }
271