1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2000-2010
4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 *
6 * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
7 * Andreas Heppel <aheppel@sysgo.de>
8 */
9
10 #include <common.h>
11 #include <command.h>
12 #include <environment.h>
13 #include <linux/stddef.h>
14 #include <search.h>
15 #include <errno.h>
16 #include <malloc.h>
17
18 DECLARE_GLOBAL_DATA_PTR;
19
20 /************************************************************************
21 * Default settings to be used when no valid environment is found
22 */
23 #include <env_default.h>
24
25 struct hsearch_data env_htab = {
26 .change_ok = env_flags_validate,
27 };
28
29 /*
30 * Read an environment variable as a boolean
31 * Return -1 if variable does not exist (default to true)
32 */
env_get_yesno(const char * var)33 int env_get_yesno(const char *var)
34 {
35 char *s = env_get(var);
36
37 if (s == NULL)
38 return -1;
39 return (*s == '1' || *s == 'y' || *s == 'Y' || *s == 't' || *s == 'T') ?
40 1 : 0;
41 }
42
43 /*
44 * Look up the variable from the default environment
45 */
env_get_default(const char * name)46 char *env_get_default(const char *name)
47 {
48 char *ret_val;
49 unsigned long really_valid = gd->env_valid;
50 unsigned long real_gd_flags = gd->flags;
51
52 /* Pretend that the image is bad. */
53 gd->flags &= ~GD_FLG_ENV_READY;
54 gd->env_valid = ENV_INVALID;
55 ret_val = env_get(name);
56 gd->env_valid = really_valid;
57 gd->flags = real_gd_flags;
58 return ret_val;
59 }
60
set_default_env(const char * s,int flags)61 void set_default_env(const char *s, int flags)
62 {
63 if (sizeof(default_environment) > ENV_SIZE) {
64 puts("*** Error - default environment is too large\n\n");
65 return;
66 }
67
68 if (s) {
69 if ((flags & H_INTERACTIVE) == 0) {
70 printf("*** Warning - %s, "
71 "using default environment\n\n", s);
72 } else {
73 puts(s);
74 }
75 } else {
76 debug("Using default environment\n");
77 }
78
79 if (himport_r(&env_htab, (char *)default_environment,
80 sizeof(default_environment), '\0', flags, 0,
81 0, NULL) == 0)
82 pr_err("## Error: Environment import failed: errno = %d\n",
83 errno);
84
85 gd->flags |= GD_FLG_ENV_READY;
86 gd->flags |= GD_FLG_ENV_DEFAULT;
87 }
88
89
90 /* [re]set individual variables to their value in the default environment */
set_default_vars(int nvars,char * const vars[],int flags)91 int set_default_vars(int nvars, char * const vars[], int flags)
92 {
93 /*
94 * Special use-case: import from default environment
95 * (and use \0 as a separator)
96 */
97 flags |= H_NOCLEAR;
98 return himport_r(&env_htab, (const char *)default_environment,
99 sizeof(default_environment), '\0',
100 flags, 0, nvars, vars);
101 }
102
103 /*
104 * Check if CRC is valid and (if yes) import the environment.
105 * Note that "buf" may or may not be aligned.
106 */
env_import(const char * buf,int check)107 int env_import(const char *buf, int check)
108 {
109 env_t *ep = (env_t *)buf;
110
111 if (check) {
112 uint32_t crc;
113
114 memcpy(&crc, &ep->crc, sizeof(crc));
115
116 if (crc32(0, ep->data, ENV_SIZE) != crc) {
117 set_default_env("bad CRC", 0);
118 return -ENOMSG; /* needed for env_load() */
119 }
120 }
121
122 if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0,
123 0, NULL)) {
124 gd->flags |= GD_FLG_ENV_READY;
125 return 0;
126 }
127
128 pr_err("Cannot import environment: errno = %d\n", errno);
129
130 set_default_env("import failed", 0);
131
132 return -EIO;
133 }
134
135 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
136 static unsigned char env_flags;
137
env_import_redund(const char * buf1,int buf1_read_fail,const char * buf2,int buf2_read_fail)138 int env_import_redund(const char *buf1, int buf1_read_fail,
139 const char *buf2, int buf2_read_fail)
140 {
141 int crc1_ok, crc2_ok;
142 env_t *ep, *tmp_env1, *tmp_env2;
143
144 tmp_env1 = (env_t *)buf1;
145 tmp_env2 = (env_t *)buf2;
146
147 if (buf1_read_fail && buf2_read_fail) {
148 puts("*** Error - No Valid Environment Area found\n");
149 } else if (buf1_read_fail || buf2_read_fail) {
150 puts("*** Warning - some problems detected ");
151 puts("reading environment; recovered successfully\n");
152 }
153
154 if (buf1_read_fail && buf2_read_fail) {
155 set_default_env("bad env area", 0);
156 return -EIO;
157 } else if (!buf1_read_fail && buf2_read_fail) {
158 gd->env_valid = ENV_VALID;
159 return env_import((char *)tmp_env1, 1);
160 } else if (buf1_read_fail && !buf2_read_fail) {
161 gd->env_valid = ENV_REDUND;
162 return env_import((char *)tmp_env2, 1);
163 }
164
165 crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) ==
166 tmp_env1->crc;
167 crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) ==
168 tmp_env2->crc;
169
170 if (!crc1_ok && !crc2_ok) {
171 set_default_env("bad CRC", 0);
172 return -ENOMSG; /* needed for env_load() */
173 } else if (crc1_ok && !crc2_ok) {
174 gd->env_valid = ENV_VALID;
175 } else if (!crc1_ok && crc2_ok) {
176 gd->env_valid = ENV_REDUND;
177 } else {
178 /* both ok - check serial */
179 if (tmp_env1->flags == 255 && tmp_env2->flags == 0)
180 gd->env_valid = ENV_REDUND;
181 else if (tmp_env2->flags == 255 && tmp_env1->flags == 0)
182 gd->env_valid = ENV_VALID;
183 else if (tmp_env1->flags > tmp_env2->flags)
184 gd->env_valid = ENV_VALID;
185 else if (tmp_env2->flags > tmp_env1->flags)
186 gd->env_valid = ENV_REDUND;
187 else /* flags are equal - almost impossible */
188 gd->env_valid = ENV_VALID;
189 }
190
191 if (gd->env_valid == ENV_VALID)
192 ep = tmp_env1;
193 else
194 ep = tmp_env2;
195
196 env_flags = ep->flags;
197 return env_import((char *)ep, 0);
198 }
199 #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */
200
201 /* Export the environment and generate CRC for it. */
env_export(env_t * env_out)202 int env_export(env_t *env_out)
203 {
204 char *res;
205 ssize_t len;
206
207 res = (char *)env_out->data;
208 len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
209 if (len < 0) {
210 pr_err("Cannot export environment: errno = %d\n", errno);
211 return 1;
212 }
213
214 env_out->crc = crc32(0, env_out->data, ENV_SIZE);
215
216 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
217 env_out->flags = ++env_flags; /* increase the serial */
218 #endif
219
220 return 0;
221 }
222
env_relocate(void)223 void env_relocate(void)
224 {
225 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
226 env_reloc();
227 env_fix_drivers();
228 env_htab.change_ok += gd->reloc_off;
229 #endif
230 if (gd->env_valid == ENV_INVALID) {
231 #if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD)
232 /* Environment not changable */
233 set_default_env(NULL, 0);
234 #else
235 bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM);
236 set_default_env("bad CRC", 0);
237 #endif
238 } else {
239 env_load();
240 }
241 }
242
243 #ifdef CONFIG_AUTO_COMPLETE
env_complete(char * var,int maxv,char * cmdv[],int bufsz,char * buf,bool dollar_comp)244 int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf,
245 bool dollar_comp)
246 {
247 ENTRY *match;
248 int found, idx;
249
250 if (dollar_comp) {
251 /*
252 * When doing $ completion, the first character should
253 * obviously be a '$'.
254 */
255 if (var[0] != '$')
256 return 0;
257
258 var++;
259
260 /*
261 * The second one, if present, should be a '{', as some
262 * configuration of the u-boot shell expand ${var} but not
263 * $var.
264 */
265 if (var[0] == '{')
266 var++;
267 else if (var[0] != '\0')
268 return 0;
269 }
270
271 idx = 0;
272 found = 0;
273 cmdv[0] = NULL;
274
275
276 while ((idx = hmatch_r(var, idx, &match, &env_htab))) {
277 int vallen = strlen(match->key) + 1;
278
279 if (found >= maxv - 2 ||
280 bufsz < vallen + (dollar_comp ? 3 : 0))
281 break;
282
283 cmdv[found++] = buf;
284
285 /* Add the '${' prefix to each var when doing $ completion. */
286 if (dollar_comp) {
287 strcpy(buf, "${");
288 buf += 2;
289 bufsz -= 3;
290 }
291
292 memcpy(buf, match->key, vallen);
293 buf += vallen;
294 bufsz -= vallen;
295
296 if (dollar_comp) {
297 /*
298 * This one is a bit odd: vallen already contains the
299 * '\0' character but we need to add the '}' suffix,
300 * hence the buf - 1 here. strcpy() will add the '\0'
301 * character just after '}'. buf is then incremented
302 * to account for the extra '}' we just added.
303 */
304 strcpy(buf - 1, "}");
305 buf++;
306 }
307 }
308
309 qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar);
310
311 if (idx)
312 cmdv[found++] = dollar_comp ? "${...}" : "...";
313
314 cmdv[found] = NULL;
315 return found;
316 }
317 #endif
318