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)61 void set_default_env(const char *s)
62 {
63 int flags = 0;
64
65 if (sizeof(default_environment) > ENV_SIZE) {
66 puts("*** Error - default environment is too large\n\n");
67 return;
68 }
69
70 if (s) {
71 if (*s == '!') {
72 printf("*** Warning - %s, "
73 "using default environment\n\n",
74 s + 1);
75 } else {
76 flags = H_INTERACTIVE;
77 puts(s);
78 }
79 } else {
80 debug("Using default environment\n");
81 }
82
83 if (himport_r(&env_htab, (char *)default_environment,
84 sizeof(default_environment), '\0', flags, 0,
85 0, NULL) == 0)
86 pr_err("Environment import failed: errno = %d\n", errno);
87
88 gd->flags |= GD_FLG_ENV_READY;
89 gd->flags |= GD_FLG_ENV_DEFAULT;
90 }
91
92
93 /* [re]set individual variables to their value in the default environment */
set_default_vars(int nvars,char * const vars[])94 int set_default_vars(int nvars, char * const vars[])
95 {
96 /*
97 * Special use-case: import from default environment
98 * (and use \0 as a separator)
99 */
100 return himport_r(&env_htab, (const char *)default_environment,
101 sizeof(default_environment), '\0',
102 H_NOCLEAR | H_INTERACTIVE, 0, nvars, vars);
103 }
104
105 /*
106 * Check if CRC is valid and (if yes) import the environment.
107 * Note that "buf" may or may not be aligned.
108 */
env_import(const char * buf,int check)109 int env_import(const char *buf, int check)
110 {
111 env_t *ep = (env_t *)buf;
112
113 if (check) {
114 uint32_t crc;
115
116 memcpy(&crc, &ep->crc, sizeof(crc));
117
118 if (crc32(0, ep->data, ENV_SIZE) != crc) {
119 set_default_env("!bad CRC");
120 return -EIO;
121 }
122 }
123
124 if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0,
125 0, NULL)) {
126 gd->flags |= GD_FLG_ENV_READY;
127 return 0;
128 }
129
130 pr_err("Cannot import environment: errno = %d\n", errno);
131
132 set_default_env("!import failed");
133
134 return -EIO;
135 }
136
137 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
138 static unsigned char env_flags;
139
env_import_redund(const char * buf1,int buf1_read_fail,const char * buf2,int buf2_read_fail)140 int env_import_redund(const char *buf1, int buf1_read_fail,
141 const char *buf2, int buf2_read_fail)
142 {
143 int crc1_ok, crc2_ok;
144 env_t *ep, *tmp_env1, *tmp_env2;
145
146 tmp_env1 = (env_t *)buf1;
147 tmp_env2 = (env_t *)buf2;
148
149 if (buf1_read_fail && buf2_read_fail) {
150 puts("*** Error - No Valid Environment Area found\n");
151 } else if (buf1_read_fail || buf2_read_fail) {
152 puts("*** Warning - some problems detected ");
153 puts("reading environment; recovered successfully\n");
154 }
155
156 if (buf1_read_fail && buf2_read_fail) {
157 set_default_env("!bad env area");
158 return -EIO;
159 } else if (!buf1_read_fail && buf2_read_fail) {
160 gd->env_valid = ENV_VALID;
161 return env_import((char *)tmp_env1, 1);
162 } else if (buf1_read_fail && !buf2_read_fail) {
163 gd->env_valid = ENV_REDUND;
164 return env_import((char *)tmp_env2, 1);
165 }
166
167 crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) ==
168 tmp_env1->crc;
169 crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) ==
170 tmp_env2->crc;
171
172 if (!crc1_ok && !crc2_ok) {
173 set_default_env("!bad CRC");
174 return -EIO;
175 } else if (crc1_ok && !crc2_ok) {
176 gd->env_valid = ENV_VALID;
177 } else if (!crc1_ok && crc2_ok) {
178 gd->env_valid = ENV_REDUND;
179 } else {
180 /* both ok - check serial */
181 if (tmp_env1->flags == 255 && tmp_env2->flags == 0)
182 gd->env_valid = ENV_REDUND;
183 else if (tmp_env2->flags == 255 && tmp_env1->flags == 0)
184 gd->env_valid = ENV_VALID;
185 else if (tmp_env1->flags > tmp_env2->flags)
186 gd->env_valid = ENV_VALID;
187 else if (tmp_env2->flags > tmp_env1->flags)
188 gd->env_valid = ENV_REDUND;
189 else /* flags are equal - almost impossible */
190 gd->env_valid = ENV_VALID;
191 }
192
193 if (gd->env_valid == ENV_VALID)
194 ep = tmp_env1;
195 else
196 ep = tmp_env2;
197
198 env_flags = ep->flags;
199 return env_import((char *)ep, 0);
200 }
201 #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */
202
203 /* Export the environment and generate CRC for it. */
env_export(env_t * env_out)204 int env_export(env_t *env_out)
205 {
206 char *res;
207 ssize_t len;
208
209 res = (char *)env_out->data;
210 len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
211 if (len < 0) {
212 pr_err("Cannot export environment: errno = %d\n", errno);
213 return 1;
214 }
215
216 env_out->crc = crc32(0, env_out->data, ENV_SIZE);
217
218 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
219 env_out->flags = ++env_flags; /* increase the serial */
220 #endif
221
222 return 0;
223 }
224
env_relocate(void)225 void env_relocate(void)
226 {
227 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
228 env_reloc();
229 env_fix_drivers();
230 env_htab.change_ok += gd->reloc_off;
231 #endif
232 if (gd->env_valid == ENV_INVALID) {
233 #if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD)
234 /* Environment not changable */
235 set_default_env(NULL);
236 #else
237 bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM);
238 set_default_env("!bad CRC");
239 #endif
240 } else {
241 env_load();
242 }
243 }
244
245 #if defined(CONFIG_AUTO_COMPLETE) && !defined(CONFIG_SPL_BUILD)
env_complete(char * var,int maxv,char * cmdv[],int bufsz,char * buf)246 int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf)
247 {
248 ENTRY *match;
249 int found, idx;
250
251 idx = 0;
252 found = 0;
253 cmdv[0] = NULL;
254
255 while ((idx = hmatch_r(var, idx, &match, &env_htab))) {
256 int vallen = strlen(match->key) + 1;
257
258 if (found >= maxv - 2 || bufsz < vallen)
259 break;
260
261 cmdv[found++] = buf;
262 memcpy(buf, match->key, vallen);
263 buf += vallen;
264 bufsz -= vallen;
265 }
266
267 qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar);
268
269 if (idx)
270 cmdv[found++] = "...";
271
272 cmdv[found] = NULL;
273 return found;
274 }
275 #endif
276