1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Boot config tool for initrd image
4 */
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <sys/types.h>
8 #include <sys/stat.h>
9 #include <fcntl.h>
10 #include <unistd.h>
11 #include <string.h>
12 #include <errno.h>
13 #include <endian.h>
14
15 #include <linux/bootconfig.h>
16
17 #define pr_err(fmt, ...) fprintf(stderr, fmt, ##__VA_ARGS__)
18
xbc_show_value(struct xbc_node * node,bool semicolon)19 static int xbc_show_value(struct xbc_node *node, bool semicolon)
20 {
21 const char *val, *eol;
22 char q;
23 int i = 0;
24
25 eol = semicolon ? ";\n" : "\n";
26 xbc_array_for_each_value(node, val) {
27 if (strchr(val, '"'))
28 q = '\'';
29 else
30 q = '"';
31 printf("%c%s%c%s", q, val, q, xbc_node_is_array(node) ? ", " : eol);
32 i++;
33 }
34 return i;
35 }
36
xbc_show_compact_tree(void)37 static void xbc_show_compact_tree(void)
38 {
39 struct xbc_node *node, *cnode = NULL, *vnode;
40 int depth = 0, i;
41
42 node = xbc_root_node();
43 while (node && xbc_node_is_key(node)) {
44 for (i = 0; i < depth; i++)
45 printf("\t");
46 if (!cnode)
47 cnode = xbc_node_get_child(node);
48 while (cnode && xbc_node_is_key(cnode) && !cnode->next) {
49 vnode = xbc_node_get_child(cnode);
50 /*
51 * If @cnode has value and subkeys, this
52 * should show it as below.
53 *
54 * key(@node) {
55 * key(@cnode) = value;
56 * key(@cnode) {
57 * subkeys;
58 * }
59 * }
60 */
61 if (vnode && xbc_node_is_value(vnode) && vnode->next)
62 break;
63 printf("%s.", xbc_node_get_data(node));
64 node = cnode;
65 cnode = vnode;
66 }
67 if (cnode && xbc_node_is_key(cnode)) {
68 printf("%s {\n", xbc_node_get_data(node));
69 depth++;
70 node = cnode;
71 cnode = NULL;
72 continue;
73 } else if (cnode && xbc_node_is_value(cnode)) {
74 printf("%s = ", xbc_node_get_data(node));
75 xbc_show_value(cnode, true);
76 /*
77 * If @node has value and subkeys, continue
78 * looping on subkeys with same node.
79 */
80 if (cnode->next) {
81 cnode = xbc_node_get_next(cnode);
82 continue;
83 }
84 } else {
85 printf("%s;\n", xbc_node_get_data(node));
86 }
87 cnode = NULL;
88
89 if (node->next) {
90 node = xbc_node_get_next(node);
91 continue;
92 }
93 while (!node->next) {
94 node = xbc_node_get_parent(node);
95 if (!node)
96 return;
97 if (!xbc_node_get_child(node)->next)
98 continue;
99 if (depth) {
100 depth--;
101 for (i = 0; i < depth; i++)
102 printf("\t");
103 printf("}\n");
104 }
105 }
106 node = xbc_node_get_next(node);
107 }
108 }
109
xbc_show_list(void)110 static void xbc_show_list(void)
111 {
112 char key[XBC_KEYLEN_MAX];
113 struct xbc_node *leaf;
114 const char *val;
115 int ret;
116
117 xbc_for_each_key_value(leaf, val) {
118 ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX);
119 if (ret < 0) {
120 fprintf(stderr, "Failed to compose key %d\n", ret);
121 break;
122 }
123 printf("%s = ", key);
124 if (!val || val[0] == '\0') {
125 printf("\"\"\n");
126 continue;
127 }
128 xbc_show_value(xbc_node_get_child(leaf), false);
129 }
130 }
131
132 #define PAGE_SIZE 4096
133
load_xbc_fd(int fd,char ** buf,int size)134 static int load_xbc_fd(int fd, char **buf, int size)
135 {
136 int ret;
137
138 *buf = malloc(size + 1);
139 if (!*buf)
140 return -ENOMEM;
141
142 ret = read(fd, *buf, size);
143 if (ret < 0)
144 return -errno;
145 (*buf)[size] = '\0';
146
147 return ret;
148 }
149
150 /* Return the read size or -errno */
load_xbc_file(const char * path,char ** buf)151 static int load_xbc_file(const char *path, char **buf)
152 {
153 struct stat stat;
154 int fd, ret;
155
156 fd = open(path, O_RDONLY);
157 if (fd < 0)
158 return -errno;
159 ret = fstat(fd, &stat);
160 if (ret < 0)
161 return -errno;
162
163 ret = load_xbc_fd(fd, buf, stat.st_size);
164
165 close(fd);
166
167 return ret;
168 }
169
pr_errno(const char * msg,int err)170 static int pr_errno(const char *msg, int err)
171 {
172 pr_err("%s: %d\n", msg, err);
173 return err;
174 }
175
load_xbc_from_initrd(int fd,char ** buf)176 static int load_xbc_from_initrd(int fd, char **buf)
177 {
178 struct stat stat;
179 int ret;
180 uint32_t size = 0, csum = 0, rcsum;
181 char magic[BOOTCONFIG_MAGIC_LEN];
182 const char *msg;
183
184 ret = fstat(fd, &stat);
185 if (ret < 0)
186 return -errno;
187
188 if (stat.st_size < 8 + BOOTCONFIG_MAGIC_LEN)
189 return 0;
190
191 if (lseek(fd, -BOOTCONFIG_MAGIC_LEN, SEEK_END) < 0)
192 return pr_errno("Failed to lseek for magic", -errno);
193
194 if (read(fd, magic, BOOTCONFIG_MAGIC_LEN) < 0)
195 return pr_errno("Failed to read", -errno);
196
197 /* Check the bootconfig magic bytes */
198 if (memcmp(magic, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN) != 0)
199 return 0;
200
201 if (lseek(fd, -(8 + BOOTCONFIG_MAGIC_LEN), SEEK_END) < 0)
202 return pr_errno("Failed to lseek for size", -errno);
203
204 if (read(fd, &size, sizeof(uint32_t)) < 0)
205 return pr_errno("Failed to read size", -errno);
206 size = le32toh(size);
207
208 if (read(fd, &csum, sizeof(uint32_t)) < 0)
209 return pr_errno("Failed to read checksum", -errno);
210 csum = le32toh(csum);
211
212 /* Wrong size error */
213 if (stat.st_size < size + 8 + BOOTCONFIG_MAGIC_LEN) {
214 pr_err("bootconfig size is too big\n");
215 return -E2BIG;
216 }
217
218 if (lseek(fd, stat.st_size - (size + 8 + BOOTCONFIG_MAGIC_LEN),
219 SEEK_SET) < 0)
220 return pr_errno("Failed to lseek", -errno);
221
222 ret = load_xbc_fd(fd, buf, size);
223 if (ret < 0)
224 return ret;
225
226 /* Wrong Checksum */
227 rcsum = xbc_calc_checksum(*buf, size);
228 if (csum != rcsum) {
229 pr_err("checksum error: %d != %d\n", csum, rcsum);
230 return -EINVAL;
231 }
232
233 ret = xbc_init(*buf, size, &msg, NULL);
234 /* Wrong data */
235 if (ret < 0) {
236 pr_err("parse error: %s.\n", msg);
237 return ret;
238 }
239
240 return size;
241 }
242
show_xbc_error(const char * data,const char * msg,int pos)243 static void show_xbc_error(const char *data, const char *msg, int pos)
244 {
245 int lin = 1, col, i;
246
247 if (pos < 0) {
248 pr_err("Error: %s.\n", msg);
249 return;
250 }
251
252 /* Note that pos starts from 0 but lin and col should start from 1. */
253 col = pos + 1;
254 for (i = 0; i < pos; i++) {
255 if (data[i] == '\n') {
256 lin++;
257 col = pos - i;
258 }
259 }
260 pr_err("Parse Error: %s at %d:%d\n", msg, lin, col);
261
262 }
263
init_xbc_with_error(char * buf,int len)264 static int init_xbc_with_error(char *buf, int len)
265 {
266 char *copy = strdup(buf);
267 const char *msg;
268 int ret, pos;
269
270 if (!copy)
271 return -ENOMEM;
272
273 ret = xbc_init(buf, len, &msg, &pos);
274 if (ret < 0)
275 show_xbc_error(copy, msg, pos);
276 free(copy);
277
278 return ret;
279 }
280
show_xbc(const char * path,bool list)281 static int show_xbc(const char *path, bool list)
282 {
283 int ret, fd;
284 char *buf = NULL;
285 struct stat st;
286
287 ret = stat(path, &st);
288 if (ret < 0) {
289 ret = -errno;
290 pr_err("Failed to stat %s: %d\n", path, ret);
291 return ret;
292 }
293
294 fd = open(path, O_RDONLY);
295 if (fd < 0) {
296 ret = -errno;
297 pr_err("Failed to open initrd %s: %d\n", path, ret);
298 return ret;
299 }
300
301 ret = load_xbc_from_initrd(fd, &buf);
302 close(fd);
303 if (ret < 0) {
304 pr_err("Failed to load a boot config from initrd: %d\n", ret);
305 goto out;
306 }
307 /* Assume a bootconfig file if it is enough small */
308 if (ret == 0 && st.st_size <= XBC_DATA_MAX) {
309 ret = load_xbc_file(path, &buf);
310 if (ret < 0) {
311 pr_err("Failed to load a boot config: %d\n", ret);
312 goto out;
313 }
314 if (init_xbc_with_error(buf, ret) < 0)
315 goto out;
316 }
317 if (list)
318 xbc_show_list();
319 else
320 xbc_show_compact_tree();
321 ret = 0;
322 out:
323 free(buf);
324
325 return ret;
326 }
327
delete_xbc(const char * path)328 static int delete_xbc(const char *path)
329 {
330 struct stat stat;
331 int ret = 0, fd, size;
332 char *buf = NULL;
333
334 fd = open(path, O_RDWR);
335 if (fd < 0) {
336 ret = -errno;
337 pr_err("Failed to open initrd %s: %d\n", path, ret);
338 return ret;
339 }
340
341 size = load_xbc_from_initrd(fd, &buf);
342 if (size < 0) {
343 ret = size;
344 pr_err("Failed to load a boot config from initrd: %d\n", ret);
345 } else if (size > 0) {
346 ret = fstat(fd, &stat);
347 if (!ret)
348 ret = ftruncate(fd, stat.st_size
349 - size - 8 - BOOTCONFIG_MAGIC_LEN);
350 if (ret)
351 ret = -errno;
352 } /* Ignore if there is no boot config in initrd */
353
354 close(fd);
355 free(buf);
356
357 return ret;
358 }
359
apply_xbc(const char * path,const char * xbc_path)360 static int apply_xbc(const char *path, const char *xbc_path)
361 {
362 char *buf, *data, *p;
363 size_t total_size;
364 struct stat stat;
365 const char *msg;
366 uint32_t size, csum;
367 int pos, pad;
368 int ret, fd;
369
370 ret = load_xbc_file(xbc_path, &buf);
371 if (ret < 0) {
372 pr_err("Failed to load %s : %d\n", xbc_path, ret);
373 return ret;
374 }
375 size = strlen(buf) + 1;
376 csum = xbc_calc_checksum(buf, size);
377
378 /* Backup the bootconfig data */
379 data = calloc(size + BOOTCONFIG_ALIGN +
380 sizeof(uint32_t) + sizeof(uint32_t) + BOOTCONFIG_MAGIC_LEN, 1);
381 if (!data)
382 return -ENOMEM;
383 memcpy(data, buf, size);
384
385 /* Check the data format */
386 ret = xbc_init(buf, size, &msg, &pos);
387 if (ret < 0) {
388 show_xbc_error(data, msg, pos);
389 free(data);
390 free(buf);
391
392 return ret;
393 }
394 printf("Apply %s to %s\n", xbc_path, path);
395 xbc_get_info(&ret, NULL);
396 printf("\tNumber of nodes: %d\n", ret);
397 printf("\tSize: %u bytes\n", (unsigned int)size);
398 printf("\tChecksum: %d\n", (unsigned int)csum);
399
400 /* TODO: Check the options by schema */
401 xbc_exit();
402 free(buf);
403
404 /* Remove old boot config if exists */
405 ret = delete_xbc(path);
406 if (ret < 0) {
407 pr_err("Failed to delete previous boot config: %d\n", ret);
408 free(data);
409 return ret;
410 }
411
412 /* Apply new one */
413 fd = open(path, O_RDWR | O_APPEND);
414 if (fd < 0) {
415 ret = -errno;
416 pr_err("Failed to open %s: %d\n", path, ret);
417 free(data);
418 return ret;
419 }
420 /* TODO: Ensure the @path is initramfs/initrd image */
421 if (fstat(fd, &stat) < 0) {
422 ret = -errno;
423 pr_err("Failed to get the size of %s\n", path);
424 goto out;
425 }
426
427 /* To align up the total size to BOOTCONFIG_ALIGN, get padding size */
428 total_size = stat.st_size + size + sizeof(uint32_t) * 2 + BOOTCONFIG_MAGIC_LEN;
429 pad = ((total_size + BOOTCONFIG_ALIGN - 1) & (~BOOTCONFIG_ALIGN_MASK)) - total_size;
430 size += pad;
431
432 /* Add a footer */
433 p = data + size;
434 *(uint32_t *)p = htole32(size);
435 p += sizeof(uint32_t);
436
437 *(uint32_t *)p = htole32(csum);
438 p += sizeof(uint32_t);
439
440 memcpy(p, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
441 p += BOOTCONFIG_MAGIC_LEN;
442
443 total_size = p - data;
444
445 ret = write(fd, data, total_size);
446 if (ret < total_size) {
447 if (ret < 0)
448 ret = -errno;
449 pr_err("Failed to apply a boot config: %d\n", ret);
450 if (ret >= 0)
451 goto out_rollback;
452 } else
453 ret = 0;
454
455 out:
456 close(fd);
457 free(data);
458
459 return ret;
460
461 out_rollback:
462 /* Map the partial write to -ENOSPC */
463 if (ret >= 0)
464 ret = -ENOSPC;
465 if (ftruncate(fd, stat.st_size) < 0) {
466 ret = -errno;
467 pr_err("Failed to rollback the write error: %d\n", ret);
468 pr_err("The initrd %s may be corrupted. Recommend to rebuild.\n", path);
469 }
470 goto out;
471 }
472
usage(void)473 static int usage(void)
474 {
475 printf("Usage: bootconfig [OPTIONS] <INITRD>\n"
476 "Or bootconfig <CONFIG>\n"
477 " Apply, delete or show boot config to initrd.\n"
478 " Options:\n"
479 " -a <config>: Apply boot config to initrd\n"
480 " -d : Delete boot config file from initrd\n"
481 " -l : list boot config in initrd or file\n\n"
482 " If no option is given, show the bootconfig in the given file.\n");
483 return -1;
484 }
485
main(int argc,char ** argv)486 int main(int argc, char **argv)
487 {
488 char *path = NULL;
489 char *apply = NULL;
490 bool delete = false, list = false;
491 int opt;
492
493 while ((opt = getopt(argc, argv, "hda:l")) != -1) {
494 switch (opt) {
495 case 'd':
496 delete = true;
497 break;
498 case 'a':
499 apply = optarg;
500 break;
501 case 'l':
502 list = true;
503 break;
504 case 'h':
505 default:
506 return usage();
507 }
508 }
509
510 if ((apply && delete) || (delete && list) || (apply && list)) {
511 pr_err("Error: You can give one of -a, -d or -l at once.\n");
512 return usage();
513 }
514
515 if (optind >= argc) {
516 pr_err("Error: No initrd is specified.\n");
517 return usage();
518 }
519
520 path = argv[optind];
521
522 if (apply)
523 return apply_xbc(path, apply);
524 else if (delete)
525 return delete_xbc(path);
526
527 return show_xbc(path, list);
528 }
529