diff options
Diffstat (limited to 'tools/bootconfig/main.c')
-rw-r--r-- | tools/bootconfig/main.c | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c new file mode 100644 index 000000000000..b8f174fd2a0a --- /dev/null +++ b/tools/bootconfig/main.c @@ -0,0 +1,353 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Boot config tool for initrd image + */ +#include <stdio.h> +#include <stdlib.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> +#include <string.h> +#include <errno.h> + +#include <linux/kernel.h> +#include <linux/bootconfig.h> + +int pr_output = 1; + +static int xbc_show_array(struct xbc_node *node) +{ + const char *val; + int i = 0; + + xbc_array_for_each_value(node, val) { + printf("\"%s\"%s", val, node->next ? ", " : ";\n"); + i++; + } + return i; +} + +static void xbc_show_compact_tree(void) +{ + struct xbc_node *node, *cnode; + int depth = 0, i; + + node = xbc_root_node(); + while (node && xbc_node_is_key(node)) { + for (i = 0; i < depth; i++) + printf("\t"); + cnode = xbc_node_get_child(node); + while (cnode && xbc_node_is_key(cnode) && !cnode->next) { + printf("%s.", xbc_node_get_data(node)); + node = cnode; + cnode = xbc_node_get_child(node); + } + if (cnode && xbc_node_is_key(cnode)) { + printf("%s {\n", xbc_node_get_data(node)); + depth++; + node = cnode; + continue; + } else if (cnode && xbc_node_is_value(cnode)) { + printf("%s = ", xbc_node_get_data(node)); + if (cnode->next) + xbc_show_array(cnode); + else + printf("\"%s\";\n", xbc_node_get_data(cnode)); + } else { + printf("%s;\n", xbc_node_get_data(node)); + } + + if (node->next) { + node = xbc_node_get_next(node); + continue; + } + while (!node->next) { + node = xbc_node_get_parent(node); + if (!node) + return; + if (!xbc_node_get_child(node)->next) + continue; + depth--; + for (i = 0; i < depth; i++) + printf("\t"); + printf("}\n"); + } + node = xbc_node_get_next(node); + } +} + +/* Simple real checksum */ +int checksum(unsigned char *buf, int len) +{ + int i, sum = 0; + + for (i = 0; i < len; i++) + sum += buf[i]; + + return sum; +} + +#define PAGE_SIZE 4096 + +int load_xbc_fd(int fd, char **buf, int size) +{ + int ret; + + *buf = malloc(size + 1); + if (!*buf) + return -ENOMEM; + + ret = read(fd, *buf, size); + if (ret < 0) + return -errno; + (*buf)[size] = '\0'; + + return ret; +} + +/* Return the read size or -errno */ +int load_xbc_file(const char *path, char **buf) +{ + struct stat stat; + int fd, ret; + + fd = open(path, O_RDONLY); + if (fd < 0) + return -errno; + ret = fstat(fd, &stat); + if (ret < 0) + return -errno; + + ret = load_xbc_fd(fd, buf, stat.st_size); + + close(fd); + + return ret; +} + +int load_xbc_from_initrd(int fd, char **buf) +{ + struct stat stat; + int ret; + u32 size = 0, csum = 0, rcsum; + + ret = fstat(fd, &stat); + if (ret < 0) + return -errno; + + if (stat.st_size < 8) + return 0; + + if (lseek(fd, -8, SEEK_END) < 0) { + printf("Faile to lseek: %d\n", -errno); + return -errno; + } + + if (read(fd, &size, sizeof(u32)) < 0) + return -errno; + + if (read(fd, &csum, sizeof(u32)) < 0) + return -errno; + + /* Wrong size, maybe no boot config here */ + if (stat.st_size < size + 8) + return 0; + + if (lseek(fd, stat.st_size - 8 - size, SEEK_SET) < 0) { + printf("Faile to lseek: %d\n", -errno); + return -errno; + } + + ret = load_xbc_fd(fd, buf, size); + if (ret < 0) + return ret; + + /* Wrong Checksum, maybe no boot config here */ + rcsum = checksum((unsigned char *)*buf, size); + if (csum != rcsum) { + printf("checksum error: %d != %d\n", csum, rcsum); + return 0; + } + + ret = xbc_init(*buf); + /* Wrong data, maybe no boot config here */ + if (ret < 0) + return 0; + + return size; +} + +int show_xbc(const char *path) +{ + int ret, fd; + char *buf = NULL; + + fd = open(path, O_RDONLY); + if (fd < 0) { + printf("Failed to open initrd %s: %d\n", path, fd); + return -errno; + } + + ret = load_xbc_from_initrd(fd, &buf); + if (ret < 0) + printf("Failed to load a boot config from initrd: %d\n", ret); + else + xbc_show_compact_tree(); + + close(fd); + free(buf); + + return ret; +} + +int delete_xbc(const char *path) +{ + struct stat stat; + int ret = 0, fd, size; + char *buf = NULL; + + fd = open(path, O_RDWR); + if (fd < 0) { + printf("Failed to open initrd %s: %d\n", path, fd); + return -errno; + } + + /* + * Suppress error messages in xbc_init() because it can be just a + * data which concidentally matches the size and checksum footer. + */ + pr_output = 0; + size = load_xbc_from_initrd(fd, &buf); + pr_output = 1; + if (size < 0) { + ret = size; + printf("Failed to load a boot config from initrd: %d\n", ret); + } else if (size > 0) { + ret = fstat(fd, &stat); + if (!ret) + ret = ftruncate(fd, stat.st_size - size - 8); + if (ret) + ret = -errno; + } /* Ignore if there is no boot config in initrd */ + + close(fd); + free(buf); + + return ret; +} + +int apply_xbc(const char *path, const char *xbc_path) +{ + u32 size, csum; + char *buf, *data; + int ret, fd; + + ret = load_xbc_file(xbc_path, &buf); + if (ret < 0) { + printf("Failed to load %s : %d\n", xbc_path, ret); + return ret; + } + size = strlen(buf) + 1; + csum = checksum((unsigned char *)buf, size); + + /* Prepare xbc_path data */ + data = malloc(size + 8); + if (!data) + return -ENOMEM; + strcpy(data, buf); + *(u32 *)(data + size) = size; + *(u32 *)(data + size + 4) = csum; + + /* Check the data format */ + ret = xbc_init(buf); + if (ret < 0) { + printf("Failed to parse %s: %d\n", xbc_path, ret); + free(data); + free(buf); + return ret; + } + printf("Apply %s to %s\n", xbc_path, path); + printf("\tSize: %u bytes\n", (unsigned int)size); + printf("\tChecksum: %d\n", (unsigned int)csum); + + /* TODO: Check the options by schema */ + xbc_destroy_all(); + free(buf); + + /* Remove old boot config if exists */ + ret = delete_xbc(path); + if (ret < 0) { + printf("Failed to delete previous boot config: %d\n", ret); + return ret; + } + + /* Apply new one */ + fd = open(path, O_RDWR | O_APPEND); + if (fd < 0) { + printf("Failed to open %s: %d\n", path, fd); + return fd; + } + /* TODO: Ensure the @path is initramfs/initrd image */ + ret = write(fd, data, size + 8); + if (ret < 0) { + printf("Failed to apply a boot config: %d\n", ret); + return ret; + } + close(fd); + free(data); + + return 0; +} + +int usage(void) +{ + printf("Usage: bootconfig [OPTIONS] <INITRD>\n" + " Apply, delete or show boot config to initrd.\n" + " Options:\n" + " -a <config>: Apply boot config to initrd\n" + " -d : Delete boot config file from initrd\n\n" + " If no option is given, show current applied boot config.\n"); + return -1; +} + +int main(int argc, char **argv) +{ + char *path = NULL; + char *apply = NULL; + bool delete = false; + int opt; + + while ((opt = getopt(argc, argv, "hda:")) != -1) { + switch (opt) { + case 'd': + delete = true; + break; + case 'a': + apply = optarg; + break; + case 'h': + default: + return usage(); + } + } + + if (apply && delete) { + printf("Error: You can not specify both -a and -d at once.\n"); + return usage(); + } + + if (optind >= argc) { + printf("Error: No initrd is specified.\n"); + return usage(); + } + + path = argv[optind]; + + if (apply) + return apply_xbc(path, apply); + else if (delete) + return delete_xbc(path); + + return show_xbc(path); +} |