2018-02-10 03:34:13 +08:00

423 lines
12 KiB
C

#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include "bootimg.h"
#include "magiskboot.h"
#include "utils.h"
#include "logging.h"
#include "mincrypt/sha.h"
#include "mincrypt/sha256.h"
#define INSUF_BLOCK_RET 2
#define CHROMEOS_RET 3
#define ELF32_RET 4
#define ELF64_RET 5
// Macros to determine header on-the-go
#define lheader(b, e, o) \
((b)->flags & PXA_FLAG) ? \
(((struct pxa_boot_img_hdr*) (b)->hdr)->e o) : \
(((struct boot_img_hdr*) (b)->hdr)->e o)
#define header(b, e) (lheader(b, e,))
static void dump(void *buf, size_t size, const char *filename) {
if (size == 0)
return;
int fd = creat(filename, 0644);
xwrite(fd, buf, size);
close(fd);
}
static size_t restore(const char *filename, int fd) {
int ifd = xopen(filename, O_RDONLY);
size_t size = lseek(ifd, 0, SEEK_END);
lseek(ifd, 0, SEEK_SET);
xsendfile(fd, ifd, NULL, size);
close(ifd);
return size;
}
static void restore_buf(int fd, const void *buf, size_t size) {
xwrite(fd, buf, size);
}
static void print_hdr(const boot_img *boot) {
fprintf(stderr, "KERNEL [%u]\n", header(boot, kernel_size));
fprintf(stderr, "RAMDISK [%u]\n", header(boot, ramdisk_size));
fprintf(stderr, "SECOND [%u]\n", header(boot, second_size));
fprintf(stderr, "EXTRA [%u]\n", header(boot, extra_size));
fprintf(stderr, "PAGESIZE [%u]\n", header(boot, page_size));
if (!(boot->flags & PXA_FLAG)) {
uint32_t os_version = ((boot_img_hdr*) boot->hdr)->os_version;
if (os_version) {
int a,b,c,y,m = 0;
int version, patch_level;
version = os_version >> 11;
patch_level = os_version & 0x7ff;
a = (version >> 14) & 0x7f;
b = (version >> 7) & 0x7f;
c = version & 0x7f;
fprintf(stderr, "OS_VERSION [%d.%d.%d]\n", a, b, c);
y = (patch_level >> 4) + 2000;
m = patch_level & 0xf;
fprintf(stderr, "PATCH_LEVEL [%d-%02d]\n", y, m);
}
}
fprintf(stderr, "NAME [%s]\n", header(boot, name));
fprintf(stderr, "CMDLINE [%s]\n", header(boot, cmdline));
fprintf(stderr, "CHECKSUM [");
for (int i = 0; i < ((boot->flags & SHA256_FLAG) ? SHA256_DIGEST_SIZE : SHA_DIGEST_SIZE); ++i)
fprintf(stderr, "%02x", header(boot, id)[i]);
fprintf(stderr, "]\n");
}
static void clean_boot(boot_img *boot) {
munmap(boot->map_addr, boot->map_size);
free(boot->hdr);
free(boot->k_hdr);
free(boot->r_hdr);
free(boot->b_hdr);
memset(boot, 0, sizeof(*boot));
}
#define pos_align() pos = align(pos, header(boot, page_size))
int parse_img(const char *image, boot_img *boot) {
memset(boot, 0, sizeof(*boot));
int is_blk = mmap_ro(image, &boot->map_addr, &boot->map_size);
// Parse image
fprintf(stderr, "Parsing boot image: [%s]\n", image);
for (void *head = boot->map_addr; head < boot->map_addr + boot->map_size; ++head) {
size_t pos = 0;
switch (check_fmt(head, boot->map_size)) {
case CHROMEOS:
// The caller should know it's chromeos, as it needs additional signing
boot->flags |= CHROMEOS_FLAG;
continue;
case DHTB:
boot->flags |= DHTB_FLAG;
boot->flags |= SEANDROID_FLAG;
fprintf(stderr, "DHTB_HDR\n");
continue;
case ELF32:
exit(ELF32_RET);
case ELF64:
exit(ELF64_RET);
case BLOB:
boot->flags |= BLOB_FLAG;
fprintf(stderr, "TEGRA_BLOB\n");
boot->b_hdr = malloc(sizeof(blob_hdr));
memcpy(boot->b_hdr, head, sizeof(blob_hdr));
continue;
case AOSP:
// Read the header
if (((boot_img_hdr*) head)->page_size >= 0x02000000) {
boot->flags |= PXA_FLAG;
fprintf(stderr, "PXA_BOOT_HDR\n");
boot->hdr = malloc(sizeof(pxa_boot_img_hdr));
memcpy(boot->hdr, head, sizeof(pxa_boot_img_hdr));
} else if (memcmp(((boot_img_hdr*) head)->cmdline, NOOK_MAGIC, 12) == 0) {
boot->flags |= NOOK_FLAG;
fprintf(stderr, "NOOK_GREEN_LOADER\n");
head += NOOK_PRE_HEADER_SZ - 1;
continue;
} else {
boot->hdr = malloc(sizeof(boot_img_hdr));
memcpy(boot->hdr, head, sizeof(boot_img_hdr));
}
pos += header(boot, page_size);
for (int i = SHA_DIGEST_SIZE; i < SHA256_DIGEST_SIZE; ++i) {
if (header(boot, id)[i]) {
boot->flags |= SHA256_FLAG;
break;
}
}
print_hdr(boot);
boot->kernel = head + pos;
pos += header(boot, kernel_size);
pos_align();
boot->ramdisk = head + pos;
pos += header(boot, ramdisk_size);
pos_align();
boot->second = head + pos;
pos += header(boot, second_size);
pos_align();
boot->extra = head + pos;
pos += header(boot, extra_size);
pos_align();
if (pos < boot->map_size) {
boot->tail = head + pos;
boot->tail_size = boot->map_size - pos;
}
// Check tail info, currently only for LG Bump and Samsung SEANDROIDENFORCE
if (boot->tail_size >= 16 && memcmp(boot->tail, SEANDROID_MAGIC, 16) == 0) {
boot->flags |= SEANDROID_FLAG;
} else if (boot->tail_size >= 16 && memcmp(boot->tail, LG_BUMP_MAGIC, 16) == 0) {
boot->flags |= LG_BUMP_FLAG;
}
// Search for dtb in kernel
for (uint32_t i = 0; i < header(boot, kernel_size); ++i) {
if (memcmp(boot->kernel + i, DTB_MAGIC, 4) == 0) {
boot->dtb = boot->kernel + i;
boot->dt_size = header(boot, kernel_size) - i;
lheader(boot, kernel_size, = i);
fprintf(stderr, "DTB [%u]\n", boot->dt_size);
break;
}
}
boot->k_fmt = check_fmt(boot->kernel, header(boot, kernel_size));
boot->r_fmt = check_fmt(boot->ramdisk, header(boot, ramdisk_size));
// Check MTK
if (boot->k_fmt == MTK) {
fprintf(stderr, "MTK_KERNEL_HDR\n");
boot->flags |= MTK_KERNEL;
boot->k_hdr = malloc(sizeof(mtk_hdr));
memcpy(boot->k_hdr, boot->kernel, sizeof(mtk_hdr));
fprintf(stderr, "KERNEL [%u]\n", boot->k_hdr->size);
fprintf(stderr, "NAME [%s]\n", boot->k_hdr->name);
boot->kernel += 512;
lheader(boot, kernel_size, -= 512);
boot->k_fmt = check_fmt(boot->kernel, header(boot, kernel_size));
}
if (boot->r_fmt == MTK) {
fprintf(stderr, "MTK_RAMDISK_HDR\n");
boot->flags |= MTK_RAMDISK;
boot->r_hdr = malloc(sizeof(mtk_hdr));
memcpy(boot->r_hdr, boot->kernel, sizeof(mtk_hdr));
fprintf(stderr, "RAMDISK [%u]\n", boot->r_hdr->size);
fprintf(stderr, "NAME [%s]\n", boot->r_hdr->name);
boot->ramdisk += 512;
lheader(boot, ramdisk_size, -= 512);
boot->k_fmt = check_fmt(boot->ramdisk, header(boot, ramdisk_size));
}
char fmt[16];
get_fmt_name(boot->k_fmt, fmt);
fprintf(stderr, "KERNEL_FMT [%s]\n", fmt);
get_fmt_name(boot->r_fmt, fmt);
fprintf(stderr, "RAMDISK_FMT [%s]\n", fmt);
return boot->flags & CHROMEOS_FLAG ? CHROMEOS_RET :
((is_blk && boot->tail_size < 500 * 1024) ? INSUF_BLOCK_RET : 0);
default:
continue;
}
}
LOGE("No boot image magic found!\n");
}
int unpack(const char *image) {
boot_img boot;
int ret = parse_img(image, &boot);
int fd;
// Dump kernel
if (COMPRESSED(boot.k_fmt)) {
fd = creat(KERNEL_FILE, 0644);
decomp(boot.k_fmt, fd, boot.kernel, header(&boot, kernel_size));
close(fd);
} else {
dump(boot.kernel, header(&boot, kernel_size), KERNEL_FILE);
}
// Dump dtb
dump(boot.dtb, boot.dt_size, DTB_FILE);
// Dump ramdisk
if (COMPRESSED(boot.r_fmt)) {
fd = creat(RAMDISK_FILE, 0644);
decomp(boot.r_fmt, fd, boot.ramdisk, header(&boot, ramdisk_size));
close(fd);
} else {
dump(boot.ramdisk, header(&boot, ramdisk_size), RAMDISK_FILE);
}
// Dump second
dump(boot.second, header(&boot, second_size), SECOND_FILE);
// Dump extra
dump(boot.extra, header(&boot, extra_size), EXTRA_FILE);
clean_boot(&boot);
return ret;
}
#define file_align() write_zero(fd, align_off(lseek(fd, 0, SEEK_CUR) - header_off, header(&boot, page_size)))
void repack(const char* orig_image, const char* out_image) {
boot_img boot;
off_t header_off, kernel_off, ramdisk_off, second_off, extra_off;
// Parse original image
parse_img(orig_image, &boot);
// Reset all sizes
lheader(&boot, kernel_size, = 0);
lheader(&boot, ramdisk_size, = 0);
lheader(&boot, second_size, = 0);
lheader(&boot, extra_size, = 0);
boot.dt_size = 0;
fprintf(stderr, "Repack to boot image: [%s]\n", out_image);
// Create new image
int fd = creat(out_image, 0644);
if (boot.flags & DHTB_FLAG) {
// Skip DHTB header
write_zero(fd, 512);
} else if (boot.flags & BLOB_FLAG) {
// Skip blob header
write_zero(fd, sizeof(blob_hdr));
} else if (boot.flags & NOOK_FLAG) {
restore_buf(fd, boot.map_addr, NOOK_PRE_HEADER_SZ);
}
// Skip a page for header
header_off = lseek(fd, 0, SEEK_CUR);
write_zero(fd, header(&boot, page_size));
// kernel
kernel_off = lseek(fd, 0, SEEK_CUR);
if (boot.flags & MTK_KERNEL) {
// Skip MTK header
write_zero(fd, 512);
}
if (access(KERNEL_FILE, R_OK) == 0) {
if (COMPRESSED(boot.k_fmt)) {
size_t raw_size;
void *kernel_raw;
mmap_ro(KERNEL_FILE, &kernel_raw, &raw_size);
lheader(&boot, kernel_size, = comp(boot.k_fmt, fd, kernel_raw, raw_size));
munmap(kernel_raw, raw_size);
} else {
lheader(&boot, kernel_size, = restore(KERNEL_FILE, fd));
}
// dtb
if (access(DTB_FILE, R_OK) == 0) {
lheader(&boot, kernel_size, += restore(DTB_FILE, fd));
}
file_align();
}
// ramdisk
ramdisk_off = lseek(fd, 0, SEEK_CUR);
if (boot.flags & MTK_RAMDISK) {
// Skip MTK header
write_zero(fd, 512);
}
if (access(RAMDISK_FILE, R_OK) == 0) {
if (COMPRESSED(boot.r_fmt)) {
size_t cpio_size;
void *cpio;
mmap_ro(RAMDISK_FILE, &cpio, &cpio_size);
lheader(&boot, ramdisk_size, = comp(boot.r_fmt, fd, cpio, cpio_size));
munmap(cpio, cpio_size);
} else {
lheader(&boot, kernel_size, = restore(KERNEL_FILE, fd));
}
file_align();
}
// second
second_off = lseek(fd, 0, SEEK_CUR);
if (access(SECOND_FILE, R_OK) == 0) {
lheader(&boot, second_size, = restore(SECOND_FILE, fd));
file_align();
}
// extra
extra_off = lseek(fd, 0, SEEK_CUR);
if (access(EXTRA_FILE, R_OK) == 0) {
lheader(&boot, extra_size, = restore(EXTRA_FILE, fd));
file_align();
}
// Append tail info
if (boot.flags & SEANDROID_FLAG) {
restore_buf(fd, SEANDROID_MAGIC "\xFF\xFF\xFF\xFF", 20);
}
if (boot.flags & LG_BUMP_FLAG) {
restore_buf(fd, LG_BUMP_MAGIC, 16);
}
close(fd);
// Map output image as rw
munmap(boot.map_addr, boot.map_size);
mmap_rw(out_image, &boot.map_addr, &boot.map_size);
// MTK headers
if (boot.flags & MTK_KERNEL) {
boot.k_hdr->size = header(&boot, kernel_size);
lheader(&boot, kernel_size, += 512);
memcpy(boot.map_addr + kernel_off, boot.k_hdr, sizeof(mtk_hdr));
}
if (boot.flags & MTK_RAMDISK) {
boot.r_hdr->size = header(&boot, ramdisk_size);
lheader(&boot, ramdisk_size, += 512);
memcpy(boot.map_addr + ramdisk_off, boot.r_hdr, sizeof(mtk_hdr));
}
// Update checksum
HASH_CTX ctx;
(boot.flags & SHA256_FLAG) ? SHA256_init(&ctx) : SHA_init(&ctx);
uint32_t size = header(&boot, kernel_size);
HASH_update(&ctx, boot.map_addr + kernel_off, size);
HASH_update(&ctx, &size, sizeof(size));
size = header(&boot, ramdisk_size);
HASH_update(&ctx, boot.map_addr + ramdisk_off, size);
HASH_update(&ctx, &size, sizeof(size));
size = header(&boot, second_size);
HASH_update(&ctx, boot.map_addr + second_off, size);
HASH_update(&ctx, &size, sizeof(size));
size = header(&boot, extra_size);
if (size) {
HASH_update(&ctx, boot.map_addr + extra_off, size);
HASH_update(&ctx, &size, sizeof(size));
}
memset(header(&boot, id), 0, 32);
memcpy(header(&boot, id), HASH_final(&ctx),
(boot.flags & SHA256_FLAG) ? SHA256_DIGEST_SIZE : SHA_DIGEST_SIZE);
// Print new image info
print_hdr(&boot);
// Main header
memcpy(boot.map_addr + header_off, boot.hdr,
(boot.flags & PXA_FLAG) ? sizeof(pxa_boot_img_hdr) : sizeof(boot_img_hdr));
if (boot.flags & DHTB_FLAG) {
// DHTB header
dhtb_hdr *hdr = boot.map_addr;
memcpy(hdr, DHTB_MAGIC, 8);
hdr->size = boot.map_size - 512;
SHA256_hash(boot.map_addr + 512, hdr->size, hdr->checksum);
} else if (boot.flags & BLOB_FLAG) {
// Blob headers
boot.b_hdr->size = boot.map_size - sizeof(blob_hdr);
memcpy(boot.map_addr, boot.b_hdr, sizeof(blob_hdr));
}
clean_boot(&boot);
}