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asusuimage: Cleanup code #43

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55 changes: 36 additions & 19 deletions src/asusuimage.c
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Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,13 @@

#define IH_COMP_NONE 0

#define GET_BE24(ptr) ( (((uint8_t *)(ptr))[0] << 16) | (((uint8_t *)(ptr))[1] << 8) | ((uint8_t *)(ptr))[2] )
#define SET_BE24(ptr, value) do { \
((uint8_t *)(ptr))[0] = ((value) >> 16) & 0xFF; \
((uint8_t *)(ptr))[1] = ((value) >> 8) & 0xFF; \
((uint8_t *)(ptr))[2] = (value) & 0xFF; \
} while (0)

enum volume_t {
VOL_KERNEL = 0,
VOL_RAMDISK,
Expand All @@ -49,11 +56,13 @@ typedef struct {
} __attribute__ ((packed)) version_t;

#define FS_OFFSET_PREFIX (0xA9)
#define TRX3_UNK1 (0x003000)

typedef struct {
char prod_name[23];
uint8_t unk0; // version of rootfs ???
uint32_t fs_offset; // 24 bit BE (first byte = 0xA9)
uint8_t fs_prefix; // prefix for fs_offset (0xA9)
uint8_t fs_offset[3];// offset for fs-image (24 bit BE)
} __attribute__ ((packed)) trx1_t;

typedef struct {
Expand All @@ -63,7 +72,8 @@ typedef struct {
uint8_t dummy; // likely random byte
uint8_t key; // hash value from kernel and fs
uint8_t unk[6]; // likely random bytes
uint32_t fs_offset; // 24 bit BE (first byte = 0xA9)
uint8_t fs_prefix; // prefix for fs_offset (0xA9)
uint8_t fs_offset[3];// offset for fs-image (24 bit BE)
} __attribute__ ((packed)) trx2_t; // hdr2

typedef struct {
Expand Down Expand Up @@ -310,7 +320,7 @@ int parse_args(int argc, char ** argv)
if (g_opt.trx_ver < 2 || g_opt.trx_ver > 3)
usage(EXIT_FAILURE);

return 0;
return 0;
}

static
Expand Down Expand Up @@ -387,7 +397,7 @@ static int show_info(char *img, size_t img_size)
uint16_t fcrc, fcrc_c, checksum_c;
uint8_t fs_key, kernel_key, key;
uint32_t sn, en, xx = 0;
size_t buf_size = 12;
size_t buf_size;
tail_footer_t * foot;
tail_content_t *cont;
image_header_t *hdr;
Expand All @@ -410,7 +420,7 @@ static int show_info(char *img, size_t img_size)
if (be32toh(foot->magic) == g_opt.magic)
g_opt.trx_ver = 3; /* tail with magic = DEF_ASUS_TAIL_MAGIC */

if (be32toh(hdr->tail.trx2.fs_offset) >> 24 == FS_OFFSET_PREFIX) {
if (hdr->tail.trx2.fs_prefix == FS_OFFSET_PREFIX) {
g_opt.trx_ver = 1; /* hdr1 */

for (i = 0; i < sizeof(hdr->tail.trx1.prod_name); i++) {
Expand Down Expand Up @@ -442,16 +452,18 @@ static int show_info(char *img, size_t img_size)
DBG("hdr2.en: %u (0x%04X) \n", en, htole16(trx->en));
DBG("hdr2.key: 0x%02X \n", trx->key);
buf = trx->unk;
buf_size = sizeof(trx2_t) - offsetof(trx2_t, unk);
for (size_t i = 0; i < buf_size; i += 2) {
if (buf[0] == FS_OFFSET_PREFIX && (buf[3] & 3) == 0) {
xx = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | (xx && 0xFF);
fs_offset = be32toh(xx);
buf += 2;
if (buf[i] == FS_OFFSET_PREFIX) {
xx = GET_BE24(buf + 1);
if ((xx & 3) == 0) {
fs_offset = xx;
break;
}
}
buf += 2;
}
DBG("fs_offset: 0x%08X \n", fs_offset);
if (fs_offset + 128 > img_size)
if (!fs_offset || fs_offset + 128 > img_size)
ERR("Incorrect fs_offset!");

fs_data = (uint32_t *)(img + fs_offset);
Expand Down Expand Up @@ -481,7 +493,7 @@ static int show_info(char *img, size_t img_size)
DBG("tail: footer size = 0x%lX (%lu) \n", sizeof(tail_footer_t), sizeof(tail_footer_t));
DBG("tail: footer magic: 0x%X \n", be32toh(foot->magic));

cont_len = foot->clen[0] << 24 | foot->clen[1] << 16 | foot->clen[2];
cont_len = GET_BE24(foot->clen);
DBG("tail: type = %X, flags = %X, content len = 0x%06X \n", foot->type, foot->flags, cont_len);

fcrc = foot->fcrc;
Expand Down Expand Up @@ -569,13 +581,19 @@ int process_image(void)
case 3:
prod_name = hdr->tail.trx3.prod_name;
max_prod_len = sizeof(hdr->tail.trx3.prod_name);
break;
default:
ERR("Incorrect option -v");
}

prod_name_str = (const char *)&hdr->kernel_ver;
if (g_opt.prod_name[0])
prod_name_str = g_opt.prod_name;

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wstringop-truncation"
strncpy(prod_name, prod_name_str, max_prod_len);
#pragma GCC diagnostic pop
hdr->kernel_ver = g_opt.kernel_ver;
hdr->fs_ver = g_opt.fs_ver;

Expand All @@ -593,7 +611,7 @@ int process_image(void)

for (uint32_t i = 0; i <= VOL_COUNT; i++) {
if (vol_size[i] == 0)
break;
break;
vol_count++;
}
DBG("Multi image: volumes count = %u \n", vol_count);
Expand All @@ -610,7 +628,7 @@ int process_image(void)
DBG("Multi image: volume %u has offset = 0x%08X \n", i, xoffset);
if (be32toh(vol_size[i]) > 0x4FFFFFF) {
free(img);
ERR("Multi image contain volume %u with huge size", i);
ERR("Multi image contain volume %u with huge size", i);
}

xoffset += be32toh(vol_size[i]);
Expand Down Expand Up @@ -687,15 +705,16 @@ int process_image(void)
ERR("kernel image size is too big (max size: 16MiB)");
}

trx->fs_offset = htobe32((FS_OFFSET_PREFIX << 24) + fs_offset);
trx->fs_prefix = FS_OFFSET_PREFIX;
SET_BE24(trx->fs_offset, fs_offset);
update_iheader_crc(hdr, NULL, img_size - hsz);
break;
case 3:
cont_len = 0;
cont = NULL;
foot = NULL;

hdr->tail.trx3.unk1 = htobe32(0x3000); // unknown value
hdr->tail.trx3.unk1 = htobe32(TRX3_UNK1); // unknown value

cont_len = img_size - hsz - data_size + sizeof(tail_content_t);
cont = (tail_content_t *)img_end;
Expand All @@ -713,9 +732,7 @@ int process_image(void)
ERR("Content length is too long (more than 0x%lX bytes)", 1UL << 24);
}

foot->clen[0] = (cont_len >> 16) & 0xFF; // 24bit BigEndian
foot->clen[1] = (cont_len >> 8) & 0xFF;
foot->clen[2] = cont_len & 0xFF;
SET_BE24(foot->clen, cont_len); // 24bit BigEndian

foot->magic = htobe32(g_opt.magic);
foot->type = g_opt.type;
Expand Down