You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

454 lines
11 KiB

#include "libisofs.h"
#include "eltorito.h"
#include "volume.h"
#include "util.h"
#include <assert.h>
#include <malloc.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
struct el_torito_validation_entry {
uint8_t header_id BP(1, 1);
uint8_t platform_id BP(2, 2);
uint8_t reserved BP(3, 4);
uint8_t id_string BP(5, 28);
uint8_t checksum BP(29, 30);
uint8_t key_byte1 BP(31, 31);
uint8_t key_byte2 BP(32, 32);
};
struct el_torito_default_entry {
uint8_t boot_indicator BP(1, 1);
uint8_t boot_media_type BP(2, 2);
uint8_t load_seg BP(3, 4);
uint8_t system_type BP(5, 5);
uint8_t unused1 BP(6, 6);
uint8_t sec_count BP(7, 8);
uint8_t block BP(9, 12);
uint8_t unused2 BP(13, 32);
};
struct el_torito_section_header_entry {
uint8_t header_indicator BP(1, 1);
uint8_t platform_id BP(2, 2);
uint8_t number BP(3, 4);
uint8_t character BP(5, 32);
};
struct el_torito_section_entry {
uint8_t boot_indicator BP(1, 1);
uint8_t boot_media_type BP(2, 2);
uint8_t load_seg BP(3, 4);
uint8_t system_type BP(5, 5);
uint8_t unused1 BP(6, 6);
uint8_t sec_count BP(7, 8);
uint8_t block BP(9, 12);
uint8_t selec_criteria BP(13, 13);
uint8_t vendor_sc BP(14, 32);
};
/**
* This table should be written with accuracy values at offset
* 8 of boot image, when used ISOLINUX boot loader
*/
struct boot_info_table {
uint8_t bi_pvd BP(1, 4); /* LBA of primary volume descriptor */
uint8_t bi_file BP(5, 8); /* LBA of boot file */
uint8_t bi_length BP(9, 12); /* Length of boot file */
uint8_t bi_csum BP(13, 16); /* Checksum of boot file */
uint8_t bi_reserved BP(17, 56); /* Reserved */
};
struct partition_desc {
uint8_t boot_ind;
uint8_t begin_chs[3];
uint8_t type;
uint8_t end_chs[3];
uint8_t start[4];
uint8_t size[4];
};
struct hard_disc_mbr {
uint8_t code_area[440];
uint8_t opt_disk_sg[4];
uint8_t pad[2];
struct partition_desc partition[4];
uint8_t sign1;
uint8_t sign2;
};
static struct el_torito_boot_image *
create_image(struct iso_tree_node *image,
enum eltorito_boot_media_type type)
{
struct el_torito_boot_image *boot;
int boot_media_type = 0;
int load_sectors = 0; /* number of sector to load */
unsigned char partition_type = 0;
switch (type) {
case ELTORITO_FLOPPY_EMUL:
switch (image->attrib.st_size) {
case 1200 * 1024:
boot_media_type = 1; /* 1.2 meg diskette */
break;
case 1440 * 1024:
boot_media_type = 2; /* 1.44 meg diskette */
break;
case 2880 * 1024:
boot_media_type = 3; /* 2.88 meg diskette */
break;
default:
fprintf(stderr, "Invalid image size %d Kb. Must be one of 1.2, 1.44"
"or 2.88 Mb", (int) image->attrib.st_size / 1024);
libisofs_errno = ELTORITO_WRONG_IMAGE_SIZE;
return NULL;
break;
}
/* it seems that for floppy emulation we need to load
* a single sector (512b) */
load_sectors = 1;
break;
case ELTORITO_HARD_DISC_EMUL:
{
size_t i;
int fd;
struct hard_disc_mbr mbr;
int used_partition;
/* read the MBR on disc and get the type of the partition */
fd = open(((struct iso_tree_node_file*)image)->loc.path, O_RDONLY);
if ( fd == -1 ) {
fprintf(stderr, "Can't open image file\n");
return NULL;
}
if ( read(fd, &mbr, sizeof(mbr)) ) {
fprintf(stderr, "Can't read MBR from image file\n");
close(fd);
return NULL;
}
close(fd);
/* check valid MBR signature */
if ( mbr.sign1 != 0x55 || mbr.sign2 != 0xAA ) {
fprintf(stderr, "Invalid MBR. Wrong signature.\n");
return NULL;
}
/* ensure single partition */
used_partition = -1;
for (i = 0; i < 4; ++i) {
if (mbr.partition[i].type != 0) {
/* it's an used partition */
if (used_partition != -1) {
fprintf(stderr, "Invalid MBR. At least 2 paritions: %d and "
"%d, are being used\n", used_partition, i);
return NULL;
} else
used_partition = i;
}
}
partition_type = mbr.partition[used_partition].type;
}
boot_media_type = 4;
/* only load the MBR */
load_sectors = 1;
break;
case ELTORITO_NO_EMUL:
boot_media_type = 0;
break;
}
boot = calloc(1, sizeof(struct el_torito_boot_image));
boot->bootable = 1;
boot->image = (struct iso_tree_node_file *) image;
boot->type = boot_media_type;
boot->load_size = load_sectors;
boot->partition_type = partition_type;
return boot;
}
static struct iso_tree_node_boot_catalog*
create_boot_catalog_node(struct iso_tree_node_dir *parent,
const char *name)
{
struct iso_tree_node_boot_catalog *boot;
assert( parent && name );
boot = calloc(1, sizeof(struct iso_tree_node_boot_catalog));
boot->node.attrib.st_mode = S_IFREG | 0444;
boot->node.attrib.st_atime =
boot->node.attrib.st_mtime =
boot->node.attrib.st_ctime = time(NULL);
boot->node.type = LIBISO_NODE_BOOTCATALOG;
boot->node.name = strdup(name);
iso_tree_add_child(parent, (struct iso_tree_node*) boot);
return boot;
}
struct el_torito_boot_image *
iso_volume_create_boot_catalog(struct iso_volume *volume,
struct iso_tree_node *image,
enum eltorito_boot_media_type type,
struct iso_tree_node_dir *dir,
char *name)
{
struct el_torito_boot_image *boot_image;
struct iso_tree_node_boot_catalog *boot_node;
struct el_torito_boot_catalog *catalog;
assert( volume && !volume->bootcat);
assert( image && ISO_ISREG(image) && dir && name);
boot_image = create_image(image, type);
if ( !boot_image )
return NULL;
/* creates the catalog with the given default image */
catalog = malloc(sizeof(struct el_torito_boot_catalog));
catalog->nentries = 1;
catalog->entries = malloc(sizeof(struct el_torito_boot_image *));
catalog->entries[0] = boot_image;
catalog->file = malloc(sizeof(struct iso_file));
catalog->file->size = 2048;
/* add catalog file */
boot_node = create_boot_catalog_node(dir, name);
boot_node->catalog = catalog;
volume->bootcat = catalog;
return boot_image;
}
void
el_torito_set_load_seg(struct el_torito_boot_image *bootimg, int segment)
{
if (bootimg->type != ELTORITO_NO_EMUL)
return;
bootimg->load_seg = segment;
}
void
el_torito_set_load_size(struct el_torito_boot_image *bootimg, int sectors)
{
if (bootimg->type != ELTORITO_NO_EMUL)
return;
bootimg->load_size = sectors;
}
void
el_torito_set_no_bootable(struct el_torito_boot_image *bootimg)
{
bootimg->bootable = 0;
}
void
el_torito_set_write_boot_info(struct el_torito_boot_image *bootimg)
{
bootimg->patch_isolinux = 1;
}
void el_torito_boot_catalog_free(struct el_torito_boot_catalog *cat)
{
size_t i;
assert(cat);
for(i = 0; i < cat->nentries; ++i) {
free(cat->entries[i]);
}
free(cat->entries);
free(cat->file);
free(cat);
}
void el_torito_get_image_files(struct ecma119_write_target *t)
{
size_t i;
struct el_torito_boot_catalog *cat = t->catalog;
assert(cat);
for(i = 0; i < cat->nentries; ++i) {
struct iso_tree_node_file *image = cat->entries[i]->image;
struct iso_file *file = iso_file_table_lookup(t->file_table, image);
if ( file == NULL ) {
file = iso_file_new(image);
iso_file_table_add_file(t->file_table, file);
}
cat->entries[i]->file = file;
}
}
/**
* Write the Boot Record Volume Descriptor
*/
static void
write_boot_vol_desc(struct ecma119_write_target *t, uint8_t *buf)
{
struct el_torito_boot_catalog *cat = t->catalog;
struct ecma119_boot_rec_vol_desc *vol =
(struct ecma119_boot_rec_vol_desc*)buf;
assert(cat);
vol->vol_desc_type[0] = 0;
memcpy(vol->std_identifier, "CD001", 5);
vol->vol_desc_version[0] = 1;
memcpy(vol->boot_sys_id, "EL TORITO SPECIFICATION", 23);
iso_lsb(vol->boot_catalog, cat->file->block, 4);
}
static void
write_validation_entry(struct ecma119_write_target *t, uint8_t *buf)
{
size_t i;
int checksum;
struct el_torito_validation_entry *ve =
(struct el_torito_validation_entry*)buf;
ve->header_id[0] = 1;
ve->platform_id[0] = 0; /* 0: 80x86, 1: PowerPC, 2: Mac */
ve->key_byte1[0] = 0x55;
ve->key_byte2[0] = 0xAA;
/* calculate the checksum, to ensure sum of all words is 0 */
checksum = 0;
for (i = 0; i < sizeof(struct el_torito_validation_entry); i += 2) {
checksum -= buf[i];
checksum -= (buf[i] << 8);
}
iso_lsb(ve->checksum, checksum, 2);
}
static void
patch_boot_file(struct el_torito_boot_image *img)
{
struct boot_info_table info;
int fd;
uint32_t checksum;
ssize_t len;
uint8_t buf[4];
memset(&info, 0, sizeof(info));
/* open image */
fd = open(img->image->loc.path, O_RDWR);
if ( fd == -1 ) {
//TODO what do do? exit or just continue?
fprintf(stderr, "Can't patch boot image %s\n", img->image->loc.path);
close(fd);
return;
}
/* compute checksum, as the the sum of all 32 bit words in boot image
* from offset 64 */
checksum = 0;
lseek(fd, (off_t) 64, SEEK_SET);
//TODO this can (must) be optimizied by reading to a longer buffer
while ( (len = read(fd, buf, 4) ) == 4 ) {
checksum += iso_read_lsb(buf, 4);
}
if ( len != 0 ) {
/* error reading file, or file length not multiple of 4 */
//TODO what do do? exit or just continue?
fprintf(stderr, "Can't patch boot image %s\n", img->image->loc.path);
close(fd);
return;
}
/* fill boot info table */
iso_lsb(info.bi_pvd, 16, 4); //FIXME this should be changed when we implement ms
iso_lsb(info.bi_file, img->file->block, 4);
iso_lsb(info.bi_length, img->image->node.attrib.st_size, 4);
iso_lsb(info.bi_csum, checksum, 4);
/* patch file */
lseek(fd, (off_t) 8, SEEK_SET);
write(fd, &info, sizeof(info));
close(fd);
}
void
el_torito_patch_image_files(struct ecma119_write_target *t)
{
size_t i;
struct el_torito_boot_catalog *cat = t->catalog;
assert(cat);
for (i = 0; i < cat->nentries; ++i) {
struct el_torito_boot_image *img = cat->entries[i];
if ( img->patch_isolinux )
patch_boot_file(img);
}
}
/**
* Write one section entry.
* Currently this is used for both default and other entries since we
* put selection criteria no 0 (no sel. criteria)
*/
static void
write_section_entry(uint8_t *buf, struct el_torito_boot_image *img)
{
struct el_torito_section_entry *se =
(struct el_torito_section_entry*)buf;
se->boot_indicator[0] = img->bootable ? 0x88 : 0x00;
se->boot_media_type[0] = img->type;
iso_lsb(se->load_seg, img->load_seg, 2);
se->system_type[0] = 0; //TODO need to get the partition type
iso_lsb(se->sec_count, img->load_size, 2);
iso_lsb(se->block, img->file->block, 4);
}
/**
* Write El-Torito Boot Catalog
*/
static void
write_catalog(struct ecma119_write_target *t, uint8_t *buf)
{
struct el_torito_boot_catalog *cat = t->catalog;
assert(cat);
assert(cat->nentries >= 1 && cat->nentries < 63);
write_validation_entry(t, buf);
/* write default entry */
write_section_entry(buf + 32, cat->entries[0]);
//TODO write all images
}
void
el_torito_wr_boot_vol_desc(struct ecma119_write_target *t, uint8_t *buf)
{
assert(t->catalog);
ecma119_start_chunking(t,
write_boot_vol_desc,
2048,
buf);
}
void
el_torito_wr_catalog(struct ecma119_write_target *t, uint8_t *buf)
{
assert(t->catalog);
ecma119_start_chunking(t,
write_catalog,
2048,
buf);
}