path: root/genisoimage/eltorito.c

/*
 * This file has been modified for the cdrkit suite.
 *
 * The behaviour and appearence of the program code below can differ to a major
 * extent from the version distributed by the original author(s).
 *
 * For details, see Changelog file distributed with the cdrkit package. If you
 * received this file from another source then ask the distributing person for
 * a log of modifications.
 *
 */

/* @(#)eltorito.c	1.33 05/02/27 joerg */
/*
 * Program eltorito.c - Handle El Torito specific extensions to iso9660.
 *
 *
 *  Written by Michael Fulbright <msf@redhat.com> (1996).
 *
 * Copyright 1996 RedHat Software, Incorporated
 * Copyright (c) 1999-2004 J. Schilling
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <mconfig.h>
#include "genisoimage.h"
#include <fctldefs.h>
#include <utypes.h>
#include <intcvt.h>
#include "match.h"
#include "diskmbr.h"
#include "bootinfo.h"
#include <schily.h>

#undef MIN
#define	MIN(a, b) (((a) < (b))? (a): (b))

static struct eltorito_validation_entry valid_desc;
static struct eltorito_boot_descriptor gboot_desc;
static struct disk_master_boot_record disk_mbr;
static unsigned int bcat_de_flags;

void	init_boot_catalog(const char *path);
void	insert_boot_cat(void);
static	void	get_torito_desc(struct eltorito_boot_descriptor *boot_desc);
static	void	fill_boot_desc(struct eltorito_defaultboot_entry *boot_desc_entry,
										struct eltorito_boot_entry_info *boot_entry);
void	get_boot_entry(void);
void	new_boot_entry(void);
static	int	tvd_write(FILE *outfile);


static	char	*bootcat_path;		/* filename of boot catalog */
/*
 * Make sure any existing boot catalog is excluded
 */
void
init_boot_catalog(const char *path)
{
#ifdef	SORTING
	struct eltorito_boot_entry_info * cbe;

	for (cbe = first_boot_entry;
	    cbe != NULL;
	    cbe = cbe->next) {
		char	*p;

		if (cbe->boot_image == NULL)
			comerrno(EX_BAD, "Missing boot image name, use -eltorito-boot option.\n");
		p = (char *) e_malloc(strlen(cbe->boot_image) + strlen(path) + 2);
		strcpy(p, path);
		if (p[strlen(p) - 1] != '/') {
			strcat(p, "/");
		}
		strcat(p, cbe->boot_image);
		add_sort_match(p, sort_matches(p, 1));
		free(p);
	}
#endif
	bootcat_path = (char *) e_malloc(strlen(boot_catalog) + strlen(path) + 2);
	strcpy(bootcat_path, path);
	if (bootcat_path[strlen(bootcat_path) - 1] != '/') {
		strcat(bootcat_path, "/");
	}
	strcat(bootcat_path, boot_catalog);

	/*
	 * we are going to create a virtual catalog file
	 * - so make sure any existing is excluded
	 */
	add_match(bootcat_path);

	/* flag the file as a memory file */
	bcat_de_flags = MEMORY_FILE;

	/* find out if we want to "hide" this file */
	if (i_matches(boot_catalog) || i_matches(bootcat_path))
		bcat_de_flags |= INHIBIT_ISO9660_ENTRY;

	if (j_matches(boot_catalog) || j_matches(bootcat_path))
		bcat_de_flags |= INHIBIT_JOLIET_ENTRY;

}/* init_boot_catalog(... */

/*
 * Create a boot catalog file in memory - genisoimage already uses this type of
 * file for the TRANS.TBL files. Therefore the boot catalog is set up in
 * similar way
 */
void
insert_boot_cat()
{
	struct directory_entry	*de;
	struct directory_entry	*s_entry;
	char			*p1;
	char			*p2;
	char			*p3;
	struct directory	*this_dir;
	struct directory	*dir;
	char			*buffer;

	init_fstatbuf();

	buffer = (char *) e_malloc(SECTOR_SIZE);
	memset(buffer, 0, SECTOR_SIZE);

	/*
	 * try to find the directory that will contain the boot.cat file
	 * - not very neat, but I can't think of a better way
	 */
	p1 = strdup(boot_catalog);

	/* get dirname (p1) and basename (p2) of boot.cat */
	if ((p2 = strrchr(p1, '/')) != NULL) {
		*p2 = '\0';
		p2++;

		/* find the dirname directory entry */
		de = search_tree_file(root, p1);
		if (!de) {
#ifdef	USE_LIBSCHILY
			comerrno(EX_BAD,
			"Uh oh, I cant find the boot catalog directory '%s'!\n",
								p1);
#else
			fprintf(stderr,
			"Uh oh, I cant find the boot catalog directory '%s'!\n",
								p1);
			exit(1);
#endif
		}
		this_dir = 0;

		/* get the basename (p3) of the directory */
		if ((p3 = strrchr(p1, '/')) != NULL)
			p3++;
		else
			p3 = p1;

		/* find the correct sub-directory entry */
		for (dir = de->filedir->subdir; dir; dir = dir->next)
			if (!(strcmp(dir->de_name, p3)))
				this_dir = dir;

		if (this_dir == 0) {
#ifdef	USE_LIBSCHILY
			comerrno(EX_BAD,
			"Uh oh, I cant find the boot catalog directory '%s'!\n",
								p3);
#else
			fprintf(stderr,
			"Uh oh, I cant find the boot catalog directory '%s'!\n",
								p3);
			exit(1);
#endif
		}
	} else {
		/* boot.cat is in the root directory */
		this_dir = root;
		p2 = p1;
	}

	/*
	 * make a directory entry in memory (using the same set up as for table
	 * entries
	 */
	s_entry = (struct directory_entry *)
		e_malloc(sizeof (struct directory_entry));
	memset(s_entry, 0, sizeof (struct directory_entry));
	s_entry->next = this_dir->contents;
	this_dir->contents = s_entry;

#ifdef SORTING
	/* inherit any sort weight from parent directory */
	s_entry->sort = this_dir->sort;
	s_entry->sort += 2;

	/* see if this entry should have a new weighting */
	if (do_sort) {
		s_entry->sort = sort_matches(bootcat_path, s_entry->sort);
	}
#endif /* SORTING */

	s_entry->isorec.flags[0] = ISO_FILE;
	s_entry->priority = 32768;
	iso9660_date(s_entry->isorec.date, fstatbuf.st_mtime);
	s_entry->inode = TABLE_INODE;
	s_entry->dev = (dev_t) UNCACHED_DEVICE;
	set_723(s_entry->isorec.volume_sequence_number,
						volume_sequence_number);
	set_733((char *) s_entry->isorec.size, SECTOR_SIZE);
	s_entry->size = SECTOR_SIZE;
	s_entry->filedir = this_dir;
	s_entry->name = strdup(p2);
	iso9660_file_length(p2, s_entry, 0);

	/* flag file as necessary */

	/*
	 * If the current directory is hidden, then hide this entry
	 */
	if (this_dir->dir_flags & INHIBIT_ISO9660_ENTRY)
		bcat_de_flags |= INHIBIT_ISO9660_ENTRY;
	if (this_dir->dir_flags & INHIBIT_JOLIET_ENTRY)
		bcat_de_flags |= INHIBIT_JOLIET_ENTRY;

	s_entry->de_flags = bcat_de_flags;

	if ((use_XA || use_RockRidge) &&
	    !(bcat_de_flags & INHIBIT_ISO9660_ENTRY)) {
		fstatbuf.st_mode = 0444 | S_IFREG;
		fstatbuf.st_nlink = 1;
		generate_xa_rr_attributes("",
			p2, s_entry,
			&fstatbuf, &fstatbuf, 0);
	}
	/*
	 *  memory files are stored at s_entry->table
	 * - but this is also used for each s_entry to generate
	 * TRANS.TBL entries. So if we are generating tables,
	 * store the TRANS.TBL data here for the moment
	 */
	if (generate_tables && !(bcat_de_flags & INHIBIT_ISO9660_ENTRY)) {
		sprintf(buffer, "F\t%s\n", s_entry->name);

		/* copy the TRANS.TBL entry info and clear the buffer */
		s_entry->table = strdup(buffer);
		memset(buffer, 0, SECTOR_SIZE);

		/*
		 * store the (empty) file data in the
		 * unused s_entry->whole_name element for the time being
		 * - this will be transferred to s_entry->table after any
		 * TRANS.TBL processing later
		 */
		s_entry->whole_name = buffer;
	} else {
		/* store the (empty) file data in the s_entry->table element */
		s_entry->table = buffer;
		s_entry->whole_name = NULL;
	}
}

static void
get_torito_desc(struct eltorito_boot_descriptor *boot_desc)
{
	int			checksum;
	unsigned char		*checksum_ptr;
	struct directory_entry	*de2;	/* Boot catalog */
	int			i;
	int			offset;
	struct eltorito_defaultboot_entry boot_desc_record;

	memset(boot_desc, 0, sizeof (*boot_desc));
	boot_desc->type[0] = 0;
	memcpy(boot_desc->id, ISO_STANDARD_ID, sizeof (ISO_STANDARD_ID));
	boot_desc->version[0] = 1;

	memcpy(boot_desc->system_id, EL_TORITO_ID, sizeof (EL_TORITO_ID));

	/*
	 * search from root of iso fs to find boot catalog
	 * - we already know where the boot catalog is
	 * - we created it above - but lets search for it anyway
	 * - good sanity check!
	 */
	de2 = search_tree_file(root, boot_catalog);
	if (!de2 || !(de2->de_flags & MEMORY_FILE)) {
#ifdef	USE_LIBSCHILY
		comerrno(EX_BAD, "Uh oh, I cant find the boot catalog '%s'!\n",
							boot_catalog);
#else
		fprintf(stderr, "Uh oh, I cant find the boot catalog '%s'!\n",
							boot_catalog);
		exit(1);
#endif
	}
	set_731(boot_desc->bootcat_ptr,
		(unsigned int) get_733(de2->isorec.extent));

	/*
	 * we have the boot image, so write boot catalog information
	 * Next we write out the primary descriptor for the disc
	 */
	memset(&valid_desc, 0, sizeof (valid_desc));
	valid_desc.headerid[0] = 1;
	valid_desc.arch[0] = EL_TORITO_ARCH_x86;

	/*
	 * we'll shove start of publisher id into id field,
	 * may get truncated but who really reads this stuff!
	 */
	if (publisher)
		memcpy_max(valid_desc.id, publisher,
						MIN(23, strlen(publisher)));

	valid_desc.key1[0] = (char) 0x55;
	valid_desc.key2[0] = (char) 0xAA;

	/* compute the checksum */
	checksum = 0;
	checksum_ptr = (unsigned char *) &valid_desc;
	/* Set checksum to 0 before computing checksum */
	set_721(valid_desc.cksum, 0);
	for (i = 0; i < (int)sizeof (valid_desc); i += 2) {
		checksum += (unsigned int) checksum_ptr[i];
		checksum += ((unsigned int) checksum_ptr[i + 1]) * 256;
	}

	/* now find out the real checksum */
	checksum = -checksum;
	set_721(valid_desc.cksum, (unsigned int) checksum);

	/* now write it to the virtual boot catalog */
	memcpy(de2->table, &valid_desc, 32);

	for (current_boot_entry = first_boot_entry, offset = sizeof (valid_desc);
		current_boot_entry != NULL;
		current_boot_entry = current_boot_entry->next,
		offset += sizeof (boot_desc_record)) {

		if (offset >= SECTOR_SIZE) {
#ifdef	USE_LIBSCHILY
			comerrno(EX_BAD,
			"Too many El Torito boot entries\n");
#else
			fprintf(stderr,
			"Too many El Torito boot entries\n");
			exit(1);
#endif
		}
		fill_boot_desc(&boot_desc_record, current_boot_entry);
		memcpy(de2->table + offset, &boot_desc_record,
					sizeof (boot_desc_record));
	}
}/* get_torito_desc(... */

static void
fill_boot_desc(struct eltorito_defaultboot_entry *boot_desc_entry, 
					struct eltorito_boot_entry_info *boot_entry)
{
	struct directory_entry	*de;	/* Boot file */
	int			bootmbr;
	int			i;
	int			nsectors;
	int			geosec;

	if (!boot_desc_entry || !boot_entry)
		return;

	/* now adjust boot catalog lets find boot image first */
	de = search_tree_file(root, boot_entry->boot_image);
	if (!de) {
#ifdef	USE_LIBSCHILY
		comerrno(EX_BAD, "Uh oh, I cant find the boot image '%s' !\n",
							boot_entry->boot_image);
#else
		fprintf(stderr, "Uh oh, I cant find the boot image '%s' !\n",
							boot_entry->boot_image);
		exit(1);
#endif
	}
	/* now make the initial/default entry for boot catalog */
	memset(boot_desc_entry, 0, sizeof (*boot_desc_entry));
	boot_desc_entry->boot_id[0] = (char) boot_entry->not_bootable ?
				EL_TORITO_NOT_BOOTABLE : EL_TORITO_BOOTABLE;

	/* use default BIOS loadpnt */
	set_721(boot_desc_entry->loadseg, boot_entry->load_addr);

	/*
	 * figure out size of boot image in 512-byte sectors.
	 * However, round up to the nearest integral CD (2048-byte) sector.
	 * This is only used for no-emulation booting.
	 */
	nsectors = boot_entry->load_size ? boot_entry->load_size :
				ISO_BLOCKS(de->size) * (SECTOR_SIZE/512);

	if (verbose > 0) {
		fprintf(stderr,
			"Size of boot image is %d sectors -> ", nsectors);
	}

	if (boot_entry->hard_disk_boot) {
		/* sanity test hard disk boot image */
		boot_desc_entry->boot_media[0] = EL_TORITO_MEDIA_HD;
		if (verbose > 0)
			fprintf(stderr, "Emulating a hard disk\n");

		/* read MBR */
		bootmbr = open(de->whole_name, O_RDONLY | O_BINARY);
		if (bootmbr == -1) {
#ifdef	USE_LIBSCHILY
			comerr("Error opening boot image '%s' for read.\n",
							de->whole_name);
#else
			fprintf(stderr,
				"Error opening boot image '%s' for read.\n",
							de->whole_name);
			perror("");
			exit(1);
#endif
		}
		if (read(bootmbr, &disk_mbr, sizeof (disk_mbr)) !=
							sizeof (disk_mbr)) {
#ifdef	USE_LIBSCHILY
			comerr("Error reading MBR from boot image '%s'.\n",
							de->whole_name);
#else
			fprintf(stderr,
				"Error reading MBR from boot image '%s'.\n",
							de->whole_name);
			exit(1);
#endif
		}
		close(bootmbr);
		if (la_to_u_2_byte(disk_mbr.magic) != MBR_MAGIC) {
#ifdef	USE_LIBSCHILY
			errmsgno(EX_BAD,
			"Warning: boot image '%s' MBR is not a boot sector.\n",
							de->whole_name);
#else
			fprintf(stderr,
				"Warning: boot image '%s' MBR is not a boot sector.\n",
							de->whole_name);
#endif
		}
		/* find partition type */
		boot_desc_entry->sys_type[0] = PARTITION_UNUSED;
		for (i = 0; i < PARTITION_COUNT; ++i) {
			int		s_cyl_sec;
			int		e_cyl_sec;

			s_cyl_sec =
			la_to_u_2_byte(disk_mbr.partition[i].s_cyl_sec);
			e_cyl_sec =
			la_to_u_2_byte(disk_mbr.partition[i].e_cyl_sec);

			if (disk_mbr.partition[i].type != PARTITION_UNUSED) {
				if (boot_desc_entry->sys_type[0] !=
							PARTITION_UNUSED) {
#ifdef	USE_LIBSCHILY
					comerrno(EX_BAD,
					"Boot image '%s' has multiple partitions.\n",
							de->whole_name);
#else
					fprintf(stderr,
					"Boot image '%s' has multiple partitions.\n",
							de->whole_name);
					exit(1);
#endif
				}
				boot_desc_entry->sys_type[0] =
						disk_mbr.partition[i].type;

				/* a few simple sanity warnings */
				if (!boot_entry->not_bootable &&
				    disk_mbr.partition[i].status !=
							PARTITION_ACTIVE) {
					fprintf(stderr,
					"Warning: partition not marked active.\n");
				}
				if (MBR_CYLINDER(s_cyl_sec) != 0 ||
					disk_mbr.partition[i].s_head != 1 ||
					MBR_SECTOR(s_cyl_sec != 1)) {
					fprintf(stderr,
					"Warning: partition does not start at 0/1/1.\n");
				}
				geosec = (MBR_CYLINDER(e_cyl_sec) + 1) *
					(disk_mbr.partition[i].e_head + 1) *
					MBR_SECTOR(e_cyl_sec);
				if (geosec != nsectors) {
					fprintf(stderr,
					"Warning: image size does not match geometry (%d)\n",
						geosec);
				}
#ifdef DEBUG_TORITO
				fprintf(stderr, "Partition start %u/%u/%u\n",
					MBR_CYLINDER(s_cyl_sec),
					disk_mbr.partition[i].s_head,
					MBR_SECTOR(s_cyl_sec));
				fprintf(stderr, "Partition end %u/%u/%u\n",
					MBR_CYLINDER(e_cyl_sec),
					disk_mbr.partition[i].e_head,
					MBR_SECTOR(e_cyl_sec));
#endif
			}
		}
		if (boot_desc_entry->sys_type[0] == PARTITION_UNUSED) {
#ifdef	USE_LIBSCHILY
			comerrno(EX_BAD,
					"Boot image '%s' has no partitions.\n",
							de->whole_name);
#else
			fprintf(stderr,
					"Boot image '%s' has no partitions.\n",
							de->whole_name);
			exit(1);
#endif
		}
#ifdef DEBUG_TORITO
		fprintf(stderr, "Partition type %u\n",
						boot_desc_entry->sys_type[0]);
#endif
	/* load single boot sector, in this case the MBR */
		nsectors = 1;

	} else if (boot_entry->no_emul_boot) {
		/*
		 * no emulation is a simple image boot of all the sectors
		 * in the boot image
		 */
		boot_desc_entry->boot_media[0] = EL_TORITO_MEDIA_NOEMUL;
		if (verbose > 0)
			fprintf(stderr, "No emulation\n");

	} else {
		/* choose size of emulated floppy based on boot image size */
		if (nsectors == 2880) {
			boot_desc_entry->boot_media[0] = EL_TORITO_MEDIA_144FLOP;
			if (verbose > 0)
				fprintf(stderr, "Emulating a 1440 kB floppy\n");

		} else if (nsectors == 5760) {
			boot_desc_entry->boot_media[0] = EL_TORITO_MEDIA_288FLOP;
			if (verbose > 0)
				fprintf(stderr, "Emulating a 2880 kB floppy\n");

		} else if (nsectors == 2400) {
			boot_desc_entry->boot_media[0] = EL_TORITO_MEDIA_12FLOP;
			if (verbose > 0)
				fprintf(stderr, "Emulating a 1200 kB floppy\n");

		} else {
#ifdef	USE_LIBSCHILY
			comerrno(EX_BAD,
			"Error - boot image '%s' has not an allowable size.\n",
							de->whole_name);
#else
			fprintf(stderr,
			"Error - boot image '%s' has not an allowable size.\n",
							de->whole_name);
			exit(1);
#endif
		}

		/* load single boot sector for floppies */
		nsectors = 1;
	}

	/* fill in boot image details */
#ifdef DEBUG_TORITO
	fprintf(stderr, "Boot %u sectors\n", nsectors);
	fprintf(stderr, "Extent of boot images is %d\n",
				get_733(de->isorec.extent));
#endif
	set_721(boot_desc_entry->nsect, (unsigned int) nsectors);
	set_731(boot_desc_entry->bootoff,
		(unsigned int) get_733(de->isorec.extent));


	/* If the user has asked for it, patch the boot image */
	if (boot_entry->boot_info_table) {
		int		bootimage;
		unsigned int	bi_checksum;
		unsigned int	total_len;
		static char	csum_buffer[SECTOR_SIZE];
		int		len;
		struct genisoimage_boot_info bi_table;
		bootimage = open(de->whole_name, O_RDWR | O_BINARY);
		if (bootimage == -1) {
#ifdef	USE_LIBSCHILY
			comerr(
			"Error opening boot image file '%s' for update.\n",
							de->whole_name);
#else
			fprintf(stderr,
			"Error opening boot image file '%s' for update.\n",
							de->whole_name);
			perror("");
			exit(1);
#endif
		}
	/* Compute checksum of boot image, sans 64 bytes */
		total_len = 0;
		bi_checksum = 0;
		while ((len = read(bootimage, csum_buffer, SECTOR_SIZE)) > 0) {
			if (total_len & 3) {
#ifdef	USE_LIBSCHILY
				comerrno(EX_BAD,
				"Odd alignment at non-end-of-file in boot image '%s'.\n",
							de->whole_name);
#else
				fprintf(stderr,
				"Odd alignment at non-end-of-file in boot image '%s'.\n",
							de->whole_name);
				exit(1);
#endif
			}
			if (total_len < 64)
				memset(csum_buffer, 0, 64 - total_len);
			if (len < SECTOR_SIZE)
				memset(csum_buffer + len, 0, SECTOR_SIZE-len);
			for (i = 0; i < SECTOR_SIZE; i += 4)
				bi_checksum += get_731(&csum_buffer[i]);
			total_len += len;
		}

		if (total_len != de->size) {
#ifdef	USE_LIBSCHILY
			comerrno(EX_BAD,
			"Boot image file '%s' changed underneath us!\n",
						de->whole_name);
#else
			fprintf(stderr,
			"Boot image file '%s' changed underneath us!\n",
						de->whole_name);
			exit(1);
#endif
		}
		/* End of file, set position to byte 8 */
		lseek(bootimage, (off_t)8, SEEK_SET);
		memset(&bi_table, 0, sizeof (bi_table));
		/* Is it always safe to assume PVD is at session_start+16? */
		set_731(bi_table.bi_pvd, session_start + 16);
		set_731(bi_table.bi_file, de->starting_block);
		set_731(bi_table.bi_length, de->size);
		set_731(bi_table.bi_csum, bi_checksum);

		write(bootimage, &bi_table, sizeof (bi_table)); /* FIXME: check return value */
		close(bootimage);
	}
}/* fill_boot_desc(... */

void
get_boot_entry()
{
	if (current_boot_entry)
		return;

	current_boot_entry = (struct eltorito_boot_entry_info *)
			e_malloc(sizeof (struct eltorito_boot_entry_info));
	memset(current_boot_entry, 0, sizeof (*current_boot_entry));

	if (!first_boot_entry) {
		first_boot_entry = current_boot_entry;
		last_boot_entry = current_boot_entry;
	} else {
		last_boot_entry->next = current_boot_entry;
		last_boot_entry = current_boot_entry;
	}
}

void
new_boot_entry()
{
	current_boot_entry = NULL;
}

/*
 * Function to write the EVD for the disc.
 */
static int
tvd_write(FILE *outfile)
{
	/* check the boot image is not NULL */
	if (!boot_image) {
#ifdef	USE_LIBSCHILY
		comerrno(EX_BAD, "No boot image specified.\n");
#else
		fprintf(stderr, "No boot image specified.\n");
		exit(1);
#endif
	}
	/* Next we write out the boot volume descriptor for the disc */
	get_torito_desc(&gboot_desc);
	jtwrite(&gboot_desc, SECTOR_SIZE, 1, 0, FALSE);
	xfwrite(&gboot_desc, SECTOR_SIZE, 1, outfile, 0, FALSE);
	last_extent_written++;
	return (0);
}

struct output_fragment torito_desc = {NULL, oneblock_size, NULL, tvd_write, "Eltorito Volume Descriptor"};