path: root/src/xorriso-usb.sh

#!/bin/bash

. samizdat-paths.sh || exit 1

outdev=
volid=SamizdatLive
gpg_iso_path=gnupghome
gnupghome=
child_dir=$samizdat_child_dir/child.$$
vmlinuz_dir=$samizdat_linux_dir
efi_dir=$samizdat_grub_efi_dir

die() { printf "%s: Error: %s\n" "$0" "$*" >&2; exit 1; }

TEMP="$(getopt -o '' --long bootloader,reuse-child:,adam,usb,detach,in:,out:,test -n "$0" -- "$@")" ||
    die 'getopt error'
eval set -- "$TEMP"

ADAM=; DETACH=; USB=y
while [ $# -gt 0 ]; do
    case "$1" in
        --adam)   shift; ADAM=y;;
        --bootloader) shift; BOOTLOADER_ONLY=y;;
        --cdrom)    shift; USB=;;
        --detach) shift; DETACH=y;;
        --test)   shift; QUICK_TEST=y;;
        --out)    CMDLINE_OUTDEV="$2"; USB=; shift 2;;
        --in)     INPUT_DEVICE="$2"; shift 2;;
        --reuse-child) REUSE_CHILD=y; child_dir=$samizdat_child_dir/child."$2"; shift 2;;
        --)       shift; break;;
        *) die 'getopt error';;
    esac
done

if [ "$INPUT_DEVICE" ]; then
    die "support for --in is disabled because xorriso needs different arguments to produce a bootable image"

elif [ $# = 0 -a -z "$BOOTLOADER_ONLY" ]; then
    if mountpoint -q /cdrom; then
        INPUT_DEVICE=/cdrom
    elif [ -e debian-live-8.4.0-amd64-standard.btrfs -a -e layer.btrfs ]; then
        set -- debian-live-8.4.0-amd64-standard.btrfs layer.btrfs
    elif [ -e /srv/nbd.btrfs ]; then
        set -- /srv/nbd.btrfs
    elif [ "$(blockdev --getsz /dev/nbd0)" -gt 0 ]; then
        (set -x; dd if=/dev/nbd0 of=/srv/nbd.btrfs~ && mv /srv/nbd.btrfs~ /srv/nbd.btrfs) || die "failed to copy network block device"
        set -- /srv/nbd.btrfs
    else
        die "no input device and no input btrfs layers: aborting."
    fi
fi

for fs; do
    [ -f "$fs" ] || die "not a file: $fs"
    case "$fs" in
        *.btrfs) ;;
        *) die "invalid name (does not match *.btrfs): $fs" ;;
    esac
    shift
    set -- "$@" "rootfs/${fs##*/}=$fs"
done


whole_device()
{
    case "$1" in
        *-part?) false ;;
        *-part??) false ;;
        *-part???) false ;;
        */usb\*) false ;;
        *) true ;;
    esac
}

confirm_usb()
{
    local msg="This will completely overwrite device:\n\n\t%s\n\nType 'yes' to confirm.\nContinue? "
    printf "$msg" "$1" >&2
    read line
    case "$line" in
        [yY][eE][sS]) return ;;
        *) die "Aborted by user." ;;
    esac
}

choose_usb()
{
    local devs maj
    set -- /dev/disk/by-id/usb*
    for dev; do
        shift
        whole_device "$dev" || continue
        set -- "$@" "$dev"
    done
    if [ $# = 0 ]; then
        die "no usb device found"
    elif [ $# = 1 ]; then
        confirm_usb "$1" || die impossible
        outdev="$1"
    else
        die "multiple USB devices connected and choice between them is unimplemented.  ($*)"
    fi
}

choose_cdrom()
{
    die 'choose_cdrom: unimplemented; specify cdrom device with --out'
}

choose_outdev()
{
    if [ "$CMDLINE_OUTDEV" ]; then
        outdev=$CMDLINE_OUTDEV~
        NEED_STDIO=y
    elif [ "$USB" ]; then
        choose_usb
        NEED_STDIO=y
    else
        choose_cdrom
        NEED_STDIO=
    fi
}

generate_keys()
{
    if [ "$ADAM" -o "$BOOTLOADER_ONLY" ]; then
        kiki init || die 'kiki init failed'
        gnupghome=/root/.gnupg
    else
        keygen.sh "$child_dir" || die "keygen.sh failed"
        gnupghome=$child_dir/root/.gnupg
        trap 'umount "$child_dir"; rmdir "$child_dir"' EXIT
    fi
}


[ "$(id -u)" = 0 ] || die "you are not root."

grub-efi.sh || die "grub-efi.sh failed"

choose_outdev

if [ "$REUSE_CHILD" ]; then
    gnupghome=$child_dir/root/.gnupg
    [ -d "$gnupghome" ] || die "invalid child"
else
    generate_keys
fi

try_mount()
{
    # TODO: don't use /mnt
    # Ofc the real solution is to get help with xorriso.
    NEED_UNMOUNT="$1"
    mount -r "$1" /mnt && trap 'umount -l /mnt' EXIT
}

if [ "$INPUT_DEVICE" ]; then
    if [ "$INPUT_DEVICE" = /dev/md55 ]; then
        if mountpoint -q /cdrom; then
            XORRISO_IS_DRIVING_ME_INSANE='-add /=/cdrom --'
        fi
    elif [ -d "$INPUT_DEVICE" ]; then
        XORRISO_IS_DRIVING_ME_INSANE="-add /=$INPUT_DEVICE --" # TODO: escape
    elif try_mount "$INPUT_DEVICE"; then
        XORRISO_IS_DRIVING_ME_INSANE='-add /=/mnt --'
    else
        REPLACE_INITRD=
        REMOVE_BTRFS=
        ADD_BTRFS=
    fi
elif [ "$BOOTLOADER_ONLY" ]; then
    REPLACE_INITRD=
    REMOVE_BTRFS=
    ADD_BTRFS=
else
    REPLACE_INITRD=y
    REMOVE_BTRFS=y
    ADD_BTRFS=y
fi
REPLACE_INITRD= # TODO: fix initrd replacing

if [ "$QUICK_TEST" ]; then
    REMOVE_BTRFS=y
    ADD_BTRFS=
fi

if [ "$REPLACE_INITRD" ]; then
    # TODO: fix the paths so this backup isn't needed. What we need to do is
    # support tftp pointing to the cdrom. This probably means a tftp directory
    # that contains a symlink to /cdrom/linux which gets updated on success here
    mv "${vmlinuz_dir}" "${vmlinuz_dir}".bak
    mkdir "${vmlinuz_dir}"
    initrd.sh || {
        mv "${vmlinuz_dir}.bak" "${vmlinuz_dir}"
        die 'initrd.sh failed'
    }
fi

SILENT=

(set -x
xorriso \
        ${INPUT_DEVICE:+ -indev "$INPUT_DEVICE" } \
        -outdev ${NEED_STDIO:+stdio:}"$outdev" \
        -blank as_needed \
        ${SILENT:+ -report_about mishap} \
        -return_with sorry 0 \
        -volid "$volid" \
        -pathspecs on \
        \
        \
        ${XORRISO_IS_DRIVING_ME_INSANE} \
        \
        \
        ${REPLACE_INITRD:+ -rm_r linux -- -add linux="${vmlinuz_dir}" -- } \
        ${BOOTLOADER_ONLY:+ -add linux="${vmlinuz_dir}" -- } \
        ${REMOVE_BTRFS:+   -rm_r rootfs -- } \
        ${ADD_BTRFS:+      -follow link -add "$@" -- -follow default } \
        \
        \
        -rm_r "${gpg_iso_path}" -- \
        -add "${gpg_iso_path}=${gnupghome}" -- \
        \
        \
        -chown_r 0 / -- \
        -chgrp_r 0 / -- \
        -chmod_r go-rwx "${gpg_iso_path}" -- \
        \
        \
        -as mkisofs -graft-points \
        -b grub/i386-pc/eltorito.img  \
        -no-emul-boot -boot-info-table \
        --embedded-boot "${efi_dir}"/embedded.img \
        --protective-msdos-label \
        grub="${efi_dir}"/grub

) || die "xorriso exited $?"

case "$outdev" in
    *~) [ -f "$outdev" ] && mv "$outdev" "${outdev%\~}" ;;
esac

if [ "$USB" -a "$DETACH" -a $? = 0 ]; then
    udisks --detach "$outdev"
fi