path: root/rescue.py

#
# rescue.py - anaconda rescue mode setup
#
# Mike Fulbright <msf@redhat.com>
# Jeremy Katz <katzj@redhat.com>
#
# Copyright 2001-2004 Red Hat, Inc.
#
# This software may be freely redistributed under the terms of the GNU
# library public license.
#
# You should have received a copy of the GNU Library Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#

import upgrade
from snack import *
from constants_text import *
from text import WaitWindow, OkCancelWindow, ProgressWindow, stepToClasses
from flags import flags
import sys
import os
import isys
import iutil
import fsset
import shutil
import fcntl
import termios

from rhpl.translate import _

import logging
log = logging.getLogger("anaconda")

class RescueInterface:
    def waitWindow(self, title, text):
        return WaitWindow(self.screen, title, text)

    def progressWindow(self, title, text, total):
        return ProgressWindow(self.screen, title, text, total)

    def messageWindow(self, title, text, type = "ok", default = None,
                      custom_icon=None, custom_buttons=[]):
	if type == "ok":
	    ButtonChoiceWindow(self.screen, title, text,
			       buttons=[TEXT_OK_BUTTON])
        elif type == "yesno":
            if default and default == "no":
                btnlist = [TEXT_NO_BUTTON, TEXT_YES_BUTTON]
            else:
                btnlist = [TEXT_YES_BUTTON, TEXT_NO_BUTTON]
	    rc = ButtonChoiceWindow(self.screen, title, text,
			       buttons=btnlist)
            if rc == "yes":
                return 1
            else:
                return 0
	elif type == "custom":
	    tmpbut = []
	    for but in custom_buttons:
		tmpbut.append(string.replace(but,"_",""))

	    rc = ButtonChoiceWindow(self.screen, title, text, width=60,
				    buttons=tmpbut)

	    idx = 0
	    for b in tmpbut:
		if string.lower(b) == rc:
		    return idx
		idx = idx + 1
	    return 0
	else:
	    return OkCancelWindow(self.screen, title, text)

    def __init__(self, screen):
        self.screen = screen

# XXX grub-install is stupid and uses df output to figure out
# things when installing grub.  make /etc/mtab be at least
# moderately useful.  
def makeMtab(instPath, theFsset):
    child = os.fork()
    if (not child):
        os.chroot(instPath)
        f = open("/etc/mtab", "w+")
        f.write(theFsset.mtab())
        f.close()
        os._exit(0)

# make sure they have a resolv.conf in the chroot
def makeResolvConf(instPath):
    if not os.access("/etc/resolv.conf", os.R_OK):
        return

    if os.access("%s/etc/resolv.conf" %(instPath,), os.R_OK):
        f = open("%s/etc/resolv.conf" %(instPath,), "r")
        buf = f.read()
        f.close()
    else:
        buf = ""

    # already have a nameserver line, don't worry about it
    if buf.find("nameserver") != -1:
        return

    f = open("/etc/resolv.conf", "r")
    buf = f.read()
    f.close()

    # no nameserver, we can't do much about it
    if buf.find("nameserver") == -1:
        return

    shutil.copyfile("%s/etc/resolv.conf" %(instPath,),
                    "%s/etc/resolv.conf.bak" %(instPath,))
    f = open("%s/etc/resolv.conf" %(instPath,), "w+")
    f.write(buf)
    f.close()

# XXX
#     probably belongs somewhere else
#
def methodUsesNetworking(methodstr):
    for m in ['http://', 'ftp://', 'nfs:/', 'nfsiso:/']:
        if methodstr.startswith(m):
            return 1
    return 0

#
# Write out something useful for networking and start interfaces
#
def startNetworking(network, intf):
    # do lo first
    try:
        os.system("/usr/sbin/ifconfig lo 127.0.0.1")
    except:
        log.error("Error trying to start lo in rescue.py::startNetworking()")

    # start up dhcp interfaces first
    dhcpGotNS = 0
    devs = network.netdevices.keys()
    devs.sort()
    for devname in devs:
        dev = network.netdevices[devname]
        waitwin = intf.waitWindow(_("Starting Interface"),
                                  _("Attempting to start %s") % (dev.get('device'),))
        log.info("Attempting to start %s", dev.get('device'))
        if dev.get('bootproto').lower() == "dhcp":
            try:
                ns = isys.dhcpNetDevice(dev)
                if ns:
                    if not dhcpGotNS:
                        dhcpGotNS = 1

                        f = open("/etc/resolv.conf", "w")
                        f.write("nameserver %s\n" % ns)
                        f.close()
            except:
                log.error("Error trying to start %s in rescue.py::startNetworking()", dev.get('device'))
        else:
            try:
                isys.configNetDevice(dev, network.gateway)
            except:
                log.error("Error trying to start %s in rescue.py::startNetworking()", dev.get('device'))

        waitwin.pop()

    # write out resolv.conf if dhcp didn't get us one
    if not dhcpGotNS:
        f = open("/etc/resolv.conf", "w")

        if network.domains != ['localdomain'] and network.domains:
            f.write("search %s\n" % (string.joinfields(network.domains, ' '),))

        for ns in network.nameservers():
            if ns:
                f.write("nameserver %s\n" % (ns,))

        f.close()

def runShell(screen = None, msg=""):
    if screen:
        screen.suspend()

    print
    if msg:
        print (msg)
    print _("When finished please exit from the shell and your "
            "system will reboot.")
    print

    if os.path.exists("/bin/sh"):
        iutil.execConsole()
    else:
        print "Unable to find /bin/sh to execute!  Not starting shell"
        time.sleep(5)

    if screen:
        screen.finish()

def runRescue(anaconda, instClass):
    for file in [ "services", "protocols", "group", "joe", "man.config",
                  "nsswitch.conf", "selinux", "mke2fs.conf" ]:
        try:
            os.symlink('/mnt/runtime/etc/' + file, '/etc/' + file)
        except:
            pass

    # see if they would like networking enabled
    if not methodUsesNetworking(anaconda.id.methodstr):
        screen = SnackScreen()

        while 1:
            rc = ButtonChoiceWindow(screen, _("Setup Networking"),
                _("Do you want to start the network interfaces on "
                  "this system?"), [_("Yes"), _("No")])

            if rc != string.lower(_("No")):
                anaconda.intf = RescueInterface(screen)

                # need to call sequence of screens, have to look in text.py
                #
                # this code is based on main loop in text.py, and if it
                # or the network step in dispatch.py change significantly
                # then this will certainly break
                pyfile = "network_text"
                classNames = ("NetworkDeviceWindow", "NetworkGlobalWindow")

                lastrc = INSTALL_OK
                step = 0
                anaconda.dir = 1

                while 1:
                    s = "from %s import %s; nextWindow = %s" % \
                        (pyfile, classNames[step], classNames[step])
                    exec s

                    win = nextWindow()

                    rc = win(screen, anaconda, showonboot = 0)

                    if rc == INSTALL_NOOP:
                        rc = lastrc

                    if rc == INSTALL_BACK:
                        step = step - 1
                        anaconda.dir = - 1
                    elif rc == INSTALL_OK:
                        step = step + 1
                        anaconda.dir = 1

                    lastrc = rc

                    if step == -1:
                        ButtonChoiceWindow(screen, _("Cancelled"),
                                           _("I can't go to the previous step "
                                             "from here. You will have to try "
                                             "again."),
                                           buttons=[_("OK")])
                        anaconda.dir = 1
                        step = 0
                    elif step >= len(classNames):
                        break

                startNetworking(anaconda.id.network, anaconda.intf)
                break
            else:
                break

        screen.finish()

    # Early shell access with no disk access attempts
    if not anaconda.rescue_mount:
        runShell()
        sys.exit(0)

    screen = SnackScreen()
    anaconda.intf = RescueInterface(screen)
    anaconda.setMethod(instClass)

    # prompt to see if we should try and find root filesystem and mount
    # everything in /etc/fstab on that root
    rc = ButtonChoiceWindow(screen, _("Rescue"),
        _("The rescue environment will now attempt to find your "
          "Linux installation and mount it under the directory "
          "%s.  You can then make any changes required to your "
          "system.  If you want to proceed with this step choose "
          "'Continue'.  You can also choose to mount your file systems "
          "read-only instead of read-write by choosing 'Read-Only'."
          "\n\n"
          "If for some reason this process fails you can choose 'Skip' "
          "and this step will be skipped and you will go directly to a "
          "command shell.\n\n") % (anaconda.rootPath,),
          [_("Continue"), _("Read-Only"), _("Skip")] )

    if rc == string.lower(_("Skip")):
        runShell(screen)
        sys.exit(0)
    elif rc == string.lower(_("Read-Only")):
        readOnly = 1
    else:
        readOnly = 0

    disks = upgrade.findExistingRoots(anaconda, upgradeany = 1)

    if not disks:
        root = None
    elif len(disks) == 1:
        root = disks[0]
    else:
        height = min (len (disks), 12)
        if height == 12:
            scroll = 1
        else:
            scroll = 0

        partList = []
        for (drive, fs, relstr, label) in disks:
            if label:
                partList.append("%s (%s)" % (drive, label))
            else:
                partList.append(drive)

        (button, choice) = \
            ListboxChoiceWindow(screen, _("System to Rescue"),
                                _("What partition holds the root partition "
                                  "of your installation?"), partList,
                                [ _("OK"), _("Exit") ], width = 30,
                                scroll = scroll, height = height,
                                help = "multipleroot")

        if button == string.lower (_("Exit")):
            root = None
        else:
            root = disks[choice]

    rootmounted = 0

    if root:
        try:
            fs = fsset.FileSystemSet()

            # only pass first two parts of tuple for root, since third
            # element is a comment we dont want
            rc = upgrade.mountRootPartition(anaconda, root[:2], fs,
                                            allowDirty = 1, warnDirty = 1,
                                            readOnly = readOnly)

            if rc == -1:
                ButtonChoiceWindow(screen, _("Rescue"),
                    _("Your system had dirty file systems which you chose not "
                      "to mount.  Press return to get a shell from which "
                      "you can fsck and mount your partitions.  The system "
                      "will reboot automatically when you exit from the "
                      "shell."), [_("OK")], width = 50)
                rootmounted = 0
            else:
                ButtonChoiceWindow(screen, _("Rescue"),
                   _("Your system has been mounted under %s.\n\n"
                     "Press <return> to get a shell. If you would like to "
                     "make your system the root environment, run the command:\n\n"
                     "\tchroot %s\n\nThe system will reboot "
                     "automatically when you exit from the shell.") %
                                   (anaconda.rootPath, anaconda.rootPath),
                                   [_("OK")] )
                rootmounted = 1

                # now turn on swap
                if not readOnly:
                    try:
                        fs.turnOnSwap("/")
                    except:
                        log.error("Error enabling swap")

                # now that dev is udev, bind mount the installer dev there
                isys.mount("/dev", "%s/dev" %(anaconda.rootPath,), bindMount = 1)

                # and /dev/pts
                isys.mount("/dev/pts", "%s/dev/pts" %(anaconda.rootPath,), bindMount = 1)

                # and /selinux too
                if flags.selinux and os.path.isdir("%s/selinux" %(anaconda.rootPath,)):
                    try:
                        isys.mount("/selinux", "%s/selinux" %(anaconda.rootPath,),
                                   "selinuxfs")
                    except Exception, e:
                        log.error("error mounting selinuxfs: %s" %(e,))

                # set a library path to use mounted fs
                os.environ["LD_LIBRARY_PATH"] =  "/lib:/usr/lib:/usr/X11R6/lib:/lib:/mnt/usr/lib:/mnt/sysimage/lib:/mnt/sysimage/usr/lib:/mnt/sysimage/usr/X11R6/lib"

                # get man pages to work
                os.environ["MANPATH"] = "/mnt/sysimage/usr/share/man:/mnt/sysimage/usr/local/share/man"

                # find groff data dir
                try:
                    glst = os.listdir("/mnt/sysimage/usr/share/groff")

                    # find a directory which is a numeral, its where
                    # data files are
                    gversion = None
                    for gdir in glst:
                        try:
                            isone = 1
                            for idx in range(0, len(gdir)):
                                if string.find(string.digits + '.', gdir[idx]) == -1:
                                    isone = 0
                                    break
                            if isone:
                                gversion = gdir
                                break
                        except:
                            gversion = None
                            continue
                except:
                    gversion = None

                if gversion is not None:
                    gpath = "/mnt/sysimage/usr/share/groff/"+gversion
                    os.environ["GROFF_FONT_PATH"] = gpath + '/font'
                    os.environ["GROFF_TMAC_PATH"] = "%s:/mnt/sysimage/usr/share/groff/site-tmac" % (gpath + '/tmac',)

                # do we have bash?
                try:
                    if os.access("/usr/bin/bash", os.R_OK):
                        os.symlink ("/usr/bin/bash", "/bin/bash")
                except:
                    pass
        except:
            # This looks horrible, but all it does is catch every exception,
            # and reraise those in the tuple check. This lets programming
            # errors raise exceptions, while any runtime error will
            # still result in a shell
            (exc, val) = sys.exc_info()[0:2]
            log.error(val)
            if exc in (IndexError, ValueError, SyntaxError):
                raise exc, val, sys.exc_info()[2]

            ButtonChoiceWindow(screen, _("Rescue"),
                _("An error occurred trying to mount some or all of your "
                  "system. Some of it may be mounted under %s.\n\n"
                  "Press <return> to get a shell. The system will reboot "
                  "automatically when you exit from the shell.") % (anaconda.rootPath,),
                  [_("OK")] )
    else:
        ButtonChoiceWindow(screen, _("Rescue Mode"),
                           _("You don't have any Linux partitions. Press "
                             "return to get a shell. The system will reboot "
                             "automatically when you exit from the shell."),
                           [ _("OK") ], width = 50)

    msgStr = ""

    if rootmounted and not readOnly:
        makeMtab(anaconda.rootPath, fs)
        try:
            makeResolvConf(anaconda.rootPath)
        except Exception, e:
            log.error("error making a resolv.conf: %s" %(e,))
        msgStr = _("Your system is mounted under the %s directory.") % (anaconda.rootPath,)

    runShell(screen, msgStr)
    sys.exit(0)