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"):
	if type == "ok":
	    ButtonChoiceWindow(self.screen, _(title), _(text),
			       buttons = [ _("OK") ])
        elif type == "yesno":
            btnlist = [TEXT_YES_BUTTON, TEXT_NO_BUTTON]
	    rc = ButtonChoiceWindow(self.screen, _(title), _(text),
			       buttons=btnlist)
            if rc == "yes":
                return 1
            else:
                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

# XXX
#     hack to 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') == "dhcp":
	    try:
		ns = isys.pumpNetDevice(dev.get('device'))
		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'))
	elif dev.get('ipaddr') and dev.get('netmask') and network.gateway is not None:
	    try:
		isys.configNetDevice(dev.get('device'),
				     dev.get('ipaddr'),
				     dev.get('netmask'),
				     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 didnt 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.execWithRedirect("/bin/sh", [], stdout="/dev/console", stderr="/dev/console")
    else:
        print "Unable to find /bin/sh to execute!  Not starting shell"
        time.sleep(5)

    if screen:
        screen.finish()

def runRescue(anaconda):
    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)

    # lets create some devices
    iutil.makeDriveDeviceNodes()
    iutil.makeCharDeviceNodes()

    # need loopback devices too
    for lpminor in range(8):
	dev = "loop%s" % (lpminor,)
	isys.makeDevInode(dev, "/dev/" + dev)

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

    # 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 /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)