#
# iscsi.py - iscsi class
#
# Copyright (C) 2005, 2006  IBM, Inc.  All rights reserved.
# Copyright (C) 2006  Red Hat, Inc.  All rights reserved.
#
# 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 of the License, 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, see <http://www.gnu.org/licenses/>.
#

from constants import *
from udev import *
import os
import iutil
from flags import flags
import logging
import shutil
import time
import hashlib
import random
log = logging.getLogger("anaconda")

import gettext
_ = lambda x: gettext.ldgettext("anaconda", x)

has_libiscsi = True
try:
    import libiscsi
except ImportError:
    has_libiscsi = False

# Note that stage2 copies all files under /sbin to /usr/sbin
ISCSID=""
INITIATOR_FILE="/etc/iscsi/initiatorname.iscsi"

def find_iscsi_files():
    global ISCSID
    if ISCSID == "":
        for dir in ("/usr/sbin", "/tmp/updates", "/mnt/source/RHupdates"):
            path="%s/iscsid" % (dir,)
            if os.access(path, os.X_OK):
                ISCSID=path

def has_iscsi():
    find_iscsi_files()
    if ISCSID == "" or not has_libiscsi:
        return False

    log.info("ISCSID is %s" % (ISCSID,))

    # make sure the module is loaded
    if not os.access("/sys/module/iscsi_tcp", os.X_OK):
        return False
    return True

def randomIname():
    """Generate a random initiator name the same way as iscsi-iname"""
    
    s = "iqn.1994-05.com.fedora:01."
    m = hashlib.md5()
    u = os.uname()
    for i in u:
        m.update(i)
    dig = m.hexdigest()
    
    for i in range(0, 6):
        s += dig[random.randrange(0, 32)]
    return s

def stabilize(intf = None):
    # Wait for udev to create the devices for the just added disks
    if intf:
        w = intf.waitWindow(_("Scanning iSCSI nodes"),
                            _("Scanning iSCSI nodes"))
    # It is possible when we get here the events for the new devices
    # are not send yet, so sleep to make sure the events are fired
    time.sleep(2)
    udev_settle()
    if intf:
        w.pop()

class iscsi(object):
    """ iSCSI utility class.

        This class will automatically discover and login to iBFT (or
        other firmware) configured iscsi devices when the startup() method
        gets called. It can also be used to manually configure iscsi devices
        through the addTarget() method.

        As this class needs to make sure certain things like starting iscsid
        and logging in to firmware discovered disks only happens once 
        and as it keeps a global list of all iSCSI devices it is implemented as
        a Singleton.
    """

    def __init__(self):
        # This list contains all nodes
        self.nodes = []
        # This list contains nodes discovered through iBFT (or other firmware)
        self.ibftNodes = []
        self._initiator = ""
        self.initiatorSet = False
        self.started = False

        if flags.ibft:
            try:
                initiatorname = libiscsi.get_firmware_initiator_name()
                self._initiator = initiatorname
                self.initiatorSet = True
            except:
                pass

    # So that users can write iscsi() to get the singleton instance
    def __call__(self):
        return self

    def _getInitiator(self):
        if self._initiator != "":
            return self._initiator

        return randomIname()

    def _setInitiator(self, val):
        if self.initiatorSet and val != self._initiator:
            raise ValueError, "Unable to change iSCSI initiator name once set"
        if len(val) == 0:
            raise ValueError, "Must provide a non-zero length string"
        self._initiator = val

    initiator = property(_getInitiator, _setInitiator)

    def _startIBFT(self, intf = None):
        if not flags.ibft:
            return

        try:
            found_nodes = libiscsi.discover_firmware()
        except:
            # an exception here means there is no ibft firmware, just return
            return

        for node in found_nodes:
            try:
                node.login()
                self.nodes.append(node)
                self.ibftNodes.append(node)
            except IOError, e:
                log.error("Could not log into ibft iscsi target %s: %s" %
                          (node.name, str(e)))
                pass

        stabilize(intf)

    def startup(self, intf = None):
        if self.started:
            return

        if not has_iscsi():
            return

        if self._initiator == "":
            log.info("no initiator set")
            return

        if intf:
            w = intf.waitWindow(_("Initializing iSCSI initiator"),
                                _("Initializing iSCSI initiator"))

        log.debug("Setting up %s" % (INITIATOR_FILE, ))
        log.info("iSCSI initiator name %s", self.initiator)
        if os.path.exists(INITIATOR_FILE):
            os.unlink(INITIATOR_FILE)
        if not os.path.isdir("/etc/iscsi"):
            os.makedirs("/etc/iscsi", 0755)
        fd = os.open(INITIATOR_FILE, os.O_RDWR | os.O_CREAT)
        os.write(fd, "InitiatorName=%s\n" %(self.initiator))
        os.close(fd)
        self.initiatorSet = True

        for dir in ['ifaces','isns','nodes','send_targets','slp','static']:
            fulldir = "/var/lib/iscsi/%s" % (dir,)
            if not os.path.isdir(fulldir):
                os.makedirs(fulldir, 0755)

        log.info("iSCSI startup")
        iutil.execWithRedirect(ISCSID, [],
                               stdout="/dev/tty5", stderr="/dev/tty5")
        time.sleep(1)

        if intf:
            w.pop()

        self._startIBFT(intf)
        self.started = True

    def addTarget(self, ipaddr, port="3260", user=None, pw=None,
                  user_in=None, pw_in=None, intf=None):
        authinfo = None
        found = 0
        logged_in = 0

        if not has_iscsi():
            raise IOError, _("iSCSI not available")
        if self._initiator == "":
            raise ValueError, _("No initiator name set")

        if user or pw or user_in or pw_in:
            # Note may raise a ValueError
            authinfo = libiscsi.chapAuthInfo(username=user, password=pw,
                                             reverse_username=user_in,
                                             reverse_password=pw_in)
        self.startup(intf)

        # Note may raise an IOError
        found_nodes = libiscsi.discover_sendtargets(address=ipaddr,
                                                    port=int(port),
                                                    authinfo=authinfo)
        if found_nodes == None:
            raise IOError, _("No iSCSI nodes discovered")

        if intf:
            w = intf.waitWindow(_("Logging in to iSCSI nodes"),
                                _("Logging in to iSCSI nodes"))

        for node in found_nodes:
            # skip nodes we already have
            if node in self.nodes:
                continue

            found = found + 1
            try:
                if (authinfo):
                    node.setAuth(authinfo)
                node.login()
                self.nodes.append(node)
                logged_in = logged_in + 1
            except IOError, e:
                log.warning(
                    "Could not log into discovered iscsi target %s: %s" %
                    (node.name, str(e)))
                # some nodes may require different credentials
                pass

        if intf:
            w.pop()

        if found == 0:
            raise IOError, _("No new iSCSI nodes discovered")

        if logged_in == 0:
            raise IOError, _("Could not log in to any of the discovered nodes")

        stabilize(intf)

    def writeKS(self, f):
        if not self.initiatorSet:
            return
        f.write("iscsiname %s\n" %(self.initiator,))
        for n in self.nodes:
            f.write("iscsi --ipaddr %s --port %s" %(n.address, n.port))
            auth = n.getAuth()
            if auth:
                f.write(" --user %s" % auth.username)
                f.write(" --password %s" % auth.password)
                if len(auth.reverse_username):
                    f.write(" --reverse-user %s" % auth.reverse_username)
                if len(auth.reverse_password):
                    f.write(" --reverse-password %s" % auth.reverse_password)
            f.write("\n")

    def write(self, instPath, anaconda):
        if not self.initiatorSet:
            return

        # set iscsi nodes to autostart
        root = anaconda.storage.rootDevice
        for node in self.nodes:
            autostart = True
            disks = self.getNodeDisks(node, anaconda.storage)
            for disk in disks:
                # nodes used for root get started by the initrd
                if root.dependsOn(disk):
                    autostart = False

            if autostart:
                node.setParameter("node.startup", "automatic")

        if not os.path.isdir(instPath + "/etc/iscsi"):
            os.makedirs(instPath + "/etc/iscsi", 0755)
        fd = os.open(instPath + INITIATOR_FILE, os.O_RDWR | os.O_CREAT)
        os.write(fd, "InitiatorName=%s\n" %(self.initiator))
        os.close(fd)

        # copy "db" files.  *sigh*
        if os.path.isdir(instPath + "/var/lib/iscsi"):
            shutil.rmtree(instPath + "/var/lib/iscsi")
        if os.path.isdir("/var/lib/iscsi"):
            shutil.copytree("/var/lib/iscsi", instPath + "/var/lib/iscsi",
                            symlinks=True)

    def getNode(self, name, address, port):
        for node in self.nodes:
            if node.name == name and node.address == address and \
               node.port == int(port):
                return node

        return None

    def getNodeDisks(self, node, storage):
        nodeDisks = []
        iscsiDisks = storage.devicetree.getDevicesByType("iscsi")
        for disk in iscsiDisks:
            if disk.node == node:
                nodeDisks.append(disk)

        return nodeDisks

# Create iscsi singleton
iscsi = iscsi()

# vim:tw=78:ts=4:et:sw=4