#
# 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 *
import os
import errno
import string
import signal
import iutil
import isys
from flags import flags
import logging
import shutil
import time
import hashlib
import random
import partedUtils
log = logging.getLogger("anaconda")

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

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

# Note that stage2 copies all files under /sbin to /usr/sbin
global ISCSID
ISCSID=""
global ISCSIADM
ISCSIADM = ""
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
    global ISCSIADM
    if ISCSIADM == "":
        for dir in ("/usr/sbin", "/tmp/updates", "/mnt/source/RHupdates"):
            path="%s/iscsiadm" % (dir,)
            if os.access(path, os.X_OK):
                ISCSIADM=path

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

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

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

def iscsi_get_node_record(node_settings, record):
    for line in node_settings:
        if line.startswith(record):
            words = line.split(" = ")
            if len(words) == 2:
                return words[1]
            # should never happen but better safe then sorry
            break

    return None

# FIXME replace with libiscsi use
def iscsi_make_node_autostart(disk):
    sysfs_path = os.path.realpath("/sys/block/%s/device" %(disk,))
    argv = [ "-m", "session", "-r", sysfs_path ]
    log.debug("iscsiadm %s" %(string.join(argv),))
    node_settings = iutil.execWithCapture(ISCSIADM, argv, stderr="/dev/tty5").splitlines()
    node_name = iscsi_get_node_record(node_settings, "node.name")
    argv = [ "-m", "node", "-T", node_name, "-o", "update", "-n",
             "node.startup", "-v", "automatic" ]
    log.debug("iscsiadm %s" %(string.join(argv),))
    iutil.execWithRedirect(ISCSIADM, argv,
                                stdout = "/dev/tty5", stderr="/dev/tty5")

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)
    iutil.execWithRedirect("udevadm", [ "settle" ],
                           stdout = "/dev/tty5", stderr="/dev/tty5",
                           searchPath = 1)
    if intf:
        w.pop()

class iscsi(object):
    def __init__(self):
        self.nodes = []
        self._initiator = ""
        self.initiatorSet = False
        self.started = False

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

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

        return randomIname()

    def _setInitiator(self, val):
        if self._initiator != "" 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
        self.initiatorSet = True

    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)
            except:
                 # FIXME, what to do when we cannot log in to a firmware
                 # provided node ??
                 pass

        stabilize(intf)

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

        if not has_iscsi():
            return

        if not self.initiatorSet:
            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)

        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 not self.initiatorSet:
            raise ValueError, _("No initiator name set")

        self.startup(intf)

        if user:
            # Note may raise a ValueError
            authinfo = libiscsi.chapAuthInfo(username=user, password=pw,
                                             reverse_username=user_in,
                                             reverse_password=pw_in)
        # 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:
                 # 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" %(n.username,))
                f.write(" --password %s" %(n.password,))
                if len(auth.reverse_username):
                    f.write(" --reverse-user %s" % (n.reverse_username,))
                    f.write(" --reverse-password %s" % (n.reverse_password,))
            f.write("\n")

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

        if not flags.test:
            root_drives = [ ]
            req = anaconda.id.partitions.getRequestByMountPoint("/")
            root_requests = anaconda.id.partitions.getUnderlyingRequests(req)
            for req in root_requests:
                for drive in req.drive:
                    part = anaconda.id.diskset.disks[drive].getPartitionByPath("/dev/%s" % req.device)
                    if part:
                        break
                if not part:
                    continue
                if drive not in root_drives:
                    root_drives.append(drive)

            log.debug("iscsi.write: root_drives: %s" % (string.join(root_drives),))

            # set iscsi nodes not used for root to autostart
            for disk in anaconda.id.diskset.disks.keys():
                if isys.driveIsIscsi(disk) and not disk in root_drives:
                    iscsi_make_node_autostart(disk)

            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)

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