1 files changed, 598 insertions, 0 deletions
diff --git a/agents/scsi/fence_scsi.py b/agents/scsi/fence_scsi.py
new file mode 100644
index 0000000..f9e6823
--- /dev/null
+++ b/agents/scsi/fence_scsi.py
@@ -0,0 +1,598 @@
+#!@PYTHON@ -tt
+
+import sys
+import stat
+import re
+import os
+import time
+import logging
+import atexit
+import hashlib
+import ctypes
+sys.path.append("@FENCEAGENTSLIBDIR@")
+from fencing import fail_usage, run_command, atexit_handler, check_input, process_input, show_docs, fence_action, all_opt
+from fencing import run_delay
+
+STORE_PATH = "@STORE_PATH@"
+
+
+def get_status(conn, options):
+	del conn
+	status = "off"
+	for dev in options["devices"]:
+		is_block_device(dev)
+		reset_dev(options, dev)
+		if options["--key"] in get_registration_keys(options, dev):
+			status = "on"
+		else:
+			logging.debug("No registration for key "\
+				+ options["--key"] + " on device " + dev + "\n")
+			if options["--action"] == "on":
+				status = "off"
+				break
+	return status
+
+
+def set_status(conn, options):
+	del conn
+	count = 0
+	if options["--action"] == "on":
+		set_key(options)
+		for dev in options["devices"]:
+			is_block_device(dev)
+
+			register_dev(options, dev)
+			if options["--key"] not in get_registration_keys(options, dev):
+				count += 1
+				logging.debug("Failed to register key "\
+					+ options["--key"] + "on device " + dev + "\n")
+				continue
+			dev_write(dev, options)
+
+			if get_reservation_key(options, dev) is None \
+			and not reserve_dev(options, dev) \
+			and get_reservation_key(options, dev) is None:
+				count += 1
+				logging.debug("Failed to create reservation (key="\
+					+ options["--key"] + ", device=" + dev + ")\n")
+
+	else:
+		host_key = get_key()
+		if host_key == options["--key"].lower():
+			fail_usage("Failed: keys cannot be same. You can not fence yourself.")
+		for dev in options["devices"]:
+			is_block_device(dev)
+
+			if options["--key"] in get_registration_keys(options, dev):
+				preempt_abort(options, host_key, dev)
+
+		for dev in options["devices"]:
+			if options["--key"] in get_registration_keys(options, dev):
+				count += 1
+				logging.debug("Failed to remove key "\
+					+ options["--key"] + " on device " + dev + "\n")
+				continue
+
+			if not get_reservation_key(options, dev):
+				count += 1
+				logging.debug("No reservation exists on device " + dev + "\n")
+	if count:
+		logging.error("Failed to verify " + str(count) + " device(s)")
+		sys.exit(1)
+
+
+# check if host is ready to execute actions
+def do_action_monitor(options):
+	# Check if required binaries are installed
+	if bool(run_cmd(options, options["--sg_persist-path"] + " -V")["rc"]):
+		logging.error("Unable to run " + options["--sg_persist-path"])
+		return 1
+	elif bool(run_cmd(options, options["--sg_turs-path"] + " -V")["rc"]):
+		logging.error("Unable to run " + options["--sg_turs-path"])
+		return 1
+	elif ("--devices" not in options and 
+			bool(run_cmd(options, options["--vgs-path"] + " --version")["rc"])):
+		logging.error("Unable to run " + options["--vgs-path"])
+		return 1
+
+	# Keys have to be present in order to fence/unfence
+	get_key()
+	dev_read()
+
+	return 0
+
+
+# run command, returns dict, ret["rc"] = exit code; ret["out"] = output;
+# ret["err"] = error
+def run_cmd(options, cmd):
+	ret = {}
+	(ret["rc"], ret["out"], ret["err"]) = run_command(options, cmd)
+	ret["out"] = "".join([i for i in ret["out"] if i is not None])
+	ret["err"] = "".join([i for i in ret["err"] if i is not None])
+	return ret
+
+
+# check if device exist and is block device
+def is_block_device(dev):
+	if not os.path.exists(dev):
+		fail_usage("Failed: device \"" + dev + "\" does not exist")
+	if not stat.S_ISBLK(os.stat(dev).st_mode):
+		fail_usage("Failed: device \"" + dev + "\" is not a block device")
+
+
+# cancel registration
+def preempt_abort(options, host, dev):
+	reset_dev(options,dev)
+	cmd = options["--sg_persist-path"] + " -n -o -A -T 5 -K " + host + " -S " + options["--key"] + " -d " + dev
+	return not bool(run_cmd(options, cmd)["rc"])
+
+
+def reset_dev(options, dev):
+	return run_cmd(options, options["--sg_turs-path"] + " " + dev)["rc"]
+
+
+def register_dev(options, dev):
+	dev = os.path.realpath(dev)
+	if re.search(r"^dm", dev[5:]):
+		for slave in get_mpath_slaves(dev):
+			register_dev(options, slave)
+		return True
+	if get_reservation_key(options, dev, False) == options["--key"]:
+		return True
+	reset_dev(options, dev)
+	cmd = options["--sg_persist-path"] + " -n -o -I -S " + options["--key"] + " -d " + dev
+	cmd += " -Z" if "--aptpl" in options else ""
+	#cmd return code != 0 but registration can be successful
+	return not bool(run_cmd(options, cmd)["rc"])
+
+
+def reserve_dev(options, dev):
+	reset_dev(options,dev)
+	cmd = options["--sg_persist-path"] + " -n -o -R -T 5 -K " + options["--key"] + " -d " + dev
+	return not bool(run_cmd(options, cmd)["rc"])
+
+
+def get_reservation_key(options, dev, fail=True):
+	reset_dev(options,dev)
+	opts = ""
+	if "--readonly" in options:
+		opts = "-y "
+	cmd = options["--sg_persist-path"] + " -n -i " + opts + "-r -d " + dev
+	out = run_cmd(options, cmd)
+	if out["rc"] and fail:
+		fail_usage('Cannot get reservation key on device "' + dev
+                        + '": ' + out["err"])
+	match = re.search(r"\s+key=0x(\S+)\s+", out["out"], re.IGNORECASE)
+	return match.group(1) if match else None
+
+
+def get_registration_keys(options, dev, fail=True):
+	reset_dev(options,dev)
+	keys = []
+	opts = ""
+	if "--readonly" in options:
+		opts = "-y "
+	cmd = options["--sg_persist-path"] + " -n -i " + opts + "-k -d " + dev
+	out = run_cmd(options, cmd)
+	if out["rc"]:
+		fail_usage('Cannot get registration keys on device "' + dev
+                        + '": ' + out["err"], fail)
+		if not fail:
+			return []
+	for line in out["out"].split("\n"):
+		match = re.search(r"\s+0x(\S+)\s*", line)
+		if match:
+			keys.append(match.group(1))
+	return keys
+
+
+def get_cluster_id(options):
+	cmd = options["--corosync-cmap-path"] + " totem.cluster_name"
+
+	match = re.search(r"\(str\) = (\S+)\n", run_cmd(options, cmd)["out"])
+
+	if not match:
+		fail_usage("Failed: cannot get cluster name")
+
+	try:
+		return hashlib.md5(match.group(1).encode('ascii')).hexdigest()
+	except ValueError:
+		# FIPS requires usedforsecurity=False and might not be
+		# available on all distros: https://bugs.python.org/issue9216
+		return hashlib.md5(match.group(1).encode('ascii'), usedforsecurity=False).hexdigest()
+
+
+def get_node_id(options):
+	cmd = options["--corosync-cmap-path"] + " nodelist"
+	out = run_cmd(options, cmd)["out"]
+
+	match = re.search(r".(\d+).name \(str\) = " + options["--plug"] + "\n", out)
+
+	# try old format before failing
+	if not match:
+		match = re.search(r".(\d+).ring._addr \(str\) = " + options["--plug"] + "\n", out)
+
+	return match.group(1) if match else fail_usage("Failed: unable to parse output of corosync-cmapctl or node does not exist")
+
+def get_node_hash(options):
+	try:
+		return hashlib.md5(options["--plug"].encode('ascii')).hexdigest()
+	except ValueError:
+		# FIPS requires usedforsecurity=False and might not be
+		# available on all distros: https://bugs.python.org/issue9216
+		return hashlib.md5(options["--plug"].encode('ascii'), usedforsecurity=False).hexdigest()
+
+
+def generate_key(options):
+	if options["--key-value"] == "hash":
+		return "%.4s%.4s" % (get_cluster_id(options), get_node_hash(options))
+	else:
+		return "%.4s%.4d" % (get_cluster_id(options), int(get_node_id(options)))
+
+
+# save node key to file
+def set_key(options):
+	file_path = options["store_path"] + ".key"
+	if not os.path.isdir(os.path.dirname(options["store_path"])):
+		os.makedirs(os.path.dirname(options["store_path"]))
+	try:
+		f = open(file_path, "w")
+	except IOError:
+		fail_usage("Failed: Cannot open file \""+ file_path + "\"")
+	f.write(options["--key"].lower() + "\n")
+	f.close()
+
+
+# read node key from file
+def get_key(fail=True):
+	file_path = STORE_PATH + ".key"
+	try:
+		f = open(file_path, "r")
+	except IOError:
+		fail_usage("Failed: Cannot open file \""+ file_path + "\"", fail)
+		if not fail:
+			return None
+	return f.readline().strip().lower()
+
+
+def dev_write(dev, options):
+	file_path = options["store_path"] + ".dev"
+	if not os.path.isdir(os.path.dirname(options["store_path"])):
+		os.makedirs(os.path.dirname(options["store_path"]))
+	try:
+		f = open(file_path, "a+")
+	except IOError:
+		fail_usage("Failed: Cannot open file \""+ file_path + "\"")
+	f.seek(0)
+	out = f.read()
+	if not re.search(r"^" + dev + "\s+", out, flags=re.MULTILINE):
+		f.write(dev + "\n")
+	f.close()
+
+
+def dev_read(fail=True, opt=None):
+	file_path = STORE_PATH + ".dev"
+	try:
+		f = open(file_path, "r")
+	except IOError:
+		if "--suppress-errors" not in opt:
+			fail_usage("Failed: Cannot open file \"" + file_path + "\"", fail)
+		if not fail:
+			return None
+	# get not empty lines from file
+	devs = [line.strip() for line in f if line.strip()]
+	f.close()
+	return devs
+
+
+def get_clvm_devices(options):
+	devs = []
+	cmd = options["--vgs-path"] + " " +\
+	"--noheadings " +\
+	"--separator : " +\
+	"--sort pv_uuid " +\
+	"--options vg_attr,pv_name "+\
+	"--config 'global { locking_type = 0 } devices { preferred_names = [ \"^/dev/dm\" ] }'"
+	out = run_cmd(options, cmd)
+	if out["rc"]:
+		fail_usage("Failed: Cannot get clvm devices")
+	for line in out["out"].split("\n"):
+		if 'c' in line.split(":")[0]:
+			devs.append(line.split(":")[1])
+	return devs
+
+
+def get_mpath_slaves(dev):
+	if dev[:5] == "/dev/":
+		dev = dev[5:]
+	slaves = [i for i in os.listdir("/sys/block/" + dev + "/slaves/") if i[:1] != "."]
+	if slaves[0][:2] == "dm":
+		slaves = get_mpath_slaves(slaves[0])
+	else:
+		slaves = ["/dev/" + x for x in slaves]
+	return slaves
+
+
+def define_new_opts():
+	all_opt["devices"] = {
+		"getopt" : "d:",
+		"longopt" : "devices",
+		"help" : "-d, --devices=[devices]        List of devices to use for current operation",
+		"required" : "0",
+		"shortdesc" : "List of devices to use for current operation. Devices can \
+be comma-separated list of raw devices (eg. /dev/sdc). Each device must support SCSI-3 \
+persistent reservations.",
+		"order": 1
+	}
+	all_opt["nodename"] = {
+		"getopt" : ":",
+		"longopt" : "nodename",
+		"help" : "",
+		"required" : "0",
+		"shortdesc" : "",
+		"order": 1
+	}
+	all_opt["key"] = {
+		"getopt" : "k:",
+		"longopt" : "key",
+		"help" : "-k, --key=[key]                Key to use for the current operation",
+		"required" : "0",
+		"shortdesc" : "Key to use for the current operation. This key should be \
+unique to a node. For the \"on\" action, the key specifies the key use to \
+register the local node. For the \"off\" action, this key specifies the key to \
+be removed from the device(s).",
+		"order": 1
+	}
+	all_opt["aptpl"] = {
+		"getopt" : "a",
+		"longopt" : "aptpl",
+		"help" : "-a, --aptpl                    Use the APTPL flag for registrations",
+		"required" : "0",
+		"shortdesc" : "Use the APTPL flag for registrations. This option is only used for the 'on' action.",
+		"order": 1
+	}
+	all_opt["readonly"] = {
+		"getopt" : "",
+		"longopt" : "readonly",
+		"help" : "--readonly                     Open DEVICE read-only. May be useful with PRIN commands if there are unwanted side effects with the default read-write open.",
+		"required" : "0",
+		"shortdesc" : "Open DEVICE read-only.",
+		"order": 4
+	}
+	all_opt["suppress-errors"] = {
+		"getopt" : "",
+		"longopt" : "suppress-errors",
+		"help" : "--suppress-errors              Suppress error log. Suppresses error logging when run from the watchdog service before pacemaker starts.",
+		"required" : "0",
+		"shortdesc" : "Error log suppression.",
+		"order": 5
+	}
+	all_opt["logfile"] = {
+		"getopt" : ":",
+		"longopt" : "logfile",
+		"help" : "-f, --logfile                  Log output (stdout and stderr) to file",
+		"required" : "0",
+		"shortdesc" : "Log output (stdout and stderr) to file",
+		"order": 6
+	}
+	all_opt["corosync_cmap_path"] = {
+		"getopt" : ":",
+		"longopt" : "corosync-cmap-path",
+		"help" : "--corosync-cmap-path=[path]    Path to corosync-cmapctl binary",
+		"required" : "0",
+		"shortdesc" : "Path to corosync-cmapctl binary",
+		"default" : "@COROSYNC_CMAPCTL_PATH@",
+		"order": 300
+	}
+	all_opt["sg_persist_path"] = {
+		"getopt" : ":",
+		"longopt" : "sg_persist-path",
+		"help" : "--sg_persist-path=[path]       Path to sg_persist binary",
+		"required" : "0",
+		"shortdesc" : "Path to sg_persist binary",
+		"default" : "@SG_PERSIST_PATH@",
+		"order": 300
+	}
+	all_opt["sg_turs_path"] = {
+		"getopt" : ":",
+		"longopt" : "sg_turs-path",
+		"help" : "--sg_turs-path=[path]          Path to sg_turs binary",
+		"required" : "0",
+		"shortdesc" : "Path to sg_turs binary",
+		"default" : "@SG_TURS_PATH@",
+		"order": 300
+	}
+	all_opt["vgs_path"] = {
+		"getopt" : ":",
+		"longopt" : "vgs-path",
+		"help" : "--vgs-path=[path]              Path to vgs binary",
+		"required" : "0",
+		"shortdesc" : "Path to vgs binary",
+		"default" : "@VGS_PATH@",
+		"order": 300
+	}
+	all_opt["key_value"] = {
+		"getopt" : ":",
+		"longopt" : "key-value",
+		"help" : "--key-value=<id|hash>          SCSI key node generation method",
+		"required" : "0",
+		"shortdesc" : "Method used to generate the SCSI key. \"id\" (default) \
+uses the positional ID from \"corosync-cmactl nodelist\" output which can get inconsistent \
+when nodes are removed from cluster without full cluster restart. \"hash\" uses part of hash \
+made out of node names which is not affected over time but there is theoretical chance that \
+hashes can collide as size of SCSI key is quite limited.",
+		"default" : "id",
+		"order": 300
+	}
+
+
+def scsi_check_get_options(options):
+	try:
+		f = open("/etc/sysconfig/stonith", "r")
+	except IOError:
+		return options
+
+	match = re.findall(r"^\s*(\S*)\s*=\s*(\S*)\s*", "".join(f.readlines()), re.MULTILINE)
+
+	for m in match:
+		options[m[0].lower()] = m[1].lower()
+
+	f.close()
+
+	return options
+
+
+def scsi_check(hardreboot=False):
+	if len(sys.argv) >= 3 and sys.argv[1] == "repair":
+		return int(sys.argv[2])
+	options = {}
+	options["--sg_turs-path"] = "@SG_TURS_PATH@"
+	options["--sg_persist-path"] = "@SG_PERSIST_PATH@"
+	options["--power-timeout"] = "5"
+	options["retry"] = "0"
+	options["retry-sleep"] = "1"
+	options = scsi_check_get_options(options)
+	if "verbose" in options and options["verbose"] == "yes":
+		logging.getLogger().setLevel(logging.DEBUG)
+	devs = dev_read(fail=False,opt=options)
+	if not devs:
+		if "--suppress-errors" not in options:
+			logging.error("No devices found")
+		return 0
+	key = get_key(fail=False)
+	if not key:
+		logging.error("Key not found")
+		return 0
+	for dev in devs:
+		for n in range(int(options["retry"]) + 1):
+			if n > 0:
+				logging.debug("retry: " + str(n) + " of " + options["retry"])
+			if key in get_registration_keys(options, dev, fail=False):
+				logging.debug("key " + key + " registered with device " + dev)
+				return 0
+			else:
+				logging.debug("key " + key + " not registered with device " + dev)
+
+			if n < int(options["retry"]):
+				time.sleep(float(options["retry-sleep"]))
+
+	logging.debug("key " + key + " registered with any devices")
+
+	if hardreboot == True:
+		libc = ctypes.cdll['libc.so.6']
+		libc.reboot(0x1234567)
+	return 2
+
+
+def main():
+
+	atexit.register(atexit_handler)
+
+	device_opt = ["no_login", "no_password", "devices", "nodename", "port",\
+	"no_port", "key", "aptpl", "fabric_fencing", "on_target", "corosync_cmap_path",\
+	"sg_persist_path", "sg_turs_path", "readonly", "suppress-errors", "logfile", "vgs_path",\
+	"force_on", "key_value"]
+
+	define_new_opts()
+
+	all_opt["delay"]["getopt"] = "H:"
+
+	all_opt["port"]["help"] = "-n, --plug=[nodename]          Name of the node to be fenced"
+	all_opt["port"]["shortdesc"] = "Name of the node to be fenced. The node name is used to \
+generate the key value used for the current operation. This option will be \
+ignored when used with the -k option."
+
+	#fence_scsi_check
+	if os.path.basename(sys.argv[0]) == "fence_scsi_check":
+		sys.exit(scsi_check())
+	elif os.path.basename(sys.argv[0]) == "fence_scsi_check_hardreboot":
+		sys.exit(scsi_check(True))
+
+	options = check_input(device_opt, process_input(device_opt), other_conditions=True)
+
+	# hack to remove list/list-status actions which are not supported
+	options["device_opt"] = [ o for o in options["device_opt"] if o != "separator" ]
+
+	docs = {}
+	docs["shortdesc"] = "Fence agent for SCSI persistent reservation"
+	docs["longdesc"] = "fence_scsi is an I/O fencing agent that uses SCSI-3 \
+persistent reservations to control access to shared storage devices. These \
+devices must support SCSI-3 persistent reservations (SPC-3 or greater) as \
+well as the \"preempt-and-abort\" subcommand.\nThe fence_scsi agent works by \
+having each node in the cluster register a unique key with the SCSI \
+device(s). Reservation key is generated from \"node id\" (default) or from \
+\"node name hash\" (RECOMMENDED) by adjusting \"key_value\" option. \
+Using hash is recommended to prevent issues when removing nodes \
+from cluster without full cluster restart. \
+Once registered, a single node will become the reservation holder \
+by creating a \"write exclusive, registrants only\" reservation on the \
+device(s). The result is that only registered nodes may write to the \
+device(s). When a node failure occurs, the fence_scsi agent will remove the \
+key belonging to the failed node from the device(s). The failed node will no \
+longer be able to write to the device(s). A manual reboot is required.\
+\n.P\n\
+When used as a watchdog device you can define e.g. retry=1, retry-sleep=2 and \
+verbose=yes parameters in /etc/sysconfig/stonith if you have issues with it \
+failing."
+	docs["vendorurl"] = ""
+	show_docs(options, docs)
+
+	run_delay(options)
+
+	# backward compatibility layer BEGIN
+	if "--logfile" in options:
+		try:
+			logfile = open(options["--logfile"], 'w')
+			sys.stderr = logfile
+			sys.stdout = logfile
+		except IOError:
+			fail_usage("Failed: Unable to create file " + options["--logfile"])
+	# backward compatibility layer END
+
+	options["store_path"] = STORE_PATH
+
+	# Input control BEGIN
+	stop_after_error = False if options["--action"] == "validate-all" else True
+
+	if options["--action"] == "monitor":
+		sys.exit(do_action_monitor(options))
+
+	# workaround to avoid regressions
+	if "--nodename" in options and options["--nodename"]:
+		options["--plug"] = options["--nodename"]
+		del options["--nodename"]
+
+	if not (("--plug" in options and options["--plug"])\
+	or ("--key" in options and options["--key"])):
+		fail_usage("Failed: nodename or key is required", stop_after_error)
+
+	if options["--action"] != "validate-all":
+		if not ("--key" in options and options["--key"]):
+			options["--key"] = generate_key(options)
+
+		if options["--key"] == "0" or not options["--key"]:
+			fail_usage("Failed: key cannot be 0", stop_after_error)
+
+	if "--key-value" in options\
+	and (options["--key-value"] != "id" and options["--key-value"] != "hash"):
+		fail_usage("Failed: key-value has to be 'id' or 'hash'", stop_after_error)
+
+	if options["--action"] == "validate-all":
+		sys.exit(0)
+
+	options["--key"] = options["--key"].lstrip('0')
+
+	if not ("--devices" in options and options["--devices"].split(",")):
+		options["devices"] = get_clvm_devices(options)
+	else:
+		options["devices"] = options["--devices"].split(",")
+
+	if not options["devices"]:
+		fail_usage("Failed: No devices found")
+	# Input control END
+
+	result = fence_action(None, options, set_status, get_status)
+	sys.exit(result)
+
+if __name__ == "__main__":
+	main()