Develop Reference

Read data from a DDSU666 using RS485

I have tried my luck with these codes to read the data from the DDSU666-H and it seems that I am able to read data, but I don't know what to do with it. In theory it is a list of data, but I am not able to understand what I am receiving or how to translate it into something I can use
import serial # import the module
def banner_bottom():
print(' +-------------------------------------------+')
print(' | SPACE |')
print(' +-------------------------------------------+')
COM_Port = serial.Serial('COM3')
COM_Port.baudrate = 9600 # set Baud rate
COM_Port.bytesize = 8 # Number of data bits = 8
COM_Port.parity = 'N' # No parity
COM_Port.stopbits = 1 # Number of Stop bits = 1
COM_Port.setRTS(1) #RTS=1,~RTS=0 so ~RE=0,Receive mode enabled for MAX485
COM_Port.setDTR(1) #DTR=1,~DTR=0 so DE=0,(In FT232 RTS and DTR pins are inverted)
#~RE and DE LED's on USB2SERIAL board will be off
RxedData = COM_Port.readline()
print(' ',RxedData, '\n')
COM_Port.close() # Close the Serial port
banner_bottom()# Display the bottom banner
Output:
b'\x7f~\xbb\xff\xfb\xe3=\x7f~_cuI_\x0e\x7f~\xbb\xff\xfb\xe3=\x7f~_]\xd3V\'\t\x7f~\xbb\xff\xfb\xe3=\x7f~__\x07\xf5tU\x7f~\xbb\xff\xfb\xe3=\x7f~_[y\x8d\xba\x00\x7f~\xbb\xff\xfb\xe3=\x7f~_YsGe\x18\x7f~\xbb\xff\xfb\xe3=\x7f~_Y\xe3\x06n\x16\x7f~\xbb\xff\xfb\xe3=\x7f~__O]I\x1d\x7f~\xbb\xff\xfb\xe3=\x7f~_ao\xff\xf0\x05\x7f~\xbb\xff\xfb\xe3=\x7f~_co-O\x10\x7f~\xbb\xff\xfb\xe3=\x7f~__\x15\x117\x03\x7f~\xbb\xff\xfb\xe3=\x7f~__!-\xc9/\x7f~\xbb\xff\xfb\xe3=\x7f~__}\xed|\x00\x7f~\xbb\xff\xfb\xe3=\x7f~_c\xb7+\xda\x00\x7f~\xbb\xff\xfb\xe3=\x7f~_e\x8f"U\x01\x7f~\xfd\xff\xfb]\x1a\x7f~_W\xaf\x08\x975\x00\x7f~\xfd\xff\xfb]\x1a\x7f~_W\xaf\x08\x975\x00\x7f~\xfd\xff\xfb]\x1a\x7f~_W\xaf\x08\x975\x00\x7f~\xbb\xff\xfb\xe3=\x7f~_]\xd3V\'\t\x7f~\xbb\xff\xfb\xe3=\x7f~__\xd9\xadb\x08\x7f~\xbb\xff\xfb\xe3=\x7f~__\xc5[P\x05\x7f~\xbb\xff\xfb\xe3=\x7f~__\x91\xfef\x00\x7f~\xbb\xff\xfb\xe3=\x7f~_c3\xb3T\x0f\x7f~\xbb\xff\xfb\xe3=\x7f~_e\xbd\x01\xb0\x03\x7f~\xbb\xff\xfb\xe3=\x7f~_e?y\x84\x19\x7f~\xbb\xff\xfb\xe3=\x7f~_\xe349\xac\n'
Code 2:
#!/usr/bin/env python3
import serial
port = 'COM3'
ComPort = serial.Serial(port)
ComPort.baudrate = 9600
ComPort.bitesize = 8
ComPort.parity = 'N'
ComPort.stopbits = 1
dataIn=ComPort.read(6)
print(dataIn)
ComPort.close()
Ouput:
b'\x7f~\xbb\xff\xfb\xe3'
I've tried to translate the output into something I can understand, but I haven't been able to see anything either.
binary_data = b'\x7f~\xbb\xff\xfb\xe3'
aa = binary_data.hex()
print(aa)
#OUT: 7f7ebbfffbe3
bb = ''.join(['%02x' % b for b in binary_data])
print(bb)
#OUT: 7f7ebbfffbe3
s = binary_data.decode('cp855')
print(s)
#OUT:~╗ чÑ
What can I try to resolve this?

ryu (SDN) traffic controller from (example) Host 1

I created a simple network in the mininet environment with the following command:
$ sudo mn --topo single,3 --mac --controller remote --switch ovsk
I want use RYU CONTROLLER to calculate bandwidth traffic on special port of switch. I'm thinking of using an OFPEVENTPacketIn event for the incoming packet, but I do not any idea for out coming packet form port.
My code:
from operator import attrgetter
from ryu.app import simple_switch_13
from ryu.controller import ofp_event
from ryu.controller.handler import MAIN_DISPATCHER, DEAD_DISPATCHER
from ryu.controller.handler import set_ev_cls
from ryu.lib import hub
class SimpleMonitor(simple_switch_13.SimpleSwitch13):
def __init__(self, *args, **kwargs):
super(SimpleMonitor, self).__init__(*args, **kwargs)
self.datapaths = {}
self.monitor_thread = hub.spawn(self._monitor)
#set_ev_cls(ofp_event.EventOFPStateChange,
[MAIN_DISPATCHER, DEAD_DISPATCHER])
def _state_change_handler1(self, ev):
datapath = ev.datapath
if ev.state == MAIN_DISPATCHER:
if not datapath.id in self.datapaths:
self.logger.debug('register datapath: %016x', datapath.id)
self.datapaths[datapath.id] = datapath
elif ev.state == DEAD_DISPATCHER:
if datapath.id in self.datapaths:
self.logger.debug('unregister datapath: %016x', datapath.id)
del self.datapaths[datapath.id]
def _monitor(self):
while True:
for dp in self.datapaths.values():
self._request_stats(dp)
hub.sleep(10)
def _request_stats(self, datapath):
self.logger.debug('send stats request: %016x', datapath.id)
ofproto = datapath.ofproto
parser = datapath.ofproto_parser
req = parser.OFPFlowStatsRequest(datapath)
datapath.send_msg(req)
req = parser.OFPPortStatsRequest(datapath, 0, ofproto.OFPP_ANY)
datapath.send_msg(req)
#set_ev_cls(ofp_event.EventOFPFlowStatsReply, MAIN_DISPATCHER)
def _flow_stats_reply_handler(self, ev):
body = ev.msg.body
self.logger.info('datapath '
'in-port eth-dst '
'out-port packets bytes')
self.logger.info('---------------- '
'-------- ----------------- '
'-------- -------- --------')
for stat in sorted([flow for flow in body if flow.priority == 1],
key=lambda flow: (flow.match['in_port'],
flow.match['eth_dst'])):
# self.logger.info('%016x %8x %17s %8x %8d %8d',
if stat.match['in_port']==1:
self.logger.info('%x %x %s %x %d %d',
ev.msg.datapath.id,
stat.match['in_port'], stat.match['eth_dst'],
stat.instructions[0].actions[0].port,
stat.packet_count, stat.byte_count)
#for stat in [1234]#sorted([flow for flow in body if flow.priority == 1],
# key=lambda flow: (flow.match['in_port'],
# flow.match['eth_dst'])):
# self.logger.info('%016x %8x %17s %8x %8d %8d',
# if stat.match['in_port']==1:
# self.logger.info('%x %x %s %x %d %d',
# ev.msg.datapath.id,
# stat.match['in_port'], stat.match['eth_dst'],
# stat.instructions[0].actions[0].port,
# stat.packet_count, stat.byte_count)
#set_ev_cls(ofp_event.EventOFPPortStatsReply, MAIN_DISPATCHER)
def _port_stats_reply_handler(self, ev):
body = ev.msg.body
self.logger.info('datapath port '
'rx-pkts rx-bytes rx-error '
'tx-pkts tx-bytes tx-error')
self.logger.info('---------------- -------- '
'-------- -------- -------- '
'-------- -------- --------')
for stat in sorted(body, key=attrgetter('port_no')):
if stat.port_no==1:
self.logger.info('%016x %8x %8d %8d %8d %8d %8d %8d',
ev.msg.datapath.id, stat.port_no,
stat.rx_packets, stat.rx_bytes, stat.rx_errors,
stat.tx_packets, stat.tx_bytes, stat.tx_errors)
Please help me edit this code to answer my question. Thanks.

You have to add two method in your controller:
1) a method that requests stats
2) a method that captures the answers from switches.
The method for answering stats is the following:
def send_flow_stats_request(self, datapath):
ofp = datapath.ofproto
ofp_parser = datapath.ofproto_parser
cookie = cookie_mask = 0
match = ofp_parser.OFPMatch(in_port=1)
req = ofp_parser.OFPFlowStatsRequest(datapath, 0,
ofp.OFPTT_ALL,
ofp.OFPP_ANY, ofp.OFPG_ANY,
cookie, cookie_mask,
match)
datapath.send_msg(req)
The method for capturing answers is this one:
#set_ev_cls(ofp_event.EventOFPFlowStatsReply, MAIN_DISPATCHER)
def flow_stats_reply_handler(self, ev):
flows = []
for stat in ev.msg.body:
flows.append('table_id=%s '
'duration_sec=%d duration_nsec=%d '
'priority=%d '
'idle_timeout=%d hard_timeout=%d flags=0x%04x '
'cookie=%d packet_count=%d byte_count=%d '
'match=%s instructions=%s' %
(stat.table_id,
stat.duration_sec, stat.duration_nsec,
stat.priority,
stat.idle_timeout, stat.hard_timeout, stat.flags,
stat.cookie, stat.packet_count, stat.byte_count,
stat.match, stat.instructions))
self.logger.debug('FlowStats: %s', flows)
Once you capture stats you can compute bandwidth usage.
However you have also other kind of requests you can perform so i suggest you to read the rye doc.
http://ryu.readthedocs.io/en/latest/

libvirt: From state integer to string?

I have this simple script to check the memory usage of virtual machines managed by libvirt.
How can I convert the integer for state from dom.info() to a human readable string?
import libvirt
import re
import sys
def mem_total_kb():
meminfo = open('/proc/meminfo').read()
matched = re.search(r'^MemTotal:\s+(\d+)', meminfo)
return int(matched.groups()[0])
def main():
conn = libvirt.openReadOnly(None)
if conn == None:
print 'Failed to open connection to the hypervisor'
sys.exit(1)
used_mem_sum = 0
for domain_id in conn.listDomainsID():
dom = conn.lookupByID(domain_id)
state, max_mem, used_mem, vcpus, cpu_time_used = dom.info()
print(
'name=%s state=%s max_mem=%s used_mem=%s vcpus=%s cpu_time_used=%s' % (dom.name(), state, max_mem, used_mem, vcpus, cpu_time_used))
used_mem_sum += used_mem
print('Sum of used mem: %s KiB' % used_mem_sum)
mem_total = mem_total_kb()
print('Sum of physical mem: %s KiB' % mem_total)
if used_mem_sum > mem_total:
print('########## VMs use more RAM than available!')
return
mem_left=mem_total - used_mem_sum
print('Memory left: %s KiB' % (mem_left))
mem_left_should=4000000
if mem_left<mem_left_should:
print('less than mem_left_should=%sKiB left!' % mem_left_should)
if __name__ == '__main__':
main()
Docs: https://libvirt.org/html/libvirt-libvirt-domain.html#virDomainInfo
state: the running state, one of virDomainState
enum virDomainState {
VIR_DOMAIN_NOSTATE = 0
no state
VIR_DOMAIN_RUNNING = 1
the domain is running
VIR_DOMAIN_BLOCKED = 2
the domain is blocked on resource
VIR_DOMAIN_PAUSED = 3
the domain is paused by user
VIR_DOMAIN_SHUTDOWN = 4
the domain is being shut down
VIR_DOMAIN_SHUTOFF = 5
the domain is shut off
VIR_DOMAIN_CRASHED = 6
the domain is crashed
VIR_DOMAIN_PMSUSPENDED = 7
the domain is suspended by guest power management
VIR_DOMAIN_LAST = 8
NB: this enum value will increase over time as new events are added to the libvirt API. It reflects the last state supported by this version of the libvirt API.
}

Looks like at least the enum constant names are exposed in the libvirt module. The following works for me...
import libvirt
import pprint
import re
d = {}
for k, v in libvirt.__dict__.iteritems():
if re.match('VIR_DOMAIN_[A-Z]+$', k):
d[v] = k
pprint.pprint(d)
...and prints...
{0: 'VIR_DOMAIN_NOSTATE',
1: 'VIR_DOMAIN_RUNNING',
2: 'VIR_DOMAIN_BLOCKED',
3: 'VIR_DOMAIN_PAUSED',
4: 'VIR_DOMAIN_SHUTDOWN',
5: 'VIR_DOMAIN_SHUTOFF',
6: 'VIR_DOMAIN_CRASHED',
7: 'VIR_DOMAIN_PMSUSPENDED'}
The descriptions, which are likely just comments in the original source code, are probably not exposed. One of the examples defines its own dictionary on line 106...
state_names = { libvirt.VIR_DOMAIN_RUNNING : "running",
libvirt.VIR_DOMAIN_BLOCKED : "idle",
libvirt.VIR_DOMAIN_PAUSED : "paused",
libvirt.VIR_DOMAIN_SHUTDOWN : "in shutdown",
libvirt.VIR_DOMAIN_SHUTOFF : "shut off",
libvirt.VIR_DOMAIN_CRASHED : "crashed",
libvirt.VIR_DOMAIN_NOSTATE : "no state" }
...so you could just take it from there, although it seems to be incomplete.

This bash script will fetch the list of virDomainState values (excluding VIR_DOMAIN_LAST) and their descriptions in JSON format:
#!/bin/bash
HEADER=include/libvirt/libvirt-domain.h
get_header_file()
{
curl -s https://raw.githubusercontent.com/libvirt/libvirt/master/"$HEADER"
}
select_virDomainState_block()
{
sed -n '/virDomainState:/,/^\} virDomainState;/ p'
}
join_multiline_comments()
{
sed -n '\%/\*[^*]*$% N; \%/\*.*\*/$% { s/\s*\n\s*/ /; p; }'
}
enum_values_to_json_map()
{
echo '{'
sed "s/\s*VIR_DOMAIN\S\+\s*=\s*//; s^,\s*/\*\s*^ : '^; s^\s*\*/^',^;"
echo '}'
}
get_header_file \
| select_virDomainState_block \
| join_multiline_comments \
| grep 'VIR_DOMAIN\S\+\s*=' \
| enum_values_to_json_map
Example usage:
$ ./get_libvirt_domain_states
{
0 : 'no state',
1 : 'the domain is running',
2 : 'the domain is blocked on resource',
3 : 'the domain is paused by user',
4 : 'the domain is being shut down',
5 : 'the domain is shut off',
6 : 'the domain is crashed',
7 : 'the domain is suspended by guest power management',
}
Note that the script downloads a ~150KB file from the libvirt mirror repository at GitHub. It is intended for facilitating staying up-to-date with the libvirt code. Of course you can call it from your python code, but personally I wouldn't do that.

Converting multi-line script output to dictionary using regex

I got the following script output:
***************************************************
[g4u2680c]: searching for domains
---------------------------------------------------
host = g4u2680c.houston.example.com
ipaddr = [16.208.16.72]
VLAN = [352]
Gateway= [16.208.16.1]
Subnet = [255.255.248.0]
Subnet = [255.255.248.0]
Cluster= [g4u2679c g4u2680c g9u1484c g9u1485c]
host = g4u2680c.houston.example.com
ipaddr = [16.208.16.72]
VLAN = [352]
Gateway= [16.208.16.1]
Subnet = [255.255.248.0]
Subnet = [255.255.248.0]
Cluster= [g4u2679c g4u2680c g9u1484c g9u1485c]
* script completed Mon Jun 15 06:13:14 UTC 2015 **
* sleeping 30 to avoid DOS on dns via a loop **
I need to extract the 2 host list into a dictionary, with out the brackets.
Here is my code:
#!/bin/env python
import re
text="""***************************************************
[g4u2680c]: searching for domains
---------------------------------------------------
host = g4u2680c.houston.example.com
ipaddr = [16.208.16.72]
VLAN = [352]
Gateway= [16.208.16.1]
Subnet = [255.255.248.0]
Subnet = [255.255.248.0]
Cluster= [g4u2679c g4u2680c g9u1484c g9u1485c]
host = g4u2680c.houston.example.com
ipaddr = [16.208.16.72]
VLAN = [352]
Gateway= [16.208.16.1]
Subnet = [255.255.248.0]
Subnet = [255.255.248.0]
Cluster= [g4u2679c g4u2680c g9u1484c g9u1485c]
* script completed Mon Jun 15 06:13:14 UTC 2015 **
* sleeping 30 to avoid DOS on dns via a loop **
***************************************************
"""
seq = re.compile(r"host.+?\n\n",re.DOTALL)
a=seq.findall(text)
matches = re.findall(r'\w.+=.+', a[0])
matches = [m.split('=', 1) for m in matches]
matches = [ [m[0].strip().lower(), m[1].strip().lower()] for m in matches]
#should have function with regular expression to remove bracket here
d = dict(matches)
print d
What I got so far for the first host:
{'subnet': '[255.255.248.0]', 'vlan': '[352]', 'ipaddr': '[16.208.16.72]', 'cluster': '[g4u2679c g4u2680c g9u1484c g9u1485c]', 'host': 'g4u2680c.houston.example.com', 'gateway': '[16.208.16.1]'}
I need help to find the regex to remove the bracket as the value in the dictionary contain data with and without bracket.
Or if there is a better and simpler way to transform the original script output into dictionary.

You can use: (\w+)\s*=\s*\[?([^\n\]]+)\]?
demo
import re
p = re.compile(ur'(\w+)\s*=\s*\[?([^\n\]]+)\]?', re.MULTILINE)
test_str = u"host = g4u2680c.houston.example.com\n ipaddr = [16.208.16.72]\n VLAN = [352]\n Gateway= [16.208.16.1]\n Subnet = [255.255.248.0]\n Subnet = [255.255.248.0]\n Cluster= [g4u2679c g4u2680c g9u1484c g9u1485c]\n\nhost = g4u2680c.houston.example.com\n ipaddr = [16.208.16.72]\n VLAN = [352]\n Gateway= [16.208.16.1]\n Subnet = [255.255.248.0]\n Subnet = [255.255.248.0]\n Cluster= [g4u2679c g4u2680c g9u1484c g9u1485c]\n"
re.findall(p, test_str)

You can simply use re.findall and dict :
>>> dict([(i,j.strip('[]')) for i,j in re.findall(r'(\w+)\s*=\s*(.+)',text)])
{'Subnet': '255.255.248.0', 'VLAN': '352', 'ipaddr': '16.208.16.72', 'Cluster': 'g4u2679c g4u2680c g9u1484c g9u1485c', 'host': 'g4u2680c.houston.example.com', 'Gateway': '16.208.16.1'}
And about the brackets you can remove them by str.strip method.

You can try out this.
matches = [m.replace('[','').replace(']','').split('=', 1) for m in matches]

Create a .txt list of IPs in a subnet

I'd like to make a very simple text (.txt) file. This python program needs to make a list of multiple ranges of IPs in a subnet, each taking up one line.
Example:
10.10.27.1
10.10.27.5
10.10.27.6
10.10.27.26
10.10.27.27
10.10.27.28
10.10.27.29
10.10.27.51
10.10.27.52
10.10.27.53
10.10.27.54
The subnet mask will essentially always be a /24, so providing mask input is not necessary. The program can even default to only supporting a standard class C.
Also, I'd like to support common ranges for devices that we use. A prompt for say, "Printers?" will include .26 - .30. "Servers?" will include .5 - .7. "DHCP?" prompt always will include .51 - .100 of the subnet. "Abnormal?" will include .100 - .254.
Subnet? 10.10.27.1
Servers? Y
Printers? Y
DHCP? Y
Abnormal? N
Output being:
10.10.27.1
10.10.27.5
10.10.27.6
10.10.27.7
10.10.27.26
10.10.27.27
10.10.27.28
10.10.27.29
10.10.27.30
10.10.27.51 (all the way to .100)
What is the best way to code this?

It looks like a few for loops are all you need:
network = '10.10.27'
for host in xrange(100, 255):
print("{network}.{host}".format(**locals()))

I would keep the script simple, just output all addresses as needed :)
def yesno(question):
output = input(question).lower()
if output == 'y':
return True
elif output == 'n':
return False
else:
print '%r is not a valid response, only "y" and "n" are allowed.' % output
return yesno(question)
addresses = []
subnet = input('Subnet? ')
# Remove the last digit and replace it with a %d for formatting later
subnet, address = subnet.rsplit('.', 1)
subnet += '%d'
addresses.append(int(address))
if yesno('Servers? '):
addresses += range(5, 8)
if yesno('Printers? '):
addresses += range(26, 31)
if yesno('DHCP? '):
addresses += range(51, 101)
if yesno('Abnormal? '):
addresses += range(100, 255)
for address in addresses:
print subnet % address

Here is a quick little script I threw together...
import socket
import sys
ranges = {'servers':(5, 8), 'printers':(26, 31), 'dhcp':(51, 101), 'abnormal':(101, 256)}
subnet = raw_input("Subnet? ")
try:
socket.inet_aton(subnet)
except socket.error:
print "Not a valid subnet"
sys.exit(1)
ip_parts = subnet.split(".")
if len(ip_parts) < 3:
print "Need at least three octets"
sys.exit(1)
ip_parts = ip_parts[:3]
ip = ".".join(ip_parts)
include_groups = []
last_octets = []
servers = raw_input("Servers? ")
printers = raw_input("Printers? ")
dhcp = raw_input("DHCP? ")
abnormal = raw_input("Abnormal? ")
if servers == "Y":
include_groups.append('servers')
if printers == "Y":
include_groups.append('printers')
if dhcp == "Y":
include_groups.append('dhcp')
if abnormal == "Y":
include_groups.append('abnormal')
for group in include_groups:
last_octets.extend([x for x in xrange(ranges[group][0], ranges[group][1])])
print "%s.1" %(ip)
for octet in last_octets:
print "%s.%s" %(ip, octet)