flow-accounting: T1890: Fixed bugs in flow-accounting

* fixed improper `process.returncode` invokes
* added check for if an in-memory table is active before using IMT for flows show
* replaced `--nflog-range` to `--nflog-size` in iptables rules, as `--nflog-range` had never works. **WARNING: this change break compatibility with Debian 8!**

2 files changed, 12 insertions, 4 deletions

diff --git a/src/conf_mode/flow_accounting_conf.py b/src/conf_mode/flow_accounting_conf.py
index 75dee4e64..0bc50482c 100755
--- a/src/conf_mode/flow_accounting_conf.py
+++ b/src/conf_mode/flow_accounting_conf.py
@@ -154,7 +154,7 @@ def _iptables_get_nflog():
         process = subprocess.Popen(iptables_command, stdout=subprocess.PIPE, shell=True, universal_newlines=True)
         stdout, stderr = process.communicate()
         if not process.returncode == 0:
-            print("Failed to get flows list: command \"{}\" returned exit code: {}\nError: {}".format(command, process.returncode(), stderr))
+            print("Failed to get flows list: command \"{}\" returned exit code: {}\nError: {}".format(command, process.returncode, stderr))
             sys.exit(1)
         iptables_out = stdout.splitlines()
 
@@ -196,7 +196,7 @@ def _iptables_config(configured_ifaces):
 
     # create missed rules
     for iface_extended in configured_ifaces_extended:
-        rule_definition = "{0} -i {1} -m comment --comment FLOW_ACCOUNTING_RULE -j NFLOG --nflog-group 2 --nflog-range {2} --nflog-threshold 100".format(iptables_nflog_chain, iface_extended['iface'], default_captured_packet_size)
+        rule_definition = "{0} -i {1} -m comment --comment FLOW_ACCOUNTING_RULE -j NFLOG --nflog-group 2 --nflog-size {2} --nflog-threshold 100".format(iptables_nflog_chain, iface_extended['iface'], default_captured_packet_size)
         iptable_commands.append("sudo {0} -t {1} -I {2}".format(iface_extended['iptables_variant'], iptables_nflog_table, rule_definition))
 
     # change iptables
diff --git a/src/op_mode/flow_accounting_op.py b/src/op_mode/flow_accounting_op.py
index caaf22b31..a39eaf871 100755
--- a/src/op_mode/flow_accounting_op.py
+++ b/src/op_mode/flow_accounting_op.py
@@ -20,6 +20,7 @@ import argparse
 import re
 import ipaddress
 import subprocess
+import os.path
 from tabulate import tabulate
 
 # some default values
@@ -83,7 +84,7 @@ def _get_ifaces_dict():
     process = subprocess.Popen(command.split(' '), stdout=subprocess.PIPE, universal_newlines=True)
     stdout, stderr = process.communicate()
     if not process.returncode == 0:
-        print("Failed to get interfaces list: command \"{}\" returned exit code: {}".format(command, process.returncode()))
+        print("Failed to get interfaces list: command \"{}\" returned exit code: {}".format(command, process.returncode))
         sys.exit(1)
 
     # read output
@@ -106,7 +107,7 @@ def _get_flows_list():
     process = subprocess.Popen(command.split(' '), stdout=subprocess.PIPE, universal_newlines=True)
     stdout, stderr = process.communicate()
     if not process.returncode == 0:
-        print("Failed to get flows list: command \"{}\" returned exit code: {}\nError: {}".format(command, process.returncode(), stderr))
+        print("Failed to get flows list: command \"{}\" returned exit code: {}\nError: {}".format(command, process.returncode, stderr))
         sys.exit(1)
 
     # read output
@@ -180,6 +181,11 @@ def _flows_table_print(flows):
     except KeyboardInterrupt:
         sys.exit(0)
 
+# check if in-memory table is active
+def _check_imt():
+    if not os.path.exists(uacctd_pipefile):
+        print("In-memory table is not available")
+        sys.exit(1)
 
 # define program arguments
 cmd_args_parser = argparse.ArgumentParser(description='show flow-accounting')
@@ -210,6 +216,7 @@ if cmd_args.action == 'restart':
 
 # clear in-memory collected flows
 if cmd_args.action == 'clear':
+    _check_imt()
     # run command to clear flows
     command = "/usr/bin/pmacct -e -p {}".format(uacctd_pipefile)
     return_code = subprocess.call(command.split(' '))
@@ -219,6 +226,7 @@ if cmd_args.action == 'clear':
 
 # show table with flows
 if cmd_args.action == 'show':
+    _check_imt()
     # get interfaces index and names
     ifaces_dict = _get_ifaces_dict()
     # get flows