From d10133b0850217fdb0de5194d5a2fa650055fc08 Mon Sep 17 00:00:00 2001
From: SourceDoctor <sourcehhdoctor@googlemail.com>
Date: Wed, 17 Jun 2020 00:04:29 +0200
Subject: [PATCH] DHCP Agent Update (#303)

---
 snmp/dhcp-status.sh |  36 ------------
 snmp/dhcp.py        | 135 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 135 insertions(+), 36 deletions(-)
 delete mode 100755 snmp/dhcp-status.sh
 create mode 100755 snmp/dhcp.py

diff --git a/snmp/dhcp-status.sh b/snmp/dhcp-status.sh
deleted file mode 100755
index a629d0a..0000000
--- a/snmp/dhcp-status.sh
+++ /dev/null
@@ -1,36 +0,0 @@
-#!/bin/bash
-################################################################
-# copy this script to somewhere like /opt and make chmod +x it #
-# edit your snmpd.conf add the below line and restart snmpd    #
-# extend dhcpstats /opt/dhcp-status.sh                         #
-################################################################ 
-FILE_DHCP='/var/lib/dhcp/db/dhcpd.leases'
-BIN_CAT='/usr/bin/cat'
-BIN_GREP='/usr/bin/grep'
-BIN_TR='/usr/bin/tr'
-BIN_SED='/usr/bin/sed'
-BIN_SORT='/usr/bin/sort'
-BIN_WC='/usr/bin/wc'
-
-CONFIGFILE=/etc/snmp/dhcp-status.conf
-if [ -f $CONFIGFILE ] ; then
-    . $CONFIGFILE
-fi
-
-DHCP_LEASES='^lease'
-DHCP_ACTIVE='^lease|binding state active'
-DHCP_EXPIRED='^lease|binding state expired'
-DHCP_RELEASED='^lease|binding state released'
-DHCP_ABANDONED='^lease|binding state abandoned'
-DHCP_RESET='^lease|binding state reset'
-DHCP_BOOTP='^lease|binding state bootp'
-DHCP_BACKUP='^lease|binding state backup'
-DHCP_FREE='^lease|binding state free'
-NO_ERROR='[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3} binding'
-
-$BIN_CAT $FILE_DHCP | $BIN_GREP $DHCP_LEASES | $BIN_SORT -u | $BIN_WC -l
-
-for state in "$DHCP_ACTIVE" "$DHCP_EXPIRED" "$DHCP_RELEASED" "$DHCP_ABANDONED" "$DHCP_RESET" "$DHCP_BOOTP" "$DHCP_BACKUP" "$DHCP_FREE"
-do
-        $BIN_GREP -E "$state"  $FILE_DHCP | $BIN_TR '\n' '|' | $BIN_SED 's/ {| //g' | $BIN_TR '|' '\n' | $BIN_GREP -E "$NO_ERROR" | $BIN_SORT -u | $BIN_WC -l
-done
diff --git a/snmp/dhcp.py b/snmp/dhcp.py
new file mode 100755
index 0000000..1293737
--- /dev/null
+++ b/snmp/dhcp.py
@@ -0,0 +1,135 @@
+#!/usr/bin/env python3
+
+import subprocess
+import json
+from os.path import isfile
+
+CONFIGFILE = '/etc/snmp/dhcp.json'
+
+# Configfile is needed /etc/snmp/dhcp.json
+#
+# {"leasefile": "/var/lib/dhcp/dhcpd.leases"
+# }
+#
+
+error = 0
+error_string = ''
+version = 2
+
+with open(CONFIGFILE, 'r') as json_file:
+    try:
+        configfile = json.load(json_file)
+    except json.decoder.JSONDecodeError as e:
+        error = 1
+        error_string = "Configfile Error: '%s'" % e
+
+
+if not error:
+    leases = {'total': 0,
+              'active': 0,
+              'expired': 0,
+              'released': 0,
+              'abandoned': 0,
+              'reset': 0,
+              'bootp': 0,
+              'backup': 0,
+              'free': 0,
+             }
+    if not isfile(configfile['leasefile']):
+        error = 1
+        error_string = 'Lease File not found'
+    else:
+        with open(configfile['leasefile']) as fp:
+            line = fp.readline()
+            while line:
+                line = fp.readline()
+
+                if 'rewind' not in line:
+                    if line.startswith('lease'):
+                        leases['total'] += 1
+                    elif 'binding state active' in line:
+                        leases['active'] += 1
+                    elif 'binding state expired' in line:
+                        leases['expired'] += 1
+                    elif 'binding state released' in line:
+                        leases['released'] += 1
+                    elif 'binding state abandoned' in line:
+                        leases['abandoned'] += 1
+                    elif 'binding state reset' in line:
+                        leases['reset'] += 1
+                    elif 'binding state bootp' in line:
+                        leases['bootp'] += 1
+                    elif 'binding state backup' in line:
+                        leases['backup'] += 1
+                    elif 'binding state free' in line:
+                        leases['free'] += 1
+
+shell_cmd = "dhcpd-pools -s i -A"
+pool_data = subprocess.Popen(shell_cmd, shell=True, stdout=subprocess.PIPE).stdout.read().split(b'\n')
+
+data = {'leases': leases,
+        'pools': [],
+        'networks': [],
+        'all_networks': []
+        }
+
+category = None
+jump_line = 0
+for p in pool_data:
+    line = p.decode('utf-8')
+
+    if jump_line:
+        jump_line -= 1
+        continue
+
+    if line.startswith('Ranges:'):
+        category = 'pools'
+        jump_line = 1
+        continue
+
+    if line.startswith('Shared networks:'):
+        category = 'networks'
+        jump_line = 1
+        continue
+
+    if line.startswith('Sum of all ranges:'):
+        category = 'all_networks'
+        jump_line = 1
+        continue
+
+    if not len(line):
+        continue
+
+    p = line.split()
+
+    if category == 'pools':
+        data[category].append({'first_ip': p[1],
+                                'last_ip':p[3],
+                                'max': p[4],
+                                'cur': p[5],
+                                'percent': p[6],
+                                })
+        continue
+
+    if category == 'networks':
+        data[category].append({'network': p[0],
+                                'max': p[1],
+                                'cur': p[2],
+                                'percent': p[3],
+                                })
+        continue
+
+    if category == 'all_networks':
+        data[category] ={'max': p[2],
+                          'cur': p[3],
+                          'percent': p[4],
+                         }
+        continue
+
+
+output = {'version': version,
+          'error': error,
+          'errorString': error_string,
+          'data': data}
+
+print (json.dumps(output))