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1 #!/usr/bin/env python |
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2 |
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3 """ |
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4 Monitor DHCP use. |
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5 """ |
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6 |
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7 __version__ = '0.0' |
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8 |
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9 import pvl.args |
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10 import pvl.syslog.args |
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11 |
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12 import pvl.verkko.db as db |
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13 import pvl.syslog.dhcp |
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14 |
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15 import logging, optparse |
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16 |
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17 log = logging.getLogger('main') |
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18 |
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19 # name of process in syslog |
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20 DHCP_SYSLOG_PROG = 'dhcpd' |
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21 |
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22 def parse_options (argv) : |
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23 """ |
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24 Parse command-line arguments. |
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25 """ |
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26 |
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27 prog = argv[0] |
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28 |
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29 parser = optparse.OptionParser( |
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30 prog = prog, |
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31 usage = '%prog: [options]', |
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32 version = __version__, |
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33 |
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34 # module docstring |
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35 description = __doc__, |
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36 ) |
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37 |
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38 # options |
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39 parser.add_option_group(pvl.args.parser(parser)) |
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40 |
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41 ## syslog |
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42 parser.add_option_group(pvl.syslog.args.parser(parser, prog=DHCP_SYSLOG_PROG)) |
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43 |
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44 ## XXX: networks |
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45 parser.add_option('--network', metavar='NET', action='append', |
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46 help="Filter leases by network prefix as plugin instance") |
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47 |
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48 parser.add_option('--gateway', metavar='GW/IFACE', action='append', |
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49 help="Filter messages by gateway/interface as plugin instance") |
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50 |
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51 ## hosts |
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52 parser.add_option('--database', metavar='URI', |
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53 help="Track hosts in given database") |
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54 |
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55 parser.add_option('--create', action='store_true', |
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56 help="Initialize database") |
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57 |
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58 # defaults |
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59 parser.set_defaults( |
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60 |
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61 ) |
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62 |
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63 # parse |
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64 options, args = parser.parse_args(argv[1:]) |
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65 |
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66 # apply |
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67 pvl.args.apply(options, prog) |
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68 |
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69 if not options.database : |
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70 parser.error("Missing required option: --database") |
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71 |
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72 return options, args |
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73 |
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74 class DHCPHostsDatabase (db.Database) : |
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75 |
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76 def create (self) : |
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77 """ |
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78 CREATE TABLEs |
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79 """ |
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80 |
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81 log.info("Creating database tables: dhcp_hosts") |
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82 db.dhcp_hosts.create(self.engine) |
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83 |
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84 def insert (self, attrs) : |
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85 """ |
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86 INSERT new host |
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87 """ |
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88 |
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89 query = db.dhcp_hosts.insert().values( |
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90 ip = attrs['ip'], |
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91 mac = attrs['mac'], |
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92 gw = attrs['gw'], |
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93 |
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94 first_seen = attrs['timestamp'], |
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95 |
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96 name = attrs['name'], |
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97 last_seen = attrs['timestamp'], |
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98 last_msg = attrs['state'], |
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99 ) |
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100 result = self.engine.execute(query, **attrs) |
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101 id, = result.inserted_primary_key |
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102 |
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103 return id |
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104 |
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105 def update (self, attrs) : |
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106 """ |
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107 UPDATE existing host, or return False if not found. |
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108 """ |
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109 |
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110 table = db.dhcp_hosts |
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111 |
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112 query = table.update( |
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113 # where |
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114 (table.c.ip == attrs['ip']) & (table.c.mac == attrs['mac']) & (table.c.gw == attrs['gw']), |
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115 |
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116 # set |
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117 name = attrs['name'], |
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118 last_seen = attrs['timestamp'], |
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119 last_msg = attrs['state'], |
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120 ) |
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121 result = self.engine.execute(query, **attrs) |
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122 |
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123 # any matched rows? |
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124 return result.rowcount > 0 |
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125 |
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126 def process (self, item) : |
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127 """ |
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128 Process given DHCP syslog message to update the hosts table. |
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129 """ |
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130 |
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131 # ignore unless we have enough info to fully identify the client |
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132 # this means that we omit DHCPDISCOVER messages, but we get the OFFER/REQUEST/ACK |
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133 if any(name not in item for name in ('lease', 'hwaddr', 'gateway')) : |
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134 # ignore; we require these |
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135 return |
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136 |
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137 # db: syslog |
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138 ATTR_MAP = ( |
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139 ('ip', 'lease'), |
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140 ('mac', 'hwaddr'), |
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141 ('gw', 'gateway'), |
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142 ('name', 'hostname'), |
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143 |
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144 ('timestamp', 'timestamp'), |
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145 ('state', 'type'), |
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146 ('error', 'error'), |
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147 ) |
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148 |
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149 # attrs |
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150 attrs = dict((key, item.get(name)) for key, name in ATTR_MAP) |
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151 |
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152 # update existing? |
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153 if self.update(attrs) : |
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154 log.info("Update: %s", attrs) |
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155 |
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156 else : |
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157 # new |
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158 log.info("Insert: %s", attrs) |
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159 self.insert(attrs) |
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160 |
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161 class DHCPSyslogHandler (object) : |
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162 """ |
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163 Process lines from syslog |
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164 """ |
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165 |
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166 def __init__ (self, db) : |
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167 self.db = db |
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168 |
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169 # XXX |
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170 self.filter = pvl.syslog.dhcp.DHCPSyslogFilter() |
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171 |
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172 def process (self, item) : |
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173 """ |
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174 Handle a single item read from syslog to DB. |
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175 filter = pvl.syslog.dhcp.DHCPSyslogFilter() |
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176 """ |
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177 |
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178 dhcp_item = self.filter.parse(item['msg']) |
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179 |
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180 if not dhcp_item : |
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181 # ignore |
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182 return |
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183 |
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184 dhcp_item['timestamp'] = item['timestamp'] # XXX: fixup DHCPSyslogParser? |
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185 |
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186 self.db.process(dhcp_item) |
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187 |
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188 def main (self, source, poll) : |
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189 """ |
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190 Read items from syslog source with given polling style. |
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191 |
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192 TODO: poll = false on SIGINT |
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193 """ |
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194 |
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195 parser = pvl.syslog.parser.SyslogParser() |
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196 |
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197 # mainloop |
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198 while True : |
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199 # process from source |
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200 for item in parser.process(source) : |
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201 self.process(item) |
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202 |
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203 if poll is False : |
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204 # done |
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205 break |
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206 else : |
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207 # wait |
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208 source.poll(poll) |
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209 |
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210 log.debug("tick") |
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211 |
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212 def main (argv) : |
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213 options, args = parse_options(argv) |
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214 |
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215 # syslog |
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216 log.info("Open up syslog...") |
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217 syslog_parser = pvl.syslog.parser.SyslogParser(prog=DHCP_SYSLOG_PROG) # filter by prog |
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218 |
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219 if options.syslog_fifo : |
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220 source = pvl.syslog.fifo.Fifo(options.syslog_fifo) |
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221 poll = None # no timeout |
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222 |
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223 elif options.syslog_tail : |
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224 # continuous file tail |
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225 source = pvl.syslog.tail.TailFile(options.syslog_file) |
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226 poll = options.syslog_tail # polling interval |
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227 |
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228 elif options.syslog_file : |
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229 # one-shot file read |
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230 source = pvl.syslog.tail.TailFile(options.syslog_file) |
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231 poll = False # do not poll-loop |
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232 |
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233 else : |
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234 log.error("No syslog source given") |
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235 return 1 |
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236 |
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237 # db |
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238 log.info("Open up database: %s", options.database) |
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239 database = DHCPHostsDatabase(options.database) |
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240 |
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241 if options.create : |
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242 database.create() |
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243 |
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244 # handler + main |
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245 handler = DHCPSyslogHandler(database) |
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246 |
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247 log.info("Enter mainloop...") |
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248 handler.main(source, poll) |
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249 |
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250 # done |
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251 return 0 |
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252 |
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253 if __name__ == '__main__': |
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254 import sys |
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255 |
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256 sys.exit(main(sys.argv)) |