bwmon/proc.py

   1 # -*- coding: utf-8 -*-
   2
   3 from __future__ import absolute_import
   4
   5 import os
   6 import re
   7 import hashlib
   8
   9 def get_connections(conn_type='tcp'):
  10     """
  11     returns the connections from /proc/net/tcp indexed by their id (first
  12     column).
  13     """
  14     f = open('/proc/net/%s' % conn_type, 'r')
  15     connections = {}
  16
  17     #documentation for /proc/net/tcp in
  18     #http://lkml.indiana.edu/hypermail/linux/kernel/0409.1/2166.html
  19
  20     for line in f.readlines():
  21         line = line.strip()
  22
  23         # header line
  24         if line.startswith('s'):
  25             continue
  26
  27         parts = filter(lambda x: x, line.split(' '))
  28         index = parts[0].strip()[:-1]
  29         local_addr = ip_repr(parts[1])
  30         rem_addr = ip_repr(parts[2])
  31         inode = int(parts[9])
  32
  33         connections[index] = {
  34             'local': local_addr,
  35             'remote': rem_addr,
  36             'inode': inode
  37         }
  38
  39     return connections
  40
  41
  42 def ip_repr(ip):
  43     """
  44     returns the dotted-decimal representation of an IP addresse when given
  45     the formated used in /proc/net/tcp
  46
  47     >>> ip_repr('C8BCED82:1A0B')
  48     '130.237.188.200:6667'
  49     """
  50
  51     if ':' in ip:
  52         ip, port = ip.split(':')
  53     else:
  54         port = None
  55
  56     s = '.'.join([ repr(int(ip[x-2:x], 16)) for x in range(8, 0, -2) ])
  57     if port:
  58         s += ':%d' % int(port, 16)
  59
  60     return s
  61
  62
  63 def get_fd_map():
  64     """ returns a dictionary mapping filedescriptors to process information"""
  65
  66     proc = '/proc/'
  67     fd = 'fd'
  68     pid_dir = r'\d+'
  69     socket_regex = r'socket:\[(\d+)\]'
  70     cmdline = 'cmdline'
  71     m = {}
  72
  73     for pid in os.listdir(proc):
  74
  75         # process directories
  76         d = os.path.join(proc, pid)
  77         if not os.path.isdir(d):
  78             continue
  79
  80         if not re.match(pid_dir, pid):
  81             continue
  82
  83         fd_dir = os.path.join(d, fd)
  84         for x in os.listdir(fd_dir):
  85             path = os.path.join(fd_dir, x)
  86             try:
  87                 f_desc = os.readlink(path)
  88             except OSError:
  89                 continue
  90
  91             # search for socket file-descriptors
  92             match = re.match(socket_regex, f_desc)
  93             if match:
  94                 inode = int(match.group(1))
  95             else:
  96                 continue
  97
  98             cmd_file = open(os.path.join(d, cmdline), 'rb')
  99             cmd = cmd_file.read()
 100
 101             # Command line arguments are splitted by '\0'
 102             cmd = cmd.replace('\0', ' ')
 103
 104             m[inode] = {'inode': inode, 'cmd': cmd, 'pid': int(pid)}
 105
 106     return m
 107
 108
 109 def parse_ip_conntrack():
 110     connections = {}
 111
 112     # http://www.faqs.org/docs/iptables/theconntrackentries.html
 113     for line in open('/proc/net/ip_conntrack'):
 114         parts = line.split()
 115
 116         entry = {}
 117         for (k, v) in [x.split('=', 1) for x in parts if '=' in x]:
 118             # key-value pairs occur twice per line; if first key occurs
 119             # again, we finish the first entry and start the next one
 120             if k in entry:
 121                 key = get_key(entry)
 122                 connections[key] = entry
 123                 entry = {}
 124
 125             entry[k] = v
 126
 127         key = get_key(entry)
 128         connections[key] = entry
 129
 130     return connections
 131
 132
 133 def get_key(values):
 134     src = '%s:%s' % (values['src'], values['sport'])
 135     dst = '%s:%s' % (values['dst'], values['dport'])
 136     return ip_hash(src, dst)
 137
 138
 139 def ip_hash(src_ip, dest_ip):
 140     return '%s-%s' % (src_ip, dest_ip)
 141