scapy/arch/unix.py

## This file is part of Scapy
## See http://www.secdev.org/projects/scapy for more informations
## Copyright (C) Philippe Biondi <phil@secdev.org>
## This program is published under a GPLv2 license

"""
Common customizations for all Unix-like operating systems other than Linux
"""

import sys,os,struct,socket,time
from fcntl import ioctl
from scapy.error import warning
import scapy.config
import scapy.utils
import scapy.utils6
import scapy.arch

scapy.config.conf.use_pcap = 1
scapy.config.conf.use_dnet = 1
from pcapdnet import *


    


##################
## Routes stuff ##
##################


def read_routes():
    if scapy.arch.SOLARIS:
        f=os.popen("netstat -rvn") # -f inet
    elif scapy.arch.FREEBSD:
        f=os.popen("netstat -rnW") # -W to handle long interface names
    else:
        f=os.popen("netstat -rn") # -f inet
    ok = 0
    mtu_present = False
    prio_present = False
    routes = []
    pending_if = []
    for l in f.readlines():
        if not l:
            break
        l = l.strip()
        if l.find("----") >= 0: # a separation line
            continue
        if not ok:
            if l.find("Destination") >= 0:
                ok = 1
                mtu_present = l.find("Mtu") >= 0
                prio_present = l.find("Prio") >= 0
            continue
        if not l:
            break
        if scapy.arch.SOLARIS:
            lspl = l.split()
            if len(lspl) == 10:
                dest,mask,gw,netif,mxfrg,rtt,ref,flg = lspl[:8]
            else: # missing interface
                dest,mask,gw,mxfrg,rtt,ref,flg = lspl[:7]
                netif=None
        else:
            rt = l.split()
            dest,gw,flg = rt[:3]
            netif = rt[5+mtu_present+prio_present]
        if flg.find("Lc") >= 0:
            continue                
        if dest == "default":
            dest = 0L
            netmask = 0L
        else:
            if scapy.arch.SOLARIS:
                netmask = scapy.utils.atol(mask)
            elif "/" in dest:
                dest,netmask = dest.split("/")
                netmask = scapy.utils.itom(int(netmask))
            else:
                netmask = scapy.utils.itom((dest.count(".") + 1) * 8)
            dest += ".0"*(3-dest.count("."))
            dest = scapy.utils.atol(dest)
        if not "G" in flg:
            gw = '0.0.0.0'
        if netif is not None:
            ifaddr = scapy.arch.get_if_addr(netif)
            routes.append((dest,netmask,gw,netif,ifaddr))
        else:
            pending_if.append((dest,netmask,gw))
    f.close()

    # On Solaris, netstat does not provide output interfaces for some routes
    # We need to parse completely the routing table to route their gw and
    # know their output interface
    for dest,netmask,gw in pending_if:
        gw_l = scapy.utils.atol(gw)
        max_rtmask,gw_if,gw_if_addr, = 0,None,None
        for rtdst,rtmask,_,rtif,rtaddr in routes[:]:
            if gw_l & rtmask == rtdst:
                if rtmask >= max_rtmask:
                    max_rtmask = rtmask
                    gw_if = rtif
                    gw_if_addr = rtaddr
        if gw_if:
            routes.append((dest,netmask,gw,gw_if,gw_if_addr))
        else:
            warning("Did not find output interface to reach gateway %s" % gw)
            
    return routes

############
### IPv6 ###
############

def in6_getifaddr():
    """
    Returns a list of 3-tuples of the form (addr, scope, iface) where
    'addr' is the address of scope 'scope' associated to the interface
    'ifcace'.

    This is the list of all addresses of all interfaces available on
    the system.
    """

    ret = []
    i = dnet.intf()
    for int in i:
        ifname = int['name']
        v6 = []
        if int.has_key('alias_addrs'):
            v6 = int['alias_addrs']
        for a in v6:
            if a.type != dnet.ADDR_TYPE_IP6:
                continue

            xx = str(a).split('/')[0]
            addr = scapy.utils6.in6_ptop(xx)

            scope = scapy.utils6.in6_getscope(addr)

            ret.append((xx, scope, ifname))
    return ret

def read_routes6():
    f = os.popen("netstat -rn -f inet6")
    ok = False
    mtu_present = False
    prio_present = False
    routes = []
    lifaddr = in6_getifaddr()
    for l in f.readlines():
        if not l:
            break
        l = l.strip()
        if not ok:
            if l.find("Destination") >= 0:
                ok = 1
                mtu_present = l.find("Mtu") >= 0
                prio_present = l.find("Prio") >= 0
            continue
        # gv 12/12/06: under debugging      
        if scapy.arch.NETBSD or scapy.arch.OPENBSD:
            lspl = l.split()
            d,nh,fl = lspl[:3]
            dev = lspl[5+mtu_present+prio_present]
        else:       # FREEBSD or DARWIN 
            d,nh,fl,dev = l.split()[:4]
        if filter(lambda x: x[2] == dev, lifaddr) == []:
            continue
        if 'L' in fl: # drop MAC addresses
            continue

        if 'link' in nh:
            nh = '::'

        cset = [] # candidate set (possible source addresses)
        dp = 128
        if d == 'default':
            d = '::'
            dp = 0
        if '/' in d:
            d,dp = d.split("/")
            dp = int(dp)
        if '%' in d:
            d,dev = d.split('%')
        if '%' in nh:
            nh,dev = nh.split('%')
        if scapy.arch.LOOPBACK_NAME in dev:
            cset = ['::1']
            nh = '::'
        else:
            devaddrs = filter(lambda x: x[2] == dev, lifaddr)
            cset = scapy.utils6.construct_source_candidate_set(d, dp, devaddrs, scapy.arch.LOOPBACK_NAME)

        if len(cset) != 0:
            routes.append((d, dp, nh, dev, cset))

    f.close()
    return routes