metasploit-framework/lib/rex/socket/range_walker.rb

296 lines
6.5 KiB
Ruby

require 'rex/socket'
module Rex
module Socket
###
#
# This class provides an interface to enumerating an IP range
#
# This class uses start,stop pairs to represent ranges of addresses. This
# is very efficient for large numbers of consecutive addresses, and not
# show-stoppingly inefficient when storing a bunch of non-consecutive
# addresses, which should be a somewhat unusual case.
#
###
class RangeWalker
#
# Initializes a walker instance using the supplied range
#
def initialize(parseme)
if parseme.is_a? RangeWalker
@ranges = parseme.ranges.dup
else
@ranges = parse(parseme)
end
reset
end
def self.parse(parseme)
self.new.parse(parseme)
end
def parse(parseme)
return nil if not parseme
ranges = []
parseme.split(' ').each { |arg|
if arg.include?("/")
# Then it's CIDR notation and needs special case
if arg =~ /[,-]/
# Improper CIDR notation (can't mix with 1,3 or 1-3 style IP ranges)
return false
end
expanded = expand_cidr(arg)
if expanded
ranges += expanded
else
return false
end
elsif arg.include?(":")
# Then it's IPv6
# Can't really do much with IPv6 right now, just return it and
# hope for the best
addr = Rex::Socket.addr_atoi(arg)
ranges.push [addr, addr, true]
elsif arg =~ /[^-0-9,.*]/
# Then it's a domain name and we should send it on to addr_atoi
# unmolested to force a DNS lookup.
addr = Rex::Socket.addr_atoi(arg)
ranges.push [addr, addr]
else
expanded = expand_nmap(arg)
if expanded
ranges += expanded
else
return false
end
end
}
return ranges
end
#
# Resets the subnet walker back to its original state.
#
def reset
return false if not valid?
@curr_range = 0
@curr_addr = @ranges[0][0]
@length = 0
@ranges.each { |r| @length += r[1] - r[0] + 1 }
end
#
# Returns the next IP address.
#
def next_ip
return false if not valid?
if (@curr_addr > @ranges[@curr_range][1])
if (@curr_range >= @ranges.length - 1)
return nil
end
@curr_range += 1
@curr_addr = @ranges[@curr_range][0]
end
addr = Rex::Socket.addr_itoa(@curr_addr, @ranges[@curr_range][2])
@curr_addr += 1
return addr
end
def valid?
(@ranges and not @ranges.empty?)
end
#
# Returns true if the argument is an ip address that falls within any of
# the stored ranges.
#
def include?(addr)
return false if not @ranges
if (addr.is_a? String)
addr = Rex::Socket.addr_atoi(addr)
end
@ranges.map { |r|
if r.start <= addr and addr <= r.stop
return true
end
}
return false
end
#
# Calls the given block with each address
#
def each(&block)
while (ip = next_ip)
block.call(ip)
end
end
#
# Returns an array with one element, a Range defined by the given CIDR
# block.
#
def expand_cidr(arg)
start,stop = Rex::Socket.cidr_crack(arg)
if !start or !stop
return false
end
range = Range.new
range.start = Rex::Socket.addr_atoi(start)
range.stop = Rex::Socket.addr_atoi(stop)
range.ipv6 = (arg.include?(":"))
return [range]
end
#
# Expands an nmap-style host range x.x.x.x where x can be simply "*" which
# means 0-255 or any combination and repitition of:
# i,n
# n-m
# i,n-m
# n-m,i
# ensuring that n is never greater than m.
#
# non-unique elements will be removed
# e.g.:
# 10.1.1.1-3,2-2,2 => ["10.1.1.1", "10.1.1.2", "10.1.1.3"]
# 10.1.1.1-3,7 => ["10.1.1.1", "10.1.1.2", "10.1.1.3", "10.1.1.7"]
#
# Returns an array of Ranges
#
def expand_nmap(arg)
# Can't really do anything with IPv6
return false if arg.include?(":")
# nmap calls these errors, but it's hard to catch them with our
# splitting below, so short-cut them here
return false if arg.include?(",-") or arg.include?("-,")
bytes = []
sections = arg.split('.')
if sections.length != 4
# Too many or not enough dots
return false
end
sections.each { |section|
if section.empty?
# pretty sure this is an unintentional artifact of the C
# functions that turn strings into ints, but it sort of makes
# sense, so why not
# "10...1" => "10.0.0.1"
section = "0"
end
if section == "*"
# I think this ought to be 1-254, but this is how nmap does it.
section = "0-255"
elsif section.include?("*")
return false
end
# Break down the sections into ranges like so
# "1-3,5-7" => ["1-3", "5-7"]
ranges = section.split(',', -1)
sets = []
ranges.each { |r|
bounds = []
if r.include?('-')
# Then it's an actual range, break it down into start,stop
# pairs:
# "1-3" => [ 1, 3 ]
# if the lower bound is empty, start at 0
# if the upper bound is empty, stop at 255
#
bounds = r.split('-', -1)
return false if (bounds.length > 2)
bounds[0] = 0 if bounds[0].nil? or bounds[0].empty?
bounds[1] = 255 if bounds[1].nil? or bounds[1].empty?
bounds.map!{|b| b.to_i}
return false if bounds[0] > bounds[1]
else
# Then it's a single value
bounds[0] = r.to_i
end
return false if bounds[0] > 255 or (bounds[1] and bounds[1] > 255)
return false if bounds[1] and bounds[0] > bounds[1]
if bounds[1]
bounds[0].upto(bounds[1]) do |i|
sets.push(i)
end
elsif bounds[0]
sets.push(bounds[0])
end
}
bytes.push(sets.sort.uniq)
}
#
# Combinitorically squish all of the quads together into a big list of
# ip addresses, stored as ints
#
# e.g.:
# [[1],[1],[1,2],[1,2]]
# =>
# [atoi("1.1.1.1"),atoi("1.1.1.2"),atoi("1.1.2.1"),atoi("1.1.2.2")]
addrs = []
for a in bytes[0]
for b in bytes[1]
for c in bytes[2]
for d in bytes[3]
ip = (a << 24) + (b << 16) + (c << 8) + d
addrs.push ip
end
end
end
end
addrs.sort!
addrs.uniq!
rng = Range.new
rng.start = addrs[0]
ranges = []
1.upto(addrs.length - 1) do |idx|
if addrs[idx - 1] + 1 == addrs[idx]
# Then this address is contained in the current range
next
else
# Then this address is the upper bound for the current range
rng.stop = addrs[idx - 1]
ranges.push(rng.dup)
rng.start = addrs[idx]
end
end
rng.stop = addrs[addrs.length - 1]
ranges.push(rng.dup)
return ranges
end
#
# The total number of IPs within the range
#
attr_reader :ranges
attr_reader :length
# for backwards compatibility
alias :num_ips :length
end
class Range < Array
def start; self[0]; end
def stop; self[1]; end
def ipv6; self[2]; end
def start=(val); self[0] = val; end
def stop=(val); self[1] = val; end
def ipv6=(val); self[2] = val; end
end
end
end