class ACL

Simple Access Control Lists.

Access control lists are composed of “allow” and “deny” halves to control access. Use “all” or “*” to match any address. To match a specific address use any address or address mask that IPAddr can understand.

Example:

list = %w[
  deny all
  allow 192.168.1.1
  allow ::ffff:192.168.1.2
  allow 192.168.1.3
]

# From Socket#peeraddr, see also ACL#allow_socket?
addr = ["AF_INET", 10, "lc630", "192.168.1.3"]

acl = ACL.new
p acl.allow_addr?(addr) # => true

acl = ACL.new(list, ACL::DENY_ALLOW)
p acl.allow_addr?(addr) # => true

Constants

ALLOW_DENY: Default to allow
DENY_ALLOW: Default to deny
VERSION: The current version of ACL

Public Class Methods

new(list=nil, order = DENY_ALLOW) click to toggle source

Creates a new ACL from list with an evaluation order of DENY_ALLOW or ALLOW_DENY.

An ACL list is an Array of “allow” or “deny” and an address or address mask or “all” or “*” to match any address:

%w[
  deny all
  allow 192.0.2.2
  allow 192.0.2.128/26
]

# File drb/acl.rb, line 179
def initialize(list=nil, order = DENY_ALLOW)
  @order = order
  @deny = ACLList.new
  @allow = ACLList.new
  install_list(list) if list
end

Public Instance Methods

allow_addr?(addr) click to toggle source

Allow connections from addrinfo addr? It must be formatted like Socket#peeraddr:

["AF_INET", 10, "lc630", "192.0.2.1"]

# File drb/acl.rb, line 203
def allow_addr?(addr)
  case @order
  when DENY_ALLOW
    return true if @allow.match(addr)
    return false if @deny.match(addr)
    return true
  when ALLOW_DENY
    return false if @deny.match(addr)
    return true if @allow.match(addr)
    return false
  else
    false
  end
end

allow_socket?(soc) click to toggle source

Allow connections from Socket soc?

# File drb/acl.rb, line 191
def allow_socket?(soc)
  allow_addr?(soc.peeraddr)
end

install_list(list) click to toggle source

Adds list of ACL entries to this ACL.

# File drb/acl.rb, line 223
def install_list(list)
  i = 0
  while i < list.size
    permission, domain = list.slice(i,2)
    case permission.downcase
    when 'allow'
      @allow.add(domain)
    when 'deny'
      @deny.add(domain)
    else
      raise "Invalid ACL entry #{list}"
    end
    i += 2
  end
end