1 ******************* 2 Netlink Core Module 3 ******************* 4 5 .. py:module:: netlink.core 6 7 Examples:: 8 9 import netlink.core as netlink 10 11 =============== 12 Object 13 =============== 14 15 .. py:class:: Object 16 17 Base class for all classes representing a cacheable object 18 19 Example:: 20 obj = netlink.Object("route/link", "link") 21 22 .. py:method:: clone 23 24 Clone the object and return a duplicate (used for COW) 25 26 .. py:method:: dump([params=None]) 27 28 Call the libnl internal dump mechanism to dump the object 29 according to the parameters specified. 30 31 .. py:method:: apply(attr, val) 32 33 Applies a attribute=value pair and modifies the object accordingly. 34 Example:: 35 obj.apply("mtu", 1200) # Sets attribute mtu to 1200 (link obj) 36 37 :raises: KeyError if attribute is unknown 38 :raises: ImmutableError if attribute is not mutable 39 40 .. py:attribute:: mark 41 42 True if the object is marked, otherwise False. 43 44 .. py:attribute:: shared 45 46 True if the object is used by multiple parties, otherwise False. 47 48 .. py:attribute:: refcnt 49 50 Number of users sharing a reference to the object 51 :rtype: int 52 53 .. py:attribute:: attrs 54 55 List of attributes 56 57 :rtype: list of strings 58 59 =============== 60 Cache 61 =============== 62 63 .. py:class:: Cache 64 65 Base class for all cache implementations. 66 67 A cache is a collection of cacheable objects which is typically used 68 by netlink protocols which handle any kind of object, e.g. network 69 links, network addresses, neighbours, ... 70 71 .. py:method:: subset(filter) 72 73 Returns a new cache containing the subset which matches the 74 provided filter. 75 76 :raises: ValueError if no filter is specified 77 :rtype: :py:class:`Cache` 78 79 .. py:method:: dump([params=None, filter=None]) 80 81 Calls the libnl internal dump mechanism to dump the cache according 82 to the parameters and filter specified. 83 84 .. py:method:: clear() 85 86 Remove and possibly destroy all objects in the cache 87 88 .. py:method:: refill([socket=None]) -> :py:class:`Cache` 89 90 Clears and refills the cache with the content which is provided by 91 the kernel, e.g. for a link cache this would mean refilling the 92 cache with all configured network links. 93 94 .. py:method:: provide() 95 96 Caches which have been "provided" are made available to other users 97 (of the same application context) which "require" it. F.e. a link 98 cache is generally provided to allow others to translate interface 99 indexes to link names 100 101 102 .. py:method:: unprovide() 103 104 No longer make the cache available to others. If the cache has been 105 handed out already, that reference will still be valid. 106 107 =============== 108 AbstractAddress 109 =============== 110 111 .. py:class:: AbstractAddress 112 113 Abstract representation of an address. This class is not to be mistaken 114 with :py:class:`route.Address` which represents a configured network 115 address. This class represents the actual address in a family independent 116 way:: 117 118 addr = netlink.AbstractAddress('127.0.0.1/8') 119 print addr # => '127.0.0.1/8' 120 print addr.prefixlen # => '8' 121 print addr.family # => 'inet' 122 print len(addr) # => '4' (32bit ipv4 address) 123 124 a = netlink.AbstractAddress('10.0.0.1/24') 125 b = netlink.AbstractAddress('10.0.0.2/24') 126 print a == b # => False 127 128 .. py:attribute:: prefixlen 129 130 Length of prefix in number of bits. 131 132 :rtype: int 133 134 .. py:attribute:: family 135 136 The family type of the address. Setting the address family can be 137 done with a string or a :py:class:`AddressFamily` object. 138 139 :rtype: :py:class:`AddressFamily` 140 141 .. py:attribute:: shared 142 143 True if address is in use by multiple callers, otherwise False 144 145 :rtype: bool 146 147 =============== 148 AddressFamily 149 =============== 150 151 .. py:class:: AddressFamily 152 153 Address family representation:: 154 155 af = netlink.AddressFamily('inet6') 156 # raises: 157 # - ValueError if family name is not known 158 # - TypeError if invalid type is specified for family 159 160 print af # => 'inet6' (string representation) 161 print int(af) # => 10 (numeric representation) 162 print repr(af) # => AddressFamily('inet6') 163 164 =============== 165 Exceptions 166 =============== 167 168 .. py:exception:: NetlinkError 169 170 Generic exception raised by netlink modules. 171 172 .. py:exception:: KernelError 173 174 Raised if an error occured while communicating with the kernel. Contains 175 the error code returning which is automatically included in the error 176 message. 177 178 .. py:exception:: ImmutableError 179 180 Raised if an attribute is modified which is marked immutable. 181 182 =============== 183 Socket 184 =============== 185 186 .. py:class:: Socket 187 188 Netlink socket. 189 190 Note: It is not required to manually create and connect netlink sockets 191 when using caches. The caches will automatically lookup or create a 192 socket as needed. 193 194 .. py:attribute:: local_port 195 196 Local port (address) of netlink socket 197 198 .. py:attribute:: peer_port 199 200 Peer port (remote address) of netlink socket. If set, all messages 201 will be sent to that peer. 202 203 .. py:method:: connect(proto) 204 205 Connect the netlink socket using the specified netlink protocol:: 206 sock.connect(netlink.NETLINK_ROUTE) 207 208 .. py:method:: disconnect() 209 210 Disconnect the socket 211 212 .. py:method:: set_bufsize(rx, tx) 213 214 Sets the size of the socket buffer 215 216
