ipoe: implemented client address, router address and mask to be passed via radius

* commit '918036a3':
  cli: telnet: check for disconnect condition while processing input chars

* commit '178b27b0':
  radius: update Class attribute by CoA request

Add error detection to ensure the FD_CLOEXEC flag gets set for
every new socket.
Signed-off-by: NGuillaume Nault <g.nault@alphalink.fr>

* commit 'e04b9b2b':
  L2TP: Close sockets opened by l2tp_connect() upon failure

* commit '0b99fef7':
  L2TP: Fix socket() error handling in l2tp_connect()
  iprange: accept network with null mask (which actually disables iprange module)

Add error detection to ensure the FD_CLOEXEC flag gets set for
every new socket.
Signed-off-by: NGuillaume Nault <g.nault@alphalink.fr>

Centralise error management to ensure full cleanup upon failure.
Signed-off-by: NGuillaume Nault <g.nault@alphalink.fr>

Check if the tunnel file descriptor has been successfully created.
Explicitely check for negative values to detect socket() errors.
Signed-off-by: NGuillaume Nault <g.nault@alphalink.fr>

cli: introduced 'restart' command to restrat daemon

ipoe: send unclassified packet info to userspace via netlink