0d76751fad
This patch adds a new L2TPIP socket family and modifies the core to handle the case where there is no UDP header in the L2TP packet. L2TP/IP uses IP protocol 115. Since L2TP/UDP and L2TP/IP packets differ in layout, the datapath packet handling code needs changes too. Userspace uses an L2TPIP socket instead of a UDP socket when IP encapsulation is required. We can't use raw sockets for this because the semantics of raw sockets don't lend themselves to the socket-per-tunnel model - we need to Signed-off-by: David S. Miller <davem@davemloft.net>
71 lines
2.4 KiB
Plaintext
71 lines
2.4 KiB
Plaintext
#
|
|
# Layer Two Tunneling Protocol (L2TP)
|
|
#
|
|
|
|
menuconfig L2TP
|
|
tristate "Layer Two Tunneling Protocol (L2TP)"
|
|
depends on INET
|
|
---help---
|
|
Layer Two Tunneling Protocol
|
|
|
|
From RFC 2661 <http://www.ietf.org/rfc/rfc2661.txt>.
|
|
|
|
L2TP facilitates the tunneling of packets across an
|
|
intervening network in a way that is as transparent as
|
|
possible to both end-users and applications.
|
|
|
|
L2TP is often used to tunnel PPP traffic over IP
|
|
tunnels. One IP tunnel may carry thousands of individual PPP
|
|
connections. L2TP is also used as a VPN protocol, popular
|
|
with home workers to connect to their offices.
|
|
|
|
L2TPv3 allows other protocols as well as PPP to be carried
|
|
over L2TP tunnels. L2TPv3 is defined in RFC 3931
|
|
<http://www.ietf.org/rfc/rfc3931.txt>.
|
|
|
|
The kernel component handles only L2TP data packets: a
|
|
userland daemon handles L2TP the control protocol (tunnel
|
|
and session setup). One such daemon is OpenL2TP
|
|
(http://openl2tp.org/).
|
|
|
|
If you don't need L2TP, say N. To compile all L2TP code as
|
|
modules, choose M here.
|
|
|
|
config L2TP_V3
|
|
bool "L2TPv3 support (EXPERIMENTAL)"
|
|
depends on EXPERIMENTAL && L2TP
|
|
help
|
|
Layer Two Tunneling Protocol Version 3
|
|
|
|
From RFC 3931 <http://www.ietf.org/rfc/rfc3931.txt>.
|
|
|
|
The Layer Two Tunneling Protocol (L2TP) provides a dynamic
|
|
mechanism for tunneling Layer 2 (L2) "circuits" across a
|
|
packet-oriented data network (e.g., over IP). L2TP, as
|
|
originally defined in RFC 2661, is a standard method for
|
|
tunneling Point-to-Point Protocol (PPP) [RFC1661] sessions.
|
|
L2TP has since been adopted for tunneling a number of other
|
|
L2 protocols, including ATM, Frame Relay, HDLC and even raw
|
|
ethernet frames.
|
|
|
|
If you are connecting to L2TPv3 equipment, or you want to
|
|
tunnel raw ethernet frames using L2TP, say Y here. If
|
|
unsure, say N.
|
|
|
|
config L2TP_IP
|
|
tristate "L2TP IP encapsulation for L2TPv3"
|
|
depends on L2TP_V3
|
|
help
|
|
Support for L2TP-over-IP socket family.
|
|
|
|
The L2TPv3 protocol defines two possible encapsulations for
|
|
L2TP frames, namely UDP and plain IP (without UDP). This
|
|
driver provides a new L2TPIP socket family with which
|
|
userspace L2TPv3 daemons may create L2TP/IP tunnel sockets
|
|
when UDP encapsulation is not required. When L2TP is carried
|
|
in IP packets, it used IP protocol number 115, so this port
|
|
must be enabled in firewalls.
|
|
|
|
To compile this driver as a module, choose M here. The module
|
|
will be called l2tp_ip.
|