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>
70 lines
2.4 KiB
Text
70 lines
2.4 KiB
Text
#
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# Layer Two Tunneling Protocol (L2TP)
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#
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menuconfig L2TP
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tristate "Layer Two Tunneling Protocol (L2TP)"
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depends on INET
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---help---
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Layer Two Tunneling Protocol
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From RFC 2661 <http://www.ietf.org/rfc/rfc2661.txt>.
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L2TP facilitates the tunneling of packets across an
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intervening network in a way that is as transparent as
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possible to both end-users and applications.
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L2TP is often used to tunnel PPP traffic over IP
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tunnels. One IP tunnel may carry thousands of individual PPP
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connections. L2TP is also used as a VPN protocol, popular
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with home workers to connect to their offices.
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L2TPv3 allows other protocols as well as PPP to be carried
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over L2TP tunnels. L2TPv3 is defined in RFC 3931
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<http://www.ietf.org/rfc/rfc3931.txt>.
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The kernel component handles only L2TP data packets: a
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userland daemon handles L2TP the control protocol (tunnel
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and session setup). One such daemon is OpenL2TP
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(http://openl2tp.org/).
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If you don't need L2TP, say N. To compile all L2TP code as
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modules, choose M here.
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config L2TP_V3
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bool "L2TPv3 support (EXPERIMENTAL)"
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depends on EXPERIMENTAL && L2TP
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help
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Layer Two Tunneling Protocol Version 3
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From RFC 3931 <http://www.ietf.org/rfc/rfc3931.txt>.
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The Layer Two Tunneling Protocol (L2TP) provides a dynamic
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mechanism for tunneling Layer 2 (L2) "circuits" across a
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packet-oriented data network (e.g., over IP). L2TP, as
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originally defined in RFC 2661, is a standard method for
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tunneling Point-to-Point Protocol (PPP) [RFC1661] sessions.
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L2TP has since been adopted for tunneling a number of other
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L2 protocols, including ATM, Frame Relay, HDLC and even raw
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ethernet frames.
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If you are connecting to L2TPv3 equipment, or you want to
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tunnel raw ethernet frames using L2TP, say Y here. If
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unsure, say N.
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config L2TP_IP
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tristate "L2TP IP encapsulation for L2TPv3"
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depends on L2TP_V3
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help
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Support for L2TP-over-IP socket family.
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The L2TPv3 protocol defines two possible encapsulations for
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L2TP frames, namely UDP and plain IP (without UDP). This
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driver provides a new L2TPIP socket family with which
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userspace L2TPv3 daemons may create L2TP/IP tunnel sockets
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when UDP encapsulation is not required. When L2TP is carried
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in IP packets, it used IP protocol number 115, so this port
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must be enabled in firewalls.
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To compile this driver as a module, choose M here. The module
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will be called l2tp_ip.
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