Commit Graph

9 Commits

Author SHA1 Message Date
David Lebrun 33e34e735f ipv6: sr: remove duplicate routing header type check
As seg6_validate_srh() already checks that the Routing Header type is
correct, it is not necessary to do it again in get_srh().

Fixes: 5829d70b ("ipv6: sr: fix get_srh() to comply with IPv6 standard "RFC 8200")
Signed-off-by: David Lebrun <dlebrun@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-11 14:34:10 -07:00
Ahmed Abdelsalam 5829d70b0b ipv6: sr: fix get_srh() to comply with IPv6 standard "RFC 8200"
IPv6 packet may carry more than one extension header, and IPv6 nodes must
accept and attempt to process extension headers in any order and occurring
any number of times in the same packet. Hence, there should be no
assumption that Segment Routing extension header is to appear immediately
after the IPv6 header.

Moreover, section 4.1 of RFC 8200 gives a recommendation on the order of
appearance of those extension headers within an IPv6 packet. According to
this recommendation, Segment Routing extension header should appear after
Hop-by-Hop and Destination Options headers (if they present).

This patch fixes the get_srh(), so it gets the segment routing header
regardless of its position in the chain of the extension headers in IPv6
packet, and makes sure that the IPv6 routing extension header is of Type 4.

Signed-off-by: Ahmed Abdelsalam <amsalam20@gmail.com>
Acked-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-30 15:19:25 -07:00
David Lebrun 891ef8dd2a ipv6: sr: implement additional seg6local actions
This patch implements the following seg6local actions.

- SEG6_LOCAL_ACTION_END_T: regular SRH processing and forward to the
  next-hop looked up in the specified routing table.

- SEG6_LOCAL_ACTION_END_DX2: decapsulate an L2 frame and forward it to
  the specified network interface.

- SEG6_LOCAL_ACTION_END_DX4: decapsulate an IPv4 packet and forward it,
  possibly to the specified next-hop.

- SEG6_LOCAL_ACTION_END_DT6: decapsulate an IPv6 packet and forward it
  to the next-hop looked up in the specified routing table.

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 17:10:24 -07:00
David Lebrun d7a669dd2f ipv6: sr: add helper functions for seg6local
This patch adds three helper functions to be used with the seg6local packet
processing actions.

The decap_and_validate() function will be used by the End.D* actions, that
decapsulate an SR-enabled packet.

The advance_nextseg() function applies the fundamental operations to update
an SRH for the next segment.

The lookup_nexthop() function helps select the next-hop for the processed
SR packets. It supports an optional next-hop address to route the packet
specifically through it, and an optional routing table to use.

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 17:10:24 -07:00
David Lebrun 6285217f0c ipv6: sr: enforce IPv6 packets for seg6local lwt
This patch ensures that the seg6local lightweight tunnel is used solely
with IPv6 routes and processes only IPv6 packets.

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 17:10:23 -07:00
David Lebrun 32d99d0b67 ipv6: sr: add support for ip4ip6 encapsulation
This patch enables the SRv6 encapsulation mode to carry an IPv4 payload.
All the infrastructure was already present, I just had to add a parameter
to seg6_do_srh_encap() to specify the inner packet protocol, and perform
some additional checks.

Usage example:
ip route add 1.2.3.4 encap seg6 mode encap segs fc00::1,fc00::2 dev eth0

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 17:10:23 -07:00
David Lebrun 140f04c33b ipv6: sr: implement several seg6local actions
This patch implements the following seg6local actions.

- SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet
  is updated to the next segment and forwarded accordingly.

- SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is
  forwarded to the specified IPv6 next-hop.

- SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to
  inner IPv6 packet to the specified IPv6 next-hop.

- SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after
  the IPv6 header of the packet.

- SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within
  an outer IPv6 header, containing the specified SRH.

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07 14:16:22 -07:00
David Lebrun 2d9cc60aee ipv6: sr: add rtnetlink functions for seg6local action parameters
This patch adds the necessary functions to parse, fill, and compare
seg6local rtnetlink attributes, for all defined action parameters.

- The SRH parameter defines an SRH to be inserted or encapsulated.
- The TABLE parameter defines the table to use for the route lookup of
  the next segment or the inner decapsulated packet.
- The NH4 parameter defines the IPv4 next-hop for an inner decapsulated
  IPv4 packet.
- The NH6 parameter defines the IPv6 next-hop for the next segment or
  for an inner decapsulated IPv6 packet
- The IIF parameter defines an ingress interface index.
- The OIF parameter defines an egress interface index.

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07 14:16:22 -07:00
David Lebrun d1df6fd8a1 ipv6: sr: define core operations for seg6local lightweight tunnel
This patch implements a new type of lightweight tunnel named seg6local.
A seg6local lwt is defined by a type of action and a set of parameters.
The action represents the operation to perform on the packets matching the
lwt's route, and is not necessarily an encapsulation. The set of parameters
are arguments for the processing function.

Each action is defined in a struct seg6_action_desc within
seg6_action_table[]. This structure contains the action, mandatory
attributes, the processing function, and a static headroom size required by
the action. The mandatory attributes are encoded as a bitmask field. The
static headroom is set to a non-zero value when the processing function
always add a constant number of bytes to the skb (e.g. the header size for
encapsulations).

To facilitate rtnetlink-related operations such as parsing, fill_encap,
and cmp_encap, each type of action parameter is associated to three
function pointers, in seg6_action_params[].

All actions defined in seg6_local.h are detailed in [1].

[1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07 14:16:22 -07:00