seg6: add support for flavors in SRv6 End* behaviors
As described in RFC 8986 [1], processing operations carried out by SRv6
End, End.X and End.T (End* for short) behaviors can be modified or
extended using the "flavors" mechanism. This patch adds the support for
PSP,USP,USD flavors (defined in [1]) and for NEXT-C-SID flavor (defined
in [2]) in SRv6 End* behaviors. Specifically, we add a new optional
attribute named "flavors" that can be leveraged by the user to enable
specific flavors while creating an SRv6 End* behavior instance.
Multiple flavors can be specified together by separating them using
commas.
If a specific flavor (or a combination of flavors) is not supported by the
underlying Linux kernel, an error message is reported to the user and the
creation of the specific behavior instance is aborted.
When the flavors attribute is omitted, the regular SRv6 End* behavior is
performed.
Flavors such as PSP, USP and USD do not accept additional configuration
attributes. Conversely, the NEXT-C-SID flavor can be configured to support
user-provided Locator-Block and Locator-Node Function lengths using,
respectively, the lblen and the nflen attributes.
Both lblen and nflen values must be evenly divisible by 8 and their sum
must not exceed 128 bit (i.e. the C-SID container size).
If the lblen attribute is omitted, the default value chosen by the Linux
kernel is 32-bit. If the nflen attribute is omitted, the default value
chosen by the Linux kernel is 16-bit.
Some examples:
ip -6 route add 2001:db8::1 encap seg6local action End flavors next-csid dev eth0
ip -6 route add 2001:db8::2 encap seg6local action End flavors next-csid lblen 48 nflen 16 dev eth0
Standard Output:
ip -6 route show 2001:db8::2
2001:db8::2 encap seg6local action End flavors next-csid lblen 48 nflen 16 dev eth0 metric 1024 pref medium
JSON Output:
ip -6 -j -p route show 2001:db8::2
[ {
"dst": "2001:db8::2",
"encap": "seg6local",
"action": "End",
"flavors": [ "next-csid" ],
"lblen": 48,
"nflen": 16,
"dev": "eth0",
"metric": 1024,
"flags": [ ],
"pref": "medium"
} ]
[1] - https://datatracker.ietf.org/doc/html/rfc8986
[2] - https://datatracker.ietf.org/doc/html/draft-ietf-spring-srv6-srh-compression
Signed-off-by: Paolo Lungaroni <paolo.lungaroni@uniroma2.it>
Signed-off-by: David Ahern <dsahern@kernel.org>
3 files changed
