mirror_ubuntu-kernels/include/net/ioam6.h
Justin Iurman 9ee11f0fff ipv6: ioam: Data plane support for Pre-allocated Trace
Implement support for processing the IOAM Pre-allocated Trace with IPv6,
see [1] and [2]. Introduce a new IPv6 Hop-by-Hop TLV option, see IANA [3].

A new per-interface sysctl is introduced. The value is a boolean to accept (=1)
or ignore (=0, by default) IPv6 IOAM options on ingress for an interface:
 - net.ipv6.conf.XXX.ioam6_enabled

Two other sysctls are introduced to define IOAM IDs, represented by an integer.
They are respectively per-namespace and per-interface:
 - net.ipv6.ioam6_id
 - net.ipv6.conf.XXX.ioam6_id

The value of the first one represents the IOAM ID of the node itself (u32; max
and default value = U32_MAX>>8, due to hop limit concatenation) while the other
represents the IOAM ID of an interface (u16; max and default value = U16_MAX).

Each "ioam6_id" sysctl has a "_wide" equivalent:
 - net.ipv6.ioam6_id_wide
 - net.ipv6.conf.XXX.ioam6_id_wide

The value of the first one represents the wide IOAM ID of the node itself (u64;
max and default value = U64_MAX>>8, due to hop limit concatenation) while the
other represents the wide IOAM ID of an interface (u32; max and default value
= U32_MAX).

The use of short and wide equivalents is not exclusive, a deployment could
choose to leverage both. For example, net.ipv6.conf.XXX.ioam6_id (short format)
could be an identifier for a physical interface, whereas
net.ipv6.conf.XXX.ioam6_id_wide (wide format) could be an identifier for a
logical sub-interface. Documentation about new sysctls is provided at the end
of this patchset.

Two relativistic hash tables are used: one for IOAM namespaces, the other for
IOAM schemas. A namespace can only have a single active schema and a schema
can only be attached to a single namespace (1:1 relationship).

  [1] https://tools.ietf.org/html/draft-ietf-ippm-ioam-ipv6-options
  [2] https://tools.ietf.org/html/draft-ietf-ippm-ioam-data
  [3] https://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xhtml#ipv6-parameters-2

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-21 08:14:33 -07:00

65 lines
1.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* IPv6 IOAM implementation
*
* Author:
* Justin Iurman <justin.iurman@uliege.be>
*/
#ifndef _NET_IOAM6_H
#define _NET_IOAM6_H
#include <linux/net.h>
#include <linux/ipv6.h>
#include <linux/ioam6.h>
#include <linux/rhashtable-types.h>
struct ioam6_namespace {
struct rhash_head head;
struct rcu_head rcu;
struct ioam6_schema __rcu *schema;
__be16 id;
__be32 data;
__be64 data_wide;
};
struct ioam6_schema {
struct rhash_head head;
struct rcu_head rcu;
struct ioam6_namespace __rcu *ns;
u32 id;
int len;
__be32 hdr;
u8 data[0];
};
struct ioam6_pernet_data {
struct mutex lock;
struct rhashtable namespaces;
struct rhashtable schemas;
};
static inline struct ioam6_pernet_data *ioam6_pernet(struct net *net)
{
#if IS_ENABLED(CONFIG_IPV6)
return net->ipv6.ioam6_data;
#else
return NULL;
#endif
}
struct ioam6_namespace *ioam6_namespace(struct net *net, __be16 id);
void ioam6_fill_trace_data(struct sk_buff *skb,
struct ioam6_namespace *ns,
struct ioam6_trace_hdr *trace);
int ioam6_init(void);
void ioam6_exit(void);
#endif /* _NET_IOAM6_H */