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 per-interface sysctl ioam6_enabled is provided to process/ignore IOAM
headers. Default is ignore (= disabled). Another per-interface sysctl
ioam6_id is provided to define the IOAM (unique) identifier of the
interface. Default is 0. A per-namespace sysctl ioam6_id is provided to
define the IOAM (unique) identifier of the node. Default is 0.
Documentation is provided at the end of this patchset.

Two relativistic hash tables: 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.iur...@uliege.be>
---
 include/linux/ioam6.h      |  13 ++
 include/linux/ipv6.h       |   2 +
 include/net/ioam6.h        |  62 +++++++
 include/net/netns/ipv6.h   |   2 +
 include/uapi/linux/in6.h   |   1 +
 include/uapi/linux/ipv6.h  |   2 +
 net/ipv6/Makefile          |   2 +-
 net/ipv6/addrconf.c        |  20 +++
 net/ipv6/af_inet6.c        |   7 +
 net/ipv6/exthdrs.c         |  51 ++++++
 net/ipv6/ioam6.c           | 357 +++++++++++++++++++++++++++++++++++++
 net/ipv6/sysctl_net_ipv6.c |   7 +
 12 files changed, 525 insertions(+), 1 deletion(-)
 create mode 100644 include/linux/ioam6.h
 create mode 100644 include/net/ioam6.h
 create mode 100644 net/ipv6/ioam6.c

diff --git a/include/linux/ioam6.h b/include/linux/ioam6.h
new file mode 100644
index 000000000000..94a24b36998f
--- /dev/null
+++ b/include/linux/ioam6.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ *  IPv6 IOAM
+ *
+ *  Author:
+ *  Justin Iurman <justin.iur...@uliege.be>
+ */
+#ifndef _LINUX_IOAM6_H
+#define _LINUX_IOAM6_H
+
+#include <uapi/linux/ioam6.h>
+
+#endif /* _LINUX_IOAM6_H */
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 70b2ad3b9884..6cc372af2319 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -76,6 +76,8 @@ struct ipv6_devconf {
        __s32           disable_policy;
        __s32           ndisc_tclass;
        __s32           rpl_seg_enabled;
+       __u32           ioam6_enabled;
+       __u32           ioam6_id;
 
        struct ctl_table_header *sysctl_header;
 };
diff --git a/include/net/ioam6.h b/include/net/ioam6.h
new file mode 100644
index 000000000000..828b83c70721
--- /dev/null
+++ b/include/net/ioam6.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ *  IPv6 IOAM implementation
+ *
+ *  Author:
+ *  Justin Iurman <justin.iur...@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;
+
+       __be16 id;
+       __be64 data;
+
+       struct ioam6_schema *schema;
+};
+
+struct ioam6_schema {
+       struct rhash_head head;
+       struct rcu_head rcu;
+
+       u32 id;
+       int len;
+       __be32 hdr;
+       u8 *data;
+
+       struct ioam6_namespace *ns;
+};
+
+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
+}
+
+extern struct ioam6_namespace *ioam6_namespace(struct net *net, __be16 id);
+extern void ioam6_fill_trace_data(struct sk_buff *skb,
+                                 struct ioam6_namespace *ns,
+                                 struct ioam6_trace_hdr *trace);
+
+extern int ioam6_init(void);
+extern void ioam6_exit(void);
+
+#endif /* _NET_IOAM6_H */
diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
index 21c0debbd39e..a0c803ff382c 100644
--- a/include/net/netns/ipv6.h
+++ b/include/net/netns/ipv6.h
@@ -52,6 +52,7 @@ struct netns_sysctl_ipv6 {
        int seg6_flowlabel;
        bool skip_notify_on_dev_down;
        int fib_notify_on_flag_change;
+       unsigned int ioam6_id;
 };
 
 struct netns_ipv6 {
@@ -116,6 +117,7 @@ struct netns_ipv6 {
                spinlock_t      lock;
                u32             seq;
        } ip6addrlbl_table;
+       struct ioam6_pernet_data *ioam6_data;
 };
 
 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
diff --git a/include/uapi/linux/in6.h b/include/uapi/linux/in6.h
index 5ad396a57eb3..c4c53a9ab959 100644
--- a/include/uapi/linux/in6.h
+++ b/include/uapi/linux/in6.h
@@ -145,6 +145,7 @@ struct in6_flowlabel_req {
 #define IPV6_TLV_PADN          1
 #define IPV6_TLV_ROUTERALERT   5
 #define IPV6_TLV_CALIPSO       7       /* RFC 5570 */
+#define IPV6_TLV_IOAM          49      /* TEMPORARY IANA allocation for IOAM */
 #define IPV6_TLV_JUMBO         194
 #define IPV6_TLV_HAO           201     /* home address option */
 
diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h
index 70603775fe91..885c29e3a8d6 100644
--- a/include/uapi/linux/ipv6.h
+++ b/include/uapi/linux/ipv6.h
@@ -190,6 +190,8 @@ enum {
        DEVCONF_NDISC_TCLASS,
        DEVCONF_RPL_SEG_ENABLED,
        DEVCONF_RA_DEFRTR_METRIC,
+       DEVCONF_IOAM6_ENABLED,
+       DEVCONF_IOAM6_ID,
        DEVCONF_MAX
 };
 
diff --git a/net/ipv6/Makefile b/net/ipv6/Makefile
index cf7b47bdb9b3..b7ef10d417d6 100644
--- a/net/ipv6/Makefile
+++ b/net/ipv6/Makefile
@@ -10,7 +10,7 @@ ipv6-objs :=  af_inet6.o anycast.o ip6_output.o ip6_input.o 
addrconf.o \
                route.o ip6_fib.o ipv6_sockglue.o ndisc.o udp.o udplite.o \
                raw.o icmp.o mcast.o reassembly.o tcp_ipv6.o ping.o \
                exthdrs.o datagram.o ip6_flowlabel.o inet6_connection_sock.o \
-               udp_offload.o seg6.o fib6_notifier.o rpl.o
+               udp_offload.o seg6.o fib6_notifier.o rpl.o ioam6.o
 
 ipv6-offload :=        ip6_offload.o tcpv6_offload.o exthdrs_offload.o
 
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f2337fb756ac..b2956921e378 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -237,6 +237,8 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = {
        .addr_gen_mode          = IN6_ADDR_GEN_MODE_EUI64,
        .disable_policy         = 0,
        .rpl_seg_enabled        = 0,
+       .ioam6_enabled          = 0,
+       .ioam6_id               = 0,
 };
 
 static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
@@ -293,6 +295,8 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly 
= {
        .addr_gen_mode          = IN6_ADDR_GEN_MODE_EUI64,
        .disable_policy         = 0,
        .rpl_seg_enabled        = 0,
+       .ioam6_enabled          = 0,
+       .ioam6_id               = 0,
 };
 
 /* Check if link is ready: is it up and is a valid qdisc available */
@@ -5521,6 +5525,8 @@ static inline void ipv6_store_devconf(struct ipv6_devconf 
*cnf,
        array[DEVCONF_DISABLE_POLICY] = cnf->disable_policy;
        array[DEVCONF_NDISC_TCLASS] = cnf->ndisc_tclass;
        array[DEVCONF_RPL_SEG_ENABLED] = cnf->rpl_seg_enabled;
+       array[DEVCONF_IOAM6_ENABLED] = cnf->ioam6_enabled;
+       array[DEVCONF_IOAM6_ID] = cnf->ioam6_id;
 }
 
 static inline size_t inet6_ifla6_size(void)
@@ -6909,6 +6915,20 @@ static const struct ctl_table addrconf_sysctl[] = {
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
+       {
+               .procname       = "ioam6_enabled",
+               .data           = &ipv6_devconf.ioam6_enabled,
+               .maxlen         = sizeof(int),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec,
+       },
+       {
+               .procname       = "ioam6_id",
+               .data           = &ipv6_devconf.ioam6_id,
+               .maxlen         = sizeof(int),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec,
+       },
        {
                /* sentinel */
        }
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 802f5111805a..b47df3403bee 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -62,6 +62,7 @@
 #include <net/rpl.h>
 #include <net/compat.h>
 #include <net/xfrm.h>
+#include <net/ioam6.h>
 
 #include <linux/uaccess.h>
 #include <linux/mroute6.h>
@@ -1189,6 +1190,10 @@ static int __init inet6_init(void)
        if (err)
                goto rpl_fail;
 
+       err = ioam6_init();
+       if (err)
+               goto ioam6_fail;
+
        err = igmp6_late_init();
        if (err)
                goto igmp6_late_err;
@@ -1212,6 +1217,8 @@ static int __init inet6_init(void)
 #endif
 igmp6_late_err:
        rpl_exit();
+ioam6_fail:
+       ioam6_exit();
 rpl_fail:
        seg6_exit();
 seg6_fail:
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 6126f8bf94b3..45052f3e1ebc 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -49,6 +49,9 @@
 #include <net/seg6_hmac.h>
 #endif
 #include <net/rpl.h>
+#include <linux/ioam6.h>
+#include <net/ioam6.h>
+#include <net/dst_metadata.h>
 
 #include <linux/uaccess.h>
 
@@ -928,6 +931,50 @@ static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
        return false;
 }
 
+/* IOAM */
+
+static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff)
+{
+       struct ioam6_trace_hdr *trace;
+       struct ioam6_namespace *ns;
+       struct ioam6_hdr *hdr;
+
+       /* Must be 4n-aligned */
+       if (optoff & 3)
+               goto drop;
+
+       /* Ignore if IOAM is not enabled on ingress */
+       if (!__in6_dev_get(skb->dev)->cnf.ioam6_enabled)
+               goto ignore;
+
+       hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff);
+
+       switch (hdr->type) {
+       case IOAM6_TYPE_PREALLOC:
+               trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr));
+               ns = ioam6_namespace(ipv6_skb_net(skb), trace->namespace_id);
+
+               /* Ignore if the IOAM namespace is unknown */
+               if (!ns)
+                       goto ignore;
+
+               if (!skb_valid_dst(skb))
+                       ip6_route_input(skb);
+
+               ioam6_fill_trace_data(skb, ns, trace);
+               break;
+       default:
+               break;
+       }
+
+ignore:
+       return true;
+
+drop:
+       kfree_skb(skb);
+       return false;
+}
+
 /* Jumbo payload */
 
 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
@@ -999,6 +1046,10 @@ static const struct tlvtype_proc tlvprochopopt_lst[] = {
                .type   = IPV6_TLV_ROUTERALERT,
                .func   = ipv6_hop_ra,
        },
+       {
+               .type   = IPV6_TLV_IOAM,
+               .func   = ipv6_hop_ioam,
+       },
        {
                .type   = IPV6_TLV_JUMBO,
                .func   = ipv6_hop_jumbo,
diff --git a/net/ipv6/ioam6.c b/net/ipv6/ioam6.c
new file mode 100644
index 000000000000..dcec24e09e99
--- /dev/null
+++ b/net/ipv6/ioam6.c
@@ -0,0 +1,357 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ *  IPv6 IOAM implementation
+ *
+ *  Author:
+ *  Justin Iurman <justin.iur...@uliege.be>
+ */
+
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/net.h>
+#include <linux/ioam6.h>
+#include <linux/rhashtable.h>
+
+#include <net/addrconf.h>
+#include <net/ioam6.h>
+
+#define IOAM6_EMPTY_u16 0xffff
+#define IOAM6_EMPTY_u24 0x00ffffff
+#define IOAM6_EMPTY_u32 0xffffffff
+#define IOAM6_EMPTY_u56 0x00ffffffffffffff
+
+#define IOAM6_MASK_u24 IOAM6_EMPTY_u24
+#define IOAM6_MASK_u56 IOAM6_EMPTY_u56
+
+static inline void ioam6_ns_release(struct ioam6_namespace *ns)
+{
+       kfree_rcu(ns, rcu);
+}
+
+static inline void ioam6_sc_release(struct ioam6_schema *sc)
+{
+       kfree_rcu(sc, rcu);
+}
+
+static void ioam6_free_ns(void *ptr, void *arg)
+{
+       struct ioam6_namespace *ns = (struct ioam6_namespace *)ptr;
+
+       if (ns)
+               ioam6_ns_release(ns);
+}
+
+static void ioam6_free_sc(void *ptr, void *arg)
+{
+       struct ioam6_schema *sc = (struct ioam6_schema *)ptr;
+
+       if (sc)
+               ioam6_sc_release(sc);
+}
+
+static int ioam6_ns_cmpfn(struct rhashtable_compare_arg *arg, const void *obj)
+{
+       const struct ioam6_namespace *ns = obj;
+
+       return (ns->id != *(__be16 *)arg->key);
+}
+
+static int ioam6_sc_cmpfn(struct rhashtable_compare_arg *arg, const void *obj)
+{
+       const struct ioam6_schema *sc = obj;
+
+       return (sc->id != *(u32 *)arg->key);
+}
+
+static const struct rhashtable_params rht_ns_params = {
+       .key_len                = sizeof(__be16),
+       .key_offset             = offsetof(struct ioam6_namespace, id),
+       .head_offset            = offsetof(struct ioam6_namespace, head),
+       .automatic_shrinking    = true,
+       .obj_cmpfn              = ioam6_ns_cmpfn,
+};
+
+static const struct rhashtable_params rht_sc_params = {
+       .key_len                = sizeof(u32),
+       .key_offset             = offsetof(struct ioam6_schema, id),
+       .head_offset            = offsetof(struct ioam6_schema, head),
+       .automatic_shrinking    = true,
+       .obj_cmpfn              = ioam6_sc_cmpfn,
+};
+
+struct ioam6_namespace *ioam6_namespace(struct net *net, __be16 id)
+{
+       struct ioam6_pernet_data *nsdata = ioam6_pernet(net);
+
+       return rhashtable_lookup_fast(&nsdata->namespaces, &id, rht_ns_params);
+}
+
+static void __ioam6_fill_trace_data(struct sk_buff *skb,
+                                   struct ioam6_namespace *ns,
+                                   struct ioam6_trace_hdr *trace,
+                                   u8 sclen)
+{
+       struct __kernel_sock_timeval ts;
+       u64 raw64;
+       u32 raw32;
+       u16 raw16;
+       u8 *data;
+       u8 byte;
+
+       data = trace->data + trace->remlen*4 - trace->nodelen*4 - sclen*4;
+
+       /* hop_lim and node_id */
+       if (trace->type.bit0) {
+               byte = ipv6_hdr(skb)->hop_limit;
+               if (skb->dev)
+                       byte--;
+
+               raw32 = dev_net(skb->dev)->ipv6.sysctl.ioam6_id;
+               if (!raw32)
+                       raw32 = IOAM6_EMPTY_u24;
+               else
+                       raw32 &= IOAM6_MASK_u24;
+
+               *(__be32 *)data = cpu_to_be32((byte << 24) | raw32);
+               data += sizeof(__be32);
+       }
+
+       /* ingress_if_id and egress_if_id */
+       if (trace->type.bit1) {
+               if (!skb->dev) {
+                       raw16 = IOAM6_EMPTY_u16;
+               } else {
+                       raw16 = __in6_dev_get(skb->dev)->cnf.ioam6_id;
+                       if (!raw16)
+                               raw16 = IOAM6_EMPTY_u16;
+               }
+
+               *(__be16 *)data = cpu_to_be16(raw16);
+               data += sizeof(__be16);
+
+               if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
+                       raw16 = IOAM6_EMPTY_u16;
+               } else {
+                       raw16 = __in6_dev_get(skb_dst(skb)->dev)->cnf.ioam6_id;
+                       if (!raw16)
+                               raw16 = IOAM6_EMPTY_u16;
+               }
+
+               *(__be16 *)data = cpu_to_be16(raw16);
+               data += sizeof(__be16);
+       }
+
+       /* timestamp seconds */
+       if (trace->type.bit2) {
+               if (!skb->tstamp)
+                       __net_timestamp(skb);
+
+               skb_get_new_timestamp(skb, &ts);
+
+               *(__be32 *)data = cpu_to_be32((u32)ts.tv_sec);
+               data += sizeof(__be32);
+       }
+
+       /* timestamp subseconds */
+       if (trace->type.bit3) {
+               if (!skb->tstamp)
+                       __net_timestamp(skb);
+
+               if (!trace->type.bit2)
+                       skb_get_new_timestamp(skb, &ts);
+
+               *(__be32 *)data = cpu_to_be32((u32)ts.tv_usec);
+               data += sizeof(__be32);
+       }
+
+       /* transit delay */
+       if (trace->type.bit4) {
+               *(__be32 *)data = cpu_to_be32(IOAM6_EMPTY_u32);
+               data += sizeof(__be32);
+       }
+
+       /* namespace data */
+       if (trace->type.bit5) {
+               *(__be32 *)data = (__force __be32)ns->data;
+               data += sizeof(__be32);
+       }
+
+       /* queue depth */
+       if (trace->type.bit6) {
+               *(__be32 *)data = cpu_to_be32(IOAM6_EMPTY_u32);
+               data += sizeof(__be32);
+       }
+
+       /* checksum complement */
+       if (trace->type.bit7) {
+               *(__be32 *)data = cpu_to_be32(IOAM6_EMPTY_u32);
+               data += sizeof(__be32);
+       }
+
+       /* hop_lim and node_id (wide) */
+       if (trace->type.bit8) {
+               byte = ipv6_hdr(skb)->hop_limit;
+               if (skb->dev)
+                       byte--;
+
+               raw64 = dev_net(skb->dev)->ipv6.sysctl.ioam6_id;
+               if (!raw64)
+                       raw64 = IOAM6_EMPTY_u56;
+               else
+                       raw64 &= IOAM6_MASK_u56;
+
+               *(__be64 *)data = cpu_to_be64(((u64)byte << 56) | raw64);
+               data += sizeof(__be64);
+       }
+
+       /* ingress_if_id and egress_if_id (wide) */
+       if (trace->type.bit9) {
+               if (!skb->dev) {
+                       raw32 = IOAM6_EMPTY_u32;
+               } else {
+                       raw32 = __in6_dev_get(skb->dev)->cnf.ioam6_id;
+                       if (!raw32)
+                               raw32 = IOAM6_EMPTY_u32;
+               }
+
+               *(__be32 *)data = cpu_to_be32(raw32);
+               data += sizeof(__be32);
+
+               if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
+                       raw32 = IOAM6_EMPTY_u32;
+               } else {
+                       raw32 = __in6_dev_get(skb_dst(skb)->dev)->cnf.ioam6_id;
+                       if (!raw32)
+                               raw32 = IOAM6_EMPTY_u32;
+               }
+
+               *(__be32 *)data = cpu_to_be32(raw32);
+               data += sizeof(__be32);
+       }
+
+       /* namespace data (wide) */
+       if (trace->type.bit10) {
+               *(__be64 *)data = ns->data;
+               data += sizeof(__be64);
+       }
+
+       /* buffer occupancy */
+       if (trace->type.bit11) {
+               *(__be32 *)data = cpu_to_be32(IOAM6_EMPTY_u32);
+               data += sizeof(__be32);
+       }
+
+       /* opaque state snapshot */
+       if (trace->type.bit22) {
+               if (!ns->schema) {
+                       *(__be32 *)data = cpu_to_be32(IOAM6_EMPTY_u24);
+               } else {
+                       *(__be32 *)data = ns->schema->hdr;
+                       data += sizeof(__be32);
+
+                       memcpy(data, ns->schema->data, ns->schema->len);
+               }
+       }
+}
+
+void ioam6_fill_trace_data(struct sk_buff *skb,
+                          struct ioam6_namespace *ns,
+                          struct ioam6_trace_hdr *trace)
+{
+       u8 sclen = 0;
+
+       /* Skip if Overflow flag is set OR
+        * if an unknown type (bit 12-21) is set
+        */
+       if (trace->overflow ||
+            (trace->type.bit12 | trace->type.bit13 | trace->type.bit14 |
+             trace->type.bit15 | trace->type.bit16 | trace->type.bit17 |
+             trace->type.bit18 | trace->type.bit19 | trace->type.bit20 |
+             trace->type.bit21)) {
+               return;
+       }
+
+       /* NodeLen does not include Opaque State Snapshot length. We need to
+        * take it into account if the corresponding bit is set (bit 22) and
+        * if the current IOAM namespace has an active schema attached to it
+        */
+       if (trace->type.bit22) {
+               sclen = sizeof_field(struct ioam6_schema, hdr) / 4;
+
+               if (ns->schema)
+                       sclen += ns->schema->len / 4;
+       }
+
+       /* If there is no space remaining, we set the Overflow flag and we
+        * skip without filling the trace
+        */
+       if (!trace->remlen || trace->remlen < (trace->nodelen + sclen)) {
+               trace->overflow = 1;
+               return;
+       }
+
+       __ioam6_fill_trace_data(skb, ns, trace, sclen);
+       trace->remlen -= trace->nodelen + sclen;
+}
+
+static int __net_init ioam6_net_init(struct net *net)
+{
+       struct ioam6_pernet_data *nsdata;
+       int err = -ENOMEM;
+
+       nsdata = kzalloc(sizeof(*nsdata), GFP_KERNEL);
+       if (!nsdata)
+               goto out;
+
+       mutex_init(&nsdata->lock);
+       net->ipv6.ioam6_data = nsdata;
+
+       err = rhashtable_init(&nsdata->namespaces, &rht_ns_params);
+       if (err)
+               goto free_nsdata;
+
+       err = rhashtable_init(&nsdata->schemas, &rht_sc_params);
+       if (err)
+               goto free_rht_ns;
+
+out:
+       return err;
+free_rht_ns:
+       rhashtable_destroy(&nsdata->namespaces);
+free_nsdata:
+       kfree(nsdata);
+       net->ipv6.ioam6_data = NULL;
+       goto out;
+}
+
+static void __net_exit ioam6_net_exit(struct net *net)
+{
+       struct ioam6_pernet_data *nsdata = ioam6_pernet(net);
+
+       rhashtable_free_and_destroy(&nsdata->namespaces, ioam6_free_ns, NULL);
+       rhashtable_free_and_destroy(&nsdata->schemas, ioam6_free_sc, NULL);
+
+       kfree(nsdata);
+}
+
+static struct pernet_operations ioam6_net_ops = {
+       .init = ioam6_net_init,
+       .exit = ioam6_net_exit,
+};
+
+int __init ioam6_init(void)
+{
+       int err = register_pernet_subsys(&ioam6_net_ops);
+
+       if (err)
+               return err;
+
+       pr_info("In-situ OAM (IOAM) with IPv6\n");
+       return 0;
+}
+
+void ioam6_exit(void)
+{
+       unregister_pernet_subsys(&ioam6_net_ops);
+}
diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c
index 263ab43ed06b..2dc495072417 100644
--- a/net/ipv6/sysctl_net_ipv6.c
+++ b/net/ipv6/sysctl_net_ipv6.c
@@ -169,6 +169,13 @@ static struct ctl_table ipv6_table_template[] = {
                .extra1         = SYSCTL_ZERO,
                .extra2         = &two,
        },
+       {
+               .procname       = "ioam6_id",
+               .data           = &init_net.ipv6.sysctl.ioam6_id,
+               .maxlen         = sizeof(int),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec
+       },
        { }
 };
 
-- 
2.17.1

Reply via email to