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Message-ID: <CALx6S37UTS6PKicedPiCnNmEniBgN0zzkWDjxEDkdMuGTbn4aQ@mail.gmail.com>
Date: Wed, 24 Jun 2020 19:42:56 -0700
From: Tom Herbert <tom@...bertland.com>
To: Justin Iurman <justin.iurman@...ege.be>
Cc: Linux Kernel Network Developers <netdev@...r.kernel.org>,
"David S. Miller" <davem@...emloft.net>
Subject: Re: [PATCH net-next 3/5] ipv6: ioam: Data plane support for
Pre-allocated Trace
On Wed, Jun 24, 2020 at 12:33 PM Justin Iurman <justin.iurman@...ege.be> wrote:
>
> Implement support for processing the IOAM Pre-allocated Trace with IPv6,
> see [1] and [2]. Introduce a new IPv6 Hop-by-Hop TLV option
> IPV6_TLV_IOAM_HOPOPTS, see IANA [3].
>
> A per-interface sysctl ioam6_enabled is provided to accept/drop IOAM
> packets. Default is drop.
>
> Another per-interface sysctl ioam6_id is provided to define the IOAM
> (unique) identifier of the interface.
>
> A per-namespace sysctl ioam6_id is provided to define the IOAM (unique)
> identifier of the node.
>
> 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-01
> [2] https://tools.ietf.org/html/draft-ietf-ippm-ioam-data-09
> [3] https://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xhtml#ipv6-parameters-2
>
> Signed-off-by: Justin Iurman <justin.iurman@...ege.be>
> ---
> include/linux/ipv6.h | 2 +
> include/net/ioam6.h | 98 +++++++++++
> 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 | 67 ++++++++
> net/ipv6/ioam6.c | 326 +++++++++++++++++++++++++++++++++++++
> net/ipv6/sysctl_net_ipv6.c | 7 +
> 11 files changed, 533 insertions(+), 1 deletion(-)
> create mode 100644 include/net/ioam6.h
> create mode 100644 net/ipv6/ioam6.c
>
> diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
> index 5312a718bc7a..15732f964c6e 100644
> --- a/include/linux/ipv6.h
> +++ b/include/linux/ipv6.h
> @@ -75,6 +75,8 @@ 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..2a910bc99947
> --- /dev/null
> +++ b/include/net/ioam6.h
> @@ -0,0 +1,98 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * IOAM IPv6 implementation
> + *
> + * Author:
> + * Justin Iurman <justin.iurman@...ege.be>
> + */
> +
> +#ifndef _NET_IOAM6_H
> +#define _NET_IOAM6_H
> +
> +#include <linux/net.h>
> +#include <linux/ipv6.h>
> +#include <linux/rhashtable-types.h>
> +
> +#define IOAM6_OPT_TRACE_PREALLOC 0
> +
> +#define IOAM6_TRACE_FLAG_OVERFLOW (1 << 3)
> +
> +#define IOAM6_TRACE_TYPE0 (1 << 31)
> +#define IOAM6_TRACE_TYPE1 (1 << 30)
> +#define IOAM6_TRACE_TYPE2 (1 << 29)
> +#define IOAM6_TRACE_TYPE3 (1 << 28)
> +#define IOAM6_TRACE_TYPE4 (1 << 27)
> +#define IOAM6_TRACE_TYPE5 (1 << 26)
> +#define IOAM6_TRACE_TYPE6 (1 << 25)
> +#define IOAM6_TRACE_TYPE7 (1 << 24)
> +#define IOAM6_TRACE_TYPE8 (1 << 23)
> +#define IOAM6_TRACE_TYPE9 (1 << 22)
> +#define IOAM6_TRACE_TYPE10 (1 << 21)
> +#define IOAM6_TRACE_TYPE11 (1 << 20)
> +#define IOAM6_TRACE_TYPE22 (1 << 9)
> +
> +#define IOAM6_EMPTY_FIELD_u16 0xffff
> +#define IOAM6_EMPTY_FIELD_u24 0x00ffffff
> +#define IOAM6_EMPTY_FIELD_u32 0xffffffff
> +#define IOAM6_EMPTY_FIELD_u56 0x00ffffffffffffff
> +#define IOAM6_EMPTY_FIELD_u64 0xffffffffffffffff
> +
> +struct ioam6_common_hdr {
> + u8 opt_type;
> + u8 opt_len;
> + u8 res;
> + u8 ioam_type;
> + __be16 namespace_id;
> +} __packed;
> +
> +struct ioam6_trace_hdr {
> + __be16 info;
> + __be32 type;
> +} __packed;
> +
> +struct ioam6_namespace {
> + struct rhash_head head;
> + struct rcu_head rcu;
> +
> + __be16 id;
> + __be64 data;
> + bool remove_tlv;
> +
> + 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, int traceoff,
> + struct ioam6_namespace *ns);
> +
> +extern int ioam6_init(void);
> +extern void ioam6_exit(void);
> +
> +#endif
> diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
> index 5ec054473d81..89b27fa721f4 100644
> --- a/include/net/netns/ipv6.h
> +++ b/include/net/netns/ipv6.h
> @@ -51,6 +51,7 @@ struct netns_sysctl_ipv6 {
> int max_hbh_opts_len;
> int seg6_flowlabel;
> bool skip_notify_on_dev_down;
> + unsigned int ioam6_id;
> };
>
> struct netns_ipv6 {
> @@ -115,6 +116,7 @@ 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 9f2273a08356..1c98435220c9 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_HOPOPTS 49
> #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 13e8751bf24a..eb521b2dd885 100644
> --- a/include/uapi/linux/ipv6.h
> +++ b/include/uapi/linux/ipv6.h
> @@ -189,6 +189,8 @@ enum {
> DEVCONF_ACCEPT_RA_RT_INFO_MIN_PLEN,
> DEVCONF_NDISC_TCLASS,
> DEVCONF_RPL_SEG_ENABLED,
> + 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 840bfdb3d7bd..6c952a28ade2 100644
> --- a/net/ipv6/addrconf.c
> +++ b/net/ipv6/addrconf.c
> @@ -236,6 +236,8 @@ 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 = {
> @@ -291,6 +293,8 @@ 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 */
> @@ -5487,6 +5491,8 @@ 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)
> @@ -6867,6 +6873,20 @@ 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 b304b882e031..63a9ffc4b283 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>
> @@ -1187,6 +1188,10 @@ 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;
> @@ -1210,6 +1215,8 @@ 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 f27ab3bf2e0c..00aee1358f1c 100644
> --- a/net/ipv6/exthdrs.c
> +++ b/net/ipv6/exthdrs.c
> @@ -49,6 +49,8 @@
> #include <net/seg6_hmac.h>
> #endif
> #include <net/rpl.h>
> +#include <net/ioam6.h>
> +#include <net/dst_metadata.h>
>
> #include <linux/uaccess.h>
>
> @@ -1010,6 +1012,67 @@ static int ipv6_hop_ra(struct sk_buff *skb, int optoff)
> return TLV_REJECT;
> }
>
> +/* IOAM */
> +
> +static int ipv6_hop_ioam(struct sk_buff *skb, int optoff)
> +{
> + struct ioam6_common_hdr *ioamh;
> + struct ioam6_namespace *ns;
> +
> + /* Must be 4n-aligned */
> + if (optoff & 3)
> + goto drop;
> +
> + if (!skb_valid_dst(skb))
> + ip6_route_input(skb);
> +
> + /* IOAM must be enabled on ingress interface */
> + if (!__in6_dev_get(skb->dev)->cnf.ioam6_enabled)
> + goto drop;
> +
> + ioamh = (struct ioam6_common_hdr *)(skb_network_header(skb) + optoff);
> + ns = ioam6_namespace(ipv6_skb_net(skb), ioamh->namespace_id);
> +
> + /* Unknown IOAM namespace, either:
> + * - Drop it if IOAM is not enabled on egress interface (if any)
> + * - Ignore it otherwise
> + */
> + if (!ns) {
> + if (!__in6_dev_get(skb_dst(skb)->dev)->cnf.ioam6_enabled &&
> + !(skb_dst(skb)->dev->flags & IFF_LOOPBACK))
> + goto drop;
> +
> + goto accept;
> + }
> +
> + if (ns->remove_tlv && !(skb_dst(skb)->dev->flags & IFF_LOOPBACK))
> + goto remove;
> +
> + /* Known IOAM namespace which must not be removed:
> + * IOAM must be enabled on egress interface
> + */
> + if (!__in6_dev_get(skb_dst(skb)->dev)->cnf.ioam6_enabled &&
> + !(skb_dst(skb)->dev->flags & IFF_LOOPBACK))
> + goto drop;
> +
> + switch (ioamh->ioam_type) {
> + case IOAM6_OPT_TRACE_PREALLOC:
> + ioam6_fill_trace_data(skb, optoff + sizeof(*ioamh), ns);
> + IP6CB(skb)->flags |= IP6SKB_IOAM;
> + break;
> + default:
> + break;
> + }
> +
> +accept:
> + return TLV_ACCEPT;
> +remove:
> + return TLV_REMOVE;
> +drop:
> + kfree_skb(skb);
> + return TLV_REJECT;
> +}
Hardcoding another TLV in exthdrs.c. I still hope we can eventually
TLVs to be registered from modules like any other protocol does...
> +
> /* Jumbo payload */
>
> static int ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
> @@ -1081,6 +1144,10 @@ static const struct tlvtype_proc tlvprochopopt_lst[] = {
> .type = IPV6_TLV_ROUTERALERT,
> .func = ipv6_hop_ra,
> },
> + {
> + .type = IPV6_TLV_IOAM_HOPOPTS,
> + .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..406aa78eb504
> --- /dev/null
> +++ b/net/ipv6/ioam6.c
> @@ -0,0 +1,326 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * IOAM IPv6 implementation
> + *
> + * Author:
> + * Justin Iurman <justin.iurman@...ege.be>
> + */
> +
> +#include <linux/errno.h>
> +#include <linux/types.h>
> +#include <linux/kernel.h>
> +#include <linux/net.h>
> +#include <linux/rhashtable.h>
> +
> +#include <net/addrconf.h>
> +#include <net/ioam6.h>
> +
> +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);
> +}
> +
> +void ioam6_fill_trace_data_node(struct sk_buff *skb, int nodeoff,
> + u32 trace_type, struct ioam6_namespace *ns)
> +{
> + u8 *data = skb_network_header(skb) + nodeoff;
> + struct __kernel_sock_timeval ts;
> + u64 raw_u64;
> + u32 raw_u32;
> + u16 raw_u16;
> + u8 byte;
> +
> + /* hop_lim and node_id */
> + if (trace_type & IOAM6_TRACE_TYPE0) {
> + byte = ipv6_hdr(skb)->hop_limit - 1;
> + raw_u32 = dev_net(skb->dev)->ipv6.sysctl.ioam6_id;
> + if (!raw_u32)
> + raw_u32 = IOAM6_EMPTY_FIELD_u24;
> + else
> + raw_u32 &= IOAM6_EMPTY_FIELD_u24;
> + *(__be32 *)data = cpu_to_be32((byte << 24) | raw_u32);
> + data += sizeof(__be32);
> + }
> +
> + /* ingress_if_id and egress_if_id */
> + if (trace_type & IOAM6_TRACE_TYPE1) {
> + raw_u16 = __in6_dev_get(skb->dev)->cnf.ioam6_id;
> + if (!raw_u16)
> + raw_u16 = IOAM6_EMPTY_FIELD_u16;
> + *(__be16 *)data = cpu_to_be16(raw_u16);
> + data += sizeof(__be16);
> +
> + raw_u16 = __in6_dev_get(skb_dst(skb)->dev)->cnf.ioam6_id;
> + if (!raw_u16)
> + raw_u16 = IOAM6_EMPTY_FIELD_u16;
> + *(__be16 *)data = cpu_to_be16(raw_u16);
> + data += sizeof(__be16);
> + }
> +
> + /* timestamp seconds */
> + if (trace_type & IOAM6_TRACE_TYPE2) {
> + if (!skb->tstamp) {
> + *(__be32 *)data = cpu_to_be32(IOAM6_EMPTY_FIELD_u32);
> + } else {
> + skb_get_new_timestamp(skb, &ts);
> + *(__be32 *)data = cpu_to_be32((u32)ts.tv_sec);
> + }
> + data += sizeof(__be32);
> + }
> +
> + /* timestamp subseconds */
> + if (trace_type & IOAM6_TRACE_TYPE3) {
> + if (!skb->tstamp) {
> + *(__be32 *)data = cpu_to_be32(IOAM6_EMPTY_FIELD_u32);
> + } else {
> + if (!(trace_type & IOAM6_TRACE_TYPE2))
> + skb_get_new_timestamp(skb, &ts);
> + *(__be32 *)data = cpu_to_be32((u32)ts.tv_usec);
> + }
> + data += sizeof(__be32);
> + }
> +
> + /* transit delay */
> + if (trace_type & IOAM6_TRACE_TYPE4) {
> + *(__be32 *)data = cpu_to_be32(IOAM6_EMPTY_FIELD_u32);
> + data += sizeof(__be32);
> + }
> +
> + /* namespace data */
> + if (trace_type & IOAM6_TRACE_TYPE5) {
> + *(__be32 *)data = (__be32)ns->data;
> + data += sizeof(__be32);
> + }
> +
> + /* queue depth */
> + if (trace_type & IOAM6_TRACE_TYPE6) {
> + *(__be32 *)data = cpu_to_be32(IOAM6_EMPTY_FIELD_u32);
> + data += sizeof(__be32);
> + }
> +
> + /* hop_lim and node_id (wide) */
> + if (trace_type & IOAM6_TRACE_TYPE7) {
> + byte = ipv6_hdr(skb)->hop_limit - 1;
> + raw_u64 = dev_net(skb->dev)->ipv6.sysctl.ioam6_id;
> + if (!raw_u64)
> + raw_u64 = IOAM6_EMPTY_FIELD_u56;
> + else
> + raw_u64 &= IOAM6_EMPTY_FIELD_u56;
> + *(__be64 *)data = cpu_to_be64(((u64)byte << 56) | raw_u64);
> + data += sizeof(__be64);
> + }
> +
> + /* ingress_if_id and egress_if_id (wide) */
> + if (trace_type & IOAM6_TRACE_TYPE8) {
> + raw_u32 = __in6_dev_get(skb->dev)->cnf.ioam6_id;
> + if (!raw_u32)
> + raw_u32 = IOAM6_EMPTY_FIELD_u32;
> + *(__be32 *)data = cpu_to_be32(raw_u32);
Hmm, I wonder if the compiler is implementing this as:
*(__be32 *)data = raw_u32 ? cpu_to_be32(raw_u32) :
cpu_to_be32(IOAM6_EMPTY_FIELD_u32);
That is it realizes cpu_to_be32(IOAM6_EMPTY_FIELD_u32) is a constant expression
> + data += sizeof(__be32);
> +
> + raw_u32 = __in6_dev_get(skb_dst(skb)->dev)->cnf.ioam6_id;
> + if (!raw_u32)
> + raw_u32 = IOAM6_EMPTY_FIELD_u32;
> + *(__be32 *)data = cpu_to_be32(raw_u32);
> + data += sizeof(__be32);
> + }
> +
> + /* namespace data (wide) */
> + if (trace_type & IOAM6_TRACE_TYPE9) {
> + *(__be64 *)data = ns->data;
> + data += sizeof(__be64);
> + }
> +
> + /* buffer occupancy */
> + if (trace_type & IOAM6_TRACE_TYPE10) {
> + *(__be32 *)data = cpu_to_be32(IOAM6_EMPTY_FIELD_u32);
> + data += sizeof(__be32);
> + }
> +
> + /* checksum complement */
> + if (trace_type & IOAM6_TRACE_TYPE11) {
> + *(__be32 *)data = cpu_to_be32(IOAM6_EMPTY_FIELD_u32);
> + data += sizeof(__be32);
> + }
> +
> + /* opaque state snapshot */
> + if (trace_type & IOAM6_TRACE_TYPE22) {
> + if (!ns->schema) {
> + *(__be32 *)data = cpu_to_be32(IOAM6_EMPTY_FIELD_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, int traceoff,
> + struct ioam6_namespace *ns)
> +{
> + u8 nodelen, flags, remlen, sclen = 0;
> + struct ioam6_trace_hdr *trh;
> + int nodeoff;
> + u16 info;
> + u32 type;
> +
> + trh = (struct ioam6_trace_hdr *)(skb_network_header(skb) + traceoff);
> + info = be16_to_cpu(trh->info);
> + type = be32_to_cpu(trh->type);
> +
> + nodelen = info >> 11;
> + flags = (info >> 7) & 0xf;
> + remlen = info & 0x7f;
> +
> + /* Skip if Overflow bit is set OR
> + * if an unknown type (bit 12-21) is set
> + */
> + if ((flags & IOAM6_TRACE_FLAG_OVERFLOW) || (type & 0xffc00))
> + return;
> +
> + /* NodeLen does not include Opaque State Snapshot length. We need to
> + * take it into account if the corresponding bit is set and if current
> + * IOAM namespace has an active schema attached to it
> + */
> + if (type & IOAM6_TRACE_TYPE22) {
> + /* Opaque State Snapshot header size */
> + sclen = sizeof_field(struct ioam6_schema, hdr) / 4;
> +
> + if (ns->schema)
> + sclen += ns->schema->len / 4;
> + }
> +
> + /* Not enough space remaining: set Overflow bit and skip */
> + if (!remlen || remlen < (nodelen + sclen)) {
> + info |= IOAM6_TRACE_FLAG_OVERFLOW << 7;
> + trh->info = cpu_to_be16(info);
> + return;
> + }
> +
> + nodeoff = traceoff + sizeof(*trh) + remlen*4 - nodelen*4 - sclen*4;
> + ioam6_fill_trace_data_node(skb, nodeoff, type, ns);
> +
> + /* Update RemainingLen */
> + remlen -= nodelen + sclen;
> + info = (info & 0xff80) | remlen;
> + trh->info = cpu_to_be16(info);
> +}
> +
> +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 fac2135aa47b..da49b33ab6fc 100644
> --- a/net/ipv6/sysctl_net_ipv6.c
> +++ b/net/ipv6/sysctl_net_ipv6.c
> @@ -159,6 +159,13 @@ static struct ctl_table ipv6_table_template[] = {
> .mode = 0644,
> .proc_handler = proc_dointvec
> },
> + {
> + .procname = "ioam6_id",
> + .data = &init_net.ipv6.sysctl.ioam6_id,
> + .maxlen = sizeof(int),
> + .mode = 0644,
> + .proc_handler = proc_dointvec
> + },
> { }
> };
>
> --
> 2.17.1
>
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