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Message-ID: <CAM_iQpXb4=PP9=oNWH1vNHb81OGg7ivUtPaD8KfdQqVNYMKgoA@mail.gmail.com>
Date: Tue, 23 Feb 2016 13:44:52 -0800
From: Cong Wang <xiyou.wangcong@...il.com>
To: Jamal Hadi Salim <jhs@...atatu.com>
Cc: David Miller <davem@...emloft.net>,
Linux Kernel Network Developers <netdev@...r.kernel.org>,
Daniel Borkmann <daniel@...earbox.net>,
Alexei Starovoitov <alexei.starovoitov@...il.com>,
john fastabend <john.fastabend@...il.com>, dj@...izon.com
Subject: Re: [net-next PATCH v2 1/5] introduce IFE action
On Tue, Feb 23, 2016 at 4:49 AM, Jamal Hadi Salim <jhs@...atatu.com> wrote:
> From: Jamal Hadi Salim <jhs@...atatu.com>
>
> This action allows for a sending side to encapsulate arbitrary metadata
> which is decapsulated by the receiving end.
> The sender runs in encoding mode and the receiver in decode mode.
> Both sender and receiver must specify the same ethertype.
> At some point we hope to have a registered ethertype and we'll
> then provide a default so the user doesnt have to specify it.
> For now we enforce the user specify it.
>
> Lets show example usage where we encode icmp from a sender towards
> a receiver with an skbmark of 17; both sender and receiver use
> ethertype of 0xdead to interop.
>
> YYYY: Lets start with Receiver-side policy config:
> xxx: add an ingress qdisc
> sudo tc qdisc add dev $ETH ingress
>
> xxx: any packets with ethertype 0xdead will be subjected to ife decoding
> xxx: we then restart the classification so we can match on icmp at prio 3
> sudo $TC filter add dev $ETH parent ffff: prio 2 protocol 0xdead \
> u32 match u32 0 0 flowid 1:1 \
> action ife decode reclassify
>
> xxx: on restarting the classification from above if it was an icmp
> xxx: packet, then match it here and continue to the next rule at prio 4
> xxx: which will match based on skb mark of 17
> sudo tc filter add dev $ETH parent ffff: prio 3 protocol ip \
> u32 match ip protocol 1 0xff flowid 1:1 \
> action continue
>
> xxx: match on skbmark of 0x11 (decimal 17) and accept
> sudo tc filter add dev $ETH parent ffff: prio 4 protocol ip \
> handle 0x11 fw flowid 1:1 \
> action ok
>
> xxx: Lets show the decoding policy
> sudo tc -s filter ls dev $ETH parent ffff: protocol 0xdead
> xxx:
> filter pref 2 u32
> filter pref 2 u32 fh 800: ht divisor 1
> filter pref 2 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1 (rule hit 0 success 0)
> match 00000000/00000000 at 0 (success 0 )
> action order 1: ife decode action reclassify
> index 1 ref 1 bind 1 installed 14 sec used 14 sec
> type: 0x0
> Metadata: allow mark allow hash allow prio allow qmap
> Action statistics:
> Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
> backlog 0b 0p requeues 0
> xxx:
> Observe that above lists all metadatum it can decode. Typically these
> submodules will already be compiled into a monolithic kernel or
> loaded as modules
>
> YYYY: Lets show the sender side now ..
>
> xxx: Add an egress qdisc on the sender netdev
> sudo tc qdisc add dev $ETH root handle 1: prio
> xxx:
> xxx: Match all icmp packets to 192.168.122.237/24, then
> xxx: tag the packet with skb mark of decimal 17, then
> xxx: Encode it with:
> xxx: ethertype 0xdead
> xxx: add skb->mark to whitelist of metadatum to send
> xxx: rewrite target dst MAC address to 02:15:15:15:15:15
> xxx:
> sudo $TC filter add dev $ETH parent 1: protocol ip prio 10 u32 \
> match ip dst 192.168.122.237/24 \
> match ip protocol 1 0xff \
> flowid 1:2 \
> action skbedit mark 17 \
> action ife encode \
> type 0xDEAD \
> allow mark \
> dst 02:15:15:15:15:15
>
> xxx: Lets show the encoding policy
> sudo tc -s filter ls dev $ETH parent 1: protocol ip
> xxx:
> filter pref 10 u32
> filter pref 10 u32 fh 800: ht divisor 1
> filter pref 10 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:2 (rule hit 0 success 0)
> match c0a87aed/ffffffff at 16 (success 0 )
> match 00010000/00ff0000 at 8 (success 0 )
>
> action order 1: skbedit mark 17
> index 6 ref 1 bind 1
> Action statistics:
> Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
> backlog 0b 0p requeues 0
>
> action order 2: ife encode action pipe
> index 3 ref 1 bind 1
> dst MAC: 02:15:15:15:15:15 type: 0xDEAD
> Metadata: allow mark
> Action statistics:
> Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
> backlog 0b 0p requeues 0
> xxx:
>
> test by sending ping from sender to destination
>
> Signed-off-by: Jamal Hadi Salim <jhs@...atatu.com>
> ---
> include/net/tc_act/tc_ife.h | 60 +++
> include/uapi/linux/tc_act/tc_ife.h | 38 ++
> net/sched/Kconfig | 12 +
> net/sched/Makefile | 1 +
> net/sched/act_ife.c | 865 +++++++++++++++++++++++++++++++++++++
> 5 files changed, 976 insertions(+)
> create mode 100644 include/net/tc_act/tc_ife.h
> create mode 100644 include/uapi/linux/tc_act/tc_ife.h
> create mode 100644 net/sched/act_ife.c
>
> diff --git a/include/net/tc_act/tc_ife.h b/include/net/tc_act/tc_ife.h
> new file mode 100644
> index 0000000..fbbc23c
> --- /dev/null
> +++ b/include/net/tc_act/tc_ife.h
> @@ -0,0 +1,60 @@
> +#ifndef __NET_TC_IFE_H
> +#define __NET_TC_IFE_H
> +
> +#include <net/act_api.h>
> +#include <linux/etherdevice.h>
> +#include <linux/rtnetlink.h>
> +#include <linux/module.h>
> +
> +#define IFE_METAHDRLEN 2
> +struct tcf_ife_info {
> + struct tcf_common common;
> + u8 eth_dst[ETH_ALEN];
> + u8 eth_src[ETH_ALEN];
> + u16 eth_type;
> + u16 flags;
> + /* list of metaids allowed */
> + struct list_head metalist;
> +};
> +#define to_ife(a) \
> + container_of(a->priv, struct tcf_ife_info, common)
> +
> +struct tcf_meta_info {
> + const struct tcf_meta_ops *ops;
> + void *metaval;
> + u16 metaid;
> + struct list_head metalist;
> +};
> +
> +struct tcf_meta_ops {
> + u16 metaid; /*Maintainer provided ID */
> + u16 metatype; /*netlink attribute type (look at net/netlink.h) */
> + const char *name;
> + const char *synopsis;
> + struct list_head list;
> + int (*check_presence)(struct sk_buff *, struct tcf_meta_info *);
> + int (*encode)(struct sk_buff *, void *, struct tcf_meta_info *);
> + int (*decode)(struct sk_buff *, void *, u16 len);
> + int (*get)(struct sk_buff *skb, struct tcf_meta_info *mi);
> + int (*alloc)(struct tcf_meta_info *, void *);
> + void (*release)(struct tcf_meta_info *);
> + int (*validate)(void *val, int len);
> + struct module *owner;
> +};
> +
> +#define MODULE_ALIAS_IFE_META(metan) MODULE_ALIAS("ifemeta" __stringify_1(metan))
> +
> +int get_meta_u32(struct sk_buff *skb, struct tcf_meta_info *mi);
> +int get_meta_u16(struct sk_buff *skb, struct tcf_meta_info *mi);
> +int tlv_meta_encode(void *skbdata, u16 attrtype, u16 dlen, const void *dval);
> +int alloc_meta_u32(struct tcf_meta_info *mi, void *metaval);
> +int alloc_meta_u16(struct tcf_meta_info *mi, void *metaval);
> +int check_meta_u32(u32 metaval, struct tcf_meta_info *mi);
> +int encode_meta_u32(u32 metaval, void *skbdata, struct tcf_meta_info *mi);
> +int validate_meta_u32(void *val, int len);
> +int validate_meta_u16(void *val, int len);
> +void release_meta_gen(struct tcf_meta_info *mi);
> +int register_ife_op(struct tcf_meta_ops *mops);
> +int unregister_ife_op(struct tcf_meta_ops *mops);
These are exported to other modules, please add some prefix to protect them.
> +
> +#endif /* __NET_TC_IFE_H */
> diff --git a/include/uapi/linux/tc_act/tc_ife.h b/include/uapi/linux/tc_act/tc_ife.h
> new file mode 100644
> index 0000000..f11bcda
> --- /dev/null
> +++ b/include/uapi/linux/tc_act/tc_ife.h
> @@ -0,0 +1,38 @@
> +#ifndef __UAPI_TC_IFE_H
> +#define __UAPI_TC_IFE_H
> +
> +#include <linux/types.h>
> +#include <linux/pkt_cls.h>
> +
> +#define TCA_ACT_IFE 25
> +/* Flag bits for now just encoding/decoding */
> +#define IFE_ENCODE 1
> +#define IFE_DECODE 2
> +
> +struct tc_ife {
> + tc_gen;
> + __u16 flags;
> +};
> +
> +/*XXX: We need to encode the total number of bytes consumed */
> +enum {
> + TCA_IFE_UNSPEC,
> + TCA_IFE_PARMS,
> + TCA_IFE_TM,
> + TCA_IFE_DMAC,
> + TCA_IFE_SMAC,
> + TCA_IFE_TYPE,
> + TCA_IFE_METALST,
> + __TCA_IFE_MAX
> +};
> +#define TCA_IFE_MAX (__TCA_IFE_MAX - 1)
> +
> +#define IFE_META_SKBMARK 1
> +#define IFE_META_HASHID 2
> +#define IFE_META_PRIO 3
> +#define IFE_META_QMAP 4
> +/*Can be overriden at runtime by module option*/
> +#define __IFE_META_MAX 5
> +#define IFE_META_MAX (__IFE_META_MAX - 1)
> +
> +#endif
> diff --git a/net/sched/Kconfig b/net/sched/Kconfig
> index 8283082..4d48ef5 100644
> --- a/net/sched/Kconfig
> +++ b/net/sched/Kconfig
> @@ -739,6 +739,18 @@ config NET_ACT_CONNMARK
> To compile this code as a module, choose M here: the
> module will be called act_connmark.
>
> +config NET_ACT_IFE
> + tristate "Inter-FE action based on IETF ForCES InterFE LFB"
> + depends on NET_CLS_ACT
> + ---help---
> + Say Y here to allow for sourcing and terminating metadata
> + For details refer to netdev01 paper:
> + "Distributing Linux Traffic Control Classifier-Action Subsystem"
> + Authors: Jamal Hadi Salim and Damascene M. Joachimpillai
> +
> + To compile this code as a module, choose M here: the
> + module will be called act_ife.
> +
> config NET_CLS_IND
> bool "Incoming device classification"
> depends on NET_CLS_U32 || NET_CLS_FW
> diff --git a/net/sched/Makefile b/net/sched/Makefile
> index 690c1689..3d17667 100644
> --- a/net/sched/Makefile
> +++ b/net/sched/Makefile
> @@ -19,6 +19,7 @@ obj-$(CONFIG_NET_ACT_CSUM) += act_csum.o
> obj-$(CONFIG_NET_ACT_VLAN) += act_vlan.o
> obj-$(CONFIG_NET_ACT_BPF) += act_bpf.o
> obj-$(CONFIG_NET_ACT_CONNMARK) += act_connmark.o
> +obj-$(CONFIG_NET_ACT_IFE) += act_ife.o
> obj-$(CONFIG_NET_SCH_FIFO) += sch_fifo.o
> obj-$(CONFIG_NET_SCH_CBQ) += sch_cbq.o
> obj-$(CONFIG_NET_SCH_HTB) += sch_htb.o
> diff --git a/net/sched/act_ife.c b/net/sched/act_ife.c
> new file mode 100644
> index 0000000..153a202
> --- /dev/null
> +++ b/net/sched/act_ife.c
> @@ -0,0 +1,865 @@
> +/*
> + * net/sched/ife.c Inter-FE action based on ForCES WG InterFE LFB
> + *
> + * Refer to:
> + * draft-ietf-forces-interfelfb-03
> + * and
> + * netdev01 paper:
> + * "Distributing Linux Traffic Control Classifier-Action
> + * Subsystem"
> + * Authors: Jamal Hadi Salim and Damascene M. Joachimpillai
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version
> + * 2 of the License, or (at your option) any later version.
> + *
> + * copyright Jamal Hadi Salim (2015)
2016? ;)
> + *
> +*/
> +
> +#include <linux/types.h>
> +#include <linux/kernel.h>
> +#include <linux/string.h>
> +#include <linux/errno.h>
> +#include <linux/skbuff.h>
> +#include <linux/rtnetlink.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <net/netlink.h>
> +#include <net/pkt_sched.h>
> +#include <uapi/linux/tc_act/tc_ife.h>
> +#include <net/tc_act/tc_ife.h>
> +#include <linux/etherdevice.h>
> +
> +#define IFE_TAB_MASK 15
> +
> +static int max_metacnt = IFE_META_MAX + 1;
> +static const struct nla_policy ife_policy[TCA_IFE_MAX + 1] = {
> + [TCA_IFE_PARMS] = {.len = sizeof(struct tc_ife)},
> + [TCA_IFE_DMAC] = {.type = NLA_BINARY,.len = ETH_ALEN},
> + [TCA_IFE_SMAC] = {.type = NLA_BINARY,.len = ETH_ALEN},
> + [TCA_IFE_TYPE] = {.type = NLA_U16},
> +};
> +
> +/*
> + * Caller takes care of presenting data in network order
> +*/
> +int tlv_meta_encode(void *skbdata, u16 attrtype, u16 dlen, const void *dval)
> +{
> + u32 *tlv = (u32 *) (skbdata);
> + u16 totlen = nla_total_size(dlen); /*alignment + hdr */
> + char *dptr = (char *)tlv + NLA_HDRLEN;
> + u32 htlv = attrtype << 16 | totlen;
> +
> + *tlv = htonl(htlv);
> + memset(dptr, 0, totlen - NLA_HDRLEN);
> + memcpy(dptr, dval, dlen);
> +
> + return totlen;
> +}
> +EXPORT_SYMBOL_GPL(tlv_meta_encode);
> +
> +int get_meta_u32(struct sk_buff *skb, struct tcf_meta_info *mi)
> +{
> + if (mi->metaval)
> + return nla_put_u32(skb, mi->metaid, *(u32 *) mi->metaval);
> + else
> + return nla_put(skb, mi->metaid, 0, NULL);
> +}
> +EXPORT_SYMBOL_GPL(get_meta_u32);
> +
> +int check_meta_u32(u32 metaval, struct tcf_meta_info *mi)
> +{
> + if (metaval || mi->metaval)
> + return 8;
Why 8?
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(check_meta_u32);
> +
> +int encode_meta_u32(u32 metaval, void *skbdata, struct tcf_meta_info *mi)
> +{
> + u32 edata = metaval;
> +
> + if (mi->metaval)
> + edata = *(u32 *)mi->metaval;
> + else if (metaval)
> + edata = metaval;
> +
> + if (!edata) /* will not encode */
> + return 0;
> +
> + edata = htonl(edata);
> + return tlv_meta_encode(skbdata, mi->metaid, 4, &edata);
> +}
> +EXPORT_SYMBOL_GPL(encode_meta_u32);
> +
> +int get_meta_u16(struct sk_buff *skb, struct tcf_meta_info *mi)
> +{
> + if (mi->metaval)
> + return nla_put_u16(skb, mi->metaid, *(u16 *) mi->metaval);
> + else
> + return nla_put(skb, mi->metaid, 0, NULL);
> +}
> +EXPORT_SYMBOL_GPL(get_meta_u16);
> +
> +int alloc_meta_u32(struct tcf_meta_info *mi, void *metaval)
> +{
> + mi->metaval = kzalloc(sizeof(u32), GFP_KERNEL);
> + if (!mi->metaval)
> + return -ENOMEM;
> +
> + memcpy(mi->metaval, metaval, 4);
kmemdup()?
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(alloc_meta_u32);
> +
> +int alloc_meta_u16(struct tcf_meta_info *mi, void *metaval)
> +{
> + mi->metaval = kzalloc(sizeof(u16), GFP_KERNEL);
> + if (!mi->metaval)
> + return -ENOMEM;
> +
> + memcpy(mi->metaval, metaval, 2);
kmemdup()?
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(alloc_meta_u16);
> +
> +void release_meta_gen(struct tcf_meta_info *mi)
> +{
> + kfree(mi->metaval);
> +}
> +
> +EXPORT_SYMBOL_GPL(release_meta_gen);
> +
> +int validate_meta_u32(void *val, int len)
> +{
> + if (len == 4)
> + return 0;
> +
> + return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(validate_meta_u32);
> +
> +int validate_meta_u16(void *val, int len)
> +{
> + /* length will include padding */
> + if (len == NLA_ALIGN(2))
> + return 0;
> +
> + return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(validate_meta_u16);
> +
> +static LIST_HEAD(ifeoplist);
> +static DEFINE_RWLOCK(ife_mod_lock);
> +
> +struct tcf_meta_ops *find_ife_oplist(u16 metaid)
> +{
> + struct tcf_meta_ops *o;
> +
> + read_lock(&ife_mod_lock);
> + list_for_each_entry(o, &ifeoplist, list) {
> + if (o->metaid == metaid) {
> + if (!try_module_get(o->owner))
> + o = NULL;
> + read_unlock(&ife_mod_lock);
> + return o;
> + }
> + }
> + read_unlock(&ife_mod_lock);
> +
> + return NULL;
> +}
> +
> +int register_ife_op(struct tcf_meta_ops *mops)
> +{
> + struct tcf_meta_ops *m;
> +
> + if (!mops->metaid || !mops->metatype || !mops->name ||
> + !mops->check_presence || !mops->encode || !mops->decode ||
> + !mops->get || !mops->alloc)
> + return -EINVAL;
> +
> + write_lock(&ife_mod_lock);
> +
> + list_for_each_entry(m, &ifeoplist, list) {
> + if (m->metaid == mops->metaid ||
> + (strcmp(mops->name, m->name) == 0)) {
> + write_unlock(&ife_mod_lock);
> + return -EEXIST;
> + }
> + }
> +
> + if (!mops->release)
> + mops->release = release_meta_gen;
> +
> + INIT_LIST_HEAD(&mops->list);
No need to initi it since list_add_tail() is just one line below.
> + list_add_tail(&mops->list, &ifeoplist);
> + write_unlock(&ife_mod_lock);
> + return 0;
> +}
> +
> +int unregister_ife_op(struct tcf_meta_ops *mops)
> +{
> + struct tcf_meta_ops *m;
> + int err = -ENOENT;
> +
> + write_lock(&ife_mod_lock);
> + list_for_each_entry(m, &ifeoplist, list) {
> + if (m->metaid == mops->metaid) {
> + list_del(&mops->list);
> + err = 0;
> + break;
> + }
> + }
> + write_unlock(&ife_mod_lock);
> +
> + return err;
> +}
> +
> +EXPORT_SYMBOL_GPL(register_ife_op);
> +EXPORT_SYMBOL_GPL(unregister_ife_op);
Move them next to their definitions.
> +
> +void print_ife_oplist(void)
> +{
> + struct tcf_meta_ops *o;
> + int i = 0;
> +
> + read_lock(&ife_mod_lock);
> + list_for_each_entry(o, &ifeoplist, list) {
> + pr_debug("%d: %s metaid %d\n", ++i, o->name, o->metaid);
> + }
> + read_unlock(&ife_mod_lock);
> +}
> +
> +/* called when adding new meta information
> + * under ife->tcf_lock
> +*/
> +int load_metaops_and_vet(struct tcf_ife_info *ife, u32 metaid,
> + void *val, int len)
I failed to understand the name of this function.
> +{
> + struct tcf_meta_ops *ops = find_ife_oplist(metaid);
> + int ret = 0;
> +
> + if (!ops) {
> + ret = -ENOENT;
> +#ifdef CONFIG_MODULES
> + spin_unlock_bh(&ife->tcf_lock);
> + rtnl_unlock();
> + request_module("ifemeta%u", metaid);
> + rtnl_lock();
> + spin_lock_bh(&ife->tcf_lock);
> + ops = find_ife_oplist(metaid);
> +#endif
> + }
> +
> + if (ops) {
> + ret = 0;
> +
> + /* XXX: unfortunately cant use nla_policy at this point
> + * because a length of 0 is valid in the case of
> + * "allow". "use" semantics do enforce for proper
> + * length and i couldve use nla_policy but it makes it hard
> + * to use it just for that..
> + */
> + if (len) {
> + if (ops->validate) {
> + ret = ops->validate(val, len);
> + } else {
> + if (ops->metatype == NLA_U32) {
> + ret = validate_meta_u32(val, len);
> + } else if (ops->metatype == NLA_U16) {
> + ret = validate_meta_u16(val, len);
> + }
> + }
> + }
Sounds like this should be in a separated function.
> +
> + module_put(ops->owner);
> + }
> +
> + return ret;
> +}
> +
> +/* called when adding new meta information
> + * under ife->tcf_lock
> +*/
> +int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval, int len)
> +{
> + struct tcf_meta_info *mi = NULL;
> + struct tcf_meta_ops *ops = find_ife_oplist(metaid);
> + int ret = 0;
> +
> + if (!ops) {
> + return -ENOENT;
> + }
> +
> + mi = kzalloc(sizeof(*mi), GFP_KERNEL);
> + if (!mi) {
> + /*put back what find_ife_oplist took */
> + module_put(ops->owner);
> + return -ENOMEM;
> + }
> +
> + mi->metaid = metaid;
> + mi->ops = ops;
> + if (len > 0) {
> + ret = ops->alloc(mi, metaval);
> + if (ret != 0) {
> + kfree(mi);
> + module_put(ops->owner);
> + return ret;
> + }
> + }
> +
> + /*XXX: if it becomes necessary add per tcf_meta_info lock;
> + * for now use Thor's hammer */
What about ife->tcf_lock?
> + write_lock(&ife_mod_lock);
> + list_add_tail(&mi->metalist, &ife->metalist);
> + write_unlock(&ife_mod_lock);
> +
> + return ret;
> +}
> +
> +int use_all_metadata(struct tcf_ife_info *ife)
> +{
> + struct tcf_meta_ops *o;
> + int rc = 0;
> + int installed = 0;
> +
> + list_for_each_entry(o, &ifeoplist, list) {
> + rc = add_metainfo(ife, o->metaid, NULL, 0);
> + if (rc == 0)
> + installed +=1;
> + }
> +
> + if (installed)
> + return 0;
> + else
> + return -EINVAL;
> +}
> +
> +int dump_metalist(struct sk_buff *skb, struct tcf_ife_info *ife)
> +{
> + struct tcf_meta_info *e;
> + struct nlattr *nest;
> + unsigned char *b = skb_tail_pointer(skb);
> + int total_encoded = 0;
> +
> + /*can only happen on decode */
> + if (list_empty(&ife->metalist))
> + return 0;
> +
> + nest = nla_nest_start(skb, TCA_IFE_METALST);
> + if (nest == NULL)
> + goto out_nlmsg_trim;
> +
> + list_for_each_entry(e, &ife->metalist, metalist) {
> + if (!e->ops->get(skb, e))
> + total_encoded += 1;
> + }
> +
> + if (!total_encoded)
> + goto out_nlmsg_trim;
> +
> + nla_nest_end(skb, nest);
> +
> + return 0;
> +
> +out_nlmsg_trim:
> + nlmsg_trim(skb, b);
> + return -1;
> +}
> +
> +/* under ife->tcf_lock */
> +static void _tcf_ife_cleanup(struct tc_action *a, int bind)
> +{
> + struct tcf_ife_info *ife = a->priv;
> + struct tcf_meta_info *e, *n;
> +
> + list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
> + module_put(e->ops->owner);
> + list_del(&e->metalist);
> + if (e->metaval) {
> + if (e->ops->release)
> + e->ops->release(e);
> + else
> + kfree(e->metaval);
> + }
> + kfree(e);
> + }
> +}
> +
> +static void tcf_ife_cleanup(struct tc_action *a, int bind)
> +{
> + struct tcf_ife_info *ife = a->priv;
> +
> + spin_lock_bh(&ife->tcf_lock);
> + _tcf_ife_cleanup(a, bind);
> + spin_unlock_bh(&ife->tcf_lock);
> +}
> +
> +/* under ife->tcf_lock */
> +int populate_metalist(struct tcf_ife_info *ife, struct nlattr **tb)
> +{
> + int len = 0;
> + int rc = 0;
> + int i = 0;
> + void *val;
> +
> + for (i = 1; i < max_metacnt; i++) {
> + if (tb[i]) {
> + val = nla_data(tb[i]);
> + len = nla_len(tb[i]);
> +
> + rc = load_metaops_and_vet(ife, i, val, len);
> + if (rc != 0)
> + return rc;
> +
> + rc = add_metainfo(ife, i, val, len);
> + if (rc)
> + return rc;
> + }
> + }
> +
> + return rc;
> +}
> +
> +static int tcf_ife_init(struct net *net, struct nlattr *nla,
> + struct nlattr *est, struct tc_action *a,
> + int ovr, int bind)
> +{
> + struct nlattr *tb[TCA_IFE_MAX + 1];
> + struct nlattr *tb2[IFE_META_MAX + 1];
> + struct tcf_ife_info *ife;
> + struct tc_ife *parm;
> + u16 ife_type = 0;
> + u8 *daddr = NULL;
> + u8 *saddr = NULL;
> + int ret = 0;
> + int err;
> +
> + err = nla_parse_nested(tb, TCA_IFE_MAX, nla, ife_policy);
> + if (err < 0)
> + return err;
> +
> + if (tb[TCA_IFE_PARMS] == NULL)
> + return -EINVAL;
> +
> + parm = nla_data(tb[TCA_IFE_PARMS]);
> +
> + if ((parm->flags & IFE_ENCODE) && (parm->flags & IFE_DECODE)) {
> + pr_info("Ambigous: Cant have both encode and decode\n");
> + return -EINVAL;
> + }
Is it possible to fold them into one bit?
> + if (!(parm->flags & IFE_ENCODE) && !(parm->flags & IFE_DECODE)) {
> + pr_info("MUST have either encode or decode\n");
> + return -EINVAL;
> + }
> +
> + if (parm->flags & IFE_ENCODE) {
> + /* Until we get issued the ethertype, we cant have
> + * a default..
> + **/
> + if (tb[TCA_IFE_TYPE] == NULL) {
> + pr_info("You MUST pass etherype for encoding\n");
> + return -EINVAL;
> + }
> + }
> +
> + if (!tcf_hash_check(parm->index, a, bind)) {
> + ret = tcf_hash_create(parm->index, est, a, sizeof(*ife),
> + bind, false);
> + if (ret)
> + return ret;
> + ret = ACT_P_CREATED;
> + } else {
> + if (bind) /* dont override defaults */
> + return 0;
> + tcf_hash_release(a, bind);
> + if (!ovr)
> + return -EEXIST;
> + }
> +
> + ife = to_ife(a);
> + ife->flags = parm->flags;
> +
> + if (parm->flags & IFE_ENCODE) {
> + ife_type = *(u16 *) nla_data(tb[TCA_IFE_TYPE]);
> + if (tb[TCA_IFE_DMAC] != NULL)
> + daddr = nla_data(tb[TCA_IFE_DMAC]);
> + if (tb[TCA_IFE_SMAC] != NULL)
> + saddr = nla_data(tb[TCA_IFE_SMAC]);
> + }
> +
> + spin_lock_bh(&ife->tcf_lock);
> + ife->tcf_action = parm->action;
> +
> + if (parm->flags & IFE_ENCODE) {
> + if (daddr)
> + ether_addr_copy(ife->eth_dst, daddr);
> + else
> + eth_zero_addr(ife->eth_dst);
> +
> + if (saddr)
> + ether_addr_copy(ife->eth_src, saddr);
> + else
> + eth_zero_addr(ife->eth_src);
> +
> + ife->eth_type = ife_type;
> + }
> +
> + if (ret == ACT_P_CREATED)
> + INIT_LIST_HEAD(&ife->metalist);
> +
> + if (tb[TCA_IFE_METALST] != NULL) {
> + err = nla_parse_nested(tb2, IFE_META_MAX, tb[TCA_IFE_METALST],
> + NULL);
> + if (err) {
> +metadata_parse_err:
> + if (ret == ACT_P_CREATED)
> + _tcf_ife_cleanup(a, bind);
> +
> + spin_unlock_bh(&ife->tcf_lock);
> + return err;
> + }
> +
> + err = populate_metalist(ife, tb2);
> + if (err)
> + goto metadata_parse_err;
> +
> + } else {
> + /* if no passed metadata allow list or passed allow-all
> + * then here we process by adding as many supported metadatum
> + * as we can. You better have at least one else we are
> + * going to bail out
> + */
> + err = use_all_metadata(ife);
> + if (err) {
> + if (ret == ACT_P_CREATED)
> + _tcf_ife_cleanup(a, bind);
> +
> + spin_unlock_bh(&ife->tcf_lock);
> + return err;
> + }
> + }
> +
> + spin_unlock_bh(&ife->tcf_lock);
> +
> + if (ret == ACT_P_CREATED)
> + tcf_hash_insert(a);
> +
> + print_ife_oplist();
> + return ret;
> +}
> +
> +static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
> + int ref)
> +{
> + unsigned char *b = skb_tail_pointer(skb);
> + struct tcf_ife_info *ife = a->priv;
> + struct tc_ife opt = {
> + .index = ife->tcf_index,
> + .refcnt = ife->tcf_refcnt - ref,
> + .bindcnt = ife->tcf_bindcnt - bind,
> + .action = ife->tcf_action,
> + .flags = ife->flags,
> + };
> + struct tcf_t t;
> +
> + if (nla_put(skb, TCA_IFE_PARMS, sizeof(opt), &opt))
> + goto nla_put_failure;
> +
> + t.install = jiffies_to_clock_t(jiffies - ife->tcf_tm.install);
> + t.lastuse = jiffies_to_clock_t(jiffies - ife->tcf_tm.lastuse);
> + t.expires = jiffies_to_clock_t(ife->tcf_tm.expires);
> + if (nla_put(skb, TCA_IFE_TM, sizeof(t), &t))
> + goto nla_put_failure;
> +
> + if (!is_zero_ether_addr(ife->eth_dst)) {
> + if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, ife->eth_dst))
> + goto nla_put_failure;
> + }
> +
> + if (!is_zero_ether_addr(ife->eth_src)) {
> + if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, ife->eth_src))
> + goto nla_put_failure;
> + }
> +
> + if (nla_put(skb, TCA_IFE_TYPE, 2, &ife->eth_type))
> + goto nla_put_failure;
> +
> + if (dump_metalist(skb, ife)) {
> + /*ignore failure to dump metalist */
> + pr_info("Failed to dump metalist\n");
> + }
> +
> + return skb->len;
> +
> +nla_put_failure:
> + nlmsg_trim(skb, b);
> + return -1;
> +}
> +
> +int find_decode_metaid(struct sk_buff *skb, struct tcf_ife_info *ife,
> + u16 metaid, u16 mlen, void *mdata)
> +{
> + struct tcf_meta_info *e;
> +
> + /* XXX: use hash to speed up */
> + list_for_each_entry(e, &ife->metalist, metalist) {
> + if (metaid == e->metaid) {
> + if (e->ops) {
> + /* We check for decode presence already */
> + return e->ops->decode(skb, mdata, mlen);
> + }
> + }
> + }
> +
> + return 0;
> +}
> +
> +struct ifeheadr {
> + __be16 metalen;
> + u8 tlv_data[];
> +};
> +
> +struct meta_tlvhdr {
> + __be16 type;
> + __be16 len;
> +};
> +
> +static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
> + struct tcf_result *res)
> +{
> + struct tcf_ife_info *ife = a->priv;
> + int action = ife->tcf_action;
> + struct ifeheadr *ifehdr = (struct ifeheadr *)skb->data;
> + u16 ifehdrln = ifehdr->metalen;
> + struct meta_tlvhdr *tlv = (struct meta_tlvhdr *)(ifehdr->tlv_data);
> +
> + spin_lock(&ife->tcf_lock);
> + bstats_update(&ife->tcf_bstats, skb);
> + ife->tcf_tm.lastuse = jiffies;
> + spin_unlock(&ife->tcf_lock);
> +
> + ifehdrln = ntohs(ifehdrln);
> + if (unlikely(!pskb_may_pull(skb, ifehdrln))) {
> + spin_lock(&ife->tcf_lock);
> + ife->tcf_qstats.drops++;
> + spin_unlock(&ife->tcf_lock);
> + return TC_ACT_SHOT;
> + }
> +
> + skb_set_mac_header(skb, ifehdrln);
> + __skb_pull(skb, ifehdrln);
> + skb->protocol = eth_type_trans(skb, skb->dev);
> + ifehdrln -= IFE_METAHDRLEN;
> +
> + while (ifehdrln > 0) {
> + u8 *tlvdata = (u8 *) tlv;
> + u16 mtype = tlv->type;
> + u16 mlen = tlv->len;
> + mtype = ntohs(mtype);
> + mlen = ntohs(mlen);
> +
> + if (find_decode_metaid(skb, ife, mtype, (mlen - 4),
> + (void *)(tlvdata + 4))) {
> + /* abuse overlimits to count when we receive metadata
> + * but dont have an ops for it
> + */
> + if (net_ratelimit())
> + printk("Unknown incoming metaid %d alnlen %d\n",
> + mtype, mlen);
pr_info_ratelimited().
> + ife->tcf_qstats.overlimits++;
> + }
> +
> + tlvdata += mlen;
> + ifehdrln -= mlen;
> + tlv = (struct meta_tlvhdr *)tlvdata;
> + }
> +
> + skb_reset_network_header(skb);
> + return action;
> +}
> +
> +/*XXX: check if we can do this at install time instead of current
> + * send data path
> +**/
> +static int ife_get_sz(struct sk_buff *skb, struct tcf_ife_info *ife)
> +{
> + struct tcf_meta_info *e, *n;
> + int tot_run_sz = 0, run_sz = 0;
> +
> + list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
> + if (e->ops->check_presence) {
> + run_sz = e->ops->check_presence(skb, e);
> + tot_run_sz += run_sz;
> + }
> + }
> +
> + return tot_run_sz;
> +}
> +
> +static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
> + struct tcf_result *res)
> +{
> + struct tcf_ife_info *ife = a->priv;
> + int action = ife->tcf_action;
> + struct ethhdr *oethh; /* outer ether header */
> + struct ethhdr *iethh; /* inner eth header */
> + struct tcf_meta_info *e;
> + /*
> + OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
> + where ORIGDATA = original ethernet header ...
> + */
> + u16 metalen = ife_get_sz(skb, ife);
> + int hdrm = metalen + skb->dev->hard_header_len + IFE_METAHDRLEN;
> + unsigned int skboff = skb->dev->hard_header_len;
> + u32 at = G_TC_AT(skb->tc_verd);
> + int new_len = skb->len + hdrm;
> + int exceed_mtu = 0;
> + int err;
> +
> + if (at & AT_EGRESS) {
> + if (new_len > skb->dev->mtu) {
> + exceed_mtu = 1;
> + }
> + }
> +
> + spin_lock(&ife->tcf_lock);
> + bstats_update(&ife->tcf_bstats, skb);
> + ife->tcf_tm.lastuse = jiffies;
> +
> + if (!metalen) { /* no metadata to send */
> + spin_unlock(&ife->tcf_lock);
> + /* abuse overlimits to count when we allow packet
> + * with no metadata
> + */
> + ife->tcf_qstats.overlimits++;
> + return action;
> + }
> + /* could be stupid policy setup or mtu config
> + * so lets be conservative.. */
> + if ((action == TC_ACT_SHOT) || exceed_mtu) {
> + ife->tcf_qstats.drops++;
> + spin_unlock(&ife->tcf_lock);
> + return TC_ACT_SHOT;
> + }
> +
> + iethh = eth_hdr(skb);
> +
> + err = skb_cow_head(skb, hdrm);
> + if (unlikely(err)) {
> + ife->tcf_qstats.drops++;
> + spin_unlock(&ife->tcf_lock);
> + return TC_ACT_SHOT;
> + }
> +
> + if (!(at & AT_EGRESS)) {
> + skb_push(skb, skb->dev->hard_header_len);
> + }
> +
> + __skb_push(skb, hdrm);
> + memcpy(skb->data, iethh, skb->mac_len);
> + skb_reset_mac_header(skb);
> + oethh = eth_hdr(skb);
> +
> + /*total metadata length */
> + metalen += IFE_METAHDRLEN;
> + metalen = htons(metalen);
> + memcpy((void *)(skb->data + skboff), &metalen, IFE_METAHDRLEN);
> + skboff += IFE_METAHDRLEN;
> +
> + /*XXX: we dont have a clever way of telling encode to
> + * not repeat some of the computations that are done by
> + * ops->presence_check...
> + */
> + list_for_each_entry(e, &ife->metalist, metalist) {
> + if (e->ops->encode) {
> + err = e->ops->encode(skb, (void *)(skb->data + skboff),
> + e);
> + }
> + if (err < 0) {
> + /* too corrupt to keep around if overwritten */
> + ife->tcf_qstats.drops++;
> + spin_unlock(&ife->tcf_lock);
> + return TC_ACT_SHOT;
> + }
> + skboff += err;
> + }
> +
> + if (!is_zero_ether_addr(ife->eth_src))
> + ether_addr_copy(oethh->h_source, ife->eth_src);
> + else
> + ether_addr_copy(oethh->h_source, iethh->h_source);
> + if (!is_zero_ether_addr(ife->eth_dst))
> + ether_addr_copy(oethh->h_dest, ife->eth_dst);
> + else
> + ether_addr_copy(oethh->h_dest, iethh->h_dest);
> + oethh->h_proto = htons(ife->eth_type);
> +
> + if (!(at & AT_EGRESS)) {
> + skb_pull(skb, skb->dev->hard_header_len);
> + }
> +
> + spin_unlock(&ife->tcf_lock);
> +
> + return action;
> +}
> +
> +static int tcf_ife(struct sk_buff *skb, const struct tc_action *a,
> + struct tcf_result *res)
> +{
> + struct tcf_ife_info *ife = a->priv;
> +
> + if (ife->flags & IFE_ENCODE) {
> + return tcf_ife_encode(skb, a, res);
> + }
> +
> + if (ife->flags & IFE_DECODE) {
> + return tcf_ife_decode(skb, a, res);
> + }
> +
> + pr_info("unknown failure(policy neither de/encode\n");
> + spin_lock(&ife->tcf_lock);
> + bstats_update(&ife->tcf_bstats, skb);
> + ife->tcf_tm.lastuse = jiffies;
> + ife->tcf_qstats.drops++;
> + spin_unlock(&ife->tcf_lock);
> +
> + return TC_ACT_SHOT;
> +}
> +
> +static struct tc_action_ops act_ife_ops = {
> + .kind = "ife",
> + .type = TCA_ACT_IFE,
> + .owner = THIS_MODULE,
> + .act = tcf_ife,
> + .dump = tcf_ife_dump,
> + .cleanup = tcf_ife_cleanup,
> + .init = tcf_ife_init,
> +};
> +
> +static int __init ife_init_module(void)
> +{
> + pr_info("Loaded IFE maximum metaid %d\n", max_metacnt);
Not needed, people can use lsmod to figure it out.
> + INIT_LIST_HEAD(&ifeoplist);
It is already initialized statically.
> + return tcf_register_action(&act_ife_ops, IFE_TAB_MASK);
> +}
> +
> +static void __exit ife_cleanup_module(void)
> +{
> + pr_info("Unloaded IFE\n");
Ditto, not needed.
> + tcf_unregister_action(&act_ife_ops);
> +}
> +
> +module_init(ife_init_module);
> +module_exit(ife_cleanup_module);
> +
> +module_param(max_metacnt, int, 0);
I am sure DaveM doesn't like this.
> +MODULE_AUTHOR("Jamal Hadi Salim(2015)");
> +MODULE_DESCRIPTION("Inter-FE LFB action");
> +MODULE_LICENSE("GPL");
> +MODULE_PARM_DESC(max_metacnt, "Upper bound of metadata id");
Thanks.
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