Subject: Re: [PATCH net-next v8 10/15] p4tc: add action template create, update, delete, get, flush and dump

From: Jiri Pirko <[email-masked]>
Date: Mon, 20 Nov 2023 09:19:41 +0100

Fri, Nov 17, 2023 at 04:11:29PM CET, [email-masked] wrote:
>On Thu, Nov 16, 2023 at 11:28 AM Jiri Pirko <[email-masked]> wrote:
>>
>> Thu, Nov 16, 2023 at 03:59:43PM CET, [email-masked] wrote:
>>
>> [...]
>>
>>
>> >diff --git a/include/net/act_api.h b/include/net/act_api.h
>> >index cd5a8e86f..b95a9bc29 100644
>> >--- a/include/net/act_api.h
>> >+++ b/include/net/act_api.h
>> >@@ -70,6 +70,7 @@ struct tc_action {
>> > #define TCA_ACT_FLAGS_AT_INGRESS      (1U << (TCA_ACT_FLAGS_USER_BITS + 4))
>> > #define TCA_ACT_FLAGS_PREALLOC        (1U << (TCA_ACT_FLAGS_USER_BITS + 5))
>> > #define TCA_ACT_FLAGS_UNREFERENCED    (1U << (TCA_ACT_FLAGS_USER_BITS + 6))
>> >+#define TCA_ACT_FLAGS_FROM_P4TC       (1U << (TCA_ACT_FLAGS_USER_BITS + 7))
>> >
>> > /* Update lastuse only if needed, to avoid dirtying a cache line.
>> >  * We use a temp variable to avoid fetching jiffies twice.
>> >diff --git a/include/net/p4tc.h b/include/net/p4tc.h
>> >index ccb54d842..68b00fa72 100644
>> >--- a/include/net/p4tc.h
>> >+++ b/include/net/p4tc.h
>> >@@ -9,17 +9,23 @@
>> > #include <linux/refcount.h>
>> > #include <linux/rhashtable.h>
>> > #include <linux/rhashtable-types.h>
>> >+#include <net/tc_act/p4tc.h>
>> >+#include <net/p4tc_types.h>
>> >
>> > #define P4TC_DEFAULT_NUM_TABLES P4TC_MINTABLES_COUNT
>> > #define P4TC_DEFAULT_MAX_RULES 1
>> > #define P4TC_PATH_MAX 3
>> >+#define P4TC_MAX_TENTRIES 33554432
>>
>> Seeing define like this one always makes me happier. Where does it come
>> from? Why not 0x2000000 at least?
>
>I dont recall why we decided to do decimal - will change it.
>
>>
>> >
>> > #define P4TC_KERNEL_PIPEID 0
>> >
>> > #define P4TC_PID_IDX 0
>> >+#define P4TC_AID_IDX 1
>> >+#define P4TC_PARSEID_IDX 1
>> >
>> > struct p4tc_dump_ctx {
>> >       u32 ids[P4TC_PATH_MAX];
>> >+      struct rhashtable_iter *iter;
>> > };
>> >
>> > struct p4tc_template_common;
>> >@@ -63,8 +69,10 @@ extern const struct p4tc_template_ops p4tc_pipeline_ops;
>> >
>> > struct p4tc_pipeline {
>> >       struct p4tc_template_common common;
>> >+      struct idr                  p_act_idr;
>> >       struct rcu_head             rcu;
>> >       struct net                  *net;
>> >+      u32                         num_created_acts;
>> >       /* Accounts for how many entities are referencing this pipeline.
>> >        * As for now only P4 filters can refer to pipelines.
>> >        */
>> >@@ -109,18 +117,157 @@ p4tc_pipeline_find_byany_unsealed(struct net *net, const char *p_name,
>> >                                 const u32 pipeid,
>> >                                 struct netlink_ext_ack *extack);
>> >
>> >+struct p4tc_act *tcf_p4_find_act(struct net *net,
>> >+                               const struct tc_action_ops *a_o,
>> >+                               struct netlink_ext_ack *extack);
>> >+void
>> >+tcf_p4_put_prealloc_act(struct p4tc_act *act, struct tcf_p4act *p4_act);
>> >+
>> > static inline int p4tc_action_destroy(struct tc_action **acts)
>> > {
>> >+      struct tc_action *acts_non_prealloc[TCA_ACT_MAX_PRIO] = {NULL};
>> >       int ret = 0;
>> >
>> >       if (acts) {
>> >-              ret = tcf_action_destroy(acts, TCA_ACT_UNBIND);
>> >+              int j = 0;
>> >+              int i;
>>
>> Move declarations to the beginning of the if body.
>>
>
>Didnt follow - which specific declaration?

It should look like this:

		int j = 0;
		int i;

		ret = tcf_action_destroy(acts, TCA_ACT_UNBIND);

>
>> [...]
>>
>>
>> >diff --git a/include/uapi/linux/p4tc.h b/include/uapi/linux/p4tc.h
>> >index 4d33f44c1..7b89229a7 100644
>> >--- a/include/uapi/linux/p4tc.h
>> >+++ b/include/uapi/linux/p4tc.h
>> >@@ -4,6 +4,7 @@
>> >
>> > #include <linux/types.h>
>> > #include <linux/pkt_sched.h>
>> >+#include <linux/pkt_cls.h>
>> >
>> > /* pipeline header */
>> > struct p4tcmsg {
>> >@@ -17,9 +18,12 @@ struct p4tcmsg {
>> > #define P4TC_MSGBATCH_SIZE 16
>> >
>> > #define P4TC_MAX_KEYSZ 512
>> >+#define P4TC_DEFAULT_NUM_PREALLOC 16
>> >
>> > #define TEMPLATENAMSZ 32
>> > #define PIPELINENAMSIZ TEMPLATENAMSZ
>> >+#define ACTTMPLNAMSIZ TEMPLATENAMSZ
>> >+#define ACTPARAMNAMSIZ TEMPLATENAMSZ
>>
>> Prefix? This is uapi. Could you please be more careful with naming at
>> least in the uapi area?
>
>Good point.
>
>>
>> [...]
>>
>>
>> >diff --git a/net/sched/p4tc/p4tc_action.c b/net/sched/p4tc/p4tc_action.c
>> >new file mode 100644
>> >index 000000000..19db0772c
>> >--- /dev/null
>> >+++ b/net/sched/p4tc/p4tc_action.c
>> >@@ -0,0 +1,2242 @@
>> >+// SPDX-License-Identifier: GPL-2.0-or-later
>> >+/*
>> >+ * net/sched/p4tc_action.c    P4 TC ACTION TEMPLATES
>> >+ *
>> >+ * Copyright (c) 2022-2023, Mojatatu Networks
>> >+ * Copyright (c) 2022-2023, Intel Corporation.
>> >+ * Authors:     Jamal Hadi Salim <[email-masked]>
>> >+ *              Victor Nogueira <[email-masked]>
>> >+ *              Pedro Tammela <[email-masked]>
>> >+ */
>> >+
>> >+#include <linux/err.h>
>> >+#include <linux/errno.h>
>> >+#include <linux/init.h>
>> >+#include <linux/kernel.h>
>> >+#include <linux/kmod.h>
>> >+#include <linux/list.h>
>> >+#include <linux/module.h>
>> >+#include <linux/netdevice.h>
>> >+#include <linux/skbuff.h>
>> >+#include <linux/slab.h>
>> >+#include <linux/string.h>
>> >+#include <linux/types.h>
>> >+#include <net/flow_offload.h>
>> >+#include <net/net_namespace.h>
>> >+#include <net/netlink.h>
>> >+#include <net/pkt_cls.h>
>> >+#include <net/p4tc.h>
>> >+#include <net/sch_generic.h>
>> >+#include <net/sock.h>
>> >+#include <net/tc_act/p4tc.h>
>> >+
>> >+static LIST_HEAD(dynact_list);
>> >+
>> >+#define SEPARATOR "/"
>>
>> Prefix? Btw, why exactly do you need this. It is used only once.
>>
>
>We'll get rid of it.
>
>> To quote a few function names in this file:
>>
>> >+static void set_param_indices(struct idr *params_idr)
>> >+static void generic_free_param_value(struct p4tc_act_param *param)
>> >+static int dev_init_param_value(struct net *net, struct p4tc_act_param_ops *op,
>> >+static void dev_free_param_value(struct p4tc_act_param *param)
>> >+static void tcf_p4_act_params_destroy_rcu(struct rcu_head *head)
>> >+static int __tcf_p4_dyna_init_set(struct p4tc_act *act, struct tc_action **a,
>> >+static int tcf_p4_dyna_template_init(struct net *net, struct tc_action **a,
>> >+init_prealloc_param(struct p4tc_act *act, struct idr *params_idr,
>> >+static void p4tc_param_put(struct p4tc_act_param *param)
>> >+static void free_intermediate_param(struct p4tc_act_param *param)
>> >+static void free_intermediate_params_list(struct list_head *params_list)
>> >+static int init_prealloc_params(struct p4tc_act *act,
>> >+struct p4tc_act *p4tc_action_find_byid(struct p4tc_pipeline *pipeline,
>> >+static void tcf_p4_prealloc_list_add(struct p4tc_act *act_tmpl,
>> >+static int tcf_p4_prealloc_acts(struct net *net, struct p4tc_act *act,
>> >+tcf_p4_get_next_prealloc_act(struct p4tc_act *act)
>> >+void tcf_p4_set_init_flags(struct tcf_p4act *p4act)
>> >+static void __tcf_p4_put_prealloc_act(struct p4tc_act *act,
>> >+tcf_p4_put_prealloc_act(struct p4tc_act *act, struct tcf_p4act *p4act)
>> >+static int generic_dump_param_value(struct sk_buff *skb, struct p4tc_type *type,
>> >+static int generic_init_param_value(struct p4tc_act_param *nparam,
>> >+static struct p4tc_act_param *param_find_byname(struct idr *params_idr,
>> >+tcf_param_find_byany(struct p4tc_act *act,
>> >+tcf_param_find_byanyattr(struct p4tc_act *act, struct nlattr *name_attr,
>> >+static int __p4_init_param_type(struct p4tc_act_param *param,
>> >+static int tcf_p4_act_init_params(struct net *net,
>> >+static struct p4tc_act *p4tc_action_find_byname(const char *act_name,
>> >+static int tcf_p4_dyna_init(struct net *net, struct nlattr *nla,
>> >+static int tcf_act_fill_param_type(struct sk_buff *skb,
>> >+static void tcf_p4_dyna_cleanup(struct tc_action *a)
>> >+struct p4tc_act *p4tc_action_find_get(struct p4tc_pipeline *pipeline,
>> >+p4tc_action_find_byanyattr(struct nlattr *act_name_attr, const u32 a_id,
>> >+static void p4_put_many_params(struct idr *params_idr)
>> >+static int p4_init_param_type(struct p4tc_act_param *param,
>> >+static struct p4tc_act_param *p4_create_param(struct p4tc_act *act,
>> >+static struct p4tc_act_param *p4_update_param(struct p4tc_act *act,
>> >+static struct p4tc_act_param *p4_act_init_param(struct p4tc_act *act,
>> >+static void p4tc_action_net_exit(struct tc_action_net *tn)
>> >+static void p4_act_params_put(struct p4tc_act *act)
>> >+static int __tcf_act_put(struct net *net, struct p4tc_pipeline *pipeline,
>> >+static int _tcf_act_fill_nlmsg(struct net *net, struct sk_buff *skb,
>> >+static int tcf_act_fill_nlmsg(struct net *net, struct sk_buff *skb,
>> >+static int tcf_act_flush(struct sk_buff *skb, struct net *net,
>> >+static void p4tc_params_replace_many(struct p4tc_act *act,
>> >+                                   struct idr *params_idr)
>> >+static struct p4tc_act *tcf_act_create(struct net *net, struct nlattr **tb,
>> >+tcf_act_cu(struct net *net, struct nlmsghdr *n, struct nlattr *nla,
>>
>> Is there some secret key how you name the functions? To me, this looks
>> completely inconsistent :/
>
>What would be better? tcf_p4_xxxx?

Idk, up to you, just please maintain some basic naming consistency and
prefixes.

>A lot of the tcf_xxx is because that convention is used in that file
>but we can change it.
>
>cheers,
>jamal
>>