1/* SPDX-License-Identifier: GPL-2.0 */
  2/* Copyright (c) 2023 Isovalent */
  3#ifndef __NET_TCX_H
  4#define __NET_TCX_H
  5
  6#include <linux/bpf.h>
  7#include <linux/bpf_mprog.h>
  8
  9#include <net/sch_generic.h>
 10
 11struct mini_Qdisc;
 12
 13struct tcx_entry {
 14	struct mini_Qdisc __rcu *miniq;
 15	struct bpf_mprog_bundle bundle;
 16	bool miniq_active;
 17	struct rcu_head rcu;
 18};
 19
 20struct tcx_link {
 21	struct bpf_link link;
 22	struct net_device *dev;
 23	u32 location;
 24};
 25
 26static inline void tcx_set_ingress(struct sk_buff *skb, bool ingress)
 27{
 28#ifdef CONFIG_NET_XGRESS
 29	skb->tc_at_ingress = ingress;
 30#endif
 31}
 32
 33#ifdef CONFIG_NET_XGRESS
 34static inline struct tcx_entry *tcx_entry(struct bpf_mprog_entry *entry)
 35{
 36	struct bpf_mprog_bundle *bundle = entry->parent;
 37
 38	return container_of(bundle, struct tcx_entry, bundle);
 39}
 40
 41static inline struct tcx_link *tcx_link(const struct bpf_link *link)
 42{
 43	return container_of(link, struct tcx_link, link);
 44}
 45
 46void tcx_inc(void);
 47void tcx_dec(void);
 48
 49static inline void tcx_entry_sync(void)
 50{
 51	/* bpf_mprog_entry got a/b swapped, therefore ensure that
 52	 * there are no inflight users on the old one anymore.
 53	 */
 54	synchronize_rcu();
 55}
 56
 57static inline void
 58tcx_entry_update(struct net_device *dev, struct bpf_mprog_entry *entry,
 59		 bool ingress)
 60{
 61	ASSERT_RTNL();
 62	if (ingress)
 63		rcu_assign_pointer(dev->tcx_ingress, entry);
 64	else
 65		rcu_assign_pointer(dev->tcx_egress, entry);
 66}
 67
 68static inline struct bpf_mprog_entry *
 69tcx_entry_fetch(struct net_device *dev, bool ingress)
 70{
 71	ASSERT_RTNL();
 72	if (ingress)
 73		return rcu_dereference_rtnl(dev->tcx_ingress);
 74	else
 75		return rcu_dereference_rtnl(dev->tcx_egress);
 76}
 77
 78static inline struct bpf_mprog_entry *tcx_entry_create(void)
 79{
 80	struct tcx_entry *tcx = kzalloc(sizeof(*tcx), GFP_KERNEL);
 81
 82	if (tcx) {
 83		bpf_mprog_bundle_init(&tcx->bundle);
 84		return &tcx->bundle.a;
 85	}
 86	return NULL;
 87}
 88
 89static inline void tcx_entry_free(struct bpf_mprog_entry *entry)
 90{
 91	kfree_rcu(tcx_entry(entry), rcu);
 92}
 93
 94static inline struct bpf_mprog_entry *
 95tcx_entry_fetch_or_create(struct net_device *dev, bool ingress, bool *created)
 96{
 97	struct bpf_mprog_entry *entry = tcx_entry_fetch(dev, ingress);
 98
 99	*created = false;
100	if (!entry) {
101		entry = tcx_entry_create();
102		if (!entry)
103			return NULL;
104		*created = true;
105	}
106	return entry;
107}
108
109static inline void tcx_skeys_inc(bool ingress)
110{
111	tcx_inc();
112	if (ingress)
113		net_inc_ingress_queue();
114	else
115		net_inc_egress_queue();
116}
117
118static inline void tcx_skeys_dec(bool ingress)
119{
120	if (ingress)
121		net_dec_ingress_queue();
122	else
123		net_dec_egress_queue();
124	tcx_dec();
125}
126
127static inline void tcx_miniq_set_active(struct bpf_mprog_entry *entry,
128					const bool active)
129{
130	ASSERT_RTNL();
131	tcx_entry(entry)->miniq_active = active;
132}
133
134static inline bool tcx_entry_is_active(struct bpf_mprog_entry *entry)
135{
136	ASSERT_RTNL();
137	return bpf_mprog_total(entry) || tcx_entry(entry)->miniq_active;
138}
139
140static inline enum tcx_action_base tcx_action_code(struct sk_buff *skb,
141						   int code)
142{
143	switch (code) {
144	case TCX_PASS:
145		skb->tc_index = qdisc_skb_cb(skb)->tc_classid;
146		fallthrough;
147	case TCX_DROP:
148	case TCX_REDIRECT:
149		return code;
150	case TCX_NEXT:
151	default:
152		return TCX_NEXT;
153	}
154}
155#endif /* CONFIG_NET_XGRESS */
156
157#if defined(CONFIG_NET_XGRESS) && defined(CONFIG_BPF_SYSCALL)
158int tcx_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog);
159int tcx_link_attach(const union bpf_attr *attr, struct bpf_prog *prog);
160int tcx_prog_detach(const union bpf_attr *attr, struct bpf_prog *prog);
161void tcx_uninstall(struct net_device *dev, bool ingress);
162
163int tcx_prog_query(const union bpf_attr *attr,
164		   union bpf_attr __user *uattr);
165
166static inline void dev_tcx_uninstall(struct net_device *dev)
167{
168	ASSERT_RTNL();
169	tcx_uninstall(dev, true);
170	tcx_uninstall(dev, false);
171}
172#else
173static inline int tcx_prog_attach(const union bpf_attr *attr,
174				  struct bpf_prog *prog)
175{
176	return -EINVAL;
177}
178
179static inline int tcx_link_attach(const union bpf_attr *attr,
180				  struct bpf_prog *prog)
181{
182	return -EINVAL;
183}
184
185static inline int tcx_prog_detach(const union bpf_attr *attr,
186				  struct bpf_prog *prog)
187{
188	return -EINVAL;
189}
190
191static inline int tcx_prog_query(const union bpf_attr *attr,
192				 union bpf_attr __user *uattr)
193{
194	return -EINVAL;
195}
196
197static inline void dev_tcx_uninstall(struct net_device *dev)
198{
199}
200#endif /* CONFIG_NET_XGRESS && CONFIG_BPF_SYSCALL */
201#endif /* __NET_TCX_H */