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 */
202