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 u32 miniq_active;
17 struct rcu_head rcu;
18};
19
20struct tcx_link {
21 struct bpf_link link;
22 struct net_device *dev;
23};
24
25static inline void tcx_set_ingress(struct sk_buff *skb, bool ingress)
26{
27#ifdef CONFIG_NET_XGRESS
28 skb->tc_at_ingress = ingress;
29#endif
30}
31
32#ifdef CONFIG_NET_XGRESS
33static inline struct tcx_entry *tcx_entry(struct bpf_mprog_entry *entry)
34{
35 struct bpf_mprog_bundle *bundle = entry->parent;
36
37 return container_of(bundle, struct tcx_entry, bundle);
38}
39
40static inline struct tcx_link *tcx_link(const struct bpf_link *link)
41{
42 return container_of(link, struct tcx_link, link);
43}
44
45void tcx_inc(void);
46void tcx_dec(void);
47
48static inline void tcx_entry_sync(void)
49{
50 /* bpf_mprog_entry got a/b swapped, therefore ensure that
51 * there are no inflight users on the old one anymore.
52 */
53 synchronize_rcu();
54}
55
56static inline void
57tcx_entry_update(struct net_device *dev, struct bpf_mprog_entry *entry,
58 bool ingress)
59{
60 ASSERT_RTNL();
61 if (ingress)
62 rcu_assign_pointer(dev->tcx_ingress, entry);
63 else
64 rcu_assign_pointer(dev->tcx_egress, entry);
65}
66
67static inline struct bpf_mprog_entry *
68tcx_entry_fetch(struct net_device *dev, bool ingress)
69{
70 ASSERT_RTNL();
71 if (ingress)
72 return rcu_dereference_rtnl(dev->tcx_ingress);
73 else
74 return rcu_dereference_rtnl(dev->tcx_egress);
75}
76
77static inline struct bpf_mprog_entry *tcx_entry_create_noprof(void)
78{
79 struct tcx_entry *tcx = kzalloc_noprof(size: sizeof(*tcx), GFP_KERNEL);
80
81 if (tcx) {
82 bpf_mprog_bundle_init(bundle: &tcx->bundle);
83 return &tcx->bundle.a;
84 }
85 return NULL;
86}
87#define tcx_entry_create(...) alloc_hooks(tcx_entry_create_noprof(__VA_ARGS__))
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_inc(struct bpf_mprog_entry *entry)
128{
129 ASSERT_RTNL();
130 tcx_entry(entry)->miniq_active++;
131}
132
133static inline void tcx_miniq_dec(struct bpf_mprog_entry *entry)
134{
135 ASSERT_RTNL();
136 tcx_entry(entry)->miniq_active--;
137}
138
139static inline bool tcx_entry_is_active(struct bpf_mprog_entry *entry)
140{
141 ASSERT_RTNL();
142 return bpf_mprog_total(entry) || tcx_entry(entry)->miniq_active;
143}
144
145static inline enum tcx_action_base tcx_action_code(struct sk_buff *skb,
146 int code)
147{
148 switch (code) {
149 case TCX_PASS:
150 skb->tc_index = qdisc_skb_cb(skb)->tc_classid;
151 fallthrough;
152 case TCX_DROP:
153 case TCX_REDIRECT:
154 return code;
155 case TCX_NEXT:
156 default:
157 return TCX_NEXT;
158 }
159}
160#endif /* CONFIG_NET_XGRESS */
161
162#if defined(CONFIG_NET_XGRESS) && defined(CONFIG_BPF_SYSCALL)
163int tcx_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog);
164int tcx_link_attach(const union bpf_attr *attr, struct bpf_prog *prog);
165int tcx_prog_detach(const union bpf_attr *attr, struct bpf_prog *prog);
166void tcx_uninstall(struct net_device *dev, bool ingress);
167
168int tcx_prog_query(const union bpf_attr *attr,
169 union bpf_attr __user *uattr);
170
171static inline void dev_tcx_uninstall(struct net_device *dev)
172{
173 ASSERT_RTNL();
174 tcx_uninstall(dev, ingress: true);
175 tcx_uninstall(dev, ingress: false);
176}
177#else
178static inline int tcx_prog_attach(const union bpf_attr *attr,
179 struct bpf_prog *prog)
180{
181 return -EINVAL;
182}
183
184static inline int tcx_link_attach(const union bpf_attr *attr,
185 struct bpf_prog *prog)
186{
187 return -EINVAL;
188}
189
190static inline int tcx_prog_detach(const union bpf_attr *attr,
191 struct bpf_prog *prog)
192{
193 return -EINVAL;
194}
195
196static inline int tcx_prog_query(const union bpf_attr *attr,
197 union bpf_attr __user *uattr)
198{
199 return -EINVAL;
200}
201
202static inline void dev_tcx_uninstall(struct net_device *dev)
203{
204}
205#endif /* CONFIG_NET_XGRESS && CONFIG_BPF_SYSCALL */
206#endif /* __NET_TCX_H */
207

source code of linux/include/net/tcx.h