tcx.h

  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(sizeof(*tcx), GFP_KERNEL);
 80
 81	if (tcx) {
 82		bpf_mprog_bundle_init(&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, true);
175	tcx_uninstall(dev, 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 */