xref: /openbmc/linux/include/net/tcx.h (revision d5a9588c)
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 
11 struct mini_Qdisc;
12 
13 struct 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 
20 struct tcx_link {
21 	struct bpf_link link;
22 	struct net_device *dev;
23 	u32 location;
24 };
25 
26 static 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
34 static 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 
41 static inline struct tcx_link *tcx_link(struct bpf_link *link)
42 {
43 	return container_of(link, struct tcx_link, link);
44 }
45 
46 static inline const struct tcx_link *tcx_link_const(const struct bpf_link *link)
47 {
48 	return tcx_link((struct bpf_link *)link);
49 }
50 
51 void tcx_inc(void);
52 void tcx_dec(void);
53 
54 static inline void tcx_entry_sync(void)
55 {
56 	/* bpf_mprog_entry got a/b swapped, therefore ensure that
57 	 * there are no inflight users on the old one anymore.
58 	 */
59 	synchronize_rcu();
60 }
61 
62 static inline void
63 tcx_entry_update(struct net_device *dev, struct bpf_mprog_entry *entry,
64 		 bool ingress)
65 {
66 	ASSERT_RTNL();
67 	if (ingress)
68 		rcu_assign_pointer(dev->tcx_ingress, entry);
69 	else
70 		rcu_assign_pointer(dev->tcx_egress, entry);
71 }
72 
73 static inline struct bpf_mprog_entry *
74 tcx_entry_fetch(struct net_device *dev, bool ingress)
75 {
76 	ASSERT_RTNL();
77 	if (ingress)
78 		return rcu_dereference_rtnl(dev->tcx_ingress);
79 	else
80 		return rcu_dereference_rtnl(dev->tcx_egress);
81 }
82 
83 static inline struct bpf_mprog_entry *tcx_entry_create(void)
84 {
85 	struct tcx_entry *tcx = kzalloc(sizeof(*tcx), GFP_KERNEL);
86 
87 	if (tcx) {
88 		bpf_mprog_bundle_init(&tcx->bundle);
89 		return &tcx->bundle.a;
90 	}
91 	return NULL;
92 }
93 
94 static inline void tcx_entry_free(struct bpf_mprog_entry *entry)
95 {
96 	kfree_rcu(tcx_entry(entry), rcu);
97 }
98 
99 static inline struct bpf_mprog_entry *
100 tcx_entry_fetch_or_create(struct net_device *dev, bool ingress, bool *created)
101 {
102 	struct bpf_mprog_entry *entry = tcx_entry_fetch(dev, ingress);
103 
104 	*created = false;
105 	if (!entry) {
106 		entry = tcx_entry_create();
107 		if (!entry)
108 			return NULL;
109 		*created = true;
110 	}
111 	return entry;
112 }
113 
114 static inline void tcx_skeys_inc(bool ingress)
115 {
116 	tcx_inc();
117 	if (ingress)
118 		net_inc_ingress_queue();
119 	else
120 		net_inc_egress_queue();
121 }
122 
123 static inline void tcx_skeys_dec(bool ingress)
124 {
125 	if (ingress)
126 		net_dec_ingress_queue();
127 	else
128 		net_dec_egress_queue();
129 	tcx_dec();
130 }
131 
132 static inline void tcx_miniq_inc(struct bpf_mprog_entry *entry)
133 {
134 	ASSERT_RTNL();
135 	tcx_entry(entry)->miniq_active++;
136 }
137 
138 static inline void tcx_miniq_dec(struct bpf_mprog_entry *entry)
139 {
140 	ASSERT_RTNL();
141 	tcx_entry(entry)->miniq_active--;
142 }
143 
144 static inline bool tcx_entry_is_active(struct bpf_mprog_entry *entry)
145 {
146 	ASSERT_RTNL();
147 	return bpf_mprog_total(entry) || tcx_entry(entry)->miniq_active;
148 }
149 
150 static inline enum tcx_action_base tcx_action_code(struct sk_buff *skb,
151 						   int code)
152 {
153 	switch (code) {
154 	case TCX_PASS:
155 		skb->tc_index = qdisc_skb_cb(skb)->tc_classid;
156 		fallthrough;
157 	case TCX_DROP:
158 	case TCX_REDIRECT:
159 		return code;
160 	case TCX_NEXT:
161 	default:
162 		return TCX_NEXT;
163 	}
164 }
165 #endif /* CONFIG_NET_XGRESS */
166 
167 #if defined(CONFIG_NET_XGRESS) && defined(CONFIG_BPF_SYSCALL)
168 int tcx_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog);
169 int tcx_link_attach(const union bpf_attr *attr, struct bpf_prog *prog);
170 int tcx_prog_detach(const union bpf_attr *attr, struct bpf_prog *prog);
171 void tcx_uninstall(struct net_device *dev, bool ingress);
172 
173 int tcx_prog_query(const union bpf_attr *attr,
174 		   union bpf_attr __user *uattr);
175 
176 static inline void dev_tcx_uninstall(struct net_device *dev)
177 {
178 	ASSERT_RTNL();
179 	tcx_uninstall(dev, true);
180 	tcx_uninstall(dev, false);
181 }
182 #else
183 static inline int tcx_prog_attach(const union bpf_attr *attr,
184 				  struct bpf_prog *prog)
185 {
186 	return -EINVAL;
187 }
188 
189 static inline int tcx_link_attach(const union bpf_attr *attr,
190 				  struct bpf_prog *prog)
191 {
192 	return -EINVAL;
193 }
194 
195 static inline int tcx_prog_detach(const union bpf_attr *attr,
196 				  struct bpf_prog *prog)
197 {
198 	return -EINVAL;
199 }
200 
201 static inline int tcx_prog_query(const union bpf_attr *attr,
202 				 union bpf_attr __user *uattr)
203 {
204 	return -EINVAL;
205 }
206 
207 static inline void dev_tcx_uninstall(struct net_device *dev)
208 {
209 }
210 #endif /* CONFIG_NET_XGRESS && CONFIG_BPF_SYSCALL */
211 #endif /* __NET_TCX_H */
212