xref: /openbmc/linux/include/net/tcx.h (revision 30ff01ee)
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 	bool 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_set_active(struct bpf_mprog_entry *entry,
133 					const bool active)
134 {
135 	ASSERT_RTNL();
136 	tcx_entry(entry)->miniq_active = active;
137 }
138 
139 static 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 
145 static 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)
163 int tcx_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog);
164 int tcx_link_attach(const union bpf_attr *attr, struct bpf_prog *prog);
165 int tcx_prog_detach(const union bpf_attr *attr, struct bpf_prog *prog);
166 void tcx_uninstall(struct net_device *dev, bool ingress);
167 
168 int tcx_prog_query(const union bpf_attr *attr,
169 		   union bpf_attr __user *uattr);
170 
171 static 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
178 static inline int tcx_prog_attach(const union bpf_attr *attr,
179 				  struct bpf_prog *prog)
180 {
181 	return -EINVAL;
182 }
183 
184 static inline int tcx_link_attach(const union bpf_attr *attr,
185 				  struct bpf_prog *prog)
186 {
187 	return -EINVAL;
188 }
189 
190 static inline int tcx_prog_detach(const union bpf_attr *attr,
191 				  struct bpf_prog *prog)
192 {
193 	return -EINVAL;
194 }
195 
196 static inline int tcx_prog_query(const union bpf_attr *attr,
197 				 union bpf_attr __user *uattr)
198 {
199 	return -EINVAL;
200 }
201 
202 static 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