xref: /linux/include/net/tcx.h (revision ebc733e54a1a79ea2dde2ba5121ae73a188e20d4)
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(const struct bpf_link *link)
42 {
43 	return container_of(link, struct tcx_link, link);
44 }
45 
46 void tcx_inc(void);
47 void tcx_dec(void);
48 
49 static 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 
57 static inline void
58 tcx_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 
68 static inline struct bpf_mprog_entry *
69 tcx_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 
78 static 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 
89 static inline void tcx_entry_free(struct bpf_mprog_entry *entry)
90 {
91 	kfree_rcu(tcx_entry(entry), rcu);
92 }
93 
94 static inline struct bpf_mprog_entry *
95 tcx_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 
109 static 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 
118 static 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 
127 static 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 
134 static 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 
140 static 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)
158 int tcx_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog);
159 int tcx_link_attach(const union bpf_attr *attr, struct bpf_prog *prog);
160 int tcx_prog_detach(const union bpf_attr *attr, struct bpf_prog *prog);
161 void tcx_uninstall(struct net_device *dev, bool ingress);
162 
163 int tcx_prog_query(const union bpf_attr *attr,
164 		   union bpf_attr __user *uattr);
165 
166 static 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
173 static inline int tcx_prog_attach(const union bpf_attr *attr,
174 				  struct bpf_prog *prog)
175 {
176 	return -EINVAL;
177 }
178 
179 static inline int tcx_link_attach(const union bpf_attr *attr,
180 				  struct bpf_prog *prog)
181 {
182 	return -EINVAL;
183 }
184 
185 static inline int tcx_prog_detach(const union bpf_attr *attr,
186 				  struct bpf_prog *prog)
187 {
188 	return -EINVAL;
189 }
190 
191 static inline int tcx_prog_query(const union bpf_attr *attr,
192 				 union bpf_attr __user *uattr)
193 {
194 	return -EINVAL;
195 }
196 
197 static 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