xref: /linux/include/net/tcx.h (revision 3f41368fbfe1b3d5922d317fe1a0a0cab6846802)
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_noprof(void)
79 {
80 	struct tcx_entry *tcx = kzalloc_noprof(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 #define tcx_entry_create(...)	alloc_hooks(tcx_entry_create_noprof(__VA_ARGS__))
89 
90 static inline void tcx_entry_free(struct bpf_mprog_entry *entry)
91 {
92 	kfree_rcu(tcx_entry(entry), rcu);
93 }
94 
95 static inline struct bpf_mprog_entry *
96 tcx_entry_fetch_or_create(struct net_device *dev, bool ingress, bool *created)
97 {
98 	struct bpf_mprog_entry *entry = tcx_entry_fetch(dev, ingress);
99 
100 	*created = false;
101 	if (!entry) {
102 		entry = tcx_entry_create();
103 		if (!entry)
104 			return NULL;
105 		*created = true;
106 	}
107 	return entry;
108 }
109 
110 static inline void tcx_skeys_inc(bool ingress)
111 {
112 	tcx_inc();
113 	if (ingress)
114 		net_inc_ingress_queue();
115 	else
116 		net_inc_egress_queue();
117 }
118 
119 static inline void tcx_skeys_dec(bool ingress)
120 {
121 	if (ingress)
122 		net_dec_ingress_queue();
123 	else
124 		net_dec_egress_queue();
125 	tcx_dec();
126 }
127 
128 static inline void tcx_miniq_set_active(struct bpf_mprog_entry *entry,
129 					const bool active)
130 {
131 	ASSERT_RTNL();
132 	tcx_entry(entry)->miniq_active = active;
133 }
134 
135 static inline bool tcx_entry_is_active(struct bpf_mprog_entry *entry)
136 {
137 	ASSERT_RTNL();
138 	return bpf_mprog_total(entry) || tcx_entry(entry)->miniq_active;
139 }
140 
141 static inline enum tcx_action_base tcx_action_code(struct sk_buff *skb,
142 						   int code)
143 {
144 	switch (code) {
145 	case TCX_PASS:
146 		skb->tc_index = qdisc_skb_cb(skb)->tc_classid;
147 		fallthrough;
148 	case TCX_DROP:
149 	case TCX_REDIRECT:
150 		return code;
151 	case TCX_NEXT:
152 	default:
153 		return TCX_NEXT;
154 	}
155 }
156 #endif /* CONFIG_NET_XGRESS */
157 
158 #if defined(CONFIG_NET_XGRESS) && defined(CONFIG_BPF_SYSCALL)
159 int tcx_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog);
160 int tcx_link_attach(const union bpf_attr *attr, struct bpf_prog *prog);
161 int tcx_prog_detach(const union bpf_attr *attr, struct bpf_prog *prog);
162 void tcx_uninstall(struct net_device *dev, bool ingress);
163 
164 int tcx_prog_query(const union bpf_attr *attr,
165 		   union bpf_attr __user *uattr);
166 
167 static inline void dev_tcx_uninstall(struct net_device *dev)
168 {
169 	ASSERT_RTNL();
170 	tcx_uninstall(dev, true);
171 	tcx_uninstall(dev, false);
172 }
173 #else
174 static inline int tcx_prog_attach(const union bpf_attr *attr,
175 				  struct bpf_prog *prog)
176 {
177 	return -EINVAL;
178 }
179 
180 static inline int tcx_link_attach(const union bpf_attr *attr,
181 				  struct bpf_prog *prog)
182 {
183 	return -EINVAL;
184 }
185 
186 static inline int tcx_prog_detach(const union bpf_attr *attr,
187 				  struct bpf_prog *prog)
188 {
189 	return -EINVAL;
190 }
191 
192 static inline int tcx_prog_query(const union bpf_attr *attr,
193 				 union bpf_attr __user *uattr)
194 {
195 	return -EINVAL;
196 }
197 
198 static inline void dev_tcx_uninstall(struct net_device *dev)
199 {
200 }
201 #endif /* CONFIG_NET_XGRESS && CONFIG_BPF_SYSCALL */
202 #endif /* __NET_TCX_H */
203