include/net/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
  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(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_inc(struct bpf_mprog_entry *entry)
 129 {
 130         ASSERT_RTNL();
 131         tcx_entry(entry)->miniq_active++;
 132 }
 133
 134 static inline void tcx_miniq_dec(struct bpf_mprog_entry *entry)
 135 {
 136         ASSERT_RTNL();
 137         tcx_entry(entry)->miniq_active--;
 138 }
 139
 140 static inline bool tcx_entry_is_active(struct bpf_mprog_entry *entry)
 141 {
 142         ASSERT_RTNL();
 143         return bpf_mprog_total(entry) || tcx_entry(entry)->miniq_active;
 144 }
 145
 146 static inline enum tcx_action_base tcx_action_code(struct sk_buff *skb,
 147                                                    int code)
 148 {
 149         switch (code) {
 150         case TCX_PASS:
 151                 skb->tc_index = qdisc_skb_cb(skb)->tc_classid;
 152                 fallthrough;
 153         case TCX_DROP:
 154         case TCX_REDIRECT:
 155                 return code;
 156         case TCX_NEXT:
 157         default:
 158                 return TCX_NEXT;
 159         }
 160 }
 161 #endif /* CONFIG_NET_XGRESS */
 162
 163 #if defined(CONFIG_NET_XGRESS) && defined(CONFIG_BPF_SYSCALL)
 164 int tcx_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog);
 165 int tcx_link_attach(const union bpf_attr *attr, struct bpf_prog *prog);
 166 int tcx_prog_detach(const union bpf_attr *attr, struct bpf_prog *prog);
 167 void tcx_uninstall(struct net_device *dev, bool ingress);
 168
 169 int tcx_prog_query(const union bpf_attr *attr,
 170                    union bpf_attr __user *uattr);
 171
 172 static inline void dev_tcx_uninstall(struct net_device *dev)
 173 {
 174         ASSERT_RTNL();
 175         tcx_uninstall(dev, true);
 176         tcx_uninstall(dev, false);
 177 }
 178 #else
 179 static inline int tcx_prog_attach(const union bpf_attr *attr,
 180                                   struct bpf_prog *prog)
 181 {
 182         return -EINVAL;
 183 }
 184
 185 static inline int tcx_link_attach(const union bpf_attr *attr,
 186                                   struct bpf_prog *prog)
 187 {
 188         return -EINVAL;
 189 }
 190
 191 static inline int tcx_prog_detach(const union bpf_attr *attr,
 192                                   struct bpf_prog *prog)
 193 {
 194         return -EINVAL;
 195 }
 196
 197 static inline int tcx_prog_query(const union bpf_attr *attr,
 198                                  union bpf_attr __user *uattr)
 199 {
 200         return -EINVAL;
 201 }
 202
 203 static inline void dev_tcx_uninstall(struct net_device *dev)
 204 {
 205 }
 206 #endif /* CONFIG_NET_XGRESS && CONFIG_BPF_SYSCALL */
 207 #endif /* __NET_TCX_H */