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         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 */