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(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 */