From: Cong Wang <cong.wang@xxxxxxxxxxxxx>
Signed-off-by: Cong Wang <cong.wang@xxxxxxxxxxxxx>
---
net/sched/sch_bpf.c | 81 ++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 80 insertions(+), 1 deletion(-)
diff --git a/net/sched/sch_bpf.c b/net/sched/sch_bpf.c
index 2998d576708d..6850eb8bb574 100644
--- a/net/sched/sch_bpf.c
+++ b/net/sched/sch_bpf.c
@@ -15,6 +15,7 @@
#include <linux/slab.h>
#include <linux/filter.h>
#include <linux/bpf.h>
+#include <linux/btf_ids.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
@@ -468,9 +469,87 @@ static struct Qdisc_ops sch_bpf_qdisc_ops __read_mostly = {
.owner = THIS_MODULE,
};
+__diag_push();
+__diag_ignore_all("-Wmissing-prototypes",
+ "Global functions as their definitions will be in vmlinux BTF");
+
+/**
+ * bpf_skb_acquire - Acquire a reference to an skb. An skb acquired by this
+ * kfunc which is not stored in a map as a kptr, must be released by calling
+ * bpf_skb_release().
+ * @p: The skb on which a reference is being acquired.
+ */
+__used noinline
+struct sk_buff *bpf_skb_acquire(struct sk_buff *p)
+{
+ return skb_get(p);
+}
+
+/**
+ * bpf_skb_kptr_get - Acquire a reference on a struct sk_buff kptr. An skb
+ * kptr acquired by this kfunc which is not subsequently stored in a map, must
+ * be released by calling bpf_skb_release().
+ * @pp: A pointer to an skb kptr on which a reference is being acquired.
+ */
+__used noinline
+struct sk_buff *bpf_skb_kptr_get(struct sk_buff **pp)
+{
+ struct sk_buff *p;
+
+ rcu_read_lock();
+ p = READ_ONCE(*pp);
+ if (p && !refcount_inc_not_zero(&p->users))
+ p = NULL;
+ rcu_read_unlock();
+
+ return p;
+}
+
+/**
+ * bpf_skb_release - Release the reference acquired on a struct sk_buff *.
+ * @p: The skb on which a reference is being released.
+ */
+__used noinline void bpf_skb_release(struct sk_buff *p)
+{
+ consume_skb(p);
+}
+
+__diag_pop();
+
+BTF_SET8_START(skb_kfunc_btf_ids)
+BTF_ID_FLAGS(func, bpf_skb_acquire, KF_ACQUIRE)
+BTF_ID_FLAGS(func, bpf_skb_kptr_get, KF_ACQUIRE | KF_KPTR_GET | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_skb_release, KF_RELEASE | KF_TRUSTED_ARGS)
+BTF_SET8_END(skb_kfunc_btf_ids)
+
+static const struct btf_kfunc_id_set skb_kfunc_set = {
+ .owner = THIS_MODULE,
+ .set = &skb_kfunc_btf_ids,
+};
+
+BTF_ID_LIST(skb_kfunc_dtor_ids)
+BTF_ID(struct, sk_buff)
+BTF_ID(func, bpf_skb_release)
+
static int __init sch_bpf_mod_init(void)
{
- return register_qdisc(&sch_bpf_qdisc_ops);
+ int ret;
+ const struct btf_id_dtor_kfunc skb_kfunc_dtors[] = {
+ {
+ .btf_id = skb_kfunc_dtor_ids[0],
+ .kfunc_btf_id = skb_kfunc_dtor_ids[1]
+ },
+ };
+
+ ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_QDISC, &skb_kfunc_set);
+ if (ret)
+ return ret;
+ ret = register_btf_id_dtor_kfuncs(skb_kfunc_dtors,
+ ARRAY_SIZE(skb_kfunc_dtors),
+ THIS_MODULE);
+ if (ret == 0)
+ return register_qdisc(&sch_bpf_qdisc_ops);
+ return ret;
}
static void __exit sch_bpf_mod_exit(void)
--
2.34.1
