This patch adds another optional program to be called during
the creation of a qdisc for initializating data in the bpf world.
The program takes bpf_qdisc_ctx as context, but cannot not access
any field.
Signed-off-by: Amery Hung <amery.hung@xxxxxxxxxxxxx>
---
include/uapi/linux/bpf.h | 1 +
include/uapi/linux/pkt_sched.h | 4 ++++
kernel/bpf/syscall.c | 1 +
net/core/filter.c | 3 ++-
net/sched/sch_bpf.c | 23 ++++++++++++++++++++++-
tools/include/uapi/linux/bpf.h | 1 +
6 files changed, 31 insertions(+), 2 deletions(-)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 84669886a493..cad0788bef99 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1060,6 +1060,7 @@ enum bpf_attach_type {
BPF_QDISC_ENQUEUE,
BPF_QDISC_DEQUEUE,
BPF_QDISC_RESET,
+ BPF_QDISC_INIT,
__MAX_BPF_ATTACH_TYPE
};
diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h
index e9e1a83c22f7..61f0cf4a088c 100644
--- a/include/uapi/linux/pkt_sched.h
+++ b/include/uapi/linux/pkt_sched.h
@@ -1332,6 +1332,10 @@ enum {
TCA_SCH_BPF_RESET_PROG_FD, /* u32 */
TCA_SCH_BPF_RESET_PROG_ID, /* u32 */
TCA_SCH_BPF_RESET_PROG_TAG, /* data */
+ TCA_SCH_BPF_INIT_PROG_NAME, /* string */
+ TCA_SCH_BPF_INIT_PROG_FD, /* u32 */
+ TCA_SCH_BPF_INIT_PROG_ID, /* u32 */
+ TCA_SCH_BPF_INIT_PROG_TAG, /* data */
__TCA_SCH_BPF_MAX,
};
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 9af6fa542f2e..0959905044b9 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2507,6 +2507,7 @@ bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
case BPF_QDISC_ENQUEUE:
case BPF_QDISC_DEQUEUE:
case BPF_QDISC_RESET:
+ case BPF_QDISC_INIT:
return 0;
default:
return -EINVAL;
diff --git a/net/core/filter.c b/net/core/filter.c
index f8e17465377f..5619a12c0d06 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -8905,7 +8905,8 @@ static bool tc_qdisc_is_valid_access(int off, int size,
{
struct btf *btf;
- if (prog->expected_attach_type == BPF_QDISC_RESET)
+ if (prog->expected_attach_type == BPF_QDISC_RESET ||
+ prog->expected_attach_type == BPF_QDISC_INIT)
return false;
if (off < 0 || off >= sizeof(struct bpf_qdisc_ctx))
diff --git a/net/sched/sch_bpf.c b/net/sched/sch_bpf.c
index 3f0f809dced6..925a131016f0 100644
--- a/net/sched/sch_bpf.c
+++ b/net/sched/sch_bpf.c
@@ -43,6 +43,7 @@ struct bpf_sched_data {
struct sch_bpf_prog __rcu enqueue_prog;
struct sch_bpf_prog __rcu dequeue_prog;
struct sch_bpf_prog __rcu reset_prog;
+ struct sch_bpf_prog __rcu init_prog;
struct qdisc_watchdog watchdog;
};
@@ -88,6 +89,9 @@ static int sch_bpf_dump(struct Qdisc *sch, struct sk_buff *skb)
if (sch_bpf_dump_prog(&q->reset_prog, skb, TCA_SCH_BPF_RESET_PROG_NAME,
TCA_SCH_BPF_RESET_PROG_ID, TCA_SCH_BPF_RESET_PROG_TAG))
goto nla_put_failure;
+ if (sch_bpf_dump_prog(&q->init_prog, skb, TCA_SCH_BPF_INIT_PROG_NAME,
+ TCA_SCH_BPF_INIT_PROG_ID, TCA_SCH_BPF_INIT_PROG_TAG))
+ goto nla_put_failure;
return nla_nest_end(skb, opts);
@@ -269,6 +273,9 @@ static const struct nla_policy sch_bpf_policy[TCA_SCH_BPF_MAX + 1] = {
[TCA_SCH_BPF_RESET_PROG_FD] = { .type = NLA_U32 },
[TCA_SCH_BPF_RESET_PROG_NAME] = { .type = NLA_NUL_STRING,
.len = ACT_BPF_NAME_LEN },
+ [TCA_SCH_BPF_INIT_PROG_FD] = { .type = NLA_U32 },
+ [TCA_SCH_BPF_INIT_PROG_NAME] = { .type = NLA_NUL_STRING,
+ .len = ACT_BPF_NAME_LEN },
};
static int bpf_init_prog(struct nlattr *fd, struct nlattr *name,
@@ -348,6 +355,10 @@ static int sch_bpf_change(struct Qdisc *sch, struct nlattr *opt,
goto failure;
err = bpf_init_prog(tb[TCA_SCH_BPF_RESET_PROG_FD],
tb[TCA_SCH_BPF_RESET_PROG_NAME], &q->reset_prog, true);
+ if (err)
+ goto failure;
+ err = bpf_init_prog(tb[TCA_SCH_BPF_INIT_PROG_FD],
+ tb[TCA_SCH_BPF_INIT_PROG_NAME], &q->init_prog, true);
failure:
sch_tree_unlock(sch);
return err;
@@ -357,6 +368,8 @@ static int sch_bpf_init(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
struct bpf_sched_data *q = qdisc_priv(sch);
+ struct bpf_qdisc_ctx ctx = {};
+ struct bpf_prog *init;
int err;
qdisc_watchdog_init(&q->watchdog, sch);
@@ -370,7 +383,14 @@ static int sch_bpf_init(struct Qdisc *sch, struct nlattr *opt,
if (err)
return err;
- return qdisc_class_hash_init(&q->clhash);
+ err = qdisc_class_hash_init(&q->clhash);
+ if (err < 0)
+ return err;
+
+ init = rcu_dereference(q->init_prog.prog);
+ if (init)
+ bpf_prog_run(init, &ctx);
+ return 0;
}
static void sch_bpf_reset(struct Qdisc *sch)
@@ -420,6 +440,7 @@ static void sch_bpf_destroy(struct Qdisc *sch)
bpf_cleanup_prog(&q->enqueue_prog);
bpf_cleanup_prog(&q->dequeue_prog);
bpf_cleanup_prog(&q->reset_prog);
+ bpf_cleanup_prog(&q->init_prog);
sch_tree_unlock(sch);
}
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 84669886a493..cad0788bef99 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1060,6 +1060,7 @@ enum bpf_attach_type {
BPF_QDISC_ENQUEUE,
BPF_QDISC_DEQUEUE,
BPF_QDISC_RESET,
+ BPF_QDISC_INIT,
__MAX_BPF_ATTACH_TYPE
};
--
2.20.1
