[RFC PATCH v2 1/7] bpf: Introduce BPF_PROG_TYPE_VNET_HASH
From: Akihiko Odaki
Date: Sun Oct 15 2023 - 10:17:40 EST
This new program type will be used by tun to determine the queues to
deliver packets and the hash values and types reported with virtio-net
headers.
Signed-off-by: Akihiko Odaki <akihiko.odaki@xxxxxxxxxx>
---
Documentation/bpf/bpf_prog_run.rst | 1 +
Documentation/bpf/libbpf/program_types.rst | 2 ++
include/linux/bpf_types.h | 2 ++
include/uapi/linux/bpf.h | 5 +++++
kernel/bpf/verifier.c | 6 ++++++
net/core/filter.c | 11 +++++++++++
tools/include/uapi/linux/bpf.h | 1 +
tools/lib/bpf/libbpf.c | 2 ++
8 files changed, 30 insertions(+)
diff --git a/Documentation/bpf/bpf_prog_run.rst b/Documentation/bpf/bpf_prog_run.rst
index 4868c909df5c..0d108d867c03 100644
--- a/Documentation/bpf/bpf_prog_run.rst
+++ b/Documentation/bpf/bpf_prog_run.rst
@@ -39,6 +39,7 @@ following types:
- ``BPF_PROG_TYPE_STRUCT_OPS``
- ``BPF_PROG_TYPE_RAW_TRACEPOINT``
- ``BPF_PROG_TYPE_SYSCALL``
+- ``BPF_PROG_TYPE_VNET_HASH``
When using the ``BPF_PROG_RUN`` command, userspace supplies an input context
object and (for program types operating on network packets) a buffer containing
diff --git a/Documentation/bpf/libbpf/program_types.rst b/Documentation/bpf/libbpf/program_types.rst
index ad4d4d5eecb0..6be53201f91b 100644
--- a/Documentation/bpf/libbpf/program_types.rst
+++ b/Documentation/bpf/libbpf/program_types.rst
@@ -171,6 +171,8 @@ described in more detail in the footnotes.
+ +----------------------------------------+----------------------------------+-----------+
| | ``BPF_TRACE_RAW_TP`` | ``tp_btf+`` [#fentry]_ | |
+-------------------------------------------+----------------------------------------+----------------------------------+-----------+
+| ``BPF_PROG_TYPE_VNET_HASH`` | | ``vnet_hash`` | |
++-------------------------------------------+----------------------------------------+----------------------------------+-----------+
| ``BPF_PROG_TYPE_XDP`` | ``BPF_XDP_CPUMAP`` | ``xdp.frags/cpumap`` | |
+ + +----------------------------------+-----------+
| | | ``xdp/cpumap`` | |
diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
index fc0d6f32c687..dec83d495e82 100644
--- a/include/linux/bpf_types.h
+++ b/include/linux/bpf_types.h
@@ -34,6 +34,8 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_SK_MSG, sk_msg,
struct sk_msg_md, struct sk_msg)
BPF_PROG_TYPE(BPF_PROG_TYPE_FLOW_DISSECTOR, flow_dissector,
struct __sk_buff, struct bpf_flow_dissector)
+BPF_PROG_TYPE(BPF_PROG_TYPE_VNET_HASH, vnet_hash,
+ struct __sk_buff, struct sk_buff)
#endif
#ifdef CONFIG_BPF_EVENTS
BPF_PROG_TYPE(BPF_PROG_TYPE_KPROBE, kprobe,
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 0448700890f7..298634556fab 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -988,6 +988,7 @@ enum bpf_prog_type {
BPF_PROG_TYPE_SK_LOOKUP,
BPF_PROG_TYPE_SYSCALL, /* a program that can execute syscalls */
BPF_PROG_TYPE_NETFILTER,
+ BPF_PROG_TYPE_VNET_HASH,
};
enum bpf_attach_type {
@@ -6111,6 +6112,10 @@ struct __sk_buff {
__u8 tstamp_type;
__u32 :24; /* Padding, future use. */
__u64 hwtstamp;
+
+ __u32 vnet_hash_value;
+ __u16 vnet_hash_report;
+ __u16 vnet_rss_queue;
};
struct bpf_tunnel_key {
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index bb78212fa5b2..fd6d842635d2 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -14373,6 +14373,7 @@ static bool may_access_skb(enum bpf_prog_type type)
case BPF_PROG_TYPE_SOCKET_FILTER:
case BPF_PROG_TYPE_SCHED_CLS:
case BPF_PROG_TYPE_SCHED_ACT:
+ case BPF_PROG_TYPE_VNET_HASH:
return true;
default:
return false;
@@ -16973,6 +16974,11 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
return -EINVAL;
}
+ if (prog_type == BPF_PROG_TYPE_VNET_HASH) {
+ verbose(env, "vnet hash progs cannot use bpf_spin_lock yet\n");
+ return -EINVAL;
+ }
+
if (is_tracing_prog_type(prog_type)) {
verbose(env, "tracing progs cannot use bpf_spin_lock yet\n");
return -EINVAL;
diff --git a/net/core/filter.c b/net/core/filter.c
index a094694899c9..867edbc628de 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -10967,6 +10967,17 @@ const struct bpf_prog_ops flow_dissector_prog_ops = {
.test_run = bpf_prog_test_run_flow_dissector,
};
+const struct bpf_verifier_ops vnet_hash_verifier_ops = {
+ .get_func_proto = sk_filter_func_proto,
+ .is_valid_access = sk_filter_is_valid_access,
+ .convert_ctx_access = bpf_convert_ctx_access,
+ .gen_ld_abs = bpf_gen_ld_abs,
+};
+
+const struct bpf_prog_ops vnet_hash_prog_ops = {
+ .test_run = bpf_prog_test_run_skb,
+};
+
int sk_detach_filter(struct sock *sk)
{
int ret = -ENOENT;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 0448700890f7..60976fe86247 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -988,6 +988,7 @@ enum bpf_prog_type {
BPF_PROG_TYPE_SK_LOOKUP,
BPF_PROG_TYPE_SYSCALL, /* a program that can execute syscalls */
BPF_PROG_TYPE_NETFILTER,
+ BPF_PROG_TYPE_VNET_HASH,
};
enum bpf_attach_type {
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 96ff1aa4bf6a..e74d136eae07 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -209,6 +209,7 @@ static const char * const prog_type_name[] = {
[BPF_PROG_TYPE_SK_LOOKUP] = "sk_lookup",
[BPF_PROG_TYPE_SYSCALL] = "syscall",
[BPF_PROG_TYPE_NETFILTER] = "netfilter",
+ [BPF_PROG_TYPE_VNET_HASH] = "vnet_hash",
};
static int __base_pr(enum libbpf_print_level level, const char *format,
@@ -8858,6 +8859,7 @@ static const struct bpf_sec_def section_defs[] = {
SEC_DEF("struct_ops.s+", STRUCT_OPS, 0, SEC_SLEEPABLE),
SEC_DEF("sk_lookup", SK_LOOKUP, BPF_SK_LOOKUP, SEC_ATTACHABLE),
SEC_DEF("netfilter", NETFILTER, BPF_NETFILTER, SEC_NONE),
+ SEC_DEF("vnet_hash", VNET_HASH, 0, SEC_NONE),
};
int libbpf_register_prog_handler(const char *sec,
--
2.42.0