This patch implemented a new bpf_func_proto bpf_skc_to_mptcp_sock_proto.
Defined a new bpf_id BTF_SOCK_TYPE_MPTCP, implemented the helper
bpf_skc_to_mptcp_sock, and added a new helper bpf_mptcp_sock_from_subflow
to get struct mptcp_sock from a given subflow socket.
Co-developed-by: Nicolas Rybowski <nicolas.rybowski@tessares.net>
Signed-off-by: Nicolas Rybowski <nicolas.rybowski@tessares.net>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
include/linux/bpf.h | 9 +++++++++
include/linux/btf_ids.h | 3 ++-
include/uapi/linux/bpf.h | 7 +++++++
net/core/filter.c | 18 ++++++++++++++++++
net/mptcp/Makefile | 2 ++
net/mptcp/bpf.c | 20 ++++++++++++++++++++
scripts/bpf_doc.py | 2 ++
tools/include/uapi/linux/bpf.h | 7 +++++++
8 files changed, 67 insertions(+), 1 deletion(-)
create mode 100644 net/mptcp/bpf.c
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index f19abc59b6cd..b28b3d8c3df2 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2354,6 +2354,15 @@ static inline u32 bpf_xdp_sock_convert_ctx_access(enum bpf_access_type type,
}
#endif /* CONFIG_INET */
+#ifdef CONFIG_MPTCP
+struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk);
+#else /* CONFIG_MPTCP */
+static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk)
+{
+ return NULL;
+}
+#endif /* CONFIG_MPTCP */
+
enum bpf_text_poke_type {
BPF_MOD_CALL,
BPF_MOD_JUMP,
diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h
index bc5d9cc34e4c..335a19092368 100644
--- a/include/linux/btf_ids.h
+++ b/include/linux/btf_ids.h
@@ -178,7 +178,8 @@ extern struct btf_id_set name;
BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP6, tcp6_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP, udp_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP6, udp6_sock) \
- BTF_SOCK_TYPE(BTF_SOCK_TYPE_UNIX, unix_sock)
+ BTF_SOCK_TYPE(BTF_SOCK_TYPE_UNIX, unix_sock) \
+ BTF_SOCK_TYPE(BTF_SOCK_TYPE_MPTCP, mptcp_sock)
enum {
#define BTF_SOCK_TYPE(name, str) name,
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 3f6dcdf4b915..a88aac4457a9 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -5086,6 +5086,12 @@ union bpf_attr {
* Return
* 0 on success, or a negative error in case of failure. On error
* *dst* buffer is zeroed out.
+ *
+ * struct mptcp_sock *bpf_skc_to_mptcp_sock(void *sk)
+ * Description
+ * Dynamically cast a *sk* pointer to a *mptcp_sock* pointer.
+ * Return
+ * *sk* if casting is valid, or **NULL** otherwise.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -5280,6 +5286,7 @@ union bpf_attr {
FN(xdp_load_bytes), \
FN(xdp_store_bytes), \
FN(copy_from_user_task), \
+ FN(skc_to_mptcp_sock), \
/* */
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
diff --git a/net/core/filter.c b/net/core/filter.c
index f64454722a7e..b5a01d80f1f6 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -11121,6 +11121,19 @@ const struct bpf_func_proto bpf_skc_to_unix_sock_proto = {
.ret_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_UNIX],
};
+BPF_CALL_1(bpf_skc_to_mptcp_sock, struct sock *, sk)
+{
+ return (unsigned long)bpf_mptcp_sock_from_subflow(sk);
+}
+
+static const struct bpf_func_proto bpf_skc_to_mptcp_sock_proto = {
+ .func = bpf_skc_to_mptcp_sock,
+ .gpl_only = false,
+ .ret_type = RET_PTR_TO_BTF_ID_OR_NULL,
+ .arg1_type = ARG_PTR_TO_SOCK_COMMON,
+ .ret_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_MPTCP],
+};
+
BPF_CALL_1(bpf_sock_from_file, struct file *, file)
{
return (unsigned long)sock_from_file(file);
@@ -11163,6 +11176,11 @@ bpf_sk_base_func_proto(enum bpf_func_id func_id)
case BPF_FUNC_skc_to_unix_sock:
func = &bpf_skc_to_unix_sock_proto;
break;
+#ifdef CONFIG_MPTCP
+ case BPF_FUNC_skc_to_mptcp_sock:
+ func = &bpf_skc_to_mptcp_sock_proto;
+ break;
+#endif /* CONFIG_MPTCP */
case BPF_FUNC_ktime_get_coarse_ns:
return &bpf_ktime_get_coarse_ns_proto;
default:
diff --git a/net/mptcp/Makefile b/net/mptcp/Makefile
index 48a9d978aaeb..0a0608b6b4b4 100644
--- a/net/mptcp/Makefile
+++ b/net/mptcp/Makefile
@@ -11,3 +11,5 @@ obj-$(CONFIG_INET_MPTCP_DIAG) += mptcp_diag.o
mptcp_crypto_test-objs := crypto_test.o
mptcp_token_test-objs := token_test.o
obj-$(CONFIG_MPTCP_KUNIT_TEST) += mptcp_crypto_test.o mptcp_token_test.o
+
+obj-$(CONFIG_BPF) += bpf.o
diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
new file mode 100644
index 000000000000..da79dae559b2
--- /dev/null
+++ b/net/mptcp/bpf.c
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Multipath TCP
+ *
+ * Copyright (c) 2020, Tessares SA.
+ *
+ * Author: Nicolas Rybowski <nicolas.rybowski@tessares.net>
+ *
+ */
+
+#include <linux/bpf.h>
+#include "protocol.h"
+
+struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk)
+{
+ if (sk && sk_fullsock(sk) && sk->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk))
+ return mptcp_sk(mptcp_subflow_ctx(sk)->conn);
+
+ return NULL;
+}
+EXPORT_SYMBOL(bpf_mptcp_sock_from_subflow);
diff --git a/scripts/bpf_doc.py b/scripts/bpf_doc.py
index 096625242475..0e5a9e69ae59 100755
--- a/scripts/bpf_doc.py
+++ b/scripts/bpf_doc.py
@@ -623,6 +623,7 @@ class PrinterHelpers(Printer):
'struct udp6_sock',
'struct unix_sock',
'struct task_struct',
+ 'struct mptcp_sock',
'struct __sk_buff',
'struct sk_msg_md',
@@ -682,6 +683,7 @@ class PrinterHelpers(Printer):
'struct socket',
'struct file',
'struct bpf_timer',
+ 'struct mptcp_sock',
}
mapped_types = {
'u8': '__u8',
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 3f6dcdf4b915..a88aac4457a9 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -5086,6 +5086,12 @@ union bpf_attr {
* Return
* 0 on success, or a negative error in case of failure. On error
* *dst* buffer is zeroed out.
+ *
+ * struct mptcp_sock *bpf_skc_to_mptcp_sock(void *sk)
+ * Description
+ * Dynamically cast a *sk* pointer to a *mptcp_sock* pointer.
+ * Return
+ * *sk* if casting is valid, or **NULL** otherwise.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -5280,6 +5286,7 @@ union bpf_attr {
FN(xdp_load_bytes), \
FN(xdp_store_bytes), \
FN(copy_from_user_task), \
+ FN(skc_to_mptcp_sock), \
/* */
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
--
2.34.1