From: Geliang Tang <geliang.tang@xxxxxxxx>
This patch implements a new struct bpf_func_proto, named
bpf_skc_to_mptcp_sock_proto. Define a new bpf_id BTF_SOCK_TYPE_MPTCP,
and a new helper bpf_skc_to_mptcp_sock(), which invokes another new
helper bpf_mptcp_sock_from_subflow() in net/mptcp/bpf.c to get struct
mptcp_sock from a given subflow socket.
v2: Emit BTF type, add func_id checks in verifier.c and bpf_trace.c,
remove build check for CONFIG_BPF_JIT
v5: Drop EXPORT_SYMBOL (Martin)
Co-developed-by: Nicolas Rybowski <nicolas.rybowski@xxxxxxxxxxxx>
Signed-off-by: Nicolas Rybowski <nicolas.rybowski@xxxxxxxxxxxx>
Co-developed-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Signed-off-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Signed-off-by: Geliang Tang <geliang.tang@xxxxxxxx>
Signed-off-by: Mat Martineau <mathew.j.martineau@xxxxxxxxxxxxxxx>
---
include/linux/bpf.h | 1 +
include/linux/btf_ids.h | 3 ++-
include/net/mptcp.h | 6 ++++++
include/uapi/linux/bpf.h | 7 +++++++
kernel/bpf/verifier.c | 1 +
kernel/trace/bpf_trace.c | 2 ++
net/core/filter.c | 18 ++++++++++++++++++
net/mptcp/Makefile | 2 ++
net/mptcp/bpf.c | 21 +++++++++++++++++++++
scripts/bpf_doc.py | 2 ++
tools/include/uapi/linux/bpf.h | 7 +++++++
11 files changed, 69 insertions(+), 1 deletion(-)
create mode 100644 net/mptcp/bpf.c
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index c107392b0ba7..a3ef078401cf 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2231,6 +2231,7 @@ extern const struct bpf_func_proto bpf_skc_to_tcp_timewait_sock_proto;
extern const struct bpf_func_proto bpf_skc_to_tcp_request_sock_proto;
extern const struct bpf_func_proto bpf_skc_to_udp6_sock_proto;
extern const struct bpf_func_proto bpf_skc_to_unix_sock_proto;
+extern const struct bpf_func_proto bpf_skc_to_mptcp_sock_proto;
extern const struct bpf_func_proto bpf_copy_from_user_proto;
extern const struct bpf_func_proto bpf_snprintf_btf_proto;
extern const struct bpf_func_proto bpf_snprintf_proto;
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/net/mptcp.h b/include/net/mptcp.h
index 8b1afd6f5cc4..2ba09de955c7 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -284,4 +284,10 @@ static inline int mptcpv6_init(void) { return 0; }
static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
#endif
+#if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
+struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk);
+#else
+static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; }
+#endif
+
#endif /* __NET_MPTCP_H */
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 0210f85131b3..56688bee20d9 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -5172,6 +5172,12 @@ union bpf_attr {
* Return
* Map value associated to *key* on *cpu*, or **NULL** if no entry
* was found or *cpu* is invalid.
+ *
+ * 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), \
@@ -5370,6 +5376,7 @@ union bpf_attr {
FN(ima_file_hash), \
FN(kptr_xchg), \
FN(map_lookup_percpu_elem), \
+ FN(skc_to_mptcp_sock), \
/* */
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 9b59581026f8..14e8c17d3d8d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -509,6 +509,7 @@ static bool is_ptr_cast_function(enum bpf_func_id func_id)
func_id == BPF_FUNC_skc_to_tcp_sock ||
func_id == BPF_FUNC_skc_to_tcp6_sock ||
func_id == BPF_FUNC_skc_to_udp6_sock ||
+ func_id == BPF_FUNC_skc_to_mptcp_sock ||
func_id == BPF_FUNC_skc_to_tcp_timewait_sock ||
func_id == BPF_FUNC_skc_to_tcp_request_sock;
}
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 7141ca8a1c2d..10b157a6d73e 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1705,6 +1705,8 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_skc_to_udp6_sock_proto;
case BPF_FUNC_skc_to_unix_sock:
return &bpf_skc_to_unix_sock_proto;
+ case BPF_FUNC_skc_to_mptcp_sock:
+ return &bpf_skc_to_mptcp_sock_proto;
case BPF_FUNC_sk_storage_get:
return &bpf_sk_storage_get_tracing_proto;
case BPF_FUNC_sk_storage_delete:
diff --git a/net/core/filter.c b/net/core/filter.c
index fe0da529d00f..5af58eb48587 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -78,6 +78,7 @@
#include <linux/btf_ids.h>
#include <net/tls.h>
#include <net/xdp.h>
+#include <net/mptcp.h>
static const struct bpf_func_proto *
bpf_sk_base_func_proto(enum bpf_func_id func_id);
@@ -11281,6 +11282,20 @@ 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)
+{
+ BTF_TYPE_EMIT(struct mptcp_sock);
+ return (unsigned long)bpf_mptcp_sock_from_subflow(sk);
+}
+
+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);
@@ -11323,6 +11338,9 @@ 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;
+ case BPF_FUNC_skc_to_mptcp_sock:
+ func = &bpf_skc_to_mptcp_sock_proto;
+ break;
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 e54daceac58b..99dddf08ca73 100644
--- a/net/mptcp/Makefile
+++ b/net/mptcp/Makefile
@@ -10,3 +10,5 @@ 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_SYSCALL) += bpf.o
diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
new file mode 100644
index 000000000000..5a0a84ad94af
--- /dev/null
+++ b/net/mptcp/bpf.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Multipath TCP
+ *
+ * Copyright (c) 2020, Tessares SA.
+ * Copyright (c) 2022, SUSE.
+ *
+ * Author: Nicolas Rybowski <nicolas.rybowski@xxxxxxxxxxxx>
+ */
+
+#define pr_fmt(fmt) "MPTCP: " fmt
+
+#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;
+}
diff --git a/scripts/bpf_doc.py b/scripts/bpf_doc.py
index 096625242475..d5452f7eb996 100755
--- a/scripts/bpf_doc.py
+++ b/scripts/bpf_doc.py
@@ -633,6 +633,7 @@ class PrinterHelpers(Printer):
'struct socket',
'struct file',
'struct bpf_timer',
+ 'struct mptcp_sock',
]
known_types = {
'...',
@@ -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 0210f85131b3..56688bee20d9 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -5172,6 +5172,12 @@ union bpf_attr {
* Return
* Map value associated to *key* on *cpu*, or **NULL** if no entry
* was found or *cpu* is invalid.
+ *
+ * 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), \
@@ -5370,6 +5376,7 @@ union bpf_attr {
FN(ima_file_hash), \
FN(kptr_xchg), \
FN(map_lookup_percpu_elem), \
+ FN(skc_to_mptcp_sock), \
/* */
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
--
2.36.1
