[PATCH mptcp-next v11 0/7] add skc_to_mptcp_sock

[PATCH mptcp-next v11 0/7] add skc_to_mptcp_sock

[Geliang Tang]

v11:
 - merge "check more values from mptcp_sock" series into this series.
 - patch 2:
   - rebased.
 - patch 3:
   - rebased.
   - add 'Copyright' entry as Matt suggested in v9:
   https://patchwork.kernel.org/project/mptcp/patch/d6d33be9899118c5f542a6ce43f868d4e9e2766b.1646745228.git.geliang.tang@suse.com/
 - patch 4:
   - add test__start_subtest.
   - add some 'Copyright' entries.
 - patch 5:
   - change monitor_log_path to static
   - drop bpf_trace_printk()
 - patch 6:
   - use TCP_CA_NAME_MAX instead of strlen(val.ca_name) in strncmp().
   - use 'sysctl -b net.ipv4.tcp_congestion_control' to get ca_name.

v10:
 - merge the squash-to patch.
 - update patch 3 as Matt suggested.
 - add sync() in get_msk_token() before read().
 - add a comment for get_msk_token().
 - update subjects and commit logs.

v9:
 - update progs/mptcp.c in patch 4 and 5

v8:
 - update as Matt suggested.

v7:
 - parse msk token from the output of 'ip mptcp monitor'.
 - add Nicolas and Matt's SoB tags.

v6:
 - add skc_to_mptcp_sock helper and test

RESEND:
 - fix the CI Build Failure.
v5:
 - fix incorrect token value
 - verify the token in selftest

v4:
 - define bpf_mptcp_sock_proto as a static function, no longer export
   it in linux/bpf.h

v3:
 - use RET_PTR_TO_BTF_ID_OR_NULL instead of RET_PTR_TO_MPTCP_SOCK_OR_NULL
 - add a new bpf_id BTF_SOCK_TYPE_MPTCP

v2:
 - keep RET_PTR_TO_MPTCP_SOCK_OR_NULL. If we use RET_PTR_TO_BTF_ID_OR_NULL
instead of RET_PTR_TO_MPTCP_SOCK_OR_NULL as Alexei suggested, the
"userspace" tests developed by Nicolas will break.

Geliang Tang (7):
  Revert "selftests: bpf: add bpf_mptcp_sock() verifier tests"
  Revert "bpf: add 'bpf_mptcp_sock' structure and helper"
  bpf: add bpf_skc_to_mptcp_sock_proto
  Squash to "selftests: bpf: add MPTCP test base"
  selftests: bpf: test bpf_skc_to_mptcp_sock
  selftests: bpf: verify ca_name of struct mptcp_sock
  selftests: bpf: verify first subflow of mptcp_sock

 include/linux/bpf.h                           |  31 +---
 include/linux/btf_ids.h                       |   3 +-
 include/uapi/linux/bpf.h                      |  14 +-
 kernel/bpf/verifier.c                         |  20 ---
 net/core/filter.c                             |  22 ++-
 net/mptcp/bpf.c                               |  64 +------
 scripts/bpf_doc.py                            |   4 +-
 tools/include/uapi/linux/bpf.h                |  14 +-
 tools/testing/selftests/bpf/bpf_tcp_helpers.h |  12 ++
 .../testing/selftests/bpf/prog_tests/mptcp.c  | 159 ++++++++++++++++--
 tools/testing/selftests/bpf/progs/mptcp.c     |  44 ++++-
 tools/testing/selftests/bpf/verifier/sock.c   |  63 -------
 12 files changed, 229 insertions(+), 221 deletions(-)

-- 
2.34.1

[PATCH mptcp-next v11 1/7] Revert "selftests: bpf: add bpf_mptcp_sock() verifier tests"

[Geliang Tang]

This reverts commit f48f0143286db0d8dbded9542d9a2535533dd3b9.
---
 tools/testing/selftests/bpf/verifier/sock.c | 63 ---------------------
 1 file changed, 63 deletions(-)

diff --git a/tools/testing/selftests/bpf/verifier/sock.c b/tools/testing/selftests/bpf/verifier/sock.c
index 6fd622cc38d0..86b24cad27a7 100644
--- a/tools/testing/selftests/bpf/verifier/sock.c
+++ b/tools/testing/selftests/bpf/verifier/sock.c
@@ -731,66 +731,3 @@
 	.result_unpriv = REJECT,
 	.errstr_unpriv = "unknown func",
 },
-{
-	"bpf_mptcp_sock(skops->sk): no !skops->sk check",
-	.insns = {
-	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct bpf_sock_ops, sk)),
-	BPF_EMIT_CALL(BPF_FUNC_mptcp_sock),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	},
-	.prog_type = BPF_PROG_TYPE_SOCK_OPS,
-	.result = REJECT,
-	.errstr = "type=sock_or_null expected=sock_common",
-},
-{
-	"bpf_mptcp_sock(skops->sk): no NULL check on ret",
-	.insns = {
-	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct bpf_sock_ops, sk)),
-	BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	BPF_EMIT_CALL(BPF_FUNC_mptcp_sock),
-	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_mptcp_sock, token)),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	},
-	.prog_type = BPF_PROG_TYPE_SOCK_OPS,
-	.result = REJECT,
-	.errstr = "invalid mem access 'mptcp_sock_or_null'",
-},
-{
-	"bpf_mptcp_sock(skops->sk): msk->token",
-	.insns = {
-	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct bpf_sock_ops, sk)),
-	BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	BPF_EMIT_CALL(BPF_FUNC_mptcp_sock),
-	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
-	BPF_EXIT_INSN(),
-	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_mptcp_sock, token)),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	},
-	.prog_type = BPF_PROG_TYPE_SOCK_OPS,
-	.result = ACCEPT,
-},
-{
-	"bpf_mptcp_sock(skops->sk): msk->token cannot be modified",
-	.insns = {
-	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct bpf_sock_ops, sk)),
-	BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	BPF_EMIT_CALL(BPF_FUNC_mptcp_sock),
-	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
-	BPF_EXIT_INSN(),
-	BPF_ST_MEM(BPF_W, BPF_REG_0, offsetof(struct bpf_mptcp_sock, token), 0x2a),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	},
-	.prog_type = BPF_PROG_TYPE_SOCK_OPS,
-	.result = REJECT,
-	.errstr = "cannot write into mptcp_sock",
-},
-- 
2.34.1

[PATCH mptcp-next v11 2/7] Revert "bpf: add 'bpf_mptcp_sock' structure and helper"

[Geliang Tang]

This reverts commit 8738c0bc4122c4d2390d2f1e8305e8bebf199f14.
---
 include/linux/bpf.h            | 34 ----------------
 include/uapi/linux/bpf.h       | 13 ------
 kernel/bpf/verifier.c          | 20 ----------
 net/core/filter.c              |  4 --
 net/mptcp/Makefile             |  2 -
 net/mptcp/bpf.c                | 72 ----------------------------------
 scripts/bpf_doc.py             |  2 -
 tools/include/uapi/linux/bpf.h | 13 ------
 8 files changed, 160 deletions(-)
 delete mode 100644 net/mptcp/bpf.c

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 3f368c8b7e48..57cb6af3177a 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -407,7 +407,6 @@ enum bpf_return_type {
 	RET_PTR_TO_MAP_VALUE,		/* returns a pointer to map elem value */
 	RET_PTR_TO_SOCKET,		/* returns a pointer to a socket */
 	RET_PTR_TO_TCP_SOCK,		/* returns a pointer to a tcp_sock */
-	RET_PTR_TO_MPTCP_SOCK,		/* returns a pointer to mptcp_sock */
 	RET_PTR_TO_SOCK_COMMON,		/* returns a pointer to a sock_common */
 	RET_PTR_TO_ALLOC_MEM,		/* returns a pointer to dynamically allocated memory */
 	RET_PTR_TO_MEM_OR_BTF_ID,	/* returns a pointer to a valid memory or a btf_id */
@@ -418,7 +417,6 @@ enum bpf_return_type {
 	RET_PTR_TO_MAP_VALUE_OR_NULL	= PTR_MAYBE_NULL | RET_PTR_TO_MAP_VALUE,
 	RET_PTR_TO_SOCKET_OR_NULL	= PTR_MAYBE_NULL | RET_PTR_TO_SOCKET,
 	RET_PTR_TO_TCP_SOCK_OR_NULL	= PTR_MAYBE_NULL | RET_PTR_TO_TCP_SOCK,
-	RET_PTR_TO_MPTCP_SOCK_OR_NULL	= PTR_MAYBE_NULL | RET_PTR_TO_MPTCP_SOCK,
 	RET_PTR_TO_SOCK_COMMON_OR_NULL	= PTR_MAYBE_NULL | RET_PTR_TO_SOCK_COMMON,
 	RET_PTR_TO_ALLOC_MEM_OR_NULL	= PTR_MAYBE_NULL | MEM_ALLOC | RET_PTR_TO_ALLOC_MEM,
 	RET_PTR_TO_BTF_ID_OR_NULL	= PTR_MAYBE_NULL | RET_PTR_TO_BTF_ID,
@@ -499,7 +497,6 @@ enum bpf_reg_type {
 	PTR_TO_SOCKET,		 /* reg points to struct bpf_sock */
 	PTR_TO_SOCK_COMMON,	 /* reg points to sock_common */
 	PTR_TO_TCP_SOCK,	 /* reg points to struct tcp_sock */
-	PTR_TO_MPTCP_SOCK,	 /* reg points to struct mptcp_sock */
 	PTR_TO_TP_BUFFER,	 /* reg points to a writable raw tp's buffer */
 	PTR_TO_XDP_SOCK,	 /* reg points to struct xdp_sock */
 	/* PTR_TO_BTF_ID points to a kernel struct that does not need
@@ -528,7 +525,6 @@ enum bpf_reg_type {
 	PTR_TO_SOCKET_OR_NULL		= PTR_MAYBE_NULL | PTR_TO_SOCKET,
 	PTR_TO_SOCK_COMMON_OR_NULL	= PTR_MAYBE_NULL | PTR_TO_SOCK_COMMON,
 	PTR_TO_TCP_SOCK_OR_NULL		= PTR_MAYBE_NULL | PTR_TO_TCP_SOCK,
-	PTR_TO_MPTCP_SOCK_OR_NULL	= PTR_MAYBE_NULL | PTR_TO_MPTCP_SOCK,
 	PTR_TO_BTF_ID_OR_NULL		= PTR_MAYBE_NULL | PTR_TO_BTF_ID,
 
 	/* This must be the last entry. Its purpose is to ensure the enum is
@@ -2232,7 +2228,6 @@ extern const struct bpf_func_proto bpf_get_local_storage_proto;
 extern const struct bpf_func_proto bpf_strtol_proto;
 extern const struct bpf_func_proto bpf_strtoul_proto;
 extern const struct bpf_func_proto bpf_tcp_sock_proto;
-extern const struct bpf_func_proto bpf_mptcp_sock_proto;
 extern const struct bpf_func_proto bpf_jiffies64_proto;
 extern const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto;
 extern const struct bpf_func_proto bpf_event_output_data_proto;
@@ -2320,7 +2315,6 @@ struct sk_reuseport_kern {
 	u32 reuseport_id;
 	bool bind_inany;
 };
-
 bool bpf_tcp_sock_is_valid_access(int off, int size, enum bpf_access_type type,
 				  struct bpf_insn_access_aux *info);
 
@@ -2371,34 +2365,6 @@ static inline u32 bpf_xdp_sock_convert_ctx_access(enum bpf_access_type type,
 }
 #endif /* CONFIG_INET */
 
-#ifdef CONFIG_MPTCP
-bool bpf_mptcp_sock_is_valid_access(int off, int size,
-				    enum bpf_access_type type,
-				    struct bpf_insn_access_aux *info);
-
-u32 bpf_mptcp_sock_convert_ctx_access(enum bpf_access_type type,
-				      const struct bpf_insn *si,
-				      struct bpf_insn *insn_buf,
-				      struct bpf_prog *prog,
-				      u32 *target_size);
-#else /* CONFIG_MPTCP */
-static inline bool bpf_mptcp_sock_is_valid_access(int off, int size,
-						  enum bpf_access_type type,
-						  struct bpf_insn_access_aux *info)
-{
-	return false;
-}
-
-static inline u32 bpf_mptcp_sock_convert_ctx_access(enum bpf_access_type type,
-						    const struct bpf_insn *si,
-						    struct bpf_insn *insn_buf,
-						    struct bpf_prog *prog,
-						    u32 *target_size)
-{
-	return 0;
-}
-#endif /* CONFIG_MPTCP */
-
 enum bpf_text_poke_type {
 	BPF_MOD_CALL,
 	BPF_MOD_JUMP,
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 2a82b9353bab..4ae3cac94fb2 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -5117,14 +5117,6 @@ union bpf_attr {
  *		0 on success.
  *		**-EINVAL** for invalid input
  *		**-EOPNOTSUPP** for unsupported delivery_time_type and protocol
- *
- * struct bpf_mptcp_sock *bpf_mptcp_sock(struct bpf_sock *sk)
- *	Description
- *		This helper gets a **struct bpf_mptcp_sock** pointer from a
- *		**struct bpf_sock** pointer.
- *	Return
- *		A **struct bpf_mptcp_sock** pointer on success, or **NULL** in
- *		case of failure.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -5320,7 +5312,6 @@ union bpf_attr {
 	FN(xdp_store_bytes),		\
 	FN(copy_from_user_task),	\
 	FN(skb_set_delivery_time),      \
-	FN(mptcp_sock),			\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
@@ -5676,10 +5667,6 @@ struct bpf_tcp_sock {
 	__u32 is_mptcp;		/* Is MPTCP subflow? */
 };
 
-struct bpf_mptcp_sock {
-	__u32 token;		/* msk token */
-};
-
 struct bpf_sock_tuple {
 	union {
 		struct {
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d40982ddd255..a57db4b2803c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -430,7 +430,6 @@ static bool type_is_sk_pointer(enum bpf_reg_type type)
 	return type == PTR_TO_SOCKET ||
 		type == PTR_TO_SOCK_COMMON ||
 		type == PTR_TO_TCP_SOCK ||
-		type == PTR_TO_MPTCP_SOCK ||
 		type == PTR_TO_XDP_SOCK;
 }
 
@@ -438,7 +437,6 @@ static bool reg_type_not_null(enum bpf_reg_type type)
 {
 	return type == PTR_TO_SOCKET ||
 		type == PTR_TO_TCP_SOCK ||
-		type == PTR_TO_MPTCP_SOCK ||
 		type == PTR_TO_MAP_VALUE ||
 		type == PTR_TO_MAP_KEY ||
 		type == PTR_TO_SOCK_COMMON;
@@ -454,7 +452,6 @@ static bool reg_type_may_be_refcounted_or_null(enum bpf_reg_type type)
 {
 	return base_type(type) == PTR_TO_SOCKET ||
 		base_type(type) == PTR_TO_TCP_SOCK ||
-		base_type(type) == PTR_TO_MPTCP_SOCK ||
 		base_type(type) == PTR_TO_MEM ||
 		base_type(type) == PTR_TO_BTF_ID;
 }
@@ -554,7 +551,6 @@ static const char *reg_type_str(struct bpf_verifier_env *env,
 		[PTR_TO_SOCKET]		= "sock",
 		[PTR_TO_SOCK_COMMON]	= "sock_common",
 		[PTR_TO_TCP_SOCK]	= "tcp_sock",
-		[PTR_TO_MPTCP_SOCK]	= "mptcp_sock",
 		[PTR_TO_TP_BUFFER]	= "tp_buffer",
 		[PTR_TO_XDP_SOCK]	= "xdp_sock",
 		[PTR_TO_BTF_ID]		= "ptr_",
@@ -2784,7 +2780,6 @@ static bool is_spillable_regtype(enum bpf_reg_type type)
 	case PTR_TO_SOCKET:
 	case PTR_TO_SOCK_COMMON:
 	case PTR_TO_TCP_SOCK:
-	case PTR_TO_MPTCP_SOCK:
 	case PTR_TO_XDP_SOCK:
 	case PTR_TO_BTF_ID:
 	case PTR_TO_BUF:
@@ -3677,9 +3672,6 @@ static int check_sock_access(struct bpf_verifier_env *env, int insn_idx,
 	case PTR_TO_TCP_SOCK:
 		valid = bpf_tcp_sock_is_valid_access(off, size, t, &info);
 		break;
-	case PTR_TO_MPTCP_SOCK:
-		valid = bpf_mptcp_sock_is_valid_access(off, size, t, &info);
-		break;
 	case PTR_TO_XDP_SOCK:
 		valid = bpf_xdp_sock_is_valid_access(off, size, t, &info);
 		break;
@@ -3836,9 +3828,6 @@ static int check_ptr_alignment(struct bpf_verifier_env *env,
 	case PTR_TO_TCP_SOCK:
 		pointer_desc = "tcp_sock ";
 		break;
-	case PTR_TO_MPTCP_SOCK:
-		pointer_desc = "mptcp_sock ";
-		break;
 	case PTR_TO_XDP_SOCK:
 		pointer_desc = "xdp_sock ";
 		break;
@@ -6768,9 +6757,6 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
 	} else if (base_type(ret_type) == RET_PTR_TO_TCP_SOCK) {
 		mark_reg_known_zero(env, regs, BPF_REG_0);
 		regs[BPF_REG_0].type = PTR_TO_TCP_SOCK | ret_flag;
-	} else if (base_type(ret_type) == RET_PTR_TO_MPTCP_SOCK) {
-		mark_reg_known_zero(env, regs, BPF_REG_0);
-		regs[BPF_REG_0].type = PTR_TO_MPTCP_SOCK | ret_flag;
 	} else if (base_type(ret_type) == RET_PTR_TO_ALLOC_MEM) {
 		mark_reg_known_zero(env, regs, BPF_REG_0);
 		regs[BPF_REG_0].type = PTR_TO_MEM | ret_flag;
@@ -7485,7 +7471,6 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 	case PTR_TO_SOCKET:
 	case PTR_TO_SOCK_COMMON:
 	case PTR_TO_TCP_SOCK:
-	case PTR_TO_MPTCP_SOCK:
 	case PTR_TO_XDP_SOCK:
 		verbose(env, "R%d pointer arithmetic on %s prohibited\n",
 			dst, reg_type_str(env, ptr_reg->type));
@@ -10860,7 +10845,6 @@ static bool regsafe(struct bpf_verifier_env *env, struct bpf_reg_state *rold,
 	case PTR_TO_SOCKET:
 	case PTR_TO_SOCK_COMMON:
 	case PTR_TO_TCP_SOCK:
-	case PTR_TO_MPTCP_SOCK:
 	case PTR_TO_XDP_SOCK:
 		/* Only valid matches are exact, which memcmp() above
 		 * would have accepted
@@ -11391,7 +11375,6 @@ static bool reg_type_mismatch_ok(enum bpf_reg_type type)
 	case PTR_TO_SOCKET:
 	case PTR_TO_SOCK_COMMON:
 	case PTR_TO_TCP_SOCK:
-	case PTR_TO_MPTCP_SOCK:
 	case PTR_TO_XDP_SOCK:
 	case PTR_TO_BTF_ID:
 		return false;
@@ -12816,9 +12799,6 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env)
 		case PTR_TO_TCP_SOCK:
 			convert_ctx_access = bpf_tcp_sock_convert_ctx_access;
 			break;
-		case PTR_TO_MPTCP_SOCK:
-			convert_ctx_access = bpf_mptcp_sock_convert_ctx_access;
-			break;
 		case PTR_TO_XDP_SOCK:
 			convert_ctx_access = bpf_xdp_sock_convert_ctx_access;
 			break;
diff --git a/net/core/filter.c b/net/core/filter.c
index 7c177f247d0e..f195cf034e43 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -7889,10 +7889,6 @@ sock_ops_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 	case BPF_FUNC_tcp_sock:
 		return &bpf_tcp_sock_proto;
 #endif /* CONFIG_INET */
-#ifdef CONFIG_MPTCP
-	case BPF_FUNC_mptcp_sock:
-		return &bpf_mptcp_sock_proto;
-#endif /* CONFIG_MPTCP */
 	default:
 		return bpf_sk_base_func_proto(func_id);
 	}
diff --git a/net/mptcp/Makefile b/net/mptcp/Makefile
index 0a0608b6b4b4..48a9d978aaeb 100644
--- a/net/mptcp/Makefile
+++ b/net/mptcp/Makefile
@@ -11,5 +11,3 @@ 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
deleted file mode 100644
index 5332469fbb28..000000000000
--- a/net/mptcp/bpf.c
+++ /dev/null
@@ -1,72 +0,0 @@
-// 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"
-
-bool bpf_mptcp_sock_is_valid_access(int off, int size, enum bpf_access_type type,
-				    struct bpf_insn_access_aux *info)
-{
-	if (off < 0 || off >= offsetofend(struct bpf_mptcp_sock, token))
-		return false;
-
-	if (off % size != 0)
-		return false;
-
-	switch (off) {
-	default:
-		return size == sizeof(__u32);
-	}
-}
-
-u32 bpf_mptcp_sock_convert_ctx_access(enum bpf_access_type type,
-				      const struct bpf_insn *si,
-				      struct bpf_insn *insn_buf,
-				      struct bpf_prog *prog, u32 *target_size)
-{
-	struct bpf_insn *insn = insn_buf;
-
-#define BPF_MPTCP_SOCK_GET_COMMON(FIELD)							\
-	do {											\
-		BUILD_BUG_ON(sizeof_field(struct mptcp_sock, FIELD) >				\
-				sizeof_field(struct bpf_mptcp_sock, FIELD));			\
-		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct mptcp_sock, FIELD),		\
-							si->dst_reg, si->src_reg,		\
-							offsetof(struct mptcp_sock, FIELD));	\
-	} while (0)
-
-	if (insn > insn_buf)
-		return insn - insn_buf;
-
-	switch (si->off) {
-	case offsetof(struct bpf_mptcp_sock, token):
-		BPF_MPTCP_SOCK_GET_COMMON(token);
-		break;
-	}
-
-	return insn - insn_buf;
-}
-
-BPF_CALL_1(bpf_mptcp_sock, struct sock *, sk)
-{
-	if (sk_fullsock(sk) && sk->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk)) {
-		struct mptcp_subflow_context *mptcp_sfc = mptcp_subflow_ctx(sk);
-
-		return (unsigned long)mptcp_sfc->conn;
-	}
-	return (unsigned long)NULL;
-}
-
-const struct bpf_func_proto bpf_mptcp_sock_proto = {
-	.func           = bpf_mptcp_sock,
-	.gpl_only       = false,
-	.ret_type       = RET_PTR_TO_MPTCP_SOCK_OR_NULL,
-	.arg1_type      = ARG_PTR_TO_SOCK_COMMON,
-};
diff --git a/scripts/bpf_doc.py b/scripts/bpf_doc.py
index 6ef5c44a2a9e..096625242475 100755
--- a/scripts/bpf_doc.py
+++ b/scripts/bpf_doc.py
@@ -623,7 +623,6 @@ class PrinterHelpers(Printer):
             'struct udp6_sock',
             'struct unix_sock',
             'struct task_struct',
-            'struct bpf_mptcp_sock',
 
             'struct __sk_buff',
             'struct sk_msg_md',
@@ -683,7 +682,6 @@ class PrinterHelpers(Printer):
             'struct socket',
             'struct file',
             'struct bpf_timer',
-            'struct bpf_mptcp_sock',
     }
     mapped_types = {
             'u8': '__u8',
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 2a82b9353bab..4ae3cac94fb2 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -5117,14 +5117,6 @@ union bpf_attr {
  *		0 on success.
  *		**-EINVAL** for invalid input
  *		**-EOPNOTSUPP** for unsupported delivery_time_type and protocol
- *
- * struct bpf_mptcp_sock *bpf_mptcp_sock(struct bpf_sock *sk)
- *	Description
- *		This helper gets a **struct bpf_mptcp_sock** pointer from a
- *		**struct bpf_sock** pointer.
- *	Return
- *		A **struct bpf_mptcp_sock** pointer on success, or **NULL** in
- *		case of failure.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -5320,7 +5312,6 @@ union bpf_attr {
 	FN(xdp_store_bytes),		\
 	FN(copy_from_user_task),	\
 	FN(skb_set_delivery_time),      \
-	FN(mptcp_sock),			\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
@@ -5676,10 +5667,6 @@ struct bpf_tcp_sock {
 	__u32 is_mptcp;		/* Is MPTCP subflow? */
 };
 
-struct bpf_mptcp_sock {
-	__u32 token;		/* msk token */
-};
-
 struct bpf_sock_tuple {
 	union {
 		struct {
-- 
2.34.1

[PATCH mptcp-next v11 3/7] bpf: add bpf_skc_to_mptcp_sock_proto

[Geliang Tang]

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>
Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
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 57cb6af3177a..fdf4d2285588 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2365,6 +2365,15 @@ 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 4ae3cac94fb2..f02357cbdcbe 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -5117,6 +5117,12 @@ union bpf_attr {
  *		0 on success.
  *		**-EINVAL** for invalid input
  *		**-EOPNOTSUPP** for unsupported delivery_time_type and protocol
+ *
+ * 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),			\
@@ -5312,6 +5318,7 @@ union bpf_attr {
 	FN(xdp_store_bytes),		\
 	FN(copy_from_user_task),	\
 	FN(skb_set_delivery_time),      \
+	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 f195cf034e43..b87370e77926 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -11271,6 +11271,19 @@ 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);
@@ -11313,6 +11326,11 @@ 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..c3b6f94f033f
--- /dev/null
+++ b/net/mptcp/bpf.c
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Multipath TCP
+ *
+ * Copyright (c) 2020, Tessares SA.
+ * Copyright (c) 2022, SUSE.
+ *
+ * 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 4ae3cac94fb2..f02357cbdcbe 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -5117,6 +5117,12 @@ union bpf_attr {
  *		0 on success.
  *		**-EINVAL** for invalid input
  *		**-EOPNOTSUPP** for unsupported delivery_time_type and protocol
+ *
+ * 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),			\
@@ -5312,6 +5318,7 @@ union bpf_attr {
 	FN(xdp_store_bytes),		\
 	FN(copy_from_user_task),	\
 	FN(skb_set_delivery_time),      \
+	FN(skc_to_mptcp_sock),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
-- 
2.34.1

[PATCH mptcp-next v11 4/7] Squash to "selftests: bpf: add MPTCP test base"

[Geliang Tang]

Some cleanups.

Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 .../testing/selftests/bpf/prog_tests/mptcp.c  | 26 ++++++++++---------
 tools/testing/selftests/bpf/progs/mptcp.c     | 16 +++++++-----
 2 files changed, 23 insertions(+), 19 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
index 04aef0f147dc..24d82b19efbc 100644
--- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -1,4 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020, Tessares SA. */
+
 #include <test_progs.h>
 #include "cgroup_helpers.h"
 #include "network_helpers.h"
@@ -13,12 +15,6 @@ static int verify_sk(int map_fd, int client_fd, const char *msg, __u32 is_mptcp)
 	int err = 0, cfd = client_fd;
 	struct mptcp_storage val;
 
-	/* Currently there is no easy way to get back the subflow sk from the MPTCP
-	 * sk, thus we cannot access here the sk_storage associated to the subflow
-	 * sk. Also, there is no sk_storage associated with the MPTCP sk since it
-	 * does not trigger sockops events.
-	 * We silently pass this situation at the moment.
-	 */
 	if (is_mptcp == 1)
 		return 0;
 
@@ -28,14 +24,14 @@ static int verify_sk(int map_fd, int client_fd, const char *msg, __u32 is_mptcp)
 	}
 
 	if (val.invoked != 1) {
-		log_err("%s: unexpected invoked count %d != %d",
-			msg, val.invoked, 1);
+		log_err("%s: unexpected invoked count %d != 1",
+			msg, val.invoked);
 		err++;
 	}
 
-	if (val.is_mptcp != is_mptcp) {
-		log_err("%s: unexpected bpf_tcp_sock.is_mptcp %d != %d",
-			msg, val.is_mptcp, is_mptcp);
+	if (val.is_mptcp != 0) {
+		log_err("%s: unexpected bpf_tcp_sock.is_mptcp %d != 0",
+			msg, val.is_mptcp);
 		err++;
 	}
 
@@ -87,7 +83,7 @@ static int run_test(int cgroup_fd, int server_fd, bool is_mptcp)
 	return err;
 }
 
-void test_mptcp(void)
+void test_base(void)
 {
 	int server_fd, cgroup_fd;
 
@@ -117,3 +113,9 @@ void test_mptcp(void)
 close_cgroup_fd:
 	close(cgroup_fd);
 }
+
+void test_mptcp(void)
+{
+	if (test__start_subtest("base"))
+		test_base();
+}
diff --git a/tools/testing/selftests/bpf/progs/mptcp.c b/tools/testing/selftests/bpf/progs/mptcp.c
index be5ee8dac2b3..0d65fb889d03 100644
--- a/tools/testing/selftests/bpf/progs/mptcp.c
+++ b/tools/testing/selftests/bpf/progs/mptcp.c
@@ -1,4 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020, Tessares SA. */
+
 #include <linux/bpf.h>
 #include <bpf/bpf_helpers.h>
 
@@ -25,22 +27,22 @@ int _sockops(struct bpf_sock_ops *ctx)
 	int op = (int)ctx->op;
 	struct bpf_sock *sk;
 
+	if (op != BPF_SOCK_OPS_TCP_CONNECT_CB)
+		return 1;
+
 	sk = ctx->sk;
 	if (!sk)
 		return 1;
 
+	tcp_sk = bpf_tcp_sock(sk);
+	if (!tcp_sk)
+		return 1;
+
 	storage = bpf_sk_storage_get(&socket_storage_map, sk, 0,
 				     BPF_SK_STORAGE_GET_F_CREATE);
 	if (!storage)
 		return 1;
 
-	if (op != BPF_SOCK_OPS_TCP_CONNECT_CB)
-		return 1;
-
-	tcp_sk = bpf_tcp_sock(sk);
-	if (!tcp_sk)
-		return 1;
-
 	storage->invoked++;
 	storage->is_mptcp = tcp_sk->is_mptcp;
 
-- 
2.34.1

[PATCH mptcp-next v11 5/7] selftests: bpf: test bpf_skc_to_mptcp_sock

[Geliang Tang]

This patch extended the MPTCP test base, to test the new helper
bpf_skc_to_mptcp_sock().

Added a new function verify_msk() to verify the msk token, and a new
function get_msk_token() to parse the msk token from the output of the
command 'ip mptcp monitor'.

Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 tools/testing/selftests/bpf/bpf_tcp_helpers.h |   6 ++
 .../testing/selftests/bpf/prog_tests/mptcp.c  | 102 ++++++++++++++++--
 tools/testing/selftests/bpf/progs/mptcp.c     |  25 ++++-
 3 files changed, 123 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/bpf/bpf_tcp_helpers.h b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
index b1ede6f0b821..9ea6687c8f4d 100644
--- a/tools/testing/selftests/bpf/bpf_tcp_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
@@ -83,6 +83,12 @@ struct tcp_sock {
 	__u64	tcp_mstamp;	/* most recent packet received/sent */
 } __attribute__((preserve_access_index));
 
+struct mptcp_sock {
+	struct inet_connection_sock	sk;
+
+	__u32		token;
+} __attribute__((preserve_access_index));
+
 static __always_inline struct inet_connection_sock *inet_csk(const struct sock *sk)
 {
 	return (struct inet_connection_sock *)sk;
diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
index 24d82b19efbc..80e57ca1ea4d 100644
--- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -8,16 +8,17 @@
 struct mptcp_storage {
 	__u32 invoked;
 	__u32 is_mptcp;
+	__u32 token;
 };
 
-static int verify_sk(int map_fd, int client_fd, const char *msg, __u32 is_mptcp)
+static char monitor_log_path[64];
+
+static int verify_tsk(int map_fd, int client_fd)
 {
+	char *msg = "plain TCP socket";
 	int err = 0, cfd = client_fd;
 	struct mptcp_storage val;
 
-	if (is_mptcp == 1)
-		return 0;
-
 	if (CHECK_FAIL(bpf_map_lookup_elem(map_fd, &cfd, &val) < 0)) {
 		perror("Failed to read socket storage");
 		return -1;
@@ -38,6 +39,85 @@ static int verify_sk(int map_fd, int client_fd, const char *msg, __u32 is_mptcp)
 	return err;
 }
 
+/*
+ * Parse the token from the output of 'ip mptcp monitor':
+ *
+ * [       CREATED] token=3ca933d3 remid=0 locid=0 saddr4=127.0.0.1 ...
+ * [       CREATED] token=2ab57040 remid=0 locid=0 saddr4=127.0.0.1 ...
+ */
+static __u32 get_msk_token(void)
+{
+	char *prefix = "[       CREATED] token=";
+	char buf[BUFSIZ] = {};
+	__u32 token = 0;
+	ssize_t len;
+	int fd;
+
+	sync();
+
+	fd = open(monitor_log_path, O_RDONLY);
+	if (CHECK_FAIL(fd < 0)) {
+		log_err("Failed to open %s", monitor_log_path);
+		return token;
+	}
+
+	len = read(fd, buf, sizeof(buf));
+	if (CHECK_FAIL(len < 0)) {
+		log_err("Failed to read %s", monitor_log_path);
+		goto err;
+	}
+
+	if (strncmp(buf, prefix, strlen(prefix))) {
+		log_err("Invalid prefix %s", buf);
+		goto err;
+	}
+
+	token = strtol(buf + strlen(prefix), NULL, 16);
+
+err:
+	close(fd);
+	return token;
+}
+
+static int verify_msk(int map_fd, int client_fd)
+{
+	char *msg = "MPTCP subflow socket";
+	int err = 0, cfd = client_fd;
+	struct mptcp_storage val;
+	__u32 token;
+
+	token = get_msk_token();
+	if (token <= 0) {
+		log_err("Unexpected token %x", token);
+		return -1;
+	}
+
+	if (CHECK_FAIL(bpf_map_lookup_elem(map_fd, &cfd, &val) < 0)) {
+		perror("Failed to read socket storage");
+		return -1;
+	}
+
+	if (val.invoked != 1) {
+		log_err("%s: unexpected invoked count %d != 1",
+			msg, val.invoked);
+		err++;
+	}
+
+	if (val.is_mptcp != 1) {
+		log_err("%s: unexpected bpf_tcp_sock.is_mptcp %d != 1",
+			msg, val.is_mptcp);
+		err++;
+	}
+
+	if (val.token != token) {
+		log_err("Unexpected mptcp_sock.token %x != %x",
+			val.token, token);
+		err++;
+	}
+
+	return err;
+}
+
 static int run_test(int cgroup_fd, int server_fd, bool is_mptcp)
 {
 	int client_fd, prog_fd, map_fd, err;
@@ -72,8 +152,8 @@ static int run_test(int cgroup_fd, int server_fd, bool is_mptcp)
 		goto close_client_fd;
 	}
 
-	err += is_mptcp ? verify_sk(map_fd, client_fd, "MPTCP subflow socket", 1) :
-			  verify_sk(map_fd, client_fd, "plain TCP socket", 0);
+	err += is_mptcp ? verify_msk(map_fd, client_fd) :
+			  verify_tsk(map_fd, client_fd);
 
 close_client_fd:
 	close(client_fd);
@@ -85,6 +165,7 @@ static int run_test(int cgroup_fd, int server_fd, bool is_mptcp)
 
 void test_base(void)
 {
+	char cmd[256], tmp_dir[] = "/tmp/XXXXXX";
 	int server_fd, cgroup_fd;
 
 	cgroup_fd = test__join_cgroup("/mptcp");
@@ -102,6 +183,13 @@ void test_base(void)
 
 with_mptcp:
 	/* with MPTCP */
+	if (CHECK_FAIL(!mkdtemp(tmp_dir)))
+		goto close_cgroup_fd;
+	snprintf(monitor_log_path, sizeof(monitor_log_path),
+		 "%s/ip_mptcp_monitor", tmp_dir);
+	snprintf(cmd, sizeof(cmd), "ip mptcp monitor > %s &", monitor_log_path);
+	if (CHECK_FAIL(system(cmd)))
+		goto close_cgroup_fd;
 	server_fd = start_mptcp_server(AF_INET, NULL, 0, 0);
 	if (CHECK_FAIL(server_fd < 0))
 		goto close_cgroup_fd;
@@ -109,6 +197,8 @@ void test_base(void)
 	CHECK_FAIL(run_test(cgroup_fd, server_fd, true));
 
 	close(server_fd);
+	snprintf(cmd, sizeof(cmd), "rm -rf %s", tmp_dir);
+	system(cmd);
 
 close_cgroup_fd:
 	close(cgroup_fd);
diff --git a/tools/testing/selftests/bpf/progs/mptcp.c b/tools/testing/selftests/bpf/progs/mptcp.c
index 0d65fb889d03..afacea5ad9ca 100644
--- a/tools/testing/selftests/bpf/progs/mptcp.c
+++ b/tools/testing/selftests/bpf/progs/mptcp.c
@@ -3,6 +3,7 @@
 
 #include <linux/bpf.h>
 #include <bpf/bpf_helpers.h>
+#include "bpf_tcp_helpers.h"
 
 char _license[] SEC("license") = "GPL";
 __u32 _version SEC("version") = 1;
@@ -10,6 +11,7 @@ __u32 _version SEC("version") = 1;
 struct mptcp_storage {
 	__u32 invoked;
 	__u32 is_mptcp;
+	__u32 token;
 };
 
 struct {
@@ -24,6 +26,7 @@ int _sockops(struct bpf_sock_ops *ctx)
 {
 	struct mptcp_storage *storage;
 	struct bpf_tcp_sock *tcp_sk;
+	struct mptcp_sock *msk;
 	int op = (int)ctx->op;
 	struct bpf_sock *sk;
 
@@ -38,11 +41,25 @@ int _sockops(struct bpf_sock_ops *ctx)
 	if (!tcp_sk)
 		return 1;
 
-	storage = bpf_sk_storage_get(&socket_storage_map, sk, 0,
-				     BPF_SK_STORAGE_GET_F_CREATE);
-	if (!storage)
-		return 1;
+	if (!tcp_sk->is_mptcp) {
+		storage = bpf_sk_storage_get(&socket_storage_map, sk, 0,
+					     BPF_SK_STORAGE_GET_F_CREATE);
+		if (!storage)
+			return 1;
+
+		storage->token = 0;
+	} else {
+		msk = bpf_skc_to_mptcp_sock(sk);
+		if (!msk)
+			return 1;
+
+		storage = bpf_sk_storage_get(&socket_storage_map, msk, 0,
+					     BPF_SK_STORAGE_GET_F_CREATE);
+		if (!storage)
+			return 1;
 
+		storage->token = msk->token;
+	}
 	storage->invoked++;
 	storage->is_mptcp = tcp_sk->is_mptcp;
 
-- 
2.34.1

[PATCH mptcp-next v11 6/7] selftests: bpf: verify ca_name of struct mptcp_sock

[Geliang Tang]

This patch verified another member of struct mptcp_sock, ca_name. Added a
new function get_msk_ca_name() to read the sysctl tcp_congestion_control
and verified it in verify_msk().

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 tools/testing/selftests/bpf/bpf_tcp_helpers.h |  5 ++++
 .../testing/selftests/bpf/prog_tests/mptcp.c  | 25 +++++++++++++++++++
 tools/testing/selftests/bpf/progs/mptcp.c     |  4 +++
 3 files changed, 34 insertions(+)

diff --git a/tools/testing/selftests/bpf/bpf_tcp_helpers.h b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
index 9ea6687c8f4d..bebe382bcc7a 100644
--- a/tools/testing/selftests/bpf/bpf_tcp_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
@@ -16,6 +16,10 @@ BPF_PROG(name, args)
 #define SOL_TCP 6
 #endif
 
+#ifndef TCP_CA_NAME_MAX
+#define TCP_CA_NAME_MAX	16
+#endif
+
 #define tcp_jiffies32 ((__u32)bpf_jiffies64())
 
 struct sock_common {
@@ -87,6 +91,7 @@ struct mptcp_sock {
 	struct inet_connection_sock	sk;
 
 	__u32		token;
+	char		ca_name[TCP_CA_NAME_MAX];
 } __attribute__((preserve_access_index));
 
 static __always_inline struct inet_connection_sock *inet_csk(const struct sock *sk)
diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
index 80e57ca1ea4d..0f8ced3845c9 100644
--- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -5,10 +5,15 @@
 #include "cgroup_helpers.h"
 #include "network_helpers.h"
 
+#ifndef TCP_CA_NAME_MAX
+#define TCP_CA_NAME_MAX	16
+#endif
+
 struct mptcp_storage {
 	__u32 invoked;
 	__u32 is_mptcp;
 	__u32 token;
+	char ca_name[TCP_CA_NAME_MAX];
 };
 
 static char monitor_log_path[64];
@@ -79,14 +84,28 @@ static __u32 get_msk_token(void)
 	return token;
 }
 
+void get_msk_ca_name(char ca_name[])
+{
+	FILE *stream = popen("sysctl -b net.ipv4.tcp_congestion_control", "r");
+	ssize_t len;
+
+	len = fread(ca_name, TCP_CA_NAME_MAX, 1, stream);
+	if (CHECK_FAIL(len < 0))
+		log_err("Failed to read ca_name");
+
+	pclose(stream);
+}
+
 static int verify_msk(int map_fd, int client_fd)
 {
 	char *msg = "MPTCP subflow socket";
 	int err = 0, cfd = client_fd;
 	struct mptcp_storage val;
+	char ca_name[TCP_CA_NAME_MAX];
 	__u32 token;
 
 	token = get_msk_token();
+	get_msk_ca_name(ca_name);
 	if (token <= 0) {
 		log_err("Unexpected token %x", token);
 		return -1;
@@ -115,6 +134,12 @@ static int verify_msk(int map_fd, int client_fd)
 		err++;
 	}
 
+	if (strncmp(val.ca_name, ca_name, TCP_CA_NAME_MAX)) {
+		log_err("Unexpected mptcp_sock.ca_name %s != %s",
+			val.ca_name, ca_name);
+		err++;
+	}
+
 	return err;
 }
 
diff --git a/tools/testing/selftests/bpf/progs/mptcp.c b/tools/testing/selftests/bpf/progs/mptcp.c
index afacea5ad9ca..6e7d2abf6ce3 100644
--- a/tools/testing/selftests/bpf/progs/mptcp.c
+++ b/tools/testing/selftests/bpf/progs/mptcp.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (c) 2020, Tessares SA. */
 
+#include <string.h>
 #include <linux/bpf.h>
 #include <bpf/bpf_helpers.h>
 #include "bpf_tcp_helpers.h"
@@ -12,6 +13,7 @@ struct mptcp_storage {
 	__u32 invoked;
 	__u32 is_mptcp;
 	__u32 token;
+	char ca_name[TCP_CA_NAME_MAX];
 };
 
 struct {
@@ -48,6 +50,7 @@ int _sockops(struct bpf_sock_ops *ctx)
 			return 1;
 
 		storage->token = 0;
+		bzero(storage->ca_name, TCP_CA_NAME_MAX);
 	} else {
 		msk = bpf_skc_to_mptcp_sock(sk);
 		if (!msk)
@@ -59,6 +62,7 @@ int _sockops(struct bpf_sock_ops *ctx)
 			return 1;
 
 		storage->token = msk->token;
+		memcpy(storage->ca_name, msk->ca_name, TCP_CA_NAME_MAX);
 	}
 	storage->invoked++;
 	storage->is_mptcp = tcp_sk->is_mptcp;
-- 
2.34.1

[PATCH mptcp-next v11 7/7] selftests: bpf: verify first subflow of mptcp_sock

[Geliang Tang]

This patch verified the 'first' struct member of struct mptcp_sock, which
pointed to the first subflow of msk. Saved 'sk' in mptcp_storage, and
verified it with 'first' in verify_msk().

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 tools/testing/selftests/bpf/bpf_tcp_helpers.h  | 1 +
 tools/testing/selftests/bpf/prog_tests/mptcp.c | 8 ++++++++
 tools/testing/selftests/bpf/progs/mptcp.c      | 5 +++++
 3 files changed, 14 insertions(+)

diff --git a/tools/testing/selftests/bpf/bpf_tcp_helpers.h b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
index bebe382bcc7a..f92357597e63 100644
--- a/tools/testing/selftests/bpf/bpf_tcp_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
@@ -91,6 +91,7 @@ struct mptcp_sock {
 	struct inet_connection_sock	sk;
 
 	__u32		token;
+	struct sock	*first;
 	char		ca_name[TCP_CA_NAME_MAX];
 } __attribute__((preserve_access_index));
 
diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
index 0f8ced3845c9..325f8b51f621 100644
--- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -12,7 +12,9 @@
 struct mptcp_storage {
 	__u32 invoked;
 	__u32 is_mptcp;
+	struct sock *sk;
 	__u32 token;
+	struct sock *first;
 	char ca_name[TCP_CA_NAME_MAX];
 };
 
@@ -134,6 +136,12 @@ static int verify_msk(int map_fd, int client_fd)
 		err++;
 	}
 
+	if (val.first != val.sk) {
+		log_err("Unexpected mptcp_sock.first %p != %p",
+			val.first, val.sk);
+		err++;
+	}
+
 	if (strncmp(val.ca_name, ca_name, TCP_CA_NAME_MAX)) {
 		log_err("Unexpected mptcp_sock.ca_name %s != %s",
 			val.ca_name, ca_name);
diff --git a/tools/testing/selftests/bpf/progs/mptcp.c b/tools/testing/selftests/bpf/progs/mptcp.c
index 6e7d2abf6ce3..16055f553f29 100644
--- a/tools/testing/selftests/bpf/progs/mptcp.c
+++ b/tools/testing/selftests/bpf/progs/mptcp.c
@@ -12,7 +12,9 @@ __u32 _version SEC("version") = 1;
 struct mptcp_storage {
 	__u32 invoked;
 	__u32 is_mptcp;
+	struct sock *sk;
 	__u32 token;
+	struct sock *first;
 	char ca_name[TCP_CA_NAME_MAX];
 };
 
@@ -51,6 +53,7 @@ int _sockops(struct bpf_sock_ops *ctx)
 
 		storage->token = 0;
 		bzero(storage->ca_name, TCP_CA_NAME_MAX);
+		storage->first = NULL;
 	} else {
 		msk = bpf_skc_to_mptcp_sock(sk);
 		if (!msk)
@@ -63,9 +66,11 @@ int _sockops(struct bpf_sock_ops *ctx)
 
 		storage->token = msk->token;
 		memcpy(storage->ca_name, msk->ca_name, TCP_CA_NAME_MAX);
+		storage->first = msk->first;
 	}
 	storage->invoked++;
 	storage->is_mptcp = tcp_sk->is_mptcp;
+	storage->sk = (struct sock *)sk;
 
 	return 1;
 }
-- 
2.34.1

Re: [PATCH mptcp-next v11 0/7] add skc_to_mptcp_sock

[Matthieu Baerts]

Hi Geliang,

On 23/03/2022 10:09, Geliang Tang wrote:
> v11:
>  - merge "check more values from mptcp_sock" series into this series.
>  - patch 2:
>    - rebased.
>  - patch 3:
>    - rebased.
>    - add 'Copyright' entry as Matt suggested in v9:
>    https://patchwork.kernel.org/project/mptcp/patch/d6d33be9899118c5f542a6ce43f868d4e9e2766b.1646745228.git.geliang.tang@suse.com/
>  - patch 4:
>    - add test__start_subtest.
>    - add some 'Copyright' entries.
>  - patch 5:
>    - change monitor_log_path to static
>    - drop bpf_trace_printk()
>  - patch 6:
>    - use TCP_CA_NAME_MAX instead of strlen(val.ca_name) in strncmp().
>    - use 'sysctl -b net.ipv4.tcp_congestion_control' to get ca_name.

Thank you for the v11 and your patience!

I already applied the two first patches because they have already been
reviewed before and they were causing conflicts with latest BPF changes:

- 83c2e9333801: "squashed" patch 1/7 in "selftests: bpf: add
bpf_mptcp_sock() verifier tests"
- 3e1cf22ec63a: "squashed" patch 2/7 in "bpf: add 'bpf_mptcp_sock'
structure and helper"
- Results: 170b2a907bd7..b3fcb6331ff3 (export)

Cheers,
Matt
-- 
Tessares | Belgium | Hybrid Access Solutions
www.tessares.net

Re: [PATCH mptcp-next v11 0/7] add skc_to_mptcp_sock

[Matthieu Baerts]

Hi Geliang,

On 23/03/2022 13:48, Matthieu Baerts wrote:
> Hi Geliang,
> 
> On 23/03/2022 10:09, Geliang Tang wrote:
>> v11:
>>  - merge "check more values from mptcp_sock" series into this series.
>>  - patch 2:
>>    - rebased.
>>  - patch 3:
>>    - rebased.
>>    - add 'Copyright' entry as Matt suggested in v9:
>>    https://patchwork.kernel.org/project/mptcp/patch/d6d33be9899118c5f542a6ce43f868d4e9e2766b.1646745228.git.geliang.tang@suse.com/
>>  - patch 4:
>>    - add test__start_subtest.
>>    - add some 'Copyright' entries.
>>  - patch 5:
>>    - change monitor_log_path to static
>>    - drop bpf_trace_printk()
>>  - patch 6:
>>    - use TCP_CA_NAME_MAX instead of strlen(val.ca_name) in strncmp().
>>    - use 'sysctl -b net.ipv4.tcp_congestion_control' to get ca_name.
> 
> Thank you for the v11 and your patience!
> 
> I already applied the two first patches because they have already been
> reviewed before and they were causing conflicts with latest BPF changes:

The new patches, the modifications compared to v10 and the Squash-to
patch look good to me!

Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>

@Mat: also OK for you as you also reviewed the previous versions? :)

Cheers,
Matt
-- 
Tessares | Belgium | Hybrid Access Solutions
www.tessares.net

Re: [PATCH mptcp-next v11 6/7] selftests: bpf: verify ca_name of struct mptcp_sock

[Mat Martineau]

On Wed, 23 Mar 2022, Geliang Tang wrote:

> This patch verified another member of struct mptcp_sock, ca_name. Added a
> new function get_msk_ca_name() to read the sysctl tcp_congestion_control
> and verified it in verify_msk().
>
> Signed-off-by: Geliang Tang <geliang.tang@suse.com>
> ---
> tools/testing/selftests/bpf/bpf_tcp_helpers.h |  5 ++++
> .../testing/selftests/bpf/prog_tests/mptcp.c  | 25 +++++++++++++++++++
> tools/testing/selftests/bpf/progs/mptcp.c     |  4 +++
> 3 files changed, 34 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/bpf_tcp_helpers.h b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
> index 9ea6687c8f4d..bebe382bcc7a 100644
> --- a/tools/testing/selftests/bpf/bpf_tcp_helpers.h
> +++ b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
> @@ -16,6 +16,10 @@ BPF_PROG(name, args)
> #define SOL_TCP 6
> #endif
>
> +#ifndef TCP_CA_NAME_MAX
> +#define TCP_CA_NAME_MAX	16
> +#endif
> +
> #define tcp_jiffies32 ((__u32)bpf_jiffies64())
>
> struct sock_common {
> @@ -87,6 +91,7 @@ struct mptcp_sock {
> 	struct inet_connection_sock	sk;
>
> 	__u32		token;
> +	char		ca_name[TCP_CA_NAME_MAX];
> } __attribute__((preserve_access_index));
>
> static __always_inline struct inet_connection_sock *inet_csk(const struct sock *sk)
> diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> index 80e57ca1ea4d..0f8ced3845c9 100644
> --- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
> +++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> @@ -5,10 +5,15 @@
> #include "cgroup_helpers.h"
> #include "network_helpers.h"
>
> +#ifndef TCP_CA_NAME_MAX
> +#define TCP_CA_NAME_MAX	16
> +#endif
> +
> struct mptcp_storage {
> 	__u32 invoked;
> 	__u32 is_mptcp;
> 	__u32 token;
> +	char ca_name[TCP_CA_NAME_MAX];
> };
>
> static char monitor_log_path[64];
> @@ -79,14 +84,28 @@ static __u32 get_msk_token(void)
> 	return token;
> }
>
> +void get_msk_ca_name(char ca_name[])
> +{
> +	FILE *stream = popen("sysctl -b net.ipv4.tcp_congestion_control", "r");
> +	ssize_t len;
> +
> +	len = fread(ca_name, TCP_CA_NAME_MAX, 1, stream);
> +	if (CHECK_FAIL(len < 0))
> +		log_err("Failed to read ca_name");
> +
> +	pclose(stream);
> +}
> +
> static int verify_msk(int map_fd, int client_fd)
> {
> 	char *msg = "MPTCP subflow socket";
> 	int err = 0, cfd = client_fd;
> 	struct mptcp_storage val;
> +	char ca_name[TCP_CA_NAME_MAX];
> 	__u32 token;
>
> 	token = get_msk_token();
> +	get_msk_ca_name(ca_name);
> 	if (token <= 0) {
> 		log_err("Unexpected token %x", token);
> 		return -1;
> @@ -115,6 +134,12 @@ static int verify_msk(int map_fd, int client_fd)
> 		err++;
> 	}
>
> +	if (strncmp(val.ca_name, ca_name, TCP_CA_NAME_MAX)) {
> +		log_err("Unexpected mptcp_sock.ca_name %s != %s",
> +			val.ca_name, ca_name);

Double checking - is it guaranteed that ca_name and val.ca_name are null 
terminated?

-Mat

> +		err++;
> +	}
> +
> 	return err;
> }
>
> diff --git a/tools/testing/selftests/bpf/progs/mptcp.c b/tools/testing/selftests/bpf/progs/mptcp.c
> index afacea5ad9ca..6e7d2abf6ce3 100644
> --- a/tools/testing/selftests/bpf/progs/mptcp.c
> +++ b/tools/testing/selftests/bpf/progs/mptcp.c
> @@ -1,6 +1,7 @@
> // SPDX-License-Identifier: GPL-2.0
> /* Copyright (c) 2020, Tessares SA. */
>
> +#include <string.h>
> #include <linux/bpf.h>
> #include <bpf/bpf_helpers.h>
> #include "bpf_tcp_helpers.h"
> @@ -12,6 +13,7 @@ struct mptcp_storage {
> 	__u32 invoked;
> 	__u32 is_mptcp;
> 	__u32 token;
> +	char ca_name[TCP_CA_NAME_MAX];
> };
>
> struct {
> @@ -48,6 +50,7 @@ int _sockops(struct bpf_sock_ops *ctx)
> 			return 1;
>
> 		storage->token = 0;
> +		bzero(storage->ca_name, TCP_CA_NAME_MAX);
> 	} else {
> 		msk = bpf_skc_to_mptcp_sock(sk);
> 		if (!msk)
> @@ -59,6 +62,7 @@ int _sockops(struct bpf_sock_ops *ctx)
> 			return 1;
>
> 		storage->token = msk->token;
> +		memcpy(storage->ca_name, msk->ca_name, TCP_CA_NAME_MAX);
> 	}
> 	storage->invoked++;
> 	storage->is_mptcp = tcp_sk->is_mptcp;
> -- 
> 2.34.1
>
>
>

--
Mat Martineau
Intel

Re: [PATCH mptcp-next v11 0/7] add skc_to_mptcp_sock

[Mat Martineau]

On Wed, 23 Mar 2022, Matthieu Baerts wrote:

> Hi Geliang,
>
> On 23/03/2022 13:48, Matthieu Baerts wrote:
>> Hi Geliang,
>>
>> On 23/03/2022 10:09, Geliang Tang wrote:
>>> v11:
>>>  - merge "check more values from mptcp_sock" series into this series.
>>>  - patch 2:
>>>    - rebased.
>>>  - patch 3:
>>>    - rebased.
>>>    - add 'Copyright' entry as Matt suggested in v9:
>>>    https://patchwork.kernel.org/project/mptcp/patch/d6d33be9899118c5f542a6ce43f868d4e9e2766b.1646745228.git.geliang.tang@suse.com/
>>>  - patch 4:
>>>    - add test__start_subtest.
>>>    - add some 'Copyright' entries.
>>>  - patch 5:
>>>    - change monitor_log_path to static
>>>    - drop bpf_trace_printk()
>>>  - patch 6:
>>>    - use TCP_CA_NAME_MAX instead of strlen(val.ca_name) in strncmp().
>>>    - use 'sysctl -b net.ipv4.tcp_congestion_control' to get ca_name.
>>
>> Thank you for the v11 and your patience!
>>
>> I already applied the two first patches because they have already been
>> reviewed before and they were causing conflicts with latest BPF changes:
>
> The new patches, the modifications compared to v10 and the Squash-to
> patch look good to me!
>
> Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
>
> @Mat: also OK for you as you also reviewed the previous versions? :)

Yes, fine to add these to the export branch. If other changes are needed 
those could be squashed.

--
Mat Martineau
Intel

Re: [PATCH mptcp-next v11 6/7] selftests: bpf: verify ca_name of struct mptcp_sock

[Geliang Tang]

On Wed, Mar 23, 2022 at 11:28:50AM -0700, Mat Martineau wrote:
> On Wed, 23 Mar 2022, Geliang Tang wrote:
> 
> > This patch verified another member of struct mptcp_sock, ca_name. Added a
> > new function get_msk_ca_name() to read the sysctl tcp_congestion_control
> > and verified it in verify_msk().
> > 
> > Signed-off-by: Geliang Tang <geliang.tang@suse.com>
> > ---
> > tools/testing/selftests/bpf/bpf_tcp_helpers.h |  5 ++++
> > .../testing/selftests/bpf/prog_tests/mptcp.c  | 25 +++++++++++++++++++
> > tools/testing/selftests/bpf/progs/mptcp.c     |  4 +++
> > 3 files changed, 34 insertions(+)
> > 
> > diff --git a/tools/testing/selftests/bpf/bpf_tcp_helpers.h b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
> > index 9ea6687c8f4d..bebe382bcc7a 100644
> > --- a/tools/testing/selftests/bpf/bpf_tcp_helpers.h
> > +++ b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
> > @@ -16,6 +16,10 @@ BPF_PROG(name, args)
> > #define SOL_TCP 6
> > #endif
> > 
> > +#ifndef TCP_CA_NAME_MAX
> > +#define TCP_CA_NAME_MAX	16
> > +#endif
> > +
> > #define tcp_jiffies32 ((__u32)bpf_jiffies64())
> > 
> > struct sock_common {
> > @@ -87,6 +91,7 @@ struct mptcp_sock {
> > 	struct inet_connection_sock	sk;
> > 
> > 	__u32		token;
> > +	char		ca_name[TCP_CA_NAME_MAX];
> > } __attribute__((preserve_access_index));
> > 
> > static __always_inline struct inet_connection_sock *inet_csk(const struct sock *sk)
> > diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> > index 80e57ca1ea4d..0f8ced3845c9 100644
> > --- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
> > +++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> > @@ -5,10 +5,15 @@
> > #include "cgroup_helpers.h"
> > #include "network_helpers.h"
> > 
> > +#ifndef TCP_CA_NAME_MAX
> > +#define TCP_CA_NAME_MAX	16
> > +#endif
> > +
> > struct mptcp_storage {
> > 	__u32 invoked;
> > 	__u32 is_mptcp;
> > 	__u32 token;
> > +	char ca_name[TCP_CA_NAME_MAX];
> > };
> > 
> > static char monitor_log_path[64];
> > @@ -79,14 +84,28 @@ static __u32 get_msk_token(void)
> > 	return token;
> > }
> > 
> > +void get_msk_ca_name(char ca_name[])
> > +{
> > +	FILE *stream = popen("sysctl -b net.ipv4.tcp_congestion_control", "r");
> > +	ssize_t len;
> > +
> > +	len = fread(ca_name, TCP_CA_NAME_MAX, 1, stream);
> > +	if (CHECK_FAIL(len < 0))
> > +		log_err("Failed to read ca_name");
> > +
> > +	pclose(stream);
> > +}
> > +
> > static int verify_msk(int map_fd, int client_fd)
> > {
> > 	char *msg = "MPTCP subflow socket";
> > 	int err = 0, cfd = client_fd;
> > 	struct mptcp_storage val;
> > +	char ca_name[TCP_CA_NAME_MAX];
> > 	__u32 token;
> > 
> > 	token = get_msk_token();
> > +	get_msk_ca_name(ca_name);
> > 	if (token <= 0) {
> > 		log_err("Unexpected token %x", token);
> > 		return -1;
> > @@ -115,6 +134,12 @@ static int verify_msk(int map_fd, int client_fd)
> > 		err++;
> > 	}
> > 
> > +	if (strncmp(val.ca_name, ca_name, TCP_CA_NAME_MAX)) {
> > +		log_err("Unexpected mptcp_sock.ca_name %s != %s",
> > +			val.ca_name, ca_name);
> 
> Double checking - is it guaranteed that ca_name and val.ca_name are null
> terminated?

val.ca_name is null terminated, but ca_name isn't. I should use fgets()
instead of fread() in get_msk_ca_name().

On today's export branch, 3/7 of v11 needs to be rebased, and thers's a
build break in 4/7, so I just sent a v12 with all these changes.

Thanks,
-Geliang

> 
> -Mat
> 
> > +		err++;
> > +	}
> > +
> > 	return err;
> > }
> > 
> > diff --git a/tools/testing/selftests/bpf/progs/mptcp.c b/tools/testing/selftests/bpf/progs/mptcp.c
> > index afacea5ad9ca..6e7d2abf6ce3 100644
> > --- a/tools/testing/selftests/bpf/progs/mptcp.c
> > +++ b/tools/testing/selftests/bpf/progs/mptcp.c
> > @@ -1,6 +1,7 @@
> > // SPDX-License-Identifier: GPL-2.0
> > /* Copyright (c) 2020, Tessares SA. */
> > 
> > +#include <string.h>
> > #include <linux/bpf.h>
> > #include <bpf/bpf_helpers.h>
> > #include "bpf_tcp_helpers.h"
> > @@ -12,6 +13,7 @@ struct mptcp_storage {
> > 	__u32 invoked;
> > 	__u32 is_mptcp;
> > 	__u32 token;
> > +	char ca_name[TCP_CA_NAME_MAX];
> > };
> > 
> > struct {
> > @@ -48,6 +50,7 @@ int _sockops(struct bpf_sock_ops *ctx)
> > 			return 1;
> > 
> > 		storage->token = 0;
> > +		bzero(storage->ca_name, TCP_CA_NAME_MAX);
> > 	} else {
> > 		msk = bpf_skc_to_mptcp_sock(sk);
> > 		if (!msk)
> > @@ -59,6 +62,7 @@ int _sockops(struct bpf_sock_ops *ctx)
> > 			return 1;
> > 
> > 		storage->token = msk->token;
> > +		memcpy(storage->ca_name, msk->ca_name, TCP_CA_NAME_MAX);
> > 	}
> > 	storage->invoked++;
> > 	storage->is_mptcp = tcp_sk->is_mptcp;
> > -- 
> > 2.34.1
> > 
> > 
> > 
> 
> --
> Mat Martineau
> Intel
>