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From: Daniel Borkmann <daniel@iogearbox.net>
To: ast@kernel.org
Cc: andrii@kernel.org, martin.lau@linux.dev, razor@blackwall.org,
	sdf@google.com, john.fastabend@gmail.com, kuba@kernel.org,
	dxu@dxuuu.xyz, joe@cilium.io, toke@kernel.org,
	davem@davemloft.net, bpf@vger.kernel.org, netdev@vger.kernel.org,
	Daniel Borkmann <daniel@iogearbox.net>
Subject: [PATCH bpf-next v6 3/8] libbpf: Add opts-based attach/detach/query API for tcx
Date: Wed, 19 Jul 2023 16:08:53 +0200	[thread overview]
Message-ID: <20230719140858.13224-4-daniel@iogearbox.net> (raw)
In-Reply-To: <20230719140858.13224-1-daniel@iogearbox.net>

Extend libbpf attach opts and add a new detach opts API so this can be used
to add/remove fd-based tcx BPF programs. The old-style bpf_prog_detach() and
bpf_prog_detach2() APIs are refactored to reuse the new bpf_prog_detach_opts()
internally.

The bpf_prog_query_opts() API got extended to be able to handle the new
link_ids, link_attach_flags and revision fields.

For concrete usage examples, see the extensive selftests that have been
developed as part of this series.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
---
 tools/lib/bpf/bpf.c      | 107 ++++++++++++++++++++++++++-------------
 tools/lib/bpf/bpf.h      |  92 ++++++++++++++++++++++++++++-----
 tools/lib/bpf/libbpf.c   |  12 +++--
 tools/lib/bpf/libbpf.map |   1 +
 4 files changed, 159 insertions(+), 53 deletions(-)

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 3b0da19715e1..4131d3a1484b 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -629,55 +629,89 @@ int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type,
 	return bpf_prog_attach_opts(prog_fd, target_fd, type, &opts);
 }
 
-int bpf_prog_attach_opts(int prog_fd, int target_fd,
-			  enum bpf_attach_type type,
-			  const struct bpf_prog_attach_opts *opts)
+int bpf_prog_attach_opts(int prog_fd, int target, enum bpf_attach_type type,
+			 const struct bpf_prog_attach_opts *opts)
 {
-	const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd);
+	const size_t attr_sz = offsetofend(union bpf_attr, expected_revision);
+	__u32 relative_id, flags;
+	int ret, relative_fd;
 	union bpf_attr attr;
-	int ret;
 
 	if (!OPTS_VALID(opts, bpf_prog_attach_opts))
 		return libbpf_err(-EINVAL);
 
+	relative_id = OPTS_GET(opts, relative_id, 0);
+	relative_fd = OPTS_GET(opts, relative_fd, 0);
+	flags = OPTS_GET(opts, flags, 0);
+
+	/* validate we don't have unexpected combinations of non-zero fields */
+	if (relative_fd && relative_id)
+		return libbpf_err(-EINVAL);
+
 	memset(&attr, 0, attr_sz);
-	attr.target_fd	   = target_fd;
-	attr.attach_bpf_fd = prog_fd;
-	attr.attach_type   = type;
-	attr.attach_flags  = OPTS_GET(opts, flags, 0);
-	attr.replace_bpf_fd = OPTS_GET(opts, replace_prog_fd, 0);
+	attr.target_fd		= target;
+	attr.attach_bpf_fd	= prog_fd;
+	attr.attach_type	= type;
+	attr.replace_bpf_fd	= OPTS_GET(opts, replace_fd, 0);
+	attr.expected_revision	= OPTS_GET(opts, expected_revision, 0);
+
+	if (relative_id) {
+		attr.attach_flags = flags | BPF_F_ID;
+		attr.relative_id  = relative_id;
+	} else {
+		attr.attach_flags = flags;
+		attr.relative_fd  = relative_fd;
+	}
 
 	ret = sys_bpf(BPF_PROG_ATTACH, &attr, attr_sz);
 	return libbpf_err_errno(ret);
 }
 
-int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
+int bpf_prog_detach_opts(int prog_fd, int target, enum bpf_attach_type type,
+			 const struct bpf_prog_detach_opts *opts)
 {
-	const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd);
+	const size_t attr_sz = offsetofend(union bpf_attr, expected_revision);
+	__u32 relative_id, flags;
+	int ret, relative_fd;
 	union bpf_attr attr;
-	int ret;
+
+	if (!OPTS_VALID(opts, bpf_prog_detach_opts))
+		return libbpf_err(-EINVAL);
+
+	relative_id = OPTS_GET(opts, relative_id, 0);
+	relative_fd = OPTS_GET(opts, relative_fd, 0);
+	flags = OPTS_GET(opts, flags, 0);
+
+	/* validate we don't have unexpected combinations of non-zero fields */
+	if (relative_fd && relative_id)
+		return libbpf_err(-EINVAL);
 
 	memset(&attr, 0, attr_sz);
-	attr.target_fd	 = target_fd;
-	attr.attach_type = type;
+	attr.target_fd		= target;
+	attr.attach_bpf_fd	= prog_fd;
+	attr.attach_type	= type;
+	attr.expected_revision	= OPTS_GET(opts, expected_revision, 0);
+
+	if (relative_id) {
+		attr.attach_flags = flags | BPF_F_ID;
+		attr.relative_id  = relative_id;
+	} else {
+		attr.attach_flags = flags;
+		attr.relative_fd  = relative_fd;
+	}
 
 	ret = sys_bpf(BPF_PROG_DETACH, &attr, attr_sz);
 	return libbpf_err_errno(ret);
 }
 
-int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type)
+int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
 {
-	const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd);
-	union bpf_attr attr;
-	int ret;
-
-	memset(&attr, 0, attr_sz);
-	attr.target_fd	 = target_fd;
-	attr.attach_bpf_fd = prog_fd;
-	attr.attach_type = type;
+	return bpf_prog_detach_opts(0, target_fd, type, NULL);
+}
 
-	ret = sys_bpf(BPF_PROG_DETACH, &attr, attr_sz);
-	return libbpf_err_errno(ret);
+int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type)
+{
+	return bpf_prog_detach_opts(prog_fd, target_fd, type, NULL);
 }
 
 int bpf_link_create(int prog_fd, int target_fd,
@@ -841,8 +875,7 @@ int bpf_iter_create(int link_fd)
 	return libbpf_err_errno(fd);
 }
 
-int bpf_prog_query_opts(int target_fd,
-			enum bpf_attach_type type,
+int bpf_prog_query_opts(int target, enum bpf_attach_type type,
 			struct bpf_prog_query_opts *opts)
 {
 	const size_t attr_sz = offsetofend(union bpf_attr, query);
@@ -853,18 +886,20 @@ int bpf_prog_query_opts(int target_fd,
 		return libbpf_err(-EINVAL);
 
 	memset(&attr, 0, attr_sz);
-
-	attr.query.target_fd	= target_fd;
-	attr.query.attach_type	= type;
-	attr.query.query_flags	= OPTS_GET(opts, query_flags, 0);
-	attr.query.prog_cnt	= OPTS_GET(opts, prog_cnt, 0);
-	attr.query.prog_ids	= ptr_to_u64(OPTS_GET(opts, prog_ids, NULL));
-	attr.query.prog_attach_flags = ptr_to_u64(OPTS_GET(opts, prog_attach_flags, NULL));
+	attr.query.target_fd		= target;
+	attr.query.attach_type		= type;
+	attr.query.query_flags		= OPTS_GET(opts, query_flags, 0);
+	attr.query.count		= OPTS_GET(opts, count, 0);
+	attr.query.prog_ids		= ptr_to_u64(OPTS_GET(opts, prog_ids, NULL));
+	attr.query.link_ids		= ptr_to_u64(OPTS_GET(opts, link_ids, NULL));
+	attr.query.prog_attach_flags	= ptr_to_u64(OPTS_GET(opts, prog_attach_flags, NULL));
+	attr.query.link_attach_flags	= ptr_to_u64(OPTS_GET(opts, link_attach_flags, NULL));
 
 	ret = sys_bpf(BPF_PROG_QUERY, &attr, attr_sz);
 
 	OPTS_SET(opts, attach_flags, attr.query.attach_flags);
-	OPTS_SET(opts, prog_cnt, attr.query.prog_cnt);
+	OPTS_SET(opts, revision, attr.query.revision);
+	OPTS_SET(opts, count, attr.query.count);
 
 	return libbpf_err_errno(ret);
 }
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index c676295ab9bf..49e9d88fd9cf 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -312,22 +312,68 @@ LIBBPF_API int bpf_obj_get(const char *pathname);
 LIBBPF_API int bpf_obj_get_opts(const char *pathname,
 				const struct bpf_obj_get_opts *opts);
 
-struct bpf_prog_attach_opts {
-	size_t sz; /* size of this struct for forward/backward compatibility */
-	unsigned int flags;
-	int replace_prog_fd;
-};
-#define bpf_prog_attach_opts__last_field replace_prog_fd
-
 LIBBPF_API int bpf_prog_attach(int prog_fd, int attachable_fd,
 			       enum bpf_attach_type type, unsigned int flags);
-LIBBPF_API int bpf_prog_attach_opts(int prog_fd, int attachable_fd,
-				     enum bpf_attach_type type,
-				     const struct bpf_prog_attach_opts *opts);
 LIBBPF_API int bpf_prog_detach(int attachable_fd, enum bpf_attach_type type);
 LIBBPF_API int bpf_prog_detach2(int prog_fd, int attachable_fd,
 				enum bpf_attach_type type);
 
+struct bpf_prog_attach_opts {
+	size_t sz; /* size of this struct for forward/backward compatibility */
+	__u32 flags;
+	union {
+		int replace_prog_fd;
+		int replace_fd;
+	};
+	int relative_fd;
+	__u32 relative_id;
+	__u64 expected_revision;
+	size_t :0;
+};
+#define bpf_prog_attach_opts__last_field expected_revision
+
+struct bpf_prog_detach_opts {
+	size_t sz; /* size of this struct for forward/backward compatibility */
+	__u32 flags;
+	int relative_fd;
+	__u32 relative_id;
+	__u64 expected_revision;
+	size_t :0;
+};
+#define bpf_prog_detach_opts__last_field expected_revision
+
+/**
+ * @brief **bpf_prog_attach_opts()** attaches the BPF program corresponding to
+ * *prog_fd* to a *target* which can represent a file descriptor or netdevice
+ * ifindex.
+ *
+ * @param prog_fd BPF program file descriptor
+ * @param target attach location file descriptor or ifindex
+ * @param type attach type for the BPF program
+ * @param opts options for configuring the attachment
+ * @return 0, on success; negative error code, otherwise (errno is also set to
+ * the error code)
+ */
+LIBBPF_API int bpf_prog_attach_opts(int prog_fd, int target,
+				    enum bpf_attach_type type,
+				    const struct bpf_prog_attach_opts *opts);
+
+/**
+ * @brief **bpf_prog_detach_opts()** detaches the BPF program corresponding to
+ * *prog_fd* from a *target* which can represent a file descriptor or netdevice
+ * ifindex.
+ *
+ * @param prog_fd BPF program file descriptor
+ * @param target detach location file descriptor or ifindex
+ * @param type detach type for the BPF program
+ * @param opts options for configuring the detachment
+ * @return 0, on success; negative error code, otherwise (errno is also set to
+ * the error code)
+ */
+LIBBPF_API int bpf_prog_detach_opts(int prog_fd, int target,
+				    enum bpf_attach_type type,
+				    const struct bpf_prog_detach_opts *opts);
+
 union bpf_iter_link_info; /* defined in up-to-date linux/bpf.h */
 struct bpf_link_create_opts {
 	size_t sz; /* size of this struct for forward/backward compatibility */
@@ -495,13 +541,31 @@ struct bpf_prog_query_opts {
 	__u32 query_flags;
 	__u32 attach_flags; /* output argument */
 	__u32 *prog_ids;
-	__u32 prog_cnt; /* input+output argument */
+	union {
+		/* input+output argument */
+		__u32 prog_cnt;
+		__u32 count;
+	};
 	__u32 *prog_attach_flags;
+	__u32 *link_ids;
+	__u32 *link_attach_flags;
+	__u64 revision;
+	size_t :0;
 };
-#define bpf_prog_query_opts__last_field prog_attach_flags
+#define bpf_prog_query_opts__last_field revision
 
-LIBBPF_API int bpf_prog_query_opts(int target_fd,
-				   enum bpf_attach_type type,
+/**
+ * @brief **bpf_prog_query_opts()** queries the BPF programs and BPF links
+ * which are attached to *target* which can represent a file descriptor or
+ * netdevice ifindex.
+ *
+ * @param target query location file descriptor or ifindex
+ * @param type attach type for the BPF program
+ * @param opts options for configuring the query
+ * @return 0, on success; negative error code, otherwise (errno is also set to
+ * the error code)
+ */
+LIBBPF_API int bpf_prog_query_opts(int target, enum bpf_attach_type type,
 				   struct bpf_prog_query_opts *opts);
 LIBBPF_API int bpf_prog_query(int target_fd, enum bpf_attach_type type,
 			      __u32 query_flags, __u32 *attach_flags,
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 63311a73c16d..0f6913e1059b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -118,6 +118,8 @@ static const char * const attach_type_name[] = {
 	[BPF_TRACE_KPROBE_MULTI]	= "trace_kprobe_multi",
 	[BPF_STRUCT_OPS]		= "struct_ops",
 	[BPF_NETFILTER]			= "netfilter",
+	[BPF_TCX_INGRESS]		= "tcx_ingress",
+	[BPF_TCX_EGRESS]		= "tcx_egress",
 };
 
 static const char * const link_type_name[] = {
@@ -8696,9 +8698,13 @@ static const struct bpf_sec_def section_defs[] = {
 	SEC_DEF("ksyscall+",		KPROBE,	0, SEC_NONE, attach_ksyscall),
 	SEC_DEF("kretsyscall+",		KPROBE, 0, SEC_NONE, attach_ksyscall),
 	SEC_DEF("usdt+",		KPROBE,	0, SEC_NONE, attach_usdt),
-	SEC_DEF("tc",			SCHED_CLS, 0, SEC_NONE),
-	SEC_DEF("classifier",		SCHED_CLS, 0, SEC_NONE),
-	SEC_DEF("action",		SCHED_ACT, 0, SEC_NONE),
+	SEC_DEF("tc/ingress",		SCHED_CLS, BPF_TCX_INGRESS, SEC_NONE), /* alias for tcx */
+	SEC_DEF("tc/egress",		SCHED_CLS, BPF_TCX_EGRESS, SEC_NONE),  /* alias for tcx */
+	SEC_DEF("tcx/ingress",		SCHED_CLS, BPF_TCX_INGRESS, SEC_NONE),
+	SEC_DEF("tcx/egress",		SCHED_CLS, BPF_TCX_EGRESS, SEC_NONE),
+	SEC_DEF("tc",			SCHED_CLS, 0, SEC_NONE), /* deprecated / legacy, use tcx */
+	SEC_DEF("classifier",		SCHED_CLS, 0, SEC_NONE), /* deprecated / legacy, use tcx */
+	SEC_DEF("action",		SCHED_ACT, 0, SEC_NONE), /* deprecated / legacy, use tcx */
 	SEC_DEF("tracepoint+",		TRACEPOINT, 0, SEC_NONE, attach_tp),
 	SEC_DEF("tp+",			TRACEPOINT, 0, SEC_NONE, attach_tp),
 	SEC_DEF("raw_tracepoint+",	RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index d9ec4407befa..8d1608643c33 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -395,5 +395,6 @@ LIBBPF_1.2.0 {
 LIBBPF_1.3.0 {
 	global:
 		bpf_obj_pin_opts;
+		bpf_prog_detach_opts;
 		bpf_program__attach_netfilter;
 } LIBBPF_1.2.0;
-- 
2.34.1


  parent reply	other threads:[~2023-07-19 14:09 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-19 14:08 [PATCH bpf-next v6 0/8] BPF link support for tc BPF programs Daniel Borkmann
2023-07-19 14:08 ` [PATCH bpf-next v6 1/8] bpf: Add generic attach/detach/query API for multi-progs Daniel Borkmann
2023-07-19 14:08 ` [PATCH bpf-next v6 2/8] bpf: Add fd-based tcx multi-prog infra with link support Daniel Borkmann
2023-07-20  2:13   ` Yafang Shao
2023-07-21 12:53     ` Daniel Borkmann
2023-07-21 14:57   ` Petr Machata
2023-07-21 23:43     ` Daniel Borkmann
2023-07-19 14:08 ` Daniel Borkmann [this message]
2023-07-19 14:08 ` [PATCH bpf-next v6 4/8] libbpf: Add link-based API for tcx Daniel Borkmann
2023-07-19 14:08 ` [PATCH bpf-next v6 5/8] libbpf: Add helper macro to clear opts structs Daniel Borkmann
2023-07-19 14:08 ` [PATCH bpf-next v6 6/8] bpftool: Extend net dump with tcx progs Daniel Borkmann
2023-07-19 14:08 ` [PATCH bpf-next v6 7/8] selftests/bpf: Add mprog API tests for BPF tcx opts Daniel Borkmann
2023-07-19 14:08 ` [PATCH bpf-next v6 8/8] selftests/bpf: Add mprog API tests for BPF tcx links Daniel Borkmann
2023-07-19 17:20 ` [PATCH bpf-next v6 0/8] BPF link support for tc BPF programs patchwork-bot+netdevbpf

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