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@xxxxxxxxxxxxx>
---
tools/lib/bpf/bpf.c | 105 +++++++++++++++++++++++++--------------
tools/lib/bpf/bpf.h | 92 ++++++++++++++++++++++++++++------
tools/lib/bpf/libbpf.c | 12 +++--
tools/lib/bpf/libbpf.map | 1 +
4 files changed, 157 insertions(+), 53 deletions(-)
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 3b0da19715e1..3dfc43b477c3 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -629,55 +629,87 @@ 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;
union bpf_attr attr;
- int ret;
+ int ret, relative;
if (!OPTS_VALID(opts, bpf_prog_attach_opts))
return libbpf_err(-EINVAL);
+ relative_id = OPTS_GET(opts, relative_id, 0);
+ relative = 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 > 0 && relative_id)
+ return libbpf_err(-EINVAL);
+ if (relative_id) {
+ relative = relative_id;
+ flags |= BPF_F_ID;
+ }
+
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.attach_flags = flags;
+ attr.relative_fd = relative;
+ attr.replace_bpf_fd = OPTS_GET(opts, replace_fd, 0);
+ attr.expected_revision = OPTS_GET(opts, expected_revision, 0);
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;
union bpf_attr attr;
- int ret;
+ int ret, relative;
+
+ if (!OPTS_VALID(opts, bpf_prog_detach_opts))
+ return libbpf_err(-EINVAL);
+
+ relative_id = OPTS_GET(opts, relative_id, 0);
+ relative = 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 > 0 && relative_id)
+ return libbpf_err(-EINVAL);
+ if (relative_id) {
+ relative = relative_id;
+ flags |= BPF_F_ID;
+ }
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.attach_flags = flags;
+ attr.relative_fd = relative;
+ attr.expected_revision = OPTS_GET(opts, expected_revision, 0);
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 +873,7 @@ 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 +884,20 @@ 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 1c6588ad3e75..208aeee31823 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[] = {
@@ -8673,9 +8675,13 @@ 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..a95d39bbef90 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -396,4 +396,5 @@ LIBBPF_1.3.0 {
global:
bpf_obj_pin_opts;
bpf_program__attach_netfilter;
+ bpf_prog_detach_opts;
} LIBBPF_1.2.0;
--
2.34.1
