From fe20ce3a512649b7f883e15dfc01eb29bfcf2168 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Wed, 19 Jul 2023 16:08:53 +0200 Subject: [PATCH] libbpf: Add opts-based attach/detach/query API for tcx 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 Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20230719140858.13224-4-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov --- 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 3b0da19..4131d3a 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 c676295..49e9d88 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 63311a7..0f6913e 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 d9ec440..8d16086 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; -- 2.7.4