From patchwork Thu Feb 16 22:55:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joanne Koong X-Patchwork-Id: 13144101 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3247DC61DA4 for ; Thu, 16 Feb 2023 22:56:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229670AbjBPW43 (ORCPT ); Thu, 16 Feb 2023 17:56:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49708 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229658AbjBPW40 (ORCPT ); Thu, 16 Feb 2023 17:56:26 -0500 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 838E542DDD for ; Thu, 16 Feb 2023 14:56:23 -0800 (PST) Received: by devvm15675.prn0.facebook.com (Postfix, from userid 115148) id AE55B6A5C84F; Thu, 16 Feb 2023 14:56:09 -0800 (PST) From: Joanne Koong To: bpf@vger.kernel.org Cc: martin.lau@kernel.org, andrii@kernel.org, memxor@gmail.com, ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org, kernel-team@fb.com, Joanne Koong Subject: [PATCH v10 bpf-next 6/9] bpf: Add skb dynptrs Date: Thu, 16 Feb 2023 14:55:21 -0800 Message-Id: <20230216225524.1192789-7-joannelkoong@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230216225524.1192789-1-joannelkoong@gmail.com> References: <20230216225524.1192789-1-joannelkoong@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add skb dynptrs, which are dynptrs whose underlying pointer points to a skb. The dynptr acts on skb data. skb dynptrs have two main benefits. One is that they allow operations on sizes that are not statically known at compile-time (eg variable-sized accesses). Another is that parsing the packet data through dynptrs (instead of through direct access of skb->data and skb->data_end) can be more ergonomic and less brittle (eg does not need manual if checking for being within bounds of data_end). For bpf prog types that don't support writes on skb data, the dynptr is read-only (bpf_dynptr_write() will return an error) For reads and writes through the bpf_dynptr_read() and bpf_dynptr_write() interfaces, reading and writing from/to data in the head as well as from/to non-linear paged buffers is supported. Data slices through the bpf_dynptr_data API are not supported; instead bpf_dynptr_slice() and bpf_dynptr_slice_rdwr() (added in subsequent commit) should be used. For examples of how skb dynptrs can be used, please see the attached selftests. Signed-off-by: Joanne Koong --- include/linux/bpf.h | 14 ++++++- include/linux/filter.h | 18 ++++++++ include/uapi/linux/bpf.h | 14 ++++++- kernel/bpf/btf.c | 18 ++++++++ kernel/bpf/helpers.c | 76 +++++++++++++++++++++++++++------- kernel/bpf/verifier.c | 70 ++++++++++++++++++++++++++++++- net/core/filter.c | 67 ++++++++++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 14 ++++++- 8 files changed, 270 insertions(+), 21 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 296841a31749..3d18be35a5e6 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -607,11 +607,14 @@ enum bpf_type_flag { */ NON_OWN_REF = BIT(14 + BPF_BASE_TYPE_BITS), + /* DYNPTR points to sk_buff */ + DYNPTR_TYPE_SKB = BIT(15 + BPF_BASE_TYPE_BITS), + __BPF_TYPE_FLAG_MAX, __BPF_TYPE_LAST_FLAG = __BPF_TYPE_FLAG_MAX - 1, }; -#define DYNPTR_TYPE_FLAG_MASK (DYNPTR_TYPE_LOCAL | DYNPTR_TYPE_RINGBUF) +#define DYNPTR_TYPE_FLAG_MASK (DYNPTR_TYPE_LOCAL | DYNPTR_TYPE_RINGBUF | DYNPTR_TYPE_SKB) /* Max number of base types. */ #define BPF_BASE_TYPE_LIMIT (1UL << BPF_BASE_TYPE_BITS) @@ -1146,6 +1149,8 @@ enum bpf_dynptr_type { BPF_DYNPTR_TYPE_LOCAL, /* Underlying data is a ringbuf record */ BPF_DYNPTR_TYPE_RINGBUF, + /* Underlying data is a sk_buff */ + BPF_DYNPTR_TYPE_SKB, }; int bpf_dynptr_check_size(u32 size); @@ -2846,6 +2851,8 @@ u32 bpf_sock_convert_ctx_access(enum bpf_access_type type, struct bpf_insn *insn_buf, struct bpf_prog *prog, u32 *target_size); +int bpf_dynptr_from_skb_rdonly(struct sk_buff *skb, u64 flags, + struct bpf_dynptr_kern *ptr); #else static inline bool bpf_sock_common_is_valid_access(int off, int size, enum bpf_access_type type, @@ -2867,6 +2874,11 @@ static inline u32 bpf_sock_convert_ctx_access(enum bpf_access_type type, { return 0; } +static inline int bpf_dynptr_from_skb_rdonly(struct sk_buff *skb, u64 flags, + struct bpf_dynptr_kern *ptr) +{ + return 0; +} #endif #ifdef CONFIG_INET diff --git a/include/linux/filter.h b/include/linux/filter.h index 1727898f1641..de18e844d15e 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1542,4 +1542,22 @@ static __always_inline int __bpf_xdp_redirect_map(struct bpf_map *map, u64 index return XDP_REDIRECT; } +#ifdef CONFIG_NET +int __bpf_skb_load_bytes(const struct sk_buff *skb, u32 offset, void *to, u32 len); +int __bpf_skb_store_bytes(struct sk_buff *skb, u32 offset, const void *from, + u32 len, u64 flags); +#else /* CONFIG_NET */ +static inline int __bpf_skb_load_bytes(const struct sk_buff *skb, u32 offset, + void *to, u32 len) +{ + return -EOPNOTSUPP; +} + +static inline int __bpf_skb_store_bytes(struct sk_buff *skb, u32 offset, + const void *from, u32 len, u64 flags) +{ + return -EOPNOTSUPP; +} +#endif /* CONFIG_NET */ + #endif /* __LINUX_FILTER_H__ */ diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 1503f61336b6..4c229e0866db 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5320,11 +5320,17 @@ union bpf_attr { * Description * Write *len* bytes from *src* into *dst*, starting from *offset* * into *dst*. - * *flags* is currently unused. + * + * *flags* must be 0 except for skb-type dynptrs. + * + * For skb-type dynptrs: + * * For *flags*, please see the flags accepted by + * **bpf_skb_store_bytes**\ (). * Return * 0 on success, -E2BIG if *offset* + *len* exceeds the length * of *dst*'s data, -EINVAL if *dst* is an invalid dynptr or if *dst* - * is a read-only dynptr or if *flags* is not 0. + * is a read-only dynptr or if *flags* is not correct. For skb-type dynptrs, + * other errors correspond to errors returned by **bpf_skb_store_bytes**\ (). * * void *bpf_dynptr_data(const struct bpf_dynptr *ptr, u32 offset, u32 len) * Description @@ -5332,6 +5338,10 @@ union bpf_attr { * * *len* must be a statically known value. The returned data slice * is invalidated whenever the dynptr is invalidated. + * + * skb type dynptrs may not use bpf_dynptr_data. They should + * instead use bpf_dynptr_slice and bpf_dynptr_slice_rdwr. + * * Return * Pointer to the underlying dynptr data, NULL if the dynptr is * read-only, if the dynptr is invalid, or if the offset and length diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index ae321c358699..ea2ab8cc3710 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -207,6 +207,11 @@ enum btf_kfunc_hook { BTF_KFUNC_HOOK_TRACING, BTF_KFUNC_HOOK_SYSCALL, BTF_KFUNC_HOOK_FMODRET, + BTF_KFUNC_HOOK_CGROUP_SKB, + BTF_KFUNC_HOOK_SCHED_ACT, + BTF_KFUNC_HOOK_SK_SKB, + BTF_KFUNC_HOOK_SOCKET_FILTER, + BTF_KFUNC_HOOK_LWT, BTF_KFUNC_HOOK_MAX, }; @@ -7699,6 +7704,19 @@ static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) return BTF_KFUNC_HOOK_TRACING; case BPF_PROG_TYPE_SYSCALL: return BTF_KFUNC_HOOK_SYSCALL; + case BPF_PROG_TYPE_CGROUP_SKB: + return BTF_KFUNC_HOOK_CGROUP_SKB; + case BPF_PROG_TYPE_SCHED_ACT: + return BTF_KFUNC_HOOK_SCHED_ACT; + case BPF_PROG_TYPE_SK_SKB: + return BTF_KFUNC_HOOK_SK_SKB; + case BPF_PROG_TYPE_SOCKET_FILTER: + return BTF_KFUNC_HOOK_SOCKET_FILTER; + case BPF_PROG_TYPE_LWT_OUT: + case BPF_PROG_TYPE_LWT_IN: + case BPF_PROG_TYPE_LWT_XMIT: + case BPF_PROG_TYPE_LWT_SEG6LOCAL: + return BTF_KFUNC_HOOK_LWT; default: return BTF_KFUNC_HOOK_MAX; } diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 5b278a38ae58..b9d357bdbd1d 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -1420,11 +1420,21 @@ static bool bpf_dynptr_is_rdonly(const struct bpf_dynptr_kern *ptr) return ptr->size & DYNPTR_RDONLY_BIT; } +void bpf_dynptr_set_rdonly(struct bpf_dynptr_kern *ptr) +{ + ptr->size |= DYNPTR_RDONLY_BIT; +} + static void bpf_dynptr_set_type(struct bpf_dynptr_kern *ptr, enum bpf_dynptr_type type) { ptr->size |= type << DYNPTR_TYPE_SHIFT; } +static enum bpf_dynptr_type bpf_dynptr_get_type(const struct bpf_dynptr_kern *ptr) +{ + return (ptr->size & ~(DYNPTR_RDONLY_BIT)) >> DYNPTR_TYPE_SHIFT; +} + u32 bpf_dynptr_get_size(const struct bpf_dynptr_kern *ptr) { return ptr->size & DYNPTR_SIZE_MASK; @@ -1497,6 +1507,7 @@ static const struct bpf_func_proto bpf_dynptr_from_mem_proto = { BPF_CALL_5(bpf_dynptr_read, void *, dst, u32, len, const struct bpf_dynptr_kern *, src, u32, offset, u64, flags) { + enum bpf_dynptr_type type; int err; if (!src->data || flags) @@ -1506,13 +1517,23 @@ BPF_CALL_5(bpf_dynptr_read, void *, dst, u32, len, const struct bpf_dynptr_kern if (err) return err; - /* Source and destination may possibly overlap, hence use memmove to - * copy the data. E.g. bpf_dynptr_from_mem may create two dynptr - * pointing to overlapping PTR_TO_MAP_VALUE regions. - */ - memmove(dst, src->data + src->offset + offset, len); + type = bpf_dynptr_get_type(src); - return 0; + switch (type) { + case BPF_DYNPTR_TYPE_LOCAL: + case BPF_DYNPTR_TYPE_RINGBUF: + /* Source and destination may possibly overlap, hence use memmove to + * copy the data. E.g. bpf_dynptr_from_mem may create two dynptr + * pointing to overlapping PTR_TO_MAP_VALUE regions. + */ + memmove(dst, src->data + src->offset + offset, len); + return 0; + case BPF_DYNPTR_TYPE_SKB: + return __bpf_skb_load_bytes(src->data, src->offset + offset, dst, len); + default: + WARN_ONCE(true, "bpf_dynptr_read: unknown dynptr type %d\n", type); + return -EFAULT; + } } static const struct bpf_func_proto bpf_dynptr_read_proto = { @@ -1529,22 +1550,36 @@ static const struct bpf_func_proto bpf_dynptr_read_proto = { BPF_CALL_5(bpf_dynptr_write, const struct bpf_dynptr_kern *, dst, u32, offset, void *, src, u32, len, u64, flags) { + enum bpf_dynptr_type type; int err; - if (!dst->data || flags || bpf_dynptr_is_rdonly(dst)) + if (!dst->data || bpf_dynptr_is_rdonly(dst)) return -EINVAL; err = bpf_dynptr_check_off_len(dst, offset, len); if (err) return err; - /* Source and destination may possibly overlap, hence use memmove to - * copy the data. E.g. bpf_dynptr_from_mem may create two dynptr - * pointing to overlapping PTR_TO_MAP_VALUE regions. - */ - memmove(dst->data + dst->offset + offset, src, len); + type = bpf_dynptr_get_type(dst); - return 0; + switch (type) { + case BPF_DYNPTR_TYPE_LOCAL: + case BPF_DYNPTR_TYPE_RINGBUF: + if (flags) + return -EINVAL; + /* Source and destination may possibly overlap, hence use memmove to + * copy the data. E.g. bpf_dynptr_from_mem may create two dynptr + * pointing to overlapping PTR_TO_MAP_VALUE regions. + */ + memmove(dst->data + dst->offset + offset, src, len); + return 0; + case BPF_DYNPTR_TYPE_SKB: + return __bpf_skb_store_bytes(dst->data, dst->offset + offset, src, len, + flags); + default: + WARN_ONCE(true, "bpf_dynptr_write: unknown dynptr type %d\n", type); + return -EFAULT; + } } static const struct bpf_func_proto bpf_dynptr_write_proto = { @@ -1560,6 +1595,7 @@ static const struct bpf_func_proto bpf_dynptr_write_proto = { BPF_CALL_3(bpf_dynptr_data, const struct bpf_dynptr_kern *, ptr, u32, offset, u32, len) { + enum bpf_dynptr_type type; int err; if (!ptr->data) @@ -1572,7 +1608,19 @@ BPF_CALL_3(bpf_dynptr_data, const struct bpf_dynptr_kern *, ptr, u32, offset, u3 if (bpf_dynptr_is_rdonly(ptr)) return 0; - return (unsigned long)(ptr->data + ptr->offset + offset); + type = bpf_dynptr_get_type(ptr); + + switch (type) { + case BPF_DYNPTR_TYPE_LOCAL: + case BPF_DYNPTR_TYPE_RINGBUF: + return (unsigned long)(ptr->data + ptr->offset + offset); + case BPF_DYNPTR_TYPE_SKB: + /* skb dynptrs should use bpf_dynptr_slice / bpf_dynptr_slice_rdwr */ + return 0; + default: + WARN_ONCE(true, "bpf_dynptr_data: unknown dynptr type %d\n", type); + return 0; + } } static const struct bpf_func_proto bpf_dynptr_data_proto = { diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index babc82e93ae6..7297f0d83792 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -750,6 +750,8 @@ static enum bpf_dynptr_type arg_to_dynptr_type(enum bpf_arg_type arg_type) return BPF_DYNPTR_TYPE_LOCAL; case DYNPTR_TYPE_RINGBUF: return BPF_DYNPTR_TYPE_RINGBUF; + case DYNPTR_TYPE_SKB: + return BPF_DYNPTR_TYPE_SKB; default: return BPF_DYNPTR_TYPE_INVALID; } @@ -6286,6 +6288,9 @@ int process_dynptr_func(struct bpf_verifier_env *env, int regno, int insn_idx, case DYNPTR_TYPE_RINGBUF: err_extra = "ringbuf"; break; + case DYNPTR_TYPE_SKB: + err_extra = "skb "; + break; default: err_extra = ""; break; @@ -6712,6 +6717,24 @@ static int dynptr_ref_obj_id(struct bpf_verifier_env *env, struct bpf_reg_state return state->stack[spi].spilled_ptr.ref_obj_id; } +static enum bpf_dynptr_type dynptr_get_type(struct bpf_verifier_env *env, + struct bpf_reg_state *reg) +{ + struct bpf_func_state *state = func(env, reg); + int spi; + + if (reg->type == CONST_PTR_TO_DYNPTR) + return reg->dynptr.type; + + spi = __get_spi(reg->off); + if (spi < 0) { + verbose(env, "verifier internal error: invalid spi when querying dynptr type\n"); + return BPF_DYNPTR_TYPE_INVALID; + } + + return state->stack[spi].spilled_ptr.dynptr.type; +} + static int check_func_arg(struct bpf_verifier_env *env, u32 arg, struct bpf_call_arg_meta *meta, const struct bpf_func_proto *fn, @@ -8362,6 +8385,27 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn break; } + case BPF_FUNC_dynptr_write: + { + enum bpf_dynptr_type dynptr_type; + struct bpf_reg_state *reg; + + reg = get_dynptr_arg_reg(env, fn, regs); + if (!reg) + return -EFAULT; + + dynptr_type = dynptr_get_type(env, reg); + if (dynptr_type == BPF_DYNPTR_TYPE_INVALID) + return -EFAULT; + + if (dynptr_type == BPF_DYNPTR_TYPE_SKB) + /* this will trigger clear_all_pkt_pointers(), which will + * invalidate all dynptr slices associated with the skb + */ + changes_data = true; + + break; + } case BPF_FUNC_user_ringbuf_drain: err = __check_func_call(env, insn, insn_idx_p, meta.subprogno, set_user_ringbuf_callback_state); @@ -8872,6 +8916,7 @@ enum special_kfunc_type { KF_bpf_rbtree_remove, KF_bpf_rbtree_add, KF_bpf_rbtree_first, + KF_bpf_dynptr_from_skb, }; BTF_SET_START(special_kfunc_set) @@ -8886,6 +8931,7 @@ BTF_ID(func, bpf_rdonly_cast) BTF_ID(func, bpf_rbtree_remove) BTF_ID(func, bpf_rbtree_add) BTF_ID(func, bpf_rbtree_first) +BTF_ID(func, bpf_dynptr_from_skb) BTF_SET_END(special_kfunc_set) BTF_ID_LIST(special_kfunc_list) @@ -8902,6 +8948,7 @@ BTF_ID(func, bpf_rcu_read_unlock) BTF_ID(func, bpf_rbtree_remove) BTF_ID(func, bpf_rbtree_add) BTF_ID(func, bpf_rbtree_first) +BTF_ID(func, bpf_dynptr_from_skb) static bool is_kfunc_bpf_rcu_read_lock(struct bpf_kfunc_call_arg_meta *meta) { @@ -9642,17 +9689,25 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ return ret; break; case KF_ARG_PTR_TO_DYNPTR: + { + enum bpf_arg_type dynptr_arg_type = ARG_PTR_TO_DYNPTR; + if (reg->type != PTR_TO_STACK && reg->type != CONST_PTR_TO_DYNPTR) { verbose(env, "arg#%d expected pointer to stack or dynptr_ptr\n", i); return -EINVAL; } - ret = process_dynptr_func(env, regno, insn_idx, - ARG_PTR_TO_DYNPTR | MEM_RDONLY); + if (meta->func_id == special_kfunc_list[KF_bpf_dynptr_from_skb]) + dynptr_arg_type |= MEM_UNINIT | DYNPTR_TYPE_SKB; + else + dynptr_arg_type |= MEM_RDONLY; + + ret = process_dynptr_func(env, regno, insn_idx, dynptr_arg_type); if (ret < 0) return ret; break; + } case KF_ARG_PTR_TO_LIST_HEAD: if (reg->type != PTR_TO_MAP_VALUE && reg->type != (PTR_TO_BTF_ID | MEM_ALLOC)) { @@ -16318,6 +16373,17 @@ static int fixup_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, desc->func_id == special_kfunc_list[KF_bpf_rdonly_cast]) { insn_buf[0] = BPF_MOV64_REG(BPF_REG_0, BPF_REG_1); *cnt = 1; + } else if (desc->func_id == special_kfunc_list[KF_bpf_dynptr_from_skb]) { + bool seen_direct_write = env->seen_direct_write; + bool is_rdonly = !may_access_direct_pkt_data(env, NULL, BPF_WRITE); + + if (is_rdonly) + insn->imm = BPF_CALL_IMM(bpf_dynptr_from_skb_rdonly); + + /* restore env->seen_direct_write to its original value, since + * may_access_direct_pkt_data mutates it + */ + env->seen_direct_write = seen_direct_write; } return 0; } diff --git a/net/core/filter.c b/net/core/filter.c index 2ce06a72a5ba..34250a4d3b7a 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1721,6 +1721,12 @@ static const struct bpf_func_proto bpf_skb_store_bytes_proto = { .arg5_type = ARG_ANYTHING, }; +int __bpf_skb_store_bytes(struct sk_buff *skb, u32 offset, const void *from, + u32 len, u64 flags) +{ + return ____bpf_skb_store_bytes(skb, offset, from, len, flags); +} + BPF_CALL_4(bpf_skb_load_bytes, const struct sk_buff *, skb, u32, offset, void *, to, u32, len) { @@ -1751,6 +1757,11 @@ static const struct bpf_func_proto bpf_skb_load_bytes_proto = { .arg4_type = ARG_CONST_SIZE, }; +int __bpf_skb_load_bytes(const struct sk_buff *skb, u32 offset, void *to, u32 len) +{ + return ____bpf_skb_load_bytes(skb, offset, to, len); +} + BPF_CALL_4(bpf_flow_dissector_load_bytes, const struct bpf_flow_dissector *, ctx, u32, offset, void *, to, u32, len) @@ -11608,3 +11619,59 @@ bpf_sk_base_func_proto(enum bpf_func_id func_id) return func; } + +__diag_push(); +__diag_ignore_all("-Wmissing-prototypes", + "Global functions as their definitions will be in vmlinux BTF"); +__bpf_kfunc int bpf_dynptr_from_skb(struct sk_buff *skb, u64 flags, + struct bpf_dynptr_kern *ptr) +{ + if (flags) { + bpf_dynptr_set_null(ptr); + return -EINVAL; + } + + bpf_dynptr_init(ptr, skb, BPF_DYNPTR_TYPE_SKB, 0, skb->len); + + return 0; +} +__diag_pop(); + +int bpf_dynptr_from_skb_rdonly(struct sk_buff *skb, u64 flags, + struct bpf_dynptr_kern *ptr) +{ + int err; + + err = bpf_dynptr_from_skb(skb, flags, ptr); + if (err) + return err; + + bpf_dynptr_set_rdonly(ptr); + + return 0; +} + +BTF_SET8_START(bpf_kfunc_check_set_skb) +BTF_ID_FLAGS(func, bpf_dynptr_from_skb) +BTF_SET8_END(bpf_kfunc_check_set_skb) + +static const struct btf_kfunc_id_set bpf_kfunc_set_skb = { + .owner = THIS_MODULE, + .set = &bpf_kfunc_check_set_skb, +}; + +static int __init bpf_kfunc_init(void) +{ + int ret; + + ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &bpf_kfunc_set_skb); + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_ACT, &bpf_kfunc_set_skb); + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SK_SKB, &bpf_kfunc_set_skb); + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SOCKET_FILTER, &bpf_kfunc_set_skb); + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SKB, &bpf_kfunc_set_skb); + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_LWT_OUT, &bpf_kfunc_set_skb); + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_LWT_IN, &bpf_kfunc_set_skb); + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_LWT_XMIT, &bpf_kfunc_set_skb); + return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_LWT_SEG6LOCAL, &bpf_kfunc_set_skb); +} +late_initcall(bpf_kfunc_init); diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 1503f61336b6..4c229e0866db 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5320,11 +5320,17 @@ union bpf_attr { * Description * Write *len* bytes from *src* into *dst*, starting from *offset* * into *dst*. - * *flags* is currently unused. + * + * *flags* must be 0 except for skb-type dynptrs. + * + * For skb-type dynptrs: + * * For *flags*, please see the flags accepted by + * **bpf_skb_store_bytes**\ (). * Return * 0 on success, -E2BIG if *offset* + *len* exceeds the length * of *dst*'s data, -EINVAL if *dst* is an invalid dynptr or if *dst* - * is a read-only dynptr or if *flags* is not 0. + * is a read-only dynptr or if *flags* is not correct. For skb-type dynptrs, + * other errors correspond to errors returned by **bpf_skb_store_bytes**\ (). * * void *bpf_dynptr_data(const struct bpf_dynptr *ptr, u32 offset, u32 len) * Description @@ -5332,6 +5338,10 @@ union bpf_attr { * * *len* must be a statically known value. The returned data slice * is invalidated whenever the dynptr is invalidated. + * + * skb type dynptrs may not use bpf_dynptr_data. They should + * instead use bpf_dynptr_slice and bpf_dynptr_slice_rdwr. + * * Return * Pointer to the underlying dynptr data, NULL if the dynptr is * read-only, if the dynptr is invalid, or if the offset and length