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[213.102.90.208]) by smtp.gmail.com with ESMTPSA id x1sm1312437ljh.62.2021.02.20.07.31.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 20 Feb 2021 07:31:07 -0800 (PST) From: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= To: ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org, bpf@vger.kernel.org Cc: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , maciej.fijalkowski@intel.com, hawk@kernel.org, toke@redhat.com, magnus.karlsson@intel.com, john.fastabend@gmail.com, kuba@kernel.org, davem@davemloft.net Subject: [PATCH bpf-next v2 1/2] bpf, xdp: per-map bpf_redirect_map functions for XDP Date: Sat, 20 Feb 2021 16:30:55 +0100 Message-Id: <20210220153056.111968-2-bjorn.topel@gmail.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210220153056.111968-1-bjorn.topel@gmail.com> References: <20210220153056.111968-1-bjorn.topel@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Björn Töpel Currently the bpf_redirect_map() implementation dispatches to the correct map-lookup function via a switch-statement. To avoid the dispatching, this change adds one bpf_redirect_map() implementation per map. Correct function is automatically selected by the BPF verifier. v1->v2 : Re-added comment. (Toke) rfc->v1: Get rid of the macro and use __always_inline. (Jesper) Acked-by: Toke Høiland-Jørgensen Signed-off-by: Björn Töpel --- include/linux/bpf.h | 20 ++++++++------ include/linux/filter.h | 2 ++ include/net/xdp_sock.h | 6 ++-- kernel/bpf/cpumap.c | 2 +- kernel/bpf/devmap.c | 4 +-- kernel/bpf/verifier.c | 28 +++++++++++-------- net/core/filter.c | 62 ++++++++++++++++++++++++++++-------------- 7 files changed, 76 insertions(+), 48 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index cccaef1088ea..3dd186eeaf98 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -314,12 +314,14 @@ enum bpf_return_type { RET_PTR_TO_BTF_ID, /* returns a pointer to a btf_id */ }; +typedef u64 (*bpf_func_proto_func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); + /* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL * instructions after verifying */ struct bpf_func_proto { - u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); + bpf_func_proto_func func; bool gpl_only; bool pkt_access; enum bpf_return_type ret_type; @@ -1429,9 +1431,11 @@ struct btf *bpf_get_btf_vmlinux(void); /* Map specifics */ struct xdp_buff; struct sk_buff; +struct bpf_dtab_netdev; +struct bpf_cpu_map_entry; -struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key); -struct bpf_dtab_netdev *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key); +void *__dev_map_lookup_elem(struct bpf_map *map, u32 key); +void *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key); void __dev_flush(void); int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp, struct net_device *dev_rx); @@ -1441,7 +1445,7 @@ int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb, struct bpf_prog *xdp_prog); bool dev_map_can_have_prog(struct bpf_map *map); -struct bpf_cpu_map_entry *__cpu_map_lookup_elem(struct bpf_map *map, u32 key); +void *__cpu_map_lookup_elem(struct bpf_map *map, u32 key); void __cpu_map_flush(void); int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp, struct net_device *dev_rx); @@ -1568,14 +1572,12 @@ static inline int bpf_obj_get_user(const char __user *pathname, int flags) return -EOPNOTSUPP; } -static inline struct net_device *__dev_map_lookup_elem(struct bpf_map *map, - u32 key) +static inline void *__dev_map_lookup_elem(struct bpf_map *map, u32 key) { return NULL; } -static inline struct net_device *__dev_map_hash_lookup_elem(struct bpf_map *map, - u32 key) +static inline void *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key) { return NULL; } @@ -1615,7 +1617,7 @@ static inline int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, } static inline -struct bpf_cpu_map_entry *__cpu_map_lookup_elem(struct bpf_map *map, u32 key) +void *__cpu_map_lookup_elem(struct bpf_map *map, u32 key) { return NULL; } diff --git a/include/linux/filter.h b/include/linux/filter.h index 3b00fc906ccd..1dedcf66b694 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1472,4 +1472,6 @@ static inline bool bpf_sk_lookup_run_v6(struct net *net, int protocol, } #endif /* IS_ENABLED(CONFIG_IPV6) */ +bpf_func_proto_func get_xdp_redirect_func(enum bpf_map_type map_type); + #endif /* __LINUX_FILTER_H__ */ diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h index cc17bc957548..da4139a58630 100644 --- a/include/net/xdp_sock.h +++ b/include/net/xdp_sock.h @@ -80,8 +80,7 @@ int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp); int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp); void __xsk_map_flush(void); -static inline struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map, - u32 key) +static inline void *__xsk_map_lookup_elem(struct bpf_map *map, u32 key) { struct xsk_map *m = container_of(map, struct xsk_map, map); struct xdp_sock *xs; @@ -109,8 +108,7 @@ static inline void __xsk_map_flush(void) { } -static inline struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map, - u32 key) +static inline void *__xsk_map_lookup_elem(struct bpf_map *map, u32 key) { return NULL; } diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index 5d1469de6921..a4d2cb93cd69 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -563,7 +563,7 @@ static void cpu_map_free(struct bpf_map *map) kfree(cmap); } -struct bpf_cpu_map_entry *__cpu_map_lookup_elem(struct bpf_map *map, u32 key) +void *__cpu_map_lookup_elem(struct bpf_map *map, u32 key) { struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); struct bpf_cpu_map_entry *rcpu; diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 85d9d1b72a33..37ac4cde9713 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -258,7 +258,7 @@ static int dev_map_get_next_key(struct bpf_map *map, void *key, void *next_key) return 0; } -struct bpf_dtab_netdev *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key) +void *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key) { struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); struct hlist_head *head = dev_map_index_hash(dtab, key); @@ -392,7 +392,7 @@ void __dev_flush(void) * update happens in parallel here a dev_put wont happen until after reading the * ifindex. */ -struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key) +void *__dev_map_lookup_elem(struct bpf_map *map, u32 key) { struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); struct bpf_dtab_netdev *obj; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 3d34ba492d46..b5fb0c4e911a 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5409,7 +5409,8 @@ record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta, func_id != BPF_FUNC_map_delete_elem && func_id != BPF_FUNC_map_push_elem && func_id != BPF_FUNC_map_pop_elem && - func_id != BPF_FUNC_map_peek_elem) + func_id != BPF_FUNC_map_peek_elem && + func_id != BPF_FUNC_redirect_map) return 0; if (map == NULL) { @@ -11860,17 +11861,22 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env) } patch_call_imm: - fn = env->ops->get_func_proto(insn->imm, env->prog); - /* all functions that have prototype and verifier allowed - * programs to call them, must be real in-kernel functions - */ - if (!fn->func) { - verbose(env, - "kernel subsystem misconfigured func %s#%d\n", - func_id_name(insn->imm), insn->imm); - return -EFAULT; + if (insn->imm == BPF_FUNC_redirect_map) { + aux = &env->insn_aux_data[i]; + map_ptr = BPF_MAP_PTR(aux->map_ptr_state); + insn->imm = get_xdp_redirect_func(map_ptr->map_type) - __bpf_call_base; + } else { + fn = env->ops->get_func_proto(insn->imm, env->prog); + /* all functions that have prototype and verifier allowed + * programs to call them, must be real in-kernel functions + */ + if (!fn->func) { + verbose(env, "kernel subsystem misconfigured func %s#%d\n", + func_id_name(insn->imm), insn->imm); + return -EFAULT; + } + insn->imm = fn->func - __bpf_call_base; } - insn->imm = fn->func - __bpf_call_base; } /* Since poke tab is now finalized, publish aux to tracker. */ diff --git a/net/core/filter.c b/net/core/filter.c index adfdad234674..eeecd95aa38f 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3944,22 +3944,6 @@ void xdp_do_flush(void) } EXPORT_SYMBOL_GPL(xdp_do_flush); -static inline void *__xdp_map_lookup_elem(struct bpf_map *map, u32 index) -{ - switch (map->map_type) { - case BPF_MAP_TYPE_DEVMAP: - return __dev_map_lookup_elem(map, index); - case BPF_MAP_TYPE_DEVMAP_HASH: - return __dev_map_hash_lookup_elem(map, index); - case BPF_MAP_TYPE_CPUMAP: - return __cpu_map_lookup_elem(map, index); - case BPF_MAP_TYPE_XSKMAP: - return __xsk_map_lookup_elem(map, index); - default: - return NULL; - } -} - void bpf_clear_redirect_map(struct bpf_map *map) { struct bpf_redirect_info *ri; @@ -4110,16 +4094,16 @@ static const struct bpf_func_proto bpf_xdp_redirect_proto = { .arg2_type = ARG_ANYTHING, }; -BPF_CALL_3(bpf_xdp_redirect_map, struct bpf_map *, map, u32, ifindex, - u64, flags) +static __always_inline s64 __bpf_xdp_redirect_map(struct bpf_map *map, u32 ifindex, u64 flags, + void *lookup_elem(struct bpf_map *map, + u32 key)) { struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info); - /* Lower bits of the flags are used as return code on lookup failure */ if (unlikely(flags > XDP_TX)) return XDP_ABORTED; - ri->tgt_value = __xdp_map_lookup_elem(map, ifindex); + ri->tgt_value = lookup_elem(map, ifindex); if (unlikely(!ri->tgt_value)) { /* If the lookup fails we want to clear out the state in the * redirect_info struct completely, so that if an eBPF program @@ -4137,8 +4121,44 @@ BPF_CALL_3(bpf_xdp_redirect_map, struct bpf_map *, map, u32, ifindex, return XDP_REDIRECT; } +BPF_CALL_3(bpf_xdp_redirect_devmap, struct bpf_map *, map, u32, ifindex, u64, flags) +{ + return __bpf_xdp_redirect_map(map, ifindex, flags, __dev_map_lookup_elem); +} + +BPF_CALL_3(bpf_xdp_redirect_devmap_hash, struct bpf_map *, map, u32, ifindex, u64, flags) +{ + return __bpf_xdp_redirect_map(map, ifindex, flags, __dev_map_hash_lookup_elem); +} + +BPF_CALL_3(bpf_xdp_redirect_cpumap, struct bpf_map *, map, u32, ifindex, u64, flags) +{ + return __bpf_xdp_redirect_map(map, ifindex, flags, __cpu_map_lookup_elem); +} + +BPF_CALL_3(bpf_xdp_redirect_xskmap, struct bpf_map *, map, u32, ifindex, u64, flags) +{ + return __bpf_xdp_redirect_map(map, ifindex, flags, __xsk_map_lookup_elem); +} + +bpf_func_proto_func get_xdp_redirect_func(enum bpf_map_type map_type) +{ + switch (map_type) { + case BPF_MAP_TYPE_DEVMAP: + return bpf_xdp_redirect_devmap; + case BPF_MAP_TYPE_DEVMAP_HASH: + return bpf_xdp_redirect_devmap_hash; + case BPF_MAP_TYPE_CPUMAP: + return bpf_xdp_redirect_cpumap; + case BPF_MAP_TYPE_XSKMAP: + return bpf_xdp_redirect_xskmap; + default: + return NULL; + } +} + +/* NB! .func is NULL! get_xdp_redirect_func() is used instead! */ static const struct bpf_func_proto bpf_xdp_redirect_map_proto = { - .func = bpf_xdp_redirect_map, .gpl_only = false, .ret_type = RET_INTEGER, .arg1_type = ARG_CONST_MAP_PTR,