From 2463e073497385ef63c220571013a2b89e9b95cc Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Thu, 18 Feb 2021 20:49:41 +0000 Subject: netdevice: Add missing IFF_PHONY_HEADROOM self-definition This is harmless for now, but can be fatal for future refactors. Fixes: 871b642adebe3 ("netdev: introduce ndo_set_rx_headroom") Signed-off-by: Alexander Lobakin Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20210218204908.5455-2-alobakin@pm.me --- include/linux/netdevice.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index ddf4cfc12615..3b6f82c2c271 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1577,6 +1577,7 @@ enum netdev_priv_flags { #define IFF_L3MDEV_SLAVE IFF_L3MDEV_SLAVE #define IFF_TEAM IFF_TEAM #define IFF_RXFH_CONFIGURED IFF_RXFH_CONFIGURED +#define IFF_PHONY_HEADROOM IFF_PHONY_HEADROOM #define IFF_MACSEC IFF_MACSEC #define IFF_NO_RX_HANDLER IFF_NO_RX_HANDLER #define IFF_FAILOVER IFF_FAILOVER -- cgit v1.2.3 From c2ff53d8049f30098153cd2d1299a44d7b124c57 Mon Sep 17 00:00:00 2001 From: Xuan Zhuo Date: Thu, 18 Feb 2021 20:50:02 +0000 Subject: net: Add priv_flags for allow tx skb without linear In some cases, we hope to construct skb directly based on the existing memory without copying data. In this case, the page will be placed directly in the skb, and the linear space of skb is empty. But unfortunately, many the network card does not support this operation. For example Mellanox Technologies MT27710 Family [ConnectX-4 Lx] will get the following error message: mlx5_core 0000:3b:00.1 eth1: Error cqe on cqn 0x817, ci 0x8, qn 0x1dbb, opcode 0xd, syndrome 0x1, vendor syndrome 0x68 00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00000030: 00 00 00 00 60 10 68 01 0a 00 1d bb 00 0f 9f d2 WQE DUMP: WQ size 1024 WQ cur size 0, WQE index 0xf, len: 64 00000000: 00 00 0f 0a 00 1d bb 03 00 00 00 08 00 00 00 00 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00000020: 00 00 00 2b 00 08 00 00 00 00 00 05 9e e3 08 00 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 mlx5_core 0000:3b:00.1 eth1: ERR CQE on SQ: 0x1dbb So a priv_flag is added here to indicate whether the network card supports this feature. Suggested-by: Alexander Lobakin Signed-off-by: Xuan Zhuo Signed-off-by: Alexander Lobakin Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20210218204908.5455-3-alobakin@pm.me --- include/linux/netdevice.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 3b6f82c2c271..6cef47b76cc6 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1518,6 +1518,8 @@ struct net_device_ops { * @IFF_FAILOVER_SLAVE: device is lower dev of a failover master device * @IFF_L3MDEV_RX_HANDLER: only invoke the rx handler of L3 master device * @IFF_LIVE_RENAME_OK: rename is allowed while device is up and running + * @IFF_TX_SKB_NO_LINEAR: device/driver is capable of xmitting frames with + * skb_headlen(skb) == 0 (data starts from frag0) */ enum netdev_priv_flags { IFF_802_1Q_VLAN = 1<<0, @@ -1551,6 +1553,7 @@ enum netdev_priv_flags { IFF_FAILOVER_SLAVE = 1<<28, IFF_L3MDEV_RX_HANDLER = 1<<29, IFF_LIVE_RENAME_OK = 1<<30, + IFF_TX_SKB_NO_LINEAR = 1<<31, }; #define IFF_802_1Q_VLAN IFF_802_1Q_VLAN @@ -1584,6 +1587,7 @@ enum netdev_priv_flags { #define IFF_FAILOVER_SLAVE IFF_FAILOVER_SLAVE #define IFF_L3MDEV_RX_HANDLER IFF_L3MDEV_RX_HANDLER #define IFF_LIVE_RENAME_OK IFF_LIVE_RENAME_OK +#define IFF_TX_SKB_NO_LINEAR IFF_TX_SKB_NO_LINEAR /** * struct net_device - The DEVICE structure. -- cgit v1.2.3 From a10787e6d58c24b51e91c19c6d16c5da89fcaa4b Mon Sep 17 00:00:00 2001 From: Song Liu Date: Thu, 25 Feb 2021 15:43:14 -0800 Subject: bpf: Enable task local storage for tracing programs To access per-task data, BPF programs usually creates a hash table with pid as the key. This is not ideal because: 1. The user need to estimate the proper size of the hash table, which may be inaccurate; 2. Big hash tables are slow; 3. To clean up the data properly during task terminations, the user need to write extra logic. Task local storage overcomes these issues and offers a better option for these per-task data. Task local storage is only available to BPF_LSM. Now enable it for tracing programs. Unlike LSM programs, tracing programs can be called in IRQ contexts. Helpers that access task local storage are updated to use raw_spin_lock_irqsave() instead of raw_spin_lock_bh(). Tracing programs can attach to functions on the task free path, e.g. exit_creds(). To avoid allocating task local storage after bpf_task_storage_free(). bpf_task_storage_get() is updated to not allocate new storage when the task is not refcounted (task->usage == 0). Signed-off-by: Song Liu Signed-off-by: Alexei Starovoitov Acked-by: KP Singh Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20210225234319.336131-2-songliubraving@fb.com --- include/linux/bpf.h | 7 +++++++ include/linux/bpf_lsm.h | 22 ---------------------- include/linux/bpf_types.h | 2 +- include/linux/sched.h | 5 +++++ 4 files changed, 13 insertions(+), 23 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index cccaef1088ea..e2cfc4809219 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1499,6 +1499,7 @@ struct bpf_prog *bpf_prog_by_id(u32 id); struct bpf_link *bpf_link_by_id(u32 id); const struct bpf_func_proto *bpf_base_func_proto(enum bpf_func_id func_id); +void bpf_task_storage_free(struct task_struct *task); #else /* !CONFIG_BPF_SYSCALL */ static inline struct bpf_prog *bpf_prog_get(u32 ufd) { @@ -1684,6 +1685,10 @@ bpf_base_func_proto(enum bpf_func_id func_id) { return NULL; } + +static inline void bpf_task_storage_free(struct task_struct *task) +{ +} #endif /* CONFIG_BPF_SYSCALL */ void __bpf_free_used_btfs(struct bpf_prog_aux *aux, @@ -1886,6 +1891,8 @@ extern const struct bpf_func_proto bpf_this_cpu_ptr_proto; extern const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto; extern const struct bpf_func_proto bpf_sock_from_file_proto; extern const struct bpf_func_proto bpf_get_socket_ptr_cookie_proto; +extern const struct bpf_func_proto bpf_task_storage_get_proto; +extern const struct bpf_func_proto bpf_task_storage_delete_proto; const struct bpf_func_proto *bpf_tracing_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); diff --git a/include/linux/bpf_lsm.h b/include/linux/bpf_lsm.h index 0d1c33ace398..479c101546ad 100644 --- a/include/linux/bpf_lsm.h +++ b/include/linux/bpf_lsm.h @@ -38,21 +38,9 @@ static inline struct bpf_storage_blob *bpf_inode( return inode->i_security + bpf_lsm_blob_sizes.lbs_inode; } -static inline struct bpf_storage_blob *bpf_task( - const struct task_struct *task) -{ - if (unlikely(!task->security)) - return NULL; - - return task->security + bpf_lsm_blob_sizes.lbs_task; -} - extern const struct bpf_func_proto bpf_inode_storage_get_proto; extern const struct bpf_func_proto bpf_inode_storage_delete_proto; -extern const struct bpf_func_proto bpf_task_storage_get_proto; -extern const struct bpf_func_proto bpf_task_storage_delete_proto; void bpf_inode_storage_free(struct inode *inode); -void bpf_task_storage_free(struct task_struct *task); #else /* !CONFIG_BPF_LSM */ @@ -73,20 +61,10 @@ static inline struct bpf_storage_blob *bpf_inode( return NULL; } -static inline struct bpf_storage_blob *bpf_task( - const struct task_struct *task) -{ - return NULL; -} - static inline void bpf_inode_storage_free(struct inode *inode) { } -static inline void bpf_task_storage_free(struct task_struct *task) -{ -} - #endif /* CONFIG_BPF_LSM */ #endif /* _LINUX_BPF_LSM_H */ diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h index 99f7fd657d87..b9edee336d80 100644 --- a/include/linux/bpf_types.h +++ b/include/linux/bpf_types.h @@ -109,8 +109,8 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKHASH, sock_hash_ops) #endif #ifdef CONFIG_BPF_LSM BPF_MAP_TYPE(BPF_MAP_TYPE_INODE_STORAGE, inode_storage_map_ops) -BPF_MAP_TYPE(BPF_MAP_TYPE_TASK_STORAGE, task_storage_map_ops) #endif +BPF_MAP_TYPE(BPF_MAP_TYPE_TASK_STORAGE, task_storage_map_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_CPUMAP, cpu_map_ops) #if defined(CONFIG_XDP_SOCKETS) BPF_MAP_TYPE(BPF_MAP_TYPE_XSKMAP, xsk_map_ops) diff --git a/include/linux/sched.h b/include/linux/sched.h index 4d568288abf9..e5fbf8e6952a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -42,6 +42,7 @@ struct audit_context; struct backing_dev_info; struct bio_list; struct blk_plug; +struct bpf_local_storage; struct capture_control; struct cfs_rq; struct fs_struct; @@ -1348,6 +1349,10 @@ struct task_struct { /* Used by LSM modules for access restriction: */ void *security; #endif +#ifdef CONFIG_BPF_SYSCALL + /* Used by BPF task local storage */ + struct bpf_local_storage __rcu *bpf_storage; +#endif #ifdef CONFIG_GCC_PLUGIN_STACKLEAK unsigned long lowest_stack; -- cgit v1.2.3 From bc235cdb423a2daed6f337676006a66557429cd1 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Thu, 25 Feb 2021 15:43:15 -0800 Subject: bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete] BPF helpers bpf_task_storage_[get|delete] could hold two locks: bpf_local_storage_map_bucket->lock and bpf_local_storage->lock. Calling these helpers from fentry/fexit programs on functions in bpf_*_storage.c may cause deadlock on either locks. Prevent such deadlock with a per cpu counter, bpf_task_storage_busy. We need this counter to be global, because the two locks here belong to two different objects: bpf_local_storage_map and bpf_local_storage. If we pick one of them as the owner of the counter, it is still possible to trigger deadlock on the other lock. For example, if bpf_local_storage_map owns the counters, it cannot prevent deadlock on bpf_local_storage->lock when two maps are used. Signed-off-by: Song Liu Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20210225234319.336131-3-songliubraving@fb.com --- include/linux/bpf_local_storage.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/bpf_local_storage.h b/include/linux/bpf_local_storage.h index b2c9463f36a1..b902c580c48d 100644 --- a/include/linux/bpf_local_storage.h +++ b/include/linux/bpf_local_storage.h @@ -126,7 +126,8 @@ bpf_local_storage_lookup(struct bpf_local_storage *local_storage, struct bpf_local_storage_map *smap, bool cacheit_lockit); -void bpf_local_storage_map_free(struct bpf_local_storage_map *smap); +void bpf_local_storage_map_free(struct bpf_local_storage_map *smap, + int __percpu *busy_counter); int bpf_local_storage_map_check_btf(const struct bpf_map *map, const struct btf *btf, -- cgit v1.2.3 From 523a4cf491b3c9e2d546040d57250f1a0ca84f03 Mon Sep 17 00:00:00 2001 From: Dmitrii Banshchikov Date: Fri, 26 Feb 2021 00:26:29 +0400 Subject: bpf: Use MAX_BPF_FUNC_REG_ARGS macro Instead of using integer literal here and there use macro name for better context. Signed-off-by: Dmitrii Banshchikov Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20210225202629.585485-1-me@ubique.spb.ru --- include/linux/bpf.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index e2cfc4809219..ae2c35641619 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -506,6 +506,11 @@ enum bpf_cgroup_storage_type { */ #define MAX_BPF_FUNC_ARGS 12 +/* The maximum number of arguments passed through registers + * a single function may have. + */ +#define MAX_BPF_FUNC_REG_ARGS 5 + struct btf_func_model { u8 ret_size; u8 nr_args; -- cgit v1.2.3 From 887596095ec2a9ea39ffcf98f27bf2e77c5eb512 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Tue, 23 Feb 2021 10:49:26 -0800 Subject: bpf: Clean up sockmap related Kconfigs As suggested by John, clean up sockmap related Kconfigs: Reduce the scope of CONFIG_BPF_STREAM_PARSER down to TCP stream parser, to reflect its name. Make the rest sockmap code simply depend on CONFIG_BPF_SYSCALL and CONFIG_INET, the latter is still needed at this point because of TCP/UDP proto update. And leave CONFIG_NET_SOCK_MSG untouched, as it is used by non-sockmap cases. Signed-off-by: Cong Wang Signed-off-by: Alexei Starovoitov Reviewed-by: Lorenz Bauer Acked-by: John Fastabend Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20210223184934.6054-2-xiyou.wangcong@gmail.com --- include/linux/bpf.h | 26 ++++++++++++-------------- include/linux/bpf_types.h | 6 ++---- include/linux/skmsg.h | 18 ++++++++++++++++++ 3 files changed, 32 insertions(+), 18 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index ae2c35641619..2be47ada5f2d 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1778,7 +1778,7 @@ static inline void bpf_map_offload_map_free(struct bpf_map *map) } #endif /* CONFIG_NET && CONFIG_BPF_SYSCALL */ -#if defined(CONFIG_BPF_STREAM_PARSER) +#if defined(CONFIG_INET) && defined(CONFIG_BPF_SYSCALL) int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, struct bpf_prog *old, u32 which); int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog); @@ -1786,7 +1786,18 @@ int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype); int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value, u64 flags); void sock_map_unhash(struct sock *sk); void sock_map_close(struct sock *sk, long timeout); + +void bpf_sk_reuseport_detach(struct sock *sk); +int bpf_fd_reuseport_array_lookup_elem(struct bpf_map *map, void *key, + void *value); +int bpf_fd_reuseport_array_update_elem(struct bpf_map *map, void *key, + void *value, u64 map_flags); #else +static inline void bpf_sk_reuseport_detach(struct sock *sk) +{ +} + +#ifdef CONFIG_BPF_SYSCALL static inline int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, struct bpf_prog *old, u32 which) @@ -1811,20 +1822,7 @@ static inline int sock_map_update_elem_sys(struct bpf_map *map, void *key, void { return -EOPNOTSUPP; } -#endif /* CONFIG_BPF_STREAM_PARSER */ -#if defined(CONFIG_INET) && defined(CONFIG_BPF_SYSCALL) -void bpf_sk_reuseport_detach(struct sock *sk); -int bpf_fd_reuseport_array_lookup_elem(struct bpf_map *map, void *key, - void *value); -int bpf_fd_reuseport_array_update_elem(struct bpf_map *map, void *key, - void *value, u64 map_flags); -#else -static inline void bpf_sk_reuseport_detach(struct sock *sk) -{ -} - -#ifdef CONFIG_BPF_SYSCALL static inline int bpf_fd_reuseport_array_lookup_elem(struct bpf_map *map, void *key, void *value) { diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h index b9edee336d80..f883f01a5061 100644 --- a/include/linux/bpf_types.h +++ b/include/linux/bpf_types.h @@ -103,10 +103,6 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_HASH_OF_MAPS, htab_of_maps_map_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_DEVMAP, dev_map_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_DEVMAP_HASH, dev_map_hash_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_SK_STORAGE, sk_storage_map_ops) -#if defined(CONFIG_BPF_STREAM_PARSER) -BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKMAP, sock_map_ops) -BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKHASH, sock_hash_ops) -#endif #ifdef CONFIG_BPF_LSM BPF_MAP_TYPE(BPF_MAP_TYPE_INODE_STORAGE, inode_storage_map_ops) #endif @@ -116,6 +112,8 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_CPUMAP, cpu_map_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_XSKMAP, xsk_map_ops) #endif #ifdef CONFIG_INET +BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKMAP, sock_map_ops) +BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKHASH, sock_hash_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_REUSEPORT_SOCKARRAY, reuseport_array_ops) #endif #endif diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index 8edbbf5f2f93..db7a08be4725 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -71,7 +71,9 @@ struct sk_psock_link { }; struct sk_psock_parser { +#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) struct strparser strp; +#endif bool enabled; void (*saved_data_ready)(struct sock *sk); }; @@ -305,9 +307,25 @@ static inline void sk_psock_report_error(struct sk_psock *psock, int err) struct sk_psock *sk_psock_init(struct sock *sk, int node); +#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock); void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock); void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock); +#else +static inline int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock) +{ + return -EOPNOTSUPP; +} + +static inline void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock) +{ +} + +static inline void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock) +{ +} +#endif + void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock); void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock); -- cgit v1.2.3 From 5a685cd94b21a88efa6be77169eddef525368034 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Tue, 23 Feb 2021 10:49:27 -0800 Subject: skmsg: Get rid of struct sk_psock_parser struct sk_psock_parser is embedded in sk_psock, it is unnecessary as skb verdict also uses ->saved_data_ready. We can simply fold these fields into sk_psock, and get rid of ->enabled. Signed-off-by: Cong Wang Signed-off-by: Alexei Starovoitov Acked-by: John Fastabend Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20210223184934.6054-3-xiyou.wangcong@gmail.com --- include/linux/skmsg.h | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) (limited to 'include/linux') diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index db7a08be4725..22e26f82de33 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -70,14 +70,6 @@ struct sk_psock_link { void *link_raw; }; -struct sk_psock_parser { -#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) - struct strparser strp; -#endif - bool enabled; - void (*saved_data_ready)(struct sock *sk); -}; - struct sk_psock_work_state { struct sk_buff *skb; u32 len; @@ -92,7 +84,9 @@ struct sk_psock { u32 eval; struct sk_msg *cork; struct sk_psock_progs progs; - struct sk_psock_parser parser; +#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) + struct strparser strp; +#endif struct sk_buff_head ingress_skb; struct list_head ingress_msg; unsigned long state; @@ -102,6 +96,7 @@ struct sk_psock { void (*saved_unhash)(struct sock *sk); void (*saved_close)(struct sock *sk, long timeout); void (*saved_write_space)(struct sock *sk); + void (*saved_data_ready)(struct sock *sk); struct proto *sk_proto; struct sk_psock_work_state work_state; struct work_struct work; @@ -418,8 +413,8 @@ static inline void sk_psock_put(struct sock *sk, struct sk_psock *psock) static inline void sk_psock_data_ready(struct sock *sk, struct sk_psock *psock) { - if (psock->parser.enabled) - psock->parser.saved_data_ready(sk); + if (psock->saved_data_ready) + psock->saved_data_ready(sk); else sk->sk_data_ready(sk); } @@ -458,6 +453,6 @@ static inline bool sk_psock_strp_enabled(struct sk_psock *psock) { if (!psock) return false; - return psock->parser.enabled; + return !!psock->saved_data_ready; } #endif /* _LINUX_SKMSG_H */ -- cgit v1.2.3 From e3526bb92a2084cdaec6cb2855bcec98b280426c Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Tue, 23 Feb 2021 10:49:29 -0800 Subject: skmsg: Move sk_redir from TCP_SKB_CB to skb Currently TCP_SKB_CB() is hard-coded in skmsg code, it certainly does not work for any other non-TCP protocols. We can move them to skb ext, but it introduces a memory allocation on fast path. Fortunately, we only need to a word-size to store all the information, because the flags actually only contains 1 bit so can be just packed into the lowest bit of the "pointer", which is stored as unsigned long. Inside struct sk_buff, '_skb_refdst' can be reused because skb dst is no longer needed after ->sk_data_ready() so we can just drop it. Signed-off-by: Cong Wang Signed-off-by: Alexei Starovoitov Acked-by: John Fastabend Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20210223184934.6054-5-xiyou.wangcong@gmail.com --- include/linux/skbuff.h | 3 +++ include/linux/skmsg.h | 38 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 6d0a33d1c0db..bd84f799c952 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -755,6 +755,9 @@ struct sk_buff { void (*destructor)(struct sk_buff *skb); }; struct list_head tcp_tsorted_anchor; +#ifdef CONFIG_NET_SOCK_MSG + unsigned long _sk_redir; +#endif }; #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index 22e26f82de33..e0de45527bb6 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -455,4 +455,42 @@ static inline bool sk_psock_strp_enabled(struct sk_psock *psock) return false; return !!psock->saved_data_ready; } + +#if IS_ENABLED(CONFIG_NET_SOCK_MSG) + +/* We only have one bit so far. */ +#define BPF_F_PTR_MASK ~(BPF_F_INGRESS) + +static inline bool skb_bpf_ingress(const struct sk_buff *skb) +{ + unsigned long sk_redir = skb->_sk_redir; + + return sk_redir & BPF_F_INGRESS; +} + +static inline void skb_bpf_set_ingress(struct sk_buff *skb) +{ + skb->_sk_redir |= BPF_F_INGRESS; +} + +static inline void skb_bpf_set_redir(struct sk_buff *skb, struct sock *sk_redir, + bool ingress) +{ + skb->_sk_redir = (unsigned long)sk_redir; + if (ingress) + skb->_sk_redir |= BPF_F_INGRESS; +} + +static inline struct sock *skb_bpf_redirect_fetch(const struct sk_buff *skb) +{ + unsigned long sk_redir = skb->_sk_redir; + + return (struct sock *)(sk_redir & BPF_F_PTR_MASK); +} + +static inline void skb_bpf_redirect_clear(struct sk_buff *skb) +{ + skb->_sk_redir = 0; +} +#endif /* CONFIG_NET_SOCK_MSG */ #endif /* _LINUX_SKMSG_H */ -- cgit v1.2.3 From ae8b8332fbb512f53bf50ff6a7586dd0f90ed18a Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Tue, 23 Feb 2021 10:49:30 -0800 Subject: sock_map: Rename skb_parser and skb_verdict These two eBPF programs are tied to BPF_SK_SKB_STREAM_PARSER and BPF_SK_SKB_STREAM_VERDICT, rename them to reflect the fact they are only used for TCP. And save the name 'skb_verdict' for general use later. Signed-off-by: Cong Wang Signed-off-by: Alexei Starovoitov Reviewed-by: Lorenz Bauer Acked-by: John Fastabend Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20210223184934.6054-6-xiyou.wangcong@gmail.com --- include/linux/skmsg.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index e0de45527bb6..d9f6ec4a9cf2 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -56,8 +56,8 @@ struct sk_msg { struct sk_psock_progs { struct bpf_prog *msg_parser; - struct bpf_prog *skb_parser; - struct bpf_prog *skb_verdict; + struct bpf_prog *stream_parser; + struct bpf_prog *stream_verdict; }; enum sk_psock_state_bits { @@ -443,8 +443,8 @@ static inline int psock_replace_prog(struct bpf_prog **pprog, static inline void psock_progs_drop(struct sk_psock_progs *progs) { psock_set_prog(&progs->msg_parser, NULL); - psock_set_prog(&progs->skb_parser, NULL); - psock_set_prog(&progs->skb_verdict, NULL); + psock_set_prog(&progs->stream_parser, NULL); + psock_set_prog(&progs->stream_verdict, NULL); } int sk_psock_tls_strp_read(struct sk_psock *psock, struct sk_buff *skb); -- cgit v1.2.3 From 4675e234b9e15159894b90ead9340e1dc202b670 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Tue, 23 Feb 2021 10:49:31 -0800 Subject: sock_map: Make sock_map_prog_update() static It is only used within sock_map.c so can become static. Suggested-by: Jakub Sitnicki Signed-off-by: Cong Wang Signed-off-by: Alexei Starovoitov Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20210223184934.6054-7-xiyou.wangcong@gmail.com --- include/linux/bpf.h | 9 --------- 1 file changed, 9 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 2be47ada5f2d..e1e4d2f60527 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1779,8 +1779,6 @@ static inline void bpf_map_offload_map_free(struct bpf_map *map) #endif /* CONFIG_NET && CONFIG_BPF_SYSCALL */ #if defined(CONFIG_INET) && defined(CONFIG_BPF_SYSCALL) -int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, - struct bpf_prog *old, u32 which); int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog); int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype); int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value, u64 flags); @@ -1798,13 +1796,6 @@ static inline void bpf_sk_reuseport_detach(struct sock *sk) } #ifdef CONFIG_BPF_SYSCALL -static inline int sock_map_prog_update(struct bpf_map *map, - struct bpf_prog *prog, - struct bpf_prog *old, u32 which) -{ - return -EOPNOTSUPP; -} - static inline int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog) { -- cgit v1.2.3 From cd81cefb1abc52bd164f4d9760cd22eadc0e4468 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Tue, 23 Feb 2021 10:49:32 -0800 Subject: skmsg: Make __sk_psock_purge_ingress_msg() static It is only used within skmsg.c so can become static. Signed-off-by: Cong Wang Signed-off-by: Alexei Starovoitov Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20210223184934.6054-8-xiyou.wangcong@gmail.com --- include/linux/skmsg.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index d9f6ec4a9cf2..676d48e08159 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -340,8 +340,6 @@ static inline void sk_psock_free_link(struct sk_psock_link *link) struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock); -void __sk_psock_purge_ingress_msg(struct sk_psock *psock); - static inline void sk_psock_cork_free(struct sk_psock *psock) { if (psock->cork) { -- cgit v1.2.3 From ff9614b81be65d648ec4615b593c6e4b2dac6375 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Tue, 23 Feb 2021 10:49:34 -0800 Subject: skmsg: Remove unused sk_psock_stop() declaration It is not defined or used anywhere. Signed-off-by: Cong Wang Signed-off-by: Alexei Starovoitov Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20210223184934.6054-10-xiyou.wangcong@gmail.com --- include/linux/skmsg.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index 676d48e08159..6c09d94be2e9 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -400,7 +400,6 @@ static inline struct sk_psock *sk_psock_get(struct sock *sk) return psock; } -void sk_psock_stop(struct sock *sk, struct sk_psock *psock); void sk_psock_drop(struct sock *sk, struct sk_psock *psock); static inline void sk_psock_put(struct sock *sk, struct sk_psock *psock) -- cgit v1.2.3 From 69c087ba6225b574afb6e505b72cb75242a3d844 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Fri, 26 Feb 2021 12:49:25 -0800 Subject: bpf: Add bpf_for_each_map_elem() helper The bpf_for_each_map_elem() helper is introduced which iterates all map elements with a callback function. The helper signature looks like long bpf_for_each_map_elem(map, callback_fn, callback_ctx, flags) and for each map element, the callback_fn will be called. For example, like hashmap, the callback signature may look like long callback_fn(map, key, val, callback_ctx) There are two known use cases for this. One is from upstream ([1]) where a for_each_map_elem helper may help implement a timeout mechanism in a more generic way. Another is from our internal discussion for a firewall use case where a map contains all the rules. The packet data can be compared to all these rules to decide allow or deny the packet. For array maps, users can already use a bounded loop to traverse elements. Using this helper can avoid using bounded loop. For other type of maps (e.g., hash maps) where bounded loop is hard or impossible to use, this helper provides a convenient way to operate on all elements. For callback_fn, besides map and map element, a callback_ctx, allocated on caller stack, is also passed to the callback function. This callback_ctx argument can provide additional input and allow to write to caller stack for output. If the callback_fn returns 0, the helper will iterate through next element if available. If the callback_fn returns 1, the helper will stop iterating and returns to the bpf program. Other return values are not used for now. Currently, this helper is only available with jit. It is possible to make it work with interpreter with so effort but I leave it as the future work. [1]: https://lore.kernel.org/bpf/20210122205415.113822-1-xiyou.wangcong@gmail.com/ Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210226204925.3884923-1-yhs@fb.com --- include/linux/bpf.h | 13 +++++++++++++ include/linux/bpf_verifier.h | 3 +++ 2 files changed, 16 insertions(+) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index e1e4d2f60527..aeb1b93a4d75 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -39,6 +39,7 @@ struct bpf_local_storage; struct bpf_local_storage_map; struct kobject; struct mem_cgroup; +struct bpf_func_state; extern struct idr btf_idr; extern spinlock_t btf_idr_lock; @@ -129,6 +130,13 @@ struct bpf_map_ops { bool (*map_meta_equal)(const struct bpf_map *meta0, const struct bpf_map *meta1); + + int (*map_set_for_each_callback_args)(struct bpf_verifier_env *env, + struct bpf_func_state *caller, + struct bpf_func_state *callee); + int (*map_for_each_callback)(struct bpf_map *map, void *callback_fn, + void *callback_ctx, u64 flags); + /* BTF name and id of struct allocated by map_alloc */ const char * const map_btf_name; int *map_btf_id; @@ -295,6 +303,8 @@ enum bpf_arg_type { ARG_CONST_ALLOC_SIZE_OR_ZERO, /* number of allocated bytes requested */ ARG_PTR_TO_BTF_ID_SOCK_COMMON, /* pointer to in-kernel sock_common or bpf-mirrored bpf_sock */ ARG_PTR_TO_PERCPU_BTF_ID, /* pointer to in-kernel percpu type */ + ARG_PTR_TO_FUNC, /* pointer to a bpf program function */ + ARG_PTR_TO_STACK_OR_NULL, /* pointer to stack or NULL */ __BPF_ARG_TYPE_MAX, }; @@ -411,6 +421,8 @@ enum bpf_reg_type { PTR_TO_RDWR_BUF, /* reg points to a read/write buffer */ PTR_TO_RDWR_BUF_OR_NULL, /* reg points to a read/write buffer or NULL */ PTR_TO_PERCPU_BTF_ID, /* reg points to a percpu kernel variable */ + PTR_TO_FUNC, /* reg points to a bpf program function */ + PTR_TO_MAP_KEY, /* reg points to a map element key */ }; /* The information passed from prog-specific *_is_valid_access @@ -1887,6 +1899,7 @@ extern const struct bpf_func_proto bpf_sock_from_file_proto; extern const struct bpf_func_proto bpf_get_socket_ptr_cookie_proto; extern const struct bpf_func_proto bpf_task_storage_get_proto; extern const struct bpf_func_proto bpf_task_storage_delete_proto; +extern const struct bpf_func_proto bpf_for_each_map_elem_proto; const struct bpf_func_proto *bpf_tracing_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 971b33aca13d..51c2ffa3d901 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -68,6 +68,8 @@ struct bpf_reg_state { unsigned long raw1; unsigned long raw2; } raw; + + u32 subprogno; /* for PTR_TO_FUNC */ }; /* For PTR_TO_PACKET, used to find other pointers with the same variable * offset, so they can share range knowledge. @@ -204,6 +206,7 @@ struct bpf_func_state { int acquired_refs; struct bpf_reference_state *refs; int allocated_stack; + bool in_callback_fn; struct bpf_stack_state *stack; }; -- cgit v1.2.3 From 314ee05e2fc601a7bece14376547d2b7a04bab67 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Fri, 26 Feb 2021 12:49:27 -0800 Subject: bpf: Add hashtab support for bpf_for_each_map_elem() helper This patch added support for hashmap, percpu hashmap, lru hashmap and percpu lru hashmap. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210226204927.3885020-1-yhs@fb.com --- include/linux/bpf.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index aeb1b93a4d75..4c730863fa77 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1397,6 +1397,10 @@ void bpf_iter_map_show_fdinfo(const struct bpf_iter_aux_info *aux, int bpf_iter_map_fill_link_info(const struct bpf_iter_aux_info *aux, struct bpf_link_info *info); +int map_set_for_each_callback_args(struct bpf_verifier_env *env, + struct bpf_func_state *caller, + struct bpf_func_state *callee); + int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value); int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value); int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value, -- cgit v1.2.3 From 6ed6e1c761f6c8391af654facbbbf1748ae9f386 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Mon, 1 Mar 2021 10:48:05 -0800 Subject: skmsg: Add function doc for skb->_sk_redir This should fix the following warning: include/linux/skbuff.h:932: warning: Function parameter or member '_sk_redir' not described in 'sk_buff' Reported-by: Lorenz Bauer Signed-off-by: Cong Wang Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Acked-by: Lorenz Bauer Link: https://lore.kernel.org/bpf/20210301184805.8174-1-xiyou.wangcong@gmail.com --- include/linux/skbuff.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index bd84f799c952..0503c917d773 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -656,6 +656,7 @@ typedef unsigned char *sk_buff_data_t; * @protocol: Packet protocol from driver * @destructor: Destruct function * @tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue) + * @_sk_redir: socket redirection information for skmsg * @_nfct: Associated connection, if any (with nfctinfo bits) * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c * @skb_iif: ifindex of device we arrived on -- cgit v1.2.3 From 7c32e8f8bc33a5f4b113a630857e46634e3e143b Mon Sep 17 00:00:00 2001 From: Lorenz Bauer Date: Wed, 3 Mar 2021 10:18:13 +0000 Subject: bpf: Add PROG_TEST_RUN support for sk_lookup programs Allow to pass sk_lookup programs to PROG_TEST_RUN. User space provides the full bpf_sk_lookup struct as context. Since the context includes a socket pointer that can't be exposed to user space we define that PROG_TEST_RUN returns the cookie of the selected socket or zero in place of the socket pointer. We don't support testing programs that select a reuseport socket, since this would mean running another (unrelated) BPF program from the sk_lookup test handler. Signed-off-by: Lorenz Bauer Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20210303101816.36774-3-lmb@cloudflare.com --- include/linux/bpf.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 4c730863fa77..c931bc97019d 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1491,6 +1491,9 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog, int bpf_prog_test_run_raw_tp(struct bpf_prog *prog, const union bpf_attr *kattr, union bpf_attr __user *uattr); +int bpf_prog_test_run_sk_lookup(struct bpf_prog *prog, + const union bpf_attr *kattr, + union bpf_attr __user *uattr); bool btf_ctx_access(int off, int size, enum bpf_access_type type, const struct bpf_prog *prog, struct bpf_insn_access_aux *info); @@ -1692,6 +1695,13 @@ static inline int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog, return -ENOTSUPP; } +static inline int bpf_prog_test_run_sk_lookup(struct bpf_prog *prog, + const union bpf_attr *kattr, + union bpf_attr __user *uattr) +{ + return -ENOTSUPP; +} + static inline void bpf_map_put(struct bpf_map *map) { } -- cgit v1.2.3 From e6a4750ffe9d701c4d55212b14b615e63571d235 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Mon, 8 Mar 2021 12:29:06 +0100 Subject: bpf, xdp: Make bpf_redirect_map() a map operation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently the bpf_redirect_map() implementation dispatches to the correct map-lookup function via a switch-statement. To avoid the dispatching, this change adds bpf_redirect_map() as a map operation. Each map provides its bpf_redirect_map() version, and correct function is automatically selected by the BPF verifier. A nice side-effect of the code movement is that the map lookup functions are now local to the map implementation files, which removes one additional function call. Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann Acked-by: Jesper Dangaard Brouer Acked-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/bpf/20210308112907.559576-2-bjorn.topel@gmail.com --- include/linux/bpf.h | 26 ++++++-------------------- include/linux/filter.h | 27 +++++++++++++++++++++++++++ 2 files changed, 33 insertions(+), 20 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index c931bc97019d..a25730eaa148 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -118,6 +118,9 @@ struct bpf_map_ops { void *owner, u32 size); struct bpf_local_storage __rcu ** (*map_owner_storage_ptr)(void *owner); + /* Misc helpers.*/ + int (*map_redirect)(struct bpf_map *map, u32 ifindex, u64 flags); + /* map_meta_equal must be implemented for maps that can be * used as an inner map. It is a runtime check to ensure * an inner map can be inserted to an outer map. @@ -1450,9 +1453,9 @@ 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_flush(void); int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp, struct net_device *dev_rx); @@ -1462,7 +1465,6 @@ 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_flush(void); int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp, struct net_device *dev_rx); @@ -1593,17 +1595,6 @@ 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) -{ - return NULL; -} - -static inline struct net_device *__dev_map_hash_lookup_elem(struct bpf_map *map, - u32 key) -{ - return NULL; -} static inline bool dev_map_can_have_prog(struct bpf_map *map) { return false; @@ -1615,6 +1606,7 @@ static inline void __dev_flush(void) struct xdp_buff; struct bpf_dtab_netdev; +struct bpf_cpu_map_entry; static inline int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp, @@ -1639,12 +1631,6 @@ static inline int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, return 0; } -static inline -struct bpf_cpu_map_entry *__cpu_map_lookup_elem(struct bpf_map *map, u32 key) -{ - return NULL; -} - static inline void __cpu_map_flush(void) { } diff --git a/include/linux/filter.h b/include/linux/filter.h index 3b00fc906ccd..008691fd3b58 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1472,4 +1472,31 @@ static inline bool bpf_sk_lookup_run_v6(struct net *net, int protocol, } #endif /* IS_ENABLED(CONFIG_IPV6) */ +static __always_inline int __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 = 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 + * performs multiple lookups, the last one always takes + * precedence. + */ + WRITE_ONCE(ri->map, NULL); + return flags; + } + + ri->flags = flags; + ri->tgt_index = ifindex; + WRITE_ONCE(ri->map, map); + + return XDP_REDIRECT; +} + #endif /* __LINUX_FILTER_H__ */ -- cgit v1.2.3 From ee75aef23afe6e88497151c127c13ed69f41aaa2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Mon, 8 Mar 2021 12:29:07 +0100 Subject: bpf, xdp: Restructure redirect actions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The XDP_REDIRECT implementations for maps and non-maps are fairly similar, but obviously need to take different code paths depending on if the target is using a map or not. Today, the redirect targets for XDP either uses a map, or is based on ifindex. Here, the map type and id are added to bpf_redirect_info, instead of the actual map. Map type, map item/ifindex, and the map_id (if any) is passed to xdp_do_redirect(). For ifindex-based redirect, used by the bpf_redirect() XDP BFP helper, a special map type/id are used. Map type of UNSPEC together with map id equal to INT_MAX has the special meaning of an ifindex based redirect. Note that valid map ids are 1 inclusive, INT_MAX exclusive ([1,INT_MAX[). In addition to making the code easier to follow, using explicit type and id in bpf_redirect_info has a slight positive performance impact by avoiding a pointer indirection for the map type lookup, and instead use the cacheline for bpf_redirect_info. Since the actual map is not passed via bpf_redirect_info anymore, the map lookup is only done in the BPF helper. This means that the bpf_clear_redirect_map() function can be removed. The actual map item is RCU protected. The bpf_redirect_info flags member is not used by XDP, and not read/written any more. The map member is only written to when required/used, and not unconditionally. Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann Reviewed-by: Maciej Fijalkowski Acked-by: Jesper Dangaard Brouer Acked-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/bpf/20210308112907.559576-3-bjorn.topel@gmail.com --- include/linux/filter.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/filter.h b/include/linux/filter.h index 008691fd3b58..b2b85b2cad8e 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -646,7 +646,8 @@ struct bpf_redirect_info { u32 flags; u32 tgt_index; void *tgt_value; - struct bpf_map *map; + u32 map_id; + enum bpf_map_type map_type; u32 kern_flags; struct bpf_nh_params nh; }; @@ -1488,13 +1489,14 @@ static __always_inline int __bpf_xdp_redirect_map(struct bpf_map *map, u32 ifind * performs multiple lookups, the last one always takes * precedence. */ - WRITE_ONCE(ri->map, NULL); + ri->map_id = INT_MAX; /* Valid map id idr range: [1,INT_MAX[ */ + ri->map_type = BPF_MAP_TYPE_UNSPEC; return flags; } - ri->flags = flags; ri->tgt_index = ifindex; - WRITE_ONCE(ri->map, map); + ri->map_id = map->id; + ri->map_type = map->map_type; return XDP_REDIRECT; } -- cgit v1.2.3