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linux-stable/include/linux/bpf_types.h
Joanne Koong 9330986c03 bpf: Add bloom filter map implementation 
This patch adds the kernel-side changes for the implementation of
a bpf bloom filter map.

The bloom filter map supports peek (determining whether an element
is present in the map) and push (adding an element to the map)
operations.These operations are exposed to userspace applications
through the already existing syscalls in the following way:

BPF_MAP_LOOKUP_ELEM -> peek
BPF_MAP_UPDATE_ELEM -> push

The bloom filter map does not have keys, only values. In light of
this, the bloom filter map's API matches that of queue stack maps:
user applications use BPF_MAP_LOOKUP_ELEM/BPF_MAP_UPDATE_ELEM
which correspond internally to bpf_map_peek_elem/bpf_map_push_elem,
and bpf programs must use the bpf_map_peek_elem and bpf_map_push_elem
APIs to query or add an element to the bloom filter map. When the
bloom filter map is created, it must be created with a key_size of 0.

For updates, the user will pass in the element to add to the map
as the value, with a NULL key. For lookups, the user will pass in the
element to query in the map as the value, with a NULL key. In the
verifier layer, this requires us to modify the argument type of
a bloom filter's BPF_FUNC_map_peek_elem call to ARG_PTR_TO_MAP_VALUE;
as well, in the syscall layer, we need to copy over the user value
so that in bpf_map_peek_elem, we know which specific value to query.

A few things to please take note of:
 * If there are any concurrent lookups + updates, the user is
responsible for synchronizing this to ensure no false negative lookups
occur.
 * The number of hashes to use for the bloom filter is configurable from
userspace. If no number is specified, the default used will be 5 hash
functions. The benchmarks later in this patchset can help compare the
performance of using different number of hashes on different entry
sizes. In general, using more hashes decreases both the false positive
rate and the speed of a lookup.
 * Deleting an element in the bloom filter map is not supported.
 * The bloom filter map may be used as an inner map.
 * The "max_entries" size that is specified at map creation time is used
to approximate a reasonable bitmap size for the bloom filter, and is not
otherwise strictly enforced. If the user wishes to insert more entries
into the bloom filter than "max_entries", they may do so but they should
be aware that this may lead to a higher false positive rate.

Signed-off-by: Joanne Koong <joannekoong@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211027234504.30744-2-joannekoong@fb.com
2021-10-28 13:22:49 -07:00

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/* SPDX-License-Identifier: GPL-2.0 */
/* internal file - do not include directly */
#ifdef CONFIG_NET
BPF_PROG_TYPE(BPF_PROG_TYPE_SOCKET_FILTER, sk_filter,
struct __sk_buff, struct sk_buff)
BPF_PROG_TYPE(BPF_PROG_TYPE_SCHED_CLS, tc_cls_act,
struct __sk_buff, struct sk_buff)
BPF_PROG_TYPE(BPF_PROG_TYPE_SCHED_ACT, tc_cls_act,
struct __sk_buff, struct sk_buff)
BPF_PROG_TYPE(BPF_PROG_TYPE_XDP, xdp,
struct xdp_md, struct xdp_buff)
#ifdef CONFIG_CGROUP_BPF
BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SKB, cg_skb,
struct __sk_buff, struct sk_buff)
BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SOCK, cg_sock,
struct bpf_sock, struct sock)
BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SOCK_ADDR, cg_sock_addr,
struct bpf_sock_addr, struct bpf_sock_addr_kern)
#endif
BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_IN, lwt_in,
struct __sk_buff, struct sk_buff)
BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_OUT, lwt_out,
struct __sk_buff, struct sk_buff)
BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_XMIT, lwt_xmit,
struct __sk_buff, struct sk_buff)
BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_SEG6LOCAL, lwt_seg6local,
struct __sk_buff, struct sk_buff)
BPF_PROG_TYPE(BPF_PROG_TYPE_SOCK_OPS, sock_ops,
struct bpf_sock_ops, struct bpf_sock_ops_kern)
BPF_PROG_TYPE(BPF_PROG_TYPE_SK_SKB, sk_skb,
struct __sk_buff, struct sk_buff)
BPF_PROG_TYPE(BPF_PROG_TYPE_SK_MSG, sk_msg,
struct sk_msg_md, struct sk_msg)
BPF_PROG_TYPE(BPF_PROG_TYPE_FLOW_DISSECTOR, flow_dissector,
struct __sk_buff, struct bpf_flow_dissector)
#endif
#ifdef CONFIG_BPF_EVENTS
BPF_PROG_TYPE(BPF_PROG_TYPE_KPROBE, kprobe,
bpf_user_pt_regs_t, struct pt_regs)
BPF_PROG_TYPE(BPF_PROG_TYPE_TRACEPOINT, tracepoint,
__u64, u64)
BPF_PROG_TYPE(BPF_PROG_TYPE_PERF_EVENT, perf_event,
struct bpf_perf_event_data, struct bpf_perf_event_data_kern)
BPF_PROG_TYPE(BPF_PROG_TYPE_RAW_TRACEPOINT, raw_tracepoint,
struct bpf_raw_tracepoint_args, u64)
BPF_PROG_TYPE(BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, raw_tracepoint_writable,
struct bpf_raw_tracepoint_args, u64)
BPF_PROG_TYPE(BPF_PROG_TYPE_TRACING, tracing,
void *, void *)
#endif
#ifdef CONFIG_CGROUP_BPF
BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_DEVICE, cg_dev,
struct bpf_cgroup_dev_ctx, struct bpf_cgroup_dev_ctx)
BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SYSCTL, cg_sysctl,
struct bpf_sysctl, struct bpf_sysctl_kern)
BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SOCKOPT, cg_sockopt,
struct bpf_sockopt, struct bpf_sockopt_kern)
#endif
#ifdef CONFIG_BPF_LIRC_MODE2
BPF_PROG_TYPE(BPF_PROG_TYPE_LIRC_MODE2, lirc_mode2,
__u32, u32)
#endif
#ifdef CONFIG_INET
BPF_PROG_TYPE(BPF_PROG_TYPE_SK_REUSEPORT, sk_reuseport,
struct sk_reuseport_md, struct sk_reuseport_kern)
BPF_PROG_TYPE(BPF_PROG_TYPE_SK_LOOKUP, sk_lookup,
struct bpf_sk_lookup, struct bpf_sk_lookup_kern)
#endif
#if defined(CONFIG_BPF_JIT)
BPF_PROG_TYPE(BPF_PROG_TYPE_STRUCT_OPS, bpf_struct_ops,
void *, void *)
BPF_PROG_TYPE(BPF_PROG_TYPE_EXT, bpf_extension,
void *, void *)
#ifdef CONFIG_BPF_LSM
BPF_PROG_TYPE(BPF_PROG_TYPE_LSM, lsm,
void *, void *)
#endif /* CONFIG_BPF_LSM */
#endif
BPF_PROG_TYPE(BPF_PROG_TYPE_SYSCALL, bpf_syscall,
void *, void *)
BPF_MAP_TYPE(BPF_MAP_TYPE_ARRAY, array_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_PERCPU_ARRAY, percpu_array_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_PROG_ARRAY, prog_array_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_PERF_EVENT_ARRAY, perf_event_array_map_ops)
#ifdef CONFIG_CGROUPS
BPF_MAP_TYPE(BPF_MAP_TYPE_CGROUP_ARRAY, cgroup_array_map_ops)
#endif
#ifdef CONFIG_CGROUP_BPF
BPF_MAP_TYPE(BPF_MAP_TYPE_CGROUP_STORAGE, cgroup_storage_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE, cgroup_storage_map_ops)
#endif
BPF_MAP_TYPE(BPF_MAP_TYPE_HASH, htab_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_PERCPU_HASH, htab_percpu_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_LRU_HASH, htab_lru_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_LRU_PERCPU_HASH, htab_lru_percpu_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_LPM_TRIE, trie_map_ops)
#ifdef CONFIG_PERF_EVENTS
BPF_MAP_TYPE(BPF_MAP_TYPE_STACK_TRACE, stack_trace_map_ops)
#endif
BPF_MAP_TYPE(BPF_MAP_TYPE_ARRAY_OF_MAPS, array_of_maps_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_HASH_OF_MAPS, htab_of_maps_map_ops)
#ifdef CONFIG_NET
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)
#ifdef CONFIG_BPF_LSM
BPF_MAP_TYPE(BPF_MAP_TYPE_INODE_STORAGE, inode_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)
#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
BPF_MAP_TYPE(BPF_MAP_TYPE_QUEUE, queue_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_STACK, stack_map_ops)
#if defined(CONFIG_BPF_JIT)
BPF_MAP_TYPE(BPF_MAP_TYPE_STRUCT_OPS, bpf_struct_ops_map_ops)
#endif
BPF_MAP_TYPE(BPF_MAP_TYPE_RINGBUF, ringbuf_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_BLOOM_FILTER, bloom_filter_map_ops)
BPF_LINK_TYPE(BPF_LINK_TYPE_RAW_TRACEPOINT, raw_tracepoint)
BPF_LINK_TYPE(BPF_LINK_TYPE_TRACING, tracing)
#ifdef CONFIG_CGROUP_BPF
BPF_LINK_TYPE(BPF_LINK_TYPE_CGROUP, cgroup)
#endif
BPF_LINK_TYPE(BPF_LINK_TYPE_ITER, iter)
#ifdef CONFIG_NET
BPF_LINK_TYPE(BPF_LINK_TYPE_NETNS, netns)
BPF_LINK_TYPE(BPF_LINK_TYPE_XDP, xdp)
#endif
#ifdef CONFIG_PERF_EVENTS
BPF_LINK_TYPE(BPF_LINK_TYPE_PERF_EVENT, perf)
#endif
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