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Diffstat (limited to '')
-rw-r--r-- | include/bpf_api.h | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/include/bpf_api.h b/include/bpf_api.h new file mode 100644 index 0000000..82c4708 --- /dev/null +++ b/include/bpf_api.h @@ -0,0 +1,275 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __BPF_API__ +#define __BPF_API__ + +/* Note: + * + * This file can be included into eBPF kernel programs. It contains + * a couple of useful helper functions, map/section ABI (bpf_elf.h), + * misc macros and some eBPF specific LLVM built-ins. + */ + +#include <stdint.h> + +#include <linux/pkt_cls.h> +#include <linux/bpf.h> +#include <linux/filter.h> + +#include <asm/byteorder.h> + +#include "bpf_elf.h" + +/** libbpf pin type. */ +enum libbpf_pin_type { + LIBBPF_PIN_NONE, + /* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */ + LIBBPF_PIN_BY_NAME, +}; + +/** Type helper macros. */ + +#define __uint(name, val) int (*name)[val] +#define __type(name, val) typeof(val) *name +#define __array(name, val) typeof(val) *name[] + +/** Misc macros. */ + +#ifndef __stringify +# define __stringify(X) #X +#endif + +#ifndef __maybe_unused +# define __maybe_unused __attribute__((__unused__)) +#endif + +#ifndef offsetof +# define offsetof(TYPE, MEMBER) __builtin_offsetof(TYPE, MEMBER) +#endif + +#ifndef likely +# define likely(X) __builtin_expect(!!(X), 1) +#endif + +#ifndef unlikely +# define unlikely(X) __builtin_expect(!!(X), 0) +#endif + +#ifndef htons +# define htons(X) __constant_htons((X)) +#endif + +#ifndef ntohs +# define ntohs(X) __constant_ntohs((X)) +#endif + +#ifndef htonl +# define htonl(X) __constant_htonl((X)) +#endif + +#ifndef ntohl +# define ntohl(X) __constant_ntohl((X)) +#endif + +#ifndef __inline__ +# define __inline__ __attribute__((always_inline)) +#endif + +/** Section helper macros. */ + +#ifndef __section +# define __section(NAME) \ + __attribute__((section(NAME), used)) +#endif + +#ifndef __section_tail +# define __section_tail(ID, KEY) \ + __section(__stringify(ID) "/" __stringify(KEY)) +#endif + +#ifndef __section_xdp_entry +# define __section_xdp_entry \ + __section(ELF_SECTION_PROG) +#endif + +#ifndef __section_cls_entry +# define __section_cls_entry \ + __section(ELF_SECTION_CLASSIFIER) +#endif + +#ifndef __section_act_entry +# define __section_act_entry \ + __section(ELF_SECTION_ACTION) +#endif + +#ifndef __section_lwt_entry +# define __section_lwt_entry \ + __section(ELF_SECTION_PROG) +#endif + +#ifndef __section_license +# define __section_license \ + __section(ELF_SECTION_LICENSE) +#endif + +#ifndef __section_maps +# define __section_maps \ + __section(ELF_SECTION_MAPS) +#endif + +/** Declaration helper macros. */ + +#ifndef BPF_LICENSE +# define BPF_LICENSE(NAME) \ + char ____license[] __section_license = NAME +#endif + +/** Classifier helper */ + +#ifndef BPF_H_DEFAULT +# define BPF_H_DEFAULT -1 +#endif + +/** BPF helper functions for tc. Individual flags are in linux/bpf.h */ + +#ifndef __BPF_FUNC +# define __BPF_FUNC(NAME, ...) \ + (* NAME)(__VA_ARGS__) __maybe_unused +#endif + +#ifndef BPF_FUNC +# define BPF_FUNC(NAME, ...) \ + __BPF_FUNC(NAME, __VA_ARGS__) = (void *) BPF_FUNC_##NAME +#endif + +/* Map access/manipulation */ +static void *BPF_FUNC(map_lookup_elem, void *map, const void *key); +static int BPF_FUNC(map_update_elem, void *map, const void *key, + const void *value, uint32_t flags); +static int BPF_FUNC(map_delete_elem, void *map, const void *key); + +/* Time access */ +static uint64_t BPF_FUNC(ktime_get_ns); + +/* Debugging */ + +/* FIXME: __attribute__ ((format(printf, 1, 3))) not possible unless + * llvm bug https://llvm.org/bugs/show_bug.cgi?id=26243 gets resolved. + * It would require ____fmt to be made const, which generates a reloc + * entry (non-map). + */ +static void BPF_FUNC(trace_printk, const char *fmt, int fmt_size, ...); + +#ifndef printt +# define printt(fmt, ...) \ + ({ \ + char ____fmt[] = fmt; \ + trace_printk(____fmt, sizeof(____fmt), ##__VA_ARGS__); \ + }) +#endif + +/* Random numbers */ +static uint32_t BPF_FUNC(get_prandom_u32); + +/* Tail calls */ +static void BPF_FUNC(tail_call, struct __sk_buff *skb, void *map, + uint32_t index); + +/* System helpers */ +static uint32_t BPF_FUNC(get_smp_processor_id); +static uint32_t BPF_FUNC(get_numa_node_id); + +/* Packet misc meta data */ +static uint32_t BPF_FUNC(get_cgroup_classid, struct __sk_buff *skb); +static int BPF_FUNC(skb_under_cgroup, void *map, uint32_t index); + +static uint32_t BPF_FUNC(get_route_realm, struct __sk_buff *skb); +static uint32_t BPF_FUNC(get_hash_recalc, struct __sk_buff *skb); +static uint32_t BPF_FUNC(set_hash_invalid, struct __sk_buff *skb); + +/* Packet redirection */ +static int BPF_FUNC(redirect, int ifindex, uint32_t flags); +static int BPF_FUNC(clone_redirect, struct __sk_buff *skb, int ifindex, + uint32_t flags); + +/* Packet manipulation */ +static int BPF_FUNC(skb_load_bytes, struct __sk_buff *skb, uint32_t off, + void *to, uint32_t len); +static int BPF_FUNC(skb_store_bytes, struct __sk_buff *skb, uint32_t off, + const void *from, uint32_t len, uint32_t flags); + +static int BPF_FUNC(l3_csum_replace, struct __sk_buff *skb, uint32_t off, + uint32_t from, uint32_t to, uint32_t flags); +static int BPF_FUNC(l4_csum_replace, struct __sk_buff *skb, uint32_t off, + uint32_t from, uint32_t to, uint32_t flags); +static int BPF_FUNC(csum_diff, const void *from, uint32_t from_size, + const void *to, uint32_t to_size, uint32_t seed); +static int BPF_FUNC(csum_update, struct __sk_buff *skb, uint32_t wsum); + +static int BPF_FUNC(skb_change_type, struct __sk_buff *skb, uint32_t type); +static int BPF_FUNC(skb_change_proto, struct __sk_buff *skb, uint32_t proto, + uint32_t flags); +static int BPF_FUNC(skb_change_tail, struct __sk_buff *skb, uint32_t nlen, + uint32_t flags); + +static int BPF_FUNC(skb_pull_data, struct __sk_buff *skb, uint32_t len); + +/* Event notification */ +static int __BPF_FUNC(skb_event_output, struct __sk_buff *skb, void *map, + uint64_t index, const void *data, uint32_t size) = + (void *) BPF_FUNC_perf_event_output; + +/* Packet vlan encap/decap */ +static int BPF_FUNC(skb_vlan_push, struct __sk_buff *skb, uint16_t proto, + uint16_t vlan_tci); +static int BPF_FUNC(skb_vlan_pop, struct __sk_buff *skb); + +/* Packet tunnel encap/decap */ +static int BPF_FUNC(skb_get_tunnel_key, struct __sk_buff *skb, + struct bpf_tunnel_key *to, uint32_t size, uint32_t flags); +static int BPF_FUNC(skb_set_tunnel_key, struct __sk_buff *skb, + const struct bpf_tunnel_key *from, uint32_t size, + uint32_t flags); + +static int BPF_FUNC(skb_get_tunnel_opt, struct __sk_buff *skb, + void *to, uint32_t size); +static int BPF_FUNC(skb_set_tunnel_opt, struct __sk_buff *skb, + const void *from, uint32_t size); + +/** LLVM built-ins, mem*() routines work for constant size */ + +#ifndef lock_xadd +# define lock_xadd(ptr, val) ((void) __sync_fetch_and_add(ptr, val)) +#endif + +#ifndef memset +# define memset(s, c, n) __builtin_memset((s), (c), (n)) +#endif + +#ifndef memcpy +# define memcpy(d, s, n) __builtin_memcpy((d), (s), (n)) +#endif + +#ifndef memmove +# define memmove(d, s, n) __builtin_memmove((d), (s), (n)) +#endif + +/* FIXME: __builtin_memcmp() is not yet fully useable unless llvm bug + * https://llvm.org/bugs/show_bug.cgi?id=26218 gets resolved. Also + * this one would generate a reloc entry (non-map), otherwise. + */ +#if 0 +#ifndef memcmp +# define memcmp(a, b, n) __builtin_memcmp((a), (b), (n)) +#endif +#endif + +unsigned long long load_byte(void *skb, unsigned long long off) + asm ("llvm.bpf.load.byte"); + +unsigned long long load_half(void *skb, unsigned long long off) + asm ("llvm.bpf.load.half"); + +unsigned long long load_word(void *skb, unsigned long long off) + asm ("llvm.bpf.load.word"); + +#endif /* __BPF_API__ */ |