1 #ifndef __BPF_HELPERS_H 2 #define __BPF_HELPERS_H 3 4 /* helper macro to place programs, maps, license in 5 * different sections in elf_bpf file. Section names 6 * are interpreted by elf_bpf loader 7 */ 8 #define SEC(NAME) __attribute__((section(NAME), used)) 9 10 /* helper functions called from eBPF programs written in C */ 11 static void *(*bpf_map_lookup_elem)(void *map, void *key) = 12 (void *) BPF_FUNC_map_lookup_elem; 13 static int (*bpf_map_update_elem)(void *map, void *key, void *value, 14 unsigned long long flags) = 15 (void *) BPF_FUNC_map_update_elem; 16 static int (*bpf_map_delete_elem)(void *map, void *key) = 17 (void *) BPF_FUNC_map_delete_elem; 18 static int (*bpf_probe_read)(void *dst, int size, void *unsafe_ptr) = 19 (void *) BPF_FUNC_probe_read; 20 static unsigned long long (*bpf_ktime_get_ns)(void) = 21 (void *) BPF_FUNC_ktime_get_ns; 22 static int (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) = 23 (void *) BPF_FUNC_trace_printk; 24 25 /* llvm builtin functions that eBPF C program may use to 26 * emit BPF_LD_ABS and BPF_LD_IND instructions 27 */ 28 struct sk_buff; 29 unsigned long long load_byte(void *skb, 30 unsigned long long off) asm("llvm.bpf.load.byte"); 31 unsigned long long load_half(void *skb, 32 unsigned long long off) asm("llvm.bpf.load.half"); 33 unsigned long long load_word(void *skb, 34 unsigned long long off) asm("llvm.bpf.load.word"); 35 36 /* a helper structure used by eBPF C program 37 * to describe map attributes to elf_bpf loader 38 */ 39 struct bpf_map_def { 40 unsigned int type; 41 unsigned int key_size; 42 unsigned int value_size; 43 unsigned int max_entries; 44 }; 45 46 static int (*bpf_skb_store_bytes)(void *ctx, int off, void *from, int len, int flags) = 47 (void *) BPF_FUNC_skb_store_bytes; 48 static int (*bpf_l3_csum_replace)(void *ctx, int off, int from, int to, int flags) = 49 (void *) BPF_FUNC_l3_csum_replace; 50 static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flags) = 51 (void *) BPF_FUNC_l4_csum_replace; 52 53 #endif 54