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 */
 11static void *(*bpf_map_lookup_elem)(void *map, void *key) =
 12	(void *) BPF_FUNC_map_lookup_elem;
 13static int (*bpf_map_update_elem)(void *map, void *key, void *value,
 14				  unsigned long long flags) =
 15	(void *) BPF_FUNC_map_update_elem;
 16static int (*bpf_map_delete_elem)(void *map, void *key) =
 17	(void *) BPF_FUNC_map_delete_elem;
 18static int (*bpf_probe_read)(void *dst, int size, void *unsafe_ptr) =
 19	(void *) BPF_FUNC_probe_read;
 20static unsigned long long (*bpf_ktime_get_ns)(void) =
 21	(void *) BPF_FUNC_ktime_get_ns;
 22static int (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) =
 23	(void *) BPF_FUNC_trace_printk;
 24static void (*bpf_tail_call)(void *ctx, void *map, int index) =
 25	(void *) BPF_FUNC_tail_call;
 26static unsigned long long (*bpf_get_smp_processor_id)(void) =
 27	(void *) BPF_FUNC_get_smp_processor_id;
 28static unsigned long long (*bpf_get_current_pid_tgid)(void) =
 29	(void *) BPF_FUNC_get_current_pid_tgid;
 30static unsigned long long (*bpf_get_current_uid_gid)(void) =
 31	(void *) BPF_FUNC_get_current_uid_gid;
 32static int (*bpf_get_current_comm)(void *buf, int buf_size) =
 33	(void *) BPF_FUNC_get_current_comm;
 34static int (*bpf_perf_event_read)(void *map, int index) =
 35	(void *) BPF_FUNC_perf_event_read;
 36static int (*bpf_clone_redirect)(void *ctx, int ifindex, int flags) =
 37	(void *) BPF_FUNC_clone_redirect;
 38static int (*bpf_redirect)(int ifindex, int flags) =
 39	(void *) BPF_FUNC_redirect;
 40static int (*bpf_perf_event_output)(void *ctx, void *map, int index, void *data, int size) =
 41	(void *) BPF_FUNC_perf_event_output;
 42static int (*bpf_get_stackid)(void *ctx, void *map, int flags) =
 43	(void *) BPF_FUNC_get_stackid;
 44
 45/* llvm builtin functions that eBPF C program may use to
 46 * emit BPF_LD_ABS and BPF_LD_IND instructions
 47 */
 48struct sk_buff;
 49unsigned long long load_byte(void *skb,
 50			     unsigned long long off) asm("llvm.bpf.load.byte");
 51unsigned long long load_half(void *skb,
 52			     unsigned long long off) asm("llvm.bpf.load.half");
 53unsigned long long load_word(void *skb,
 54			     unsigned long long off) asm("llvm.bpf.load.word");
 55
 56/* a helper structure used by eBPF C program
 57 * to describe map attributes to elf_bpf loader
 58 */
 59struct bpf_map_def {
 60	unsigned int type;
 61	unsigned int key_size;
 62	unsigned int value_size;
 63	unsigned int max_entries;
 64	unsigned int map_flags;
 65};
 66
 67static int (*bpf_skb_store_bytes)(void *ctx, int off, void *from, int len, int flags) =
 68	(void *) BPF_FUNC_skb_store_bytes;
 69static int (*bpf_l3_csum_replace)(void *ctx, int off, int from, int to, int flags) =
 70	(void *) BPF_FUNC_l3_csum_replace;
 71static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flags) =
 72	(void *) BPF_FUNC_l4_csum_replace;
 73
 74#if defined(__x86_64__)
 75
 76#define PT_REGS_PARM1(x) ((x)->di)
 77#define PT_REGS_PARM2(x) ((x)->si)
 78#define PT_REGS_PARM3(x) ((x)->dx)
 79#define PT_REGS_PARM4(x) ((x)->cx)
 80#define PT_REGS_PARM5(x) ((x)->r8)
 81#define PT_REGS_RET(x) ((x)->sp)
 82#define PT_REGS_FP(x) ((x)->bp)
 83#define PT_REGS_RC(x) ((x)->ax)
 84#define PT_REGS_SP(x) ((x)->sp)
 85#define PT_REGS_IP(x) ((x)->ip)
 86
 87#elif defined(__s390x__)
 88
 89#define PT_REGS_PARM1(x) ((x)->gprs[2])
 90#define PT_REGS_PARM2(x) ((x)->gprs[3])
 91#define PT_REGS_PARM3(x) ((x)->gprs[4])
 92#define PT_REGS_PARM4(x) ((x)->gprs[5])
 93#define PT_REGS_PARM5(x) ((x)->gprs[6])
 94#define PT_REGS_RET(x) ((x)->gprs[14])
 95#define PT_REGS_FP(x) ((x)->gprs[11]) /* Works only with CONFIG_FRAME_POINTER */
 96#define PT_REGS_RC(x) ((x)->gprs[2])
 97#define PT_REGS_SP(x) ((x)->gprs[15])
 98#define PT_REGS_IP(x) ((x)->ip)
 99
100#elif defined(__aarch64__)
101
102#define PT_REGS_PARM1(x) ((x)->regs[0])
103#define PT_REGS_PARM2(x) ((x)->regs[1])
104#define PT_REGS_PARM3(x) ((x)->regs[2])
105#define PT_REGS_PARM4(x) ((x)->regs[3])
106#define PT_REGS_PARM5(x) ((x)->regs[4])
107#define PT_REGS_RET(x) ((x)->regs[30])
108#define PT_REGS_FP(x) ((x)->regs[29]) /* Works only with CONFIG_FRAME_POINTER */
109#define PT_REGS_RC(x) ((x)->regs[0])
110#define PT_REGS_SP(x) ((x)->sp)
111#define PT_REGS_IP(x) ((x)->pc)
112
113#elif defined(__powerpc__)
114
115#define PT_REGS_PARM1(x) ((x)->gpr[3])
116#define PT_REGS_PARM2(x) ((x)->gpr[4])
117#define PT_REGS_PARM3(x) ((x)->gpr[5])
118#define PT_REGS_PARM4(x) ((x)->gpr[6])
119#define PT_REGS_PARM5(x) ((x)->gpr[7])
120#define PT_REGS_RC(x) ((x)->gpr[3])
121#define PT_REGS_SP(x) ((x)->sp)
122#define PT_REGS_IP(x) ((x)->nip)
123
124#endif
125
126#ifdef __powerpc__
127#define BPF_KPROBE_READ_RET_IP(ip, ctx)		({ (ip) = (ctx)->link; })
128#define BPF_KRETPROBE_READ_RET_IP		BPF_KPROBE_READ_RET_IP
129#else
130#define BPF_KPROBE_READ_RET_IP(ip, ctx)		({				\
131		bpf_probe_read(&(ip), sizeof(ip), (void *)PT_REGS_RET(ctx)); })
132#define BPF_KRETPROBE_READ_RET_IP(ip, ctx)	({				\
133		bpf_probe_read(&(ip), sizeof(ip),				\
134				(void *)(PT_REGS_FP(ctx) + sizeof(ip))); })
135#endif
136
137#endif