samples/bpf/bpf_helpers.h

   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 static void (*bpf_tail_call)(void *ctx, void *map, int index) =
  25         (void *) BPF_FUNC_tail_call;
  26 static unsigned long long (*bpf_get_smp_processor_id)(void) =
  27         (void *) BPF_FUNC_get_smp_processor_id;
  28 static unsigned long long (*bpf_get_current_pid_tgid)(void) =
  29         (void *) BPF_FUNC_get_current_pid_tgid;
  30 static unsigned long long (*bpf_get_current_uid_gid)(void) =
  31         (void *) BPF_FUNC_get_current_uid_gid;
  32 static int (*bpf_get_current_comm)(void *buf, int buf_size) =
  33         (void *) BPF_FUNC_get_current_comm;
  34
  35 /* llvm builtin functions that eBPF C program may use to
  36  * emit BPF_LD_ABS and BPF_LD_IND instructions
  37  */
  38 struct sk_buff;
  39 unsigned long long load_byte(void *skb,
  40                              unsigned long long off) asm("llvm.bpf.load.byte");
  41 unsigned long long load_half(void *skb,
  42                              unsigned long long off) asm("llvm.bpf.load.half");
  43 unsigned long long load_word(void *skb,
  44                              unsigned long long off) asm("llvm.bpf.load.word");
  45
  46 /* a helper structure used by eBPF C program
  47  * to describe map attributes to elf_bpf loader
  48  */
  49 struct bpf_map_def {
  50         unsigned int type;
  51         unsigned int key_size;
  52         unsigned int value_size;
  53         unsigned int max_entries;
  54 };
  55
  56 static int (*bpf_skb_store_bytes)(void *ctx, int off, void *from, int len, int flags) =
  57         (void *) BPF_FUNC_skb_store_bytes;
  58 static int (*bpf_l3_csum_replace)(void *ctx, int off, int from, int to, int flags) =
  59         (void *) BPF_FUNC_l3_csum_replace;
  60 static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flags) =
  61         (void *) BPF_FUNC_l4_csum_replace;
  62
  63 #if defined(__x86_64__)
  64
  65 #define PT_REGS_PARM1(x) ((x)->di)
  66 #define PT_REGS_PARM2(x) ((x)->si)
  67 #define PT_REGS_PARM3(x) ((x)->dx)
  68 #define PT_REGS_PARM4(x) ((x)->cx)
  69 #define PT_REGS_PARM5(x) ((x)->r8)
  70 #define PT_REGS_RET(x) ((x)->sp)
  71 #define PT_REGS_FP(x) ((x)->bp)
  72 #define PT_REGS_RC(x) ((x)->ax)
  73 #define PT_REGS_SP(x) ((x)->sp)
  74
  75 #elif defined(__s390x__)
  76
  77 #define PT_REGS_PARM1(x) ((x)->gprs[2])
  78 #define PT_REGS_PARM2(x) ((x)->gprs[3])
  79 #define PT_REGS_PARM3(x) ((x)->gprs[4])
  80 #define PT_REGS_PARM4(x) ((x)->gprs[5])
  81 #define PT_REGS_PARM5(x) ((x)->gprs[6])
  82 #define PT_REGS_RET(x) ((x)->gprs[14])
  83 #define PT_REGS_FP(x) ((x)->gprs[11]) /* Works only with CONFIG_FRAME_POINTER */
  84 #define PT_REGS_RC(x) ((x)->gprs[2])
  85 #define PT_REGS_SP(x) ((x)->gprs[15])
  86
  87 #endif
  88 #endif