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 static int (*bpf_perf_event_read)(void *map, int index) =
  35         (void *) BPF_FUNC_perf_event_read;
  36 static int (*bpf_clone_redirect)(void *ctx, int ifindex, int flags) =
  37         (void *) BPF_FUNC_clone_redirect;
  38 static int (*bpf_redirect)(int ifindex, int flags) =
  39         (void *) BPF_FUNC_redirect;
  40 static int (*bpf_perf_event_output)(void *ctx, void *map, int index, void *data, int size) =
  41         (void *) BPF_FUNC_perf_event_output;
  42 static 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  */
  48 struct sk_buff;
  49 unsigned long long load_byte(void *skb,
  50                              unsigned long long off) asm("llvm.bpf.load.byte");
  51 unsigned long long load_half(void *skb,
  52                              unsigned long long off) asm("llvm.bpf.load.half");
  53 unsigned 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  */
  59 struct 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
  67 static int (*bpf_skb_store_bytes)(void *ctx, int off, void *from, int len, int flags) =
  68         (void *) BPF_FUNC_skb_store_bytes;
  69 static int (*bpf_l3_csum_replace)(void *ctx, int off, int from, int to, int flags) =
  70         (void *) BPF_FUNC_l3_csum_replace;
  71 static 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