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,
  41                                     unsigned long long flags, void *data,
  42                                     int size) =
  43         (void *) BPF_FUNC_perf_event_output;
  44 static int (*bpf_get_stackid)(void *ctx, void *map, int flags) =
  45         (void *) BPF_FUNC_get_stackid;
  46 static int (*bpf_probe_write_user)(void *dst, void *src, int size) =
  47         (void *) BPF_FUNC_probe_write_user;
  48 static int (*bpf_current_task_under_cgroup)(void *map, int index) =
  49         (void *) BPF_FUNC_current_task_under_cgroup;
  50 static int (*bpf_skb_get_tunnel_key)(void *ctx, void *key, int size, int flags) =
  51         (void *) BPF_FUNC_skb_get_tunnel_key;
  52 static int (*bpf_skb_set_tunnel_key)(void *ctx, void *key, int size, int flags) =
  53         (void *) BPF_FUNC_skb_set_tunnel_key;
  54 static int (*bpf_skb_get_tunnel_opt)(void *ctx, void *md, int size) =
  55         (void *) BPF_FUNC_skb_get_tunnel_opt;
  56 static int (*bpf_skb_set_tunnel_opt)(void *ctx, void *md, int size) =
  57         (void *) BPF_FUNC_skb_set_tunnel_opt;
  58 static unsigned long long (*bpf_get_prandom_u32)(void) =
  59         (void *) BPF_FUNC_get_prandom_u32;
  60 static int (*bpf_xdp_adjust_head)(void *ctx, int offset) =
  61         (void *) BPF_FUNC_xdp_adjust_head;
  62
  63 /* llvm builtin functions that eBPF C program may use to
  64  * emit BPF_LD_ABS and BPF_LD_IND instructions
  65  */
  66 struct sk_buff;
  67 unsigned long long load_byte(void *skb,
  68                              unsigned long long off) asm("llvm.bpf.load.byte");
  69 unsigned long long load_half(void *skb,
  70                              unsigned long long off) asm("llvm.bpf.load.half");
  71 unsigned long long load_word(void *skb,
  72                              unsigned long long off) asm("llvm.bpf.load.word");
  73
  74 /* a helper structure used by eBPF C program
  75  * to describe map attributes to elf_bpf loader
  76  */
  77 struct bpf_map_def {
  78         unsigned int type;
  79         unsigned int key_size;
  80         unsigned int value_size;
  81         unsigned int max_entries;
  82         unsigned int map_flags;
  83         unsigned int inner_map_idx;
  84 };
  85
  86 static int (*bpf_skb_load_bytes)(void *ctx, int off, void *to, int len) =
  87         (void *) BPF_FUNC_skb_load_bytes;
  88 static int (*bpf_skb_store_bytes)(void *ctx, int off, void *from, int len, int flags) =
  89         (void *) BPF_FUNC_skb_store_bytes;
  90 static int (*bpf_l3_csum_replace)(void *ctx, int off, int from, int to, int flags) =
  91         (void *) BPF_FUNC_l3_csum_replace;
  92 static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flags) =
  93         (void *) BPF_FUNC_l4_csum_replace;
  94 static int (*bpf_skb_under_cgroup)(void *ctx, void *map, int index) =
  95         (void *) BPF_FUNC_skb_under_cgroup;
  96 static int (*bpf_skb_change_head)(void *, int len, int flags) =
  97         (void *) BPF_FUNC_skb_change_head;
  98
  99 #if defined(__x86_64__)
 100
 101 #define PT_REGS_PARM1(x) ((x)->di)
 102 #define PT_REGS_PARM2(x) ((x)->si)
 103 #define PT_REGS_PARM3(x) ((x)->dx)
 104 #define PT_REGS_PARM4(x) ((x)->cx)
 105 #define PT_REGS_PARM5(x) ((x)->r8)
 106 #define PT_REGS_RET(x) ((x)->sp)
 107 #define PT_REGS_FP(x) ((x)->bp)
 108 #define PT_REGS_RC(x) ((x)->ax)
 109 #define PT_REGS_SP(x) ((x)->sp)
 110 #define PT_REGS_IP(x) ((x)->ip)
 111
 112 #elif defined(__s390x__)
 113
 114 #define PT_REGS_PARM1(x) ((x)->gprs[2])
 115 #define PT_REGS_PARM2(x) ((x)->gprs[3])
 116 #define PT_REGS_PARM3(x) ((x)->gprs[4])
 117 #define PT_REGS_PARM4(x) ((x)->gprs[5])
 118 #define PT_REGS_PARM5(x) ((x)->gprs[6])
 119 #define PT_REGS_RET(x) ((x)->gprs[14])
 120 #define PT_REGS_FP(x) ((x)->gprs[11]) /* Works only with CONFIG_FRAME_POINTER */
 121 #define PT_REGS_RC(x) ((x)->gprs[2])
 122 #define PT_REGS_SP(x) ((x)->gprs[15])
 123 #define PT_REGS_IP(x) ((x)->psw.addr)
 124
 125 #elif defined(__aarch64__)
 126
 127 #define PT_REGS_PARM1(x) ((x)->regs[0])
 128 #define PT_REGS_PARM2(x) ((x)->regs[1])
 129 #define PT_REGS_PARM3(x) ((x)->regs[2])
 130 #define PT_REGS_PARM4(x) ((x)->regs[3])
 131 #define PT_REGS_PARM5(x) ((x)->regs[4])
 132 #define PT_REGS_RET(x) ((x)->regs[30])
 133 #define PT_REGS_FP(x) ((x)->regs[29]) /* Works only with CONFIG_FRAME_POINTER */
 134 #define PT_REGS_RC(x) ((x)->regs[0])
 135 #define PT_REGS_SP(x) ((x)->sp)
 136 #define PT_REGS_IP(x) ((x)->pc)
 137
 138 #elif defined(__powerpc__)
 139
 140 #define PT_REGS_PARM1(x) ((x)->gpr[3])
 141 #define PT_REGS_PARM2(x) ((x)->gpr[4])
 142 #define PT_REGS_PARM3(x) ((x)->gpr[5])
 143 #define PT_REGS_PARM4(x) ((x)->gpr[6])
 144 #define PT_REGS_PARM5(x) ((x)->gpr[7])
 145 #define PT_REGS_RC(x) ((x)->gpr[3])
 146 #define PT_REGS_SP(x) ((x)->sp)
 147 #define PT_REGS_IP(x) ((x)->nip)
 148
 149 #elif defined(__sparc__)
 150
 151 #define PT_REGS_PARM1(x) ((x)->u_regs[UREG_I0])
 152 #define PT_REGS_PARM2(x) ((x)->u_regs[UREG_I1])
 153 #define PT_REGS_PARM3(x) ((x)->u_regs[UREG_I2])
 154 #define PT_REGS_PARM4(x) ((x)->u_regs[UREG_I3])
 155 #define PT_REGS_PARM5(x) ((x)->u_regs[UREG_I4])
 156 #define PT_REGS_RET(x) ((x)->u_regs[UREG_I7])
 157 #define PT_REGS_RC(x) ((x)->u_regs[UREG_I0])
 158 #define PT_REGS_SP(x) ((x)->u_regs[UREG_FP])
 159 #if defined(__arch64__)
 160 #define PT_REGS_IP(x) ((x)->tpc)
 161 #else
 162 #define PT_REGS_IP(x) ((x)->pc)
 163 #endif
 164
 165 #endif
 166
 167 #ifdef __powerpc__
 168 #define BPF_KPROBE_READ_RET_IP(ip, ctx)         ({ (ip) = (ctx)->link; })
 169 #define BPF_KRETPROBE_READ_RET_IP               BPF_KPROBE_READ_RET_IP
 170 #elif defined(__sparc__)
 171 #define BPF_KPROBE_READ_RET_IP(ip, ctx)         ({ (ip) = PT_REGS_RET(ctx); })
 172 #define BPF_KRETPROBE_READ_RET_IP               BPF_KPROBE_READ_RET_IP
 173 #else
 174 #define BPF_KPROBE_READ_RET_IP(ip, ctx)         ({                              \
 175                 bpf_probe_read(&(ip), sizeof(ip), (void *)PT_REGS_RET(ctx)); })
 176 #define BPF_KRETPROBE_READ_RET_IP(ip, ctx)      ({                              \
 177                 bpf_probe_read(&(ip), sizeof(ip),                               \
 178                                 (void *)(PT_REGS_FP(ctx) + sizeof(ip))); })
 179 #endif
 180
 181 #endif