prog_iter.c 2.4 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /* Copyright (c) 2020 Facebook */
  3. #include <linux/bpf.h>
  4. #include <linux/fs.h>
  5. #include <linux/filter.h>
  6. #include <linux/kernel.h>
  7. #include <linux/btf_ids.h>
  8. struct bpf_iter_seq_prog_info {
  9. u32 prog_id;
  10. };
  11. static void *bpf_prog_seq_start(struct seq_file *seq, loff_t *pos)
  12. {
  13. struct bpf_iter_seq_prog_info *info = seq->private;
  14. struct bpf_prog *prog;
  15. prog = bpf_prog_get_curr_or_next(&info->prog_id);
  16. if (!prog)
  17. return NULL;
  18. if (*pos == 0)
  19. ++*pos;
  20. return prog;
  21. }
  22. static void *bpf_prog_seq_next(struct seq_file *seq, void *v, loff_t *pos)
  23. {
  24. struct bpf_iter_seq_prog_info *info = seq->private;
  25. ++*pos;
  26. ++info->prog_id;
  27. bpf_prog_put((struct bpf_prog *)v);
  28. return bpf_prog_get_curr_or_next(&info->prog_id);
  29. }
  30. struct bpf_iter__bpf_prog {
  31. __bpf_md_ptr(struct bpf_iter_meta *, meta);
  32. __bpf_md_ptr(struct bpf_prog *, prog);
  33. };
  34. DEFINE_BPF_ITER_FUNC(bpf_prog, struct bpf_iter_meta *meta, struct bpf_prog *prog)
  35. static int __bpf_prog_seq_show(struct seq_file *seq, void *v, bool in_stop)
  36. {
  37. struct bpf_iter__bpf_prog ctx;
  38. struct bpf_iter_meta meta;
  39. struct bpf_prog *prog;
  40. int ret = 0;
  41. ctx.meta = &meta;
  42. ctx.prog = v;
  43. meta.seq = seq;
  44. prog = bpf_iter_get_info(&meta, in_stop);
  45. if (prog)
  46. ret = bpf_iter_run_prog(prog, &ctx);
  47. return ret;
  48. }
  49. static int bpf_prog_seq_show(struct seq_file *seq, void *v)
  50. {
  51. return __bpf_prog_seq_show(seq, v, false);
  52. }
  53. static void bpf_prog_seq_stop(struct seq_file *seq, void *v)
  54. {
  55. if (!v)
  56. (void)__bpf_prog_seq_show(seq, v, true);
  57. else
  58. bpf_prog_put((struct bpf_prog *)v);
  59. }
  60. static const struct seq_operations bpf_prog_seq_ops = {
  61. .start = bpf_prog_seq_start,
  62. .next = bpf_prog_seq_next,
  63. .stop = bpf_prog_seq_stop,
  64. .show = bpf_prog_seq_show,
  65. };
  66. BTF_ID_LIST(btf_bpf_prog_id)
  67. BTF_ID(struct, bpf_prog)
  68. static const struct bpf_iter_seq_info bpf_prog_seq_info = {
  69. .seq_ops = &bpf_prog_seq_ops,
  70. .init_seq_private = NULL,
  71. .fini_seq_private = NULL,
  72. .seq_priv_size = sizeof(struct bpf_iter_seq_prog_info),
  73. };
  74. static struct bpf_iter_reg bpf_prog_reg_info = {
  75. .target = "bpf_prog",
  76. .ctx_arg_info_size = 1,
  77. .ctx_arg_info = {
  78. { offsetof(struct bpf_iter__bpf_prog, prog),
  79. PTR_TO_BTF_ID_OR_NULL },
  80. },
  81. .seq_info = &bpf_prog_seq_info,
  82. };
  83. static int __init bpf_prog_iter_init(void)
  84. {
  85. bpf_prog_reg_info.ctx_arg_info[0].btf_id = *btf_bpf_prog_id;
  86. return bpf_iter_reg_target(&bpf_prog_reg_info);
  87. }
  88. late_initcall(bpf_prog_iter_init);